Screening Efficiency Analysis of Vibrosieves with the Circular Vibrations

NASA Astrophysics Data System (ADS)

Djoković, Jelena M.; Tanikić, Dejan I.; Nikolić, Ružica R.; Kalinović, Saša M.

2017-06-01

The analysis of influence of factors that depend on construction characteristics of the vibrosieves with circular vibrations on screening efficiency is presented in this paper. The dependence of the screening efficiency on the aperture size, length and inclination of the screen, as well as on vibration amplitude, is considered. Based on obtained results, one can see that the screening efficiency increases with vibration amplitude and the screen length increase. Further, increases of the screen inclination and aperture size are causing an initial increase of the screening efficiency, which is later decreasing.

Racial and ethnic disparities in universal cervical length screening with transvaginal ultrasound

PubMed Central

Haviland, Miriam J; Shainker, Scott A; Hacker, Michele R; Burris, Heather H

2016-01-01

Objective Determine if race or ethnicity is associated with missed or late transvaginal cervical length screening in a universal screening program. Methods Retrospective cohort study of nulliparous women with singleton gestations and a fetal anatomical ultrasound from 16-24 weeks' gestation from January, 2012 through November, 2013. We classified women into mutually exclusive racial and ethnic groups: non-Hispanic black (black), Hispanic, Asian, non-Hispanic white (white), and other or unknown race. We used log-binomial regression to calculate the risk ratio (RR) and 95% confidence interval (CI) of missed or late (≥ 20 weeks' gestation) screening vs. optimally-timed screening between the different racial and ethnic groups. Results Among the 2 967 women in our study population, 971 (32.7%) had either missed or late cervical length screening. Compared to white women, black (RR: 1.3; 95% CI:1.1-1.5) and Hispanic (RR:1.2; 95% CI:1.01-1.5) women were more likely to have missed or late screening. Among women screened, black (vs. white) women were more likely to be screened late (RR: 2.2; 95% CI: 1.6-3.1). Conclusions Black and Hispanic women may be more likely to have missed or late cervical length screenings. PMID:26987873

Efficacy of screens in removing long fibers from an aerosol stream – sample preparation technique for toxicology studies

PubMed Central

Ku, Bon Ki; Deye, Gregory J.; Turkevich, Leonid A.

2015-01-01

Fiber dimension (especially length) and biopersistence are thought to be important variables in determining the pathogenicity of asbestos and other elongate mineral particles. In order to prepare samples of fibers for toxicology studies, it is necessary to develop and evaluate methods for separating fibers by length in the micrometer size range. In this study, we have filtered an aerosol of fibers through nylon screens to investigate whether such screens can efficiently remove the long fibers (L >20 μm, a typical macrophage size) from the aerosol stream. Such a sample, deficient in long fibers, could then be used as the control in a toxicology study to investigate the role of length. A well-dispersed aerosol of glass fibers (a surrogate for asbestos) was generated by vortex shaking a Japan Fibrous Material Research Association (JFMRA) glass fiber powder. Fibers were collected on a mixed cellulose ester (MCE) filter, imaged with phase contrast microscopy (PCM) and lengths were measured. Length distributions of the fibers that penetrated through various screens (10, 20 and 60 μm mesh sizes) were analyzed; additional study was made of fibers that penetrated through double screen and centrally blocked screen configurations. Single screens were not particularly efficient in removing the long fibers; however, the alternative configurations, especially the centrally blocked screen configuration, yielded samples substantially free of the long fibers. PMID:24417374

Plasma-screening effects on the electron-impact excitation of hydrogenic ions in dense plasmas

NASA Technical Reports Server (NTRS)

Jung, Young-Dae

1993-01-01

Plasma-screening effects are investigated on electron-impact excitation of hydrogenic ions in dense plasmas. Scaled cross sections Z(exp 4) sigma for 1s yields 2s and 1s yields 2p are obtained for a Debye-Hueckel model of the screened Coulomb interaction. Ground and excited bound wave functions are modified in the screened Coulomb potential (Debye-Hueckel model) using the Ritz variation method. The resulting atomic wave functions and their eigenenergies agree well with the numerical and high-order perturbation theory calculations for the interesting domain of the Debye length not less than 10. The Born approximation is used to describe the continuum states of the projectile electron. Plasma screening effects on the atomic electrons cannot be neglected in the high-density cases. Including these effects, the cross sections are appreciably increased for 1s yields 2s transitions and decreased for 1s yields 2p transitions.

Radiographic screen-film noise power spectrum: variation with microdensitometer slit length.

PubMed

Sandrik, J M; Wagner, R F

1981-08-15

When the noise power spectrum (NPS) of a radiographic screen-film system is measured by microdensito-metrically scanning the film with a long narrow slit, sufficient slit length allows estimation of a section of the 2-D NPS from the 1-D film scans; insufficient length causes underestimation of the NPS, particularly at low frequencies ( greater, similar1 cycle/mm). Spectra of Hi-Plus, Par Speed, and Detail screens used with XRP films measured as a function of microdensitometer slit length tended to plateau at long slit lengths. The slit length was considered sufficient when NPS components at 0.4 cycle/mm were within 5% of the plateau. This occurred for slit lengths of at least 4.2, 2.6, and 2.5 mm for Hi-Plus, Par Speed, and Detail systems, respectively.

Generalized charge-screening in relativistic Thomas–Fermi model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Akbari-Moghanjoughi, M.

In this paper, we study the charge shielding within the relativistic Thomas-Fermi model for a wide range of electron number-densities and the atomic-number of screened ions. A generalized energy-density relation is obtained using the force-balance equation and taking into account the Chandrasekhar's relativistic electron degeneracy pressure. By numerically solving a second-order nonlinear differential equation, the Thomas-Fermi screening length is investigated, and the results are compared for three distinct regimes of the solid-density, warm-dense-matter, and white-dwarfs (WDs). It is revealed that our nonlinear screening theory is compatible with the exponentially decaying Thomas-Fermi-type shielding predicted by the linear response theory. Moreover, themore » variation of relative Thomas-Fermi screening length shows that extremely dense quantum electron fluids are relatively poor charge shielders. Calculation of the total number of screening electrons around a nucleus shows that there is a position of maximum number of screening localized electrons around the screened nucleus, which moves closer to the point-like nucleus by increase in the plasma number density but is unaffected due to increase in the atomic-number value. It is discovered that the total number of screening electrons, (N{sub s}∝r{sub TF}{sup 3}/r{sub d}{sup 3} where r{sub TF} and r{sub d} are the Thomas-Fermi and interparticle distance, respectively) has a distinct limit for extremely dense plasmas such as WD-cores and neutron star crusts, which is unique for all given values of the atomic-number. This is equal to saying that in an ultrarelativistic degeneracy limit of electron-ion plasma, the screening length couples with the system dimensionality and the plasma becomes spherically self-similar. Current analysis can provide useful information on the effects of relativistic correction to the charge screening for a wide range of plasma density, such as the inertial-confined plasmas and compact stellar objects.« less

Dressed ion theory of size-asymmetric electrolytes: effective ionic charges and the decay length of screened Coulomb potential and pair correlations.

PubMed

Forsberg, Björn; Ulander, Johan; Kjellander, Roland

2005-02-08

The effects of ionic size asymmetry on long-range electrostatic interactions in electrolyte solutions are investigated within the primitive model. Using the formalism of dressed ion theory we analyze correlation functions from Monte Carlo simulations and the hypernetted chain approximation for size asymmetric 1:1 electrolytes. We obtain decay lengths of the screened Coulomb potential, effective charges of ions, and effective permittivity of the solution. It is found that the variation of these quantities with the degree of size asymmetry depends in a quite intricate manner on the interplay between the electrostatic coupling and excluded volume effects. In most cases the magnitude of the effective charge of the small ion species is larger than that of the large species; the difference increases with increasing size asymmetry. The effective charges of both species are larger (in absolute value) than the bare ionic charge, except for high asymmetry where the effective charge of the large ions can become smaller than the bare charge.

Surface plasmon resonances of arbitrarily shaped nanometallic structures in the small-screening-length limit

PubMed Central

Giannini, Vincenzo; Maier, Stefan A.; Craster, Richard V.

2016-01-01

According to the hydrodynamic Drude model, surface plasmon resonances of metallic nanostructures blueshift owing to the non-local response of the metal’s electron gas. The screening length characterizing the non-local effect is often small relative to the overall dimensions of the metallic structure, which enables us to derive a coarse-grained non-local description using matched asymptotic expansions; a perturbation theory for the blueshifts of arbitrary-shaped nanometallic structures is then developed. The effect of non-locality is not always a perturbation and we present a detailed analysis of the ‘bonding’ modes of a dimer of nearly touching nanowires where the leading-order eigenfrequencies and eigenmode distributions are shown to be a renormalization of those predicted assuming a local metal permittivity. PMID:27493575

Effectiveness of common fish screen materials for protecting lamprey ammocoetes—Influence of sweeping velocities and decreasing flows

USGS Publications Warehouse

Mesa, Matthew G.; Liedtke, Theresa L.; Weiland, Lisa K.; Christiansen, Helena E.

2017-12-14

In previous tests of the effectiveness of four common fish screen materials for excluding lamprey ammocoetes, we determined that woven wire (WW) allowed substantially more entrainment than perforated plate (PP), profile bar (PB), or Intralox (IL) material. These tests were simplistic because they used small vertically-oriented screens positioned perpendicular to the flow without a bypass or a sweeping velocity (SV). In the subsequent test discussed in this report, we exposed ammocoetes to much larger (2.5-m-wide) screen panels with flows up to 10 ft3 /s, a SV component, and a simulated bypass channel. The addition of a SV modestly improved protection of lamprey ammocoetes for all materials tested. A SV of 35 cm/s with an approach velocity (AV) of 12 cm/s, was able to provide protection for fish about 5–15 mm smaller than the protection provided by an AV of 12 cm/s without a SV component. The best-performing screen panels (PP, IL, and PB) provided nearly complete protection from entrainment for fish greater than 50-mm toal length, but the larger openings in the WW material only protected fish greater than 100-mm total length. Decreasing the AV and SV by 50 percent expanded the size range of protected lampreys by about 10–15 mm for those exposed to IL and WW screens, and it decreased the protective ability of PP screens by about 10 mm. Much of the improvement for IL and WW screens under the reduced flow conditions resulted from an increase in the number of lampreys swimming away from the screen. Fish of all sizes became impinged (that is, stuck on the screen surface for more than 1 s) on the screens, with the rate of impingement highest on PP (39– 72 percent) and lowest on WW (7–22 percent). Although impingements were common, injuries were rare, and 24-h post-test survival was greater than 99 percent. Our results refined the level of protection provided by these screen materials when both an AV and SV are present and confirmed our earlier recommendation that WW screens be replaced with more effective materials. Future work should focus on determining the risks associated with other screen types (for example, rotary drum screens, horizontal flat plate screens) and exploring the effectiveness of higher SV:AV ratios, because it may help expand the range of sizes protected by the best performing materials.

Importance of the Debye Screening Length on Nanowire Field Effect Transistor Sensors

PubMed Central

Stern, Eric; Wagner, Robin; Sigworth, Fred J.; Breaker, Ronald; Fahmy, Tarek M.; Reed, Mark A.

2009-01-01

Nanowire field effect transistors (NW-FETs) can serve as ultrasensitive detectors for label-free reagents. The NW-FET sensing mechanism assumes a controlled modification in the local channel electric field created by the binding of charged molecules to the nanowire surface. Careful control of the solution Debye length is critical for unambiguous selective detection of macromolecules. Here we show the appropriate conditions under which the selective binding of macromolecules is accurately sensed with NW-FET sensors. PMID:17914853

Importance of the Debye screening length on nanowire field effect transistor sensors.

PubMed

Stern, Eric; Wagner, Robin; Sigworth, Fred J; Breaker, Ronald; Fahmy, Tarek M; Reed, Mark A

2007-11-01

Nanowire field effect transistors (NW-FETs) can serve as ultrasensitive detectors for label-free reagents. The NW-FET sensing mechanism assumes a controlled modification in the local channel electric field created by the binding of charged molecules to the nanowire surface. Careful control of the solution Debye length is critical for unambiguous selective detection of macromolecules. Here we show the appropriate conditions under which the selective binding of macromolecules is accurately sensed with NW-FET sensors.

Relativistic effects in the photoionization of hydrogen-like ions with screened Coulomb interaction

NASA Astrophysics Data System (ADS)

Xie, L. Y.; Wang, J. G.; Janev, R. K.

2014-06-01

The relativistic effects in the photoionization of hydrogen-like ion with screened Coulomb interaction of Yukawa type are studied for a broad range of screening lengths and photoelectron energies. The bound and continuum wave functions have been determined by solving the Dirac equation. The study is focused on the relativistic effects manifested in the characteristic features of photoionization cross section for electric dipole nl →ɛ,l±1 transitions: shape resonances, Cooper minima and cross section enhancements due to near-zero-energy states. It is shown that the main source of relativistic effects in these cross section features is the fine-structure splitting of bound state energy levels. The relativistic effects are studied in the photoionization of Fe25+ ion, as an example.

Relativistic effects in the photoionization of hydrogen-like ions with screened Coulomb interaction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xie, L. Y.; Key Laboratory of Computational Physics, Institute of Applied Physics and Computational Mathematics, P.O. Box 8009-26, Beijing 100088; Wang, J. G.

2014-06-15

The relativistic effects in the photoionization of hydrogen-like ion with screened Coulomb interaction of Yukawa type are studied for a broad range of screening lengths and photoelectron energies. The bound and continuum wave functions have been determined by solving the Dirac equation. The study is focused on the relativistic effects manifested in the characteristic features of photoionization cross section for electric dipole nl→ε,l±1 transitions: shape resonances, Cooper minima and cross section enhancements due to near-zero-energy states. It is shown that the main source of relativistic effects in these cross section features is the fine-structure splitting of bound state energy levels.more » The relativistic effects are studied in the photoionization of Fe{sup 25+} ion, as an example.« less

Electrostatic contribution to the persistence length of a semiflexible dipolar chain.

PubMed

Podgornik, Rudi

2004-09-01

We investigate the electrostatic contribution to the persistence length of a semiflexible polymer chain whose segments interact via a screened Debye-Hückel dipolar interaction potential. We derive the expressions for the renormalized persistence length on the level of a 1/D-expansion method already successfully used in other contexts of polyelectrolye physics. We investigate different limiting forms of the renormalized persistence length of the dipolar chain and show that, in, general, it depends less strongly on the screening length than in the context of a monopolar chain. We show that for a dipolar chain the electrostatic persistence length in the same regime of the parameter phase space as the original Odijk-Skolnick-Fixman (OSF) form for a monopolar chain depends logarithmically on the screening length rather than quadratically. This can be understood solely on the basis of a swifter decay of the dipolar interactions with separation compared to the monopolar electrostatic interactions. We comment also on the general contribution of higher multipoles to the electrostatic renormalization of the bending rigidity.

Ionic screening and dissociation are crucial for understanding chemical self-propulsion in polar solvents.

PubMed

Brown, Aidan T; Poon, Wilson C K; Holm, Christian; de Graaf, Joost

2017-02-08

Polar solvents like water support the bulk dissociation of themselves and their solutes into ions, and the re-association of these ions into neutral molecules in a dynamic equilibrium, e.g., H 2 O 2 ⇌ H + + HO 2 - . Using continuum theory, we study the influence of these association-dissociation reactions on the self-propulsion of colloids driven by surface chemical reactions (chemical swimmers). We find that association-dissociation reactions should have a strong influence on swimmers' behaviour, and therefore should be included in future modelling. In particular, such bulk reactions should permit charged swimmers to propel electrophoretically even if all species involved in the surface reactions are neutral. The bulk reactions also significantly modify the predicted speed of chemical swimmers propelled by ionic currents, by up to an order of magnitude. For swimmers whose surface reactions produce both anions and cations (ionic self-diffusiophoresis), the bulk reactions produce an additional reactive screening length, analogous to the Debye length in electrostatics. This in turn leads to an inverse relationship between swimmer radius and swimming speed, which could provide an alternative explanation for recent experimental observations on Pt-polystyrene Janus swimmers [S. Ebbens et al., Phys. Rev. E: Stat., Nonlinear, Soft Matter Phys., 2012, 85, 020401]. We also use our continuum theory to investigate the effect of the Debye screening length itself, going beyond the infinitely-thin-screening-length approximation used by previous analytical theories. We identify significant departures from this limiting behaviour for micron-sized swimmers under typical experimental conditions and find that the approximation fails entirely for nanoscale swimmers.

The charmonium dissociation in an ''anomalous wind''

DOE PAGES

Sadofyev, Andrey V.; Yin, Yi

2016-01-11

We study the charmonium dissociation in a strongly coupled chiral plasma in the presence of magnetic field and axial charge imbalance. This type of plasma carries "anomalous flow" induced by the chiral anomaly and exhibits novel transport phenomena such as chiral magnetic effect. We found that the "anomalous flow" would modify the charmonium color screening length by using the gauge/gravity correspondence. We derive an analytical expression quantifying the "anomalous flow" experienced by a charmonium for a large class of chiral plasma with a gravity dual. We elaborate on the similarity and it qualitative difference between anomalous effects on the charmoniummore » color screening length which are model-dependent and those on the heavy quark drag force which are fixed by the second law of thermodynamics. As a result, we speculate on the possible charmonium dissociation induced by the chiral anomaly in heavy ion collisions.« less

Passive Control of Vortex Shedding via Screen Shroud

NASA Astrophysics Data System (ADS)

Azmi, A. M.; Zhou, T.

2017-12-01

The turbulent wake of screen-shrouded cylinders were experimentally investigated using flow visualization. Screen cylinders made from screen mesh of various porosity (37%, 49%, 61% and 67%) were used as the shrouds. The main purpose of the study is to examine the effect of screen porosity, β and screen diameter ratio, dw /D (wire diameter to cylinder diameter ratio) on the vortex development behind the shrouded cylinders, particularly in supressing the vortex shedding from a circular cylinder. The diameter ratio between the screen shroud and the plain cylinder, D/d was 2.0. The flow Reynolds number based on the shroud diameter, ReD was about 1000. Results showed that the inclusion of the screen shrouds has significant impact on the wake of the circular cylinder. With larger value of the non-dimensional parameter βdw /D, vortex was impaired and the formation length was longer in the shrouded cylinder wake. The vortex generation mechanism was also discussed.

Ion extraction from a plasma

NASA Technical Reports Server (NTRS)

Aston, G.; Wilbur, P. J.

1981-01-01

The physical processes governing ion extraction from a plasma have been examined experimentally. The screen hole plasma sheath (the transition region wherein significant ion acceleration and complete electron retardation occurs) has been defined by equipotential plots for a variety of ion accelerator system geometries and operating conditions. It was found that the screen hole plasma sheath extends over a large distance, and influences ion and electron trajectories at least 15 Debye lengths within the discharge chamber. The electron density variation within the screen hole plasma sheath satisfied a Maxwell-Boltzmann density distribution at an effective electron temperature dependent on the discharge plasma primary-to-Maxwellian electron density ratio. Plasma ion flow up to and through the sheath was predominantly one-dimensional, and the ions entered the sheath region with a modified Bohm velocity. Low values of the screen grid thickness to screen hole diameter ratio were found to give good ion focusing and high extracted ion currents because of the effect of screen webbing on ion focusing.

Implication of forage particle length on chewing activities and milk production in dairy goats.

PubMed

Lu, C D

1987-07-01

Twenty-four primiparous Alpine does fed a high concentrate ration were utilized to study the effect of forage particle length on chewing activity, ruminal components, and milk composition. Treatments were Bermudagrass hay with mean particle length of 2.38 and 3.87 mm. Forage particle length was determined with an oscillating screen particle separator. Feeding forage with 3.87-mm mean particle length to lactating dairy goats resulted in higher total chewing and rumination times, slightly higher milk fat content, and fat-corrected milk production. Results from this experiment support the hypothesis that forage particle length affects chewing activities and production of milk fat precursors in the rumen and alters milk fat content and output of fat-corrected milk. Forage particle length appeared to be an important index for forage quality and a quantitative approach could be feasible to establish a system relating forage particle length to milk production in dairy goats.

Clinical and cost-effectiveness analysis of early detection of patients at nutrition risk during their hospital stay through the new screening method CIPA: a study protocol.

PubMed

Suárez-Llanos, José Pablo; Benítez-Brito, Néstor; Vallejo-Torres, Laura; Delgado-Brito, Irina; Rosat-Rodrigo, Adriá; Hernández-Carballo, Carolina; Ramallo-Fariña, Yolanda; Pereyra-García-Castro, Francisca; Carlos-Romero, Juan; Felipe-Pérez, Nieves; García-Niebla, Jennifer; Calderón-Ledezma, Eduardo Mauricio; González-Melián, Teresa de Jesús; Llorente-Gómez de Segura, Ignacio; Barrera-Gómez, Manuel Ángel

2017-04-20

Malnutrition is highly prevalent in hospitalized patients and results in a worsened clinical course as well as an increased length of stay, mortality, and costs. Therefore, simple nutrition screening systems, such as CIPA (control of food intake, protein, anthropometry), may be implemented to facilitate the patient's recovery process. The aim of this study is to evaluate the effectiveness and cost-effectiveness of implementing such screening tool in a tertiary hospital, consistent with the lack of similar, published studies on any hospital nutrition screening system. The present study is carried out as an open, controlled, randomized study on patients that were admitted to the Internal Medicine and the General and Digestive Surgery ward; the patients were randomized to either a control or an intervention group (n = 824, thereof 412 patients in each of the two study arms). The control group underwent usual inpatient clinical care, while the intervention group was evaluated with the CIPA screening tool for early detection of malnutrition and treated accordingly. CIPA nutrition screening was performed upon hospital admission and classified positive when at least one of the following parameters was met: 72 h food intake control < 50%, serum albumin < 3 g/dL, body mass index < 18.5 kg/m 2 (or mid-upper arm circumference ≤ 22.5 cm). In this case, the doctor decided on whether or not providing nutrition support. The following variables will be evaluated: hospital length of stay (primary endpoint), mortality, 3-month readmission, and in-hospital complications. Likewise, the quality of life questionnaires EQ-5D-5 L are being collected for all patients at hospital admission, discharge, and 3 months post-discharge. Analysis of cost-effectiveness will be performed by measuring effectiveness in terms of quality-adjusted life years (QALYs). The cost per patient will be established by identifying health care resource utilization; cost-effectiveness will be determined through the incremental cost-effectiveness ratio (ICER). We will calculate the incremental cost per QALY gained with respect to the intervention. This ongoing trial aims to evaluate the cost-effectiveness of implementing the malnutrition screening tool CIPA in a tertiary hospital. Clinical Trial.gov ( NCT02721706 ). First receivevd: March 1, 2016 Last updated: April 8, 2017 Last verified: April 2017.

The Effects of Cannabis on Inpatient Agitation, Aggression, and Length of Stay.

PubMed

Johnson, Joseph M; Wu, Chris Y; Winder, Gerald Scott; Casher, Michael I; Marshall, Vincent D; Bostwick, Jolene R

2016-01-01

This study examines the association between cannabis use and the hospital course of patients admitted to the psychiatric inpatient unit with a diagnosis of schizophrenia, schizoaffective disorder, or bipolar disorder. Many confounding variables potentially contribute to the clinical presentation of hospitalized patients in the psychiatric unit. Illicit drug use, in particular, has been associated with acute agitation, and questions can be raised as to what lasting effects drug use prior to admission may have throughout a patient's hospital stay. Subjects with a discharge diagnosis of bipolar disorder, schizophrenia, schizoaffective disorder, or psychosis not otherwise specified (N = 201) were retrospectively identified, and those with positive results of urine drug screen for cannabis on admission were compared to negative counterparts. Agitation and aggression were measured using an adaptation of the Excited Component of the Positive and Negative Syndrome Scale (PANSS-EC). These markers were also quantified by comparing charted episodes of restraint and seclusion and administration of as needed medications, such as benzodiazepines and antipsychotics. Positive urine drug screen results for cannabis was correlated with young (p = .001) males (p = .003) with bipolar disorder (p = .009) exhibiting active manic symptoms (p = .003) at the time of admission. Cannabis use was further associated with a shorter length of stay (p = .008), agitation triggering adapted PANSS-EC nursing assessments (p = .029), and oral medications as needed (p = .002) for agitation. Cannabis use, as defined by positive urine drug screen results, was more common in patients with bipolar disorder and was accompanied by a higher incidence of inpatient agitation. Although these patients also had short hospital lengths of stay, there was no clear relationship between level of agitation and length of stay across all patient groups. One possible explanation for patients with bipolar disorder experiencing short lengths of stay is that their source of agitation may be more closely related to a complex effect of cannabis use rather than a sole etiology of mental illness. Inpatient clinicians should be aware of patient cannabis use proximate to admission.

Initial Observations of Micropulse Elongation of Electron Beams in a SCRF Accelerator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lumpkin, A. H.; Thurman-Keup, R.; Edstrom Jr., D.

2016-10-09

Commissioning at the SCRF accelerator at the Fermilab Accelerator Science and Technology (FAST) Facility has included the implementation of a versatile bunch-length monitor located after the 4-dipole chicane bunch compressor for electron beam energies of 20-50 MeV and integrated charges in excess of 10 nC. The team has initially used a Hamamatsu C5680 synchroscan streak camera to assess the effects of space charge on the electron beam bunch lengths. An Al-coated Si screen was used to generate optical transition radiation (OTR) resulting from the beam’s interaction with the screen. The chicane bypass beamline allowed the measurements of the bunch lengthmore » without the compression stage at the downstream beamline location using OTR and the streak camera. We have observed electron beam bunch lengths from 5 to 16 ps (sigma) for micropulse charges of 60 pC to 800 pC, respectively. We also report a compressed sub-ps micropulse case.« less

Early Dysphagia Screening by Trained Nurses Reduces Pneumonia Rate in Stroke Patients: A Clinical Intervention Study.

PubMed

Palli, Christoph; Fandler, Simon; Doppelhofer, Kathrin; Niederkorn, Kurt; Enzinger, Christian; Vetta, Christian; Trampusch, Esther; Schmidt, Reinhold; Fazekas, Franz; Gattringer, Thomas

2017-09-01

Dysphagia is a common stroke symptom and leads to serious complications such as aspiration and pneumonia. Early dysphagia screening can reduce these complications. In many hospitals, dysphagia screening is performed by speech-language therapists who are often not available on weekends/holidays, which results in delayed dysphagia assessment. We trained the nurses of our neurological department to perform formal dysphagia screening in every acute stroke patient by using the Gugging Swallowing Screen. The impact of a 24/7 dysphagia screening (intervention) over swallowing assessment by speech-language therapists during regular working hours only was compared in two 5-month periods with time to dysphagia screening, pneumonia rate, and length of hospitalization as outcome variables. Overall, 384 patients (mean age, 72.3±13.7 years; median National Institutes of Health Stroke Scale score of 3) were included in the study. Both groups (pre-intervention, n=198 versus post-intervention, n=186) were comparable regarding age, sex, and stroke severity. Time to dysphagia screening was significantly reduced in the intervention group (median, 7 hours; range, 1-69 hours) compared with the control group (median, 20 hours; range, 1-183; P =0.001). Patients in the intervention group had a lower rate of pneumonia (3.8% versus 11.6%; P =0.004) and also a reduced length of hospital stay (median, 8 days; range, 2-40 versus median, 9 days; range, 1-61 days; P =0.033). 24/7 dysphagia screening can be effectively performed by nurses and leads to reduced pneumonia rates. Therefore, empowering nurses to do a formal bedside screening for swallowing dysfunction in stroke patients timely after admission is warranted whenever speech-language therapists are not available. © 2017 American Heart Association, Inc.

Maternal ethnicity and variation of fetal femur length calculations when screening for Down syndrome.

PubMed

Kovac, Christine M; Brown, Jennifer A; Apodaca, Christina C; Napolitano, Peter G; Pierce, Brian; Patience, Troy; Hume, Roderick F; Calhoun, Byron C

2002-07-01

To determine whether current methods for detecting Down syndrome based on fetal femur length calculations are influenced by ethnicity. The study population consisted of all fetuses scanned between 14 and 20 completed weeks' gestation from April 1, 1997, to January 1, 2000. The expected femur length was calculated from the biparietal diameter. The variance from the expected femur length, compared with the biparietal diameter, was calculated, and the mean variations were compared by maternal race. Ethnic-specific formulas for expected femur length were derived by simple regression. There was a statistically significant difference in femur length in the Asian group compared with all other groups, as well as the white group compared with the black and Asian groups (P < .05). However, there was no significant difference between the black and Hispanic groups or the white and Hispanic groups. The Asian group had the largest variation, with the measured femur length being less than the expected femur length. All groups studied had a mean expected femur length less than the mean measured femur length. On the basis of the ethnic-specific formulas for femur length, there was a significant decrease in patients that would undergo further evaluation for Down syndrome. There is a significant difference in the mean expected femur length by biparietal diameter among fetuses in the second trimester with regard to ethnicity. Using ethnic-specific formulas for expected femur length can have a considerable impact on the use of sonographic risk factors for Down syndrome screening. Further data are required for use of femur length as a screening tool in the genetic sonogram.

Toxicological Profiling of Highly Purified Single-Walled Carbon Nanotubes with Different Lengths in the Rodent Lung and Escherichia Coli.

PubMed

Wang, Xiang; Lee, Jae-Hyeok; Li, Ruibin; Liao, Yu-Pei; Kang, Joohoon; Chang, Chong Hyun; Guiney, Linda M; Mirshafiee, Vahid; Li, Linjiang; Lu, Jianqin; Xia, Tian; Hersam, Mark C; Nel, André E

2018-06-01

Carbon nanotubes (CNTs) exhibit a number of physicochemical properties that contribute to adverse biological outcomes. However, it is difficult to define the independent contribution of individual properties without purified materials. A library of highly purified single-walled carbon nanotubes (SWCNTs) of different lengths is prepared from the same base material by density gradient ultracentrifugation, designated as short (318 nm), medium (789 nm), and long (1215 nm) SWCNTs. In vitro screening shows length-dependent interleukin-1β (IL-1β) production, in order of long > medium > short. However, there are no differences in transforming growth factor-β1 production in BEAS-2B cells. Oropharyngeal aspiration shows that all the SWCNTs induce profibrogenic effects in mouse lung at 21 d postexposure, but there are no differences between tube lengths. In contrast, these SWCNTs demonstrate length-dependent antibacterial effects on Escherichia coli, with the long SWCNT exerting stronger effects than the medium or short tubes. These effects are reduced by Pluronic F108 coating or supplementing with glucose. The data show length-dependent effects on proinflammatory response in macrophage cell line and antibacterial effects, but not on collagen deposition in the lung. These data demonstrate that over the length scale tested, the biological response to highly purified SWCNTs is dependent on the complexity of the nano/bio interface. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effect of screening on the transport of polyelectrolytes through nanopores

NASA Astrophysics Data System (ADS)

Oukhaled, G.; Bacri, L.; Mathé, J.; Pelta, J.; Auvray, L.

2008-05-01

We study the transport of dextran sulfate molecules (Mw=8000 Da) through a bacterial α-hemolysin channel inserted into a bilayer lipid membrane submitted to an external electric field. We detect the current blockades induced by the molecules threading through one pore and vary the ionic strength in an unexplored range starting at 10-3 M. In the conditions of the experiment, the polyelectrolyte molecules enter the pore only if the Debye screening length is smaller than the pore radius in agreement with theory. We also observe that large potentials favour the passage of the molecules. The distribution of blockade durations suggests that a complex process governs the kinetics of the molecules. The dwelling time increases sharply as the Debye length increases and approaches the pore radius.

Swelling of biological and semiflexible polyelectrolytes.

PubMed

Dobrynin, Andrey V; Carrillo, Jan-Michael Y

2009-10-21

We have developed a theoretical model of swelling of semiflexible (biological) polyelectrolytes in salt solutions. Our approach is based on separation of length scales which allowed us to split a chain's electrostatic energy into two parts that describe local and remote electrostatic interactions along the polymer backbone. The local part takes into account interactions between charged monomers that are separated by distances along the polymer backbone shorter than the chain's persistence length. These electrostatic interactions renormalize chain persistence length. The second part includes electrostatic interactions between remote charged pairs along the polymer backbone located at distances larger than the chain persistence length. These interactions are responsible for chain swelling. In the framework of this approach we calculated effective chain persistence length and chain size as a function of the Debye screening length, chain degree of ionization, bare persistence length and chain degree of polymerization. Our crossover expression for the effective chain's persistence length is in good quantitative agreement with the experimental data on DNA. We have been able to fit experimental datasets by using two adjustable parameters: DNA ionization degree (α = 0.15-0.17) and a bare persistence length (l(p) = 40-44 nm).

Influence of rhizobacterial volatiles on the root system architecture and the production and allocation of biomass in the model grass Brachypodium distachyon (L.) P. Beauv.

PubMed

Delaplace, Pierre; Delory, Benjamin M; Baudson, Caroline; Mendaluk-Saunier de Cazenave, Magdalena; Spaepen, Stijn; Varin, Sébastien; Brostaux, Yves; du Jardin, Patrick

2015-08-12

Plant growth-promoting rhizobacteria are increasingly being seen as a way of complementing conventional inputs in agricultural systems. The effects on their host plants are diverse and include volatile-mediated growth enhancement. This study sought to assess the effects of bacterial volatiles on the biomass production and root system architecture of the model grass Brachypodium distachyon (L.) Beauv. An in vitro experiment allowing plant-bacteria interaction throughout the gaseous phase without any physical contact was used to screen 19 bacterial strains for their growth-promotion ability over a 10-day co-cultivation period. Five groups of bacteria were defined and characterised based on their combined influence on biomass production and root system architecture. The observed effects ranged from unchanged to greatly increased biomass production coupled with increased root length and branching. Primary root length was increased only by the volatile compounds emitted by Enterobacter cloacae JM22 and Bacillus pumilus T4. Overall, the most significant results were obtained with Bacillus subtilis GB03, which induced an 81 % increase in total biomass, as well as enhancing total root length, total secondary root length and total adventitious root length by 88.5, 201.5 and 474.5 %, respectively. This study is the first report on bacterial volatile-mediated growth promotion of a grass plant. Contrasting modulations of biomass production coupled with changes in root system architecture were observed. Most of the strains that increased total plant biomass also modulated adventitious root growth. Under our screening conditions, total biomass production was strongly correlated with the length and branching of the root system components, except for primary root length. An analysis of the emission kinetics of the bacterial volatile compounds is being undertaken and should lead to the identification of the compounds responsible for the observed growth-promotion effects. Within the context of the inherent characteristics of our in vitro system, this paper identifies the next critical experimental steps and discusses them from both a fundamental and an applied perspective.

Design and fabrication of segmented-in-series solid oxide fuel cells

NASA Astrophysics Data System (ADS)

Lai, Tammy S.

Segmented-in-series solid oxide fuel cells (SS-SOFC) consist of several thick film cells deposited onto a porous, flattened tubular substrate. SS-SOFCs have a reduced need for gas-tight seals relative to planar SOFCs and can have a short current path compared to tubular SOFCs, limiting electrode ohmic resistance. Like tubular SOFCs, SS-SOFCs are suitable for stationary power generation. Their potentially small cell size makes them candidates for portable applications as well. The goals of this thesis project were to develop SS-SOFCs with 1-2 mm cell lengths and to analyze the effects of cell geometry and support current shunting on performance. Standard SOFC materials were chosen for the active components: yttria stabilized zirconia (YSZ) electrolyte; Ni-YSZ cermet anode; and (La,Sr)MnO 3-based cathode. A Pt-YSZ cermet was used as the interconnect material. Screen printing was the deposition method for all layers due to its low cost and patterning ability. A power density of >900 mW/cm2 was achieved with a cathode sheet resistance of ≈3 O/□ (≈90 mum LSM thickness). A D-optimal study was conducted to find processing conditions yielding substrates with ≥30 vol% porosity and high strength. Uniaxially pressed partially stabilized zirconia (PSZ) with 15 wt% starch pore former met the requirements, though 20 wt% graphite pore former was later found to give a smoother surface that improved screen printed layer quality. Calculations presented in this thesis take into account losses due to cell resistances, electrode ohmic resistances, interconnect resistance, and shunting by a weakly-conductive support material. Power density was maximized at an optimal cell length---it decreased at larger cell lengths due to electrode lateral resistance loss and at smaller cell lengths due to a decreasing fraction of cell active area. Assuming dimensions expected for screen printing and typical area specific resistances (RAS), optimal cell lengths typically ranged from 1 to 3 mm. The calculated and experimental values for the array RAS (active and inactive areas) showed similar dependences on cathode sheet resistance. The impact of shunting current increased with decreasing cell lengths. Shunting current was predicted to decrease array current by ˜10% for a 1.5 mm active cell length, though experimental measurements suggest that the calculation may overestimate the shunting effect.

Breaking Through the Multi-Mesa-Channel Width Limited of Normally Off GaN HEMTs Through Modulation of the Via-Hole-Length.

PubMed

Chien, Cheng-Yen; Wu, Wen-Hsin; You, Yao-Hong; Lin, Jun-Huei; Lee, Chia-Yu; Hsu, Wen-Ching; Kuan, Chieh-Hsiung; Lin, Ray-Ming

2017-12-01

We present new normally off GaN high-electron-mobility transistors (HEMTs) that overcome the typical limitations in multi-mesa-channel (MMC) width through modulation of the via-hole-length to regulate the charge neutrality screen effect. We have prepared enhancement-mode (E-mode) GaN HEMTs having widths of up to 300 nm, based on an enhanced surface pinning effect. E-mode GaN HEMTs having MMC structures and widths as well as via-hole-lengths of 100 nm/2 μm and 300 nm/6 μm, respectively, exhibited positive threshold voltages (V th ) of 0.79 and 0.46 V, respectively. The on-resistances of the MMC and via-hole-length structures were lower than those of typical tri-gate nanoribbon GaN HEMTs. In addition, the devices not only achieved the E-mode but also improved the power performance of the GaN HEMTs and effectively mitigated the device thermal effect. We controlled the via-hole-length sidewall surface pinning effect to obtain the E-mode GaN HEMTs. Our findings suggest that via-hole-length normally off GaN HEMTs have great potential for use in next-generation power electronics.

Ion extraction from a plasma. Ph.D. Thesis. Progress Report, 1 Dec. 1979 - 1 Dec. 1980

NASA Technical Reports Server (NTRS)

Aston, G.

1980-01-01

An experimental investigation of the physical processes governing ion extraction from a plasma is presented. The screen hole plasma sheath of a multiaperture ion accelerator system is defined by equipotential plots for a variety of accelerator system geometries and operating conditions. A sheath thickness of at least fifteen Debye lengths is shown to be typical. The electron density variation within the sheath satisfies a Maxwell Boltzmann density distribution at an effective electron temperature dependent on the discharge plasma primary to Maxwellian electron density ratio. Plasma ion flow up to and through the sheath is predominately one dimensional and the ions enter the sheath with a modified Bohm velocity. Low values of the screen grid thickness to screen hole diameter ratio give good ion focusing and high extracted ion currents because of the effect of screen webbing on ion focusing.

Evaluation of nutritional status as an independent predictor of post-operative complications and morbidity after gastro-intestinal surgery.

PubMed

van der Kroft, G; Janssen-Heijnen, M L G; van Berlo, C L H; Konsten, J L M

2015-08-01

Nutritional Risk Screening-2002 (NRS-2002) and the Malnutrition Universal Screening Tool (MUST) are screening tools for nutritional risk that have also been used to predict post-operative complications and morbidity, though not all studies confirm the reliability of nutritional screening. Our study aims to evaluate the independent predictive value of nutritional risk screening in addition to currently documented medical, surgical and anesthesiological risk factors for post-operative complications, as well as length of hospital stay. This study is a prospective observational cohort study of 129 patients undergoing elective gastro-intestinal-surgery. Patients were screened for nutritional risk upon admission using both MUST and NRS-2002 screening tools. Univariate and multivariate analyses were performed to investigate the independent predictive value of nutritional risk for post-operative complications and length of hospital stay. MUST ≥2 (OR 2.87; 95% CI 1.05-7.87) and peri-operative transfusion (OR 2.78; 95% CI 1.05-7.40) were significant independent predictors for the occurrence of post-operative complications. Peri-operative transfusion (HR 2.40; 95% CI 1.45-4.00), age ≥70 (HR 1.50; 95% CI 1.05-2.16) and open surgery versus laparoscopic surgery (HR 1.39; 95% CI 0.94-2.05) were independent predictors for increased length of hospital stay, whereas American Society of Anesthesiology Score (ASA) and MUST were not. Nutritional risk screening (MUST ≥2) is an independent predictor for post-operative complications, but not for increased length of hospital stay. Copyright © 2015 European Society for Clinical Nutrition and Metabolism. Published by Elsevier Ltd. All rights reserved.

Duration of stimulus presentation and screening for perceptual disabilities.

PubMed

Rohr, M E; Ayers, J B

1975-02-01

This study examined the effects of increasing the stimulus-presentation time of a motion picture test for identifying perceptual disabilities in the performance of Ss in regular first and fourth grade classrooms and on a sample of Ss in special education classes who had been identified as having varying degrees of perceptual deficiencies. The length of stimulus presentation increased the total performance of Ss on the motion picture test but did not add to the value of the instrument as a screening device.

Growth characteristics and enzyme production optimization of lipase Producing Strain

NASA Astrophysics Data System (ADS)

Zheng, Chaocheng

2018-01-01

55 samples from different regions were selected and screened by Rhodamine B flat transparent circle method to observe lipase producing effect, among which, LHY-1, identified as Serratia sp. has the characteristics of fast growth, high enzyme production and stable ability. The colony of this strain is white, the edge is smooth and tidy, the surface is moist, the cell is straight, rod-shaped, gram negative, 0.1-0.2 μm in diameter and, length 0.3-0.5 μm in length.

Brownian dynamics simulations of polyelectrolyte adsorption in shear flow with hydrodynamic interaction

NASA Astrophysics Data System (ADS)

Hoda, Nazish; Kumar, Satish

2007-12-01

The adsorption of single polyelectrolyte molecules in shear flow is studied using Brownian dynamics simulations with hydrodynamic interaction (HI). Simulations are performed with bead-rod and bead-spring chains, and electrostatic interactions are incorporated through a screened Coulombic potential with excluded volume accounted for by the repulsive part of a Lennard-Jones potential. A correction to the Rotne-Prager-Yamakawa tensor is derived that accounts for the presence of a planar wall. The simulations show that migration away from an uncharged wall, which is due to bead-wall HI, is enhanced by increases in the strength of flow and intrachain electrostatic repulsion, consistent with kinetic theory predictions. When the wall and polyelectrolyte are oppositely charged, chain behavior depends on the strength of electrostatic screening. For strong screening, chains get depleted from a region close to the wall and the thickness of this depletion layer scales as N1/3Wi2/3 at high Wi, where N is the chain length and Wi is the Weissenberg number. At intermediate screening, bead-wall electrostatic attraction competes with bead-wall HI, and it is found that there is a critical Weissenberg number for desorption which scales as N-1/2κ-3(lB∣σq∣)3/2, where κ is the inverse screening length, lB is the Bjerrum length, σ is the surface charge density, and q is the bead charge. When the screening is weak, adsorbed chains are observed to align in the vorticity direction at low shear rates due to the effects of repulsive intramolecular interactions. At higher shear rates, the chains align in the flow direction. The simulation method and results of this work are expected to be useful for a number of applications in biophysics and materials science in which polyelectrolyte adsorption plays a key role.

A high-throughput platform for population reformatting and mammalian expression of phage display libraries to enable functional screening as full-length IgG.

PubMed

Xiao, Xiaodong; Douthwaite, Julie A; Chen, Yan; Kemp, Ben; Kidd, Sara; Percival-Alwyn, Jennifer; Smith, Alison; Goode, Kate; Swerdlow, Bonnie; Lowe, David; Wu, Herren; Dall'Acqua, William F; Chowdhury, Partha S

Phage display antibody libraries are a rich resource for discovery of potential therapeutic antibodies. Single-chain variable fragment (scFv) libraries are the most common format due to the efficient display of scFv by phage particles and the ease by which soluble scFv antibodies can be expressed for high-throughput screening. Typically, a cascade of screening and triaging activities are performed, beginning with the assessment of large numbers of E. coli-expressed scFv, and progressing through additional assays with individual reformatting of the most promising scFv to full-length IgG. However, use of high-throughput screening of scFv for the discovery of full-length IgG is not ideal because of the differences between these molecules. Furthermore, the reformatting step represents a bottle neck in the process because each antibody has to be handled individually to preserve the unique VH and VL pairing. These problems could be resolved if populations of scFv could be reformatted to full-length IgG before screening without disrupting the variable region pairing. Here, we describe a novel strategy that allows the reformatting of diverse populations of scFv from phage selections to full-length IgG in a batch format. The reformatting process maintains the diversity and variable region pairing with high fidelity, and the resulted IgG pool enables high-throughput expression of IgG in mammalian cells and cell-based functional screening. The improved process led to the discovery of potent candidates that are comparable or better than those obtained by traditional methods. This strategy should also be readily applicable to Fab-based phage libraries. Our approach, Screening in Product Format (SiPF), represents a substantial improvement in the field of antibody discovery using phage display.

Focus Article: Oscillatory and long-range monotonic exponential decays of electrostatic interactions in ionic liquids and other electrolytes: The significance of dielectric permittivity and renormalized charges

NASA Astrophysics Data System (ADS)

Kjellander, Roland

2018-05-01

A unified treatment of oscillatory and monotonic exponential decays of interactions in electrolytes is displayed, which highlights the role of dielectric response of the fluid in terms of renormalized (effective) dielectric permittivity and charges. An exact, but physically transparent statistical mechanical formalism is thereby used, which is presented in a systematic, pedagogical manner. Both the oscillatory and monotonic behaviors are given by an equation for the decay length of screened electrostatic interactions that is very similar to the classical expression for the Debye length. The renormalized dielectric permittivities, which have similar roles for electrolytes as the dielectric constant has for pure polar fluids, consist in general of several entities with different physical meanings. They are connected to dielectric response of the fluid on the same length scale as the decay length of the screened interactions. Only in cases where the decay length is very long, these permittivities correspond approximately to a dielectric response in the long-wavelength limit, like the dielectric constant for polar fluids. Experimentally observed long-range exponentially decaying surface forces are analyzed as well as the oscillatory forces observed for short to intermediate surface separations. Both occur in some ionic liquids and in concentrated as well as very dilute electrolyte solutions. The coexisting modes of decay are in general determined by the bulk properties of the fluid and not by the solvation of the surfaces; in the present cases, they are given by the behavior of the screened Coulomb interaction of the bulk fluid. The surface-fluid interactions influence the amplitudes and signs or phases of the different modes of the decay, but not their decay lengths and wavelengths. The similarities between some ionic liquids and very dilute electrolyte solutions as regards both the long-range monotonic and the oscillatory decays are analyzed.

Acquisition and utilisation of anthropometric measurements on admission in a paediatric hospital before and after the introduction of a malnutrition screening tool.

PubMed

Milani, S; Wright, C; Purcell, O; Macleod, I; Gerasimidis, K

2013-06-01

Acquisition of anthropometric measurements and assessment of growth in paediatric inpatients remains poor. The introduction of malnutrition screening tools that incorporate weight and height/length measurements might improve their acquisition and utilisation in other aspects of patient care. Documentation of weight and/length measurements and their plotting on growth charts was evaluated using a case notes review in paediatric inpatients who were admitted before (n = 146), during (n = 154) and after the pilot (n = 151) and official (n = 128) clinical use of a screening tool. Documentation of weight was high in all periods (> 97% of patients). Height/length measurement documentation was negligible (4% of patients) but improved after the introduction of the screening tool (> 62%; P < 0.0001), except in infants, who were not part of the screening programme. Introduction of a screening tool improved the acquisition of anthropometric measurements by nursing staff, although its utilisation by medical staff remained poor. © 2013 The Authors Journal of Human Nutrition and Dietetics © 2013 The British Dietetic Association Ltd.

The processing of spatial information in short-term memory: insights from eye tracking the path length effect.

PubMed

Guérard, Katherine; Tremblay, Sébastien; Saint-Aubin, Jean

2009-10-01

Serial memory for spatial locations increases as the distance between successive stimuli locations decreases. This effect, known as the path length effect [Parmentier, F. B. R., Elford, G., & Maybery, M. T. (2005). Transitional information in spatial serial memory: Path characteristics affect recall performance. Journal of Experimental Psychology: Learning, Memory & Cognition, 31, 412-427], was investigated in a systematic manner using eye tracking and interference procedures to explore the mechanisms responsible for the processing of spatial information. In Experiment 1, eye movements were monitored during a spatial serial recall task--in which the participants have to remember the location of spatially and temporally separated dots on the screen. In the experimental conditions, eye movements were suppressed by requiring participants to incessantly move their eyes between irrelevant locations. Ocular suppression abolished the path length effect whether eye movements were prevented during item presentation or during a 7s retention interval. In Experiment 2, articulatory suppression was combined with a spatial serial recall task. Although articulatory suppression impaired performance, it did not alter the path length effect. Our results suggest that rehearsal plays a key role in serial memory for spatial information, though the effect of path length seems to involve other processes located at encoding, such as the time spent fixating each location and perceptual organization.

Finite temperature static charge screening in quantum plasmas

NASA Astrophysics Data System (ADS)

Eliasson, B.; Akbari-Moghanjoughi, M.

2016-07-01

The shielding potential around a test charge is calculated, using the linearized quantum hydrodynamic formulation with the statistical pressure and Bohm potential derived from finite temperature kinetic theory, and the temperature effects on the force between ions is assessed. The derived screening potential covers the full range of electron degeneracy in the equation of state of the plasma electrons. An attractive force between shielded ions in an arbitrary degenerate plasma exists below a critical temperature and density. The effect of the temperature on the screening potential profile qualitatively describes the ion-ion bound interaction strength and length variations. This may be used to investigate physical properties of plasmas and in molecular-dynamics simulations of fermion plasma. It is further shown that the Bohm potential including the kinetic corrections has a profound effect on the Thomson scattering cross section in quantum plasmas with arbitrary degeneracy.

Elevated Blood Lead Levels by Length of Time From Resettlement to Health Screening in Kentucky Refugee Children.

PubMed

Kotey, Stanley; Carrico, Ruth; Wiemken, Timothy Lee; Furmanek, Stephen; Bosson, Rahel; Nyantakyi, Florence; VanHeiden, Sarah; Mattingly, William; Zierold, Kristina M

2018-02-01

To examine elevated blood lead levels (EBLLs) in refugee children by postrelocation duration with control for several covariates. We assessed EBLLs (≥ 5µg/dL) between 2012 and 2016 of children younger than 15 years (n = 1950) by the duration of resettlement to health screening by using logistic regression, with control for potential confounders (gender, region of birth, age of housing, and intestinal infestation) in a cross-sectional study. Prevalence of EBLLs was 11.2%. Length of time from resettlement to health screening was inversely associated with EBLLs (tertile 2 unadjusted odds ratio [OR] = 0.79; 95% confidence interval [CI] = 0.56, 1.12; tertile 3 OR = 0.62; 95% CI = 0.42, 0.90; tertile 2 adjusted odds ratio [AOR] = 0.62; 95% CI = 0.39, 0.97; tertile 3 AOR = 0.57; 95% CI = 0.34, 0.93). There was a significant interaction between intestinal infestation and age of housing (P < .003), indicating significant risk in the joint exposure of intestinal infestation (a pica proxy) and age of house. Elevated blood lead levels were reduced with increasing length of time of resettlement in unadjusted and adjusted models. Improved housing, early education, and effective safe-house inspections may be necessary to address EBLLs in refugees.

Reading Touch Screen Storybooks with Mothers Negatively Affects 7-Year-Old Readers’ Comprehension but Enriches Emotional Engagement

PubMed Central

Ross, Kirsty M.; Pye, Rachel E.; Randell, Jordan

2016-01-01

Touch screen storybooks turn reading into an interactive multimedia experience, with hotspot-activated animations, sound effects, and games. Positive and negative effects of reading multimedia stories have been reported, but the underlying mechanisms which explain how children’s learning is affected remain uncertain. The present study examined the effect of storybook format (touch screen and print) on story comprehension, and considered how level of touch screen interactivity (high and low) and shared reading behaviors (cognitive and emotional scaffolding, emotional engagement) might contribute to comprehension. Seven-year-olds (n = 22) were observed reading one touch screen storybook and one print storybook with their mothers. Story comprehension was inferior for the touch screen storybooks compared to the print formats. Touch screen interactivity level had no significant effect on comprehension but did affect shared reading behaviors. The mother–child dyads spent less time talking about the story in the highly interactive touch screen condition, despite longer shared reading sessions because of touch screen interactions. Positive emotional engagement was greater for children and mothers in the highly interactive touch screen condition, due to additional positive emotions expressed during touch screen interactions. Negative emotional engagement was greater for children when reading and talking about the story in the highly interactive condition, and some mothers demonstrated negative emotional engagement with the touch screen activities. The less interactive touch screen storybook had little effect on shared reading behaviors, but mothers controlling behaviors were more frequent. Storybook format had no effect on the frequency of mothers’ cognitive scaffolding behaviors (comprehension questions, word help). Relationships between comprehension and shared reading behaviors were examined for each storybook, and although length of the shared reading session and controlling behaviors had significant effects on comprehension, the mechanisms driving comprehension were not fully explained by the data. The potential for touch screen storybooks to contribute to cognitive overload in 7-year-old developing readers is discussed, as is the complex relationship between cognitive and emotional scaffolding behaviors, emotional engagement, and comprehension. Sample characteristics and methodological limitations are also discussed to help inform future research. PMID:27899903

Holographic screening length in a hot plasma of two sphere

NASA Astrophysics Data System (ADS)

Atmaja, A. Nata; Kassim, H. Abu; Yusof, N.

2015-11-01

We study the screening length L_{max} of a moving quark-antiquark pair in a hot plasma, which lives in a two sphere, S^2, using the AdS/CFT correspondence in which the corresponding background metric is the four-dimensional Schwarzschild-AdS black hole. The geodesic of both ends of the string at the boundary, interpreted as the quark-antiquark pair, is given by a stationary motion in the equatorial plane by which the separation length L of both ends of the string is parallel to the angular velocity ω . The screening length and total energy H of the quark-antiquark pair are computed numerically and show that the plots are bounded from below by some functions related to the momentum transfer P_c of the drag force configuration. We compare the result by computing the screening length in the reference frame of the moving quark-antiquark pair, in which the background metrics are "Boost-AdS" and Kerr-AdS black holes. Comparing both black holes, we argue that the mass parameters M_{Sch} of the Schwarzschild-AdS black hole and M_{Kerr} of the Kerr-AdS black hole are related at high temperature by M_{Kerr}=M_{Sch}(1-a^2l^2)^{3/2}, where a is the angular momentum parameter and l is the AdS curvature.

Quark and Gluon Relaxation in Quark-Gluon Plasmas

NASA Technical Reports Server (NTRS)

Heiselberg, H.; Pethick, C. J.

1993-01-01

The quasiparticle decay rates for quarks and gluons in quark-gluon plasmas are calculated by solving the kinetic equation. Introducing an infrared cutoff to allow for nonperturbative effects, we evaluate the quasiparticle lifetime at momenta greater than the inverse Debye screening length to leading order in the coupling constant.

Cost-utility analysis of screening for diabetic retinopathy in Japan: a probabilistic Markov modeling study.

PubMed

Kawasaki, Ryo; Akune, Yoko; Hiratsuka, Yoshimune; Fukuhara, Shunichi; Yamada, Masakazu

2015-02-01

To evaluate the cost-effectiveness for a screening interval longer than 1 year detecting diabetic retinopathy (DR) through the estimation of incremental costs per quality-adjusted life year (QALY) based on the best available clinical data in Japan. A Markov model with a probabilistic cohort analysis was framed to calculate incremental costs per QALY gained by implementing a screening program detecting DR in Japan. A 1-year cycle length and population size of 50,000 with a 50-year time horizon (age 40-90 years) was used. Best available clinical data from publications and national surveillance data was used, and a model was designed including current diagnosis and management of DR with corresponding visual outcomes. One-way and probabilistic sensitivity analyses were performed considering uncertainties in the parameters. In the base-case analysis, the strategy with a screening program resulted in an incremental cost of 5,147 Japanese yen (¥; US$64.6) and incremental effectiveness of 0.0054 QALYs per person screened. The incremental cost-effectiveness ratio was ¥944,981 (US$11,857) per QALY. The simulation suggested that screening would result in a significant reduction in blindness in people aged 40 years or over (-16%). Sensitivity analyses suggested that in order to achieve both reductions in blindness and cost-effectiveness in Japan, the screening program should screen those aged 53-84 years, at intervals of 3 years or less. An eye screening program in Japan would be cost-effective in detecting DR and preventing blindness from DR, even allowing for the uncertainties in estimates of costs, utility, and current management of DR.

Cut-To-Length Harvesting of Short Rotation Eucalyptus at Simpson Tehama Fiber Farm

Treesearch

Bruce R. Hartsough; David J. Cooper

1999-01-01

A system consisting of a cut-to-length harvester, forwarder, mobile chipper and chip screen was tested in a 7-year-old plantation. Three levels of debarking effort by the harvester (minimal, partial and full), and two levels of screening (with and without) were evaluated. The harvester had the lowest production rate and highest cost of the system elements. Harvester...

Nonlocal electrostatics in ionic liquids: The key to an understanding of the screening decay length and screened interactions.

PubMed

Kjellander, Roland

2016-09-28

Screened electrostatic interactions in ionic liquids are investigated by means of exact statistical mechanical analysis combined with physical arguments that enhance the transparency and conceptual accessibility of the analysis and results. The constituent ions and immersed particles in the liquid can have arbitrary shapes and any internal charge distributions. The decay of the screened electrostatic potential and the free energy of interaction in ionic liquids can be exponentially damped oscillatory (like in molten simple salts) as well as plain exponential and long-ranged (like in dilute electrolyte solutions). Both behaviors are in agreement with the exact statistical mechanical analysis and reasons for their appearances are investigated. Exact but surprisingly simple expressions for the decay parameter κ of the screened electrostatics are obtained, which replace the classical expression for the Debye-Hückel parameter κ DH (the reciprocal Debye length). The expressions are applicable both for cases with plain exponential and oscillatory behaviors. The key importance of nonlocal electrostatics is thereby demonstrated explicitly. Dielectric properties of ionic liquids and other electrolytes are investigated, in particular the static dielectric function ϵ̃(k) and some effective relative permittivities (E r eff and E r ∗ ), which take roles that the dielectric constant ε r has for polar liquids consisting of electroneutral molecules. The dielectric constant in the latter case, which is the limit of ϵ̃(k) when the wave number k → 0, can be expressed solely in terms of dipolar features of the molecules. In contrast to this, the effective dielectric permittivities of ionic liquids have contributions also from quadrupolar, octupolar, and higher multipolar features of the constituent ions. The "dielectric constant" of electrolytes does not exist since ϵ̃(k)→∞ when k → 0, a well-known effect of perfect screening. The effective relative permittivities, E r eff , and E r ∗ of ionic liquids are obtained from the non-diverging part of ϵ̃(k), but not as a k → 0 limit. Influences of ion associations, especially pairing, are investigated for screened electrostatics and these permittivities. A general, multipolar expansion of ϵ̃(k) is derived and used to analyze dielectric properties of ionic liquids and other electrolytes.

Nonlocal electrostatics in ionic liquids: The key to an understanding of the screening decay length and screened interactions

NASA Astrophysics Data System (ADS)

Kjellander, Roland

2016-09-01

Screened electrostatic interactions in ionic liquids are investigated by means of exact statistical mechanical analysis combined with physical arguments that enhance the transparency and conceptual accessibility of the analysis and results. The constituent ions and immersed particles in the liquid can have arbitrary shapes and any internal charge distributions. The decay of the screened electrostatic potential and the free energy of interaction in ionic liquids can be exponentially damped oscillatory (like in molten simple salts) as well as plain exponential and long-ranged (like in dilute electrolyte solutions). Both behaviors are in agreement with the exact statistical mechanical analysis and reasons for their appearances are investigated. Exact but surprisingly simple expressions for the decay parameter κ of the screened electrostatics are obtained, which replace the classical expression for the Debye-Hückel parameter κDH (the reciprocal Debye length). The expressions are applicable both for cases with plain exponential and oscillatory behaviors. The key importance of nonlocal electrostatics is thereby demonstrated explicitly. Dielectric properties of ionic liquids and other electrolytes are investigated, in particular the static dielectric function ɛ ˜ ( k ) and some effective relative permittivities ( Er eff and Er ∗ ), which take roles that the dielectric constant ɛr has for polar liquids consisting of electroneutral molecules. The dielectric constant in the latter case, which is the limit of ɛ ˜ ( k ) when the wave number k → 0, can be expressed solely in terms of dipolar features of the molecules. In contrast to this, the effective dielectric permittivities of ionic liquids have contributions also from quadrupolar, octupolar, and higher multipolar features of the constituent ions. The "dielectric constant" of electrolytes does not exist since ɛ ˜ ( k ) → ∞ when k → 0, a well-known effect of perfect screening. The effective relative permittivities, Er eff , and Er ∗ of ionic liquids are obtained from the non-diverging part of ɛ ˜ ( k ) , but not as a k → 0 limit. Influences of ion associations, especially pairing, are investigated for screened electrostatics and these permittivities. A general, multipolar expansion of ɛ ˜ ( k ) is derived and used to analyze dielectric properties of ionic liquids and other electrolytes.

Defect-driven flexochemical coupling in thin ferroelectric films

NASA Astrophysics Data System (ADS)

Eliseev, Eugene A.; Vorotiahin, Ivan S.; Fomichov, Yevhen M.; Glinchuk, Maya D.; Kalinin, Sergei V.; Genenko, Yuri A.; Morozovska, Anna N.

2018-01-01

Using the Landau-Ginzburg-Devonshire theory, we considered the impact of the flexoelectrochemical coupling on the size effects in polar properties and phase transitions of thin ferroelectric films with a layer of elastic defects. We investigated a typical case, when defects fill a thin layer below the top film surface with a constant concentration creating an additional gradient of elastic fields. The defective surface of the film is not covered with an electrode, but instead with an ultrathin layer of ambient screening charges, characterized by a surface screening length. Obtained results revealed an unexpectedly strong effect of the joint action of Vegard stresses and flexoelectric effect (shortly flexochemical coupling) on the ferroelectric transition temperature, distribution of the spontaneous polarization and elastic fields, domain wall structure and period in thin PbTi O3 films containing a layer of elastic defects. A nontrivial result is the persistence of ferroelectricity at film thicknesses below 4 nm, temperatures lower than 350 K, and relatively high surface screening length (˜0.1 nm ) . The origin of this phenomenon is the flexoelectric coupling leading to the rebuilding of the domain structure in the film (namely the cross-over from c-domain stripes to a-type closure domains) when its thickness decreases below 4 nm. The ferroelectricity persistence is facilitated by negative Vegard effect. For positive Vegard effect, thicker films exhibit the appearance of pronounced maxima on the thickness dependence of the transition temperature, whose position and height can be controlled by the defect type and concentration. The revealed features may have important implications for miniaturization of ferroelectric-based devices.

Weight-for-length/height growth curves for children and adolescents in China in comparison with body mass index in prevalence estimates of malnutrition.

PubMed

Zong, Xinnan; Li, Hui; Zhang, Yaqin; Wu, Huahong

2017-05-01

It is important to update weight-for-length/height growth curves in China and re-examine their performance in screening malnutrition. To develop weight-for-length/height growth curves for Chinese children and adolescents. A total of 94 302 children aged 0-19 years with complete sex, age, weight and length/height data were obtained from two cross-sectional large-scaled national surveys in China. Weight-for-length/height growth curves were constructed using the LMS method before and after average spermarcheal/menarcheal ages, respectively. Screening performance in prevalence estimates of wasting, overweight and obesity was compared between weight-for-height and body mass index (BMI) criteria based on a test population of 21 416 children aged 3-18. The smoothed weight-for-length percentiles and Z-scores growth curves with length 46-110 cm for both sexes and weight-for-height with height 70-180 cm for boys and 70-170 cm for girls were established. The weight-for-height and BMI-for-age had strong correlation in screening wasting, overweight and obesity in each age-sex group. There was no striking difference in prevalence estimates of wasting, overweight and obesity between two indicators except for obesity prevalence at ages 6-11. This set of smoothed weight-for-length/height growth curves may be useful in assessing nutritional status from infants to post-pubertal adolescents.

Circulating water traveling screen modifications to improve impinged fish survival and debris handling at Salem Generating Station

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ronafalvy, J.P.; Cheesman, R.R.; Matejek, W.M.

This paper summarizes modifications made to the Salem Generating Station`s (Salem) Circulating Water Traveling Screens (CWTS) as required by Salem`s New Jersey Pollutant Discharge Elimination System Permit (NJPDES Permit). The modifications incorporated newly designed CWTS baskets with hydrodynamically improved fish buckets (greatly reduced turbulence in the bucket); smooth woven mesh screens with 0.250 x 0.500 inch rectangular mesh openings (formerly 0.375 inch square mesh openings); lighter composite basket frame material allowing increased screen rotation speed; improved low and high pressure spray wash patterns; improved screen to sluice trough flap seal design and miscellaneous reliability improvements. In order to address themore » overall effects of the CWTS modifications on fish losses, the effect of both entrainment and impingement by fish size was addressed in a comparison study between modified and unmodified units. The results of the assessment indicate a 51% reduction in overall weakfish (Cynoscion regales) losses (expressed as equivalent adults, larger than 187 mm total length individuals). These modifications also enhanced debris removal capability of the CWTSs. 5 refs., 5 figs.« less

The layer boundary effect on multi-layer mesoporous TiO 2 film based dye sensitized solar cells

DOE PAGES

Xu, Feng; Zhu, Kai; Zhao, Yixin

2016-10-10

Multi-layer mesoporous TiO 2 prepared by screen printing is widely used for fabrication of high-efficiency dye-sensitized solar cells (DSSCs). Here, we compare the three types of ~10 um thick mesoporous TiO 2 films, which were screen printed as 1-, 2- and 4-layers using the same TiO 2 nanocrystal paste. The layer boundary of the multi-layer mesoporous TiO 2 films was observed in the cross-section SEM. The existence of a layer boundary could reduce the photoelectron diffusion length with the increase of layer number. However, the photoelectron diffusion lengths of the Z907 dye sensitized solar cells based on these different layeredmore » mesoporous TiO 2 films are all longer than the film thickness. Consequently, the photovoltaic performance seems to have little dependence on the layer number of the multi-layer TiO 2 based DSSCs.« less

The layer boundary effect on multi-layer mesoporous TiO 2 film based dye sensitized solar cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Feng; Zhu, Kai; Zhao, Yixin

Multi-layer mesoporous TiO 2 prepared by screen printing is widely used for fabrication of high-efficiency dye-sensitized solar cells (DSSCs). Here, we compare the three types of ~10 um thick mesoporous TiO 2 films, which were screen printed as 1-, 2- and 4-layers using the same TiO 2 nanocrystal paste. The layer boundary of the multi-layer mesoporous TiO 2 films was observed in the cross-section SEM. The existence of a layer boundary could reduce the photoelectron diffusion length with the increase of layer number. However, the photoelectron diffusion lengths of the Z907 dye sensitized solar cells based on these different layeredmore » mesoporous TiO 2 films are all longer than the film thickness. Consequently, the photovoltaic performance seems to have little dependence on the layer number of the multi-layer TiO 2 based DSSCs.« less

Photoconductivity, pH Sensitivity, Noise, and Channel Length Effects in Si Nanowire FET Sensors

NASA Astrophysics Data System (ADS)

Gasparyan, Ferdinand; Zadorozhnyi, Ihor; Khondkaryan, Hrant; Arakelyan, Armen; Vitusevich, Svetlana

2018-03-01

Silicon nanowire (NW) field-effect transistor (FET) sensors of various lengths were fabricated. Transport properties of Si NW FET sensors were investigated involving noise spectroscopy and current-voltage (I-V) characterization. The static I-V dependencies demonstrate the high quality of fabricated silicon FETs without leakage current. Transport and noise properties of NW FET structures were investigated under different light illumination conditions, as well as in sensor configuration in an aqueous solution with different pH values. Furthermore, we studied channel length effects on the photoconductivity, noise, and pH sensitivity. The magnitude of the channel current is approximately inversely proportional to the length of the current channel, and the pH sensitivity increases with the increase of channel length approaching the Nernst limit value of 59.5 mV/pH. We demonstrate that dominant 1/f-noise can be screened by the generation-recombination plateau at certain pH of the solution or external optical excitation. The characteristic frequency of the generation-recombination noise component decreases with increasing of illumination power. Moreover, it is shown that the measured value of the slope of 1/f-noise spectral density dependence on the current channel length is 2.7 which is close to the theoretically predicted value of 3.

The National Lung Screening Trial: overview and study design.

PubMed

Aberle, Denise R; Berg, Christine D; Black, William C; Church, Timothy R; Fagerstrom, Richard M; Galen, Barbara; Gareen, Ilana F; Gatsonis, Constantine; Goldin, Jonathan; Gohagan, John K; Hillman, Bruce; Jaffe, Carl; Kramer, Barnett S; Lynch, David; Marcus, Pamela M; Schnall, Mitchell; Sullivan, Daniel C; Sullivan, Dorothy; Zylak, Carl J

2011-01-01

The National Lung Screening Trial (NLST) is a randomized multicenter study comparing low-dose helical computed tomography (CT) with chest radiography in the screening of older current and former heavy smokers for early detection of lung cancer, which is the leading cause of cancer-related death in the United States. Five-year survival rates approach 70% with surgical resection of stage IA disease; however, more than 75% of individuals have incurable locally advanced or metastatic disease, the latter having a 5-year survival of less than 5%. It is plausible that treatment should be more effective and the likelihood of death decreased if asymptomatic lung cancer is detected through screening early enough in its preclinical phase. For these reasons, there is intense interest and intuitive appeal in lung cancer screening with low-dose CT. The use of survival as the determinant of screening effectiveness is, however, confounded by the well-described biases of lead time, length, and overdiagnosis. Despite previous attempts, no test has been shown to reduce lung cancer mortality, an endpoint that circumvents screening biases and provides a definitive measure of benefit when assessed in a randomized controlled trial that enables comparison of mortality rates between screened individuals and a control group that does not undergo the screening intervention of interest. The NLST is such a trial. The rationale for and design of the NLST are presented. © RSNA, 2010

Effectiveness of common fish screen materials to protect lamprey ammocoetes

USGS Publications Warehouse

Rose, Brien P.; Mesa, Matthew G.

2012-01-01

Understanding the effects of irrigation diversions on populations of Pacific lampreyLampetra tridentata in the Columbia River basin is needed for their recovery. We tested the effectiveness of five common fish screen materials for excluding lamprey ammocoetes: interlock (IL), vertical bar (VB), perforated plate (PP), and 12-gauge and 14-gauge wire cloth (WC12) and (WC14). When fish (28–153 mm) were exposed for 60 min to screen panels perpendicular to an approach velocity of 12 cm/s in a recirculating flume, the percentage of ammocoetes entrained (i.e., passed through the screen) was 26% for the IL, 18% for the PP, 33% for the VB, 62% for the WC14, and 65% for the WC12 screens. For all screens, most fish were entrained within the first 15–20 min. Fish length significantly influenced entrainment, with the PP, VB, and IL screens preventing fish greater than 50–65 mm from entrainment and the WC14 and WC12 screens preventing entrainment of fish greater than 90–110 mm. Fish of all sizes repeatedly became impinged (i.e., contacting the screen for more than 1 s) on the screens, with the frequency of impingement events increasing during the first 5 min and becoming relatively stable thereafter. Impingement ranges were highest on the IL screen (36–62%), lowest on the WC14 and WC12 screens (13–31%), and intermediate on the PP and VB screens (23–54%). However, the WC14 and WC12 screens had fewer and larger fish remaining as time elapsed because so many were entrained. For all screen types, injuries were rare and minor, and no fish died after overnight posttest holding. Our results indicate that wire cloth screens should be replaced, where practical, with perforated plate, vertical bar, or interlocking bar screens to reduce lamprey entrainment at water diversions.

An integrated PCR colony hybridization approach to screen cDNA libraries for full-length coding sequences.

PubMed

Pollier, Jacob; González-Guzmán, Miguel; Ardiles-Diaz, Wilson; Geelen, Danny; Goossens, Alain

2011-01-01

cDNA-Amplified Fragment Length Polymorphism (cDNA-AFLP) is a commonly used technique for genome-wide expression analysis that does not require prior sequence knowledge. Typically, quantitative expression data and sequence information are obtained for a large number of differentially expressed gene tags. However, most of the gene tags do not correspond to full-length (FL) coding sequences, which is a prerequisite for subsequent functional analysis. A medium-throughput screening strategy, based on integration of polymerase chain reaction (PCR) and colony hybridization, was developed that allows in parallel screening of a cDNA library for FL clones corresponding to incomplete cDNAs. The method was applied to screen for the FL open reading frames of a selection of 163 cDNA-AFLP tags from three different medicinal plants, leading to the identification of 109 (67%) FL clones. Furthermore, the protocol allows for the use of multiple probes in a single hybridization event, thus significantly increasing the throughput when screening for rare transcripts. The presented strategy offers an efficient method for the conversion of incomplete expressed sequence tags (ESTs), such as cDNA-AFLP tags, to FL-coding sequences.

Locking-In Effects Due to Early Interventions? An Evaluation of a Multidisciplinary Screening Programs for Avoiding Long-Term Sickness

ERIC Educational Resources Information Center

Johansson, Per; Lindahl, Erica

2012-01-01

Objective: In this article, we estimate the effect of a multidisciplinary collaboration program on the length of sickness absence. The intention with the program was to avoid long-term sickness absence by providing an early and holistic evaluation of the sick-listed individuals' conditions. The target group was individuals who were at risk of…

Screening length and quantum capacitance in graphene by scanning probe microscopy.

PubMed

Giannazzo, F; Sonde, S; Raineri, V; Rimini, E

2009-01-01

A nanoscale investigation on the capacitive behavior of graphene deposited on a SiO2/n(+) Si substrate (with SiO2 thickness of 300 or 100 nm) was carried out by scanning capacitance spectroscopy (SCS). A bias V(g) composed by an AC signal and a slow DC voltage ramp was applied to the macroscopic n(+) Si backgate of the graphene/SiO(2)/Si capacitor, while a nanoscale contact was obtained on graphene by the atomic force microscope tip. This study revealed that the capacitor effective area (A(eff)) responding to the AC bias is much smaller than the geometrical area of the graphene sheet. This area is related to the length scale on which the externally applied potential decays in graphene, that is, the screening length of the graphene 2DEG. The nonstationary charges (electrons/holes) induced by the AC potential spread within this area around the contact. A(eff) increases linearly with the bias and in a symmetric way for bias inversion. For each bias V(g), the value of A(eff) is related to the minimum area necessary to accommodate the not stationary charges, according to the graphene density of states (DOS) at V(g). Interestingly, by decreasing the SiO(2) thickness from 300 to 100 nm, the slope of the A(eff) versus bias curve strongly increases (by a factor of approximately 50). The local quantum capacitance C(q) in the contacted graphene region was calculated starting from the screening length, and the distribution of the values of C(q) for different tip positions was obtained. Finally the lateral variations of the DOS in graphene was determined.

The effect of path length and display size on memory for spatial information.

PubMed

Guérard, Katherine; Tremblay, Sébastien

2012-01-01

In serial memory for spatial information, some studies showed that recall performance suffers when the distance between successive locations increases relatively to the size of the display in which they are presented (the path length effect; e.g., Parmentier et al., 2005) but not when distance is increased by enlarging the size of the display (e.g., Smyth & Scholey, 1994). In the present study, we examined the effect of varying the absolute and relative distance between to-be-remembered items on memory for spatial information. We manipulated path length using small (15″) and large (64″) screens within the same design. In two experiments, we showed that distance was disruptive mainly when it is varied relatively to a fixed reference frame, though increasing the size of the display also had a small deleterious effect on recall. The insertion of a retention interval did not influence these effects, suggesting that rehearsal plays a minor role in mediating the effects of distance on serial spatial memory. We discuss the potential role of perceptual organization in light of the pattern of results.

A Genome-Wide RNAi Screen for Modifiers of the Circadian Clock in Human Cells

PubMed Central

Zhang, Eric E.; Liu, Andrew C.; Hirota, Tsuyoshi; Miraglia, Loren J.; Welch, Genevieve; Pongsawakul, Pagkapol Y.; Liu, Xianzhong; Atwood, Ann; Huss, Jon W.; Janes, Jeff; Su, Andrew I.; Hogenesch, John B.; Kay, Steve A.

2009-01-01

Summary Two decades of research identified more than a dozen clock genes and defined a biochemical feedback mechanism of circadian oscillator function. To identify additional clock genes and modifiers, we conducted a genome-wide siRNA screen in a human cellular clock model. Knockdown of nearly a thousand genes reduced rhythm amplitude. Potent effects on period length or increased amplitude were less frequent; we found hundreds of these and confirmed them in secondary screens. Characterization of a subset of these genes demonstrated a dosage-dependent effect on oscillator function. Protein interaction network analysis showed that dozens of gene products directly or indirectly associate with known clock components. Pathway analysis revealed these genes are overrepresented for components of insulin and hedgehog signaling, the cell cycle, and the folate metabolism. Coupled with data showing many of these pathways are clock-regulated, we conclude the clock is interconnected with many aspects of cellular function. PMID:19765810

[Screening for malnutrition among hospitalized patients in a Colombian University Hospital].

PubMed

Cruz, Viviana; Bernal, Laura; Buitrago, Giancarlo; Ruiz, Álvaro J

2017-04-01

On admission, 30 to 50% of hospitalized patients have some degree of malnutrition, which is associated with longer length of stay, higher rates of complications, mortality and greater costs. To determine the frequency of screening for risk of malnutrition in medical records and assess the usefulness of the Malnutrition Screening Tool (MST). In a cross-sectional study, we searched for malnutrition screening in medical records, and we applied the MST tool to hospitalized patients at the Internal Medicine Wards of San Ignacio University Hospital. Of 295 patients included, none had been screened for malnutrition since hospital admission. Sixty one percent were at nutritional risk, with a higher prevalence among patients with HIV (85.7%), cancer (77.5%) and pneumonia. A positive MST result was associated with a 3.2 days increase in length of hospital stay (p = 0.024). The prevalence of malnutrition risk in hospitalized patients is high, but its screening is inadequate and it is underdiagnosed. The MST tool is simple, fast, low-cost, and has a good diagnostic performance.

Characteristic length of the knotting probability revisited

NASA Astrophysics Data System (ADS)

Uehara, Erica; Deguchi, Tetsuo

2015-09-01

We present a self-avoiding polygon (SAP) model for circular DNA in which the radius of impermeable cylindrical segments corresponds to the screening length of double-stranded DNA surrounded by counter ions. For the model we evaluate the probability for a generated SAP with N segments having a given knot K through simulation. We call it the knotting probability of a knot K with N segments for the SAP model. We show that when N is large the most significant factor in the knotting probability is given by the exponentially decaying part exp(-N/NK), where the estimates of parameter NK are consistent with the same value for all the different knots we investigated. We thus call it the characteristic length of the knotting probability. We give formulae expressing the characteristic length as a function of the cylindrical radius rex, i.e. the screening length of double-stranded DNA.

Low energy electron-impact ionization of hydrogen atom for coplanar equal-energy-sharing kinematics in Debye plasmas

NASA Astrophysics Data System (ADS)

Li, Jun; Zhang, Song Bin; Ye, Bang Jiao; Wang, Jian Guo; Janev, R. K.

2016-12-01

Low energy electron-impact ionization of hydrogen atom in Debye plasmas has been investigated by employing the exterior complex scaling method. The interactions between the charged particles in the plasma have been represented by Debye-Hückel potentials. Triple differential cross sections (TDCS) in the coplanar equal-energy-sharing geometry at an incident energy of 15.6 eV for different screening lengths are reported. As the screening strength increases, TDCS change significantly. The evolutions of dominant typical peak structures of the TDCS are studied in detail for different screening lengths and for different coplanar equal-energy-sharing geometries.

Theory of polyelectrolytes in solvents.

PubMed

Chitanvis, Shirish M

2003-12-01

Using a continuum description, we account for fluctuations in the ionic solvent surrounding a Gaussian, charged chain and derive an effective short-ranged potential between the charges on the chain. This potential is repulsive at short separations and attractive at longer distances. The chemical potential can be derived from this potential. When the chemical potential is positive, it leads to a meltlike state. For a vanishingly low concentration of segments, this state exhibits scaling behavior for long chains. The Flory exponent characterizing the radius of gyration for long chains is calculated to be approximately 0.63, close to the classical value obtained for second order phase transitions. For short chains, the radius of gyration varies linearly with N, the chain length, and is sensitive to the parameters in the interaction potential. The linear dependence on the chain length N indicates a stiff behavior. The chemical potential associated with this interaction changes sign, when the screening length in the ionic solvent exceeds a critical value. This leads to condensation when the chemical potential is negative. In this state, it is shown using the mean-field approximation that spherical and toroidal condensed shapes can be obtained. The thickness of the toroidal polyelectrolyte is studied as a function of the parameters of the model, such as the ionic screening length. The predictions of this theory should be amenable to experimental verification.

Effects of energy chirp on bunch length measurement in linear accelerator beams

NASA Astrophysics Data System (ADS)

Sabato, L.; Arpaia, P.; Giribono, A.; Liccardo, A.; Mostacci, A.; Palumbo, L.; Vaccarezza, C.; Variola, A.

2017-08-01

The effects of assumptions about bunch properties on the accuracy of the measurement method of the bunch length based on radio frequency deflectors (RFDs) in electron linear accelerators (LINACs) are investigated. In particular, when the electron bunch at the RFD has a non-negligible energy chirp (i.e. a correlation between the longitudinal positions and energies of the particle), the measurement is affected by a deterministic intrinsic error, which is directly related to the RFD phase offset. A case study on this effect in the electron LINAC of a gamma beam source at the Extreme Light Infrastructure-Nuclear Physics (ELI-NP) is reported. The relative error is estimated by using an electron generation and tracking (ELEGANT) code to define the reference measurements of the bunch length. The relative error is proved to increase linearly with the RFD phase offset. In particular, for an offset of {{7}\\circ} , corresponding to a vertical centroid offset at a screen of about 1 mm, the relative error is 4.5%.

Ionic Size Effects: Generalized Boltzmann Distributions, Counterion Stratification, and Modified Debye Length.

PubMed

Liu, Bo; Liu, Pei; Xu, Zhenli; Zhou, Shenggao

2013-10-01

Near a charged surface, counterions of different valences and sizes cluster; and their concentration profiles stratify. At a distance from such a surface larger than the Debye length, the electric field is screened by counterions. Recent studies by a variational mean-field approach that includes ionic size effects and by Monte Carlo simulations both suggest that the counterion stratification is determined by the ionic valence-to-volume ratios. Central in the mean-field approach is a free-energy functional of ionic concentrations in which the ionic size effects are included through the entropic effect of solvent molecules. The corresponding equilibrium conditions define the generalized Boltzmann distributions relating the ionic concentrations to the electrostatic potential. This paper presents a detailed analysis and numerical calculations of such a free-energy functional to understand the dependence of the ionic charge density on the electrostatic potential through the generalized Boltzmann distributions, the role of ionic valence-to-volume ratios in the counterion stratification, and the modification of Debye length due to the effect of ionic sizes.

Ionic Size Effects: Generalized Boltzmann Distributions, Counterion Stratification, and Modified Debye Length

PubMed Central

Liu, Bo; Liu, Pei; Xu, Zhenli; Zhou, Shenggao

2013-01-01

Near a charged surface, counterions of different valences and sizes cluster; and their concentration profiles stratify. At a distance from such a surface larger than the Debye length, the electric field is screened by counterions. Recent studies by a variational mean-field approach that includes ionic size effects and by Monte Carlo simulations both suggest that the counterion stratification is determined by the ionic valence-to-volume ratios. Central in the mean-field approach is a free-energy functional of ionic concentrations in which the ionic size effects are included through the entropic effect of solvent molecules. The corresponding equilibrium conditions define the generalized Boltzmann distributions relating the ionic concentrations to the electrostatic potential. This paper presents a detailed analysis and numerical calculations of such a free-energy functional to understand the dependence of the ionic charge density on the electrostatic potential through the generalized Boltzmann distributions, the role of ionic valence-to-volume ratios in the counterion stratification, and the modification of Debye length due to the effect of ionic sizes. PMID:24465094

Antiproton-impact ionization of hydrogen atom with Yukawa interaction

NASA Astrophysics Data System (ADS)

Jakimovski, Dragan; Grozdanov, Tasko P.; Janev, Ratko K.

2018-01-01

The process of ionization of hydrogen atom by antiproton impact is studied when the interparticle interactions in the system are described by screened interactions of Yukawa type. The collision dynamics is described by the semiclassical atomic-orbital close-coupling method in which the bound atomic states and positive energy continuum pseudostates are determined by diagonalization of target Hamiltonian in a sufficiently large even-tempered basis to ensure convergence of the results at each value of the screening length λ of the interaction. With decreasing the screening length, the bound states in the Yukawa potential become unbound, thus increasing the number of continuum pseudostates. At low collision energies, this leads to the increase of the ionization cross section. It is observed that the energies of pseudostates, generated by the exit of nl bound states in the continuum, at certain critical values λ nl c exhibit series of avoided crossings when λ is varied. The avoided crossings appear between the ( n + k) l and ( n + k + 1) l ( n = 1, 2, 3, … ; k = 0, 1, 2, …) states at screening lengths close to the critical screening length λ nl c . The avoided crossings become increasingly less pronounced with increasing n, k and l. The matrix elements for the ( n + k) l - ( n + k + 1) l transitions at the avoided crossings λ x,(n+k)l (n+k+1)l exhibit maxima and are reflected in the structure of the cross sections for population of the lower nl pseudostates. These structures are, however, smeared out in the total ionization cross section.

Micropillar arrays as a high-throughput screening platform for therapeutics in multiple sclerosis.

PubMed

Mei, Feng; Fancy, Stephen P J; Shen, Yun-An A; Niu, Jianqin; Zhao, Chao; Presley, Bryan; Miao, Edna; Lee, Seonok; Mayoral, Sonia R; Redmond, Stephanie A; Etxeberria, Ainhoa; Xiao, Lan; Franklin, Robin J M; Green, Ari; Hauser, Stephen L; Chan, Jonah R

2014-08-01

Functional screening for compounds that promote remyelination represents a major hurdle in the development of rational therapeutics for multiple sclerosis. Screening for remyelination is problematic, as myelination requires the presence of axons. Standard methods do not resolve cell-autonomous effects and are not suited for high-throughput formats. Here we describe a binary indicant for myelination using micropillar arrays (BIMA). Engineered with conical dimensions, micropillars permit resolution of the extent and length of membrane wrapping from a single two-dimensional image. Confocal imaging acquired from the base to the tip of the pillars allows for detection of concentric wrapping observed as 'rings' of myelin. The platform is formatted in 96-well plates, amenable to semiautomated random acquisition and automated detection and quantification. Upon screening 1,000 bioactive molecules, we identified a cluster of antimuscarinic compounds that enhance oligodendrocyte differentiation and remyelination. Our findings demonstrate a new high-throughput screening platform for potential regenerative therapeutics in multiple sclerosis.

Analytical models for use in fan inflow control structure design. Inflow distortion and acoustic transmission models

NASA Technical Reports Server (NTRS)

Gedge, M. R.

1979-01-01

Analytical models were developed to study the effect of flow contraction and screening on inflow distortions to identify qualitative design criteria. Results of the study are that: (1) static testing distortions are due to atmospheric turbulence, nacelle boundary layer, exhaust flow reingestion, flow over stand, ground plane, and engine casing; (2) flow contraction suppresses, initially, turbulent axial velocity distortions and magnifies turbulent transverse velocity distortions; (3) perforated plate and gauze screens suppress axial components of velocity distortions to a degree determined by the screen pressure loss coefficient; (4) honeycomb screen suppress transverse components of velocity distortions to a degree determined by the length to diameter ratio of the honeycomb; (5) acoustic transmission loss of perforated plate is controlled by the reactance of its acoustic impedance; (6) acoustic transmission loss of honeycomb screens is negligible; and (7) a model for the direction change due to a corner between honeycomb panels compares favorably with measured data.

ERICA: use of screens and consumption of meals and snacks by Brazilian adolescents

PubMed Central

Oliveira, Juliana Souza; Barufaldi, Laura Augusta; Abreu, Gabriela de Azevedo; Leal, Vanessa Sá; Brunken, Gisela Soares; Vasconcelos, Sandra Mary Lima; dos Santos, Marize Melo; Bloch, Katia Vergetti

2016-01-01

ABSTRACT OBJECTIVE To describe the length of exposure to screens and the prevalence of consumption of meals and snacks by Brazilian adolescents in front of screens. METHODS We evaluated 74,589 12 to 17-year old adolescents from 1,247 schools in 124 Brazilian municipalities. A self-administered questionnaire was used. Its segment regarding nutrition contained questions about using TV, computers, and video game systems, having meals while watching TV, and consuming snacks in front of screens. Consumption of meals and snacks in front of screens was analyzed according to the following variables: geographical region, gender, age range, type of school (public or private), and school shift. The prevalences and their respective 95% confidence intervals were estimated under a complex sampling design. RESULTS A great deal of the adolescents (73.5%, 95%CI 72.3-74.7) reported spending two or more hours a day in front of screens. That habit was more frequent among male adolescents, private school students, morning shift students, and students from Brazil’s South region. More than half of the adolescents (56.6%, 95%CI 55.4-57.8) reported almost always or always having meals in front of TV, and 39.6% (95%CI 38.8-40.5) of them said they consumed snacks in front of screens exactly as often. Both situations were the most prevalent ones among the girls, who attended public schools and were from Brazil’s Midwest region. CONCLUSIONS Length of exposure to screens and consumption of meals and snacks almost always or always in front of screens are high among Brazilian adolescents. It is necessary to develop strategies aiming to reduce the length of screen use, considering the media reality that children and adolescents have been experiencing from earlier and earlier ages. That context must therefore be analyzed in an indissociable way. PMID:26910539

ERICA: use of screens and consumption of meals and snacks by Brazilian adolescents.

PubMed

Oliveira, Juliana Souza; Barufaldi, Laura Augusta; Abreu, Gabriela de Azevedo; Leal, Vanessa Sá; Brunken, Gisela Soares; Vasconcelos, Sandra Mary Lima; dos Santos, Marize Melo; Bloch, Katia Vergetti

2016-02-01

OBJECTIVE To describe the length of exposure to screens and the prevalence of consumption of meals and snacks by Brazilian adolescents in front of screens. METHODS We evaluated 74,589 12 to 17-year old adolescents from 1,247 schools in 124 Brazilian municipalities. A self-administered questionnaire was used. Its segment regarding nutrition contained questions about using TV, computers, and video game systems, having meals while watching TV, and consuming snacks in front of screens. Consumption of meals and snacks in front of screens was analyzed according to the following variables: geographical region, gender, age range, type of school (public or private), and school shift. The prevalences and their respective 95% confidence intervals were estimated under a complex sampling design. RESULTS A great deal of the adolescents (73.5%, 95%CI 72.3-74.7) reported spending two or more hours a day in front of screens. That habit was more frequent among male adolescents, private school students, morning shift students, and students from Brazil's South region. More than half of the adolescents (56.6%, 95%CI 55.4-57.8) reported almost always or always having meals in front of TV, and 39.6% (95%CI 38.8-40.5) of them said they consumed snacks in front of screens exactly as often. Both situations were the most prevalent ones among the girls, who attended public schools and were from Brazil's Midwest region. CONCLUSIONS Length of exposure to screens and consumption of meals and snacks almost always or always in front of screens are high among Brazilian adolescents. It is necessary to develop strategies aiming to reduce the length of screen use, considering the media reality that children and adolescents have been experiencing from earlier and earlier ages. That context must therefore be analyzed in an indissociable way.

Detection beyond the Debye screening length in a high-frequency nanoelectronic biosensor.

PubMed

Kulkarni, Girish S; Zhong, Zhaohui

2012-02-08

Nanosensors based on the unique electronic properties of nanotubes and nanowires offer high sensitivity and have the potential to revolutionize the field of Point-of-Care (POC) medical diagnosis. The direct current (dc) detection of a wide array of organic and inorganic molecules has been demonstrated on these devices. However, sensing mechanism based on measuring changes in dc conductance fails at high background salt concentrations, where the sensitivity of the devices suffers from the ionic screening due to mobile ions present in the solution. Here, we successfully demonstrate that the fundamental ionic screening effect can be mitigated by operating single-walled carbon nanotube field effect transistor as a high-frequency biosensor. The nonlinear mixing between the alternating current excitation field and the molecular dipole field can generate mixing current sensitive to the surface-bound biomolecules. Electrical detection of monolayer streptavidin binding to biotin in 100 mM buffer solution is achieved at a frequency beyond 1 MHz. Theoretical modeling confirms improved sensitivity at high frequency through mitigation of the ionic screening effect. The results should promise a new biosensing platform for POC detection, where biosensors functioning directly in physiologically relevant condition are desired. © 2012 American Chemical Society

The risk of finding focal cancer (less than 3 mm) remains high on re-biopsy of patients with persistently increased prostate specific antigen but the clinical significance is questionable.

PubMed

Zackrisson, Bjørn; Aus, Gunnar; Bergdahl, Svante; Lilja, Hans; Lodding, Pär; Pihl, Carl-Gustav; Hugosson, Jonas

2004-04-01

We evaluated the significance of focal prostate cancer found in sextant biopsies in men participating in a biennial prostate specific antigen (PSA) based screening program. In 1995, 10000 men 50 to 65 years old were randomized to biennial screening with PSA testing. Sextant biopsies were recommended when total PSA was 3 ng/ml or greater at screening rounds 1 and 2, and 2.54 ng/ml or greater at subsequent screening rounds. Focal cancer was defined as total a core cancer length of less than 3 mm in the biopsy specimen. Low volume cancer was defined as a total tumor volume of less than 0.5 cm in the radical retropubic prostatectomy specimen. The number of men who underwent biopsy and the number of cancers detected in the 5 possible sets of biopsies were 1725 and 402, 706 and 124, 307 and 36, 103 and 9, and 13 and 0, respectively. The risk of detecting focal cancer was 7.9%, 10.2%, 7.5%, 5.8% and 0%, respectively, but the relative ratio (focal-to-all cancers) increased 34%, 58%, 64%, 67% and, not applicable, respectively. In men with a total core cancer length of less than 10 mm there was no correlation between core cancer length and total tumor volume, as measured in the prostatectomy specimen. Two-thirds of men with a total core cancer length of less than 3 mm had a tumor volume of greater than 0.5 cm, while the risk of low volume cancer was less than 5% only in men with a total core cancer length of greater than 10 mm. In a repeat PSA based screening program sextant biopsies are of little or no value for predicting tumor volume.

Correlation of normal-range FMR1 repeat length or genotypes and reproductive parameters.

PubMed

Maslow, Bat-Sheva L; Davis, Stephanie; Engmann, Lawrence; Nulsen, John C; Benadiva, Claudio A

2016-09-01

This study aims to ascertain whether the length of normal-ranged CGG repeats on the FMR1 gene correlates with abnormal reproductive parameters. We performed a retrospective, cross-sectional study of all FMR1 carrier screening performed as part of routine care at a large university-based fertility center from January 2011 to March 2014. Correlations were performed between normal-range FMR1 length and baseline serum anti-Müllerian hormone (AMH), cycle day 3 follicle stimulating hormone (FSH), ovarian volumes (OV), antral follicle counts (AFC), and incidence of diminished ovarian reserve (DOR), while controlling for the effect of age. Six hundred three FMR1 screening results were collected. One subject was found to be a pre-mutation carrier and was excluded from the study. Baseline serum AMH, cycle day 3 FSH, OV, and AFC data were collected for the 602 subjects with normal-ranged CGG repeats. No significant difference in median age was noted amongst any of the FMR1 repeat genotypes. No significant correlation or association was found between any allele length or genotype, with any of the reproductive parameters or with incidence of DOR at any age (p > 0.05). However, subjects who were less than 35 years old with low/low genotype were significantly more likely to have below average AMH levels compared to those with normal/normal genotype (RR 3.82; 95 % CI 1.38-10.56). This large study did not demonstrate any substantial association between normal-range FMR1 repeat lengths and reproductive parameters.

Interaction force in a vertical dust chain inside a glass box.

PubMed

Kong, Jie; Qiao, Ke; Matthews, Lorin S; Hyde, Truell W

2014-07-01

Small number dust particle clusters can be used as probes for plasma diagnostics. The number of dust particles as well as cluster size and shape can be easily controlled employing a glass box placed within a Gaseous Electronics Conference (GEC) rf reference chamber to provide confinement of the dust. The plasma parameters inside this box and within the larger plasma chamber have not yet been adequately defined. Adjusting the rf power alters the plasma conditions causing structural changes of the cluster. This effect can be used to probe the relationship between the rf power and other plasma parameters. This experiment employs the sloshing and breathing modes of small cluster oscillations to examine the relationship between system rf power and the particle charge and plasma screening length inside the glass box. The experimental results provided indicate that both the screening length and dust charge decrease as rf power inside the box increases. The decrease in dust charge as power increases may indicate that ion trapping plays a significant role in the sheath.

In situ superexchange electron transfer through a single molecule: a rectifying effect.

PubMed

Kornyshev, Alexei A; Kuznetsov, Alexander M; Ulstrup, Jens

2006-05-02

An increasingly comprehensive body of literature is being devoted to single-molecule bridge-mediated electronic nanojunctions, prompted by their prospective applications in molecular electronics and single-molecule analysis. These junctions may operate in gas phase or electrolyte solution (in situ). For biomolecules, the latter is much closer to their native environment. Convenient target molecules are aromatic molecules, peptides, oligonucleotides, transition metal complexes, and, broadly, molecules with repetitive units, for which the conducting orbitals are energetically well below electronic levels of the solvent. A key feature for these junctions is rectification in the current-voltage relation. A common view is that asymmetric molecules or asymmetric links to the electrodes are needed to acquire rectification. However, as we show here, this requirement could be different in situ, where a structurally symmetric system can provide rectification because of the Debye screening of the electric field in the nanogap if the screening length is smaller than the bridge length. The Galvani potentials of each electrode can be varied independently and lead to a transistor effect. We explore this behavior for the superexchange mechanism of electron transport, appropriate for a wide class of molecules. We also include the effect of conformational fluctuations on the lowest unoccupied molecular orbital (LUMO) energy levels; that gives rise to non-Arrhenius temperature dependence of the conductance, affected by the molecule length. Our study offers an analytical formula for the current-voltage characteristics that demonstrates all these features. A detailed physical interpretation of the results is given with a discussion of reported experimental data.

Three-disk microswimmer in a supported fluid membrane

NASA Astrophysics Data System (ADS)

Ota, Yui; Hosaka, Yuto; Yasuda, Kento; Komura, Shigeyuki

2018-05-01

A model of three-disk micromachine swimming in a quasi-two-dimensional supported membrane is proposed. We calculate the average swimming velocity as a function of the disk size and the arm length. Due to the presence of the hydrodynamic screening length in the quasi-two-dimensional fluid, the geometric factor appearing in the average velocity exhibits three different asymptotic behaviors depending on the microswimmer size and the hydrodynamic screening length. This is in sharp contrast with a microswimmer in a three-dimensional bulk fluid that shows only a single scaling behavior. We also find that the maximum velocity is obtained when the disks are equal-sized, whereas it is minimized when the average arm lengths are identical. The intrinsic drag of the disks on the substrate does not alter the scaling behaviors of the geometric factor.

Surface and finite size effects impact on the phase diagrams, polar, and dielectric properties of (Sr,Bi)Ta{sub 2}O{sub 9} ferroelectric nanoparticles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eliseev, E. A.; Fomichov, Y. M.; Glinchuk, M. D.

2016-05-28

In the framework of the thermodynamic approach Landau-Ginzburg-Devonshire (LGD) combined with the equations of electrostatics, we investigated the effect of polarization surface screening on finite size effects of the phase diagrams, polar, and dielectric properties of ferroelectric nanoparticles of different shapes. We obtained and analyzed the analytical results for the dependences of the ferroelectric phase transition temperature, critical size, spontaneous polarization, and thermodynamic coercive field on the shape and size of the nanoparticles. The pronounced size effect of these characteristics on the scaling parameter, the ratio of the particle characteristic size to the length of the surface screening, was revealed.more » Also our modeling predicts a significant impact of the flexo-chemical effect (that is a joint action of flexoelectric effect and chemical pressure) on the temperature of phase transition, polar, and dielectric properties of nanoparticles when their chemical composition deviates from the stoichiometric one. We showed on the example of the stoichiometric nanosized SrBi{sub 2}Ta{sub 2}O{sub 9} particles that except the vicinity of the critical size, where the system splitting into domains has an important role, results of analytical calculation of the spontaneous polarization have a little difference from the numerical ones. We revealed a strong impact of the flexo-chemical effect on the phase transition temperature, polar, and dielectric properties of Sr{sub y}Bi{sub 2+x}Ta{sub 2}O{sub 9} nanoparticles when the ratio Sr/Bi deviates from the stoichiometric value of 0.5 within the range from 0.35 to 0.65. From the analysis of experimental data, we derived the parameters of the theory, namely, the coefficients of expansion of the LGD functional, the contribution of flexo-chemical effect, and the length of the surface screening.« less

Localization of interictal epileptic spikes with MEG: optimization of an automated beamformer screening method (SAMepi) in a diverse epilepsy population

PubMed Central

Scott, Jonathan M.; Robinson, Stephen E.; Holroyd, Tom; Coppola, Richard; Sato, Susumu; Inati, Sara K.

2016-01-01

OBJECTIVE To describe and optimize an automated beamforming technique followed by identification of locations with excess kurtosis (g2) for efficient detection and localization of interictal spikes in medically refractory epilepsy patients. METHODS Synthetic Aperture Magnetometry with g2 averaged over a sliding time window (SAMepi) was performed in 7 focal epilepsy patients and 5 healthy volunteers. The effect of varied window lengths on detection of spiking activity was evaluated. RESULTS Sliding window lengths of 0.5–10 seconds performed similarly, with 0.5 and 1 second windows detecting spiking activity in one of the 3 virtual sensor locations with highest kurtosis. These locations were concordant with the region of eventual surgical resection in these 7 patients who remained seizure free at one year. Average g2 values increased with increasing sliding window length in all subjects. In healthy volunteers kurtosis values stabilized in datasets longer than two minutes. CONCLUSIONS SAMepi using g2 averaged over 1 second sliding time windows in datasets of at least 2 minutes duration reliably identified interictal spiking and the presumed seizure focus in these 7 patients. Screening the 5 locations with highest kurtosis values for spiking activity is an efficient and accurate technique for localizing interictal activity using MEG. SIGNIFICANCE SAMepi should be applied using the parameter values and procedure described for optimal detection and localization of interictal spikes. Use of this screening procedure could significantly improve the efficiency of MEG analysis if clinically validated. PMID:27760068

Thumb Reach of Indonesian Young Adult When Interacting with Touchscreen of Single-Handed Device: A Preliminary Study

NASA Astrophysics Data System (ADS)

Umami, M. K.

2018-01-01

This study is a preliminary survey on thumb reach of Indonesian population when interacting with single-handed device. This study was aimed to know the thumb reach envelope on the screen of mobile phone. The correlation between the thumb reach vs. the hand length and thumb length was also identified. Thirty young adults participated in the study. All participants had normal body stature and were right-handed person. In the observational phase, the participant was asked to colour the canvas area on the screen of the mobile phone by using his/her thumb. The participant had to complete the task by applying the single hand interaction. The participant should grab the mobile phone as he/she use it normally in his/her daily activities. The thumb reach envelope of participants was identified from the coloured area of the canvas. The results of this study found that participants with a large hand length and thumb length tend to have a large thumb reach. The results of this study also show the thumb reach area of the participants is forming an elliptical shape that runs from the northeast to southwest on the device screen.

Low-energy electron elastic scattering and impact ionization with hydrogenlike helium in Debye plasmas

NASA Astrophysics Data System (ADS)

Li, Jun; Zhang, Song Bin; Ye, Bang Jiao; Wang, Jian Guo; Janev, R. K.

2017-09-01

Low-energy electron elastic scattering and impact ionization with hydrogenlike helium in Debye plasmas have been investigated by employing the exterior complex scaling method. The interactions between charged particles in the plasmas have been represented by Debye-Hückel potentials. The 1 s -1 s elastic collision strengths below the n =2 excitation threshold of He+ dominated by resonance structures are calculated for different screening lengths. As the screening strength increases, the resonance peaks studied [2(1,0) 2 +1Se,3Po,1De , and 2(0,1) 2 +1Po] exhibit blueshifts and then redshifts with a further increase of the screening strength, which results in dramatic changes of the collision strengths. It is found that these dynamic variation features of the resonances are related to the changes of energy levels of He+ in the screened potential and geometric configurations of resonances. Triple-differential-ionization cross sections in coplanar geometries at 6-Ry incident electron energy are also reported, significant changes are observed with varying screening length.

Asian American Women in California: A Pooled Analysis of Predictors for Breast and Cervical Cancer Screening

PubMed Central

Breen, Nancy; Liu, Benmei; Lee, Richard; Kagawa-Singer, Marjorie

2015-01-01

Objectives. We examined patterns of cervical and breast cancer screening among Asian American women in California and assessed their screening trends over time. Methods. We pooled weighted data from 5 cycles of the California Health Interview Survey (2001, 2003, 2005, 2007, 2009) to examine breast and cervical cancer screening trends and predictors among 6 Asian nationalities. We calculated descriptive statistics, bivariate associations, multivariate logistic regressions, predictive margins, and 95% confidence intervals. Results. Multivariate analyses indicated that Papanicolaou test rates did not significantly change over time (77.9% in 2001 vs 81.2% in 2007), but mammography receipt increased among Asian American women overall (75.6% in 2001 vs 81.8% in 2009). Length of time in the United States was associated with increased breast and cervical cancer screening among all nationalities. Sociodemographic and health care access factors had varied effects, with education and insurance coverage significantly predicting screening for certain groups. Overall, we observed striking variation by nationality. Conclusions. Our results underscore the need for intervention and policy efforts that are targeted to specific Asian nationalities, recent immigrants, and individuals without health care access to increase screening rates among Asian women in California. PMID:25521898

Hot QCD equations of state and relativistic heavy ion collisions

NASA Astrophysics Data System (ADS)

Chandra, Vinod; Kumar, Ravindra; Ravishankar, V.

2007-11-01

We study two recently proposed equations of state obtained from high-temperature QCD and show how they can be adapted to use them for making predictions for relativistic heavy ion collisions. The method involves extracting equilibrium distribution functions for quarks and gluons from the equation of state (EOS), which in turn will allow a determination of the transport and other bulk properties of the quark gluon-plasma. Simultaneously, the method also yields a quasiparticle description of interacting quarks and gluons. The first EOS is perturbative in the QCD coupling constant and has contributions of O(g5). The second EOS is an improvement over the first, with contributions up to O[g6ln(1/g)]; it incorporates the nonperturbative hard thermal contributions. The interaction effects are shown to be captured entirely by the effective chemical potentials for the gluons and the quarks, in both cases. The chemical potential is seen to be highly sensitive to the EOS. As an application, we determine the screening lengths, which are, indeed, the most important diagnostics for QGP. The screening lengths are seen to behave drastically differently depending on the EOS considered and therefore yield a way to distinguish the two equations of state in heavy ion collisions.

The National Lung Screening Trial: Overview and Study Design1

PubMed Central

2011-01-01

The National Lung Screening Trial (NLST) is a randomized multicenter study comparing low-dose helical computed tomography (CT) with chest radiography in the screening of older current and former heavy smokers for early detection of lung cancer, which is the leading cause of cancer-related death in the United States. Five-year survival rates approach 70% with surgical resection of stage IA disease; however, more than 75% of individuals have incurable locally advanced or metastatic disease, the latter having a 5-year survival of less than 5%. It is plausible that treatment should be more effective and the likelihood of death decreased if asymptomatic lung cancer is detected through screening early enough in its preclinical phase. For these reasons, there is intense interest and intuitive appeal in lung cancer screening with low-dose CT. The use of survival as the determinant of screening effectiveness is, however, confounded by the well-described biases of lead time, length, and overdiagnosis. Despite previous attempts, no test has been shown to reduce lung cancer mortality, an endpoint that circumvents screening biases and provides a definitive measure of benefit when assessed in a randomized controlled trial that enables comparison of mortality rates between screened individuals and a control group that does not undergo the screening intervention of interest. The NLST is such a trial. The rationale for and design of the NLST are presented. © RSNA, 2010 Clinical trial registration no. NCT 00047385 Supplemental material: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.10091808/-/DC1 PMID:21045183

Energy deposition of heavy ions in the regime of strong beam-plasma correlations.

PubMed

Gericke, D O; Schlanges, M

2003-03-01

The energy loss of highly charged ions in dense plasmas is investigated. The applied model includes strong beam-plasma correlation via a quantum T-matrix treatment of the cross sections. Dynamic screening effects are modeled by using a Debye-like potential with a velocity dependent screening length that guarantees the known low and high beam velocity limits. It is shown that this phenomenological model is in good agreement with simulation data up to very high beam-plasma coupling. An analysis of the stopping process shows considerably longer ranges and a less localized energy deposition if strong coupling is treated properly.

Acculturation and cancer screening among Asian Americans: role of health insurance and having a regular physician.

PubMed

Lee, Sunmin; Chen, Lu; Jung, Mary Y; Baezconde-Garbanati, Lourdes; Juon, Hee-Soon

2014-04-01

Cancer is the leading cause of death among Asian Americans, but screening rates are significantly lower in Asians than in non-Hispanic Whites. This study examined associations between acculturation and three types of cancer screening (colorectal, cervical, and breast), focusing on the role of health insurance and having a regular physician. A cross-sectional study of 851 Chinese, Korean, and Vietnamese Americans was conducted in Maryland. Acculturation was measured using an abridged version of the Suinn-Lew Asian Self-Identity Acculturation Scale, acculturation clusters, language preference, length of residency in the US, and age at arrival. Age, health insurance, regular physician, gender, ethnicity, income, marital status, and health status were adjusted in the multivariate analysis. Logistic regression analysis showed that various measures of acculturation were positively associated with the odds of having all cancer screenings. Those lived for more than 20 years in the US were about 2-4 times [odds ratio (OR) and 95 % confidence interval (CI) colorectal: 2.41 (1.52-3.82); cervical: 1.79 (1.07-3.01); and breast: 2.11 (1.25-3.57)] more likely than those who lived for less than 10 years to have had cancer screening. When health insurance and having a regular physician were adjusted, the associations between length of residency and colorectal cancer [OR 1.72 (1.05-2.81)] was reduced and the association between length of residency and cervical and breast cancer became no longer significant. Findings from this study provide a robust and comprehensive picture of AA cancer screening behavior. They will provide helpful information on future target groups for promoting cancer screening.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Gyeong Won; Shim, Jaewon; Jung, Young-Dae, E-mail: ydjung@hanyang.ac.kr

The influence of renormalization plasma screening on the entanglement fidelity for the elastic electron-atom scattering is investigated in partially ionized dense hydrogen plasmas. The partial wave analysis and effective interaction potential are employed to obtain the scattering entanglement fidelity in dense hydrogen plasmas as functions of the collision energy, the Debye length, and the renormalization parameter. It is found that the renormalization plasma shielding enhances the scattering entanglement fidelity. Hence, we show that the transmission of the quantum information can be increased about 10% due to the renormalization shielding effect in dense hydrogen plasmas. It is also found that themore » renormalization shielding effect on the entanglement fidelity for the electron-atom collision increases with an increase of the collision energy. In addition, the renormalization shielding function increases with increasing collision energy and saturates to the unity with an increase of the Debye length.« less

Transvaginal cervical length and tobacco use in Appalachian women: association with increased risk for spontaneous preterm birth.

PubMed

Findley, Joseph; Seybold, Dara J; Broce, Mike; Yadav, Dolly; Calhoun, Byron C

2015-01-01

Currently ACOG recommends that a mid-term screening strategy may be considered to identify short cervix in low risk populations in an effort to prevent preterm birth. Vaginal progesterone is recommended for women with a cervical length ≤20 mm. Cerclage is recommended for women with prior spontaneous preterm birth who are already receiving progesterone supplementition and CL is <25 mm. This study examined risk factors for spontaneous preterm birth (SPB) <35 weeks among a general obstetrical population prior to these ACOG recommendations. However, cervical cerclage was a possible intervention. Study population included 1,074 patients from 1 Jan 2007-30 Jun 2008 receiving mid-trimester transvaginal ultrasounds during prenatal care at a tertiary medical center clinic. Receiver operator characteristic (ROC) curve cutoff optimal value was ≤34 mm, (n=224), corresponding to 8.9% SPB with shortened cervices compared to 1.4% in patients with normal cervices (>34 mm; n=850; p<0.001 (Area Under the Curve (AUC) 76.6, p<0.001). Cervical lengths <30 mm had 12 times the risk of SPB (p<0.001) while 30-34 mm had 5 times (p=0.005). Tobacco use (≥10 cigarettes per day), p=0.030, and low BMI, p=0.034, had additive effect. Shortened cervical length during routine screening independently predicted SPB while heavy smoking with shortened cervix during pregnancy doubled risk compared to shortened cervix alone.

Transvaginal Cervical Length and Tobacco Use in Appalachian Women: Association with Increased Risk for Spontaneous Preterm Birth

PubMed Central

Findley, Joseph; Seybold, Dara J.; Broce, Mike; Yadav, Dolly; Calhoun, Byron C.

2015-01-01

Currently ACOG recommends that a mid-term screening strategy may be considered to identify short cervix in low risk populations in an effort to prevent preterm birth. Vaginal progesterone is recommended for women with a cervical length ≤20 mm. Cerclage is recommended for women with prior spontaneous preterm birth who are already receiving progesterone supplementation and CL is <25 mm. This study examined risk factors for spontaneous preterm birth (SPB) <35 weeks among a general obstetrical population prior to these ACOG recommendations. However, cervical cerclage was a possible intervention. Study population included 1,074 patients from 1 Jan 2007-30 Jun 2008 receiving mid-trimester transvaginal ultrasounds during prenatal care at a tertiary medical center clinic. Receiver operator characteristic (ROC) curve cutoff optimal value was ≤34 mm, (n=224), corresponding to 8.9% SPB with shortened cervices compared to 1.4% in patients with normal cervices (>34 mm; n=850; p<0.001 (Area Under the Curve (AUC) 76.6, p<0.001). Cervical lengths <30 mm had 12 times the risk of SPB (p<0.001) while 30-34 mm had 5 times (p=0.005). Tobacco use (≥10 cigarettes per day), p=0.030, and low BMI, p=0.034, had additive effect. Shortened cervical length during routine screening independently predicted SPB while heavy smoking with shortened cervix during pregnancy doubled risk compared to shortened cervix alone. PMID:26050294

Debye screening and a Thomas - Fermi model of a dyonic atom in a two potential theory of electromagnetism

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wolf, C.

1993-02-01

We study the screening of a central Abelian dyon by a surrounding dyon cloud in a two potential theory of electromagnetism. A generalized formula for the Debye screening length is obtained and a Thomas - Fermi Model for a charged cloud surrounding a central Dyonic Core is studied. 20 refs.

Effect of the screened Coulomb disorder on magneto-transport in Weyl semimetals

NASA Astrophysics Data System (ADS)

Ji, Xuan-Ting; Lu, Hai-Zhou; Zhu, Zhen-Gang; Su, Gang

2018-05-01

The observation of negative longitudinal magnetoresistivity (NLMR) in Weyl semimetals has gained strong support in recent experiments. It is believed that charged impurities play an important role in the measurement of NLMR. We thus employ a screened Coulomb disorder to model charged impurities and derive a general screening length depending on the magnetic field, chemical potential and temperature. We study the magneto-transport in a two-node Weyl semimetal in which the intra-valley scattering and the inter-valley scattering can be explored simultaneously. We also calculate the effect of the misalignment of the external electric field and the magnetic field on the longitudinal and transverse magnetoconductivities, recovering the experimental observations. We show that the former (latter) is suppressed (enhanced) sensitively with the density of the impurity. This feature makes it hard to observe the NLMR in experiments in the heavy doping case. These results may be exploited to explain the sample-dependent observation of NLMR and deepen our understanding of magneto-transport in Weyl semimetals.

Screening of Israeli Holstein-Friesian cattle for restriction fragment length polymorphisms using homologous and heterologous deoxyribonucleic acid probes.

PubMed

Hallerman, E M; Nave, A; Soller, M; Beckmann, J S

1988-12-01

Genomic DNA of Israeli Holstein-Friesian dairy cattle were screened with a battery of 17 cloned or subcloned DNA probes in an attempt to document restriction fragment length polymorphisms at a number of genetic loci. Restriction fragment length polymorphisms were observed at the chymosin, oxytocin-neurophysin I, lutropin beta, keratin III, keratin VI, keratin VII, prolactin, and dihydrofolate reductase loci. Use of certain genomic DNA fragments as probes produced hybridization patterns indicative of satellite DNA at the respective loci. Means for distinguishing hybridizations to coding sequences for unique genes from those to satellite DNA were developed. Results of this study are discussed in terms of strategy for the systematic development of large numbers of bovine genomic polymorphisms.

Field Emission Enhancement and the Field-Screening Effect Reduction using Carbon Nanopipettes as Cold Cathodes

NASA Astrophysics Data System (ADS)

Safir, Abdelilah; Mudd, David; Yazdanpanah, Mehdi; Dobrokhotov, Vladimir; Sumanasekera, Gamini; Cohn, Robert

2008-03-01

In this work, we report a recent experimental study of high emission current densities exceeding 10mA/cm^2 and breakdown electric field lower than 5Volts/μm from novel cold cathodes such as conical shaped carbon nanopipettes (CNP). CNP were grown by CVD on Pt wire and have apex as sharp as 10nm with length between 3-6μm. The emission experiments were conducted under vacuum in a scanning electron microscope for individual CNP and in a dedicated chamber for bulk samples. CNP's conical bases and low density contribute significantly to the reduction of the screening effect and to the field emission enhancement. The experimental value for the field enhancement factor, γ, was about 867. Comparing emission results taken from CNP and aligned multiwall carbon nanotubes (MWNT) show that the ratio between γCNP and γMWNT is ˜1.6 which contributes to the reduction of screening effect. The emission from multilayers of graphene was also studied. High emission current (20μA) demonstrates promising emission properties of graphene.

FOOTPRINT: A Screening Model for Estimating the Area of a Plume Produced From Gasoline Containing Ethanol

EPA Pesticide Factsheets

FOOTPRINT is a screening model used to estimate the length and surface area of benzene, toluene, ethylbenzene, and xylene (BTEX) plumes in groundwater, produced from a gasoline spill that contains ethanol.

Functional screening assays with neurons generated from pluripotent stem cell-derived neural stem cells.

PubMed

Efthymiou, Anastasia; Shaltouki, Atossa; Steiner, Joseph P; Jha, Balendu; Heman-Ackah, Sabrina M; Swistowski, Andrzej; Zeng, Xianmin; Rao, Mahendra S; Malik, Nasir

2014-01-01

Rapid and effective drug discovery for neurodegenerative disease is currently impeded by an inability to source primary neural cells for high-throughput and phenotypic screens. This limitation can be addressed through the use of pluripotent stem cells (PSCs), which can be derived from patient-specific samples and differentiated to neural cells for use in identifying novel compounds for the treatment of neurodegenerative diseases. We have developed an efficient protocol to culture pure populations of neurons, as confirmed by gene expression analysis, in the 96-well format necessary for screens. These differentiated neurons were subjected to viability assays to illustrate their potential in future high-throughput screens. We have also shown that organelles such as nuclei and mitochondria could be live-labeled and visualized through fluorescence, suggesting that we should be able to monitor subcellular phenotypic changes. Neurons derived from a green fluorescent protein-expressing reporter line of PSCs were live-imaged to assess markers of neuronal maturation such as neurite length and co-cultured with astrocytes to demonstrate further maturation. These studies confirm that PSC-derived neurons can be used effectively in viability and functional assays and pave the way for high-throughput screens on neurons derived from patients with neurodegenerative disorders.

Pressure dependence of effective Coulomb interaction parameters in BaFe2As2 by first-principle calculation

NASA Astrophysics Data System (ADS)

Aghajani, M.; Hadipour, H.; Akhavan, M.

2018-05-01

Pressure dependence of the onsite Coulomb interactions of the BaFe2As2 has been studied by employing the constrained random phase approximation within first-principle calculations. Analyzing total and projected density of states, a pseudogap is found for dxy band at the energy roughly 0.25 eV higher than the Fermi level. Also, by applying pressure the spectral weight of the dxy orbital vanishes while other orbitals remain metallic. The different screening channels, as discussed in four different models, affect significantly on the Hubbard U while the Hund J remains almost unchanged. The average onsite bare and partially and fully screened Coulomb interactions increase with different rates upon compression. These different rates can be explained by competition between the electronic screening and reduction of bond lengths.

Resonant charge exchange for H-H+ in Debye plasmas

NASA Astrophysics Data System (ADS)

Laricchiuta, Annarita; Colonna, Gianpiero; Capitelli, Mario; Kosarim, Alexander; Smirnov, Boris M.

2017-11-01

The dynamics of resonant charge exchange in proton-hydrogen collisions embedded in plasma is investigated in the framework of the asymptotic approach, modified to account for the effect of Debye-Hückel screening in particle interactions. The cross sections exhibit a marked dependence on the Debye length in regimes of severe plasma confinement. Processes involving excited states H( n)-H+ are also discussed.

Estimating Hyrdologic Properties of Groundwater Wells Using Tracer Pulse Dynamic Flow Profiling

NASA Astrophysics Data System (ADS)

Miles, K. A.; Heller, N.

2016-12-01

Traditional groundwater well design places the pump intake above the top of the well screen. It is common in this case to design the well screen for uniform entrance velocity along the profile of the well screen, even though non-uniform flow may occur. Particularly in the case where the pump is set near the very top or bottom of the well, there are instances where the zonal testing with a test pump indicates favorable water quality at one pump depth of the groundwater production well, and the water quality results yielded from the well at another depth are not compliant with federal and state regulatory limits for various naturally occurring and anthropogenic compounds. Well bore flow velocity and chemistry were determined using the USGS Tracer Pulse Dynamic Flow Profiling method along the length of well screens, while varying the pump depth. The information was then used to perform a flow and chemical mass balance to characterize the distribution of flow and chemical contribution, groundwater well screen entrance velocities, and hydrologic parameters. The presented results show pump placement affecting the average chemical discharge, and entrance velocities along the length of well screens.

[Nutritional risk screening and its clinical significance in 706 children hospitalized in the surgical department].

PubMed

Peng, Lu-Ting; Li, Rong; Zhao, Wei-Hua; Chen, Yin-Hua; Li, Xiao-Mei; Chen, Meng-Ying; Cao, Jia; Li, Xiao-Nan

2013-10-01

To investigate nutritional risk and its relationship with clinical outcome in children hospitalized in the surgical department, and to provide a scientific basis for clinical nutrition management. Nutritional risk screening was performed on 706 children hospitalized in the surgical department using the Screening Tool for Risk on Nutritional Status and Growth. The data on nutritional support during hospitalization, incidence of infectious complications, length of hospital stay, post operative length of hospital stay and total hospital expenses were recorded. Of the 706 cases, 11.5% had high nutritional risk, 46.0% had moderate nutritional risk, and 42.5% had low nutritional risk. Congenital hypertrophic pyloric stenosis, intestinal obstruction and congenital heart disease were the three most common types of high nutritional risk. The incidence of high nutritional risk was significantly higher in infants than in other age groups (P<0.01). Fifty-two (64.2%) of the eighty-one children with high nutritional risk received parenteral nutrition. Children with high nutritional risk were significantly more likely to have weight loss than children with low nutritional risk (P<0.05). Children with high nutritional risk had significantly increased incidence of infectious complications, length of hospital stay, post operative length of hospital stay and total hospital expenses compared with those with moderate or low nutritional risk (P<0.01). Moderate or high nutritional risk is seen in children hospitalized in the surgical department. Nutritional risk score is correlated with clinical outcome. Nutritional support for these children is not yet properly provided. Nutritional risk screening and standard nutritional support should be widely applied among hospitalized children.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thurman-Keup, R.; Lumpkin, A. H.; Thangaraj, J.

FAST is a facility at Fermilab that consists of a photoinjector, two superconducting capture cavities, one superconducting ILC-style cryomodule, and a small ring for studying non-linear, integrable beam optics called IOTA. This paper discusses the layout for the optical transport system that provides optical radiation to an externally located streak camera for bunch length measurements, and THz radiation to a Martin-Puplett interferometer, also for bunch length measurements. It accepts radiation from two synchrotron radiation ports in a chicane bunch compressor and a diffraction/transition radiation screen downstream of the compressor. It also has the potential to access signal from a transitionmore » radiation screen or YAG screen after the spectrometer magnet for measurements of energy-time correlations. Initial results from both the streak camera and Martin-Puplett will be presented.« less

A study of characteristics of a reliable and practical breath alcohol screening test. Part A

DOT National Transportation Integrated Search

1975-08-01

The objectives of this study were (1) to investigate several commercially available breath-alcohol screening test devices of the length-of-stain type, under standardized laboratory conditions, with respect to their ability satisfactorily to detect an...

Dual laser optical system and method for studying fluid flow

NASA Technical Reports Server (NTRS)

Owen, R. B.; Witherow, W. K. (Inventor)

1983-01-01

A dual laser optical system and method is disclosed for visualization of phenomena in transport substances which induce refractive index gradients such as fluid flow and pressure and temperature gradients in fluids and gases. Two images representing mutually perpendicular components of refractive index gradients may be viewed simultaneously on screen. Two lasers having wave lengths in the visible range but separated by about 1000 angstroms are utilized to provide beams which are collimated into a beam containing components of the different wave lengths. The collimated beam is passed through a test volume of the transparent substance. The collimated beam is then separated into components of the different wave lengths and focused onto a pair of knife edges arranged mutually perpendicular to produce and project images onto the screen.

Four Principles to Consider Before Advising Women on Screening Mammography.

PubMed

Keen, John D; Jørgensen, Karsten J

2015-11-01

This article reviews four important screening principles applicable to screening mammography in order to facilitate informed choice. The first principle is that screening may help, hurt, or have no effect. In order to reduce mortality and mastectomy rates, screening must reduce the rate of advanced disease, which likely has not happened. Through overdiagnosis, screening produces substantial harm by increasing both lumpectomy and mastectomy rates, which offsets the often-promised benefit of less invasive therapy. Next, all-cause mortality is the most reliable way to measure the efficacy of a screening intervention. Disease-specific mortality is biased due to difficulties in attribution of cause of death and to increased mortality due to overdiagnosis and the resulting overtreatment with radiotherapy and chemotherapy. To enhance participation, the benefit from screening is often presented in relative instead of absolute terms. Third, some screening statistics must be interpreted with caution. Increased survival time and the percentage of early-stage tumors at detection sound plausible, but are affected by lead-time and length biases. In addition, analyses that only include women who attend screening cannot reliably correct for selection bias. The final principle is that accounting for tumor biology is important for accurate estimates of lead time, and the potential benefit from screening. Since "early detection" is actually late in a tumor's lifetime, the time window when screen detection might extend a woman's life is narrow, as many tumors that can form metastases will already have done so. Instead of encouraging screening mammography, physicians should help women make an informed decision as with any medical intervention.

Agents that Stabilize Mutated von Hippel Lindau Protein Result in Differential Post-Translational Modification and Subcellular Localization

PubMed Central

Ding, Zhiyong; German, Peter; Bai, Shanshan; Feng, Zhehui; Gao, Meng; Si, Wendy; Sobieski, Mary M.; Stephan, Clifford C.; Mills, Gordon B.; Jonasch, Eric

2014-01-01

Background von Hippel Lindau (VHL) disease is an autosomal dominant inherited disorder that results in multiple organ systems being affected. Treatment is mainly surgical, however, effective systemic therapies are needed. We developed and tested a cell-based screening tool to identify compounds that stabilize or upregulate full-length, point mutated VHL. Methods The 786-0 cell line was infected with full-length W117A mutated VHL linked to a C-terminal Venus fluorescent protein. This VHL-W117A-Venus line was used to screen the Prestwick drug library and was tested against the known proteasome inhibitors MG132 and bortezomib. Western blot validation and evaluation of downstream functional readouts, including HIF and GLUT1 levels, were performed. Results Bortezomib, MG132, and the Prestwick compounds 8-azaguanine, thiostrepton and thioguanosine were found to reliably upregulate VHL-W117A-Venus in 786-0 cells. 8-azaguanine was found to downregulate HIF2α levels, and was augmented by the presence of VHL W117A. VHL p30 band intensities varied as a function of compound used, suggesting alternate post-translational processing. In addition, nuclear-cytoplasmic localization of pVHL varied amongst the different compounds. Conclusion 786-0 cells containing VHL-W117A-Venus can be successfully used to identify compounds that upregulate VHL levels, and that have a differential effect on pVHL intracellular localization and posttranslational processing. Further screening efforts will broaden the number of pharmacophores available to develop therapeutic agents that will upregulate and refunctionalize mutated VHL. PMID:22357874

Enhancing neonatal wellness with home visitation.

PubMed

Parker, Carlo; Warmuskerken, Geene; Sinclair, Lorna

2015-01-01

We planned and implemented an evidence-based program to screen for jaundice and to try to increase the proportion of women breastfeeding for 6 months. The program involved home visitation by a registered nurse to provide education on and support of breastfeeding, and to perform physical assessment of both mothers and newborns, including screening for neonatal jaundice. Quantitative data showed increased breastfeeding rates at 6 months. In addition, readmission rates for jaundice were higher when compared to regional benchmarks. However, the average length of stay for treatment of jaundice was shorter than regional benchmarks. Qualitative data indicated that the program was effective at achieving its goals and was valued by participants. © 2015 AWHONN.

Gender may have an influence on the relationship between Functional Movement Screen scores and gait parameters in elite junior athletes - A pilot study.

PubMed

Magyari, N; Szakács, V; Bartha, C; Szilágyi, B; Galamb, K; Magyar, M O; Hortobágyi, T; Kiss, R M; Tihanyi, J; Négyesi, J

2017-09-01

Aims The aim of this study was to examine the effects of gender on the relationship between Functional Movement Screen (FMS) and treadmill-based gait parameters. Methods Twenty elite junior athletes (10 women and 10 men) performed the FMS tests and gait analysis at a fixed speed. Between-gender differences were calculated for the relationship between FMS test scores and gait parameters, such as foot rotation, step length, and length of gait line. Results Gender did not affect the relationship between FMS and treadmill-based gait parameters. The nature of correlations between FMS test scores and gait parameters was different in women and men. Furthermore, different FMS test scores predicted different gait parameters in female and male athletes. FMS asymmetry and movement asymmetries measured by treadmill-based gait parameters did not correlate in either gender. Conclusion There were no interactions between FMS, gait parameters, and gender; however, correlation analyses support the idea that strength and conditioning coaches need to pay attention not only to how to score but also how to correctly use FMS.

The effect of dose reduction on the detection of anatomical structures on panoramic radiographs.

PubMed

Kaeppler, G; Dietz, K; Reinert, S

2006-07-01

The aim was to evaluate the effect of dose reduction on diagnostic accuracy using different screen-film combinations and digital techniques for panoramic radiography. Five observers assessed 201 pairs of panoramic radiographs (a total of 402 panoramic radiographs) taken with the Orthophos Plus (Sirona, Bensheim, Germany), for visualization of 11 anatomical structures on each side, using a 3-point scale -1, 0 and 1. Two radiographs of each patient were taken at two different times (conventional setting and setting with decreased dose, done by increasing tube potential settings or halving tube current). To compare the dose at different tube potential settings dose-length product was measured at the secondary collimator. Films with medium and regular intensifying screens (high and low tube potential settings) and storage phosphor plates (low tube potential setting, tube current setting equivalent to regular intensifying screen and halved) were compared. The five observers made 27 610 assessments. Intrarater agreement was expressed by Cohen's kappa coefficient. The results demonstrated an equivalence of regular screens (low tube potential setting) and medium screens (high and low tube potential settings). A significant difference existed between medium screens (low tube potential setting, mean score 0.92) and the group of regular film-screen combinations at high tube potential settings (mean score 0.89) and between all film-screen combinations and the digital system irrespective of exposure (mean score below 0.82). There were no significant differences between medium and regular screens (mean score 0.88 to 0.92) for assessment of the periodontal ligament space, but there was a significant difference compared with the digital system (mean score below 0.76). The kappa coefficient for intrarater agreement was moderate (0.55). New regular intensifying screens can replace medium screens at low tube potential settings. Digital panoramic radiographs should be taken at low tube potential levels with an exposure equivalent at least to a regular intensifying screen.

Effective electrostatic interactions among charged thermo-responsive microgels immersed in a simple electrolyte

DOE Office of Scientific and Technical Information (OSTI.GOV)

González-Mozuelos, P.

This work explores the nature and thermodynamic behavior of the effective electrostatic interactions among charged microgels immersed in a simple electrolyte, taking special interest in the effects due to the thermally induced variation of the microgel size while the remaining parameters (microgel charge and concentration, plus the amount of added salt) are kept constant. To this end, the rigorous approach obtained from applying the precise methodology of the dressed ion theory to the proper definition of the effective direct correlation functions, which emerge from tracing-out the degrees of freedom of the microscopic ions, is employed to provide an exact descriptionmore » of the parameters characterizing such interactions: screening length, effective permittivity, and renormalized charges. A model solution with three components is assumed: large permeable anionic spheres for the microgels, plus small charged hard spheres of equal size for the monovalent cations and anions. The two-body correlations among the components of this model suspension, used as the input for the determination of the effective interaction parameters, are here calculated by using the hyper-netted chain approximation. It is then found that at finite microgel concentrations the values of these parameters change as the microgel size increases, even though the ionic strength of the supporting electrolyte and the bare charge of the microgels remain fixed during this process. The variation of the screening length, as well as that of the effective permittivity, is rather small, but still interesting in view of the fact that the corresponding Debye length stays constant. The renormalized charges, in contrast, increase markedly as the microgels swell. The ratio of the renormalized charge to the corresponding analytic result obtained in the context of an extended linear response theory allows us to introduce an effective charge that accounts for the non-linear effects induced by the short-ranged association of microions to the microgels. The behavior of these effective charges as a function of the amount of added salt and the macroion charge, size, and concentration reveals the interplay among all these system parameters.« less

Nonlinear conductance in weakly disordered mesoscopic wires: Interaction and magnetic field asymmetry

NASA Astrophysics Data System (ADS)

Texier, Christophe; Mitscherling, Johannes

2018-02-01

We study the nonlinear conductance G ˜∂2I /∂ V2|V =0 in coherent quasi-one-dimensional weakly disordered metallic wires. Our analysis is based on the scattering approach and includes the effect of Coulomb interaction. The nonlinear conductance correlations can be related to integrals of two fundamental correlation functions: the correlator of functional derivatives of the conductance and the correlator of injectivities (the injectivity is the contribution to the local density of states of eigenstates incoming from one contact). These correlators are obtained explicitly by using diagrammatic techniques for weakly disordered metals. In a coherent wire of length L , we obtain rms (G )≃0.006 ETh-1 (and =0 ), where ETh=ℏ D /L2 is the Thouless energy of the wire and D the diffusion constant; the small dimensionless factor results from screening, i.e., cannot be obtained within a simple theory for noninteracting electrons. Electronic interactions are also responsible for an asymmetry under magnetic field reversal; the antisymmetric part of the nonlinear conductance (at high magnetic field) being much smaller than the symmetric one, rms (Ga)≃0.001 (gETh) -1 , where g ≫1 is the dimensionless (linear) conductance of the wire. In a weakly coherent wire (i.e., Lφ≪L , where Lφ is the phase coherence length), the nonlinear conductance is of the same order as the result G0 of a free electron calculation (although screening again strongly reduces the dimensionless prefactor); we get G ˜G0˜(Lφ/L ) 7 /2ETh-1 , while the antisymmetric part (at high magnetic field) now behaves as Ga˜(Lφ/L ) 11 /2(gETh) -1≪G . The effect of thermal fluctuations is studied: when the thermal length LT=√{ℏ D /kBT } is the smallest length scale, LT≪Lφ≪L , the free electron result G0˜(LT/L ) 3(Lφ/L ) 1 /2ETh-1 is negligible and the dominant contribution is provided by screening, G ˜(LT/L ) (Lφ/L ) 7 /2ETh-1 ; in this regime, the antisymmetric part is Ga˜(LT/L ) 2(Lφ/L ) 7 /2(gETh) -1 . All the precise dimensionless prefactors are obtained. Crossovers from zero to strong magnetic field regimes are also analyzed.

Estimating the effect of gestational age on test performance of combined first-trimester screening for Down syndrome: a preliminary study.

PubMed

van Heesch, Peter N; Struijk, Pieter C; Laudy, Jaqueline A M; Steegers, Eric A P; Wildschut, Hajo I J

2010-05-01

To establish how different methods of estimating gestational age (GA) affect reliability of first-trimester screening for Down syndrome. Retrospective single-center study of 100 women with a viable singleton pregnancy, who had first-trimester screening. We calculated multiples of the median (MoM) for maternal-serum free beta human chorionic gonadotropin (free beta-hCG) and pregnancy associated plasma protein-A (PAPP-A), derived from either last menstrual period (LMP) or ultrasound-dating scans. In women with a regular cycle, LMP-derived estimates of GA were two days longer (range -11 to 18), than crown-rump length (CRL)-derived estimates of GA whereas this discrepancy was more pronounced in women who reported to have an irregular cycle, i.e., six days (range -7 to 32). Except for PAPP-A in the regular-cycle group, all differences were significant. Consequently, risk estimates are affected by the mode of estimating GA. In fact, LMP-based estimates revealed ten "screen-positive" cases compared to five "screen-positive" cases where GA was derived from dating-scans. Provided fixed values for nuchal translucency are applied, dating-scans reduce the number of screen-positive findings on the basis of biochemical screening. We recommend implementation of guidelines for Down syndrome screening based on CRL-dependent rather than LMP-dependent parameters of GA.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gratia, Pierre; Hu, Wayne; Enrico Fermi Institute and Kavli Institute for Cosmological Physics, University of Chicago,South Ellis Avenue, Chicago, IL 60637

Attempts to modify gravity in the infrared typically require a screening mechanism to ensure consistency with local tests of gravity. These screening mechanisms fit into three broad classes; we investigate theories which are capable of exhibiting more than one type of screening. Specifically, we focus on a simple model which exhibits both Vainshtein and kinetic screening. We point out that due to the two characteristic length scales in the problem, the type of screening that dominates depends on the mass of the sourcing object, allowing for different phenomenology at different scales. We consider embedding this double screening phenomenology in amore » broader cosmological scenario and show that the simplest examples that exhibit double screening are radiatively stable.« less

Nutritional Risk Screening 2002, Short Nutritional Assessment Questionnaire, Malnutrition Screening Tool, and Malnutrition Universal Screening Tool Are Good Predictors of Nutrition Risk in an Emergency Service.

PubMed

Rabito, Estela Iraci; Marcadenti, Aline; da Silva Fink, Jaqueline; Figueira, Luciane; Silva, Flávia Moraes

2017-08-01

There is an international consensus that nutrition screening be performed at the hospital; however, there is no "best tool" for screening of malnutrition risk in hospitalized patients. To evaluate (1) the accuracy of the MUST (Malnutrition Universal Screening Tool), MST (Malnutrition Screening Tool), and SNAQ (Short Nutritional Assessment Questionnaire) in comparison with the NRS-2002 (Nutritional Risk Screening 2002) to identify patients at risk of malnutrition and (2) the ability of these nutrition screening tools to predict morbidity and mortality. A specific questionnaire was administered to complete the 4 screening tools. Outcomes measures included length of hospital stay, transfer to the intensive care unit, presence of infection, and incidence of death. A total of 752 patients were included. The nutrition risk was 29.3%, 37.1%, 33.6%, and 31.3% according to the NRS-2002, MUST, MST, and SNAQ, respectively. All screening tools showed satisfactory performance to identify patients at nutrition risk (area under the receiver operating characteristic curve between 0.765-0.808). Patients at nutrition risk showed higher risk of very long length of hospital stay as compared with those not at nutrition risk, independent of the tool applied (relative risk, 1.35-1.78). Increased risk of mortality (2.34 times) was detected by the MUST. The MUST, MST, and SNAQ share similar accuracy to the NRS-2002 in identifying risk of malnutrition, and all instruments were positively associated with very long hospital stay. In clinical practice, the 4 tools could be applied, and the choice for one of them should be made per the particularities of the service.

Optimise inlet condition and design parameters of a new sewer overflow screening device using numerical model.

PubMed

Aziz, M A; Imteaz, M A; Huda, Nazmul; Naser, J

2014-01-01

After heavy rainfall, sewer overflow spills to receiving water bodies cause serious concern for the environment, aesthetics and public health. To overcome these problems this study investigated a new self-cleansing sewer overflow screening device. The device has a sewer overflow chamber, a rectangular tank and a slotted ogee weir to capture the gross pollutants. To design an efficient screening device a numerical computational fluid dynamic (CFD) model was used. A plausibility check of the CFD model was done using a one-dimensional analytical model. Results showed that an inlet parallel to the weir ensured better self-cleansing than an inlet perpendicular to the weir. Perforations should be at the bottom of the weir to get increased velocity and shear stress to create a favourable self-cleaning effect of the screening device. Increasing inlet length from 0.3 to 1.5 m reduced wave reflection up to 10%, which increased flow uniformity downstream and improved self-cleansing effect. The orientation of the ogee weir with the rectangular tank was found most uniform with a 1:3 (horizontal:vertical) slope. These results will help to maximise functional efficiency of the new sewer overflow screening device. Otherwise it would be too expensive to alter after installation and at times difficult to customise accordingly to existing urban drainage systems.

Electrostatic interactions between ions near Thomas-Fermi substrates and the surface energy of ionic crystal at imperfect metals

PubMed Central

Kaiser, V.; Comtet, J.; Niguès, A.; Siria, A.; Coasne, B.; Bocquet, L.

2017-01-01

The electrostatic interaction between two charged particles is strongly modified in the vicinity of a metal. This situation is usually accounted for by the celebrated image charges approach, which was further extended to account for the electronic screening properties of the metal at the level of the Thomas-Fermi description. In this paper we build upon the approach by [Kornyshev et al. Zh. Eksp. Teor. Fiz., 78(3):1008–1019, 1980] and successive works to calculate the 1-body and 2-body electrostatic energy of ions near a metal in terms of the Thomas-Fermi screening length. We propose workable approximations suitable for molecular simulations of ionic systems close to metallic walls. Furthermore, we use this framework to calculate analytically the electrostatic contribution to the surface energy of a one dimensional crystal at a metallic wall and its dependence on the Thomas-Fermi screening length. These calculations provide a simple interpretation for the surface energy in terms of image charges, which allow for an estimate of interfacial properties in more complex situations of a disordered ionic liquid close to a metal surface. A counterintuitive outcome is that electronic screening, as characterized by a molecular Thomas-Fermi length ℓTF, profoundly affects the wetting of ionic systems close to a metal, in line with the recent experimental observation of capillary freezing of ionic liquids in metallic confinement. PMID:28436506

Analytical energy gradient for the two-component normalized elimination of the small component method

NASA Astrophysics Data System (ADS)

Zou, Wenli; Filatov, Michael; Cremer, Dieter

2015-06-01

The analytical gradient for the two-component Normalized Elimination of the Small Component (2c-NESC) method is presented. The 2c-NESC is a Dirac-exact method that employs the exact two-component one-electron Hamiltonian and thus leads to exact Dirac spin-orbit (SO) splittings for one-electron atoms. For many-electron atoms and molecules, the effect of the two-electron SO interaction is modeled by a screened nucleus potential using effective nuclear charges as proposed by Boettger [Phys. Rev. B 62, 7809 (2000)]. The effect of spin-orbit coupling (SOC) on molecular geometries is analyzed utilizing the properties of the frontier orbitals and calculated SO couplings. It is shown that bond lengths can either be lengthened or shortened under the impact of SOC where in the first case the influence of low lying excited states with occupied antibonding orbitals plays a role and in the second case the jj-coupling between occupied antibonding and unoccupied bonding orbitals dominates. In general, the effect of SOC on bond lengths is relatively small (≤5% of the scalar relativistic changes in the bond length). However, large effects are found for van der Waals complexes Hg2 and Cn2, which are due to the admixture of more bonding character to the highest occupied spinors.

Graphene decorated with mu-opioid receptor: the ionic screening effect and detection of enkephalin

NASA Astrophysics Data System (ADS)

Ping, Jinglei; Johnson, A. T. Charlie; Liu, Renyu; A. T. Charlie Johnson Team; Renyu Liu Collaboration

2015-03-01

We investigated the properties of graphene field effect transistors (GFETs) decorated with a computaionally redesigned, water-soluble variant of the human mu-opioid receptor (wsMOR) in physiological buffer solution. The shift of the Fermi level in the GFETs is quantitatively described by chemical-gating effect of charges on the wsMOR that are screened by the ionic solution. Our results suggest that sensitivity to the molecular target is lost when the Debye screening length of the solution is shorter than the distance from the graphene to the wsMOR; thus de-salting may be necessary when wsMOR decorated GFETs are used as biosensors in solution. We used this insight to detect DAMGO, a synthetic analog to the endogenous opioid peptide encephalin, at a concentration of 10 pM (5.1 pg/mL) in artificial cerebrospinal fluid (aCSF) diluted to 5% of its normal salt concentration. When the sensors were measured in a dry state, the limit of detection for DAGMO was 1 pM (0.5 pg/mL), one-third of the baseline in human body.Funding for this work was provided by DARPA.

Flow-induced resonance of screen-covered cavities

NASA Technical Reports Server (NTRS)

Soderman, Paul T.

1990-01-01

An experimental study of screen-covered cavities exposed to airflow tangent to the screen is described. The term screen refers to a thin metal plate perforated with a repetitive pattern of round holes. The purpose was to find the detailed aerodynamic and acoustic mechanisms responsible for screen-covered cavity resonance and to find ways to control the pressure oscillations. Results indicate that strong cavity acoustic resonances are created by screen orifices that shed vortices which couple resonance by choosing hole spacings such that shed vortices do not arrive at a downstream orifice in synchronization with cavity pressure oscillations. The proper hole pattern is effective at all airspeeds. It was also discovered that a reduction of orifice size tended to weaken the screen/cavity interaction regardless of hole pattern, probably because of viscous flow losses at the orifices. The screened cavities that resonated did so at much higher frequencies than the equivalent open cavity. The classical large eddy phenomenon occurs at the relatively small scale of the orifices (the excitation is typically of high frequency). The wind tunnel study was made at airspeeds from 0 to 100m/sec. The 457-mm-long by 1.09-m-high rectangular cavities had length-to-depth ratios greater than one, which is indicative of shallow cavities. The cavity screens were perforated in straight rows and columns with hole diameters ranging from 1.59 to 6.35 mm and with porosities from 2.6 to 19.6 percent.

Quantifying rooting at depth in a wheat doubled haploid population with introgression from wild emmer.

PubMed

Clarke, Christina K; Gregory, Peter J; Lukac, Martin; Burridge, Amanda J; Allen, Alexandra M; Edwards, Keith J; Gooding, Mike J

2017-09-01

The genetic basis of increased rooting below the plough layer, post-anthesis in the field, of an elite wheat line (Triticum aestivum 'Shamrock') with recent introgression from wild emmer (T. dicoccoides), is investigated. Shamrock has a non-glaucous canopy phenotype mapped to the short arm of chromosome 2B (2BS), derived from the wild emmer. A secondary aim was to determine whether genetic effects found in the field could have been predicted by other assessment methods. Roots of doubled haploid (DH) lines from a winter wheat ('Shamrock' × 'Shango') population were assessed using a seedling screen in moist paper rolls, in rhizotrons to the end of tillering, and in the field post-anthesis. A linkage map was produced using single nucleotide polymorphism markers to identify quantitative trait loci (QTLs) for rooting traits. Shamrock had greater root length density (RLD) at depth than Shango, in the field and within the rhizotrons. The DH population exhibited diversity for rooting traits within the three environments studied. QTLs were identified on chromosomes 5D, 6B and 7B, explaining variation in RLD post-anthesis in the field. Effects associated with the non-glaucous trait on RLD interacted significantly with depth in the field, and some of this interaction mapped to 2BS. The effect of genotype was strongly influenced by the method of root assessment, e.g. glaucousness expressed in the field was negatively associated with root length in the rhizotrons, but positively associated with length in the seedling screen. To our knowledge, this is the first study to identify QTLs for rooting at depth in field-grown wheat at mature growth stages. Within the population studied here, our results are consistent with the hypothesis that some of the variation in rooting is associated with recent introgression from wild emmer. The expression of genetic effects differed between the methods of root assessment. © The Author 2017. Published by Oxford University Press on behalf of the Annals of Botany Company.

Review of a two-year methicillin-resistant Staphylococcus aureus screening program and cost-effectiveness analysis in Singapore.

PubMed

Win, Mar-Kyaw; Soliman, Tarek Abdellatif Aly; Lee, Linda Kay; Wong, Chia Siong; Chow, Angela; Ang, Brenda; Roman, Carrasco L; Leo, Yee-Sin

2015-09-29

Methicillin-resistant Staphylococcus aureus (MRSA) poses an increasingly large disease and economic burden worldwide. The effectiveness of screening programs in the tropics is poorly understood. The aims of this study are: (i) to analyze the factors affecting MRSA colonization at admission and acquisition during hospitalization and (ii) to evaluate the cost-effectiveness of a screening program which aims to control MRSA incidence during hospitalization. We conducted a retrospective case-control study of patients admitted to the Communicable Disease Centre (CDC) in Singapore between Jan 2009 and Dec 2010 when there was an ongoing selective screening and isolation program. Risk factors contributing to MRSA colonization on admission and acquisition during hospital stay were evaluated using a logistic regression model. In addition, a cost-effectiveness analysis was conducted to determine the cost per disability-adjusted life year (DALY) averted due to implementing the screening and isolation program. The average prevalence rate of screened patients at admission and the average acquisition rate at discharge during the study period were 12.1 and 4.8 % respectively. Logistic regression models showed that older age (adjusted odds ratio (OR) 1.03, 95 % CI 1.02-1.04, p < 0.001) and dermatological conditions (adjusted OR 1.49, 95 % CI 1.11-1.20, p = 0.008) were independently associated with an increased risk of MRSA colonization at admission. Age (adjusted OR 1.02, 95 % CI 1.01-1.03, p = 0.002) and length of stay in hospital (adjusted OR 1.04, 95 % CI 1.03-1.06, p < 0.001) were independent factors associated with MRSA acquisition during hospitalization. The screening and isolation program reduced the acquisition rate by 1.6 % and was found to be cost saving. For the whole study period, the program cost US$129,916, while it offset hospitalization costs of US$103,869 and loss of productivity costs of US$50,453 with -400 $/DALY averted. This study is the first to our knowledge that evaluates the cost-effectiveness of screening and isolation of MRSA patients in a tropical country. Another unique feature of the analysis is the evaluation of acquisition rates among specific types of patients (dermatological, HIV and infectious disease patients)and the comparison of the cost-effectiveness of screening and isolation between them. Overall our results indicate high MRSA prevalence that can be cost effectively reduced by selective screening and isolation programs in Singapore.

Feasibility of Screening Patients With Nonpsychiatric Complaints for Suicide Risk in a Pediatric Emergency Department

PubMed Central

Horowitz, Lisa; Ballard, Elizabeth; Teach, Stephen J.; Bosk, Abigail; Rosenstein, Donald L.; Joshi, Paramjit; Dalton, Marc E.; Pao, Maryland

2012-01-01

Objective Screening children for suicide risk when they present to the emergency department (ED) with nonpsychiatric complaints could lead to better identification and treatment of high-risk youth. Before suicide screening protocols can be implemented for nonpsychiatric patients in pediatric EDs, it is essential to determine whether such efforts are feasible. Methods As part of an instrument validation study, ED patients (10–21 years old) with both psychiatric and nonpsychiatric presenting complaints were recruited to take part in suicide screening. Clinically significant suicidal thoughts, as measured by the Suicidal Ideation Questionnaire, and suicidal behaviors were assessed, as well as patient opinions about suicide screening. Recruitment rates for the study as well as impact on length of stay were assessed. Results Of the 266 patients and parents approached for the study, 159 (60%) agreed to participate. For patients entering the ED for nonpsychiatric reasons (n = 106), 5.7% (n = 6) reported previous suicidal behavior, and 5.7% (n = 6) reported clinically significant suicidal ideation. There were no significant differences for mean length of stay in the ED for nonpsychiatric patients with positive triggers and those who screened negative (means, 382 [SD, 198] and 393 [SD, 166] minutes, respectively; P = 0.80). Ninety-six percent of participants agreed that suicide screening should occur in the ED. Conclusions Suicide screening of nonpsychiatric patients in the ED is feasible in terms of acceptability to parents, prevalence of suicidal thoughts and behaviors, practicality to ED flow, and patient opinion. Future endeavors should address brief screening tools validated on nonpsychiatric populations. PMID:20944511

TR-DB: an open-access database of compounds affecting the ethylene-induced triple response in Arabidopsis.

PubMed

Hu, Yuming; Callebert, Pieter; Vandemoortel, Ilse; Nguyen, Long; Audenaert, Dominique; Verschraegen, Luc; Vandenbussche, Filip; Van Der Straeten, Dominique

2014-02-01

Small molecules which act as hormone agonists or antagonists represent useful tools in fundamental research and are widely applied in agriculture to control hormone effects. High-throughput screening of large chemical compound libraries has yielded new findings in plant biology, with possible future applications in agriculture and horticulture. To further understand ethylene biosynthesis/signaling and its crosstalk with other hormones, we screened a 12,000 compound chemical library based on an ethylene-related bioassay of dark-grown Arabidopsis thaliana (L.) Heynh. seedlings. From the initial screening, 1313 (∼11%) biologically active small molecules altering the phenotype triggered by the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC), were identified. Selection and sorting in classes were based on the angle of curvature of the apical hook, the length and width of the hypocotyl and the root. A MySQL-database was constructed (https://chaos.ugent.be/WE15/) including basic chemical information on the compounds, images illustrating the phenotypes, phenotype descriptions and classification. The research perspectives for different classes of hit compounds will be evaluated, and some general screening tips for customized high-throughput screening and pitfalls will be discussed. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Medical training fails to prepare providers to care for patients with chronic hepatitis B infection

PubMed Central

Chao, Stephanie D; Wang, Bing-Mei; Chang, Ellen T; Ma, Li; So, Samuel K

2015-01-01

AIM: To investigate physicians’ knowledge including chronic hepatitis B (CHB) diagnosis, screening, and management in various stages of their training. METHODS: A voluntary 20-question survey was administered in Santa Clara County, CA where Asian and Pacific Islanders (API) account for a third of the population. Among the 219 physician participants, there were 63 interns, 60 second-year residents, 26 chief residents and 70 attending physicians. The survey asked questions regarding respondents’ demographics, general hepatitis B virus knowledge questions (i.e., transmission, prevalence, diagnostic testing, prevention, and treatment options), as well as, self-reported practice behavior and confidence in knowledge. RESULTS: Knowledge about screening and managing patients with CHB was poor: only 24% identified the correct tests to screen for CHB, 13% knew the next steps for patients testing positive for CHB, 18% knew the high prevalence rate among API, and 31% knew how to screen for liver cancer. Wald chi-square analysis determined the effect of training level on knowledge; in all cases except for knowledge of liver cancer screening (P = 0.0032), knowledge did not significantly increase with length in residency training or completion of residency. CONCLUSION: Even in a high-risk region, both medical school and residency training have not adequately prepared physicians in the screening and management of CHB. PMID:26078568

Implementing a screening program for acromegaly in Latin America: necessity versus feasibility.

PubMed

Danilowicz, Karina; Fainstein Day, Patricia; Manavela, Marcos P; Herrera, Carlos Javier; Deheza, María Laura; Isaac, Gabriel; Juri, Ariel; Katz, Debora; Bruno, Oscar D

2016-08-01

Acromegaly is a rare disease with a large burden due its associated comorbidities and the life-long management required. Since the occurrence and severity of associated complications are related to length of exposure to the excess growth hormone seen in acromegaly, early diagnosis is imperative. The delay in diagnosis, however, can be long, and may be the result of a lack of disease awareness and screening programs. Since acromegaly is an uncommon disease, finding ways to increase recognition and diagnosis that would permit early detection in a logical and cost-effective manner could be a challenge. We conducted a retrospective literature review for information relating to the screening and diagnosis of acromegaly using PubMed. The aim was to assess whether an acromegaly-screening program in Latin America (and elsewhere) would be both of use and be feasible. An earlier diagnosis allows earlier initiation of treatment, such as surgery and/or drugs, which leads to more successful disease management (biochemical control) and better outcomes. Since the delay in diagnosis can be long, we believe that clear opportunities exist for earlier (and increased) detection of acromegaly. This can be achieved by increasing disease awareness for earlier recognition of symptoms and by using targeted screening (rather than mass screening) programs.

Incentives in Diabetic Eye Assessment by Screening (IDEAS): study protocol of a three-arm randomized controlled trial using financial incentives to increase screening uptake in London.

PubMed

Judah, Gaby; Vlaev, Ivo; Gunn, Laura; King, Dominic; King, Derek; Valabhji, Jonathan; Darzi, Ara; Bicknell, Colin

2016-03-18

Diabetes is an increasing public health problem in the UK and globally. Diabetic retinopathy is a microvascular complication of diabetes, and is one of the leading causes of blindness in the UK working age population. The diabetic eye screening programme in England aims to invite all people with diabetes aged 12 or over for retinal photography to screen for the presence of diabetic retinopathy. However, attendance rates are only 81 %, leaving many people at risk of preventable sight loss. This is a three arm randomized controlled trial to investigate the impact of different types of financial incentives (based on principles from behavioral economics) on increasing attendance at diabetic eye screening appointments in London. Eligible participants will be aged 16 or over, and are those who have been invited to screening appointments annually, but who have not attended, or telephoned to rearrange an appointment, within the last 24 months. Eligible participants will be randomized to one of three conditions: 1. Control condition (usual invitation letter) 2. Fixed incentive condition (usual invitation letter, including a voucher for £10 if they attend their appointment) 3. Probabilistic incentive condition (invitation letter, including a voucher for a 1 in 100 chance of winning £1000 if they attend their appointment). Participants will be sent invitation letters, and the primary outcome will be whether or not they attend their appointment. One thousand participants will be included in total, randomized with a ratio of 1.4:1:1. In order to test whether the incentive scheme has a differential impact on patients from different demographic or socio-economic groups, information will be recorded on age, gender, distance from screening center, socio-economic status and length of time since they were last screened. A cost-effectiveness analysis will also be performed. This study will be the first trial of financial incentives for improving uptake of diabetic eye screening. If effective, the intervention may suggest a cost-effective way to increase screening rates, thus reducing unnecessary blindness. ISRCTN14896403, 25 February 2016.

In vivo imaging and quantitative analysis of changes in axon length using transgenic zebrafish embryos.

PubMed

Kanungo, Jyotshnabala; Lantz, Susan; Paule, Merle G

2011-01-01

We describe an imaging procedure to measure axon length in zebrafish embryos in vivo. Automated fluorescent image acquisition was performed with the ImageXpress Micro high content screening reader and further analysis of axon lengths was performed on archived images using AcuityXpress software. We utilized the Neurite Outgrowth Application module with a customized protocol (journal) to measure the axons. Since higher doses of ethanol (2-2.5%, v/v) have been shown to deform motor neurons and axons during development, here we used ethanol to treat transgenic [hb9:GFP (green fluorescent protein)] zebrafish embryos at 28 hpf (hours post-fertilization). These embryos express GFP in the motor neurons and their axons. Embryos after ethanol treatment were arrayed in 384-well plates for automated fluorescent image acquisition in vivo. Average axon lengths of high dose ethanol-treated embryos were significantly lower than the control. Another experiment showed that there was no significant difference in the axon lengths between the embryos grown for 24h at 22°C and 28.5°C. These test experiments demonstrate that using axon development as an end-point, compound screening can be performed in a time-efficient manner. Published by Elsevier Inc.

Segregating YKU80 and TLC1 alleles underlying natural variation in telomere properties in wild yeast.

PubMed

Liti, Gianni; Haricharan, Svasti; Cubillos, Francisco A; Tierney, Anna L; Sharp, Sarah; Bertuch, Alison A; Parts, Leopold; Bailes, Elizabeth; Louis, Edward J

2009-09-01

In yeast, as in humans, telomere length varies among individuals and is controlled by multiple loci. In a quest to define the extent of variation in telomere length, we screened 112 wild-type Saccharomyces sensu stricto isolates. We found extensive telomere length variation in S. paradoxus isolates. This phenotype correlated with their geographic origin: European strains were observed to have extremely short telomeres (<150 bp), whereas American isolates had telomeres approximately three times as long (>400 bp). Insertions of a URA3 gene near telomeres allowed accurate analysis of individual telomere lengths and telomere position effect (TPE). Crossing the American and European strains resulted in F1 spores with a continuum of telomere lengths consistent with what would be predicted if many quantitative trait loci (QTLs) were involved in length maintenance. Variation in TPE is similarly quantitative but only weakly correlated with telomere length. Genotyping F1 segregants indicated several QTLs associated with telomere length and silencing variation. These QTLs include likely candidate genes but also map to regions where there are no known genes involved in telomeric properties. We detected transgressive segregation for both phenotypes. We validated by reciprocal hemizygosity that YKU80 and TLC1 are telomere-length QTLs in the two S. paradoxus subpopulations. Furthermore, we propose that sequence divergence within the Ku heterodimer generates negative epistasis within one of the allelic combinations (American-YKU70 and European-YKU80) resulting in very short telomeres.

Segregating YKU80 and TLC1 Alleles Underlying Natural Variation in Telomere Properties in Wild Yeast

PubMed Central

Liti, Gianni; Haricharan, Svasti; Cubillos, Francisco A.; Tierney, Anna L.; Sharp, Sarah; Bertuch, Alison A.; Parts, Leopold; Bailes, Elizabeth; Louis, Edward J.

2009-01-01

In yeast, as in humans, telomere length varies among individuals and is controlled by multiple loci. In a quest to define the extent of variation in telomere length, we screened 112 wild-type Saccharomyces sensu stricto isolates. We found extensive telomere length variation in S. paradoxus isolates. This phenotype correlated with their geographic origin: European strains were observed to have extremely short telomeres (<150 bp), whereas American isolates had telomeres approximately three times as long (>400 bp). Insertions of a URA3 gene near telomeres allowed accurate analysis of individual telomere lengths and telomere position effect (TPE). Crossing the American and European strains resulted in F1 spores with a continuum of telomere lengths consistent with what would be predicted if many quantitative trait loci (QTLs) were involved in length maintenance. Variation in TPE is similarly quantitative but only weakly correlated with telomere length. Genotyping F1 segregants indicated several QTLs associated with telomere length and silencing variation. These QTLs include likely candidate genes but also map to regions where there are no known genes involved in telomeric properties. We detected transgressive segregation for both phenotypes. We validated by reciprocal hemizygosity that YKU80 and TLC1 are telomere-length QTLs in the two S. paradoxus subpopulations. Furthermore, we propose that sequence divergence within the Ku heterodimer generates negative epistasis within one of the allelic combinations (American-YKU70 and European-YKU80) resulting in very short telomeres. PMID:19763176

Effects of ten antibiotics on seed germination and root elongation in three plant species.

PubMed

Hillis, Derek G; Fletcher, James; Solomon, Keith R; Sibley, Paul K

2011-02-01

We applied a screening-level phytotoxicity assay to evaluate the effects of 10 antibiotics (at concentrations ranging from 1 to 10,000 μg/L) on germination and early plant growth using three plant species: lettuce (Lactuca sativa), alfalfa (Medicago sativa), and carrot (Daucus carota). The range of phytotoxicity of the antibiotics was large, with EC₂₅s ranging from 3.9 μg/L to >10,000 μg/L. Chlortetracycline, levofloxacin, and sulfamethoxazole were the most phytotoxic antibiotics. D. carota was the most sensitive plant species, often by an order of magnitude or more, followed by L. sativa and then M. sativa. Plant germination was insensitive to the antibiotics, with no significant decreases up to the highest treatment concentration of 10,000 μg/L. Compared with shoot and total length measurements, root elongation was consistently the most sensitive end point. Overall, there were few instances where measured soil concentrations, if available in the publicly accessible literature, would be expected to exceed the effect concentrations of the antibiotics evaluated in this study. The use of screening assays as part of a tiered approach for evaluating environmental impacts of antibiotics can provide insight into relative species sensitivity and serve as a basis by which to screen the potential for toxic effects of novel compounds to plants.

Unified concept of effective one component plasma for hot dense plasmas

DOE PAGES

Clerouin, Jean; Arnault, Philippe; Ticknor, Christopher; ...

2016-03-17

Orbital-free molecular dynamics simulations are used to benchmark two popular models for hot dense plasmas: the one component plasma (OCP) and the Yukawa model. A unified concept emerges where an effective OCP (EOCP) is constructed from the short-range structure of the plasma. An unambiguous ionization and the screening length can be defined and used for a Yukawa system, which reproduces the long-range structure with finite compressibility. Similarly, the dispersion relation of longitudinal waves is consistent with the screened model at vanishing wave number but merges with the OCP at high wave number. Additionally, the EOCP reproduces the overall relaxation timemore » scales of the correlation functions associated with ionic motion. Lastly, in the hot dense regime, this unified concept of EOCP can be fruitfully applied to deduce properties such as the equation of state, ionic transport coefficients, and the ion feature in x-ray Thomson scattering experiments.« less

Debye screening in single-molecule carbon nanotube field-effect sensors.

PubMed

Sorgenfrei, Sebastian; Chiu, Chien-Yang; Johnston, Matthew; Nuckolls, Colin; Shepard, Kenneth L

2011-09-14

Point-functionalized carbon nanotube field-effect transistors can serve as highly sensitive detectors for biomolecules. With a probe molecule covalently bound to a defect in the nanotube sidewall, two-level random telegraph noise (RTN) in the conductance of the device is observed as a result of a charged target biomolecule binding and unbinding at the defect site. Charge in proximity to the defect modulates the potential (and transmission) of the conductance-limiting barrier created by the defect. In this Letter, we study how these single-molecule electronic sensors are affected by ionic screening. Both charge in proximity to the defect site and buffer concentration are found to affect RTN amplitude in a manner that follows from simple Debye length considerations. RTN amplitude is also dependent on the potential of the electrolyte gate as applied to the reference electrode; at high enough gate potentials, the target DNA is completely repelled and RTN is suppressed.

Soft Coulomb gap and asymmetric scaling towards metal-insulator quantum criticality in multilayer MoS2.

PubMed

Moon, Byoung Hee; Bae, Jung Jun; Joo, Min-Kyu; Choi, Homin; Han, Gang Hee; Lim, Hanjo; Lee, Young Hee

2018-05-24

Quantum localization-delocalization of carriers are well described by either carrier-carrier interaction or disorder. When both effects come into play, however, a comprehensive understanding is not well established mainly due to complexity and sparse experimental data. Recently developed two-dimensional layered materials are ideal in describing such mesoscopic critical phenomena as they have both strong interactions and disorder. The transport in the insulating phase is well described by the soft Coulomb gap picture, which demonstrates the contribution of both interactions and disorder. Using this picture, we demonstrate the critical power law behavior of the localization length, supporting quantum criticality. We observe asymmetric critical exponents around the metal-insulator transition through temperature scaling analysis, which originates from poor screening in insulating regime and conversely strong screening in metallic regime due to free carriers. The effect of asymmetric scaling behavior is weakened in monolayer MoS 2 due to a dominating disorder.

Debye screening in single-molecule carbon nanotube field-effect transistors

PubMed Central

Sorgenfrei, Sebastian; Chiu, Chien-yang; Johnston, Matthew; Nuckolls, Colin; Shepard, Kenneth L.

2013-01-01

Point-functionalized carbon nanotube field-effect transistors can serve as highly sensitive detectors for biomolecules. With a probe molecule covalently bound to a defect in the nanotube sidewall, two-level random telegraph noise (RTN) in the conductance of the device is observed as a result of a charged target biomolecule binding and unbinding at the defect site. Charge in proximity to the defect modulates the potential (and transmission) of the conductance-limiting barrier created by the defect. In this Letter, we study how these single-molecule electronic sensors are affected by ionic screening. Both charge in proximity to the defect site and buffer concentration are found to affect RTN amplitude in a manner that follows from simple Debye length considerations. RTN amplitude is also dependent on the potential of the electrolyte gate as applied to the reference electrode; at high enough repulsive potentials, the target DNA is completely repelled and RTN is suppressed. PMID:21806018

Preliminary design of the beam screen cooling for the Future Circular Collider of hadron beams

NASA Astrophysics Data System (ADS)

Kotnig, C.; Tavian, L.

2015-12-01

Following recommendations of the recent update of the European strategy in particle physics, CERN has undertaken an international study of possible future circular colliders beyond the LHC. This study considers an option for a very high energy (100 TeV) hadron-hadron collider located in a quasi-circular underground tunnel having a circumference of 80 to 100 km. The synchrotron radiation emitted by the high-energy hadron beam increases by more than two orders of magnitude compared to the LHC. To reduce the entropic load on the superconducting magnets’ refrigeration system, beam screens are indispensable to extract the heat load at a higher temperature level. After illustrating the decisive constraints of the beam screen's refrigeration design, this paper presents a preliminary design of the length of a continuous cooling loop comparing helium and neon, for different cooling channel geometries with emphasis on the cooling length limitations and the exergetic efficiency.

A Stretchable Radio-Frequency Strain Sensor Using Screen Printing Technology

PubMed Central

Jeong, Heijun; Lim, Sungjoon

2016-01-01

In this paper, we propose a stretchable radio-frequency (RF) strain sensor fabricated with screen printing technology. The RF sensor is designed using a half-wavelength patch that resonates at 3.7 GHz. The resonant frequency is determined by the length of the patch, and it therefore changes when the patch is stretched. Polydimethylsiloxane (PDMS) is used to create the substrate, because of its stretchable and screen-printable surface. In addition, Dupont PE872 (Dupont, NC, American) silver conductive ink is used to create the stretchable conductive patterns. The sensor performance is demonstrated both with full-wave simulations and with measurements carried out on a fabricated sample. When the length of the patch sensor is increased by a 7.8% stretch, the resonant frequency decreases from 3.7 GHz to 3.43 GHz, evidencing a sensitivity of 3.43 × 107 Hz/%. Stretching the patch along its width does not change the resonant frequency. PMID:27827833

General strategy for biodetection in high ionic strength solutions using transistor-based nanoelectronic sensors.

PubMed

Gao, Ning; Zhou, Wei; Jiang, Xiaocheng; Hong, Guosong; Fu, Tian-Ming; Lieber, Charles M

2015-03-11

Transistor-based nanoelectronic sensors are capable of label-free real-time chemical and biological detection with high sensitivity and spatial resolution, although the short Debye screening length in high ionic strength solutions has made difficult applications relevant to physiological conditions. Here, we describe a new and general strategy to overcome this challenge for field-effect transistor (FET) sensors that involves incorporating a porous and biomolecule permeable polymer layer on the FET sensor. This polymer layer increases the effective screening length in the region immediately adjacent to the device surface and thereby enables detection of biomolecules in high ionic strength solutions in real-time. Studies of silicon nanowire field-effect transistors with additional polyethylene glycol (PEG) modification show that prostate specific antigen (PSA) can be readily detected in solutions with phosphate buffer (PB) concentrations as high as 150 mM, while similar devices without PEG modification only exhibit detectable signals for concentrations ≤10 mM. Concentration-dependent measurements exhibited real-time detection of PSA with a sensitivity of at least 10 nM in 100 mM PB with linear response up to the highest (1000 nM) PSA concentrations tested. The current work represents an important step toward general application of transistor-based nanoelectronic detectors for biochemical sensing in physiological environments and is expected to open up exciting opportunities for in vitro and in vivo biological sensing relevant to basic biology research through medicine.

Automated touch screen device for recording complex rodent behaviors

PubMed Central

Mabrouk, O.S.; Dripps, I.J.; Ramani, S.; Chang, C.; Han, J.L.; Rice, KC; Jutkiewicz, E.M.

2016-01-01

Background Monitoring mouse behavior is a critical step in the development of modern pharmacotherapies. New Method Here we describe the application of a novel method that utilizes a touch display computer (tablet) and software to detect, record, and report fine motor behaviors. A consumer-grade tablet device is placed in the bottom of a specially made acrylic cage allowing the animal to walk on the device (MouseTrapp). We describe its application in open field (for general locomotor studies) which measures step lengths and velocity. The device can perform light-dark (anxiety) tests by illuminating half of the screen and keeping the other half darkened. A divider is built into the lid of the device allowing the animal free access to either side. Results Treating mice with amphetamine and the delta opioid peptide receptor agonist SNC80 stimulated locomotor activity on the device. Amphetamine increased step velocity but not step length during its peak effect (40–70 min after treatment), thus indicating detection of subtle amphetamine-induced effects. Animals showed a preference (74% of time spent) for the darkened half compared to the illuminated side. Comparison with Existing Method Animals were videotaped within the chamber to compare quadrant crosses to detected motion on the device. The slope, duration and magnitude of quadrant crosses tightly correlated with overall locomotor activity as detected by Mousetrapp. Conclusions We suggest that modern touch display devices such as MouseTrapp will be an important step toward automation of behavioral analyses for characterizing phenotypes and drug effects. PMID:24952323

Enhancing the Breadth and Efficacy of Therapeutic Vaccines for Breast Cancer

DTIC Science & Technology

2014-10-01

us to generate full length recombinant TCR proteins that will be used to screen against the bacteriophage peptide library the Slansky/Kappler team has...the Denver team bacteriophage peptide library for HLA-A2 to screen these T cells. As a result we have abandoned this approach in order to focus our

Microplate Bioassay for Determining Substrate Selectivity of "Candida rugosa" Lipase

ERIC Educational Resources Information Center

Wang, Shi-zhen; Fang, Bai-shan

2012-01-01

Substrate selectivity of "Candida rugosa" lipase was tested using "p"-nitrophenyl esters of increasing chain length (C[subscript 1], C[subscript 7], C[subscript 15]) using the high-throughput screening method. A fast and easy 96-well microplate bioassay was developed to help students learn and practice biotechnological specificity screen. The…

Footprint (A Screening Model for Estimating the Area of a Plume Produced from Gasoline Containing Ethanol

EPA Science Inventory

FOOTPRINT is a simple and user-friendly screening model to estimate the length and surface area of BTEX plumes in ground water produced from a spill of gasoline that contains ethanol. Ethanol has a potential negative impact on the natural biodegradation of BTEX compounds in groun...

Dynamic leg length asymmetry during gait is not a valid method for estimating mild anatomic leg length discrepancy.

PubMed

Leporace, Gustavo; Batista, Luiz Alberto; Serra Cruz, Raphael; Zeitoune, Gabriel; Cavalin, Gabriel Armondi; Metsavaht, Leonardo

2018-03-01

The purpose of this study was to test the validity of dynamic leg length discrepancy (DLLD) during gait as a radiation-free screening method for measuring anatomic leg length discrepancy (ALLD). Thirty-three subjects with mild leg length discrepancy walked along a walkway and the dynamic leg length discrepancy (DLLD) was calculated using a motion analysis system. Pearson correlation and paired Student t -tests were applied to calculate the correlation and compare the differences between DLLD and ALLD (α = 0.05). The results of our study showed DLLD is not a valid method to predict ALLD in subjects with mild limb discrepancy.

First-trimester fetal nasal bone length in an ethnic Chinese population.

PubMed

Sahota, D S; Leung, T Y; Chan, L W; Law, L W; Fung, T Y; Chan, O K; Lau, T K

2009-07-01

To determine reference ranges of fetal nasal bone length (NBL) in a Chinese population and to assess the value of NBL measurement in screening for chromosomal defects in the first trimester. In this prospective study the fetal profile was examined and the fetal NBL and crown-rump length (CRL) were measured in Chinese women presenting with singleton pregnancies for first-trimester screening for aneuploidy between January 2004 and June 2007. Screening was performed on the basis of nuchal translucency (NT) measurement and maternal serum free beta-human chorionic gonadotropin and pregnancy-associated plasma protein-A levels. NBL was measured in 7543 fetuses, of which 7517 were euploid. The best fit equation for median NBL in euploid fetuses in relation to CRL was: NBL (mm) = 0.4593 + (0.0186 x CRL(mm)). The NBL for gestational age (GA, in days) was given by the equation NBL(mm) = 0.2392 + (0.0027 x GA). There was no correlation between log(10)(NBL multiples of the median (MoM)) and log(10)(NT MoM) in unaffected pregnancies (r = - 0.009; P = 0.43). Only two of the 11 cases with trisomy 21 had an NBL outside the 5(th) or 95(th) centiles of the reference range for euploid fetuses. Reference ranges for NBL in a Chinese population suitable for screening for aneuploidy between 11 and 13 + 6 weeks' gestation have been derived. The NBL in Chinese fetuses is similar to that of other ethnic groups. However, unlike the determination of presence vs. absence of the nasal bone, NBL measurement is unlikely to further improve screening for aneuploidy. (c) 2009 ISUOG.

Change in Breast Cancer Screening Intervals Since the 2009 USPSTF Guideline.

PubMed

Wernli, Karen J; Arao, Robert F; Hubbard, Rebecca A; Sprague, Brian L; Alford-Teaster, Jennifer; Haas, Jennifer S; Henderson, Louise; Hill, Deidre; Lee, Christoph I; Tosteson, Anna N A; Onega, Tracy

2017-08-01

In 2009, the U.S. Preventive Services Task Force (USPSTF) recommended biennial mammography for women aged 50-74 years and shared decision-making for women aged 40-49 years for breast cancer screening. We evaluated changes in mammography screening interval after the 2009 recommendations. We conducted a prospective cohort study of women aged 40-74 years who received 821,052 screening mammograms between 2006 and 2012 using data from the Breast Cancer Surveillance Consortium. We compared changes in screening intervals and stratified intervals based on whether the mammogram at the end of the interval occurred before or after the 2009 recommendation. Differences in mean interval length by woman-level characteristics were compared using linear regression. The mean interval (in months) minimally decreased after the 2009 USPSTF recommendations. Among women aged 40-49 years, the mean interval decreased from 17.2 months to 17.1 months (difference -0.16%, 95% confidence interval [CI] -0.30 to -0.01). Similar small reductions were seen for most age groups. The largest change in interval length in the post-USPSTF period was declines among women with a first-degree family history of breast cancer (difference -0.68%, 95% CI -0.82 to -0.54) or a 5-year breast cancer risk ≥2.5% (difference -0.58%, 95% CI -0.73 to -0.44). The 2009 USPSTF recommendation did not lengthen the average mammography interval among women routinely participating in mammography screening. Future studies should evaluate whether breast cancer screening intervals lengthen toward biennial intervals following new national 2016 breast cancer screening recommendations, particularly among women less than 50 years of age.

Electrostatic interactions between ions near Thomas-Fermi substrates and the surface energy of ionic crystals at imperfect metals.

PubMed

Kaiser, V; Comtet, J; Niguès, A; Siria, A; Coasne, B; Bocquet, L

2017-07-01

The electrostatic interaction between two charged particles is strongly modified in the vicinity of a metal. This situation is usually accounted for by the celebrated image charges approach, which was further extended to account for the electronic screening properties of the metal at the level of the Thomas-Fermi description. In this paper we build upon a previous approach [M. A. Vorotyntsev and A. A. Kornyshev, Zh. Eksp. Teor. Fiz., 1980, 78(3), 1008-1019] and successive works to calculate the 1-body and 2-body electrostatic energy of ions near a metal in terms of the Thomas-Fermi screening length. We propose workable approximations suitable for molecular simulations of ionic systems close to metallic walls. Furthermore, we use this framework to calculate analytically the electrostatic contribution to the surface energy of a one dimensional crystal at a metallic wall and its dependence on the Thomas-Fermi screening length. These calculations provide a simple interpretation for the surface energy in terms of image charges, which allows for an estimation of the interfacial properties in more complex situations of a disordered ionic liquid close to a metal surface. The counter-intuitive outcome is that electronic screening, as characterized by a molecular Thomas-Fermi length l TF , profoundly affects the wetting of ionic systems close to a metal, in line with the recent experimental observation of capillary freezing of ionic liquids in metallic confinement.

Repulsion Between Finite Charged Plates with Strongly Overlapped Electric Double Layers.

PubMed

Ghosal, Sandip; Sherwood, John D

2016-09-20

Screened Coulomb interactions between uniformly charged flat plates are considered at very small plate separations for which the Debye layers are strongly overlapped, in the limit of small electrical potentials. If the plates are of infinite length, the disjoining pressure between the plates decays as an inverse power of the plate separation. If the plates are of finite length, we show that screening Debye layer charges close to the edge of the plates are no longer constrained to stay between the plates, but instead spill out into the surrounding electrolyte. The resulting change in the disjoining pressure is calculated analytically: the force between the plates is reduced by this edge correction when the charge density is uniform over the surface of the plates, and is increased when the surface is at constant potential. A similar change in disjoining pressure due to loss of lateral confinement of the Debye layer charges should occur whenever the sizes of the interacting charged objects become small enough to approach the Debye scale. We investigate the effect here in the context of a two-dimensional model problem that is sufficiently simple to yield analytical results.

Employee response to a company-sponsored program of colorectal and prostate cancer screening.

PubMed

Myers, R E; Vernon, S W; Carpenter, A V; Balshem, A M; Lewis, P G; Wolf, T A; Hilbert, J; DeFonso, L R; Ross, E A

1997-01-01

Studies done in the mid-1970s documented increased risk for respiratory cancer and leukemia among employees in a chemical company manufacturing plant where chloromethyl ethers were used in production from 1948 to 1971. In the late 1980s, the company informed current and former employees about the results of follow-up studies which showed a moderation of risk of respiratory cancer and leukemia. New data showing elevated rates of mortality from colorectal, prostate, bladder, and pancreatic cancer in the population were also reported. Via mailed correspondence, the company made a no-cost program of colorectal and prostate cancer screening available to employees upon request; and information about bladder and pancreatic cancer was made available. Thirteen percent of employees in the population indicated interest in colorectal and prostate cancer screening (response). Thirty-one percent of these responders were screened (adherence). Multivariate analyses showed that education and length of employment in the plant were positively associated with response. Being white was positively associated with response for younger workers; while among older workers being male was positively associated with response. In terms of adherence, we found that older, more highly educated workers were more likely to have a screening examination. Findings indicate that employee participation in workplace-sponsored colorectal and prostate cancer screening can vary according to worker sociodemographic factors and length of employment in areas of potential exposure.

Interaction of vortex rings with multiple permeable screens

NASA Astrophysics Data System (ADS)

Musta, Mustafa N.; Krueger, Paul S.

2014-11-01

Interaction of a vortex ring impinging on multiple permeable screens orthogonal to the ring axis was studied to experimentally investigate the persistence and decay of vortical structures inside the screen array using digital particle image velocimetry in a refractive index matched environment. The permeable screens had porosities (open area ratios) of 83.8%, 69.0%, and 55.7% and were held by a transparent frame that allowed the screen spacing to be changed. Vortex rings were generated using a piston-cylinder mechanism at nominal jet Reynolds numbers of 1000, 2000, and 3000 with piston stroke length-to-diameter ratios of 2 and 3. The interaction of vortex rings with the porous medium showed a strong dependence of the overall flow evolution on the screen porosity, with a central flow being preserved and vortex ring-like structures (with smaller diameter than the primary vortex ring) being generated near the centerline. Due to the large rod size used in the screens, immediate reformation of the transmitted vortex ring with size comparable to the primary ring (as has been observed with thin screens) was not observed in most cases. Since the screens have lower complexity and high open area ratios, centerline vortex ring-like flow structures formed with comparable size to the screen pore size and penetrated through the screens. In the case of low porosity screens (55.7%) with large screen spacing, re-emergence of large scale (large separation), weak vortical structures/pairs (analogous to a transmitted vortex ring) was observed downstream of the first screen. Additional smaller scale vortical structures were generated by the interaction of the vortex ring with subsequent screens. The size distribution of the generated vortical structures were shown to be strongly affected by porosity, with smaller vortical structures playing a stronger role as porosity decreased. Finally, porosity significantly affected the decay of total energy, but the effect of screen spacing decreased as porosity decreased.

Interactions regulating the head-to-tail directed assembly of biological Janus rods

DOE Office of Scientific and Technical Information (OSTI.GOV)

Greene, A. C.; Bachand, M.; Gomez, A.

We can generalize the directed, head-to-tail self-assembly of microtubule filaments in the context of Janus colloidal rods. Specifically, their assembly at the tens of micron-length scale involves a careful balance between long-range electrostatic repulsion and short-range attractive forces. We show that the addition of counterion salts increases the rate of directed assembly by screening the electrostatic forces and enhancing the effectiveness of short-range interactions at the microtubule ends.

Interactions regulating the head-to-tail directed assembly of biological Janus rods

DOE PAGES

Greene, A. C.; Bachand, M.; Gomez, A.; ...

2017-03-31

We can generalize the directed, head-to-tail self-assembly of microtubule filaments in the context of Janus colloidal rods. Specifically, their assembly at the tens of micron-length scale involves a careful balance between long-range electrostatic repulsion and short-range attractive forces. We show that the addition of counterion salts increases the rate of directed assembly by screening the electrostatic forces and enhancing the effectiveness of short-range interactions at the microtubule ends.

Novel small molecule modulators of plant growth and development identified by high-content screening with plant pollen.

PubMed

Chuprov-Netochin, Roman; Neskorodov, Yaroslav; Marusich, Elena; Mishutkina, Yana; Volynchuk, Polina; Leonov, Sergey; Skryabin, Konstantin; Ivashenko, Andrey; Palme, Klaus; Touraev, Alisher

2016-09-06

Small synthetic molecules provide valuable tools to agricultural biotechnology to circumvent the need for genetic engineering and provide unique benefits to modulate plant growth and development. We developed a method to explore molecular mechanisms of plant growth by high-throughput phenotypic screening of haploid populations of pollen cells. These cells rapidly germinate to develop pollen tubes. Compounds acting as growth inhibitors or stimulators of pollen tube growth are identified in a screen lasting not longer than 8 h high-lighting the potential broad applicability of this assay to prioritize chemicals for future mechanism focused investigations in plants. We identified 65 chemical compounds that influenced pollen development. We demonstrated the usefulness of the identified compounds as promotors or inhibitors of tobacco and Arabidopsis thaliana seed growth. When 7 days old seedlings were grown in the presence of these chemicals twenty two of these compounds caused a reduction in Arabidopsis root length in the range from 4.76 to 49.20 % when compared to controls grown in the absence of the chemicals. Two of the chemicals sharing structural homology with thiazolidines stimulated root growth and increased root length by 129.23 and 119.09 %, respectively. The pollen tube growth stimulating compound (S-02) belongs to benzazepin-type chemicals and increased Arabidopsis root length by 126.24 %. In this study we demonstrate the usefulness of plant pollen tube based assay for screening small chemical compound libraries for new biologically active compounds. The pollen tubes represent an ultra-rapid screening tool with which even large compound libraries can be analyzed in very short time intervals. The broadly applicable high-throughput protocol is suitable for automated phenotypic screening of germinating pollen resulting in combination with seed germination assays in identification of plant growth inhibitors and stimulators.

Effect of rehabilitation length of stay on outcomes in individuals with traumatic brain injury or spinal cord injury: a systematic review protocol.

PubMed

Lamontagne, Marie-Eve; Gagnon, Cynthia; Allaire, Anne-Sophie; Noreau, Luc

2013-07-20

Rehabilitation interventions are a key component of the services required by individuals with neurotrauma to recover or compensate for altered abilities and achieve optimal social participation. Primary studies have produced evidence of the effect of rehabilitation length of stay on individuals with neurotrauma. However, to date no systematic review of this evidence has been performed. This makes it difficult for managers and clinicians to base their rehabilitation practices upon evidence. Supported by a committee of stakeholders, we will search electronic databases for research articles examining the association between length of stay or intensity of inpatient rehabilitation services and outcomes or the determinants of inpatient rehabilitation length of stay in adults with neurotrauma published after January 1990. Two researchers will independently screen the article titles and abstracts for inclusion. Two reviewers will independently extract the data. Primary outcomes of interest will be level of function, participation and return to work. If the data allow it, a meta-analysis of the studies will be performed. The results of this systematic review will clarify the factors that influence length of stay and intensity of rehabilitation services for individuals with TBI and SCI. They will give clinicians indications for optimal length of stay in these patient populations, contributing to better quality of care and better functional results. This review protocol has been registered on the PROSPERO database (CRD42012003120) and is available at http://www.crd.york.ac.uk/PROSPERO/display_record.asp?ID=CRD42012003120.

A time-motion study of cardiovascular disease risk factor screening integrated into HIV clinic visits in Swaziland.

PubMed

Palma, Anton M; Rabkin, Miriam; Simelane, Samkelo; Gachuhi, Averie B; McNairy, Margaret L; Nuwagaba-Biribonwoha, Harriet; Bongomin, Pido; Okello, Velephi N; Bitchong, Raymond A; El-Sadr, Wafaa M

2018-03-01

Screening of modifiable cardiovascular disease (CVD) risk factors is recommended but not routinely provided for HIV-infected patients, especially in low-resource settings. Potential concerns include limited staff time and low patient acceptability, but little empirical data exists. As part of a pilot study of screening in a large urban HIV clinic in Swaziland, we conducted a time-motion study to assess the impact of screening on patient flow and HIV service delivery and exit interviews to assess patient acceptability. A convenience sample of patients ≥40 years of age attending routine HIV clinic visits was screened for hypertension, diabetes, hyperlipidemia and tobacco smoking. We observed HIV visits with and without screening and measured time spent on HIV and CVD risk factor screening activities. We compared screened and unscreened patients on total visit time and time spent receiving HIV services using Wilcoxon rank-sum tests. A separate convenience sample of screened patients participated in exit interviews to assess their satisfaction with screening. We observed 172 patient visits (122 with CVD risk factor screening and 50 without). Screening increased total visit time from a median (range) of 4 minutes (2 to 11) to 15 minutes (9 to 30) (p < 0.01). Time spent on HIV care was not affected: 4 (2 to 10) versus 4 (2 to 11) (p = 0.57). We recruited 126 patients for exit interviews, all of whom indicated that they would recommend screening to others. Provision of CVD risk factor screening more than tripled the length of routine HIV clinic visits but did not reduce the time spent on HIV services. Programme managers need to take longer visit duration into account in order to effectively integrate CVD risk factor screening and counselling into HIV programmes. © 2018 The Authors. Journal of the International AIDS Society published by John Wiley & sons Ltd on behalf of the International AIDS Society.

Simulation optimization of PSA-threshold based prostate cancer screening policies

PubMed Central

Zhang, Jingyu; Denton, Brian T.; Shah, Nilay D.; Inman, Brant A.

2013-01-01

We describe a simulation optimization method to design PSA screening policies based on expected quality adjusted life years (QALYs). Our method integrates a simulation model in a genetic algorithm which uses a probabilistic method for selection of the best policy. We present computational results about the efficiency of our algorithm. The best policy generated by our algorithm is compared to previously recommended screening policies. Using the policies determined by our model, we present evidence that patients should be screened more aggressively but for a shorter length of time than previously published guidelines recommend. PMID:22302420

Spatially resolving density-dependent screening around a single charged atom in graphene

NASA Astrophysics Data System (ADS)

Wong, Dillon; Corsetti, Fabiano; Wang, Yang; Brar, Victor W.; Tsai, Hsin-Zon; Wu, Qiong; Kawakami, Roland K.; Zettl, Alex; Mostofi, Arash A.; Lischner, Johannes; Crommie, Michael F.

2017-05-01

Electrons in two-dimensional graphene sheets behave as interacting chiral Dirac fermions and have unique screening properties due to their symmetry and reduced dimensionality. By using a combination of scanning tunneling spectroscopy measurements and theoretical modeling we have characterized how graphene's massless charge carriers screen individual charged calcium atoms. A backgated graphene device configuration has allowed us to directly visualize how the screening length for this system can be tuned with carrier density. Our results provide insight into electron-impurity and electron-electron interactions in a relativistic setting with important consequences for other graphene-based electronic devices.

Effects of electrostatic screening on the conformation of single DNA molecules confined in a nanochannel

NASA Astrophysics Data System (ADS)

Zhang, Ce; Zhang, Fang; van Kan, Jeroen A.; van der Maarel, Johan R. C.

2008-06-01

Single T4-DNA molecules were confined in rectangular-shaped channels with a depth of 300 nm and a width in the range of 150-300 nm casted in a poly(dimethylsiloxane) nanofluidic chip. The extensions of the DNA molecules were measured with fluorescence microscopy as a function of the ionic strength and composition of the buffer as well as the DNA intercalation level by the YOYO-1 dye. The data were interpreted with the scaling theory for a wormlike polymer in good solvent, including the effects of confinement, charge, and self-avoidance. It was found that the elongation of the DNA molecules with decreasing ionic strength can be interpreted in terms of an increase of the persistence length. Self-avoidance effects on the extension are moderate, due to the small correlation length imposed by the channel cross-sectional diameter. Intercalation of the dye results in an increase of the DNA contour length and a partial neutralization of the DNA charge, but besides effects of electrostatic origin it has no significant effect on the bare bending rigidity. In the presence of divalent cations, the DNA molecules were observed to contract, but they do not collapse into a condensed structure. It is proposed that this contraction results from a divalent counterion mediated attractive force between the segments of the DNA molecule.

Analytical energy gradient for the two-component normalized elimination of the small component method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zou, Wenli; Filatov, Michael; Cremer, Dieter, E-mail: dcremer@smu.edu

2015-06-07

The analytical gradient for the two-component Normalized Elimination of the Small Component (2c-NESC) method is presented. The 2c-NESC is a Dirac-exact method that employs the exact two-component one-electron Hamiltonian and thus leads to exact Dirac spin-orbit (SO) splittings for one-electron atoms. For many-electron atoms and molecules, the effect of the two-electron SO interaction is modeled by a screened nucleus potential using effective nuclear charges as proposed by Boettger [Phys. Rev. B 62, 7809 (2000)]. The effect of spin-orbit coupling (SOC) on molecular geometries is analyzed utilizing the properties of the frontier orbitals and calculated SO couplings. It is shown thatmore » bond lengths can either be lengthened or shortened under the impact of SOC where in the first case the influence of low lying excited states with occupied antibonding orbitals plays a role and in the second case the jj-coupling between occupied antibonding and unoccupied bonding orbitals dominates. In general, the effect of SOC on bond lengths is relatively small (≤5% of the scalar relativistic changes in the bond length). However, large effects are found for van der Waals complexes Hg{sub 2} and Cn{sub 2}, which are due to the admixture of more bonding character to the highest occupied spinors.« less

Patient navigation and time to diagnostic resolution: results for a cluster randomized trial evaluating the efficacy of patient navigation among patients with breast cancer screening abnormalities, Tampa, FL.

PubMed

Lee, Ji-Hyun; Fulp, William; Wells, Kristen J; Meade, Cathy D; Calcano, Ercilia; Roetzheim, Richard

2013-01-01

The objective of this study was to evaluate a patient navigation (PN) program that attempts to reduce the time between a breast cancer screening abnormality and definitive diagnosis among medically underserved populations of Tampa Bay, Florida. The Moffitt Patient Navigation Research Program conducted a cluster randomized design with 10 primary care clinics. Patients were navigated from time of a breast screening abnormality to diagnostic resolution. This paper examined the length of time between breast abnormality and definitive diagnosis, using a shared frailty Cox proportional hazard model to assess PN program effect. 1,039 patients were eligible for the study because of an abnormal breast cancer screening/clinical abnormality (494 navigated; 545 control). Analysis of PN effect by two time periods of resolution (0-3 months and > 3 months) showed a lagged effect of PN. For patients resolving in the first three months, the adjusted Hazard Ratio (aHR) was 0.85 (95% Confidence Interval [CI]: 0.64-1.13) suggesting that PN had no effect on resolution time during this period. Beyond three months, however, navigated patients resolved more quickly to diagnostic resolution compared with the control group (aHR 2.8, 95%CI: 1.30-6.13). The predicted aHR at 3 months was 1.2, which was not statistically significant, while PN had a significant positive effect beyond 4.7 months. PN programs may increase the timeliness of diagnostic resolution for patients with a breast cancer-related abnormality. PN did not speed diagnostic resolution during the initial three months of follow up but started to reduce time to diagnostic resolution after three months and showed a significant effect after 4.7 months. ClinicalTrials.gov NCT00375024.

Maximum step length: relationships to age and knee and hip extensor capacities.

PubMed

Schulz, Brian W; Ashton-Miller, James A; Alexander, Neil B

2007-07-01

Maximum Step Length may be used to identify older adults at increased risk for falls. Since leg muscle weakness is a risk factor for falls, we tested the hypotheses that maximum knee and hip extension speed, strength, and power capacities would significantly correlate with Maximum Step Length and also that the "step out and back" Maximum Step Length [Medell, J.L., Alexander, N.B., 2000. A clinical measure of maximal and rapid stepping in older women. J. Gerontol. A Biol. Sci. Med. Sci. 55, M429-M433.] would also correlate with the Maximum Step Length of its two sub-tasks: stepping "out only" and stepping "back only". These sub-tasks will be referred to as versions of Maximum Step Length. Unimpaired younger (N=11, age=24[3]years) and older (N=10, age=73[5]years) women performed the above three versions of Maximum Step Length. Knee and hip extension speed, strength, and power capacities were determined on a separate day and regressed on Maximum Step Length and age group. Version and practice effects were quantified and subjective impressions of test difficulty recorded. Hypotheses were tested using linear regressions, analysis of variance, and Fisher's exact test. Maximum Step Length explained 6-22% additional variance in knee and hip extension speed, strength, and power capacities after controlling for age group. Within- and between-block and test-retest correlation values were high (>0.9) for all test versions. Shorter Maximum Step Lengths are associated with reduced knee and hip extension speed, strength, and power capacities after controlling for age. A single out-and-back step of maximal length is a feasible, rapid screening measure that may provide insight into underlying functional impairment, regardless of age.

Multi-Scale Structure of Coacervates formed by Oppositely Charged Polyelectrolytes

NASA Astrophysics Data System (ADS)

Rubinstein, Michael

We develop a scaling model of coacervates formed by oppositely charged polyelectrolytes and demonstrate that they self-organize into multi-scale structures. The intramolecular electrostatic interactions in dilute polyanion or polycation solutions are characterized by the electrostatic blobs with size D- and D+ respectively, that repel neighboring blobs on the same chains with electrostatic energy on the order of thermal energy kT . After mixing, electrostatic intramolecular repulsion of polyelectrolytes with higher charged density, say polyanions, keeps these polyanions in coacervates aligned into stretched arrays of electrostatic blobs of size D-

Microgravity Passive Phase Separator

NASA Technical Reports Server (NTRS)

Paragano, Matthew; Indoe, William; Darmetko, Jeffrey

2012-01-01

A new invention disclosure discusses a structure and process for separating gas from liquids in microgravity. The Microgravity Passive Phase Separator consists of two concentric, pleated, woven stainless- steel screens (25-micrometer nominal pore) with an axial inlet, and an annular outlet between both screens (see figure). Water enters at one end of the center screen at high velocity, eventually passing through the inner screen and out through the annular exit. As gas is introduced into the flow stream, the drag force exerted on the bubble pushes it downstream until flow stagnation or until it reaches an equilibrium point between the surface tension holding bubble to the screen and the drag force. Gas bubbles of a given size will form a front that is moved further down the length of the inner screen with increasing velocity. As more bubbles are added, the front location will remain fixed, but additional bubbles will move to the end of the unit, eventually coming to rest in the large cavity between the unit housing and the outer screen (storage area). Owing to the small size of the pores and the hydrophilic nature of the screen material, gas does not pass through the screen and is retained within the unit for emptying during ground processing. If debris is picked up on the screen, the area closest to the inlet will become clogged, so high-velocity flow will persist farther down the length of the center screen, pushing the bubble front further from the inlet of the inner screen. It is desired to keep the velocity high enough so that, for any bubble size, an area of clean screen exists between the bubbles and the debris. The primary benefits of this innovation are the lack of any need for additional power, strip gas, or location for venting the separated gas. As the unit contains no membrane, the transport fluid will not be lost due to evaporation in the process of gas separation. Separation is performed with relatively low pressure drop based on the large surface area of the separating screen. Additionally, there are no moving parts, and there are no failure modes that involve fluid loss. A patent application has been filed.

Surface wave excitation study

NASA Astrophysics Data System (ADS)

Burke, G. J.; King, R. J.; Miller, E. K.

1984-09-01

Relative communication efficiency (RCE) as defined by Fenwick and Weeks compares the field of a test antenna to that of a reference antenna at the same location for equal input plower to each antenna. Thus, RCE is similar to power gain but is definable in the presence of ground. The effectiveness of antennas in launching TM surface waves was compared. Antennas considered included the vertical dipole, monople on a ground stake, monopole on a radial-wire ground screen, Beverage antenna and vertical half rhombic. Since the performance of these antennas is strongly dependent on parameters such as the number wires in a ground screen or the length of a Beverage antenna, results are presented with parameters varying over a reasonable range. Thus, antenna performance can be weighed against the effort and limitations of construction.

Cut-to-length harvesting of short-rotation Eucalyptus

Treesearch

Bruce R. Hartsough; David J. Cooper

1999-01-01

Traditional whole-tree harvesting systems work well in short-rotation hardwood plantations, but other methods are needed where it is desirable to leave the residues on the site. We tested a system consisting of a cut-to-length harvester, forwarder, mobile chipper, and chip screen to clearcut a 7-year-old plantation of Eucalyptus viminalis. Three...

Cost-benefit and effectiveness analysis of rapid testing for MRSA carriage in a hospital setting.

PubMed

Henson, Gay; Ghonim, Elham; Swiatlo, Andrea; King, Shelia; Moore, Kimberly S; King, S Travis; Sullivan, Donna

2014-01-01

A cost-effectiveness analysis was conducted comparing the polymerase chain reaction assay and traditional microbiological culture as screening tools for the identification of methicillin-resistant Staphylococcus aureus (MRSA) in patients admitted to the pediatric and surgical intensive care units (PICU and SICU) at a 722 bed academic medical center. In addition, the cost benefits of identification of colonized MRSA patients were determined. The cost-effectiveness analysis employed actual hospital and laboratory costs, not patient costs. The actual cost of the PCR assay was higher than the microbiological culture identification of MRSA ($602.95 versus $364.30 per positive carrier identified). However, this did not include the decreased turn-around time of PCR assays compared to traditional culture techniques. Patient costs were determined indirectly in the cost-benefit analysis of clinical outcome. There was a reduction in MRSA hospital-acquired infection (3.5 MRSA HAI/month without screening versus 0.6/month with screening by PCR). A cost-benefit analysis based on differences in length of stay suggests an associated savings in hospitalization costs: MRSA HAI with 29.5 day median LOS at $63,810 versus MRSA identified on admission with 6 day median LOS at $14,561, a difference of $49,249 per hospitalization. Although this pilot study was small and it is not possible to directly relate the cost-effectiveness and cost-benefit analysis due to confounding factors such as patient underlying morbidity and mortality, a reduction of 2.9 MRSA HAI/month associated with PCR screening suggests potential savings in hospitalization costs of $142,822 per month.

Screening in ionic systems: simulations for the Lebowitz length.

PubMed

Kim, Young C; Luijten, Erik; Fisher, Michael E

2005-09-30

Simulations of the Lebowitz length, xiL (T, rho), are reported for the restricted primitive model hard-core (diameter a) 1:1 electrolyte for densities rho approximately < 4rho(c) and T(c) approximately < T approximately < 40T(c). Finite-size effects are elucidated for the charge fluctuations in various subdomains that serve to evaluate xiL. On extrapolation to the bulk limit for T approximately > 10T(c) the exact low-density expansions are seen to fail badly when rho > 1/10 rho(c) (with rho(c)a3 approximately = 0.08). At higher densities xiL rises above the Debye length, xiD proportional to square root(T/rho), by 10%-30% (up to rho approximately =1.3rho(c)); the variation is portrayed fairly well by the generalized Debye-Hückel theory. On approaching criticality at fixed rho or fixed T, xiL (T, rho) remains finite with xiL(c) approximately = 0.30a approximately = 1.3xiD(c) but displays a weak entropylike singularity.

[Mammographic screening. An analysis of the characteristics of interval carcinomas observed in the program in the province of Firenze (1989-1991)].

PubMed

Ciatto, S; Rosselli del Turco, M; Bonardi, R; Bianchi, S

1994-04-01

The authors evaluated 30 interval cancers consecutively observed from 1989 to 1991 and compared them to 98 screening-detected cancers observed in the same period. Interval cancers have a more advanced stage (stage I = 13 lesions, stage II + = 17 lesions) with respect to screening-detected cancers (stage 0 = 10 lesions, stage I = 61 lesions, stage II + = 27 lesions). This finding seems unrelated to an intrinsically higher aggressivity of interval cancers (length biased sampling) which do not differ significantly from screening-detected cancers as far as histopathologic characteristics of prognostic value are concerned. Diagnostic delay due to technical or reading error (9 cases), to radiologically occult cancer in clear (10 cases) or dense parenchymal areas (11 cases) is most likely. This seems to be confirmed by the low frequency observed among interval cancers of easily visible lesions such as isolated microcalcifications (3% vs. 35%) or stellate opacities (13% vs. 31%), and by the higher frequency of opacities with irregular margins (57% vs. 26%) which are more likely masked by dense parenchyma. The chances of reducing interval cancer rate by attempting to increase sensitivity or by increasing screening frequency are discussed, as well as the possible negative consequences of such protocols in terms of cost-effectiveness.

Identifying protein domains by global analysis of soluble fragment data.

PubMed

Bulloch, Esther M M; Kingston, Richard L

2014-11-15

The production and analysis of individual structural domains is a common strategy for studying large or complex proteins, which may be experimentally intractable in their full-length form. However, identifying domain boundaries is challenging if there is little structural information concerning the protein target. One experimental procedure for mapping domains is to screen a library of random protein fragments for solubility, since truncation of a domain will typically expose hydrophobic groups, leading to poor fragment solubility. We have coupled fragment solubility screening with global data analysis to develop an effective method for identifying structural domains within a protein. A gene fragment library is generated using mechanical shearing, or by uracil doping of the gene and a uracil-specific enzymatic digest. A split green fluorescent protein (GFP) assay is used to screen the corresponding protein fragments for solubility when expressed in Escherichia coli. The soluble fragment data are then analyzed using two complementary approaches. Fragmentation "hotspots" indicate possible interdomain regions. Clustering algorithms are used to group related fragments, and concomitantly predict domain location. The effectiveness of this Domain Seeking procedure is demonstrated by application to the well-characterized human protein p85α. Copyright © 2014 Elsevier Inc. All rights reserved.

What are the effects of hypertonic saline plus furosemide in acute heart failure?

PubMed

Zepeda, Patricio; Rain, Carmen; Sepúlveda, Paola

2015-08-27

In search of new therapies to solve diuretic resistance in acute heart failure, the addition of hypertonic saline has been proposed. Searching in Epistemonikos database, which is maintained by screening 30 databases, we identified two systematic reviews including nine pertinent randomized controlled trials. We combined the evidence and generated a summary of findings following the GRADE approach. We concluded hypertonic saline associated with furosemide probably decrease mortality, length of hospital stay and hospital readmission in patients with acute decompensated heart failure.

The Significant Impact of Different Insurance Enrollment Criteria on the HEDIS Chlamydia Screening Measure for Young Women Enrolled in Medicaid and Commercial Insurance Plans.

PubMed

Patel, Chirag G; Tao, Guoyu

2015-10-01

The impact of length of enrollment in a health plan on eligibility of women under the Healthcare Effectiveness Data and Information Set (HEDIS) chlamydia screening measure is not fully understood. We assessed the representativeness of the measure among the proportion of women aged 15 to 24 years with a gap in coverage for Medicaid and commercial health insurance. Truven Health Marketscan Medicaid and commercial health insurance data from 2006 to 2012 were used to make comparisons between proportions of women with a gap in coverage to those enrolled in insurance plans for different numbers of months. Approximately 48% of Medicaid-insured women and 31% of commercially insured women had an at least 2-month gap that disqualified them from eligibility for inclusion in the HEDIS chlamydia screening measure. Extending eligibility to women with at least 6 months of coverage, regardless of gap, would increase the proportion of insured women included in the HEDIS measure to 76% (from 52%) for Medicaid and 83% (from 69%) for commercial insurance, without much effect on chlamydia testing rate. This would make the measure more representative of all insured women. The large proportion of young women who had a 2-month or greater gap in coverage in Medicaid had a significant impact on the overall representativeness of the current HEDIS chlamydia screening measure.

Flexible piezoelectric nanogenerators based on a transferred ZnO nanorod/Si micro-pillar array

NASA Astrophysics Data System (ADS)

Baek, Seong-Ho; Park, Il-Kyu

2017-03-01

Flexible piezoelectric nanogenerators (PNGs) based on a composite of ZnO nanorods (NRs) and an array of Si micro-pillars (MPs) are demonstrated by a transfer process. The flexible composite structure was fabricated by hydrothermal growth of ZnO NRs on an electrochemically etched Si MP array with various lengths followed by mechanically delaminating the Si MP arrays from the Si substrate after embedding them in a polydimethylsiloxane matrix. Because the Si MP arrays act as a supporter to connect the ZnO NRs electrically and mechanically, verified by capacitance measurement, the output voltage from the flexible PNGs increased systematically with the increased density ZnO NRs depending on the length of the Si MPs. The flexible PNGs showed 3.2 times higher output voltage with a small change in current with increasing Si MP length from 5 to 20 μm. The enhancement of the output voltage is due to the increased number of series-connected ZnO NRs and the beneficial effect of a ZnO NR/Si MP heterojunction on reducing free charge screening effects. The flexible PNGs can be attached on fingers as a wearable electrical power source or motion sensor.

A Platform for Gastric Cancer Screening in Low- and Middle-Income Countries

PubMed Central

Caprara, Robert; Obstein, Keith L.; Scozzarro, Gabriel; Natali, Christian Di; Beccani, Marco; Morgan, Douglas R.; Valdastri, Pietro

2015-01-01

Gastric cancer is the second leading cause of cancer death worldwide and screening programs have had a significant impact on reducing mortality. The majority of cases occur in low- and middle-income countries (LMIC), where endoscopy resources are traditionally limited. In this paper, we introduce a platform designed to enable inexpensive gastric screening to take place in remote areas of LMIC. The system consists of a swallowable endoscopic capsule connected to an external water distribution system by a multi-channel soft tether. Pressurized water is ejected from the capsule to orient the view of the endoscopic camera. After completion of a cancer screening procedure, the outer shell of the capsule and the soft tether can be disposed, while the endoscopic camera is reclaimed without needing further reprocessing. The capsule, measuring 12 mm in diameter and 28 mm in length, is able to visualize the inside of the gastric cavity by combining waterjet actuation and the adjustment of the tether length. Experimental assessment was accomplished through a set of bench trials, ex vivo analysis, and in vivo feasibility validation. During the ex vivo trials, the platform was able to visualize the main landmarks that are typically observed during a gastric cancer screening procedure in less than 8 minutes. Given the compact footprint, the minimal cost of the disposable parts, and the possibility of running on relatively available and inexpensive resources, the proposed platform can potentially widen gastric cancer screening programs in LMIC. PMID:25561586

The Top 10 Greatest Screen Legends and What Their Definitive Roles Demonstrate about Management and Organizational Behaviour

ERIC Educational Resources Information Center

Dunphy, Steve; Meyer, David; Linton, Sara

2008-01-01

Those interested in using multimedia films for the purpose of illustrating, critiquing and even correcting behavior in organizations face a daunting array of choices from training films to television to full length movies. The authors suggest that the top screen "legends" of Hollywood and their definitive roles should be considered as an…

Nutritional screening for improving professional practice for patient outcomes in hospital and primary care settings.

PubMed

Omidvari, Amir-Houshang; Vali, Yasaman; Murray, Susan M; Wonderling, David; Rashidian, Arash

2013-06-06

Given the prevalence of under-nutrition and reports of inadequate nutritional management of patients in hospitals and the community, nutritional screening may play a role in reducing the risks of malnutrition. Screening programmes can invoke costs to health systems and patients. It is therefore important to assess the effectiveness of nutritional screening programmes. To examine the effectiveness of nutritional screening in improving quality of care (professional practice) and patient outcomes compared with usual care. We searched the following databases: CENTRAL (The Cochrane Library), MEDLINE, EMBASE and CINAHL up to June 2012 to find relevant studies. Randomised controlled studies, controlled clinical trials, controlled before-after studies and interrupted time series studies assessing the effectiveness of nutritional screening were eligible for inclusion in the review. We considered process outcomes (for example patient identification, referral to dietitian) and patient outcomes (for example mortality, change in body mass index (BMI)). Participants were adult patients aged 16 years or over. We included studies conducted in different settings, including hospitals, out-patient clinics, primary care or long term care settings. We independently assessed the risk of bias and extracted data from the included studies. Meta-analysis was considered but was not conducted due to the discrepancies between the studies. The studies were heterogeneous in their design, setting, intervention and outcomes. We analysed the data using a narrative synthesis approach. After conducting initial searches and screening the titles and abstracts of the identified literature, 77 full text papers were retrieved and read. Ultimately three studies were included. Two controlled before-after studies were conducted in hospital settings (one in the UK and one in the Netherlands) and one cluster randomised controlled trial was conducted in a primary care setting (in the USA).The study conducted in primary care reported that physicians were receptive to the screening intervention, but the intervention did not result in any improvements in the malnutrition detection rate or nutritional intervention rate. The two studies conducted in hospitals had important methodological limitations. One study reported that as a result of the intervention, the recording of patients' weight increased in the intervention wards. No significant changes were observed in the referral rates to dietitians or care at meal time. The third study reported weight gains and a reduction in hospital acquired infection rate in the intervention hospital. They found no significant differences in length of stay, pressure sores, malnutrition and treatment costs per patient between the two hospitals. Current evidence is insufficient to support the effectiveness of nutritional screening, although equally there is no evidence of no effect. Therefore, more high quality studies should be conducted to assess the effectiveness of nutritional screening in different settings.

Large divalent cations and electrostatic potentials adjacent to membranes. Experimental results with hexamethonium.

PubMed Central

Alvarez, O; Brodwick, M; Latorre, R; McLaughlin, A; McLaughlin, S; Szabo, G

1983-01-01

A simple extension of the Gouy-Chapman theory predicts that the ability of a divalent cation to screen charges at a membrane-solution interface decreases significantly if the distance between the charges on the cation is comparable with the Debye length. We tested this prediction by investigating the effect of hexamethonium on the electrostatic potential adjacent to negatively charged phospholipid bilayer membranes. The distance between the two charges of an extended hexamethonium molecule is approximately 1 nm, which is the Debye length in the 0.1 M monovalent salt solutions used in these experiments. Six different experimental approaches were utilized. We measured the electrophoretic mobility of multilamellar vesicles to determine the zeta potential, the line width of the 31P nuclear magnetic resonance (NMR) signal from sonicated vesicles to calculate the change in potential at the phosphodiester moiety of the lipid, and the conductance of planar bilayer membranes exposed to either carriers (nonactin) or pore formers (gramicidin) to estimate the change in potential within the membrane. We also measured directly the effect of hexamethonium on the potential above a monolayer formed from negative lipids, and attempted to calculate the change in the surface potential of a bilayer membrane from capacitance measurements. With the exception of the capacitance calculations, each of the techniques gave comparable results: hexamethonium exerts a smaller effect on the potential than that predicted by the classic screening theory. The results are consistent with the predictions of the extended Gouy-Chapman theory and are relevant to the interpretation of physiological and pharmacological experiments that utilize hexamethonium and other large divalent cations. PMID:6198001

Determination of a correction factor for the interaction potential of He + ions backscattered from a Cu(1 0 0) surface

NASA Astrophysics Data System (ADS)

Draxler, M.; Walker, M.; McConville, C. F.

2006-08-01

We have used coaxial impact collision ion scattering spectroscopy (CAICISS) data collected from 3 keV He+ ions backscattered from a Cu(1 0 0) surface in different azimuthal orientations to investigate the influence of the screening length on CAICISS polar angle scans. We have compared the experimental data to computer simulations generated with the FAN code and found that for our experimental conditions an exceptionally low value of 0.53 was required for the correction factor to the Firsov screening length used with the Thomas-Fermi-Moliere potential. In addition we found that the Ziegler-Biersack-Littmark potential is not applicable, resulting in incorrect peak positions in the CAICISS polar angle plots.

Terahertz and Optical Measurement Apparatus for the Fermilab ASTA Injector

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thurman-Keup, R.; Lumpkin, A. H.; Thangaraj, J.

2014-01-01

ASTA is a facility at Fermilab that, once completed, will consist of a photoinjector with two superconducting capture cavities, at least one superconducting ILC-style cryomodule, and a small ring for studying non-linear, integrable beam optics. This paper discusses the layout for the optical transport system that will provide THz radiation to a Martin-Puplett interferometer for bunch length measurements as well as optical radiation to an externally located streak camera, also for bunch length measurements. It will be able to accept radiation from two synchrotron radiation ports in the bunch compressor, a diffraction/transition radiation screen downstream of the compressor, and amore » transition radiation screen after the spectrometer magnet for measurements of energy-time correlations.« less

Correlation potential of a test ion near a strongly charged plate.

PubMed

Lu, Bing-Sui; Xing, Xiangjun

2014-03-01

We analytically calculate the correlation potential of a test ion near a strongly charged plate inside a dilute m:-n electrolyte. We do this by calculating the electrostatic Green's function in the presence of a nonlinear background potential, the latter having been obtained using the nonlinear Poisson-Boltzmann theory. We consider the general case where the dielectric constants of the plate and the electrolyte are distinct. The following generic results emerge from our analyses: (1) If the distance to the plate Δz is much larger than a Gouy-Chapman length, the plate surface will behave effectively as an infinitely charged surface, and the dielectric constant of the plate effectively plays no role. (2) If Δz is larger than a Gouy-Chapman length but shorter than a Debye length, the correlation potential can be interpreted in terms of an image charge that is three times larger than the source charge. This behavior is independent of the valences of the ions. (3) The Green's function vanishes inside the plate if the surface charge density is infinitely large; hence the electrostatic potential is constant there. In this respect, a strongly charged plate behaves like a conductor plate. (4) If Δz is smaller than a Gouy-Chapman length, the correlation potential is dominated by the conventional image charge due to the dielectric discontinuity at the interface. (5) If Δz is larger than a Debye length, the leading order behavior of the correlation potential will depend on the valences of the ions in the electrolyte. Furthermore, inside an asymmetric electrolyte, the correlation potential is singly screened, i.e., it undergoes exponential decay with a decay width equal to the Debye length.

Nanoconfined ionic liquids: Disentangling electrostatic and viscous forces

NASA Astrophysics Data System (ADS)

Lhermerout, Romain; Perkin, Susan

2018-01-01

Recent reports of surface forces across nanoconfined ionic liquids have revealed the existence of an anomalously long-ranged interaction apparently of electrostatic origin. Ionic liquids are viscous, and therefore it is important to inspect rigorously whether the observed repulsive forces are indeed equilibrium forces or, rather, arise from the viscous force during drainage of the fluid between two confining surfaces. In this paper we present our direct measurements of surface forces between mica sheets approaching in the ionic liquid [C2C1Im ] [NTf2] , exploring three orders of magnitude in approach velocity. Trajectories are systematically fitted by solving the equation of motion, allowing us to disentangle the viscous and equilibrium contributions. First, we find that the drainage obeys classical hydrodynamics with a negative slip boundary condition in the range of the structural force, implying that a nanometer -thick portion of the liquid in the vicinity of the solid surface is composed of ordered molecules that do not contribute to the flow. Second, we show that a long-range static force must indeed be invoked, in addition to the viscous force, in order to describe the data quantitatively. This equilibrium interaction decays exponentially and with decay length in agreement with the screening length reported for the same system in previous studies. In those studies the decay was simply checked to be independent of velocity and measured at a low approach rate, rather than explicitly taking account of viscous effects: we explain why this gives indistinguishable outcomes for the screening length by noting that the viscous force is linear to very good approximation over a wide range of distances.

Integrating preconcentrator heat controller

DOEpatents

Bouchier, Francis A.; Arakaki, Lester H.; Varley, Eric S.

2007-10-16

A method and apparatus for controlling the electric resistance heating of a metallic chemical preconcentrator screen, for example, used in portable trace explosives detectors. The length of the heating time-period is automatically adjusted to compensate for any changes in the voltage driving the heating current across the screen, for example, due to gradual discharge or aging of a battery. The total deposited energy in the screen is proportional to the integral over time of the square of the voltage drop across the screen. Since the net temperature rise, .DELTA.T.sub.s, of the screen, from beginning to end of the heating pulse, is proportional to the total amount of heat energy deposited in the screen during the heating pulse, then this integral can be calculated in real-time and used to terminate the heating current when a pre-set target value has been reached; thereby providing a consistent and reliable screen temperature rise, .DELTA.T.sub.s, from pulse-to-pulse.

Promoting Declines in the Prevalence of Late-Life Disability: Comparisons of Three Potentially High-Impact Interventions

PubMed Central

Freedman, Vicki A; Hodgson, Nancy; Lynn, Joanne; Spillman, Brenda C; Waidmann, Timothy; Wilkinson, Anne M; Wolf, Douglas A

2006-01-01

Although the prevalence of late-life disability has been declining, how best to promote further reductions remains unclear. This article develops and then demonstrates an approach for comparing the effects of interventions on the prevalence of late-life disability. We review evidence for three potentially high-impact strategies: physical activity, depression screening and treatment, and fall prevention. Because of the large population at risk for falling, the demonstrated efficacy of multi-component interventions in preventing falls, and the strong links between falls and disability, we conclude that, in the short run, multi-component fall-prevention efforts would likely have a higher impact than either physical activity or depression screening and treatment. However, longer-term comparisons cannot be made based on the current literature and may differ from short-run conclusions, since increases in longevity may temper the influences of these interventions on prevalence. Additional research is needed to evaluate longer-term outcomes of interventions, including effects on length and quality of life. PMID:16953808

Mother-Daughter Dyad Recruitment and Cancer Intervention Challenges in an African American Sample

PubMed Central

Mosavel, Maghboeba; Ports, Katie; Leighton-Herrmann, Ellyn

2014-01-01

Developing an effective youth-based health messaging intervention for African American women, who remain disparately impacted by cancer, presents unique challenges. This paper reports on the challenges with recruiting familial dyads from predominantly low-income, African American neighborhoods, as well as the challenges associated with designing and implementing an upward-directed cancer screening intervention. We developed and pilot tested an educational workshop that provided adolescents with cancer screening information to share with their mother or female relative. Data from follow-up interviews and focus groups, as well as observation records regarding implementation obstacles highlight important lessons learned. The use of familial dyads as well as issues of access posed challenges for recruitment and follow-up. Workshop-related challenges stemmed from the approach, content and length. Finally, personal and environmental factors presented barriers to adolescent message delivery and adult follow-through. By identifying these challenges, we hope to influence and enable the future development of effective adolescent-initiated health messaging interventions. PMID:25489496

Evaluating the Effect of Peptoid Lipophilicity on Antimicrobial Potency, Cytotoxicity, and Combinatorial Library Design.

PubMed

Turkett, Jeremy A; Bicker, Kevin L

2017-04-10

Growing prevalence of antibiotic resistant bacterial infections necessitates novel antimicrobials, which could be rapidly identified from combinatorial libraries. We report the use of the peptoid library agar diffusion (PLAD) assay to screen peptoid libraries against the ESKAPE pathogens, including the optimization of assay conditions for each pathogen. Work presented here focuses on the tailoring of combinatorial peptoid library design through a detailed study of how peptoid lipophilicity relates to antibacterial potency and mammalian cell toxicity. The information gleaned from this optimization was then applied using the aforementioned screening method to examine the relative potency of peptoid libraries against Staphylococcus aureus, Acinetobacter baumannii, and Enterococcus faecalis prior to and following functionalization with long alkyl tails. The data indicate that overall peptoid hydrophobicity and not simply alkyl tail length is strongly correlated with mammalian cell toxicity. Furthermore, this work demonstrates the utility of the PLAD assay in rapidly evaluating the effect of molecular property changes in similar libraries.

Comparative cost-effectiveness of HPV vaccines in the prevention of cervical cancer in Malaysia.

PubMed

Ezat, Sharifa W P; Aljunid, Syed

2010-01-01

Cervical cancer (CC) had the second highest incidence of female cancers in Malaysia in 2003-2006. Prevention is possible by both Pap smear screening and HPV vaccination with either the bivalent vaccine (BV) or the quadrivalent vaccine (QV). In the present study, cost effectiveness options were compared for three programs i.e. screening via Pap smear; modeling of HPV vaccination (QV and BV) and combined strategy (screening plus vaccination). A scenario based sensitivity analysis was conducted using screening population coverages (40-80%) and costs of vaccines (RM 100-200/dose) were calculated. This was an economic burden, cross sectional study in 2006-2009 of respondents interviewed from six public Gynecology-Oncology hospitals. Methods included expert panel discussions to estimate treatment costs of CC, genital warts and vulva/vagina cancers by severity and direct interviews with respondents using costing and SF-36 quality of life questionnaires. A total of 502 cervical cancer patients participated with a mean age at 53.3±11.2 years and a mean marriage length of 27.7±12.1 years, Malays accounting for 44.2%. Cost/quality adjusted life year (QALY) for Pap smear in the base case was RM 1,215 and RM 1,100 at increased screening coverage. With QV only, in base case it was RM 15,662 and RM 24,203 when the vaccination price was increased. With BV only, the respective figures were RM 1,359,057 and RM 2,530,018. For QV combined strategy cost/QALY in the base case it was RM 4,937, reducing to RM 3,395 in the best case and rising to RM 7,992 in the worst case scenario. With the BV combined strategy, these three cost/QALYs were RM 6,624, RM 4,033 and RM 10,543. Incremental cost-effectiveness ratio (ICER) showed that screening at 70% coverage or higher was highly cost effective at RM 946.74 per QALYs saved but this was preceded by best case combined strategy with QV at RM 515.29 per QALYs saved. QV is more cost effective than BV. The QV combined strategy had a higher CE than any method including Pap smear screening at high population coverage.

Lung cancers diagnosed at annual CT screening: volume doubling times.

PubMed

Henschke, Claudia I; Yankelevitz, David F; Yip, Rowena; Reeves, Anthony P; Farooqi, Ali; Xu, Dongming; Smith, James P; Libby, Daniel M; Pasmantier, Mark W; Miettinen, Olli S

2012-05-01

To empirically address the distribution of the volume doubling time (VDT) of lung cancers diagnosed in repeat annual rounds of computed tomographic (CT) screening in the International Early Lung Cancer Action Program (I-ELCAP), first and foremost with respect to rates of tumor growth but also in terms of cell types. All CT screenings in I-ELCAP from 1993 to 2009 were performed according to HIPAA-compliant protocols approved by the institutional review boards of the collaborating institutions. All instances of first diagnosis of primary lung cancer after a negative screening result 7-18 months earlier were identified, with symptom-prompted diagnoses included. Lesion diameter was calculated by using the measured length and width of each cancer at the time when the nodule was first identified for further work-up and at the time of the most recent prior screening, 7-18 months earlier. The length and width were measured a second time for each cancer, and the geometric mean of the two calculated diameters was used to calculate the VDT. The χ(2) statistic was used to compare the VDT distributions. The median VDT for 111 cancers was 98 days (interquartile range, 108). For 56 (50%) cancers it was less than 100 days, and for three (3%) cancers it was more than 400 days. Adenocarcinoma was the most frequent cell type (50%), followed by squamous cell carcinoma (19%), small cell carcinoma (19%), and others (12%). Lung cancers manifesting as subsolid nodules had significantly longer VDTs than those manifesting as solid nodules (P < .0001). Lung cancers diagnosed in annual repeat rounds of CT screening, as manifest by the VDT and cell-type distributions, are similar to those diagnosed in the absence of screening.

An integral transform approach for a mixed boundary problem involving a flowing partially penetrating well with infinitesimal well skin

NASA Astrophysics Data System (ADS)

Chang, Chien-Chieh; Chen, Chia-Shyun

2002-06-01

A flowing partially penetrating well with infinitesimal well skin is a mixed boundary because a Cauchy condition is prescribed along the screen length and a Neumann condition of no flux is stipulated over the remaining unscreened part. An analytical approach based on the integral transform technique is developed to determine the Laplace domain solution for such a mixed boundary problem in a confined aquifer of finite thickness. First, the mixed boundary is changed into a homogeneous Neumann boundary by substituting the Cauchy condition with a Neumann condition in terms of well bore flux that varies along the screen length and is time dependent. Despite the well bore flux being unknown a priori, the modified model containing this homogeneous Neumann boundary can be solved with the Laplace and the finite Fourier cosine transforms. To determine well bore flux, screen length is discretized into a finite number of segments, to which the Cauchy condition is reinstated. This reinstatement also restores the relation between the original model and the solutions obtained. For a given time, the numerical inversion of the Laplace domain solution yields the drawdown distributions, well bore flux, and the well discharge. This analytical approach provides an alternative for dealing with the mixed boundary problems, especially when aquifer thickness is assumed to be finite.

A rapid, controlled-environment seedling root screen for wheat correlates well with rooting depths at vegetative, but not reproductive, stages at two field sites

PubMed Central

Watt, M.; Moosavi, S.; Cunningham, S. C.; Kirkegaard, J. A.; Rebetzke, G. J.; Richards, R. A.

2013-01-01

Background and Aims Root length and depth determine capture of water and nutrients by plants, and are targets for crop improvement. Here we assess a controlled-environment wheat seedling screen to determine speed, repeatability and relatedness to performance of young and adult plants in the field. Methods Recombinant inbred lines (RILs) and diverse genotypes were grown in rolled, moist germination paper in growth cabinets, and primary root number and length were measured when leaf 1 or 2 were fully expanded. For comparison, plants were grown in the field and root systems were harvested at the two-leaf stage with either a shovel or a soil core. From about the four-leaf stage, roots were extracted with a steel coring tube only, placed directly over the plant and pushed to the required depth with a hydraulic ram attached to a tractor. Key Results In growth cabinets, repeatability was greatest (r = 0·8, P < 0·01) when the paper was maintained moist and seed weight, pathogens and germination times were controlled. Scanned total root length (slow) was strongly correlated (r = 0·7, P < 0·01) with length of the two longest seminal axile roots measured with a ruler (fast), such that 100–200 genotypes were measured per day. Correlation to field-grown roots at two sites at two leaves was positive and significant within the RILs and cultivars (r = 0·6, P = 0·01), and at one of the two sites at the five-leaf stage within the RILs (r = 0·8, P = 0·05). Measurements made in the field with a shovel or extracted soil cores were fast (5 min per core) and had significant positive correlations to scanner measurements after root washing and cleaning (>2 h per core). Field measurements at two- and five-leaf stages did not correlate with root depth at flowering. Conclusions The seedling screen was fast, repeatable and reliable for selecting lines with greater total root length in the young vegetative phase in the field. Lack of significant correlation with reproductive stage root system depth at the field sites used in this study reflected factors not captured in the screen such as time, soil properties, climate variation and plant phenology. PMID:23821620

Dual-Screened Vertical Circulation Wells for Groundwater Lowering in Unconfined Aquifers.

PubMed

Jin, Yulan; Holzbecher, Ekkehard; Sauter, Martin

2016-01-01

A new type of vertical circulation well (VCW) is used for groundwater dewatering at construction sites. This type of VCW consists of an abstraction screen in the upper part and an injection screen in the lower part of a borehole, whereby drawdown is achieved without net withdrawal of groundwater from the aquifer. The objective of this study is to evaluate the operation of such wells including the identification of relevant factors and parameters based on field data of a test site and comprehensive numerical simulations. The numerical model is able to delineate the drawdown of groundwater table, defined as free-surface, by coupling the arbitrary Lagrangian-Eulerian algorithm with the groundwater flow equation. Model validation is achieved by comparing the field observations with the model results. Eventually, the influences of selected well operation and aquifer parameters on drawdown and on the groundwater flow field are investigated by means of parameter sensitivity analysis. The results show that the drawdown is proportional to the flow rate, inversely proportional to the aquifer conductivity, and almost independent of the aquifer anisotropy in the direct vicinity of the well. The position of the abstraction screen has a stronger effect on drawdown than the position of the injection screen. The streamline pattern depends strongly on the separation length of the screens and on the aquifer anisotropy, but not on the flow rate and the horizontal hydraulic conductivity. © 2015, National Ground Water Association.

Costs and possible benefits of a two-tier infection control management strategy consisting of active screening for multidrug-resistant organisms and tailored control measures.

PubMed

Mutters, N T; Günther, F; Frank, U; Mischnik, A

2016-06-01

Multidrug-resistant organisms (MDROs) are an economic burden, and infection control (IC) measures are cost- and labour-intensive. A two-tier IC management strategy was developed, including active screening, in order to achieve effective use of limited resources. Briefly, high-risk patients were differentiated from other patients, distinguished according to type of MDRO, and IC measures were implemented accordingly. To evaluate costs and benefits of this IC management strategy. The study period comprised 2.5 years. All high-risk patients underwent microbiological screening. Gram-negative bacteria (GNB) were classified as multidrug-resistant (MDR) and extensively drug-resistant (XDR). Expenses consisted of costs for staff, materials, laboratory, increased workload and occupational costs. In total, 39,551 patients were screened, accounting for 24.5% of all admissions. Of all screened patients, 7.8% (N=3,104) were MDRO positive; these patients were mainly colonized with vancomycin-resistant enterococci (37.3%), followed by meticillin-resistant Staphylococcus aureus (30.3%) and MDR-GNB (28.3%). The median length of stay (LOS) for all patients was 10 days (interquartile range 3-20); LOS was twice as long in colonized patients (P<0.001). Screening costs totalled 255,093.82€, IC measures cost 97,701.36€, and opportunity costs were 599,225.52€. The savings of this IC management strategy totalled 500,941.84€. Possible transmissions by undetected carriers would have caused additional costs of 613,648.90-4,974,939.26€ (i.e. approximately 600,000-5 million €). Although the costs of a two-tier IC management strategy including active microbiological screening are not trivial, these data indicate that the approach is cost-effective when prevented transmissions are included in the cost estimate. Copyright © 2016 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Two-Step Process for ED UTI Screening in Febrile Young Children: Reducing Catheterization Rates.

PubMed

Lavelle, Jane M; Blackstone, Mercedes M; Funari, Mary Kate; Roper, Christine; Lopez, Patricia; Schast, Aileen; Taylor, April M; Voorhis, Catherine B; Henien, Mira; Shaw, Kathy N

2016-07-01

Urinary tract infection (UTI) screening in febrile young children can be painful and time consuming. We implemented a screening protocol for UTI in a high-volume pediatric emergency department (ED) to reduce urethral catheterization, limiting catheterization to children with positive screens from urine bag specimens. This quality-improvement initiative was implemented using 3 Plan-Do-Study-Act cycles, beginning with a small test of the proposed change in 1 ED area. To ensure appropriate patients received timely screening, care teams discussed patient risk factors and created patient-specific, appropriate procedures. The intervention was extended to the entire ED after providing education. Finally, visual cues were added into the electronic health record, and nursing scripts were developed to enlist family participation. A time-series design was used to study the impact of the 6-month intervention by using a p-chart to determine special cause variation. The primary outcome measure for the study was defined as the catheterization rate in febrile children ages 6 to 24 months. The ED reduced catheterization rates among febrile young children from 63% to <30% over a 6-month period with sustained results. More than 350 patients were spared catheterization without prolonging ED length of stay. Additionally, there was no change in the revisit rate or missed UTIs among those followed within the hospital's network. A 2-step less-invasive process for screening febrile young children for UTI can be instituted in a high-volume ED without increasing length of stay or missing cases of UTI. Copyright © 2016 by the American Academy of Pediatrics.

Early life factors and type 2 diabetes in south India: Do the associations change with age?

PubMed

Veena, Sargoor R; Wills, Andrew K; Fisher, David J; Stein, Claudia E; Kumaran, Kalyanaraman; Krishnaveni, Ghattu V; Kiran, Krishnarajasagara N; Coakley, Patsy J; Fall, Caroline H D

2009-09-01

Studies since the early 1990s have shown that birth size can be a predictor of the development of Type 2 diabetes mellitus (T2DM). In the present study, we evaluated changes in the strength of associations between T2DM and birth size and maternal weight with age. In 1993-1994 (t₀), 509 men and women (mean age 46 years) who had been born in Holdsworth Memorial Hospital were screened for diabetes, with increased diabetes risk identified in those who were shorter at birth and those born to heavier mothers. Ten years later (t₁₀), the screening was repeated in 266 subjects who were non-diabetic at t₀ (70% of survivors).   At t₁₀, 56 new cases of diabetes were found. The incidence of diabetes decreased with increasing birth length (odds ratio (OR) = 0.90, 95% confidence interval (CI) 0.84-0.97/cm birth length; P = 0.006) after adjustment for sex, age, socioeconomic status, family history, and current body mass index. Overall, there were no significant differences in OR for the association between birth length and diabetes at t₀ compared with t₁₀, but limiting analysis to subjects with normal glucose tolerance at t₀ resulted in a stronger association at t₁₀ (OR = 0.71, 95% CI 0.58-0.87) than at t₀ (OR = 0.95, 95% CI 0.86-1.05; P = 0.015 for the difference). There was a positive correlation between maternal weight and incident disease at t₀ (OR = 1.08, 95% CI 1.03-1.14; P = 0.001), but not at t₁₀ (OR = 0.98/kg, 95% CI 0.92-1.05; P = 0.6; P = 0.02 for the difference).   Short birth length remains a risk factor for diabetes. Changes in the effects of birth length and maternal weight on diabetes risk with age may indicate different causal pathways. These findings require replication in studies with more accurate dating of the onset of diabetes. © 2009 Ruijin Hospital, Shanghai Jiaotong University School of Medicine and Blackwell Publishing Asia Pty Ltd.

Hospital Malnutrition: Prevalence, Identification and Impact on Patients and the Healthcare System

PubMed Central

Barker, Lisa A.; Gout, Belinda S.; Crowe, Timothy C.

2011-01-01

Malnutrition is a debilitating and highly prevalent condition in the acute hospital setting, with Australian and international studies reporting rates of approximately 40%. Malnutrition is associated with many adverse outcomes including depression of the immune system, impaired wound healing, muscle wasting, longer lengths of hospital stay, higher treatment costs and increased mortality. Referral rates for dietetic assessment and treatment of malnourished patients have proven to be suboptimal, thereby increasing the likelihood of developing such aforementioned complications. Nutrition risk screening using a validated tool is a simple technique to rapidly identify patients at risk of malnutrition, and provides a basis for prompt dietetic referrals. In Australia, nutrition screening upon hospital admission is not mandatory, which is of concern knowing that malnutrition remains under-reported and often poorly documented. Unidentified malnutrition not only heightens the risk of adverse complications for patients, but can potentially result in foregone reimbursements to the hospital through casemix-based funding schemes. It is strongly recommended that mandatory nutrition screening be widely adopted in line with published best-practice guidelines to effectively target and reduce the incidence of hospital malnutrition. PMID:21556200

Effects of Diagnosis by Newborn Screening for Cystic Fibrosis on Weight and Length in the First Year of Life.

PubMed

Leung, Daniel H; Heltshe, Sonya L; Borowitz, Drucy; Gelfond, Daniel; Kloster, Margaret; Heubi, James E; Stalvey, Michael; Ramsey, Bonnie W

2017-06-01

Since the implementation of universal newborn screening (NBS) for cystic fibrosis (CF), the timing and magnitude of growth deficiency or its association with correlates of disease among infants with CF who underwent NBS has not been well described. To examine incremental weight gain, linear growth, and clinical features in the first year of life among infants with CF who underwent NBS. The Baby Observational and Nutrition Study (BONUS), a multicenter, longitudinal, observational cohort study, was conducted during regular CF clinic visits in the first 12 months of life at 28 US Cystic Fibrosis Foundation-accredited Care Centers from January 7, 2012, through May 31, 2015. Participants included 231 infants younger than 3.5 months who underwent NBS and had confirmed CF, with a gestational age of at least 35 weeks, birth weight of at least 2.5 kg, and toleration of full oral feeds. Of these, 222 infants (96.1%) had follow-up beyond 6 months of age and 215 (93.1%) completed 12 months of follow-up. Cystic fibrosis. Attained weight and length for age and World Health Organization normative z scores at ages 1 to 6 and 8, 10, and 12 months (defined a priori). Of the 231 infants enrolled, 110 infants (47.6%) were female and 121 (52.4%) were male, with a mean (SD) age of 2.58 (0.69) months. BONUS infants had lower than mean birth weights (mean z score, -0.15; 95% CI, -0.27 to -0.04) and higher birth lengths (mean z score, 0.44; 95% CI, 0.26 to 0.62). They achieved normal weight by 12 months, a significant improvement over a prescreening cohort of newborns with CF from 20 years before the contemporary cohort (mean z score increase, 0.57; 95% CI, 0.37-0.77). However, length was lower than the mean at 12 months (mean z score, -0.56; 95% CI, -0.70 to -0.42). Only 30 infants (13.6%) were at less than the 10th percentile of weight for age, whereas 53 (23.9%) were at less than the 10th percentile of length for age at more than half their visits. Male sex, pancreatic insufficiency, meconium ileus, histamine blocker use, and respiratory Pseudomonas aeruginosa infection were associated with lower weight or length during the first year. Insulinlike growth factor 1 levels were significantly lower among low-length infants. Persistently low-weight infants consumed significantly more calories, and weight and length z scores were negatively correlated with caloric intake. Since initiation of universal NBS for CF, significant improvement has occurred in nutritional status, with normalization of weight in the first year of life. However, length stunting remains common.

Effect of specialized diagnostic assessment units on the time to diagnosis in screen-detected breast cancer patients.

PubMed

Jiang, L; Gilbert, J; Langley, H; Moineddin, R; Groome, P A

2015-05-26

The duration of the cancer diagnostic process has considerable influence on patients' psychosocial well-being. Breast diagnostic assessment units (DAUs) in Ontario, Canada are designed to improve the quality and timeliness of care during a breast cancer diagnosis. We compared the diagnostic duration of patients diagnosed through a DAU vs usual care (UC). Retrospective population-based cohort study of 2499 screen-detected breast cancers (2011) using administrative health-care databases linked to the Ontario Cancer Registry. The diagnostic interval was measured from the initial screen to cancer diagnosis. Diagnostic assessment unit use was based on the biopsy and/or surgery hospital. We compared the length of the diagnostic interval between the DAU groups using multivariable quantile regression. Diagnostic assessment units had a higher proportion of patients diagnosed within the 7-week target compared with UC (79.1% vs 70.2%, P<0.001). The median time to diagnosis at DAUs was 26 days, which was 9 days shorter compared with UC (95% CI: 6.4-11.6). This effect was reduced to 8.3 days after adjusting for all study covariates. Adjusted DAU differences were similar at the 75th and 90th percentiles of the diagnostic interval distribution. Diagnosis through an Ontario DAU was associated with a reduced time to diagnosis for screen-detected breast cancer patients, which likely reduces the anxiety and distress associated with waiting for a diagnosis.

High-speed spectral nanocytology for early cancer screening

PubMed Central

Subramanian, Hariharan; Maneval, Charles D.; White, Craig A.; Levenson, Richard M.; Backman, Vadim

2013-01-01

Abstract. High-throughput partial wave spectroscopy (HTPWS) is introduced as a high-speed spectral nanocytology technique that utilizes the field effect of carcinogenesis to perform minimally invasive cancer screening on at-risk populations. HTPWS uses fully automated hardware and an acousto-optic tunable filter to scan slides at low magnification, to select cells, and to rapidly acquire spectra at each spatial pixel in a cell between 450 and 700 nm, completing measurements of 30 cells in 40 min. Statistical quantitative analysis on the size and density of intracellular nanostructures extracted from the spectra at each pixel in a cell yields the diagnostic biomarker, disorder strength (Ld). Linear correlation between Ld and the length scale of nanostructures was measured in phantoms with R2=0.93. Diagnostic sensitivity was demonstrated by measuring significantly higher Ld from a human colon cancer cell line (HT29 control vector) than a less aggressive variant (epidermal growth factor receptor knockdown). Clinical diagnostic performance for lung cancer screening was tested on 23 patients, yielding a significant difference in Ld between smokers and cancer patients, p=0.02 and effect size=1.00. The high-throughput performance, nanoscale sensitivity, and diagnostic sensitivity make HTPWS a potentially clinically relevant modality for risk stratification of the large populations at risk of developing cancer. PMID:24193949

Immunomagnetic Nano-Screening Chip for Circulating Tumor Cells Detection in Blood

NASA Astrophysics Data System (ADS)

Horton, A. P.; Lane, N.; Tam, J.; Sokolov, K.; Garner, H. R.; Uhr, J. W.; Zhang, X. J.

2010-03-01

We present a novel method towards diagnose cancer at an early stage via a blood test. Early diagnosis is high on the future agenda of oncologists because of significant evidence that it will result in a higher cure rate. Capture of circulating tumor cells (CTCs) which are known to escape from carcinomas at an early stage offers such an opportunity. We design, fabricate and optimize the nanomagnetic-screening chip that captures the CTCs in microfluid, and further integrate the nano-chip with the new multispectral imaging system so that it can quantify different tumor markers and automate the entire instrument. Specifically, hybrid plasmonic (Fe2O3-core Au shell) nanoparticles, conjugated a collection of antibodies especially chosen to target breast cancer CTCs, with high magnetic susceptibility will be used for effective immunomagnetic CTC isolation. Greatly increased sensitivity over previous attempts is demonstrated by decreasing the length scale for interactions between the magnetic-nanoparticle-tagged CTCs and the isolative magnetic field, while increasing the effective cross-sectional area over which this interaction takes place. The screening chip is integrated with a novel hyperspectral microscopic imaging (HMI) platform capable of recording the entire emission spectra in a single pass evaluation. The combined system will precisely quantify up to 10 tumor markers on CTCs.

Gas-liquid phase coexistence and crossover behavior of binary ionic fluids with screened Coulomb interactions.

PubMed

Patsahan, O

2014-06-01

We study the effects of an interaction range on the gas-liquid phase diagram and the crossover behavior of a simple model of ionic fluids: an equimolar binary mixture of equisized hard spheres interacting through screened Coulomb potentials which are repulsive between particles of the same species and attractive between particles of different species. Using the collective variables theory, we find explicit expressions for the relevant coefficients of the effective φ{4} Ginzburg-Landau Hamiltonian in a one-loop approximation. Within the framework of this approximation, we calculate the critical parameters and gas-liquid phase diagrams for varying inverse screening length z. Both the critical temperature scaled by the Yukawa potential contact value and the critical density rapidly decrease with an increase of the interaction range (a decrease of z) and then for z<0.05 they slowly approach the values found for a restricted primitive model (RPM). We find that gas-liquid coexistence region reduces with an increase of z and completely vanishes at z≃2.78. Our results clearly show that an increase in the interaction range leads to a decrease of the crossover temperature. For z≃0.01, the crossover temperature is the same as for the RPM.

Rapid and efficient cDNA library screening by self-ligation of inverse PCR products (SLIP).

PubMed

Hoskins, Roger A; Stapleton, Mark; George, Reed A; Yu, Charles; Wan, Kenneth H; Carlson, Joseph W; Celniker, Susan E

2005-12-02

cDNA cloning is a central technology in molecular biology. cDNA sequences are used to determine mRNA transcript structures, including splice junctions, open reading frames (ORFs) and 5'- and 3'-untranslated regions (UTRs). cDNA clones are valuable reagents for functional studies of genes and proteins. Expressed Sequence Tag (EST) sequencing is the method of choice for recovering cDNAs representing many of the transcripts encoded in a eukaryotic genome. However, EST sequencing samples a cDNA library at random, and it recovers transcripts with low expression levels inefficiently. We describe a PCR-based method for directed screening of plasmid cDNA libraries. We demonstrate its utility in a screen of libraries used in our Drosophila EST projects for 153 transcription factor genes that were not represented by full-length cDNA clones in our Drosophila Gene Collection. We recovered high-quality, full-length cDNAs for 72 genes and variously compromised clones for an additional 32 genes. The method can be used at any scale, from the isolation of cDNA clones for a particular gene of interest, to the improvement of large gene collections in model organisms and the human. Finally, we discuss the relative merits of directed cDNA library screening and RT-PCR approaches.

Biomolecular Recognition of Semiconductors and Magnetic Materials to Assemble Nanoparticle Heterostructures

DTIC Science & Technology

2002-01-01

shown that engineered viruses can recognize specific semiconductor surfaces through the selection by combinatorial phage display method. These specific... phage display libraries. The screening method selected for binding affinity of a population of random peptides displayed as part of the pIII minor coat...shorter spacing than expected distance ( M13 phage length: 880 nm) corresponds to the length scale imposed by the phage which formed the tilted

On gel electrophoresis of dielectric charged particles with hydrophobic surface: A combined theoretical and numerical study.

PubMed

Majee, Partha Sarathi; Bhattacharyya, Somnath; Gopmandal, Partha Pratim; Ohshima, Hiroyuki

2018-03-01

A theoretical study on the gel electrophoresis of a charged particle incorporating the effects of dielectric polarization and surface hydrophobicity at the particle-liquid interface is made. A simplified model based on the weak applied field and low charge density assumption is also presented and compared with the full numerical model for a nonpolarizable particle to elucidate the nonlinear effects such as double layer polarization and relaxation as well as surface conduction. The main motivation of this study is to analyze the electrophoresis of the surface functionalized nanoparticle with tunable hydrophobicity or charged fluid drop in gel medium by considering the electrokinetic effects and hydrodynamic interactions between the particle and the gel medium. An effective medium approach, in which the transport in the electrolyte-saturated hydrogel medium is governed by the Brinkman equation, is adopted in the present analysis. The governing electrokinetic equations based on the conservation principles are solved numerically. The Navier-slip boundary condition along with the continuity condition of dielectric displacement are imposed on the surface of the hydrophobic polarizable particle. The impact of the slip length on the electrophoresis is profound for a thinner Debye layer, however, surface conduction effect also becomes significant for a hydrophobic particle. Impact of hydrophobicity and relaxation effects are higher for a larger particle. Dielectric polarization creates a reduction in its electrophoretic propulsion and has negligible impact at the thinner Debye length as well as lower gel screening length. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Light rays and the tidal gravitational pendulum

NASA Astrophysics Data System (ADS)

Farley, A. N. St J.

2018-05-01

Null geodesic deviation in classical general relativity is expressed in terms of a scalar function, defined as the invariant magnitude of the connecting vector between neighbouring light rays in a null geodesic congruence projected onto a two-dimensional screen space orthogonal to the rays, where λ is an affine parameter along the rays. We demonstrate that η satisfies a harmonic oscillator-like equation with a λ-dependent frequency, which comprises terms accounting for local matter affecting the congruence and tidal gravitational effects from distant matter or gravitational waves passing through the congruence, represented by the amplitude, of a complex Weyl driving term. Oscillating solutions for η imply the presence of conjugate or focal points along the rays. A polarisation angle, is introduced comprising the orientation of the connecting vector on the screen space and the phase, of the Weyl driving term. Interpreting β as the polarisation of a gravitational wave encountering the light rays, we consider linearly polarised waves in the first instance. A highly non-linear, second-order ordinary differential equation, (the tidal pendulum equation), is then derived, so-called due to its analogy with the equation describing a non-linear, variable-length pendulum oscillating under gravity. The variable pendulum length is represented by the connecting vector magnitude, whilst the acceleration due to gravity in the familiar pendulum formulation is effectively replaced by . A tidal torque interpretation is also developed, where the torque is expressed as a coupling between the moment of inertia of the pendulum and the tidal gravitational field. Precessional effects are briefly discussed. A solution to the tidal pendulum equation in terms of familiar gravitational lensing variables is presented. The potential emergence of chaos in general relativity is discussed in the context of circularly, elliptically or randomly polarised gravitational waves encountering the null congruence.

On the coupled unsaturated-saturated flow process induced by vertical, horizontal, and slant wells in unconfined aquifers

NASA Astrophysics Data System (ADS)

Liang, Xiuyu; Zhan, Hongbin; Zhang, You-Kuan; Liu, Jin

2017-03-01

Conventional models of pumping tests in unconfined aquifers often neglect the unsaturated flow process. This study concerns the coupled unsaturated-saturated flow process induced by vertical, horizontal, and slant wells positioned in an unconfined aquifer. A mathematical model is established with special consideration of the coupled unsaturated-saturated flow process and the well orientation. Groundwater flow in the saturated zone is described by a three-dimensional governing equation and a linearized three-dimensional Richards' equation in the unsaturated zone. A solution in the Laplace domain is derived by the Laplace-finite-Fourier-transform and the method of separation of variables, and the semi-analytical solutions are obtained using a numerical inverse Laplace method. The solution is verified by a finite-element numerical model. It is found that the effects of the unsaturated zone on the drawdown of a pumping test exist at any angle of inclination of the pumping well, and this impact is more significant in the case of a horizontal well. The effects of the unsaturated zone on the drawdown are independent of the length of the horizontal well screen. The vertical well leads to the largest water volume drained from the unsaturated zone (W) during the early pumping time, and the effects of the well orientation on W values become insignificant at the later time. The screen length of the horizontal well does not affect W for the whole pumping period. The proposed solutions are useful for the parameter identification of pumping tests with a general well orientation (vertical, horizontal, and slant) in unconfined aquifers affected from above by the unsaturated flow process.

Pharmacological interventions for sleepiness and sleep disturbances caused by shift work.

PubMed

Liira, Juha; Verbeek, Jos H; Costa, Giovanni; Driscoll, Tim R; Sallinen, Mikael; Isotalo, Leena K; Ruotsalainen, Jani H

2015-02-01

Shift work results in sleep-wake disturbances, which cause sleepiness during night shifts and reduce sleep length and quality in daytime sleep after the night shift. In its serious form it is also called shift work sleep disorder. Various pharmacological products are used to ameliorate symptoms of sleepiness or poor sleep length and quality. To evaluate the effects of pharmacological interventions to reduce sleepiness or to improve alertness at work and decrease sleep disturbances whilst of work, or both, in workers undertaking shift work. We searched CENTRAL, MEDLINE, EMBASE, PubMed and PsycINFO up to 20 September 2013 and ClinicalTrials.gov up to July 2013. We also screened reference lists of included trials and relevant reviews. We included all eligible randomised controlled trials (RCTs), including cross-over RCTs, of pharmacological products among workers who were engaged in shift work (including night shifts) in their present jobs and who may or may not have had sleep problems. Primary outcomes were sleep length and sleep quality while of work, alertness and sleepiness, or fatigue at work. Two authors independently selected studies, extracted data and assessed risk of bias in included trials. We performed meta-analyses where appropriate. We included 15 randomised placebo-controlled trials with 718 participants. Nine trials evaluated the effect of melatonin and two the effect of hypnotics for improving sleep problems. One trial assessed the effect of modafinil, two of armodafinil and one examined caffeine plus naps to decrease sleepiness or to increase alertness.

Dynamic screening in a two-species asymmetric exclusion process

NASA Astrophysics Data System (ADS)

Kim, Kyung Hyuk; den Nijs, Marcel

2007-08-01

The dynamic scaling properties of the one-dimensional Burgers equation are expected to change with the inclusion of additional conserved degrees of freedom. We study this by means of one-dimensional (1D) driven lattice gas models that conserve both mass and momentum. The most elementary version of this is the Arndt-Heinzel-Rittenberg (AHR) process, which is usually presented as a two-species diffusion process, with particles of opposite charge hopping in opposite directions and with a variable passing probability. From the hydrodynamics perspective this can be viewed as two coupled Burgers equations, with the number of positive and negative momentum quanta individually conserved. We determine the dynamic scaling dimension of the AHR process from the time evolution of the two-point correlation functions, and find numerically that the dynamic critical exponent is consistent with simple Kardar-Parisi-Zhang- (KPZ) type scaling. We establish that this is the result of perfect screening of fluctuations in the stationary state. The two-point correlations decay exponentially in our simulations and in such a manner that in terms of quasiparticles, fluctuations fully screen each other at coarse grained length scales. We prove this screening rigorously using the analytic matrix product structure of the stationary state. The proof suggests the existence of a topological invariant. The process remains in the KPZ universality class but only in the sense of a factorization, as (KPZ)2 . The two Burgers equations decouple at large length scales due to the perfect screening.

Length-free near infrared measurement of newborn malnutrition

NASA Astrophysics Data System (ADS)

Mustafa, Fatin Hamimi; Bek, Emily J.; Huvanandana, Jacqueline; Jones, Peter W.; Carberry, Angela E.; Jeffery, Heather E.; Jin, Craig T.; McEwan, Alistair L.

2016-11-01

Under-nutrition in neonates can cause immediate mortality, impaired cognitive development and early onset adult disease. Body fat percentage measured using air-displacement-plethysmography has been found to better indicate under-nutrition than conventional birth weight percentiles. However, air-displacement-plethysmography equipment is expensive and non-portable, so is not suited for use in developing communities where the burden is often the greatest. We proposed a new body fat measurement technique using a length-free model with near-infrared spectroscopy measurements on a single site of the body - the thigh. To remove the need for length measurement, we developed a model with five discrete wavelengths and a sex parameter. The model was developed using air-displacement-plethysmography measurements in 52 neonates within 48 hours of birth. We identified instrumentation required in a low-cost LED-based screening device and incorporated a receptor device that can increase the amount of light collected. This near-infrared method may be suitable as a low cost screening tool for detecting body fat levels and monitoring nutritional interventions for malnutrition in neonates and young children in resource-constrained communities.

Mechanistic Design of Chemically Diverse Polymers with Applications in Oral Drug Delivery.

PubMed

Mosquera-Giraldo, Laura I; Borca, Carlos H; Meng, Xiangtao; Edgar, Kevin J; Slipchenko, Lyudmila V; Taylor, Lynne S

2016-11-14

Polymers play a key role in stabilizing amorphous drug formulations, a recent strategy employed to improve solubility and bioavailability of drugs delivered orally. However, the molecular mechanism of stabilization is unclear, therefore, the rational design of new crystallization-inhibiting excipients remains a substantial challenge. This article presents a combined experimental and computational approach to elucidate the molecular features that improve the effectiveness of cellulose polymers as solution crystallization inhibitors, a crucial first step toward their rational design. Polymers with chemically diverse substituents including carboxylic acids, esters, ethers, alcohols, amides, amines, and sulfides were synthesized. Measurements of nucleation induction times of the model drug, telaprevir, show that the only effective polymers contained carboxylate groups in combination with an optimal hydrocarbon chain length. Computational results indicate that polymer conformation as well as solvation free energy are important determinants of effectiveness at inhibiting crystallization and show that simulations are a promising predictive tool in the screening of polymers. This study suggests that polymers need to have an adequate hydrophilicity to promote solvation in an aqueous environment, and sufficient hydrophobic regions to drive interactions with the drug. Particularly, the right balance between key substituent groups and lengths of hydrocarbon side chains is needed to create effective materials.

Biochemical markers assisted screening of Fusarium wilt resistant Musa paradisiaca (L.) cv. puttabale micropropagated clones.

PubMed

Venkatesh; Krishna, V; Kumar, K Girish; Pradeepa, K; Kumar, S R Santosh; Kumar, R Shashi

2013-07-01

An efficient protocol was standardized for screening of panama wilt resistant Musa paradisiaca cv. Puttabale clones, an endemic cultivar of Karnataka, India. The synergistic effect of 6-benzyleaminopurine (2 to 6 mg/L) and thidiazuron (0.1 to 0.5 mg/L) on MS medium provoked multiple shoot induction from the excised meristem. An average of 30.10 +/- 5.95 shoots was produced per propagule at 4 mg/L 6-benzyleaminopurine and 0.3 mg/L thidiazuron concentrations. Elongation of shoots observed on 5 mg/L BAP augmented medium with a mean length of 8.38 +/- 0.30 shoots per propagule. For screening of disease resistant clones, multiple shoot buds were mutated with 0.4% ethyl-methane-sulfonate and cultured on MS medium supplemented with Fusarium oxysporum f. sp. cubense (FOC) culture filtrate (5-15%). Two month old co-cultivated secondary hardened plants were used for screening of disease resistance against FOC by the determination of biochemical markers such as total phenol, phenylalanine ammonia lyase, oxidative enzymes like peroxidase, polyphenol oxidase, catalase and PR-proteins like chitinase, beta-1-3 glucanase activities. The mutated clones of M. paradisiaca cv. Puttabale cultured on FOC culture filtrate showed significant increase in the levels of biochemical markers as an indicative of acquiring disease resistant characteristics to FOC wilt.

Static electric dipole polarizability of lithium atoms in Debye plasmas

NASA Astrophysics Data System (ADS)

Ning, Li-Na; Qi, Yue-Ying

2012-12-01

The static electric dipole polarizabilities of the ground state and n <= 3 excited states of a lithium atom embedded in a weekly coupled plasma environment are investigated as a function of the plasma screening radium. The plasma screening of the Coulomb interaction is described by the Debye—Hückel potential and the interaction between the valence electron and the atomic core is described by a model potential. The electron energies and wave functions for both the bound and continuum states are calculated by solving the Schrödinger equation numerically using the symplectic integrator. The oscillator strengths, partial-wave, and total static dipole polarizabilities of the ground state and n <= 3 excited states of the lithium atom are calculated. Comparison of present results with those of other authors, when available, is made. The results for the 2s ground state demonstrated that the oscillator strengths and the static dipole polarizabilities from np orbitals do not always increase or decrease with the plasma screening effect increasing, unlike that for hydrogen-like ions, especially for 2s→3p transition there is a zero value for both the oscillator strength and the static dipole polarizability for screening length D = 10.3106a0, which is associated with the Cooper minima.

Patient Navigation and Time to Diagnostic Resolution: Results for a Cluster Randomized Trial Evaluating the Efficacy of Patient Navigation among Patients with Breast Cancer Screening Abnormalities, Tampa, FL

PubMed Central

Lee, Ji-Hyun; Fulp, William; Wells, Kristen J.; Meade, Cathy D.; Calcano, Ercilia; Roetzheim, Richard

2013-01-01

Objectives The objective of this study was to evaluate a patient navigation (PN) program that attempts to reduce the time between a breast cancer screening abnormality and definitive diagnosis among medically underserved populations of Tampa Bay, Florida. Methods The Moffitt Patient Navigation Research Program conducted a cluster randomized design with 10 primary care clinics. Patients were navigated from time of a breast screening abnormality to diagnostic resolution. This paper examined the length of time between breast abnormality and definitive diagnosis, using a shared frailty Cox proportional hazard model to assess PN program effect. Results 1,039 patients were eligible for the study because of an abnormal breast cancer screening/clinical abnormality (494 navigated; 545 control). Analysis of PN effect by two time periods of resolution (0-3 months and > 3 months) showed a lagged effect of PN. For patients resolving in the first three months, the adjusted Hazard Ratio (aHR) was 0.85 (95% Confidence Interval [CI]: 0.64-1.13) suggesting that PN had no effect on resolution time during this period. Beyond three months, however, navigated patients resolved more quickly to diagnostic resolution compared with the control group (aHR 2.8, 95%CI: 1.30-6.13). The predicted aHR at 3 months was 1.2, which was not statistically significant, while PN had a significant positive effect beyond 4.7 months. Conclusions PN programs may increase the timeliness of diagnostic resolution for patients with a breast cancer-related abnormality. PN did not speed diagnostic resolution during the initial three months of follow up but started to reduce time to diagnostic resolution after three months and showed a significant effect after 4.7 months. Trial Registration ClinicalTrials.gov NCT00375024 PMID:24066145

Numerical experiments on charging of a spherical body in a plasma with Maxwellian distributions of charged particles

NASA Astrophysics Data System (ADS)

Krasovsky, Victor L.; Kiselyov, Alexander A.

2017-12-01

New results of numerical simulation of collisionless plasma perturbation caused by a sphere absorbing electrons and ions are presented. Consideration is given to nonstationary phenomena accompanying the process of charging as well as to plasma steady state reached at long times. Corresponding asymptotic values of charges of the sphere and trapped-ion cloud around it have been found along with self-consistent electric field pattern depending on parameters of the unperturbed plasma. It is established that contribution of the trapped ions to screening of the charged sphere can be quite significant, so that the screening becomes essentially nonlinear in nature. A simple interconnection between the sphere radius, electron and ion Debye lengths has been revealed as the condition for maximum trapped-ion effect. Kinetic structure of the space charge induced in the plasma is discussed with relation to the specific form of the unperturbed charged particle distribution functions.

Strong Quantum Coherence between Fermi Liquid Mahan Excitons

NASA Astrophysics Data System (ADS)

Paul, J.; Stevens, C. E.; Liu, C.; Dey, P.; McIntyre, C.; Turkowski, V.; Reno, J. L.; Hilton, D. J.; Karaiskaj, D.

2016-04-01

In modulation doped quantum wells, the excitons are formed as a result of the interactions of the charged holes with the electrons at the Fermi edge in the conduction band, leading to the so-called "Mahan excitons." The binding energy of Mahan excitons is expected to be greatly reduced and any quantum coherence destroyed as a result of the screening and electron-electron interactions. Surprisingly, we observe strong quantum coherence between the heavy hole and light hole excitons. Such correlations are revealed by the dominating cross-diagonal peaks in both one-quantum and two-quantum two-dimensional Fourier transform spectra. Theoretical simulations based on the optical Bloch equations where many-body effects are included phenomenologically reproduce well the experimental spectra. Time-dependent density functional theory calculations provide insight into the underlying physics and attribute the observed strong quantum coherence to a significantly reduced screening length and collective excitations of the many-electron system.

Strong Quantum Coherence between Fermi Liquid Mahan Excitons.

PubMed

Paul, J; Stevens, C E; Liu, C; Dey, P; McIntyre, C; Turkowski, V; Reno, J L; Hilton, D J; Karaiskaj, D

2016-04-15

In modulation doped quantum wells, the excitons are formed as a result of the interactions of the charged holes with the electrons at the Fermi edge in the conduction band, leading to the so-called "Mahan excitons." The binding energy of Mahan excitons is expected to be greatly reduced and any quantum coherence destroyed as a result of the screening and electron-electron interactions. Surprisingly, we observe strong quantum coherence between the heavy hole and light hole excitons. Such correlations are revealed by the dominating cross-diagonal peaks in both one-quantum and two-quantum two-dimensional Fourier transform spectra. Theoretical simulations based on the optical Bloch equations where many-body effects are included phenomenologically reproduce well the experimental spectra. Time-dependent density functional theory calculations provide insight into the underlying physics and attribute the observed strong quantum coherence to a significantly reduced screening length and collective excitations of the many-electron system.

Identification of several high-risk HPV inhibitors and drug targets with a novel high-throughput screening assay

PubMed Central

Toots, Mart; Ustav, Mart; Männik, Andres; Mumm, Karl; Tämm, Kaido; Tamm, Tarmo; Ustav, Mart

2017-01-01

Human papillomaviruses (HPVs) are oncogenic viruses that cause numerous different cancers as well as benign lesions in the epithelia. To date, there is no effective cure for an ongoing HPV infection. Here, we describe the generation process of a platform for the development of anti-HPV drugs. This system consists of engineered full-length HPV genomes that express reporter genes for evaluation of the viral copy number in all three HPV replication stages. We demonstrate the usefulness of this system by conducting high-throughput screens to identify novel high-risk HPV-specific inhibitors. At least five of the inhibitors block the function of Tdp1 and PARP1, which have been identified as essential cellular proteins for HPV replication and promising candidates for the development of antivirals against HPV and possibly against HPV-related cancers. PMID:28182794

Supramolecular Packing Controls H 2 Photocatalysis in Chromophore Amphiphile Hydrogels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weingarten, Adam S.; Kazantsev, Roman V.; Palmer, Liam C.

2015-11-21

Light harvesting supramolecular assemblies are potentially useful structures as components of solar-to-fuel conversion materials. The development of these functional constructs requires an understanding of optimal packing modes for chromophores. We investigated here assembly in water and the photocatalytic function of perylene monoimide chromophore amphiphiles with different alkyl linker lengths separating their hydrophobic core and the hydrophilic carboxylate headgroup. We found that these chromophore amphiphiles (CAs) self-assemble into charged nanostructures of increasing aspect ratio as the linker length is increased. The addition of salt to screen the charged nanostructures induced the formation of hydrogels and led to internal crystallization within somemore » of the nanostructures. For linker lengths up to seven methylenes, the CAs were found to pack into 2D crystalline unit cells within ribbon-shaped nanostructures, whereas the nine methylene CAs assembled into long nanofibers without crystalline molecular packing. At the same time, the different molecular packing arrangements after charge screening led to different absorbance spectra, despite the identical electronic properties of all PMI amphiphiles. While the crystalline CAs formed electronically coupled H-aggregates, only CAs with intermediate linker lengths showed evidence of high intermolecular orbital overlap. Photocatalytic hydrogen production using a nickel-based catalyst was observed in all hydrogels, with the highest turnovers observed for CA gels having intermediate linker lengths. We conclude that the improved photocatalytic performance of the hydrogels formed by supramolecular assemblies of the intermediate linker CA molecules likely arises from improved exciton splitting efficiencies due to their higher orbital overlap.« less

How do dairy cows chew?--particle size analysis of selected feeds with different particle length distributions and of respective ingested bolus particles.

PubMed

Schadt, I; Ferguson, J D; Azzaro, G; Petriglieri, R; Caccamo, M; Van Soest, P; Licitra, G

2012-08-01

Not only feed but also respective bolus particle size could alter diet efficiency and cow performance. The objective of this project was to characterize particle size of selected feeds and respective swallowed boli. Feed samples included 6 different particle length rye grass hay samples, 1 grass silage, 1 corn silage, and 1 total mixed ration (TMR). Rye grass hay samples consisted of long hay and chopped hay particles retained on the 19- (19_PSPS hay), 8- (8_PSPS hay), and 1.18-mm (1.18_PSPS hay) Penn State Particle Separator (PSPS) screens and those collected on the pan (PSPS_pan hay). A sixth hay treatment was rye grass forage cut at 50-mm lengths and dried to hay (50-mm hay). Treatments were offered to 4 nonlactating and 4 lactating cows following rumen evacuation. Swallowed boli were collected and the number of chews per gram of ingested feed dry matter was determined. Feed and bolus particles of lengths ≥5mm were collected on a 1.6-mm screen using a horizontal wet sieving technique. This cut point was chosen, as the literature suggests that most fecal particles are shorter than 5mm. Dry matter proportions on this screen (PROP_1.6) were determined and particle lengths of retained particles were measured by image analysis. Mean particle lengths (ML) were calculated considering particles ≥5mm in length. Boli of long hay, of 19_PSPS hay, of 8_PSPS hay, and of 50-mm hay had similar ML of 10 to 11mm. Bolus PROP_1.6 were also similar between these treatments, ranging from 0.54 to 0.69. Bolus particle lengths and distributions of these treatments were not related to respective hay particles. Bolus of 1.18_PSPS hay had PROP_1.6 of 0.51 and a smaller ML of 8mm. The PSPS_pan hay had PROP_1.6 of only 0.33, but was still chewed intensely. Apparently, little particle size reduction occurred when cows ate the TMR or the silages. Feed and respective bolus PROP_1.6 were as follows: 0.66 and 0.59 in grass silage, 0.52 and 0.55 in corn silage, and 0.44 and 0.38 in the TMR. Feed and respective bolus ML were as follows: 13.8 and 11.6mm in grass silage, 12.0 and 11.2mm in corn silage, and 13.1 and 12.5mm in the TMR. Rye grass hay particles retained on PSPS screens ≥8mm, with ML of at least 25mm were longer compared with TMR particles, but respective bolus particles were shorter. Bolus particle size is not associated with the size of large feed particles chewed to a constant size that is appropriate for deglutition. This size may be related to feed chemical composition. Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Underscreening in ionic liquids: a first principles analysis.

PubMed

Rotenberg, Benjamin; Bernard, Olivier; Hansen, Jean-Pierre

2018-02-07

An attempt is made to understand the underscreening effect, observed in concentrated electrolyte solutions or melts, on the basis of simple, admittedly crude models involving charged (for the ions) and neutral (for the solvent molecules) hard spheres. The thermodynamic and structural properties of these 'primitive' and 'semi-primitive' models are calculated within mean spherical approximation, which provides the basic input required to determine the partial density response functions. The screening length [Formula: see text], which is unambiguously defined in terms of the wave-number-dependent response functions, exhibits a cross-over from a low density, Debye-like regime, to a regime where [Formula: see text] increases with density beyond a critical density at which the Debye length [Formula: see text] becomes comparable to the ion diameter. In this high density regime the ratio [Formula: see text] increases according to a power law, in qualitative agreement with experimental measurements, albeit at a much slower rate.

Underscreening in ionic liquids: a first principles analysis

NASA Astrophysics Data System (ADS)

Rotenberg, Benjamin; Bernard, Olivier; Hansen, Jean-Pierre

2018-02-01

An attempt is made to understand the underscreening effect, observed in concentrated electrolyte solutions or melts, on the basis of simple, admittedly crude models involving charged (for the ions) and neutral (for the solvent molecules) hard spheres. The thermodynamic and structural properties of these ‘primitive’ and ‘semi-primitive’ models are calculated within mean spherical approximation, which provides the basic input required to determine the partial density response functions. The screening length λS , which is unambiguously defined in terms of the wave-number-dependent response functions, exhibits a cross-over from a low density, Debye-like regime, to a regime where λS increases with density beyond a critical density at which the Debye length λD becomes comparable to the ion diameter. In this high density regime the ratio λ_S/λD increases according to a power law, in qualitative agreement with experimental measurements, albeit at a much slower rate.

The width-tapered double cantilever beam for interlaminar fracture testing

NASA Technical Reports Server (NTRS)

Bascom, W. D.; Jensen, R. M.; Bullman, G. W.; Hunston, D. L.

1984-01-01

The width-tapered double-cantilever-beam (WTDCB) specimen configuration used to determine the Mode-I interlaminar fracture energy (IFE) of composites has special advantages for routine development work and for quality-assurance purposes. These advantages come primarily from the simplicity of testing and the fact that the specimen is designed for constant change in compliance with crack length, so that the computation of Mode-I IFE is independent of crack length. In this paper, a simplified technique for fabrication and testing WTDCB specimens is described. Also presented are the effects of fiber orientation and specimen dimensions, a comparison of data obtained using the WTDCB specimens and other specimen geometries, and comparison of data obtained at different laboratories. It is concluded that the WTDCB gives interlaminar Mode-I IFE essentially equal to other type specimens, and that it can be used for rapid screening in resin-development work and for quality assurance of composite materials.

Impact of dietary fiber and physical form on performance of lactating dairy cows.

PubMed

Woodford, J A; Jorgensen, N A; Barrington, G P

1986-04-01

Two trials were conducted to study the effects of forage intake and physical form on lactating cow performance. In trial 1, four cows in a 4 X 4 Latin square were fed long alfalfa hay at 28, 36, 45, and 53% of total dry matter plus concentrate. Total dry matter intake was not affected by forage percent. Total chewing time and milk fat percentage increased linearly with increasing forage consumption. Maximum 4% fat-corrected milk production occurred when diets contained 27% neutral detergent fiber and 18% acid detergent fiber. In trial 2, four cows in a 4 X 4 Latin square were fed diets of chopped alfalfa hay and concentrate in proportions to supply 27.4% total ration neutral detergent fiber. Mean particle length measured with an oscillating screen particle separator of the chopped hay was .26, .46, .64, and .90 cm. Total dry matter and forage dry matter intakes and total chewing were not influenced by forage mean particle length. Mean particle length did not affect actual milk or 4% fat-corrected milk production. Depression of milk fat percentage was prevented when forage mean particle length was greater than or equal .64 cm. Apparent digestibility of dietary constituents and rate of passage of hay and concentrate was not influenced by forage intake or physical form.

Microcredit participation and women's health: results from a cross-sectional study in Peru.

PubMed

Hamad, Rita; Fernald, Lia C H

2015-08-05

Social and economic conditions are powerful determinants of women's health status. Microcredit, which involves the provision of small loans to low-income women in the hopes of improving their living conditions, is an increasingly popular intervention to improve women's socioeconomic status. Studies examining the health effects of microcredit programs have had mixed results. We conduct a cross-sectional study among female clients of a non-profit microcredit program in Peru (N = 1,593). The predictor variable is length of microcredit participation. We conduct bivariate and multivariate linear regressions to examine the associations between length of microcredit participation and a variety of measures of women's health. We control for participants' sociodemographic characteristics. We find that longer participation is associated with decreased depressive symptoms, increased social support, and increased perceived control, but these differences are attenuated with the inclusion of covariates. We find no association between length of participation and contraception use, cancer screening, or self-reported days sick. These results demonstrate a positive association between length of microcredit participation and measures of women's psychological health, but not physical health. These findings contribute to the discussion on the potential of microcredit programs to address the socioeconomic determinants of health, and suggest that addressing socioeconomic status may be a key way to improve women's health worldwide.

A Pathway to Freedom: An Evaluation of Screening Tools for the Identification of Trafficking Victims.

PubMed

Bespalova, Nadejda; Morgan, Juliet; Coverdale, John

2016-02-01

Because training residents and faculty to identify human trafficking victims is a major public health priority, the authors review existing assessment tools. PubMed and Google were searched using combinations of search terms including human, trafficking, sex, labor, screening, identification, and tool. Nine screening tools that met the inclusion criteria were found. They varied greatly in length, format, target demographic, supporting resources, and other parameters. Only two tools were designed specifically for healthcare providers. Only one tool was formally assessed to be valid and reliable in a pilot project in trafficking victim service organizations, although it has not been validated in the healthcare setting. This toolbox should facilitate the education of resident physicians and faculty in screening for trafficking victims, assist educators in assessing screening skills, and promote future research on the identification of trafficking victims.

Calculation of Energy Diagram of Asymmetric Graded-Band-Gap Semiconductor Superlattices.

PubMed

Monastyrskii, Liubomyr S; Sokolovskii, Bogdan S; Alekseichyk, Mariya P

2017-12-01

The paper theoretically investigates the peculiarities of energy diagram of asymmetric graded-band-gap superlattices with linear coordinate dependences of band gap and electron affinity. For calculating the energy diagram of asymmetric graded-band-gap superlattices, linearized Poisson's equation has been solved for the two layers forming a period of the superlattice. The obtained coordinate dependences of edges of the conduction and valence bands demonstrate substantial transformation of the shape of the energy diagram at changing the period of the lattice and the ratio of width of the adjacent layers. The most marked changes in the energy diagram take place when the period of lattice is comparable with the Debye screening length. In the case when the lattice period is much smaller that the Debye screening length, the energy diagram has the shape of a sawtooth-like pattern.

Prenatal Depression and Adverse Birth Outcomes: An Updated Systematic Review

PubMed Central

Accortt, Eynav Elgavish; Cheadle, Alyssa C. D.; Schetter, Christine Dunkel

2015-01-01

Complications related to preterm birth (PTB) and low birth weight (LBW) are leading causes of infant morbidity and mortality. Prenatal depression is a hypothesized psychosocial risk factor for both birth outcomes. The purpose of this systematic review was to examine evidence published between 1977 and 2013 on prenatal depression and risks of these primary adverse birth outcomes. A systematic search of the PUBMED and PsycINFO databases was conducted to identify studies testing the associations between prenatal depressive symptoms, or diagnoses of depression, and risk of PTB or LBW. We systematically selected 50 published reports on PTB and length of gestation, and 33 reports on LBW and BW. Results were reviewed by two independent reviewers and we evaluated the quality of the evidence with an established systematic review method, the Newcastle Ottawa Scale. We then undertook a narrative synthesis of the results following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Less than a quarter of 50 published reports found that prenatal depression was significantly associated with PTB or gestational age. In contrast, slightly more than half of the 33 reports found that prenatal depression was associated with LBW or BW. When weighing methodological features, we determined that the effects of prenatal depression on LBW are more consistent than effects on length of gestation or PTB. Although the evidence may not be strong enough to support routine depression screening for risk of adverse outcomes, screening to enable detection and timely treatment to reduce risk of postpartum depression is warranted. Further rigorous research on prenatal depression and adverse birth outcomes is needed. PMID:25452215

The application of CRISPR technology to high content screening in primary neurons.

PubMed

Callif, Ben L; Maunze, Brian; Krueger, Nick L; Simpson, Matthew T; Blackmore, Murray G

2017-04-01

Axon growth is coordinated by multiple interacting proteins that remain incompletely characterized. High content screening (HCS), in which manipulation of candidate genes is combined with rapid image analysis of phenotypic effects, has emerged as a powerful technique to identify key regulators of axon outgrowth. Here we explore the utility of a genome editing approach referred to as CRISPR (Clustered Regularly Interspersed Palindromic Repeats) for knockout screening in primary neurons. In the CRISPR approach a DNA-cleaving Cas enzyme is guided to genomic target sequences by user-created guide RNA (sgRNA), where it initiates a double-stranded break that ultimately results in frameshift mutation and loss of protein production. Using electroporation of plasmid DNA that co-expresses Cas9 enzyme and sgRNA, we first verified the ability of CRISPR targeting to achieve protein-level knockdown in cultured postnatal cortical neurons. Targeted proteins included NeuN (RbFox3) and PTEN, a well-studied regulator of axon growth. Effective knockdown lagged at least four days behind transfection, but targeted proteins were eventually undetectable by immunohistochemistry in >80% of transfected cells. Consistent with this, anti-PTEN sgRNA produced no changes in neurite outgrowth when assessed three days post-transfection. When week-long cultures were replated, however, PTEN knockdown consistently increased neurite lengths. These CRISPR-mediated PTEN effects were achieved using multi-well transfection and automated phenotypic analysis, indicating the suitability of PTEN as a positive control for future CRISPR-based screening efforts. Combined, these data establish an example of CRISPR-mediated protein knockdown in primary cortical neurons and its compatibility with HCS workflows. Copyright © 2017 Elsevier Inc. All rights reserved.

Evaluation of nutritional screening tools for patients scheduled for cardiac surgery.

PubMed

Lomivorotov, Vladimir V; Efremov, Sergey M; Boboshko, Vladimir A; Nikolaev, Dmitry A; Vedernikov, Pavel E; Lomivorotov, Vladimir N; Karaskov, Alexander M

2013-02-01

The aim of this study was to assess the prognostic value of different nutritional screening tools in patients undergoing cardiopulmonary bypass with regard to an adverse clinical course. This prospective cohort study analyzed 894 adult patients who underwent cardiopulmonary bypass. Patients were screened using four nutritional screening tools: Nutritional Risk Screening 2002 (NRS-2002), the Malnutrition Universal Screening Tool (MUST), the Mini-Nutritional Assessment (MNA), and the Short Nutritional Assessment Questionnaire (SNAQ). Nutritional status was assessed using the Subjective Global Assessment. In-hospital mortality, postoperative complications, length of stay in the intensive care unit, and length of hospitalization were analyzed. The sensitivities of the SNAQ, MUST, and NRS-2002 to detect the malnutrition confirmed by the Subjective Global Assessment were 91.5%, 97.9%, and 38.3%, respectively, and the MNA showed a sensitivity of 81.8% for the elderly. Malnutrition detected by the SNAQ, MUST, and NRS-2002 was associated with postoperative complications (odds ratios [ORs] 1.75, 1.98, and 1.82, respectively) and a stay in the intensive care unit longer than 2 d (ORs 1.46, 1.56, and 2.8). Malnutrition as detected by the SNAQ and MUST was also associated with prolonged hospitalization (ORs 1.49 and 1.59). According to multivariate logistic regression analysis, postoperative complications were independently predicted by the European System for Cardiac Operative Risk Evaluation (OR 1.1, P < 0.0001), cardiopulmonary bypass time (OR 1.01, P < 0.0001), and malnutrition identified by the MUST (OR 1.2, P = 0.01). The MUST independently predicts postoperative complications. The SNAQ and MUST have comparable accuracy in detecting malnutrition. Whether preoperative nutritional therapy would improve the outcome in malnourished patients needs to be studied. Copyright © 2013 Elsevier Inc. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jung, Young-Dae

The plasmon and screening effects on the entanglement fidelity for the elastic electron-ion collision are investigated in hot quantum plasmas. The partial wave analysis and effective interaction including the plasmon couplings are employed to obtain the entanglement fidelity function in hot quantum plasmas. It is shown that the plasmon effect enhances the entanglement fidelity in quantum plasmas for 0<{beta}({identical_to}({Dirac_h}/2{pi}){omega}{sub p}/k{sub B}T)<0.8 and, however, suppresses the entanglement fidelity for 0.8<{beta}<1, where {omega}{sub p} is the plasmon frequency, k{sub B} is the Boltzmann constant, and T is the plasma temperature. It is also found that the entanglement fidelity decreases with increasing Debyemore » length and collision energy.« less

Peptide mediators of cholesterol efflux

DOEpatents

Bielicki, John K.; Johansson, Jan

2013-04-09

The present invention provides a family of non-naturally occurring polypeptides having cholesterol efflux activity that parallels that of full-length apolipoproteins (e.g., Apo AI and Apo E), and having high selectivity for ABAC1 that parallels that of full-length apolipoproteins. The invention also provides compositions comprising such polypeptides, methods of identifying, screening and synthesizing such polypeptides, and methods of treating, preventing or diagnosing diseases and disorders associated with dyslipidemia, hypercholesterolemia and inflammation.

Potent and selective mediators of cholesterol efflux

DOEpatents

Bielicki, John K; Johansson, Jan

2015-03-24

The present invention provides a family of non-naturally occurring polypeptides having cholesterol efflux activity that parallels that of full-length apolipoproteins (e.g., Apo AI and Apo E), and having high selectivity for ABAC1 that parallels that of full-length apolipoproteins. The invention also provides compositions comprising such polypeptides, methods of identifying, screening and synthesizing such polypeptides, and methods of treating, preventing or diagnosing diseases and disorders associated with dyslipidemia, hypercholesterolemia and inflammation.

Effects of a screening and treatment protocol with haloperidol on post-cardiotomy delirium: a prospective cohort study†

PubMed Central

Schrøder Pedersen, Sofie; Kirkegaard, Thomas; Balslev Jørgensen, Martin; Lind Jørgensen, Vibeke

2014-01-01

OBJECTIVES Post-cardiotomy delirium is common and associated with increased morbidity and mortality. No gold standard exists for detecting delirium, and evidence to support the choice of treatment is needed. Haloperidol is widely used for treating delirium, but indication, doses and therapeutic targets vary. Moreover, doubt has been raised regarding overall efficacy. The purpose of this study was to assess the effect of a combination of early detection and standardized treatment with haloperidol on post-cardiotomy delirium, with the hypothesis that the proportion of delirium- and coma-free days could be increased. Length of stay (LOS), complications and 180-day mortality are reported. METHODS Prospective interventional cohort study. One hundred and seventeen adult patients undergoing cardiac surgery were included before introduction of a screening and treatment protocol with haloperidol for delirium, and 123 patients were included after. Nurses screened patients using validated tools (the Delirium Observation Screening (DOS) scale and confusion assessment method for the intensive care unit (CAM-ICU)). In case of delirium, a checklist to eliminate precipitating/ inducing factors and a protocol for standardized dosing with haloperidol was applied. Group comparison was done using non-parametric tests and analysis of fractions, and associations between delirium and predefined covariates were analysed with logistic regression. RESULTS Incidence of delirium after cardiac surgery was 21 (14–29) and 22 (15–30) %, onset was on postoperative day 1 (1–4) and 1 (1–3), duration was 1 (1–4) day and 3 (1–5) days, respectively, with no significant difference (Period 1 vs 2, all values are given as the median and 95% confidence interval). The proportion of delirium- and coma-free days was 67 (61–73) and 65 (60–70) %, respectively (ns). There was no difference in LOS or complication rate. Delirium was associated to increasing age, increased length of stay and complications. CONCLUSIONS We observed no increase in the proportion of delirium- and coma-free days after introduction of a combination of early detection and standardized treatment with haloperidol on post-cardiotomy delirium. Most patients were not severely affected, and the few who were, proved difficult to treat, indicating that a simple treatment protocol with haloperidol was ineffective. PMID:24357472

Multiresolution wavelet analysis for efficient analysis, compression and remote display of long-term physiological signals.

PubMed

Khuan, L Y; Bister, M; Blanchfield, P; Salleh, Y M; Ali, R A; Chan, T H

2006-06-01

Increased inter-equipment connectivity coupled with advances in Web technology allows ever escalating amounts of physiological data to be produced, far too much to be displayed adequately on a single computer screen. The consequence is that large quantities of insignificant data will be transmitted and reviewed. This carries an increased risk of overlooking vitally important transients. This paper describes a technique to provide an integrated solution based on a single algorithm for the efficient analysis, compression and remote display of long-term physiological signals with infrequent short duration, yet vital events, to effect a reduction in data transmission and display cluttering and to facilitate reliable data interpretation. The algorithm analyses data at the server end and flags significant events. It produces a compressed version of the signal at a lower resolution that can be satisfactorily viewed in a single screen width. This reduced set of data is initially transmitted together with a set of 'flags' indicating where significant events occur. Subsequent transmissions need only involve transmission of flagged data segments of interest at the required resolution. Efficient processing and code protection with decomposition alone is novel. The fixed transmission length method ensures clutter-less display, irrespective of the data length. The flagging of annotated events in arterial oxygen saturation, electroencephalogram and electrocardiogram illustrates the generic property of the algorithm. Data reduction of 87% to 99% and improved displays are demonstrated.

Barley processing, forage:concentrate, and forage length effects on chewing and digesta passage in lactating cows.

PubMed

Yang, W Z; Beauchemin, K A; Rode, L M

2001-12-01

Dietary factors that alter fermentability, NDF content, or particle size of the diet were evaluated for their effects on chewing behavior and distribution and passage of feed particles in the digestive tract of dairy cows. A double 4 x 4 quasi-Latin square design with a 2(3) factorial arrangement of treatments was used. The dietary factors were: extent of barley grain processing, coarse (1.60 mm) or flat (1.36 mm); forage-to-concentrate ratio (F:C), low (35:65) or high (55:45) (dry matter basis); and forage particle length, long (7.59 mm) or short (6.08 mm). Eight lactating cows with ruminal and duodenal cannulas were offered ad libitum access to total mixed diets. Chewing time, expressed as minutes per day or per kilogram of dry matter or neutral detergent fiber (NDF), was increased with high F:C diets due to increased eating and ruminating times but was decreased when expressed per kilogram of NDF intake from forage. The influence of forage particle length or grain processing on chewing activity was less pronounced than F:C ratio. Chewing activity was positively correlated to proportion of long forage particles in the diet but not to particle length of the diets. Influence of feed particle size on particle size distribution in different sites of the digestive tract was minimal. Particle size distributions of duodenal digesta and feces differed; the proportion of particles retained on the 3.35- or 1.18-mm screens was higher, but proportion of particles that passed through the 1.18-mm screen was lower in duodenal digesta than in feces. Relationships between chewing activities and ruminal pH or fractional passage rate of rumen contents were not significant. These results indicate that particle size of barley-based diets was not a reliable indicator of chewing activity. Forage particle size and NDF content of the diets were more reliable indicators of chewing activity than was the NDF content of forage. Fecal particle size was not an appropriate means of estimating the size of particles exiting the reticulorumen, at least for barley-based diets. Breakdown of coarse particles was necessary, but not a rate-limiting step for particles exiting the rumen. Passage rate of the rumen contents was affected by numerous factors including chewing activity.

An alternative screening model for the estimation of outdoor air concentration at large contaminated sites

NASA Astrophysics Data System (ADS)

Verginelli, Iason; Nocentini, Massimo; Baciocchi, Renato

2017-09-01

Simplified analytical solutions of fate and transport models are often used to carry out risk assessment on contaminated sites, to evaluate the long-term air quality in relation to volatile organic compounds in either soil or groundwater. Among the different assumptions employed to develop these solutions, in this work we focus on those used in the ASTM-RBCA ;box model; for the evaluation of contaminant dispersion in the atmosphere. In this simple model, it is assumed that the contaminant volatilized from the subsurface is dispersed in the atmosphere within a mixing height equal to two meters, i.e. the height of the breathing zone. In certain cases, this simplification could lead to an overestimation of the outdoor air concentration at the point of exposure. In this paper we first discuss the maximum source lengths (in the wind direction) for which the application of the ;box model; can be considered acceptable. Specifically, by comparing the results of ;box model; with the SCREEN3 model of U.S.EPA we found that under very stable atmospheric conditions (class F) the ASTM-RBCA approach provides acceptable results for source lengths up to 200 m while for very unstable atmospheric conditions (class A and B) the overestimation of the concentrations at the point of the exposure can be already observed for source lengths of only 10 m. In the latter case, the overestimation of the ;box model; can be of more than one order of magnitude for source lengths above 500 m. To overcome this limitation, in this paper we introduce a simple analytical solution that can be used for the calculation of the concentration at the point of exposure for large contaminated sites. The method consists in the introduction of an equivalent mixing zone height that allows to account for the dispersion of the contaminants along the source length while keeping the simplistic ;box model; approach that is implemented in most of risk assessment tools that are based on the ASTM-RBCA standard (e.g. RBCA toolkit). Based on our testing, we found that the developed model replicates very well the results of the more sophisticated dispersion SCREEN3 model with deviations always below 10%. The key advantage of this approach is that it can be very easily incorporated in the current risk assessment screening tools that are based on the ASTM standards while ensuring a more accurate evaluation of the concentration at the point of exposure.

A Novel Polyaminocarboxylate Compound To Treat Murine Pulmonary Aspergillosis by Interfering with Zinc Metabolism.

PubMed

Laskaris, Paris; Vicentefranqueira, Rocío; Helynck, Olivier; Jouvion, Grégory; Calera, José Antonio; du Merle, Laurence; Suzenet, Franck; Buron, Frédéric; de Sousa, Rodolphe Alves; Mansuy, Daniel; Cavaillon, Jean-Marc; Latgé, Jean-Paul; Munier-Lehmann, Hélène; Ibrahim-Granet, Oumaima

2018-06-01

Aspergillus fumigatus can cause pulmonary aspergillosis in immunocompromised patients and is associated with a high mortality rate due to a lack of reliable treatment options. This opportunistic pathogen requires zinc in order to grow and cause disease. Novel compounds that interfere with fungal zinc metabolism may therefore be of therapeutic interest. We screened chemical libraries containing 59,223 small molecules using a resazurin assay that compared their effects on an A. fumigatus wild-type strain grown under zinc-limiting conditions and on a zinc transporter knockout strain grown under zinc-replete conditions to identify compounds affecting zinc metabolism. After a first screen, 116 molecules were selected whose inhibitory effects on fungal growth were further tested by using luminescence assays and hyphal length measurements to confirm their activity, as well as by toxicity assays on HeLa cells and mice. Six compounds were selected following a rescreening, of which two were pyrazolones, two were porphyrins, and two were polyaminocarboxylates. All three groups showed good in vitro activity, but only one of the polyaminocarboxylates was able to significantly improve the survival of immunosuppressed mice suffering from pulmonary aspergillosis. This two-tier screening approach led us to the identification of a novel small molecule with in vivo fungicidal effects and low murine toxicity that may lead to the development of new treatment options for fungal infections by administration of this compound either as a monotherapy or as part of a combination therapy. Copyright © 2018 American Society for Microbiology.

Introducing depression and developmental screenings into the national programme on immunization (NPI) in southeast Nigeria: an experimental cross-sectional assessment.

PubMed

Bakare, Muideen O; Okoye, Jane O; Obindo, James T

2014-01-01

This study investigates the possibility of introducing depression and developmental screening tools into the National Programme on Immunization (NPI) in southeast Nigeria. The specific objectives were to determine the prevalence of postpartum depression (PPD) among mothers attending immunization clinics and to assess the association of maternal PPD and infant growth in relation to World Health Organization (WHO) recommendations. Four hundred and eight (408) mothers completed the sociodemographic questionnaire and the self-report Edinburgh Postnatal Depression Scale (EPDS). The weights, lengths and head circumferences of their infants were recorded, while the WHO recommended equivalents at 50th percentiles were also recorded for each child. The mothers were then interviewed with the major depressive episode module of Mini International Neuropsychiatric Interview (M.I.N.I.) to make diagnosis of depression. About 24.8% and 15.2% of the mothers were found to be depressed using EPDS and major depressive episode module of M.I.N.I., respectively. It was found that maternal PPD is significantly associated with the growth parameters of weights and lengths of the infants studied but not their head circumference. NPI may provide appropriate forum for early screening of mothers for PPD and interventions in Nigeria. The NPI would also serve a useful avenue of screening for developmental concerns in Nigerian children. © 2014.

Screening of a dust particle charge in a humid air plasma created by an electron beam

NASA Astrophysics Data System (ADS)

Filippov, A. V.; Derbenev, I. N.; Kurkin, S. A.

2018-01-01

A kinetic model has been developed for charged particle reactions in a humid air plasma produced by a fast electron beam. The model includes over 550 reactions with electrons, 33 positive ion species and 14 negative ion species. The model has been tested by solving 48 non-steady state equations for number densities of charged particles in humid air electron beam plasma, and by comparing with the available experimental data. The system of 48 steady state equations has been solved by iterative method in order to define the main ion species of the humid air plasma. A reduced kinetic model has been developed to describe the processes with the main ions and electrons. Screening constants have been calculated on the basis of the reduced system by means of Leverrier-Fadeev method. The dependencies of screening constants on gas ionization rates have been found for the rates from 10 to 1018 cm-3s-1 and the fraction of water molecules from 0 to 2%. The analysis of the constants has revealed that one of them is close to the inverse Debye length, and the other constants are defined by the inverse diffusion lengths passed by ions in the characteristic times of the attachment, recombination, and ion conversion. Pure imaginary screening constants appear at low rates of gas ionization.

Postpartum screening practices, progression to abnormal glucose tolerance and its related risk factors in Asian women with a known history of gestational diabetes: A systematic review and meta-analysis.

PubMed

Nouhjah, Sedigheh; Shahbazian, Hajieh; Amoori, Neda; Jahanfar, Shayesteh; Shahbazian, Nahid; Jahanshahi, Alireza; Cheraghian, Bahman

2017-12-01

Rate of postpartum screening and progression to glucose intolerance (diabetes and/or pre-diabetes) in Asian women with prior GDM and risk factors of diversion to abnormal glucose tolerance were reviewed. We searched Pub Med, Cochrane Library, Web of Science, EMBASE, and Ovid data base. About 1300 studies were screened and 27 articles were selected. Meta-analysis using Comprehensive Meta -Analysis software was conducted. All results were reported at the pooled ORs and 95% CI. Quantitative heterogeneity (I 2 ) was assessed. To estimate the variances between studies, the statistical method "tau-squared" was applied. Statistical models like fixed effect or Mantel-Haenszel, and random effect (REM) or Dersimonian-laird were used for the analysis and integration of results. Rate of glucose testing ranged from 13.1% to 81.9%. Prevalence of pre-diabetes was 3.9%-50.9%. Diabetes was reported in 2.8%-58% of women with history of gestational diabetes based on length of follow-up. Factor associated with postpartum diabetes mellitus included family History of diabetes mellitus, gestational age at diagnosis of GDM, insulin use during pregnancy and pre-pregnancy BMI. Rate of postpartum screening in most of the Asian countries population is sub-optimal, in spite of high rate of glucose intolerance in this high risk group of women. Risk factors of progression to pre-diabetes and diabetes are similar to previous reported in developed countries. Copyright © 2017 Diabetes India. All rights reserved.

Liquid Acquisition Device Design Sensitivity Study

NASA Technical Reports Server (NTRS)

VanDyke, M. K.; Hastings, L. J.

2012-01-01

In-space propulsion often necessitates the use of a capillary liquid acquisition device (LAD) to assure that gas-free liquid propellant is available to support engine restarts in microgravity. If a capillary screen-channel device is chosen, then the designer must determine the appropriate combination screen mesh and channel geometry. A screen mesh selection which results in the smallest LAD width when compared to any other screen candidate (for a constant length) is desirable; however, no best screen exists for all LAD design requirements. Flow rate, percent fill, and acceleration are the most influential drivers for determining screen widths. Increased flow rates and reduced percent fills increase the through-the-screen flow pressure losses, which drive the LAD to increased widths regardless of screen choice. Similarly, increased acceleration levels and corresponding liquid head pressures drive the screen mesh selection toward a higher bubble point (liquid retention capability). After ruling out some screens on the basis of acceleration requirements alone, candidates can be identified by examining screens with small flow-loss-to-bubble point ratios for a given condition (i.e., comparing screens at certain flow rates and fill levels). Within the same flow rate and fill level, the screen constants inertia resistance coefficient, void fraction, screen pore or opening diameter, and bubble point can become the driving forces in identifying the smaller flow-loss-to-bubble point ratios.

Selection of full-length IgGs by tandem display on filamentous phage particles and Escherichia coli fluorescence-activated cell sorting screening.

PubMed

Mazor, Yariv; Van Blarcom, Thomas; Carroll, Sean; Georgiou, George

2010-05-01

Phage display of antibody libraries is a powerful tool for antibody discovery and evolution. Recombinant antibodies have been displayed on phage particles as scFvs or Fabs, and more recently as bivalent F(ab')(2). We recently developed a technology (E-clonal) for screening of combinatorial IgG libraries using bacterial periplasmic display and selection by fluorescence-activated cell sorting (FACS) [Mazor Y et al. (2007) Nat Biotechnol 25, 563-565]. Although, as a single-cell analysis technique, FACS is very powerful, especially for the isolation of high-affinity binders, even with state of the art instrumentation the screening of libraries with diversity > 10(8) is technically challenging. We report here a system that takes advantage of display of full-length IgGs on filamentous phage particles as a prescreening step to reduce library size and enable subsequent rounds of FACS screening in Escherichia coli. For the establishment of an IgG phage display system, we utilized phagemid-encoded IgG with the fUSE5-ZZ phage as a helper phage. These phage particles display the Fc-binding ZZ protein on all copies of the phage p3 coat protein, and are exploited as both helper phages and anchoring surfaces for the soluble IgG. We demonstrate that tandem phage selection followed by FACS allows the selection of a highly diversified profile of binders from antibody libraries without undersampling, and at the same time capitalizes on the advantages of FACS for real-time monitoring and optimization of the screening process.

Operational and financial impact of physician screening in the ED.

PubMed

Soremekun, Olanrewaju A; Biddinger, Paul D; White, Benjamin A; Sinclair, Julia R; Chang, Yuchiao; Carignan, Sarah B; Brown, David F M

2012-05-01

Physician screening is one of many front-end interventions being implemented to improve emergency department (ED) efficiency. We aimed to quantify the operational and financial impact of this intervention at an urban tertiary academic center. We conducted a 2-year before-after analysis of a physician screening system at an urban tertiary academic center with 90 000 annual visits. Financial impact consisted of the ED and inpatient revenue generated from the incremental capacity and the reduction in left without being seen (LWBS) rates. The ED and inpatient margin contribution as well as capital expenditure were based on available published data. We summarized the financial impact using net present value of future cash flows performing sensitivity analysis on the assumptions. Operational outcome measures were ED length of stay and percentage of LWBS. During the first year, we estimate the contribution margin of the screening system to be $2.71 million and the incremental operational cost to be $1.86 million. Estimated capital expenditure for the system was $1 200 000. The NPV of this investment was $2.82 million, and time to break even from the initial investment was 13 months. Operationally, despite a 16.7% increase in patient volume and no decrease in boarding hours, there was a 7.4% decrease in ED length of stay and a reduction in LWBS from 3.3% to 1.8%. In addition to improving operational measures, the implementation of a physician screening program in the ED allowed for an incremental increase in patient care capacity leading to an overall positive financial impact. Copyright © 2012 Elsevier Inc. All rights reserved.

FETAX assay for evaluation of developmental toxicity.

PubMed

Mouche, Isabelle; Malesic, Laure; Gillardeaux, Olivier

2011-01-01

The Frog Embryo Teratogenesis Assay Xenopus (FETAX) test is a development toxicity screening test. Due to the small amount of compound needed and the capability to study organogenesis in a short period of time (96 h), FETAX test constitutes an efficient development toxicity alert test when performed early in drug safety development. The test is conducted on fertilized Xenopus laevis mid-blastula stage eggs over the organogenesis period. Compound teratogenic potential is determined after analysis of the mortality and malformation observations on larva. In parallel, FETAX test provides also information concerning embryotoxic effect based on larva length.

FETAX Assay for Evaluation of Developmental Toxicity.

PubMed

Mouche, Isabelle; Malésic, Laure; Gillardeaux, Olivier

2017-01-01

The frog embryo teratogenesis assay Xenopus (FETAX) test is a development toxicity screening test. Due to the small amount of compound needed and the capability to study organogenesis in a short period of time (96 h), FETAX test constitutes an efficient development toxicity alert test when performed early in drug safety development. The test is conducted on fertilized Xenopus laevis mid-blastula-stage eggs over the organogenesis period. Compound teratogenic potential is determined after analysis of the mortality and malformation observations on larvae. In parallel, FETAX test provides also information concerning embryotoxic effect based on larva length.

Parameters of a collisional radio-frequency sheath and dust characteristics resulting from the microparticle levitation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yaroshenko, V. V.; Antonova, T.; Thomas, H. M.

2009-10-15

The screening length, the time-average electric field, and the particle charge as well as the local vertical gradients of these quantities are determined experimentally within a sheath of a capacitively coupled rf, 13.56 MHz, discharge at enhanced argon gas pressures of 30, 55, and 100 Pa. The parameters are derived directly from comparative measurements of levitation positions of the particles of different sizes and variations in the levitation heights caused by formation of new dust layers. The electrostatic effect of the horizontally extended dust layers on the sheath electric field is investigated.

Ground-up-to-Space (GUTS) Laser Propagation Code Description and Manual

DTIC Science & Technology

1984-06-01

34itteiy bean quality, and turbulence. Essentially, these effects are replaced by a phase screen at the aperture which multiplies the initial complex ...coherence length # Po , in terms of Fned’s [fief. 35] coher- ence cianeter , r». 75 Po = r /2 . 1 (3.21) Substituting Fried’s definition for r Po = 2.1 ? Ql f...comhination of the two are used, lrel tb = j~l-(d/b) 21 lrel u + (d/b) 2 Irel t (3-WJ kuere d is the apertue dianeter and b is the waist cianeter cf th€ teas

What is the effect of chest physiotherapy in hospitalized children with pneumonia?

PubMed

Damiani, Felipe; Adasme, Rodrigo

2015-10-19

Chest physiotherapy is applied in clinical practice for the treatment of pneumonia. However, its use is still controversial. Searching in Epistemonikos database, which is maintained by screening 30 databases, we identified one systematic review including two relevant randomized controlled trials. We combined the evidence using meta-analysis and generated a summary of findings table following the GRADE approach. We concluded it is unclear whether chest physiotherapy increases or decreases the length of hospitalization, severity, or the time to clinical improvement in children with pneumonia because the certainty of the evidence is very low.

Restriction fragment length polymorphism among Israeli Holstein-Friesian dairy bulls.

PubMed

Beckmann, J S; Kashi, Y; Hallerman, E M; Nave, A; Soller, M

1986-01-01

Israeli Holstein-Friesian dairy bulls were screened for restriction fragment length polymorphisms by hybridizing cloned DNA probes for bovine growth hormone, for chymosin, and for rat muscle beta-actin to restriction endonuclease-digested DNA immobilized on nitrocellulose filters. The population proved to be polymorphic at the growth hormone locus, with evidence consistent with the phenotypes being inherited in allelic fashion. A low level of polymorphism was also observed at one of the beta-actin gene family loci. The chymosin locus was monomorphic with the restriction enzymes utilized. The results illustrate the power of restriction fragment length polymorphism methodology in visualizing genetic variability in dairy cattle populations.

Effects of Diagnosis by Newborn Screening for Cystic Fibrosis on Weight and Length in the First Year of Life

PubMed Central

Leung, Daniel H.; Heltshe, Sonya L.; Borowitz, Drucy; Gelfond, Daniel; Kloster, Margaret; Heubi, James E.; Stalvey, Michael; Ramsey, Bonnie W.

2017-01-01

IMPORTANCE Since the implementation of universal newborn screening (NBS) for cystic fibrosis (CF), the timing and magnitude of growth deficiency or its association with correlates of disease among infants with CF who underwent NBS has not been well described. OBJECTIVE To examine incremental weight gain, linear growth, and clinical features in the first year of life among infants with CF who underwent NBS. DESIGN, SETTING, AND PARTICIPANTS The Baby Observational and Nutrition Study (BONUS), a multicenter, longitudinal, observational cohort study, was conducted during regular CF clinic visits in the first 12 months of life at 28 US Cystic Fibrosis Foundation–accredited Care Centers from January 7, 2012, through May 31, 2015. Participants included 231 infants younger than 3.5 months who underwent NBS and had confirmed CF, with a gestational age of at least 35 weeks, birth weight of at least 2.5 kg, and toleration of full oral feeds. Of these, 222 infants (96.1%) had follow-up beyond 6 months of age and 215 (93.1%) completed 12 months of follow-up. EXPOSURE Cystic fibrosis. MAIN OUTCOME AND MEASURES Attained weight and length for age and World Health Organization normative z scores at ages 1 to 6 and 8, 10, and 12 months (defined a priori). RESULTS Of the 231 infants enrolled, 110 infants (47.6%) were female and 121 (52.4%) were male, with a mean (SD) age of 2.58 (0.69) months. BONUS infants had lower than mean birth weights (mean z score, −0.15; 95% CI, −0.27 to −0.04) and higher birth lengths (mean z score, 0.44; 95% CI, 0.26 to 0.62). They achieved normal weight by 12 months, a significant improvement over a prescreening cohort of newborns with CF from 20 years before the contemporary cohort (mean z score increase, 0.57; 95% CI, 0.37–0.77). However, length was lower than the mean at 12 months (mean z score, −0.56; 95% CI, −0.70 to −0.42). Only 30 infants (13.6%) were at less than the 10th percentile of weight for age, whereas 53 (23.9%) were at less than the 10th percentile of length for age at more than half their visits. Male sex, pancreatic insufficiency, meconium ileus, histamine blocker use, and respiratory Pseudomonas aeruginosa infection were associated with lower weight or length during the first year. Insulinlike growth factor 1 levels were significantly lower among low-length infants. Persistently low-weight infants consumed significantly more calories, and weight and length z scores were negatively correlated with caloric intake. CONCLUSIONS AND RELEVANCE Since initiation of universal NBS for CF, significant improvement has occurred in nutritional status, with normalization of weight in the first year of life. However, length stunting remains common. PMID:28437538

Supramolecular Packing Controls H 2 Photocatalysis in Chromophore Amphiphile Hydrogels

DOE PAGES

Weingarten, Adam S.; Kazantsev, Roman V.; Palmer, Liam C.; ...

2015-11-21

Light harvesting supramolecular assemblies are potentially useful structures as components of solar-to-fuel conversion materials. The development of these functional constructs requires an understanding of optimal packing modes for chromophores. Here, we investigated assembly in water and the photocatalytic function of perylene monoimide chromophore amphiphiles with different alkyl linker lengths separating their hydrophobic core and the hydrophilic carboxylate headgroup. We found that these chromophore amphiphiles (CAs) self-assemble into charged nanostructures of increasing aspect ratio as the linker length is increased. The addition of salt to screen the charged nanostructures induced the formation of hydrogels and led to internal crystallization within somemore » of the nanostructures. For linker lengths up to seven methylenes, the CAs were found to pack into 2D crystalline unit cells within ribbon-shaped nanostructures, whereas the nine methylene CAs assembled into long nanofibers without crystalline molecular packing. At the same time, the different molecular packing arrangements after charge screening led to different absorbance spectra, despite the identical electronic properties of all PMI amphiphiles. While the crystalline CAs formed electronically coupled H-aggregates, only CAs with intermediate linker lengths showed evidence of high intermolecular orbital overlap. Photocatalytic hydrogen production using a nickel-based catalyst was observed in all hydrogels, with the highest turnovers observed for CA gels having intermediate linker lengths. Lastly, we conclude that the improved photocatalytic performance of the hydrogels formed by supramolecular assemblies of the intermediate linker CA molecules likely arises from improved exciton splitting efficiencies due to their higher orbital overlap.« less

Disease management for the diabetic foot: effectiveness of a diabetic foot prevention program to reduce amputations and hospitalizations.

PubMed

Lavery, Lawrence A; Wunderlich, Robert P; Tredwell, Jeffrey L

2005-10-01

To demonstrate the effectiveness of a diabetic foot disease management program in a managed care organization. We implemented a lower extremity disease management program consisting of screening and treatment protocols for diabetic members in a managed care organization. Screening consisted of evaluation of neuropathy, peripheral vascular disease, deformities, foot pressures, and history of lower extremity pathology. We stratified patients into low and high-risk groups, and implemented preventive or acute care protocols. Utilization was tracked for 28 months and compared to 12 months of historic data prior to implementation of the disease management program. After we implemented the disease management program, the incidence of amputations decreased 47.4% from 12.89 per 1000 diabetics per year to 6.18 (p<0.05). The number of foot-related hospital admissions decreased 37.8% from 22.86 per 1000 members per year to 14.23 (37.8%). The average inpatient length-of-stay (LOS) was reduced 21.7% from 4.75 to 3.72 days (p<0.05). In addition, there was a 69.8% reduction in the number of skilled nursing facility (SNF) admissions per 1000 members per year (Table 1) and a 38.2% reduction in the average SNF LOS from 8.72 to 6.52 days (p<0.05). A population-based screening and treatment program for the diabetic foot can dramatically reduce hospitalizations and clinical outcomes.

Mycobacterium avium restriction fragment length polymorphism-IS IS1245 and the simple double repetitive element polymerase chain reaction typing method to screen genetic diversity in Brazilian strains.

PubMed

Sequeira, Patrícia Carvalho de; Fonseca, Leila de Souza; Silva, Marlei Gomes da; Saad, Maria Helena Féres

2005-11-01

Simple double repetitive element polymerase chain reaction (MaDRE-PCR) and Pvu II-IS1245 restriction fragment length polymorphism (RFLP) typing methods were used to type 41 Mycobacterium avium isolates obtained from 14 AIDS inpatients and 10 environment and animals specimens identified among 53 mycobacteria isolated from 237 food, chicken, and pig. All environmental and animals strains showed orphan patterns by both methods. By MaDRE-PCR four patients, with multiple isolates, showed different patterns, suggesting polyclonal infection that was confirmed by RFLP in two of them. This first evaluation of MaDRE-PCR on Brazilian M. avium strains demonstrated that the method seems to be useful as simple and less expensive typing method for screening genetic diversity in M. avium strains on selected epidemiological studies, although with limitation on analysis identical patterns except for one band.

Rapid and Facile Microwave-Assisted Surface Chemistry for Functionalized Microarray Slides

PubMed Central

Lee, Jeong Heon; Hyun, Hoon; Cross, Conor J.; Henary, Maged; Nasr, Khaled A.; Oketokoun, Rafiou; Choi, Hak Soo; Frangioni, John V.

2011-01-01

We describe a rapid and facile method for surface functionalization and ligand patterning of glass slides based on microwave-assisted synthesis and a microarraying robot. Our optimized reaction enables surface modification 42-times faster than conventional techniques and includes a carboxylated self-assembled monolayer, polyethylene glycol linkers of varying length, and stable amide bonds to small molecule, peptide, or protein ligands to be screened for binding to living cells. We also describe customized slide racks that permit functionalization of 100 slides at a time to produce a cost-efficient, highly reproducible batch process. Ligand spots can be positioned on the glass slides precisely using a microarraying robot, and spot size adjusted for any desired application. Using this system, we demonstrate live cell binding to a variety of ligands and optimize PEG linker length. Taken together, the technology we describe should enable high-throughput screening of disease-specific ligands that bind to living cells. PMID:23467787

Specific features of direct formation of graphite-like microstructures in polycarbonate samples by single femtosecond laser pulses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ganin, D V; Lapshin, K E; Obidin, A Z

2015-11-30

We present the result of the experiments on producing graphite-like cylindrical microstructures by focusing single femtosecond laser pulses into the bulk of a transparent polymer (polycarbonate). The microstructures are embedded in a cladding with a modified refractive index, possessing waveguide properties. In the experiments with nontransparent screens and diaphragms, placed in the laser beam in front of the entrance pupil of the objective with a large numerical aperture, we have found that the paraxial rays are blocked by the peripheral ones, which reduces the length of the destruction region in the pre-focal zone. In the experiments with transparent screens andmore » diaphragms, introducing optical delays τ{sub d} between the paraxial and peripheral rays, the quantitative dependence of the destruction region length in the pre-focal zone on the value of τ{sub d} is determined. (interaction of laser radiation with matter. laser plasma)« less

Kinetics of interior loop formation in semiflexible chains.

PubMed

Hyeon, Changbong; Thirumalai, D

2006-03-14

Loop formation between monomers in the interior of semiflexible chains describes elementary events in biomolecular folding and DNA bending. We calculate analytically the interior distance distribution function for semiflexible chains using a mean field approach. Using the potential of mean force derived from the distance distribution function we present a simple expression for the kinetics of interior looping by adopting Kramers theory. For the parameters, that are appropriate for DNA, the theoretical predictions in comparison with the case are in excellent agreement with explicit Brownian dynamics simulations of wormlike chain (WLC) model. The interior looping times (tauIC) can be greatly altered in the cases when the stiffness of the loop differs from that of the dangling ends. If the dangling end is stiffer than the loop then tauIC increases for the case of the WLC with uniform persistence length. In contrast, attachment of flexible dangling ends enhances rate of interior loop formation. The theory also shows that if the monomers are charged and interact via screened Coulomb potential then both the cyclization (tauc) and interior looping (tauIC) times greatly increase at low ionic concentration. Because both tauc and tauIC are determined essentially by the effective persistence length [lp(R)] we computed lp(R) by varying the range of the repulsive interaction between the monomers. For short range interactions lp(R) nearly coincides with the bare persistence length which is determined largely by the backbone chain connectivity. This finding rationalizes the efficacy of describing a number of experimental observations (response of biopolymers to force and cyclization kinetics) in biomolecules using WLC model with an effective persistence length.

GFP-based fluorescence assay for CAG repeat instability in cultured human cells.

PubMed

Santillan, Beatriz A; Moye, Christopher; Mittelman, David; Wilson, John H

2014-01-01

Trinucleotide repeats can be highly unstable, mutating far more frequently than point mutations. Repeats typically mutate by addition or loss of units of the repeat. CAG repeat expansions in humans trigger neurological diseases that include myotonic dystrophy, Huntington disease, and several spinocerebellar ataxias. In human cells, diverse mechanisms promote CAG repeat instability, and in mice, the mechanisms of instability are varied and tissue-dependent. Dissection of mechanistic complexity and discovery of potential therapeutics necessitates quantitative and scalable screens for repeat mutation. We describe a GFP-based assay for screening modifiers of CAG repeat instability in human cells. The assay exploits an engineered intronic CAG repeat tract that interferes with expression of an inducible GFP minigene. Like the phenotypes of many trinucleotide repeat disorders, we find that GFP function is impaired by repeat expansion, in a length-dependent manner. The intensity of fluorescence varies inversely with repeat length, allowing estimates of repeat tract changes in live cells. We validate the assay using transcription through the repeat and engineered CAG-specific nucleases, which have previously been reported to induce CAG repeat instability. The assay is relatively fast and should be adaptable to large-scale screens of chemical and shRNA libraries.

GFP-Based Fluorescence Assay for CAG Repeat Instability in Cultured Human Cells

PubMed Central

Santillan, Beatriz A.; Moye, Christopher; Mittelman, David; Wilson, John H.

2014-01-01

Trinucleotide repeats can be highly unstable, mutating far more frequently than point mutations. Repeats typically mutate by addition or loss of units of the repeat. CAG repeat expansions in humans trigger neurological diseases that include myotonic dystrophy, Huntington disease, and several spinocerebellar ataxias. In human cells, diverse mechanisms promote CAG repeat instability, and in mice, the mechanisms of instability are varied and tissue-dependent. Dissection of mechanistic complexity and discovery of potential therapeutics necessitates quantitative and scalable screens for repeat mutation. We describe a GFP-based assay for screening modifiers of CAG repeat instability in human cells. The assay exploits an engineered intronic CAG repeat tract that interferes with expression of an inducible GFP minigene. Like the phenotypes of many trinucleotide repeat disorders, we find that GFP function is impaired by repeat expansion, in a length-dependent manner. The intensity of fluorescence varies inversely with repeat length, allowing estimates of repeat tract changes in live cells. We validate the assay using transcription through the repeat and engineered CAG-specific nucleases, which have previously been reported to induce CAG repeat instability. The assay is relatively fast and should be adaptable to large-scale screens of chemical and shRNA libraries. PMID:25423602

When and Why Threats Go Undetected: Impacts of Event Rate and Shift Length on Threat Detection Accuracy During Airport Baggage Screening.

PubMed

Meuter, Renata F I; Lacherez, Philippe F

2016-03-01

We aimed to assess the impact of task demands and individual characteristics on threat detection in baggage screeners. Airport security staff work under time constraints to ensure optimal threat detection. Understanding the impact of individual characteristics and task demands on performance is vital to ensure accurate threat detection. We examined threat detection in baggage screeners as a function of event rate (i.e., number of bags per minute) and time on task across 4 months. We measured performance in terms of the accuracy of detection of Fictitious Threat Items (FTIs) randomly superimposed on X-ray images of real passenger bags. Analyses of the percentage of correct FTI identifications (hits) show that longer shifts with high baggage throughput result in worse threat detection. Importantly, these significant performance decrements emerge within the first 10 min of these busy screening shifts only. Longer shift lengths, especially when combined with high baggage throughput, increase the likelihood that threats go undetected. Shorter shift rotations, although perhaps difficult to implement during busy screening periods, would ensure more consistently high vigilance in baggage screeners and, therefore, optimal threat detection and passenger safety. © 2015, Human Factors and Ergonomics Society.

A study of the antibacterial activity of L-phenylalanine and L-tyrosine esters in relation to their CMCs and their interactions with 1,2-dipalmitoyl-sn-glycero-3-phosphocholine, DPPC as model membrane.

PubMed

Joondan, Nausheen; Jhaumeer-Laulloo, Sabina; Caumul, Prakashanand

2014-01-01

Cationic amino acid-based surfactants are known to interact with the lipid bilayer of cell membranes resulting in depolarization, lysis and cell death through a disruption of the membrane topology. A range of cationic surfactant analogues derived from L-Phenylalanine (C1-C20) and L-Tyrosine (C8-C14) esters have been synthesized and screened for their antibacterial activity. The esters were more active against gram positive than gram negative bacteria. The activity increased with increasing chain length, exhibiting a cut-off effect at C12 for gram positive and C8/C10 for gram negative bacteria. The cut-off effect for gram negative bacteria was observed at a lower alkyl chain length. The CMC was correlated with the MIC, inferring that micellar activity contribute to the cut-off effect in antibacterial activity. The interaction of the cationic surfactants with the phospholipid vesicles (1,2-dipalmitoyl-sn-glycero-3-phosphocholine, DPPC) in the presence of 1-anilino-8-naphthalene sulfonate (ANS) and 1,6-diphenyl-1,3,5-hexatriene (DPH) as fluorescence probes showed that an increase in ionic interaction causes an increase in antibacterial activity. Increase in hydrophobic interaction increases the antibacterial activity only to a certain chain length, attributing to the cut-off effect. Therefore, both electrostatic and hydrophobic interactions, involving the polar and nonpolar moieties are of paramount importance for the bactericidal properties. Copyright © 2014 Elsevier GmbH. All rights reserved.

The Genetic and Molecular Organization of the Dopa Decarboxylase Gene Cluster of Drosophila Melanogaster

PubMed Central

Stathakis, D. G.; Pentz, E. S.; Freeman, M. E.; Kullman, J.; Hankins, G. R.; Pearlson, N. J.; Wright, TRF.

1995-01-01

We report the complete molecular organization of the Dopa decarboxylase gene cluster. Mutagenesis screens recovered 77 new Df(2L)TW130 recessive lethal mutations. These new alleles combined with 263 previously isolated mutations in the cluster to define 18 essential genes. In addition, seven new deficiencies were isolated and characterized. Deficiency mapping, restriction fragment length polymorphism (RFLP) analysis and P-element-mediated germline transformation experiments determined the gene order for all 18 loci. Genomic and cDNA restriction endonuclease mapping, Northern blot analysis and DNA sequencing provided information on exact gene location, mRNA size and transcriptional direction for most of these loci. In addition, this analysis identified two transcription units that had not previously been identified by extensive mutagenesis screening. Most of the loci are contained within two dense subclusters. We discuss the effectiveness of mutagens and strategies used in our screens, the variable mutability of loci within the genome of Drosophila melanogaster, the cytological and molecular organization of the Ddc gene cluster, the validity of the one band-one gene hypothesis and a possible purpose for the clustering of genes in the Ddc region. PMID:8647399

Prenasal thickness to nasal bone length ratio: effectiveness as a second or third trimester marker for Down syndrome.

PubMed

Tournemire, A; Groussolles, M; Ehlinger, V; Lusque, A; Morin, M; Benevent, J B; Arnaud, C; Vayssière, C

2015-08-01

To assess the value of the prenasal thickness to nasal bone length ratio (PT/NBL) for detecting trisomy 21 (T21) after the first trimester. Two examiners blinded to fetal T21 status retrospectively measured prenasal thickness (PT) and nasal bone length (NBL) of T21 and control fetuses at 15-36 weeks' gestational age on two-dimensional images from all T21-screening ultrasounds from November 2010 to April 2013. ROC curve analysis and its diagnostic values determined the best cut-off value for the ratio. Interobserver reproducibility was assessed. Good quality ultrasound profile images were available for 26 fetuses with T21 compared to 91 normal fetuses. The median PT/NBL ratio was 1.28 for T21 and 0.73 for control fetuses (p<0.0001). The PT/NBL ratio performed significantly better (AUC 0.99; 95%CI 0.97-1) than either PT (0.82; 0.73-0.91) or NBL (0.91; 0.85-0.98). The optimal PT/NBL ratio cut-off was 0.98, with a sensitivity of 88.5% [76.2-100%] and a specificity of 100%. Interobserver variability was low. The PT/NBL ratio is a strong marker for detecting T21 in the second and third trimesters, significantly more effective than either indicator alone. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Echohydrology of a floodplain forest: relationships between vegetation and groundwater resources at Congaree National Park, South Carolina USA

Treesearch

Timothy Callahan; Lauren Senn

2016-01-01

The goal of this project was to investigate the relationship between the shallow, unconfined aquifer and woody vegetation at eight sites of the Congaree Observation Well Network at Congaree National Park near Hopkins, South Carolina. Eight piezometers with screens of 1.5-m length (top-of-screen depths ranging from 3.0 to 5.0 m below ground surface) along a 1.8-km cross...

Minoxidil is a potential neuroprotective drug for paclitaxel-induced peripheral neuropathy

PubMed Central

Chen, Yi-Fan; Chen, Li-Hsien; Yeh, Yu-Min; Wu, Pei-Ying; Chen, Yih-Fung; Chang, Lian-Yun; Chang, Jang-Yang; Shen, Meng-Ru

2017-01-01

Chemotherapy-induced peripheral neuropathy (CIPN) is a common side effect of cancer treatment. No medication has been shown to be effective in the treatment of CIPN. This study aims to integrate the image-based high-content screening, mouse behavior models and mechanistic cell-based assays to discover potential neuroprotective drugs. Among screened compounds, minoxidil showed the most potent neuroprotective effect against paclitaxel, with regard to neurite outgrowth of dorsal root ganglia (DRG). Minoxidil protected mice from thermal insensitivity and alleviated mechanical allodynia in paclitaxel-treated mice. The ultrastructure and quantified G-ratio of myelin integrity of sciatic nerve tissues supported the observations in mouse behavioral tests. The mechanistic study on DRG neurons suggested that minoxidil suppressed neuroinflammation and remodeled the dysregulation of intracellular calcium homeostasis provoked by paclitaxel. Importantly, minoxidil showed a synergistic anti-tumor effect with paclitaxel both in tumor xenograft models of cervical and breast cancer. Interestingly, the quantitative assays on hair length and hair growth both exhibited that minoxidil significantly improved the hair quality after chemotherapy. Since minoxidil is a drug approved by the Food and Drug Administration (FDA), the safety and biocompatibility are well documented. The immediate next step is to launch an early-stage clinical trial intending to prevent CIPN by minoxidil. PMID:28349969

Long-range electrostatic screening in ionic liquids

PubMed Central

Gebbie, Matthew A.; Dobbs, Howard A.; Valtiner, Markus; Israelachvili, Jacob N.

2015-01-01

Electrolyte solutions with high concentrations of ions are prevalent in biological systems and energy storage technologies. Nevertheless, the high interaction free energy and long-range nature of electrostatic interactions makes the development of a general conceptual picture of concentrated electrolytes a significant challenge. In this work, we study ionic liquids, single-component liquids composed solely of ions, in an attempt to provide a novel perspective on electrostatic screening in very high concentration (nonideal) electrolytes. We use temperature-dependent surface force measurements to demonstrate that the long-range, exponentially decaying diffuse double-layer forces observed across ionic liquids exhibit a pronounced temperature dependence: Increasing the temperature decreases the measured exponential (Debye) decay length, implying an increase in the thermally driven effective free-ion concentration in the bulk ionic liquids. We use our quantitative results to propose a general model of long-range electrostatic screening in ionic liquids, where thermally activated charge fluctuations, either free ions or correlated domains (quasiparticles), take on the role of ions in traditional dilute electrolyte solutions. This picture represents a crucial step toward resolving several inconsistencies surrounding electrostatic screening and charge transport in ionic liquids that have impeded progress within the interdisciplinary ionic liquids community. More broadly, our work provides a previously unidentified way of envisioning highly concentrated electrolytes, with implications for diverse areas of inquiry, ranging from designing electrochemical devices to rationalizing electrostatic interactions in biological systems. PMID:26040001

[Phenotype-based primary screening for drugs promoting neuronal subtype differentiation in embryonic stem cells with light microscope].

PubMed

Gao, Yi-ning; Wang, Dan-ying; Pan, Zong-fu; Mei, Yu-qin; Wang, Zhi-qiang; Zhu, Dan-yan; Lou, Yi-jia

2012-07-01

To set up a platform for phenotype-based primary screening of drug candidates promoting neuronal subtype differentiation in embryonic stem cells (ES) with light microscope. Hanging drop culture 4-/4+ method was employed to harvest the cells around embryoid body (EB) at differentiation endpoint. Morphological evaluation for neuron-like cells was performed with light microscope. Axons for more than three times of the length of the cell body were considered as neuron-like cells. The compound(s) that promote neuron-like cells was further evaluated. Icariin (ICA, 10(-6)mol/L) and Isobavachin (IBA, 10(-7)mol/L) were selected to screen the differentiation-promoting activity on ES cells. Immunofluorescence staining with specific antibodies (ChAT, GABA) was used to evaluate the neuron subtypes. The cells treated with IBA showed neuron-like phenotype, but the cells treated with ICA did not exhibit the morphological changes. ES cells treated with IBA was further confirmed to be cholinergic and GABAergic neurons. Phenotypic screening with light microscope for molecules promoting neuronal differentiation is an effective method with advantages of less labor and material consuming and time saving, and false-positive results derived from immunofluorescence can be avoided. The method confirms that IBA is able to facilitate ES cells differentiating into neuronal cells, including cholinergic neurons and GABAergic neurons.

Novel Connections Between DNA Replication, Telomere Homeostasis, and the DNA Damage Response Revealed by a Genome-Wide Screen for TEL1/ATM Interactions in Saccharomyces cerevisiae

PubMed Central

Piening, Brian D.; Huang, Dongqing; Paulovich, Amanda G.

2013-01-01

Tel1 is the budding yeast ortholog of the mammalian tumor suppressor and DNA damage response (DDR) kinase ATM. However, tel1-Δ cells, unlike ATM-deficient cells, do not exhibit sensitivity to DNA-damaging agents, but do display shortened (but stably maintained) telomere lengths. Neither the extent to which Tel1p functions in the DDR nor the mechanism by which Tel1 contributes to telomere metabolism is well understood. To address the first question, we present the results from a comprehensive genome-wide screen for genetic interactions with tel1-Δ that cause sensitivity to methyl methanesulfonate (MMS) and/or ionizing radiation, along with follow-up characterizations of the 13 interactions yielded by this screen. Surprisingly, many of the tel1-Δ interactions that confer DNA damage sensitivity also exacerbate the short telomere phenotype, suggesting a connection between these two phenomena. Restoration of normal telomere length in the tel1-Δ xxx-Δ mutants results in only minor suppression of the DNA damage sensitivity, demonstrating that the sensitivity of these mutants must also involve mechanisms independent of telomere length. In support of a model for increased replication stress in the tel1-Δ xxx-Δ mutants, we show that depletion of dNTP pools through pretreatment with hydroxyurea renders tel1-Δ cells (but not wild type) MMS-sensitive, demonstrating that, under certain conditions, Tel1p does indeed play a critical role in the DDR. PMID:23378069

Remanent-magnetization decay in CoCr films

NASA Astrophysics Data System (ADS)

Skorjanec, J.; Cottles, V.; Close, J.; Iverson, P.; Edwards, J.; Dahlberg, E. Dan

1990-05-01

The decay of the remanent magnetization of several thin films of CoCr has been studied using the extraordinary Hall effect as a probe of the component of the magnetization perpendicular to the plane of the films. Consistent with previous measurements of CoCr, the remanent magnetization decays quasilogarithmically with time after the removal of a saturating magnetic field. In the present work the effect of a magnetically soft keeper layer on the decay of the magnetization has been investigated. It is found that the keeper layer does not affect the remanent magnetization nor does it decrease the decay rate of the perpendicular magnetization. This result indicates that the soft keeper layer is not effective at screening the demagnetization field on a length scale relevant to the decay-producing fields.

On the Impact of Electrostatic Correlations on the Double-Layer Polarization of a Spherical Particle in an Alternating Current Field.

PubMed

Alidoosti, Elaheh; Zhao, Hui

2018-05-15

At concentrated electrolytes, the ion-ion electrostatic correlation effect is considered an important factor in electrokinetics. In this paper, we compute, in theory and simulation, the dipole moment for a spherical particle (charged, dielectric) under the action of an alternating electric field using the modified continuum Poisson-Nernst-Planck (PNP) model by Bazant et al. [ Double Layer in Ionic Liquids: Overscreening Versus Crowding . Phys. Rev. Lett. 2011 , 106 , 046102 ] We investigate the dependency of the dipole moment in terms of frequency and its variation with such quantities like ζ-potential, electrostatic correlation length, and double-layer thickness. With thin electric double layers, we develop simple models through performing an asymptotic analysis of the modified PNP model. We also present numerical results for an arbitrary Debye screening length and electrostatic correlation length. From the results, we find a complicated impact of electrostatic correlations on the dipole moment. For instance, with increasing the electrostatic correlation length, the dipole moment decreases and reaches a minimum and then it goes up. This is because of initially decreasing of surface conduction and finally increasing due to the impact of ion-ion electrostatic correlations on ion's convection and migration. Also, we show that in contrast to the standard PNP model, the modified PNP model can qualitatively explain the data from the experimental results in multivalent electrolytes.

Bone architecture and strength in the growing skeleton: the role of sedentary time.

PubMed

Gabel, Leigh; McKay, Heather A; Nettlefold, Lindsay; Race, Douglas; Macdonald, Heather M

2015-02-01

Today's youths spend close to 60% of their waking hours in sedentary activities; however, we know little about the potentially deleterious effects of sedentary time on bone health during this key period of growth and development. Thus, our objective was to determine whether sedentary time is associated with bone architecture, mineral density, and strength in children, adolescents, and young adults. We used high-resolution peripheral quantitative computed tomography (Scanco Medical) to measure bone architecture (trabecular and cortical microstructure and bone macrostructure) and cortical and total bone mineral density (BMD) at the distal tibia (8% site) in 154 males and 174 females (9-20 yr) who were participants in the University of British Columbia Healthy Bones III study. We applied finite element analysis to high-resolution peripheral quantitative computed tomography scans to estimate bone strength. We assessed self-reported screen time in all participants using a questionnaire and sedentary time (volume and patterns) in a subsample of participants with valid accelerometry data (89 males and 117 females; ActiGraph GT1M). We fit sex-specific univariate multivariable regression models, controlling for muscle cross-sectional area, limb length, maturity, ethnicity, dietary calcium, and physical activity. We did not observe independent effect of screen time on bone architecture, BMD, or strength in either sex (P > 0.05). Likewise, when adjusted for muscle cross-sectional area, limb length, maturity, ethnicity, dietary calcium, and physical activity, accelerometry-derived volume of sedentary time and breaks in bouts of sedentary time were not a determinant of bone architecture, BMD, or strength in either sex (P > 0.05). Further study is warranted to determine whether the lack of association between sedentary time and bone architecture, BMD, and strength at the distal tibia is also present at other skeletal sites.

Radiographic Investigation of the Distal Extension of Fractures Into the Articular Surface of the Tibia (The RIDEFAST Study).

PubMed

Marchand, Lucas S; Rane, Ajinkya A; Working, Zachary M; Jacobson, Lance G; Kubiak, Erik N; Higgins, Thomas F; Rothberg, David L

2017-12-01

To determine whether radiographic measurements are predictive of involvement of the distal tibia articular surface in tibial shaft fractures. Retrospective review. Academic Level-I trauma hospital. Two-hundred seventeen patients with tibial shaft fractures distal to the isthmus (OTA/AO: 42-A1-3; 42-B1-3; 42-C1-3; and 43-A1-3). Analysis of anteroposterior (AP) and lateral radiographs. The following parameters were measured: (1) angle between the predominant fracture line and the plane of the tibial plafond (α-angle), (2) length of the shaft fracture, (3) distance from the most inferior extent of the shaft fracture to the tibial plafond (DTP), (4) width of the tibial plafond, (5) width of the tibial isthmus, (6) ratio of fracture length to DTP (FTP), and (7) fibular fracture distance. Distal intra-articular involvement (DIA). A total of 217 patients were identified, 56 (26%) with DIA. The FTP ratio as measured on both the AP (odds ratio: 8.20, confidence interval, 4.26-17.22, P < 0.0001) and lateral radiographs (10.00, 4.78-23.23, <0.0001) was the most effective screening measurement for DIA. AP and lateral FTP ratios of 0.224 and 0.255, respectively, achieved a negative predictive value of 100%, eliminating the need for computed tomography in 16%-23% of injuries. Involvement of the distal articular surface in patients with distal tibial shaft fractures is significantly associated with fracture geometry and pattern. The FTP ratio may be used as an effective screening tool to rule out of intra-articular involvement. Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Influence of salt tolerant Trichoderma spp. on growth of maize (Zea mays) under different salinity conditions.

PubMed

Kumar, Krishna; Manigundan, K; Amaresan, Natarajan

2017-02-01

In the present study, a total of 70 Trichoderma spp. were isolated from the rhizosphere soils of vegetable and spice crops that were grown in Andaman and Nicobar Islands, India. Initial screening of Trichoderma spp. for salt tolerant properties showed 32 isolates were able to tolerate 10% NaCl. Furthermore, these isolates were screened for their potential plant growth-promoting characteristics such as IAA production, phosphate solubilization, and siderophore production. Among 32 isolates, nine isolates were able to produce IAA, siderophore, and solubilize phosphate. Jar trial was carried out on maize under axenic conditions at 1.67, 6.25, 11.25, 17.2, and 22.9 dS m -1 salt stress using the best nine isolates. Three isolates (TRC3, NRT2, and THB3) were effective in improving germination percentage, reducing reduction percentage of germination (RPG) and also in increasing the shoot and root length under axenic conditions. These three isolates were further tested under pot trial at 52 (sea water), 27, 15, 7, and 1.67 dS m -1 . TRC3 was found to be the most effective isolate compared to the other isolates and significantly increased the physiological parameters like shoot, root length, leaf area, total biomass, and stem and leaf fresh weight at all stress levels. Similarly, total chlorophyll content also increased by TRC3 over control. All three isolates, NRT2, TRC3, and THB3 showed lower accumulation of malondialdehyde (MDA) content whereas, proline and phenol content were higher than the uninoculated control plants under both normal and saline conditions. The results suggest that these isolates could be utilized for the alleviation of salinity stress in maize. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Complex fluids with mobile charge-regulating macro-ions

NASA Astrophysics Data System (ADS)

Markovich, Tomer; Andelman, David; Podgornik, Rudi

2017-10-01

We generalize the concept of charge regulation of ionic solutions, and apply it to complex fluids with mobile macro-ions having internal non-electrostatic degrees of freedom. The suggested framework provides a convenient tool for investigating systems where mobile macro-ions can self-regulate their charge (e.g., proteins). We show that even within a simplified charge-regulation model, the charge dissociation equilibrium results in different and notable properties. Consequences of the charge regulation include a positional dependence of the effective charge of the macro-ions, a non-monotonic dependence of the effective Debye screening length on the concentration of the monovalent salt, a modification of the electric double-layer structure, and buffering by the macro-ions of the background electrolyte.

Use of microwaves for the detection of corrosion under insulation: The effect of bends

NASA Astrophysics Data System (ADS)

Jones, R. E.; Simonetti, F.; Lowe, M. J. S.; Bradley, I. P.

2012-05-01

The detection of corrosion under insulation is an ongoing challenge in the oil and gas industry. An early warning of areas of pipe at risk of corrosion can be obtained by screening along the length of the pipeline to inspect the insulation layer for the presence of water, as water is a necessary precursor to corrosion. Long-range detection of water volumes can be achieved with microwave signals, using the structure of the clad and insulated pipeline as a coaxial waveguide, with water volumes presenting an impedance contrast and producing reflections of the incident microwave signal. An investigation into what effect bends in the pipeline will have on this inspection technique is presented here.

Spinning fluids reactor

DOEpatents

Miller, Jan D; Hupka, Jan; Aranowski, Robert

2012-11-20

A spinning fluids reactor, includes a reactor body (24) having a circular cross-section and a fluid contactor screen (26) within the reactor body (24). The fluid contactor screen (26) having a plurality of apertures and a circular cross-section concentric with the reactor body (24) for a length thus forming an inner volume (28) bound by the fluid contactor screen (26) and an outer volume (30) bound by the reactor body (24) and the fluid contactor screen (26). A primary inlet (20) can be operatively connected to the reactor body (24) and can be configured to produce flow-through first spinning flow of a first fluid within the inner volume (28). A secondary inlet (22) can similarly be operatively connected to the reactor body (24) and can be configured to produce a second flow of a second fluid within the outer volume (30) which is optionally spinning.

Effects of Word Width and Word Length on Optimal Character Size for Reading of Horizontally Scrolling Japanese Words

PubMed Central

Teramoto, Wataru; Nakazaki, Takuyuki; Sekiyama, Kaoru; Mori, Shuji

2016-01-01

The present study investigated, whether word width and length affect the optimal character size for reading of horizontally scrolling Japanese words, using reading speed as a measure. In Experiment 1, three Japanese words, each consisting of four Hiragana characters, sequentially scrolled on a display screen from right to left. Participants, all Japanese native speakers, were instructed to read the words aloud as accurately as possible, irrespective of their order within the sequence. To quantitatively measure their reading performance, we used rapid serial visual presentation paradigm, where the scrolling rate was increased until the participants began to make mistakes. Thus, the highest scrolling rate at which the participants’ performance exceeded 88.9% correct rate was calculated for each character size (0.3°, 0.6°, 1.0°, and 3.0°) and scroll window size (5 or 10 character spaces). Results showed that the reading performance was highest in the range of 0.6° to 1.0°, irrespective of the scroll window size. Experiment 2 investigated whether the optimal character size observed in Experiment 1 was applicable for any word width and word length (i.e., the number of characters in a word). Results showed that reading speeds were slower for longer than shorter words and the word width of 3.6° was optimal among the word lengths tested (three, four, and six character words). Considering that character size varied depending on word width and word length in the present study, this means that the optimal character size can be changed by word width and word length in scrolling Japanese words. PMID:26909052

Effects of Word Width and Word Length on Optimal Character Size for Reading of Horizontally Scrolling Japanese Words.

PubMed

Teramoto, Wataru; Nakazaki, Takuyuki; Sekiyama, Kaoru; Mori, Shuji

2016-01-01

The present study investigated, whether word width and length affect the optimal character size for reading of horizontally scrolling Japanese words, using reading speed as a measure. In Experiment 1, three Japanese words, each consisting of four Hiragana characters, sequentially scrolled on a display screen from right to left. Participants, all Japanese native speakers, were instructed to read the words aloud as accurately as possible, irrespective of their order within the sequence. To quantitatively measure their reading performance, we used rapid serial visual presentation paradigm, where the scrolling rate was increased until the participants began to make mistakes. Thus, the highest scrolling rate at which the participants' performance exceeded 88.9% correct rate was calculated for each character size (0.3°, 0.6°, 1.0°, and 3.0°) and scroll window size (5 or 10 character spaces). Results showed that the reading performance was highest in the range of 0.6° to 1.0°, irrespective of the scroll window size. Experiment 2 investigated whether the optimal character size observed in Experiment 1 was applicable for any word width and word length (i.e., the number of characters in a word). Results showed that reading speeds were slower for longer than shorter words and the word width of 3.6° was optimal among the word lengths tested (three, four, and six character words). Considering that character size varied depending on word width and word length in the present study, this means that the optimal character size can be changed by word width and word length in scrolling Japanese words.

SINGLE-INTERVAL GAS PERMEABILITY ESTIMATION

EPA Science Inventory

Single-interval, steady-steady-state gas permeability testing requires estimation of pressure at a screened interval which in turn requires measurement of friction factors as a function of mass flow rate. Friction factors can be obtained by injecting air through a length of pipe...

Bunch Length Measurements Using CTR at the AWA with Comparison to Simulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neveu, N.; Spentzouris, L.; Halavanau, A.

In this paper we present electron bunch length measurements at the Argonne Wakefield Accelerator (AWA) photoinjector facility. The AWA accelerator has a large dynamic charge density range, with electron beam charge varying between 0.1 nC - 100 nC, and laser spot size diameter at the cathode between 0.1 mm - 18 mm. The bunch length measurements were taken at different charge densities using a metallic screen and a Michelson interferometer to perform autocorrelation scans of the corresponding coherent transition radiation (CTR). A liquid helium-cooled 4K bolometer was used to register the interferometer signal. The experimental results are compared with OPAL-Tmore » numerical simulations.« less

Electronic transport properties of nano-scale Si films: an ab initio study

NASA Astrophysics Data System (ADS)

Maassen, Jesse; Ke, Youqi; Zahid, Ferdows; Guo, Hong

2010-03-01

Using a recently developed first principles transport package, we study the electronic transport properties of Si films contacted to heavily doped n-type Si leads. The quantum transport analysis is carried out using density functional theory (DFT) combined with nonequilibrium Green's functions (NEGF). This particular combination of NEGF-DFT allows the investigation of Si films with thicknesses in the range of a few nanometers and lengths up to tens of nanometers. We calculate the conductance, the momentum resolved transmission, the potential profile and the screening length as a function of length, thickness, orientation and surface structure. Moreover, we compare the properties of Si films with and without a top surface passivation by hydrogen.

National Survey of Preventive Health Services in US Emergency Departments

PubMed Central

Delgado, M. Kit; Acosta, Colleen D.; Ginde, Adit A.; Wang, N. Ewen; Strehlow, Matthew C.; Khandwala, Yash S.; Camargo, Carlos A.

2012-01-01

Study objective We describe the availability of preventive health services in US emergency departments (EDs), as well as ED directors’ preferred service and perceptions of barriers to offering preventive services. Methods Using the 2007 National Emergency Department Inventory (NEDI)–USA, we randomly sampled 350 (7%) of 4,874 EDs. We surveyed directors of these EDs to determine the availability of (1) screening and referral programs for alcohol, tobacco, geriatric falls, intimate partner violence, HIV, diabetes, and hypertension; (2) vaccination programs for influenza and pneumococcus; and (3) linkage programs to primary care and health insurance. ED directors were asked to select the service they would most like to implement and to rate 5 potential barriers to offering preventive services. Results Two hundred seventy-seven EDs (80%) responded across 46 states. Availability of services ranged from 66% for intimate partner violence screening to 19% for HIV screening. ED directors wanted to implement primary care linkage most (17%) and HIV screening least (2%). ED directors “agreed/strongly agreed” that the following are barriers to ED preventive care: cost (74%), increased patient length of stay (64%), lack of follow-up (60%), resource shifting leading to worse patient outcomes (53%), and philosophical opposition (27%). Conclusion Most US EDs offer preventive services, but availability and ED director preference for type of service vary greatly. The majority of EDs do not routinely offer Centers for Disease Control and Prevention–recommended HIV screening. Most ED directors are not philosophically opposed to offering preventive services but are concerned with added costs, effects on ED operations, and potential lack of follow-up. PMID:20889237

Glucose Fuel Cells with a MicroChannel Fabricated on Flexible Polyimide Film

NASA Astrophysics Data System (ADS)

Sano, Ryohei; Fukushi, Yudai; Sasaki, Tsubasa; Mogi, Hiroshi; Koide, Syohei; Ikoma, Ryuta; Akatsuka, Wataru; Tsujimura, Seiya; Nishioka, Yasushiro

2013-12-01

In this work, a glucose fuel cell was fabricated using microfabrication processes assigned for microelectromechanical systems. The fuel cell was equipped with a microchannel to flow an aqueous solution of glucose. The cell was fabricated on a flexible polyimide substrate, and its porous carbon-coated aluminum (Al) electrodes of 2.8 mm in width and 11 mm in length were formed using photolithography and screen printing techniques. Porous carbon was deposited by screen printing of carbon black ink on the Al electrode surfaces in order to increase the effective electrode surface area and to absorb more enzymes on the electrode surfaces. The microchannel with a depth of 200 μm was fabricated using a hot embossing technique. A maximum power of 0.45 μW at 0.5 V that corresponds to a power density of 1.45 μW/cm2 was realized by introducing a 200 mM concentrated glucose solution at room temperature.

Strong quantum coherence between Fermi liquid Mahan excitons

DOE PAGES

Paul, J.; Stevens, C. E.; Liu, C.; ...

2016-04-14

In modulation doped quantum wells, the excitons are formed as a result of the interactions of the charged holes with the electrons at the Fermi edge in the conduction band, leading to the so-called “Mahan excitons.” The binding energy of Mahan excitons is expected to be greatly reduced and any quantum coherence destroyed as a result of the screening and electron-electron interactions. Surprisingly, we observe strong quantum coherence between the heavy hole and light hole excitons. Such correlations are revealed by the dominating cross-diagonal peaks in both one-quantum and two-quantum two-dimensional Fourier transform spectra. Theoretical simulations based on the opticalmore » Bloch equations where many-body effects are included phenomenologically reproduce well the experimental spectra. Furthermore, time-dependent density functional theory calculations provide insight into the underlying physics and attribute the observed strong quantum coherence to a significantly reduced screening length and collective excitations of the many-electron system.« less

Working While Ill as a Risk Factor for Serious Coronary Events: The Whitehall II Study

PubMed Central

Kivimäki, Mika; Head, Jenny; Ferrie, Jane E.; Hemingway, Harry; Shipley, Martin J.; Vahtera, Jussi; Marmot, Michael G.

2005-01-01

Objectives. Although sick, some people take no time off work, a phenomenon called “sickness presenteeism.” This study examined the association between sickness presenteeism and incidence of serious coronary events. Methods. The analyses were based on a cohort of 5071 male British civil servants without previous myocardial infarction. Baseline screening included measurements of health status and coronary risk factors. Absence records were assessed for the 3 years subsequent to baseline screening. The outcome of interest was incident nonfatal myocardial infarction or fatal coronary heart disease (mean length of follow-up=9.1 years). Results. Seventeen percent of unhealthy employees took no absence during the 3-year follow-up. Their incidence of serious coronary events was twice as high as that of the unhealthy employees with moderate levels of sickness absenteeism (after adjustment for conventional risk factors, hazard ratio 1.97, 95% confidence interval=1.02, 3.83). Conclusions. Employers and employees should be aware of the potential harmful effects caused by sickness presenteeism. PMID:15623867

Analysis of Differentially Expressed Genes Associated with Coronatine-Induced Laticifer Differentiation in the Rubber Tree by Subtractive Hybridization Suppression

PubMed Central

Zhang, Shi-Xin; Wu, Shao-Hua; Chen, Yue-Yi; Tian, Wei-Min

2015-01-01

The secondary laticifer in the secondary phloem is differentiated from the vascular cambia of the rubber tree (Hevea brasiliensis Muell. Arg.). The number of secondary laticifers is closely related to the rubber yield potential of Hevea. Pharmacological data show that jasmonic acid and its precursor linolenic acid are effective in inducing secondary laticifer differentiation in epicormic shoots of the rubber tree. In the present study, an experimental system of coronatine-induced laticifer differentiation was developed to perform SSH identification of genes with differential expression. A total of 528 positive clones were obtained by blue-white screening, of which 248 clones came from the forward SSH library while 280 clones came from the reverse SSH library. Approximately 215 of the 248 clones and 171 of the 280 clones contained cDNA inserts by colony PCR screening. A total of 286 of the 386 ESTs were detected to be differentially expressed by reverse northern blot and sequenced. Approximately 147 unigenes with an average length of 497 bp from the forward and 109 unigenes with an average length of 514 bp from the reverse SSH libraries were assembled and annotated. The unigenes were associated with the stress/defense response, plant hormone signal transduction and structure development. It is suggested that Ca2+ signal transduction and redox seem to be involved in differentiation, while PGA and EIF are associated with the division of cambium initials for COR-induced secondary laticifer differentiation in the rubber tree. PMID:26147807

MK-801 reduces sensitivity to Müller-Lyer's illusion in capuchin monkeys.

PubMed

Jacobsen, M E; Barros, M; Maior, R S

2017-01-01

The Müller-Lyer's illusion (MLI) is a visual illusion in which the presence of contextual cues (i.e., the orientation of arrowheads) changes the perception of the length of straight lines. An altered sensitivity to the MLI has been proposed as a marker for the progression of perceptual deficits in schizophrenia. Since dizocilpine (MK-801), a noncompetitive antagonist of the NMDA glutamate receptor, induces schizophrenic-like sensory impairments, it may have potential value for investigating the neurochemical basis of the perceptual changes in schizophrenia. Here we tested the effects of MK-801 on the perception of the MLI in a nonhuman primate. Five capuchin monkeys Sapajus spp. were trained on a MLI task using a touch screen monitor. After training, the Point of Subjective Equality (PSE; i.e., the minimum difference in length between two lines which the subject can distinguish) was determined for each subject. Then, during 12 consecutive days, we evaluated changes in PSE in response to vehicle, MK-801 (5.6μg/kg, i.m.) and a no-treatment protocol (post- test). Each of these was given as a single daily treatment, on four consecutive days. Results showed that MK-801 increased the monkeys' performance in the MLI task, suggesting that NMDA receptor modulation reduces sensitivity to this illusion, similar to prodromal stage in schizophrenia patients. The MLI protocol may thus be used in nonhuman primates to screen potential antipsychotic drugs for early stages of this disease. Copyright © 2016 Elsevier B.V. All rights reserved.

[Nutritional screening tool versus anthropometric assessment in hospitalized children: which method is better associated to clinical outcomes?].

PubMed

Márquez Costa, María Verónica; Alberici Pastore, Carla

2015-03-01

Hospitalization contributes to worsening of the nutritional status and malnutrition is associate to increase in morbidity and mortality. The aim of the study was to asses nutritional status/risk using anthropometry and the Screening Tool for Risk on Nutritional Status and Growth (STRONGkids), comparing their results to clinical outcomes. For that propose, was conducted an observational longitudinal study with children up to one month of life, hospitalized in Pediatric ward of a teaching hospital. Nutritional status was assessed by Body Mass Index for age and weight for age. Nutritional risk was classified as high, intermediate or low. The length of stay, clinical outcome and complications were taken of the medical records. This project was approved by the Ethics Committee on Research. Were evaluated 181 children, from both sexes. The median age was 8.8 (IQR 3.3; 26.9) months and the median length of stay was 7 (IQR 4; 10) days. There was 20.8% of malnutrition in children younger than one year. Most of the children (55.3%) were classified as in intermediate nutritional risk. The length of stay was associated to nutritional risk, while anthropometry was associated to only in those younger than one year. There were five infectious complication, not associated to nutritional status/risk. Therefore, nutritional risk was significantly associated to length of stay, showing that STRONGkids was a better method compared to anthropometric nutritional assessment to predict this outcome.

HCS-Neurons: identifying phenotypic changes in multi-neuron images upon drug treatments of high-content screening.

PubMed

Charoenkwan, Phasit; Hwang, Eric; Cutler, Robert W; Lee, Hua-Chin; Ko, Li-Wei; Huang, Hui-Ling; Ho, Shinn-Ying

2013-01-01

High-content screening (HCS) has become a powerful tool for drug discovery. However, the discovery of drugs targeting neurons is still hampered by the inability to accurately identify and quantify the phenotypic changes of multiple neurons in a single image (named multi-neuron image) of a high-content screen. Therefore, it is desirable to develop an automated image analysis method for analyzing multi-neuron images. We propose an automated analysis method with novel descriptors of neuromorphology features for analyzing HCS-based multi-neuron images, called HCS-neurons. To observe multiple phenotypic changes of neurons, we propose two kinds of descriptors which are neuron feature descriptor (NFD) of 13 neuromorphology features, e.g., neurite length, and generic feature descriptors (GFDs), e.g., Haralick texture. HCS-neurons can 1) automatically extract all quantitative phenotype features in both NFD and GFDs, 2) identify statistically significant phenotypic changes upon drug treatments using ANOVA and regression analysis, and 3) generate an accurate classifier to group neurons treated by different drug concentrations using support vector machine and an intelligent feature selection method. To evaluate HCS-neurons, we treated P19 neurons with nocodazole (a microtubule depolymerizing drug which has been shown to impair neurite development) at six concentrations ranging from 0 to 1000 ng/mL. The experimental results show that all the 13 features of NFD have statistically significant difference with respect to changes in various levels of nocodazole drug concentrations (NDC) and the phenotypic changes of neurites were consistent to the known effect of nocodazole in promoting neurite retraction. Three identified features, total neurite length, average neurite length, and average neurite area were able to achieve an independent test accuracy of 90.28% for the six-dosage classification problem. This NFD module and neuron image datasets are provided as a freely downloadable MatLab project at http://iclab.life.nctu.edu.tw/HCS-Neurons. Few automatic methods focus on analyzing multi-neuron images collected from HCS used in drug discovery. We provided an automatic HCS-based method for generating accurate classifiers to classify neurons based on their phenotypic changes upon drug treatments. The proposed HCS-neurons method is helpful in identifying and classifying chemical or biological molecules that alter the morphology of a group of neurons in HCS.

The genetics of rhizosheath size in a multiparent mapping population of wheat.

PubMed

Delhaize, Emmanuel; Rathjen, Tina M; Cavanagh, Colin R

2015-08-01

Rhizosheaths comprise soil that adheres to plant roots and, in some species, are indicative of root hair length. In this study, the genetics of rhizosheath size in wheat was investigated by screening the progeny of multiparent advanced generation intercrosses (MAGIC). Two MAGIC populations were screened for rhizosheath size using a high throughput method. One MAGIC population was developed from intercrosses between four parents (4-way) and the other from intercrosses between eight parents (8-way). Transgressive segregation for rhizosheath size was observed in both the 4-way and 8-way MAGIC populations. A quantitative trait loci (QTL) analysis of the 4-way population identified six major loci located on chromosomes 2B, 4D, 5A, 5B, 6A, and 7A together accounting for 42% of the variation in rhizosheath size. Rhizosheath size was strongly correlated with root hair length and was robust across different soil types in the absence of chemical constraints. Rhizosheath size in the MAGIC populations was a reliable surrogate for root hair length and, therefore, the QTL identified probably control root hair elongation. Members of the basic helix-loop-helix family of transcription factors have previously been identified to regulate root hair length in Arabidopsis and rice. Since several wheat members of the basic helix-loop-helix family of genes are located within or near the QTL, these genes are candidates for controlling the long root hair trait. The QTL for rhizosheath size identified in this study provides the opportunity to implement marker-assisted selection to increase root hair length for improved phosphate acquisition in wheat. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Fasting Might Not Be Necessary Before Lipid Screening: A Nationally Representative Cross-sectional Study

PubMed Central

Skinner, Asheley Cockrell; Perrin, Eliana M.

2011-01-01

BACKGROUND: There are barriers to fasting lipid screening for at-risk children. Results of studies in adults have suggested that lipid testing might be reliably performed without fasting. OBJECTIVE: To examine population-level differences in pediatric lipid values based on length of fast before testing. METHODS: We used the National Health and Nutrition Examination Survey (1999–2008) to examine total cholesterol (TC), HDL (high-density lipoprotein), LDL (low-density lipoprotein), and triglyceride cholesterol components on the basis of the period of fasting. Young children fasted for varying times before being tested, and children older than 12 years were asked to fast; however, adherence was variable. We used ordinary least-squares regression to test for differences in lipid values that were based on fasting times, controlling for weight status, age, race, ethnicity, and gender. RESULTS: TC, HDL, LDL, or triglyceride values were available for 12 744 children. Forty-eight percent of the TC and HDL samples and 80% of the LDL and triglyceride samples were collected from children who had fasted ≥8 hours. Fasting had a small positive effect for TC, HDL, and LDL, resulting in a mean value for the sample that was 2 to 5 mg/dL higher with a 12-hour fast compared with a no-fast sample. Fasting time had a negative effect on triglycerides (β = −0.859; P = .02), which resulted in values in the fasting group that were 7 mg/dL lower. DISCUSSION: Comparison of cholesterol screening results for a nonfasting group of children compared with results for a similar fasting group resulted in small differences that are likely not clinically important. Physicians might be able to decrease the burden of childhood cholesterol screening by not requiring prescreening fasting for these components. PMID:21807697

Electron collection theory for a D-region subsonic blunt electrostatic probe

NASA Technical Reports Server (NTRS)

Wai-Kwong Lai, T.

1974-01-01

Blunt probe theory for subsonic flow in a weakly ionized and collisional gas is reviewed, and an electron collection theory for the relatively unexplored case, Deybye length approximately 1, which occurs in the lower ionosphere (D-region), is developed. It is found that the dimensionless Debye length is no longer an electric field screening parameter, and the space charge field effect can be negelected. For ion collection, Hoult-Sonin theory is recognized as a correct description of the thin, ion density-perturbed layer adjacent the blunt probe surface. The large volume with electron density perturbed by a positively biased probe renders the usual thin boundary layer analysis inapplicable. Theories relating free stream conditions to the electron collection rate for both stationary and moving blunt probes are obtained. A model based on experimental nonlinear electron drift velocity data is proposed. For a subsonically moving probe, it is found that the perturbed region can be divided into four regions with distinct collection mechanisms.

Concentration Fluctuations and Capacitive Response in Dense Ionic Solutions.

PubMed

Uralcan, Betul; Aksay, Ilhan A; Debenedetti, Pablo G; Limmer, David T

2016-07-07

We use molecular dynamics simulations in a constant potential ensemble to study the effects of solution composition on the electrochemical response of a double layer capacitor. We find that the capacitance first increases with ion concentration following its expected ideal solution behavior but decreases upon approaching a pure ionic liquid in agreement with recent experimental observations. The nonmonotonic behavior of the capacitance as a function of ion concentration results from the competition between the independent motion of solvated ions in the dilute regime and solvation fluctuations in the concentrated regime. Mirroring the capacitance, we find that the characteristic decay length of charge density correlations away from the electrode is also nonmonotonic. The correlation length first decreases with ion concentration as a result of better electrostatic screening but increases with ion concentration as a result of enhanced steric interactions. When charge fluctuations induced by correlated ion-solvent fluctuations are large relative to those induced by the pure ionic liquid, such capacitive behavior is expected to be generic.

The high-throughput synthesis and phase characterisation of amphiphiles: a sweet case study.

PubMed

Feast, George C; Hutt, Oliver E; Mulet, Xavier; Conn, Charlotte E; Drummond, Calum J; Savage, G Paul

2014-03-03

A new method for the discovery of amphiphiles by using high-throughput (HT) methods to synthesise and characterise a library of galactose- and glucose-containing amphiphilic compounds is presented. The copper-catalysed azide–alkyne cycloaddition (CuAAC) “click” reaction between azide-tethered simple sugars and alkyne-substituted hydrophobic tails was employed to synthesise a library of compounds with systematic variations in chain length and unsaturation in a 24-vial array format. The liquid–crystalline phase behaviour was characterised in a HT manner by using synchrotron small-angle X-ray scattering (SSAXS). The observed structural variation with respect to chain parameters, including chain length and degree of unsaturation, is discussed, as well as hydration effects and degree of hydrogen bonding between head groups. The validity of our HT screening approach was verified by resynthesising a short-chain glucose amphiphile. A separate phase analysis of this compound confirmed the presence of numerous lyotropic liquid–crystalline phases.

Progressive friction mobilization and enhanced Janssen's screening in confined granular rafts

NASA Astrophysics Data System (ADS)

Saavedra V., Oscar; Elettro, Hervé; Melo, Francisco

2018-04-01

Confined two-dimensional assemblies of floating particles, known as granular rafts, are prone to develop a highly nonlinear response under compression. Here we investigate the transition to the friction-dominated jammed state and map the gradual development of the internal stress profile with flexible pressure sensors distributed along the raft surface. Surprisingly, we observe that the surface stress screening builds up much more slowly than previously thought and that the typical screening distance later dramatically decreases. We explain this behavior in terms of progressive friction mobilization, where the full amplitude of the frictional forces is only reached after a macroscopic local displacement. At further stages of compression, rafts of large length-to-width aspect ratio experience much stronger screenings than the full mobilization limit described by the Janssen's model. We solve this paradox using a simple mathematical analysis and show that such enhanced screening can be attributed to a localized compaction front, essentially shielding the far field from compressive stresses.

Self-propulsion and interactions of catalytic particles in a chemically active medium.

PubMed

Banigan, Edward J; Marko, John F

2016-01-01

Enzymatic "machines," such as catalytic rods or colloids, can self-propel and interact by generating gradients of their substrates. We theoretically investigate the behaviors of such machines in a chemically active environment where their catalytic substrates are continuously synthesized and destroyed, as occurs in living cells. We show how the kinetic properties of the medium modulate self-propulsion and pairwise interactions between machines, with the latter controlled by a tunable characteristic interaction range analogous to the Debye screening length in an electrolytic solution. Finally, we discuss the effective force arising between interacting machines and possible biological applications, such as partitioning of bacterial plasmids.

Enhanced recovery pathways in abdominal gynecologic surgery: a systematic review and meta-analysis.

PubMed

de Groot, Jeanny J A; Ament, Stephanie M C; Maessen, José M C; Dejong, Cornelis H C; Kleijnen, Jos M P; Slangen, Brigitte F M

2016-04-01

Enhanced recovery pathways have been widely accepted and implemented for different types of surgery. Their overall effect in abdominal gynecologic surgery is still underdetermined. A systematic review and meta-analysis were performed to provide an overview of current evidence and to examine their effect on postoperative outcomes in women undergoing open gynecologic surgery. Searches were conducted using Embase, Medline, CINAHL, and the Cochrane Library up to 27 June 2014. Reference lists were screened to identify additional studies. Studies were included if at least four individual items of an enhanced recovery pathway were described. Outcomes included length of hospital stay, complication rates, readmissions, and mortality. Quantitative analysis was limited to comparative studies. Effect sizes were presented as relative risks or as mean differences (MD) with 95% confidence intervals (CI). Thirty-one records, involving 16 observational studies, were included. Diversity in reported elements within studies was observed. Preoperative education, early oral intake, and early mobilization were included in all pathways. Five studies, with a high risk of bias, were eligible for quantitative analysis. Enhanced recovery pathways reduced primary (MD -1.57 days, 95% CI CI -2.94 to -0.20) and total (MD -3.05 days, 95% CI -4.87 to -1.23) length of hospital stay compared with traditional perioperative care, without an increase in complications, mortality or readmission rates. The available evidence based on a broad range of non-randomized studies at high risk of bias suggests that enhanced recovery pathways may reduce length of postoperative hospital stay in abdominal gynecologic surgery. © 2015 Nordic Federation of Societies of Obstetrics and Gynecology.

Structure and dynamics of hyaluronic acid semidilute solutions: a dielectric spectroscopy study.

PubMed

Vuletić, T; Dolanski Babić, S; Ivek, T; Grgicin, D; Tomić, S; Podgornik, R

2010-07-01

Dielectric spectroscopy is used to investigate fundamental length scales describing the structure of hyaluronic acid sodium salt (Na-HA) semidilute aqueous solutions. In salt-free regime, the length scale of the relaxation mode detected in MHz range scales with HA concentration as c(HA)(-0.5) and corresponds to the de Gennes-Pfeuty-Dobrynin correlation length of polyelectrolytes in semidilute solution. The same scaling was observed for the case of long, genomic DNA. Conversely, the length scale of the mode detected in kilohertz range also varies with HA concentration as c(HA)(-0.5) which differs from the case of DNA (c(DNA)(-0.25)). The observed behavior suggests that the relaxation in the kilohertz range reveals the de Gennes-Dobrynin renormalized Debye screening length, and not the average size of the chain, as the pertinent length scale. Similarly, with increasing added salt the electrostatic contribution to the HA persistence length is observed to scale as the Debye length, contrary to scaling pertinent to the Odijk-Skolnick-Fixman electrostatic persistence length observed in the case of DNA. We argue that the observed features of the kilohertz range relaxation are due to much weaker electrostatic interactions that lead to the absence of Manning condensation as well as a rather high flexibility of HA as compared to DNA.

High-Content Screening in Zebrafish Embryos Identifies Butafenacil as a Potent Inducer of Anemia

PubMed Central

Leet, Jessica K.; Lindberg, Casey D.; Bassett, Luke A.; Isales, Gregory M.; Yozzo, Krystle L.; Raftery, Tara D.; Volz, David C.

2014-01-01

Using transgenic zebrafish (fli1:egfp) that stably express enhanced green fluorescent protein (eGFP) within vascular endothelial cells, we recently developed and optimized a 384-well high-content screening (HCS) assay that enables us to screen and identify chemicals affecting cardiovascular development and function at non-teratogenic concentrations. Within this assay, automated image acquisition procedures and custom image analysis protocols are used to quantify body length, heart rate, circulation, pericardial area, and intersegmental vessel area within individual live embryos exposed from 5 to 72 hours post-fertilization. After ranking developmental toxicity data generated from the U.S. Environmental Protection Agency's (EPA's) zebrafish teratogenesis assay, we screened 26 of the most acutely toxic chemicals within EPA's ToxCast Phase-I library in concentration-response format (0.05–50 µM) using this HCS assay. Based on this screen, we identified butafenacil as a potent inducer of anemia, as exposure from 0.39 to 3.125 µM butafenacil completely abolished arterial circulation in the absence of effects on all other endpoints evaluated. Butafenacil is an herbicide that inhibits protoporphyrinogen oxidase (PPO) – an enzyme necessary for heme production in vertebrates. Using o-dianisidine staining, we then revealed that severe butafenacil-induced anemia in zebrafish was due to a complete loss of hemoglobin following exposure during early development. Therefore, six additional PPO inhibitors within the ToxCast Phase-I library were screened to determine whether anemia represents a common adverse outcome for these herbicides. Embryonic exposure to only one of these PPO inhibitors – flumioxazin – resulted in a similar phenotype as butafenacil, albeit not as severe as butafenacil. Overall, this study highlights the potential utility of this assay for (1) screening chemicals for cardiovascular toxicity and (2) prioritizing chemicals for future hypothesis-driven and mechanism-focused investigations within zebrafish and mammalian models. PMID:25090246

Effect of Several Negative Rounds of Human Papillomavirus and Cytology Co-testing on Safety Against Cervical Cancer: An Observational Cohort Study.

PubMed

Castle, Philip E; Kinney, Walter K; Xue, Xiaonan; Cheung, Li C; Gage, Julia C; Zhao, Fang-Hui; Fetterman, Barbara; Poitras, Nancy E; Lorey, Thomas S; Wentzensen, Nicolas; Katki, Hormuzd A; Schiffman, Mark

2018-01-02

Current U.S. cervical cancer screening and management guidelines do not consider previous screening history, because data on multiple-round human papillomavirus (HPV) and cytology "co-testing" have been unavailable. To measure cervical cancer risk in routine practice after successive negative screening co-tests at 3-year intervals. Observational cohort study. Integrated health care system (Kaiser Permanente Northern California, Oakland, California). 990 013 women who had 1 or more co-tests from 2003 to 2014. 3- and 5-year cumulative detection of (risk for) cervical intraepithelial neoplasia grade 3, adenocarcinoma in situ, and cervical cancer (≥CIN3) in women with different numbers of negative co-tests, overall and within subgroups defined by previous co-test results or baseline age. Five-year ≥CIN3 risks decreased after each successive negative co-test screening round (0.098%, 0.052%, and 0.035%). Five-year ≥CIN3 risks for an HPV-negative co-test, regardless of the cytology result, nearly matched the performance (reassurance) of a negative co-test for each successive round of screening (0.114%, 0.061%, and 0.041%). By comparison, ≥CIN3 risks for the cytology-negative co-test, regardless of the HPV result, also decreased with each successive round, but 3-year risks were as high as 5-year risks after an HPV-negative co-test (0.199%, 0.065%, and 0.043%). No interval cervical cancer cases were diagnosed after the second negative co-test. Independently, ≥CIN3 risks decreased with age. Length of previous screening interval did not influence future ≥CIN3 risks. Interval-censored observational data. After 1 or more negative cervical co-tests (or HPV tests), longer screening intervals (every 5 years or more) might be feasible and safe. National Cancer Institute Intramural Research Program.

Modality dependence and intermodal transfer in the Corsi Spatial Sequence Task: Screen vs. Floor.

PubMed

Röser, Andrea; Hardiess, Gregor; Mallot, Hanspeter A

2016-07-01

Four versions of the Corsi Spatial Sequence Task (CSST) were tested in a complete within-subject design, investigating whether participants' performance depends on the modality of task presentation and reproduction that put different demands on spatial processing. Presentation of the sequence (encoding phase) and the reproduction (recall phase) were each carried out either on a computer screen or on the floor of a room, involving actual walking in the recall phase. Combinations of the two different encoding and recall procedures result in the modality conditions Screen-Screen, Screen-Floor, Floor-Screen, and Floor-Floor. Results show the expected decrease in performance with increasing sequence length, which is likely due to processing limitations of working memory. We also found differences in performance between the modality conditions indicating different involvements of spatial working memory processes. Participants performed best in the Screen-Screen modality condition. Floor-Screen and Floor-Floor modality conditions require additional working memory resources for reference frame transformation and spatial updating, respectively; the resulting impairment of the performance was about the same in these two conditions. Finally, the Screen-Floor modality condition requires both types of additional spatial demands and led to the poorest performance. Therefore, we suggest that besides the well-known spatial requirements of CSST, additional working memory resources are demanded in walking CSST supporting processes such as spatial updating, mental rotation, reference frame transformation, and the control of walking itself.

The effect of colour and design in labour and delivery: A scientific approach

NASA Astrophysics Data System (ADS)

Duncan, Jane

2011-03-01

This study was part of a broader three year research project at London's Chelsea and Westminster Hospital, "A Study of the Effect of the Visual and Performing Arts in Healthcare", exploring whether visual and performing arts have any measurable effect on physiological, psychological and biological outcomes of clinical significance on patient recovery, and providing a potential cost saving benefit to the NHS. In this specific study of women in labour, two measurements were identified as having clinical significance for achieving optimal outcomes during labour and delivery: length of labour and frequency of requirement for analgesia. A screen was designed to hide emergency equipment with the joint aim of reducing women's anxieties and (through visual art) acting as a focal point of attention and distraction during labour, thus diminishing requirements for analgesia. Results demonstrated, in the presence of the screen, a statistically significant shortening of the duration of labour by 2.1h with frequency of requests for epidural analgesia 7% lower in the study group than in the control group. The significant clinical outcomes of this research provide the evidence of the value of integrating visual art into the environment of a labour and delivery room, improving the quality of the maternity service and potentially delivering real cost savings benefits to Hospitals.

Multiplex screening for RB1 germline mutations in 106 patients with hereditary retinoblastoma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lohmann, D.R.; Brandt, B.; Passarge, E.

1994-09-01

The identification of germline mutations in the retinoblastoma susceptibility gene (RB1) is important for genetic counseling in hereditary retinoblastoma. Due to the complex genomic organization of this gene and the heterogeneity of mutations, efficient screening procedures are important for rapid mutation detection. We have developed methods based on simultaneous analysis of multiple regions of this gene in an ABI automated DNA fragment analyzer to examine 106 patients with hereditary retinoblastoma in which no alteration was identified by Southern blot hybridization. Primers for the amplification of all 27 exons of the RB1 gene as well as the promoter and poly(A) signalmore » sequences were labelled with distinct fluorescent dyes (FAM, HEX, TAMRA) to enable simultaneous electrophoretic analysis of PCR products with similar mobility. PCR fragments distinguishable by size or color were co-amplified by multiplex PCR and analyzed for length by GENESCAN analysis. Using this approach, small deletions ranging from 1 bp to 22 bp were identified in 24 patients (23%). Short sequence repeats or polypyrimidine runs were present in the vicinity of most of these deletions. In 4 patients (4%), insertions from 1 bp to 4 bp were found. The majority of length mutations resulted in a truncated gene product due to frameshift and premature termination. No mutation was identified in exons 25 to 27 possibly indicating that the encoded protein domains have minor functional importance. In order to screen for base substitutions that are not detectable by fragment length analysis, we adapted heteroduplex analysis for the use in the DNA fragment analyzer. During the optimization of this method we detected 10 single base substitutions most of which generated stop codons. Intriguingly, two identical missense mutations were identified in two unrelated families with a low-penetrance phenotype.« less

Telomere length and genetics are independent colorectal tumour risk factors in an evaluation of biomarkers in normal bowel.

PubMed

Fernandez-Rozadilla, Ceres; Kartsonaki, Christiana; Woolley, Connor; McClellan, Michael; Whittington, Deb; Horgan, Gareth; Leedham, Simon; Kriaucionis, Skirmantas; East, James; Tomlinson, Ian

2018-03-06

Colorectal cancer (CRC) screening might be improved by using a measure of prior risk to modulate screening intensity or the faecal immunochemical test threshold. Intermediate molecular biomarkers could aid risk prediction by capturing both known and unknown risk factors. We sampled normal bowel mucosa from the proximal colon, distal colon and rectum of 317 individuals undergoing colonoscopy. We defined cases as having a personal history of colorectal polyp(s)/cancer, and controls as having no history of colorectal neoplasia. Molecular analyses were performed for: telomere length (TL); global methylation; and the expression of genes in molecular pathways associated with colorectal tumourigenesis. We also calculated a polygenic risk score (PRS) based on CRC susceptibility polymorphisms. Bowel TL was significantly longer in cases than controls, but was not associated with blood TL. PRS was significantly and independently higher in cases. Hypermethylation showed a suggestive association with case:control status. No gene or pathway was differentially expressed between cases and controls. Gene expression often varied considerably between bowel locations. PRS and bowel TL (but not blood TL) may be clinically-useful predictors of CRC risk. Sample collection to assess these biomarkers is feasible in clinical practice, especially where population screening uses flexible sigmoidoscopy or colonoscopy.

Test-retest reliability of the Capute scales for neurodevelopmental screening of a high risk sample: Impact of test-retest interval and degree of neonatal risk.

PubMed

McCurdy, M; Bellows, A; Deng, D; Leppert, M; Mahone, E; Pritchard, A

2015-01-01

Reliable and valid screening and assessment tools are necessary to identify children at risk for neurodevelopmental disabilities who may require additional services. This study evaluated the test-retest reliability of the Capute Scales in a high-risk sample, hypothesizing adequate reliability across 6- and 12-month intervals. Capute Scales scores (N = 66) were collected via retrospective chart review from a NICU follow-up clinic within a large urban medical center spanning three age-ranges: 12-18, 19-24, and 25-36 months. On average, participants were classified as very low birth weight and premature. Reliability of the Capute Scales was evaluated with intraclass correlation coefficients across length of test-retest interval, age at testing, and degree of neonatal complications. The Capute Scales demonstrated high reliability, regardless of length of test-retest interval (ranging from 6 to 14 months) or age of participant, for all index scores, including overall Developmental Quotient (DQ), language-based skill index (CLAMS) and nonverbal reasoning index (CAT). Linear regressions revealed that greater neonatal risk was related to poorer test-retest reliability; however, reliability coefficients remained strong. The Capute Scales afford clinicians a reliable and valid means of screening and assessing for neurodevelopmental delay within high-risk infant populations.

Short stature before puberty: which children should be screened for SHOX deficiency?

PubMed

Wolters, Barbara; Lass, Nina; Wunsch, Rainer; Böckmann, Beatrix; Austrup, Frank; Reinehr, Thomas

2013-01-01

We studied the prevalence of deficiency in the short stature homeobox containing gene (SHOX) in prepubertal short-statured children and analyzed the clinical and radiological signs. Screening for SHOX deficiency was performed in 449 prepubertal short-statured children (54% females, aged 4-10 years) by direct sequencing and multiplex ligation probe-dependent amplification. Children with SHOX deficiency were compared to 1:2 age- and gender-matched prepubertal children without SHOX deficiency with respect to left-hand radiographs and anthropometrics including different ratios to height and proposed scores. We identified 22 (4.9%) patients with SHOX deficiency (64% point mutations). Children with SHOX deficiency demonstrated a mesomelic shortening of extremities. Lower leg lengths but not forearm length was reduced in children <8 years with SHOX deficiency. 36% of all children and none of the children <8 years with SHOX deficiency demonstrated any typical radiologic sign. Increased sitting height-to-height ratio and decreased extremities-to-trunk ratio demonstrated the best positive and negative predictive values to identify SHOX deficiency. Screening for SHOX deficiency seems rational, especially in children with increased sitting height-to-height ratio or decreased extremities-to-trunk ratio. These criteria were also valid in young children. © 2013 S. Karger AG, Basel.

National Dam Inspection Program. Lake Catalpa Dam (NDS-ID Number PA-560), (DER-ID Number 40-57) Susquehanna River Basin, Falls Creek, Luzerne County, Pennsylvania. Phase I Inspection Report,

DTIC Science & Technology

1980-09-01

Ogee spillway crest 1269.5 Sharp crest weir (rigid fish screen) 1271.5 N Upstream invert of spillway 1265.4 Downstream invert of spillway 1260.9 Maximum...Sluice gate Access Valve house upstream Regulating facilities Sluice gate i. Spillway. Type Concrete ogee to sharp crested weir Length 26 feet Ogee... crest elevation 1269.5 Sharp crest weir (rigid fish screen) 1271.5 Upstream channel Lake Downstream channel Reinforced concrete channel for

A chemical biology approach reveals period shortening of the mammalian circadian clock by specific inhibition of GSK-3beta.

PubMed

Hirota, Tsuyoshi; Lewis, Warren G; Liu, Andrew C; Lee, Jae Wook; Schultz, Peter G; Kay, Steve A

2008-12-30

The circadian clock controls daily oscillations of gene expression at the cellular level. We report the development of a high-throughput circadian functional assay system that consists of luminescent reporter cells, screening automation, and a data analysis pipeline. We applied this system to further dissect the molecular mechanisms underlying the mammalian circadian clock using a chemical biology approach. We analyzed the effect of 1,280 pharmacologically active compounds with diverse structures on the circadian period length that is indicative of the core clock mechanism. Our screening paradigm identified many compounds previously known to change the circadian period or phase, demonstrating the validity of the assay system. Furthermore, we found that small molecule inhibitors of glycogen synthase kinase 3 (GSK-3) consistently caused a strong short period phenotype in contrast to the well-known period lengthening by lithium, another presumed GSK-3 inhibitor. siRNA-mediated knockdown of GSK-3beta also caused a short period, confirming the phenotype obtained with the small molecule inhibitors. These results clarify the role of GSK-3beta in the period regulation of the mammalian clockworks and highlight the effectiveness of chemical biology in exploring unidentified mechanisms of the circadian clock.

Diffuse-charge dynamics of ionic liquids in electrochemical systems.

PubMed

Zhao, Hui

2011-11-01

We employ a continuum theory of solvent-free ionic liquids accounting for both short-range electrostatic correlations and steric effects (finite ion size) [Bazant et al., Phys. Rev. Lett. 106, 046102 (2011)] to study the response of a model microelectrochemical cell to a step voltage. The model problem consists of a 1-1 symmetric ionic liquid between two parallel blocking electrodes, neglecting any transverse transport phenomena. Matched asymptotic expansions in the limit of thin double layers are applied to analyze the resulting one-dimensional equations and study the overall charge-time relation in the weakly nonlinear regime. One important conclusion is that our simple scaling analysis suggests that the length scale √(λ*(D)l*(c)) accurately characterizes the double-layer structure of ionic liquids with strong electrostatic correlations where l*(c) is the electrostatic correlation length (in contrast, the Debye screening length λ*(D) is the primary double-layer length for electrolytes) and the response time of λ(D)(*3/2)L*/(D*l(c)(1/2)) (not λ*(D)L*/D* that is the primary charging time of electrolytes) is the correct charging time scale of ionic liquids with strong electrostatic correlations where D* is the diffusivity and L* is the separation length of the cell. With these two new scales, data of both electric potential versus distance from the electrode and the total diffuse charge versus time collapse onto each individual master curve in the presence of strong electrostatic correlations. In addition, the dependance of the total diffuse charge on steric effects, short-range correlations, and driving voltages is thoroughly examined. The results from the asymptotic analysis are compared favorably with those from full numerical simulations. Finally, the absorption of excess salt by the double layer creates a depletion region outside the double layer. Such salt depletion may bring a correction to the leading order terms and break down the weakly nonlinear analysis. A criterion which justifies the weakly nonlinear analysis is verified with numerical simulations.

Model for screened, charge-regulated electrostatics of an eye lens protein: Bovine gammaB-crystallin

PubMed Central

Wahle, Christopher W.; Martini, K. Michael; Hollenbeck, Dawn M.; Langner, Andreas; Ross, David S.; Hamilton, John F.; Thurston, George M.

2018-01-01

We model screened, site-specific charge regulation of the eye lens protein bovine gammaB-crystallin (γ B) and study the probability distributions of its proton occupancy patterns. Using a simplified dielectric model, we solve the linearized Poisson-Boltzmann equation to calculate a 54 × 54 work-of-charging matrix, each entry being the modeled voltage at a given titratable site, due to an elementary charge at another site. The matrix quantifies interactions within patches of sites, including γB charge pairs. We model intrinsic pK values that would occur hypothetically in the absence of other charges, with use of experimental data on the dependence of pK values on aqueous solution conditions, the dielectric model, and literature values. We use Monte Carlo simulations to calculate a model grand-canonical partition function that incorporates both the work-of-charging and the intrinsic pK values for isolated γB molecules and we calculate the probabilities of leading proton occupancy configurations, for 4 < pH < 8 and Debye screening lengths from 6 to 20 Å. We select the interior dielectric value to model γB titration data. At pH 7.1 and Debye length 6.0 Å, on a given γB molecule the predicted top occupancy pattern is present nearly 20% of the time, and 90% of the time one or another of the first 100 patterns will be present. Many of these occupancy patterns differ in net charge sign as well as in surface voltage profile. We illustrate how charge pattern probabilities deviate from the multinomial distribution that would result from use of effective pK values alone and estimate the extents to which γB charge pattern distributions broaden at lower pH and narrow as ionic strength is lowered. These results suggest that for accurate modeling of orientation-dependent γB-γB interactions, consideration of numerous pairs of proton occupancy patterns will be needed. PMID:29346981

Model for screened, charge-regulated electrostatics of an eye lens protein: Bovine gammaB-crystallin.

PubMed

Wahle, Christopher W; Martini, K Michael; Hollenbeck, Dawn M; Langner, Andreas; Ross, David S; Hamilton, John F; Thurston, George M

2017-09-01

We model screened, site-specific charge regulation of the eye lens protein bovine gammaB-crystallin (γB) and study the probability distributions of its proton occupancy patterns. Using a simplified dielectric model, we solve the linearized Poisson-Boltzmann equation to calculate a 54×54 work-of-charging matrix, each entry being the modeled voltage at a given titratable site, due to an elementary charge at another site. The matrix quantifies interactions within patches of sites, including γB charge pairs. We model intrinsic pK values that would occur hypothetically in the absence of other charges, with use of experimental data on the dependence of pK values on aqueous solution conditions, the dielectric model, and literature values. We use Monte Carlo simulations to calculate a model grand-canonical partition function that incorporates both the work-of-charging and the intrinsic pK values for isolated γB molecules and we calculate the probabilities of leading proton occupancy configurations, for 4

Model for screened, charge-regulated electrostatics of an eye lens protein: Bovine gammaB-crystallin

NASA Astrophysics Data System (ADS)

Wahle, Christopher W.; Martini, K. Michael; Hollenbeck, Dawn M.; Langner, Andreas; Ross, David S.; Hamilton, John F.; Thurston, George M.

2017-09-01

We model screened, site-specific charge regulation of the eye lens protein bovine gammaB-crystallin (γ B ) and study the probability distributions of its proton occupancy patterns. Using a simplified dielectric model, we solve the linearized Poisson-Boltzmann equation to calculate a 54 ×54 work-of-charging matrix, each entry being the modeled voltage at a given titratable site, due to an elementary charge at another site. The matrix quantifies interactions within patches of sites, including γ B charge pairs. We model intrinsic p K values that would occur hypothetically in the absence of other charges, with use of experimental data on the dependence of p K values on aqueous solution conditions, the dielectric model, and literature values. We use Monte Carlo simulations to calculate a model grand-canonical partition function that incorporates both the work-of-charging and the intrinsic p K values for isolated γ B molecules and we calculate the probabilities of leading proton occupancy configurations, for 4

Back reaction effects on the dynamics of heavy probes in heavy quark cloud

NASA Astrophysics Data System (ADS)

Chakrabortty, Shankhadeep; Dey, Tanay K.

2016-05-01

We holographically study the effect of back reaction on the hydrodynamical properties of {N}=4 strongly coupled super Yang-Mills (SYM) thermal plasma. The back reaction we consider arises from the presence of static heavy quarks uniformly distributed over {N}=4 SYM plasma. In order to study the hydrodynamical properties, we use heavy quark as well as heavy quark-antiquark bound state as probes and compute the jet quenching parameter, screening length and binding energy. We also consider the rotational dynamics of heavy probe quark in the back-reacted plasma and analyse associated energy loss. We observe that the presence of back reaction enhances the energy-loss in the thermal plasma. Finally, we show that there is no effect of angular drag on the rotational motion of quark-antiquark bound state probing the back reacted thermal plasma.

Superconducting Effects in Optimization of Magnetic Penetration Thermometers for X-ray Microcalorimeters

NASA Technical Reports Server (NTRS)

Stevenson, Thomas R.; Balvin, M. A.; Denis, K. L.; Hsieh, W.-T.; Sadleir, J. E.; Bandler, Simon E.; Busch, Sarah E.; Merrell, W.; Kelly, Daniel P.; Nagler, Peter C.;

Changes in the saltwater interface corresponding to the installation of a seepage barrier near Lake Okeechobee, Florida

USGS Publications Warehouse

Prinos, Scott T.; Valderrama, Robert

2015-01-01

At five of the monitoring-well cluster locations, a long-screened well was also installed for monitoring and comparison purposes. These long-screened wells are 160 to 200 ft deep, and have open intervals ranging from 145 to 185 ft in length. Water samples were collected at depth intervals of about 5 to 10 ft, using 3-ft-long straddle packers to isolate each sampling interval. The results of monitoring conducted using these long-screened interval wells were generally too variable to identify any changes that might be associated with the seepage barrier. Samples from one of these long-screened interval wells failed to detect the saltwater interface evident in samples and TSEMIL datasets from a collocated well cluster. This failure may have been caused by downward flow of freshwater from above the saltwater interface in the well bore.

Peptides having reduced toxicity that stimulate cholesterol efflux

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bielicki, John K.; Johansson, Jan; Danho, Waleed

The present invention provides a family of non-naturally occurring polypeptides having cholesterol efflux activity that parallels that of full-length apolipoproteins (e.g., Apo AI and Apo E), and having high selectivity for ABCA1 that parallels that of full-length apolipoproteins. Further, the peptides of the invention have little or no toxicity when administered at therapeutic and higher doses. The invention also provides compositions comprising such polypeptides, methods of identifying, screening and synthesizing such polypeptides, and methods of treating, preventing or diagnosing diseases and disorders associated with dyslipidemia, hypercholesterolemia and inflammation.

Prioritizing quantitative trait loci for root system architecture in tetraploid wheat

PubMed Central

Maccaferri, Marco; El-Feki, Walid; Nazemi, Ghasemali; Salvi, Silvio; Canè, Maria Angela; Colalongo, Maria Chiara; Stefanelli, Sandra; Tuberosa, Roberto

2016-01-01

Optimization of root system architecture (RSA) traits is an important objective for modern wheat breeding. Linkage and association mapping for RSA in two recombinant inbred line populations and one association mapping panel of 183 elite durum wheat (Triticum turgidum L. var. durum Desf.) accessions evaluated as seedlings grown on filter paper/polycarbonate screening plates revealed 20 clusters of quantitative trait loci (QTLs) for root length and number, as well as 30 QTLs for root growth angle (RGA). Divergent RGA phenotypes observed by seminal root screening were validated by root phenotyping of field-grown adult plants. QTLs were mapped on a high-density tetraploid consensus map based on transcript-associated Illumina 90K single nucleotide polymorphisms (SNPs) developed for bread and durum wheat, thus allowing for an accurate cross-referencing of RSA QTLs between durum and bread wheat. Among the main QTL clusters for root length and number highlighted in this study, 15 overlapped with QTLs for multiple RSA traits reported in bread wheat, while out of 30 QTLs for RGA, only six showed co-location with previously reported QTLs in wheat. Based on their relative additive effects/significance, allelic distribution in the association mapping panel, and co-location with QTLs for grain weight and grain yield, the RSA QTLs have been prioritized in terms of breeding value. Three major QTL clusters for root length and number (RSA_QTL_cluster_5#, RSA_QTL_cluster_6#, and RSA_QTL_cluster_12#) and nine RGA QTL clusters (QRGA.ubo-2A.1, QRGA.ubo-2A.3, QRGA.ubo-2B.2/2B.3, QRGA.ubo-4B.4, QRGA.ubo-6A.1, QRGA.ubo-6A.2, QRGA.ubo-7A.1, QRGA.ubo-7A.2, and QRGA.ubo-7B) appear particularly valuable for further characterization towards a possible implementation of breeding applications in marker-assisted selection and/or cloning of the causal genes underlying the QTLs. PMID:26880749

Consensus statement of the Academy of Nutrition and Dietetics/American Society for Parenteral and Enteral Nutrition: indicators recommended for the identification and documentation of pediatric malnutrition (undernutrition).

PubMed

Becker, Patricia; Carney, Liesje Nieman; Corkins, Mark R; Monczka, Jessica; Smith, Elizabeth; Smith, Susan E; Spear, Bonnie A; White, Jane V

2015-02-01

The Academy of Nutrition and Dietetics (the Academy) and the American Society for Parenteral and Enteral Nutrition (A.S.P.E.N.), utilizing an evidence-informed, consensus-derived process, recommend that a standardized set of diagnostic indicators be used to identify and document pediatric malnutrition (undernutrition) in routine clinical practice. The recommended indicators include z scores for weight-for-height/length, body mass index-for-age, or length/height-for-age or mid-upper arm circumference when a single data point is available. When 2 or more data points are available, indicators may also include weight gain velocity (<2 years of age), weight loss (2-20 years of age), deceleration in weight for length/height z score, and inadequate nutrient intake. The purpose of this consensus statement is to identify a basic set of indicators that can be used to diagnose and document undernutrition in the pediatric population ages 1 month to 18 years. The indicators are intended for use in multiple settings (eg, acute, ambulatory care/outpatient, residential care). Several screening tools have been developed for use in hospitalized children. However, identifying criteria for use in screening for nutritional risk is not the purpose of this paper. Clinicians should use as many data points as available to identify and document the presence of malnutrition. The universal use of a single set of diagnostic parameters will expedite the recognition of pediatric undernutrition, lead to the development of more accurate estimates of its prevalence and incidence, direct interventions, and promote improved outcomes. A standardized diagnostic approach will also inform the prediction of the human and financial responsibilities and costs associated with the prevention and treatment of undernutrition in this vulnerable population and help to further ensure the provision of high-quality, cost-effective nutritional care. © 2014 American Society for Parenteral and Enteral Nutrition and Academy of Nutrition and Dietetics.

Evaluation of bus emissions generated near bus stops

NASA Astrophysics Data System (ADS)

Yu, Qian; Li, Tiezhu

2014-03-01

The purpose of this research is to demonstrate a methodology for quantification of bus emissions generated near bus stops based on the real-world on-road emissions data collected by the Portable Emission Measurement System (PEMS). Data collection was carried out on an urban diesel bus throughout a bus line under normal operation condition on four work days. Stop influence zone is defined as the area in which the normal bus driving is interrupted by bus stops. The second-by-second data were screened out within the stop influence zone. And the bus running state near a stop was classified into three driving modes, deceleration, idling, and acceleration. Then emission characteristics were analyzed for each mode. Under the idling condition, the emission rates (g s-1) were not constant all the time. The NOX emission rate decreased in the first 4-6 s while the corresponding emission rates of CO2, CO, NOX, and HC increased in the last 4 s of idling. Besides, the influence of bus stop characteristics on emissions was investigated using statistical methods. Platform type, length and location of bus stops showed significant effects on the length of the stop influence zone. However, there were no significant effects on distance-based emission factors.

Kinetic Theory of Plasmas

DTIC Science & Technology

2009-09-01

RTO-EN-AVT-162 means of a Coulomb potential screened at the Debye length (Delcroix and Bers, 1984; Balescu , 1988). 4. The plasma is composed of...Theory of Plasmas 2 - 28 RTO-EN-AVT-162 References Balescu , R. (1988). Transport Processes in Plasmas. Elsevier, Amsterdam. Barth, T. (2008

Determination and analysis of the full-length chicken parvovirus genome.

USDA-ARS?s Scientific Manuscript database

Viral enteric disease in poultry is an ongoing problem in many parts of the world. Many enteric viruses have been identified in turkeys and chickens, including avian astroviruses, rotaviruses, reoviruses, and coronaviruses. Through the application of a molecular screening method targeting particle-a...

A molecular Debye-Huckel theory of solvation in polar fluids: An extension of the Born model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xiao, Tiejun; Song, Xueyu

A dielectric response theory of solvation beyond the conventional Born model for polar fluids is presented. The dielectric response of a polar fluid is described by a Born response mode and a linear combination of Debye-Hückel-like response modes that capture the nonlocal response of polar fluids. The Born mode is characterized by a bulk dielectric constant, while a Debye-Hückel mode is characterized by its corresponding Debye screening length. Both the bulk dielectric constant and the Debye screening lengths are determined from the bulk dielectric function of the polar fluid. The linear combination coefficients of the response modes are evaluated inmore » a self-consistent way and can be used to evaluate the electrostatic contribution to the thermodynamic properties of a polar fluid. In conclusion, our theory is applied to a dipolar hard sphere fluid as well as interaction site models of polar fluids such as water, where the electrostatic contribution to their thermodynamic properties can be obtained accurately.« less

A molecular Debye-Huckel theory of solvation in polar fluids: An extension of the Born model

DOE PAGES

Xiao, Tiejun; Song, Xueyu

2017-12-06

A dielectric response theory of solvation beyond the conventional Born model for polar fluids is presented. The dielectric response of a polar fluid is described by a Born response mode and a linear combination of Debye-Hückel-like response modes that capture the nonlocal response of polar fluids. The Born mode is characterized by a bulk dielectric constant, while a Debye-Hückel mode is characterized by its corresponding Debye screening length. Both the bulk dielectric constant and the Debye screening lengths are determined from the bulk dielectric function of the polar fluid. The linear combination coefficients of the response modes are evaluated inmore » a self-consistent way and can be used to evaluate the electrostatic contribution to the thermodynamic properties of a polar fluid. In conclusion, our theory is applied to a dipolar hard sphere fluid as well as interaction site models of polar fluids such as water, where the electrostatic contribution to their thermodynamic properties can be obtained accurately.« less

A molecular Debye-Hückel theory of solvation in polar fluids: An extension of the Born model

NASA Astrophysics Data System (ADS)

Xiao, Tiejun; Song, Xueyu

2017-12-01

A dielectric response theory of solvation beyond the conventional Born model for polar fluids is presented. The dielectric response of a polar fluid is described by a Born response mode and a linear combination of Debye-Hückel-like response modes that capture the nonlocal response of polar fluids. The Born mode is characterized by a bulk dielectric constant, while a Debye-Hückel mode is characterized by its corresponding Debye screening length. Both the bulk dielectric constant and the Debye screening lengths are determined from the bulk dielectric function of the polar fluid. The linear combination coefficients of the response modes are evaluated in a self-consistent way and can be used to evaluate the electrostatic contribution to the thermodynamic properties of a polar fluid. Our theory is applied to a dipolar hard sphere fluid as well as interaction site models of polar fluids such as water, where the electrostatic contribution to their thermodynamic properties can be obtained accurately.

A molecular Debye-Hückel theory of solvation in polar fluids: An extension of the Born model.

PubMed

Xiao, Tiejun; Song, Xueyu

2017-12-07

A dielectric response theory of solvation beyond the conventional Born model for polar fluids is presented. The dielectric response of a polar fluid is described by a Born response mode and a linear combination of Debye-Hückel-like response modes that capture the nonlocal response of polar fluids. The Born mode is characterized by a bulk dielectric constant, while a Debye-Hückel mode is characterized by its corresponding Debye screening length. Both the bulk dielectric constant and the Debye screening lengths are determined from the bulk dielectric function of the polar fluid. The linear combination coefficients of the response modes are evaluated in a self-consistent way and can be used to evaluate the electrostatic contribution to the thermodynamic properties of a polar fluid. Our theory is applied to a dipolar hard sphere fluid as well as interaction site models of polar fluids such as water, where the electrostatic contribution to their thermodynamic properties can be obtained accurately.

Structure and screening in molecular and metallic hydrogen at high pressure

NASA Technical Reports Server (NTRS)

Wood, D. M.; Ashcroft, N. W.

1981-01-01

A variational wavefunction is used to express the (spin restricted) Hartree-Fock energy as reciprocal lattice sums for static lattice FCC monatomic hydrogen and diatomic Pa3 molecular hydrogen. In the monatomic phase the hydrogenic orbital range closely parallels the inverse Thomas-Fermi wavevector; the corresponding energy E has a minimum of -0.929 Ryd/electron at r sub s = 1.67. For the diatomic phase E(r sub s) is similar, but the constituent energies, screening, and bond length reflect a qualitative change in the nature of the solid at r sub s = 2.8. This change is interpreted in terms of a transition from protons as structural units (at high density) to weakly interacting models (at low density). Insensitivity of the total energy to a rapid fall in the bond length suggests association with the rotational transition where the rapid molecular orientations characteristic of high pressures disappear and the molecules rotate freely at low pressure.

Biological screening of some Turkish medicinal plant extracts for antimicrobial and toxicity activities.

PubMed

Turker, A U; Usta, C

2008-01-20

Screening of antibacterial activity and toxicity of 22 aqueous plant extracts from 17 Turkish plants was conducted. Antibacterial activity was performed with six bacteria including Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Streptococcus pyogenes, Staphylococcus aureus and Staphylococcus epidermidis. Extracts of Tussilago farfara leaves, Helichyrsum plicatum flowers, Solanum dulcamara aerial parts and Urtica dioica leaves gave the best inhibitory activity against S. pyogenes, S. aureus and S. epidermidis. Of the 22 plant extracts, 20 extracts displayed toxicity (LC50 was <1000 mg L(-1)) in the brine shrimp bioassay. For radish seed bioassay, two different determinations (root length and seed germination) were performed with a comparison between two concentrations (50,000 mg L(-1) and 10,000 mg L(-1)). At low concentration (10,000 mg L(-1)), S. dulcamara aerial parts and Primula vulgaris leaf extracts were observed to inhibit the root length more than the other plant extracts. Also, the most inhibitive plant extract for seed germination was obtained with S. dulcamara aerial parts.

Persistence length changes dramatically as RNA folds.

PubMed

Caliskan, G; Hyeon, C; Perez-Salas, U; Briber, R M; Woodson, S A; Thirumalai, D

2005-12-31

We determine the persistence length l(p) for a bacterial group I ribozyme as a function of concentration of monovalent and divalent cations by fitting the distance distribution functions P(r) obtained from small angle x-ray scattering intensity data to the asymptotic form of the calculated P(WLC)(r) for a wormlike chain. The l(p) values change dramatically over a narrow range of Mg(2+) concentration from approximately 21 Angstroms in the unfolded state (U) to approximately 10 Angstroms in the compact (I(C)) and native states. Variations in l(p) with increasing Na(+) concentration are more gradual. In accord with the predictions of polyelectrolyte theory we find l(p) alpha 1/kappa(2) where kappa is the inverse Debye-screening length.

Risk stratification in cervical cancer screening by complete screening history: Applying bioinformatics to a general screening population.

PubMed

Baltzer, Nicholas; Sundström, Karin; Nygård, Jan F; Dillner, Joakim; Komorowski, Jan

2017-07-01

Women screened for cervical cancer in Sweden are currently treated under a one-size-fits-all programme, which has been successful in reducing the incidence of cervical cancer but does not use all of the participants' available medical information. This study aimed to use women's complete cervical screening histories to identify diagnostic patterns that may indicate an increased risk of developing cervical cancer. A nationwide case-control study was performed where cervical cancer screening data from 125,476 women with a maximum follow-up of 10 years were evaluated for patterns of SNOMED diagnoses. The cancer development risk was estimated for a number of different screening history patterns and expressed as Odds Ratios (OR), with a history of 4 benign cervical tests as reference, using logistic regression. The overall performance of the model was moderate (64% accuracy, 71% area under curve) with 61-62% of the study population showing no specific patterns associated with risk. However, predictions for high-risk groups as defined by screening history patterns were highly discriminatory with ORs ranging from 8 to 36. The model for computing risk performed consistently across different screening history lengths, and several patterns predicted cancer outcomes. The results show the presence of risk-increasing and risk-decreasing factors in the screening history. Thus it is feasible to identify subgroups based on their complete screening histories. Several high-risk subgroups identified might benefit from an increased screening density. Some low-risk subgroups identified could likely have a moderately reduced screening density without additional risk. © 2017 UICC.

Meissner effect in normal-superconducting proximity-contact double layers

NASA Astrophysics Data System (ADS)

Higashitani, Seiji; Nagai, Katsuhiko

1995-02-01

The Meissner effect in normal-superconducting proximity-contact double layers is discussed in the clean limit. The diamagnetic current is calculated using the quasi-classical Green's function. We obtain the quasi-classical Green's function linear in the vector potential in the proximity-contact double layers with a finite reflection coefficient at the interface. It is found that the diamagnetic current in the clean normal layer is constant in space, therefore, the magnetic field linearly decreases in the clean normal layer. We give an explicit expression for the screening length in the clean normal layer and study its temperature dependence. We show that the temperature dependence in the clean normal layer is considerably different from that in the dirty normal layer and agrees with a recent experiment in Au-Nb system.

Phase diagram, correlation gap, and critical properties of the coulomb glass.

PubMed

Goethe, Martin; Palassini, Matteo

2009-07-24

We investigate the lattice Coulomb glass model in three dimensions via Monte Carlo simulations. No evidence for an equilibrium glass phase is found down to very low temperatures, although the correlation length increases rapidly near T = 0. A charge-ordered phase exists at low disorder. The transition to this phase is consistent with the random field Ising universality class, which shows that the interaction is effectively screened at moderate temperature. For large disorder, the single-particle density of states near the Coulomb gap satisfies the scaling relation g(epsilon, T) = T;{delta}f(|epsilon|/T) with delta = 2.01 +/- 0.05 in agreement with the prediction of Efros and Shklovskii. For decreasing disorder, a crossover to a larger effective exponent occurs due to the proximity of the charge-ordered phase.

Identification of species by multiplex analysis of variable-length sequences

PubMed Central

Pereira, Filipe; Carneiro, João; Matthiesen, Rune; van Asch, Barbara; Pinto, Nádia; Gusmão, Leonor; Amorim, António

2010-01-01

The quest for a universal and efficient method of identifying species has been a longstanding challenge in biology. Here, we show that accurate identification of species in all domains of life can be accomplished by multiplex analysis of variable-length sequences containing multiple insertion/deletion variants. The new method, called SPInDel, is able to discriminate 93.3% of eukaryotic species from 18 taxonomic groups. We also demonstrate that the identification of prokaryotic and viral species with numeric profiles of fragment lengths is generally straightforward. A computational platform is presented to facilitate the planning of projects and includes a large data set with nearly 1800 numeric profiles for species in all domains of life (1556 for eukaryotes, 105 for prokaryotes and 130 for viruses). Finally, a SPInDel profiling kit for discrimination of 10 mammalian species was successfully validated on highly processed food products with species mixtures and proved to be easily adaptable to multiple screening procedures routinely used in molecular biology laboratories. These results suggest that SPInDel is a reliable and cost-effective method for broad-spectrum species identification that is appropriate for use in suboptimal samples and is amenable to different high-throughput genotyping platforms without the need for DNA sequencing. PMID:20923781

Diffusion of isolated DNA molecules: dependence on length and topology.

PubMed

Robertson, Rae M; Laib, Stephan; Smith, Douglas E

2006-05-09

The conformation and dynamics of circular polymers is a subject of considerable theoretical and experimental interest. DNA is an important example because it occurs naturally in different topological states, including linear, relaxed circular, and supercoiled circular forms. A fundamental question is how the diffusion coefficients of isolated polymers scale with molecular length and how they vary for different topologies. Here, diffusion coefficients D for relaxed circular, supercoiled, and linear DNA molecules of length L ranging from approximately 6 to 290 kbp were measured by tracking the Brownian motion of single molecules. A topology-independent scaling law D approximately L(-nu) was observed with nu(L) = 0.571 +/- 0.014, nu(C) = 0.589 +/- 0.018, and nu(S) = 0.571 +/- 0.057 for linear, relaxed circular, and supercoiled DNA, respectively, in good agreement with the scaling exponent of nu congruent with 0.588 predicted by renormalization group theory for polymers with significant excluded volume interactions. Our findings thus provide evidence in support of several theories that predict an effective diameter of DNA much greater than the Debye screening length. In addition, the measured ratio D(Circular)/D(Linear) = 1.32 +/- 0.014 was closer to the value of 1.45 predicted by using renormalization group theory than the value of 1.18 predicted by classical Kirkwood hydrodynamic theory and agreed well with a value of 1.31 predicted when incorporating a recently proposed expression for the radius of gyration of circular polymers into the Zimm model.

Induced sensitivity of Bacillus subtilis colony morphology to mechanical media compression

PubMed Central

Polka, Jessica K.

2014-01-01

Bacteria from several taxa, including Kurthia zopfii, Myxococcus xanthus, and Bacillus mycoides, have been reported to align growth of their colonies to small features on the surface of solid media, including anisotropies created by compression. While the function of this phenomenon is unclear, it may help organisms navigate on solid phases, such as soil. The origin of this behavior is also unknown: it may be biological (that is, dependent on components that sense the environment and regulate growth accordingly) or merely physical. Here we show that B. subtilis, an organism that typically does not respond to media compression, can be induced to do so with two simple and synergistic perturbations: a mutation that maintains cells in the swarming (chained) state, and the addition of EDTA to the growth media, which further increases chain length. EDTA apparently increases chain length by inducing defects in cell separation, as the treatment has only marginal effects on the length of individual cells. These results lead us to three conclusions. First, the wealth of genetic tools available to B. subtilis will provide a new, tractable chassis for engineering compression sensitive organisms. Second, the sensitivity of colony morphology to media compression in Bacillus can be modulated by altering a simple physical property of rod-shaped cells. And third, colony morphology under compression holds promise as a rapid, simple, and low-cost way to screen for changes in the length of rod-shaped cells or chains thereof. PMID:25289183

New three-dimensional visualization system based on angular image differentiation

NASA Astrophysics Data System (ADS)

Montes, Juan D.; Campoy, Pascual

1995-03-01

This paper presents a new auto-stereoscopic system capable of reproducing static or moving 3D images by projection with horizontal parallax or with horizontal and vertical parallaxes. The working principle is based on the angular differentiation of the images which are projected onto the back side of the new patented screen. The most important features of this new system are: (1) Images can be seen by naked eye, without the use of glasses or any other aid. (2) The 3D view angle is not restricted by the angle of the optics making up the screen. (3) Fine tuning is not necessary, independently of the parallax and of the size of the 3D view angle. (4) Coherent light is not necessary neither in capturing the image nor in its reproduction, but standard cameras and projectors. (5) Since the images are projected, the size and depth of the reproduced scene is unrestricted. (6) Manufacturing cost is not excessive, due to the use of optics of large focal length, to the lack of fine tuning and to the use of the same screen several reproduction systems. (7) This technology can be used for any projection system: slides, movies, TV cannons,... A first prototype of static images has been developed and tested with a 3D view angle of 90 degree(s) and a photographic resolution over a planar screen of 900 mm, of diagonal length. Present developments have success on a dramatic size reduction of the projecting system and of its cost. Simultaneous tasks have been carried out on the development of a prototype of 3D moving images.

Improvement of nutritional support strategies after surgery for benign liver tumor through nutritional risk screening: a prospective, randomized, controlled, single-blind clinical study.

PubMed

Lu, Xin; Li, Ying; Yang, Huayu; Sang, Xinting; Zhao, Haitao; Xu, Haifeng; Du, Shunda; Xu, Yiyao; Chi, Tianyi; Zhong, Shouxian; Yu, Kang; Mao, Yilei

2013-02-01

The rising of individualized therapy requires nutritional risk screening has become a major topic for each particular disease, yet most of the screenings were for malignancies, less for benign diseases. There is no report on the screening of patients with benign liver tumors postoperatively. We aim to evaluate the nutritional support strategies post operation for benign liver tumors through nutritional risk screening. In this prospective, randomized, controlled study, 95 patients who underwent hepatectomy for benign tumors were divided into two groups. Fifty patients in the control group were given routine permissive underfeeding nutritional supply (75 kJ/kg/d), and 45 patients in the experimental group were given lower energy (42 kJ/kg/d) in accordance of their surgical trauma. Routine blood tests, liver/kidney function were monitored before surgery and at the day 1, 3, 5, 9 after surgery, patients were observed for the time of flatus, complications, length of hospitalization (LOH), nutrition-related costs, and other clinical parameters. This completed study is registered with Clinicaltrials.gov, number NCT01292330. The nutrition-related expenses (494.0±181.0 vs. 1,514.4±348.4 RMB, P<0.05) and the total hospital costs (18,495.2±4735.0 vs. 21,432.7±8,291.2 RMB, P<0.05) for patients in the experimental group were significantly lower than those in the control group. Meanwhile, the lowered energy supply after the surgeries did not have adverse effects on clinical parameters, complications, and LOH. Patient with benign liver tumors can adopt an even lower postoperative nutritional supply that close to that for mild non-surgical conditions, and lower than the postoperative permissive underfeeding standard.

Screening for Adverse Childhood Experiences in a Family Medicine Setting: A Feasibility Study.

PubMed

Glowa, Patricia T; Olson, Ardis L; Johnson, Deborah J

2016-01-01

The role of adverse childhood experiences (ACEs) in predicting later adverse adult health outcomes is being widely recognized by makers of public policy. ACE questionnaires have the potential to identify in clinical practice unaddressed key social issues that can influence current health risks, morbidity, and early mortality. This study seeks to explore the feasibility of implementing the ACE screening of adults during routine family medicine office visits. At 3 rural clinical practices, the 10-question ACE screen was used before visits with 111 consecutive patients of 7 clinicians. Clinician surveys about the use of the results and the effect on the visits were completed immediately after the visits. The presence of any ACE risk and "high-risk" ACE scores (≥4) were compared with clinician survey responses. A risk of ACEs was present in 62% of patients; 22% had scores ≥4. Clinicians were more likely to have discussed ACE issues for high-risk patients (score 0-3, 36.8%; score ≥4, 83.3%; P =. 00). Clinicians also perceived that they gained new information (score 0-3, 35.6%; score ≥4, 83.3%; P = .00). Clinical care changed for a small proportion of high-risk patients, with no change in immediate referrals or plan for follow-up. In 91% of visits where a risk of ACEs was present, visit length increased by ≤5 minutes. Incorporation of ACE screening during routine care is feasible and merits further study. ACE screening offers clinicians a more complete picture of important social determinants of health. Primary care-specific interventions that incorporate treatment of early life trauma are needed. © Copyright 2016 by the American Board of Family Medicine.

Selection of the optimum font type and size interface for on screen continuous reading by young adults: an ergonomic approach.

PubMed

Banerjee, Jayeeta; Bhattacharyya, Moushum

2011-12-01

There is a rapid shifting of media: from printed paper to computer screens. This transition is modifying the process of how we read and understand text. The efficiency of reading is dependent on how ergonomically the visual information is presented. Font types and size characteristics have been shown to affect reading. A detailed investigation of the effect of the font type and size on reading on computer screens has been carried out by using subjective, objective and physiological evaluation methods on young adults. A group of young participants volunteered for this study. Two types of fonts were used: Serif fonts (Times New Roman, Georgia, Courier New) and Sans serif fonts (Verdana, Arial, Tahoma). All fonts were presented in 10, 12 and 14 point sizes. This study used a 6 X 3 (font type X size) design matrix. Participants read 18 passages of approximately the same length and reading level on a computer monitor. Reading time, ranking and overall mental workload were measured. Eye movements were recorded by a binocular eye movement recorder. Reading time was minimum for Courier New l4 point. The participants' ranking was highest and mental workload was least for Verdana 14 point. The pupil diameter, fixation duration and gaze duration were least for Courier New 14 point. The present study recommends using 14 point sized fonts for reading on computer screen. Courier New is recommended for fast reading while for on screen presentation Verdana is recommended. The outcome of this study will help as a guideline to all the PC users, software developers, web page designers and computer industry as a whole.

Budget Impact of a Comprehensive Nutrition-Focused Quality Improvement Program for Malnourished Hospitalized Patients

PubMed Central

Sulo, Suela; Feldstein, Josh; Partridge, Jamie; Schwander, Bjoern; Sriram, Krishnan; Summerfelt, Wm. Thomas

2017-01-01

Background Nutrition interventions can alleviate the burden of malnutrition by improving patient outcomes; however, evidence on the economic impact of medical nutrition intervention remains limited. A previously published nutrition-focused quality improvement program targeting malnourished hospitalized patients showed that screening patients with a validated screening tool at admission, rapidly administering oral nutritional supplements, and educating patients on supplement adherence result in significant reductions in 30-day unplanned readmissions and hospital length of stay. Objectives To assess the potential cost-savings associated with decreased 30-day readmissions and hospital length of stay in malnourished inpatients through a nutrition-focused quality improvement program using a web-based budget impact model, and to demonstrate the clinical and fiscal value of the intervention. Methods The reduction in readmission rate and length of stay for 1269 patients enrolled in the quality improvement program (between October 13, 2014, and April 2, 2015) were compared with the pre–quality improvement program baseline and validation cohorts (4611 patients vs 1319 patients, respectively) to calculate potential cost-savings as well as to inform the design of the budget impact model. Readmission rate and length-of-stay reductions were calculated by determining the change from baseline to post–quality improvement program as well as the difference between the validation cohort and the post–quality improvement program, respectively. Results As a result of improved health outcomes for the treated patients, the nutrition-focused quality improvement program led to a reduction in 30-day hospital readmissions and length of stay. The avoided hospital readmissions and reduced number of days in the hospital for the patients in the quality improvement program resulted in cost-savings of $1,902,933 versus the pre–quality improvement program baseline cohort, and $4,896,758 versus the pre–quality improvement program in the validation cohort. When these costs were assessed across the entire patient population enrolled in the quality improvement program, per-patient net savings of $1499 when using the baseline cohort as the comparator and savings per patient treated of $3858 when using the validated cohort as the comparator were achieved. Conclusion The nutrition-focused quality improvement program reduced the per-patient healthcare costs by avoiding 30-day readmissions and through reduced length of hospital stay. These clinical and economic outcomes provide a rationale for merging patient care and financial modeling to advance the delivery of value-based medicine in a malnourished hospitalized population. The use of a novel web-based budget impact model supports the integration of comparative effectiveness analytics and healthcare resource management in the hospital setting to provide optimal quality of care at a reduced overall cost. PMID:28975010

Budget Impact of a Comprehensive Nutrition-Focused Quality Improvement Program for Malnourished Hospitalized Patients.

PubMed

Sulo, Suela; Feldstein, Josh; Partridge, Jamie; Schwander, Bjoern; Sriram, Krishnan; Summerfelt, Wm Thomas

2017-07-01

Nutrition interventions can alleviate the burden of malnutrition by improving patient outcomes; however, evidence on the economic impact of medical nutrition intervention remains limited. A previously published nutrition-focused quality improvement program targeting malnourished hospitalized patients showed that screening patients with a validated screening tool at admission, rapidly administering oral nutritional supplements, and educating patients on supplement adherence result in significant reductions in 30-day unplanned readmissions and hospital length of stay. To assess the potential cost-savings associated with decreased 30-day readmissions and hospital length of stay in malnourished inpatients through a nutrition-focused quality improvement program using a web-based budget impact model, and to demonstrate the clinical and fiscal value of the intervention. The reduction in readmission rate and length of stay for 1269 patients enrolled in the quality improvement program (between October 13, 2014, and April 2, 2015) were compared with the pre-quality improvement program baseline and validation cohorts (4611 patients vs 1319 patients, respectively) to calculate potential cost-savings as well as to inform the design of the budget impact model. Readmission rate and length-of-stay reductions were calculated by determining the change from baseline to post-quality improvement program as well as the difference between the validation cohort and the post-quality improvement program, respectively. As a result of improved health outcomes for the treated patients, the nutrition-focused quality improvement program led to a reduction in 30-day hospital readmissions and length of stay. The avoided hospital readmissions and reduced number of days in the hospital for the patients in the quality improvement program resulted in cost-savings of $1,902,933 versus the pre-quality improvement program baseline cohort, and $4,896,758 versus the pre-quality improvement program in the validation cohort. When these costs were assessed across the entire patient population enrolled in the quality improvement program, per-patient net savings of $1499 when using the baseline cohort as the comparator and savings per patient treated of $3858 when using the validated cohort as the comparator were achieved. The nutrition-focused quality improvement program reduced the per-patient healthcare costs by avoiding 30-day readmissions and through reduced length of hospital stay. These clinical and economic outcomes provide a rationale for merging patient care and financial modeling to advance the delivery of value-based medicine in a malnourished hospitalized population. The use of a novel web-based budget impact model supports the integration of comparative effectiveness analytics and healthcare resource management in the hospital setting to provide optimal quality of care at a reduced overall cost.

Bias in ground-water data caused by well-bore flow in long-screen wells

USGS Publications Warehouse

Church, P.E.; Granato, G.E.

1996-01-01

The results of a field experiment comparing water-quality constituents, specific conductance, geophysical measurements, and well-bore hydraulics in two long-screen wells and adjacent vertical clusters of short-screen wells show bias in ground-water data caused by well-bore flow in long-screen wells. The well screen acts as a conduit for vertical flow because it connects zones of different head and transmissivity, even in a relatively homogeneous, unconfined, sand and gravel aquifer where such zones are almost indistinguishable. Flow in the well bore redistributes water and solutes in the aquifer adjacent to the well, increasing the risk of bias in water-quality samples, failure of plume detection, and cross-contamination of the aquifer. At one site, downward flow from a contaminated zone redistributes solutes over the entire length of the long-screen well. At another site, upward flow from an uncontaminated zone masks the presence of road salt plume. Borehole induction logs, conducted in a fully penetrating short-screen well, can provide a profile of solutes in the aquifer that is not attainable in long-screen wells. In this study, the induction-log profiles show close correlation with data from analyses of water-quality samples from the short-screen wells; however, both of these data sets differ markedly from the biased water-quality samples from the long-screen wells. Therefore, use of induction logs in fully cased wells for plume detection and accurate placement of short-screen wells is a viable alternative to use of long screen wells for water-quality sampling.

Additional weekend allied health services reduce length of stay in subacute rehabilitation wards but their effectiveness and cost-effectiveness are unclear in acute general medical and surgical hospital wards: a systematic review.

PubMed

Sarkies, Mitchell N; White, Jennifer; Henderson, Kate; Haas, Romi; Bowles, John

2018-06-18

Are additional weekend allied health services effective and cost-effective for acute general medical and surgical wards, and subacute rehabilitation hospital wards? Systematic review and meta-analysis of studies published between January 2000 and May 2017. Two reviewers independently screened studies for inclusion, extracted data, and assessed methodological quality. Meta-analyses were conducted for relative measures of effect estimates. Patients admitted to acute general medical and surgical wards, and subacute rehabilitation wards. All services delivered by allied health professionals during weekends (Saturday and/or Sunday). This study limited allied health professions to: occupational therapy, physiotherapy, social work, speech pathology, dietetics, art therapy, chiropractic, exercise physiology, music therapy, oral health (not dentistry), osteopathy, podiatry, psychology, and allied health assistants. Hospital length of stay, hospital re-admission, adverse events, discharge destination, functional independence, health-related quality of life, and cost of hospital care. Nineteen articles (20 studies) were identified, comprising 10 randomised and 10 non-randomised trials. Physiotherapy was the most commonly investigated profession. A meta-analysis of randomised, controlled trials showed that providing additional weekend allied health services in subacute rehabilitation wards reduced hospital length of stay by 2.35days (95% CI 0.45 to 4.24, I 2 =0%), and may be a cost-effective way to improve function (SMD 0.09, 95% CI -0.01 to 0.19, I 2 =0%), and health-related quality of life (SMD 0.10, 95% CI -0.01 to 0.20, I 2 =0%). For acute general medical and surgical hospital wards, it was unclear whether the weekend allied health service model provided in the two identified randomised trials led to significant changes in measured outcomes. The benefit of providing additional allied health services is clearer in subacute rehabilitation settings than for acute general medical and surgical wards in hospitals. PROSPERO CRD76771. [Sarkies MN, White J, Henderson K, Haas R, Bowles J, Evidence Translation in Allied Health (EviTAH) Group (2018) Additional weekend allied health services reduce length of stay in subacute rehabilitation wards but their effectiveness and cost-effectiveness are unclear in acute general medical and surgical hospital wards: a systematic review. Journal of Physiotherapy XX: XX-XX]. Copyright © 2018 Australian Physiotherapy Association. Published by Elsevier B.V. All rights reserved.

Integration of geriatric mental health screening into a primary care practice: a patient satisfaction survey.

PubMed

Samuels, S; Abrams, R; Shengelia, R; Reid, M C; Goralewicz, R; Breckman, R; Anderson, M A; Snow, C E; Woods, E C; Stern, A; Eimicke, J P; Adelman, R D

2015-05-01

Colocation of mental health screening, assessment, and treatment in primary care reduces stigma, improves access, and increases coordination of care between mental health and primary care providers. However, little information exists regarding older adults' attitudes about screening for mental health problems in primary care. The objective of this study was to evaluate older primary care patients' acceptance of and satisfaction with screening for depression and anxiety. The study was conducted at an urban, academically affiliated primary care practice serving older adults. Study patients (N = 107) were screened for depression/anxiety and underwent a post-screening survey/interview to assess their reactions to the screening experience. Most patients (88.6%) found the length of the screening to be "just right." A majority found the screening questions somewhat or very acceptable (73.4%) and not at all difficult (81.9%). Most participants did not find the questions stressful (84.9%) or intrusive (91.5%); and a majority were not at all embarrassed (93.4%), upset (93.4%), or uncomfortable (88.8%) during the screening process. When asked about frequency of screening, most patients (72.4%) desired screening for depression/anxiety yearly or more. Of the 79 patients who had spoken with their physicians about mental health during the visit, 89.8% reported that it was easy or very easy to talk with their physicians about depression/anxiety. Multivariate results showed that patients with higher anxiety had a lower positive reaction to the screen when controlling for gender, age, and patient-physician communication. These results demonstrate strong patient support for depression and anxiety screening in primary care. Copyright © 2014 John Wiley & Sons, Ltd.

Measurement of heat conduction through stacked screens

NASA Technical Reports Server (NTRS)

Lewis, M. A.; Kuriyama, T.; Kuriyama, F.; Radebaugh, R.

1998-01-01

This paper describes the experimental apparatus for the measurement of heat conduction through stacked screens as well as some experimental results taken with the apparatus. Screens are stacked in a fiberglass-epoxy cylinder, which is 24.4 mm in diameter and 55 mm in length. The cold end of the stacked screens is cooled by a Gifford-McMahon (GM) cryocooler at cryogenic temperature, and the hot end is maintained at room temperature. Heat conduction through the screens is determined from the temperature gradient in a calibrated heat flow sensor mounted between the cold end of the stacked screens and the GM cryocooler. The samples used for these experiments consisted of 400-mesh stainless steel screens, 400-mesh phosphor bronze screens, and two different porosities of 325-mesh stainless steel screens. The wire diameter of the 400-mesh stainless steel and phosphor bronze screens was 25.4 micrometers and the 325-mesh stainless steel screen wire diameters were 22.9 micrometers and 27.9 micrometers. Standard porosity values were used for the experimental data with additional porosity values used on selected experiments. The experimental results showed that the helium gas between each screen enhanced the heat conduction through the stacked screens by several orders of magnitude compared to that in vacuum. The conduction degradation factor is the ratio of actual heat conduction to the heat conduction where the regenerator material is assumed to be a solid rod of the same cross sectional area as the metal fraction of the screen. This factor was about 0.1 for the stainless steel and 0.022 for the phosphor bronze, and almost constant for the temperature range of 40 to 80 K at the cold end.

Measurement of heat conduction through stacked screens.

PubMed

Lewis, M A; Kuriyama, T; Kuriyama, F; Radebaugh, R

1998-01-01

This paper describes the experimental apparatus for the measurement of heat conduction through stacked screens as well as some experimental results taken with the apparatus. Screens are stacked in a fiberglass-epoxy cylinder, which is 24.4 mm in diameter and 55 mm in length. The cold end of the stacked screens is cooled by a Gifford-McMahon (GM) cryocooler at cryogenic temperature, and the hot end is maintained at room temperature. Heat conduction through the screens is determined from the temperature gradient in a calibrated heat flow sensor mounted between the cold end of the stacked screens and the GM cryocooler. The samples used for these experiments consisted of 400-mesh stainless steel screens, 400-mesh phosphor bronze screens, and two different porosities of 325-mesh stainless steel screens. The wire diameter of the 400-mesh stainless steel and phosphor bronze screens was 25.4 micrometers and the 325-mesh stainless steel screen wire diameters were 22.9 micrometers and 27.9 micrometers. Standard porosity values were used for the experimental data with additional porosity values used on selected experiments. The experimental results showed that the helium gas between each screen enhanced the heat conduction through the stacked screens by several orders of magnitude compared to that in vacuum. The conduction degradation factor is the ratio of actual heat conduction to the heat conduction where the regenerator material is assumed to be a solid rod of the same cross sectional area as the metal fraction of the screen. This factor was about 0.1 for the stainless steel and 0.022 for the phosphor bronze, and almost constant for the temperature range of 40 to 80 K at the cold end.

The association of telomere length and genetic variation in telomere biology genes.

PubMed

Mirabello, Lisa; Yu, Kai; Kraft, Peter; De Vivo, Immaculata; Hunter, David J; Prescott, Jennifer; Wong, Jason Y Y; Chatterjee, Nilanjan; Hayes, Richard B; Savage, Sharon A

2010-09-01

Telomeres cap chromosome ends and are critical for genomic stability. Many telomere-associated proteins are important for telomere length maintenance. Recent genome-wide association studies (GWAS) have identified single nucleotide polymorphisms (SNPs) in genes encoding telomere-associated proteins (RTEL1 and TERT-CLPTM1) as markers of cancer risk. We conducted an association study of telomere length and 743 SNPs in 43 telomere biology genes. Telomere length in peripheral blood DNA was determined by Q-PCR in 3,646 participants from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial and Nurses' Health Study. We investigated associations by SNP, gene, and pathway (functional group). We found no associations between telomere length and SNPs in TERT-CLPTM1L or RTEL1. Telomere length was not significantly associated with specific functional groups. Thirteen SNPs from four genes (MEN1, MRE11A, RECQL5, and TNKS) were significantly associated with telomere length. The strongest findings were in MEN1 (gene-based P=0.006), menin, which associates with the telomerase promoter and may negatively regulate telomerase. This large association study did not find strong associations with telomere length. The combination of limited diversity and evolutionary conservation suggest that these genes may be under selective pressure. More work is needed to explore the role of genetic variants in telomere length regulation. Published 2010 Wiley-Liss, Inc.

Fear of birth in clinical practice: A structured review of current measurement tools.

PubMed

Richens, Yana; Smith, Debbie M; Lavender, Dame Tina

2018-06-01

To identify measurement tools which screen for the presence of fear of birth (FOB) and to determine the most effective tool/s for use in clinical practice. Fear or birth (FOB) is internationally recognised as a cause for increasing concern, despite a lack of consensus on a definition or optimal measure of assessment. There is a wide array of FOB measurement tools, however little clarity on which tool should be used to screen for FOB in clinical practice. This review explores the use of tools that are used to screen for FOB and discusses the perceived effectiveness of such tools. A structured literature review was undertaken. Electronic databases were searched in July 2017 and manuscripts reviewed for quality. The review included 46 papers. The majority of studies were undertaken in Scandinavia (n = 29) and a range of tools were used to measure FOB. The most widely used tool was the Wijma Delivery Expectancy Experience Questionnaire' (W-DEQ). Inconsistencies were found in the way this tool was used, including variations in assessment cut-off points, implementation and use across a range of cultural settings and women of varying gestations. Moreover, the tool may be too lengthy to use in clinical practice. The Fear of Birth Scale (FOBS) has been shown to be as effective as W-DEQ but has the advantage of being short and easy to administer. The inconsistencies in tools reflect the difficulties in defining FOB. A clear consensus definition of FOB would aid comparisons across practice and research. The W-DEQ is not used in clinical practice; this may be due to its length and complexity. The FOBS is likely to be a more versatile tool that can be used in clinical practice. Copyright © 2018 Elsevier B.V. All rights reserved.

Discovery of peroxisome proliferator-activated receptor α (PPARα) activators with a ligand-screening system using a human PPARα-expressing cell line.

PubMed

Tachibana, Keisuke; Yuzuriha, Tomohiro; Tabata, Ryotaro; Fukuda, Syohei; Maegawa, Takashi; Takahashi, Rika; Tanimoto, Keiichi; Tsujino, Hirofumi; Nunomura, Kazuto; Lin, Bangzhong; Matsuura, Yoshiharu; Tanaka, Toshiya; Hamakubo, Takao; Sakai, Juro Js; Kodama, Tatsuhiko; Kobayashi, Tadayuki; Ishimoto, Kenji; Miyachi, Hiroyuki; Doi, Takefumi

2018-05-15

Peroxisome proliferator-activated receptor alpha (PPARα) is a ligand-activated transcription factor that belongs to the superfamily of nuclear hormone receptors. PPARα is mainly expressed in the liver, where it activates fatty acid oxidation and lipoprotein metabolism and improves plasma lipid profiles. Therefore, PPARα activators are often used to treat patients with dyslipidemia. To discover additional PPARα activators as potential compounds for use in hypolipidemic drugs, here we established human hepatoblastoma cell lines with luciferase reporter expression from the promoters containing peroxisome proliferator responsive elements (PPRE) and tetracycline-regulated expression of full-length human PPARα to quantify the effects of chemical ligands on PPARα activity. Using the established cell-based PPARα-activator screening system to screen a library of > 12,000 chemical compounds, we identified several hit compounds with basic chemical skeletons different from those of known PPARα agonists. One of the hit compounds, a 1H-pyrazolo[3,4-b]pyridine-4-carboxylic acid derivative we termed compound 3, selectively up-regulated PPARα transcriptional activity, leading to PPARα target gene expression both in vitro and in vivo. Of note, the half-maximal effective concentrations of the hit compounds were lower than that of the known PPARα ligand fenofibrate. Finally, fenofibrate or compound 3 treatment of high fructose-fed rats having elevated plasma triglyceride levels for 14 days indicated that compound 3 reduces plasma triglyceride levels with similar efficiency as fenofibrate. These observations raise the possibility that 1H-pyrazolo[3,4-b]pyridine-4-carboxylic acid derivatives might be effective drug candidates for selective targeting of PPARα to manage dyslipidemia. Published under license by The American Society for Biochemistry and Molecular Biology, Inc.

Preliminary study on evaluation of the pancreatic tail observable limit of transabdominal ultrasonography using a position sensor and CT-fusion image.

PubMed

Sumi, Hajime; Itoh, Akihiro; Kawashima, Hiroki; Ohno, Eizaburo; Itoh, Yuya; Nakamura, Yosuke; Hiramatsu, Takeshi; Sugimoto, Hiroyuki; Hayashi, Daijuro; Kuwahara, Takamichi; Morishima, Tomomasa; Kawai, Manabu; Furukawa, Kazuhiro; Funasaka, Kohei; Nakamura, Masanao; Miyahara, Ryoji; Katano, Yoshiaki; Ishigami, Masatoshi; Ohmiya, Naoki; Goto, Hidemi; Hirooka, Yoshiki

2014-08-01

Transabdominal ultrasonography (US) is commonly used for the initial screening of bilio-pancreatic diseases in Asian countries due to its widespread availability, the non-invasiveness and the cost-effectiveness. However, it is considered that US has limits to observe the area, namely the blind area. The observation of the pancreatic tail is particularly difficult. The goal of this study was to examine the pancreatic tail region that cannot be visualized on transverse scanning of the upper abdomen using US with spatial positional information and factors related to visualization, and observation of the tail from the splenic hilum. Thirty-nine patients with pancreatic/biliary tract disease underwent CT and US with GPS-like technology and fusion imaging for measurement of the real pancreatic length and the predicted/real unobservable (PU and RU) length of the pancreatic tail. RU from US on transverse scanning and the real pancreatic length were used to determine the unobservable area (UA: RU/the real pancreatic length). Relationships of RU with physical and hematological variables that might influence visualization of the pancreatic tail were investigated. The real pancreatic length was 160.9 ± 16.4mm, RU was 41.0 ± 17.8mm, and UA was 25.3 ± 10.4%. RU was correlated with BMI (R=0.446, P=0.004) and waist circumferences (R=0.354, P=0.027), and strongly correlated with PU (R=0.788, P<0.001). The pancreatic tail was visible from the splenic hilum in 22 (56%) subjects and was completely identified in 13 (33%) subjects. Combined GPS-like technology with fusion imaging was useful for the objective estimation of the pancreatic blind area. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Quark structure of static correlators in high temperature QCD

NASA Astrophysics Data System (ADS)

Bernard, Claude; DeGrand, Thomas A.; DeTar, Carleton; Gottlieb, Steven; Krasnitz, A.; Ogilvie, Michael C.; Sugar, R. L.; Toussaint, D.

1992-07-01

We present results of numerical simulations of quantum chromodynamics at finite temperature with two flavors of Kogut-Susskind quarks on the Intel iPSC/860 parallel processor. We investigate the properties of the objects whose exchange gives static screening lengths by reconstructing their correlated quark-antiquark structure.

Transport of Multivalent Electrolyte Mixtures in Micro- and Nanochannels

DTIC Science & Technology

2013-11-08

equations for this process are the unsteady Navier-Stokes equations along with continuity and the Poisson- Nernst -Planck system for the electro- static part...about five times the Debye screening length D (the 1/e lengthscale for the potential from the solution of the linearized Poisson- Boltzmann equation

Screening Educational Equity: A Filmography.

ERIC Educational Resources Information Center

American Univ., Washington, DC. Mid-Atlantic Center for Sex Equity.

Films, filmstrips, and videotape cassettes portraying a variety of multicultural experiences are listed in this catalog. All are educationally appropriate for use in the classroom and/or for staff development. Each entry in the alphabetical listing contains the length of the item, the date it was made, the target audience, and a brief description…

From what should we protect future generations: germ-line therapy or genetic screening?

PubMed

Mallia, Pierre; ten Have, Henk

2003-01-01

This paper discusses the issue of whether we have responsibilities to future generations with respect to genetic screening, including for purposes of selective abortion or discard. Future generations have been discussed at length among scholars. The concept of 'Guardian for Future Generations' is tackled and its main criticisms discussed. Whilst germ-line cures, it is argued, can only affect family trees, genetic screening and testing can have wider implications. If asking how this may affect future generations is a legitimate question and since we indeed make retrospective moral judgements, it would be wise to consider that future generations will make the same retrospective judgements on us. Moreover such technologies affect present embryos to which we indeed can be considered to have an obligation.

Large-scale DNA Barcode Library Generation for Biomolecule Identification in High-throughput Screens.

PubMed

Lyons, Eli; Sheridan, Paul; Tremmel, Georg; Miyano, Satoru; Sugano, Sumio

2017-10-24

High-throughput screens allow for the identification of specific biomolecules with characteristics of interest. In barcoded screens, DNA barcodes are linked to target biomolecules in a manner allowing for the target molecules making up a library to be identified by sequencing the DNA barcodes using Next Generation Sequencing. To be useful in experimental settings, the DNA barcodes in a library must satisfy certain constraints related to GC content, homopolymer length, Hamming distance, and blacklisted subsequences. Here we report a novel framework to quickly generate large-scale libraries of DNA barcodes for use in high-throughput screens. We show that our framework dramatically reduces the computation time required to generate large-scale DNA barcode libraries, compared with a naїve approach to DNA barcode library generation. As a proof of concept, we demonstrate that our framework is able to generate a library consisting of one million DNA barcodes for use in a fragment antibody phage display screening experiment. We also report generating a general purpose one billion DNA barcode library, the largest such library yet reported in literature. Our results demonstrate the value of our novel large-scale DNA barcode library generation framework for use in high-throughput screening applications.

Efficient hit-finding approaches for histone methyltransferases: the key parameters.

PubMed

Ahrens, Thomas; Bergner, Andreas; Sheppard, David; Hafenbradl, Doris

2012-01-01

For many novel epigenetics targets the chemical ligand space and structural information were limited until recently and are still largely unknown for some targets. Hit-finding campaigns are therefore dependent on large and chemically diverse libraries. In the specific case of the histone methyltransferase G9a, the authors have been able to apply an efficient process of intelligent selection of compounds for primary screening, rather than screening the full diverse deck of 900 000 compounds to identify hit compounds. A number of different virtual screening methods have been applied for the compound selection, and the results have been analyzed in the context of their individual success rates. For the primary screening of 2112 compounds, a FlashPlate assay format and full-length histone H3.1 substrate were employed. Validation of hit compounds was performed using the orthogonal fluorescence lifetime technology. Rated by purity and IC(50) value, 18 compounds (0.9% of compound screening deck) were finally considered validated primary G9a hits. The hit-finding approach has led to novel chemotypes being identified, which can facilitate hit-to-lead projects. This study demonstrates the power of virtual screening technologies for novel, therapeutically relevant epigenetics protein targets.

Screening for domestic violence in public welfare offices: an analysis of case manager and client interactions.

PubMed

Lindhorst, Taryn; Meyers, Marcia; Casey, Erin

2008-01-01

Despite a high prevalence of domestic violence among welfare clients, most studies of the implementation of the Family Violence Option (FVO) under welfare reform find that women rarely receive domestic violence services in welfare offices. This study reviews findings from current research on the factors that improve the likelihood that women will reveal their domestic violence experiences to service personnel, and uses the guidelines drawn from this review to evaluate domestic violence screening practices in welfare offices using 782 transcribed interviews between welfare workers and clients from 11 sites in four states. The analysis found that only 9.3% of case encounters involved screening for domestic violence. Screening rates differed by state, interview type, and length of worker employment. Qualitative analysis of the interviews showed that the majority of screening by workers was routine or consisted of informing clients of the domestic violence policy without asking about abuse. Only 1.2% of the interviews incorporated at least two of the procedures that increase the likelihood of disclosure among domestic violence survivors, suggesting deeply inadequate approaches to screening for abuse within the context of welfare offices, and a need for improved training, protocol, and monitoring of FVO implementation.

Debye screening of dislocations.

PubMed

Groma, I; Györgyi, G; Kocsis, B

2006-04-28

Debye-like screening by edge dislocations of some externally given stress is studied by means of a variational approach to coarse grained field theory. Explicitly given are the force field and the induced geometrically necessary dislocation (GND) distribution, in the special case of a single glide axis in 2D, for (i) a single edge dislocation and (ii) a dislocation wall. Numerical simulation demonstrates that the correlation in relaxed dislocation configurations is in good agreement with the induced GND in case (i). Furthermore, the result (ii) well predicts the experimentally observed decay length for the GND developing close to grain boundaries.

Federal Logistics Information Systems. FLIS Procedures Manual. Document Identifier Code Input/Output Formats (Variable Length). Volume 9.

DTIC Science & Technology

1997-04-01

DATA COLLABORATORS 0001N B NQ 8380 NUMBER OF DATA RECEIVERS 0001N B NQ 2533 AUTHORIZED ITEM IDENTIFICATION DATA COLLABORATOR CODE 0002 ,X B 03 18 TD...01 NC 8268 DATA ELEMENT TERMINATOR CODE 000iX VT 9505 TYPE OF SCREENING CODE 0001A 01 NC 8268 DATA ELEMENT TERMINATOR CODE 000iX VT 4690 OUTPUT DATA... 9505 TYPE OF SCREENING CODE 0001A 2 89 2910 REFERENCE NUMBER CATEGORY CODE (RNCC) 0001X 2 89 4780 REFERENCE NUMBER VARIATION CODE (RNVC) 0001 N 2 89

New, Improved Version of the mCOP-PCR Screening System for Detection of Spinal Muscular Atrophy Gene (SMN1) Deletion.

PubMed

Shinohara, Masakazu; Ar Rochmah, Mawaddah; Nakanishi, Kenta; Harahap, Nur Imma Fatimah; Niba, Emma Tabe Eko; Saito, Toshio; Saito, Kayoko; Takeuchi, Atsuko; Bouike, Yoshihiro; Nishio, Hisahide

2017-09-07

Spinal muscular atrophy (SMA) is a frequent autosomal recessive disorder, characterized by lower motor neuron loss in the spinal cord. More than 95% of SMA patients show homozygous survival motor neuron 1 (SMN1) deletion. We previously developed a screening system for SMN1 deletion based on a modified competitive oligonucleotide priming-PCR (mCOP-PCR) technique. However, non-specific amplification products were observed with mCOP-PCR, which might lead to erroneous interpretation of the screening results. To establish an improved version of the mCOP-PCR screening system without non-specific amplification. DNA samples were assayed using a new version of the mCOP-PCR screening system. DNA samples had already been genotyped by PCR-restriction fragment length polymorphism (PCR-RFLP), showing the presence or absence of SMN1 exon 7. The new mCOP-PCR method contained a targeted pre-amplification step of the region, including an SMN1-specific nucleotide, prior to the mCOP-PCR step. mCOP-PCR products were electrophoresed on agarose gels. No non-specific amplification products were detected in electrophoresis gels with the new mCOP-PCR screening system. An additional targeted pre-amplification step eliminated non-specific amplification from mCOP-PCR screening.

Is physiotherapy effective in the management of child and adolescent conversion disorder? A systematic review.

PubMed

FitzGerald, Tara L; Southby, Alesha K; Haines, Terrence P; Hough, Janet P; Skinner, Elizabeth H

2015-02-01

Child and adolescent conversion disorder has the potential to impart significant burden on health-care services and affect quality of life. Clinically, physiotherapists are involved in conversion disorder management; however, no systematic reviews have examined physiotherapy effectiveness in its management. The aim of this review is to identify the efficacy of physiotherapy management of child and adolescent conversion disorder. A search of multiple databases (Medline, CINAHL, Embase, PsychINFO, PEDro and the Cochrane Library) was completed along with manual searching of relevant reference lists to identify articles including children 0-18 years with a diagnosis of conversion disorder who received physical management. Two independent reviewers screened titles and abstracts using criteria. Data were extracted regarding study characteristics, functional outcome measures, length of stay, physiotherapy service duration and resolution of conversion symptoms. Methodological quality was assessed using a tool designed for observational studies. Twelve observational studies were included. No functional outcome measures were used to assess the effectiveness of the treatment protocols in the case studies. Resolution of symptoms occurred in all but two cases, with conversion symptoms still present at 11 months and at 2 years. Length of stay varied from 3 days to 16 weeks, with similar variation evident in length of physiotherapy service provision (2.5 weeks to 16 weeks). There was limited and poor quality evidence to establish the efficacy of physiotherapy management of child and adolescent conversion disorders. More rigorous study designs with consistent use of reliable, valid and sensitive functional outcome measures are needed in this area. © 2014 The Authors. Journal of Paediatrics and Child Health © 2014 Paediatrics and Child Health Division (Royal Australasian College of Physicians).

Miscibility phase diagram of ring-polymer blends: A topological effect.

PubMed

Sakaue, Takahiro; Nakajima, Chihiro H

2016-04-01

The miscibility of polymer blends, a classical problem in polymer science, may be altered, if one or both of the component do not have chain ends. Based on the idea of topological volume, we propose a mean-field theory to clarify how the topological constraints in ring polymers affect the phase behavior of the blends. While the large enhancement of the miscibility is expected for ring-linear polymer blends, the opposite trend toward demixing, albeit comparatively weak, is predicted for ring-ring polymer blends. Scaling formulas for the shift of critical point for both cases are derived. We discuss the valid range of the present theory, and the crossover to the linear polymer blends behaviors, which is expected for short chains. These analyses put forward a view that the topological constraints could be represented as an effective excluded-volume effects, in which the topological length plays a role of the screening factor.

Is it worth screening for vancomycin-resistant Enterococcus faecium colonization?: Financial burden of screening in a developing country.

PubMed

Ulu-Kilic, Aysegul; Özhan, Esra; Altun, Dilek; Perçin, Duygu; Güneş, Tamer; Alp, Emine

2016-04-01

The screening of critically ill patients at high risk of vancomycin resistant enterococci (VRE) colonization, to detect and isolate colonized patients, is recommended to prevent and control the transmission of VRE. Screening asymptomatic carriers brings financial burden for institutions. In this study, we performed risk analysis for VRE colonization and determined the financial burden of screening in a middle-income country, Turkey. We retrospectively analyzed the VRE surveillance data from a pediatric hospital between 2010 and 2014. A case-control study was conducted to identify the risk factors of colonization. Total cost of VRE screening and additional costs for a VRE colonized patient (including active surveillance cultures and contact isolation) were calculated. During the 4-year period, 6,372 patients were screened for perirectal VRE colonization. The rate of culture-positive specimens among all patients screened was 239 (3.75%). The rate of VRE infection was 0.04% (n = 3) among all patients screened. Length of hospital stay, malignancy, and being transferred from another institution were independently associated risk factors for colonization. Annual estimated costs for the laboratory were projected as $19,074 (76,295/4) for all patients screened. Cost of contact isolation for each patient colonized in a ward and an intensive care unit was $270 and $718, respectively. In developing countries, institutions should identify their own high-risk patients; screening priorities should be based on prevalence of infection and hospital financial resources. Copyright © 2016 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Direct measurement of sub-Debye-length attraction between oppositely charged surfaces.

PubMed

Kampf, Nir; Ben-Yaakov, Dan; Andelman, David; Safran, S A; Klein, Jacob

2009-09-11

Using a surface force balance with fast video analysis, we have measured directly the attractive forces between oppositely charged solid surfaces (charge densities sigma(+), sigma(-)) across water over the entire range of interaction, in particular, at surface separations D below the Debye screening length lambda(S). At very low salt concentration we find a long-ranged attraction between the surfaces (onset ca. 100 nm), whose variation at D

Modeling the Dynamics of High-Grade Serous Ovarian Cancer Progression for Transvaginal Ultrasound-Based Screening and Early Detection

PubMed Central

Lee, Jung-Min; Levy, Doron

2016-01-01

High-grade serous ovarian cancer (HGSOC) represents the majority of ovarian cancers and accounts for the largest proportion of deaths from the disease. A timely detection of low volume HGSOC should be the goal of any screening studies. However, numerous transvaginal ultrasound (TVU) detection-based population studies aimed at detecting low-volume disease have not yielded reduced mortality rates. A quantitative invalidation of TVU as an effective HGSOC screening strategy is a necessary next step. Herein, we propose a mathematical model for a quantitative explanation on the reported failure of TVU-based screening to improve HGSOC low-volume detectability and overall survival.We develop a novel in silico mathematical assessment of the efficacy of a unimodal TVU monitoring regimen as a strategy aimed at detecting low-volume HGSOC in cancer-positive cases, defined as cases for which the inception of the first malignant cell has already occurred. Our findings show that the median window of opportunity interval length for TVU monitoring and HGSOC detection is approximately 1.76 years. This does not translate into reduced mortality levels or improved detection accuracy in an in silico cohort across multiple TVU monitoring frequencies or detection sensitivities. We demonstrate that even a semiannual, unimodal TVU monitoring protocol is expected to miss detectable HGSOC. Lastly, we find that circa 50% of the simulated HGSOC growth curves never reach the baseline detectability threshold, and that on average, 5–7 infrequent, rate-limiting stochastic changes in the growth parameters are associated with reaching HGSOC detectability and mortality thresholds respectively. Focusing on a malignancy poorly studied in the mathematical oncology community, our model captures the dynamic, temporal evolution of HGSOC progression. Our mathematical model is consistent with recent case reports and prospective TVU screening population studies, and provides support to the empirical recommendation against frequent HGSOC screening. PMID:27257824

Determining an anthropometric surrogate measure for identifying low birth weight babies in Uganda: a hospital-based cross sectional study.

PubMed

Elizabeth, Nabiwemba L; Christopher, Orach Garimoi; Patrick, Kolsteren

2013-04-12

Achieving Millennium Development Goal 4 is dependent on significantly reducing neonatal mortality. Low birth weight is an underlying factor in most neonatal deaths. In developing countries the missed opportunity for providing life saving care is mainly a result of failure to identify low birth weight newborns. This study aimed at identifying a reliable anthropometric measurement for screening low birth weight and determining an operational cut-off point in the Uganda setting. This simple measurement is required because of lack of weighing scales in the community, and sometimes in the health facilities. This was a hospital-based cross-sectional study. Two midwives weighed 706 newborns and measured their foot length, head, chest, thigh and mid-upper arm circumferences within 24 hours after birth.Data was analysed using STATA version 10.0. Correlation with birth weight using Pearson's correlation coefficient and Receiver Operating Characteristics curve analysis were done to determine the measure that best predicts birth weight. Sensitivity and specificity were calculated for a range of measures to obtain operational cut-off points; and Likelihood Ratios and Diagnostic Odds Ratio were determined for each cut-off point. Birth weights ranged from 1370-5350 grams with a mean of 3050 grams (SD 0.53) and 85 (12%) babies weighed less than 2500 grams. All anthropometric measurements had a positive correlation with birth weight, with foot length showing the strongest (r = 0.76) and thigh circumference the weakest (r = 0.62) correlations. Foot length had the highest predictive value for low birth weight (AUC = 0.97) followed by mid-upper arm circumference (AUC = 0.94). Foot length and chest circumference had the highest sensitivity (94%) and specificity (90%) respectively for screening low birth weight babies at the selected cut-off points. Chest circumference had a significantly higher positive likelihood ratio (8.7) than any other measure, and foot length had the lowest negative likelihood ratio. Chest circumference and foot length had diagnostic odds ratios of 97% and 77% respectively. Foot length was easier to measure and it involved minimal exposure of the baby to cold. A cut-off of foot length 7.9 cm had sensitivity of 94% and specificity of 83% for predicting low birth weight. This study suggests foot length as the most appropriate predictor for low birth weight in comparison to chest, head, mid-upper arm and thigh circumference in the Uganda setting. Use of low cost and easy to use tools to identify low birth weight babies by village health teams could support community efforts to save newborns.

Phytotoxicity of water-soluble substances from alfalfa and barley soil extracts on four crop species.

PubMed

Read, J J; Jensen, E H

1989-02-01

Problems associated with continuously planting alfalfa (Medicago saliva L.) or seeding to thicken depleted alfalfa stands may be due to autotoxicity, an intraspecific form of allelopathy. A bioassay approach was utilized to characterize the specificity and chemical nature of phytotoxins in extracts of alfalfa soils as compared to fallow soil or soil where a cereal was the previous crop. In germination chamber experiments, water-soluble substances present in methanol extracts of soil cropped to alfalfa or barley (Hordeum vulgare L.) decreased seedling root length of alfalfa L-720, winter wheat (Triticum aestivum L. Nugaines) and radish (Raphanus sativa L. Crimson Giant). Five days after germination, seedling dry weights of alfalfa and radish in alfalfa soil extracts were lower compared to wheat or red clover (Trifolium pralense L. Kenland). Growth of red clover was not significantly reduced by soil extracts from cropped soil. Extracts of crop residue screened from soil cropped to alfalfa or barley significantly reduced seedling root length; extracts of alfalfa residue caused a greater inhibition of seedling dry weight than extracts of barely residue. A phytotoxic, unidentified substance present in extracts of crop residue screened from alfalfa soil, which inhibited seedling root length of alfalfa, was isolated by thin-layer chromatography (TLC). Residues from a soil cropped continuously to alfalfa for 10 years had the greatest phytotoxic activity.

Fetal nasal bone length at 11(+0) - 13(+6) weeks of gestation: an evaluation of 554 consecutive cases.

PubMed

Cansu, A; Ozgur, H; Guven, S; Dinc, G; Dinc, H

2014-01-01

To develop a nomogram for estimating nasal bone length (NBL) at 11(+0) - 13(+6) weeks of gestation in 554 consecutive cases and to determine the value of NBL measurement in screening for chromosomal abnormalities. NBL and crown-rump length (CRL) were examined in 554 fetuses at 11(+0) - 13(+6) weeks' gestation. A nomogram for NBL was developed with data from 479 healthy fetuses in which fetal profile examination was possible. Reference values, including percentiles, weie calculated for each gestational age. A linear correlation was noted between CRL and NBL in healthy fetuses at 11(+0) - 11(+6), 12(+0) - 12(+6) and 13(+0) - 13(+6) weeks of gestation. Mean NBL was 2.18 +/- 0.53 mm, 2.46 +/- 0.45 mm, and 2.91 +/- 0.55 mm in healthy fetuses, for these time frames, respectively. NBL increased significantly with CRL from respective means of 2.26 +/- 0.43, 2.60 +/- 0.48, 2.77 +/- 0.43, and 3.16 +/- 0.52 mm at 45 - 54.9, 55 - 64.9, 65 +/- 74.9, and 75 - 84 mm. The authors developed a NBL nomogram with data from normal, healthy Turkish fetuses at 11(+0) - 13(+6) weeks of gestation. These reference ranges may prove useful in prenatal screening and diagnosis of syndromes known to be associated with nasal hypoplasia.

General relativistic screening in cosmological simulations

NASA Astrophysics Data System (ADS)

Hahn, Oliver; Paranjape, Aseem

2016-10-01

We revisit the issue of interpreting the results of large volume cosmological simulations in the context of large-scale general relativistic effects. We look for simple modifications to the nonlinear evolution of the gravitational potential ψ that lead on large scales to the correct, fully relativistic description of density perturbations in the Newtonian gauge. We note that the relativistic constraint equation for ψ can be cast as a diffusion equation, with a diffusion length scale determined by the expansion of the Universe. Exploiting the weak time evolution of ψ in all regimes of interest, this equation can be further accurately approximated as a Helmholtz equation, with an effective relativistic "screening" scale ℓ related to the Hubble radius. We demonstrate that it is thus possible to carry out N-body simulations in the Newtonian gauge by replacing Poisson's equation with this Helmholtz equation, involving a trivial change in the Green's function kernel. Our results also motivate a simple, approximate (but very accurate) gauge transformation—δN(k )≈δsim(k )×(k2+ℓ-2)/k2 —to convert the density field δsim of standard collisionless N -body simulations (initialized in the comoving synchronous gauge) into the Newtonian gauge density δN at arbitrary times. A similar conversion can also be written in terms of particle positions. Our results can be interpreted in terms of a Jeans stability criterion induced by the expansion of the Universe. The appearance of the screening scale ℓ in the evolution of ψ , in particular, leads to a natural resolution of the "Jeans swindle" in the presence of superhorizon modes.

The use of high-throughput screening techniques to evaluate mitochondrial toxicity.

PubMed

Wills, Lauren P

2017-11-01

Toxicologists and chemical regulators depend on accurate and effective methods to evaluate and predict the toxicity of thousands of current and future compounds. Robust high-throughput screening (HTS) experiments have the potential to efficiently test large numbers of chemical compounds for effects on biological pathways. HTS assays can be utilized to examine chemical toxicity across multiple mechanisms of action, experimental models, concentrations, and lengths of exposure. Many agricultural, industrial, and pharmaceutical chemicals classified as harmful to human and environmental health exert their effects through the mechanism of mitochondrial toxicity. Mitochondrial toxicants are compounds that cause a decrease in the number of mitochondria within a cell, and/or decrease the ability of mitochondria to perform normal functions including producing adenosine triphosphate (ATP) and maintaining cellular homeostasis. Mitochondrial dysfunction can lead to apoptosis, necrosis, altered metabolism, muscle weakness, neurodegeneration, decreased organ function, and eventually disease or death of the whole organism. The development of HTS techniques to identify mitochondrial toxicants will provide extensive databases with essential connections between mechanistic mitochondrial toxicity and chemical structure. Computational and bioinformatics approaches can be used to evaluate compound databases for specific chemical structures associated with toxicity, with the goal of developing quantitative structure-activity relationship (QSAR) models and mitochondrial toxicophores. Ultimately these predictive models will facilitate the identification of mitochondrial liabilities in consumer products, industrial compounds, pharmaceuticals and environmental hazards. Copyright © 2017 Elsevier B.V. All rights reserved.

Ferroelectricity and tunneling electroresistance effect in asymmetric ferroelectric tunnel junctions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tao, L. L.; Wang, J., E-mail: jianwang@hku.hk

2016-06-14

We report the investigation on the ferroelectricity and tunneling electroresistance (TER) effect in PbTiO{sub 3} (PTO)-based ferroelectric tunnel junctions (FTJs) using first-principles calculations. For symmetric FTJs, we have calculated the average polarizations of PTO film and effective screening lengths of different metal electrodes for a number of FTJs, which is useful for experimental research. For asymmetric FTJs, significant asymmetric ferroelectric displacements in PTO film are observed, which is attributed to the intrinsic field generated by the two dissimilar electrodes. Moreover, by performing quantum transport calculations on those asymmetric FTJs, a sizable TER effect is observed. It is found that themore » asymmetry of ferroelectric displacements in PTO barrier, which is determined by the difference of work functions of the electrodes, controls the observed TER effect. Our results will help unravel the TER mechanism of asymmetric FTJs in most experiments and will be useful for the designing of FTJ-based devices.« less

Fluorescence self-quenching assay for the detection of target collagen sequences using a short probe peptide.

PubMed

Nian, Linge; Hu, Yue; Fu, Caihong; Song, Chen; Wang, Jie; Xiao, Jianxi

2018-01-01

The development of novel assays to detect collagen fragments is of utmost importance for diagnostic, prognostic and therapeutic decisions in various collagen-related diseases, and one essential question is to discover probe peptides that can specifically recognize target collagen sequences. Herein we have developed the fluorescence self-quenching assay as a convenient tool to screen the capability of a series of fluorescent probe peptides of variable lengths to bind with target collagen peptides. We have revealed that the targeting ability of probe peptides is length-dependent, and have discovered a relatively short probe peptide FAM-G(POG) 8 capable to identify the target peptide. We have further demonstrated that fluorescence self-quenching assay together with this short probe peptide can be applied to specifically detect the desired collagen fragment in complex biological media. Fluorescence self-quenching assay provides a powerful new tool to discover effective peptides for the recognition of collagen biomarkers, and it may have great potential to identify probe peptides for various protein biomarkers involved in pathological conditions. Copyright © 2017 Elsevier B.V. All rights reserved.

Self-assembled nanogaps for molecular electronics.

PubMed

Tang, Qingxin; Tong, Yanhong; Jain, Titoo; Hassenkam, Tue; Wan, Qing; Moth-Poulsen, Kasper; Bjørnholm, Thomas

2009-06-17

A nanogap for molecular devices was realized using solution-based self-assembly. Gold nanorods were assembled to gold nanoparticle-coated conducting SnO2:Sb nanowires via thiol end-capped oligo(phenylenevinylene)s (OPVs). The molecular gap was easily created by the rigid molecule itself during self-assembly and the gap length was determined by the molecule length. The gold nanorods and gold nanoparticles, respectively covalently bonded at the two ends of the molecule, had very small dimensions, e.g. a width of approximately 20 nm, and hence were expected to minimize the screening effect. The ultra-long conducting SnO2:Sb nanowires provided the bridge to connect one of the electrodes of the molecular device (gold nanoparticle) to the external circuit. The tip of the atomic force microscope (AFM) was contacted onto the other electrode (gold nanorod) for the electrical measurement of the OPV device. The conductance measurement confirmed that the self-assembly of the molecules and the subsequent self-assembly of the gold nanorods was a feasible method for the fabrication of the nanogap of the molecular devices.

Bivalent ligands incorporating curcumin and diosgenin as multifunctional compounds against Alzheimer's disease.

PubMed

Chojnacki, Jeremy E; Liu, Kai; Saathoff, John M; Zhang, Shijun

2015-11-15

In an effort to combat the multifaceted nature of Alzheimer's disease (AD) progression, a series of multifunctional, bivalent compounds containing curcumin and diosgenin were designed, synthesized, and biologically characterized. Screening results in MC65 neuroblastoma cells established that compound 38 with a spacer length of 17 atoms exhibited the highest protective potency with an EC50 of 111.7 ± 9.0 nM. A reduction in protective activity was observed as spacer length was increased up to 28 atoms and there is a clear structural preference for attachment to the methylene carbon between the two carbonyl moieties of curcumin. Further study suggested that antioxidative ability and inhibitory effects on amyloid-β oligomer (AβO) formation may contribute to the neuroprotective outcomes. Additionally, compound 38 was found to bind directly to Aβ, similar to curcumin, but did not form complexes with the common biometals Cu, Fe, and Zn. Altogether, these results give strong evidence to support the bivalent design strategy in developing novel compounds with multifunctional ability for the treatment of AD. Copyright © 2015 Elsevier Ltd. All rights reserved.

The older persons' assessment and liaison team 'OPAL': evaluation of comprehensive geriatric assessment in acute medical inpatients.

PubMed

Harari, D; Martin, F C; Buttery, A; O'Neill, S; Hopper, A

2007-11-01

Reducing hospital length of stay (LOS) in older acute medical inpatients is a key productivity measure. Evidence-based predictors of greater LOS may be targeted through Comprehensive Geriatric Assessment (CGA). Evaluate a novel service model for CGA screening of older acute medical inpatients linked to geriatric intervention. Urban teaching hospital. Acute medical inpatients aged 70+ years. Multidisciplinary CGA screening of all acute medical admissions aged 70+ years leading to (a) rapid transfer to geriatric wards or (b) case-management on general medical wards by Older Persons Assessment and Liaison team (OPAL). Prospective pre-post comparison with statistical adjustment for baseline factors, and use of national benchmarking LOS data. Pre-OPAL (n = 46) and post-OPAL (n = 49) cohorts were similarly identified as high-risk by the CGA screening tool, but only post-OPAL patients received the intervention. Pre-OPAL, 0% fallers versus 92% post-OPAL were specifically assessed and/or referred to a falls service post-discharge. Management of delirium, chronic pain, constipation, and urinary incontinence similarly improved. Over twice as many patients were transferred to geriatric wards, with mean days from admission to transfer falling from 10 to 3. Mean LOS fell by 4 days post-OPAL. Only the OPAL intervention was associated with LOS (P = 0.023) in multiple linear regression including case-mix variables (e.g. age, function, 'geriatric giants'). Benchmarking data showed the LOS reduction to be greater than comparable hospitals. CGA screening of acute medical inpatients leading to early geriatric intervention (ward-based case management, appropriate transfer to geriatric wards), improved clinical effectiveness and general hospital performance.

Do screening-preventative interventions in asymptomatic pregnancies reduce the risk of preterm delivery--a critical appraisal of the literature.

PubMed

Varma, Rajesh; Gupta, Janesh K; James, David K; Kilby, Mark D

2006-08-01

Recent research has suggested that women who experience preterm delivery (PTD) may be identified earlier in pregnancy and before onset of symptoms. Interventions commenced at this earlier asymptomatic stage may offer an opportunity to prevent PTD or lengthen gestation sufficiently to reduce adverse perinatal outcome. Our objective was to examine the evidence that supports or refutes this approach to preventing PTD. We therefore conducted a systematic search and critical appraisal of the identified literature. We found evidence that introducing screening-preventative strategies for asymptomatic pregnancies may reduce the rate of PTD. Evidence for screening and selective treatment exists for: asymptomatic bacteriuria; bacterial vaginosis in low-risk population groups; elective cervical cerclage in high-risk pregnancies; indicated cervical cerclage in women with short cervical length on ultrasound; prophylactic progesterone supplementation in high-risk pregnancies, and smoking cessation. However, for most other strategies, such as increased antenatal attendance, or routine administration of prophylactic micronutrients, the evidence is inconsistent and conflicting. Information on neonatal outcomes apart from PTD (such as serious neonatal morbidity and mortality) was found to be lacking in most studies. It was therefore not possible to establish whether preventing PTD or prolonging gestation would correlate to improved perinatal outcome, and this lessened the potential clinical usefulness of any proposed preventative strategy. No studies were found that evaluated the effectiveness of combining screening-preventative strategies. The review concludes with a suggested an antenatal management plan designed to prevent PTD based on current practice and the evidence presented in this article.

Neurodevelopmental Outcome of Children with Congenital Hypothyroidism Diagnosed in a National Screening Program in Turkey.

PubMed

Baysal, Bahar Toklu; Baysal, Bora; Genel, Ferah; Erdur, Baris; Ozbek, Erhan; Demir, Korcan; Ozkan, Behzat

2017-05-15

To study the factors affecting a neurodevelopmental status of children with congenital hypothyroidism, diagnosed on national screening program. The study was performed in the Pediatric Endocrinology Department of Dr. Behcet Uz Children's Hospital between May 2012 and May 2013. Children with congenital hypothyroidism, aged between 24 and 36 months, diagnosed by national screening program were included in the study group. Healthy subjects at the same age group consisted of the control group. For the neurodevelopmental evaluation, Bayley Scale of Infant Development- II (BSID-II) was used. Factors possibly effective on neurodevelopment were evaluated. 42 patients and 40 healthy children (mean (SD) age, 29.4 (3.7) and 29.2 (3.5), respectively were included in the study. The mean MDI score [92.6 (7.07) vs 97.1 (9.69), P=0.14)] and the mean PDI score [97.8 (15.68) vs 99.1 (10.57), P=0.66)] in the study group and control group were not significantly different. Among the patient, 4.6% and 4.7% children were moderately retarded as per the MDI scores and PPI scores, respectively. The sex, socioeconomic status, birth weight, screening levels of TSH, severity of the congenital hypothyroidism, initiation time and the dosage of thyroid hormone replacement, length of the normalization period of TSH, and adherence to treatment were not found to affect the MDI and PDI scores of the patients. Some children with congenital hypothyrodism may have mild to moderate neurodevelopmental retardation, despite the early diagnosis and treatment, and thus need to be under regular follow-up for neurodevelopmental status.

Trade-offs between enzyme fitness and solubility illuminated by deep mutational scanning

PubMed Central

Bacik, John-Paul; Wrenbeck, Emily E.; Michalczyk, Ryszard; Whitehead, Timothy A.

2017-01-01

Proteins are marginally stable, and an understanding of the sequence determinants for improved protein solubility is highly desired. For enzymes, it is well known that many mutations that increase protein solubility decrease catalytic activity. These competing effects frustrate efforts to design and engineer stable, active enzymes without laborious high-throughput activity screens. To address the trade-off between enzyme solubility and activity, we performed deep mutational scanning using two different screens/selections that purport to gauge protein solubility for two full-length enzymes. We assayed a TEM-1 beta-lactamase variant and levoglucosan kinase (LGK) using yeast surface display (YSD) screening and a twin-arginine translocation pathway selection. We then compared these scans with published experimental fitness landscapes. Results from the YSD screen could explain 37% of the variance in the fitness landscapes for one enzyme. Five percent to 10% of all single missense mutations improve solubility, matching theoretical predictions of global protein stability. For a given solubility-enhancing mutation, the probability that it would retain wild-type fitness was correlated with evolutionary conservation and distance to active site, and anticorrelated with contact number. Hybrid classification models were developed that could predict solubility-enhancing mutations that maintain wild-type fitness with an accuracy of 90%. The downside of using such classification models is the removal of rare mutations that improve both fitness and solubility. To reveal the biophysical basis of enhanced protein solubility and function, we determined the crystallographic structure of one such LGK mutant. Beyond fundamental insights into trade-offs between stability and activity, these results have potential biotechnological applications. PMID:28196882

Birth weight and time spent in outdoor physical activity during adolescence.

PubMed

Gopinath, Bamini; Hardy, Louise L; Baur, Louise A; Burlutsky, George; Mitchell, Paul

2013-03-01

We investigated the association between birth parameters (weight, length, and head circumference) and time spent in physical activity (outdoor and indoor) and screen time (TV viewing, computer, and videogame usage) among adolescents. A longitudinal cohort study surveyed 1794 children in 2004-2005 (median age = 12.7 yr), and 752 were resurveyed 5 yr later in 2009-2010 (age = 17-18 yr). Adolescents completed detailed activity questionnaires. Parents extracted birth parameter data from their child's health record booklet. After adjusting for age, sex, ethnicity, gestational age, parental education, home ownership, exposure to passive smoking, and body mass index, 12-yr-old children in the highest compared with the lowest quartile of birth weight spent on average approximately 56 and 62 min more in total (Ptrend = 0.02) and outdoor physical activity (Ptrend = 0.02) per week, respectively. Similarly, 12-yr-old children in the high (>4000 g) versus very low (<2000 g) birth weight group spent approximately 1.3 h·wk more in outdoor activity (Ptrend = 0.02). Among those age 17-18 yr, increasing birth weight (lowest to highest quartile) was associated with greater time spent in outdoor physical activity (∼1 h·wk-1, Ptrend = 0.04). Significant associations were not observed between all birth parameters and recreational screen time. Also, no associations were observed between head circumference or birth length with physical activity and screen time. Birth weight could be a potential determinant of physical activity, but not of screen time during adolescence. Hence, this could be part of the underlying mechanism between prenatal influences and future disease risk and could have possible clinical implications.

Utility of an improved model of amyloid-beta (Aβ1-42) toxicity in Caenorhabditis elegans for drug screening for Alzheimer’s disease

PubMed Central

2012-01-01

Background The definitive indicator of Alzheimer’s disease (AD) pathology is the profuse accumulation of amyloid-ß (Aß) within the brain. Various in vitro and cell-based models have been proposed for high throughput drug screening for potential therapeutic benefit in diseases of protein misfolding. Caenorhabditis elegans offers a convenient in vivo system for examination of Aß accumulation and toxicity in a complex multicellular organism. Ease of culturing and a short life cycle make this animal model well suited to rapid screening of candidate compounds. Results We have generated a new transgenic strain of C. elegans that expresses full length Aß1-42. This strain differs from existing Aß models that predominantly express amino-truncated Aß3-42. The Aß1-42 is expressed in body wall muscle cells, where it oligomerizes, aggregates and results in severe, and fully penetrant, age progressive-paralysis. The in vivo accumulation of Aß1-42 also stains positive for amyloid dyes, consistent with in vivo fibril formation. The utility of this model for identification of potential protective compounds was examined using the investigational Alzheimer’s therapeutic PBT2, shown to be neuroprotective in mouse models of AD and significantly improve cognition in AD patients. We observed that treatment with PBT2 provided rapid and significant protection against the Aß-induced toxicity in C. elegans. Conclusion This C. elegans model of full length Aß1-42 expression can now be adopted for use in screens to rapidly identify and assist in development of potential therapeutics and to study underlying toxic mechanism(s) of Aß. PMID:23171715

A Chemogenomic Screen Reveals Novel Snf1p/AMPK Independent Regulators of Acetyl-CoA Carboxylase.

PubMed

Bozaquel-Morais, Bruno L; Madeira, Juliana B; Venâncio, Thiago M; Pacheco-Rosa, Thiago; Masuda, Claudio A; Montero-Lomeli, Monica

2017-01-01

Acetyl-CoA carboxylase (Acc1p) is a key enzyme in fatty acid biosynthesis and is essential for cell viability. To discover new regulators of its activity, we screened a Saccharomyces cerevisiae deletion library for increased sensitivity to soraphen A, a potent Acc1p inhibitor. The hits identified in the screen (118 hits) were filtered using a chemical-phenotype map to exclude those associated with pleiotropic drug resistance. This enabled the identification of 82 ORFs that are genetic interactors of Acc1p. The main functional clusters represented by these hits were "transcriptional regulation", "protein post-translational modifications" and "lipid metabolism". Further investigation of the "transcriptional regulation" cluster revealed that soraphen A sensitivity is poorly correlated with ACC1 transcript levels. We also studied the three top unknown ORFs that affected soraphen A sensitivity: SOR1 (YDL129W), SOR2 (YIL092W) and SOR3 (YJR039W). Since the C18/C16 ratio of lipid acyl lengths reflects Acc1p activity levels, we evaluated this ratio in the three mutants. Deletion of SOR2 and SOR3 led to reduced acyl lengths, suggesting that Acc1p is indeed down-regulated in these strains. Also, these mutants showed no differences in Snf1p/AMPK activation status and deletion of SNF1 in these backgrounds did not revert soraphen A sensitivity completely. Furthermore, plasmid maintenance was reduced in sor2Δ strain and this trait was shared with 18 other soraphen A sensitive hits. In summary, our screen uncovered novel Acc1p Snf1p/AMPK-independent regulators.

Poor Performance on a Preoperative Cognitive Screening Test Predicts Postoperative Complications in Older Orthopedic Surgical Patients.

PubMed

Culley, Deborah J; Flaherty, Devon; Fahey, Margaret C; Rudolph, James L; Javedan, Houman; Huang, Chuan-Chin; Wright, John; Bader, Angela M; Hyman, Bradley T; Blacker, Deborah; Crosby, Gregory

2017-11-01

The American College of Surgeons and the American Geriatrics Society have suggested that preoperative cognitive screening should be performed in older surgical patients. We hypothesized that unrecognized cognitive impairment in patients without a history of dementia is a risk factor for development of postoperative complications. We enrolled 211 patients 65 yr of age or older without a diagnosis of dementia who were scheduled for an elective hip or knee replacement. Patients were cognitively screened preoperatively using the Mini-Cog and demographic, medical, functional, and emotional/social data were gathered using standard instruments or review of the medical record. Outcomes included discharge to place other than home (primary outcome), delirium, in-hospital medical complications, hospital length-of-stay, 30-day emergency room visits, and mortality. Data were analyzed using univariate and multivariate analyses. Fifty of 211 (24%) patients screened positive for probable cognitive impairment (Mini-Cog less than or equal to 2). On age-adjusted multivariate analysis, patients with a Mini-Cog score less than or equal to 2 were more likely to be discharged to a place other than home (67% vs. 34%; odds ratio = 3.88, 95% CI = 1.58 to 9.55), develop postoperative delirium (21% vs. 7%; odds ratio = 4.52, 95% CI = 1.30 to 15.68), and have a longer hospital length of stay (hazard ratio = 0.63, 95% CI = 0.42 to 0.95) compared to those with a Mini-Cog score greater than 2. Many older elective orthopedic surgical patients have probable cognitive impairment preoperatively. Such impairment is associated with development of delirium postoperatively, a longer hospital stay, and lower likelihood of going home upon hospital discharge.

Pediatric cataract

PubMed Central

Khokhar, Sudarshan Kumar; Pillay, Ganesh; Dhull, Chirakshi; Agarwal, Esha; Mahabir, Manish; Aggarwal, Pulak

2017-01-01

Pediatric cataract is a leading cause of childhood blindness. Untreated cataracts in children lead to tremendous social, economical, and emotional burden to the child, family, and society. Blindness related to pediatric cataract can be treated with early identification and appropriate management. Most cases are diagnosed on routine screening whereas some may be diagnosed after the parents have noticed leukocoria or strabismus. Etiology of pediatric cataract is varied and diagnosis of specific etiology aids in prognostication and effective management. Pediatric cataract surgery has evolved over years, and with improving knowledge of myopic shift and axial length growth, outcomes of these patients have become more predictable. Favorable outcomes depend not only on effective surgery, but also on meticulous postoperative care and visual rehabilitation. Hence, it is the combined effort of parents, surgeons, anesthesiologists, pediatricians, and optometrists that can make all the difference. PMID:29208814

Electrostatic and hydrodynamics effects in a sedimented magnetorheological suspension.

PubMed

Domínguez-García, P; Pastor, J M; Melle, Sonia; Rubio, Miguel A

2009-08-01

We present experimental results on the equilibrium microstructure of a sedimented magnetorheological suspension, namely, an aqueous suspension of micron-sized superparamagnetic particles. We develop a study of the electrical interactions on the suspension by processing video-microscopy images of the sedimented particles. We calculate the pair distribution function, g(r), which yields the electrostatic pair potential u(r), showing an anomalous attractive interaction for distances on the order of twice the particle diameter, with characteristic parameters whose values show a dependence with the two-dimensional concentration of particles. The repulsive body of the potential is adjusted to a DLVO expression in order to calculate the Debye screening length and the effective surface charge density. Influence of confinement and variations on the Boltzmann sedimentation profile because of the electrostatic interactions appear to be essential for the interpretation of experimental results.

[Evaluation of physical development of children with congenital hypothyroidism detected in the screening test--personal observations].

PubMed

Kik, Eugenia; Noczyńska, Anna

2011-01-01

Congenital hypothyroidism (CH) is the most prevalent endocrinopathy resulting from thyroid hormones deficiency or lack of thyroid hormones (TH). Aim of the study is to evaluate the physical development of children with congenital hypothyroidism detected in screening tests, determine the effect of TSH level, thyroid hormones and perinatal, parental and environmental factors on the physical development of children. the study involved 79 children (47 girls, 32 boys) aged 3-18 years (mean age 7.3±3.5) with CH diagnosed in screening tests. Children's development was analysed in correlation with TSH value in the screening test, time of commencement of therapy with LT4, the initial dose of the LT4, mean TSH level in the first year of life, mean value of TSH and LT4 in the 2-year follow-up period, social origin, place of residence (village, city), parents': anthropometric parameters (BMI, height), age, level of education of the parents, which pregnancy it was, time of pregnancy. In children: body mass and length at birth, score on Apgar scale, additional chronic disease. Too low body mass was usually observed in the 2-4 month of life - 11.1%, while in the following months, the number of children with body mass below the 3 centile became lower. In children diagnosed with too low body mass <18 month of life, in the subsequent months was observed a normalisation. No correlation was between the body mass and TSH in infancy, the place of residence and level of education of the parents in all examined groups. According to Palczewska, BMI >97 centile occurred more often in the group of children with CH in the age range of 11 months - 6.9 years than in the control group, whereas ≥7 years obesity did not occur. The number of children with insufficient body length increased in the age groups: 11-18 months - 7.4%; 1.6-3.9 years - 7.9 % and 4-6.9 years - 9.1%. Children ≥7 years with height <3 centile were not observed. The number of children with height >97 centile in three age groups did not go beyond 4%. The biggest number of children >97 centile was noted in the age group 1.6-3.9 years (7.9%). Mean height SDS in all age groups was within the norm (±1 SDS for healthy population). 1. Physical development of children in infancy was in normal range. 2. Mean SDS of body mass in children was in the range of 1sds for healthy population in each age quarter. 3. Mean SDS for BMI in all age groups was above zero. 4. Mean SDS for body length in all age groups was in the range ±1 SDS for healthy population. 5. Early initiation of therapy HT is a prerequisite for proper physical development of children with congenital hypothyroidism.

Adolescent Risk Screening Instruments for Primary Care: An Integrative Review Utilizing the Donabedian Framework.

PubMed

Hiott, Deanna B; Phillips, Shannon; Amella, Elaine

2017-07-31

Adolescent risk-taking behavior choices can affect future health outcomes. The purpose of this integrative literature review is to evaluate adolescent risk screening instruments available to primary care providers in the United States using the Donabedian Framework of structure, process, and outcome. To examine the literature concerning multidimensional adolescent risk screening instruments available in the United States for use in the primary care setting, library searches, ancestry searches, and Internet searches were conducted. Library searches included a systematic search of the Cumulative Index to Nursing and Allied Health Literature (CINAHL), Academic Search Premier, Health Source Nursing Academic Ed, Medline, PsycINFO, the Psychology and Behavioral Sciences Collection, and PubMed databases with CINAHL headings using the following Boolean search terms: "primary care" and screening and pediatric. Criteria for inclusion consisted of studies conducted in the United States that involved broad multidimensional adolescent risk screening instruments for use in the pediatric primary care setting. Instruments that focused solely on one unhealthy behavior were excluded, as were developmental screens and screens not validated or designed for all ages of adolescents. In all 25 manuscripts reviewed, 16 screens met the inclusion criteria and were included in the study. These 16 screens were examined for factors associated with the Donabedian structure-process-outcome model. This review revealed that many screens contain structural issues related to cost and length that inhibit provider implementation in the primary care setting. Process limitations regarding the report method and administration format were also identified. The Pediatric Symptom Checklist was identified as a free, short tool that is valid and reliable.

Genome-wide RNA interference screen identifies previously undescribed regulators of polyglutamine aggregation

PubMed Central

Nollen, Ellen A. A.; Garcia, Susana M.; van Haaften, Gijs; Kim, Soojin; Chavez, Alejandro; Morimoto, Richard I.; Plasterk, Ronald H. A.

2004-01-01

Protein misfolding and the formation of aggregates are increasingly recognized components of the pathology of human genetic disease and hallmarks of many neurodegenerative disorders. As exemplified by polyglutamine diseases, the propensity for protein misfolding is associated with the length of polyglutamine expansions and age-dependent changes in protein-folding homeostasis, suggesting a critical role for a protein homeostatic buffer. To identify the complement of protein factors that protects cells against the formation of protein aggregates, we tested transgenic Caenorhabditis elegans strains expressing polyglutamine expansion yellow fluorescent protein fusion proteins at the threshold length associated with the age-dependent appearance of protein aggregation. We used genome-wide RNA interference to identify genes that, when suppressed, resulted in the premature appearance of protein aggregates. Our screen identified 186 genes corresponding to five principal classes of polyglutamine regulators: genes involved in RNA metabolism, protein synthesis, protein folding, and protein degradation; and those involved in protein trafficking. We propose that each of these classes represents a molecular machine collectively comprising the protein homeostatic buffer that responds to the expression of damaged proteins to prevent their misfolding and aggregation. PMID:15084750

Human in vitro 3D co-culture model to engineer vascularized bone-mimicking tissues combining computational tools and statistical experimental approach.

PubMed

Bersini, Simone; Gilardi, Mara; Arrigoni, Chiara; Talò, Giuseppe; Zamai, Moreno; Zagra, Luigi; Caiolfa, Valeria; Moretti, Matteo

2016-01-01

The generation of functional, vascularized tissues is a key challenge for both tissue engineering applications and the development of advanced in vitro models analyzing interactions among circulating cells, endothelium and organ-specific microenvironments. Since vascularization is a complex process guided by multiple synergic factors, it is critical to analyze the specific role that different experimental parameters play in the generation of physiological tissues. Our goals were to design a novel meso-scale model bridging the gap between microfluidic and macro-scale studies, and high-throughput screen the effects of multiple variables on the vascularization of bone-mimicking tissues. We investigated the influence of endothelial cell (EC) density (3-5 Mcells/ml), cell ratio among ECs, mesenchymal stem cells (MSCs) and osteo-differentiated MSCs (1:1:0, 10:1:0, 10:1:1), culture medium (endothelial, endothelial + angiopoietin-1, 1:1 endothelial/osteo), hydrogel type (100%fibrin, 60%fibrin+40%collagen), tissue geometry (2 × 2 × 2, 2 × 2 × 5 mm(3)). We optimized the geometry and oxygen gradient inside hydrogels through computational simulations and we analyzed microvascular network features including total network length/area and vascular branch number/length. Particularly, we employed the "Design of Experiment" statistical approach to identify key differences among experimental conditions. We combined the generation of 3D functional tissue units with the fine control over the local microenvironment (e.g. oxygen gradients), and developed an effective strategy to enable the high-throughput screening of multiple experimental parameters. Our approach allowed to identify synergic correlations among critical parameters driving microvascular network development within a bone-mimicking environment and could be translated to any vascularized tissue. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effects of regenerator geometry on pulse tube refrigerator performance

NASA Technical Reports Server (NTRS)

Lewis, M.; Kuriyama, T.; Xiao, J. H.; Radebaugh, R.

1998-01-01

This paper gives results of the cooling performance of a double-inlet pulse tube refrigerator using various regenerators. The same pulse tube was used for all the experiments and measured 4.76 mm in diameter and 46.2 mm in length. A commercial linear compressor with a swept volume of 4 cm3 was used in these experiments. The operating conditions were held constant at a mean pressure of 2.0 MPa and a frequency of 54 Hz. Using finite difference software called REGEN3.1, developed at NIST, and recent experiment results, we optimized a series of regenerators based on dimensions, materials and screen packing. The values used for calculating the thermal conduction through stacked screens by REGEN3.1 were based on recent experimental results from NIST. The regenerator tubes were designed using 316 stainless steel and titanium materials. The regenerator matrices investigated were 400-mesh and 500-mesh stainless steel screen. The valve settings for both orifices were adjusted to minimize the no-load temperature for all regenerators. A cooling capacity curve from 0 to 3 W was also determined. The performance of the pulse tube refrigerator using the different regenerators is discussed. The experimental results from the various regenerators are evaluated and compared with their corresponding numerically calculated coefficient of performance (COP) and regenerator design as determined by REGEN3.1.

Entanglement between pairing and screening in the Gorkov-Melik-Barkhudarov correction to the critical temperature throughout the BCS-BEC crossover

NASA Astrophysics Data System (ADS)

Pisani, L.; Perali, A.; Pieri, P.; Strinati, G. Calvanese

2018-01-01

The problem of the theoretical description of the critical temperature Tc of a Fermi superfluid dates back to the work by Gorkov and Melik-Barkhudarov (GMB), who addressed it for a weakly coupled (dilute) superfluid in what would today be referred to as the (extreme) BCS (weak-coupling) limit of the BCS-BEC crossover. The point made in this context by GMB was that particle-particle (pairing) excitations, which are responsible for superfluidity to occur below Tc, and particle-hole excitations, which give rise to screening also in a normal system, get effectively disentangled from each other in the BCS limit, thus yielding a reduction by a factor of 2.2 of the value of Tc obtained when neglecting screening effects. Subsequent work on this topic, that was aimed at extending the original GMB argument away from the BCS limit with diagrammatic methods, has tout court kept this disentangling between pairing and screening throughout the BCS-BEC crossover, without realizing that the conditions for it to be valid are soon violated away from the BCS limit. Here, we reconsider this problem from a more general perspective and argue that pairing and screening are intrinsically entangled with each other along the whole BCS-BEC crossover but for the BCS limit considered by GMB, with the particle-hole excitations soon transmuting into particle-particle excitations away from this limit. We substantiate our argument by performing a detailed numerical calculation of the GMB diagrammatic contribution suitably extended to the whole BCS-BEC crossover, where the full wave-vector and frequency dependence occurring in the repeated in-medium two-particle scattering is duly taken into account. Our numerical calculations are tested against analytic results available in both the BCS and BEC limits, and the contribution of the GMB diagrammatic term to the scattering length of composite bosons in the BEC limit is highlighted. We calculate Tc throughout the BCS-BEC crossover and find that it agrees quite well with quantum Monte Carlo calculations and experimental data available in the unitarity regime.

Tapered Screened Channel PMD for Cryogenic Liquids

NASA Astrophysics Data System (ADS)

Dodge, Franklin T.; Green, Steve T.; Walter, David B.

2004-02-01

If a conventional spacecraft propellant management device (PMD) of the screened channel type were employed with a cryogenic liquid, vapor bubbles generated within the channel by heat transfer could ``dry out'' the channel screens and thereby cause the channels to admit large amounts of vapor from the tank into the liquid outflow. This paper describes a new tapered channel design that passively `pumps' bubbles away from the outlet port and vents them into the tank. A predictive mathematical model of the operating principle is presented and discussed. Scale-model laboratory tests were conducted and the mathematical model agreed well with the measured rates of bubble transport velocity. Finally, an example of the use of the predictive model for a realistic spacecraft application is presented. The model predicts that bubble clearing rates are acceptable even in tanks up to 2 m in length.

Fragment screening using capillary electrophoresis (CEfrag) for hit identification of heat shock protein 90 ATPase inhibitors.

PubMed

Austin, Carol; Pettit, Simon N; Magnolo, Sharon K; Sanvoisin, Jonathan; Chen, Wenjie; Wood, Stephen P; Freeman, Lauren D; Pengelly, Reuben J; Hughes, Dallas E

2012-08-01

CEfrag is a new fragment screening technology based on affinity capillary electrophoresis (ACE). Here we report on the development of a mobility shift competition assay using full-length human heat shock protein 90α (Hsp90α), radicicol as the competitor probe ligand, and successful screening of the Selcia fragment library. The CEfrag assay was able to detect weaker affinity (IC(50) >500 µM) fragments than were detected by a fluorescence polarization competition assay using FITC-labeled geldanamycin. The binding site of selected fragments was determined by co-crystallization with recombinant Hsp90α N-terminal domain and X-ray analysis. The results of this study confirm that CEfrag is a sensitive microscale technique enabling detection of fragments binding to the biological target in near-physiological solution.

Differential endothelial transcriptomics identifies semaphorin 3G as a vascular class 3 semaphorin.

PubMed

Kutschera, Simone; Weber, Holger; Weick, Anja; De Smet, Frederik; Genove, Guillem; Takemoto, Minoru; Prahst, Claudia; Riedel, Maria; Mikelis, Constantinos; Baulande, Sylvain; Champseix, Catherine; Kummerer, Petra; Conseiller, Emmanuel; Multon, Marie-Christine; Heroult, Melanie; Bicknell, Roy; Carmeliet, Peter; Betsholtz, Christer; Augustin, Hellmut G

2011-01-01

To characterize the role of a vascular-expressed class 3 semaphorin (semaphorin 3G [Sema3G]). Semaphorins have been identified as axon guidance molecules. Yet, they have more recently also been characterized as attractive and repulsive regulators of angiogenesis. Through a transcriptomic screen, we identified Sema3G as a molecule of angiogenic endothelial cells. Sema3G-deficient mice are viable and exhibit no overt vascular phenotype. Yet, LacZ expression in the Sema3G locus revealed intense arterial vascular staining in the angiogenic vasculature, starting at E9.5, which was detectable throughout adolescence and downregulated in adult vasculature. Sema3G is expressed as a full-length 100-kDa secreted molecule that is processed by furin proteases to yield 95- and a 65-kDa Sema domain-containing subunits. Full-length Sema3G binds to NP2, whereas processed Sema3G binds to NP1 and NP2. Expression profiling and cellular experiments identified autocrine effects of Sema3G on endothelial cells and paracrine effects on smooth muscle cells. Although the mouse knockout phenotype suggests compensatory mechanisms, the experiments identify Sema3G as a primarily endothelial cell-expressed class 3 semaphorin that controls endothelial and smooth muscle cell functions in autocrine and paracrine manners, respectively.

Quantitative CRISPR interference screens in yeast identify chemical-genetic interactions and new rules for guide RNA design.

PubMed

Smith, Justin D; Suresh, Sundari; Schlecht, Ulrich; Wu, Manhong; Wagih, Omar; Peltz, Gary; Davis, Ronald W; Steinmetz, Lars M; Parts, Leopold; St Onge, Robert P

2016-03-08

Genome-scale CRISPR interference (CRISPRi) has been used in human cell lines; however, the features of effective guide RNAs (gRNAs) in different organisms have not been well characterized. Here, we define rules that determine gRNA effectiveness for transcriptional repression in Saccharomyces cerevisiae. We create an inducible single plasmid CRISPRi system for gene repression in yeast, and use it to analyze fitness effects of gRNAs under 18 small molecule treatments. Our approach correctly identifies previously described chemical-genetic interactions, as well as a new mechanism of suppressing fluconazole toxicity by repression of the ERG25 gene. Assessment of multiple target loci across treatments using gRNA libraries allows us to determine generalizable features associated with gRNA efficacy. Guides that target regions with low nucleosome occupancy and high chromatin accessibility are clearly more effective. We also find that the best region to target gRNAs is between the transcription start site (TSS) and 200 bp upstream of the TSS. Finally, unlike nuclease-proficient Cas9 in human cells, the specificity of truncated gRNAs (18 nt of complementarity to the target) is not clearly superior to full-length gRNAs (20 nt of complementarity), as truncated gRNAs are generally less potent against both mismatched and perfectly matched targets. Our results establish a powerful functional and chemical genomics screening method and provide guidelines for designing effective gRNAs, which consider chromatin state and position relative to the target gene TSS. These findings will enable effective library design and genome-wide programmable gene repression in many genetic backgrounds.

ISOCT study of collagen crosslinking of collagen in cancer models (Conference Presentation)

NASA Astrophysics Data System (ADS)

Spicer, Graham; Young, Scott T.; Yi, Ji; Shea, Lonnie D.; Backman, Vadim

2016-03-01

The role of extracellular matrix modification and signaling in cancer progression is an increasingly recognized avenue for the progression of the disease. Previous study of field effect carcinogenesis with Inverse Spectroscopic Optical Coherence Tomography (ISOCT) has revealed pronounced changes in the nanoscale-sensitive mass fractal dimension D measured from field effect tissue when compared to healthy tissue. However, the origin of this difference in tissue ultrastructure in field effect carcinogenesis has remained poorly understood. Here, we present findings supporting the idea that enzymatic crosslinking of the extracellular matrix is an effect that presents at the earliest stages of carcinogenesis. We use a model of collagen gel with crosslinking induced by lysyl oxidase (LOXL4) to recapitulate the difference in D previously reported from healthy and cancerous tissue biopsies. Furthermore, STORM imaging of this collagen gel model verifies the morphologic effects of enzymatic crosslinking at length scales as small as 40 nm, close to the previously reported lower length scale sensitivity threshold of 35 nm for ISOCT. Analysis of the autocorrelation function from STORM images of collagen gels and subsequent fitting to the Whittle-Matérn correlation function shows a similar effect of LOXL4 on D from collagen measured with ISOCT and STORM. We extend this to mass spectrometric study of tissue to directly measure concentrations of collagen crosslink residues. The validation of ISOCT as a viable tool for non-invasive rapid quantification of collagen ultrastructure lends it to study other physiological phenomena involving ECM restructuring such as atherosclerotic plaque screening or cervical ripening during pregnancy.

Effects of adding a virtual reality environment to different modes of treadmill walking.

PubMed

Sloot, L H; van der Krogt, M M; Harlaar, J

2014-03-01

Differences in gait between overground and treadmill walking are suggested to result from imposed treadmill speed and lack of visual flow. To counteract this effect, feedback-controlled treadmills that allow the subject to control the belt speed along with an immersive virtual reality (VR) have recently been developed. We studied the effect of adding a VR during both fixed speed (FS) and self-paced (SP) treadmill walking. Nineteen subjects walked on a dual-belt instrumented treadmill with a simple endless road projected on a 180° circular screen. A main effect of VR was found for hip flexion offset, peak hip extension, peak knee extension moment, knee flexion moment gain and ankle power during push off. A consistent interaction effect between VR and treadmill mode was found for 12 out of 30 parameters, although the differences were small and did not exceed 50% of the within subject stride variance. At FS, the VR seemed to slightly improve the walking pattern towards overground walking, with for example a 6.5mm increase in stride length. At SP, gait became slightly more cautious by adding a VR, with a 9.1mm decrease in stride length. Irrespective of treadmill mode, subjects rated walking with the VR as more similar to overground walking. In the context of clinical gait analysis, the effects of VR are too small to be relevant and are outweighed by the gains of adding a VR, such as a more stimulating experience and possibility of augmenting it by real-time feedback. Copyright © 2013 Elsevier B.V. All rights reserved.

ICANT, a code for the self-consistent computation of ICRH antenna coupling

NASA Astrophysics Data System (ADS)

Pécoul, S.; Heuraux, S.; Koch, R.; Leclert, G.

1996-02-01

The code deals with 3D antenna structures (finite length antennae) that are used to launch electromagnetic waves into tokamak plasmas. The antenna radiation problem is solved using a finite boundary element technique combined with a spectral solution of the interior problem. The slab approximation is used, and periodicity in y and z directions is introduced to account for toroidal geometry. We present results for various types of antennae radiating in vacuum: antenna with a finite Faraday screen and ideal Faraday screen, antenna with side limiters and phased antenna arrays. The results (radiated power, current profile) obtained are very close to analytical solutions when available.

Environmental Test Screening Procedure

NASA Technical Reports Server (NTRS)

Zeidler, Janet

2000-01-01

This procedure describes the methods to be used for environmental stress screening (ESS) of the Lightning Mapper Sensor (LMS) lens assembly. Unless otherwise specified, the procedures shall be completed in the order listed, prior to performance of the Acceptance Test Procedure (ATP). The first unit, S/N 001, will be subjected to the Qualification Vibration Levels, while the remainder will be tested at the Operational Level. Prior to ESS, all units will undergo Pre-ESS Functional Testing that includes measuring the on-axis and plus or minus 0.95 full field Modulation Transfer Function and Back Focal Length. Next, all units will undergo ESS testing, and then Acceptance testing per PR 460.

Affordable Care Act Provision Lowered Out-Of-Pocket Cost And Increased Colonoscopy Rates Among Men In Medicare.

PubMed

Hamman, Mary K; Kapinos, Kandice A

2015-12-01

Colorectal cancer screening is one of the few cancer screenings with an "A" rating from the US Preventive Services Task Force, meaning that the procedure confers a substantial health benefit. However, 40 percent of people who should receive colorectal cancer screenings do not receive them. Colonoscopies are the most thorough method of screening because they allow physicians to view the entire length of the colon and remove polyps as needed. Billing methods that distinguish between screening and therapeutic procedures have kept expected colonoscopy costs high. However, the Affordable Care Act partially closed the so-called colonoscopy loophole and reduced expected out-of-pocket expenses for all Medicare beneficiaries. Using data from the Behavioral Risk Factor Surveillance System, we found that annual colonoscopy rates among men ages 66-75 increased significantly (by 4.0 percentage points) after the Affordable Care Act policy change, and we found some evidence of even larger increases among socioeconomically disadvantaged men. We found no significant increases among women, a result that may be explained by health behavior and other factors and that requires further study. Our research indicates that cost may be an important barrier to colorectal cancer screening, at least among men, and that making further policy changes to close remaining loopholes may improve screening rates. Project HOPE—The People-to-People Health Foundation, Inc.

Simulation and modelling of slip flow over surfaces grafted with polymer brushes and glycocalyx fibres

PubMed Central

Deng, Mingge; Li, Xuejin; Liang, Haojun; Caswell, Bruce; Karniadakis, George Em

2013-01-01

Fabrication of functionalized surfaces using polymer brushes is a relatively simple process and parallels the presence of glycocalyx filaments coating the luminal surface of our vasculature. In this paper, we perform atomistic-like simulations based on dissipative particle dynamics (DPD) to study both polymer brushes and glycocalyx filaments subject to shear flow, and we apply mean-field theory to extract useful scaling arguments on their response. For polymer brushes, a weak shear flow has no effect on the brush density profile or its height, while the slip length is independent of the shear rate and is of the order of the brush mesh size as a result of screening by hydrodynamic interactions. However, for strong shear flow, the polymer brush is penetrated deeper and is deformed, with a corresponding decrease of the brush height and an increase of the slip length. The transition from the weak to the strong shear regime can be described by a simple ‘blob’ argument, leading to the scaling γ̇0 ∝ σ3/2, where γ̇0 is the critical transition shear rate and σ is the grafting density. Furthermore, in the strong shear regime, we observe a cyclic dynamic motion of individual polymers, causing a reversal in the direction of surface flow. To study the glycocalyx layer, we first assume a homogeneous flow that ignores the discrete effects of blood cells, and we simulate microchannel flows at different flow rates. Surprisingly, we find that, at low Reynolds number, the slip length decreases with the mean flow velocity, unlike the behaviour of polymer brushes, for which the slip length remains constant under similar conditions. (The slip length and brush height are measured with respect to polymer mesh size and polymer contour length, respectively.) We also performed additional DPD simulations of blood flow in a tube with walls having a glycocalyx layer and with the deformable red blood cells modelled accurately at the spectrin level. In this case, a plasma cell-free layer is formed, with thickness more than three times the glycocalyx layer. We then find our scaling arguments based on the homogeneous flow assumption to be valid for this physiologically correct case as well. Taken together, our findings point to the opposing roles of conformational entropy and bending rigidity – dominant effects for the brush and glycocalyx, respectively – which, in turn, lead to different flow characteristics, despite the apparent similarity of the two systems. PMID:24353347

Driver steering dynamics measured in car simulator under a range of visibility and roadmaking conditions

NASA Technical Reports Server (NTRS)

Allen, R. W.; Mcruer, D. T.

1977-01-01

A simulation experiment was conducted to determine the effect of reduced visibility on driver lateral (steering) control. The simulator included a real car cab and a single lane road image projected on a screen six feet in front of the driver. Simulated equations of motion controlled apparent car lane position in response to driver steering actions, wind gusts, and road curvature. Six drivers experienced a range of visibility conditions at various speeds with assorted roadmaking configurations (mark and gap lengths). Driver describing functions were measured and detailed parametric model fits were determined. A pursuit model employing a road curvature feedforward was very effective in explaining driver behavior in following randomly curving roads. Sampled-data concepts were also effective in explaining the combined effects of reduced visibility and intermittent road markings on the driver's dynamic time delay. The results indicate the relative importance of various perceptual variables as the visual input to the driver's steering control process is changed.

Full Implementation of Screening for Nutritional Risk and Dysphagia in an Acute Stroke Unit: A Clinical Audit.

PubMed

Kampman, Margitta T; Eltoft, Agnethe; Karaliute, Migle; Børvik, Margrethe T; Nilssen, Hugo; Rasmussen, Ida; Johnsen, Stein H

2015-10-01

In patients with acute stroke, undernutrition and aspiration pneumonia are associated with increased mortality and length of hospital stay. Formal screening for nutritional risk and dysphagia helps to ensure optimal nutritional management in all patients with stroke and to reduce the risk of aspiration in patients with dysphagia. We developed a national guideline for nutritional and dysphagia screening in acute stroke, which was introduced in our stroke unit on June 1, 2012. The primary objective was to audit adherence to the guideline and to achieve full implementation. Second, we assessed the prevalence of nutritional risk and dysphagia. We performed a chart review to assess performance of screening for nutritional risk and dysphagia in all patients with stroke hospitalized for ≥48 hours between June 1, 2012, and May 31, 2013. Next we applied a "clinical microsystems approach" with rapid improvement cycles and audits over a 6-month period to achieve full implementation. The chart review showed that nutritional risk screening was performed in 65% and swallow testing in 91% of eligible patients (n = 185). Proactive implementation resulted in >95% patients screened (n = 79). The overall prevalence of nutritional risk was 29%, and 23% of the patients failed the initial swallow test. Proactive implementation is required to obtain high screening rates for nutritional risk and swallowing difficulties using validated screening tools. The proportion of patients at nutritional risk and the prevalence of dysphagia at initial swallow test were in the lower range of previous reports.

Cost-effectiveness analysis of an enteral nutrition protocol for children with common gastrointestinal diseases in China: good start but still a long way to go.

PubMed

Yang, Min; Chen, Pei-Yu; Gong, Si-Tang; Lyman, Beth; Geng, Lan-Lan; Liu, Li-Ying; Liang, Cui-Ping; Xu, Zhao-Hui; Li, Hui-Wen; Fang, Tie-Fu; Li, Ding-You

2014-11-01

A standard nutrition screening and enteral nutrition (EN) protocol was implemented in January 2012 in a tertiary children's center in China. The aims of the present study were to evaluate the cost-effectiveness of a standard EN protocol in hospitalized patients. A retrospective chart review was performed in the gastroenterology inpatient unit. We included all inpatient children requiring EN from January 1, 2010, to December 31, 2013, with common gastrointestinal (GI) diseases. Children from January 1, 2012, to December 31, 2013, served as the standard EN treatment group, and those from January 1, 2010, to December 31, 2011, were the control EN group. Pertinent patient information was collected. We also analyzed the length of hospital stay, cost of care, and in-hospital infection rates. The standard EN treatment group received more nasojejunal tube feedings. There was a tendency for the standard EN treatment group to receive more elemental and hydrolyzed protein formulas. Implementation of a standard EN protocol significantly reduced the time to initiate EN (32.38 ± 24.50 hours vs 18.76 ± 13.53 hours; P = .011) and the time to reach a targeted calorie goal (7.42 ± 3.98 days vs 5.06 ± 3.55 days; P = .023); length of hospital stay was shortened by 3.2 days after implementation of the standard EN protocol but did not reach statistical significance. However, the shortened length of hospital stay contributed to a significant reduction in the total cost of hospital care (13,164.12 ± 6722.95 Chinese yuan [CNY] vs 9814.96 ± 4592.91 CNY; P < .032). Implementation of a standard EN protocol resulted in early initiation of EN, shortened length of stay, and significantly reduced total cost of care in hospitalized children with common GI diseases. © 2014 American Society for Parenteral and Enteral Nutrition.

Cost-Effectiveness of Osteoporosis Screening Strategies for Men

PubMed Central

Nayak, Smita; Greenspan, Susan L.

2016-01-01

Osteoporosis affects many men, with significant morbidity and mortality. However, the best osteoporosis screening strategies for men are unknown. We developed an individual-level state-transition cost-effectiveness model with a lifetime time horizon to identify the cost-effectiveness of different osteoporosis screening strategies for U.S. men involving various screening tests (dual-energy x-ray absorptiometry (DXA); the Osteoporosis Self-Assessment Tool (OST); or a fracture risk assessment strategy using age, femoral neck bone mineral density (BMD), and Vertebral Fracture Assessment (VFA)); screening initiation ages (50, 60, 70, or 80); and repeat screening intervals (5 years or 10 years). In base-case analysis, no screening was a less effective option than all other strategies evaluated; furthermore, no screening was more expensive than all strategies that involved screening with DXA or the OST risk assessment instrument, and thus no screening was “dominated” by screening with DXA or OST at all evaluated screening initiation ages and repeat screening intervals. Screening strategies that most frequently appeared as most cost-effective in base-case analysis and one-way sensitivity analyses when assuming willingness-to-pay of $50,000/QALY or $100,000/QALY included screening initiation at age 50 with the fracture risk assessment strategy and repeat screening every 10 years; screening initiation at age 50 with fracture risk assessment and repeat screening every 5 years; and screening initiation at age 50 with DXA and repeat screening every 5 years. In conclusion, expansion of osteoporosis screening for U.S. men to initiate routine screening at age 50 or 60 would be expected to be effective and of good value for improving health outcomes. A fracture risk assessment strategy using variables of age, femoral neck BMD, and VFA is likely to be the most effective of the evaluated strategies within accepted cost-effectiveness parameters. DXA and OST are also reasonable screening options, albeit likely slightly less effective than the evaluated fracture risk assessment strategy. PMID:26751984

Induced Polarization Surveying for Acid Rock Screening in Highway Design

NASA Astrophysics Data System (ADS)

Butler, K. E.; Al, T.; Bishop, T.

2004-05-01

Highway and pipeline construction agencies have become increasingly vigilant in their efforts to avoid cutting through sulphide-bearing bedrock that has potential to produce acid rock drainage. Blasting and fragmentation of such rock increases the surface area available for sulphide oxidation and hence increases the risk of acid rock drainage unless the rock contains enough natural buffering capacity to neutralize the pH. In December, 2001, the New Brunswick Department of Transportation (NBOT) sponsored a field trial of geophysical surveying in order to assess its suitability as a screening tool for locating near-surface sulphides along proposed highway alignments. The goal was to develop a protocol that would allow existing programs of drilling and geochemical testing to be targeted more effectively, and provide design engineers with the information needed to reduce rock cuts where necessary and dispose of blasted material in a responsible fashion. Induced polarization (IP) was chosen as the primary geophysical method given its ability to detect low-grade disseminated mineralization. The survey was conducted in dipole-dipole mode using an exploration-style time domain IP system, dipoles 8 to 25 m in length, and six potential dipoles for each current dipole location (i.e. n = 1 - 6). Supplementary information was provided by resistivity and VLF-EM surveys sensitive to lateral changes in electrical conductivity, and by magnetic field surveying chosen for its sensitivity to the magnetic susceptibility of pyrrhotite. Geological and geochemical analyses of samples taken from several IP anomalies located along 4.3 line-km of proposed highway confirmed the effectiveness of the screening technique. IP pseudosections from a region of metamorphosed shales and volcaniclastic rocks identified discrete, well-defined mineralized zones. Stronger, overlapping, and more laterally extensive IP anomalies were observed over a section of graphitic and sulphide-bearing metasedimentary rocks. Attempts to use spectral IP characteristics to determine relative abundances of sulphides and graphite were not conclusive. The overall effectiveness of the screening technique however encouraged NBDOT to apply it to an additional 50 km of planned rock cuts along the corridor selected for the new Trans-Canada Highway.

An Experimental Study of Upward Burning Over Long Solid Fuels: Facility Development and Comparison

NASA Technical Reports Server (NTRS)

Kleinhenz, Julie; Yuan, Zeng-Guang

2011-01-01

As NASA's mission evolves, new spacecraft and habitat environments necessitate expanded study of materials flammability. Most of the upward burning tests to date, including the NASA standard material screening method NASA-STD-6001, have been conducted in small chambers where the flame often terminates before a steady state flame is established. In real environments, the same limitations may not be present. The use of long fuel samples would allow the flames to proceed in an unhindered manner. In order to explore sample size and chamber size effects, two large chambers were developed at NASA GRC under the Flame Prevention, Detection and Suppression (FPDS) project. The first was an existing vacuum facility, VF-13, located at NASA John Glenn Research Center. This 6350 liter chamber could accommodate fuels sample lengths up to 2 m. However, operational costs and restricted accessibility limited the test program, so a second laboratory scale facility was developed in parallel. By stacking additional two chambers on top of an existing combustion chamber facility, this 81 liter Stacked-chamber facility could accommodate a 1.5 m sample length. The larger volume, more ideal environment of VF-13 was used to obtain baseline data for comparison with the stacked chamber facility. In this way, the stacked chamber facility was intended for long term testing, with VF-13 as the proving ground. Four different solid fuels (adding machine paper, poster paper, PMMA plates, and Nomex fabric) were tested with fuel sample lengths up to 2 m. For thin samples (papers) with widths up to 5 cm, the flame reached a steady state length, which demonstrates that flame length may be stabilized even when the edge effects are reduced. For the thick PMMA plates, flames reached lengths up to 70 cm but were highly energetic and restricted by oxygen depletion. Tests with the Nomex fabric confirmed that the cyclic flame phenomena, observed in small facility tests, continued over longer sample. New features were also observed at the higher oxygen/pressure conditions available in the large chamber. Comparison of flame behavior between the two facilities under identical conditions revealed disparities, both qualitative and quantitative. This suggests that, in certain ranges of controlling parameters, chamber size and shape could be one of the parameters that affect the material flammability. If this proves to be true, it may limit the applicability of existing flammability data.

Outcomes of Ethics Consultations in Adult ICUs: A Systematic Review and Meta-Analysis.

PubMed

Au, Selena S; Couillard, Philippe; Roze des Ordons, Amanda; Fiest, Kirsten M; Lorenzetti, Dianne L; Jette, Nathalie

2018-05-01

Clinical ethics consultation as a mechanism for supporting patients, family, and staff during ethically challenging situations has become standard of care. Despite this, there is a lack of consensus about the effectiveness of clinical ethics consultation consultation in the ICU. We performed a systematic review of outcomes associated with clinical ethics consultation within adult ICUs. We searched MEDLINE, PubMed, Cochrane CENTRAL, Embase, PsycINFO, and Cumulative Index to Nursing and Allied Health Literature from 1984 to May 2017. Two reviewers independently screened articles, assessed eligibility, extracted data, and assessed risk of bias using the Cochrane Collaboration Risk of Bias tool and the Newcastle-Ottawa Scale. Pooled estimates of effect were calculated where possible. We screened 3,970 abstracts and reviewed 325 full-text articles of which 16 met all eligibility criteria. We examined changes in processes and outcomes as a result of clinical ethics consultation in the ICU. Categories of outcomes included user perception, clinical decision, or conflict resolution and resource utilization. The use of clinical ethics consultation in the ICU was associated with positive user experience (383/435 found clinical ethics consultation helpful), although stress and disagreement with clinical ethics consultation recommendations was greater in a subset (113/431 surrogates and providers). Consensus for a clinical decision was more frequently achieved with clinical ethics consultation (odds ratio, 4.09; 95% CI, 1.01-16.55; p = 0.05). Clinical ethics consultation was associated with lower resource utilization including significantly decreased ICU length of stay (mean difference, -4.65 d; 95% CI, -8.86 to -0.44; p = 0.03). Our review identified outcome-based assessment as the predominant measure used to report effectiveness of clinical ethics consultation consultations. In particular, clinical ethics consultation decreased ICU length of stay and increased family and healthcare provider satisfaction. However, using outcome measures as the primary endpoint may not reflect the original intent of the clinical ethics consultation service. Based on our review, we propose a list of process measures that may better capture the key domains of a quality clinical ethics consultation.

Contribution of Zinc Solubilizing Bacteria in Growth Promotion and Zinc Content of Wheat.

PubMed

Kamran, Sana; Shahid, Izzah; Baig, Deeba N; Rizwan, Muhammad; Malik, Kauser A; Mehnaz, Samina

2017-01-01

Zinc is an imperative micronutrient required for optimum plant growth. Zinc solubilizing bacteria are potential alternatives for zinc supplementation and convert applied inorganic zinc to available forms. This study was conducted to screen zinc solubilizing rhizobacteria isolated from wheat and sugarcane, and to analyze their effect on wheat growth and development. Fourteen exo-polysaccharides producing bacterial isolates of wheat were identified and characterized biochemically as well as on the basis of 16S rRNA gene sequences. Along these, 10 identified sugarcane isolates were also screened for zinc solubilizing ability on five different insoluble zinc sources. Out of 24, five strains, i.e., EPS 1 ( Pseudomonas fragi) , EPS 6 ( Pantoea dispersa) , EPS 13 ( Pantoea agglomerans) , PBS 2 ( E. cloacae) and LHRW1 ( Rhizobium sp.) were selected (based on their zinc solubilizing and PGP activities) for pot scale plant experiments. ZnCO 3 was used as zinc source and wheat seedlings were inoculated with these five strains, individually, to assess their effect on plant growth and development. The effect on plants was analyzed based on growth parameters and quantifying zinc content of shoot, root and grains using atomic absorption spectroscopy. Plant experiment was performed in two sets. For first set of plant experiments (harvested after 1 month), maximum shoot and root dry weights and shoot lengths were noted for the plants inoculated with Rhizobium sp. (LHRW1) while E. cloacae (PBS 2) increased both shoot and root lengths. Highest zinc content was found in shoots of E. cloacae (PBS 2) and in roots of P. agglomerans (EPS 13) followed by zinc supplemented control. For second set of plant experiment, when plants were harvested after three months, Pantoea dispersa (EPS 6), P. agglomerans (EPS 13) and E. cloacae (PBS 2) significantly increased shoot dry weights. However, significant increase in root dry weights and maximum zinc content was recorded for Pseudomonas fragi (EPS 1) inoculated plants, isolated from wheat rhizosphere. While maximum zinc content for roots was quantified in the control plants indicating the plant's inability to transport zinc to grains, supporting accelerated bioavailability of zinc to plant grains with zinc solubilizing rhizobacteria.

Screening and Evaluation of the Bioremediation Potential of Cu/Zn-Resistant, Autochthonous Acinetobacter sp. FQ-44 from Sonchus oleraceus L.

PubMed

Fang, Qing; Fan, Zhengqiu; Xie, Yujing; Wang, Xiangrong; Li, Kun; Liu, Yafeng

2016-01-01

The quest for new, promising and indigenous plant growth-promoting rhizobacteria and a deeper understanding of their relationship with plants are important considerations in the improvement of phytoremediation. This study focuses on the screening of plant beneficial Cu/Zn-resistant strains and assessment of their bioremediation potential (metal solubilization/tolerance/biosorption and effects on growth of Brassica napus seedlings) to identify suitable rhizobacteria and examine their roles in microbes-assisted phytoremediation. Sixty Cu/Zn-resistant rhizobacteria were initially isolated from Sonchus oleraceus grown at a multi-metal-polluted site in Shanghai, China. From these strains, 19 isolates that were all resistant to 300 mg⋅L -1 Cu as well as 300 mg⋅L -1 Zn, and could simultaneously grow on Dworkin-Foster salt minimal medium containing 1-aminocyclopropane-1-carboxylic acid were preliminarily selected. Of those 19 isolates, 10 isolates with superior plant growth-promoting properties (indole-3-acetic acid production, siderophore production, and insoluble phosphate solubilization) were secondly chosen and further evaluated to identify those with the highest bioremediation potential and capacity for bioaugmentation. Strain S44, identified as Acinetobacter sp. FQ-44 based on 16S rDNA sequencing, was specifically chosen as the most favorable strain owing to its strong capabilities to (1) promote the growth of rape seedlings (significantly increased root length, shoot length, and fresh weight by 92.60%, 31.00%, and 41.96%, respectively) under gnotobiotic conditions; (2) tolerate up to 1000 mg⋅L -1 Cu and 800 mg⋅L -1 Zn; (3) mobilize the highest concentrations of water-soluble Cu, Zn, Pb, and Fe (16.99, 0.98, 0.08, and 3.03 mg⋅L -1 , respectively); and (4) adsorb the greatest quantities of Cu and Zn (7.53 and 6.61 mg⋅g -1 dry cell, respectively). Our findings suggest that Acinetobacter sp. FQ-44 could be exploited for bacteria-assisted phytoextraction. Moreover, the present study provides a comprehensive method for the screening of rhizobacteria for phytoremediation of multi-metal-polluted soils, especially those sewage sludge-amended soils contaminated with Cu/Zn.

Screening and Evaluation of the Bioremediation Potential of Cu/Zn-Resistant, Autochthonous Acinetobacter sp. FQ-44 from Sonchus oleraceus L.

PubMed Central

Fang, Qing; Fan, Zhengqiu; Xie, Yujing; Wang, Xiangrong; Li, Kun; Liu, Yafeng

2016-01-01

The quest for new, promising and indigenous plant growth-promoting rhizobacteria and a deeper understanding of their relationship with plants are important considerations in the improvement of phytoremediation. This study focuses on the screening of plant beneficial Cu/Zn-resistant strains and assessment of their bioremediation potential (metal solubilization/tolerance/biosorption and effects on growth of Brassica napus seedlings) to identify suitable rhizobacteria and examine their roles in microbes-assisted phytoremediation. Sixty Cu/Zn-resistant rhizobacteria were initially isolated from Sonchus oleraceus grown at a multi-metal-polluted site in Shanghai, China. From these strains, 19 isolates that were all resistant to 300 mg⋅L-1 Cu as well as 300 mg⋅L-1 Zn, and could simultaneously grow on Dworkin–Foster salt minimal medium containing 1-aminocyclopropane-1-carboxylic acid were preliminarily selected. Of those 19 isolates, 10 isolates with superior plant growth-promoting properties (indole-3-acetic acid production, siderophore production, and insoluble phosphate solubilization) were secondly chosen and further evaluated to identify those with the highest bioremediation potential and capacity for bioaugmentation. Strain S44, identified as Acinetobacter sp. FQ-44 based on 16S rDNA sequencing, was specifically chosen as the most favorable strain owing to its strong capabilities to (1) promote the growth of rape seedlings (significantly increased root length, shoot length, and fresh weight by 92.60%, 31.00%, and 41.96%, respectively) under gnotobiotic conditions; (2) tolerate up to 1000 mg⋅L-1 Cu and 800 mg⋅L-1 Zn; (3) mobilize the highest concentrations of water-soluble Cu, Zn, Pb, and Fe (16.99, 0.98, 0.08, and 3.03 mg⋅L-1, respectively); and (4) adsorb the greatest quantities of Cu and Zn (7.53 and 6.61 mg⋅g-1 dry cell, respectively). Our findings suggest that Acinetobacter sp. FQ-44 could be exploited for bacteria-assisted phytoextraction. Moreover, the present study provides a comprehensive method for the screening of rhizobacteria for phytoremediation of multi-metal-polluted soils, especially those sewage sludge-amended soils contaminated with Cu/Zn. PMID:27746807

Cultural Beliefs and Attitudes About Breast Cancer and Screening Practices Among Arabic Women in Australia.

PubMed

Kwok, Cannas; Endrawes, Gihane; Lee, Chun Fan

2016-01-01

Arabic women have been consistently reported as having remarkably low participation rates in breast cancer screening measures in their home countries and after migration to Western countries. Little is known about the screening behaviors of Arabic women in Australia. This study aimed to report breast cancer screening practices among Arabic women in Australia and to examine the relationship between (1) demographic factors and (2) the Arabic version of the Breast Cancer Screening Beliefs Questionnaire (BCSBQ) score and women's breast screening behaviors. A descriptive cross-sectional method was used. Both English and Arabic versions of the BCSBQ were administered to the 251 Arabic Australian women 18 years or older who participated in the study. The majority of participants (62.9%-92%) had heard of breast awareness, clinical breast examination, and mammography. However, only 7.6% practiced breast awareness monthly, 21.4% had undergone clinical breast examination annually, and 40.3% had biannual mammography. Length of stay in Australia, being retired, and being unemployed were positively associated with the recommended performance of breast awareness and mammography. In terms of BCSBQ scores, women who engaged in the 3 screening practices had significantly higher scores on the attitudes to health check-ups and barriers to mammography subscales. Attitudes toward health check-ups and perceived barriers to mammography were important determinants of breast cancer screening practices among Arabic Australian women. To fully understand barriers discouraging Arabic Australian women from participating in breast cancer screening practices, efforts should be focused on specific subgroup (ie, working group) of Arabic Australian women.

Breast cancer knowledge, attitudes and screening behaviors among Indian-Australian women.

PubMed

Kwok, C; Tranberg, R; Lee, F C

2015-12-01

The aims of the study were to report breast cancer screening practices among Indian-Australian women and to examine the relationship between demographic characteristics, cultural beliefs and women's breast cancer screening (BCS) behaviors. A descriptive and cross-sectional method was used. Two hundred and forty two Indian-Australian women were recruited from several Indian organizations. English versions of the Breast Cancer Screening Beliefs Questionnaire (BCSBQ) were administered. The main research variables are BCS practices, demographic characteristics and total scores on each of the BCSBQ subscales. The majority of participants (72.7%-81.4%) had heard of breast awareness, clinical breast examination (CBE) and mammograms. Only 28.9% performed a BSE monthly and although 60% had practiced CBE, only 27.3% of women within the targeted age group had annual CBE. Only 23.6% of women within the targeted age group reported they had a mammogram biennial. Marital status and length of stay in Australia were positively associated with women's screening behaviors. In terms of BCSBQ score, women who had the three screening practices regularly as recommended obtained significantly higher scores on the "attitude towards general health check-ups" and "barriers to mammographic screening" subscales. There was a significant difference in the mean score of the "knowledge and perceptions about breast cancer" between women who did and who did not engage in breast awareness. Our study reveals that attitudes toward health check-ups and perceived barriers to mammographic screening were influential in determining compliance with breast cancer screening practices among Indian-Australian women. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effects of perchlorate on growth of four wetland plants and its accumulation in plant tissues.

PubMed

He, Hongzhi; Gao, Haishuo; Chen, Guikui; Li, Huashou; Lin, Hai; Shu, Zhenzhen

2013-10-01

Perchlorate contamination in water is of concern because of uncertainties about toxicity and health effects, impact on ecosystems, and possible indirect exposure pathways to humans. Therefore, it is very important to investigate the ecotoxicology of perchlorate and to screen plant species for phytoremediation. Effects of perchlorate (20, 200, and 500 mg/L) on the growth of four wetland plants (Eichhornia crassipes, Acorus calamus L., Thalia dealbata, and Canna indica) as well as its accumulation in different plant tissues were investigated through water culture experiments. Twenty milligrams per liter of perchlorate had no significant effects on height, root length, aboveground part weight, root weight, and oxidizing power of roots of four plants, except A. calamus, and increasing concentrations of perchlorate showed that out of the four wetland plants, only A. calamus had a significant (p<0.05) dose-dependent decrease in these parameters. When treated with 500 mg/L perchlorate, these parameters and chlorophyll content in the leaf of plants showed significant decline contrasted to control groups, except the root length of E. crassipes and C. indica. The order of inhibition rates of perchlorate on root length, aboveground part weight and root weight, and oxidizing power of roots was: A. calamus > C. indica > T. dealbata > E. crassipes and on chlorophyll content in the leaf it was: A. calamus > T. dealbata > C. indica > E. crassipes. The higher the concentration of perchlorate used, the higher the amount of perchlorate accumulation in plants. Perchlorate accumulation in aboveground tissues was much higher than that in underground tissues and leaf was the main tissue for perchlorate accumulation. The order of perchlorate accumulation content and the bioconcentration factor in leaf of four plants was: E. crassipes > C. indica > T. dealbata > A. calamus. Therefore, E. crassipes might be an ideal plant with high tolerance ability and accumulation ability for constructing wetland to remediate high levels of perchlorate polluted water.

Increased nuchal translucency and short femur length as possible early signs of osteogenesis imperfecta type III.

PubMed

Vimercati, Antonella; Panzarino, Mariantonietta; Totaro, Ilaria; Chincoli, Annarosa; Selvaggi, Luigi

2013-01-01

this paper reports an association between an increased Nuchal Translucency (NT) and Osteogenesis Imperfecta (OI), a type of skeletal dysplasia. Measurement of fetal NT at 10-14 weeks of gestation is a sensitive and effective screening method for chromosomal abnormalities. a 35-year- old Caucasian woman in her fourth pregnancy was referred to our clinic for an ultrasound scan at 12 weeks of gestation, that confirmed increased Nuchal Translucency. Chorionic villi sampling was performed, showing a normal karyotype. The patient was evaluated by a team of experienced ultra sonographers for pregnancy follow-up at our Department, that is a tertiary center. in our case the ultrasound scan at 12 week of gestation revealed only an increased NT (3 mm). Cytogenetic analysis on chorionic villi demonstrated a normal male karyotype. US follow-up, performed every 3-4 weeks, confirmed normal anthropometric parameters except for shortening of both femurs, but at 23 weeks an incorrect attitude of the feet was revealed. A clinical and radiographic diagnosis of OI type III was made only at birth, and through follow-up continuing to date. NT screening was successful for chromosomal abnormalities at 11-14 weeks of gestation. An increased NT thickness is also associated with numerous fetal anomalies and genetic syndromes in a chromosomally normal fetus. In our case there were no sonographic signs of imperfect osteogenesis in the first trimester, although there was an increased NT with a normal karyotype. currently, in literature, there are not other cases of OI type III associated with an increased NT. Our report is the first to suggest an association between an increased nuchal translucency, short femur length and osteogenesis imperfecta type III.

Octopamine-signaling in the metazoan pathogen, Schistosoma mansoni: localization, small-molecule screening and opportunities for drug development.

PubMed

El-Sakkary, Nelly; Chen, Steven; Arkin, Michelle R; Caffrey, Conor R; Ribeiro, Paula

2018-06-20

Schistosomiasis is a tropical disease caused by a flatworm trematode parasite that infects over 240 million people worldwide. Treatment and control of the disease rely on just one drug, praziquantel. The possibility of drug resistance coupled with praziquantel's variable efficacy encourages the identification of new drugs and drug targets. Disruption of neuromuscular homeostasis in parasitic worms is a validated strategy for drug development. However, in schistosomes, much remains to be understood about the organization of the nervous system, its component neurotransmitters and potential for drug discovery. Using synapsin as a neuronal marker, we map the central and peripheral nervous systems in the Schistosoma mansoni adult and schistosomulum (post-infective larva). We discover the widespread presence of octopamine (OA), a tyrosine-derived and invertebrate-specific neurotransmitter involved in neuromuscular coordination. OA-labeling facilitated the discovery of two pairs of ganglia in the brain of the adult schistosome rather than the one pair thus far reported for this or other trematodes. In quantitative phenotypic assays, OA and structurally-related tyrosine-derived phenolamine and catecholamine neurotransmitters differentially modulated schistosomulum motility and length. Similarly, from a screen of 28 drug agonists and antagonists of tyrosine derivative-signaling, certain drugs that act on OA and dopamine receptors induced robust and sometimes complex concentration-dependent effects on schistosome motility and length, including at concentrations achievable in vivo The present data advance our knowledge of the organization of the nervous system in this globally important pathogen and identify a number of drugs that interfere with tyrosine-derived signaling, one or more of which may provide the basis for a new chemotherapeutic approach to treat schistosomiasis. © 2018. Published by The Company of Biologists Ltd.

Theoretical study of magnetic layers of nickel on copper; dead or alive?

NASA Astrophysics Data System (ADS)

Ernst, A.; Lueders, M.; Temmerman, W. M.; Szotek, Z.; van der Laan, G.

2000-07-01

We studied the persistence of magnetism in ultrathin nickel films on copper. Layer-dependent magnetic moments in Ni films on the (001), (110) and (111) surfaces of Cu have been calculated using the Korringa-Kohn-Rostoker Green's function method. The results show that, at temperature T = 0, a single nickel monolayer is ferromagnetic on Cu(001) and Cu(110) but magnetically `dead' on the more closely packed Cu(111) surface. Films of two and more layers of Ni are always ferromagnetic, with the magnetic moment enhanced in the surface layer but strongly reduced in the interface layer. Due to the short screening length, both the effect of the interface and that of the surface are confined to only a few atomic layers.

The potential of imaging techniques as a screening tool for colorectal cancer: a cost-effectiveness analysis.

PubMed

Greuter, Marjolein J E; Berkhof, Johannes; Fijneman, Remond J A; Demirel, Erhan; Lew, Jie-Bin; Meijer, Gerrit A; Stoker, Jaap; Coupé, Veerle M H

2016-07-01

Imaging may be promising for colorectal cancer (CRC) screening, since it has test characteristics comparable with colonoscopy but is less invasive. We aimed to assess the potential of CT colonography (CTC) and MR colonography (MRC) in terms of (cost-effectiveness) using the Adenoma and Serrated pathway to Colorectal CAncer model. We compared several CTC and MRC strategies with 5- or 10-yearly screening intervals with no screening, 10-yearly colonoscopy screening and biennial faecal immunochemical test (FIT) screening. We assumed trial-based participation rates in the base-case analyses and varied the rates in sensitivity analyses. Incremental lifetime costs and health effects were estimated from a healthcare perspective. The health gain of CTC and MRC was similar and ranged from 0.031 to 0.048 life-year gained compared with no screening, for 2-5 screening rounds. Lifetime costs per person for MRC strategies were €60-110 higher than those for CTC strategies with an equal number of screening rounds. All imaging-based strategies were cost-effective compared with no screening. FIT screening was the dominant screening strategy, leading to most LYG and highest cost-savings. Compared with three rounds of colonoscopy screening, CTC with five rounds was found to be cost-effective in an incremental analysis of imaging strategies. Assumptions on screening participation have a major influence on the ordering of strategies in terms of costs and effects. CTC and MRC have potential for CRC screening, compared with no screening and compared with three rounds of 10-yearly colonoscopy screening. When taking FIT screening as the reference, imaging is not cost-effective. Participation is an important driver of effectiveness and cost estimates. This is the first study to assess the cost-effectiveness of MRC screening for CRC.

Prioritizing quantitative trait loci for root system architecture in tetraploid wheat.

PubMed

Maccaferri, Marco; El-Feki, Walid; Nazemi, Ghasemali; Salvi, Silvio; Canè, Maria Angela; Colalongo, Maria Chiara; Stefanelli, Sandra; Tuberosa, Roberto

2016-02-01

Optimization of root system architecture (RSA) traits is an important objective for modern wheat breeding. Linkage and association mapping for RSA in two recombinant inbred line populations and one association mapping panel of 183 elite durum wheat (Triticum turgidum L. var. durum Desf.) accessions evaluated as seedlings grown on filter paper/polycarbonate screening plates revealed 20 clusters of quantitative trait loci (QTLs) for root length and number, as well as 30 QTLs for root growth angle (RGA). Divergent RGA phenotypes observed by seminal root screening were validated by root phenotyping of field-grown adult plants. QTLs were mapped on a high-density tetraploid consensus map based on transcript-associated Illumina 90K single nucleotide polymorphisms (SNPs) developed for bread and durum wheat, thus allowing for an accurate cross-referencing of RSA QTLs between durum and bread wheat. Among the main QTL clusters for root length and number highlighted in this study, 15 overlapped with QTLs for multiple RSA traits reported in bread wheat, while out of 30 QTLs for RGA, only six showed co-location with previously reported QTLs in wheat. Based on their relative additive effects/significance, allelic distribution in the association mapping panel, and co-location with QTLs for grain weight and grain yield, the RSA QTLs have been prioritized in terms of breeding value. Three major QTL clusters for root length and number (RSA_QTL_cluster_5#, RSA_QTL_cluster_6#, and RSA_QTL_cluster_12#) and nine RGA QTL clusters (QRGA.ubo-2A.1, QRGA.ubo-2A.3, QRGA.ubo-2B.2/2B.3, QRGA.ubo-4B.4, QRGA.ubo-6A.1, QRGA.ubo-6A.2, QRGA.ubo-7A.1, QRGA.ubo-7A.2, and QRGA.ubo-7B) appear particularly valuable for further characterization towards a possible implementation of breeding applications in marker-assisted selection and/or cloning of the causal genes underlying the QTLs. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

[Effects, safety and cost-benefit analysis of Down syndrome screening in first trimester].

PubMed

Shengmou, Lin; Min, Chen; Chenhong, Wang; Shengli, Li; Jiansheng, Xie; Hui, Yuan; Dinghao, Lin; Xiaoxia, Wu; Wei, Wang; Hongyun, Zhang; Haiyan, Tang

2014-05-01

To investigate the effects, safety and cost-benefit analysis of Down syndrome screening in first trimester. From January 2009 to December 2012, 43 729 pregnant women undergoing 3 methods of Down syndrome traditional screening strategies in Shenzhen Maternity and Child Healthcare Hospital were studied retrospectively, including in 17 502 cases in pregnancy associated plasma protein A (PAPP-A) and free β-hCG measured biochemistry screening, 14 080 cases in nuchal translucency (NT) screening and 12 147 cases in combined screening, meanwhile, 7 389 cases on non-invasive fetal trisomy test (NIFTY) were performed in Huada Gene Research Institute(BGI). The effects and safety of four screening strategies were assessed throughout a decision tree. The economical characters of each screening strategy were compared by cost-effectiveness analysis as well as cost-benefit analysis. (1) The effects of four strategies are: NIFTY > combined screening > NT screening > biochemistry screening. (2) The safety of four strategies are: NIFTY > combined screening > NT screening > biochemistry screening. (3) Cost-effectiveness analysis and cost-benefit analysis:the biochemistry screening has lowest cost-effectiveness ratio (CER) and highest cost-benefit ratio (CBR), which performed a better economical efficiency. The incremental CER of three traditional screening strategies are all less than the economical burden of Down syndrome.NIFTY has highest CER and negative net present value (NPV), NPV would be positive and CBR would be more than 1 if the price of NIFTY reduce to 1 434 Yuan. Combined screening possess best screening efficiency, while biochemistry screening was demonstrated more economical in traditional screening.NIFTY is the future of Down syndrome screening.

Have Users Changed Their Style? A Survey of CD-ROM vs. OPAC Product Usage.

ERIC Educational Resources Information Center

Anderson, Judy

1995-01-01

A survey of online search techniques of 50 undergraduate and graduate students at Arizona State University's Hayden Library revealed heavy reliance on simple subject searching. The analysis included search types, use of library personnel and online help screens, exposure to library instruction, and length of time at the terminal for citation…

Length polymorphism scanning is an efficient approach for revealing chloroplast DNA variation.

Treesearch

Matthew E. Horning; Richard C. Cronn

2006-01-01

Phylogeographic and population genetic screens of chloroplast DNA (cpDNA) provide insights into seedbased gene flow in angiosperms, yet studies are frequently hampered by the low mutation rate of this genome. Detection methods for intraspecific variation can be either direct (DNA sequencing) or indirect (PCR-RFLP), although no single method incorporates the best...

School-Aged Children with Mild Bilateral and Unilateral Hearing Loss: Parents' Reflections on Services, Experiences, and Outcomes

ERIC Educational Resources Information Center

Grandpierre, Viviane; Fitzpatrick, Elizabeth M.; Na, Eunjung; Mendonca, Oreen

2018-01-01

Following the establishment of newborn hearing screening programs, age of identification and length of time before receiving interventions has been reduced for children, including those with milder degrees of hearing loss who were previously not identified until school age. This population of early-identified children requires new support programs…

An assistant workforce to improve screening rates and quality of care for older patients in the emergency department: findings of a pre- post, mixed methods study.

PubMed

Hullick, Carolyn; Conway, Jane; Higgins, Isabel; Hewitt, Jacqueline; Stewart, Bernadette; Dilworth, Sophie; Attia, John

2018-05-30

Older people who present to the Emergency Department (ED) experience high rates of prevalent and incident delirium. This study aimed to determine whether an assistant workforce in the ED could effectively conduct screening to inform assessment and care planning for older people as well as enhance supportive care activities for prevention of delirium. Using a pre-post design, data was collected before and after the introduction of Older Person Technical Assistants (OPTAs) in the ED. OPTA activity was recorded during the intervention period and a medical record audit undertaken prior to and 9 months after implementation. Data were analysed using descriptive statistics for OPTA activities. Weighted Kappa scores were calculated comparing concordance in screening scores between OPTAs and Aged Services Emergency Team Registered Nurses. Changes in the rates of documented screening and supportive care were analysed using Chi-square tests. Focus groups were conducted to explore clinicians' experiences of the OPTA role. Three thousand five hundred fourty two people were seen by OPTAs in 4563 ED Presentations between 1st July 2011 and 2012. The reproducibility of all screening tools were found to be high between the OPTAs and the RNs, with Kappas and ICCs generally all above 0.9. The medical record audit showed significant improvement in the rates of documented screening, including cognition from 1.5 to 38% (p < 0.001) and review of pain from 29 to 75% (p < 0.001). Supportive care such as being given fluids or food also improved from 13 to 49% (p < 0.001) and pressure care from 4.8 to 30% (p < 0.001). This was accomplished with no increase in ED length of stay among this age group. Focus group interviews described mixed responses and support for the OPTA role. An assistant workforce in an ED setting was found to provide comparable screening results and improve the rates of documented screening and supportive care provided to older people with or at risk of developing delirium in the ED. There is a need for a shared philosophy to the care of older people in the ED. Australian New Zealand Clinical Trials Registration number is ACTRN12617000742370. It was retrospectively registered on 22nd May 2017.

The Snakelike Chain Character of Unstructured RNA

PubMed Central

Jacobson, David R.; McIntosh, Dustin B.; Saleh, Omar A.

2013-01-01

In the absence of base-pairing and tertiary structure, ribonucleic acid (RNA) assumes a random-walk conformation, modulated by the electrostatic self-repulsion of the charged, flexible backbone. This behavior is often modeled as a Kratky-Porod “wormlike chain” (WLC) with a Barrat-Joanny scale-dependent persistence length. In this study we report measurements of the end-to-end extension of poly(U) RNA under 0.1 to 10 pN applied force and observe two distinct elastic-response regimes: a low-force, power-law regime characteristic of a chain of swollen blobs on long length scales and a high-force, salt-valence-dependent regime consistent with ion-stabilized crumpling on short length scales. This short-scale structure is additionally supported by force- and salt-dependent quantification of the RNA ion atmosphere composition, which shows that ions are liberated under stretching; the number of ions liberated increases with increasing bulk salt concentration. Both this result and the observation of two elastic-response regimes directly contradict the WLC model, which predicts a single elastic regime across all forces and, when accounting for scale-dependent persistence length, the opposite trend in ion release with salt concentration. We conclude that RNA is better described as a “snakelike chain,” characterized by smooth bending on long length scales and ion-stabilized crumpling on short length scales. In monovalent salt, these two regimes are separated by a characteristic length that scales with the Debye screening length, highlighting the determining importance of electrostatics in RNA conformation. PMID:24314087

Determining an anthropometric surrogate measure for identifying low birth weight babies in Uganda: a hospital-based cross sectional study

PubMed Central

2013-01-01

Background Achieving Millennium Development Goal 4 is dependent on significantly reducing neonatal mortality. Low birth weight is an underlying factor in most neonatal deaths. In developing countries the missed opportunity for providing life saving care is mainly a result of failure to identify low birth weight newborns. This study aimed at identifying a reliable anthropometric measurement for screening low birth weight and determining an operational cut-off point in the Uganda setting. This simple measurement is required because of lack of weighing scales in the community, and sometimes in the health facilities. Methods This was a hospital-based cross-sectional study. Two midwives weighed 706 newborns and measured their foot length, head, chest, thigh and mid-upper arm circumferences within 24 hours after birth. Data was analysed using STATA version 10.0. Correlation with birth weight using Pearson’s correlation coefficient and Receiver Operating Characteristics curve analysis were done to determine the measure that best predicts birth weight. Sensitivity and specificity were calculated for a range of measures to obtain operational cut-off points; and Likelihood Ratios and Diagnostic Odds Ratio were determined for each cut-off point. Results Birth weights ranged from 1370–5350 grams with a mean of 3050 grams (SD 0.53) and 85 (12%) babies weighed less than 2500 grams. All anthropometric measurements had a positive correlation with birth weight, with foot length showing the strongest (r = 0.76) and thigh circumference the weakest (r = 0.62) correlations. Foot length had the highest predictive value for low birth weight (AUC = 0.97) followed by mid-upper arm circumference (AUC = 0.94). Foot length and chest circumference had the highest sensitivity (94%) and specificity (90%) respectively for screening low birth weight babies at the selected cut-off points. Chest circumference had a significantly higher positive likelihood ratio (8.7) than any other measure, and foot length had the lowest negative likelihood ratio. Chest circumference and foot length had diagnostic odds ratios of 97% and 77% respectively. Foot length was easier to measure and it involved minimal exposure of the baby to cold. A cut-off of foot length 7.9 cm had sensitivity of 94% and specificity of 83% for predicting low birth weight. Conclusions This study suggests foot length as the most appropriate predictor for low birth weight in comparison to chest, head, mid-upper arm and thigh circumference in the Uganda setting. Use of low cost and easy to use tools to identify low birth weight babies by village health teams could support community efforts to save newborns. PMID:23587297

Effects of Promotional Materials on Attitudes and Fear towards Colorectal Cancer Screening among Chinese Older Adults: An Experimental Study.

PubMed

Leung, Doris Y P; Chen, Joanne M T; Lou, Vivian W Q; Wong, Eliza M L; Chan, Aileen W K; So, Winnie K W; Chan, Carmen W H

2017-07-13

Colorectal cancer (CRC) screening is a cost-effective prevention and control strategy. However, the promotion of CRC screening for older adults may be difficult because reading CRC prevention information may evoke embarrassment, fear, and anxiety towards the screening procedure and cancer diagnosis. This study aims to (1) examine the effects of three promotional materials for CRC screening on the attitudes toward CRC screening tests (screening interest, screening effectiveness, and trust in the screening results) and cancer fear, and (2) to explore the interaction effect of cancer fear with screening effectiveness and trust in the screening results on screening interest of the three screening tests (fecal occult blood test (FOBT), flexible sigmoidoscopy, and colonoscopy) among Chinese older adults. A total of 114 community-dwelling older adults were asked to look at the corresponding promotional materials (pamphlet, cartoon, and video) of one of the three study groups. The pamphlet and video represent convention strategies and the cartoon represents an innovative strategy. No significant difference was observed in the screening interest and cancer fear across groups. FOBT was the most preferred screening modality. The video group has a large proportion agreed screening effectiveness of flexible sigmoidoscopy than pamphlet and cartoon groups and trusted in the screening results for FOBT and flexible sigmoidoscopy than the pamphlet group. Logistic regression results showed that the effect of trust in the screening results on screening interest for colonoscopy was greater among participants with higher cancer fear than those with lower cancer fear level. In conclusion, the three promotional groups had produced similar results in their attitudes toward CRC screening and cancer fear. The use of cartoons may be a comparable approach with conventional methods in the promotion of CRC screening. Additional components that can arouse fear and boost response efficacy simultaneously might also be useful for the effective promotion of colonoscopy among Chinese older adults.

Effects of Promotional Materials on Attitudes and Fear towards Colorectal Cancer Screening among Chinese Older Adults: An Experimental Study

PubMed Central

Leung, Doris Y. P.; Chen, Joanne M. T.; Lou, Vivian W. Q.; Wong, Eliza M. L.; So, Winnie K. W.; Chan, Carmen W. H.

2017-01-01

Colorectal cancer (CRC) screening is a cost-effective prevention and control strategy. However, the promotion of CRC screening for older adults may be difficult because reading CRC prevention information may evoke embarrassment, fear, and anxiety towards the screening procedure and cancer diagnosis. This study aims to (1) examine the effects of three promotional materials for CRC screening on the attitudes toward CRC screening tests (screening interest, screening effectiveness, and trust in the screening results) and cancer fear, and (2) to explore the interaction effect of cancer fear with screening effectiveness and trust in the screening results on screening interest of the three screening tests (fecal occult blood test (FOBT), flexible sigmoidoscopy, and colonoscopy) among Chinese older adults. A total of 114 community-dwelling older adults were asked to look at the corresponding promotional materials (pamphlet, cartoon, and video) of one of the three study groups. The pamphlet and video represent convention strategies and the cartoon represents an innovative strategy. No significant difference was observed in the screening interest and cancer fear across groups. FOBT was the most preferred screening modality. The video group has a large proportion agreed screening effectiveness of flexible sigmoidoscopy than pamphlet and cartoon groups and trusted in the screening results for FOBT and flexible sigmoidoscopy than the pamphlet group. Logistic regression results showed that the effect of trust in the screening results on screening interest for colonoscopy was greater among participants with higher cancer fear than those with lower cancer fear level. In conclusion, the three promotional groups had produced similar results in their attitudes toward CRC screening and cancer fear. The use of cartoons may be a comparable approach with conventional methods in the promotion of CRC screening. Additional components that can arouse fear and boost response efficacy simultaneously might also be useful for the effective promotion of colonoscopy among Chinese older adults. PMID:28703752

Examining the cost-effectiveness of cancer screening promotion.

PubMed

Andersen, M Robyn; Urban, Nicole; Ramsey, Scott; Briss, Peter A

2004-09-01

Cost-effectiveness analyses (CEAs) can help to quantify the contribution of the promotion of a screening program to increased participation in screening. The cost-effectiveness (C/E) of screening promotion depends in large part on the endpoints of interest. At the most fundamental level, the C/E of a strategy for promoting screening would focus on the attendance rate, or cost per person screened, and the C/E would be influenced by the costs of promotion, as well as by the size and responsiveness of the target population. In addition, the costs of screening promotion (measured as the cost per additional participant in screening) can be included in a CEA estimate of the screening technology. In this case, depending on the efficacy of the screening test and the costs and influence of the promotion, the C/E of screening may improve or become poorer. In the current study, the authors reviewed the literature on the C/E of cancer screening promotion. The following lessons were learned regarding the C/E of screening and its promotion: 1) high-quality information on the C/E of screening is increasingly available; 2) cost-effective promotion of screening is dependent on cost-effective screening strategies; 3) quality-of-life effects may be important in assessing the overall C/E of screening programs; 4) research efforts aimed at identifying cost-effective approaches to screening promotion are useful but sparse; 5) C/E studies should be better incorporated into well designed effectiveness research efforts; 6) variations in C/E according to intervention characteristics, population characteristics, and context should be evaluated in greater depth; 7) the long-term effects of screening promotion are critical to assessing C/E; 8) the effects of promotion on costs of screening must be better understood; and 9) CEA must be interpreted in light of other information. The authors showed that CEA can be a valuable tool for understanding the merits of health promotion interventions and that CEA is particularly valuable in identifying screening strategies that might be promoted most cost-effectively.

Search for Screened Interactions Associated with Dark Energy below the 100 μm Length Scale.

PubMed

Rider, Alexander D; Moore, David C; Blakemore, Charles P; Louis, Maxime; Lu, Marie; Gratta, Giorgio

2016-09-02

We present the results of a search for unknown interactions that couple to mass between an optically levitated microsphere and a gold-coated silicon cantilever. The scale and geometry of the apparatus enable a search for new forces that appear at distances below 100  μm and which would have evaded previous searches due to screening mechanisms. The data are consistent with electrostatic backgrounds and place upper limits on the strength of new interactions at <0.1  fN in the geometry tested. For the specific example of a chameleon interaction with an inverse power law potential, these results exclude matter couplings β>5.6×10^{4} in the region of parameter space where the self-coupling Λ≳5  meV and the microspheres are not fully screened.

Maximum Likelihood Estimations and EM Algorithms with Length-biased Data

PubMed Central

Qin, Jing; Ning, Jing; Liu, Hao; Shen, Yu

2012-01-01

SUMMARY Length-biased sampling has been well recognized in economics, industrial reliability, etiology applications, epidemiological, genetic and cancer screening studies. Length-biased right-censored data have a unique data structure different from traditional survival data. The nonparametric and semiparametric estimations and inference methods for traditional survival data are not directly applicable for length-biased right-censored data. We propose new expectation-maximization algorithms for estimations based on full likelihoods involving infinite dimensional parameters under three settings for length-biased data: estimating nonparametric distribution function, estimating nonparametric hazard function under an increasing failure rate constraint, and jointly estimating baseline hazards function and the covariate coefficients under the Cox proportional hazards model. Extensive empirical simulation studies show that the maximum likelihood estimators perform well with moderate sample sizes and lead to more efficient estimators compared to the estimating equation approaches. The proposed estimates are also more robust to various right-censoring mechanisms. We prove the strong consistency properties of the estimators, and establish the asymptotic normality of the semi-parametric maximum likelihood estimators under the Cox model using modern empirical processes theory. We apply the proposed methods to a prevalent cohort medical study. Supplemental materials are available online. PMID:22323840

Effect of the size of charged spherical macroparticles on their electrostatic interaction in an equilibrium plasma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Filippov, A. V., E-mail: fav@triniti.ru; Derbenev, I. N.

The effect of the size of two charged spherical macroparticles on their electrostatic interaction in an equilibrium plasma is analyzed within the linearized Poisson–Botzmann model. It is established that, under the interaction of two charged dielectric macroparticles in an equilibrium plasma, the forces acting on each particle turn out to be generally unequal. The forces become equal only in the case of conducting macroparticles or in the case of dielectric macroparticles of the same size and charge. They also turn out to be equal when the surface potentials of the macroparticles remain constant under the variation of interparticle distances. Formulasmore » are proposed that allow one to calculate the interaction force with a high degree of accuracy under the condition that the radii of macroparticles are much less than the screening length, which is usually satisfied in experiments with dusty plasmas.« less

Electrostatics-Driven Hierarchical Buckling of Charged Flexible Ribbons.

PubMed

Yao, Zhenwei; Olvera de la Cruz, Monica

2016-04-08

We investigate the rich morphologies of an electrically charged flexible ribbon, which is a prototype for many beltlike structures in biology and nanomaterials. Long-range electrostatic repulsion is found to govern the hierarchical buckling of the ribbon from its initially flat shape to its undulated and out-of-plane twisted conformations. In this process, the screening length is the key controlling parameter, suggesting that a convenient way to manipulate the ribbon morphology is simply to change the salt concentration. We find that these shapes originate from the geometric effect of the electrostatic interaction, which fundamentally changes the metric over the ribbon surface. We also identify the basic modes by which the ribbon reshapes itself in order to lower the energy. The geometric effect of the physical interaction revealed in this Letter has implications for the shape design of extensive ribbonlike materials in nano- and biomaterials.

Development of a prototype regenerable carbon dioxide absorber for portable life support systems. [for astronaut EVA

NASA Technical Reports Server (NTRS)

Onischak, M.; Baker, B.

1977-01-01

The design and development of a prototype carbon dioxide absorber using potassium carbonate (K2CO3) is described. Absorbers are constructed of thin, porous sheets of supported K2CO3 that are spirally wound to form a cylindrical reactor. Axial gas passages are formed between the porous sheets by corrugated screen material. Carbon dioxide and water in an enclosed life support system atmosphere react with potassium carbonate to form potassium bicarbonate. The potassium carbonate is regenerated by heating the potassium bicarbonate to 150 C at ambient pressure. The extravehicular mission design conditions are for one man for 8 h. Results are shown for a subunit test module investigating the effects of heat release, length-to-diameter ratio, and active cooling upon performance. The most important effect upon carbon dioxide removal is the temperature of the potassium carbonate.

Electric analog studies of flow to wells in the Punjab aquifer of West Pakistan

USGS Publications Warehouse

Mundorff, Maurice John; Bennett, G.D.; Ahmad, Masood

1972-01-01

A series of experiments was performed with a steady-state electric analog simulating a cylindrical segment of the aquifer underlying the plains of the Punjab region of West Pakistan. In most of the experiments recharge was assumed to be from the surface, within a specified radius of influence, and distributed uniformly over the area within this radius. Experiments were made with different anisotropies (ratios of lateral to vertical resistance) so that various possible combinations of aquifer thickness and effective radius or radius of influence and combinations .of lateral and vertical permeability could be included in the models. Flow nets were constructed to show distribution of potential in the vertical section and intersections of stream surfaces with the vertical plane. The series of experiments in which the screened interval is in the upper part of the aquifer shows that flow decreases and stream tubes shift progressively toward the upper part of the aquifer as anisotropy increases. Another series illustrates that total yield increases and yield per foot of screen decreases as screen length increases. The experiments indicate that, under conditions prevalent in the Punjab, the Distance-drawdown method for determining permeability gives results with an error of 10 percent or less provided that at least one piezometer or observation well is within a few feet of the pumped well and that no observation well or piezometer used is more than 100 feet from the pumped well. Relative traveltime for each of 10 stream tubes is given for three models. Relative traveltimes for one-fourth and one-half the effective radius are given for selected stream tubes. By substituting values for the aquifer parameters, actual traveltimes are computed from the relative-traveltime data.

Screening strategies for atrial fibrillation: a systematic review and cost-effectiveness analysis.

PubMed

Welton, Nicky J; McAleenan, Alexandra; Thom, Howard Hz; Davies, Philippa; Hollingworth, Will; Higgins, Julian Pt; Okoli, George; Sterne, Jonathan Ac; Feder, Gene; Eaton, Diane; Hingorani, Aroon; Fawsitt, Christopher; Lobban, Trudie; Bryden, Peter; Richards, Alison; Sofat, Reecha

2017-05-01

Atrial fibrillation (AF) is a common cardiac arrhythmia that increases the risk of thromboembolic events. Anticoagulation therapy to prevent AF-related stroke has been shown to be cost-effective. A national screening programme for AF may prevent AF-related events, but would involve a substantial investment of NHS resources. To conduct a systematic review of the diagnostic test accuracy (DTA) of screening tests for AF, update a systematic review of comparative studies evaluating screening strategies for AF, develop an economic model to compare the cost-effectiveness of different screening strategies and review observational studies of AF screening to provide inputs to the model. Systematic review, meta-analysis and cost-effectiveness analysis. Primary care. Adults. Screening strategies, defined by screening test, age at initial and final screens, screening interval and format of screening {systematic opportunistic screening [individuals offered screening if they consult with their general practitioner (GP)] or systematic population screening (when all eligible individuals are invited to screening)}. Sensitivity, specificity and diagnostic odds ratios; the odds ratio of detecting new AF cases compared with no screening; and the mean incremental net benefit compared with no screening. Two reviewers screened the search results, extracted data and assessed the risk of bias. A DTA meta-analysis was perfomed, and a decision tree and Markov model was used to evaluate the cost-effectiveness of the screening strategies. Diagnostic test accuracy depended on the screening test and how it was interpreted. In general, the screening tests identified in our review had high sensitivity (> 0.9). Systematic population and systematic opportunistic screening strategies were found to be similarly effective, with an estimated 170 individuals needed to be screened to detect one additional AF case compared with no screening. Systematic opportunistic screening was more likely to be cost-effective than systematic population screening, as long as the uptake of opportunistic screening observed in randomised controlled trials translates to practice. Modified blood pressure monitors, photoplethysmography or nurse pulse palpation were more likely to be cost-effective than other screening tests. A screening strategy with an initial screening age of 65 years and repeated screens every 5 years until age 80 years was likely to be cost-effective, provided that compliance with treatment does not decline with increasing age. A national screening programme for AF is likely to represent a cost-effective use of resources. Systematic opportunistic screening is more likely to be cost-effective than systematic population screening. Nurse pulse palpation or modified blood pressure monitors would be appropriate screening tests, with confirmation by diagnostic 12-lead electrocardiography interpreted by a trained GP, with referral to a specialist in the case of an unclear diagnosis. Implementation strategies to operationalise uptake of systematic opportunistic screening in primary care should accompany any screening recommendations. Many inputs for the economic model relied on a single trial [the Screening for Atrial Fibrillation in the Elderly (SAFE) study] and DTA results were based on a few studies at high risk of bias/of low applicability. Comparative studies measuring long-term outcomes of screening strategies and DTA studies for new, emerging technologies and to replicate the results for photoplethysmography and GP interpretation of 12-lead electrocardiography in a screening population. This study is registered as PROSPERO CRD42014013739. The National Institute for Health Research Health Technology Assessment programme.

Can sinogram-affirmed iterative (SAFIRE) reconstruction improve imaging quality on low-dose lung CT screening compared with traditional filtered back projection (FBP) reconstruction?

PubMed

Yang, Wen Jie; Yan, Fu Hua; Liu, Bo; Pang, Li Fang; Hou, Liang; Zhang, Huan; Pan, Zi Lai; Chen, Ke Min

2013-01-01

To evaluate the performance of sinogram-affirmed iterative (SAFIRE) reconstruction on image quality of low-dose lung computed tomographic (CT) screening compared with filtered back projection (FBP). Three hundred four patients for annual low-dose lung CT screening were examined by a dual-source CT system at 120 kilovolt (peak) with reference tube current of 40 mA·s. Six image serials were reconstructed, including one data set of FBP and 5 data sets of SAFIRE with different reconstruction strengths from 1 to 5. Image noise was recorded; and subjective scores of image noise, images artifacts, and the overall image quality were also assessed by 2 radiologists. The mean ± SD weight for all patients was 66.3 ± 12.8 kg, and the body mass index was 23.4 ± 3.2. The mean ± SD dose-length product was 95.2 ± 30.6 mGy cm, and the mean ± SD effective dose was 1.6 ± 0.5 mSv. The observation agreements for image noise grade, artifact grade, and the overall image quality were 0.785, 0.595 and 0.512, respectively. Among the overall 6 data sets, both the measured mean objective image noise and the subjective image noise of FBP was the highest, and the image noise decreased with the increasing of SAFIRE reconstruction strength. The data sets of S3 obtained the best image quality scores. Sinogram-affirmed iterative reconstruction can significantly improve image quality of low-dose lung CT screening compared with FBP, and SAFIRE with reconstruction strength 3 was a pertinent choice for low-dose lung CT.

Accelerating Gene Discovery by Phenotyping Whole-Genome Sequenced Multi-mutation Strains and Using the Sequence Kernel Association Test (SKAT)

PubMed Central

Garland, Stephanie J.; Mohan, Swetha; Flibotte, Stephane; Muncaster, Quintin; Cai, Jerry; Rademakers, Suzanne; Moerman, Donald G.; Leroux, Michel R.

2016-01-01

Forward genetic screens represent powerful, unbiased approaches to uncover novel components in any biological process. Such screens suffer from a major bottleneck, however, namely the cloning of corresponding genes causing the phenotypic variation. Reverse genetic screens have been employed as a way to circumvent this issue, but can often be limited in scope. Here we demonstrate an innovative approach to gene discovery. Using C. elegans as a model system, we used a whole-genome sequenced multi-mutation library, from the Million Mutation Project, together with the Sequence Kernel Association Test (SKAT), to rapidly screen for and identify genes associated with a phenotype of interest, namely defects in dye-filling of ciliated sensory neurons. Such anomalies in dye-filling are often associated with the disruption of cilia, organelles which in humans are implicated in sensory physiology (including vision, smell and hearing), development and disease. Beyond identifying several well characterised dye-filling genes, our approach uncovered three genes not previously linked to ciliated sensory neuron development or function. From these putative novel dye-filling genes, we confirmed the involvement of BGNT-1.1 in ciliated sensory neuron function and morphogenesis. BGNT-1.1 functions at the trans-Golgi network of sheath cells (glia) to influence dye-filling and cilium length, in a cell non-autonomous manner. Notably, BGNT-1.1 is the orthologue of human B3GNT1/B4GAT1, a glycosyltransferase associated with Walker-Warburg syndrome (WWS). WWS is a multigenic disorder characterised by muscular dystrophy as well as brain and eye anomalies. Together, our work unveils an effective and innovative approach to gene discovery, and provides the first evidence that B3GNT1-associated Walker-Warburg syndrome may be considered a ciliopathy. PMID:27508411

Natural history of vasa previa across gestation using a screening protocol.

PubMed

Rebarber, Andrei; Dolin, Cara; Fox, Nathan S; Klauser, Chad K; Saltzman, Daniel H; Roman, Ashley S

2014-01-01

The purpose of this study was to estimate the prevalence and persistence rate of vasa previa in at-risk pregnancies using a standardized screening protocol. We conducted a descriptive study of patients with a diagnosis of vasa previa from a single ultrasound unit between June 2005 and June 2012. Vasa previa was defined as a fetal vessel within 2 cm of the internal cervical os on transvaginal sonography. Screening for vasa previa using transvaginal sonography with color flow mapping was performed routinely in the following situations: resolved placenta previa, prior pregnancy with vasa previa, velamentous insertion of the cord in the lower uterine segment, placenta succenturiata in the lower uterine segment, and twin gestations. A total of 27,573 patients were referred to our unit for fetal anatomic surveys over the study period. Thirty-one cases of vasa previa were identified, for an incidence of 1.1 per 1000 pregnancies. Twenty-nine cases had full records available for analysis. Five patients (17.2%) had migration and resolution of the vasa previa. When the diagnosis was made during the second trimester (<26 weeks), there was a 23.8% resolution rate (5 of 21); when the diagnosis was made in the third trimester, none resolved (0 of 8 cases). Of the 24 pregnancies (5 twin gestations and 19 singleton gestations) with persistent vasa previa, there was 100% perinatal survival and a median length of gestation of 35 weeks (range, 27 weeks 5 days-36 weeks 5 days). No known missed cases were identified over the study period. The use of standardized screening for vasa previa based on focused criteria was found to be effective in diagnosing vasa previa, with a 100% survival rate. Vasa previa diagnosed during the second trimester resolves in approximately 25% of cases.

Computer-automated dementia screening using a touch-tone telephone.

PubMed

Mundt, J C; Ferber, K L; Rizzo, M; Greist, J H

2001-11-12

This study investigated the sensitivity and specificity of a computer-automated telephone system to evaluate cognitive impairment in elderly callers to identify signs of early dementia. The Clinical Dementia Rating Scale was used to assess 155 subjects aged 56 to 93 years (n = 74, 27, 42, and 12, with a Clinical Dementia Rating Scale score of 0, 0.5, 1, and 2, respectively). These subjects performed a battery of tests administered by an interactive voice response system using standard Touch-Tone telephones. Seventy-four collateral informants also completed an interactive voice response version of the Symptoms of Dementia Screener. Sixteen cognitively impaired subjects were unable to complete the telephone call. Performances on 6 of 8 tasks were significantly influenced by Clinical Dementia Rating Scale status. The mean (SD) call length was 12 minutes 27 seconds (2 minutes 32 seconds). A subsample (n = 116) was analyzed using machine-learning methods, producing a scoring algorithm that combined performances across 4 tasks. Results indicated a potential sensitivity of 82.0% and specificity of 85.5%. The scoring model generalized to a validation subsample (n = 39), producing 85.0% sensitivity and 78.9% specificity. The kappa agreement between predicted and actual group membership was 0.64 (P<.001). Of the 16 subjects unable to complete the call, 11 provided sufficient information to permit us to classify them as impaired. Standard scoring of the interactive voice response-administered Symptoms of Dementia Screener (completed by informants) produced a screening sensitivity of 63.5% and 100% specificity. A lower criterion found a 90.4% sensitivity, without lowering specificity. Computer-automated telephone screening for early dementia using either informant or direct assessment is feasible. Such systems could provide wide-scale, cost-effective screening, education, and referral services to patients and caregivers.

Correlates of video game screen time among males: body mass, physical activity, and other media use.

PubMed

Ballard, Mary; Gray, Melissa; Reilly, Jenny; Noggle, Matthew

2009-08-01

This study examined the correlations between media use, body mass variables, and physical activity among 116 male undergraduates (white n=106; African American n=5, Latin American n=1, Asian American n=2, and 2 others). Length of video game play during one sitting was positively related to body mass index (BMI; r=.27, p<.01) and negatively correlated with frequency of exercise (r=-.21, p<.05) and days of walking (r=-.22, p<.05). Frequency of video game play was negatively correlated with length of exercising (r=-.21, p<.05). Years of video game play was negatively correlated with length of exercise (r=-.21, p<.05). These results were stronger among those who play online games. Hierarchical regression analyses indicated that video game use predicted BMI, accounting for 6.9% of the variance. The implications of the results are discussed.

A systematic review of evidence on the links between patient experience and clinical safety and effectiveness

PubMed Central

Doyle, Cathal; Lennox, Laura; Bell, Derek

2013-01-01

Objective To explore evidence on the links between patient experience and clinical safety and effectiveness outcomes. Design Systematic review. Setting A wide range of settings within primary and secondary care including hospitals and primary care centres. Participants A wide range of demographic groups and age groups. Primary and secondary outcome measures A broad range of patient safety and clinical effectiveness outcomes including mortality, physical symptoms, length of stay and adherence to treatment. Results This study, summarising evidence from 55 studies, indicates consistent positive associations between patient experience, patient safety and clinical effectiveness for a wide range of disease areas, settings, outcome measures and study designs. It demonstrates positive associations between patient experience and self-rated and objectively measured health outcomes; adherence to recommended clinical practice and medication; preventive care (such as health-promoting behaviour, use of screening services and immunisation); and resource use (such as hospitalisation, length of stay and primary-care visits). There is some evidence of positive associations between patient experience and measures of the technical quality of care and adverse events. Overall, it was more common to find positive associations between patient experience and patient safety and clinical effectiveness than no associations. Conclusions The data presented display that patient experience is positively associated with clinical effectiveness and patient safety, and support the case for the inclusion of patient experience as one of the central pillars of quality in healthcare. It supports the argument that the three dimensions of quality should be looked at as a group and not in isolation. Clinicians should resist sidelining patient experience as too subjective or mood-oriented, divorced from the ‘real’ clinical work of measuring safety and effectiveness. PMID:23293244

Impact of nutrition support on clinical outcome and cost-effectiveness analysis in patients at nutritional risk: A prospective cohort study with propensity score matching.

PubMed

Zhang, Hui; Wang, Yang; Jiang, Zhu-Ming; Kondrup, Jens; Fang, Hai; Andrews, Martha; Nolan, Marie T; Mu, Shao-Yu; Zhang, Jun; Yu, Kang; Lu, Qian; Kang, Wei-Ming

2017-05-01

There is a lack of evidence regarding the economic effects of nutrition support in patients at nutritional risk. The aim of this study was to perform a cost-effectiveness analysis by comparing an adequate nutrition support cohort with a no-support cohort. A prospective observational study was performed in the surgical and medical gastroenterology wards. We identified patients at nutritional risk and the provision of nutrition support by the staff, unaware of the risk status, was recorded. Cost data were obtained from each patient's statement of accounts, and effectiveness was measured by the rate of infectious complication. To control for potential confounding variables, the propensity score method with matching was carried out. The incremental cost-effectiveness ratio was calculated based on the matched population. We screened 3791 patients, and 440 were recruited for the analysis. Patients in the nutrition support cohort had a lower incidence of infectious complications than those in the no-support cohort (9.1 versus 18.1%; P = 0.007). This result was similar in the 149 propensity matched pairs (9.4 versus 24.2%; P < 0.001). The median hospital length of stay was significantly reduced among the matched nutrition support patients (13 versus 15 d; P < 0.001). The total costs were similar among the matched pairs (US $6219 versus $6161). The incremental cost-effectiveness analysis suggested that nutrition support cost US $392 per patient prevented from having infectious complications. Nutrition support was associated with fewer infectious complications and shorter length of stay in patients at nutritional risk. The incremental cost-effectiveness ratio indicated that nutrition support had not increased costs significantly. Copyright © 2016 Elsevier Inc. All rights reserved.

Evaluation of Cloud and Aerosol Screening of Early Orbiting Carbon Observatory-2 (OCO-2) Observations with Collocated MODIS Cloud Mask

NASA Astrophysics Data System (ADS)

Nelson, R. R.; Taylor, T.; O'Dell, C.; Cronk, H. Q.; Partain, P.; Frankenberg, C.; Eldering, A.; Crisp, D.; Gunson, M. R.; Chang, A.; Fisher, B.; Osterman, G. B.; Pollock, H. R.; Savtchenko, A.; Rosenthal, E. J.

2015-12-01

Effective cloud and aerosol screening is critically important to the Orbiting Carbon Observatory-2 (OCO-2), which can accurately determine column averaged dry air mole fraction of carbon dioxide (XCO2) only when scenes are sufficiently clear of scattering material. It is crucial to avoid sampling biases, in order to maintain a globally unbiased XCO2 record for inversion modeling to determine sources and sinks of carbon dioxide. This work presents analysis from the current operational B7 data set, which is identifying as clear approximately 20% of the order one million daily soundings. Of those soundings that are passed to the L2 retrieval algorithm, we find that almost 80% are yielding XCO2 estimates that converge. Two primary preprocessor algorithms are used to cloud screen the OCO-2 soundings. The A-Band Preprocessor (ABP) uses measurements in the Oxygen-A band near 0.76 microns (mm) to determine scenes with large photon path length modifications due to scattering by aerosol and clouds. The Iterative Maximum A-Posteriori (IMAP) Differential Optical Absorption Spectroscopy (DOAS) algorithm (IDP) computes ratios of retrieved CO2 (and H2O) in the 1.6mm (weak CO2) and 2.0mm (strong CO2) spectral bands to determine scenes with spectral differences, indicating contamination by scattering materials. We demonstrate that applying these two algorithms in tandem provides robust cloud screening of the OCO-2 data set. We compare the OCO-2 cloud screening results to collocated Moderate Resolution Imaging Spectroradiometer (MODIS) cloud mask data and show that agreement between the two sensors is approximately 85-90%. A detailed statistical analysis is performed on a winter and spring 16-day repeat cycle for the nadir-land, glint-land and glint-water viewing geometries. No strong seasonal, spatial or footprint dependencies are found, although the agreement tends to be worse at high solar zenith angles and for snow and ice covered surfaces.

Effect of screens in wide-angle diffusers

NASA Technical Reports Server (NTRS)

Schubauer, G B; Spangenberg, W G

1949-01-01

An experimental investigation at low airspeeds was made of the filling effect observed when a screen or similar resistance is placed across a diffuser. The filling effect is found to be real in that screens can prevent separation or restore separated flow in diffusers even of extreme divergence and to depend principally on screen location and pressure-drop coefficient of the screen. Results are given for three different diffusers of circular cross section with a variety of screen arrangements. Effects of single screens and multiple screens are shown. The mechanics of the filling effect is explained, and possible efficiencies are discussed. Results of arrangements of multiple screens in wide-angle diffusers are given to show a possible application to damping screens as used in wind tunnels to reduce turbulence. (author)

Structure of flexible and semiflexible polyelectrolyte chains in confined spaces of slit micro/nanochannels.

PubMed

Jeon, Jonggu; Chun, Myung-Suk

2007-04-21

Understanding the behavior of a polyelectrolyte in confined spaces has direct relevance in design and manipulation of microfluidic devices, as well as transport in living organisms. In this paper, a coarse-grained model of anionic semiflexible polyelectrolyte is applied, and its structure and dynamics are fully examined with Brownian dynamics (BD) simulations both in bulk solution and under confinement between two negatively charged parallel plates. The modeling is based on the nonlinear bead-spring discretization of a continuous chain with additional long-range electrostatic, Lennard-Jones, and hydrodynamic interactions between pairs of beads. The authors also consider the steric and electrostatic interactions between the bead and the confining wall. Relevant model parameters are determined from experimental rheology data on the anionic polysaccharide xanthan reported previously. For comparison, both flexible and semiflexible models are developed accompanying zero and finite intrinsic persistence lengths, respectively. The conformational changes of the polyelectrolyte chain induced by confinements and their dependence on the screening effect of the electrolyte solution are faithfully characterized with BD simulations. Depending on the intrinsic rigidity and the medium ionic strength, the polyelectrolyte can be classified as flexible, semiflexible, or rigid. Confined flexible and semiflexible chains exhibit a nonmonotonic variation in size, as measured by the radius of gyration and end-to-end distance, with changing slit width. For the semiflexible chain, this is coupled to the variations in long-range bond vector correlation. The rigid chain, realized at low ionic strength, does not have minima in size but exhibits a sigmoidal transition. The size of confined semiflexible and rigid polyelectrolytes can be well described by the wormlike chain model once the electrostatic effects are taken into account by the persistence length measured at long length scale.

Effect of hyperconcavity of the lumbar vertebral endplates on the playing careers of professional american football linemen.

PubMed

Paxton, E Scott; Moorman, Claude T; Chehab, Eric L; Barnes, Ronnie P; Warren, Russell F; Brophy, Robert H

2010-11-01

Hyperconcavity of the lumbar spine has been found in a disproportionate percentage of college football lineman evaluated at the National Football League (NFL) Combine compared with age-matched controls. College football linemen with hyperconcavity of the lumbar spine are more likely to play in the NFL and to have a longer career in professional football. Cohort study; Level of evidence, 3. Ninety three linemen from the 1992 and 1993 NFL Combines with hyperconcavity of the lumbar spine were compared with 191 linemen from the same combines without these changes in the lumbar spine. The percentage of athletes who played at least 1 game for an NFL team and the average length of career was calculated for both groups. In addition, the length of career for players with these changes was compared with those of matched controls based on other injuries and surgeries, year drafted, and round drafted. There was no difference in the likelihood of playing professional football between linemen with lumbar spine changes (54 of 93 [58%]) and those without (101 of 191 [53%]) (P = .41). There was no significant difference between the 2 groups in length of career in terms of years played, games played, or games started. Hyperconcavity of the lumbar spine does not appear to have any effect on the potential professional American football careers of college football linemen entering the NFL. Endplate changes on radiographs are not a significant screening tool for elite American football linemen. Further study of larger populations is needed to definitively answer whether these adaptive changes in the lumbar spine have any clinical relevance to these athletes.

Microplate-based method to screen inhibitors of isozymes of cyclic nucleotide phosphodiesterase fused to SUMO.

PubMed

Chen, Chunyan; Liu, Miaomiao; Wu, Jing; Yang, Xiaolan; Hu, Xiaolei; Pu, Jun; Long, Gaobo; Xie, Yanling; Jiang, Hairong; Yuan, Yonghua; Liao, Fei

2014-12-01

The feasibility for microplate-based screening of inhibitors of isozymes of cyclic nucleotide phosphodiesterase (PDE) was tested via the coupled action of a phosphatase on adenosine-5'-monophosphate and an improved malachite green assay of phosphate. Human full-length PDE4B2 and truncated mutant (152-528aa) were expressed in Escherichia coli via fusion to SUMO, which after purification through Ni-NTA column exhibited specific activities >0.017 U mg(-1). In the presence of proteins <30 mg L(-1), absorbance for 10 µΜ phosphate was measurable; a PDE isozyme of specific activity over 0.008 U mg(-1) after reaction for 20 min thus suited for microplate-based screening of inhibitors. By using Biotek ELX 800 microplate reader, affinities of two forms of PEDE4B2 for cAMP, rolipram and papaverine varied over three magnitudes and were consistent with those by routine assay, respectively. Hence, the proposed method was promising for high-throughput-screening of inhibitors of phosphate-releasing enzymes bearing specific activities over 0.008 U mg(-1).

A Proposed Method to Predict Preterm Birth Using Clinical Data, Standard Maternal Serum Screening, and Cholesterol

PubMed Central

ALLEMAN, Brandon W.; SMITH, Amanda R.; BYERS, Heather M.; BEDELL, Bruce; RYCKMAN, Kelli K.; MURRAY, Jeffrey C.; BOROWSKI, Kristi S.

2013-01-01

Objective To create a predictive model for preterm birth (PTB) from available clinical data and serum analytes. Study Design Serum analytes, routine pregnancy screening plus cholesterol and corresponding health information were linked to birth certificate data for a cohort of 2699 Iowa women with serum sampled in the first and second trimester. Stepwise logistic regression was used to select the best predictive model for PTB. Results Serum screening markers remained significant predictors of PTB even after controlling for maternal characteristics. The best predictive model included maternal characteristics, first trimester total cholesterol (TC), TC change between trimesters and second trimester alpha-fetoprotein and inhibin A. The model showed better discriminatory ability than PTB history alone and performed similarly in subgroups of women without past PTB. Conclusions Using clinical and serum screening data a potentially useful predictor of PTB was constructed. Validation and replication in other populations, and incorporation of other measures that identify PTB risk, like cervical length, can be a step towards identifying additional women who may benefit from new or currently available interventions. PMID:23500456

Design of a high temperature subsurface thermal energy storage system

NASA Astrophysics Data System (ADS)

Zheng, Qi

Solar thermal energy is taking up increasing proportions of future power generation worldwide. Thermal energy storage technology is a key method for compensating for the inherent intermittency of solar resources and solving the time mismatch between solar energy supply and electricity demand. However, there is currently no cost-effective high-capacity compact storage technology available (Bakker et al., 2008). The goal of this work is to propose a high temperature subsurface thermal energy storage (HSTES) technology and demonstrate its potential energy storage capability by developing a solar-HSTES-electricity generation system. In this work, main elements of the proposed system and their related state-of-art technologies are reviewed. A conceptual model is built to illustrate the concept, design, operating procedure and application of such a system. A numerical base model is built within the TOUGH2-EOS1 multiphase flow simulator for the evaluation of system performance. Additional models are constructed and simulations are done to identify the effect of different operational and geological influential factors on the system performance. Our work shows that when the base model is run with ten years operation of alternate injection and production processes - each for a month - with a thermal power input of 10.85 MW, about 83% of the injected thermal energy could be recovered within each working cycle from a stabilized HSTES system. After the final conversion into electrical energy, a relative (compared with the direct use of hot water) electricity generation efficiency of 73% is obtained. In a typical daily storage scenario, the simulated thermal storage efficiency could exceed 78% and the relative electricity generation efficiency is over 66% in the long run. In a seasonal storage scenario, these two efficiencies reach 69% and 53% respectively by the end of the simulation period of 10 years. Additional simulations reveal a thinner storage aquifer with a higher horizontal-to-vertical permeability ratio is favored by the storage system. A basin-shape reservoir is more favored than a flat reservoir, while a flat reservoir is better than a dome-shape reservoir. The effect of aquifer stratification is variable: it depends on the relative position of the well screen and the impermeable lenses within the reservoir. From the operational aspect, the well screen position is crucial and properly shortening the screen length can help heat recovery. The proportion of the injection/storage/recovery processes within a cycle, rather than their exact lengths, affects the storage efficiency. Reservoir preheating helps improve the energy storage efficiency for the first several cycles. However, it does not contribute much to the system performance in the long run. Simulations also indicate that buoyancy effect is of significant importance in heat distribution and the plume migration. Reducing the gravity override effect of the heat plume could be an important consideration in efficiency optimization.

Specific detection of biomolecules in physiological solutions using graphene transistor biosensors

PubMed Central

Gao, Ning; Gao, Teng; Yang, Xiao; Dai, Xiaochuan; Zhou, Wei; Zhang, Anqi; Lieber, Charles M.

2016-01-01

Nanomaterial-based field-effect transistor (FET) sensors are capable of label-free real-time chemical and biological detection with high sensitivity and spatial resolution, although direct measurements in high–ionic-strength physiological solutions remain challenging due to the Debye screening effect. Recently, we demonstrated a general strategy to overcome this challenge by incorporating a biomolecule-permeable polymer layer on the surface of silicon nanowire FET sensors. The permeable polymer layer can increase the effective screening length immediately adjacent to the device surface and thereby enable real-time detection of biomolecules in high–ionic-strength solutions. Here, we describe studies demonstrating both the generality of this concept and application to specific protein detection using graphene FET sensors. Concentration-dependent measurements made with polyethylene glycol (PEG)-modified graphene devices exhibited real-time reversible detection of prostate specific antigen (PSA) from 1 to 1,000 nM in 100 mM phosphate buffer. In addition, comodification of graphene devices with PEG and DNA aptamers yielded specific irreversible binding and detection of PSA in pH 7.4 1x PBS solutions, whereas control experiments with proteins that do not bind to the aptamer showed smaller reversible signals. In addition, the active aptamer receptor of the modified graphene devices could be regenerated to yield multiuse selective PSA sensing under physiological conditions. The current work presents an important concept toward the application of nanomaterial-based FET sensors for biochemical sensing in physiological environments and thus could lead to powerful tools for basic research and healthcare. PMID:27930344

Specific detection of biomolecules in physiological solutions using graphene transistor biosensors.

PubMed

Gao, Ning; Gao, Teng; Yang, Xiao; Dai, Xiaochuan; Zhou, Wei; Zhang, Anqi; Lieber, Charles M

2016-12-20

Nanomaterial-based field-effect transistor (FET) sensors are capable of label-free real-time chemical and biological detection with high sensitivity and spatial resolution, although direct measurements in high-ionic-strength physiological solutions remain challenging due to the Debye screening effect. Recently, we demonstrated a general strategy to overcome this challenge by incorporating a biomolecule-permeable polymer layer on the surface of silicon nanowire FET sensors. The permeable polymer layer can increase the effective screening length immediately adjacent to the device surface and thereby enable real-time detection of biomolecules in high-ionic-strength solutions. Here, we describe studies demonstrating both the generality of this concept and application to specific protein detection using graphene FET sensors. Concentration-dependent measurements made with polyethylene glycol (PEG)-modified graphene devices exhibited real-time reversible detection of prostate specific antigen (PSA) from 1 to 1,000 nM in 100 mM phosphate buffer. In addition, comodification of graphene devices with PEG and DNA aptamers yielded specific irreversible binding and detection of PSA in pH 7.4 1x PBS solutions, whereas control experiments with proteins that do not bind to the aptamer showed smaller reversible signals. In addition, the active aptamer receptor of the modified graphene devices could be regenerated to yield multiuse selective PSA sensing under physiological conditions. The current work presents an important concept toward the application of nanomaterial-based FET sensors for biochemical sensing in physiological environments and thus could lead to powerful tools for basic research and healthcare.

An Evaluation of the Bouwer and Rice Method of Slug Test Analysis

NASA Astrophysics Data System (ADS)

Brown, David L.; Narasimhan, T. N.; Demir, Z.

1995-05-01

The method of Bouwer and Rice (1976) for analyzing slug test data is widely used to estimate hydraulic conductivity (K). Based on steady state flow assumptions, this method is specifically intended to be applicable to unconfined aquifers. Therefore it is of practical value to investigate the limits of accuracy of the K estimates obtained with this method. Accordingly, using a numerical model for transient flow, we evaluate the method from two perspectives. First, we apply the method to synthetic slug test data and study the error in estimated values of K. Second, we analyze the logical basis of the method. Parametric studies helped assess the role of the effective radius parameter, specific storage, screen length, and well radius on the estimated values of K. The difference between unconfined and confined systems was studied via conditions on the upper boundary of the flow domain. For the cases studied, the Bouwer and Rice analysis was found to give good estimates of K, with errors ranging from 10% to 100%. We found that the estimates of K were consistently superior to those obtained with Hvorslev's (1951) basic time lag method. In general, the Bouwer and Rice method tends to underestimate K, the greatest errors occurring in the presence of a damaged zone around the well or when the top of the screen is close to the water table. When the top of the screen is far removed from the upper boundary of the system, no difference is manifest between confined and unconfined conditions. It is reasonable to infer from the simulated results that when the screen is close to the upper boundary, the results of the Bouwer and Rice method agree more closely with a "confined" idealization than an "unconfined" idealization. In effect, this method treats the aquifer system as an equivalent radial flow permeameter with an effective radius, Re, which is a function of the flow geometry. Our transient simulations suggest that Re varies with time and specific storage. Thus the effective radius may be reasonably viewed as a time-averaged mean value. The fact that the method provides reasonable estimates of hydraulic conductivity suggests that the empirical, electric analog experiments of Bouwer and Rice have yielded shape factors that are better than the shape factors implicit in the Hvorslev method.

Cost-Effectiveness Analysis of Screening for and Managing Identified Hypertension for Cardiovascular Disease Prevention in Vietnam

PubMed Central

Nguyen, Thi-Phuong-Lan; Wright, E. Pamela; Nguyen, Thanh-Trung; Schuiling-Veninga, C. C. M.; Bijlsma, M. J.; Nguyen, Thi-Bach-Yen; Postma, M. J.

2016-01-01

Objective To inform development of guidelines for hypertension management in Vietnam, we evaluated the cost-effectiveness of different strategies on screening for hypertension in preventing cardiovascular disease (CVD). Methods A decision tree was combined with a Markov model to measure incremental cost-effectiveness of different approaches to hypertension screening. Values used as input parameters for the model were taken from different sources. Various screening intervals (one-off, annually, biannually) and starting ages to screen (35, 45 or 55 years) and coverage of treatment were analysed. We ran both a ten-year and a lifetime horizon. Input parameters for the models were extracted from local and regional data. Probabilistic sensitivity analysis was used to evaluate parameter uncertainty. A threshold of three times GDP per capita was applied. Results Cost per quality adjusted life year (QALY) gained varied in different screening scenarios. In a ten-year horizon, the cost-effectiveness of screening for hypertension ranged from cost saving to Int$ 758,695 per QALY gained. For screening of men starting at 55 years, all screening scenarios gave a high probability of being cost-effective. For screening of females starting at 55 years, the probability of favourable cost-effectiveness was 90% with one-off screening. In a lifetime horizon, cost per QALY gained was lower than the threshold of Int$ 15,883 in all screening scenarios among males. Similar results were found in females when starting screening at 55 years. Starting screening in females at 45 years had a high probability of being cost-effective if screening biannually was combined with increasing coverage of treatment by 20% or even if sole biannual screening was considered. Conclusion From a health economic perspective, integrating screening for hypertension into routine medical examination and related coverage by health insurance could be recommended. Screening for hypertension has a high probability of being cost-effective in preventing CVD. An adequate screening strategy can best be selected based on age, sex and screening interval. PMID:27192051

Transactivation Assays that Identify Indirect and Direct Activators of Human Pregnane X Receptor (PXR, NR1I2) and Constitutive Androstane Receptor (CAR, NR1I3).

PubMed

Pinne, Marija; Ponce, Elsa; Raucy, Judy L

2017-01-01

Nuclear Receptors (NRs), including PXR and CAR, are presumed to be ligand-dependent transcription factors, but ligand binding is not an absolute requirement for activation. Indeed, many compounds activate PXR and CAR by indirect mechanisms. Detecting these indirect activators of specific nuclear receptors in vitro has been difficult. As NR activation of either or both PXR and CAR can lead to drug-drug interactions and adverse drug effects, false negatives obtained with screening tools incapable of detecting indirect activators could present liabilities. The aim of this study was to establish assays that identify indirect activators of human PXR and CAR. Commercially available human PXR and CAR transactivation assays were used for analyses. We show that transactivation assays containing full-length nuclear receptors with native promoters can identify indirect activators of human CAR and PXRwhen compared to those of commercially available assays containing only the LBD of PXR and CAR. Of these two assay systems, only human PXR and CAR1 assays with full-length receptors and native promoters are capable of detecting indirect and ligand activators. With this capability, several kinase inhibitors were identified that activate PXR and CAR by indirect mechanisms. Furthermore by using both the LBD and full-length receptors, phenobarbital and midostaurin were found to be direct and indirect activators of PXR while human CAR activation by phenobarbital occurs by indirect mechanisms only. Cell based transactivation assays employing the full-length receptors and native promoters identify both direct and indirect activators of either or both human PXR and CAR. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

The Potential Cost-Effectiveness of Amblyopia Screening Programs

PubMed Central

Rein, David B.; Wittenborn, John S.; Zhang, Xinzhi; Song, Michael; Saaddine, Jinan B.

2013-01-01

Background To estimate the incremental cost-effectiveness of amblyopia screening at preschool and kindergarten, we compared the costs and benefits of 3 amblyopia screening scenarios to no screening and to each other: (1) acuity/stereopsis (A/S) screening at kindergarten, (2) A/S screening at preschool and kindergarten, and (3) photoscreening at preschool and A/S screening at kindergarten. Methods We programmed a probabilistic microsimulation model of amblyopia natural history and response to treatment with screening costs and outcomes estimated from 2 state programs. We calculated the probability that no screening and each of the 3 interventions were most cost-effective per incremental quality-adjusted life year (QALY) gained and case avoided. Results Assuming a minimal 0.01 utility loss from monocular vision loss, no screening was most cost-effective with a willingness to pay (WTP) of less than $16,000 per QALY gained. A/S screening at kindergarten alone was most cost-effective between a WTP of $17,000 and $21,000. A/S screening at preschool and kindergarten was most cost-effective between a WTP of $22,000 and $75,000, and photoscreening at preschool and A/S screening at kindergarten was most cost-effective at a WTP greater than $75,000. Cost-effectiveness substantially improved when assuming a greater utility loss. All scenarios were cost-effective when assuming a WTP of $10,500 per case of amblyopia cured. Conclusions All 3 screening interventions evaluated are likely to be considered cost-effective relative to many other potential public health programs. The choice of screening option depends on budgetary resources and the value placed on monocular vision loss prevention by funding agencies. PMID:21877675

Resolution effects in the hybrid strong/weak coupling model

NASA Astrophysics Data System (ADS)

Hulcher, Zachary; Pablos, Daniel; Rajagopal, Krishna

2018-03-01

Within the context of a hybrid strong/weak coupling model of jet quenching, we study the consequences of the fact that the plasma produced in a heavy ion collision cannot resolve the substructure of a collimated parton shower propagating through it with arbitrarily fine spatial resolution. We introduce a screening length parameter, L res, proportional to the inverse of the local temperature in the plasma, estimating a range for the value of the proportionality constant via comparing weakly coupled QCD calculations and holographic calculations appropriate in strongly coupled plasma. We then modify the hybrid model so that when a parton in a jet shower splits, its two offspring are initially treated as unresolved, and are only treated as two separate partons losing energy independently after they are separated by a distance L res. This modification delays the quenching of partons with intermediate energy, resulting in the survival of more hadrons in the final state with p T in the several GeV range. We analyze the consequences of different choices for the value of the resolution length, L res, and demonstrate that introducing a nonzero L res results in modifications to the jet shapes and jet fragmentations functions, as it makes it more probable for particles carrying a small fraction of the jet energy at larger angles from the jet axis to survive their passage through the quark-gluon plasma. These effects are, however, small in magnitude, something that we confirm via checking for effects on missing- p T observables.

Contingent use of fetal fibronectin testing and cervical length measurement in women with preterm labour.

PubMed

Audibert, François; Fortin, Suzanne; Delvin, Edgard; Djemli, Anissa; Brunet, Suzanne; Dubé, Johanne; Fraser, William D

2010-04-01

To evaluate the contingent use of fetal fibronectin (fFN) testing and cervical length (CL) measurement to predict preterm delivery, and to validate the use of phosphorylated IGFBP-1 as a predictor of preterm delivery. We recruited 71 women with a clinical diagnosis of preterm labour between 24 and 34 weeks, and tested for the presence of fFN and IGFBP-1 in the cervicovaginal secretions of all women immediately before CL measurement. Among the 66 women with complete outcome, four were excluded from the final analysis as two had assessment for fFN but no CL measurement, and another two had CL measured but no screening for fFN. Among 62 women with complete results, the mean gestational age at recruitment was 29.4 +/- 2.5 weeks. Six women (9.6%) delivered within two weeks of assessment, and 14 (22.5%) delivered before 34 weeks. A positive fFN test resulted in a sensitivity of 83%, a specificity of 84%, a positive predictive value of 36%, and a negative predictive value of 98% for delivery within two weeks; for CL < 25 mm, these figures were 50%, 52%, 10%, and 91%, respectively, and for a positive IGFBP-1, they were 17%, 93%, 20%, and 91%, respectively. A policy of contingent use of fFN (in which the test was assumed to be positive if CL < or = 15 mm, and fFN was only measured if the CL was between 16 and 30 mm) gave sensitivity, specificity, positive and negative predictive values of 80%, 61%, 17%, and 97%, respectively for delivery within two weeks. Using this contingent use protocol, only one third of women needed fFN screening after CL measurement. In this study, IGFBP-1 screening did not predict preterm delivery and fFN screening provided the best predictive capacity. A policy of contingent use of testing for fFN after CL measurement, or contingent use of CL measurement after fFN screening (depending on available resources) is a promising approach to limit use of resources.

Evaluating linear response in active systems with no perturbing field: Application to the calculation of an effective temperature

NASA Astrophysics Data System (ADS)

Szamel, Grzegorz

We present a method for the evaluation of time-dependent linear response functions for systems of active particles propelled by a persistent (colored) noise from unperturbed simulations. The method is inspired by the Malliavin weights sampling method proposed earlier for systems of (passive) Brownian particles. We illustrate our method by evaluating a linear response function for a single active particle in an external harmonic potential. As an application, we calculate the time-dependent mobility function and an effective temperature, defined through the Einstein relation between the self-diffusion and mobility coefficients, for a system of active particles interacting via a screened-Coulomb potential. We find that this effective temperature decreases with increasing persistence time of the self-propulsion. Initially, for not too large persistence times, it changes rather slowly, but then it decreases markedly when the persistence length of the self-propelled motion becomes comparable with the particle size. Supported by NSF and ERC.

Beyond the Debye length in high ionic strength solution: direct protein detection with field-effect transistors (FETs) in human serum.

PubMed

Chu, Chia-Ho; Sarangadharan, Indu; Regmi, Abiral; Chen, Yen-Wen; Hsu, Chen-Pin; Chang, Wen-Hsin; Lee, Geng-Yen; Chyi, Jen-Inn; Chen, Chih-Chen; Shiesh, Shu-Chu; Lee, Gwo-Bin; Wang, Yu-Lin

2017-07-12

In this study, a new type of field-effect transistor (FET)-based biosensor is demonstrated to be able to overcome the problem of severe charge-screening effect caused by high ionic strength in solution and detect proteins in physiological environment. Antibody or aptamer-immobilized AlGaN/GaN high electron mobility transistors (HEMTs) are used to directly detect proteins, including HIV-1 RT, CEA, NT-proBNP and CRP, in 1X PBS (with 1%BSA) or human sera. The samples do not need any dilution or washing process to reduce the ionic strength. The sensor shows high sensitivity and the detection takes only 5 minutes. The designs of the sensor, the methodology of the measurement, and the working mechanism of the sensor are discussed and investigated. A theoretical model is proposed based on the finding of the experiments. This sensor is promising for point-of-care, home healthcare, and mobile diagnostic device.

Performance and Design Considerations of a Novel Dual-Material Gate Carbon Nanotube Field-Effect Transistors: Nonequilibrium Green's Function Approach

NASA Astrophysics Data System (ADS)

Arefinia, Zahra; Orouji, Ali A.

2009-02-01

The concept of dual-material gate (DMG) is applied to the carbon nanotube field-effect transistor (CNTFET) with doped source and drain extensions, and the features exhibited by the resulting new structure, i.e., the DMG-CNTFET structure, have been examined for the first time by developing a two-dimensional (2D) full quantum simulation. The simulations have been done by the self-consistent solution of 2D Poisson-Schrödinger equations, within the nonequilibrium Green's function (NEGF) formalism. The results show DMG-CNTFET decreases significantly leakage current and drain conductance and increases on-off current ratio and voltage gain as compared to the single material gate counterparts CNTFET. It is seen that short channel effects in this structure are suppressed because of the perceivable step in the surface potential profile, which screens the drain potential. Moreover, these unique features can be controlled by engineering the workfunction and length of the gate metals. Therefore, this work provides an incentive for further experimental exploration.

The effect of UV-B radiation on photosynthesis and respiration of phytoplankton, benthic macroalgae and seagrasses.

PubMed

Larkum, A W; Wood, W F

1993-04-01

Several species of marine benthic algae, four species of phytoplankton and two species of seagrass have been subjected to ultraviolet B irradiation for varying lengths of time and the effects on respiration, photosynthesis and fluorescence rise kinetics studied. No effect on respiration was found. Photosynthesis was inhibited to a variable degree in all groups of plants after irradiation over periods of up to 1 h and variable fluorescence was also inhibited in a similar way. The most sensitive plants were phytoplankton and deep-water benthic algae. Intertidal benthic algae were the least sensitive to UV-B irradiation and this may be related to adaptation, through the accumulation of UV-B screening compounds, to high light/high UV-B levels. Inhibition of variable fluorescence (Fv) of the fluorescence rise curve was a fast and sensitive indicator of UV-B damage. Two plants studied, a brown alga and a seagrass, showed very poor recovery of Fv over a period of 32 h.

Cloning of TPS gene from eelgrass species Zostera marina and its functional identification by genetic transformation in rice.

PubMed

Zhao, Feng; Li, Qiuying; Weng, Manli; Wang, Xiuliang; Guo, Baotai; Wang, Li; Wang, Wei; Duan, Delin; Wang, Bin

2013-12-01

The full-length cDNA sequence (2613 bp) of the trehalose-6-phosphate synthase (TPS) gene of eelgrass Zostera marina (ZmTPS) was identified and cloned. Z. marina is a kind of seed-plant growing in sea water during its whole life history. The open reading frame (ORF) region of ZmTPS gene encodes a protein of 870 amino acid residues and a stop codon. The corresponding genomic DNA sequence is 3770 bp in length, which contains 3 exons and 2 introns. The ZmTPS gene was transformed into rice variety ZH11 via Agrobacterium-mediated transformation method. After antibiotic screening, molecular characterization, salt-tolerance and trehalose content determinations, two transgenic lines resistant to 150 mM NaCL solutions were screened. Our study results indicated that the ZmTPS gene was integrated into the genomic DNA of the two transgenic rice lines and could be expressed well. Moreover, the detection of the transformed ZmTPS gene in the progenies of the two transgenic lines was performed from T1 to T4 generations; and results suggested that the transformed ZmTPS gene can be transmitted from parent to the progeny in transgenic rice. © 2013.

Case study of landfill leachate recirculation using small-diameter vertical wells.

PubMed

Jain, Pradeep; Ko, Jae Hac; Kumar, Dinesh; Powell, Jon; Kim, Hwidong; Maldonado, Lizmarie; Townsend, Timothy; Reinhart, Debra R

2014-11-01

A case study of landfill liquids addition using small diameter (5 cm) vertical wells is reported. More than 25,000 m(3) of leachate was added via 134 vertical wells installed 3 m, 12 m, and 18 m deep over five years in a landfill in Florida, US. Liquids addition performance (flow rate per unit screen length per unit liquid head) ranged from 5.6×10(-8) to 3.6×10(-6) m(3) s(-1) per m screen length per m liquid head. The estimated radial hydraulic conductivity ranged from 3.5×10(-6) to 4.2×10(-4) m s(-1). The extent of lateral moisture movement ranged from 8 to 10 m based on the responses of moisture sensors installed around vertical well clusters, and surface seeps were found to limit the achievable liquids addition rates, despite the use of concrete collars under a pressurized liquids addition scenario. The average moisture content before (51 samples) and after (272 samples) the recirculation experiments were 23% (wet weight basis) and 45% (wet weight basis), respectively, and biochemical methane potential measurements of excavated waste indicated significant (p<0.025) decomposition. Copyright © 2014 Elsevier Ltd. All rights reserved.

Structural insights into Cydia pomonella pheromone binding protein 2 mediated prediction of potentially active semiochemicals

NASA Astrophysics Data System (ADS)

Tian, Zhen; Liu, Jiyuan; Zhang, Yalin

2016-03-01

Given the advantages of behavioral disruption application in pest control and the damage of Cydia pomonella, due progresses have not been made in searching active semiochemicals for codling moth. In this research, 31 candidate semiochemicals were ranked for their binding potential to Cydia pomonella pheromone binding protein 2 (CpomPBP2) by simulated docking, and this sorted result was confirmed by competitive binding assay. This high predicting accuracy of virtual screening led to the construction of a rapid and viable method for semiochemicals searching. By reference to binding mode analyses, hydrogen bond and hydrophobic interaction were suggested to be two key factors in determining ligand affinity, so is the length of molecule chain. So it is concluded that semiochemicals of appropriate chain length with hydroxyl group or carbonyl group at one head tended to be favored by CpomPBP2. Residues involved in binding with each ligand were pointed out as well, which were verified by computational alanine scanning mutagenesis. Progress made in the present study helps establish an efficient method for predicting potentially active compounds and prepares for the application of high-throughput virtual screening in searching semiochemicals by taking insights into binding mode analyses.

Sequences characterization of microsatellite DNA sequences in Pacific abalone ( Haliotis discus hannai)

NASA Astrophysics Data System (ADS)

Li, Qi; Akihiro, Kijima

2007-01-01

The microsatellite-enriched library was constructed using magnetic bead hybridization selection method, and the microsatellite DNA sequences were analyzed in Pacific abalone Haliotis discus hannai. Three hundred and fifty white colonies were screened using PCR-based technique, and 84 clones were identified to potentially contain microsatellite repeat motif. The 84 clones were sequenced, and 42 microsatellites and 4 minisatellites with a minimum of five repeats were found (13.1% of white colonies screened). Besides the motif of CA contained in the oligoprobe, we also found other 16 types of microsatellite repeats including a dinucleotide repeat, two tetranucleotide repeats, twelve pentanucleotide repeats and a hexanucleotide repeat. According to Weber (1990), the microsatellite sequences obtained could be categorized structurally into perfect repeats (73.3%), imperfect repeats (13.3%), and compound repeats (13.4%). Among the microsatellite repeats, relatively short arrays (<20 repeats) were most abundant, accounting for 75.0%. The largest length of microsatellites was 48 repeats, and the average number of repeats was 13.4. The data on the composition and length distribution of microsatellites obtained in the present study can be useful for choosing the repeat motifs for microsatellite isolation in other abalone species.

From The Cover: Genome-wide RNA interference screen identifies previously undescribed regulators of polyglutamine aggregation

NASA Astrophysics Data System (ADS)

Nollen, Ellen A. A.; Garcia, Susana M.; van Haaften, Gijs; Kim, Soojin; Chavez, Alejandro; Morimoto, Richard I.; Plasterk, Ronald H. A.

2004-04-01

Protein misfolding and the formation of aggregates are increasingly recognized components of the pathology of human genetic disease and hallmarks of many neurodegenerative disorders. As exemplified by polyglutamine diseases, the propensity for protein misfolding is associated with the length of polyglutamine expansions and age-dependent changes in protein-folding homeostasis, suggesting a critical role for a protein homeostatic buffer. To identify the complement of protein factors that protects cells against the formation of protein aggregates, we tested transgenic Caenorhabditis elegans strains expressing polyglutamine expansion yellow fluorescent protein fusion proteins at the threshold length associated with the age-dependent appearance of protein aggregation. We used genome-wide RNA interference to identify genes that, when suppressed, resulted in the premature appearance of protein aggregates. Our screen identified 186 genes corresponding to five principal classes of polyglutamine regulators: genes involved in RNA metabolism, protein synthesis, protein folding, and protein degradation; and those involved in protein trafficking. We propose that each of these classes represents a molecular machine collectively comprising the protein homeostatic buffer that responds to the expression of damaged proteins to prevent their misfolding and aggregation. protein misfolding | neurodegenerative diseases

Analysis of the interactions between He + ions and transition metal surfaces using co-axial impact collision ion scattering spectroscopy

NASA Astrophysics Data System (ADS)

Walker, M.; Brown, M. G.; Draxler, M.; Fishwick, L.; Dowsett, M. G.; McConville, C. F.

2011-01-01

The interactions between low energy He + ions and a series of transition metal surfaces have been studied using co-axial impact collision ion scattering spectroscopy (CAICISS). Experimental data were collected from the Ni(110), Cu(100), Pd(111), Pt(111) and Au(111) surfaces using ion beams with primary energies between 1.5 keV and 4.0 keV. The shadow cone radii deduced from the experimental surface peak positions were found to closely match theoretical predictions. Data analysis was performed using both the FAN and Kalypso simulation codes, revealing a consistent requirement for a reduction of 0.252 in the screening length correction in the Molière approximation within the Thomas-Fermi (TFM) interaction potential. The adjustments of the screening length in the TFM potential, predicted by O'Connor, and the uncorrected Ziegler-Biersack-Littmark (ZBL) potential both yielded inaccurate results for all of the surfaces and incident energies studied. We also provide evidence that, despite their different computational methodologies, the FAN and Kalypso simulation codes generate similar results given identical input parameters for the analysis of 180° backscattering spectra.

Development of allele-specific multiplex PCR to determine the length of poly-T in intron 8 of CFTR

PubMed Central

Prada, Anne E.

2014-01-01

Cystic fibrosis transmembrane conductance regulator (CFTR) gene mutation analysis has been implemented for Cystic Fibrosis (CF) carrier screening, and molecular diagnosis of CF and congenital bilateral absence of the vas deferens (CBAVD). Although poly-T allele analysis in intron 8 of CFTR is required when a patient is positive for R117H, it is not recommended for routine carrier screening. Therefore, commercial kits for CFTR mutation analysis were designed either to mask the poly-T allele results, unless a patient is R117H positive, or to have the poly-T analysis as a standalone reflex test using the same commercial platform. There are other standalone assays developed to detect poly-T alleles, such as heteroduplex analysis, High Resolution Melting (HRM) curve analysis, allele-specific PCR (AS-PCR) and Sanger sequencing. In this report, we developed a simple and easy-to-implement multiplex AS-PCR assay using unlabeled standard length primers, which can be used as a reflex or standalone test for CFTR poly-T track analysis. Out of 115 human gDNA samples tested, results from our new AS-PCR matched to the previous known poly-T results or results from Sanger sequencing. PMID:25071991

Structural insights into Cydia pomonella pheromone binding protein 2 mediated prediction of potentially active semiochemicals

PubMed Central

Tian, Zhen; Liu, Jiyuan; Zhang, Yalin

2016-01-01

Given the advantages of behavioral disruption application in pest control and the damage of Cydia pomonella, due progresses have not been made in searching active semiochemicals for codling moth. In this research, 31 candidate semiochemicals were ranked for their binding potential to Cydia pomonella pheromone binding protein 2 (CpomPBP2) by simulated docking, and this sorted result was confirmed by competitive binding assay. This high predicting accuracy of virtual screening led to the construction of a rapid and viable method for semiochemicals searching. By reference to binding mode analyses, hydrogen bond and hydrophobic interaction were suggested to be two key factors in determining ligand affinity, so is the length of molecule chain. So it is concluded that semiochemicals of appropriate chain length with hydroxyl group or carbonyl group at one head tended to be favored by CpomPBP2. Residues involved in binding with each ligand were pointed out as well, which were verified by computational alanine scanning mutagenesis. Progress made in the present study helps establish an efficient method for predicting potentially active compounds and prepares for the application of high-throughput virtual screening in searching semiochemicals by taking insights into binding mode analyses. PMID:26928635

Dynamic programming-based hot spot identification approach for pedestrian crashes.

PubMed

Medury, Aditya; Grembek, Offer

2016-08-01

Network screening techniques are widely used by state agencies to identify locations with high collision concentration, also referred to as hot spots. However, most of the research in this regard has focused on identifying highway segments that are of concern to automobile collisions. In comparison, pedestrian hot spot detection has typically focused on analyzing pedestrian crashes in specific locations, such as at/near intersections, mid-blocks, and/or other crossings, as opposed to long stretches of roadway. In this context, the efficiency of the some of the widely used network screening methods has not been tested. Hence, in order to address this issue, a dynamic programming-based hot spot identification approach is proposed which provides efficient hot spot definitions for pedestrian crashes. The proposed approach is compared with the sliding window method and an intersection buffer-based approach. The results reveal that the dynamic programming method generates more hot spots with a higher number of crashes, while providing small hot spot segment lengths. In comparison, the sliding window method is shown to suffer from shortcomings due to a first-come-first-serve approach vis-à-vis hot spot identification and a fixed hot spot window length assumption. Copyright © 2016 Elsevier Ltd. All rights reserved.

Baseline and annual repeat rounds of screening: implications for optimal regimens of screening.

PubMed

Henschke, Claudia I; Salvatore, Mary; Cham, Matthew; Powell, Charles A; DiFabrizio, Larry; Flores, Raja; Kaufman, Andrew; Eber, Corey; Yip, Rowena; Yankelevitz, David F

2018-03-01

Differences in results of baseline and subsequent annual repeat rounds provide important information for optimising the regimen of screening. A prospective cohort study of 65,374 was reviewed to examine the frequency/percentages of the largest noncalcified nodule (NCN), lung cancer cell types and Kaplan-Meier (K-M) survival rates, separately for baseline and annual rounds. Of 65,374 baseline screenings, NCNs were identified in 28,279 (43.3%); lung cancer in 737 (1.1%). Of 74,482 annual repeat screenings, new NCNs were identified in 4959 (7%); lung cancer in 179 (0.24%). Only adenocarcinoma was diagnosed in subsolid NCNs. Percentages of lung cancers by cell type were significantly different (p < 0.0001) in the baseline round compared with annual rounds, reflecting length bias, as were the ratios, reflecting lead times. Long-term K-M survival rate was 100% for typical carcinoids and for adenocarcinomas manifesting as subsolid NCNs; 85% (95% CI 81-89%) for adenocarcinoma, 74% (95% CI 63-85%) for squamous cell, 48% (95% CI 34-62%) for small cell. The rank ordering by lead time was the same as the rank ordering by survival rates. The significant differences in the frequency of NCNs and frequency and aggressiveness of diagnosed cancers in baseline and annual repeat need to be recognised for an optimal regimen of screening. • Lung cancer aggressiveness varies considerably by cell type and nodule consistency. • Kaplan-Meier survival rates varied by cell type between 100% and 48%. • The percentages of lung cancers by cell type in screening rounds reflect screening biases. • Rank ordering by cell type survival is consistent with that by lead times. • Empirical evidence provides critical information for the regimen of screening.

Searching for a two-factor model of marriage duration: commentary on Gottman and Levenson.

PubMed

DeKay, Michael L; Greeno, Catherine G; Houck, Patricia R

2002-01-01

Gottman and Levenson (2002) report a number of post hoc ordinary least squares regressions to "predict" the length of marriage, given that divorce has occurred. We argue that the type of statistical model they use is inappropriate for answering clinically relevant questions about the causes and timing of divorce, and present several reasons why an alternative family of models called duration models would be more appropriate. The distribution of marriage length is not bimodal, as Gottman and Levenson suggest, and their search for a two-factor model for explaining marriage length is misguided. Their regression models omit many variables known to affect marriage length, and instead use variables that were pre-screened for their predictive ability. Their final model is based on data for only 15 cases, including one unusual case that has undue influence on the results. For these and other technical reasons presented in the text, we believe that Gottman and Levenson's results are not replicable, and that they should not be used to guide interventions for couples in clinical settings.

Acanthocheilonema delicata n. sp. (Nematoda: Filarioidea) from Japanese badgers (Meles anakuma): description, molecular identification, and Wolbachia screening.

PubMed

Uni, Shigehiko; Bain, Odile; Suzuki, Kazuo; Agatsuma, Takeshi; Harada, Masashi; Motokawa, Masaharu; Martin, Coralie; Lefoulon, Emilie; Fukuda, Masako; Takaoka, Hiroyuki

2013-02-01

Acanthocheilonema delicata n. sp. (Filarioidea: Onchocercidae: Onchocercinae) is described based on adult filarioids and microfilariae obtained from subcutaneous connective tissues and skin, respectively, of Japanese badgers (Meles anakuma) in Wakayama Prefecture, Japan. No endemic species of the genus had been found in Japan. Recently, some filarioids (e.g., Acanthocheilonema reconditum, Dirofilaria spp., and Onchocerca spp.) have come to light as causative agents of zoonosis worldwide. The new species was readily distinguished from its congeners by morphologic characteristics such as body length, body width, esophagus length, spicule length, and the length of microfilariae. Based on the molecular data of the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene, A. delicata n. sp. was included in the clade of the genus Acanthocheilonema but differed from two other congeneric species available for study, A. viteae and A. reconditum. Acanthocheilonema delicata n. sp. did not harbor Wolbachia. It is likely that the fauna of filarioids from mammals on the Japanese islands is characterized by a high level of endemicity. Copyright © 2012 Elsevier B.V. All rights reserved.

Development of a Magnetic Microbead Affinity Selection Screen (MagMASS) Using Mass Spectrometry for Ligands to the Retinoid X Receptor-α

NASA Astrophysics Data System (ADS)

Rush, Michael D.; Walker, Elisabeth M.; Prehna, Gerd; Burton, Tristesse; van Breemen, Richard B.

2017-03-01

To overcome limiting factors in mass spectrometry-based screening methods such as automation while still facilitating the screening of complex mixtures such as botanical extracts, magnetic microbead affinity selection screening (MagMASS) was developed. The screening process involves immobilization of a target protein on a magnetic microbead using a variety of possible chemistries, incubation with mixtures of molecules containing possible ligands, a washing step that removes non-bound compounds while a magnetic field retains the beads in the microtiter well, and an organic solvent release step followed by LC-MS analysis. Using retinoid X receptor-α (RXRα) as an example, which is a nuclear receptor and target for anti-inflammation therapy as well as cancer treatment and prevention, a MagMASS assay was developed and compared with an existing screening assay, pulsed ultrafiltration (PUF)-MS. Optimization of MagMASS involved evaluation of multiple protein constructs and several magnetic bead immobilization chemistries. The full-length RXRα construct immobilized with amylose beads provided optimum results. Additional enhancements of MagMASS were the application of 96-well plates to enable automation, use of UHPLC instead of HPLC for faster MS analyses, and application of metabolomics software for faster, automated data analysis. Performance of MagMASS was demonstrated using mixtures of synthetic compounds and known ligands spiked into botanical extracts.

Interlayer tunneling in double-layer quantum hall pseudoferromagnets.

PubMed

Balents, L; Radzihovsky, L

2001-02-26

We show that the interlayer tunneling I-V in double-layer quantum Hall states displays a rich behavior which depends on the relative magnitude of sample size, voltage length scale, current screening, disorder, and thermal lengths. For weak tunneling, we predict a negative differential conductance of a power-law shape crossing over to a sharp zero-bias peak. An in-plane magnetic field splits this zero-bias peak, leading instead to a "derivative" feature at V(B)(B(parallel)) = 2 pi Planck's over 2 pi upsilon B(parallel)d/e phi(0), which gives a direct measurement of the dispersion of the Goldstone mode corresponding to the spontaneous symmetry breaking of the double-layer Hall state.

Restriction fragment length polymorphisms for growth hormone, prolactin, osteonectin, alpha crystallin, gamma crystallin, fibronectin and 21-steroid hydroxylase in cattle.

PubMed

Theilmann, J L; Skow, L C; Baker, J F; Womack, J E

1989-01-01

Genomic DNAs from animals representing six breeds of cattle (Angus, Brahman, Hereford, Holstein, Jersey and Texas Longhorn) were screened with cloned gene probes in a search for restriction fragment length polymorphisms (RFLPs). Eleven RFLPs were identified using seven different probes: growth hormone, prolactin, osteonectin, alpha A-crystallin, gamma crystallin, fibronectin and 21-steroid hydroxylase. The frequencies of the alleles identified by each probe were calculated and compared in a limited sampling of the six bovine breeds. These polymorphisms greatly enhance the pool of immunogenetic, biochemical and molecular markers available in cattle for linkage analysis, testing of parentage, and distinction of breeds.

Ionic liquids behave as dilute electrolyte solutions

PubMed Central

Gebbie, Matthew A.; Valtiner, Markus; Banquy, Xavier; Fox, Eric T.; Henderson, Wesley A.; Israelachvili, Jacob N.

2013-01-01

We combine direct surface force measurements with thermodynamic arguments to demonstrate that pure ionic liquids are expected to behave as dilute weak electrolyte solutions, with typical effective dissociated ion concentrations of less than 0.1% at room temperature. We performed equilibrium force–distance measurements across the common ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([C4mim][NTf2]) using a surface forces apparatus with in situ electrochemical control and quantitatively modeled these measurements using the van der Waals and electrostatic double-layer forces of the Derjaguin–Landau–Verwey–Overbeek theory with an additive repulsive steric (entropic) ion–surface binding force. Our results indicate that ionic liquids screen charged surfaces through the formation of both bound (Stern) and diffuse electric double layers, where the diffuse double layer is comprised of effectively dissociated ionic liquid ions. Additionally, we used the energetics of thermally dissociating ions in a dielectric medium to quantitatively predict the equilibrium for the effective dissociation reaction of [C4mim][NTf2] ions, in excellent agreement with the measured Debye length. Our results clearly demonstrate that, outside of the bound double layer, most of the ions in [C4mim][NTf2] are not effectively dissociated and thus do not contribute to electrostatic screening. We also provide a general, molecular-scale framework for designing ionic liquids with significantly increased dissociated charge densities via judiciously balancing ion pair interactions with bulk dielectric properties. Our results clear up several inconsistencies that have hampered scientific progress in this important area and guide the rational design of unique, high–free-ion density ionic liquids and ionic liquid blends. PMID:23716690

A screening-level assessment of the health risks of chronic smoke exposure for wildland firefighters.

PubMed

Booze, Thomas F; Reinhardt, Timothy E; Quiring, Sharon J; Ottmar, Roger D

2004-05-01

A screening health risk assessment was performed to assess the upper-bound risks of cancer and noncancer adverse health effects among wildland firefighters performing wildfire suppression and prescribed burn management. Of the hundreds of chemicals in wildland fire smoke, we identified 15 substances of potential concern from the standpoints of concentration and toxicology; these included aldehydes, polycyclic aromatic hydrocarbons, carbon monoxide, benzene, and respirable particulate matter. Data defining daily exposures to smoke at prescribed burns and wildfires, potential days of exposure in a year, and career lengths were used to estimate average and reasonable maximum career inhalation exposures to these substances. Of the 15 substances in smoke that were evaluated, only benzene and formaldehyde posed a cancer risk greater than 1 per million, while only acrolein and respirable particulate matter exposures resulted in hazard indices greater than 1.0. The estimated upper-bound cancer risks ranged from 1.4 to 220 excess cancers per million, and noncancer hazard indices ranged from 9 to 360, depending on the exposure group. These values only indicate the likelihood of adverse health effects, not whether they will or will not occur. The risk assessment process narrows the field of substances that deserve further assessment, and the hazards identified by risk assessment generally agree with those identified as a concern in occupational exposure assessments.

Combinatorial and high-throughput screening of the effect of siloxane composition on the surface properties of crosslinked siloxane-polyurethane coatings.

PubMed

Ekin, Abdullah; Webster, Dean C

2007-01-01

Libraries of siloxane-polyurethane coatings were designed, formulated, and screened using high-throughput experimentation. Four independent variables that were analyzed were the molecular weight of poly(dimethylsiloxane) (PDMS), presence or absence of poly(epsilon-caprolactone) (PCL) blocks attached to the PDMS backbone, the length of the PCL blocks, and the siloxane polymer level in the coating formulations. In addition to the siloxane libraries (3-aminopropyl-terminated PDMS and poly(epsilon-caprolactone)-poly(dimethylsiloxane)-poly(epsilon-caprolactone) (PCL-PDMS-PCL) triblock copolymers), the coating formulation included a trifunctional isocyanate crosslinker, trifunctional poly(epsilon-caprolactone) polyol, 2,4-pentanedione (pot-life extender), dibutyltin diacetate (catalyst), and a blend of solvents. The resulting coatings were analyzed for their surface energy and pseudobarnacle adhesion both before and after aging the coatings for 30 days in water. The water and methylene iodide contact angle averages increase with increasing molecular weight of PDMS. Coatings prepared from PCL-PDMS-PCL triblock copolymers have lower surface energies than coatings prepared from 3-aminopropyl-terminated PDMS; however, lower pseudobarnacle adhesion results were obtained for the coatings prepared from 3-aminopropyl-terminated PDMS than coatings prepared from PCL-PDMS-PCL triblock copolymers. The siloxane polymer level in the coating formulations does not have a significant effect on the surface energy of the coatings, but it resulted in higher pseudobarnacle adhesion.

What is the most cost-effective strategy to screen for left ventricular systolic dysfunction: natriuretic peptides, the electrocardiogram, hand-held echocardiography, traditional echocardiography, or their combination?

PubMed

Galasko, Gavin I W; Barnes, Sophie C; Collinson, Paul; Lahiri, Avijit; Senior, Roxy

2006-01-01

To assess the screening characteristics and cost-effectiveness of screening for left ventricular systolic dysfunction (LVSD) in community subjects. A total of 1392 members of the general public and 928 higher risk subjects were randomly selected from seven community practices. Attending subjects underwent an ECG, N-terminal pro-brain natriuretic peptide (NTproBNP) serum levels, and traditional echocardiography (TE). A total of 533 consecutive subjects underwent hand-held echocardiography (HE). The screening characteristics and cost-effectiveness (cost per case of LVSD diagnosed) of eight strategies to predict LVSD (LVSD <45% on TE) were compared. A total of 1205 subjects attended. Ninety six per cent of subjects with LVSD in the general population had identifiable risk factors. All screening strategies gave excellent negative predictive value. Screening high-risk subjects was most cost-effective, screening low-risk subjects least cost-effective. TE screening was the least cost-effective strategy. NTproBNP screening gave similar cost savings to ECG screening; HE screening greater cost-savings, and HE screening following NTproBNP or ECG pre-screening the greatest cost-savings, costing approximately 650 Euros per case of LVSD diagnosed in high-risk subjects (63% cost-savings vs.TE). Thus several different modalities allow cost-effective community-based screening for LVSD, especially in high-risk subjects. Such programmes would be cost-effective and miss few cases of LVSD in the community.

Bilateral cochlear implants in infants: a new approach--Nucleus Hybrid S12 project.

PubMed

Gantz, Bruce J; Dunn, Camille C; Walker, Elizabeth A; Kenworthy, Maura; Van Voorst, Tanya; Tomblin, Bruce; Turner, Chris

2010-10-01

The purpose of this feasibility study was to evaluate whether the use of a shorter-length cochlear implant (10 mm) on one ear and a standard electrode (24 mm) on the contralateral ear is a viable bilateral option for children with profound bilateral sensorineural hearing loss. A secondary purpose of this study was to determine whether the ear with the shorter-length electrode performs similarly to the standard-length electrode. Our goal was to provide an option of electrical stimulation that theoretically might preserve the structures of the scala media and organ of Corti. The study is being conducted as a repeated-measure, single-subject experiment. University of Iowa-Department of Otolaryngology. Eight pediatric patients with profound bilateral sensorineural hearing loss between the ages of 12 and 24 months. Nucleus Hybrid S12 10-mm electrode and a Nucleus Freedom implant in the contralateral ear. The Infant-Toddler Meaningful Auditory Integration Scale (IT-MAIS) parent questionnaire, Early Speech Perception, Glendonald Auditory Screening Procedure word test, and Children's Vowel tests will be used to evaluate speech perception and the Minnesota Child Development Inventory and Preschool Language Scales 3 test will be used to evaluate language growth. Preliminary results for 8 children have been collected before and after the operation using the IT-MAIS. All 3 children showed incremental improvements in their IT-MAIS scores overtime. Early Speech Perception, Glendonald Auditory Screening Procedure word test, and Children's Vowel word perception results indicated no difference between the individual ears for the 2 children tested. Performance compared with age-matched children implanted with standard bilateral cochlear implants showed similar results to the children implanted with Nucleus Hybrid S12 10-mm electrode and a Nucleus Freedom implant in contralateral ears. The use of a shorter-length cochlear implant on one ear and a standard-length electrode on the contralateral ear might provide a viable option for bilateral cochlear implantation in children with bilateral profound sensorineural hearing loss. Further study of this patient population will be continued.

Bilateral Cochlear Implants in Infants: A New Approach—Nucleus Hybrid S12 Project

PubMed Central

Gantz, Bruce J.; Dunn, Camille C.; Walker, Elizabeth A.; Kenworthy, Maura; Van Voorst, Tanya; Tomblin, Bruce; Turner, Chris

2010-01-01

Objective The purpose of this feasibility study was to evaluate whether the use of a shorter-length cochlear implant (10 mm) on one ear and a standard electrode (24 mm) on the contralateral ear is a viable bilateral option for children with profound bilateral sensorineural hearing loss. A secondary purpose of this study was to determine whether the ear with the shorter-length electrode performs similarly to the standard-length electrode. Our goal was to provide an option of electrical stimulation that theoretically might preserve the structures of the scala media and organ of Corti. Study Design The study is being conducted as a repeated-measure, single-subject experiment. Setting University of Iowa—Department of Otolaryngology. Patients Eight pediatric patients with profound bilateral sensorineural hearing loss between the ages of 12 and 24 months. Interventions Nucleus Hybrid S12 10-mm electrode and a Nucleus Freedom implant in the contralateral ear. Main Outcome Measures The Infant-Toddler Meaningful Auditory Integration Scale (IT-MAIS) parent questionnaire, Early Speech Perception, Glendonald Auditory Screening Procedure word test, and Children’s Vowel tests will be used to evaluate speech perception and the Minnesota Child Development Inventory and Preschool Language Scales 3 test will be used to evaluate language growth. Results Preliminary results for 8 children have been collected before and after the operation using the IT-MAIS. All 3 children showed incremental improvements in their IT-MAIS scores overtime. Early Speech Perception, Glendonald Auditory Screening Procedure word test, and Children’s Vowel word perception results indicated no difference between the individual ears for the 2 children tested. Performance compared with age-matched children implanted with standard bilateral cochlear implants showed similar results to the children implanted with Nucleus Hybrid S12 10-mm electrode and a Nucleus Freedom implant in contralateral ears. Conclusion The use of a shorter-length cochlear implant on one ear and a standard-length electrode on the contralateral ear might provide a viable option for bilateral cochlear implantation in children with bilateral profound sensorineural hearing loss. Further study of this patient population will be continued. PMID:20802369

WebPrInSeS: automated full-length clone sequence identification and verification using high-throughput sequencing data.

PubMed

Massouras, Andreas; Decouttere, Frederik; Hens, Korneel; Deplancke, Bart

2010-07-01

High-throughput sequencing (HTS) is revolutionizing our ability to obtain cheap, fast and reliable sequence information. Many experimental approaches are expected to benefit from the incorporation of such sequencing features in their pipeline. Consequently, software tools that facilitate such an incorporation should be of great interest. In this context, we developed WebPrInSeS, a web server tool allowing automated full-length clone sequence identification and verification using HTS data. WebPrInSeS encompasses two separate software applications. The first is WebPrInSeS-C which performs automated sequence verification of user-defined open-reading frame (ORF) clone libraries. The second is WebPrInSeS-E, which identifies positive hits in cDNA or ORF-based library screening experiments such as yeast one- or two-hybrid assays. Both tools perform de novo assembly using HTS data from any of the three major sequencing platforms. Thus, WebPrInSeS provides a highly integrated, cost-effective and efficient way to sequence-verify or identify clones of interest. WebPrInSeS is available at http://webprinses.epfl.ch/ and is open to all users.

WebPrInSeS: automated full-length clone sequence identification and verification using high-throughput sequencing data

PubMed Central

Massouras, Andreas; Decouttere, Frederik; Hens, Korneel; Deplancke, Bart

2010-01-01

High-throughput sequencing (HTS) is revolutionizing our ability to obtain cheap, fast and reliable sequence information. Many experimental approaches are expected to benefit from the incorporation of such sequencing features in their pipeline. Consequently, software tools that facilitate such an incorporation should be of great interest. In this context, we developed WebPrInSeS, a web server tool allowing automated full-length clone sequence identification and verification using HTS data. WebPrInSeS encompasses two separate software applications. The first is WebPrInSeS-C which performs automated sequence verification of user-defined open-reading frame (ORF) clone libraries. The second is WebPrInSeS-E, which identifies positive hits in cDNA or ORF-based library screening experiments such as yeast one- or two-hybrid assays. Both tools perform de novo assembly using HTS data from any of the three major sequencing platforms. Thus, WebPrInSeS provides a highly integrated, cost-effective and efficient way to sequence-verify or identify clones of interest. WebPrInSeS is available at http://webprinses.epfl.ch/ and is open to all users. PMID:20501601

Polymorphisms in the Myostatin-1 gene and their association with growth traits in Ancherythroculter nigrocauda

NASA Astrophysics Data System (ADS)

Sun, Yanhong; Li, Qing; Wang, Guiying; Zhu, Dongmei; Chen, Jian; Li, Pei; Tong, Jingou

2017-05-01

Myostatin ( MSTN) is a member of the transforming growth factor-β gene superfamily that negatively regulates skeletal muscle development and growth. In the present study, partial genomic fragments of Myostatin-1 ( MSTN-1) in two commercial hatchery populations of Ancherythroculter nigrocauda, an economically important freshwater fish, were screened for single nucleotide polymorphisms (SNPs) and then genotyped by direct sequencing of PCR products. Five SNPs were identified in intron 1 and exon 2, including a non-synonymous mutation causing an amino acid change (Val to Ile) at position 180. Association analyses based on 300 individuals revealed that the g.1129T>C SNP locus was significantly associated with total length (TL), body length (BL), body height (BH) and body weight (BW) in 6- and 18-month-old populations, while the g.1289G>A locus was significantly associated with BH and BW in the 6-month-old population. Haplotype analyses revealed that fish with the genotype combinations TC/TC or TC/GA showed better growth performance. Our results suggest that g.1129T>C and g.1289G>A have positive effects on growth traits and may be candidate gene markers for marker-assisted selection in A. nigrocauda.

A Novel Modified Omega-K Algorithm for Synthetic Aperture Imaging Lidar through the Atmosphere

PubMed Central

Guo, Liang; Xing, Mendao; Tang, Yu; Dan, Jing

2008-01-01

The spatial resolution of a conventional imaging lidar system is constrained by the diffraction limit of the telescope's aperture. The combination of the lidar and synthetic aperture (SA) processing techniques may overcome the diffraction limit and pave the way for a higher resolution air borne or space borne remote sensor. Regarding the lidar transmitting frequency modulation continuous-wave (FMCW) signal, the motion during the transmission of a sweep and the reception of the corresponding echo were expected to be one of the major problems. The given modified Omega-K algorithm takes the continuous motion into account, which can compensate for the Doppler shift induced by the continuous motion efficiently and azimuth ambiguity for the low pulse recurrence frequency limited by the tunable laser. And then, simulation of Phase Screen (PS) distorted by atmospheric turbulence following the von Karman spectrum by using Fourier Transform is implemented in order to simulate turbulence. Finally, the computer simulation shows the validity of the modified algorithm and if in the turbulence the synthetic aperture length does not exceed the similar coherence length of the atmosphere for SAIL, we can ignore the effect of the turbulence. PMID:27879865

Construction of recombinant FGFR1 containing full-length gene and its potential application.

PubMed

Zhou, Yali; Luo, Wenjuan; Zheng, Lei; Li, Miao; Zhang, Yanmin

2010-07-01

FGFR1, one of the four fibroblast growth factor receptors, has been found to be over-expressed in many cancers. In this study, a full-length expression plasmid for FGFR1 was obtained by fragment amplification. The amplified PCR product was then digested and inserted into the pcDNA3.1(+) vector. A recombinant eukaryotic expression vector containing the complete CDS region of FGFR1 was successfully constructed. After it was transfected to Hek293 cell, the expression of the FGFR1 receptor in recombinant Hek293/FGFR1 was 18 times higher than that of Hek293 cell. The biological activities of high expression FGFR1 cell (Hek293/FGFR1) were verified by FCM, immunofluorescent, RT-PCR, western blot and cell cycle analysis. Then, Hek293/FGFR1 was used to screen taspine with cell membrane chromatography (CMC). Finally, we analyzed the effects of taspine on Hek293/FGFR1 cell and MCF-7 cell. In conclusion, Hek293/FGFR1 was successfully constructed. The results demonstrate that taspine can down-regulate phosphorylation of FGFR1 and ERK, and inhibit Hek293/FGFR1 and MCF-7 cell proliferation. Copyright 2010 Elsevier Inc. All rights reserved.