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The discovery of the superconducting material Y1Ba2Cu3O6+δ ( “123” material) resulted in a world wide interest in the pseudo-ternary system BaO·YO·CuO. A complete study of the phases present in this system was initiated to develop a better understanding and processing of the superconducting 123 material. The crystal structures were established for two of the three ternary compounds in this system immediately after the discovery of superconductivity. One such phase was a green insulating compound Y2Ba1Cu1O5 (”211”) which has the space group. The superconducting 123 compound was found to have the space group Pmmm and an ordered triple-celled perovskite structure.
The role that vitamin D plays in pulmonary function remains uncertain. Epidemiological studies reported mixed findings for serum 25-hydroxyvitamin D (25(OH)D)–pulmonary function association. We conducted the largest cross-sectional meta-analysis of the 25(OH)D–pulmonary function association to date, based on nine European ancestry (EA) cohorts (n 22 838) and five African ancestry (AA) cohorts (n 4290) in the Cohorts for Heart and Aging Research in Genomic Epidemiology Consortium. Data were analysed using linear models by cohort and ancestry. Effect modification by smoking status (current/former/never) was tested. Results were combined using fixed-effects meta-analysis. Mean serum 25(OH)D was 68 (sd 29) nmol/l for EA and 49 (sd 21) nmol/l for AA. For each 1 nmol/l higher 25(OH)D, forced expiratory volume in the 1st second (FEV1) was higher by 1·1 ml in EA (95 % CI 0·9, 1·3; P<0·0001) and 1·8 ml (95 % CI 1·1, 2·5; P<0·0001) in AA (Prace difference=0·06), and forced vital capacity (FVC) was higher by 1·3 ml in EA (95 % CI 1·0, 1·6; P<0·0001) and 1·5 ml (95 % CI 0·8, 2·3; P=0·0001) in AA (Prace difference=0·56). Among EA, the 25(OH)D–FVC association was stronger in smokers: per 1 nmol/l higher 25(OH)D, FVC was higher by 1·7 ml (95 % CI 1·1, 2·3) for current smokers and 1·7 ml (95 % CI 1·2, 2·1) for former smokers, compared with 0·8 ml (95 % CI 0·4, 1·2) for never smokers. In summary, the 25(OH)D associations with FEV1 and FVC were positive in both ancestries. In EA, a stronger association was observed for smokers compared with never smokers, which supports the importance of vitamin D in vulnerable populations.
We first analytically show, starting with the Navier–Stokes equations, that the value of the derivative flatness is controlled by pressure diffusion of energy, viscous destructive effects and large-scale effects (decay and/or production). The latter two terms tend to zero when the Taylor-microscale Reynolds number
is sufficiently large. We argue that the pressure-diffusion term should also tend to a constant at large
. Available data for the velocity derivative flatness,
, in different turbulent flows are re-examined and interpreted in the light of the finite-Reynolds-number effect. It is found that
can differ from flow to flow at moderate
; for a given flow,
may also depend on the initial conditions. The data for
in various flows, e.g. along the axis in the far field of plane and circular jets, and grid turbulence, show that it approaches a constant, with a value slightly larger than 10, when
is sufficiently large. This behaviour for
is supported, at least qualitatively, by our analytical considerations. The constancy of
violates the refined similarity hypothesis introduced by Kolmogorov (J. Fluid Mech., vol. 13, 1962, pp. 82–85) to account for the intermittency of the energy dissipation rate. It is not, however, inconsistent with Kolmogorov’s original similarity hypothesis (Dokl. Akad. Nauk SSSR, vol. 30, 1941, pp. 299–303), although we contend that the power-law relation
(Kolmogorov 1962), which is widely accepted in the literature, has in reality been almost invariably used to ‘model’ the finite-Reynolds-number effect for the laboratory data and has been strongly influenced by the weighting given to the atmospheric surface layer data. The inclusion of the latter data has misled previous investigations of how
In 2013, the Cystic Fibrosis (CF) Foundation developed an updated guideline for infection prevention and control (IP&C) practices for CF. We sought to assess the adoption of specific recommendations by CF care centers.
Directors of the 277 CF care centers in the United States were asked to complete a confidential online survey regarding the adoption of selected IP&C recommendations. Selected recommendations were those we considered less likely to be incorporated into a center’s written IP&C policies.
Center directors from 198 of 277 CF centers (71%) completed the survey between December 2015 and June 2016; pediatric and larger centers were more likely to do so. Overall, 70% have adopted ≥75% of the selected recommendations. As recommended, almost all provided education to CF center staff (98%) and patients and families (97%); fewer developed educational materials in collaboration with local IP&C teams (59%) and/or patients and families (37%). Among 108 centers with non–English-speaking patients, 65 (60%) provided educational materials in relevant languages. Most (74%) held group education events; of the 138 centers with in-person meetings, 45% allowed 1 individual with CF to attend, and 51% allowed no individuals with CF to attend. Most centers (93%) held outdoor events, and 84% allowed >1 individual with CF to attend. Audits of exam-room cleaning were performed by 49% of CF centers.
Cystic fibrosis centers in the United States have adopted many of the recommendations addressed in this survey. Nonetheless, these findings suggest opportunities for improvement. More CF centers should provide education to non–English-speaking patients and families, and CF centers should perform audits of room cleaning.
Coinfection with human immunodeficiency virus (HIV) and viral hepatitis is associated with high morbidity and mortality in the absence of clinical management, making identification of these cases crucial. We examined characteristics of HIV and viral hepatitis coinfections by using surveillance data from 15 US states and two cities. Each jurisdiction used an automated deterministic matching method to link surveillance data for persons with reported acute and chronic hepatitis B virus (HBV) or hepatitis C virus (HCV) infections, to persons reported with HIV infection. Of the 504 398 persons living with diagnosed HIV infection at the end of 2014, 2.0% were coinfected with HBV and 6.7% were coinfected with HCV. Of the 269 884 persons ever reported with HBV, 5.2% were reported with HIV. Of the 1 093 050 persons ever reported with HCV, 4.3% were reported with HIV. A greater proportion of persons coinfected with HIV and HBV were males and blacks/African Americans, compared with those with HIV monoinfection. Persons who inject drugs represented a greater proportion of those coinfected with HIV and HCV, compared with those with HIV monoinfection. Matching HIV and viral hepatitis surveillance data highlights epidemiological characteristics of persons coinfected and can be used to routinely monitor health status and guide state and national public health interventions.
This paper reports the measurement of the energy loss of protons at the energy of 100 keV penetrating a partially ionized hydrogen plasma. The plasma of ne ≈ 1015–16 cm−3; Te ≈ 1–2 eV and lifetime of about 8 µs is created by the hydrogen gas discharge. The experimental results show an increase of a factor of 2.8 in the energy loss, which are in good agreement with the Bethe, Standard Stopping Model, Li–Petrasso and Vlasov models’ predictions within the error limit. The Bethe–Bloch Coulomb logarithm term is found to increase by a factor of 4.0 for free electrons as compared with the situation where bound electrons prevail. The potential application of protons energy loss for diagnosing the electron density in plasma is proposed too.
To investigate the effectiveness and usability of automated procedural guidance during virtual temporal bone surgery.
Two randomised controlled trials were performed to evaluate the effectiveness, for medical students, of two presentation modalities of automated real-time procedural guidance in virtual reality simulation: full and step-by-step visual presentation of drillable areas. Presentation modality effectiveness was determined through a comparison of participants’ dissection quality, evaluated by a blinded otologist, using a validated assessment scale.
While the provision of automated guidance on procedure improved performance (full presentation, p = 0.03; step-by-step presentation, p < 0.001), usage of the two different presentation modalities was vastly different (full presentation, 3.73 per cent; step-by-step presentation, 60.40 per cent).
Automated procedural guidance in virtual temporal bone surgery is effective in improving trainee performance. Step-by-step presentation of procedural guidance was engaging, and therefore more likely to be used by the participants.
The discovery of the first electromagnetic counterpart to a gravitational wave signal has generated follow-up observations by over 50 facilities world-wide, ushering in the new era of multi-messenger astronomy. In this paper, we present follow-up observations of the gravitational wave event GW170817 and its electromagnetic counterpart SSS17a/DLT17ck (IAU label AT2017gfo) by 14 Australian telescopes and partner observatories as part of Australian-based and Australian-led research programs. We report early- to late-time multi-wavelength observations, including optical imaging and spectroscopy, mid-infrared imaging, radio imaging, and searches for fast radio bursts. Our optical spectra reveal that the transient source emission cooled from approximately 6 400 K to 2 100 K over a 7-d period and produced no significant optical emission lines. The spectral profiles, cooling rate, and photometric light curves are consistent with the expected outburst and subsequent processes of a binary neutron star merger. Star formation in the host galaxy probably ceased at least a Gyr ago, although there is evidence for a galaxy merger. Binary pulsars with short (100 Myr) decay times are therefore unlikely progenitors, but pulsars like PSR B1534+12 with its 2.7 Gyr coalescence time could produce such a merger. The displacement (~2.2 kpc) of the binary star system from the centre of the main galaxy is not unusual for stars in the host galaxy or stars originating in the merging galaxy, and therefore any constraints on the kick velocity imparted to the progenitor are poor.
Characterizing ruminal parameters in the context of sampling routine and feed efficiency is fundamental to understand the efficiency of feed utilization in the bovine. Therefore, we evaluated microbial and volatile fatty acid (VFA) profiles, rumen papillae epithelial and stratum corneum thickness and rumen pH (RpH) and temperature (RT) in feedlot cattle. In all, 48 cattle (32 steers plus 16 bulls), fed a high moisture corn and haylage-based ration, underwent a productive performance test to determine residual feed intake (RFI) using feed intake, growth, BW and composition traits. Rumen fluid was collected, then RpH and RT logger were inserted 5.5±1 days before slaughter. At slaughter, the logger was recovered and rumen fluid and rumen tissue were sampled. The relative daily time spent in specific RpH and RT ranges were determined. Polynomial regression analysis was used to characterize RpH and RT circadian patterns. Animals were divided into efficient and inefficient groups based on RFI to compare productive performance and ruminal parameters. Efficient animals consumed 1.8 kg/day less dry matter than inefficient cattle (P⩽0.05) while achieving the same productive performance (P⩾0.10). Ruminal bacteria population was higher (P⩽0.05) (7.6×1011v. 4.3×1011 copy number of 16S rRNA gene/ml rumen fluid) and methanogen population was lower (P⩽0.05) (2.3×109v. 4.9×109 copy number of 16S rRNA gene/ml rumen fluid) in efficient compared with inefficient cattle at slaughter with no differences (P⩾0.10) between samples collected on-farm. No differences (P⩾0.10) in rumen fluid VFA were also observed between feed efficiency groups either on-farm or at slaughter. However, increased (P⩽0.05) acetate, and decreased (P⩽0.05) propionate, butyrate, valerate and caproate concentrations were observed at slaughter compared with on-farm. Efficient had increased (P⩽0.05) rumen epithelium thickness (136 v. 126 µm) compared with inefficient cattle. Efficient animals also spent 318% and 93.2% more time (P⩽0.05) in acidotic (4.14% v. 1.30%) (pH⩽5.6) and optimal (5.6<pH<6.0) (8.53% v. 4.42%) RpH range compared with inefficient cattle. The circadian patterns revealed lower (P⩽0.05) RpH and no differences (P⩾0.10) in RT pre-, during, and post-prandial periods in efficient compared with inefficient cattle. In essence, superior feed efficiency in cattle seems linked to rumen features consistent with improved efficiency of feed utilization. Microbial abundance, rumen epithelial histomorphology, and RpH, may serve as indicators for feed efficiency in cattle. The divergences of assessments made on-farm and at slaughter should be considered in the development of proxies for feed efficiency.
This cross-sectional study aimed to examine and compare prevalence and correlates of whole blood Epstein–Barr virus (EBV) DNA between HIV-positive and HIV-negative men who have sex with men (MSM). Five hundred and four HIV-positive MSM and 504 age-matched HIV-negative MSM were recruited from an HIV counseling and testing clinic in Shanghai, China from November 2014 to November 2015 and were administered with a face-to-face questionnaire interview. Whole blood EBV DNA was tested by nested polymerase chain reaction assays on EBNA-1, EBNA-2, and LMP-1 genes. The prevalence of whole blood EBV DNA was 56·0% (95% CI 51·7–60·3%) among HIV-positive MSM and 26·0% (95% CI 22·4–30·0%) among HIV-negative MSM. Whole blood EBV DNA positivity was significantly associated with HIV infection (adjusted odds ratio (aOR) 3·43, 95% CI 2·58–4·57) and frequent intake of pickled, smoked, or salty food (aOR 1·71, 95% CI 1·02–2·86) in the whole sample, and with <200 cells/μl CD4 cell counts (aOR 1·79, 95% CI 1·05–3·05) and pickled, smoked, or salty food intake (aOR 3·14, 95% CI 1·39–7·08) in HIV-positive group. HIV-infected MSM are at higher risk of active EBV replication than HIV-uninfected MSM, underscoring needs of surveillance and research on EBV-related carcinogenesis in this population.
The effect of large-scale forcing on the second- and third-order longitudinal velocity structure functions, evaluated at the Taylor microscale
, is assessed in various turbulent flows at small to moderate values of the Taylor microscale Reynolds number
. It is found that the contribution of the large-scale terms to the scale by scale energy budget differs from flow to flow. For a fixed
, this contribution is largest on the centreline of a fully developed channel flow but smallest for stationary forced periodic box turbulence. For decaying-type flows, the contribution lies between the previous two cases. Because of the difference in the large-scale term between flows, the third-order longitudinal velocity structure function at
differs from flow to flow at small to moderate
. The effect on the second-order velocity structure functions appears to be negligible. More importantly, the effect of
on the scaling range exponent of the longitudinal velocity structure function is assessed using measurements of the streamwise velocity fluctuation
in the range 500–1100, on the axis of a plane jet. It is found that the magnitude of the exponent increases as
increases and the rate of increase depends on the order
. The trend of published structure function data on the axes of an axisymmetric jet and a two-dimensional wake confirms this dependence. For a fixed
, the exponent can vary from flow to flow and for a given flow, the larger
is, the closer the exponent is to the value predicted by Kolmogorov (Dokl. Akad. Nauk SSSR, vol. 30, 1941a, pp. 299–303) (hereafter K41). The major conclusion is that the finite Reynolds number effect, which depends on the flow, needs to be properly accounted for before determining whether corrections to K41, arising from the intermittency of the energy dissipation rate, are needed. We further point out that it is imprudent, if not incorrect, to associate the finite Reynolds number effect with a consequence of the modified similarity hypothesis introduced by Kolmogorov (J. Fluid Mech., vol. 13, 1962, pp. 82–85) (K62); we contend that this association has misled the vast majority of post K62 investigations of the consequences of K62.
To prospectively assess treatment outcomes of chronic rhinosinusitis patients undergoing functional endoscopic sinus surgery and post-operative medical treatment over a prolonged follow-up period.
Patients undergoing functional endoscopic sinus surgery in the tertiary referral practice of a single surgeon were studied prospectively. Symptoms were scored by patients pre-operatively and over a minimum follow-up period of 12 months.
The study comprised 200 non-consecutive patients. The median pre-operative symptom score was 16 (out of a maximum of 25) (95 per cent confidence interval = 15 to 17). Symptom scores reduced to a median of 7 (95 per cent confidence interval = 6 to 8) after 12 months of follow up (p < 0.0001). The median symptom score improved for all symptoms and across all patient subgroups.
Extensive functional endoscopic sinus surgery offers significant and durable symptom improvement in patients with chronic rhinosinusitis refractory to medical treatment. This improvement extends to all patient subgroups. Prolonged medical therapy is recommended after functional endoscopic sinus surgery.
Hundreds of small-scale influenza outbreaks in schools are reported in mainland China every year, leading to a heavy disease burden which seriously impacts the operation of affected schools. Knowing the transmissibility of each outbreak in the early stage has become a major concern for public health policy-makers and primary healthcare providers. In this study, we collected all the small-scale outbreaks in Changsha (a large city in south central China with ~7·04 million population) from January 2005 to December 2013. Four simple and popularly used models were employed to calculate the reproduction number (R) of these outbreaks. Given that the duration of a generation interval Tc = 2·7 and the standard deviation (s.d.)σ = 1·1, the mean R estimated by an epidemic model, normal distribution and delta distribution were 2·51 (s.d. = 0·73), 4·11 (s.d. = 2·20) and 5·88 (s.d. = 5·00), respectively. When Tc = 2·9 and σ = 1·4, the mean R estimated by the three models were 2·62 (s.d. = 0·78), 4·72 (s.d. = 2·82) and 6·86 (s.d. = 6·34), respectively. The mean R estimated by gamma distribution was 4·32 (s.d. = 2·47). We found that the values of R in small-scale outbreaks in schools were higher than in large-scale outbreaks in a neighbourhood, city or province. Normal distribution, delta distribution, and gamma distribution models seem to more easily overestimate the R of influenza outbreaks compared to the epidemic model.
Salience network (SN) dysconnectivity has been hypothesized to contribute to schizophrenia. Nevertheless, little is known about the functional and structural dysconnectivity of SN in subjects at risk for psychosis. We hypothesized that SN functional and structural connectivity would be disrupted in subjects with At-Risk Mental State (ARMS) and would be associated with symptom severity and disease progression.
We examined 87 ARMS and 37 healthy participants using both resting-state functional magnetic resonance imaging and diffusion tensor imaging. Group differences in SN functional and structural connectivity were examined using a seed-based approach and tract-based spatial statistics. Subject-level functional connectivity measures and diffusion indices of disrupted regions were correlated with CAARMS scores and compared between ARMS with and without transition to psychosis.
ARMS subjects exhibited reduced functional connectivity between the left ventral anterior insula and other SN regions. Reduced fractional anisotropy (FA) and axial diffusivity were also found along white-matter tracts in close proximity to regions of disrupted functional connectivity, including frontal-striatal-thalamic circuits and the cingulum. FA measures extracted from these disrupted white-matter regions correlated with individual symptom severity in the ARMS group. Furthermore, functional connectivity between the bilateral insula and FA at the forceps minor were further reduced in subjects who transitioned to psychosis after 2 years.
Our findings support the insular dysconnectivity of the proximal SN hypothesis in the early stages of psychosis. Further developed, the combined structural and functional SN assays may inform the prognosis of persons at-risk for psychosis.
We present a scheme of electron beam radiography to dynamically diagnose the high energy density (HED) matter in three orthogonal directions simultaneously based on electron Linear Accelerator. The dynamic target information such as, its profile and density could be obtained through imaging the scattered electron beam passing through the target. Using an electron bunch train with flexible time structure, a very high temporal evolution could be achieved. In this proposed scheme, it is possible to obtain 1010 frames/second in one experimental event, and the temporal resolution can go up to 1 ps, spatial resolution to 1 µm. Successful demonstration of this concept will have a major impact for both future inertial confinement fusion science and HED physics research.
Self-preservation (SP) analyses are applied to the mean momentum and the scale-by-scale energy budget equations in the far wake of a circular cylinder. The scale-by-scale SP analysis, which is a two-point analysis, complements the SP analysis of the mean momentum equation. Power-law variations are derived for different length scales (e.g. the Taylor microscale and the Kolmogorov length scale) and velocity scales (e.g. the root mean square and the Kolmogorov velocity scale). Further, the SP solutions for the scale-by-scale energy budget equation are exploited to develop an exact relation to estimate the mean turbulent kinetic energy dissipation rate
on the wake axis. These SP solutions and the new
relation are well supported by hot-wire data in the far wake at a Reynolds number of 2000 based on the free stream velocity and the cylinder diameter. On the far-wake axis, both the energy spectra and the structure functions exhibit an almost perfect collapse over all wavenumbers and separations, irrespective of the set of scaling variables used for normalisation. This is consistent with a complete self-preservation (i.e. SP is satisfied at all scales of motion) in the far wake.
The transport equation for the isotropic turbulent energy dissipation rate
along the centreline in the far-wake of a circular cylinder is derived by applying the limit at small separations to the two-point energy budget equation. It is found that the imbalance between the production and the destruction of
, respectively due to vortex stretching and viscosity, is governed by both the streamwise advection and the lateral turbulent diffusion (the former contributes more to the budget than the latter). This imbalance differs intrinsically from that in other flows, e.g. grid turbulence and the flow along the centreline of a fully developed channel, where either the streamwise advection or the lateral turbulent diffusion of
governs the imbalance. More importantly, the different types of imbalance represent different constraints on the relation between the skewness of the longitudinal velocity derivative
and the destruction coefficient of enstrophy
. This results in a non-universal approach of
towards a constant value as the Taylor microscale Reynolds number
increases. For the present flow, the magnitude of
decreases initially (
) before increasing (
) towards this constant value. The constancy of
violates the modified similarity hypothesis introduced by Kolmogorov (J. Fluid Mech., vol. 13, 1962, pp. 82–85) but is consistent with the original similarity hypotheses (Kolmogorov, Dokl. Akad. Nauk SSSR, vol. 30, 1941b, pp. 299–303 (see also 1991 Proc. R. Soc. Lond. A, vol. 434, pp. 9–13)) (
), and, more importantly, with the almost completely self-preserving nature of the plane far-wake.
The transport equation for the mean turbulent energy dissipation rate
along the centreline of a fully developed channel flow is derived by applying the limit at small separations to the two-point budget equation. Since the ratio of the isotropic energy dissipation rate to the mean turbulent energy dissipation rate
is sufficiently close to 1 on the centreline, our main focus is on the isotropic form of the transport equation. It is found that the imbalance between the production of
due to vortex stretching and the destruction of
caused by the action of viscosity is governed by the diffusion of
by the wall-normal velocity fluctuation. This imbalance is intrinsically different from the advection-driven imbalance in decaying-type flows, such as grid turbulence, jets and wakes. In effect, the different types of imbalance represent different constraints on the relation between the skewness of the longitudinal velocity derivative
and the destruction coefficient
of enstrophy in different flows, thus resulting in non-universal approaches of
towards a constant value as the Taylor microscale Reynolds number,
, increases. For example, the approach is slower for the measured values of
along either the channel or pipe centreline than along the axis in the self-preserving region of a round jet. The data for
collected in different flows strongly suggest that, in each flow, the magnitude of
is bounded, the value being slightly larger than 0.5.