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The effect of hot streaks from a gas turbine combustor on the thermodynamic load of internally air-cooled nozzle guide vanes (NGVs) and shrouds has been numerically investigated under flight conditions. The study follows two steps: one for the high-fidelity 60° combustor sector with simplified ten NGVs and three thermocouples attached; and the other for the NGV sectors where each sector consists of one high-fidelity NGV (probe NGV) and nine dummy NGVs. The first step identifies which NGV has the highest thermal load and provides the inlet flow boundary conditions for the second step. In the second step, the flow fields and thermal loads of the probe NGVs are resolved in detail.
With the systematically validated physical models, the two-phase flowfield of the combustor-NGVs sector has been successfully simulated. The predicted mean and maximum temperature at the combustor sector exit are in excellent agreement with the experimental data, which provides a solid basis for the hot-streak effect investigation. The results indicate that the second NGV, looking upstream from left, has the highest thermal load. Its maximum surface temperature is 8.4% higher than that for the same NGV but with the mean inlet boundary conditions, and 14.1% higher than the ninth NGV. The finding is consistent with the field-observed NGV damage pattern. To extend the service life of these vulnerable NGVs, some protection methods should be considered.
We used a survey to characterize contemporary infection prevention and antibiotic stewardship program practices across 64 healthcare facilities, and we compared these findings to those of a similar 2013 survey. Notable findings include decreased frequency of active surveillance for methicillin-resistant Staphylococcus aureus, frequent active surveillance for carbapenem-resistant Enterobacteriaceae, and increased support for antibiotic stewardship programs.
Antenna-pattern measurements obtained from a double-metal supra-terahertz-frequency (supra-THz) quantum cascade laser (QCL) are presented. The QCL is mounted within a mechanically micro-machined waveguide cavity containing dual diagonal feedhorns. Operating in continuous-wave mode at 3.5 THz, and at an ambient temperature of ~60 K, QCL emission has been directed via the feedhorns to a supra-THz detector mounted on a multi-axis linear scanner. Comparison of simulated and measured far-field antenna patterns shows an excellent degree of correlation between beamwidth (full-width-half-maximum) and sidelobe content and a very substantial improvement when compared with unmounted devices. Additionally, a single output has been used to successfully illuminate and demonstrate an optical breadboard arrangement associated with a future supra-THz Earth observation space-borne payload. Our novel device has therefore provided a valuable demonstration of the effectiveness of supra-THz diagonal feedhorns and QCL devices for future space-borne ultra-high-frequency Earth-observing heterodyne radiometers.
Resonant optical dipole antennas, consisting either of two arms coupled by a small gap or of a single, uncoupled arm only, are fabricated by the application of electron beam lithography and gold evaporation. Using dark-field microscopy, scattering spectra of structures with varied antenna arm length and varied gap size are obtained. The results show not only a spectral redshift for coupled structures compared to single arm structures, but also that the far-field scattering intensity is significantly higher for two arm structures with gap. In addition to the dipole structures, first fabrication results on quadrupole antennas and split-ring antennas are presented, offering novel pathways for an enhancement of the optical response function.
The second order nonlinear optical (NLO) properties of two different ionic selfassembled multilayer (ISAM) films combined with Ag nanoparticles have been investigated. The plasmon resonances in the Ag particles concentrate the incident light, markedly increasing in the NLO efficiencies of the films. We find that the efficiency enhancement is significantly larger in conventional ISAM films compared to films made using a hybrid covalent ISAM technique (HCISAM), even though the intrinsic bulk second order non-linear susceptibility (χ(2)) is much larger for HCISAM films. We attribute this to the interfaces in HCISAM films being much easier to disrupt by external perturbations such as the metal deposition by which the nanoparticles are fabricated. We conclude that because the plasmon decay length is very short, the plasmonic enhancement of NLO effects primarily occurs at and near the film-particle interface. To discern the importance of the interfaces, we surrounded thin ISAM and HCISAM films with NLOinactive buffer layers, which confirmed this hypothesis, particularly in the case of HCISAM films.
To ascertain opinions regarding etiology and preventability of hospital-onset bacteremia and fungemia (HOB) and perspectives on HOB as a potential outcome measure reflecting quality of infection prevention and hospital care.
Hospital epidemiologists and infection preventionist members of the Society for Healthcare Epidemiology of America (SHEA) Research Network.
A web-based, multiple-choice survey was administered via the SHEA Research Network to 133 hospitals.
A total of 89 surveys were completed (67% response rate). Overall, 60% of respondents defined HOB as a positive blood culture on or after hospital day 3. Central line-associated bloodstream infections and intra-abdominal infections were perceived as the most frequent etiologies. Moreover, 61% thought that most HOB events are preventable, and 54% viewed HOB as a measure reflecting a hospital’s quality of care. Also, 29% of respondents’ hospitals already collect HOB data for internal purposes. Given a choice to publicly report central-line–associated bloodstream infections (CLABSIs) and/or HOB, 57% favored reporting either HOB alone (22%) or in addition to CLABSI (35%) and 34% favored CLABSI alone.
Among the majority of SHEA Research Network respondents, HOB is perceived as preventable, reflective of quality of care, and potentially acceptable as a publicly reported quality metric. Further studies on HOB are needed, including validation as a quality measure, assessment of risk adjustment, and formation of evidence-based bundles and toolkits to facilitate measurement and improvement of HOB rates.
While proxy records have been used to reconstruct late Quaternary climate parameters throughout the European Alps, our knowledge of deglacial climate conditions in the Maritime Alps is limited. Here, we report temperatures recorded by a new and independent geochemical technique—cosmogenic noble gas paleothermometry—in the Maritime Alps since the last glacial maximum. We measured cosmogenic 3He in quartz from boulders in nested moraines in the Gesso Valley, Italy. Paired with cosmogenic 10Be measurements and 3He diffusion experiments on quartz from the same boulders, the cosmogenic 3He abundances record the temperatures these boulders experienced during their exposure. We calculate effective diffusion temperatures (EDTs) over the last ∼22 ka ranging from 8°C to 25°C. These EDTs, which are functionally related to, but greater than, mean ambient temperatures, are consistent with temperatures inferred from other proxies in nearby Alpine regions and those predicted by a transient general circulation model. In detail, however, we also find different EDTs for boulders from the same moraines, thus limiting our ability to interpret these temperatures. We explore possible causes for these intra-moraine discrepancies, including variations in radiative heating, our treatment of complex helium diffusion, uncertainties in our grain size analyses, and unaccounted-for erosion or cosmogenic inheritance.
Multiple human immunodeficiency virus (HIV)-1 genotypes in China were first discovered in Yunnan Province before disseminating throughout the country. As the HIV-1 epidemic continues to expand in Yunnan, genetic characteristics and transmitted drug resistance (TDR) should be further investigated among the recently infected population. Among 2828 HIV-positive samples newly reported in the first quarter of 2014, 347 were identified as recent infections with BED-captured enzyme immunoassay (CEIA). Of them, 291 were successfully genotyped and identified as circulating recombinant form (CRF)08_BC (47.4%), unique recombinant forms (URFs) (18.2%), CRF01_AE (15.8%), CRF07_BC (14.4%), subtype C (2.7%), CRF55_01B (0.7%), subtype B (0.3%) and CRF64_BC (0.3%). CRF08_BC and CRF01_AE were the predominant genotypes among heterosexual and homosexual infections, respectively. CRF08_BC, URFs, CRF01_AE and CRF07_BC expanded with higher prevalence in central and eastern Yunnan. The recent common ancestor of CRF01_AE, CRF07_BC and CRF08_BC dated back to 1983.1, 1992.1 and 1989.5, respectively. The effective population sizes (EPS) for CRF01_AE and CRF07_BC increased exponentially during 1991–1999 and 1994–1999, respectively. The EPS for CRF08_BC underwent two exponential growth phases in 1994–1998 and 2001–2002. Lastly, TDR-associated mutations were identified in 1.8% of individuals. These findings not only enhance our understanding of HIV-1 evolution in Yunnan but also have implications for vaccine design and patient management strategies.
Seed shape (SS) affects the yield and appearance of soybean seeds significantly. However, little detailed information has been reported about the quantitative trait loci (QTL) affecting SS, especially SS components such as seed length (SL), seed width (SW) and seed thickness (ST), and their mutual ratios of length-to-weight (SLW), length-to-thickness (SLT) and weight-to-thickness (SWT). The aim of the present study was to identify QTL underlying SS components using 129 recombinant inbred lines derived from a cross between Dongnong46 and L-100. Phenotypic data were collected from this population after it was grown across nine environments. A total of 213 simple sequence repeat markers were used to construct the genetic linkage map, which covered approximately 3623·39 cM, with an average distance of 17·01 cM between markers. Five QTL were identified as being associated with SL, five with SW, three with ST, four with SLW, two with SLT and three with SWT. These QTL could explain 1·46–22·16% of the phenotypic variation in SS component traits. Three QTL were identified in more than six tested environments three for SL, two for SW, one for ST, two for SLW and one for SLT. These QTL have great potential value for marker-assistant selection of SS in soybean seeds.
(−)-Hydroxycitric acid (HCA), a major component of Garcinia cambogia extracts, has been shown to suppress BW gain and fat accumulation in animals and humans. However, the mechanism remains unknown. In this study, gas chromatography-mass spectrometry was used to analyse serum metabolites, and principal component analysis and partial least-squares-discriminant analysis models were generated to analyse serum metabolite changes in broiler chickens after the administration of (−)-HCA at 0, 1000, 2000 and 3000 mg/kg diets for 28 days. Metabolites showing significant changes were screened by ‘variable importance in the projection’ plots. The results showed that 20 metabolites in the 1000 mg/kg (−)-HCA treatment group and 16 metabolites in 3000 mg/kg (−)-HCA treatment group were significantly altered. Metabolites pathway enrichment analysis indicated that these metabolites were mainly associated with metabolism of amino acids, protein synthesis, citric acid cycle, and uric acid and fatty acid synthesis. The data indicated that (−)-HCA promoted protein synthesis by regulating the metabolic directions of amino acids. At the same time, (−)-HCA treatment inhibited fatty acid synthesis by promoting the citric acid cycle, resulting in reduced cytosolic acetyl-CoA content in broiler chickens. The present study identified global changes in metabolites and analysed the main canonical metabolic pathways in broiler chickens supplemented with (−)-HCA. These results will deepen our understanding of the mechanism of (−)-HCA’s effects in animals.
Omics research has indicated that heat shock protein 70 (HSP70) is a potential biomarker of meat quality. However, the specific changes and the potential role of HSP70 in postmortem meat quality development need to be further defined. In this study, Arbor Acres broiler chickens (n=126) were randomly categorized into three treatment groups of unstressed control (C), 0.5-h transport (T) and subsequent water shower spray following transport (T/W). Each treatment consisted of six replicates with seven birds each. The birds were transported according to a designed protocol. The pectoralis major (PM) muscles of the transport-stressed broilers were categorized as normal and pale, soft and exudative (PSE)-like muscle samples according to L* and pH24 h values to test the expression and location of HSP70. Results revealed that the activities of plasma creatine kinase and lactate dehydrogenase increased significantly (P<0.05) in normal and PSE-like muscle samples after transportation. The mRNA expression of HSP70 in normal muscle samples increased significantly (P<0.05) compared with that in the controls after stress. The protein expression of HSP70 increased significantly in normal muscle samples and decreased significantly (P<0.05) in PSE-like muscles. Immuno-fluorescence showed that HSP70 was present in the cytoplasm and on surface membranes of PM muscle cells in the normal samples following stress. Meanwhile, HSP70 was present on the surface membranes and extracellular matrix but was barely visible in the cytoplasm of the PSE-like samples. Principal component analysis showed high correlations between HSP70 and meat quality and stress indicators. In conclusion, this research suggests that the variation in HSP70 expression may provide a novel insight into the pathways underlying meat quality development.
To determine the frequency of incidental findings found on magnetic resonance imaging scans of the internal auditory meatus performed to investigate audiovestibular symptoms, and to determine how to best manage these when found.
A retrospective review was conducted of internal auditory meatus magnetic resonance imaging scans during a three-month period in the radiology department at a UK district general hospital.
A total of 109 scans were reviewed. Of these, 92.7 per cent showed no retrocochlear pathology, 0.9 per cent showed vestibular schwannoma, 6.4 per cent revealed vascular loops, and 2.8 per cent showed incidental findings that warranted further action and investigation. Of the scans, 40.4 per cent showed other incidental pathologies such as age-related ischaemic changes, and sinus disease that required no further intervention. Of the magnetic resonance imaging scans reviewed, 49.5 per cent were entirely normal.
Almost half of the scans investigating audiovestibular symptoms showed incidental findings. Otolaryngologists should have an understanding of the significance of the most commonly encountered incidental findings, and should counsel patients appropriately and refer them onward when necessary.
A new and unique radiocarbon accelerator mass spectrometry (AMS) facility has been constructed at the Woods Hole Oceanographic Institution. The defining characteristic of the new system is its large-gap optical elements that provide a larger-than-standard beam acceptance. Such a system is ideally suited for high-throughput, high-precision measurements of 14C. Details and performance of the new system are presented.
A nationwide population-based cohort was used to examine the severity of liver cirrhosis and risk of mortality from oral cancer.
The cohort consisted of 3583 patients with oral cancer treated by surgery between 2008 and 2011 in Taiwan. They were grouped on the basis of normal liver function (n = 3471), cirrhosis without decompensation (n = 72) and cirrhosis with decompensation (n = 40). The primary endpoint was mortality. Hazard ratios of death were also determined.
The mortality rates in the respective groups were 14.8 per cent, 20.8 per cent and 37.5 per cent at one year (p < 0.001). The adjusted hazard ratios of death at one year for each group compared to the normal group were 2.01 (p = 0.021) for cirrhotic patients without decompensation, 4.84 (p < 0.001) for those with decompensation and 2.65 (p < 0.001) for those receiving chemotherapy.
Liver cirrhosis can be used to predict one-year mortality in oral cancer patients. Chemotherapy should be used with caution and underlying co-morbidities should be managed in cirrhotic patients to reduce mortality risk.
Residual feed intake (RFI), defined as the difference between an animal’s actual feed intake and expected feed intake over a specific period, is an inheritable character of feed conversion efficiency in dairy cows. Research has shown that a lower RFI could improve the profitability of milk production. This study explored variation in RFI by comparing the differences in body size, milk performance, feeding behavior, and serum metabolites in 29 Holstein cows in mid lactation. The cows were selected from a total of 84 animals based on their RFI following feedlot tests. Selected cows were ranked into high RFI (RFI >1 SD above the mean, n=14) and low RFI (RFI<1 SD below the mean, n=15). The low RFI cows (more efficient) consumed 1.59 kg/day less dry matter than the high RFI group (P<0.01), while they produced nearly equal 4% fat-corrected milk. The milk : feed ratio was higher for the low RFI group than for the high RFI group (P<0.05). The levels of milk protein (P<0.01), total solids (P<0.05), and nonfat solids (P<0.05) were also higher for the low RFI group, whereas milk urea nitrogen was lower (P<0.01). The daily feeding duration was shorter for the low RFI group than for the high RFI group (P<0.01). No significant differences were found in levels of glucose, β-hydroxybutyrate, prolactin, insulin, IGF-1, growth hormone or ghrelin, but the level of neuropeptide Y was higher (P<0.01) and levels of leptin and non-esterified fatty acid (P<0.05) were lower for the low RFI group than for the high RFI group. There were substantial differences between cows with different RFI, which might affect the efficiency of milk protein metabolism and fat mobilization.
Overweight and obese individuals have an increased risk of developing the metabolic syndrome because of subsequent chronic inflammation and oxidative stress, which the antioxidant nutrient lycopene can reduce. However, studies indicate that different BMI statuses can alter the positive effects of lycopene. Therefore, the purpose of this study was to examine how BMI influences the association between serum lycopene and the metabolic syndrome. The tertile rank method was used to divide 13 196 participants, aged 20 years and older, into three groups according to serum concentrations of lycopene. The associations between serum lycopene and the metabolic syndrome were analysed separately for normal-weight, overweight and obese participants. Overall, the prevalence of the metabolic syndrome was significantly higher in the first tertile group (OR 38·6 %; 95 % CI 36·9, 40·3) compared with the second tertile group (OR 29·3 %; 95 % CI 27·5, 31·1) and the third tertile group (OR 26·6 %; 95 % CI 24·9, 28·3). However, the associations between lycopene and the metabolic syndrome were only significant for normal-weight and overweight participants (P<0·05), but not for obese participants (P>0·05), even after adjusting for possible confounding variables. In conclusion, BMI appears to strongly influence the association between serum lycopene and the metabolic syndrome.
The objective of this study was to investigate the effects of maternal protein or energy restriction on hormonal and metabolic status of pregnant goats during late gestation and their postnatal male kids. Forty-five pregnant goats were fed a control (CON), 40% protein-restricted (PR) or 40% energy-restricted (ER) diet from 90 days of gestation until parturition. Plasma of mothers (90, 125 and 145 days of gestation) and kids (6 weeks of age) were sampled to determine metabolites and hormones. Glucose concentration for pregnant goats subjected to PR or ER was less (P<0.001) than that of CON goats at 125 and 145 days of gestation. However, plasma nonesterified fatty acids concentration was greater (P<0.01) at 125 and 145 days for PR and ER than CON. Protein restriction increased (P<0.01) maternal cortisol concentration by 145 days of gestation, and ER decreased (P<0.01) maternal insulin concentration at 125 days of gestation. Moreover, maternal amino acid (AA) concentrations were affected by nutritional restriction, with greater (P<0.05) total AA (TAA) and nonessential AA (NEAA) for PR goats but less (P<0.05) TAA and NEAA for ER goats at 125 days of gestation. After 6 weeks of nutritional recovery, plasma concentrations of most metabolic and hormonal parameters in restricted kids were similar to CON kids, except for reduced (P<0.05) insulin concentration in ER, and reduced (P<0.05) Asp concentration in PR and ER kids. These results provide information on potential metabolic mechanisms responsible for fetal programming.