bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cycle Optimization Potential of Composite Cycle and Turbocompound Aero-Engines
Authors: Klein Felix , Staudacher Stephan 
Published: April 2020

Abstract
Fair comparison of future aircraft engine concepts requires the assumption of similar technological risk and a transparent book keeping of losses. A 1000 km and a 7000 km flight mission of a single-aisle airplane similar to the Aribus A321neo LR have been used to compare composite cycle engines, turbocompound engines and advanced gas turbines as potential options for an entry-into-service time frame of 2050+. A 2035 technology gas turbine serves as reference. The cycle optimization has been carried out with a peak pressure ratio of 250 and a maximum cycle temperature of 2200 K at cruise as boundary conditions. With the associated heat loss and the low efficiency of the gas exchange process limiting piston component efficiency, the cycle optimization filtered out composite cycle concepts. Taking mission fuel burn (MFB) as the most relevant criterion, the highest MFB reduction of 13.7% compared to the 2035 reference gas turbine is demonstrated for an air-cooled turbocompound concept with additional combustion chamber. An intercooled, hectopressure gas turbine with pressure gain combustion achieves 20.6% reduction in MFB relative to the 2035 reference gas turbine.
Control of Chip Formation and Improved Chip Ejection in Drilling With Modulation-Assisted Machining
Authors: Guo Yang , Mann James B. 
Published: April 2020

Abstract
Drilling with modulation-assisted machining (MAM) superimposes a low-frequency oscillation onto the drill feed motion. The otherwise continuous cutting in the drilling process is converted into a series of discrete cutting events. The result is a discrete chip formation process and concurrent improvement in chip ejection. The discrete chip formation and ejection in drilling with MAM were investigated via systematic experiments in OFHC Cu and Ti6Al4V using a two-flute twist drill and a single-flute gun drill. Drilling thrust force and chip morphologies for various modulation conditions are examined. The continuous cutting and discrete cutting regimes of modulation-assisted drilling are compared with conditions determined by a kinematic model. The results show that chip formation in the continuous cutting regime with MAM can influence chip breakage by random fracture at thin sections of the chip, but in this regime the resulting chip size is variable and not controlled. In contrast, when MAM conditions operate in the regime of discrete cutting, the deformed chip size can be directly controlled. The ability to control the chip size improves chip ejection and drilling process stability. A set of modulation conditions for enhanced performance of chip ejection are proposed. The study shows that modulation-assisted machining offers distinct advantages as a method for deep-hole drilling applications.
Performance Evaluation of Hybrid Photovoltaic Thermal Thermoelectric Collector Using Grasshopper Optimization Algorithm With Simulated Annealing
Authors: Gupta Anmol , Agrawal Sanjay , Pal Yash 
Published: April 2020

Abstract
In this paper, a mathematical model of a single-channel photovoltaic thermal (PVT) air collector incorporated with a thermoelectric (TE) module has been presented. The overall electrical energy obtained from the photovoltaic thermal-thermoelectric (PVT-TE) collector is 5.78% higher than the PVT collector. Further, the grasshopper optimization algorithm (GOA) and hybrid grasshopper optimization algorithm with simulated annealing (GOA-SA) have been proposed and implemented to optimize the parameters of opaque PVT-TE collector. Although there are different parameters that influence the performance of PVT-TE system, yet in this study only four parameters, viz., length of the channel (L), width of the channel (b), mass flowrate of air in the channel (mair), and temperature of air at the inlet of channel (Tair,i) are considered for optimization. The simulation result demonstrates that the hybrid GOA-SA algorithm turned out to be an exceptionally effective method for optimal tuning of the parameters of the PVT-TE system. The result explicitly shows that the average value of overall electrical efficiency and exergy gain are 15.27% and 27.0565 W, respectively, when the parameters are optimized by the suggested GOA-SA algorithm which is way ahead with respect to the outcomes obtained with that of the calculated values or using GOA algorithm alone.
Optimizing Interval Training Through Power-Output Variation Within the Work Intervals
Authors: Bossi Arthur H. , Mesquida Cristian , Passfield Louis , Rønnestad Bent R. , Hopker James G. 
Published: April 2020

Purpose: Maximal oxygen uptake () is a key determinant of endurance performance. Therefore, devising high-intensity interval training (HIIT) that maximizes stress of the oxygen-transport and -utilization systems may be important to stimulate further adaptation in athletes. The authors compared physiological and perceptual responses elicited by work intervals matched for duration and mean power output but differing in power-output distribution. Methods: Fourteen cyclists ( 69.2 [6.6] mL·kg−1·min−1) completed 3 laboratory visits for a performance assessment and 2 HIIT sessions using either varied-intensity or constant-intensity work intervals. Results: Cyclists spent more time at during HIIT with varied-intensity work intervals (410 [207] vs 286 [162] s, P = .02), but there were no differences between sessions in heart-rate- or perceptual-based training-load metrics (all P ≥ .1). When considering individual work intervals, minute ventilation () was higher in the varied-intensity mode (F = 8.42, P = .01), but not respiratory frequency, tidal volume, blood lactate concentration [La], ratings of perceived exertion, or cadence (all F ≤ 3.50, ≥ .08). Absolute changes (Δ) between HIIT sessions were calculated per work interval, and Δ total oxygen uptake was moderately associated with (r = .36, P = .002). Conclusions: In comparison with an HIIT session with constant-intensity work intervals, well-trained cyclists sustain higher fractions of when work intervals involved power-output variations. This effect is partially mediated by an increased oxygen cost of hyperpnea and not associated with a higher [La], perceived exertion, or training-load metrics.
Pole Length’s Influence on Performance During Classic-Style Snow Skiing in Well-Trained Cross-Country Skiers
Authors: Trøen Erik , Rud Bjarne , Karlsson Øyvind , Carlsen Camilla Høivik , Gilgien Matthias , Paulsen Gøran , Tosterud Ola Kristoffer , Losnegard Thomas 
Published: April 2020

Purpose: To investigate how self-selected pole length (PL) of ∼84% (PL84%) compared with ∼90% (PL90%) of body height influenced performance during a 700-m time trial with undulating terrain on snow. Methods: Twenty-one cross-country skiers, 7 of whom were women, performed 4 trials at a maximal effort in a counterbalanced fashion with PL84% and PL90% separated by 20-minute breaks between trials. In trials I and II, only double poling was allowed, while in trials III and IV, skiers used self-selected classical subtechniques. Continuous speed, cyclic parameters, and heart rate were collected using microsensors in addition to a post-time-trial rating of perceived exertion (RPE). Results: The 700-m times with only double poling were significantly shorter with PL90% than PL84% (mean ± 95% confidence limits –1.6% ± 1.0%). Segment analyses showed higher speed with PL90% in uphill sections than with PL84% (3.7% ± 2.1%), with the greatest difference found for the female skiers (5.6% ± 2.9%). In contrast, on flat terrain at high skiing speeds, speed was reduced with PL90% compared with PL84% (–1.5% ± 1.4%); this was only significant for the male skiers. During free choice of classical subtechniques, PL did not influence performance in any segments, choice of subtechnique, or cycle rate during the trials. No differences in rating of perceived exertion or heart rate between PLs were found. Conclusions: PL90% improved performance in uphills at low speeds when using double poling but hindered performance on flat terrain and at higher speeds compared with self-selected PLs. Choice of PL should, therefore, be based on racecourse topography, preferred subtechniques, and the skier’s physiological and technical abilities.
Chromogenic Detection of Aminoglycoside Phosphotransferases
Authors: Amoroso Ana M. , Gutkind Gabriel O. 
Published: April 2020

ABSTRACT
A coupled chromogenic reaction (based on an agar overlay combining NADH, pyruvate kinase, lactate dehydrogenase, phosphoenolpyruvate, ATP, and kanamycin sulfate with thiazolyl blue-phenazine methosulfate for detection of NADH consumption) was optimized for the detection of aminoglycoside phosphotransferases (APHs). When used after analytical isoelectrofocusing of bacterial extracts from APH-producing strains, this method revealed one band in each of two strains with a genetically confirmed APH (3′) I and two bands in another strain with both APH (3′) I and APH (3′) VI, whereas no bands were detected in susceptible control strains or in aminoglycoside-resistant microorganisms without APH genes.
Differential Release of Lipoteichoic and Teichoic Acids from
Streptococcus pneumoniae
as a Result of Exposure to β-Lactam Antibiotics, Rifamycins, Trovafloxacin, and Quinupristin-Dalfopristin
Authors: Stuertz K. , Schmidt H. , Eiffert H. , Schwartz P. , Mäder M. , Nau R. 
Published: April 2020

ABSTRACT

The release of lipoteichoic acid (LTA) and teichoic acid (TA) from a
Streptococcus pneumoniae
type 3 strain during exposure to ceftriaxone, meropenem, rifampin, rifabutin, quinupristin-dalfopristin, and trovafloxacin in tryptic soy broth was monitored by a newly developed enzyme-linked immunosorbent assay. At a concentration of 10 μg/ml, a rapid and intense release of LTA and TA occurred during exposure to ceftriaxone (3,248 ± 1,688 ng/ml at 3 h and 3,827 ± 2,133 ng/ml at 12 h) and meropenem (2,464 ± 1,081 ng/ml at 3 h and 2,900 ± 1,364 ng/ml at 12 h). Three hours after exposure to rifampin, rifabutin, quinupristin-dalfopristin, and trovafloxacin, mean LTA and TA concentrations of less than 460 ng/ml were observed (for each group,
P
< 0.01 versus the concentrations after exposure to ceftriaxone). After 12 h of treatment, the LTA and TA concentrations were 463 ± 126 ng/ml after exposure to rifampin, 669 ± 303 ng/ml after exposure to rifabutin, and 1,236 ± 772 ng/ml after exposure to quinupristin-dalfopristin (for each group,
P
< 0.05 versus the concentrations after exposure to ceftriaxone) and 1,745 ± 1,185 ng/ml after exposure to trovafloxacin (
P
= 0.12 versus the concentration after exposure to ceftriaxone). At 10 μg/ml, bactericidal antibacterial agents that do not primarily affect cell wall synthesis reduced the amount of LTA and TA released during their cidal action against
S. pneumoniae
in comparison with the amount released after exposure to β-lactams. Larger quantities of LTA and TA were released after treatment with low concentrations (1× the MIC and 1× the minimum bactericidal concentration) than after no treatment for all antibacterial agents except the rifamycins. This does not support the concept of using a low first antibiotic dose to prevent the release of proinflammatory cell wall components.
β-Lactamase Inhibitors Are Substrates for the Multidrug Efflux Pumps of
Pseudomonas aeruginosa
Authors: Li Xian-Zhi , Zhang Li , Srikumar Ramakrishnan , Poole Keith 
Published: April 2020

ABSTRACT

The MexAB-OprM multidrug efflux system exports a number of antimicrobial compounds, including β-lactams. In an attempt to define more fully the range of antimicrobial compounds exported by this system, and, in particular, to determine whether β-lactamase inhibitors were also accommodated by the MexAB-OprM pump, the influence of pump status (its presence or absence) on the intrinsic antibacterial activities of these compounds and on their abilities to enhance β-lactam susceptibility in intact cells was assessed. MIC determinations clearly demonstrated that all three compounds tested, clavulanate, cloxacillin, and BRL42715, were accommodated by the pump. Moreover, by using β-lactams which were readily hydrolyzed by the
Pseudomonas aeruginosa
class C chromosomal β-lactamase, it was demonstrated that elimination of the
mexAB-oprM
-encoded efflux system greatly enhanced the abilities of cloxacillin and BRL42715 (but not clavulanate) to increase β-lactam susceptibility. With β-lactams which were poorly hydrolyzed, however, the inhibitors failed to enhance β-lactam susceptibility in MexAB-OprM
+
strains, although BRL42715 did enhance β-lactam susceptibility in MexAB-OprM
−
strains, suggesting that even with poorly hydrolyzed β-lactams this inhibitor was effective when it was not subjected to efflux. MexEF-OprN-overexpressing strains, but not MexCD-OprJ-overexpressing strains, also facilitated resistance to β-lactamase inhibitors, indicating that these compounds are also substrates for the MexEF-OprN pump. These data indicate that an ability to inactivate MexAB-OprM (and like efflux systems in other bacteria) will markedly enhance the efficacies of β-lactam–β-lactamase inhibitor combinations in treating bacterial infections.
Repeated-Dose Pharmacokinetics of an Oral Solution of Itraconazole in Infants and Children
Authors: de Repentigny Louis , Ratelle Johanne , Leclerc Jean-Marie , Cornu Guy , Sokal Étienne M. , Jacqmin Philippe , de Beule Karel 
Published: April 2020

ABSTRACT

The safety, tolerability, and pharmacokinetics of an oral solution of itraconazole and its active metabolite hydroxyitraconazole were investigated in an open multicenter study of 26 infants and children aged 6 months to 12 years with documented mucosal fungal infections or at risk for the development of invasive fungal disease. The most frequent underlying illness was acute lymphoblastic leukemia, except in the patients aged 6 months to 2 years, of whom six were liver transplant recipients. The patients were treated with itraconazole at a dosage of 5 mg/kg of body weight once daily for 2 weeks. Blood samples were taken after the first dose, during treatment, and up to 8 days after the last itraconazole dose. On day 1, the mean peak concentrations in plasma after the first and last doses (
C
max
) and areas under the concentration-time curve from 0 to 24 h (AUC
0–24
) for itraconazole and hydroxyitraconazole were lower in the children aged 6 months to 2 years than in children aged 2 to 12 years but were comparable on day 14. The mean AUC
0–24
-based accumulation factors of itraconazole and hydroxyitraconazole from day 1 to 14 ranged from 3.3 to 8.6 and 2.3 to 11.4, respectively. After 14 days of treatment,
C
max
, AUC
0–24
, and the half-life, respectively, were (mean ± standard deviation) 571 ± 416 ng/ml, 6,930 ± 5,830 ng · h/ml, and 47 ± 55 h in the children aged 6 months to 2 years; 534 ± 431 ng/ml, 7,330 ± 5,420 ng · h/ml, and 30.6 ± 25.3 h in the children aged 2 to 5 years; and 631 ± 358 ng/ml, 8,770 ± 5,050 ng · h/ml, and 28.3 ± 9.6 h in the children aged 5 to 12 years. There was a tendency to have more frequent low minimum concentrations of the drugs in plasma for both itraconazole and hydroxyitraconazole for the children aged 6 months to 2 years. The oral bioavailability of the solubilizer hydroxypropyl-β-cyclodextrin was less than 1% in the majority of the patients. In conclusion, an itraconazole oral solution given at 5 mg/kg/day provides potentially therapeutic concentrations in plasma, which are, however, substantially lower than those attained in adult cancer patients, and is well tolerated and safe in infants and children.
Pharmacokinetics and Inflammatory Fluid Penetration of Clinafloxacin
Authors: Wise R. , Jones S. , Das I. , Andrews J. M. 
Published: April 2020

ABSTRACT
A single 200-mg dose of clinafloxacin was given orally to each of nine healthy male volunteers, and the concentrations of the drug were measured in plasma, cantharidin-induced inflammatory fluid, and urine over the following 24 h (48 h in the case of urine). The mean maximum concentration in plasma was 1.34 μg/ml at a mean time of 1.8 h postdose. The mean maximum concentration in the inflammatory fluid was 1.3 μg/ml at 3.8 h postdose. The mean elimination half-life of clinafloxacin in plasma was 5.65 h. The overall penetration into the inflammatory fluid was 93.1%, as assessed by determining the ratio of area under the concentration-time curves. Recovery of clinafloxacin in urine was 58.8% by 24 h and 71.8% by 48 h postdose.
Rationale for and Efficacy of Prolonged-Interval Treatment Using Liposome-Encapsulated Amikacin in Experimental
Mycobacterium avium
Infection
Authors: Leitzke S. , Bucke W. , Borner K. , Müller R. , Hahn H. , Ehlers S. 
Published: April 2020

ABSTRACT

The potential of liposome-encapsulated antibiotics for prolonging drug application intervals was investigated by using a murine model of chronic lethal
Mycobacterium avium
infection. Liposomal encapsulation of amikacin, but not of ciprofloxacin, resulted in high and sustained drug levels in infected tissues, exceeding the minimal inhibitory concentration for
M. avium
for at least 28 days. As a consequence, once-weekly and even once-monthly treatments with liposomal amikacin significantly reduced bacterial replication in infected tissues and extended the survival time of infected mice.
Bilateral morphometric analysis of corneal sub-basal nerve plexus in patients undergoing unilateral cataract surgery: a preliminary in vivo confocal microscopy study
Authors: Giannaccare Giuseppe , Bernabei Federico , Pellegrini Marco , Guaraldi Fabio , Turchi Federica , Torrazza Carlo , Senni Carlotta , Scotto Riccardo , Sindaco Daniele , Di Cello Luca , Versura Piera , Scorcia Vincenzo , Traverso Carlo E , Vagge Aldo 
Published: April 2020

AimsTo evaluate bilateral morphometric changes of corneal sub-basal nerve plexus (CSNP) occurring after unilateral cataract surgery by in vivo confocal microscopy (IVCM) images analysed with automated software.MethodsIVCM was performed before (V0) and 1 month after surgery (V1) in both operated eyes (OEs) and unoperated eyes (UEs) of 30 patients. Thirty age and sex-matched subjects acted as controls. Corneal nerve fibre density (CNFD), corneal nerve branch density (CNBD), corneal nerve fibre length (CNFL), corneal nerve total branch density (CTBD), corneal nerve fibre area (CNFA), corneal nerve fibre width, corneal nerve fractal dimension (CNFrD) and dendritic cells density were calculated.ResultsMean CNFD, CNBD, CNFL, CTBD, CNFA and CNFrD significantly decreased at V1 versus V0 in both eyes (respectively, 15.35±7.00 vs 21.21±6.56 n/mm2 in OEs and 20.11±6.69 vs 23.20±7.26 in UEs; 13.57±12.16 vs 26.79±16.91 n/mm2 in OEs and 24.28±14.88 vs 29.76±15.25 in UEs; 9.67±3.44 mm/mm2 vs 13.49±3.42 in OEs and 12.53±3.60 vs 14.02±3.82 in UEs; 22.81±18.77 vs 42.25±24.64 n/mm2 in OEs and 38.06±20.52 vs 43.93±22.27 in UEs; 0.0040±0.0021 vs 0.0058±0.0020 mm2/mm2 in OEs and 0.0049±0.0016 vs 0.0057±0.0019 in UEs; 1.418±0.058 vs 1.470±0.037 in OEs and 1.466±0.040 vs 1.477±0.036 in UEs; always p<0.049).ConclusionPatients undergoing cataract surgery exhibit bilateral alterations of CSNP. This finding could have broad implications in the setting of sequential cataract surgery.
Vision loss in anterior uveitis
Authors: Al-Ani Haya H , Sims Joanne L , Tomkins-Netzer Oren , Lightman Susan , Niederer Rachael L 
Published: April 2020

AimsTo evaluate the long-term risk of permanent vision loss in subjects with anterior uveitis.MethodsRetrospective study of subjects attending uveitis clinic at Auckland District Health Board and Moorfields Eye Hospital between 2008 and 2018. Main outcome measures were: best corrected visual acuity (BCVA); moderate vision loss (MVL ≤20/50); and severe vision loss (SVL ≤20/200).Results2526 eyes of 1814 subjects were included with a mean follow-up of 6.8 years (17 235.4 eye-years of follow-up). MVL occurred in 240 eyes (9.5%) during the follow-up period, of which 97 (3.8%) had permanent MVL due to uveitis. The incidence of permanent MVL due to uveitis was 0.006 per eye-year with a cumulative risk at 10 years of 6.6% (5.2%–8.4%). The most common cause of permanent MVL due to uveitis was uveitic glaucoma (31.3%), followed by cystoid macular oedema (27.1%) and corneal scar (21.9%). SVL occurred in 80 eyes (3.2%) during the follow-up period, of which 39 (1.5%) had permanent SVL due to uveitis. The incidence of permanent SVL due to uveitis was 0.002 per eye-year with a cumulative risk at 10 years of 2.6% (1.8%–3.7%). Multivariate analysis showed older age at presentation, chronic anterior uveitis (CAU), infectious aetiology and poor presenting BCVA were all risk factors for permanent MVL due to uveitis.ConclusionsAlthough vision loss is an uncommon complication in anterior uveitis, the risk is greatest in those with CAU, infectious aetiology and poor presenting BCVA. Uveitic glaucoma is the most common cause of vision loss.
Relationship of obesity to adipose tissue insulin resistance
Authors: Jiang Jiajia , Cai Xueli , Pan Yuesong , Du Xiaoyan , Zhu Huiping , Yang Xinghua , Zheng Deqiang , Gaisano Herbert , Wei Tiemin , He Yan 
Published: April 2020

AimsThis study aimed to examine the association of different anatomical forms of obesity with adipose tissue insulin resistance and to assess the diagnostic value and contribution of obesity to adipose tissue insulin resistance.MethodsThis cross-sectional study included a total of 499 subjects aged 50 years or over. Multivariate regression analysis was conducted to clarify the association of different forms of obesity with adipose tissue insulin resistance (calculated as fasting insulin level×fasting free fatty acids level). Receiver operating characteristic cure analyses were used to assess the diagnostic value of each anthropometric indicator for adipose tissue insulin resistance. Attributable risk per cent and population attributable risk per cent were calculated to assess the contribution of obesity to adipose tissue insulin resistance.ResultsAfter adjustment for potential confounders, we showed that anthropometric indicators were all positively associated with adipose tissue insulin resistance. In males, waist circumference (WC) was the strongest associated factor (OR, 3.43 (95% CI 2.03 to 5.82)) and indicator (area under the curve (AUC): 0.79) of adipose tissue insulin resistance among those indicators. Here, abdominal obesity (WC≥90 cm) accounted for 64.9% of adipose tissue insulin resistance in the abdominal obese males. Accordingly, body mass index (BMI) was the strongest associated factor (OR,3.08 (95% CI 2.04 to 4.66)) and indicator (AUC: 0.78) of adipose tissue insulin resistance in females. Here, general obesity of BMI≥25 kg/m2accounted for 66.2% of the adipose tissue insulin resistance in the general obese females. We further demonstrated that adipose tissue insulin resistance was associated or trended to be associated with the metabolic diseases of cardiovascular disease, type 2 diabetes and fatty liver in subjects with normal BMI and WC.ConclusionsMaintaining WC in males and BMI in females to a normal range could be an important strategy to significantly reduce the occurrence of adipose tissue insulin resistance and the subsequent metabolic diseases.