bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigating the Influence of Mainstream Turbulence and Large Vortices on Gas Turbine Trenched Film Cooling Flows Using Planar Temperature-Velocity Imaging
Authors: Straußwald Michael , Sander Tobias , Abram Christopher , Pfitzner Michael 
Published: March 2022

Abstract
Film cooling is a critical gas turbine technology to reduce heat loads on the combustion chamber and the turbine vanes and blades. To improve film cooling performance, trenched cooling configurations where the holes are connected by a cross-stream slot in the surface have been developed. In this study, for the first time, we experimentally examine the influence of mainstream turbulence and large vortices on trenched film cooling flows. We apply an imaging technique based on thermographic phosphor particles seeded into the flow to measure 2D time-resolved gas temperature and velocity distributions in film cooling flows established in a closed-loop heated wind tunnel. Two trenched configurations (straight and an optimized zigzag design) are compared with ordinary effusion holes at momentum ratios (I=3.5,5.7, and 8.3) relevant to gas turbine combustors. Furthermore, two turbulence generation methods were used to create realistic mainstream turbulence levels (Tu=16.4% and 22.7%) and large vortices, so film cooling flows at typical wind tunnel turbulence (Tu=5.3%) can be compared with combustor-relevant conditions. By comparing the film position derived from the time-average temperature fields, the optimized trench performs best at low momentum ratios and turbulence levels but the performance rapidly drops when the momentum ratio rises or the turbulence level is increased. The straight trench performs best across all conditions studied and this configuration is therefore recommended for combustor liner cooling where main flow turbulence levels are high. In general, increased turbulence intensity reduces the effective length of the cooling film for all geometries. The straight trench, however, produces a more stable cooling film than typical effusion holes or the optimized trench configuration. Both phase-locked and time-resolved data indicate that, in the presence of a dominating frequency in the turbulent main flow field produced using a vortex generator, there are instances where the cooling films are strongly disturbed in the streamwise direction and hot gas is locally in contact with the surface.
Personalized Hydration Requirements of Runners
Authors: Cheuvront Samuel N. , Kenefick Robert W. 
Published: March 2022

This study sought to (a) estimate how the duration of running influences sweat losses and contributes to the daily fluid requirement, and (b) empirically estimate the drinking rates required to prevent significant dehydration (≥2% body weight as body water). Individual sweating data and running duration were obtained from male (n = 83) and female (n = 36) runners (n = 146 total observations) performing under highly heterogeneous conditions and over a range of exercise durations (33–280 min). Running <60 min/day increased daily fluid needs by a factor of 1.3, whereas running >60 min/day increased the daily fluid need by a factor of 1.9–2.3. Running <60 min/day generally required no fluid intake to prevent significant dehydration before run completion (31/35 runners). In contrast, running >60 min/day required more than 50% replacement of sweating rates to prevent the same (65/111 runners). Overall sweat losses ranged from ∼0.2 to ∼5.0 L/day, whereas the drinking rates required to prevent significant dehydration ranged from 0 to 1.4 L/hr. The characterization of sweat losses, sweat rate, and required drinking among runners in this study indicate wide individual variability that warrants personalized hydration practices, particularly when running is prolonged (>60 min) and performance is important. This study may serve as a useful guidepost for sports dietitians when planning and communicating fluid needs to athletes, as well as complement guidance related to both personalized programmed and thirst-driven drinking strategies.
Weight loss during ambulatory tube weaning: don’t put the feeds back up
Authors: Wright Charlotte Margaret , McNair Stephanie , Milligan Beatrice , Livingstone Jennifer , Fraser Emily 
Published: March 2022

ObjectiveTo describe the prevalence of weight loss during tube weaning and its impact on wean duration and growth.SettingTertiary feeding clinic, UK.PatientsAll children seen for weaning from long-term enteral feeding between 2008 and 2016.InterventionsOutpatient withdrawal of enteral feeding.DesignCase series of children being weaned from tube feeding, documenting clinical details, periods of weight loss and timing of feed changes, as well as height and weight at baseline and within 1 year after feed cessation.Main outcome measuresAmount and frequency of weight loss, wean duration, change in body mass index (BMI) and height SD z score.ResultsWeaning was attempted in 58 children, median age 2.7 years, and 90% had stopped feeds after median (range) 5.9 (1–40) months. Weight loss was seen in 51 (88%) children and was more common and severe in children with initially higher BMI. Time to feed cessation reduced by median 4.9 months between 2008–2011 and 2012–2016, while having feeds increased prolonged the wean duration, by median 13 months. After feed cessation, mean (95% CI) BMI had dropped by 0.84 (0.5 to 1.2) z scores, but neither change in BMI, nor the amount and frequency of weight loss, related to growth.ConclusionsShort-term weight loss is to be expected during tube weaning and is not associated with compromised growth. It is important to avoid overfeeding enterally fed children and not to increase feeds again in response to weight loss.
Menthol versus non-menthol flavouring and switching to e-cigarettes in black and Latinx adult menthol combustible cigarette smokers: secondary analyses from a randomised clinical trial
Authors: Nollen Nicole L , Leavens Eleanor L S , Ahluwalia Jasjit S , Rice Myra , Mayo Matthew S , Pulvers Kim 
Published: March 2022

BackgroundAs the US Food and Drug Administration takes regulatory action on menthol cigarettes, debate continues about how restricting menthol e-liquids might impact adult menthol smokers in switching to e-cigarettes.MethodsSwitching patterns and e-cigarette acceptability were assessed at week 6 among 64 black and Latinx menthol cigarette smokers who used JUUL menthol (n=39) or non-menthol e-cigarettes ((n=25), primarily mint or mango) as part of a randomised switching trial.ResultsNo clear evidence of effects was found between menthol versus non-menthol e-cigarettes on use or subjective effects/acceptability, effect sizes for all comparisons were small (effect size=0.0–0.2), and Bayes factor ranged from 0.10 to 0.15. Specifically, 82.1% of participants who used menthol-flavoured e-cigarettes fully or partially switched to e-cigarettes compared with 88.0% of participants who used a non-menthol (p=0.75). Further, both groups demonstrated substantial reductions in cigarettes per day (menthol e-cigarettes: −8.5±10.4 vs non-menthol e-cigarettes: −8.8±5.8, p=0.87), comparable grams of e-liquid consumed (menthol e-cigarettes: 9.2±9.8 g vs non-menthol e-cigarettes: 11.0±11.0 g, p=0.47), and positive subjective effects, including ‘just right’ throat hit (menthol e-cigarettes: 70.7% vs non-menthol e-cigarettes: 66.7%, p=0.93) and flavour liking (menthol e-cigarettes: 75.6% vs non-menthol e-cigarettes: 66.7%, p=0.32).ConclusionsBoth menthol and non-menthol e-cigarettes were associated with high rates of use and acceptability among menthol smokers. Findings require confirmation in a fully powered non-inferiority or equivalence study but provide preliminary evidence to inform regulatory action on menthol e-cigarettes that could slow youth initiation without impacting black and Latinx menthol cigarette smokers interested in switching to e-cigarettes.Trial registration numberNCT03511001.
Coincidence mass spectrometry study of double ionization of anthracene by 70 eV electron impact
Authors: van der Burgt Peter J. M. , Gradziel Marcin L. 
Published: March 2022

AbstractDouble ionization of anthracene molecules by 70 eV electron impact results in a number of prominent fragmentations producing two singly ionized fragments. In our experiment, ionized fragments were detected using a reflectron time-of-flight mass spectrometer. A field programmable gate array was used for the timing and the recording of mass spectra on an event-by-event basis. A detailed model of the coincidence data acquisition was developed, enabling us to reliably obtain the map of true coincidences. Our measurements show that fragmentations for which the total number of carbon atoms in the two singly ionized fragments is even are generally significantly stronger than fragmentations for which the total is odd. No fragmentations are observed for a total number of 13 carbon atoms. There are only very weak fragmentations where one of the fragments only contains one carbon atom. Most of the fragments have 2 or 3 hydrogen atoms. There are several fragmentations in which the larger fragment has 9, 10, 11 or 12 carbon atoms and 5, 6, 7 or 8 hydrogen atoms. Fragments with only carbon atoms and no hydrogen atoms are not present, and only few fragmentations are observed with a fragment containing only one hydrogen atom.
Graphical abstract
Reducing Subspaces for Toeplitz Operator

T

z
1

k

1

z
2

k

2

+
a

z
¯

1

l

1

z
¯

2

l

2

on the Weighted Hardy Space over the Bidisk
Authors: Wei Changguo , Ding Xin , Shi Yanyue 
Published: March 2022

In this paper, we completely characterize the reducing subspaces for

T

φ

a

on weighted Hardy space

ℋ
ω
2

D

2

under three assumptions on

ω

, where

φ

a

=

z

k

+
a

z
¯

l

,

k
,
l
∈

ℕ

2

,

k
≠
l

, and

a
∈

0,1

. It is shown that the coefficient

a
∈

0,1

does not affect the reducing subspaces for

T

φ

a

. We also prove that, for every

δ
>
0

, weighted Dirichlet space

D
δ
2

D

2

is a weighted Hardy space which satisfies these assumptions. As an application, we describe the reducing subspaces for

T

φ

a

on

D
δ
2

D

2

and get the structure of commutant algebra

V

∗

T

φ

a

.
The Association of Prepregnancy Body Mass Index with Pregnancy Outcomes in Chinese Women
Authors: Zhang Jing , An Wensheng , Lin Li 
Published: March 2022

Our study was to evaluate the association between prepregnancy body mass index (BMI) and pregnancy outcomes. A total of 1546 women who attended prenatal care clinics and delivered at the Peking University International Hospital, Beijing, China, from October 2018 to April 2020 was included. This research explored gestational, perinatal, and postpartum outcomes, including gestational diabetes, anemia, preeclampsia, preterm premature rupture of membranes (PPROM), and postpartum hemorrhage. Participants were divided into underweight (

BMI
<
18.5

kg
/

m

2

), normal weight (

18.5

kg
/

m

2

≤
BMI
≤
23.9

kg
/

m

2

), overweight (

24

kg
/

m

2

≤
BMI
≤
27.9

kg
/

m

2

), and obese (

BMI
≥
28

kg
/

m

2

) groups. Logistic regression analysis was used to analyze the association between prepregnancy BMI and pregnancy outcomes, and odds ratio (OR) with 95% confidence interval (95% CI) was calculated. After adjusting potential confounders, the risk of PPROM was higher in the underweight group than the normal weight group (

OR
=
1.864

, 95% CI: 1.269-2.737,

P
<
0.01

). Prepregnancy obesity was associated with higher odds of gestational diabetes (

OR
=
2.649

, 95% CI: 1.701-4.126,

P
<
0.001

) and preeclampsia (

OR
=
3.654

, 95% CI: 1.420-9.404,

P
<
0.01

) than the normal weight group, whereas it correlated with the lower risk of anemia (

OR
=
0.300

, 95% CI: 0.128-0.704,

P
<
0.01

). Our findings may provide evidence for the importance of keeping normal weight for Chinese women when preparing for pregnancy.
First record of Doherty’s Dull Oakblue Arhopala khamti Doherty, 1891 from upper Assam, India
Authors: Singh Arun Pratap 
Published: March 2022

The paper gives the first record of Doherty’s Dull Oakblue, Arhopala khamti Doherty, 1891 from Upper Assam which is a rare species known from the region. The distingusihing features of this species with it congener Hewitson’s Dull Oakblue A. oenea (Hewitson, [1869]) which has an overlapping range with it in NE India are also given.
Identification of Incident Atrial Fibrillation From Electronic Medical Records
Authors: Chamberlain Alanna M. , Roger Véronique L. , Noseworthy Peter A. , Chen Lin Y. , Weston Susan A. , Jiang Ruoxiang , Alonso Alvaro 
Published: March 2022

Background
Electronic medical records are increasingly used to identify disease cohorts; however, computable phenotypes using electronic medical record data are often unable to distinguish between prevalent and incident cases.

Methods and Results

We identified all Olmsted County, Minnesota residents aged ≥18 with a first‐ever
International Classification of Diseases, Ninth Revision (ICD‐9)
diagnostic code for atrial fibrillation or atrial flutter from 2000 to 2014 (N=6177), and a random sample with an
International Classification of Diseases, Tenth Revision (ICD‐10)
code from 2016 to 2018 (N=200). Trained nurse abstractors reviewed all medical records to validate the events and ascertain the date of onset (incidence date). Various algorithms based on number and types of codes (inpatient/outpatient), medications, and procedures were evaluated. Positive predictive value (PPV) and sensitivity of the algorithms were calculated. The lowest PPV was observed for 1 code (64.4%), and the highest PPV was observed for 2 codes (any type) >7 days apart but within 1 year (71.6%). Requiring either 1 inpatient or 2 outpatient codes separated by >7 days but within 1 year had the best balance between PPV (69.9%) and sensitivity (95.5%). PPVs were slightly higher using
ICD‐10
codes. Requiring an anticoagulant or antiarrhythmic prescription or electrical cardioversion in addition to diagnostic code(s) modestly improved the PPVs at the expense of large reductions in sensitivity.

Conclusions
We developed simple, exportable, computable phenotypes for atrial fibrillation using structured electronic medical record data. However, use of diagnostic codes to identify incident atrial fibrillation is prone to some misclassification. Further study is warranted to determine whether more complex phenotypes, including unstructured data sources or using machine learning techniques, may improve the accuracy of identifying incident atrial fibrillation.
Wnt Site Signaling Inhibitor Secreted Frizzled‐Related Protein 3 Protects Mitral Valve Endothelium From Myocardial Infarction–Induced Endothelial‐to‐Mesenchymal Transition
Authors: Alvandi Zahra , Nagata Yasufumi , Passos Livia Silva Araúujo , Hashemi Gheinani Ali , Guerrero J. Luis , Wylie‐Sears Jill , Romero Dayana Carolina , Morris Brittan A. , Sullivan Suzanne M. , Yaghoubian Koushiar M. , Alvandi Amirhossein , Adam Rosalyn M. , Aikawa Elena , Levine Robert A. , Bischoff Joyce 
Published: March 2022

Background
The onset and mechanisms of endothelial‐to‐mesenchymal transition (EndMT) in mitral valve (MV) leaflets following myocardial infarction (MI) are unknown, yet these events are closely linked to stiffening of leaflets and development of ischemic mitral regurgitation. We investigated whether circulating molecules present in plasma within days after MI incite EndMT in MV leaflets.

Methods and Results
We examined the onset of EndMT in MV leaflets from 9 sheep with inferior MI, 8 with sham surgery, and 6 naïve controls. Ovine MVs 8 to 10 days after inferior MI displayed EndMT, shown by increased vascular endothelial cadherin/α‐smooth muscle actin–positive cells. The effect of plasma on EndMT in MV endothelial cells (VECs) was assessed by quantitative polymerase chain reaction, migration assays, and immunofluorescence. In vitro, post‐MI plasma induced EndMT marker expression and enhanced migration of mitral VECs; sham plasma did not. Analysis of sham versus post‐MI plasma revealed a significant drop in the Wnt signaling antagonist sFRP3 (secreted frizzled‐related protein 3) in post‐MI plasma. Addition of recombinant sFRP3 to post‐MI plasma reversed its EndMT‐inducing effect on mitral VECs. RNA‐sequencing analysis of mitral VECs exposed to post‐MI plasma showed upregulated FOXM1 (forkhead box M1). Blocking FOXM1 reduced EndMT transcripts in mitral VECs treated with post‐MI plasma. Finally, FOXM1 induced by post‐MI plasma was downregulated by sFRP3.

Conclusions
Reduced sFRP3 in post‐MI plasma facilitates EndMT in mitral VECs by increasing the transcription factor FOXM1. Restoring sFRP3 levels or inhibiting FOXM1 soon after MI may provide a novel strategy to modulate EndMT in the MV to prevent ischemic mitral regurgitation and heart failure.
Impact of Implicit Abdominal Aortic Aneurysm Screening in the Veterans Affairs Health Care System Over 10 Years
Authors: Leach Joseph R. , Shen Hui , Huo Eugene , Hope Thomas A. , Mitsouras Dimitrios , Whooley Mary A. , Hope Michael D. 
Published: March 2022

Background
Abdominal aortic aneurysm (AAA) screening programs have been active in the United States since 2005, but are not the only way AAAs are detected. AAA management and outcomes have not been investigated broadly in the context of “implicit AAA screening,” whereby radiologic examinations not intended for focused screening can identify AAAs.

Methods and Results

We examined the association between imaging‐based AAA screening, both explicit and implicit, and various outcomes for ≈1.6 million veterans in the Veterans Affairs health care system from 2005 to 2015. Screened‐positive, screened‐negative, and unscreened veterans were identified in the overall cohort and within a subgroup of veterans aged 65 years in 2005. The yearly composite screening rate increased over 10 years, from 11.7% to 18.3%, whereas the screened‐positive rate decreased from 7.3% to 4.9%. Only 12.9% of screening examinations were explicit AAA screening ultrasounds. The subgroup’s composite screening rate was 74% within its 10‐year eligibility window, with implicit screening accounting for 91.8% of examinations. In the 2005 subgroup, all‐cause mortality and Charlson comorbidity scores were higher for veterans who underwent screening compared with those unscreened (31.2% versus 23.1% and 0.47 versus 0.25, respectively;
P
<0.001). AAA rupture rates were similar between those unscreened and screened‐negative individuals.

Conclusions
Accounting for both explicit and implicit screening, AAA screening in the Veterans Affairs population has moderate reach. Efforts to expand explicit AAA screening are not likely to impact either all‐cause mortality or AAA rupture on the population scale as significantly as a careful accounting for and use of implicit screening data.
The Influence of Intraseasonal Oscillations on Humid Heat in the Persian Gulf and South Asia
Authors: Ivanovich Catherine , Anderson Weston , Horton Radley , Raymond Colin , Sobel Adam 
Published: March 2022

Abstract
Humans’ essential ability to combat heat stress through sweat-based evaporative cooling is modulated by ambient air temperature and humidity, making humid heat a critical factor for human health. In this study, we relate the occurrence of extreme humid heat in two focus regions to two related modes of intraseasonal climate variability: the Madden–Julian oscillation (MJO) and the boreal summer intraseasonal oscillation (BSISO). In the Persian Gulf and South Asia during the May–June and July–August seasons, wet-bulb temperatures of 28°C are found to be almost twice as likely during certain oscillation phases than in others. Variations in moisture are found, to varying degrees, to be an important ingredient in anomalously high wet-bulb temperatures in all three areas studied, influenced by distinct local circulation anomalies. In the Persian Gulf, weakening of climatological winds associated with the intraseasonal oscillation’s propagating center of convection allows for anomalous onshore advection of humid air. Anomalously high wet-bulb temperatures in the northwestern region of South Asia are closely aligned with positive specific humidity anomalies associated with the convectively active phase of the oscillation. On the southeastern coast of India, high wet-bulb temperatures are associated with convectively inactive phases of the intraseasonal oscillation, suggesting that they may be driven by increased surface insolation and reduced evaporative cooling during monsoon breaks. Our results aid in building a foundation for subseasonal predictions of extreme humid heat in regions where it is highly impactful.

Significance Statement
Understanding when and why extreme humid heat occurs is essential for informing public health efforts protecting against heat stress. This analysis works to improve our understanding of humid heat variability in two at-risk regions, the Persian Gulf and South Asia. By exploring how subseasonal oscillations affect daily extreme events, this analysis helps bridge the prediction gap between weather and climate. We find that extreme humid heat is more than twice as likely during specific phases of these oscillations than in others. Extremes depend to different extents upon combinations of above-average temperature and humidity. This new knowledge of the regional drivers of humid heat variability is important to better prepare for the increasingly widespread health and socioeconomic impacts of heat stress.
Deep-Current Intraseasonal Variability Interpreted as Topographic Rossby Waves and Deep Eddies in the Xisha Islands of the South China Sea
Authors: Shu Yeqiang , Wang Jinghong , Xue Huijie , Huang Rui Xin , Chen Ju , Wang Dongxiao , Wang Qiang , Xie Qiang , Wang Weiqiang 
Published: March 2022

Abstract
Strong subinertial variability near a seamount at the Xisha Islands in the South China Sea was revealed by mooring observations from January 2017 to January 2018. The intraseasonal deep flows presented two significant frequency bands, with periods of 9–20 and 30–120 days, corresponding to topographic Rossby waves (TRWs) and deep eddies, respectively. The TRW and deep eddy signals explained approximately 60% of the kinetic energy of the deep subinertial currents. The TRWs at the Ma, Mb, and Mc moorings had 297, 262, and 274 m vertical trapping lengths, and ∼43, 38, and 55 km wavelengths, respectively. Deep eddies were independent from the upper layer, with the largest temperature anomaly being >0.4°C. The generation of the TRWs was induced by mesoscale perturbations in the upper layer. The interaction between the cyclonic–anticyclonic eddy pair and the seamount topography contributed to the generation of deep eddies. Owing to the potential vorticity conservation, the westward-propagating tilted interface across the eddy pair squeezed the deep-water column, thereby giving rise to negative vorticity west of the seamount. The strong front between the eddy pair induced a northward deep flow, thereby generating a strong horizontal velocity shear because of lateral friction and enhanced negative vorticity. Approximately 4 years of observations further confirmed the high occurrence of TRWs and deep eddies. TRWs and deep eddies might be crucial for deep mixing near rough topographies by transferring mesoscale energy to small scales.