bluuebunny/crossref_metadata_2025_split huggingface dataset:
Assessments of hydropower plants start-up sequences and equivalent runner damage under transient operation
Authors: Seydoux M , Vagnoni E , Nicolet C , Alligné S , Hugo N , Paolone M 
Published: October 2022

Abstract
With specific reference to the HPP start-up sequence, the conventional process requires to operate the runner in a particular operating regime called Speed-No-Load (SNL) that is detrimental for the runner. Thanks to last decade’s improvements in MW-class power electronics, new generators’ technologies have emerged providing an additional degree of freedom to HPPs control. In this respect, the control of the hydraulic turbine speed can be used to decrease the level of damage induced on the runner by choosing the appropriate trajectory for transient operations. Variable speed is a recent technology and its capability to improve the transient operation of hydraulic machines is not fully addressed in literature and, specifically, for start-up sequences. To fully take advantage of such an added degree of freedom, an in-depth experimental study has been performed at EPFL (PTMH) on a specific speed homologous reduced scale model of the unit 5 of Z’Mutt HPP equipped with a reversible pump-turbine. The paper presents a methodology to (i) investigate different transient sequences to start-up the hydraulic machine, which have been tested on reduced scale model, and to (ii) evaluate the equivalent damage impact on the runner. The results of this study highlight the advantages of leveraging the variable speed technology during the unit start-up.
Variation law of pressure pulsation during variable speed operation of pumped storage units
Authors: Li Yulan , Yang Weijia , Huang Yifan , Ma Weichao , Zhao Zhigao , Yang Jiebin , Yang Jiandong 
Published: October 2022

Abstract
Variable speed operation technology has become an emerging development direction in hydropower industry. Variable-speed pumped storage plants (VSPSPs) constantly undergo various transient processes, and ensuring the amplitude of pressure pulsation within the control range is critical to the safe operation of variable-speed pumped storage units (VSPSUs). However, its extreme value is usually determined by rule of thumb in design stage, and few researches focus on the relationship between pressure pulsation and variable speed operation of VSPSUs. In this paper, characteristic curves of pressure pulsation are plotted by processing model test results with Gridfit function, taking a real VSPSP as an example. The total pressure during transient processes is predicted by simulation of a numerical model. Load rejection conditions (change initial speed) and large load regulation conditions (change speed command and power command) are simulated, and the influence of operating trajectory on pressure pulsation during variable speed operation is analyzed. The results show that with the increase of initial speed or speed command, the value of pressure pulsation increases; the trajectory passes through more high-amplitude pressure pulsation region and gradually shifts to the S-shaped region, causing the pressure oscillation. This study could provide theoretical reference for the operation of VSPSUs.
Dynamic performance and sensitivity of grid-connected hydropower station under uncertain disturbance
Authors: Liu Y , Guo W C , Cao R , Chen Z , Wang L 
Published: October 2022

Abstract
The grid-connected operating condition of hydropower station is a common operation mode to provide electric energy for the load side. This paper investigates the dynamic performance and sensitivity of grid-connected hydropower station (GCHS) under uncertain disturbance. Firstly, the nonlinear uncertain model of GCHS under uncertain disturbance is established. Then, the dynamic performance of GCHS is studied when the governor parameters change under certain step disturbance, periodic disturbance and uncertain random disturbance, respectively. Finally, based on the sensitivity index of the uncertain output obtained from the extended Fourier amplitude sensitivity test method, the sensitivity of the uncertain random disturbance at different input positions is studied. The results indicate that the GCHS under periodic disturbances or random disturbances have more complex dynamic performance than that under certain step disturbance. Under periodic disturbance, the forced oscillations and high frequency resonances are generated in dynamic response of GCHS. Under the uncertain random disturbance, the system of GCHS always presents random oscillation. The state variables q

H
, z, qP, y, x

s
, x

t
, and δ of GCHS are the most sensitive to uncertain disturbances, which are introduced at the generator or surge tank. The uncertain disturbances have significant interaction on the dynamic response of GCHS.
Multifunctional water tower
Authors: Jandourek Pavel , Pochylý František 
Published: October 2022

Abstract
The aim of this article is to present a new technical solution of the multifunctional water tower. The principle of the new designed a water tower is fundamentally based on self-sufficiency and independence of energy sources, either the energy of the sun or the wind is used. To the conversion of this energy into mechanical energy for pumping of water to storage tank is used a ball screw mechanism, which driving a high discharge displacement pump based on the piston principle.
Randomized placebo-controlled crossover trial of memantine in children with epileptic encephalopathy
Authors: Schiller Katharina , Berrahmoune Saoussen , Dassi Christelle , Corriveau Isabelle , Ayash Taghreed A , Osterman Bradley , Poulin Chantal , Shevell Michael I , Simard-Tremblay Elisabeth , Sébire Guillaume , Myers Kenneth A 
Published: October 2022

AbstractMemantine is an N-methyl-D-aspartate receptor antagonist, approved for dementia treatment. There is limited evidence of memantine showing benefit for paediatric neurodevelopmental phenotypes, but no randomized placebo-controlled trials in children with developmental and epileptic encephalopathy.In this randomized double-blind placebo-controlled crossover trial (Trial registration: https://clinicaltrials.gov/ct2/show/NCT03779672), patients with developmental and epileptic encephalopathy received memantine and placebo, each for a 6-week period separated by a 2-week washout phase. Electroencephalography, seizure diary, patient caregivers’ global impression, serum inflammatory markers and neuropsychological evaluation were performed at baseline and after each treatment phase. The primary outcome measure was classification as a ‘responder’, defined as ≥2 of: &gt;50% seizure frequency reduction, electroencephalography improvement, caregiver clinical impression improvement or clear neuropsychological testing improvement.Thirty-one patients (13 females) enrolled. Two patients withdrew prior to initiating medication and two (twins) had to be removed from analysis. Of the remaining 27 patients, nine (33%) were classified as responders to memantine versus two (7%) in the placebo group (P &lt; 0.02). Electroencephalography improvement was seen in eight patients on memantine compared to two on placebo (P &lt; 0.04). Seizure improvement was observed in eight patients on memantine and two on placebo (P &lt; 0.04). Caregivers reported overall clinical improvement in 10 patients on memantine compared to seven on placebo (not significant). Statistical analysis of neuropsychological evaluation suggested improvements in symptoms of attention-deficit hyperactivity disorder and autism.Memantine is a safe and effective treatment for children with developmental and epileptic encephalopathy, having the potential to improve both seizure control and cognitive function.
Urine Tenofovir Levels Strongly Correlate With Virologic Suppression in Patients With Human Immunodeficiency Virus on Tenofovir Alafenamide-Based Antiretroviral Therapy
Authors: Johnson Kelly A , Okochi Hideaki , Arreguin Mireya , Watabe Joseph , Glidden David V , Chattopadhyay Anindita , Imbert Elizabeth , Hickey Matthew D , Gandhi Monica , Spinelli Matthew 
Published: October 2022

Abstract
We found that urine tenofovir (TFV) levels &gt;1500 ng/mL strongly predict virologic suppression among people with human immunodeficiency virus taking tenofovir alafenamide (odds ratio, 5.66; 95% confidence interval, 1.59–20.14; P = .007). This suggests an existing point-of-care assay developed for tenofovir disoproxil fumarate will support adherence monitoring for patients on all TFV-based antiretrovirals.
circSMAD4 Promotes Experimental Colitis and Impairs Intestinal Barrier Functions by Targeting Janus Kinase 2 Through Sponging miR-135a-5p
Authors: Zhao Jie , Lin Zhiliang , Ying Pu , Zhao Zhibin , Yang Haojun , Qian Jun , Gong Yu , Zhou Yan , Dai Yi , Jiao Yuwen , Zhu Weiming , Wang Honggang , Tang Liming 
Published: October 2022

Abstract

Background
Numerous studies have explored the association between circular RNAs [circRNAs] and Crohn’s disease [CD]. However, the pathological role, biological functions, and molecular mechanisms of circRNAs in CD have not been fully elucidated.

Methods
The circRNA microarray analysis was performed to identify deregulated circRNAs in colon tissues. The identified circRNAs were verified through quantitative real-time polymerase chain reaction [qRT-PCR]. In vivo and in vitro functional studies were performed to verify the role of circSMAD4 in CD and investigate the mechanisms involved.

Results
We found that circSMAD4 was the most significantly upregulated circRNA. The expression level of circSMAD4 was positively correlated with levels of inflammatory factors. Overexpression of circSMAD4 impaired tight junction [TJ] proteins and enhanced apoptosis of epithelial cells. These effects were reversed by treatment with miR-135a-5p mimic. Mechanistic studies showed that circSMAD4 exerts its effects on CD by ‘sponging’ miR-135a-5p to regulate Janus kinase 2 [JAK2]. Si-circSMAD4 delivery through microspheres ameliorated experimental colitis and protected the intestinal barrier function in IL-10 knockout mice.

Conclusion
This study shows that circSMAD4 regulates the progression of experimental colitis via the miR-135a-5p/JAK2 signalling axis and it may be a potential therapeutic target.
A validated score to predict one-year and long-term mortality in patients with significant tricuspid regurgitation
Authors: Hochstadt Aviram , Maor Elad , Ghantous Eihab , Merdler Ilan , Granot Yoav , Rubinshtein Ronen , Banai Shmuel , Segev Amit , Kuperstein Rafael , Topilsky Yan 
Published: October 2022

Abstract

Aims
Most patients with significant (defined as ≥ moderate) tricuspid regurgitation (TR) are treated conservatively. Individual mortality rates are markedly variable. We developed a risk score based on comprehensive clinical and echocardiographic evaluation, predicting mortality on an individual patient level.

Methods and results
The cohort included 1701 consecutive patients with significant TR, half with isolated TR, admitted to a single hospital, treated conservatively. We derived a scoring system predicting 1-year mortality and validated it using k-fold cross-validation and with external validation on another cohort of 5141 patients. Score utility was compared with matched patients without significant TR. One-year mortality rate was 31.3%. The risk score ranged 0–17 points and included 11 parameters: age (0–3), body mass index ≤ 25 (0–1), history of liver disease (0–2), history of chronic lung disease (0–2), estimated glomerular filtration rate (0–5), haemoglobin (0–2), left-ventricular ejection fraction (0–1), right-ventricular dysfunction (0–1), right atrial pressure (0–2), stroke volume index (SVI) (0–1) and left-ventricular end-diastolic diameter (0–1). One-year mortality rates increased from 0 to 100%, as the score increased up to ≥16. Areas under the receiver operating curves were 0.78, 0.70, and 0.73, for the original, external validation, and external validation with SVI measured cohorts. The score remained valid in subpopulations of patients with quantified RV function, quantified TR and isolated TR. Significant TR compared to no TR, affected 1-year mortality stronger with higher scores, with a significantly positive interaction term.

Conclusion
We suggest a robust risk score for inpatients with significant TR, assisting risk stratification and decision-making. Our findings underscore the burden of TR providing benchmarks for clinical trial design.
Effect of Motexafin lutetium-mediated ultrasound-guided red laser photodynamic therapy on endothelial dysfunction using a new automatic ultrasound image processing software
Authors: Mehrad H 
Published: October 2022

Abstract

Background
As is well recognized, the majority of atherosclerosis start with an inflammatory process, resulting in endothelial dysfunction.

Purpose
In this study, we developed an experimental photosensitizer Motexafin lutetium (Lu-Tex)-mediated photodynamic therapy system, and investigated its effectiveness on endothelial dysfunction improvement in an animal model of balloon dilation injury, using a new automatic ultrasound image processing software.

Methods
Briefly, Golden Syrian hamsters' femoral artery underwent balloon dilatation injury. After four weeks, femoral arteries of the treatment group at the lesion region, treated using Motexafin lutetium - mediated fiber optic catheter-based red low level laser (742 nm, 150 J/cm2) photodynamic therapy. In order to evaluate endothelial-dependent relaxation, acetylcholine-mediated dilation (AMD) was measured during the infusion of acetylcholine at a rate of 0.5 μg/kg/min and endothelial independent relaxation was evaluated by measuring nitroglycerin mediated dilation (NMD) during the infusion of nitroglycerin at a rate of 5μg/kg/min. For off-line analysis, a computerized analysis method for evaluating instantaneous changes in the wall of the hamster femoral artery was used. For automatic measurement of the mean wall thickness and the lumen diameter from longitudinal B-mode ultrasound images, two algorithms, i.e., maximum gradient and dynamic programming were composed and implemented. Reference points and cost function were based on dynamic programming and maximum gradient, respectively.

Results
Results from computerized B-mode ultrasound image processing software showed significant differences in AMD between the treated and the non-treated hamsters (p&lt;0.05), whereas there were no significant differences in NMD between the treatment and normal groups (p&gt;0.05).

Conclusion
Cytotoxic and anti-inflammatory effect of Motexafin lutetium, induced by red laser photodynamic therapy accompanied by photobiomodulation effect of red laser, can cause to reduce the immune cells in intimal layer and improve the endothelial dysfunction via increasing the endothelial nitric oxide synthase function. Furthermore, it is concluded that the new automatic method enables accurate and repeated evaluation of the endothelial dysfunction using photodynamic therapy in this model.

Funding Acknowledgement
Type of funding sources: Public Institution(s). Main funding source(s): Mehrad Research Lab
LA strain helps identifying the cardioembolic etiology of transient ischemic attacks
Authors: Arnautu D A , Vacarescu C , Arnautu S F , Gaita L , Cozma D 
Published: October 2022

Abstract

Background
Patients who have transient ischemic attacks (TIA) often suffer from asymptomatic and paroxysmal atrial fibrillation (AF). Due to the fact that AF is located in the atria, we sought to determine whether abnormalities in left atrial (LA) structure and function could help identify the cardioembolic cause of TIA in patients with sinus rhythm but with documented episodes of paroxysmal AF.

Methods
The research included 190 individuals with TIA and classified them into two groups based on the presence (group I) or absence (group II) of confirmed paroxysmal AF. The diagnosis of paroxysmal AF was established by an assessment of medical records. To prevent assessing atrial stunning, cardiac ultrasonography was conducted in sinus rhythm at least 14 days following the initiation the TIA.

Results
The results indicated that patients in group I were older, more often female, had a history of stroke or TIA, and had a higher CHA2DS2-VASc score. Additionally, they exhibited increased LA volumes, a decreased LA emptying fraction, and markedly altered LA deformation patterns. Three factors were found as being independently associated with paroxysmal AF using multivariate logistic regression: age, LA reservoir strain, and LA emptying fraction (P&lt;0.0001). The variables had as cut-off values: age &gt;55 years, LA reservoir strain&lt;−17%, and LA emptying fraction &lt;51%.

Conclusion
The current research establishes that LA strains are independently associated with paroxysmal AF in patients with TIA and may aid in determining the cardioembolic origin of these events.
Our findings have considerable clinical implications because, until now, LA 2D-STE was not included in the usual evaluation of TIA patients, but it may be the ideal next step in this regard.

Funding Acknowledgement
Type of funding sources: None.
Global longitudinal strain assessment in long-term survivors of childhood acute lymphoblastic leukemia
Authors: Gonzalez-Manzanares R , Pericet-Rodriguez C , Fernandez-Ruiz A , Fernandez-Aviles C , Heredia-Campos G , Resua-Collazo A , Castillo-Dominguez J C 
Published: October 2022

Abstract

Background
The role of global longitudinal strain (GLS) in the long-term cardiac evaluation of childhood acute lymphoblastic leukemia (ALL) survivors is not clearly defined.

Purpose
To assess the prevalence of subclinical left ventricular systolic dysfunction (SLVD) in long-term survivors of ALL. We also aimed to compare echocardiographic measurements with a control group.

Methods
Patients &lt;18 years of age diagnosed with ALL between 1985–2015 at our center were enrolled. Healthy siblings willing to participate were conformed the control group. GLS was measured with an automated software (AutoStrain, Tomtec). SLVD was defined as GLS&lt;18.5% (absolute value) based on the lower limit of the 95% confidence interval in the control group. Group differences were accounted with nverse probability of treatment weighting.

Results
Of the 90 survivors included (37.8% female, time from diagnosis 18 [11–26] years), 24 (26.6%) had SLVD. Left ventricular systolic but not diastolic measurements were reduced compared to the control group (Table 1). Predictors of GLS in the survivors were smoking (p=0.004) and history of hematopoietic stem-cell transplantation (p=0.042) (Table 2).

Conclusions
Over ¼ of childhood ALL survivors had abnormal GLS values after a median follow-up of 18 years. Left-ventricular systolic parameters were reduced compared to a control group.

Funding Acknowledgement
Type of funding sources: Foundation. Main funding source(s): Sociedad Española de Cardiología. Sociedad Andaluza de Cardiología.
Changes in right ventricular two-dimensional echocardiographic speckle-tracking indices in adult LVAD population: a prospective clinical study
Authors: Stapor M , Pilat A , Gorkiewicz-Kot I , Kleczynski P , Zmudka K , Legutko J , Kapelak B , Wierzbicki K , Gackowski A 
Published: October 2022

Abstract

Objective
Preserved right ventricular (RV) function is crucial in patients supported with left ventricular assist devices (LVAD). The use of strain derived from speckle tracking echocardiography (STE) is recommended by recent guidelines to evaluate intricate RV contractility. The data regarding long-term RV observation in LVAD patients using STE are limited. Thus, the study aimed to determine RV systolic function by STE in the remote period after LVAD implantation.

Methods
Patients with implanted third-generation LVADs with hydrodynamic bearing were prospectively enrolled (NCT05063006). The RV STE indices were analyzed before and after LVAD implantation, both at rest and during the cycle ergometer exercise test.

Results
We included 22 patients, the mean age was 58.4±7 years, 95.5% were men, and 45.5% had dilated cardiomyopathy. Stress tests were conducted 7 months postoperatively. The RV strain analysis was feasible in all subjects both in rest and exercise. The RV free wall strain (RVFWS) worsened from −13% (IQR, −17.3 to −10.9) to −11.3% (IQR, −12.9 to −6; p=0.033) after LVAD implantation with the particular decline in the apical RV segment [−11.3% (IQR, −16.4 to −6.2) vs −7.8% (IQR, −11.7 to −3.9; p=0.012)]. The RV four-chamber longitudinal strain (RV4CSL) remained unchanged [−8.5% (IQR, −10.8 to −6.9) vs −7.3% (IQR, −9.8 to −4.7; p=0.184)]. Neither RVFWS (−11.3% (IQR, −12.9 to −6) vs −9.9% (IQR, −13.5 to −7.5; p=0.077) nor RV4CSL [−7.3% (IQR, −9.8 to −4.7) vs −7.9% (IQR, −9.8 to −6.3; p=0.548)] changed during cycle ergometer stress test.

Conclusion
The RVFWS worsens after LVAD implantation presumably due to impaired apical contractility. In LVAD-supported patients during the cycle ergometer stress test, the detailed RV strain analysis is feasible and its indices remain unchanged.

Funding Acknowledgement
Type of funding sources: Other. Main funding source(s): 1. Cor Aegrum Foundation of Cardiac Surgery Development in Cracow2. Medtronic Poland sp. z o.o.
Could echocardiographic left atrial characterization have additive value for detecting risks of atrial arrhythmias and stroke in patients with hypertrophic cardiomyopathy?
Authors: Al Wazzan A , Galli E , Lacout M , Paven E , L'official G , Schnell F , Oger E , Donal E 
Published: October 2022

Abstract

Background
Atrial arrhythmia (AA) is considered a turning point for prognosis in hypertrophic cardiomyopathy (HCM) patients. Prediction of AA and associated stroke risk in patients with HCM is an important clinical challenge as these events can occur in young subjects and significantly impact their quality of life. (1) (2)

Purpose
We sought to assess whether an echocardiographic evaluation focused on the left atrial (LA) characterization could estimate the occurrence of AA and stroke in HCM patients.

Methods
216 HCM-patients (52±16 years old) were enrolled between 2016 and 2019. All patients underwent transthoracic echocardiography for the evaluation of left atrial volume (LAV), left ventricular global longitudinal strain (LV-GLS), peak left atrial strain (PLAS) and peak atrial contraction strain (PACS) by speckle-tracking imaging. A composite endpoint was defined as a history of AA and/or a history of stroke or peripheral embolism and/or occurrence of AA.

Results
The patients were followed for 2.9 years. Among the 216 patients, 78 (36%) met the composite endpoint. These patients were older (50.3±16.7 vs. 57.1±14.4 years, p=0.0035), had a higher prevalence of arterial hypertension (42.3% vs. 62.3%; p=0.005) and had higher NT-proBNP levels. LAV (37.2±15.7 vs. 47±20 ml/m2, p=0.0001) was significantly higher in patients who met the composite endpoint, whereas PLAS and PACS were significantly impaired (26.6±9.12 vs. 19.3±9.54%; p&lt;0.0001 and 13.1±6.3% vs. 8.8±6.5%; p&lt;0.0001, respectively). After adjustment, PLAS and PACS remained independently associated with events with an odds ratio (OR) of 0.42 for PLAS (95% CI, [0.29–0.61]; p&lt;0.0001). Stroke occurred in 67% of the patients without any clinical AA. PLAS with a cut-off of under 15.5% provided event detection with 91% specificity and demonstrated a predictive value for new-onset of AA. Although there was a high correlation between PLAS and LV-GLS, LV-GLS was not associated with the events.

Conclusion
The impairment of LA function assessed by 2D speckle-tracking echocardiography was strongly associated with AA and the risk of stroke, even in patients without any documented AA. Its value for guiding the management of HCM-patients requires further investigation.

Funding Acknowledgement
Type of funding sources: None.