bluuebunny/crossref_metadata_2025_split huggingface dataset:
Copper-catalyzed multicomponent cascade synthesis of polyfunctionalized β-ketone sulfones
Authors: Luo Chun-Mei , Sun Yong-Bin , Wang Ling-Tao , Dai Nan-Nan , Li Jiao-Zhe , Zhang Jianfeng , Chen Jin-Yang , Wei Wen-Ting , Ge Guo-Ping 
Published: July 2023

Polyfunctionalized β-ketone sulfones are prepared in one-pot through a series of processes including radical relay, radical addition, hydrogen abstraction, hydrolysis or oxidation.
Resilience analysis and optimal control of grid‐connected converters under unbalanced voltage conditions
Authors: Wang Qi , Yu Peng , Wang Peng 
Published: July 2023

AbstractThe operational stability of grid‐connected converters is affected by unbalanced grid voltage, which often leads to overcurrent. The traditional control method maintains the grid‐into current within the rated limit by adjusting the current reference value. However, this method limits the output active power of the converters and affects their reliability, which can cause active power shortage or even disconnection of the power grid. To deal with this issue, this paper proposes an effective control strategy. First, the interaction between AC and DC sides of the converters under unbalanced voltage conditions is analysed. Second, the resilience is defined and elaborated. Third, considering various constraints such as the grid‐into current harmonics, power fluctuations and DC side voltage fluctuations, the operation resilience range of the converters is calculated. Based on the resilience range, an optimal operating point is selected and an optimal strategy is developed. Compared with the traditional strategy, the proposed strategy allows improving the maximum active power output capacity and resilience of the grid‐connected converters under unbalanced grid conditions, while simultaneously limiting the power fluctuations and grid‐into current distortions within an allowable range. Last, simulation and experimental results show the effectiveness and feasibility of the proposed strategy.
Resilient planning for high‐renewable‐integrated transmission systems under the impacts of ice storm disasters
Authors: Niu Tao , Huang Qianqian , Fang Sidun , Chen Guanhong , Liao Ruijin 
Published: July 2023

AbstractIce storm disasters pose great challenges to the safe and stable operation of transmission systems, especially in high‐renewable‐integration scenarios. However, as one of the major types of natural disasters that can have severe consequences, ice storm disasters are much less studied than hurricanes and earthquakes. Ice storm disasters are characterized by a long duration and wide scope, which affect the source, network, and load side of the power grid. It is difficult to formulate a quantitative evaluation of resilience and establish effective planning strategies. Here, a resilient planning method considering the interactive effects of ice disasters on sources, networks, and loads is therefore proposed. First, the two‐stage Monte Carlo method is used to generate multiple grid fault scenarios for different levels of ice storm disasters. Then, an index is proposed to quantify the grid resilience as the total amount of system power loss caused by ice storm disasters. Based on this approach, a two‐layer mathematical model is established with grid resilience and total investment cost objectives in each fault scenario. Hierarchical reinforcement and the protection of generating units and transmission lines are selected as investment strategies to mitigate the impact of ice storm disasters. Finally, the IEEE‐24 node transmission system is used to verify the feasibility and effectiveness of the proposed method. Optimizing the planning strategy can significantly improve system resilience with minimal investment cost.
Direction‐of‐arrival estimation for wideband linear frequency modulated signals with weighted l1‐norm in the fractional Fourier domain
Authors: Zhong Jun , Chen Zhong , Peng Fei , Bi Xiaowen , Chen Tingting 
Published: July 2023

AbstractDirection‐of‐arrival (DOA) estimation methods for wideband linear frequency modulated (LFM) signals based on fractional Fourier transform (FRFT) typically use the single snapshot vector in the fractional Fourier (FRF) domain. However, the low‐rank problem of the second‐order statistics in the single snapshot vector can decrease the DOA estimation resolution and cause issues in DOA estimation for coherent sources. In order to address these problems, a weighted l1‐norm method based on FRFT is proposed. The proposed method utilises the energy aggregation property of FRFT for LFM signals. This allows for obtaining a single snapshot vector in the FRF domain. Subsequently, a sparse representation DOA estimation model is established by taking advantage of the sparsity of the target distribution in the spatial domain. The DOA estimation is then obtained by minimising the l1‐norm. To further enhance the DOA estimation performance, we construct a matrix by rearranging the elements of the eigenvectors corresponding to the nonzero eigenvalue of the covariance matrix in the FRF domain. The rank of this matrix is equal to the number of sources, ensuring the orthogonality of the subspace obtained by the reconstructed matrix. Finally, a weighted matrix is constructed by exploiting the subspace orthogonality principle to adjust the sparsity penalty of the l1 constraint model. Simulation results demonstrate that our method is capable of achieving high angular resolution and accuracy even at low SNR and can process coherent signals directly.
The space weather around the exoplanet GJ 436b
Authors: Bellotti S. , Fares R. , Vidotto A. A. , Morin J. , Petit P. , Hussain G. A. J. , Bourrier V. , Donati J. F. , Moutou C. , Hébrard É. M. 
Published: July 2023

Context. The space environment in which planets are embedded mainly depends on the host star and impacts the evolution of the planetary atmosphere. The quiet M dwarf GJ 436 hosts a close-in hot Neptune which is known to feature a comet-like tail of hydrogen atoms that escaped from its atmosphere due to energetic stellar irradiation. Understanding such star-planet interactions is essential to shed more light on planet formation and evolution theories, in particular the scarcity of Neptune-sized planets below a 3 d orbital period, also known as the ‘Neptune desert’.
Aims. We aimed to characterise the stellar environment around GJ 436, which requires accurate knowledge of the stellar magnetic field. The latter is studied efficiently with spectropolarimetry, since it is possible to recover the geometry of the large-scale magnetic field by applying tomographic inversion on time series of circularly polarised spectra.
Methods. We used spectropolarimetric data collected in the optical domain with Narval in 2016 to compute the longitudinal magnetic field, examine its periodic content via Lomb-Scargle periodogram and Gaussian process regression analysis, and finally reconstruct the large-scale field configuration by means of Zeeman-Doppler imaging.
Results. We found an average longitudinal field of −12 G and a stellar rotation period of 46.6 d using a Gaussian process model and 40.1 d using Zeeman-Doppler imaging, which are both consistent with the literature. The Lomb-Scargle analysis did not reveal any significant periodicity. The reconstructed large-scale magnetic field is predominantly poloidal, dipolar, and axisymmetric, with a mean strength of 16 G. This is in agreement with magnetic topologies seen for other stars of a similar spectral type and rotation rate.
Der Einfluss von Selbstwirksamkeit auf die tägliche Bewältigung von Schmerzen bei Patient*innen mit muskuloskelettalen Beschwerden
Authors: Didion Nick , Kramp Annalena , Karstens Sven 
Published: July 2023

Zusammenfassung
Hintergrund In der Physiotherapie findet das Konzept der Selbstwirksamkeit zunehmend Anwendung. Die subjektive Überzeugung von Patient*innen, in der Lage zu sein, ein bestimmtes Leistungsniveau bei einer Tätigkeit zu erreichen, soll gefördert werden.
Ziel Die Studie soll einen Überblick geben, wie sich Selbstwirksamkeit aus subjektiver Sicht von Patient*innen mit muskuloskelettalen Erkrankungen auf ihre Schmerzbewältigung im Alltag auswirkt.
Methode Es wurde eine qualitative Synthese durchgeführt. Für die Literaturrecherche wurden die Suchmaschinen PubMed und Google Scholar genutzt. Eingeschlossen wurden qualitative Studien mit Patient*innen mit muskuloskelettalen Beschwerden, die die Auswirkungen von Selbstwirksamkeit auf physische Symptome untersuchten. Die Qualitätsüberprüfung der Studien wurde anhand der „JBI Checklist for qualitative Synthesis“ durchgeführt. Die Auswertung der Daten orientierte sich an der strukturierenden Inhaltsanalyse. Die 4 Hauptkategorien wurden zunächst deduktiv anhand einer Theorie zur Selbstwirksamkeit gebildet.
Ergebnisse Es wurden 10 Studien in die Untersuchung einbezogen. Bei der Auswertung konnte der positive Effekt der erhöhten Selbstwirksamkeit auf eine bessere Schmerzverarbeitung ermittelt werden. Weiterhin konnten eine Verbesserung der Schmerzintensität sowie eine langfristige Verbesserung in allen Bereichen der Selbstwirksamkeitsaspekte herausgearbeitet werden.
Schlussfolgerung Die Stärkung der Selbstwirksamkeit von Patient*innen mit muskuloskelettalen Beschwerden sollte in physiotherapeutische Ansätze integriert werden. Durch die Stärkung der Selbstwirksamkeit entwickeln Patient*innen eine andere Einstellung zu Beschwerden und sind darauf aufbauend in der Lage, Ziele effizienter zu erreichen. Weitere Langzeitstudien zur Erfassung der Auswirkungen von Selbstwirksamkeit im physiotherapeutischen Kontext sind empfehlenswert.
Acute Glycemic Variability and Early Outcomes After Cardiac Surgery:
A Meta-Analysis
Authors: Chang Shuo , Xu Mian , Wang Yu , Zhang Yanbo 
Published: July 2023

AbstractThe influence of acute glycemic variability (GV) on early outcomes of patients
after cardiac surgery remains not fully determined. We performed a systematic
review and meta-analysis to evaluate the association between acute GV and
in-hospital outcomes of patients after cardiac surgery. Relevant observational
studies were obtained by search of electronic databases including Medline,
Embase, Cochrane Library, and Web of Science. A randomized-effects model was
selected to pool the data by incorporating the influence of potential
heterogeneity. Nine cohort studies involving 16 411 patients after cardiac
surgery were included in this meta-analysis. Pooled results showed that a high
acute GV was associated with an increased risk of major adverse events (MAE)
during hospitalization for patients after cardiac surgery [odds ratio [OR]:
1.29, 95% CI: 1.15 to 1.45, p<0.001, I22=38%].
Sensitivity analysis limited to studies of on-pump surgery and GV evaluated by
coefficient of variation of blood glucose showed similar results. Subgroup
analysis suggested that a high acute GV was related to an increased incidence of
MAE in patients after coronary artery bypass graft, but not for those after
isolated valvular surgery (p=0.04), and the association was weakened
after adjustment of glycosylated hemoglobin (p=0.01). Moreover, a high
acute GV was also related to an increased risk of in-hospital mortality (OR:
1.55, 95% CI: 1.15 to 2.09, p=0.004; I22=0%). A
high acute GV may be associated with poor in-hospital outcomes in patients after
cardiac surgery.
A Case Report of Madelung's Disease
Authors: Lee Bo Hyun , Lee Young Mann , Park Seong Oh , Chang Lan Sook , Kim Youn Hawn 
Published: July 2023

AbstractMadelung's disease (MD) is a rare disease characterized by diffuse, nonencapsulated, multiple fat masses in different areas of the body. In this case report, we present a case of MD in Asia and its management. A 66-year-old man with a history of hypertension presented with massive growth of soft tissue around the neck, breasts, upper back, and lower abdomen. Preoperative magnetic resonance imaging revealed remarkably hypertrophic fat tissue around the neck and anterior chest was wall, which consistent with the diagnosis of MD. Multiple linear incisions were made on the neck and 763, 186, 635 g of posterior, right, and left fat tissues were excised, respectively. A single wide, transverse incision was done to excise 1,072 g of fat from the upper back. Masses of both breasts were excised, preserving the inferior pedicle, weighing 1,086 (right) and 1,164 g (left). The recovery was optimal and the patient was discharged without complications. In this case, we excised the adipose masses as much as possible and improved contour and symmetry. However, the fat infiltrations in the patient were diffusely distributed, making total fat excision difficult. This rare case report may help in managing patients with MD.
Validity evidence for simulator-based obstetric ultrasound competency assessment tool: a multi-center study
Authors: Zhao Yongfeng , Zhou Ping , Zhu Wenhui , Xiao Jidong , Liu Wengang , Luo Yingchun , Zhang Junhui , Yang Lan , Xu Yan , Tang Xiaohong 
Published: July 2023

Abstract
Purpose To collect validity evidence for a simulator-based obstetric ultrasound competency assessment tool (OUCAT).
Methods 89 sonographers from three centers (XY, MC, DT), including novices (n=21), experienced trainees (n=44), and experts (n=24), participated in the competency assessment. Validity evidence of OUCAT was collected according to Standards for Educational and Psychological Testing. Content validity was ensured by reviewing guidelines and reaching expert consensus. The response process was ensured via training raters. Internal structure was explored through internal consistency, inter-rater reliability, and test-retest reliability. Relations to other variables were explored by comparing OUCAT scores of sonographers with different experience. Evidence for consequences was collected by determining the pass/fail level.
Results OUCAT included 123 items, of which 117 items could effectively distinguish novices from experts (P<0.05). The internal consistency was represented by the Cronbach’s α coefficient (0.978). The inter-rater reliability was high, with XY being 0.868, MC being 0.877, and DT being 0.937 (P<0.001). Test-retest reliability was 0.732 (P=0.001). The performance of experts was significantly better than experienced trainees, and the performance of experienced trainees was significantly better than novices (70.3±10.7 vs. 39.8±15.0 vs. 20.5±10.6, P<0.001). The pass/fail level determined by contrast group method was 45 points. The passing rate of novices, experienced trainees and experts was 0% (0/21), 31.8% (14/44), and 100% (24/24), respectively.
Conclusion Simulator-based OUCAT exhibits good reliability and validity in assessing obstetric ultrasound skills.
The Validation and Modification of the Caprini Risk Assessment Model for Evaluating Venous Thromboembolism after Joint Arthroplasty
Authors: Qiao Liang , Yao Yao , Wu Dengxian , Xu Ruijuan , Cai Honggang , Shen Ying , Xu Zhihong , Jiang Qing 
Published: July 2023

Background The Caprini risk assessment model (RAM) is the most commonly used tool for evaluating venous thromboembolism (VTE) risk, a high score for arthroplasty can result in patients being classified as high risk for VTE. Therefore, its value in post-arthroplasty has been subject to debate.
Methods Retrospective data were collected from patients who underwent arthroplasty between August 2015 and December 2021. The study cohort included 3,807 patients, all of whom underwent a thorough evaluation using Caprini RAM and vascular Doppler ultrasonography preoperatively.
Results A total of 432 individuals (11.35%) developed VTE, while 3,375 did not. Furthermore, 32 (0.84%) presented with symptomatic VTE, while 400 (10.51%) were detected as asymptomatic. Additionally, 368 (9.67%) VTE events occurred during the hospitalization period, and 64 (1.68%) cases were detected during postdischarge follow-up. Statistical analysis revealed significant differences between the VTE and non-VTE groups in terms of ages, blood loss, D-dimer, body mass index >25, visible varicose veins, swollen legs, smoking, history of blood clots, broken hip, percent of female, hypertension, and knee joint arthroplasty (p < 0.05). The Caprini score was found to be significantly higher in the VTE group (10.10 ± 2.23) compared with the non-VTE group (9.35 ± 2.14) (p < 0.001). Furthermore, there was a significant correlation between the incidence of VTE and the Caprini score (r = 0.775, p = 0.003). Patients with a score ≥9 are at a high-risk threshold for postoperative VTE.
Conclusion The Caprini RAM shows a significant correlation with the occurrence of VTE. A higher score indicates a greater likelihood of developing VTE. The score ≥9 is at particularly high risk of developing VTE.
Effects of 24-week Polarized Training vs. Threshold Training in Obese
Male Adults
Authors: D’Alleva Mattia , Giovanelli Nicola , Graniero Francesco , Billat Veronique Louise , Fiori Federica , Marinoni Michela , Parpinel Maria , Lazzer Stefano 
Published: July 2023

AbstractThe combination of high volume of moderate-intensity continuous training with a
low volume of high-intensity interval training improved body composition and
physical capacities in individuals with obesity. However, polarized training
(POL) has never been used in adult men with obesity. Thus, the purpose of this
study was to investigate changes in body composition and physical capacities
induced by a 24-week POL or threshold (THR) program in obese male adults. Twenty
male patients (mean age 39.8±6.3 yrs; mean body mass index [BMI]
31.6±2.7 kg∙m−2) participated in
this study (n: 10 POL, n: 10 THR). After 24-week, body mass (BM) and fat mass
(FM) decreased by -3.20±3.10 kg (P<0.05) and
-3.80±2.80 kg (P<0.05), respectively, similarly in both
groups. Maximal oxygen uptake (  ̇VO2max) and
̇VO2 at respiratory compensation point (RCP)
increased in the POL group (+8.5±12.2
and+9.0±17.0%, P<0.05) and in the THR group
(+4.24±8.64 and+4.0±6.70%,
P<0.05), as well   ̇VO2 at gas exchange
threshold (GET) increased similarly in both groups
(+12.8±12.0%, P<0.05). POL and THR were equally
effective in improving body composition and physical capacities in obese
subjects. Future studies are needed to determine whether adherence to the
training program can be improved by adding a running competition compared with a
group without competition at the end of the training program.
Who is in the emergency room matters when we talk about door-to-needle time: a single-center experience
Authors: Brunser Alejandro M. , Nuñez Juan-Cristobal , Mansilla Eloy , Cavada Gabriel , Olavarría Verónica , Muñoz Venturelli Paula , Lavados Pablo M. 
Published: July 2023

Abstract
Background The efficacy of intravenous thrombolysis (IVT) is time-dependent.
Objective To compare the door-to-needle (DTN) time of stroke neurologists (SNs) versus non-stroke neurologists (NSNs) and emergency room physicians (EPs). Additionally, we aimed to determine elements associated with DTN ≤ 20 minutes.
Methods Prospective study of patients with IVT treated at Clínica Alemana between June 2016 and September 2021.
Results A total of 301 patients underwent treatment for IVT. The mean DTN time was 43.3 ± 23.6 minutes. One hundred seventy-three (57.4%) patients were evaluated by SNs, 122 (40.5%) by NSNs, and 6 (2.1%) by EPs. The mean DTN times were 40.8 ± 23, 46 ± 24.7, and 58 ± 22.5 minutes, respectively. Door-to-needle time ≤ 20 minutes occurred more frequently when patients were treated by SNs compared to NSNs and EPs: 15%, 4%, and 0%, respectively (odds ratio [OR]: 4.3, 95% confidence interval [95%CI]: 1.66–11.5, p = 0.004). In univariate analysis DTN time ≤ 20 minutes was associated with treatment by a SN (p = 0.002), coronavirus disease 2019 pandemic period (p = 0.21), time to emergency room (ER) (p = 0.21), presence of diabetes (p = 0.142), hypercholesterolemia (p = 0.007), atrial fibrillation (p < 0.09), score on the National Institutes of Health Stroke Scale (NIHSS) (p = 0.001), lower systolic (p = 0.143) and diastolic (p = 0.21) blood pressures, the Alberta Stroke Program Early CT Score (ASPECTS; p = 0.09), vessel occlusion (p = 0.05), use of tenecteplase (p = 0.18), thrombectomy (p = 0.13), and years of experience of the physician (p < 0.001). After multivariate analysis, being treated by a SN (OR: 3.95; 95%CI: 1.44–10.8; p = 0.007), NIHSS (OR: 1.07; 95%CI: 1.02–1.12; p < 0.002) and lower systolic blood pressure (OR: 0.98; 95%CI: 0.96–0.99; p < 0.003) remained significant.
Conclusion Treatment by a SN resulted in a higher probability of treating the patient in a DTN time within 20 minutes.
A novel approach to predicting customer lifetime value in B2B SaaS companies
Authors: Curiskis Stephan , Dong Xiaojing , Jiang Fan , Scarr Mark 
Published: July 2023

AbstractIn this paper, we propose a flexible machine learning framework to predict customer lifetime value (CLV) in the Business-to-Business (B2B) Software-as-a-Service (SaaS) setting. The substantive and modeling challenges that surface in this context relate to more nuanced customer relationships, highly heterogeneous populations, multiple product offerings, and temporal data constraints. To tackle these issues, we treat the CLV estimation as a lump sum prediction problem across multiple products and develop a hierarchical ensembled CLV model. Lump sum prediction enables the use of a wide range of supervised machine learning techniques, which provide additional flexibility, richer features and exhibit an improvement over more conventional forecasting methods. The hierarchical approach is well suited to constrained temporal data and a customer segment model ensembling strategy is introduced as a hyperparameter model-tuning step. The proposed model framework is implemented on data from a B2B SaaS company and empirical results demonstrate its advantages in tackling a practical CLV prediction problem over simpler heuristics and traditional CLV approaches. Finally, several business applications are described where CLV predictions are employed to optimize marketing spend, ROI, and drive critical managerial insights in this context.
Beyond the hype: examining the relationship between Wikipedia attention and realised skewness for crypto assets
Authors: Nyakurukwa Kingstone , Seetharam Yudhvir 
Published: July 2023

AbstractThis study investigates the relationship between Wikipedia searches and the next day’s realised skewness for the top four cryptocurrencies between 2020 and 2022, using a time-varying framework. Daily realised skewness was calculated using one-minute data, and Wikipedia queries were used as a proxy for investor attention. The study reports a positive time-varying relationship between today’s Wikipedia attention and the next day’s realised skewness, with increases in Wikipedia attention on a given day associated with higher realised skewness on the following day. However, there was no significant contemporaneous relationship between Wikipedia attention and realised skewness. The study also found that the relationship between Wikipedia attention and realised skewness becomes more stable over time. The findings suggest that Wikipedia attention may be a useful predictor of realised skewness for cryptocurrencies, which could have implications for investors and market participants.
The function of extra negation
Authors: Fortuin Egbert 
Published: July 2023

AbstractThis paper provides insight into the phenomenon of extra negation, also known as non-compositional, expletive, or pleonastic negation. It provides a corpus-based analysis of the Dutch negative privative construction, which consists ofzonder‘without’ andniet‘not’, in which one negation does not cancel the other. Two basic factors that trigger an extra negation are discussed, and an explanation of why these factors facilitate the use of an extra negation is offered. It is argued that the extra negation has a semantic-pragmatic function that is reminiscent of similar instances of extra negation in Dutch and other languages, specifically sentences consisting of a main clause and a subordinate clause containing a word which expresses implicit negation. It is shown that in complex hypotactic constructions, the extra negation is used to make explicit in the subordinate clause that the presupposition of non-occurrence is rejected.