bluuebunny/crossref_metadata_2025_split huggingface dataset:
Extraction kinetics of tea aroma compounds as a function brewing temperature, leaf size and water hardness
Authors: Sánchez‐López José A. , Yener Sine , Smrke Samo , Märk Tilmann D. , Bonn Günther , Zimmermann Ralf , Biasioli Franco , Yeretzian Chahan 
Published: March 2020

AbstractChanges in the headspace volatile profile of tea infusion during brewing were determined by analysing the aliquots taken every 30 s using proton transfer reaction time‐of‐flight mass spectrometry in conjunction with principal component analysis and hierarchical cluster analysis. The effect of three different brewing temperatures (60, 70 and 80°C), two leaf sizes (broken and full leaves) and two water mineralizations (soft and hard), on the concentration of volatile compounds in the headspace of tea, was studied as a function of infusion time. An increase in brewing temperature resulted in increased volatile content in the headspace, reflecting an increase in extraction efficiency. Such differences on extraction efficiency were more pronounced with increasing brewing times. Leaf size had also a big impact on the extraction of volatile compounds, but mainly during the early phase of brewing. Water mineralization had a low but noticeable impact on the volatile content. Furthermore, clusters of samples prepared with different combinations of brewing parameters but resulting in analogous volatile profiles could be identified using hierarchical clustering analysis.
Inductive Low‐Frequency Processes in PEMFC‐Impedance Spectra
Authors: Schiefer A. , Heinzmann M. , Weber A. 
Published: March 2020

AbstractImpedance spectra of polymer electrolyte membrane (PEM) fuel cells often comprise an “inductive loop” at low frequencies from 1 Hz to 1 mHz additionally to the typically polarization resistances with capacitive behavior between 1 MHz to 1 Hz.To investigate this inductive behavior, systematic variations of operating parameters as humidity, current density and gas compositions are performed. The impedance spectra, including their inductive parts, are deconvoluted by an extended version of the distribution of relaxation times (DRT). Two inductive processes are identified in the DRT and subsequently quantified by fitting the spectra to an extended equivalent circuit model exhibiting negative resistances and constant phase elements.Both inductive processes are depending on relative humidity and current density. The inductive behavior seems to be dominated by the oxygen reduction reaction (ORR) at the cathode, whereas changes in membrane hydration can be excluded as the main cause for the inductive low‐frequency processes. Measurements in symmetrical H2/H2 operating mode prove that the inductive behavior cannot be solely related to the ORR.The ratio of the inductive processes to the ohmic and capacitive loss processes ranges from 15% to 30%. Thus, a considerable cell performance improvement related to the existence of these inductive low‐frequency processes has to be taken into account.
Accessory Ultrasonographic Findings in Chronic Liver Disease: Diameter of Splenic and Hepatic Arteries, Fasting Gallbladder Volume, and Course of Left Portal Vein
Authors: Toni Roberto , Bolondi Luigi , Gaiani Stefano , Re Giuseppe , Calabrese Luigi , Cavalli Giancarlo , Labò Giuseppe 
Published: March 2020

AbstractWe have assessed the incidence and significance of changes in the caliber of the splenic and hepatic arteries, in fasting gallbladder volume, and in the intrahepatic course of the left portal vein in a group of 46 patients affected by chronic liver disease (24 with chronic active hepatitis and 22 with liver cirrhosis). Thirty normal subjects were examined as a control group. Mean diameters of the splenic and hepatic arteries were significantly greater in cases of liver cirrhosis than in the control group. In the case of chronic active hepatitis, only the splenic artery proved significantly enlarged in comparison with the control group. These results demonstrate that caliber modification occurs in the splenic and hepatic arteries during chronic liver disease. In particular, changes in the splenic artery precede the onset of clinically evident portal hypertension. Gallbladder volume was significantly increased in patients affected by liver cirrhosis. Finally, statistical analysis did not reveal any significant difference in the angles formed by the transverse and longitudinal tracts of the left portal vein in controls and in subjects with liver disease.
Multidimensional skills and the returns to schooling: Evidence from an interactive fixed‐effects approach and a linked survey‐administrative data set
Authors: Kejriwal Mohitosh , Li Xiaoxiao , Totty Evan 
Published: March 2020

SummaryThis paper presents new evidence on returns to schooling based on an interactive fixed‐effects framework that allows for multiple unobserved skills with potentially time‐varying prices as well as individual‐level heterogeneity in returns. This constitutes a substantive generalization of most existing approaches. Our empirical analysis employs a unique linked survey‐administrative panel data set on education and earnings. We find average marginal returns to schooling of about 2.8–4.4% relative to least squares/instrumental variable estimates between 7.7% and 12.7%. Omitted ability accounts for a larger fraction of the aggregate least squares bias compared to heterogeneity. We also find considerable heterogeneity in individual returns.
Multispectral optoacoustic tomography of muscle perfusion and oxygenation under arterial and venous occlusion: A human pilot study
Authors: Karlas Angelos , Kallmayer Michael , Fasoula Nikolina‐Alexia , Liapis Evangelos , Bariotakis Michail , Krönke Markus , Anastasopoulou Maria , Reber Josefine , Eckstein Hans‐Henning , Ntziachristos Vasilis 
Published: March 2020

AbstractPerfusion and oxygenation are critical parameters of muscle metabolism in health and disease. They have been both the target of many studies, in particular using near‐infrared spectroscopy (NIRS). However, difficulties with quantifying NIRS signals have limited a wide dissemination of the method to the clinics. Our aim was to investigate whether clinical multispectral optoacoustic tomography (MSOT) could enable the label‐free imaging of muscle perfusion and oxygenation under clinically relevant challenges: the arterial and venous occlusion. We employed a hybrid clinical MSOT/ultrasound system equipped with a hand‐held scanning probe to visualize hemodynamic and oxygenation changes in skeletal muscle under arterial and venous occlusions. Four (N = 4) healthy volunteers were scanned over the forearm for both 3‐minute occlusion challenges. MSOT‐recorded pathophysiologically expected results during tests of disturbed blood flow with high resolution and without the need for contrast agents. During arterial occlusion, MSOT‐extracted Hb‐values showed an increase, while HbO2‐ and total blood volume (TBV)‐values remained roughly steady, followed by a discrete increase during the hyperemic period after cuff deflation. During venous occlusion, results showed a clear increase in intramuscular HbO2, Hb and TBV within the segmented muscle area. MSOT was found to be capable of label‐free non‐invasive imaging of muscle hemodynamics and oxygenation under arterial and venous occlusion. We introduce herein MSOT as a novel modality for the assessment of vascular disorders characterized by disturbed blood flow, such as acute limb ischemia and venous thrombosis.
Taking another look at the sense of community index: Six confirmatory factor analyses
Authors: Cope Michael R. , Ward Carol , Jackson Jorden E. , Muirbrook Kayci A. , Andre Alex Nicholas 
Published: March 2020

AbstractPrevious studies focusing on the effects of the social aspects of community have often used the Sense of Community Index (SCI), despite other research showing that it is not a good‐fit measure for its expected dimensions. Using a sample of students from Brigham Young University, we performed confirmatory factor analysis of the SCI to assess 1‐factor, 4‐factor, 1‐factor revised, 3‐factor revised, 1‐factor revised, 4‐factor revised, and 1‐factor revised models. Our study resulted in mixed findings: models were neither a poor‐fit nor a good fit. Although the 4‐factor revised model was the best fit, it did not measure the intended dimensions well. Our analysis indicates that future research investigating sense of community should use measures other than the SCI.
A peer support and peer mentoring approach to enhancing resilience and empowerment among refugees settled in southern Spain
Authors: Paloma Virginia , de la Morena Irene , Sladkova Jana , López‐Torres Clara 
Published: March 2020

AbstractThis study aims to analyze the processes of resilience and empowerment experienced by refugees in southern Spain during their participation in a community‐based intervention. Intervention design covered two phases over 15 weeks: (a) accompanying a group of 10 settled refugees to become mentors, making use of a peer‐support‐group format; and (b) holding four cultural peer‐support groups made up of newly arrived refugees led by the previously trained settled refugees, following a peer‐mentoring format. We analyzed the mentors' narratives and written evaluations produced over the course of the intervention program. Mentor resilience increased during the first program phase and remained high and stable during the second phase. Mentor empowerment steadily increased throughout the duration of the program, and was fueled when participants became mentors to newly arrived refugees during the second phase. This study highlights how a peer‐support and peer‐mentoring approach is useful for enhancing the resilience and empowerment of refugees in receiving societies.
Learning through making: The development of engineering discourse in an out‐of‐school maker club
Authors: Martin Lee , Betser Sagit 
Published: March 2020

AbstractBackgroundLearning to be an engineer means learning to participate in engineering discourse: the words, visuals, routines, and narratives through which engineers think and communicate. An important goal for engineering education is uncovering the processes by which young people take up and become fluent in engineering discourse, and how teachers and mentors can aid them in this process. Growing evidence suggests that participation in out‐of‐school maker activities—a class of informal design and build activities—holds promise to help youth gain interest and skill in engineering design.Purpose/HypothesisThis study investigates how youth learn engineering design through participation in a maker club. It is theoretically grounded in Sfard's (2008) commognition framework, an approach that views learning to be an engineer as learning to participate in engineering discourse.Design/MethodThe study employed case study methods of interaction analysis of video‐recorded observations. The analysis closely examines interactions to uncover the mechanisms of discourse development.ResultsFindings showed that a newcomer to the discourse could show substantive growth within a single work session. The analysis examined how the youth and a mentor collaborated within a hands‐on learning environment to create opportunities for discourse development. Such growth is not inevitable as seen in an analysis of a missed opportunity.ConclusionsThis article shows that making can be a fruitful context for the development of engineering discourse, and it illustrates mechanisms through which that learning can occur, including explorative imitation of engineering discourse routines within hands‐on learning environments. It shows that professional engineers can play an important role in youth learning.
Editorial for “Histogram Analysis Comparison of Monoexponential, Advanced Diffusion‐ Weighted Imaging, and Dynamic Contrast‐Enhanced MRI for Differentiating Borderline From Malignant Epithelial Ovarian Tumors”
Authors: Ye Zezhong 
Published: March 2020

Level of Evidence4Technical EfficacyStage 2J. Magn. Reson. Imaging 2020;52:269–270.
Artificial intelligence and convolution neural networks assessing mammographic images: a narrative literature review
Authors: Wong Dennis Jay , Gandomkar Ziba , Wu Wan‐Jing , Zhang Guijing , Gao Wushuang , He Xiaoying , Wang Yunuo , Reed Warren 
Published: March 2020

AbstractStudies have shown that the use of artificial intelligence can reduce errors in medical image assessment. The diagnosis of breast cancer is an essential task; however, diagnosis can include ‘detection’ and ‘interpretation’ errors. Studies to reduce these errors have shown the feasibility of using convolution neural networks (CNNs). This narrative review presents recent studies in diagnosing mammographic malignancy investigating the accuracy and reliability of these CNNs. Databases including ScienceDirect, PubMed, MEDLINE, British Medical Journal and Medscape were searched using the terms ‘convolutional neural network or artificial intelligence’, ‘breast neoplasms [MeSH] or breast cancer or breast carcinoma’ and ‘mammography [MeSH Terms]’. Articles collected were screened under the inclusion and exclusion criteria, accounting for the publication date and exclusive use of mammography images, and included only literature in English. After extracting data, results were compared and discussed. This review included 33 studies and identified four recurring categories of studies: the differentiation of benign and malignant masses, the localisation of masses, cancer‐containing and cancer‐free breast tissue differentiation and breast classification based on breast density. CNN's application in detecting malignancy in mammography appears promising but requires further standardised investigations before potentially becoming an integral part of the diagnostic routine in mammography.
Empirical analysis of shared leadership promotion and team creativity: An adaptive leadership perspective
Authors: Ali Ahsan , Wang Hongwei , Johnson Russell E. 
Published: March 2020

SummaryPromoting shared leadership in teams and enhancing team creativity is aided by complementarity between leader and team member characteristics. We integrate insights from social learning theory and dominance complementarity perspective with the team leadership and creativity literature to explore the facilitating role of formal participative leadership for enhancing team creativity indirectly by promoting shared leadership. The relationships among formal participative leadership, shared leadership, and team creativity are bounded by team voice behavior and team creative efficacy. To test our theoretical model, we collected multisource and multiwave survey data from 382 members of 73 teams. Results revealed a significant positive relationship of participative leadership with shared leadership in teams, which in turn was positively associated with team creativity. Team voice behavior and team creative efficacy moderated these relationships, respectively, by strengthening the positive relationships. We discuss the theoretical contributions, practical implications, and future directions of our findings.
Analysis of the absorption and accumulation characteristics of rare earth elements in Chinese tea
Authors: Wang Haibin , Chen Xiaoting , Ye Jianghua , Jia Xiaoli , Zhang Qi , He Haibin 
Published: March 2020

AbstractBACKGROUNDRare earth elements (REEs) played an important role in enhancing the yield and quality of tea, and have been widely used in tea cultivation. In the present study, 3011 tea samples of four tea types, namely black tea, green tea, oolong tea and dark tea, were collected from the mainly tea producing areas in different provinces of China to analyze the contents of 16 REEs by inductively coupled plasma mass spectrometry.RESULTSThe results obtained showed that the higher average content of REEs was 2.960 mg kg−1 in black tea from Henan province, 2.500 mg·kg−1 in green tea from Shanxi province, 3.870 mg·kg−1 in oolong tea from Guizhou province and 2.955 mg·kg−1 in dark tea from Hunan province. The sum percentage of five elements (Sc, Y, La, Ce, and Nd) to total REEs was 84.39% in black tea, 85.07% in green tea, 83.67% in oolong tea and 84.42% in dark tea. In addition, the content of Ce in tea was greatest, regardless of the province of China. The content trend of the five REEs was Ce > La > Sc > Nd > Y in black and green tea, respectively. However, the content trend was Ce > Y > Sc > Nd > La in oolong tea and Ce > Y > La > Nd > Sc in dark tea.CONCLUSIONThe tea leaves mainly accumulated light REEs rather than heavy REEs. These results provided an important theoretical basis for investigation of the accumulation characteristics of REEs in Chinese tea. © 2020 Society of Chemical Industry
Preparing molecularly imprinted nanoparticles of saponins via cooperative imprinting strategy
Authors: Zhang Hao , Zhang Yanan , Wang Hailing , Wen Han , Yan Zhifeng , Huang Ailan , Bie Zijun , Chen Yang 
Published: March 2020

AbstractSaponin is an important class of natural products with various pharmacological activities. The selective separation of saponins is an essential step before further analysis. Molecular imprinting has been an effective strategy for preparing antibody mimics. However, a facile and efficient imprinting strategy for saponins is still lacking owing to their amphiphilic nature. Herein, we have prepared the saponins imprinted nanoparticles via cooperative imprinting strategy. This new strategy relies on the combination of various non‐covalent interactions (hydrophobic and hydrogen bonding) and covalent boronate affinity interactions. The obtained imprinted nanoparticles could rebind specific saponins from complex matrices with good selectivity, superb tolerance to interference, and fast binding equilibrium. This method was verified to be versatile and facile. Thus, this strategy could greatly facilitate the preparation of imprinted nanoparticles for the specific recognition of saponins.
A Novel Classification: Anomalous Routes of the Facial Nerve in Relation to Inner Ear Malformations
Authors: Sennaroğlu Levent , Tahir Emel 
Published: March 2020

Objectives/HypothesisThe objective of this study was to classify anomalous facial nerve (FN) routes and to determine their association with inner ear malformations (IEMs).Study DesignRetrospective cross sectional study.MethodsThe computed tomography images of 519 patients (796 ears) with IEMs were retrospectively evaluated, and the abnormal routes of the FN were classified as: Meatal segment: type 1, normal internal auditory canal (IAC); type 2, narrow IAC; type 3, facial canal (FC) only; type 4: separate FC/duplicated IAC. Labyrinthine segment (LS): type 1, normal; type 2a/b/c, mild/moderate/severe anterior displacement; type 3, superior displacement; type 4: straight LS. Tympanic segment (TS): type 1, normal; type 2, superiorly displaced TS; type 3, TS at the oval window; type 4: TS inferior to the oval window; type 5: unclassified. Mastoid segment: type 1, normal facial recess (FR)/normal mastoid segment; type 2: narrow FR; type 3, unclassified.ResultsIn meatal segment classification, a narrow IAC was common in ears with cochlear hypoplasia (CH) (76.1%), and only FC was common in ears with severe IEMs (62.7%) such as Michel deformity, common cavity, and cochlear aplasia. Incomplete partition‐III has its unique superiorly displaced LS (100%). CH‐IV also has its unique mild anterosuperior displacement. Ears with a superiorly displaced TS usually (93.1%) had aplastic or hypoplastic semicircular canals. The FR is likely to be narrow in CH and severe IEMs.ConclusionsThe FN route is affected in IEMs, which must be kept in mind when operating on ears with IEMs. Especially in CH cases, all segments of the FN can be abnormal.Level of Evidence4 Laryngoscope, 130:E696–E703, 2020
Time series assessment of Thaumarchaeota ecotypes in Monterey Bay reveals the importance of water column position in predicting distribution–environment relationships
Authors: Tolar Bradley B. , Reji Linta , Smith Jason M. , Blum Marguerite , Pennington J. Timothy , Chavez Francisco P. , Francis Christopher A. 
Published: March 2020

AbstractNitrification plays a key role in marine ecosystems where Thaumarchaeota are thought to be responsible for most of the ammonia oxidation in the water column. Over a 2‐yr, near‐monthly time series at two sites in Monterey Bay we observed repeatable seasonal and depth‐based patterns of Thaumarchaeota ecotype abundance that highlighted a clear delineation between populations in shallow euphotic (< 50 m) vs. deeper mesopelagic (60–500 m) depths. Euphotic depths show greater seasonality and influence from light, while mesopelagic waters have trends based on water mass and other covarying features with depth. Three major ecotypes were recovered: a Nitrosopumilus‐like (NP) group, a Nitrosopelagicus‐like ecotype containing “shallow” water column A (WCA) members, and an ecotype affiliated with the “deep” water column B (WCB) Thaumarchaeota. These ecotypes show a strong depth distribution, with WCB dominant at ≥ 200 m depth and WCA most abundant in surface (5–100 m) waters. The NP ecotype was found throughout the water column with the highest abundance in summer, and was the only ecotype showing a correlation with measured nitrification rates. We also found three abundant taxa related to Nitrospina—the major nitrite‐oxidizing bacteria in the ocean; these showed clear connections to each of the three Thaumarchaeota ecotypes, suggesting a specific relationship between both steps of nitrification. Our results support the importance of ecotype‐based analysis of Thaumarchaeota and show that their abundance and distribution are controlled based on their water column position, with a distinct shift at 50 m between euphotic and mesopelagic depths.
Links between S‐adenosylmethionine and Agr‐based quorum sensing for biofilm development in Listeria monocytogenes EGD‐e
Authors: Lee Yue‐Jia , Wang Chinling 
Published: March 2020

AbstractListeria monocytogenes is the causative agent of human listeriosis which has high hospitalization and mortality rates for individuals with weakened immune systems. The survival and dissemination of L. monocytogenes in adverse environments can be reinforced by the formation of biofilms. Therefore, this study aimed to understand the mechanisms underlying listerial biofilm development. Given that both nutrient availability and quorum sensing (QS) have been known as the factors influencing biofilm development, we hypothesized that the signal from a sentinel metabolite S‐adenosylmethionine (SAM) and Agr‐based QS could be synchronous in L. monocytogenes to modulate nutrient availability, the synthesis of extracellular polymeric substances (EPSs), and biofilm formation. We performed biofilm assays and quantitative real‐time PCR to investigate how biofilm volumes and the expression of genes for the synthesis of EPS were affected by SAM supplementation, agr deletion, or both. We found that exogenously applied SAM induced biofilm formation and that the expression of genes encoding the EPS synthesis machineries was regulated by SAM and/or Agr QS. Moreover, the gene transcription of components acting in the methyl cycle for SAM synthesis and Agr QS was affected by the signals from the other system. In summary, we reveal an interconnection at the transcriptional level between metabolism and QS in L. monocytogenes and highlight the critical role of metabolite‐oriented QS in biofilm development.