bluuebunny/crossref_metadata_2025_split huggingface dataset:
Aluminum increases net carbon fixation by marine diatoms and decreases their decomposition: Evidence for the iron–aluminum hypothesis
Authors: Zhou Linbin , Liu Fengjie , Liu Qingxia , Fortin Claude , Tan Yehui , Huang Liangmin , Campbell Peter G. C. 
Published: May 2021

AbstractRecent studies indicate that aluminum (Al) could play an important role in the ocean carbon cycle by increasing phytoplankton carbon fixation and reducing organic carbon decomposition. However, how Al may influence the decomposition of organic carbon has not yet been explicitly examined. Here we report the effects of Al on carbon fixation by marine diatoms and their subsequent decomposition. By using radiocarbon as a tracer, the carbon fixation and decomposition of three model marine diatoms were examined in Aquil* media at different concentrations (0, 40, 200, and 2000 nM) of dissolved Al. Addition of Al enhanced net carbon fixation by the diatoms in the declining growth phase (by 9%–29% for Thalassiosira pseudonana, 15%–20% for T. oceanica, 15%–23% for T. weissflogii). Under axenic conditions the decomposition rates (d−1) of the diatom‐produced particulate organic carbon (POC) significantly decreased (by 21%–57% for T. pseudonana, 0%–41% for T. oceanica, 29%–58% for T. weissflogii) in the Al‐enriched treatments. In the presence of bacteria, the decomposition rates of T. weissflogii‐produced POC were still 37%–38% lower in Al‐enriched treatments compared to the control. Significant increases in cell size, cellular carbon content (pmol C/cell) and cellular carbon density (pmol C/μm3) of T. weissflogii were also observed in the Al‐enriched treatments compared to the control. The Al‐related increase in net carbon fixation and cell size, and the decrease in POC decomposition rate may facilitate carbon export to ocean depths. The study provides new evidence for the iron–aluminum hypothesis, which suggests that Al could increase phytoplankton uptake of atmospheric CO2 and influence climate change.
3D Printable Conducting and Biocompatible PEDOT‐graft‐PLA Copolymers by Direct Ink Writing
Authors: Dominguez‐Alfaro Antonio , Gabirondo Elena , Alegret Nuria , De León‐Almazán Claudia María , Hernandez Robert , Vallejo‐Illarramendi Ainara , Prato Maurizio , Mecerreyes David 
Published: May 2021

AbstractTailor‐made polymers are needed to fully exploit the possibilities of additive manufacturing, constructing complex, and functional devices in areas such as bioelectronics. In this paper, the synthesis of a conducting and biocompatible graft copolymer which can be 3D printed using direct melting extrusion methods is shown. For this purpose, graft copolymers composed by conducting polymer poly(3,4‐ethylenedioxythiophene) (PEDOT) and a biocompatible polymer polylactide (PLA) are designed. The PEDOT‐g‐PLA copolymers are synthesized by chemical oxidative polymerization between 3,4‐ethylenedioxythiophene and PLA macromonomers. PEDOT‐g‐PLA copolymers with different compositions are obtained and fully characterized. The rheological characterization indicates that copolymers containing below 20 wt% of PEDOT show the right complex viscosity values suitable for direct ink writing (DIW). The 3D printing tests using the DIW methodology allows printing different parts with different shapes with high resolution (200 µm). The conductive and biocompatible printed patterns of PEDOT‐g‐PLA show excellent cell growth and maturation of neonatal cardiac myocytes cocultured with fibroblasts.
All‐Organic Dielectrics with High Breakdown Strength and Energy Storage Density for High‐Power Capacitors
Authors: Feng Qi‐Kun , Ping Jiang‐Bo , Zhu Jing , Pei Jia‐Yao , Huang Lei , Zhang Dong‐Li , Zhao Yu , Zhong Shao‐Long , Dang Zhi‐Min 
Published: May 2021

AbstractPolymer‐based film capacitors with high breakdown strength and excellent flexibility are crucial in the field of advanced electronic devices and electric power systems. Although massive works are carried to enhance the energy storage performances, it is still a great challenge to improve the energy density of polymer composites under the premise of large‐scale industrial production. Herein, a general strategy is proposed to improve the intrinsic breakdown strength and energy storage performances by blending core‐shell structured methyl methacrylate‐butadiene‐styrene (MBS) rubber particles into a polymer matrix. Good compatibility and uniform dispersion state of MBS particles are observed in the matrix. Polarizing microscopy images show that blended films exhibit clear reduction of crystalline grains with the addition of MBS particles. Accordingly, an increased breakdown strength of 515 MV m−1 and discharged energy density of 12.33 J cm−3 are observed in poly(vinylidene fluoride‐co‐hexafluoropropylene)‐based composite films. Through comprehensive characterizations, it is believed that the superior energy storage performance of composite films is attributed to decreased crystalline grains, improved mechanical properties, and restriction on carrier motion. These results provide a novel design of dielectric polymers for high breakdown strength and discharged energy density applications.
NNI‐SMOTE‐XGBoost: A Novel Small Sample Analysis Method for Properties Prediction of Polymer Materials
Authors: Li Dazi , Liu Jianxun , Liu Jun 
Published: May 2021

AbstractDespite the usage of machine learning accelerating the properties prediction of polymer materials, obtaining a large number of samples to achieve accurate and fast predictions remains a challenge because of the complex and lengthy experimental process. In this work, an advanced prediction model for the small sample analysis is presented by an ensemble learning algorithm called extreme gradient boosting (XGBoost) based on nearest neighbor interpolation (NNI) and synthetic minority oversampling technique (SMOTE). Different from directly using small sample prediction algorithms, a brand‐new idea based on feature engineering is proposed. NNI algorithm is used to interpolate the original data set to solve the data insufficiency. SMOTE algorithm is used to solve the data imbalance problem by increasing minority samples. The expanded data set is used to build an XGBoost prediction model. A model for predicting Akron abrasion of rubber through mechanical properties is established via the proposed method. The original data set is expanded to 710 samples through two different interpolations. Experimental results show that better prediction accuracy and generalization ability are obtained than traditional algorithms. The Akron abrasion is found to be the most related to the elongation at break of polymer materials.
Ein Schub für Preprintserver
Authors: Renn Oliver , Betschart Leo , Dolenc Jozica 
Published: May 2021

AbstractIn der Corona‐Pandemie wurde der Druck groß, neue wissenschaftliche Erkenntnisse so schnell wie möglich allen zugänglich zu machen – als Basis für weiterführende Arbeiten und auch für politische Entscheidungen. Forschungsergebnisse zu Sars‐Cov‐2 wurden daher besonders häufig vorab auf Preprintservern veröffentlicht. Diese Server verändern auch das Publikationsverhalten in der Chemie.
Sprachförderung im Unterricht
Authors: Becker Hans‐Jürgen , Kemper Anne‐Kathrin 
Published: May 2021

AbstractSprachbildendes Chemielernen bleibt auch in Zeiten der Digitalisierung im Blickpunkt von Bildung und Unterricht, vor allem unterstützt durch staatliche Bildungsangebote und ‐projekte in Kooperation mit Universitäten.
Trends für das mittlere Infrarot
Authors: Krafft Christoph , Mayerhöfer Thomas , Popp Jürgen 
Published: May 2021

AbstractLaserstrahlungsquellen für IR‐Spektrometer und ‐Mikroskope ermöglichen neue Messkonzepte, die weit über die bekannten Absorptionsmethoden hinausgehen. Anwendungen eröffnen sich in der medizinischen Diagnostik, in Pharma‐, Lebensmittel‐ und Umweltanalytik.
Using Creel Data to Evaluate Blue and Channel Catfish Aggregate Harvest Regulations for Texas Reservoirs
Authors: Nisbet Mitchell T. , Myers Randall A. , Binion Greg R. , McDonald Dusty 
Published: May 2021

Abstract
The Texas Parks and Wildlife Department’s strategic management plan for catfishes (Ictaluridae) called for the development of alternative harvest regulations for Blue Catfish Ictalurus furcatus and Channel Catfish I. punctatus. Angler harvest of these species in most Texas reservoirs has been regulated using a 305-mm minimum length limit (MLL) and a 25-fish aggregate daily bag limit (DBL) since 1995. Using existing creel data collected in 2003–2018 at 86 Texas reservoirs managed under this statewide harvest regulation, we examined Blue and Channel Catfish harvest size structure and composition, percent release of legally harvestable-size fish, and harvest density (number and biomass). Additionally, for reservoirs having long-term creel data, we evaluated temporal change in percent release of legally harvestable-size fish and harvest size structure, and we estimated the impact of alternative harvest regulations by using a theoretical harvest reduction (THR) model. Channel Catfish were the predominant species harvested (&gt;75% of harvest) in 63% of the reservoirs. Harvest size structures of Blue and Channel catfish differed, but the difference in percent harvest of fish smaller than 406 mm was negligible (52% and 48%, respectively). Percent release of legally harvestable-size fish (≥305 mm) was low at most reservoirs (median = 13%). Total number of catfish harvested per hectare per quarter (HHQ) ranged widely (0.0–11.3) but was less than 1.0 at 58% of reservoirs. Harvest size structure was truncated over time coincident with a high harvest level (HHQ &gt; 3.0) at two of four reservoirs with long-term data, suggesting growth overfishing. The THR model revealed that increases in MLL resulted in variable harvest reductions among reservoirs and that removal of the 305-mm MLL could increase harvest by 6–39%. Additionally, we found that length-graduated DBLs would have a negligible impact on reducing the harvest of larger fish. We suggest that MLLs are not necessary for most Texas catfish fisheries and that a 356-mm MLL may be appropriate for high-harvest fisheries.
Improving oxygen vacancies by cobalt doping in MoO2 nanorods for efficient electrocatalytic hydrogen evolution reaction
Authors: Li Hailong , Li Hong , Qiu Yu , Liu Shuangquan , Fan Jianxiong , Guo XiaoHui 
Published: May 2021

AbstractRecently, molybdenum dioxide (MoO2) has gained intensive attention as an eco‐friendly and earth abundant catalyst for electrocatalytic hydrogen evolution from water splitting. However, the catalytic activity of MoO2 catalyst for hydrogen evolution reaction (HER) is severely limited by the less exposed active sites. Herein, we present Co‐doped MoO2 for efficient HER through a facile wet chemistry synthesis followed by calcination treatment process. The optimized Co‐MoO2‐0.01 nanorods (NRs) delivers a very low overpotential of 26 mV at 10 mA cm−2 and a small Tafel slope of 30.9 mV dec−1, which is much better than that of pure MoO2 NRs and the commercial Pt/C catalyst in HER. Experimental and theoretical results reveal that Co doping not only produce more oxygen vacancies in MoO2, which can activate adjacent oxygen atoms as active sites and thus increase the exposed active sites on the surface of catalyst, but also enhance the electrical conductivity of catalyst during HER process. In a word, this work provides a new promising synthetic strategy for developing earth‐abundant and cost‐effective HER electrocatalysts through rational defect‐engineering design.
Salvage cystectomy and ileal conduit urinary diversion as a last‐line option for benign diseases—perioperative safety and postoperative health‐related quality of life
Authors: Volz Yannic , Eismann Lennert , Pfitzinger Paulo L. , Jokisch Jan‐Friedrich , Schulz Gerald , Rodler Severin , Buchner Alexander , Schlenker Boris , Stief Christian G. , Kretschmer Alexander 
Published: May 2021

AbstractAimsRadical cystectomy and urinary diversion impact various dimensions of patients' health‐related‐quality‐of‐life (HRQOL). Yet, less is known about salvage cystectomy as a last‐line option for treatment‐refractory benign diseases. Therefore, our aim is to provide HRQOL data from a contemporary cohort of open salvage cystectomies for benign conditions.MethodsFifty‐four consecutive patients were enrolled in one single tertiary referral center. Analysis was limited to patients undergoing urinary diversion via ileal conduit (IC). Complications were assessed via Clavien–Dindo‐scale. HRQOL was measured using the validated European Organization for Research and Treatment of Cancer QLQ‐C30 and QLQ‐BLM30 questionnaire. HRQOL QLQ‐C30 domains were measured preoperatively and up to 3 years postoperatively. Longitudinal changes were analyzed using Friedman's rank test. Primary endpoint was good general HRQOL based on QLQ‐C30 global health status (GHS). Multivariate analysis was performed using logistic regression models with a step‐wise backward selection procedure.ResultsLongitudinal analysis of HRQOL subdomains revealed significantly improved pain (p = .005) and fatigue (p = .002) scores as well as improved social functioning (p = .038). Furthermore, general HRQOL (GHS scores) improved significantly during the follow‐up period (28.0 vs. 50.6 [36 months], p = .045). In multivariate analysis, the indication for salvage cystectomy could not be identified as an independent predictor for good general HRQOL. We observed a total number of 10 (41.7%) high‐grade (Clavien ≥III) 90 day‐complications. Limitations include limited follow‐up rates at respective time‐points.ConclusionSalvage cystectomy and IC can be safely performed as a last‐line treatment for benign conditions and increases general HRQOL in the long‐term follow‐up. Thus, it can play a role in a holistic approach for a challenging clinical setting.
Leading temporary project teams: An analysis of task‐ and person‐focused leadership over time
Authors: Couture Mathieu , Harvey Jean‐François 
Published: May 2021

AbstractNonprofit organizations are increasingly relying on temporary project teams to carry out their activities. Time is of the essence with such endeavors. Diverse individuals join a project team and work through several phases in order to reach their goal. Because team needs will fluctuate over time, the focus of leadership is also likely to change. Unfortunately, very little is known about these dynamics, because research has overly focused on the individual characteristics of leaders. In this study, we gained access to archival data on the interactions among the individuals working on a temporary project team, which allowed us to compare how both task‐ and person‐focused leadership evolved over time. We found that both types of leadership increase in intensity over the lifetime of the project, but also that the need for person‐focused leadership is greater later on, while task‐focused leadership is prevalent at earlier stages. Our results help generate key insights for both the theory and practice of project team leadership.
Correlations of social isolation and anxiety and depression symptoms among patients with breast cancer of Heilongjiang province in China: The mediating role of social support
Authors: Liu Bingshuo , Wu Xinyu , Shi Lei , Li Han , Wu Di , Lai Xin , Li Yuyan , Yang Yue , Li Danni 
Published: May 2021

AbstractObjectivesTo explore the correlations among social isolation and symptoms of anxiety and depression among patients with breast cancer in China and to further verify the mediating role of social support in social isolation and symptoms of depression or anxiety.DesignA cross‐sectional survey.SettingsThe cluster sampling method was conducted for 456 female inpatients diagnosed with breast cancer at the Tumor Hospital Affiliated of Harbin Medical University from April 2019–September 2019.MethodsPearson correlation analysis was used for identifying correlations among all the variables. Mediation effect analysis was used to examine the role of social support in social isolation and symptoms of depression or anxiety.ResultsThe results showed a prevalence of 73.26% and 70.44% for anxiety and depression symptoms in patients with breast cancer, respectively. Anxiety was significantly negatively correlated with social support (r = −.334,p < .01) and significantly positively correlated with social isolation (r = .369,p < .01). Similarly, depression was significantly negatively correlated with social support (r = −.289,p < .01) and significantly positively correlated with social isolation (r = .466,p < .01). Social support played a mediating role in social isolation and f symptoms of anxiety or depression among these patients.ConclusionsSocial isolation was positively correlated with symptoms of anxiety and depression in patients with breast cancer, respectively. Social support for patients with breast cancer has a mediating effect on the patients’ social isolation and symptoms of anxiety and depression. Therefore, the support of family, friends, hospitals, and organizations plays a positive role in reducing social isolation as well as symptoms of depression and anxiety in these patients.
Polyvinyl alcohol nanofibers reinforced with polybenzimidazole: Facile preparation and properties of an anion exchange membrane
Authors: Coppola Roxana E. , Molinari Fabricio N. , D'Accorso Norma B. , Abuin Graciela C. 
Published: May 2021

AbstractThe search of novel materials for anion exchange membranes (AEMs) is a key factor in addressing challenges of electrochemical energy conversion and storage devices in terms of cost, durability, efficiency, and up‐scalability; and composite materials based in electrospun nanofibers have a great potential in this regard. We report a facile preparation method of an AEM composed by polyvinyl alcohol (PVA) nanofibers crosslinked with glutaraldehyde (GA) and reinforced with poly[2‐2′‐(m‐phenylene)‐5‐5′‐bibenzimidazole] (ABPBI) polymer, characterizing it as an AEM in a liquid alkaline water electrolyzer (LAWE) device. Homogeneous and flexible membranes were obtained, with a good chemical stability in the doping solution (15 wt.% KOH), and better swelling resistance than pure ABPBI membranes. The membranes also showed a specific ionic conductivity of 36 mS·cm−1 at 60°C and 41 mS·cm−1 at 80°C, with an activation energy value of 3.5 kJ·mol−1. Regarding LAWE performances, it attained current densities of 236 and 271 mA·cm−2 for a 2 V cell voltage when operated at 50°C and 70°C, respectively. During chronopotentiometric test, neither potential drop nor change in material integrity were observed. These results provide a facile and scalable method for low cost AEMs preparation, contributing as an alternative material for its use in electrolyzers.
New genetic and clinical evidence associated with fetal Beckwith–Wiedemann syndrome
Authors: Traisrisilp Kuntharee , Chankhunaphas Wisit , Sirilert Sirinart , Kuwutiyakorn Varangtip , Tongsong Theera 
Published: May 2021

AbstractEarly detection of Beckwith–Wiedemann syndrome (BWS) is very important since it is very useful regarding counseling of parents concerning the risk of developing embryonic tumors, selection of the mode of delivery due to potential adrenal cysts that might bleed during labor, prevention of neonatal hypoglycemia and even options of pregnancy termination in non‐viable fetuses. This report describes the prenatal classic sonographic triad of fetal BWS (omphalocele, macrosomia, macroglossia) and other supporting findings (hepatomegaly, adrenal enlargement) as well as additional postnatal evidence. Also, it demonstrates new molecular genetic evidence potentially associated with the disease (the presence of a novel heterozygous c.358G>T variant of theCDKN1Cgene). Importantly, we provide new evidence indicating that elevated levels of the four serum biomarkers (alpha‐fetoprotein, beta‐human gonadotropin, unconjugated estriol, and inhibin‐A) in late first or early second trimester might be strongly suggestive of BWS which may facilitate early detection especially in cases of no obvious anomaly. In conclusion, this study emphasizes on early detection of BWS as early as at 14 weeks of gestation, based on the abnormal rise of the four serum biomarkers together with omphalocele. To the best of our knowledge, this is the earliest prenatal detection of BWS ever reported. Finally, we provide new molecular genetic evidence that is, potentially associated with BWS.
Changes in plant responses induced by an arthropod influence the colonization behavior of a subsequent herbivore
Authors: Silva Diego B , Jiménez Alejandro , Urbaneja Alberto , Pérez‐Hedo Meritxell , Bento José MS 
Published: May 2021

AbstractBACKGROUNDPlants in nature can be sequentially attacked by different arthropod herbivores. Feeding by one arthropod species may induce plant‐defense responses that might affect the performance of a later‐arriving herbivorous species. Understanding these interactions can help in developing pest‐management strategies. In tomato, the sweet‐potato whitefly Bemisia tabaci and the two‐spotted spider mite Tetranychus urticae are key pests that frequently cohabit on the same plant. We studied whether colonization by one species can either facilitate or impede later colonization of tomato plants by conspecific or heterospecific individuals.RESULTSB. tabaci females showed a strong preference for and increased oviposition on plants previously colonized by conspecifics. In contrast, plants infested with T. urticae repelled B. tabaci females and reduced their oviposition rate by 86%. Although females of T. urticae showed no preference between conspecific‐infested or uninfested plants, we observed a 50% reduction in the number of eggs laid on conspecific‐infested plants. Both herbivorous arthropods up‐regulated the expression of genes involving the jasmonic acid and abscisic acid pathways, increasing emissions of fatty‐acid derivatives, but only B. tabaci increased the expression of genes related to the salicylic acid pathway and the total amount of phenylpropanoids released. Terpenoids were the most abundant compounds in the volatile blends; many terpenoids were emitted at different rates, which might have influenced the arthropods' host selection.CONCLUSIONOur results indicate that B. tabaci infestation facilitated subsequent infestations by conspecifics and mites, while T. urticae infestation promoted herbivore‐induced resistance. Based on both the molecular and behavioral findings, a novel sustainable pest‐management strategy is discussed.