bluuebunny/crossref_metadata_2025_split huggingface dataset:
Porovnání aktuálních metodik identifikace funkčních a anaerobních prahů na bicyklovém ergometru u triatlonistů
Authors: Kovářová Lenka , Berka Martin , Pánek David 
Published: January 2018

The aim of the study was to compare the currently methodics for identification functional and anaerobic thresholds on a bicycle ergometer by triathletes. The sample included triathletes (men), regular participants in the Czech triathlon cup (n = 10, age 35.89 ± 7.94 years, body height 181.83 ± 6.52 cm, weight 80.65 ± 6.53 kg). In the study, we compared the evaluation methodics using lactate curve, respiratory parameters, theoretical calculation, motor test and Conconi test. For statistical data processing we used the Repeated Measures, for evaluating the significance of differences between each test method then pairwise comparation (Bonferroni test). Results showed statistically significant differences (p = 0.000). Significantly higher values are reached in Conconi test (173 ± 14.2 beats.min–1, 313 ± 74.8 W). In pairwise comparison of methodics are differences between lactate and Conconi test in HR values (p = 0.037) as well as the difference between HR lactate test and theoretical calculation (p = 0.039). Most statistical variations in the watts evaluation is found again in connection with Conconi test (time trial: p = 0.039; lactate test: p = 0.013; spiroergometry: p = 0.041).
Kategorie prostoru (nejen) v kinantropologii
Authors: Bednář Miloš 
Published: January 2018

The objective of this article is to reflect the concept of space – both from a general perspective and with focusing on the area which is covered with a scientific branch of kinanthropology. The concrete examples are taken especially from the field of sports. The general part is a short historical overview per apices and bigger attention is paid to the doctrine of Descartes and Kant. Then „anthropologically settled“ space, encompassing sacral dimension in relation to the foundations of olympism as well, was analyzed. Uexküll´s and Husserl´s concept of Umwelt was used as the apt explanatory principle. The article is culminated in the analyses of „bodies dialogue“ in both natural and social space using findings of posturics and proxemics. In the conclusion, the question of possible territorial behaviour in the field of sports is put.
De la dérive ethnographique
Authors: Rousseau Phillip 
Published: January 2018

Ce texte relève une série d’embrouilles méthodologiques qui découlent d’une expérience de terrain à l’UNESCO – j’y étais en fonction de suivre les négociations menant à l’adoption de la Convention visant la protection et la promotion de la diversité des expressions culturelles en 2005. Une mauvaise synchronisation entre l’anthropologue et son terrain est à la source d’un premier constat qui laissait perplexe : s’approcher de la Convention semblait constamment mener à se détourner de l’institution hôte (UNESCO). Face à un objet aussi peu coopératif à se laisser cerner sous les traits disciplinaires, j’en viens d’abord à me demander dans quelle mesure la recherche pouvait être considérée comme un terrain. J’expose aussi comment, à partir d’une posture instable – un pied dans le terrain, l’autre non – l’objet tendait à se décliner d’une manière préalablement insoupçonnée.
Le « terrain », mais pour quoi faire ?
Authors: Messu Michel 
Published: January 2018

Considérant que les sciences du social sont des sciences de l’empirie, cet article propose une réflexion sur la manière dont ces sciences peuvent remplir cet objectif lorsqu’elles disent procéder depuis un « terrain ». Il cherchera à établir combien le « terrain » peut, et doit, être heuristique dans la démarche de recherche. Combien il peut se révéler crucial dans la mise à l’épreuve de la problématique de recherche. Combien, enfin, il « oblige » le chercheur. Bien plus, si les sciences du social arrivent à partager une même compréhension du terrain, elles pourront s’engager dans une épistémologie de la découverte autrement plus conforme à celle qui guide les autres sciences.
S’impliquer pour enquêter
Authors: Jouan Adrien 
Published: January 2018

À partir d’une enquête réalisée à Montréal dans un groupe militant pour le droit à l’éducation pour les enfants sans-papiers, on discutera de la place de l’enquêteur en terrain militant et des problèmes, classiques en ethnographie et décisifs dans l’étude des mobilisations, qui se nouent autour de son double statut d’observateur et de participant. On commencera par décrire certaines contraintes qui ont configuré l’enquête comme une participation-observante à découvert, comme la politique d’enquête des enquêtés qui confronte l’enquêteur à un impératif participatif. Ensuite, on défendra l’idée que l’implication de l’enquêteur, qui s’éloigne d’une « épistémologie de la non-perturbation », ouvre des voies d’investigation intéressantes ; on abordera en même temps la question des limites de sa participation. Enfin, on formulera des propositions de solutions à deux dilemmes rencontrés au fil de cette enquête in situ : le respect des règles des comités d’éthique et « l’enclicage » de l’enquêteur.
Quelques leçons que les atlanticistes ont apprises de l’Atlantique français1
Authors: Laramée François Dominic 
Published: January 2018

Qu’avons-nous appris de la récente floraison de travaux sur l’Atlantique français de l’époque moderne menés par les historiens francophones et anglophones ? Ce bilan historiographique se penche sur trois aspects importants de la question : le raffinement et la remise en question du modèle de l’Atlantique en tant qu’espace économique cohérent et intégré ; l’esclavage, ses conséquences et ses résistances ; et la création et la circulation des savoirs. Les études portant sur des particularités locales, voire individuelles, s’y révèlent particulièrement éclairantes. Quelques avenues de recherches ultérieures sont également proposées.
Understanding the Dynamics of the Oxic‐Anoxic Interface in the Black Sea
Authors: Stanev Emil V. , Poulain Pierre‐Marie , Grayek Sebastian , Johnson Kenneth S. , Claustre Hervé , Murray James W. 
Published: January 2018

AbstractThe Black Sea, the largest semienclosed anoxic basin on Earth, can be considered as an excellent natural laboratory for oxic and anoxic biogeochemical processes. The suboxic zone, a thin interface between oxic and anoxic waters, still remains poorly understood because it has been undersampled. This has led to alternative concepts regarding the underlying processes that create it. Existing hypotheses suggest that the interface originates either by isopycnal intrusions that introduce oxygen or the dynamics of manganese redox cycling that are associated with the sinking of particles or chemosynthetic bacteria. Here we reexamine these concepts using high‐resolution oxygen, sulfide, nitrate, and particle concentration profiles obtained with sensors deployed on profiling floats. Our results show an extremely stable structure in density space over the entire basin with the exception of areas near the Bosporus plume and in the southern areas dominated by coastal anticyclones. The absence of large‐scale horizontal intrusive signatures in the open‐sea supports a hypothesis prioritizing the role of biogeochemical processes.
Bioorthogonal Strategies for Engineering Extracellular Matrices
Authors: Madl Christopher M. , Heilshorn Sarah C. 
Published: January 2018

AbstractHydrogels are commonly used as engineered extracellular matrix (ECM) mimics in applications ranging from tissue engineering to in vitro disease models. Ideal mechanisms used to crosslink ECM‐mimicking hydrogels do not interfere with the biology of the system. However, most common hydrogel crosslinking chemistries exhibit some form of crossreactivity. The field of bioorthogonal chemistry has arisen to address the need for highly specific and robust reactions in biological contexts. Accordingly, bioorthogonal crosslinking strategies are incorporated into hydrogel design, allowing for gentle and efficient encapsulation of cells in various hydrogel materials. Furthermore, the selective nature of bioorthogonal chemistries can permit dynamic modification of hydrogel materials in the presence of live cells and other biomolecules to alter matrix mechanical properties and biochemistry on demand. This review provides an overview of bioorthogonal strategies used to prepare cell‐encapsulating hydrogels and highlights the potential applications of bioorthogonal chemistries in the design of dynamic engineered ECMs.
Tilted Spiro‐Type Thermally Activated Delayed Fluorescence Host for ≈100% Exciton Harvesting in Red Phosphorescent Electronics with Ultralow Doping Ratio
Authors: Wang Ya‐Kun , Li Si‐Hua , Wu Sheng‐Fan , Huang Chen‐Chao , Kumar Sarvendra , Jiang Zuo‐Quan , Fung Man‐Keung , Liao Liang‐Sheng 
Published: January 2018

AbstractDespite promising efficiency, the high fabrication cost due to the required high concentrations of noble metal based phosphors is still problematic for phosphorescent organic light‐emitting diodes (PhOLEDs). This situation becomes even serious considering some practical applications need high luminance, which in turn requires a higher concentration of emitters. A paradigm shift to circumvent these issues can be development of materials that are able to operate efficiently in very low concentrations (<1 wt%). Here, two thermally activated delayed fluorescence hosts (OSTFPCN and OSTFPB) with tilted spiro geometry, small singlet‐triplet splitting (Δ
E
st), and effective resonance energy transfer are developed. Within expectation, record performances with a power efficiency of 63.6 lm W−1 and an external quantum efficiency (EQE) of 31.2% for the red phosphor Ir(MDQ)2(acac) (2.0 wt%) are achieved with OSTFPCN as host. Additionally, a high power efficiency around 58 lm W−1 is also gained even at an ultralow dopant concentration of 0.5 wt% for a OSTFPB based device. Mechanism studies demonstrate that efficiency roll‐off can be effectively suppressed in such low concentrations. These findings pave a new way to exploit low cost and high efficiency PhOLEDs.
The Current Landscape of 3D In Vitro Tumor Models: What Cancer Hallmarks Are Accessible for Drug Discovery?
Authors: Rodenhizer Darren , Dean Teresa , D'Arcangelo Elisa , McGuigan Alison P. 
Published: January 2018

AbstractCancer prognosis remains a lottery dependent on cancer type, disease stage at diagnosis, and personal genetics. While investment in research is at an all‐time high, new drugs are more likely to fail in clinical trials today than in the 1970s. In this review, a summary of current survival statistics in North America is provided, followed by an overview of the modern drug discovery process, classes of models used throughout different stages, and challenges associated with drug development efficiency are highlighted. Then, an overview of the cancer hallmarks that drive clinical progression is provided, and the range of available clinical therapies within the context of these hallmarks is categorized. Specifically, it is found that historically, the development of therapies is limited to a subset of possible targets. This provides evidence for the opportunities offered by novel disease‐relevant in vitro models that enable identification of novel targets that facilitate interactions between the tumor cells and their surrounding microenvironment. Next, an overview of the models currently reported in literature is provided, and the cancer biology they have been used to explore is highlighted. Finally, four priority areas are suggested for the field to accelerate adoption of in vitro tumour models for cancer drug discovery.
Magnetic Macroporous Hydrogels as a Novel Approach for Perfused Stem Cell Culture in 3D Scaffolds via Contactless Motion Control
Authors: Rödling Lisa , Volz Esther Magano , Raic Annamarija , Brändle Katharina , Franzreb Matthias , Lee‐Thedieck Cornelia 
Published: January 2018

AbstractThere is an urgent need for 3D cell culture systems that avoid the oversimplifications and artifacts of conventional culture in 2D. However, 3D culture within the cavities of porous biomaterials or large 3D structures harboring high cell numbers is limited by the needs to nurture cells and to remove growth‐limiting metabolites. To overcome the diffusion‐limited transport of such soluble factors in 3D culture, mixing can be improved by pumping, stirring or shaking, but this in turn can lead to other problems. Using pumps typically requires custom‐made accessories that are not compatible with conventional cell culture disposables, thus interfering with cell production processes. Stirring or shaking allows little control over movement of scaffolds in media. To overcome these limitations, magnetic, macroporous hydrogels that can be moved or positioned within media in conventional cell culture tubes in a contactless manner are presented. The cytocompatibility of the developed biomaterial and the applied magnetic fields are verified for human hematopoietic stem and progenitor cells (HSPCs). The potential of this technique for perfusing 3D cultures is demonstrated in a proof‐of‐principle study that shows that controlled contactless movement of cell‐laden magnetic hydrogels in culture media can mimic the natural influence of differently perfused environments on HSPCs.
Superfast Room‐Temperature Activation of SnO2 Thin Films via Atmospheric Plasma Oxidation and their Application in Planar Perovskite Photovoltaics
Authors: Yu Haejun , Yeom Hye‐In , Lee Jong Woo , Lee Kisu , Hwang Doyk , Yun Juyoung , Ryu Jaehoon , Lee Jungsup , Bae Sohyeon , Kim Seong Keun , Jang Jyongsik 
Published: January 2018

AbstractThe power conversion efficiency (PCE) of perovskite solar cells (PSCs) has now exceeded 20%; thus, research focus has shifted to establishing the foundations for commercialization. One of the pivotal themes is to curtail the overall fabrication time, to reduce unit cost, and mass‐produce PSCs. Additionally, energy dissipation during the thermal annealing (TA) stage must be minimized by realizing a genuine low‐temperature (LT) process. Here, tin oxide (SnO2) thin films (TFs) are formulated at extremely high speed, within 5 min, under an almost room‐temperature environment (<50 °C), using atmospheric Ar/O2 plasma energy (P‐SnO2) and are applied as an electron transport layer of a “n–i–p”‐type planar PSC. Compared with a thermally annealed SnO2 TF (T‐SnO2), the P‐SnO2 TF yields a more even surface but also outstanding electrical conductivity with higher electron mobility and a lower number of charge trap sites, consequently achieving a superior PCE of 19.56% in P‐SnO2‐based PSCs. These findings motivate the use of a plasma strategy to fabricate various metal oxide TFs using the sol–gel route.
Novel MOF‐Derived Co@N‐C Bifunctional Catalysts for Highly Efficient Zn–Air Batteries and Water Splitting
Authors: Zhang Mingdao , Dai Quanbin , Zheng Hegen , Chen Mindong , Dai Liming 
Published: January 2018

AbstractMetal–organic frameworks (MOFs) and MOF‐derived materials have recently attracted considerable interest as alternatives to noble‐metal electrocatalysts. Herein, the rational design and synthesis of a new class of Co@N‐C materials (C‐MOF‐C2‐T) from a pair of enantiotopic chiral 3D MOFs by pyrolysis at temperature T is reported. The newly developed C‐MOF‐C2‐900 with a unique 3D hierarchical rodlike structure, consisting of homogeneously distributed cobalt nanoparticles encapsulated by partially graphitized N‐doped carbon rings along the rod length, exhibits higher electrocatalytic activities for oxygen reduction and oxygen evolution reactions (ORR and OER) than that of commercial Pt/C and RuO2, respectively. Primary Zn–air batteries based on C‐MOF‐900 for the oxygen reduction reaction (ORR) operated at a discharge potential of 1.30 V with a specific capacity of 741 mA h gZn–1 under 10 mA cm–2. Rechargeable Zn–air batteries based on C‐MOF‐C2‐900 as an ORR and OER bifunctional catalyst exhibit initial charge and discharge potentials at 1.81 and 1.28 V (2 mA cm–2), along with an excellent cycling stability with no increase in polarization even after 120 h – outperform their counterparts based on noble‐metal‐based air electrodes. The resultant rechargeable Zn–air batteries are used to efficiently power electrochemical water‐splitting systems, demonstrating promising potential as integrated green energy systems for practical applications.
Engineered and Laser‐Processed Chitosan Biopolymers for Sustainable and Biodegradable Triboelectric Power Generation
Authors: Wang Ruoxing , Gao Shengjie , Yang Zhen , Li Yule , Chen Weinong , Wu Benxin , Wu Wenzhuo 
Published: January 2018

AbstractRecent advances achieved in triboelectric nanogenerators (TENG) focus on boosting power generation and conversion efficiency. Nevertheless, obstacles concerning economical and biocompatible utilization of TENGs continue to prevail. Being an abundant natural biopolymer from marine crustacean shells, chitosan enables exciting opportunities for low‐cost, biodegradable TENG applications in related fields. Here, the development of biodegradable and flexible TENGs based on chitosan is presented for the first time. The physical and chemical properties of the chitosan nanocomposites are systematically studied and engineered for optimized triboelectric power generation, transforming the otherwise wasted natural materials into functional energy devices. The feasibility of laser processing of constituent materials is further explored for the first time for engineering the TENG performance. The laser treatment of biopolymer films offers a potentially promising scheme for surface engineering in polymer‐based TENGs. The chitosan‐based TENGs present efficient energy conversion performance and tunable biodegradation rate. Such a new class of TENGs derived from natural biomaterials may pave the way toward the economically viable and ecologically friendly production of flexible TENGs for self‐powered nanosystems in biomedical and environmental applications.
Accelerated Hydrogen Evolution Kinetics on NiFe‐Layered Double Hydroxide Electrocatalysts by Tailoring Water Dissociation Active Sites
Authors: Chen Guangbo , Wang Tao , Zhang Jian , Liu Pan , Sun Hanjun , Zhuang Xiaodong , Chen Mingwei , Feng Xinliang 
Published: January 2018

AbstractOwing to its earth abundance, low kinetic overpotential, and superior stability, NiFe‐layered double hydroxide (NiFe‐LDH) has emerged as a promising electrocatalyst for catalyzing water splitting, especially oxygen evolution reaction (OER), in alkaline solutions. Unfortunately, as a result of extremely sluggish water dissociation kinetics (Volmer step), hydrogen evolution reaction (HER) activity of the NiFe‐LDH is rather poor in alkaline environment. Here a novel strategy is demonstrated for substantially accelerating the hydrogen evolution kinetics of the NiFe‐LDH by partially substituting Fe atoms with Ru. In a 1 m KOH solution, the as‐synthesized Ru‐doped NiFe‐LDH nanosheets (NiFeRu‐LDH) exhibit excellent HER performance with an overpotential of 29 mV at 10 mA cm−2, which is much lower than those of noble metal Pt/C and reported electrocatalysts. Both experimental and theoretical results reveal that the introduction of Ru atoms into NiFe‐LDH can efficiently reduce energy barrier of the Volmer step, eventually accelerating its HER kinetics. Benefitting from its outstanding HER activity and remained excellent OER activity, the NiFeRu‐LDH steadily drives an alkaline electrolyzer with a current density of 10 mA cm−2 at a cell voltage of 1.52 V, which is much lower than the values for Pt/C–Ir/C couple and state‐of‐the‐art overall water‐splitting electrocatalysts.
Nanocrystalline Precursors for the Co‐Assembly of Crack‐Free Metal Oxide Inverse Opals
Authors: Phillips Katherine R. , Shirman Tanya , Shirman Elijah , Shneidman Anna V. , Kay Theresa M. , Aizenberg Joanna 
Published: January 2018

AbstractInorganic microstructured materials are ubiquitous in nature. However, their formation in artificial self‐assembly systems is challenging as it involves a complex interplay of competing forces during and after assembly. For example, colloidal assembly requires fine‐tuning of factors such as the size and surface charge of the particles and electrolyte strength of the solvent to enable successful self‐assembly and minimize crack formation. Co‐assembly of templating colloidal particles together with a sol–gel matrix precursor material helps to release stresses that accumulate during drying and solidification, as previously shown for the formation of high‐quality inverse opal (IO) films out of amorphous silica. Expanding this methodology to crystalline materials would result in microscale architectures with enhanced photonic, electronic, and catalytic properties. This work describes tailoring the crystallinity of metal oxide precursors that enable the formation of highly ordered, large‐area (mm2) crack‐free titania, zirconia, and alumina IO films. The same bioinspired approach can be applied to other crystalline materials as well as structures beyond IOs.
In Situ Monitoring of MicroRNA Replacement Efficacy and Accurate Imaging‐Guided Cancer Therapy through Light‐Up Inter‐Polyelectrolyte Nanocomplexes
Authors: Deng Xiongwei , Yin Zhaoxia , Lu Jianqing , Li Xianlei , Shao Leihou , Zhao Caiyan , Yang Yishu , Hu Qin , Wu Yan , Sheng Wang 
Published: January 2018

AbstractReplacement of downregulated tumor‐suppressive microRNA (Ts‐miRNA) is recognized as an alternative approach for tumor gene therapy. However, in situ monitoring of miRNA replacement efficacy in a real‐time manner via noninvasive imaging is continually challenging. Here, glutathione (GSH)‐activated light‐up peptide‐polysaccharide‐inter‐polyelectrolyte nanocomplexes are established through self‐assembly of carboxymethyl dextran with disulfide‐bridged (“SS”) oligoarginine peptide (S‐Arg4), in which microRNA‐34a (miR‐34a) and indocyanine green (ICG) are simultaneously embedded and the nanocomplexes are subsequently stabilized by intermolecular cross‐linking. Upon confinement within the robust nanocomplexes, the near‐infrared fluorescence (NIRF) of ICG is considerably quenched (“off”) due to the aggregation‐caused quenching effect. However, after intracellular delivery, the disulfide bond in S‐Arg4 can be cleaved by intracellular GSH, which leads to the dissociation of nanocomplexes and triggers the simultaneous release of miR‐34a and ICG. The NIRF of ICG is concomitantly activated through dequenching of the aggregated ICG. Very interestingly, a good correlation between time‐dependent increase in NIRF intensity and miR‐34a replacement efficacy is found in nanocomplexes‐treated tumor cells and tumor tissues through either intratumoral or intravenous injections. Systemic nanocomplexes‐mediated miR‐34a replacement significantly suppresses the growth of HepG‐2‐ and MDA‐MB‐231‐derived tumor xenografts, and provides a pronounced survival benefit in these animal models.