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https://www.readbyqxmd.com/read/28535344/clarifying-the-controversial-catalytic-performance-of-co-oh-2-and-co3o4-for-oxygen-reduction-evolution-reactions-toward-efficient-zn-air-batteries
#1
Zhishuang Song, Xiaopeng Han, Yida Deng, Naiqin Zhao, Wenbin Hu, Cheng Zhong
Cobalt-based nanomaterials have been widely studied as catalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) due to their remarkable bifunctional catalytic activity, low cost and easy available. However, controversial results concerning OER/ORR performance exist between different types of cobalt-based catalysts, especially for Co(OH)2 and Co3O4. To address this issue, we develop a facile electrochemical deposition method to grow Co(OH)2 directly on the skeleton of carbon cloth, and further Co3O4 was obtained by post thermal treatment...
May 23, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28535198/transcatheter-aortic-valve-implantation-for-recurrent-valsalva-sinus-re-dissection-and-severe-aortic-regurgitation-shortly-after-surgery-for-type-a-aortic-dissection
#2
Elena Caporali, Giovanni Pedrazzini, Stefanos Demertzis, Enrico Ferrari
Delayed aortic regurgitation following Valsalva sinus re-dissection is a well-known complication that can occur at any time after surgery for type-A aortic dissection without root replacement. We describe a case of acute type-A dissection in an 81-year-old lady successfully treated with aortic valve resuspension and ascending aorta replacement with a 28-mm vascular graft. A month later, the patient was readmitted for worsening heart failure and a transthoracic echocardiogram showed severe aortic regurgitation secondary to non-coronary Valsalva sinus re-dissection and non-coronary aortic valve leaflet prolapse also confirmed at computed tomography scan...
May 23, 2017: Interactive Cardiovascular and Thoracic Surgery
https://www.readbyqxmd.com/read/28535047/electronic-and-morphological-dual-modulation-of-cobalt-carbonate-hydroxides-by-mn-doping-towards-highly-efficient-and-stable-bifunctional-electrocatalysts-for-overall-water-splitting
#3
Tang Tang, Wen-Jie Jiang, Shuai Niu, Ning Liu, Hao Luo, Yu-Yun Chen, Shi-Feng Jin, Feng Gao, Li-Jun Wan, Jin-Song Hu
Developing bifunctional non-noble electrocatalysts for efficient and durable oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is highly desirable and challenging for overall water splitting. Herein, Co-Mn carbonate hydroxide (CoMnCH) nanosheet arrays with controllable morphology and composition were developed on nickel foam (NF) as such bifunctional electrocatalysts. It was discovered that Mn doping in CoCH can simultaneously modulate the nanosheet morphology to significantly increase the electrochemical active surface area for exposing more accessible active sites and tune the electronic structure of Co center to effectively boost its intrinsic activity...
May 23, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28534630/an-approach-to-study-the-interactions-between-ellagitannins-and-oxygen-during-oak-wood-aging
#4
Ignacio García-Estévez, Cristina Alcalde-Eon, Ana María Martínez-Gil, Julian C Rivas-Gonzalo, M Teresa Escribano-Bailon, Ignacio Nevares, Maria Del Alamo-Sanza
During the aging of red wine in oak wood barrels, or in alternative aging systems, interactions between the compounds released from wood, the compounds of the wine and oxygen can take place. The main objective of the present work was to study oxygen-ellagitannin interactions by monitoring their levels in three model systems all containing the same amounts of French oak chips and only differing in the oxygen content: total absence, only the oxygen released from the chips and air-saturated (model systems F, OW and OS, respectively)...
May 23, 2017: Journal of Agricultural and Food Chemistry
https://www.readbyqxmd.com/read/28534609/au-promoted-nickel-iron-layered-double-hydroxide-nanoarrays-a-modular-catalyst-enabling-high-performance-oxygen-evolution
#5
Wenxin Zhu, Lizhi Liu, Zhihao Yue, Wentao Zhang, Xiaoyue Yue, Jing Wang, Shaoxuan Yu, Li Wang, Jianlong Wang
Oxygen evolution reaction (OER) has played a pivotal role in many energy conversion and storage technologies like water electrolysis, fuel cells, and metal-air batteries. However, the slow kinetics of OER limit the performance and commercialization of such devices. Herein, we report on NiFe LDH@Au hybrid nanoarrays on Ni foam for much enhanced OER. By hybridization of electronegative Au and NiFe LDH with intrinsic remarkable OER catalytic activity, this modular electrode could drive an overall ultrahigh-performance and robust OER in base with the demand of overpotentials of only 221, 235 and 270 mV to afford 50, 100 and 500 mA cm-2, respectively...
May 23, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28533875/-management-of-spontaneous-pneumothorax-about-138-cases
#6
Bouchra Habibi, Leila Achachi, Sohaib Hayoun, Mohammed Raoufi, Laila Herrak, Mustapha El Ftouh
Pneumothorax is a collection of air in the pleural cavity. We conducted a retrospective study of patients with spontaneous pneumothorax in the Department of Pneumology at the Ibn Sina Hospital in Rabat (2009-2011) with the aim to determine the epidemiological, clinical, radiological, therapeutic and evolutionary manifestation of spontaneous pneumothorax. The study involved 138 patients: 128 men and 10 women (17-83 years), with an average age of 44.5 +/- 17.4 years and sex ratio of 12/8. 81.2% of patients were smokers...
2017: Pan African Medical Journal
https://www.readbyqxmd.com/read/28533386/metabolic-basis-to-sherpa-altitude-adaptation
#7
James A Horscroft, Aleksandra O Kotwica, Verena Laner, James A West, Philip J Hennis, Denny Z H Levett, David J Howard, Bernadette O Fernandez, Sarah L Burgess, Zsuzsanna Ament, Edward T Gilbert-Kawai, André Vercueil, Blaine D Landis, Kay Mitchell, Monty G Mythen, Cristina Branco, Randall S Johnson, Martin Feelisch, Hugh E Montgomery, Julian L Griffin, Michael P W Grocott, Erich Gnaiger, Daniel S Martin, Andrew J Murray
The Himalayan Sherpas, a human population of Tibetan descent, are highly adapted to life in the hypobaric hypoxia of high altitude. Mechanisms involving enhanced tissue oxygen delivery in comparison to Lowlander populations have been postulated to play a role in such adaptation. Whether differences in tissue oxygen utilization (i.e., metabolic adaptation) underpin this adaptation is not known, however. We sought to address this issue, applying parallel molecular, biochemical, physiological, and genetic approaches to the study of Sherpas and native Lowlanders, studied before and during exposure to hypobaric hypoxia on a gradual ascent to Mount Everest Base Camp (5,300 m)...
May 22, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28532521/animal-board-invited-review-sheep-birth-distribution-in-past-herds-a-review-for-prehistoric-europe-6th-to-3rd-millennia-bc
#8
M Balasse, A Tresset, A Bălăşescu, E Blaise, C Tornero, H Gandois, D Fiorillo, É Á Nyerges, D Frémondeau, E Banffy, M Ivanova
In temperate latitudes sheep have a seasonal reproductive behaviour, which imposes strong constraints on husbandry in terms of work organization and availability of animal products. During the last 50 years, researchers have focused on understanding the mechanisms driving small ruminants' reproduction cycles and finding ways to control them. This characteristic is inherited from their wild ancestor. However, the history of its evolution over the 10 millennia that separates present day European sheep from their Near Eastern ancestors' remains to be written...
May 23, 2017: Animal: An International Journal of Animal Bioscience
https://www.readbyqxmd.com/read/28530739/phase-controllable-synthesis-of-cobalt-hydroxide-for-electrocatalytic-oxygen-evolution
#9
Fenglei Lyu, Yaocai Bai, Qingfa Wang, Li Wang, Xiangwen Zhang, Yadong Yin
Identification of active sites for oxygen evolution reaction (OER) plays a key role in the design and fabrication of high-performance cobalt-based electrocatalysts. Herein, we report the synthesis of two types of two-dimensional monometallic cobalt hydroxide nanoplates in aqueous solution for OER: α-Co(OH)2 with both Co(2+)Td and Co(2+)Oh sites and β-Co(OH)2 with Co(2+)Oh sites. Electrochemical characterization reveals that α-Co(OH)2 is more active than β-Co(OH)2 towards OER. The better activity can be attributed to the presence of Co(2+)Td sites in α-Co(OH)2, which are more active than Co(2+)Oh sites...
May 22, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28524192/advanced-oxygen-evolution-catalysis-by-bimetallic-ni-fe-phosphide-nanoparticles-encapsulated-in-nitrogen-phosphorus-and-sulphur-tri-doped-porous-carbon
#10
Ping Li, Hua Chun Zeng
Through molecular design of a solid precursor, we engineer a novel nanocomposite composed of bimetallic (Ni-Fe) phosphide nanoparticles encapsulated in a N,P,S-tri-doped porous carbon matrix. With tailorable compositional and architectural features, the resultant nanocomposite presents remarkable performance in electrochemical water oxidation.
May 19, 2017: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/28523861/a-bifunctional-hybrid-electrocatalyst-for-oxygen-reduction-and-evolution-cobalt-oxide-nanoparticles-strongly-coupled-to-b-n-decorated-graphene
#11
Yun Tong, Pengzuo Chen, Tianpei Zhou, Kun Xu, Wangsheng Chu, Changzheng Wu, Yi Xie
The electrocatalyzed oxygen reduction and evolution reactions (ORR and OER, respectively) are the core components of many energy conversion systems, including water splitting, fuel cells, and metal-air batteries. Rational design of highly efficient non-noble materials as bifunctional ORR/OER electrocatalysts is of great importance for large-scale practical applications. A new strongly coupled hybrid material is presented, which comprises CoOx nanoparticles rich in oxygen vacancies grown on B,N-decorated graphene (CoOx NPs/BNG) and operates as an efficient bifunctional OER/ORR electrocatalyst...
May 19, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28514161/interdiffusion-reaction-assisted-hybridization-of-two-dimensional-metal-organic-frameworks-and-ti3c2tx-nanosheets-for-electrocatalytic-oxygen-evolution
#12
Li Zhao, Biliang Dong, Shaozhou Li, Lijun Zhou, Linfei Lai, Zhiwei Wang, Shulin Zhao, Min Han, Kai Gao, Min Lu, Xiaoji Xie, Bo Chen, Zhengdong Liu, Xiangjing Wang, Hao Zhang, Hai Li, Juqing Liu, Hua Zhang, Xiao Huang, Wei Huang
Two-dimensional (2D) metal-organic framework (MOF) nanosheets have been recently regarded as the model electrocatalysts due to their porous structure, fast mass and ion transfer through the thickness, and large portion of exposed active metal centers. Combining them with electrically conductive 2D nanosheets is anticipated to achieve further improved performance in electrocatalysis. In this work, we in situ hybridized 2D cobalt 1,4-benzenedicarboxylate (CoBDC) with Ti3C2Tx (the MXene phase) nanosheets via an interdiffusion reaction-assisted process...
May 22, 2017: ACS Nano
https://www.readbyqxmd.com/read/28513886/regulating-water-reduction-kinetics-in-cobalt-phosphide-for-enhancing-her-catalytic-activity-in-alkaline-solution
#13
Kun Xu, Hui Ding, Mengxing Zhang, Min Chen, Zikai Hao, Lidong Zhang, Changzheng Wu, Yi Xie
Electrochemical water splitting to produce hydrogen renders a promising pathway for renewable energy storage. Considering limited electrocatalysts have good oxygen-evolution reaction (OER) catalytic activity in acid solution while numerous economical materials show excellent OER catalytic performance in alkaline solution, developing new strategies that enhance the alkaline hydrogen-evolution reaction (HER) catalytic activity of cost-effective catalysts is highly desirable for achieving highly efficient overall water splitting...
May 17, 2017: Advanced Materials
https://www.readbyqxmd.com/read/28513678/mechanochemically-induced-sulfur-doping-in-zno-via-oxygen-vacancy-formation
#14
Y Daiko, J Schmidt, G Kawamura, S Romeis, D Segets, Y Iwamoto, W Peukert
Surface defects of ZnO nanoparticles were induced via mechanical stressing using a Turbula shaker mixer and a planetary ball mill, and the possibilities for surface modification and functionalization of the ZnO nanoparticles were exemplified by sulfur doping of activated ZnO. Raman spectroscopy reveals that the formation of oxygen vacancies (VO) does not only occur under high stressing conditions in a planetary ball mill but even upon rather 'mild stressing' in the shaker mixer. The temporal evolution of the vacancy concentration in ZnO stressed under different conditions can be described by a model that accounts for stress number and vacancy diffusion with diffusion coefficients of VO of 3...
May 17, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28513671/temporal-analysis-of-blister-evolution-during-anion-intercalation-in-graphite
#15
R Yivlialin, G Bussetti, L Magagnin, F Ciccacci, L Duò
In the currently accepted picture, when graphite is immersed and polarized in a diluted sulfuric acid electrolyte, the surface undergoes an invasive process due to the intercalation of solvated sulphate anions inside the crystal. The following evolution of CO, CO2 and O2 promotes the surface swelling and the growth of blisters. Here, we give evidence that the appearance of blisters affects the graphite surface as soon as the oxygen potential is reached, i.e. before the traditionally accepted anion intercalation stage, which instead is demonstrated slowing the blister development...
May 17, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28513669/the-open-cubane-oxo-oxyl-coupling-mechanism-dominates-photosynthetic-oxygen-evolution-a-comprehensive-dft-investigation-on-o-o-bond-formation-in-the-s4-state
#16
Yu Guo, Hui Li, Lan-Lan He, Dong-Xia Zhao, Li-Dong Gong, Zhong-Zhi Yang
The dioxygen formation mechanism of biological water oxidation in nature has long been the focus of argument; many diverse mechanistic hypotheses have been proposed. Based on a recent breakthrough in the resolution of the electronic and structural properties of the oxygen-evolving complex in the S3 state, our density functional theory (DFT) calculations reveal that the open-cubane oxo-oxyl coupling mechanism, whose substrates preferably originate from W2 and O5 in the S2 state, emerges as the best candidate for O-O bond formation in the S4 state...
May 17, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28513468/structural-evolution-during-calcination-and-sintering-of-a-la-sub-0-6-sub-sr-sub-0-4-sub-sub-0-99-sub-coo-sub-3-%C3%AE-sub-nanofiber-prepared-by-electrospinning
#17
Søren Simonsen, Jing Shao, Wenjing Zhang
Design of 3-dimensional metal oxide nanofibers by electrospinning is being widely explored. However, the impacts of calcination and sintering on the resulting morphology remain unknown. For the first time, (La<sub>0.6</sub>Sr<sub>0.4</sub>)<sub>0.99</sub>CoO<sub>3-δ</sub> (LSC) nanofiber, which is among the most promising electrode materials for solid oxide fuel cells, was synthesized by sol-gel electrospinning. By elevating the temperature in oxygen using in situ transmission electron microscopy, we discovered the structural transitions from nanofibers to nanotubes and then to nano-pearl strings...
May 17, 2017: Nanotechnology
https://www.readbyqxmd.com/read/28509401/transitions-between-marine-and-freshwater-environments-provide-new-clues-about-the-origins-of-multicellular-plants-and-algae
#18
REVIEW
Simon M Dittami, Svenja Heesch, Jeanine L Olsen, Jonas Collén
Marine-freshwater and freshwater-marine transitions have been key events in the evolution of life, and most major groups of organisms have independently undergone such events at least once in their history. Here we first compile an inventory of bidirectional freshwater and marine transitions in multicellular photosynthetic eukaryotes. While green and red algae have mastered multiple transitions in both directions, brown algae have colonized fresh water on a maximum of six known occasions, and angiosperms have made the transition to marine environments only two or three times...
May 16, 2017: Journal of Phycology
https://www.readbyqxmd.com/read/28509363/ni-fe-nitride-nanoplates-on-nitrogen-doped-graphene-as-a-synergistic-catalyst-for-reversible-oxygen-evolution-reaction-and-rechargeable-zn-air-battery
#19
Yuchi Fan, Shintaro Ida, Aleksandar Staykov, Taner Akbay, Hidehisa Hagiwara, Junko Matsuda, Kenji Kaneko, Tatsumi Ishihara
Obtaining bifunctional electrocatalysts with high activity for the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) is a main hurdle in the application of rechargeable metal-air batteries. Earth-abundant 3d transition metal-based catalysts have been developed for the OER and ORR; however, most of these are based on oxides, whose insulating nature strongly restricts their catalytic performance. This study describes a metallic Ni-Fe nitride/nitrogen-doped graphene hybrid in which 2D Ni-Fe nitride nanoplates are strongly coupled with the graphene support...
May 16, 2017: Small
https://www.readbyqxmd.com/read/28508567/p-doped-moo3-x-nanosheets-as-efficient-and-stable-electrocatalysts-for-hydrogen-evolution
#20
Ling Li, Ting Zhang, Junqing Yan, Xuediao Cai, Shengzhong Frank Liu
A P doped MoO3-x nanocomposite material with rich oxygen vacancies is successfully fabricated by a two-step intercalation method, which presents superior activity for the hydrogen evolution reaction with low overpotential and fast electron transfer. In 0.5 m H2 SO4 , it displays an overpotential of 166 mV for driving the current density of 10 mA cm(-2) . Moreover, it also shows a good catalytic stability in the electrolytes with different pH, 0.5 m H2 SO4 (strong acid), 0.5 m Na2 SO4 (neutral solution), and 0...
May 16, 2017: Small
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