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Carbon dating

Mingchu Zou, Wenqi Zhao, Huaisheng Wu, Hui Zhang, Wenjing Xu, Liusi Yang, Shiting Wu, Yunsong Wang, Yijun Chen, Lu Xu, Anyuan Cao
Carbon fiber (CF) grafted with a layer of carbon nanotubes (CNTs) plays an important role in composite materials and other fields; to date, the applications of CNTs@CF multiscale fibers are severely hindered by the limited amount of CNTs grafted on individual CFs and the weak interfacial binding force. Here, monolithic CNTs@CF fibers consisting of a 3D highly porous CNT sponge layer with macroscopic-thickness (up to several millimeters), which is directly grown on a single CF, are fabricated. Mechanical tests reveal high sponge-CF interfacial strength owing to the presence of a thin transitional layer, which completely inhibits the CF slippage from the matrix upon fracture in CNTs@CF fiber-epoxy composites...
February 19, 2018: Advanced Materials
Jasmin Schiefer, Georg J Lair, Christopher Lüthgens, Eva Maria Wild, Peter Steier, Winfried E H Blum
During COP 21 in Paris 2015, several states and organizations agreed on the "4/1000" initiative for food security and climate. This initiative aims to increase world's soil organic carbon (SOC) stocks by 4‰ annually. The influence of soil development status on SOC dynamics is very important but usually not considered in studies. We analyse SOC accumulation under forest, grassland and cropping systems along a soil age gradient (10-17,000years) to show the influence of soil development status on SOC increase...
February 15, 2018: Science of the Total Environment
Stefanie De Jesus, Harry Prapavessis
INTRODUCTION: Previous research has shown reductions in cigarette consumption during the pre-quit period of exercise-aided smoking cessation interventions. Smoking topography and sensation patterns during this period is unknown and may provide valuable insight into compensation and cessation readiness. METHODS: Female smokers (N = 236, M age = 43, M cigarettes/day = 17.0) enrolled in an exercise-aided smoking cessation intervention self-reported daily cigarette use and cigarette sensory experiences...
February 15, 2018: Addictive Behaviors
Urška Sivka, Nataša Toplak, Simon Koren, Jernej Jakše
Lithophaga lithophaga is a rock-boring bivalve with an ability to dissolve carbonate substrata with its siphonal and pallial gland secretions. However, the molecular mechanism that enables this species to bore into calcareous rocks is not yet known. In order to identify genes potentially involved in chemical boring we performed transcriptome sequencing of pallial-gland tissue samples of L. lithophaga. Transcriptome sequencing using an Ion Torrent platform generated 60.563 million clean reads with an average read length of 96 bp...
February 6, 2018: Comparative Biochemistry and Physiology. Part D, Genomics & Proteomics
Henriqueta Louro
The manufactured nanomaterials (NMs) have specific physicochemical properties that confer unique mechanical, optical, electrical and magnetic characteristics that are beneficial for biomedical and industrial applications. However, recent studies have suggested that such specific physicochemical properties of the NMs may define nano-bio interactions thereby determining their toxic potential.One of the major concerns about NMs is the potential to induce cancer, suggested by some experimental studies, as seen for titanium dioxide nanomaterials or carbon nanotubes...
2018: Advances in Experimental Medicine and Biology
E J Fleming, T Woyke, A R Donatello, M M M Kuypers, A Sczyrba, S Littmann, D Emerson
Leptothrix ochracea is known for producing large volumes of iron-oxyhydroxide sheaths that alter wetland biogeochemistry. For over a century, these delicate structures have fascinated microbiologists and geoscientists. Because L. ochracea still resists long-term in vitro culture, the debate regarding its metabolic classification dates back to 1885. We developed a novel culturing technique for L. ochracea using in situ natural waters, and coupled this with single cell genomics and nanoscale secondary ion mass spectrophotometry (nanoSIMS) to probe L...
February 16, 2018: Applied and Environmental Microbiology
Megumi Honjo, Hidenobu Tanihara
Rho-associated protein kinase (ROCK), a ubiquitously expressed signaling messenger and downstream effector of Rho, is activated by several bioactive factors in the aqueous humor (AH). Rho-ROCK signaling regulates a wide spectrum of fundamental cellular events, including cell adhesion, motility, proliferation, differentiation, and apoptosis. Previous studies, including our own, found that ROCK inhibitor lowers intraocular pressure (IOP) via a direct effect on the conventional AH outflow pathway, by regulation of contractile properties, fibrotic activity, and permeability of the trabecular meshwork (TM) and Schlemm's canal (SC) tissues, influencing extracellular matrix (ECM) production...
February 14, 2018: Japanese Journal of Ophthalmology
Pratap C Naha, Sourav P Mukherjee, Hugh J Byrne
Engineered nanomaterials are increasingly being developed for paints, sunscreens, cosmetics, industrial lubricants, tyres, semiconductor devices, and also for biomedical applications such as in diagnostics, therapeutics, and contrast agents. As a result, nanomaterials are being manufactured, transported, and used in larger and larger quantities, and potential impacts on environmental and human health have been raised. Poly(amidoamine) (PAMAM) dendrimers are specifically suitable for biomedical applications...
February 14, 2018: International Journal of Environmental Research and Public Health
Miroslav Vetrík, Martin Parizek, Daniel Hadraba, Olivia Kukackova, Jiří Brus, Helena Hlídková, Lucie Komankova, Jiri Hodan, Ondrej Sedlacek, Miroslav Slouf, Lucie Bacakova, Martin Hruby
Heat-treated polyacrylonitrile (HT-PAN), also referred to as Black Orlon (BO), is a promising carbon-based material used for applications in tissue engineering and regenerative medicine. To the best of our knowledge, no such complex bone morphology-mimicking three-dimensional (3D) BO structure has been reported to date. We report that BO can be easily made into 3D cryogel scaffolds with porous structures, using succinonitrile as a porogen. The cryogels possess a porous morphology, similar to bone tissue. The prepared scaffolds showed strong osteoconductive activity, providing excellent support for the adhesion, proliferation and mitochondrial activity of human bone-derived cells...
February 13, 2018: ACS Applied Materials & Interfaces
Jens Karstens, Haflidi Haflidason, Lukas W M Becker, Christian Berndt, Lars Rüpke, Sverre Planke, Volker Liebetrau, Mark Schmidt, Jürgen Mienert
Large amounts of methane are stored in continental margins as gas hydrates. They are stable under high pressure and low, but react sensitively to environmental changes. Bottom water temperature and sea level changes were considered as main contributors to gas hydrate dynamics after the last glaciation. However, here we show with numerical simulations that pulses of increased sedimentation dominantly controlled hydrate stability during the end of the last glaciation offshore mid-Norway. Sedimentation pulses triggered widespread gas hydrate dissociation and explains the formation of ubiquitous blowout pipes in water depths of 600 to 800 m...
February 12, 2018: Nature Communications
Michael A Mallin, Matthew R McIver
Concentrated (or confined) animal feed operations (CAFOs) are the principal means of livestock production in the United States, and such facilities pollute nearby waterways because of their waste management practices; CAFO waste is pumped from the confinement structure into a cesspit and sprayed on a field. Stocking Head Creek is located in eastern North Carolina, a state with >9,000,000 head of swine confined in CAFOs. This watershed contains 40 swine CAFOs; stream water quality was investigated at seven sites during 2016, with five sampling dates in early spring and five in summer...
February 2018: Journal of Water and Health
Davor Copic, Laura Maggini, Michael De Volder
Carbon nanotube (CNT)-based filters have the potential to revolutionize water treatment because of their high capacity and fast kinetics in sorption of organic, inorganic, and biological pollutants. To date, CNT filters either rely on CNTs dispersed in liquids, which are difficult to recover and cause safety concerns, or on CNT buckypaper, which offers high efficiency, but suffers from an intrinsic trade-off between filter permeability and capacity. Here, a new approach is presented that bypasses this trade-off and achieves buckypaper-like efficiency combined with filter-column-like permeability and capacity...
February 9, 2018: Advanced Materials
A Pérez, W Machado, D Gutiérrez, A C Borges, S R Patchineelam, C J Sanders
A dated sediment core from an eutrophic mangrove area presented non-significant differences in carbon accumulation rates before (55.7±10.2gm-2yr-1) and after three decades of deforestation (59.7±7.2gm-2yr-1). Although eutrophication effects appear to compensate the loss of mangrove organic matter input, the results in this work show a threefold lower carbon accumulation than the global averages estimated for mangrove sediments. The effects of increasing eutrophication and enhanced sediment dry bulk density observed after deforestation (~30% higher) did not result in higher carbon stocks...
January 2018: Marine Pollution Bulletin
In-Jung Jun, Myong Kim, Joonho Lee, Se-Ung Park, Jai-Hyun Hwang, Jun Hyuk Hong, Young-Kug Kim
INTRODUCTION: Carbon dioxide pneumoperitoneum and the steep Trendelenburg position during robot-assisted laparoscopic prostatectomy (RALP) can increase the intracranial pressure (ICP). Mannitol is widely used to treat increased ICP. However, no studies to date have specifically evaluated the effect of mannitol on ICP in patients undergoing RALP. Ultrasonographic measurement of the optic nerve sheath diameter (ONSD) is considered a reliable technique to noninvasively evaluate the ICP. Therefore, this study compared ONSDs as a surrogate for ICP before and after mannitol administration in prostate cancer patients undergoing RALP...
February 7, 2018: Journal of Endourology
Shalaya Kipp, William C Byrnes, Rodger Kram
We compared ten published equations for calculating energy expenditure from oxygen consumption and carbon dioxide production using data for 10 high-caliber male distance runners over a wide range of running velocities. We found up to a 5.2% difference in calculated metabolic rate between two widely used equations. We urge our fellow researchers abandon out-of-date equations with published acknowledgments of errors or inappropriate biochemical/physical assumptions.
February 5, 2018: Applied Physiology, Nutrition, and Metabolism, Physiologie Appliquée, Nutrition et Métabolisme
Amanda R Amori, Zhentao Hou, Todd D Krauss
Understanding exciton dynamics in single-walled carbon nanotubes (SWCNTs) is essential to unlocking the many potential applications of these materials. This review summarizes recent progress in understanding exciton photophysics and, in particular, exciton dynamics in SWCNTs. We outline the basic physical and electronic properties of SWCNTs, as well as bright and dark transitions within the framework of a strongly bound one-dimensional excitonic model. We discuss the many facets of ultrafast carrier dynamics in SWCNTs, including both single-exciton states (bright and dark) and multiple-exciton states...
January 24, 2018: Annual Review of Physical Chemistry
Chengjun Wang, Kyoseung Sim, Jin Chen, Hojin Kim, Zhoulyu Rao, Yuhang Li, Weiqiu Chen, Jizhou Song, Rafael Verduzco, Cunjiang Yu
Soft robots outperform the conventional hard robots on significantly enhanced safety, adaptability, and complex motions. The development of fully soft robots, especially fully from smart soft materials to mimic soft animals, is still nascent. In addition, to date, existing soft robots cannot adapt themselves to the surrounding environment, i.e., sensing and adaptive motion or response, like animals. Here, compliant ultrathin sensing and actuating electronics innervated fully soft robots that can sense the environment and perform soft bodied crawling adaptively, mimicking an inchworm, are reported...
February 5, 2018: Advanced Materials
Dewen Wang, Qun Li, Ce Han, Zhicai Xing, Xiurong Yang
The development of low-cost, high-efficiency, and stable bifunctional electrocatalysts toward the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is of paramount importance for large-scale water splitting. Here, we develop a new strategy for the first design and synthesis of a NiO@Ni decorated WS2 nanosheet array on carbon cloth (NiO@Ni/WS2/CC) composite. This composite serves as a unique three-dimensional (3D) synergistic electrocatalyst that not only combines the intrinsic properties of individual NiO@Ni and WS2, but also exhibits significantly improved HER and OER activities when compared to that of pure NiO@Ni and WS2...
January 24, 2018: ACS Central Science
Stephanie W Chun, Meagan E Hinze, Meredith A Skiba, Alison R Narayan
Like many complex natural products, the intricate architecture of saxitoxin (STX) has hindered full exploration of this scaffold's utility as a tool for studying voltage-gated sodium ion channels and as a pharmaceutical agent. Established chemical strategies can provide access to the natural product; however, a chemoenzymatic route to saxitoxin that could provide expedited access to related compounds has not been devised. The first step toward realizing a chemoenzymatic approach toward this class of molecules is the elucidation of the saxitoxin biosynthetic pathway...
February 1, 2018: Journal of the American Chemical Society
Damien J Cabral, Jenna I Wurster, Peter Belenky
Persistence is a phenomenon during which a small fraction of a total bacterial population survives treatment with high concentrations of antibiotics for an extended period of time. In conjunction with biofilms, antibiotic persisters represent a major cause of recalcitrant and recurring infections, resulting in significant morbidity and mortality. In this review, we discuss the clinical significance of persister cells and the central role of bacterial metabolism in their formation, specifically with respect to carbon catabolite repression, sugar metabolism, and growth regulation...
February 1, 2018: Pharmaceuticals
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