80 research outputs found

    Quasi-freestanding and single-atom thick layer of hexagonal boron nitride as a substrate for graphene synthesis

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    We demonstrate that freeing a single-atom thick layer of hexagonal boron nitride (hbn) from tight chemical bonding to a Ni(111) thin film grown on a W(110) substrate can be achieved by intercalation of Au atoms into the interface. This process has been systematically investigated using angle-resolved photoemission spectroscopy, X-ray photoemission and absorption techniques. It has been demonstrated that the transition of the hbn layer from the "rigid" into the "quasi-freestanding" state is accompanied by a change of its lattice constant. Using chemical vapor deposition, graphene has been successfully synthesized on the insulating, quasi-freestanding hbn monolayer. We anticipate that the in situ synthesized weakly interacting graphene/hbn double layered system could be further developed for technological applications and may provide perspectives for further inquiry into the unusual electronic properties of graphene.Comment: in print in Phys. Rev.

    Insight into Bio-metal Interface Formation in vacuo: Interplay of S-layer Protein with Copper and Iron

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    The mechanisms of interaction between inorganic matter and biomolecules, as well as properties of resulting hybrids, are receiving growing interest due to the rapidly developing field of bionanotechnology. The majority of potential applications for metal-biohybrid structures require stability of these systems under vacuum conditions, where their chemistry is elusive, and may differ dramatically from the interaction between biomolecules and metal ions in vivo. Here we report for the first time a photoemission and X-ray absorption study of the formation of a hybrid metal-protein system, tracing step-by-step the chemical interactions between the protein and metals (Cu and Fe) in vacuo. Our experiments reveal stabilization of the enol form of peptide bonds as the result of protein-metal interactions for both metals. The resulting complex with copper appears to be rather stable. In contrast, the system with iron decomposes to form inorganic species like oxide, carbide, nitride, and cyanide

    A global spectral library to characterize the world's soil

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    Soil provides ecosystem services, supports human health and habitation, stores carbon and regulates emissions of greenhouse gases. Unprecedented pressures on soil from degradation and urbanization are threatening agro-ecological balances and food security. It is important that we learn more about soil to sustainably manage and preserve it for future generations. To this end, we developed and analyzed a global soil visible-near infrared (vis-NIR) spectral library. It is currently the largest and most diverse database of its kind. We show that the information encoded in the spectra can describe soil composition and be associated to land cover and its global geographic distribution, which acts as a surrogate for global climate variability. We also show the usefulness of the global spectra for predicting soil attributes such as soil organic and inorganic carbon, clay, silt, sand and iron contents, cation exchange capacity, and pH. Using wavelets to treat the spectra, which were recorded in different laboratories using different spectrometers and methods, helped to improve the spectroscopic modelling. We found that modelling a diverse set of spectra with a machine learning algorithm can find the local relationships in the data to produce accurate predictions of soil properties. The spectroscopic models that we derived are parsimonious and robust, and using them we derived a harmonized global soil attribute dataset, which might serve to facilitate research on soil at the global scale. This spectroscopic approach should help to deal with the shortage of data on soil to better understand it and to meet the growing demand for information to assess and monitor soil at scales ranging from regional to global. New contributions to the library are encouraged so that this work and our collaboration might progress to develop a dynamic and easily updatable database with better global coverage. We hope that this work will reinvigorate our community's discussion towards larger, more coordinated collaborations. We also hope that use of the database will deepen our understanding of soil so that we might sustainably manage it and extend the research outcomes of the soil, earth and environmental sciences towards applications that we have not yet dreamed of

    Long‑Term Safety and Efectiveness of PF‑05280014 (a Trastuzumab Biosimilar) Treatment in Patients with HER2‑Positive Metastatic Breast cancer: Updated Results of a Randomized, Double‑Blind Study

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    Background PF-05280014 was compared with trastuzumab sourced from the European Union (trastuzumab-EU), each plus paclitaxel, as frst-line treatment for human epidermal growth factor receptor 2-positive metastatic breast cancer in a phase III study. Equivalence between treatment groups was demonstrated. Objective The aim of this study was to report long-term safety and overall survival (OS) over 6 years after the frst patient was screened. Patients and methods Randomized patients received intravenous PF-05280014 or trastuzumab-EU, each plus paclitaxel, until objective disease progression. OS, long-term safety, subgroup safety (patients ongoing after day 378), and time-totreatment discontinuation (TTD) were assessed based on the fnal statistical analysis plan amended for the ad-hoc analyses. Results Of 707 randomized patients (n = 352, PF-05280014; n = 355, trastuzumab-EU), 252 (71.6%) in the PF-05280014 and 251 (70.7%) in the trastuzumab-EU group discontinued treatment due to objective progression. Overall, 451 (63.8%) patients completed the study. Between groups (PF-05280014; trastuzumab-EU), estimated median TTDs were 12.25 and 12.06 months (p = 0.692); 61 (17.3%) and 67 (18.9%) patients died; stratifed hazard ratio for OS was 0.929 (95% confdence interval 0.656–1.316; p = 0.339); estimated survival rates were 82.3 and 77.4% at 2 years and 77.2 and 75.3% at 3 years. The incidences of treatment-emergent adverse events (TEAEs) overall (98.6%; 96.6%) and for grades ≥3 (41.0%; 43.1%) were comparable between groups. In patients (n = 265; n = 264) ongoing after day 378, the incidences of any TEAEs, grade ≥3 TEAEs, and serious TEAEs were comparable between the treatment groups. Conclusion Long-term safety and OS were consistent with previous results and demonstrated no clinically meaningful differences between treatment groups. Trial registration ClinicalTrials.gov: NCT01989676 (21 November 2013); and EudraCT: 2013-001352-34 (18 December 2013)

    Internet of Things in Water Management and Treatment

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    The goal of the water security IoT chapter is to present a comprehensive and integrated IoT based approach to environmental quality and monitoring by generating new knowledge and innovative approaches that focus on sustainable resource management. Mainly, this chapter focuses on IoT applications in wastewater and stormwater, and the human and environmental consequences of water contaminants and their treatment. The IoT applications using sensors for sewer and stormwater monitoring across networked landscapes, water quality assessment, treatment, and sustainable management are introduced. The studies of rate limitations in biophysical and geochemical processes that support the ecosystem services related to water quality are presented. The applications of IoT solutions based on these discoveries are also discussed

    Current Advances in Internet of Underground Things

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    The latest developments in Internet of Underground Things are covered in this chapter. First, the IOUT Architecture is discussed followed by the explanation of the challenges being faced in this paradigm. Moreover, a comprehensive coverage of the different IOUT components is presented that includes communications, sensing, and system integration with the cloud. An in-depth coverage of the applications of the IOUT in various disciplines is also surveyed. These applications include areas such as decision agriculture, pipeline monitoring, border control, and oil wells

    Internet of Things in Agricultural Innovation and Security

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    The agricultural Internet of Things (Ag-IoT) paradigm has tremendous potential in transparent integration of underground soil sensing, farm machinery, and sensor-guided irrigation systems with the complex social network of growers, agronomists, crop consultants, and advisors. The aim of the IoT in agricultural innovation and security chapter is to present agricultural IoT research and paradigm to promote sustainable production of safe, healthy, and profitable crop and animal agricultural products. This chapter covers the IoT platform to test optimized management strategies, engage farmer and industry groups, and investigate new and traditional technology drivers that will enhance resilience of the farmers to the socio-environmental changes. A review of state-of-the-art communication architectures and underlying sensing technologies and communication mechanisms is presented with coverage of recent advances in the theory and applications of wireless underground communications. Major challenges in Ag-IoT design and implementation are also discussed

    A global spectral library to characterize the world's soil

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    Soil provides ecosystem services, supports human health and habitation, stores carbon and regulates emissions of greenhouse gases. Unprecedented pressures on soil from degradation and urbanization are threatening agro-ecological balances and food security. It is important that we learn more about soil to sustainably manage and preserve it for future generations. To this end, we developed and analyzed a global soil visible-near infrared (vis-NIR) spectral library. It is currently the largest and most diverse database of its kind. We show that the information encoded in the spectra can describe soil composition and be associated to land cover and its global geographic distribution, which acts as a surrogate for global climate variability. We also show the usefulness of the global spectra for predicting soil attributes such as soil organic and inorganic carbon, clay, silt, sand and iron contents, cation exchange capacity, and pH. Using wavelets to treat the spectra, which were recorded in different laboratories using different spectrometers and methods, helped to improve the spectroscopic modelling. We found that modelling a diverse set of spectra with a machine learning algorithm can find the local relationships in the data to produce accurate predictions of soil properties. The spectroscopic models that we derived are parsimonious and robust, and using them we derived a harmonized global soil attribute dataset, which might serve to facilitate research on soil at the global scale. This spectroscopic approach should help to deal with the shortage of data on soil to better understand it and to meet the growing demand for information to assess and monitor soil at scales ranging from regional to global. New contributions to the library are encouraged so that this work and our collaboration might progress to develop a dynamic and easily updatable database with better global coverage. We hope that this work will reinvigorate our community's discussion towards larger, more coordinated collaborations. We also hope that use of the database will deepen our understanding of soil so that we might sustainably manage it and extend the research outcomes of the soil, earth and environmental sciences towards applications that we have not yet dreamed of
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