Search results for "carbon"
showing 10 items of 6057 documents
Direct Visualization of Molecule Deprotonation on an Insulating Surface
2012
Elucidating molecular-scale details of basic reaction steps on surfaces is decisive for a fundamental understanding of molecular reactivity within many fields, including catalysis and on-surface synthesis. Here, the deprotonation of 2,5-dihydroxybenzoic acid (DHBA) deposited onto calcite (101;4) held at room temperature is followed in situ by noncontact atomic force microscopy. After deposition, the molecules form two coexisting phases, a transient striped phase and a stable dense phase. A detailed analysis of high-resolution noncontact atomic force microscopy images indicates the transient striped phase being a bulk-like phase, which requires hydrogen bonds between the carboxylic acid moie…
Recent progress in metal-organic frameworks (MOFs) for CO2 capture at different pressures
2022
Global climate change ensued by the rise in atmospheric CO2 levels is one of the greatest challenges our planet is facing today. This worldwide distress demands technologies that can contribute to our society toward “negative carbon emissions”. Carbon capture and storage (CCS) technologies are in in important role for capturing CO2 from existing emission sources, such as industrial and energy production point sources, before new more prominent modifications to the energy infrastructure can be implemented. Recently, alongside point source capture, direct air capture (DAC) processes have emerged as highly sought-after technologies that are able to capture CO2 from the ambient air. Alongside t…
A stable isotope study of the hydrological and carbon cycle in meromictic lake, Lovojärvi
2012
Lake Lovojärvi, at its deepest point of 17.5 m, is permanently stratified forming two water layers. The mixolimnion (the upper layer, from 0 to 10 m depth) is affected by seasonal changes while the monimolimnion (bottom layer, from 10 to 17.5 m depth) does not mix and is not affected by seasonal changes. As a result, the lake stores large quantities of dissolved inorganic carbon and methane. I used a multiple stable isotope approach to gain insight into the carbon cycle and water balance of Lovojärvi. The δ18O and δ2H profiles reveal that at the 7 m depth in the mixolimnion, there is a sub-surface stream whose isotopic characteristics are similar to surface streams from a nearby mire, sugge…
Effect of Germacrene-Rich Essential Oil of Parentucellia latifolia (L.) Caruel Collected in Central Sicily on the Growth of Microorganisms Inhabiting…
2022
In the present study, the chemical composition of the essential oil from aerial parts of Parentucellia latifolia (L.) Caruel collected in Central Sicily was analyzed by gas chromatography and gas chromatography–mass spectrometry. The results showed the presence of sesquiterpene hydrocarbons, with germacrene D and germacrene B accounting, respectively, for 59.2% and 24.3% of the total oil. Different colonies of bacteria and fungi frequently affect cellulosic objects such as books stored in libraries and museums. The antibacterial and antifungal activity against some microorganisms infesting historical-artistic craftsmanship was determined, demonstrating that the essential oil was particular…
Carbon Dioxide Activation and Reaction Induced by Electron Transfer at an Oxide-Metal Interface
2015
A model system has been created to shuttle electrons through a metal-insulator-metal (MIM) structure to induce the formation of a CO2 anion radical from adsorbed gas-phase carbon dioxide that subsequently reacts to form an oxalate species. The process is completely reversible, and thus allows the elementary steps involved to be studied at the atomic level. The oxalate species at the MIM interface have been identified locally by scanning tunneling microscopy, chemically by IR spectroscopy, and their formation verified by density functional calculations.
Genetic profile and immunohistochemical study of clear cell renal carcinoma: Pathological-anatomical correlation and prognosis.
2021
Abstract Introduction Renal cell carcinoma (RCC) accounts for 2–3% of all tumors being the most frequent solid lesion in the kidney. Objective To determine what genetic alterations and immunohistochemical (IHC) of clear cell renal carcinoma (ccRCC) are associated with prognosis and tumor aggressiveness. Patients and Methods Experimental analytical study with 57 patients who underwent radical and partial nephrectomy between 2005 and 2011, all with diagnosis of ccRCC and minimum post-operative follow-up of 36 months. The pathological study included IHC determination of biomarkers associated (CAIX, CAM 5.2, CD10, c-erbB-2, EGFR, HIF-1a, Ki67, MDM2, PAX-2 y 8, p53, survivin and VEGFR 1 and 2). …
Influence of aryl hydrocarbon- (Ah) receptor and genotoxins on DNA repair gene expression and cell survival of mouse hepatoma cells
2009
The aryl hydrocarbon receptor (AhR) mediates toxicity of a variety of environmental pollutants such as polycyclic aromatic hydrocarbons (PAHs) and dioxins. However, the underlying mechanisms and genetic programmes regulated by AhR to cause adverse effects but also to counteract poisoning are still poorly understood. Here we analysed the effects of two AhR ligands, benzo[a]pyrene (B[a]P), a DNA damaging tumour initiator and promotor and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a pure tumour promoter, on cell survival and on nucleotide excision repair (NER) gene expression. NER deals with so called "bulky" DNA adducts including those generated by enzymatically activated B[a]P. Therefore, t…
L'estratègia per a la integració del sistema energètic
2023
El documento ha recibido ayuda de la Cátedra UNESCO 2023 de la Universitat de València. En esta publicació estudie l'Estratègia per a la integració del sistema energètic dins del Pacte Verd Europeu. In this publication I discuss the European Commission's Strategy for Energy System Integration in the framework of the European Green Deal.
La Estrategia para la integración del sistema energético
2023
El documento ha recibido ayuda de la Cátedra UNESCO 2023 de la Universitat de València. En esta publicación abordo el estudio de la Estrategia para la integración del sistema energético de la Comisión Europea en el marco del Pacto Verde Europeo. In this publication I discuss the European Commission's Strategy for Energy System Integration in the framework of the European Green Deal.
Identification of Brassicadiene, a Diterpene Hydrocarbon Attractive to the Invasive Stink Bug Bagrada hilaris, from Volatiles of Cauliflower Seedling…
2020
Brassicadiene, a novel tricyclic diterpene hydrocarbon, was identified by a combination of mass spectrometry, microchemical tests, and analysis of NMR spectra. The compound constitutes >90% of the volatile organic compounds produced by cauliflower seedlings, Brassica oleracea var. botrytis. The invasive stink bug Bagrada hilaris is strongly attracted to brassicadiene, providing a mechanism for this herbivore, which specializes on cruciferous plants, to locate its hosts in a nutrient-rich and vulnerable stage.