Search results for " nitrogen"
showing 10 items of 319 documents
Mapping landscape canopy nitrogen content from space using PRISMA data
2021
Abstract Satellite imaging spectroscopy for terrestrial applications is reaching maturity with recently launched and upcoming science-driven missions, e.g. PRecursore IperSpettrale della Missione Applicativa (PRISMA) and Environmental Mapping and Analysis Program (EnMAP), respectively. Moreover, the high-priority mission candidate Copernicus Hyperspectral Imaging Mission for the Environment (CHIME) is expected to globally provide routine hyperspectral observations to support new and enhanced services for, among others, sustainable agricultural and biodiversity management. Thanks to the provision of contiguous visible-to-shortwave infrared spectral data, hyperspectral missions open enhanced …
The Use of 15N NMR for the Understanding of Nitrogen Physisorption.
1994
Abstract Nitrogen adsorption at liquid nitrogen temperature, 77K, is universally employed to determine pore dimensions. The nature of nitrogen physisorbed within the micropores of ZSM-5 zeolite was studied by in situ15N NMR as it depends on the partial pressure of the nitrogen and the temperature above and below 77K. An increase in the volume of adsorption of nitrogen at 77K occurs at a relative pressure of ~0.18 for this zeolite. The nature of the nitrogen was studied below and above this increase in nitrogen adsorption. We find that two states (phases) of nitrogen are evident. We conclude that two phases can be present but that a solid phase of nitrogen is not evident even as the temperat…
Central obesity and hypertensive renal disease: association between higher levels of BMI, circulating transforming growth factor beta1 and urinary al…
2004
OBJECTIVE: In this study, the relationship between circulating transforming growth factor beta1 (TGFbeta1) and urinary albumin excretion (UAE) has been investigated in non-obese and central obese hypertensive patients. DESIGN AND PATIENTS: Fifty-eight consecutive hypertensive outpatients both lean and with central obesity were enrolled and divided in three groups, according to their body mass index (BMI) values. Group A: 16 lean hypertensives (men with BMI or = 25 kg/m2 and 24.7 kg/m2 and or = 30 kg/m2 and women with BMI > or = 27.3 kg/m2). MEASURES: In all patients, UAE, by immunonephelometric assay, circulating TGFbeta1 by a solid-phase specific sandwich enzyme-linked immunosorbent assay …
Storage of human oocytes in the vapor phase of nitrogen
2009
Objective To evaluate the effectiveness of long-term vapor-phase nitrogen storage of vitrified human oocytes as a strategy for preventing the risk of cross-contamination due to direct contact with the liquid nitrogen (LN). Design Prospective randomized study. Setting Private infertility center, IVI, Valencia. Patient(s) Oocyte donors (n = 44) and recipients (n = 46). Intervention(s) Vitrification by the Cryotop method. Storage of vitrified oocytes in a vapor-phase nitrogen storage freezer and a traditional LN storage tank. Donation of the surviving oocytes and evaluation of fertilization, embryo development, and clinical results. Main Outcome Measure(s) Survival, fertilization, and cleavage…
Inflammation and oxidative stress in vertebrate host–parasite systems
2008
Innate, inflammation-based immunity is the first line of vertebrate defence against micro-organisms. Inflammation relies on a number of cellular and molecular effectors that can strike invading pathogens very shortly after the encounter between inflammatory cells and the intruder, but in a non-specific way. Owing to this non-specific response, inflammation can generate substantial costs for the host if the inflammatory response, and the associated oxygen-based damage, get out of control. This imposes strong selection pressure that acts to optimize two key features of the inflammatory response: the timing of activation and resolution (the process of downregulation of the response). In this p…
Nasal Cellularity in 183 Unselected Schoolchildren Aged 9 to 11 Years
2002
Objective. Although rhinitis is extremely frequent in children, methods for assessing the severity of nasal inflammation produce results with wide variability and hence weak clinical significance. We designed this epidemiologic investigation to define the clinical usefulness of assessing nasal cellularity in children. Methods. We studied 183 of 203 eligible unselected schoolchildren who were aged 9 to 11 years and whose parents gave informed consent and completed a questionnaire on the history of atopic and respiratory symptoms. In all children, nasal swabs were obtained from both nostrils and eluted in saline and slides were prepared from cytospin preparations for staining and white cell c…
Effetti della concimazione sulla qualità dell'aglio coltivato in Sicilia. Effects of fertilization on the quality of garlic grown in Sicily.
2010
In order to expand this crop and to improve bulbs quality a study was carried out to evaluate different fertilization techniques. Four fertilization formulas were evaluated: 1) mineral fertilization commonly used by Paceco producers - pre-planting with 55, 110 and 80 kg ha-1 of N, P2O5 and K2O - post planting with 47 and 46 kg ha-1 of N and K2O; 2) organic fertilization with an organic mix - pre-planting with 320 and 240 kg ha-1 of N and P2O5; 3) mineral fertilization - pre-planting with 40, 70 and 100 kg ha-1 of N, P2O5 and K2O - post-planting with 80 kg ha-1 of N half at 3-4 leaves and half at bulbs formation; 4) only post-planting fertilization with 52 and 184 kg ha-1 of N and K2O, half …
Inducible Co-Stimulator Null MRL-Fas lpr Mice
2005
MRL/MpJ-Tnfrsf6lpr (MRL-Faslpr) mice develop a spontaneous T cell-dependent autoimmune disease that shares features with human lupus, including fatal nephritis, systemic pathology, and autoantibodies (autoAb). The inducible co-stimulator (ICOS) is upregulated on activated T cells and modulates T cell-mediated responses. To investigate whether ICOS has an essential role in regulating autoimmune lupus nephritis and the systemic illness in MRL-Faslpr mice, ICOS null (-/-) MRL Faslpr and ICOS intact (+/+) MRL-Faslpr strains (wild-type [WT]) were generated and compared. It was determined that in ICOS-/- MRL-Faslpr as compared with the WT strain, (1) there is a significant reduction in circulatin…
Drugs modulating the biological effects of peroxynitrite and related nitrogen species.
2007
The term “reactive nitrogen species” includes nitrogen monoxide, commonly called nitric oxide, and some other remarkable chemical entities (peroxynitrite, nitrosoperoxycarbonate, etc.) formed mostly from nitrogen monoxide itself in biological environments. Regardless of the specific mechanisms implicated in their effects, however, it is clear that an integrated pharmacological approach to peroxynitrite and related species is only just beginning to take shape. The array of affected chemical and pathological processes is extremely broad. One of the most conspicuous mechanisms observed thus far has been the scavenging of the peroxynitrite anion by molecules endowed with antioxidant activity. T…
Free radical biology of the cardiovascular system
2012
Most cardiovascular diseases (CVDs), as well as age-related cardiovascular alterations, are accompanied by increases in oxidative stress, usually due to increased generation and/or decreased metabolism of ROS (reactive oxygen species; for example superoxide radicals) and RNS (reactive nitrogen species; for example peroxynitrite). The superoxide anion is generated by several enzymatic reactions, including a variety of NADPH oxidases and uncoupled eNOS (endothelial NO synthase). To relieve the burden caused by this generation of free radicals, which also occurs as part of normal physiological processes, such as mitochondrial respiratory chain activity, mammalian systems have developed endogen…