136 research outputs found
Basal Respiration as a Proxy to Understand Spatial Trends in CO2 Emissions in the Moscow Region
Soil respiration (Rs) is an important terrestrial CO2 efflux and receives significant attention at different scale levels. However, the sampling density is limited and global Rs databases are biased towards natural ecosystems. Urbanization is among the most important current land-use trends and its role will likely grow in the future. Urban soils store considerable amount of carbon and are very heterogeneous and dynamic, which affects Rs. Our understanding of the Rs spatial variability is limited, especially for the regions with heterogeneous bioclimatic conditions and high urbanization level. The methodological constraints of direct Rs measurements in the field limit the number of observations. As an alternative approach to approximate the spatial variability of Rs, we used basal respiration (BR) as an indirect measurement. We implemented digital soil mapping technique to map BR as a proxy of Rs in a heterogeneous and urbanized Moscow Region. Topsoil and subsoils BR maps were developed for the region and spatial variability per land-use and soil type was analyzed. BR averaged for the urban areas was lower than in forests and meadows, however, urban areas became the hotspots of BR’s spatial variability in the region. Considerable contribution of subsoil layers to the total BR was also found with the maximal 30% contribution in urban soils. Although the absolute levels of respiration remained uncertain, the spatial patterns of BR are likely to correspond well with Rs patterns, determined by soil type, land use and allocation of urban areas
Experiense of treatment with a growth hormone receptor antagonist in patients with hereditary form of acromegaly: clinical cases
Acromegaly is a severe neuroendocrine disease caused by chronic excessive production of somatotropic hormone (STH), characterized by specific changes in appearance, metabolic disorders. In 95% of cases, the cause of pathology is STH-producing pituitary adenomas. The priority method of treatment for acromegaly is transnasal transsphenoidal adenomectomy. If it is impossible to carry out neurosurgical intervention, in order to prevent the progression of the disease and the development of complications, patients are recommended drug therapy with long-acting somatostatin analogues, and if their effectiveness is low, additional radiation therapy may be applied to the neoplasm area. The usage of a relatively new group of drugs, antagonists of STH receptors, namely Pegvisomant for the purpose of drug treatment of acromegaly demonstrates high efficacy even in cases of aggressive forms resistant to other types of treatment. In this article we present two clinical cases of hereditary acromegaly, when the initiation of Pegvisomant therapy led to the achievement of clinical and laboratory remission of acromegaly in patients with an aggressive form of the disease, accompanied by continued growth of residual neoplasm tissue and preservation of its secreting ability even after surgical interventions, radiatiotherapy and long-term drug treatment with somatostatin analogues. The results of the above clinical cases confirm the success of mono- or combined (in cases with continued growth of the neoplasm) therapy with a growth hormone receptor antagonist, Pegvisomant, especially in the case of aggressive acromegaly
Orbital effects of a monochromatic plane gravitational wave with ultra-low frequency incident on a gravitationally bound two-body system
We analytically compute the long-term orbital variations of a test particle
orbiting a central body acted upon by an incident monochromatic plane
gravitational wave. We assume that the characteristic size of the perturbed
two-body system is much smaller than the wavelength of the wave. Moreover, we
also suppose that the wave's frequency is much smaller than the particle's
orbital one. We make neither a priori assumptions about the direction of the
wavevector nor on the orbital geometry of the planet. We find that, while the
semi-major axis is left unaffected, the eccentricity, the inclination, the
longitude of the ascending node, the longitude of pericenter and the mean
anomaly undergo non-vanishing long-term changes. They are not secular trends
because of the slow modulation introduced by the tidal matrix coefficients and
by the orbital elements themselves. They could be useful to indepenedently
constrain the ultra-low frequency waves which may have been indirectly detected
in the BICEP2 experiment. Our calculation holds, in general, for any
gravitationally bound two-body system whose characteristic frequency is much
larger than the frequency of the external wave. It is also valid for a generic
perturbation of tidal type with constant coefficients over timescales of the
order of the orbital period of the perturbed particle.Comment: LaTex2e, 24 pages, no figures, no tables. Changes suggested by the
referees include
Structural features and physico-mechanical properties of AlN-TiB2-TiSi2 amorphous-like coatings
Casemix, management, and mortality of patients receiving emergency neurosurgery for traumatic brain injury in the Global Neurotrauma Outcomes Study: a prospective observational cohort study
Peculiarities of the formation of multicomponent AlN-TiB2-TiSi2 composite ceramics coatings during heat treatment
Human iPSC-Derived Cardiomyocytes for Investigation of Disease Mechanisms and Therapeutic Strategies in Inherited Arrhythmia Syndromes: Strengths and Limitations
Screening out irrelevant cell-based models of disease
The common and persistent failures to translate promising preclinical drug candidates into clinical success highlight the limited effectiveness of disease models currently used in drug discovery. An apparent reluctance to explore and adopt alternative cell-and tissue-based model systems, coupled with a detachment from clinical practice during assay validation, contributes to ineffective translational research. To help address these issues and stimulate debate, here we propose a set of principles to facilitate the definition and development of disease-relevant assays, and we discuss new opportunities for exploiting the latest advances in cell-based assay technologies in drug discovery, including induced pluripotent stem cells, three-dimensional (3D) co-culture and organ-on-a-chip systems, complemented by advances in single-cell imaging and gene editing technologies. Funding to support precompetitive, multidisciplinary collaborations to develop novel preclinical models and cell-based screening technologies could have a key role in improving their clinical relevance, and ultimately increase clinical success rates
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