132 research outputs found
Nighttime chlorine monoxide observations by the Odin satellite and implications for the ClO/Cl2O2 equilibrium
We use measurements of chlorine monoxide (ClO) by the SMR instrument onboard the Odin satellite to study the nighttime thermal equilibrium between ClO and its dimer Cl2O2. Observations performed in the polar vortex during the 2002–2003 Arctic winter showed enhanced amounts of nighttime ClO over a wide range of stratospheric temperatures (185 < T < 225 K). Odin/SMR measurements are here compared to three-dimensional model calculations using various published estimations of the Keq equilibrium constant between ClO and Cl2O2. Our results show that the value of Keq currently recommended by JPL (Sander et al., 2003) leads to a large underestimation of the observed nighttime ClO amounts, and that a realistic estimation of Keq must lie between the values determined by Cox and Hayman (1988) and Von Hobe et al. (2005)
CUANTIFICACIÓN DE ALCALOIDES DE Ladenbergia oblongifolia (HUMB. EX MUTIS) L. ANDERSSON “ÁRBOL DE LA QUINA”
Dentro de la megafitodiversidad del Perú, se enmarcan muchas especies de los géneros Cinchona, Ladenbergia y Remijia; conocidas indistintamente por los pobladores de las Comunidades andino-amazónicas como “árboles de la quina”, “quina” o “cascarillas” y a las que le atribuyen propiedades medicinales frente a la malaria, enfermedades bronco-respiratorias y especialmente el Covid-19. Sin embargo, la explotación indiscriminada y el poco interés de la investigación ha contribuido a la extinción y confusión en la identificación de las especies en géneros diferentes; ante ello se propuso como objetivo investigación cuantificar los alcaloides de Ladenbergia oblongifolia “árbol de la quina”; a fin de fomentar la revalorización de esta especie como recurso etnobotánico promisorio que busque correlacionar sus principios activos o metabolitos secundarios con las consiguientes acciones farmacológicas que le atribuyen. Para ello se empleó corteza y hojas de L. oblongifolia, procedentes de Chiclín, Chicama, Ascope, La Libertad, Perú; la determinación taxonómica se realizó en el Herbarium Truxillense (HUT); mientras que la extracción y cuantificación de alcaloides en el Laboratorio de Métodos Instrumentales, Departamento de Química, Facultad de Ingeniería Química de la Universidad Nacional de Trujillo. Se concluye que las hojas de L. oblongifolia contienen 0,1039 mmol alcaloides/g materia seca, pudiendo extraerse estos metabolitos directamente de las hojas, sin necesidad de cortar o destruir los árboles, por lo que urge implementar mecanismos de uso de las hojas en lugar de la corteza, evitando así su extinción.
Palabras claves: Metabolito secundario, alcaloides hojas, árbol nacional, flora, Perú.
ABSTRACTThe megadiversity of Peru, has many species framed in the genus Cinchona, Ladenbergia and Remijia, and that the inhabitants of the Andean-Amazonian Communities know them indistinctly as "quina trees", "quina" or "cascarillas" and which They attribute medicinal properties to them against malaria, broncho-respiratory diseases and especially Covid-19. However, the indiscriminate exploitation and the little interest of the investigation has contributed to the extinction and confusion in the identification of the species in different genera; In view of this, the research objective was to quantify the alkaloids of Ladenbergia oblongifolia “quina tree”; in order to promote the revaluation of this species as a promising ethnobotanical resource that seeks to correlate its active principles or secondary metabolites with the consequent pharmacological actions attributed to it. For this, bark and leaves of L. oblongifolia were used, from Chiclin, Chicama, Ascope, La Libertad, Peru; the taxonomic determination was carried out in the Herbarium Truxillense (HUT); while the extraction and quantification of alkaloids in the Laboratory of Instrumental Methods, Department of Chemistry, Faculty of Chemical Engineering of the National University of Trujillo. It is concluded that the leaves of L. oblongifolia contain 0.1039 mmol alkaloids / g dry matter, and these metabolites can be extracted directly from the leaves, without the need to cut or destroy the trees, so it is urgent to implement mechanisms of use of the leaves instead of the bark, thus avoiding their extinction.Keywords: Secondary metabolite, alkaloids, national tree, flora, Peru.
DOI: http://dx.doi.org/10.17268/rebiol.2020.40.02.0
Commissioning of the vacuum system of the KATRIN Main Spectrometer
The KATRIN experiment will probe the neutrino mass by measuring the
beta-electron energy spectrum near the endpoint of tritium beta-decay. An
integral energy analysis will be performed by an electro-static spectrometer
(Main Spectrometer), an ultra-high vacuum vessel with a length of 23.2 m, a
volume of 1240 m^3, and a complex inner electrode system with about 120000
individual parts. The strong magnetic field that guides the beta-electrons is
provided by super-conducting solenoids at both ends of the spectrometer. Its
influence on turbo-molecular pumps and vacuum gauges had to be considered. A
system consisting of 6 turbo-molecular pumps and 3 km of non-evaporable getter
strips has been deployed and was tested during the commissioning of the
spectrometer. In this paper the configuration, the commissioning with bake-out
at 300{\deg}C, and the performance of this system are presented in detail. The
vacuum system has to maintain a pressure in the 10^{-11} mbar range. It is
demonstrated that the performance of the system is already close to these
stringent functional requirements for the KATRIN experiment, which will start
at the end of 2016.Comment: submitted for publication in JINST, 39 pages, 15 figure
Regulation of mammary gland branching morphogenesis by the extracellular matrix and its remodeling enzymes.
A considerable body of research indicates that mammary gland branching morphogenesis is dependent, in part, on the extracellular matrix (ECM), ECM-receptors, such as integrins and other ECM receptors, and ECM-degrading enzymes, including matrix metalloproteinases (MMPs) and their inhibitors, tissue inhibitors of metalloproteinases (TIMPs). There is some evidence that these ECM cues affect one or more of the following processes: cell survival, polarity, proliferation, differentiation, adhesion, and migration. Both three-dimensional culture models and genetic manipulations of the mouse mammary gland have been used to study the signaling pathways that affect these processes. However, the precise mechanisms of ECM-directed mammary morphogenesis are not well understood. Mammary morphogenesis involves epithelial 'invasion' of adipose tissue, a process akin to invasion by breast cancer cells, although the former is a highly regulated developmental process. How these morphogenic pathways are integrated in the normal gland and how they become dysregulated and subverted in the progression of breast cancer also remain largely unanswered questions
Epidemiology of traumatic spinal cord injury in Galicia, Spain: trends over a 20-year period
[Abstract] Study design: Observational study with prospective and retrospective monitoring.
Objective: To describe the epidemiological and demographic characteristics of traumatic spinal cord injury (TSCI), and to analyze its epidemiological changes.
Setting: Unidad de Lesionados Medulares, Complejo Hospitalario Universitario A Coruña, in Galicia (Spain).
Methods: The study included patients with TSCI who had been hospitalized between January 1995 and December 2014. Relevant data were extracted from the admissions registry and electronic health record.
Results: A total of 1195 patients with TSCI were admitted over the specified period of time; 76.4% male and 23.6% female. Mean patient age at injury was 50.20 years. Causes of injury were falls (54.2%), traffic accidents (37%), sports/leisure-related accidents (3.5%) and other traumatic causes (5.3%). Mean patient age increased significantly over time (from 46.40 to 56.54 years), and the number of cases of TSCI related to traffic accidents decreased (from 44.5% to 23.7%), whereas those linked to falls increased (from 46.9% to 65.6%). The most commonly affected neurological level was the cervical level (54.9%), increasing in the case of levels C1–C4 over time, and the most frequent ASIA (American Spinal Injury Association) grade was A (44.3%). The crude annual incidence rate was 2.17/100 000 inhabitants, decreasing significantly over time at an annual percentage rate change of −1.4%.
Conclusions: The incidence rate of TSCI tends to decline progressively. Mean patient age has increased over time and cervical levels C1–C4 are currently the most commonly affected ones. These epidemiological changes will eventually result in adjustments in the standard model of care for TSCI
Ectodomain shedding of the hypoxia-induced carbonic anhydrase IX is a metalloprotease-dependent process regulated by TACE/ADAM17
Carbonic anhydrase IX (CA IX) is a transmembrane protein whose expression is strongly induced by hypoxia in a broad spectrum of human tumours. It is a highly active enzyme functionally involved in both pH control and cell adhesion. Its presence in tumours usually indicates poor prognosis. Ectodomain of CA IX is detectable in the culture medium and body fluids of cancer patients, but the mechanism of its shedding has not been thoroughly investigated. Here, we analysed several cell lines with natural and ectopic expression of CA IX to show that its ectodomain release is sensitive to metalloprotease inhibitor batimastat (BB-94) and that hypoxia maintains the normal rate of basal shedding, thus leading to concomitant increase in cell-associated and extracellular CA IX levels. Using CHO-M2 cells defective in shedding, we demonstrated that the basal CA IX ectodomain release does not require a functional TNFα-converting enzyme (TACE/ADAM17), whereas the activation of CA IX shedding by both phorbol-12-myristate-13-acetate and pervanadate is TACE-dependent. Our results suggest that the cleavage of CA IX ectodomain is a regulated process that responds to physiological factors and signal transduction stimuli and may therefore contribute to adaptive changes in the protein composition of tumour cells and their microenvironment
A phase I randomized therapeutic MVA-B vaccination improves the magnitude and quality of the T cell immune responses in HIV-1-infected subjects on HAART
Trial Design
Previous studies suggested that poxvirus-based vaccines might be instrumental in the therapeutic
HIV field. A phase I clinical trial was conducted in HIV-1-infected patients on highly
active antiretroviral therapy (HAART), with CD4 T cell counts above 450 cells/mm3 and
undetectable viremia. Thirty participants were randomized (2:1) to receive either 3 intramuscular
injections of MVA-B vaccine (coding for clade B HIV-1 Env, Gag, Pol and Nef antigens)
or placebo, followed by interruption of HAART.
Methods
The magnitude, breadth, quality and phenotype of the HIV-1-specific T cell response were
assayed by intracellular cytokine staining (ICS) in 22 volunteers pre- and post-vaccination.
Results
MVA-B vaccine induced newly detected HIV-1-specific CD4 T cell responses and expanded
pre-existing responses (mostly against Gag, Pol and Nef antigens) that were high in magnitude,
broadly directed and showed an enhanced polyfunctionality with a T effector memory
(TEM) phenotype, while maintaining the magnitude and quality of the pre-existing HIV-1-
specific CD8 T cell responses. In addition, vaccination also triggered preferential CD8+ T
cell polyfunctional responses to the MVA vector antigens that increase in magnitude after
two and three booster doses
Improving implementation of evidence-based practice in mental health service delivery: protocol for a cluster randomised quasi-experimental investigation of staff-focused values interventions
BACKGROUND: There is growing acceptance that optimal service provision for individuals with severe and recurrent mental illness requires a complementary focus on medical recovery (i.e., symptom management and general functioning) and personal recovery (i.e., having a ‘life worth living’). Despite significant research attention and policy-level support, the translation of this vision of healthcare into changed workplace practice continues to elude. Over the past decade, evidence-based training interventions that seek to enhance the knowledge, attitudes, and skills of staff working in the mental health field have been implemented as a primary redress strategy. However, a large body of multi-disciplinary research indicates disappointing rates of training transfer. There is an absence of empirical research that investigates the importance of worker-motivation in the uptake of desired workplace change initiatives. ‘Autonomy’ is acknowledged as important to human effectiveness and as a correlate of workplace variables like productivity, and wellbeing. To our knowledge, there have been no studies that investigate purposeful and structured use of values-based interventions to facilitate increased autonomy as a means of promoting enhanced implementation of workplace change. METHODS: This study involves 200 mental health workers across 22 worksites within five community-managed organisations in three Australian states. It involves cluster-randomisation of participants within organisation, by work site, to the experimental (values) condition, or the control (implementation). Both conditions receive two days of training focusing on an evidence-based framework of mental health service delivery. The experimental group receives a third day of values-focused intervention and 12 months of values-focused coaching. Well-validated self-report measures are used to explore variables related to values concordance, autonomy, and self-reported implementation success. Audits of work files and staff work samples are reviewed for each condition to determine the impact of implementation. Self-determination theory and theories of organisational change are used to interpret the data. DISCUSSION: The research adds to the current knowledge base related to worker motivation and uptake of workplace practice. It describes a structured protocol that aims to enhance worker autonomy for imposed workplace practices. The research will inform how best to measure and conceptualise transfer. These findings will apply particularly to contexts where individuals are not ‘volunteers’ in requisite change processes. TRIAL REGISTRATION: ACTRN: ACTRN12613000353796
Uncovering the Prevalence and Diversity of Integrating Conjugative Elements in Actinobacteria
Horizontal gene transfer greatly facilitates rapid genetic adaptation of bacteria to shifts in environmental conditions and colonization of new niches by allowing one-step acquisition of novel functions. Conjugation is a major mechanism of horizontal gene transfer mediated by conjugative plasmids and integrating conjugative elements (ICEs). While in most bacterial conjugative systems DNA translocation requires the assembly of a complex type IV secretion system (T4SS), in Actinobacteria a single DNA FtsK/SpoIIIE-like translocation protein is required. To date, the role and diversity of ICEs in Actinobacteria have received little attention. Putative ICEs were searched for in 275 genomes of Actinobacteria using HMM-profiles of proteins involved in ICE maintenance and transfer. These exhaustive analyses revealed 144 putative FtsK/SpoIIIE-type ICEs and 17 putative T4SS-type ICEs. Grouping of the ICEs based on the phylogenetic analyses of maintenance and transfer proteins revealed extensive exchanges between different sub-families of ICEs. 17 ICEs were found in Actinobacteria from the genus Frankia, globally important nitrogen-fixing microorganisms that establish root nodule symbioses with actinorhizal plants. Structural analysis of ICEs from Frankia revealed their unexpected diversity and a vast array of predicted adaptive functions. Frankia ICEs were found to excise by site-specific recombination from their host's chromosome in vitro and in planta suggesting that they are functional mobile elements whether Frankiae live as soil saprophytes or plant endosymbionts. Phylogenetic analyses of proteins involved in ICEs maintenance and transfer suggests that active exchange between ICEs cargo-borne and chromosomal genes took place within the Actinomycetales order. Functionality of Frankia ICEs in vitro as well as in planta lets us anticipate that conjugation and ICEs could allow the development of genetic manipulation tools for this challenging microorganism and for many other Actinobacteria
Atendimentos de emergência por lesões decorrentes de causas externas: características das vítimas e local de ocorrência, Estado de São Paulo, Brasil, 2005
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