289 research outputs found
Aprovechamiento de merma de cosecha de Manzana Israel (Pyrus malas l.) a través del hongo (Saccharomyces cerevisiaé) para la elaboración de Bioetanol 2G, San Miguel - Huaral
En San Miguel - Huaral producen manzana Israel aproximadamente
920,4 tn/año y generando aproximadamente 74.700 tn/año manzana de
descarte, En la presente tesis se ha realizado un estudio experimental (a
nivel laboratorio) para la obtención del bioetanol con características físicas
para ser usado como etanol anhidro (grado alcohólico, rendimiento y
volumen) a partir de jarabe de fructosa de dicha merma. Se determinará la
mejor dosis de levadura de Saccharomyces cerevisiae en 3 niveles (3g, 4g,
5g), que genere el mayor (grado alcohólico, rendimiento y volumen)
Pertenece una investigación experimental, porque existirá una experiencia
empírica para relacionar dos variables. Asimismo, tendrá un tipo de estudio,
descriptivo relacional y experimental, porque se realiza una experiencia de
análisis inéditos en donde se está buscando obtener alcohol a través de
manzana un proceso fermentativo, variando la levadura (Saccharomyse
cereviciae). Los procesos para la obtención de bioetanol 2G a nivel de
laboratorio, fue la siguiente: Adecuación de materia prima, pretratamiento,
fermentación y destilación fraccionada.
Se determinó que los mayores resultados se obtiene mediante el uso de 5g
de hongo Saccharomyces cerevisiae, generando un grado alcohólico
promedio de 95.8 % de pureza y un rendimiento etílico promedio de 4.98 %,
y un volumen promedio de 58.2
En conclusión, es factible la Elaboración de bioetanol 2G a partir de la
merma de manzana Israel, ya que cumple con los requisitos del etanol
carburante, teniendo una producción posible de 2730.22 L por año, es
necesario investigar con otras especies para producción de alcohol
carburante, ya que con merma de manzana no sería posible abastecer al
mercado e investigar la mejora de condiciones óptimas para cada proceso
con el fin de implementar dicha tecnología a nivel industrial
Antitumor Compounds from Marine Actinomycetes
Chemotherapy is one of the main treatments used to combat cancer. A great number of antitumor compounds are natural products or their derivatives, mainly produced by microorganisms. In particular, actinomycetes are the producers of a large number of natural products with different biological activities, including antitumor properties. These antitumor compounds belong to several structural classes such as anthracyclines, enediynes, indolocarbazoles, isoprenoides, macrolides, non-ribosomal peptides and others, and they exert antitumor activity by inducing apoptosis through DNA cleavage mediated by topoisomerase I or II inhibition, mitochondria permeabilization, inhibition of key enzymes involved in signal transduction like proteases, or cellular metabolism and in some cases by inhibiting tumor-induced angiogenesis. Marine organisms have attracted special attention in the last years for their ability to produce interesting pharmacological lead compounds
Severe aortic stenosis with preserved ejection fraction and evidence of impairment in structure, myocardial strain and ventricular function: A new contribution to clinical decision making
Background: Left ventricular ejection fraction (LVEF) is among the parameters that are usually employed to define surgical timing of severe aortic stenosis (AS). Our hypothesis states that even when their LVEF is preserved, patients with severe symptomatic AS have impaired myocardial structure and function, and such impairment is related to the deleterious progression of left ventricular hypertrophy (LVH) from the compensated to the decompensated stage, as shown by the changes in diastolic function and the increase in left ventricular end-diastolic pressure (LVEDP).
Methods and Results: A total of 26 patients with severe AS and LVEF > 50% referred for aortic valve replacement underwent catheterization, echocardiography and an intraoperative biopsy. Patients with severe symptomatic AS were classified as: group 1 (G1; compensated LVH, LVEDP < 15 mm Hg without coronary artery disease [CAD], n = 7), group 2a (G2a, decompensated LVH, without CAD, n = 7), and group 2b (G2b, decompensated LVH with CAD, n = 12). Differences were seen in the following: myocyte area [μm2]: G1: 328 ± 66, G2a: 376 ± 22, G2b: 385 ± 13, p < 0.01; collagen volume [%]: G1: 4.77 ± 1.27, G2a: 8.40 ± 1.27, G2b: 11.05 ± 3.08, p < 0.01; LVEDP normalized by diastolic diameter [mm Hg/mm]: G1: 0.27 ± 0.01, G2a: 0.39 ± 0.06, G2b: 0.44 ± 0.11, p < 0.02; +dP/dtmax/LVEDP [mm Hg/s/mm Hg]: G1: 176 ± 45, G2a: 89.6 ± 20, G2b: 113.1 ± 41, p < 0.01; two-dimensional peak systolic longitudinal strain [%]: G1: –17.7 ± 4.75, G2a: –13.4 ± 3.04, G2b: –13.5 ± 3.13, p < 0.05.
Conclusions: Patients with severe symptomatic AS and preserved ejection fraction who develop decompensated LVH characterized by increased LVEDP, exhibit an abnormal myocardial structure and diastolic and systolic impairment
Relevamiento de nubes de alta velocidad
Un extenso relevamiento del cielo austral, observado en la línea de 21 cm del HI y con alta sensibilidad, está siendo llevado a cabo en el IAR. La primera etapa del mismo comprende todo el cielo al sur de l < -30̣° y es observada cada 2° en declinación y cada 2° / cos δ en ascensión recta. Dicho relevamiento cubre un rango de velocidades comprendidas entre 630 y -630 km s⁻¹ y es observado con una resolución de velocidad de 16 km s⁻¹.Asociación Argentina de Astronomí
Relevamiento de nubes de alta velocidad del hemisferio sur
Se presentan resultados preliminares de un relevamiento de nubes de hidrógeno neutro de alta velocidad del hemisferio sur comenzando a mediados de 1980. Este relevamiento se complementará con el que está realizando A.N.M. Hulsbosch en el hemisferio norte. Actualmente se completó una primera etapa de observaciones cubriendo una red de 2° x 2° entre el Polo Sur Celeste y la declinación δ = -15̣egre. Esto forma una red de 6000 puntos que fueron observados en dos frecuencias con 10 minutos de integración en cada una. El rango de velocidades cubierto es -630 ≤ Vₗₛᵣ ≤ 630 km/s con una resolución de 16 km/s. Los datos ya se encuentran reducidos y se están analizando los resultados.Asociación Argentina de Astronomí
Human Monocytotropic Ehrlichiosis, Missouri
To determine the incidence, clinical and laboratory characteristics, and utility of molecular diagnosis of human monocytotropic ehrlichiosis (HME) in the primary care setting, we conducted a prospective study in an outpatient primary care clinic in Cape Girardeau, Missouri. One hundred and two patients with a history of fever for 3 days (>37.7°C), tick bite or exposure, and no other infectious disease diagnosis were enrolled between March 1997 and December 1999. HME was diagnosed in 29 patients by indirect immunofluorescent antibody assay and polymerase chain reaction (PCR). Clinical and laboratory manifestations included fever (100%), headache (72%), myalgia or arthralgia (69%), chills (45%), weakness (38%), nausea (38%), leukopenia (60%), thrombocytopenia (56%), and elevated aspartate aminotransferase level (52%). Hospitalization occurred in 41% of case-patients. PCR sensitivity was 56%; specificity, 100%. HME is a prevalent, potentially severe disease in southeastern Missouri that often requires hospitalization. Because clinical presentation of HME is nonspecific, PCR is useful in the diagnosis of acute HME
Apolipoprotein E genotype status affects habitual human blood mononuclear cell gene expression and its response to fish oil intervention
SCOPE: People who carry the apolipoprotein E4 (APOE4) SNP have an increased risk of cardiovascular disease (CVD). Fish-oil supplementation may help in the prevention of CVD, though inter-individual differences in the response to n-3 PUFAs have been observed. We aimed to assess the impact of APOE genotype on peripheral blood mononuclear cell (PBMC) whole genome gene expression at baseline and following a fish-oil intervention. METHODS AND RESULTS: Participants received 6 months of fish-oil supplementation containing 1800 mg of eicosapentaenoic acid and docosahexaenoic acid per day. APOE genotype and PBMC whole genome gene expression before and after supplementation were measured. We characterized the differences in gene expression profiles in carriers of APOE4 (N = 8) compared to non-carriers (N = 15). At baseline, 1320 genes were differentially expressed and the fish-oil supplementation differentially regulated 866 genes between APOE4 carriers and non-carriers. Gene set enrichment analysis showed that carriers had a higher gene expression of cholesterol biosynthesis and interferon (IFN) signaling pathways. Fish-oil supplementation reduced expression of IFN-related genes in carriers only. CONCLUSION: The increased expression of IFN signaling and cholesterol biosynthesis pathways might explain part of the association between APOE4 and CVD. Fish-oil supplementation may particularly benefit APOE4 carriers by decreasing expression of IFN-related genes. This article is protected by copyright. All rights reserved
Lymph node hemophagocytosis in rickettsial diseases: a pathogenetic role for CD8 T lymphocytes in human monocytic ehrlichiosis (HME)?
BACKGROUND: Human monocytic ehrlichiosis (HME) and Rocky Mountain spotted fever (RMSF) are caused by Ehrlichia chaffeensis and Rickettsia rickettsii, respectively. The pathogenesis of RMSF relates to rickettsia-mediated vascular injury, but it is unclear in HME. METHODS: To study histopathologic responses in the lymphatic system for correlates of immune injury, lymph nodes from patients with HME (n = 6) and RMSF (n = 5) were examined. H&E-stained lymph node tissues were examined for five histopathologic features, including hemophagocytosis, cellularity, necrosis, and vascular congestion and edema. The relative proportions of CD68 macrophages, CD8 and CD4 T lymphocytes, and CD20 B lymphocytes were evaluated by immunohistochemical staining. RESULTS: Hemophagocytosis was similar in HME and RMSF, and was greater than in control cases (p = .015). Cellularity in HME was not different from controls, whereas RMSF lymph nodes were markedly less cellular (p < 0.002). E. chaffeensis-infected mononuclear phagocytes were infrequent compared to R. rickettsii-infected endothelial cells. More CD8 cells in lymph nodes were observed with HME (p < .001), but no quantitative differences in CD4 lymphocytes, macrophages, or B lymphocytes were identified. CONCLUSION: Hemophagocytosis, CD8 T cell expansion, and the paucity of infected cells in HME, suggest that E. chaffeensis infection leads to macrophage activation and immune-mediated injury
The Role of Dwarf Galaxy Interactions in Shaping the Magellanic System and Implications for Magellanic Irregulars
We present a novel pair of numerical models of the interaction history
between the Large and Small Magellanic Clouds (LMC and SMC, respectively) and
our Milky Way (MW) in light of recent high precision proper motions
(Kallivayalil et al. 2006a,b). Given the new velocities, cosmological
simulations of structure formation favor a scenario where the Magellanic Clouds
(MCs) are currently on their first infall towards our Galaxy (Boylan-Kolchin et
al. 2011, Busha et al. 2011). We illustrate here that the observed irregular
morphology and internal kinematics of the MCs (in gas and stars) are naturally
explained by interactions between the LMC and SMC, rather than gravitational
interactions with the MW. This picture further supports a first infall scenario
(Besla et a. 2007). In particular, we demonstrate that the Magellanic Stream, a
band of HI gas trailing behind the MCs 150 degrees across the sky, can be
accounted for by the action of LMC tides on the SMC before the system was
accreted by the MW. We further demonstrate that the off-center, warped stellar
bar of the LMC and its one-armed spiral, can be naturally explained by a recent
direct collision with the SMC. Such structures are key morphological
characteristics of a class of galaxies referred to as Magellanic Irregulars (de
Vaucouleurs & Freeman 1972), the majority of which are not associated with
massive spiral galaxies. We infer that dwarf-dwarf galaxy interactions are
important drivers for the morphological evolution of Magellanic Irregulars and
can dramatically affect the efficiency of baryon removal from dwarf galaxies
via the formation of extended tidal bridges and tails. Such interactions are
important not only for the evolution of dwarf galaxies but also have direct
consequences for the buildup of baryons in our own MW, as LMC-mass systems are
believed to be the dominant building blocks of MW-type halos.Comment: 33 pages, 21 figures, Accepted for publication in MNRAS, Dec 23 201
Rapid Formation of Molecular Clouds and Stars in the Solar Neighborhood
Observations of both star-forming regions and young, gas-free stellar
associations indicate that most nearby molecular clouds form stars only over a
short time span before dispersal; large-scale flows in the diffuse interstellar
medium have the potential for forming clouds sufficiently rapidly, and for
producing stellar populations with ages much less than the lateral crossing
times of their host molecular clouds. We identify four important factors for
understanding rapid star formation and short cloud lifetimes. First, much of
the accumulation and dispersal of clouds near the solar circle might occur in
the atomic phase; only the high-density portion of a cloud's lifecycle is spent
in the molecular phase, thus helping to limit molecular cloud ``lifetimes''.
Second, once a cloud achieves a high enough column density to form \h2 and
CO, gravitational forces become larger than typical interstellar pressure
forces; thus star formation can follow rapidly upon molecular gas formation and
turbulent dissipation in limited areas of each cloud complex. Third, typical
magnetic fields are not strong enough to prevent rapid cloud formation and
gravitational collapse. Fourth, rapid dispersal of gas by newly-formed stars,
and reduction of shielding by a small expansion of the cloud after the first
events of star formation, might limit the length of the star formation epoch
and the lifetime of a cloud in its molecular state. This picture emphasizes the
importance of large-scale boundary conditions for understanding molecular cloud
formation, and implies that star formation is a highly dynamic, rather than
quasi-static, process.Comment: 41 pages, 10 figures, accepted by Ap
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