451 research outputs found
GASTROINTESTINAL DIGESTION OF KAHAI PROTEIN CONCENTRATE (CARYODENDRON ORINOCENSE KARST)
Objective: The aim of this study was to obtain kahai protein concentrate from Caryodendron orinocense karst cultivated in the region Amazonia of Ecuador and characterizes its gastric and duodenal hydrolysates using the sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) electrophoresis method and the reversed-phase ultra-high-performance liquid chromatography (RP-UHPLC) method.Methods: Kahai seeds (C. orinocense karst) were utilized to obtain kahai protein concentrate at pH 5.0 using the isoelectric precipitation method and then subject to gastric hydrolysis with pepsin enzyme (2000 U/mg of protein) at pH 1.2, pH 2.0, and pH 3.2 at 37°C for 2 h with agitation in simulated gastric fluids and then to duodenal hydrolysis with pancreatin (mix enzymes) at pH 7.0 at 37°C for 3 h with agitation in simulated intestinal fluid. Gastric and duodenal hydrolysates from kahai were characterized using the SDS-PAGE electrophoresis method and the RP-UHPLC chromatography method.Results: Proteins obtained from kahai (C. orinocense karst) were hydrolyzed with pepsin, only one protein with molecular weight of 100 kDa presented resistance to hydrolysis with pepsin at all pHs assayed. All proteins from kahai protein concentrate were totally hydrolyzed with pancreatin in in vitro conditions.Conclusion: This study suggests that kahai protein concentrates have a high grade of digestibility in vitro when using the gastroduodenal model of digestion. Kahai protein can be a good source of alternative vegetal proteins to be consumed by animals and humans
Phalanx morphology in salamanders: A reflection of microhabitat use, life cycle or evolutionary constraints?
Morphological patterns are modeled by the interaction of functional, phylogenetic, ecological, and/or developmental constraints. In addition, the evolution of life cycle complexity can favor phenotypic diversity; however, the correlation between stages of development may constrain the evolution of some organs. Salamanders present microhabitat and life cycle diversity, providing an excellent framework for testing how these factors constrain phenotypic evolution. We reconstructed the morphological evolution of the terminal phalanx using a sample of 60 extinct and living species of salamanders. Using a geometric morphometric approach combined with comparative analyses, we further investigated the impact of phylogenetic, ecological, and/or life cycle factors on the shape of the terminal phalanx. We find that the phylogeny has some influence in determining the dorsal shape of the phalanges; whereas a relationship between microhabitat or life cycle and the dorsal and lateral shapes of the phalanx was not observed in the analyzed species. The allometric pattern found in the phalanx shape implies that small phalanges are more curved and with more truncated end than bigger phalanges. The evolutionary rate of phalanx shape was higher in the semiaquatic species, and the morphological disparity was significantly higher on biphasic groups. These results contradict the hypothesis that a complex life cycle constrains body shape. Finally, the phalanx shape of the salamander remains quite conserved from the Mesozoic. This configuration would allow them to occur in the different microhabitats occupied by the salamander lineages.Fil: Ponssa, María Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; ArgentinaFil: Fratani Da Silva, Jéssica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; ArgentinaFil: Barrionuevo, J. Sebastián. Fundación Miguel Lillo; Argentin
Sox9 and Sox8 protect the adult testis from male-to-female genetic reprogramming and complete degeneration.
The new concept of mammalian sex maintenance establishes that particular key genes must remain active in the differentiated gonads to avoid genetic sex reprogramming, as described in adult ovaries after Foxl2 ablation. Dmrt1 plays a similar role in postnatal testes, but the mechanism of adult testis maintenance remains mostly unknown. Sox9 and Sox8 are required for postnatal male fertility, but their role in the adult testis has not been investigated. Here we show that after ablation of Sox9 in Sertoli cells of adult, fertile Sox8(-/-) mice, testis-to-ovary genetic reprogramming occurs and Sertoli cells transdifferentiate into granulosa-like cells. The process of testis regression culminates in complete degeneration of the seminiferous tubules, which become acellular, empty spaces among the extant Leydig cells. DMRT1 protein only remains in non-mutant cells, showing that SOX9/8 maintain Dmrt1 expression in the adult testis. Also, Sox9/8 warrant testis integrity by controlling the expression of structural proteins and protecting Sertoli cells from early apoptosis. Concluding, this study shows that, in addition to its crucial role in testis development, Sox9, together with Sox8 and coordinately with Dmrt1, also controls adult testis maintenance
Ferroelectric Capped Magnetization in Multiferroic PZT/LSMO Tunnel Junctions
Self-poled ultra-thin ferroelectric PbZr0.52Ti0.48O3 (PZT) (5 and 7 nm) films
have been grown by pulsed laser deposition technique on ferromagnetic
La0.67Sr0.33MnO3 (LSMO) (30 nm) to check the effect of polar capping on
magnetization for ferroelectric tunnel junction (FTJ) devices. PZT/LSMO
heterostructures with thick polar PZT (7 nm) capping show nearly 100%
enhancement in magnetization compared with thin polar PZT (5 nm) films,
probably due to excess hole transfer from the ferroelectric to the
ferromagnetic layers. Core-level X-ray photoelectron spectroscopy studies
revealed the presence of larger Mn 3s exchange splitting and higher Mn3+/Mn4+
ion ratio in the LMSO with 7 nm polar capping.Comment: 17 pages, 5 figure
Non-linearities in the Rod and Cone Photoreceptor Inputs to the Afferent Pupil Light Response
Purpose: To assess the nature and extent of non-linear processes in pupil responses using rod- and cone-isolating visual beat stimuli.Methods: A four-primary photostimulating method based on the principle of silent substitution was implemented to generate rod or cone isolating and combined sinusoidal stimuli at a single component frequency (1, 4, 5, 8, or 9 Hz) or a 1 Hz beat frequency (frequency pairs: 4 + 5, 8 + 9 Hz). The component frequencies were chosen to minimize the melanopsin photoresponse of intrinsically photosensitive retinal ganglion cells (ipRGCs) such that the pupil response was primarily driven by outer retinal photoreceptor inputs. Full-field (Ganzfeld) pupil responses and electroretinograms (ERGs) were recorded to the same stimuli at two mesopic light levels (−0.9 and 0 log cd/m2). Fourier analysis was used to derive the amplitudes and phases of the pupil and ERG responses.Results: For the beat frequency condition, when modulation was restricted to the same photoreceptor type at the higher mesopic level (0 log cd/m2), there was a pronounced pupil response to the 1 Hz beat frequency with the 4 + 5 Hz frequency pair and rare beat responses for the 8 + 9 Hz frequency pair. At the lower mesopic level there were few and inconsistent beat responses. When one component modulated the rod excitation and the other component modulated the cone excitation, responses to the beat frequency were rare and lower than the 1 Hz component frequency condition responses. These results were confirmed by ERG recordings.Conclusions: There is non-linearity in both the pupil response and electroretinogram to rod and cone inputs at mesopic light levels. The presence of a beat response for modulation components restricted to a single photoreceptor type, but not for components with cross-photoreceptor types, indicates that the location of a non-linear process in the pupil pathway occurs at a retinal site earlier than where the rod and cone signals are combined, that is, at the photoreceptor level
Desorden linfoproliferativo germinotrópico asociado al HHV8/KSVH y EBV
We described a case of KSHV and EBV associated germinotropic lymphoproliferative disorder, the first report of this entity was made in Blood in 2002 (1), at the moment there are around 20 cases reported (2,3). Is classified as one of the HHV8/KSVH associated lymphoproliferative disorders (4)(5). Clinically is presented by immunocompetent patients like an indolent, localized adenopathy and showed favorable response to chemotherapy, radiotherapy, or surgery (6). The histology presents plasmablasts that are positive for both HHV8/KSVH and EBV, these plasmablasts are involving the germinal centers of the lymphoid follicles (6), microdissected KSHV-positive plasmablast shows a policlonal or oligoclonal pattern, this feature is the reason why this is a “disorder” and non a neoplasia (6). Lymphomagenesis is produced by co-infection of germinal center B cells; the HHV8/KSVH stays in a latency state in the infected cell, then occurs the “second genetic hit” (7): Epstein Barr virus infection, in an immunocompetent host produce a germinotropic lymphoprolifetive disorder.Describimos el caso de un paciente portador de Desorden Linfoproliferativo Germinotrópico (DLG) Asociado a Virus Epstein Baar (EBV) y herpesvirus 8 (HHV8/KSVH), el primer reporte de esta entidad se realizo en la revista Blood del año 2002 (1) y a la fecha se han descrito alrededor de 20 casos (2,3); esta clasificada dentro de los desordenes linfoproliferativos asociados al herpesvirus 8 (HHV8/KSVH) (4)(5). Clínicamente se caracteriza por presentarse en pacientes inmunocompetentes, como una adenopatía localizada, de curso indolente, con respuesta favorable a la quimioterapia, radioterapia o escisión quirúrgica (6). Histológicamente se observan plasmablastos que marcan positivo a EBV y HHV8/KSVH formando agregados confluentes que tienden a invadir los centros germinales (germinotropismo) (6); al hacer la microdisección de los plasmablastos y estudio cadena de reacción de polimesasa (PCR), muestran un patrón policlonal u oligoclonal, por esto es catalogado como un “desorden” y no como una neoplasia propiamente dicha (6). La linfomagenesis esta dada por la co-infección de una célula B de origen centrogerminal; inicialmente tenemos a las células B como reservorio latente del HHV8/KSVH y posteriormente recibe el “second genetic hit” por el Virus Epstein Barr (EBV) (7), desarrollando en un paciente inmunocompetente el DLG
Miocene deformation in the orogenic front of the Malargüe fold-and-thrust belt (35°30′–36° S): Controls on the migration of magmatic and hydrocarbon fluids
The integration of surface observations and sub-surface data (wellbore and seismic) from the orogenic front of the Malargüe fold-and-thrust belt allows us to study its kinematics and to interpret the local stress field and its control over fluid (magmatic and hydrocarbon) migration. Reverse faults correspond to inverted NNW-striking Mesozoic normal faults and N-S striking Cenozoic low-angle thrusts parallel to the orogen. Oblique structures with strike-slip movement are also present. The magmatic activity in the study area was strongly controlled by this structural framework and the in-situ stress field. Miocene dykes and sills were emplaced in relation to strike-slip and reverse faults, respectively. We propose an evolution of the study region from a foredeep sector, in the early-middle Miocene, to a peak in deformation in the late Miocene, and finally a waning of deformation from the Pliocene to the present. Our structural model suggests that during the evolution of the thrust front, the in-situ stress field changed from a compressional to strike-slip/compressional stress field, favouring the synchronous emplacement of sills and dykes. This alternation of stress regimes favours hydrocarbon migration through both thrusts and subvertical strike-slip faults. This exchange between both stress regimes is likely related to the similar values of the minimum (σ3) and intermediate (σ2) principal stress with an E-W oriented maximum principal stress (σ1) according to the plate convergence vector.Fil: Barrionuevo, Matías. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Giambiagi, Laura Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Mescua, Jose Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Suriano, Julieta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: de la Cal, Hernán Gabriel. Roch S.A.; ArgentinaFil: Soto, J. L.. Roch S.A.; ArgentinaFil: Lossada, Ana Clara. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; Argentin
Efficient generation of highly crystalline carbon quantum dots via electrooxidation of ethanol for rapid photodegradation of organic dyes
Achieving versatile routes to generate crystalline carbon-based
nanostructures has become a fervent pursuit in photocatalysis-related fields.
We demonstrate that the direct electrooxidation of ethanol, performed on Ni
foam, yields ultra-small and highly crystalline graphene-like structures named
carbon quantum dots (CQDs). We perform simulations of various sp2 and sp3
domains in order to understand the optical properties of CQDs by accounting
their contribution as absorbance/luminescent centers in the overall optical
response. Experiments and simulations reveal that absorbance bands for
as-synthesized CQDs are dominated by small sp2 domains comprised of r7
aromatic-rings. After 48 h synthesis, the dispersion transition from yellow to
red, exhibiting new and red shifted absorbance bands. Furthermore, fluorescence
emission is governed by medium-sized sp 2 domains (with aromatic ring counts
r12) and oxygen-containing groups. These oxygen-rich groups within the CQDs,
confirmed by FT-IR and XPS, are responsible for the fast photodegradation of
organic dyes, with B90% of methylene blue (MB) being degraded within the first
5 min of light exposure. Our work provides crucial insights about the
electrochemical synthesis and overall optical properties of carbon
nanostructures, while being effective and reliable toward the degradation of
contaminants in water
Hypocalcemia: A key biomarker in hospitalized COVID-19 patients
BACKGROUND: At the end of 2019 a new respiratory syndrome emerged in China named Coronavirus disease 2019 (COVID-19). Considering the severity of the disease in adult subjects with one or more chronic pathologies, it was mandatory to find simple and effective biomarkers for negative prognosis of the disease easily available at the admission to the hospital. MATERIAL AND METHODS: To identify possible parameters showing association with the outcome in COVID-19 patients with previous chronic diseases, blood biochemical profiles of 511 patients, enrolled from March to June 2020, were retrospectively evaluated. The pathologies taken into consideration were diabetes, arterial hypertension, chronic kidney disease, cardiovascular diseases, chronic obstructive pulmonary disease, obesity, and cancer. All the data were collected upon admission to the emergency room (ER) during the indicated period. RESULTS AND DISCUSSION: In accord with previous studies, we observed that serum and ionized calcium were prevalently altered in our cohort. We determined that hypocalcemia was a major parameter associated with mechanical ventilation and poor prognosis, correlating also with the presence of comorbidities such as cardiovascular diseases, chronic kidney disease, and cancer. In addition, we found a positive correlation between hypocalcemia and clinical complications during hospitalizations, strengthening the relevance of calcium concentration as a useful prognostic biomarker in COVID-19 patients
Stress field and active faults in the orogenic front of the Andes in the Malargüe fold-and-thrust belt (35°–36°S)
We integrate field and wellbore data to discuss the stress field in the frontal sector of the Malargüe fold-and-thrust belt (Andes of Argentina). Surface observations indicate N-S thrusts and NW to WNW and ESE strike-slip faults are active in the study area. Inversion of fault kinematic indicators, combined with borehole breakout data and a mini-frac test within the study area, constrain the Quaternary to recent stress state, which is characterized by a subhorizontal, E-W oriented maximum stress, and by intermediate and minimum stresses with similar magnitudes that are locally interchanged, producing a setting in which reverse and strike-slip faults are alternatively active. The implications of the recognized structures for earthquake hazard are examined.Fil: Mescua, Jose Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Barrionuevo, Matías. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Giambiagi, Laura Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Suriano, Julieta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Spagnotto, Silvana Liz. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Departamento de Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Stahlschmidt, E.. El Trébol S.a.; ArgentinaFil: de la Cal, H.. Roch S.a.; ArgentinaFil: Soto, J. L.. Roch S.a.; ArgentinaFil: Mazzitelli, Manuela Amelia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentin
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