2,570 research outputs found
Gastrointestinal neuromuscular apparatus: An underestimated target of gut microbiota
Over the last few years, the importance of the resident
intestinal microbiota in the pathogenesis of several gastro-
intestinal diseases has been largely investigated. Growing
evidence suggest that microbiota can influence gastro-
intestinal motility. The current working hypothesis is that
dysbiosis-driven mucosal alterations induce the production
of several inflammatory/immune mediators which affect
gut neuro-muscular functions. Besides these indirect
mucosal-mediated effects, the present review highlights
that recent evidence suggests that microbiota can directly
affect enteric nerves and smooth muscle cells functions
through its metabolic products or bacterial molecular
components translocated from the intestinal lumen. Toll-
like receptors, the bacterial recognition receptors, are
expressed both on enteric nerves and smooth muscle and
are emerging as potential mediators between microbiota
and the enteric neuromuscular apparatus. Furthermore,
the ongoing studies on probiotics support the hypothesis
that the neuromuscular apparatus may represent a target
of intervention, thus opening new physiopathological and
therapeutic scenarios
Non-Invasive Estimation of Plasma Sodium Concentration During Hemodialysis via Capacitively-Coupled Electrical Impedance Spectroscopy
This paper presents a compact, low-cost, and noninvasive system for real-time estimation of plasma sodium
concentration ([Na]Pl) during a hemodialysis (HD) session with
state-of-the-art accuracy. It is based on electrical impedance
spectroscopy (EIS) performed with a capacitively-coupled
impedance sensing cell and a high-frequency measurement
device, both custom-built. The EIS data are processed to infer the
resistance of the liquid inside the cell, which is used together with
an optical hemoglobin sensor to estimate the [Na]Pl. Validation of
the EIS was performed by estimating the conductivity of bloodmimicking fluid (BMF). The complete method was validated
using whole bovine blood, comparing the results to those
obtained with standard instruments. The system was able to
estimate the [Na]Pl with sufficient accuracy (RMS error of 3.0
mol/m3 with respect to reference data) to provide clinically useful
information. The proof-of-concept hardware can be converted to
a cheap and compact circuit board for integration into an HD
machine
Volcanic synchronization of Dome Fuji and Dome C Antarctic deep ice cores over the past 216 kyr
Abstract. Two deep ice cores, Dome Fuji (DF) and EPICA Dome C (EDC), drilled at remote dome summits in Antarctica, were synchronized to better understand their chronology. A total of 1401 volcanic tie points were identified covering the past 216 kyr. DFO2006, the chronology for the DF core characterized by strong constraining by the O2/N2 age markers, was compared with AICC2012, the chronology for 5 cores including the EDC core, and characterized by glaciological approaches combining ice flow modelling with various age markers. The age gaps between the two chronologies are within 2 kyr, except at Marine Isotope Stage (MIS) 5. DFO2006 gives ages older than AICC2012, with peak values of the gap of 4.5 and 3.1 kyr at MIS 5d and MIS 5b, respectively. Accordingly, ratios of duration DFO2006/AICC2012 are 85% at a period from the late stage of MIS 6 to MIS 5d and 114% at a period from MIS 5d to 5b. We then compared the DFO2006 with another chronology of the DF core, DFGT2006, characterized by glaciological approaches with weaker constraining by age markers. Features of the DFO2006/DFGT2006 age gaps are very similar to those of the DFO2006/AICC2012 age gaps. This fact lead us to hypothesize that a cause of the systematic DFO2006/AICC2012 age gaps at MIS 5 are associated with differences in the dating approaches. Besides, ages of speleothem records from China agreed well with DFO2006 at MIS 5c and 5d but not at MIS 5b. Thus, we hypothesize at least at MIS 5c and 5d, major sources of the gaps are systematic errors in surface mass balance estimation in the glaciological approach. Compatibility of the age markers should be carefully assessed in future.
This work is a contribution to the European Project for Ice Coring in Antarctica (EPICA), a joint European Science Foundation/European Commission scientific program, funded by the European Union and by national contributions from Belgium, Denmark, France, Germany, Italy, the Netherlands, Norway, Sweden, Switzerland and the United Kingdom.
This study was supported in part by a Grant-in-Aid for Scientific Research (A) (20241007) from the Japan Society for the Promotion of Science (JSPS).This is the final version of the article. It first appeared from Copernicus Publications via http://dx.doi.org/10.5194/cpd-11-407-201
Volcanic synchronization of Dome Fuji and Dome C Antarctic deep ice cores over the past 216 kyr
第6回極域科学シンポジウム[OM] 極域気水圏11月16日(月) 国立極地研究所1階交流アトリウ
Development of a CO2 sensor for extracorporeal life support applications
Measurement of carbon dioxide (CO2) in medical applications is a well-established method for monitoring patient’s pulmonary function in a noninvasive way widely used in emergency, intensive care, and during anesthesia. Even in extracorporeal-life support applications, such as Extracorporeal Carbon Dioxide Removal (ECCO2R), Extracorporeal Membrane Oxygenation (ECMO), and cardiopulmonary by-pass (CPB), measurement of the CO2 concentration in the membrane oxygenator exhaust gas is proven to be useful to evaluate the treatment progress as well as the performance of the membrane oxygenator. In this paper, we present a new optical sensor specifically designed for the measurement of CO2 concentration in oxygenator exhaust gas. Further, the developed sensor allows measurement of the gas flow applied to the membrane oxygenator as well as the estimation of the CO2 removal rate. A heating module is implemented within the sensor to avoid water vapor condensation. Effects of temperature on the sensor optical elements of the sensors are disclosed, as well as a method to avoid signal–temperature dependency. The newly developed sensor has been tested and compared against a reference device routinely used in clinical practice in both laboratory and in vivo conditions. Results show that sensor accuracy fulfills the requirements of the ISO standard, and that is suitable for clinical applications
Cambios en los hábitos alimentarios y actividad física durante el aislamiento físico durante el COVID -19: estudio descriptivo sobre una muestra de trabajadores (Uruguay, abril 2020)
C. Severi: Departamento de Medicina Preventiva y Social, Facultad de Medicina, Universidad de la República.--
M. Medina, Facultad de Medicina, Universidad de la República. Doctoranda de la Universidad de Granada.--Antecedentes: La aparición en Uruguay del coronavirus, hizo que el gobierno declarara emergencia sanitaria Entre otras medidas sugirió a la población evitar en forma voluntaria, la circulación fuera de su casa. Esto trajo algunas consecuencias en el cambio de hábitos alimentarios y la actividad física.Objetivo: Identificar los cambios en el comportamiento respecto a la alimentación y la actividad física en la emergencia sanitaria, en los trabajadores donde se implementó trabajo a distancia.Metodología: Se aplicó una encuesta telefónica sobre una muestra por conveniencia de 170 trabajadores de una empresa sobre sus hábitos alimentarios y actividad física. Resultados: La tercera parte de los trabajadores (30,6 %) perciben incremento de peso, y cambiaron su comportamiento, casi el 47 % manifiesta que come más o con mayor frecuencia. Respecto al tipo de alimentos la mayor parte refiere que incrementaron alimentos ricos en carbohidratos y ultra procesados. En un porcentaje alto la población redujo su actividad física. En gran parte de los hogares conviven niños, lo que genera un ambiente obesogénico, que incrementa el riego de exceso de peso a corto y mediano plazo. Conclusión: Existen cambios de comportamiento alimentario y de actividad física no saludables y que promueven el riego de enfermedades crónicas no transmisibles. Se sugiere tomar medidas que acompañen las ya realizadas para contener la transmisión del coronavirus en la comunidad
Anti-Candida targets and cytotoxicity of casuarinin isolated from Plinia cauliflora leaves in a bioactivity-guided study
Peer reviewedPublisher PD
High resolution chemical stratigraphies of atmospheric depositions from a 4 m depth snow pit at dome C (East Antarctica)
In this work, we present chemical stratigraphies of two sampling lines collected within a 4 m depth snow pit dug in Dome C during the Antarctic summer Campaign 2017/2018, 12 years after the last reported snow pit. The first sampling line was analyzed for nine anionic and cationic species using Ion Chromatography (IC); the second sampling line was analyzed for seven major elements in an innovative way with Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) after sample pre-concentration, allowing the study of deposition processes of new markers especially related to crustal source. This coupled analysis, besides confirming previous studies, allowed us to investigate the depositions of the last decades at Dome C, enriching the number of the detected chemical markers, and yielding these two techniques complementary for the study of different markers in this kind of matrix. As a result of the dating, the snow layers analyzed covered the last 50 years of snow depositions. The assessment of the accumulation rate, estimated about 9 cm yr−1, was accomplished only for the period 1992–2016, as the eruption of 1992 constituted the only tie-point found in nssSO42− depth profile. Na, the reliable sea salt marker, together with Mg and Sr, mainly arose from marine sources, whereas Ca, Al and Fe originated from crustal inputs. Post-depositional processes occurred on Cl− as well as on NO3− and methanesulfonic acid (MSA); compared to the latter, Cl− had a more gradual decrease, reporting a threshold at 2.5 m for the post-depositional process completion. For NO3− and MSA, instead, the threshold was shallower, at about 1 m depth, with a loss of 87% for NO3− and of 50% for MSA
Myelodysplastic syndromes: the pediatric point of view.
Myelodysplastic syndromes (MDS) are clonal disorders of the multipotent hematopoietic stem cell characterized by ineffective hematopoiesis and associated with marrow hypercellularity, increased intramedullary cell death and peripheral cytopenias of varying severity. Patients with myelodysplasia have a propensity (20% to 30% of cases) to undergo transformation into acute myeloid leakemia (AML), and a large body of evidence indicates that MDS represent steps in the multiphasic evolution of AML. Progression of the disease is characterized by expansion of the abnormal clone and inhibition of normal hematopoiesis leading to deterioration of the blood cell count and/or development of AML. MDS are relatively unusual in childhood, representing only 3% of pediatric hematological malignancies, although it has been reported that up to 17% of pediatric AML cases may have a previous myelodysplastic phase. The first systematic attempt at morphological classification of MDS was provided by the French-American-British (FAB) group. However, the FAB classification of MDS is only partially applicable in children. Some variants are extremely rare or absent (refractory anemia with ring sideroblasts and chronic myelomonocytic leukemia), and other peculiar pediatric disorders, represented by juvenile chronic myelogenous leukemia (JCML) and the monosomy 7 syndrome, are not included. Moreover, since there is a partial overlap between pediatric MDS and myeloproliferative disorders and the variants occurring in young children have rather specific features, some confusion still surrounds the nosographical definition of childhood MDS, so that none of the proposed classifications are widely accepted and used. Characteristically, some genetic conditions such as Fanconi's anemia, Shwachman's and Down's syndromes predispose to the development of MDS in childhood. The most common variants of childhood MDS are represented by JCML and the monosomy 7 syndrome, both disorders typically occurring in young children. JCML is characterized by a spontaneous growth of granulocyte-macrophage progenitors that show a striking hypersensitivity to granulocyte-macrophage colony-stimulating factor. Clinical presentation resembles that of some myeloproliferative disorders, with massive organomegaly usually not observed in the classically reported variants of MDS. Clinical features of the monosomy 7 syndrome resemble those observed in JCML and a differential diagnosis between these two entities relies upon the higher percentage of fetal hemoglobin, the more pronounced decrease in platelet count and, in some cases, the lack of the peculiar cytogenetic abnormality in the latter. With the number of children being cured of cancer constantly rising, a significant increase in secondary or chemotherapy-related myelodysplasia is being observed, and these disorders represent a formidable challenge for pediatric hematologists due to their poor response to chemotherapy. As a matter of fact, owing to their biological heterogeneity and aggressive clinical course in childhood, all MDS variants pose serious difficulties for successful management. If a compatible donor is available, allogeneic bone marrow transplantation (BMT) becomes the treatment of choice and should be performed during the early stages of the disease. Supportive therapy, differentiative treatments and low-dose chemotherapy, while valuable alternative therapeutic options in adults, have limited application in pediatric patients. The role of intensive chemotherapy and autologous BMT has not yet been clearly defined, and the use of hematopoietic growth factors does not seem to have a significant influence on the natural history of the disease. In the future, new insights into the events leading to progressive genetic changes in the clonal population and into the molecular basis of these genetic lesions could result in interesting new therapeutic approaches directed either at the oncogenes involved in the pathogenesis of the disease, or at the cytokines and/or their receptors causing the abnormal differentiation and proliferation of the myelodysplastic clone
Design of a custom-made device for real-time optical measurement of differential mineral concentrations in three-dimensional scaffolds for bone tissue engineering
Monitoring bone tissue engineered (TEed) constructs during their maturation is important to ensure the quality of applied protocols. Several destructive, mainly histochemical, methods are conventionally used to this aim, requiring the sacrifice of the investigated samples. This implies (i) to plan several scaffold replicates, (ii) expensive and time consuming procedures and (iii) to infer the maturity level of a given tissue construct from a cognate replica. To solve these issues, non-destructive techniques such as light spectroscopy-based methods have been reported to be useful. Here, a miniaturized and inexpensive custom-made spectrometer device is proposed to enable the non-destructive analysis of hydrogel scaffolds. Testing involved samples with a differential amount of calcium salt. When compared to a reference standard device, this custom-made spectrometer demonstrates the ability to perform measurements without requiring elaborate sample preparation and/or a complex instrumentation. This preliminary study shows the feasibility of light spectroscopy-based methods as useful for the non-destructive analysis of TEed constructs. Based on these results, this custom-made spectrometer device appears as a useful option to perform real-time/in-line analysis. Finally, this device can be considered as a component that can be easily integrated on board of recently prototyped bioreactor systems, for the monitoring of TEed constructs during their conditioning
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