Experimental validation for chatter stability prediction

This research focused on the experimental validation for chatter stability prediction. An optimum machining was aimed to maximize the material removal rate, whilst maintaining a sufficient stability margin to assure the surface quality. High material removal rate in machining produced self-excited vibration or chatter of the cutting tool and the workpiece. This resulted in a poor surface finish and dimensional accuracy, chipping of the cutter teeth, and also may damage the workpiece as well as machining tool. Frequency response function of a single degree freedom flexural was measured and the cutting stiffness of tools were determined in order to be used in predicting chatter stability using semi discretization method. The aluminium 7075 specimens were used in the milling cutting experiment to validate the chatter stability diagram of mill uniform and variable cutters, where a set of spindle speed and depth of cut had tested. The vibration conditions of machining were identified by analysing the vibration signals and FFT spectrum whether it was stable or in a chatter condition. There are good agreement between predicted stability and cutting experiment for the down-milling operation using uniform 4 flute cutting tool. Stable conditions were shown outside the boundary of chatter region. The optimized cutting tool was predicted to suppress chatter. Machining experiment tests showed there were no chatter vibration conditions during machining process until 1.5 mm depth of cut. According to the results of machining experiment, it was proven that the variable tool had more capability to machining without producing chatter vibration as compared to the regular tool

Factores laboratoriales asociados a dengue con signos de alarma en pacientes de un hospital de Chiclayo, 2023

Objetivo: Determinar la asociación entre los factores laboratoriales y dengue con signos de alarma en pacientes de un hospital de Chiclayo, 2023. Método: El análisis del estudio fue de tipo descriptivo, correlacional y retrospectivo a través de una ficha de recolección de datos que fue creada por los investigadores la cual contiene ítems respecto a dengue con signos de alarma y factores de laboratorio, la cual fue aplicada a 190 pacientes del Hospital Regional Docente Las Mercedes que cumplieron con los criterios de selección, que posteriormente, los datos obtenidos fueron organizados en tablas. Resultados: Los parámetros de laboratorio que marcaron una diferencia significativa fue perfil de coagulación, perfil hepático a excepción de Bilirrubinas totales, solo creatinina dentro del perfil renal, perfil lipídico a excepción de colesterol y triglicéridos y dentro de hemograma solo plaquetas y glóbulos blancos para la presencia de dengue con signos de alarma en pacientes de un hospital de Chiclayo, 2023. La frecuencia de manifestaciones clínicas más frecuente en dengue con signos de alarma fueron: Dolor abdominal intenso y continuo (38%), vómitos persistentes (30.6%) y sangrado de piel y/o mucosas (22.5%). Conclusiones: Encontramos diferencia significativa asociando así los factores laboratoriales ya mencionados a dengue con signos de alarma en pacientes de un hospital de Chiclayo, 2023 con un nivel de confianza del 95%.TesisCalidad de vida, promoción de la salud del individuo y la comunidad para el desarrollo de la socieda

Therapeutic Strategies of Secretome of Mesenchymal Stem Cell

Great progress has been made in the therapeutic strategies of multiple diseases that lack curative treatments with the transplantation of mesenchymal stem cells (MSC), such as in onco-hematological diseases, myocardial infarction (MI), cerebrovascular diseases, degenerative diseases of the nervous system (multiple sclerosis, Alzheimer’s disease), and diseases of the immune system, among others. Stem cells (SC) participate in the biological processes of tissue regeneration and repair through cell replication. Recently, the beneficial therapeutic effects of SCs that are generated by the release of proteins with paracrine actions and not by cell differentiation are more well known, and 80% of the therapeutic effect of SC is attributed to paracrine actions. The MSCs release large amounts of proteins and growth factors (GF), nucleic acids, proteasomes, exosomes, and microRNA, and membrane vesicles known as the secretome are released into the extracellular space, regulating multiple biological processes. Currently, the therapeutic strategies in tissue engineering (TE) and regenerative medicine (RM) are focused on the management of products derived from cells that act, both locally and remotely, in the affected tissue or organ, achieving regenerative actions. The application of new knowledge of the secretome initiates a change in the paradigm of regenerative therapy by knowing more about and using cell products derived from cells as a “factory” for biological drugs

How the Assumed Size Distribution of Dust Minerals Affects the Predicted Ice Forming Nuclei

The formation of ice in clouds depends on the availability of ice forming nuclei (IFN). Dust aerosol particles are considered the most important source of IFN at a global scale. Recent laboratory studies have demonstrated that the mineral feldspar provides the most efficient dust IFN for immersion freezing and together with kaolinite for deposition ice nucleation, and that the phyllosilicates illite and montmorillonite (a member of the smectite group) are of secondary importance.A few studies have applied global models that simulate mineral specific dust to predict the number and geographical distribution of IFN. These studies have been based on the simple assumption that the mineral composition of soil as provided in data sets from the literature translates directly into the mineral composition of the dust aerosols. However, these tables are based on measurements of wet-sieved soil where dust aggregates are destroyed to a large degree. In consequence, the size distribution of dust is shifted to smaller sizes, and phyllosilicates like illite, kaolinite, and smectite are only found in the size range 2 m. In contrast, in measurements of the mineral composition of dust aerosols, the largest mass fraction of these phyllosilicates is found in the size range 2 m as part of dust aggregates. Conversely, the mass fraction of feldspar is smaller in this size range, varying with the geographical location. This may have a significant effect on the predicted IFN number and its geographical distribution.An improved mineral specific dust aerosol module has been recently implemented in the NASA GISS Earth System ModelE2. The dust module takes into consideration the disaggregated state of wet-sieved soil, on which the tables of soil mineral fractions are based. To simulate the atmospheric cycle of the minerals, the mass size distribution of each mineral in aggregates that are emitted from undispersed parent soil is reconstructed. In the current study, we test the null-hypothesis that simulating the presence of a large mass fraction of phyllosilicates in dust aerosols in the size range 2 m, in comparison to a simple model assumption where this is neglected, does not yield a significant effect on the magnitude and geographical distribution of the predicted IFN number. Results from sensitivity experiments are presented as well

Atmospheric processing of iron in mineral and combustion aerosols: development of an intermediate-complexity mechanism suitable for Earth system models

Atmospheric processing of iron in dust and combustion aerosols is simulated using an intermediate-complexity soluble iron mechanism designed for Earth system models. The solubilization mechanism includes both a dependence on aerosol water pH and in-cloud oxalic acid. The simulations of size-resolved total, soluble and fractional iron solubility indicate that this mechanism captures many but not all of the features seen from cruise observations of labile iron. The primary objective was to determine the extent to which our solubility scheme could adequately match observations of fractional iron solubility. We define a semi-quantitative metric as the model mean at points with observations divided by the observational mean (MMO). The model is in reasonable agreement with observations of fractional iron solubility with an MMO of 0.86. Several sensitivity studies are performed to ascertain the degree of complexity needed to match observations; including the oxalic acid enhancement is necessary, while different parameterizations for calculating model oxalate concentrations are less important. The percent change in soluble iron deposition between the reference case (REF) and the simulation with acidic processing alone is 63.8%, which is consistent with previous studies. Upon deposition to global oceans, global mean combustion iron solubility to total fractional iron solubility is 8.2%; however, the contribution of fractional iron solubility from combustion sources to ocean basins below 15°S is approximately 50%. We conclude that, in many remote ocean regions, sources of iron from combustion and dust aerosols are equally important. Our estimates of changes in deposition of soluble iron to the ocean since preindustrial climate conditions suggest roughly a doubling due to a combination of higher dust and combustion iron emissions along with more efficient atmospheric processing

Bacillus Calmette–Guérin-Induced Human Mast Cell Activation Relies on IL-33 Priming

Bacillus Calmette–Guérin (BCG) vaccine is an attenuated strain of Mycobacterium bovis that provides weak protection against tuberculosis (TB). Mast cells (MCs) are tissue-resident immune cells strategically that serve as the first line of defence against pathogenic threats. In this study, we investigated the response of human MCs (hMCs) to BCG. We found that naïve hMCs exposed to BCG did not secrete cytokines, degranulate, or support the uptake and intracellular growth of bacteria. Since we could show that in hMCs IL-33 promotes the transcription of host-pathogen interaction, cell adhesion and activation genes, we used IL-33 for cell priming. The treatment of hMCs with IL-33, but not IFN-γ, before BCG stimulation increased IL-8, MCP-1 and IL-13 secretion, and induced an enhanced expression of the mycobacteria-binding receptor CD48. These effects were comparable to those caused by the recombinant Mycobacterium tuberculosis (Mtb) 19-KDa lipoprotein. Finally, stimulation of hMCs with IL-33 incremented MC-BCG interactions. Thus, we propose that IL-33 may improve the immunogenicity of BCG vaccine by sensitising hMCs

Apoyo sanitario durante la invasión y campaña militar de Antonio Maceo en Pinar del Rio

ABSTRACT Introduction: a personality who stood out significantly within Pinar del Río and national society during the War of Independence of 1895-1896 was Major General Antonio Maceo. Much has been written about his military exploits, but there are still aspects that are not well supported historically. On the occasion of a political-ideological day in the provinceSubject: of military health was discussed; the insufficient literatures was the reason for undertaking a research aimed at researching the structure of military health that Maceo supposedly had in Pinar del Río during the military campaign in 1896.Methods: A qualitative, historical, situational, and descriptive research was carried out, using the primary and the secondary sources of information collected. The main sources to obtain the data were found in the History Archive and in the Provincial Library of Pinar del Río of the main historical moments with reference to Antonio Maceo.Development: that were published at that time; which allowed to create geographical, chronological and specific thematic aspects, and state.Conclusions: concerning the doctors that really accompanied him and also had a great performance in the attention of the wounded in the main combats, the number of casualties and deaths in the combat actions, the mentioned blood hospitals and the burials carried out in the province. In the opinion of the author, historical facts are mentioned that are typical from Pinar del Río in that military conflict of Maceo.Introducción: una personalidad que sobresalió de manera significativa dentro de la sociedad pinareña y nacional durante la guerra de independencia de 1895 -1896 fue el Mayor General Antonio Maceo. Mucho se ha escrito sobre sus hazañas militares, pero quedan aspectos que no están bien sustentados históricamente. En ocasión de una jornada política ideológica en la provincia donde se abordaba el tema de la sanidad militar; la insuficiente bibliografía, fue motivo para emprender una investigación.Objetivo:  indagar sobre la estructura de Sanidad Militar que suponía tenía Maceo en Pinar del Río durante la Campaña militar durante el año 1896.Métodos: se ha realizado una investigación cualitativa, histórica y situacional, descriptiva, utilizando fuentes primarias y secundarias de recolección de información. Las principales fuentes para la obtención de los datos, se encontraron en el Archivo de Historia y en la Biblioteca Provincial de Pinar del Río.Desarrollo: los principales momentos históricos que sobre Antonio Maceo  se publicaron en esa época; lo que permitió conformar con aspectos geográficos, cronológicos y la temática específica.Conclusiones: sobre los médicos que realmente lo acompañaron y tuvieron además gran actuación en la atención de heridos en los combates principales, la cifra de bajas y muertos en las acciones combativas, los hospitales de sangre mencionados y los enterramientos realizados en la provincia. A opinión de los autores se mencionan hechos históricos que le son propios a Pinar del Río en esa contienda militar de Maceo

Apoyo sanitario durante la invasión y campaña militar de Antonio Maceo en Pinar del Rio

ABSTRACT Introduction: a personality who stood out significantly within Pinar del Río and national society during the War of Independence of 1895-1896 was Major General Antonio Maceo. Much has been written about his military exploits, but there are still aspects that are not well supported historically. On the occasion of a political-ideological day in the provinceSubject: of military health was discussed; the insufficient literatures was the reason for undertaking a research aimed at researching the structure of military health that Maceo supposedly had in Pinar del Río during the military campaign in 1896.Methods: A qualitative, historical, situational, and descriptive research was carried out, using the primary and the secondary sources of information collected. The main sources to obtain the data were found in the History Archive and in the Provincial Library of Pinar del Río of the main historical moments with reference to Antonio Maceo.Development: that were published at that time; which allowed to create geographical, chronological and specific thematic aspects, and state.Conclusions: concerning the doctors that really accompanied him and also had a great performance in the attention of the wounded in the main combats, the number of casualties and deaths in the combat actions, the mentioned blood hospitals and the burials carried out in the province. In the opinion of the author, historical facts are mentioned that are typical from Pinar del Río in that military conflict of Maceo.Introducción: una personalidad que sobresalió de manera significativa dentro de la sociedad pinareña y nacional durante la guerra de independencia de 1895 -1896 fue el Mayor General Antonio Maceo. Mucho se ha escrito sobre sus hazañas militares, pero quedan aspectos que no están bien sustentados históricamente. En ocasión de una jornada política ideológica en la provincia donde se abordaba el tema de la sanidad militar; la insuficiente bibliografía, fue motivo para emprender una investigación.Objetivo:  indagar sobre la estructura de Sanidad Militar que suponía tenía Maceo en Pinar del Río durante la Campaña militar durante el año 1896.Métodos: se ha realizado una investigación cualitativa, histórica y situacional, descriptiva, utilizando fuentes primarias y secundarias de recolección de información. Las principales fuentes para la obtención de los datos, se encontraron en el Archivo de Historia y en la Biblioteca Provincial de Pinar del Río.Desarrollo: los principales momentos históricos que sobre Antonio Maceo  se publicaron en esa época; lo que permitió conformar con aspectos geográficos, cronológicos y la temática específica.Conclusiones: sobre los médicos que realmente lo acompañaron y tuvieron además gran actuación en la atención de heridos en los combates principales, la cifra de bajas y muertos en las acciones combativas, los hospitales de sangre mencionados y los enterramientos realizados en la provincia. A opinión de los autores se mencionan hechos históricos que le son propios a Pinar del Río en esa contienda militar de Maceo

Why Is Improvement of Earth System Models so Elusive? Challenges and Strategies from Dust Aerosol Modeling

Past decades have seen an accelerating increase in computing efficiency, while climate models are representing a rapidly widening set of physical processes. Yet simulations of some fundamental aspects of climate like precipitation or aerosol forcing remain highly uncertain and resistant to progress. Dust aerosol modeling of soil particles lofted by wind erosion has seen a similar conflict between increasing model sophistication and remaining uncertainty. Dust aerosols perturb the energy and water cycles by scattering radiation and acting as ice nuclei, while mediating atmospheric chemistry and marine photosynthesis (and thus the carbon cycle). These effects take place across scales from the dimensions of an ice crystal to the planetary-scale circulation that disperses dust far downwind of its parent soil. Representing this range leads to several modeling challenges. Should we limit complexity in our model, which consumes computer resources and inhibits interpretation? How do we decide if a process involving dust is worthy of inclusion within our model? Can we identify a minimal representation of a complex process that is efficient yet retains the physics relevant to climate? Answering these questions about the appropriate degree of representation is guided by model evaluation, which presents several more challenges. How do we proceed if the available observations do not directly constrain our process of interest? (This could result from competing processes that influence the observed variable and obscure the signature of our process of interest.) Examples will be presented from dust modeling, with lessons that might be more broadly applicable. The end result will either be clinical depression or there assuring promise of continued gainful employment as the community confronts these challenges