Experimental evaluation of the effect of ozone treatment on the oxidation and removal of dry soot deposits of the exhaust gas recirculation system.

The integration of alternative energy sources as a replacement for fossil fuels across various industrial sectors, including power generation, emergency systems, or marine applications, is uncertain. As a result, the utilization of traditional fuels is not anticipated to be fully phased out in the near future. To address this, new technologies, such as those that employ oxidising atmospheres, have been explored as a means to enhance the pollution control capabilities of existing technologies, as the Exhaust Gas Recirculation (EGR) system. In this regard, the present study has assessed the efficacy of ozone atmosphere exposure in mitigating the formation of undesired fouling deposits within the system, with the aim of facilitating more efficient operation of EGR devices and extending their service life. To this end, dry soot samples have been exposed to various ozone atmospheres at different temperatures and ozone concentrations through the utilization of an experimental test bench. The oxidation potential of these atmospheres has been evaluated through the analysis of the deposit mass loss. Likewise, confocal microscopy techniques have been employed to obtain the 3D topography of the fouling samples before and after the ozone treatment, allowing the assessment of the deposit thickness reduction, as well as the surface roughness variation. Additionally, thermogravimetric analysis has been conducted to examine the effects of the oxidation processes on fouling samples composition. The findings of this study have revealed that ozone atmospheres have been effective in reducing deposit mass at ozone treatment temperatures above 100 °C. The reduction in mass has reached 78.5% and 91.8% with treatment temperature of 140 °C with ozone concentrations of 30 gO3/m³ and 50 gO3/m³, respectively. It has also been established that treatment conditions with ozone concentrations of 30 gO3/m³ and 50 gO3/m³ are effective in reducing the thickness of deposits even at intermediate treatment temperatures, resulting in a thickness reduction of 78.6% and 81.1% at 80 °C, respectively. Additionally, it has been observed that the ozone exposure leads to the increase in the proportion of volatile material within the deposit.

Carbon fiber: Characterization and evaluation of the inflammatory response and toxicity in rats.

This study aimed to evaluate the Carbon Fiber obtained from PAN textile and cotton fiber in their different forms of presentation: non-activated carbon fiber felt (NACFF), activated carbon fiber felt (ACFF), silver activated carbon fiber felt (Ag-ACFF), and activated carbon fiber tissue (ACFT), to obtain scaffolds as a potential material with properties related to the synthetic bone graft. Characterization tests performed: surface wettability, traction, swelling, and in vivo tests: evaluation of the inflammatory response by implanting the materials in the subcutaneous tissue of 14 Wistar rats, evaluation of collagen fibers by picrosirius red staining and assessment of toxicity in the following organs: heart, spleen, liver, and kidney. In the wettability test, NACFF and ACFT were hydrophobic (θ124° and 114°), ACFF and Ag-ACFF were hydrophilic. For maximum stress, ACFF was more resistant (2.983 ± 1.059) p < .05. In the swelling test, the Ag-ACFF and ACFF groups showed the highest absorption percentage for the PBS solution and distilled water (p < .001). The organs showed no signs of acute systemic toxicity. The implant regions showed mild to moderate inflammatory infiltrate at 7 and 21 days. Only the ACFT group did not show the maturation of type I collagen fibers in 21 days. Through the conducted analyses, the ACFT shows little potential to be indicated as a possible scaffold. Therefore NACFF, ACFF, and Ag-ACFF have the potential to be considered scaffolds due to the following characteristics presented: good absorption rate, hydrophilicity, and non-toxic.

Colangiografía videolaparoscópica intraoperatoria y colangiopancreatografía retrógrada endoscópica en pacientes con sospecha de colédocolitiasis / Intraoperative Videolaparoscopic Cholangiography and Endoscopic Retrograde Cholangiopancreatography in Patients with Suspected Choledocholithiasis

Introducción: La coledocolitiasis se ha convertido en un problema de salud para el cual existen disímiles opciones de tratamiento. Objetivo: Exponer los resultados obtenidos con la colangiografía videolaparoscópica intraoperatoria y la colangiopancreatografía retrógrada endoscópica en pacientes con sospecha de coledocolitiasis. Métodos: Se realizó un estudio descriptivo retrospectivo en pacientes con sospecha de coledocolitiasis sometidos a colangiografía videolaparoscópica y la colangiopancreatografía endoscópica en el Hospital Militar Clínico Quirúrgico Docente de Camagüey Dr. Octavio de la Concepción y de la Pedraja durante el período de enero de 2015 a diciembre de 2019. El universo lo conformaron los 117 pacientes sometidos a ambos procederes. Se controlaron las variables de sospecha de coledocolitiasis, grupos de edades, sexo, hallazgos imagenológicos, complicaciones e índice de sospecha de coledocolitiasis. Resultados: En la colangiografía videolaparoscópica intraoperatoria fue mayor la posibilidad diagnóstica y menor las complicaciones. El diagnóstico de coledocolitiasis fue mayor en los pacientes sometidos a colangiopancreatografía retrógrada endoscópica, aunque esta no permitió evaluar a pacientes con bajo riesgo. Los pacientes del sexo femenino fueron más frecuentes en ambos grupos y la sospecha de coledocolitiasis se observó en grupo de edades entre 31 y 45 años. Sin embargo, fue normal el hallazgo de las vías biliares en ambos procederes. Conclusiones: Ambos métodos son seguros y útiles en el estudio en pacientes con sospecha de coledocolitiasis, con mayor eficacia diagnóstica para la técnica videolaparoscópica y menos complicaciones. El hallazgo normal de la vía biliar fue el resultado que prevaleció en ambos procederes(AU)

Introduction: Choledocholithiasis has become a health problem for which there are dissimilar treatment options. Objective: To present the results obtained with intraoperative videolaparoscopic cholangiography and endoscopic retrograde cholangiopancreatography in patients with suspected choledocholithiasis. Methods: A retrospective and descriptive study was conducted in patients with suspected choledocholithiasis and submitted to videolaparoscopic cholangiography and endoscopic cholangiopancreatography at Hospital Militar Clínico Quirúrgico Docente Dr. Octavio de la Concepción y de la Pedraja, of Camagüey, during the period from January 2015 to December 2019. The study universe consisted of 117 patients submitted to both procedures. The variables of suspected choledocholithiasis, age groups, sex, imaging findings, complications and index of suspected choledocholithiasis were controlled. Results: Intraoperative videolaparoscopic cholangiography had a higher diagnostic possibility and lower complications. The diagnosis of choledocholithiasis was higher in patients submitted to endoscopic retrograde cholangiopancreatography, although this did not allow the assessment of low-risk patients. Female patients were more frequent in both groups, while suspected choledocholithiasis was observed in patients between 31 and 45 years of age. However, the finding of a normal biliary tract was common to both procedures. Conclusions: Both methods are safe and useful in the study in patients with suspected choledocholithiasis, with greater diagnostic efficacy, as well as fewer complications, for the videolaparoscopic technique. The finding of a normal biliary tract was the prevailing result in both procedures(AU)

Magmatic plumbing and dynamic evolution of the 2021 La Palma eruption.

The 2021 volcanic eruption at La Palma, Canary Islands, was the island's most voluminous historical eruption. Little is known about this volcano's feeding system. During the eruption, seismicity was distributed in two clusters at ~10-14 km and ~33-39 km depth, separated by an aseismic zone. This gap coincides with the location of weak seismic swarms in 2017-2021 and where petrological data have implied pre-eruptive magma storage. Here we use seismological methods to understand the seismic response to magma transfer, with 8,488 hypocentral relocations resolving small-scale seismogenic structures, and 156 moment tensors identifying stress heterogeneities and principal axes flips. Results suggest a long-lasting preparatory stage with the progressive destabilisation of an intermediate, mushy reservoir, and a co-eruptive stage with seismicity controlled by the drainage and interplay of two localised reservoirs. Our study provides new insights into the plumbing system that will improve the monitoring of future eruptions in the island.

Experimental Investigation and CFD Analysis of Pressure Drop in an ORC Boiler for a WHRS Implementation.

Waste heat dissipated in the exhaust system of a combustion engine represents a major source of energy to be recovered and converted into useful work. The Waste Heat Recovery System (WHRS) based in an Organic Rankine Cycle (ORC) is an approach for recovering energy from heat sources, achieving a significant reduction in fuel consumption and, as a result, exhaust emissions. This paper studies pressure drop in an ORC shell-and-tubes boiler for a WHRS implementation experimentally and with computational simulations based on a 1-dimensional heat transfer model coupled with 3D calculations. An experimental database is developed, using ethanol in a pressure range of 10-15 absolute bar as working fluid, with mass fluxes inside the tubes in the range of 349.31 kg/s-m2 and 523.97 kg/s-m2, and inlet temperatures in the range of 60 °C and 80 °C. Thus, the friction factor of different regions of the boiler were estimated using both CFD simulations, experimental data, and bibliographic correlations. Simulations of operating points and the results of the experimental test bench showed good agreement in pressure drop results, with a mean absolute error of 15.47%, without a significant increment in the computational cost.

Numerical modelling of osteocyte growth on different bone tissue scaffolds.

The most common solution for the regeneration or replacement of damaged bones is the implantation of prostheses comprising ceramic or metallic materials. However, these implants are known to cause problems such as post-operative infections, collapse of the prosthesis, and lack of osseointegration. Consequently, bone tissue engineering was established because of the limitations of such implants. Osteogenic implants offer promising solutions for bone regeneration; however, three-dimensional scaffolds should be used as supportive structures. It is challenging to correctly design these structures and their compositions or properties to provide a microenvironment that promotes tissue regeneration and expedites bone formation. Computational fluid dynamics can be used to model the main phenomena that occur in bioreactors, such as cell metabolism, nutrient transport, and cell culture growth, or to model the influence of several key mechanisms related to the fluid medium, in particular, the wall shear stress. In this work, a new numerical bone cell growth model was developed, which considered the oxygen and nutrient consumption as well as the wall shear stress effect on cell proliferation. The model was implemented using 35 three-dimensional scaffolds of different porosities, and the effect of the main geometrical parameters involved in each scaffold type was analysed. The porosity plays an important role, however, a similar porosity did not guarantee similar shear stress or cell growth among the scaffolds. Randomised trabecular scaffolds, that more closely resembled trabecular bone, showed the highest cell growth values, so these are the best candidates for cell growth in a bioreactor.

Valoración de la colangiopancreatografía retrógrada endoscópica como medio diagnóstico/terapéutico en pacientes con íctero obstructivo / Assessment of the endoscopic retrograde cholangiopancreatography as a diagnostic/therapeutic mean in patients with obstructive jaundice

RESUMEN Introducción: las enfermedades del eje pancreático/biliar son una consecuencia en la morbimortalidad del aparato digestivo, y es la causa en ocasiones de una obstrucción biliar. La colangiopancreatografía retrógrada endoscópica es un método preciso para el diagnóstico de la obstrucción biliar, y se asocia con una elevada tasa de sensibilidad y especificidad. Materiales y métodos: se realizó un estudio observacional descriptivo de corte transversal, con el objetivo de valorar el comportamiento de la colangiopancreatografía retrógrada endoscópica como medio diagnóstico y terapéutico en una muestra de 90 pacientes con dictamen presuntivo de íctero obstructivo. Resultados: predominaron las féminas en el grupo de edad superior a los 50 años. La coluria, la acolia y el íctero como representativos de una enfermedad obstructiva de las vías biliares, fueron las manifestaciones más frecuentes, corroboradas por el estudio endoscópico, donde la litiasis coledociana fue la principal causa de íctero. Conclusión: la esfinterotomía endoscópica fue el proceder terapéutico de elección, y la pancreatitis aguda postintervención fue la complicación más frecuente (AU).

ABSTRACT Introduction: the diseases of the pancreatic-biliary axis are a consequence in the digestive tract morbidity-mortality, and sometimes they are the cause of a biliary obstruction. The endoscopic retrograde cholangiopancreatography is a precise method for diagnosing the biliary obstruction, and is associated to high rates of sensitivity and specificity. Materials and methods: a cross-sectional, descriptive, observational study was carried out with the aim of assessing the behavior of endoscopic retrograde cholangiopancreatography as a therapeutic and diagnostic mean in a sample of 90 patients with presumptive report of obstructive jaundice. Results: women aged more than 50 years predominated. Choluria, acholia and jaundice, as representative of the biliary ducts obstructive disease, were the most frequent manifestations, corroborated by the endoscopic study, where choledocal lithiasis was the main cause of jaundice. Conclusions: endoscopic sphincterotomy was the elective therapeutic procedure, and post-intervention acute pancreatitis was the most frequent complication (AU).

Lignin-Based Polyols with Controlled Microstructure by Cationic Ring Opening Polymerization.

Lignin-based polyols (LBPs) with controlled microstructure were obtained by cationic ring opening polymerization (CROP) of oxiranes in an organosolv lignin (OL) tetrahydrofuran (THF) solution. The control on the microstructure and consequently on the properties of the LBPs such as hydroxyl number, average molecular weight, melting, crystallization and decomposition temperatures, are crucial to determine the performance and application of the derived-products. The influence of key parameters, for example, molar ratio between the oxirane and the hydroxyl groups content in OLO, initial OL concentration in THF, temperature, specific flow rate and oxirane nature has been investigated. LBPs with hydroxyl numbers from 35 to 217 mg KOH/g, apparent average Mw between 5517 and 52,900 g/mol and melting temperatures from -8.4 to 18.4 °C were obtained. The CROP procedure allows obtaining of tailor-made LBPs for specific applications in a very simple way, opening the way to introduce LBPs as a solid alternative to substitute currently used fossil-based polyols.

Non-Alcoholic Fatty Liver Disease in Cuba.

INTRODUCTION: With a global adult prevalence of 24%, non-alcoholic fatty liver disease is a global health problem that parallels the worldwide increase of obesity. Its frequency, clinical characteristics and related diseases in Cuba remain unknown. OBJECTIVE: Describe the clinical characteristics, comorbidities and personal habits of patients with non-alcoholic fatty liver disease who are being treated in secondary and tertiary health facilities in seven Cuban provinces. METHODS: A cross-sectional, multicenter study was carried out in 6601 adults seen at gastroenterology outpatient clinics of nine hospitals in seven Cuban provinces from September 2018 through May 2019. Non-alcoholic fatty liver disease was diagnosed by abdominal ultrasound. The study included 1070 patients who met the diagnostic and study criteria and agreed to participate. Their personal habits and anthropometric and clinical characteristics, comorbidities and other aspects of their medical histories were recorded. RESULTS: Of the 1070 participants, 60.7% (649) were women. Participants' average age was 54.5 years and average body mass index was 30.5 kg/m2. A total of 397 (37.1%) were overweight and 574 (53.6%) were obese, 945 (88.3%) led a sedentary lifestyle, 564 (52.7%) had high blood pressure, 406 (37.9%) had lipid disorders and 301 (28.1%) were diabetic. While 484 (45.2%) of patients were asymptomatic, the most frequent clinical signs and symptoms were fatigue (262; 24.5%), dyspepsia (209; 19.5%), abdominal pain (306; 28.5%) and hepatomegaly (189; 17.7%). Liver cirrhosis was present in 37 (3.5%) patients at the time of diagnosis. Family history of type 2 diabetes mellitus and obesity were identified in 391 (36.5%) and 279 (26.1%) of participants, respectively. CONCLUSIONS: Prevalence of non-alcoholic fatty liver disease in these Cuban patients coincides with that reported in the Caribbean region, which has high levels of obesity, overweight and sedentary lifestyles. Most were asymptomatic, female or had metabolism-related comorbidities such as high blood pressure, type 2 diabetes mellitus and dyslipidemia.

Bone repair assessment of critical size defects in rats treated with mineralized bovine bone (Bio-Oss®) and photobiomodulation therapy: a histomorphometric and immunohistochemical study.

This study aimed to investigate the effects of administering photobiomodulation therapy (PBM) with bovine bone matrix on critical size defects in rats. Seventy-two adult male rats (albinus, Wistar), 90 days old, were used. Defect of 5 mm in diameter was made in their calvaria. The animals were divided into 4 groups: C-blood clot, B-Bio-Oss®, L-PBM, B+L-Bio-Oss®+PBM. Each group has been subdivided into 07, 30, and 60 days of observation. For PBM, a low GaAlAs energy of 660 nm was irradiated, total energy density of 45 J/cm2 . PBM was conducted in a trans-surgical form once only. For immunohistochemistry, a semi-quantitative analysis was made of expression of osteoprotegerin (OPG), nuclear kappa B-factor ligand receptor activator (RANKL), and tartrate-resistant acid phosphatase (TRAP). All histomorphometric data were statistically analyzed by ANOVA and Tukey test, significance level of 5%. The groups that showed the highest proportion of neoformation were L (0.39% ± 0.13) and C (0.37% ± 0.97), but groups B and B+L had larger defect size (C-1.75 mm2 ± 0.40, B-3.02 mm2 ± 0.63, L-2.45 mm2 ± 0.53, B+L-3.23 mm2 ± 1.01). In immunohistochemistry, groups B and B+L had higher immunostaining scores for OPG and RANKL at 60 days, and TRAP immunostaining increased in all groups at 30 days, but group L was the only one to present specimens with score 0. Although, at 60 days, groups L and C presented the highest proportion of bone neoformation, at 30 days group B+L had more than twice as much bone neoformation as group B, the choice of treatment application should depend on the aim of the treatment.

Avaliação do reparo ósseo de defeitos críticos tratados com matriz óssea mineralizada de osso bovino (Bio-Oss®) e fibrina rica em plaquetas: estudo histomorfométrico e imunológico em ratos / Bone repair evaluation of critical sized defects treated with bovine bone mineralized bone matrix (Bio-oss®) and platelet-rich fibrin: histomorphometric study in rats

O objetivo deste estudo foi avaliar o reparo ósseo de defeitos de tamanho crítico em ratos tratados com matriz óssea bovina (Bio-Oss®) e fibrina rica em plaquetas (PRF) por meio de análise histomorfométrica. Foram utilizados 54 ratos adultos (albinus, Wistar), com 90 dias de idade. Dois defeitos ósseos críticos com 5 mm de diâmetro foram confeccionados na calvária de cada rato. Os animais foram divididos em 4 grupos: C-Coágulo de sangue, B-Bio-Oss®, FPRF, B+F-Bio-Oss® + PRF. Cada grupo foi subdividido nos períodos de observação de 30 e 60 dias. Todos os dados foram analisados pelo teste de Kruskal-Wallis, teste de Dunn e teste de sinais de postos de Wilcoxon, o nível de confiança foi de 5%. Todos os grupos apresentaram resultados semelhantes quanto à proporção de neoformação óssea. Aos 30 dias na proporção de neoformação lamelar, GF apresentou maiores resultados estatisticamente com GB (GBvs.GF, p = 0,0256). Em relação ao fechamento do defeito, aos 30 dias o GF apresentou diferença estatística ao GC (GFvs.GC, p = 0,0374) e aos 60 dias o GB apresentou diferença estatística ao GC (GBvs.GC, p = 0,0374). Por meio da estatística descritiva, foi possível observar que o FRP tem ação positiva para o processo inicial de neoformação óssea. A associação Bio-Oss® e L-PRF parece estar relacionada à manutenção da arquitetura de neoformação óssea. No entanto, mais estudos são necessários para confirmar esse achado.

The aim of this study was to evaluate the bone repair of critical size defects in rats treated with bovine bone matrix (Bio-Oss®) and platelet rich fibrin (PRF) through histomorphometric analysis. Fifty-four adult rats (albinus, Wistar), 90 days old, were used. Two critical bone defects with 5mm of diameter were made in the calvaria. The animals were divided into 4 groups: C-Blood clot, B-BioOss®, F-PRF, B+F-Bio-Oss®+PRF. Each group was subdivided in the observation periods of 30 and 60 days. All data was analyzed by Kruskal-Wallis test, Dunn test and Wilcoxon signed-rank test, confidence level was 5%. All groups presented similar results regards proportion of bone neoformation. At 30 days in the proportion of lamellar neoformation, GF presented higher results when compared with GB (GBvs.GF, p=0.0256). Regarding the closure of the defect, at 30 days the GF and GC presented statistically different (GFvs.GC, p=0.0374) and at 60 days the GB and GC were statistically different (GBvs.GC, p=0.0374). Through descriptive statistics, it was possible to observe that FRP has positive action for the initial bone neoformation process. The association Bio-Oss and L-PRF seems to be related to the maintenance of the bone neoformation architecture. However, more studies are needed to confirm this finding.

Reporte de un caso atípico de esquizencefalia de labio abierto / Report of an atypical case of open lip schizencephaly

RESUMEN Fundamento: la esquizencefalia de labio abierto, es una malformación del grupo de los trastornos de migración cerebral, la cual se considera como una enfermedad poco común en todo el mundo y cursa con lesiones estructurales graves, dentro de las manifestaciones clínicas más comunes se encuentran las crisis epilépticas de difícil manejo, las alteraciones en el desarrollo del lenguaje, los defectos visuales y la microcefalia. Objetivo: presentar un caso poco común de malformación cerebral, diagnosticada como consecuencia de una complicación aguda, donde se encontraron otras características atípicas neurológicas, psicológicas y oftalmológicas. Presentación del caso: mujer de 19 años, con antecedentes prenatales de una malformación congénita del sistema nervioso central que presentaba una hemiparesia espástica desde el nacimiento, pero sin convulsiones ni retraso mental. Fue admitida en servicio de urgencia por signos de hipertensión intracraneal agudos, durante su estancia se realizó tomografía axial computarizada que mostró una esquizencefalia de labio abierto. Fue operada y luego de su recuperación se realizaron exámenes neuropsicológicos y oftalmológicos que mostraron características inusuales en la paciente. Conclusiones: la presencia de un defecto motor desde el nacimiento necesita de una evaluación imagenológica para estimación estructural de las posibles malformaciones existentes, que permitirá anticiparnos a la aparición de otros síntomas o de complicaciones. La estimulación neuropsicológica precoz activará los mecanismos de plasticidad cerebral con mejora de la calidad de vida.

ABSTRACT Background: open-lip schizencephaly is a cerebral malformation of the group of cerebral migration disorders, which is considered a rare disease worldwide and has serious structural lesions, and within the most common clinical manifestations find epileptic seizures that are difficult to manage, alterations in language development, visual defects and microcephaly. Objective: to present an unusual case of brain malformation, diagnosed as a consequence of an acute complication, where other atypical neurological, psychological and ophthalmological features were found. Clinical case: 19 years old woman; with a prenatal history of a congenital malformation of the central nervous system due to a spastic hemiparesis from birth, but without seizures or mental retardation. She was admitted to the emergency department for signs of acute intracranial hypertension, and during her stay, computed tomography was performed, which showed an open lip schizencephaly. She underwent surgery and after her recovery, neuropsychological and ophthalmological exams were performed which showed unusual characteristics in the patient. Conclusions: the presence of a motor defect from birth requires an imaging evaluation for structural estimation of the possible existing malformations, which will allow us to anticipate the appearance of other symptoms or complications. The early neuropsychological stimulation will activate the mechanisms of cerebral plasticity with improvement of the quality of life.

Síndrome de Lemmel: presentación de un caso / Lemmel syndrome: presentation of a Case

RESUMEN Fundamento: el duodeno corresponde a la segunda localización, con más frecuencia se presentan en los divertículos gastrointestinales después del colon. El síndrome de Lemmel también conocido como ictericia obstructiva intermitente, presencia de divertículos duodenales próximos a la papila de Váter podría favorecer al desarrollo de enfermedades pancreatobiliares. Objetivo: presentar el caso de una adulta mayor con ictericia en mucosa y piel intermitente asociada con episodios febriles no cuantificados y dolor en hipocondrio derecho. Presentación del caso: paciente de 67 años de edad, femenina, con un síndrome ictérico obstructivo, sin presencia de coledocolitiasis u otra alteración del árbol biliar distinta a la presencia de un divertículo duodenal. Por esta sintomatología es remitido a consulta de Gastroenterología del Hospital Universitario Manuel Ascunce Domenech de la provincia Camagüey. Conclusiones: el síndrome de Lemmel es una enfermedad poco frecuente que debe tenerse en cuenta como causa de ictericia obstructiva.

ABTRACT Background: the duodenum corresponds to the second location where the gastrointestinal diverticula are most frequently presented after the colon. Lemmel's syndrome, also known as intermittent obstructive jaundice, presence of duodenal diverticula near the papilla of Vater could favor the development of pancreatic biliary diseases. Objective: to present the case of an older adult with jaundice in mucosa and intermittent skin associated with febrile episodes not quantified and pain in the right hypochondrium. Case report: a 67-year-old female patient with an obstructive jaundice syndrome, without the presence of choledocholithiasis or other alteration of the biliary tree other than the presence of a duodenal diverticulum. For this symptomatology is referred to Gastroenterology consultation. Conclusions: Lemmel's syndrome is a rare pathology that must be taken into account as a cause of obstructive jaundice.

Synthesis of Nixantphos Core-Functionalized Amphiphilic Nanoreactors and Application to Rhodium-Catalyzed Aqueous Biphasic 1-Octene Hydroformylation.

A latex of amphiphilic star polymer particles, functionalized in the hydrophobic core with nixantphos and containing P(MAA-co-PEOMA) linear chains in the hydrophilic shell (nixantphos-functionalized core-crosslinked micelles, or nixantphos@CCM), has been prepared in a one-pot three-step convergent synthesis using reversible addition-fragmentation chain transfer (RAFT) polymerization in water. The synthesis involves polymerization-induced self-assembly (PISA) in the second step and chain crosslinking with di(ethylene glycol) dimethacrylate (DEGDMA) in the final step. The core consists of a functionalized polystyrene, obtained by incorporation of a new nixantphos-functionalized styrene monomer (nixantphos-styrene), which is limited to 1 mol%. The nixantphos-styrene monomer was synthesized in one step by nucleophilic substitution of the chloride of 4-chloromethylstyrene by deprotonated nixantphos in DMF at 60 °C, without interference of either phosphine attack or self-induced styrene polymerization. The polymer particles, after loading with the [Rh(acac)(CO)2] precatalyst to yield Rh-nixantphos@CCM, function as catalytic nanoreactors under aqueous biphasic conditions for the hydroformylation of 1-octene to yield n-nonanal selectively, with no significant amounts of the branched product 2-methyl-octanal.

Elucidating the ionic liquid distribution in monolithic SILP hydroformylation catalysts by magnetic resonance imaging.

Monolithic silicon carbide supported ionic liquid-phase (SILP) Rh-catalysts have very recently been introduced for gas-phase hydroformylation as an important step toward industrial upscaling. This study investigates the monolithic catalyst system in combination with different impregnation procedures with non-invasive magnetic resonance imaging (MRI). The findings were supported by X-ray microtomography (micro-CT) data of the monolithic pore structure and a catalytic performance test of the catalyst system for 1-butene gas-phase hydroformylation. MRI confirmed a homogeneous impregnation of the liquid phase throughout the full cross-section of the cylindrical monoliths. Consistent impregnations from one side to the other of the monoliths were achieved with a stabilizer in the system that helped preventing inhomogeneous rim formation. External influences relevant for industrial application, such as long-term storage and temperature exposure, did not affect the homogeneous liquid-phase distribution of the catalyst. The work elucidates important parameters to improve liquid-phase catalyst impregnation to obtain efficient monolithic catalysts for industrial exploitation in gas-phase hydroformylation as well as other important industrial processes.

Theoretical UV-Vis spectra of tetracationic porphyrin: effects of environment on electronic spectral properties.

Electronic and spectroscopic properties of tetracationic 5,10,15,20-tetrakis(1-methyl-4-pyridyl)-21H,23H-porphyrin (TMPyP) were investigated in the framework of the density functional theory (DFT). Modeling of implicit solvent, charge effects, and medium acidity were performed and compared with experimental results. Various hybrid exchange correlation functionals in the Kohn-Sham Scheme of the DFT were employed and various porphyrin models were constructed, simulating different environmental conditions. Since porphyrins present several technological applications with a plethora of interacting systems and the optical spectra profiles are often used to characterize these macrocyclic compounds, the study performed here aims to stablish a correct description of the UV-Vis spectrum. These results allowed to reproduce, both qualitatively as well as quantitatively, the Soret band of the TMPyP.

Urticaria por frío en un adolescente / Urticaria caused by cold in an adolescent

Se presenta el caso clínico de un paciente blanco de 17 años de edad, campesino, con antecedente de rinitis alérgica desde hacía aproximadamente 4 años, quien acudió a la consulta de Alergología del Hospital Provincial Eduardo Agramonte Piña de Camagüey, por presentar un cuadro urticariforme exacerbado en el tiempo que, a pesar de la dieta y de las medidas generales, se mantenía. Se realizó una prueba de provocación específica que resultó positiva; por tanto, se diagnosticó una urticaria crónica inducible de tipo físico, específicamente por frío. Se le indicó tratamiento con ketotifeno y a los 6 meses se repitió la prueba que mostró un resultado favorable.

The case report of a 17 years peasant white patient, is presented with a history of allergic rhinitis for approximately 4 years, who visited the Alergology Service of Eduardo Agramonte Piña Provincial Hospital in Camagüey, to present a sustained urticariform pattern exacerbated with time in spite of the diet and general measures. An specific provocation test which was positive was carried out; therefore, an inducible chronic urticaria of physical type was diagnosed, caused specifically by cold. Treatment with ketotifen was indicated and 6 months later the test was repeated, showing a favorable result.

Development of a Pattern Recognition Methodology with Thermography and Implementation in an Experimental Study of a Boiler for a WHRS-ORC.

Waste heat dissipated in the exhaust system in a combustion engine represents a major source of energy to be recovered and converted into useful work. A waste heat recovery system (WHRS) based on an Organic Rankine Cycle (ORC) is a promising approach, and it gained interest in the last few years in an automotive industry interested in reducing fuel consumption and exhaust emissions. Understanding the thermodynamic response of the boiler employed in an ORC plays an important role in steam cycle performance prediction and control system design. The aim of this study is, therefore, to present a methodology to study these devices by means of pattern recognition with infrared thermography. In addition, the experimental test bench and its operating conditions are described. The methodology proposed identifies the wall coordinates, traces the paths, and tracks the wall temperature along them in a way that can be exported for subsequent post-processing and analysis. As for the results, through the wall temperature paths on both sides (exhaust gas and working fluid), it was possible to quantitatively estimate the temperature evolution along the boiler and, in particular, the beginning and end of evaporation.