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1.
Acta biol. colomb ; 26(3): 466-469, sep.-dic. 2021.
Artículo en Inglés | LILACS-Express | LILACS | ID: biblio-1360041

RESUMEN

ABSTRACT In this work, the wasp Brachymeria podagrica is recorded for the first time for Colombia, a solitary parasitoid of larvae of the Peckia collusor fly. Third instar larvae of P. collusor were exposed to outdoor ambient conditions for 6 hours in the garden of the Tecnológico de Antioquia (Medellín, Colombia). 29 B. podagrica adults were obtained from the host pupae. Prevalence of parasitism was 14.5 %.


RESUMEN En este trabajo se reporta por primera vez a la avispa Brachymeria podagrica para Colombia y como parasitoide solitario de larvas de la mosca Peckia collusor. Los enemigos naturales fueron atraídos al exponer 200 larvas de P. collusor en tercer instar a condiciones ambientales naturales durante 6 horas el 16 de abril de 2015 en el jardín del Tecnológico de Antioquia (Medellín, Colombia). Como resultado, 29 adultos de B. Podagrica emergieron de las pupas. La prevalencia de parasitismo fue del 14,5 %.

3.
Nat Plants ; 7(10): 1397-1408, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34650267

RESUMEN

Cryptochromes (CRYs) are photoreceptors that mediate light regulation of the circadian clock in plants and animals. Here we show that CRYs mediate blue-light regulation of N6-methyladenosine (m6A) modification of more than 10% of messenger RNAs in the Arabidopsis transcriptome, especially those regulated by the circadian clock. CRY2 interacts with three subunits of the METTL3/14-type N6-methyladenosine RNA methyltransferase (m6A writer): MTA, MTB and FIP37. Photo-excited CRY2 undergoes liquid-liquid phase separation (LLPS) to co-condense m6A writer proteins in vivo, without obviously altering the affinity between CRY2 and the writer proteins. mta and cry1cry2 mutants share common defects of a lengthened circadian period, reduced m6A RNA methylation and accelerated degradation of mRNA encoding the core component of the molecular oscillator circadian clock associated 1 (CCA1). These results argue for a photoregulatory mechanism by which light-induced phase separation of CRYs modulates m6A writer activity, mRNA methylation and abundance, and the circadian rhythms in plants.


Asunto(s)
Adenosina/análogos & derivados , Arabidopsis/genética , Relojes Circadianos/genética , Criptocromos/metabolismo , Fotorreceptores de Plantas/metabolismo , Adenosina/metabolismo , Arabidopsis/metabolismo , Arabidopsis/efectos de la radiación
4.
Rev. colomb. cancerol ; 24(supl.1): 227-240, oct.-dic. 2020. tab, graf
Artículo en Español | LILACS | ID: biblio-1251510

RESUMEN

Resumen La enfermedad por COVID-19 fue detectada a finales de 2019 en Wuhan, China. Debido a su rápida propagación fue declarada emergencia sanitaria de forma inicial y luego de identificar casos fuera de China con transmisión autóctona y caracterizado por una mortalidad considerablemente alta en países como Italia y España, fue declarada pandemia por la Organización Mundial de la Salud. Se ha evidenciado que los pacientes mayores y con antecedentes de enfermedades crónicas incluido el cáncer desarrollan una enfermedad severa, presentando mayor riesgo de mortalidad por SARS-CoV2/ COVID-19. Lo anterior es por supuesto especialmente importante en el manejo de pacientes con Mieloma Múltiple (MM), generando en el personal Médico nuevos desafíos, oportunidades de mejora y aprendizajes, que aporten al análisis riesgo-beneficio del tratamiento inmunodepresor en este tipo de patologías. El consenso tiene como objetivo brindar orientación sobre el manejo de pacientes con MM en estos momentos donde el profesional de la salud requiere información para llevar a cabo terapias eficientes en el cuidado del paciente.


Abstract COVID-19 disease was detected in late 2019 in Wuhan, China. Due to its rapid spread, it was initially declared a health emergency, but after cases with indigenous transmission were identified outside China, characterized by considerably high mortality in countries such as Italy and Spain, it was declared a pandemic by the World Health Organization. It has been shown that elderly patients with a history of chronic diseases, including cancer, develop a severe disease, presenting a higher risk of mortality from SARS-CoV2 / COVID-19. This becomes especially important in the management of patients with Multiple Myeloma (MM), generating new challenges, opportunities for improvement and learning opportunities in the health professionals, which will contribute to the risk-benefit analysis of immunosuppressive treatment for this type of pathology. The consensus aims to provide guidance for the management of patients with MM in these times when the health professional requires information to deliver efficient therapies in patient care.


Asunto(s)
Humanos , Consenso , COVID-19 , Mieloma Múltiple , Terapéutica
5.
Proc Natl Acad Sci U S A ; 117(45): 27962-27970, 2020 11 10.
Artículo en Inglés | MEDLINE | ID: mdl-33106421

RESUMEN

Cyanobacteriochromes (CBCRs) are photoswitchable linear tetrapyrrole (bilin)-based light sensors in the phytochrome superfamily with a broad spectral range from the near UV through the far red (330 to 760 nm). The recent discovery of far-red absorbing CBCRs (frCBCRs) has garnered considerable interest from the optogenetic and imaging communities because of the deep penetrance of far-red light into mammalian tissue and the small size of the CBCR protein scaffold. The present studies were undertaken to determine the structural basis for far-red absorption by JSC1_58120g3, a frCBCR from the thermophilic cyanobacterium Leptolyngbya sp. JSC-1 that is a representative member of a phylogenetically distinct class. Unlike most CBCRs that bind phycocyanobilin (PCB), a phycobilin naturally occurring in cyanobacteria and only a few eukaryotic phototrophs, JSC1_58120g3's far-red absorption arises from incorporation of the PCB biosynthetic intermediate 181,182-dihydrobiliverdin (181,182-DHBV) rather than the more reduced and more abundant PCB. JSC1_58120g3 can also yield a far-red-absorbing adduct with the more widespread linear tetrapyrrole biliverdin IXα (BV), thus circumventing the need to coproduce or supplement optogenetic cell lines with PCB. Using high-resolution X-ray crystal structures of 181,182-DHBV and BV adducts of JSC1_58120g3 along with structure-guided mutagenesis, we have defined residues critical for its verdin-binding preference and far-red absorption. Far-red sensing and verdin incorporation make this frCBCR lineage an attractive template for developing robust optogenetic and imaging reagents for deep tissue applications.


Asunto(s)
Ficobilinas/metabolismo , Fitocromo/genética , Porfirinas/genética , Proteínas Bacterianas/metabolismo , Biliverdina/química , Cianobacterias/genética , Cianobacterias/metabolismo , Luz , Células Fotorreceptoras/metabolismo , Fotorreceptores Microbianos/química , Ficobilinas/genética , Ficocianina/genética , Ficocianina/metabolismo , Fitocromo/metabolismo , Porfirinas/metabolismo
6.
Zootaxa ; 4604(2): zootaxa.4604.2.4, 2019 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-31717191

RESUMEN

The genus Fannia Robineau-Desvoidy is a group of calyptrate Diptera distributed in all biogeographic regions and comprises about 300 species. The present study described five new species from Colombia: Fannia aburrae sp. nov., Fannia copacabana sp. nov., Fannia isa sp. nov., Fannia pseudoconstricta sp. nov., Fannia spinosa sp. nov. Male specimens are described, and morphological characters and terminalia are illustrated. Likewise, an updated identification key for males and an updated checklist for the 37 species present in Colombia are provided. New records are presented for the country.


Asunto(s)
Dípteros , Muscidae , Animales , Colombia , Masculino
7.
Chemosphere ; 180: 239-246, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28411539

RESUMEN

The degradation of methylene blue in aqueous solution as a model dye using a non thermal microwave (2.45 GHz) plasma jet at atmospheric pressure has been investigated. Argon has been used as feed gas and aqueous solutions with different concentrations of the dye were treated using the effluent from plasma jet in a remote exposure. The removal efficiency increased as the dye concentration decreased from 250 to 5 ppm. Methylene blue degrades after different treatment times, depending on the experimental plasma conditions. Thus, kinetic constants up to 0.177 min-1 were obtained. The higher the Ar flow, the faster the degradation rate. Optical emission spectroscopy (OES) was used to gather information about the species present in the gas phase, specifically excited argon atoms. Argon excited species and hydrogen peroxide play an important role in the degradation of the dye. In fact, the conversion of methylene blue was directly related to the density of argon excited species in the gas phase and the concentration of hydrogen peroxide in the aqueous liquid phase. Values of energy yield at 50% dye conversion of 0.296 g/kWh were achieved. Also, the use of two plasma applicators in parallel has been proven to improve energy efficiency.


Asunto(s)
Presión Atmosférica , Azul de Metileno/química , Microondas , Eliminación de Residuos Líquidos/métodos , Contaminantes Químicos del Agua/química , Argón/química , Peróxido de Hidrógeno/química , Cinética , Modelos Teóricos , Eliminación de Residuos Líquidos/instrumentación , Aguas Residuales/química , Agua/química , Contaminantes Químicos del Agua/análisis , Purificación del Agua/métodos
8.
Biomed Environ Sci ; 29(11): 834-839, 2016 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-27998391

RESUMEN

This study analyze the relation between body composition, physical activity (PA), and sex in Chilean children from rural and urban public educational institutions. The prevalence of obesity (according to BMI) was 30.88% in urban children and 28.93% in rural children. Central obesity presented mainly in the rural girls. Approximately 90% of the participants reported <7 h of PA/week, regardless of residential area. In addition, central fat was strongly associated with rural residence; the children reported lower PA levels, and they presented a higher prevalence of central fat. The results reflect the need to implement programs to improve PA conditions in the child urban-rural population.


Asunto(s)
Distribución de la Grasa Corporal/estadística & datos numéricos , Ejercicio Físico , Obesidad/epidemiología , Población Rural/estadística & datos numéricos , Población Urbana/estadística & datos numéricos , Adolescente , Niño , Chile/epidemiología , Femenino , Humanos , Masculino
9.
Artículo en Inglés | MEDLINE | ID: mdl-26117196

RESUMEN

In this work, we analysed the preparatory layer and paintings in the hypocaustum of the Roman villa of El Ruedo (Almedinilla, southern Spain). The specimens studied were from the III and IV centuries. Raman microscopy was for the first time used here to examine Roman pictures in the south of the Iberian peninsula. The results obtained allowed us to establish the chemical nature of the different pigments used by the Roman artists. All were applied over a preparatory layer consisting of limewash. The different colours used (black, white, red, yellow, green and blue) were obtained by using carbon, calcite, gypsum, hematite, goethite, green earth and Egyptian blue. Some exhibited various hues that were obtained by mixing the previous compounds. Worth special note is the incipient presence of blue pigments, which were rarely used in Roman Hispania owing to their scarcity and high price.

10.
BMC Nephrol ; 15: 65, 2014 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-24755192

RESUMEN

BACKGROUND: Left ventricular hypertrophy (LVH) is common in kidney transplant (KT) recipients. LVH is associated with a worse outcome, though m-TOR therapy may help to revert this complication. We therefore conducted a longitudinal study to assess morphological and functional echocardiographic changes after conversion from CNI to m-TOR inhibitor drugs in nondiabetic KT patients who had previously received RAS blockers during the follow-up. METHODS: We undertook a 1-year nonrandomized controlled study in 30 non-diabetic KT patients who were converted from calcineurin inhibitor (CNI) to m-TOR therapy. A control group received immunosuppressive therapy based on CNIs. Two echocardiograms were done during the follow-up. RESULTS: Nineteen patients were switched to SRL and 11 to EVL. The m-TOR group showed a significant reduction in LVMi after 1 year (from 62 ± 22 to 55 ± 20 g/m2.7; P=0.003, paired t-test). A higher proportion of patients showing LVMi reduction was observed in the m-TOR group (53.3 versus 29.3%, P=0.048) at the study end. In addition, only 56% of the m-TOR patients had LVH at the study end compared to 77% of the control group (P=0.047). A significant change from baseline in deceleration time in early diastole was observed in the m-TOR group compared with the control group (P=0.019). CONCLUSIONS: Switching from CNI to m-TOR therapy in non-diabetic KT patients may regress LVH, independently of blood pressure changes and follow-up time. This suggests a direct non-hemodynamic effect of m-TOR drugs on cardiac mass.


Asunto(s)
Antagonistas de Receptores de Angiotensina/administración & dosificación , Inhibidores de la Enzima Convertidora de Angiotensina/administración & dosificación , Hipertrofia Ventricular Izquierda/etiología , Hipertrofia Ventricular Izquierda/prevención & control , Trasplante de Riñón/efectos adversos , Inhibidores de Proteínas Quinasas/administración & dosificación , Serina-Treonina Quinasas TOR/antagonistas & inhibidores , Quimioterapia Combinada , Femenino , Humanos , Hipertrofia Ventricular Izquierda/diagnóstico , Inmunosupresores/administración & dosificación , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Resultado del Tratamiento
11.
Eur J Clin Invest ; 43(10): 1060-8, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23980841

RESUMEN

AIMS: (i) To evaluate glucometabolic status of patients without known diabetes hospitalized due to coronary artery disease (CAD), (ii) to assess markers of systemic inflammation determined during admission and to evaluate their relationship with glucometabolic status and (iii) to analyse usefulness of HbA1c determined during admission in patients with CAD to detect abnormal glucose regulation (AGR). MATERIALS & METHODS: We studied 440 patients with CAD admitted to the cardiology ward. Patients were grouped in four groups during admission according to clinical data, fasting plasma glucose and HbA1c: diabetes, HbA1c > 5·9%, stress hyperglycaemia (SH) and normal. In 199 subjects without known diabetes, an oral glucose tolerance test (OGTT) was performed 3 months after discharge, and they were reclassified according to WHO 1998 criteria. Biochemical and inflammatory markers were measured. RESULTS: The OGTT showed that 27·4% of subjects without known diabetes at admission had diabetes, 11·2% had impaired fasting glucose + impaired glucose tolerance, 33·5% impaired glucose tolerance, 3·6% impaired fasting glucose, and 24·4% normal glucose metabolism. Odds ratio for having diabetes 3 months after discharge in HbA1c > 5·9% group was 5·91 (P < 0·0001) and in SH group was 1·82 (P = 0·38). The best HbA1c cut-off point to predict AGR was 5·85%. HbA1c levels during admission were highly predictive of having AGR (AUC ROC 0·76 [95% CI 0·67-0·84]). CONCLUSION: We reported a high prevalence of AGR in subjects with CAD. Stress hyperglycaemia in patients with CAD was not associated with an increased risk of diabetes 3 months later. HbA1c in patients hospitalized with CAD was a useful tool to detect AGR.


Asunto(s)
Enfermedad de la Arteria Coronaria/terapia , Diabetes Mellitus Tipo 2/diagnóstico , Angiopatías Diabéticas/diagnóstico , Hiperglucemia/psicología , Estrés Psicológico/complicaciones , Anciano , Glucemia/metabolismo , Enfermedad de la Arteria Coronaria/diagnóstico , Ayuno/sangre , Femenino , Intolerancia a la Glucosa/etiología , Hemoglobina Glucada/metabolismo , Hospitalización , Humanos , Masculino
12.
Materials (Basel) ; 6(4): 1554-1565, 2013 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-28809228

RESUMEN

Three periodic mesoporous materials, i.e., two organosilicas with either ethylene or phenylene bridges and one silica, have been used as supports for Pd nanoparticles. All Pd-supported samples (1.0 wt%) were prepared by the incipient wetness method and subsequently reduced in an H2 stream at 200 °C. Both hydrogen chemisorption and temperature programmed reduction experiments revealed significant differences depending on the support. Pd2+ species were more reducible on the mesoporous organosilicas than on their silica counterpart. Also, remarkable differences on the particle morphology were observed by transmission electron microscopy. All Pd-supported samples were active in the Suzuki cross-coupling reaction between bromobenzene and phenylboronic acid.

13.
Zootaxa ; 3750: 389-95, 2013 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-25113708

RESUMEN

Fannia Robineau-Desvoidy is a genus of calyptrate Diptera that comprises 89 Neotropical species, of which only 23 occur in Colombia. Based on male characters (including terminalia), two new species from the Department of Antioquia (Fannia colazorrensis sp. nov. and Fannia laclara sp. nov.) are described. Illustrations of the male are presented.


Asunto(s)
Muscidae/clasificación , Distribución Animal , Estructuras Animales/anatomía & histología , Animales , Colombia , Ecosistema , Masculino , Muscidae/anatomía & histología
14.
Rev. esp. cardiol. (Ed. impr.) ; 64(3): 208-212, mar. 2011. tab, ilus
Artículo en Español | IBECS | ID: ibc-86034

RESUMEN

Introducción y objetivos. Los accesos mínimamente invasivos en cardiopatías no complejas ofrecen alternativas que disminuyen las secuelas estéticas. Asimismo, la cirugía se indica en edades más tempranas. En trabajos previos, comparamos la incisión submamaria con la esternotomía media. Presentamos nuestra experiencia inicial en el acceso axilar para el cierre de las comunicaciones interauriculares con circulación extracorpórea en comparación con el acceso submamario. Métodos. Se recoge en total a 20 pacientes: 10 casos por vía submamaria derecha (7 ostium secundum, 2 seno venoso, 1 ostium primum) y 10 casos operados a través de la axila derecha (7 ostium secundum, 3 seno venoso). Las medias de edad y de peso eran 6,4±3,62 (3-13) años y 23,5±8,74 (12-38) kg en el grupo submamaria y 5,5±2,04 (3-9) años y 19,7±5,88 (14-29) kg en el grupo axilar. En todos ellos, el procedimiento (canulación y corrección) se realiza completamente a través de la propia incisión respetando grupos musculares, sin puertos complementarios. Resultados. No se registran defectos residuales en la ecografía de control al alta. Ningún caso precisó reconversión a esternotomía media. Las maniobras de abordaje y canulación axilares son algo más complejas que las submamarias. Los tiempos de circulación extracorpórea y pinzamiento son superponibles en ambos grupos, comparados por enfermedades (p>0,05). Conclusiones. En pacientes seleccionados y con defectos abordables a través de la aurícula, la vía axilar derecha es tan segura como la submamaria. El resultado estético es excelente(AU)


Introduction and objectives: Minimally invasive approaches in less-complex cardiac procedures can avoid unpleasant cosmetic results. Moreover, surgery can be scheduled in younger patients. In previous papers, we compared submammary and midline sternotomy.We present our initial experience with an axillary, compared to submammary, approach to repair atrial septal defects under extracorporeal circulation. Methods: 20 patients are included: 10 in the submammary group (7 ostium secundum, 2 sinus venosus, 1 ostium primum) and 10 in the axillary group (7 ostium secundum, 3 sinus venosus). Mean age and weight are 6.4 +/- 3.62 years (range 3-13) and 23.5 +/- 8.74 Kg (range 12-38) in the submammary group, and 5.5 +/- 2.04 years (range 3-9) and 19.7 +/- 5.88 Kg (range 14-29) in the axillary one, respectively. Muscles are spared (pectoralis in submammary and latissimus in axillary). The whole procedure (cannulation and correction) is performed through a single incision, with no side ports. Results: No residual defects were found at discharge. Surgical approach maneuvers are more cumbersome through the axillary than the submammary approach. In a peer comparison, extracorporeal circulation and cross-clamp time were similar in both groups (P > .05). Conclusions: 1. Axillary approach is as safe as submammary access in selected patients and for defects approached through the atrium. 2. Cosmetic result is excellent(AU)


Asunto(s)
Humanos , Femenino , Niño , Procedimientos Quirúrgicos Mínimamente Invasivos/métodos , Procedimientos Quirúrgicos Mínimamente Invasivos , Defectos del Tabique Interatrial/cirugía , Defectos del Tabique Interatrial , Cateterismo/tendencias , Cateterismo , Axila/anatomía & histología , Axila/cirugía , Esternón/cirugía , Esternón
15.
Rev Esp Cardiol ; 64(3): 208-12, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21330035

RESUMEN

INTRODUCTION AND OBJECTIVES: Minimally invasive approaches in less-complex cardiac procedures can avoid unpleasant cosmetic results. Moreover, surgery can be scheduled in younger patients. In previous papers, we compared submammary and midline sternotomy. We present our initial experience with an axillary, compared to submammary, approach to repair atrial septal defects under extracorporeal circulation. METHODS: 20 patients are included: 10 in the submammary group (7 ostium secundum, 2 sinus venosus, 1 ostium primum) and 10 in the axillary group (7 ostium secundum, 3 sinus venosus). Mean age and weight are 6.4±3.62 years (range 3-13) and 23.5±8.74 Kg (range 12-38) in the submammary group, and 5.5±2.04 years (range 3-9) and 19.7±5.88 Kg (range 14-29) in the axillary one, respectively. Muscles are spared (pectoralis in submammary and latissimus in axillary). The whole procedure (cannulation and correction) is performed through a single incision, with no side ports. RESULTS: No residual defects were found at discharge. Surgical approach maneuvers are more cumbersome through the axillary than the submammary approach. In a peer comparison, extracorporeal circulation and cross-clamp time were similar in both groups (P>.05). CONCLUSIONS: 1. Axillary approach is as safe as submammary access in selected patients and for defects approached through the atrium. 2. Cosmetic result is excellent.


Asunto(s)
Procedimientos Quirúrgicos Cardíacos/métodos , Defectos del Tabique Interatrial/cirugía , Adolescente , Axila , Mama , Niño , Preescolar , Femenino , Humanos , Procedimientos Quirúrgicos Mínimamente Invasivos/métodos
16.
Artículo en Inglés | MEDLINE | ID: mdl-21227740

RESUMEN

An Mg/Al layered double hydroxide (LDH) containing carbonate ion in its interlayer region was examined by medium infrared (MIR) and near infrared reflectance spectroscopy (NIRS). The MIR and NIR spectroscopy techniques was also used to study two organo-hybrid LDHs containing interlayer dodecylbenzenesulphonate (DBS) and dodecylsulphate (DS) ions, respectively. The NIR spectra for the latter solids were found to exhibit the overtone and combination bands for the hydroxyl groups in addition to those typical bands of the organic host functions.


Asunto(s)
Hidróxidos/química , Espectroscopía Infrarroja Corta/métodos , Ácidos Alcanesulfónicos/química , Bencenosulfonatos/química , Carbonatos/química , Tensoactivos/química
17.
Hist. enferm., Rev. eletronica ; 2(2): 4-18, 20110000.
Artículo en Español | BDENF - Enfermería, LILACS | ID: biblio-1028936

RESUMEN

A construção histórica da enfermagem avança continuamente, mas pouco se sabe sobre quem são seus historiadores, suas origens e motivações, seus interesses ou contribuições sociais e científicas. O estudo analisa entrevistas semi-estruturadas e sistêmicas, realizadas com dois historiadores Latino-Americanos da Enfermagem: a Enfermeira Velandia Mora o Historiador Souza Campos. O resultado apresenta pontos de convergências e diferenças sobre o interesse por pesquisar a história da enfermagem, influências teóricas e processos investigativos iniciais, atuais e futuros, assim como ganhos pessoais e para a profissão. A conclusão permite considerar que a história provê aos estudantes de enfermagem consciência crítica, além da extensão de benefícios a outras áreas da saúde, projetando a investigação em enfermagem, assim como a imagem social da enfermeira, legitimando sua identidade profissional. O estudo considera conteúdos e problemáticas propostas pela história da enfermagem como ferramenta básica na formação profissional de enfermeiros


Asunto(s)
Historia del Siglo XX , Historia de la Enfermería , Enseñanza , Historia , Investigación
18.
J Nanosci Nanotechnol ; 10(10): 6562-6, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21137762

RESUMEN

A combination of delamination and ion exchange allowed us to obtain new solids consisting of nanolayers of double hydroxides containing hydroxyl as charge balancing ion (i.e., meixnerite monolayers). The solids were prepared from Mg/Al HLCs containing dodecylbenzenesulphonate (DBS) anion in the interlayer region, using a procedure involving sonication and swelling of the interlayer region in the presence of 1-butanol as solvent. This treatment converts the initial, milky dispersion, into a translucent dispersion suggesting that the solid is completely exfoliated. Then, the translucent dispersion is treated with an NaOH solution in 1-butanol in order to exchange DBS- ions with OH- ions and simultaneously precipitate the DBS sodium salt while offsetting charge deficiencies in the solid layers. The exchange process results in no relamination of the structure, which allows a new material consisting of individual nanolayers of meixnerite to be prepared.

19.
J Colloid Interface Sci ; 302(2): 568-75, 2006 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-16887134

RESUMEN

The efficiency of various heterogeneous solids consisting of palladium supported on hydrotalcite as catalysts in the Suzuki cross-coupling reaction between bromobenzene and phenylboronic acid was studied. Based on the catalytic activity results, the reaction develops to an acceptable extent with 100% selectivity at moderate temperatures in the presence of some of the catalysts. The best results were provided by a catalyst consisting of an acetate-pyridine complex of Pd supported on hydrotalcite that gave high conversion values even after three reuses. The reactions conditions were very mild (a temperature of 55 degrees C and atmospheric pressure). In fact, the catalyst provided conversion and selectivity results surpassing those of existing heterogeneous phase catalysts and most homogeneous phase catalysts for the same purpose.


Asunto(s)
Hidróxido de Aluminio/química , Compuestos de Bifenilo/síntesis química , Hidróxido de Magnesio/química , Compuestos Organometálicos/química , Paladio/química , Adsorción , Compuestos de Bifenilo/química , Ácidos Borónicos/química , Bromobencenos/química , Catálisis , Espectroscopía de Resonancia Magnética/métodos , Estructura Molecular , Compuestos Organometálicos/síntesis química , Tamaño de la Partícula , Sensibilidad y Especificidad , Solventes/química , Espectrofotometría Infrarroja/métodos , Propiedades de Superficie , Temperatura
20.
Rev Esp Cardiol ; 55(8): 872-4, 2002 Aug.
Artículo en Español | MEDLINE | ID: mdl-12199985

RESUMEN

We report a case of spontaneous intramural left atrial hematoma with chest pain and pulmonary edema as the primary clinical manifestations. Echocardiographic techniques revealed obstruction of the left atrial cavity by cyst-like masses attached to the posterior and anterior atrial wall. A large intramural hematoma due to extensive atrial wall dissection was observed by magnetic resonance imaging. Surgery confirmed the diagnosis of intramural left atrial hematoma with no complications. We review the clinical and diagnostic profile of the three cases of spontaneous intramural left atrial hematoma reported in the world medical literature.


Asunto(s)
Atrios Cardíacos , Cardiopatías/diagnóstico , Hematoma/diagnóstico , Imagen por Resonancia Magnética , Adulto , Dolor en el Pecho/etiología , Drenaje , Ecocardiografía , Electrocardiografía , Femenino , Estudios de Seguimiento , Cardiopatías/diagnóstico por imagen , Cardiopatías/cirugía , Hematoma/diagnóstico por imagen , Hematoma/cirugía , Humanos , Factores de Tiempo , Ultrasonografía Doppler en Color
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