75 research outputs found
Microwave-Promoted Copper-Free Sonogashira–Hagihara Couplings of Aryl Imidazolylsulfonates in Water
Aryl imidazol-1-ylsulfonates have been efficiently cross-coupled with aryl-, alkyl-, and silylacetylenes in neat water under copper-free conditions at 110 °C assisted by microwave irradiation. Using 0.5 mol% of an oxime palladacycle as precatalyst, 2-dicyclohexylphosphino-2′,6′-dimethoxybiphenyl (SPhos, 2 mol%) as ligand, hexadecyltrimethylammonium bromide (CTAB) as additive, and triethylamine (TEA) as base, a wide array of disubstituted alkynes has been prepared in good to high yields in only 30 min.Financial support from the MICINN (Projects CTQ2007-62771/BQU, CTQ2010-20387 and Consolider INGENIO 2010 CSD2007-00006), FEDER, from the Generalitat Valenciana (Project PROMETEO/2009/038), and the University of Alicante is acknowledged
Some Lessons for the Future from the Global Malaria Eradication Programme (1955–1969)
Jose Najera and colleagues identify lessons from the Global Malaria Eradication Programme (1955–1969) relevant to current elimination and eradication efforts
Un análisis transversal del ecoturismo: Arte místico y riesgo alternativo
En el marco de promoción del emprendimiento local para el desarrollo regional sustentable, los estudios del turismo se han centrado en el análisis de la experiencia vital como antecedente de la satisfacción turística y el retorno vacacional, pero sin considerarlos como parte de un ciclo de recreación y esparcimiento que podría ser explicado desde las representaciones sociales. En tal sentido, se llevó a cabo un trabajo exploratorio, transversal y cualitativo con una selección de informantes, considerando sus recorridos a un museo natural surrealista del centro de México. Las interpretaciones en torno a las respuestas a preguntas derivadas de las categorías de núcleo de esparcimiento, periferia recreativa y experiencia vacacional muestran similitudes en cuanto a la búsqueda de un significado del recorrido y el escenario, pero también diferencias en cuanto a la integración con el escenario, orientando futuras líneas de investigación hacia las diferencias entre generacione
Vaccination programs, parity, and calving season as factors affecting the risk of fetal losses and mummified fetuses in Holstein cows
Aim of the study: To investigate vaccination programs, parity, and calving season as factors affecting the risk of abortion and mummified fetuses in Holstein cows.Area of study: Hot zone of Northeast Mexico.Material and methods: Multiple logistic regression models were used to examine the relationship between peripartum disorders, parity, previous occurrence of abortion, season of calving, vaccination program, incidence of abortion, and mummified fetuses in Holstein cows.Main results: For 7014 pregnancies (2886 cows), the percentage of cows aborting and having mummified fetuses was 17.7% and 1.1%, respectively. As the number of brucellosis vaccinations increased, the incidence of abortion increased (10.4% for a single vaccination and 38.0% for 6 accumulated vaccinations). Abortion for cows having 1-2 previous abortions (56%) and >2 abortions (77%) was fivefold and sevenfold greater (p<0.01), respectively, than that for cows without previous abortion. Other important risk factors for abortion were number of calvings (19.8% for nulliparous and primiparous vs. 13.8% for >3 parturitions; OR=1.7, p<0.01), leptospirosis vaccine application <55 days postpartum (dpp; OR=1.3, p<0.05), viral vaccine application >37 dpp (OR=1.3, p<0.01), brucellosis vaccine application >20 dpp (OR=1.6, p<0.01), and no application of clostridial vaccine (OR=3.7, p<0.01). Significant risk factors for mummified fetuses were application of ≥3 brucellosis vaccinations (OR=3.3, p<0.01), no application of 10-way clostridial vaccine (OR=2.3, p<0.01), >2 previous abortions (OR=18.4, p<0.01), and calving in autumn (OR=0.4, compared to winter, p<0.05).Research highlights: Risk of abortion and mummified fetuses in Holstein cows has been found to be related to vaccination programs
Molecular mechanisms of resveratrol as chemo and radiosensitizer in cancer
One of the primary diseases that cause death worldwide is cancer. Cancer cells can be intrinsically resistant or acquire resistance to therapies and drugs used for cancer treatment through multiple mechanisms of action that favor cell survival and proliferation, becoming one of the leading causes of treatment failure against cancer. A promising strategy to overcome chemoresistance and radioresistance is the co-administration of anticancer agents and natural compounds with anticancer properties, such as the polyphenolic compound resveratrol (RSV). RSV has been reported to be able to sensitize cancer cells to chemotherapeutic agents and radiotherapy, promoting cancer cell death. This review describes the reported molecular mechanisms by which RSV sensitizes tumor cells to radiotherapy and chemotherapy treatment
Lecciones aprendidas del terremoto de Lorca de 2011.
El terremoto de Lorca del 11 de mayo de 2011, de magnitud Mw=5,2, causó un enorme impacto en la ciudad y una gran alarma social, provocando 9 víctimas mortales, centenares de heridos y cuantiosos daños materiales. Este trabajo recoge las opiniones de varios expertos que tuvieron un papel destacado en la gestión y análisis del suceso, y la de 627 lorquinos a través de una encuesta llevada a cabo por estudiantes del I.E.S. Ramón Arcas de Lorca. Aunque cada uno de los expertos y los ciudadanos inciden en aspectos diferentes, el análisis de sus opiniones nos permite concluir, como principal lección aprendida, que terremotos futuros como el de Lorca pueden producir muchos menos daños si se trabaja conjuntamente en mejorar: (1) la investigación sísmica, (2) la calidad de las construcciones, (3) la gestión de las catástrofes naturales y (4) la formación de la ciudadanía. Esta aproximación multidisciplinar al terremoto de Lorca puede resultar interesante para los estudiantes, y puede aportar ideas a los docentes para el análisis de futuros terremotos
Identification of tomato accessions as source of new genes for improving heat tolerance: from controlled experiments to field
Background: Due to global warming, the search for new sources for heat tolerance and the identification of genes involved in this process has become an important challenge as of today. The main objective of the current research was to verify whether the heat tolerance determined in controlled greenhouse experiments could be a good predictor of the agronomic performance in field cultivation under climatic high temperature stress. Results: Tomato accessions were grown in greenhouse under three temperature regimes: control (T1), moderate (T2) and extreme heat stress (T3). Reproductive traits (flower and fruit number and fruit set) were used to define heat tolerance. In a first screening, heat tolerance was evaluated in 219 tomato accessions. A total of 51 accessions were identified as being potentially heat tolerant. Among those, 28 accessions, together with 10 accessions from Italy (7) and Bulgaria (3), selected for their heat tolerance in the field in parallel experiments, were re-evaluated at three temperature treatments. Sixteen tomato accessions showed a significant heat tolerance at T3, including five wild species, two traditional cultivars and four commercial varieties, one accession from Bulgaria and four from Italy. The 15 most promising accessions for heat tolerance were assayed in field trials in Italy and Bulgaria, confirming the good performance of most of them at high temperatures. Finally, a differential gene expression analysis in pre-anthesis (ovary) and post-anthesis (developing fruit) under heat stress among pairs of contrasting genotypes (tolerant and sensitive from traditional and modern groups) showed that the major differential responses were produced in post-anthesis fruit. The response of the sensitive genotypes included the induction of HSP genes, whereas the tolerant genotype response included the induction of genes involved in the regulation of hormones or enzymes such as abscisic acid and transferases. Conclusions: The high temperature tolerance of fifteen tomato accessions observed in controlled greenhouse experiments were confirmed in agronomic field experiments providing new sources of heat tolerance that could be incorporated into breeding programs. A DEG analysis showed the complex response of tomato to heat and deciphered the different mechanisms activated in sensitive and tolerant tomato accessions under heat stress
Incidence of chromosome numerical changes in multiple myeloma: fluorescence in situ hybridization analysis using 15 chromosome-specific probes
Fue el primer trabajo precursor de los estudios con FISH en pacientes con Mieloma múltiple continuando la exitosa línea de investigación en mieloma del grupo de Salamanca, y por añadidura, del Grupo español de mieloma. La metodología FISH es hoy en día la principal herramienta de pronóstico en mieloma múltiple en todo el mundo.[EN]The presence of complex karotypes with frequent numerical and structural abnormalities has been reported in 20 to 50% of multiple myeloma (MM) patients. This variability is mainly due to the difficulty of conventional cytogenetics to obtain tumor metaphases representative of all possible neoplastic clones in MM. To gain insight into the real incidence of numerical chromosome changes in MM we have studied by fluorescence in situ hybridization technique 15 different human chromosomes, 1, 3, 6, 7, 8, 9, 10, 11, 12, 13, 15, 17, 18, X, and Y, in a series of 52 MM patients. In all cases, the DNA index assessed by a propidium iodide/CD38 double-staining technique with flow cytometry was simultaneously investigated for correlation, with fluorescence in situ hybridization results. Additional aims of this study were 1) to analyze whether the abnormalities detected were common to all plasma cells or were present in only a subpopulation of tumor cells, 2) to explore changes caused by disease progression, and 3) to establish possible associations among the altered chromosomes. Although the overall incidence of numerical abnormalities was 67%, this frequency increased to 80% in the 41 cases in which 7 or more chromosomes were analyzed. Trisomies were significantly more common than monosomies (84% versus 16%). Chromosomes 9 and 15 were the most frequently altered (52% and 48% of cases, respectively), with all of their abnormalities corresponding to trisomies. The most frequent losses involved chromosomes 13 (26%) and X in females (32%). Other common numerical changes corresponded to chromosomes 1 (39%), 11 (37%), 6 (32%), 3 (31%), 18 (29%), 7 (28%), and 17 (22%). By contrast, chromosomes 8(13%), 10(8%), and 12(3%) were rarely altered. DNA aneuploidy by flow cytometry was detected in 67% of patients, and a high degree of correlation was observed between the DNA index obtained by flow cytometry and the chromosome index derived from fluorescence in situ hybridization studies, calculated according to two mathematical formulas (coefficient of correlation of 0.82 and 0.91 when at least 7 or 12 chromosomes were considered, respectively). The frequency of numeric chromosome aberrations was higher in those patients with progressive disease and, interestingly, trisomy of chromosome 8 was exclusively detected in this latter group of patients. Our study shows that, with the exception of chromosome 8, a possible marker of clonal evolution, the numeric chromosome changes are present in nearly all malignant plasma cells (r > 0.84). Finally, frequent associations between chromosomal aberrations were observed (ie, chromosomes 6, 7, 9, and 17; 7 and 15; and 11 and 17). By excluding them, it was found that two triple combinations of chromosome-specific probes, chromosomes 1 and 9 together with either chromosome 13 or 15, could be a useful marker for detection of residual disease, as it permits the identification of most MM patients displaying numerical changes.University Hosptial of Salamanca
Universidad de SalamancaHospital Universitario de Salamanc
Tamizaje en cáncer cervical: conocimiento de la utilidad y uso de citología cervical en México
OBJECTIVE: To identify and evaluate the predisposing factors regarding the utilization of the Pap smears in the population seen in the Cervical Cancer Screening Program in Mexico METHODS: A cross-sectional study was conducted from January 1997 through December 1998 in Mexico city. A questionnaire was applied to a total of 2,107 women of reproductive age who attended a family planning program and data was collected regarding the following topics: social-demographics, reproductive risk factors associated with cervical cancer, sexual behavior and partner history, birth control, knowledge about Pap smear' benefits, and its utilization. Statistic analysis was conducted using Student´s test and non-conditional multiple logistic regression model for determining significance. RESULTS: The predisposing factors were: knowledge about Pap smear's benefits (OR=6.00, CI 95% 4.70-7.67), history of using at least two birth control methods (OR=2.38, CI 95% 1.75-3.24), previous history of vaginal infection (OR=2.18, CI 95% 1.73-2.75), sexual partner's approval of gynecological examinations (OR=1.56, CI 95% 1.07-2.29). CONCLUSIONS: Educational programs on cancer prevention in this population should include the benefits of screening tests. Pap smears for Mexican women of reproductive age are mostly offered opportunely. The previous use of health services is a determinant factor for the utilization of the Cervical Cancer Screening Program. These results show the need to strengthen health promotion programs to women at high risk of cervical cancer and their sexual partners.OBJETIVO: Identificar y evaluar los factores que predisponen a la utilización de la prueba de Papanicolaou en la población que usa el servicio del Programa Nacional de Detección Oportuna de Cáncer en México. MÉTODOS: Se realizó un estudio del tipo transversal de enero de 1997 a diciembre de 1998, en la Ciudad de México; se incluyeron a 2.107 mujeres en edad reproductiva que acudieron a un servicio de planificación familiar, las cuáles respondieron a un cuestionario con preguntas sobre características: sociodemográficas, factores de riesgo reproductivo asociados a cáncer cervical, historia de vida sexual, uso de métodos anticonceptivos, conocimiento de la utilidad y utilización del Papanicolaou. Para el análisis de los datos se construyeron modelos multivariados de regresión logística no condicional. RESULTADOS: Los predisponentes de utilización del programa de detección oportuna de cáncer en esta población fueron: el conocimiento de la utilidad del Papanicolaou incrementó en seis veces más la posibilidad de utilización (IC 95% 4,70-7,67); el antecedente de utilización de dos o más métodos de planificación familiar (OR=2,38; IC 95% 1,75-3,24); el antecedente de historia de infección vaginal (OR=2,18; IC 95% 1,73-2,75), y la aceptación del esposo para la realización de exploraciones ginecológicas (OR=1,56; IC 95% 1,07-2,29). CONCLUSIONES: La implementación de programas educativos en la prevención de cáncer, deberán incluir la utilidad de las pruebas de detección. En México, en mujeres en edad reproductiva utilización de la prueba de Papanicolaou se ofrece predominantemente en forma oportunista, por lo que el antecedente de utilización de los Servicios de Salud es un determinante para la utilización del Programa de Detección Oportuna de Cáncer Cervical. Estos resultados muestran la necesidad de ampliar la promoción a la salud de este programa a las mujeres de alto riesgo, incluyendo a sus parejas sexuales
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