702 research outputs found
Prokaryotic picoplankton distribution within the oxygen minimum zone of the central Mexican Pacific across environmental gradients
O picophytoplankton marinho tornou-se uma questão importante para compreender a ecologia global das formas fototróficas, devido à sua ampla distribuição e contribuição para a biomassa e a produtividade. Estudamos os pigmentos de abundância, distribuição e assinatura do picofitoplâncton procarionte Prochlorococcus e Synechococcus durante um cruzeiro oceanográfico no Pacífico central mexicano, uma zona mínima de oxigênio relativamente poco conhecida (OMZ) e o efeito de três gradientes ambientais. As abundâncias de Prochlorococcus e Synechococcus foram comparáveis às encontradas em outras áreas tropicais (0.17 to 30.37 X 104 células mL1, e 0.9 to 30.97 X 104 células mL-1, respectivamente). As abundâncias de Prochlorococcus atingiram o maior número em águas mais profundas, coincidindo frequentemente com a segunda intensidade de fluorescência in situ profunda (e clorofila a), em estações oceânicas, abaixo da nitratoclina, enquanto as abundâncias de Synechococcus foram maiores nas águas de subsuperficie e sua concentração máxima geralmente coincidiu com os máximos de subsuperficie de fluorescência in situ, com abundâncias ligeiramente mais altas nas estações costeiras. As análises estatísticas suportam significativamente esses resultados. A distribuição da divinil-clorofila a foi errática ao longo da coluna de água e coincidiu ocasionalmente com os máximos de fluorescência in situ profundos, enquanto que a distribuição da zeaxantina seguiu geralmente a da clorofila a e as abundâncias de Synechococcus e atingiu o pico. Estes resultados são semelhantes aos encontrados anteriormente na área de estudo e em zonas mais temperadas, e também à tendência geral na OMZ, mas confirmam que a clorofila profunda a maxima é atribuída a altas densidades de Prochlorococcus. Além disso, encontramos a abundância e distribuição de Prochlorococcus e Synechococcus fortemente conduzida pelos gradientes ambientais observados.Marine picophytoplankton has become an important issue to understand the global ecology of phototrophic forms, due to its wide distribution and contribution to biomass and productivity. We studied the abundance, distribution and signature pigments of the prokaryote picophytoplankters Prochlorococcus and Synechococcus during an oceanographic cruise (26 April to 7 May, 2011) in the central Mexican Pacific, a relatively poorlyknown oxygen minimum zone (OMZ), and the effect of three environmental gradients. Prochlorococcus and Synechococcus abundances were comparable with those found in other tropical areas (0.17 to 30.37 X 104 cells mL-1, and 0.9 to 30.97 X 104 cells mL-1, respectively). Prochlorococcus abundances reached highest numbers in deeper waters, often coinciding with the second deep in situ fluorescence (and chlorophyll α) maxima, at oceanic stations, below the nitratecline, whereas Synechococcus abundances were higher at subsurface waters and its concentration maxima usually coincided with the subsurface in situ fluorescence maxima, with slightly higher abundances in coastal stations. Statistical analyses support significantly these results. Distribution of divinyl-chlorophyll α was erratic along the water column and occasionally coincided with the deep in situ fluorescence maxima, whereas the distribution of zeaxanthin usually followed that of chlorophyll α and the abundances of Synechococcus, and peaked together. These results are similar to those previously found in the study area and in more temperate zones, and also to the general trend in OMZ, but confirm that the second deep chlorophyll α maxima are attributed to high Prochlorococcus densities. We additionally found the abundance and distribution of Prochlorococcus and Synechococcus strongly driven by the environmental gradients observed
Ultrashort pulse propagation through depressed-cladding channel waveguides in YAG crystal: Spatio-temporal characterization
[EN]Inscription of optical waveguides by direct femtosecond laser irradiation has become a very versatile tool for the development of integrated photonic devices, such as waveguide lasers, frequency converters or photonic lanterns, among many others. The potential application of such devices for the control and manipulation of ultrashort pulses requires the precise knowledge of the temporal distortions that may be induced in the pulse propagation. Currently, research in this topic is scarce, and to our knowledge there is no previous experimental study on the spatio-temporal characterization at the output of waveguides inscribed inside crystals. Here, we have firstly fabricated depressed-cladding waveguides with different modal behavior in YAG crystal by direct femtosecond laser irradiation. Then, we implemented an experimental method based on the fiber coupler assisted spectral interferometry technique, that allows obtaining: (1) the temporal dispersion of a pulse at the output of an inscribed waveguide and, (2) full spatio-spectral and spatio-temporal characterization of the output of single-mode and multi-mode waveguides. Our results suggest that the main contribution to the pulse dispersion is due to the material dispersion. Moreover, we found that multimodal waveguides may induce an appreciable inhomogeneity in the temporal features of the pulses that needs to be taken into account in the design of complex devices.This work was supported by Junta de Castilla y León (Project SA046U16 and SA287P18) and MINECO (Projects FIS2017-87970-R, EQC2018-004117-P). M.M.-V. acknowledges support from Junta de Castilla y León grant (No. SA046U16) and from Generalitat Valenciana, Spain, under project CDEIGENT/2018/024
Tumor testicular de saco vitelino con metástasis a pleura: primer caso reportado en la literatura
ResumenEl cáncer testicular es el tumor urológico maligno más común en hombres jóvenes. Más del 90% corresponden a tumores de células germinales. El objetivo del estudio es el reporte del primer caso de cáncer testicular de tumores de células germinales con metástasis a pleura.Paciente masculino de 21 años, inicia su padecimiento con dolor en hemitórax derecho; la radiografía de tórax presenta una radioopacidad en lóbulo medio de pulmón derecho y la tomografía de tórax detecta una masa intratorácica y extrapulmonar. La biopsia torácica guiada por ultrasonido muestra una masa sólida adosada a la pared torácica, con efecto de desplazamiento sobre la pleura, conocido como «efecto en cola de cometa». La biopsia fue positiva para lesión neoplásica maligna poco diferenciada de la pleura. A la exploración encontramos testículo derecho con tumoración en polo inferior el cual se corrobora por ultrasonido. Los marcadores tumorales solo con elevación de alfa-fetoproteína 295.87ng/dL y deshidrogenasa láctica en 2,380UI/L. En la tomografía de abdomen se identificó actividad ganglionar interaortocava. Realizamos orquiectomía radical derecha. Reporte patológico: tumor testicular de saco vitelino, pT1N2M1S2.En este caso se pudo comprobar que las metástasis fueron a nivel pleural, que lo ubica como una forma de diseminación excepcional.AbstractTesticular cancer is the most common malignant urologic tumor in young men. More than 90% are germ cell tumors. The aim of this study was to report the first case of germ cell tumor testicular cancer with metastasis to the pleura.A 21-year-old man had disease onset with pain in the right hemithorax. The chest x-ray showed radio-opacity in the middle lobe of the right lung. A chest tomography scan detected an intrathoracic and extrapulmonary mass. Ultrasound-guided thoracic biopsy revealed a solid mass attached to the thoracic wall, displaced over the pleura, known as the “comet tail effect”. The biopsy was positive for a poorly differentiated malignant neoplastic lesion of the pleura. Upon physical examination we encountered a right testis with a tumor at the lower pole; this was corroborated through ultrasound. In relation to tumor markers, only alpha-fetoprotein was elevated at 295.87ng/dl and lactate dehydrogenase at 2,380 IU/l. An abdominal tomography scan identified interaortocaval lymph node activity. We performed a right radical orchiectomy and the pathology report was testicular yolk sac tumor, pT1N2M1S2.In our patient, metastasis at the level of the pleura was confirmed, making this a case with an exceptional form of spread
Primary Hepatosplenic Large B-Cell Lymphoma: A Rare Aggressive Tumor
Diffuse large B-cell lymphoma is the most common form of lymphoma. It usually begins in the lymph nodes; up to 40% may have an extranodal presentation. According to a definition of primary extranodal lymphoma with presentation only in extranodal sites, there are reports of large B-cell lymphomas limited to liver or spleen as separate entities, and to date there have been only three documented cases of primary hepatosplenic presentation. This paper reports a fourth case. Due to a review of the literature and the clinical course of the case reported, we conclude that primary hepatosplenic large B-cell lymphoma has been found predominantly in females older than 60 years. The patients reported had <2 months of evolution prior to diagnosis, prominent B symptoms, splenomegaly in three and hepatomegaly in two, none with lymph node involvement. All had thrombocytopenia and abnormal liver function tests; three had anemia and elevated serum lactic dehydrogenase levels, two with hemophagocytosis in bone marrow. Because of the previously mentioned data, it can be stated that primary hepatosplenic lymphoma is an uncommon and aggressive form of disease that requires immediate recognition and treatment
A triple action CDK4/6-PI3K-BET inhibitor with augmented cancer cell cytotoxicity
National Institutes of Health GM125195, GM135671, CA192656, FD00511
Similarities between the lipid proile of Mexican patients with lupus and the general population
Premature cardiovascular events have been observed in systemic lupus erythematosus (SLE) patients, but the reason for this accelerated process is still debatable; although traditional risk factors are more prevalent in such patients than in the general population, the
do not seem to fully explain that enhanced risk. One of the most important conditions is a proatherogenic
lipid proile. There is not enough data about it in Mexican SLE patients. Objective: To establish the differences in the lipid proiles between Mexican patients with SLE and the general population. Material and methods: Observational, transversal, descriptive and comparative study, between SLE patients and age-sex-matched healthy volunteers. We performed a full lipid proile (by spectrophotometry) 14 hours of fast. The results obtained were analyzed by the statistical program
SPSS® Statistics version 17. Results: We studied the full lipid proiles of 138 subjects, 69 with a diagnosis of SLE and 69 agesex- matched healthy volunteers; 95.7% were females and 4.3% males. Average age was 30 years;
average body mass index (BMI) 25.96 ± 5.96 kg/m² in SLE patients and 26.72 ± 4.36 kg/m² in the control group (p = 0.396). Average of total cholesterol 156 mg/dl in the SLE patients and 169.4 mg/dl in the control group (p =0.028); average of low density lipoprotein (LDL) cholesterol 85.27 mg/dl in the SLE patients and 97.57 mg/dl in the control group (p = 0.023). Conclusions: We did not ind statistical differences in the lipid proiles among patients and healthy volunteers, which could explain increased cardiovascular morbidity and mortality observed
in SLE patient
La no realización del autoexamen de mama en Tunja, Colombia
Objective. To identify sociocultural and psychosocial factors that determine non realisation of Breast Self-Examination (BSE) in women resident in Tunja, Colombia. Materials and methods. A nested case-control study was carried with 218 cases and 225 controls. The sample was selected by statified random sample. Assessment was made of sociocultural factors, knowledge and BSE practice. Results. Mean age 32.9 years (SD = 9.44), 58.7% with steady partner, 42.4% work, 25.6% incomplete secondary, 23.5% smokers, 21.5% uses hormonal methods, 10.6% have a family history of breast carcinoma, 10.2% attend promotion and prevention programs, 7.2% have history of breast disease. The factors that were significantly associated with non-practice of the BSE were not having received information about BSE (OR = 14.08); non attendance at Promotion and Prevention programs (OR = 9.21), low levels of knowledge about breast cancer (OR = 8.96), BSE was not considered important (OR = 8.71); not having family support (OR = 3.18); not recognizing breastfeeding as a protective factor in breast cancer (OR = 2.46 ), no physical activity (OR = 2.38) not completed high school (OR = 1.94), not using contraception (OR = 2.27); not attending the review consultation BSE (OR = 1.97 ) subsidized or linked health-regime (OR = 1.77), less than 3 years use of planning methods (OR = 1.94), no record of abortion (OR = 1.92), not in work (OR = 1 , 47). Conclusion. We found risk factors that are susceptible to educational intervention which could substantially improve the cover of Health Promotion and Disease Prevention programs and adherence to the practice of BSE.Objetivo. Identificar factores socioculturales y psicosociales determinantes de no realización del auto examen de mamas (AEM) en mujeres residentes en Tunja, Colombia. Materiales y métodos. Un estudio anidado de casos y controles se llevó a cabo a partir de 218 casos y 225 controles. La muestra se seleccionó mediante muestreo aleatorio estratificado. Se evaluó sobre los factores socioculturales, el conocimiento y la práctica del AEM. Resultados. Edad promedio 32,9 años (SD=9,44); 58,7% con pareja estable; 42,4% trabaja; 25,6% secundaria incompleta; 23,5% fuma; 21,5% planifica con métodos hormonales; 10,6% tiene antecedentes familiares de carcinoma mamario; 10,2% asiste a programas de promoción y prevención; 7,2% antecedente de enfermedad mamaria. Los factores que se encontraron significativamente asociados con la no realización del AEM son: no haber recibido información (OR=14,08); no asistir a programas de prevención del cáncer de mamá (OR=9,21); bajo nivel de conocimientos sobre cáncer de mama (OR=8,96); no considerar importante AEM (OR=8,71); no contar con apoyo familiar (OR=3,18); no reconoce la lactancia como factor protector en cáncer de mama (OR=2,46); no realizar actividad física (OR=2,38); no haber terminado la secundaria (OR=1,94); no uso de anticoncepción (OR=2,27); no ha consultado sobre AEM (OR=1,97); régimen subsidiado o vinculado (OR=1,77); uso de métodos de planificación menor de 3 años (OR=1,94); no tener antecedente de aborto (OR=1,92); no trabajar (OR=1,47). Conclusión. Se encuentran factores de riesgo, susceptibles de intervención educativa, que podrían mejorar sustancialmente la cobertura de los programas de P y P y la adherencia a la práctica del AEM
Improving the sensitivity of Higgs boson searches in the golden channel
Leptonic decays of the Higgs boson in the ZZ* channel yield what is known as
the golden channel due to its clean signature and good total invariant mass
resolution. In addition, the full kinematic distribution of the decay products
can be reconstructed, which, nonetheless, is not taken into account in
traditional search strategy relying only on measurements of the total invariant
mass. In this work we implement a type of multivariate analysis known as the
matrix element method, which exploits differences in the full production and
decay matrix elements between the Higgs boson and the dominant irreducible
background from q bar{q} -> ZZ*. Analytic expressions of the differential
distributions for both the signal and the background are also presented. We
perform a study for the Large Hadron Collider at sqrt{s}=7 TeV for Higgs masses
between 175 and 350 GeV. We find that, with an integrated luminosity of 2.5
fb^-1 or higher, improvements in the order of 10 - 20 % could be obtained for
both discovery significance and exclusion limits in the high mass region, where
the differences in the angular correlations between signal and background are
most pronounced.Comment: 31 pages, 8 figures. v2: Minus signs in definitions of angles
corrected. Typos fixed. Reference added. Cosmetic changes to Figure 4.
Additional sentence added for clarificatio
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