3,235 research outputs found

    Early Science with the Large Millimetre Telescope: Molecules in the Extreme Outflow of a proto-Planetary Nebula

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    Extremely high velocity emission likely related to jets is known to occur in some proto-Planetary Nebulae. However, the molecular complexity of this kinematic component is largely unknown. We observed the known extreme outflow from the proto-Planetary Nebula IRAS 16342-3814, a prototype water fountain, in the full frequency range from 73 to 111 GHz with the RSR receiver on the Large Millimetre Telescope. We detected the molecules SiO, HCN, SO, and 13^{13}CO. All molecular transitions, with the exception of the latter are detected for the first time in this source, and all present emission with velocities up to a few hundred km s−1^{-1}. IRAS 16342-3814 is therefore the only source of this kind presenting extreme outflow activity simultaneously in all these molecules, with SO and SiO emission showing the highest velocities found of these species in proto-Planetary Nebulae. To be confirmed is a tentative weak SO component with a FWHM ∼\sim 700 km s−1^{-1}. The extreme outflow gas consists of dense gas (nH2>_{\rm H_2} > 104.8^{4.8}--105.7^{5.7} cm−3^{-3}), with a mass larger than ∼\sim 0.02--0.15 M⊙_{\odot}. The relatively high abundances of SiO and SO may be an indication of an oxygen-rich extreme high velocity gas.Comment: Accepted for publication in Monthly Notices of the Royal Astronomical Society Letter

    Lindane and Endosulfan Sulfate Isomers in Crassostrea virginica (Gmelin, 1791) Oyster Populations in Lagoon Systems from Central Gulf of Mexico

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    The aim of this study was to determine Lindane and Endosulfan Sulfate isomers in Crassostrea virginica oyster populations (Gmelin, 1791) in the Mandinga and Alvarado lagoon systems located in the central Gulf of Mexico. Samples were taken from the main oyster banks of each lagoon system, during the three representative seasons of the region, wet, dry and north winds. By means of free diving, 30 commercial size oysters (7 ± 3 cm) were collected in four oyster banks or stations of the Mandinga lagoon system, totaling 360 organisms, while in the Alvarado lagoon system there were a total of 90 oysters during the annual cycle. Concentration of lindane and endosulfan sulfate isotopes in C. virginica was performed with a gas chromatograph (Thermo Electron Model Trace GC Ultra 115V, Thermo Fisher Scientific Inc©, Monterrey, Nuevo León, México) with an Electron capture detector. Results showed that in the Alvarado Lagoon system mean concentrations of C. virginica oysters for lindane pesticide were 4.11 ± 3.83 ng⋅g-1, whereas for the Mandinga lagoon system, were 8.69 ± 5.15 ng⋅g-1. Endosulfan sulfate showed the highest average concentration in the Mandinga lagoon system with 24.68 ± 1.20 ng ⋅g-1. In addition, the endosulfan sulfate presents differences in its spatial distribution; high concentration levels in the Mandinga lagoon system whereas the lindane heterogeneity at all sampling points in both lagoons. Values of concentrations and relationships between compounds suggest recent contributions that could correspond to the excessive fluctuations of water discharged into the lagoon caused by the atypical rains of the year of sampling. It was concluded that endosulfan sulfate and lindane show concentration in all the points of sampling in both lagoons

    Properties of iron-modified-by-silver supported on mordenite as catalysts for nox reduction

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    A series of mono and bimetallic catalysts based on a Fe-Ag mixture deposited on mordenite was prepared by ion-exchange and evaluated in the catalytic activity test of the de-NOx reaction in the presence of CO/C3H6. The activity results showed that the most active samples were the Fe-containing ones, and at high temperatures, a co-promoter effect of Ag on the activity of Fe catalysts was also observed. The influence of the order of cation deposition on catalysts formation and their physicochemical properties was studied by FTIR (Fourier Transform Infrared Spectroscopy) of adsorbed NO, XANES (X-ray Absorption Near-Edge Structure), and EXAFS (Extended X-ray Absorption Fine Structure) and discussed in terms of the state of iron. Results of Fe K-edge XANES oscillations showed that, in FeMOR catalysts, iron was present in a disordered state as Fe3+ and Fe2+. In FeAgMOR, the prevailing species was Fe3+, while in the AgFeMOR catalyst, the state of iron was intermediate or mixed between FeMOR and FeAgMOR. The Fe K-edge EXAFS results were characteristic of a disordered phase, the first coordination sphere being asymmetric with two different Fe-O distances. In FeAgMOR and AgFeMOR, coordination of Fe-O was similar to Fe2O3 with a few amount of Fe2+ species. We may conclude that, in the bimetallic FeAgMOR and AgFeMOR samples, a certain amount of tetrahedral Al3+ ions in the mordenite framework is replaced by Fe3+ ions, confirming the previous reports that these species are active sites for the de-NOx reaction. Based on the thermodynamic analysis and experimental data, also, it was confirmed that the order of deposition of the components influenced the mechanism of active sites’ formation during the two steps ion-exchange synthesis

    La Importancia de la logística, la distribución física nacional, con miras a potencializar la competitividad para la organizaciones

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    La gestión administrativa y contable se presenta a través de operaciones que se generan en la Distribución Físicas Internacional y se relacionan con la logística de las organizaciones y las naciones adquiere relevancia a partir de la economía de mercado y los TLC, Tratados de Libre Comercio, ya que una adecuado uso de DFI , permite el orden específico para la gestión de la movilidad y permite liderar costos en el aprovisionamiento, claves con una debida gestión haciendo énfasis en la documentación y el justo a tiempo, no es posible entonces sin el flujo adecuado de los materiales o la provisión que se desea enviar y el flujo de la información, si se tiene en cuenta lo anterior, los agentes y actores involucrados en la cadena logística, permitirán menores costos de operación y mayor calidad en cada servicio, manteniendo los clientes claves y llevando el proceso al cambio y mejora

    Role of KLHL3 and dietary K<sup>+</sup> in regulating KS-WNK1 expression

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    This is the author accepted manuscript. The final version is available from the American Physiological Society via the DOI in this recordThe physiological role of the shorter isoform of WNK1 that is exclusively expressed in the kidney (KS-WNK1), with particular abundance in the distal convoluted tubule, remains elusive. KS-WNK1 despite lacking the kinase domain, is nevertheless capable of stimulating the NaCl cotransporter (NCC), apparently through activation of WNK4. It has recently been shown that a less severe form of the Familial Hyperkalemic Hypertension featuring only hyperkalemia is caused by missense mutations in the WNK1 acidic domain that preferentially affect CUL3-KLHL3 E3-induced degradation of KS-WNK1, rather than that of the full-length WNK1 (L-WNK1). Here we show that L-WNK1 is indeed less impacted by the CUL3-KLHL3 E3 ligase complex compared to KS-WNK1. We demonstrate that the unique 30 amino acid amino N-terminal fragment of KS-WNK1 is essential for its activating effect on NCC and recognition by KLHL3. We identify specific amino acid residues in this region critical for the functional effect of KS-WNK1 and KLHL3 sensitivity. To further explore this, we generated KLHL3-R528H knock-in mice that mimic human mutations causing Familial Hyperkalemic Hypertension. These mice revealed that the KLHL3 mutation specifically increased expression of KS-WNK1 in the kidney. We also observed that in wild type mice, expression of KS-WNK1 is only detectable after exposure to low potassium diet. These findings provide new insights into the regulation and function of KS-WNK1 by the CUL3-KLHL3 complex in DCT and indicate that this pathway is regulated by dietary K+ levels.National Institutes of Health (NIH)Conacyt MexicoPAPIIT UNAML'OréalMedical Research Council (MRC

    Genomic adaptations to aquatic and aerial life in mayflies and the origin of insect wings

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    The evolution of winged insects revolutionized terrestrial ecosystems and led to the largest animal radiation on Earth. However, we still have an incomplete picture of the genomic changes that underlay this diversification. Mayflies, as one of the sister groups of all other winged insects, are key to understanding this radiation. Here, we describe the genome of the mayfly Cloeon dipterum and its gene expression throughout its aquatic and aerial life cycle and specific organs. We discover an expansion of odorant-binding-protein genes, some expressed specifically in breathing gills of aquatic nymphs, suggesting a novel sensory role for this organ. In contrast, flying adults use an enlarged opsin set in a sexually dimorphic manner, with some expressed only in males. Finally, we identify a set of wing-associated genes deeply conserved in the pterygote insects and find transcriptomic similarities between gills and wings, suggesting a common genetic program. Globally, this comprehensive genomic and transcriptomic study uncovers the genetic basis of key evolutionary adaptations in mayflies and winged insects

    HER2 expression in cervical cancer as a potential therapeutic target

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    BACKGROUND: Trastuzumab, a humanized monoclonal antibody against the HER2 receptor is currently being used in breast and other tumor types. Early studies have shown that a variable proportion of cervical carcinoma tumors overexpress the HER2 receptor as evaluated by diverse techniques and antibodies. Currently it is known that a tumor response to trastuzumab strongly correlates with the level of HER2 expression evaluated by the Hercep Test, thus, it seems desirable to evaluate the status of expression of this receptor using the FDA-approved Hercep Test and grading system to gain insight in the feasibility of using trastuzumab in cervical cancer patients. METHODS: We analyzed a series of cervical cancer cell lines, the primary tumors of 35 cases of cervical cancer patients and four recurrent cases, with the Hercep Test in order to establish whether this tumor type overexpress HER2 at level of 2+/3+ as trastuzumab is currently approved for breast cancer having such level of expression. RESULTS: The results indicate that only 1 out of 35 primary tumors cases overexpress the receptor at this level, however, two out of four recurrent tumors that tested negative at diagnosis shifted to Hercep Test 2+ and 3+ respectively. CONCLUSIONS: The low frequency of expression in primary cases suggests that trastuzumab could have a limited value for the primary management of cervical cancer patients, however, the finding of "conversion" to Hercep Test 2+ and 3+ of recurrent tumors indicates the need to further evaluate the expression of HER2 in the metastatic and recurrent cases
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