340 research outputs found

    Field Testing of a Two-Micron DIAL System for Profiling Atmospheric Carbon Dioxide

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    A 2-m DIAL system has been developed at NASA Langley Research Center through the NASA Instrument Incubator Program. The system utilizes a tunable 2-m pulsed laser and an IR phototransistor for the transmitter and the receiver, respectively. The system targets the CO2 absorption line R22 in the 2.05-m band. Field experiments were conducted at West Branch, Iowa, for evaluating the system for CO2 measurement by comparison with in-situ sensors. The CO2 in-situ sensors were located on the NOAA's WBI tower at 31, 99 and 379 m altitudes, besides the NOAA s aircraft was sampling at higher altitudes. Preliminary results demonstrated the capabilities of the DIAL system in profiling atmospheric CO2 using the 2-m wavelength. Results of these experiments will be presented and discussed

    A Developmental Switch of Gene Expression in the Barley Seed Mediated by HvVP1 (Viviparous-1) and HvGAMYB Interactions

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    The accumulation of storage compounds in the starchy endosperm of developing cereal seeds is highly regulated at the transcriptional level. These compounds, mainly starch and proteins, are hydrolyzed upon germination to allow seedling growth. The transcription factor HvGAMYB is a master activator both in the maturation phase of seed development and upon germination, acting in combination with other transcription factors. However, the precise mechanism controlling the switch from maturation to germination programs remains unclear. We report here the identification and molecular characterization of Hordeum vulgare VIVIPAROUS1 (HvVP1), orthologous to ABA-INSENSITIVE3 from Arabidopsis thaliana. HvVP1 transcripts accumulate in the endosperm and the embryo of developing seeds at early stages and in the embryo and aleurone of germinating seeds up to 24 h of imbibition. In transient expression assays, HvVP1 controls the activation of Hor2 and Amy6.4 promoters exerted by HvGAMYB. HvVP1 interacts with HvGAMYB in Saccharomyces cerevisiae and in the plant nuclei, hindering its interaction with other transcription factors involved in seed gene expression programs, like BPBF. Similarly, this interaction leads to a decrease in the DNA binding of HvGAMYB and the Barley Prolamine-Box binding Factor (BPBF) to their target sequences. Our results indicate that the HvVP1 expression pattern controls the full Hor2 expression activated by GAMYB and BPBF in the developing endosperm and the Amy6.4 activation in postgerminative reserve mobilization mediated by GAMYB. All these data demonstrate the participation of HvVP1 in antagonistic gene expression programs and support its central role as a gene expression switch during seed maturation and germination

    Prevalence and Distribution of High-Risk Genotypes of HPV in Women with Severe Cervical Lesions in Madrid, Spain: Importance of Detecting Genotype 16 and Other High-Risk Genotypes

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    Background. Persistent infection with high-risk human papillomavirus (HR-HPV) has been demonstrated to be the necessary causal factor for developing cervical cancer. To know the most prevalent HR-HPV in different geographical areas is important to design diagnostic tests and implementation of vaccines. Objectives. The goal of this study is to evaluate the prevalence of HR-HPV in a total of 1001 patients, 198 with normal cytology results, 498 with low-grade squamous intraepithelial lesion (LSIL), and 205 with high-grade squamous intraepithelial lesion (HSIL) who attended our gynaecology department for opportunistic screening of HPV infection. Study design. Cervical samples were taken in a PreservCyt vial (Cytyc Corporation, Boxborough, MA). Hybrid capture assay was carried out following the manufacturer's instructions (Digene Corp., Gaithersburg, MD). All samples were further studied with polymerase chain reaction (PCR) (Linear Array HPV Genotyping Test, Roche Diagnostics, Mannheim, Germany). Results. Genotype 16 was the most prevalent HR-HPV in the three groups, 17.8% in the patients with normal cytology results, 22.3% in the LSIL group, and 60% in the HSIL group. Genotype 18 had a very low prevalence in all groups. Other HR-HPV genotypes such as genotype 31, genotype 58 and genotype 52 were found in significant numbers in HSIL patients. Discussion. Our data show that genotypes 16, 31, 58, and 52 are the most prevalent HR-HPV in cervical samples with severe intraepithelial lesion in Spain. There may be some geographical variation in prevalence of carcinogenic types, and it must be considered for designing diagnostic tests and vaccine

    Prevalence and Distribution of High-Risk Genotypes of HPV in Women with Severe Cervical Lesions in Madrid, Spain: Importance of Detecting Genotype 16 and Other High-Risk Genotypes

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    Background. Persistent infection with high-risk human papillomavirus (HR-HPV) has been demonstrated to be the necessary causal factor for developing cervical cancer. To know the most prevalent HR-HPV in different geographical areas is important to design diagnostic tests and implementation of vaccines. Objectives. The goal of this study is to evaluate the prevalence of HR-HPV in a total of 1001 patients, 198 with normal cytology results, 498 with low-grade squamous intraepithelial lesion (LSIL), and 205 with high-grade squamous intraepithelial lesion (HSIL) who attended our gynaecology department for opportunistic screening of HPV infection. Study design. Cervical samples were taken in a PreservCyt vial (Cytyc Corporation, Boxborough, MA). Hybrid capture assay was carried out following the manufacturer's instructions (Digene Corp., Gaithersburg, MD). All samples were further studied with polymerase chain reaction (PCR) (Linear Array HPV Genotyping Test, Roche Diagnostics, Mannheim, Germany). Results. Genotype 16 was the most prevalent HR-HPV in the three groups, 17.8% in the patients with normal cytology results, 22.3% in the LSIL group, and 60% in the HSIL group. Genotype 18 had a very low prevalence in all groups. Other HR-HPV genotypes such as genotype 31, genotype 58 and genotype 52 were found in significant numbers in HSIL patients. Discussion. Our data show that genotypes 16, 31, 58, and 52 are the most prevalent HR-HPV in cervical samples with severe intraepithelial lesion in Spain. There may be some geographical variation in prevalence of carcinogenic types, and it must be considered for designing diagnostic tests and vaccine

    Influence of Salix babylonica and Leucaena leucocephala leaf extracts on ruminal fermentation characteristics, urinary purine derivative excretion and microbial protein synthesis of lambs

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    Extract of L. leucocephala or S. babylonica leaves was prepared as described before in Salem et al. (2011a). Briefly, leaves of each tree species were collected randomly from several young and mature trees during summer. Leaves (1.25 kg) were fresh chopped into 1 to 2 cm lengths and immediately extracted in 10 l of a solvent mixture containing 1 l of methanol, 1 l of ethanol and 8 l of distilled water. Extraction was at 25–301 C for 48–72 h in 20 l closed jars, followed by incubation at 391 C for 1 h, and then filtered. Filtrates were collected and stored at 41 C for further use. Plant extracts were weekly prepared. The 1:1 mixture extract was also prepared weekly by mixing the SB and LL extracts (0.5:0.5, vol:vol).Sixteen growing Katahdin Pelibuey lambs (2470.3 kg body weight) were used to study the effects of oral administration of extracts of Salix babylonica (SB) and Leucaena leucocephala (LL) leaves on ruminal pH, total and individual volatile fatty acids (VFA) and NH3-N concentrations, as well as ruminal protozoal counts, urinary purine derivatives (PD) excretion and estimated microbial protein synthesis. Lambs were fed a total mixed ration (TMR) containing 219 and 141 g kg 1 of CP and NDF, respectively. Four treatments (4 lambs/treatment) were Control (no extract added), SB (SB extract at 30 ml d 1), LL (LL extract at 30 ml d 1) and SBLL (mixture of SB at 15 ml d 1þLL at 15 ml d 1). Extracts were administered orally to each lamb before the morning meal daily. Measurements were on days 22 (P1), 43 (P2) and 63 (P3) of the experiment. Ruminal pH increased (P¼0.014) with SBLL extract and decreased with SB. The ratio of acetate to propionate was higher (P¼0.042) with SBLL compared to the control. Ruminal NH3-N concentration was not affected by extract administration (P¼0.309) or experimental period (P¼0.087). Protozoal counts were not affected (P¼0.489) by extract addition but decreased (Po0.001) in P3 compared with P1 and P2. Uric acid concentration increased (Po0.001) with individual extracts of SB and LL compared with the control or SBLL. Excretion of other purine derivatives (allantoin, xanthine, and hypoxanthine), creatinine and microbial protein synthesis were not changed (P40.05) by extracts administration. Overall, oral administration of S. babylonica and L. leucocephala extracts, or their 1:1 mixture, to lambs for 63 d had only minor effects on ruminal fermentation, urinary purine derivative excretion and microbial protein synthesis

    Hollow Gold Nanoparticles Produced by Femtosecond Laser Irradiation

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    [EN] Metallic hollow nanoparticles exhibit interesting optical properties that can be controlled by geometrical parameters. Irradiation with femtosecond laser pulses has emerged recently as a valuable tool for reshaping and size modification of plasmonic metal nanoparticles, thereby enabling the synthesis of nanostructures with unique morphologies. In this Letter, we use classical molecular dynamics simulations to investigate the solid-to-hollow conversion of gold nanoparticles upon femtosecond laser irradiation. Here, we suggest an efficient method for producing hollow nanoparticles under certain specific conditions, namely that the particles should be heated to a maximum temperature between 2500 and 3500 K, followed by a fast quenching to room temperature, with cooling rates lower than 120 ps. Therefore, we describe the experimental conditions for efficiently producing hollow nanoparticles, opening a broad range of possibilities for applications in key areas, such as energy storage and catalysis.This work has been funded by the Spanish Ministry of Science, Innovation and Universities (MICIU) (Grants RTI2018-095844-B-I00, PGC2018-096444-B-I00, and MAT2017-86659-R), the EUROfusion Consortium through Project ENR-IFE19.CCFE-01, and the Madrid Regional Government (Grants P2018/NMT-4389 and P2018/EMT-4437). A.P. is thankful for the support of FONDECYT under Grants 3190123 and 11180557, as well as from Financiamiento Basal para Centros Cientificos y Tecnologicos de Excelencia FB-0807. K.L. acknowledges the support of the Russian Science Foundation (Project 19-19-00683). The authors acknowledge the computer resources and technical assistance provided by the Centro de Supercomputacion y Visualizacion de Madrid (CeSViMa) and the supercomputing infrastructure of the NLHPC (ECM-02). This Letter is based upon work from COST Action TUMIEE (CA17126)Castro-Palacio, JC.; Ladutenko, K.; Prada, A.; Gonzalez-Rubio, G.; Diaz-Nunez, P.; Guerrero-Martinez, A.; Fernández De Córdoba, P.... (2020). Hollow Gold Nanoparticles Produced by Femtosecond Laser Irradiation. The Journal of Physical Chemistry Letters. 11(13):5108-5114. https://doi.org/10.1021/acs.jpclett.0c01233S51085114111

    Overexpression of CYB5R3 and NQO1, Two NAD\u3csup\u3e+\u3c/sup\u3e-Producing Enzymes, Mimics Aspects of Caloric Restriction

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    Calorie restriction (CR) is one of the most robust means to improve health and survival in model organisms. CR imposes a metabolic program that leads to increased stress resistance and delayed onset of chronic diseases, including cancer. In rodents, CR induces the upregulation of two NADH‐dehydrogenases, namely NAD(P)H:quinone oxidoreductase 1 (Nqo1) and cytochrome b5 reductase 3 (Cyb5r3), which provide electrons for energy metabolism. It has been proposed that this upregulation may be responsible for some of the beneficial effects of CR, and defects in their activity are linked to aging and several age‐associated diseases. However, it is unclear whether changes in metabolic homeostasis solely through upregulation of these NADH‐dehydrogenases have a positive impact on health and survival. We generated a mouse that overexpresses both metabolic enzymes leading to phenotypes that resemble aspects of CR including a modest increase in lifespan, greater physical performance, a decrease in chronic inflammation, and, importantly, protection against carcinogenesis, one of the main hallmarks of CR. Furthermore, these animals showed an enhancement of metabolic flexibility and a significant upregulation of the NAD+/sirtuin pathway. The results highlight the importance of these NAD+ producers for the promotion of health and extended lifespan

    Genetic variability in CYP3A4 and CYP3A5 in primary liver, gastric and colorectal cancer patients

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    <p>Abstract</p> <p>Background</p> <p>Drug-metabolizing enzymes play a role in chemical carcinogenesis through enzymatic activation of procarcinogens to biologically reactive metabolites. The role of gene polymorphisms of several cytochrome P450 enzymes in digestive cancer risk has been extensively investigated. However, the drug-metabolizing enzymes with the broader substrate specificity, CYP3A4 and CYP3A5, have not been analyzed so far. This study aims to examine associations between common CYP3A4 and CYP3A5 polymorphisms and digestive cancer risk.</p> <p>Methods</p> <p>CYP3A4 and CYP3A5 genotypes were determined in 574 individuals including 178 patients with primary liver cancer, 82 patients with gastric cancer, 151 patients with colorectal cancer, and 163 healthy individuals.</p> <p>Results</p> <p>The variant allele frequencies for patients with liver cancer, gastric cancer, colorectal cancer and healthy controls, respectively, were: <it>CYP3A4*1B</it>, 4.8 % (95% C.I. 2.6–7.0), 3.7 % (0.8–6.6) 4.3% (2.0–6.6) and 4.3% (2.1–6.5); <it>CYP3A5*3</it>, 91.8 % (93.0–97.4), 95.7% (92.6–98.8), 91.7% (88.6–94.8) and 90.8% (87.7–93.9). The association between <it>CYP3A4*1B </it>and <it>CYP3A5*3 </it>variant alleles did not significantly differ among patients and controls. No differences in genotypes, allele frequencies, or association between variant alleles were observed with regard to gender, age at diagnosis, tumour site or stage.</p> <p>Conclusion</p> <p>Common polymorphisms on <it>CYP3A4 </it>and <it>CYP3A5 </it>genes do not modify the risk of developing digestive cancers in Western Europe.</p
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