Mission design for LISA Pathfinder

Here we describe the mission design for SMART-2/LISA Pathfinder. The best trade-off between the requirements of a low-disturbance environment and communications distance is found to be a free-insertion Lissajous orbit around the first co-linear Lagrange point of the Sun-Earth system L1, 1.5x 10^6 km from Earth. In order to transfer SMART-2/LISA Pathfinder from a low Earth orbit, where it will be placed by a small launcher, the spacecraft carries out a number of apogee-raise manoeuvres, which ultimatively place it to a parabolic escape trajectory towards L1. The challenges of the design of a small mission are met, fulfilling the very demanding technology demonstration requirements without creating excessive requirements on the launch system or the ground segment.Comment: 7 pages, 6 figures, 5th International LISA Symposium, see http://www.landisoft.de/Markus-Landgra

Frameshift mutations in Fas, Apaf-1, and Bcl-10 in gastro-intestinal cancer of the microsatellite mutator phenotype

Dear Editor, in a letter to the editor in a recent issue of Cell Death and Differentiation, Abdel-Rahman et al1. reported the absence of mutations in the death pathways gene Fas (Apo-1/CD95) in colorectal carcinomas. From the absence of mutations in 24 colon cancers, 12 of which were classified as replication error positive (RER+), Abdel-Rahman et al1. concluded that such mutations confer no substantial growth advantage in colorectal carcinogenesis. In agreement with this report, we identified Fas mutations in only 10% of colon and gastric cancers of the microsatellite mutator phenotype (MMP), also denominated as RER or microsatellite instability (MSI). Mutations were also found in Apaf-1 and Bcl-10, two other genes involved in the cell death pathways. The mutations were detected in mononucleotide tracts within these three genes (Figure 1). The frequency of these frameshift mutations was low (Table 1) and they appeared to be heterozygous (Figure 2). However, considering the peculiar features of these tumors, we suggest that these frameshift mutations contribute to cancer progression by providing survival advantage

Unsupervised classification of children’s bodies using currents

Object classification according to their shape and size is of key importance in many scientific fields. This work focuses on the case where the size and shape of an object is characterized by a current. A current is a mathematical object which has been proved relevant to the modeling of geometrical data, like submanifolds, through integration of vector fields along them. As a consequence of the choice of a vector-valued reproducing kernel Hilbert space (RKHS) as a test space for integrating manifolds, it is possible to consider that shapes are embedded in this Hilbert Space. A vector-valued RKHS is a Hilbert space of vector fields; therefore, it is possible to compute a mean of shapes, or to calculate a distance between two manifolds. This embedding enables us to consider size-and-shape clustering algorithms. These algorithms are applied to a 3D database obtained from an anthropometric survey of the Spanish child population with a potential application to online sales of children’s wear

Photografted fluoropolymers as novel chromatographic supports for polymeric monolithic stationary phases

[EN] In this study, porous polymer monoliths were in situ synthesized in fluoropolymers tubing to prepare microbore HPLC columns. To ensure the formation of robust homogeneous polymer monoliths in these housing supports, the inner surface of fluoropolymer tubing was modified in a two-step photografting process. Raman spectroscopy and scanning electron microscopy (SEM) confirmed the successful modification of the inner poly(ethylene-co-tetrafluoroethylene) (ETFE) wall and the subsequent attachment of a monolith onto the wall. Poly(glycidyl methacrylate-co-divinylbenzene), poly(butyl methacrylate-co-ethyleneglycol dimethacrylate) and poly(styrene-co-divinylbenzene) monoliths were in situ synthesized by thermal polymerization within the confines of surface vinylized ETFE tubes. The resulting monoliths exhibited good permeability and mechanical stability (pressure resistance up to 9¿MPa). The chromatographic performance of these different monolithic columns was evaluated via the separation of alkyl benzenes and proteins in a conventional HPLC system.This work was supported by project PROMETEO/2016/145 (Conselleria d'Educacio, Investigacio, Cultura i Esport,Esport, Generalitat Valenciana, Spain). The authors also thank Dr. S. Laredo-Ortiz from the Atomic Spectroscopy section of the SCSIE (University of Valencia), for her help in Raman measurements.Catalá-Icardo, M.; Torres-Cartas, S.; Meseguer-Lloret, S.; Simó-Alfonso, E.; Herrero Martínez, J. (2018). Photografted fluoropolymers as novel chromatographic supports for polymeric monolithic stationary phases. Talanta. 187:216-222. doi:10.1016/j.talanta.2018.05.026S21622218

Recent Advances in Molecularly Imprinted Membranes for Sample Treatment and Separation

[EN] This review describes the recent advances from the past five years concerning the development and applications of molecularly imprinted membranes (MIMs) in the field of sample treatment and separation processes. After a short introduction, where the importance of these materials is highlighted, a description of key aspects of membrane separation followed by the strategies of preparation of these materials is described. The review continues with several analytical applications of these MIMs for sample preparation as well as for separation purposes covering pharmaceutical, food, and environmental areas. Finally, a discussion focused on possible future directions of these materials in extraction and separation field is also given.This work was supported by project RTI2018-095536-B-I00 (Ministry of Science, Innovation and Universities, Spain).Torres-Cartas, S.; Catalá-Icardo, M.; Meseguer-Lloret, S.; Simó-Alfonso, EF.; Herrero-Martínez, JM. (2020). Recent Advances in Molecularly Imprinted Membranes for Sample Treatment and Separation. Separations. 7(4):1-28. https://doi.org/10.3390/separations7040069S1287

Extraction and preconcentration of organophosphorus pesticides in water by using a polymethacrylate-based sorbent modified with magnetic nanoparticles

[EN] A polymethacrylate-based sorbent modified with magnetic nanoparticles (MNPs) has been synthesized and used as sorbent for solid-phase extraction (SPE) and magnetic solid-phase extraction (MSPE) of three organophosphorus pesticides (phosmet, pirimiphos-methyl, and chlorpyrifos) in water samples followed by high-performance liquid chromatography diode array detection. The sorbent was prepared from a glycidyl methacrylate-based polymer, modified with a silanizing agent, followed by immobilization of MNPs on the surface of the material. The sorbent was characterized by scanning electron microscopy and Fourier transform infrared spectroscopy. Comparative studies of this support were done both in conventional SPE cartridge and MSPE approach. Several extraction parameters (loading pH, elution solvent, eluting volume, and loading flow rate) were investigated in detail. Under optimal conditions, the proposed sorbent gave an excellent enrichment efficiency of analytes and detection limits between 0.01 and 0.25 μg L−1. The recoveries of organophosphorus pesticides in spiked water samples were in the range of 71 98%, and the developed sorbent showed a high reusability (up to 50 uses without losses in recovery). The proposed method was satisfactorily applied to the analysis of these pesticides in water samples from different sources.This work was supported by projects CTQ2014-52765-R (MINECO of Spain and FEDER) and PROMETEO/2016/145 (Conselleria de Educacion, Investigacion, Cultura y Deporte of Generalitat Valenciana, Spain).Meseguer-Lloret, S.; Torres-Cartas, S.; Catalá-Icardo, M.; Simó-Alfonso, EF.; Herrero-Martínez, JM. (2017). Extraction and preconcentration of organophosphorus pesticides in water by using a polymethacrylate-based sorbent modified with magnetic nanoparticles. 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Determination of 3,5,6-trichloro-2-pyridinol, phoxim and chlorpyrifos-methyl in water samples using a new pretreatment method coupled with high-performance liquid chromatography. J Sep Sci. 2016;38:4204–10.Báez ME, Rodríguez M, Lastra O, Contreras P. Solid phase extraction of organophosphorus, triazine, and triazole-derived pesticides from water samples. A critical study. J High Resolut Chrom. 1997;20:591–6.Rocha AA, Monteiro SH, Andrade GCRM, Vilca FZ, Tornisielo CL. Monitoring of pesticides residues in surface and subsurface waters, sediments and fish in center-pivot irrigation areas. J Braz Chem Soc. 2015;25(11):2269–78.Hadjmohammadi MR, Peyrovi M, Biparva P. Comparison of C18 silica and multi-walled carbon nanotubes as the adsorbents for the solid-phase extraction of Chlorpyrifos and Phosalone in water samples using HPLC. J Sep Sci. 2010;33:1044–51.Pelit L, Dizdas TN. Preparation and application of a polythiophene solid-phase microextraction fiber for the determination of endocrine-disruptor pesticides in well waters. J Sep Sci. 2013;36:3234–41.Ibrahim WAW, Nodeh HR, Aboul-Enein HY, Sanagi MM. Magnetic solid phase extraction based on modified ferum oxides for enrichment, preconcentration and isolation of pesticides and selected pollutants. Crit Rev Anal Chem. 2015;45:270–87.Li XS, Zhu GT, Luo YB, Yuan BF, Feng YQ. Synthesis and applications of functionalized magnetic materials in sample preparation. Trends Anal Chem. 2013;45:233–47.Maddah B, Shamsi J. Extraction and preconcentration of trace amounts of diazinon and fenitrothion from environmental water by magnetite octadecylsilane nanoparticles. J Chromatogr A. 2012;1256:40–5.Xie J, Liu T, Song G, Hu Y, Deng C. Simultaneous analysis of organophosphorus pesticides in water by magnetic solid phase extraction coupled with GC-MS. Chromatographia. 2013;76:535–40.Heidari H, Razmi H. Multiresponse optimization of magnetic solid phase extraction based on carbon coated Fe3O4 nanoparticles using desirability function approach for the determination of the organophosphorus pesticides in aquatic samples by HPLC-UV. Talanta. 2012;99:13–21.Yan S, Qi TT, Chen DW, Li Z, Li XJ, Pan SY. Magnetic solid-phase extraction based on magnetite/reduced graphene oxide nanoparticles for determination of trace isocarbophos residues in different matrices. J Chromatogr A. 2014;1347:30–8.Tavakoli M, Hajimahmoodi M, Shemirani F. Trace level monitoring of pesticides in water samples using fatty acid coated magnetic nanoparticles prior to GC-MS. Anal Methods. 2014;6:2988–97.Tang Q, Wang X, Yu F, Qiao X, Xu Z. Simultaneous determination of ten organophosphorus pesticide residues in fruits by gas chromatography coupled with magnetic separation. J Sep Sci. 2014;27:820–7.Shen H, Zhu Y, Wen X, Zhuang Y. Preparation of Fe3O4-C18 nano-magnetic composite materials and their cleanup properties for organophosphorous pesticides. Anal Bioanal Chem. 2007;387:2227–37.Bagheri H, Zandi O, Aghakhani A. Magnetic nanoparticle-based micro-solid phase extraction and GC–MS determination of oxadiargyl in aqueous samples. Chromatographia. 2011;74:483–8.Moravcova D, Rantamaki AH, Dusa F, Wiedmer SK. Monoliths in capillary electrochromatography and capillary liquid chromatography in conjunction with mass spectrometry. Electrophoresis. 2016;37(7–8):880–912.Nema T, Chan ECY, Ho PC. Applications of monolithic materials for sample preparation. J Pharm Biomed Anal. 2014;87:130–41.Vergara-Barberán M, Lerma-García MJ, Simó-Alfonso EF, Herrero-Martínez JM. Solid-phase extraction based on ground methacrylate monolith modified with gold nanoparticles for isolation of proteins. Anal Chim Acta. 2016;917:37–43.Vukoje ID, Dzunuzovic ES, Vodnik VV, Dimitrijevic S, Ahrenkiel SP, Nedeljkovic JM. Synthesis, characterization, and antimicrobial activity of poly(GMA-co-EGDMA) polymer decorated with silver nanoparticles. J Mater Sci. 2014;49:6838–44.Krenkova J, Foret F. Iron oxide nanoparticle coating of organic polymer-based monolithic columns for phosphopeptide enrichment. J Sep Sci. 2011;34(16–17):2106–12.Daou TJ, Begin-Colin S, Grenèche JM, Thomas F, Derory A, Bernhardt P, et al. Phosphate adsorption properties of magnetite-based nanoparticles. Chem Mater. 2007;19:4494–505.Mezenner NY, Bensmaili A. Kinetics and thermodynamic study of phosphate adsorption on iron hydroxide-eggshell waste. Chem Eng J. 2009;147:87–96.Yang C, Wang G, Lu Z, Sun J, Zhuang J, Yang W. Effect of ultrasonic treatment on dispersibility of Fe3O4 nanoparticles and synthesis of multi-core Fe3O4/SiO2 core/shell nanoparticles. J Mater Chem. 2005;15:4252–7.Carrasco-Correa EJ, Ramis-Ramos G, Herrero-Martínez JM. Methacrylate monolithic columns functionalized with epinephrine for capillary electrochromatography applications. J Chromatogr A. 2013;1298:61–7.Waldron RD. Infrared spectra of ferrites. Phys Rev. 1955;99:1727–35.Yamaura M, Camilo RL, Sampaio LC, Macedo MA, Nakamura M, Toma HE. Preparation and characterization of (3-aminopropyl)triethoxysilane-coated magnetite nanoparticles. J Magn Magn Mat. 2004;279:210–7.Jiang L, Sun W, Kim J. Preparation and characterization of ω-functionalized polystyrene–magnetite nanocomposites. Mater Chem Phys. 2007;101:291–6.Dallas P, Georgakilas V, Niarchos D, Komninou P, Kehagias T, Petridis D. Synthesis, characterization and thermal properties of polymer/magnetite nanocomposites. Nanotechnology. 2006;17:2046–53.Zhao XL, Shi YL, Wang T, Cai YQ, Jiang GB. Preparation of silica-magnetite nanoparticle mixed hemimicelle sorbents for extraction of several typical phenolic compounds from environmental water samples. 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Combining microfluidic paper-based platform and metal–organic frameworks in a single device for phenolic content assessment in fruits

A microfluidic paper-based device (µPAD) has been combined with metal–organic frameworks (MOFs) for total phenolic compounds (TPC) quantification in fruit samples for the first time. The performance of the µPAD, based upon the vertical flow approach, was enhanced in order to determine the TPC content with high accuracy in fruit samples. The method was based on the traditional Folin-Ciocalteu Index using gallic acid or oenotannin as reference phenolic compounds. This novel design and construction of the device are in agreement with the principles of Green Chemistry avoiding wax technology (lower toxicity). The analytical parameters that affect the colorimetric method (using digital imaging of the colored zone) performance were optimized including design, sample volume, and MOF amount. Then, the analytical features of the developed method were investigated such as dynamic range (1.6–30 mg L−1), limit of detection (0.5 mg L−1), and precision (RSD < 9%). Besides, the in-field analysis is achievable with a color stability up to 6 h after the loading process of the sample and storage stability for at least 15 days without performance losses (under vacuum at − 20 °C). Furthermore, the MOF ZIF-8@paper was characterized to study its composition and the successful combination. The feasibility of the proposed method was demonstrated by determining the TPC in 5 fruit samples using oenotannin as reference solute. The accuracy was validated by comparison of the data with the results obtained with the recommended protocol proposed by the International Organisation of Vine and Wine (OIV).info:eu-repo/semantics/publishedVersio

Genome-Wide DNA Methylation Analysis Identifies Novel Hypomethylated Non-Pericentromeric Genes with Potential Clinical Implications in ICF Syndrome

Introduction and Results Immunodeficiency, centromeric instability and facial anomalies syndrome (ICF) is a rare autosomal recessive disease, characterized by severe hypomethylation in pericentromeric regions of chromosomes (1, 16 and 9), marked immunodeficiency and facial anomalies. The majority of ICF patients present mutations in the DNMT3B gene, affecting the DNA methyltransferase activity of the protein. In the present study, we have used the Infinium 450K DNA methylation array to evaluate the methylation level of 450,000 CpGs in lymphoblastoid cell lines and untrasformed fibroblasts derived from ICF patients and healthy donors. Our results demonstrate that ICF-specific DNMT3B variants A603T/STP807ins and V699G/R54X cause global DNA hypomethylation compared to wild-type protein. We identified 181 novel differentially methylated positions (DMPs) including subtelomeric and intrachromosomic regions, outside the classical ICF-related pericentromeric hypomethylated positions. Interestingly, these sites were mainly located in intergenic regions and inside the CpG islands. Among the identified hypomethylated CpG-island associated genes, we confirmed the overexpression of three selected genes, BOLL, SYCP2 and NCRNA00221, in ICF compared to healthy controls, which are supposed to be expressed in germ line and silenced in somatic tissues. Conclusions In conclusion, this study contributes in clarifying the direct relationship between DNA methylation defect and gene expression impairment in ICF syndrome, identifying novel direct target genes of DNMT3B. A high percentage of the DMPs are located in the subtelomeric regions, indicating a specific role of DNMT3B in methylating these chromosomal sites. Therefore, we provide further evidence that hypomethylation in specific non-pericentromeric regions of chromosomes might be involved in the molecular pathogenesis of ICF syndrome. The detection of DNA hypomethylation at BOLL, SYCP2 and NCRNA00221 may pave the way for the development of specific clinical biomarkers with the aim to facilitate the identification of ICF patients

Continuation of the exponentially small transversality for the splitting of separatrices to a whiskered torus with silver ratio

We study the exponentially small splitting of invariant manifolds of whiskered (hyperbolic) tori with two fast frequencies in nearly-integrable Hamiltonian systems whose hyperbolic part is given by a pendulum. We consider a torus whose frequency ratio is the silver number $\Omega=\sqrt{2}-1$. We show that the Poincar\'e-Melnikov method can be applied to establish the existence of 4 transverse homoclinic orbits to the whiskered torus, and provide asymptotic estimates for the tranversality of the splitting whose dependence on the perturbation parameter $\varepsilon$ satisfies a periodicity property. We also prove the continuation of the transversality of the homoclinic orbits for all the sufficiently small values of $\varepsilon$, generalizing the results previously known for the golden number.Comment: 17 pages, 2 figure