272 research outputs found

    Self-trapping of a binary Bose-Einstein condensate induced by interspecies interaction

    Full text link
    The problem of self-trapping of a Bose-Einstein condensate (BEC) and a binary BEC in an optical lattice (OL) and double well (DW) is studied using the mean-field Gross-Pitaevskii equation. For both DW and OL, permanent self-trapping occurs in a window of the repulsive nonlinearity gg of the GP equation: gc1<g<gc2g_{c1}<g<g_{c2}. In case of OL, the critical nonlinearities gc1g_{c1} and gc2g_{c2} correspond to a window of chemical potentials μc1<μ<μc2\mu_{c1}<\mu<\mu_{c2} defining the band gap(s) of the periodic OL. The permanent self-trapped BEC in an OL usually represents a breathing oscillation of a stable stationary gap soliton. The permanent self-trapped BEC in a DW, on the other hand, is a dynamically stabilized state without any stationary counterpart. For a binary BEC with intraspecies nonlinearities outside this window of nonlinearity, a permanent self trapping can be induced by tuning the interspecies interaction such that the effective nonlinearities of the components fall in the above window

    A dipolar self-induced bosonic Josephson junction

    Full text link
    We propose a new scheme for observing Josephson oscillations and macroscopic quantum self-trapping phenomena in a toroidally confined Bose-Einstein condensate: a dipolar self-induced Josephson junction. Polarizing the atoms perpendicularly to the trap symmetry axis, an effective ring-shaped, double-well potential is achieved which is induced by the dipolar interaction. By numerically solving the three-dimensional time-dependent Gross-Pitaevskii equation we show that coherent tunneling phenomena such as Josephson oscillations and quantum self-trapping can take place. The dynamics in the self-induced junction can be qualitatively described by a two-mode model taking into account both s-wave and dipolar interactions.Comment: Major changes. Accepted for publication in EP

    Cyclopalladated Benzophenone Imines: Synthesis, Antitumor Activity, Cell Accumulation, DNA Interaction, and Cathepsin B Inhibition.

    Get PDF
    The synthesis of the endo five-membered cyclo-ortho-palladated benzophenone imines [Pd{C6H4(Ph)C═NR}]2(μ-X)2 [1 (X = OAc), 2 (X = Cl), a (R = phenyl), b (R = 1-naphthyl), c (R = benzyl), d (R = α-methylbenzyl)], and trans-N,P-[Pd{C6H4(Ph)C═NR}X(PPh3)] [3 (X = OAc), 4 (X = Cl), a (R = phenyl), b (R = 1-naphthyl), c (R = benzyl), d (R = α-methylbenzyl)] and the X-ray molecular structure of 1a, 1c, 1d, 4a, 4b, and 4c are reported. The antitumor activity, DNA interaction, and cathepsin B inhibition of palladium compounds a-d were studied and compared with those previously reported for palladium compounds e with R = H and compound 4f analogous to 4e but with a platinum(II) center. The IC50 values against a panel of human cancer cell lines allowed the establishment of a qualitative relationship between their structure and antitumor activity. Compounds 3e, 4e, and 4f were the most active ones in relation to their in vitro anticancer activity. Compounds 3e and 4e were about 4 times more active than cisplatin against the MDA-MB-231 and MCF-7 breast human cancer lines, and compound 4f was about 4 times more active than cisplatin against the cisplatin-resistant HCT-116 colon human cancer cell line. In addition, compound 3e was 3 times less cytotoxic than cisplatin toward the quiescent HUVEC cells. Accumulation of palladium compounds e and b in the MDA-MB-231 cell line was considerably greater than that of cisplatin in the same cell line, but palladium compounds b were noncytotoxic. Some of these complexes altered the DNA tertiary structure in a similar way to cisplatin but at higher concentration, and most cytotoxic ones did not present a high efficiency as cathepsin B inhibitors

    Tracing the Evolution of the Floral Homeotic B- and C-Function Genes through Genome Synteny

    Get PDF
    The evolution of the floral homeotic genes has been characterized using phylogenetic and functional studies. It is possible to enhance these studies by comparing gene content and order between species to determine the evolutionary history of the regulatory genes. Here, we use a synteny-based approach to trace the evolution of the floral B- and C-function genes that are required for specification of the reproductive organs. Consistent with previous phylogenetic studies, we show that the euAP3–TM6 split occurred after the monocots and dicots diverged. The Arabidopsis TM6 and papaya euAP3 genes are absent from the respective genomes, and we have detected loci from which these genes were lost. These data indicate that either the TM6 or the euAP3 lineage genes can be lost without detriment to flower development. In contrast, PI is essential for male reproductive organ development; yet, contrary to predictions, complex genomic rearrangements have resulted in almost complete breakdown of synteny at the PI locus. In addition to showing the evolution of B-function genes through the prediction of ancestral loci, similar reconstructions reveal the origins of the C-function AG and PLE lineages in dicots, and show the shared ancestry with the monocot C-function genes. During our studies, we found that transposable elements (TEs) present in sequenced Antirrhinum genomic clones limited comparative studies. A pilot survey of the Antirrhinum data revealed that gene-rich regions contain an unusually high degree of TEs of very varied types, which will be an important consideration for future genome sequencing efforts

    Requirement of CHROMOMETHYLASE3 for somatic inheritance of the spontaneous tomato epimutation Colourless non-ripening

    Get PDF
    Naturally-occurring epimutants are rare and have mainly been described in plants. However how these mutants maintain their epigenetic marks and how they are inherited remain unknown. Here we report that CHROMOMETHYLASE3 (SlCMT3) and other methyltransferases are required for maintenance of a spontaneous epimutation and its cognate Colourless non-ripening (Cnr) phenotype in tomato. We screened a series of DNA methylation-related genes that could rescue the hypermethylated Cnr mutant. Silencing of the developmentally-regulated SlCMT3 gene results in increased expression of LeSPL-CNR, the gene encodes the SBP-box transcription factor residing at the Cnr locus and triggers Cnr fruits to ripen normally. Expression of other key ripening-genes was also up-regulated. Targeted and whole-genome bisulfite sequencing showed that the induced ripening of Cnr fruits is associated with reduction of methylation at CHG sites in a 286-bp region of the LeSPL-CNR promoter, and a decrease of DNA methylation in differentially-methylated regions associated with the LeMADS-RIN binding sites. Our results indicate that there is likely a concerted effect of different ethyltransferases at the Cnr locus and the plant-specific SlCMT3 is essential for sustaining Cnr epi-allele. Maintenance of DNA methylation dynamics is critical for the somatic stability of Cnr epimutation and for the inheritance of tomato non-ripening phenotype

    Genetic polymorphisms located in genes related to immune and inflammatory processes are associated with end-stage renal disease: a preliminary study

    Get PDF
    Background Chronic kidney disease progression has been linked to pro-inflammatory cytokines and markers of inflammation. These markers are also elevated in end-stage renal disease (ESRD), which constitutes a serious public health problem. Objective To investigate whether single nucleotide polymorphisms (SNPs) located in genes related to immune and inflammatory processes, could be associated with ESRD development. Design and methods A retrospective case-control study was carried out on 276 patients with ESRD and 288 control subjects. Forty-eight SNPs were genotyped via SNPlex platform. Logistic regression was used to assess the relationship between each sigle polymorphism and the development of ESRD. Results Four polymorphisms showed association with ESRD: rs1801275 in the interleukin 4 receptor (IL4R) gene (OR: 0.66 (95%CI=0.46-0.95); p=0.025; overdominant model), rs4586 in chemokine (C-C motif) ligand 2 (CCL2) gene (OR: 0.70 (95%CI=0.54-0.90); p=0.005; additive model), rs301640 located in an intergenic binding site for signal transducer and activator of transcription 4 (STAT4) (OR: 1.82 (95%CI=1.17-2.83); p=0.006; additive model) and rs7830 in the nitric oxide synthase 3 (NOS3) gene (OR: 1.31 (95%CI=1.01-1.71); p=0.043; additive model). After adjusting for multiple testing, results lost significance. Conclusion Our preliminary data suggest that four genetic polymorphisms located in genes related to inflammation and immune processes could help to predict the risk of developing ESRD.This work was supported by grants from Instituto de Salud Carlos III (Ref: PI08/0738 and PI11/00245) to SR and Junta de Castilla y Leon (Ref: GRS 234/A/08) to ET. MAJS is supported by a grant from Instituto de Salud Carlos III (CM10/00105).Jimenez-Sousa, MA.; López, E.; Fernandez-Rodriguez, A.; Tamayo, E.; Fernández-Navarro, P.; Segura Roda, L.; Heredia, M.... (2012). Genetic polymorphisms located in genes related to immune and inflammatory processes are associated with end-stage renal disease: a preliminary study. BMC Medical Genetics. 13(58):1-6. https://doi.org/10.1186/1471-2350-13-58S161358Otero A, de Francisco A, Gayoso P, Garcia F: Prevalence of chronic renal disease in Spain: results of the EPIRCE study. Nefrologia. 2010, 30 (1): 78-86.Kottgen A: Genome-wide association studies in nephrology research. Am J Kidney Dis. 2010, 56 (4): 743-758. 10.1053/j.ajkd.2010.05.018.Gansevoort RT, Matsushita K, van der Velde M, Astor BC, Woodward M, Levey AS, Jong PE, Coresh J, de Jong PE, El-Nahas M, et al: Lower estimated GFR and higher albuminuria are associated with adverse kidney outcomes in both general and high-risk populations. A collaborative meta-analysis of general and high-risk population cohorts. Kidney Int. 2011, 80 (1): 93-104. 10.1038/ki.2010.531.Reich HN, Gladman DD, Urowitz MB, Bargman JM, Hladunewich MA, Lou W, Fan SC, Su J, Herzenberg AM, Cattran DC, et al: Persistent proteinuria and dyslipidemia increase the risk of progressive chronic kidney disease in lupus erythematosus. Kidney Int. 2011, 9 (8): 914-920.Rao M, Wong C, Kanetsky P, Girndt M, Stenvinkel P, Reilly M, Raj DS: Cytokine gene polymorphism and progression of renal and cardiovascular diseases. Kidney Int. 2007, 72 (5): 549-556. 10.1038/sj.ki.5002391.Munshi R, Hsu C, Himmelfarb J: Advances in understanding ischemic acute kidney injury. BMC Med. 2011, 9 (1): 11-10.1186/1741-7015-9-11.Kottgen A, Pattaro C, Boger CA, Fuchsberger C, Olden M, Glazer NL, Parsa A, Gao X, Yang Q, Smith AV, et al: New loci associated with kidney function and chronic kidney disease. Nat Genet. 2010, 42 (5): 376-384. 10.1038/ng.568.Chambers JC, Zhang W, Lord GM, van der Harst P, Lawlor DA, Sehmi JS, Gale DP, Wass MN, Ahmadi KR, Bakker SJ, et al: Genetic loci influencing kidney function and chronic kidney disease. Nat Genet. 2010, 42 (5): 373-375. 10.1038/ng.566.Ribases M, Ramos-Quiroga JA, Sanchez-Mora C, Bosch R, Richarte V, Palomar G, Gastaminza X, Bielsa A, Arcos-Burgos M, Muenke M, et al: Contribution of LPHN3 to the genetic susceptibility to ADHD in adulthood: a replication study. Genes Brain Behav. 2010, 10 (2): 149-157.Sole X, Guino E, Valls J, Iniesta R, Moreno V: SNPStats: a web tool for the analysis of association studies. Bioinformatics. 2006, 22 (15): 1928-1929. 10.1093/bioinformatics/btl268.Fried L, Solomon C, Shlipak M, Seliger S, Stehman-Breen C, Bleyer AJ, Chaves P, Furberg C, Kuller L, Newman A: Inflammatory and prothrombotic markers and the progression of renal disease in elderly individuals. J Am Soc Nephrol. 2004, 15 (12): 3184-3191. 10.1097/01.ASN.0000146422.45434.35.Wolkow PP, Niewczas MA, Perkins B, Ficociello LH, Lipinski B, Warram JH, Krolewski AS: Association of urinary inflammatory markers and renal decline in microalbuminuric type 1 diabetics. J Am Soc Nephrol. 2008, 19 (4): 789-797. 10.1681/ASN.2007050556.Nakamura E, Megumi Y, Kobayashi T, Kamoto T, Ishitoya S, Terachi T, Tachibana M, Matsushiro H, Habuchi T, Kakehi Y, et al: Genetic polymorphisms of the interleukin-4 receptor alpha gene are associated with an increasing risk and a poor prognosis of sporadic renal cell carcinoma in a Japanese population. Clin Cancer Res. 2002, 8 (8): 2620-2625.Burgos PI, Causey ZL, Tamhane A, Kelley JM, Brown EE, Hughes LB, Danila MI, van Everdingen A, Conn DL, Jonas BL, et al: Association of IL4R single-nucleotide polymorphisms with rheumatoid nodules in African Americans with rheumatoid arthritis. Arthritis Res Ther. 2010, 12 (3): R75-10.1186/ar2994.Tachdjian R, Mathias C, Al Khatib S, Bryce PJ, Kim HS, Blaeser F, O'Connor BD, Rzymkiewicz D, Chen A, Holtzman MJ, et al: Pathogenicity of a disease-associated human IL-4 receptor allele in experimental asthma. J Exp Med. 2009, 206 (10): 2191-2204. 10.1084/jem.20091480.Zheng G, Wang Y, Xiang SH, Tay YC, Wu H, Watson D, Coombes J, Rangan GK, Alexander SI, Harris DC: DNA vaccination with CCL2 DNA modified by the addition of an adjuvant epitope protects against "nonimmune" toxic renal injury. J Am Soc Nephrol. 2006, 17 (2): 465-474. 10.1681/ASN.2005020164.Kang YS, Lee MH, Song HK, Ko GJ, Kwon OS, Lim TK, Kim SH, Han SY, Han KH, Lee JE, et al: CCR2 antagonism improves insulin resistance, lipid metabolism, and diabetic nephropathy in type 2 diabetic mice. Kidney Int. 2010, 78 (9): 883-894. 10.1038/ki.2010.263.Dai R, Ahmed SA: MicroRNA, a new paradigm for understanding immunoregulation, inflammation, and autoimmune diseases. Transl Res. 2011, 157 (4): 163-179. 10.1016/j.trsl.2011.01.007.Messeguer X, Escudero R, Farre D, Nunez O, Martinez J, Alba MM: PROMO: detection of known transcription regulatory elements using species-tailored searches. Bioinformatics. 2002, 18 (2): 333-334. 10.1093/bioinformatics/18.2.333.Farre D, Roset R, Huerta M, Adsuara JE, Rosello L, Alba MM, Messeguer X: Identification of patterns in biological sequences at the ALGGEN server: PROMO and MALGEN. Nucleic Acids Res. 2003, 31 (13): 3651-3653. 10.1093/nar/gkg605.Wei L, Vahedi G, Sun HW, Watford WT, Takatori H, Ramos HL, Takahashi H, Liang J, Gutierrez-Cruz G, Zang C, et al: Discrete roles of STAT4 and STAT6 transcription factors in tuning epigenetic modifications and transcription during T helper cell differentiation. Immunity. 2010, 32 (6): 840-851. 10.1016/j.immuni.2010.06.003.Nakayama T, Sato W, Kosugi T, Zhang L, Campbell-Thompson M, Yoshimura A, Croker BP, Johnson RJ, Nakagawa T: Endothelial injury due to eNOS deficiency accelerates the progression of chronic renal disease in the mouse. Am J Physiol Renal Physiol. 2009, 296 (2): F317-327.Webber JL, Tooze SA: New insights into the function of Atg9. FEBS Lett. 2010, 584 (7): 1319-1326. 10.1016/j.febslet.2010.01.020.Kullo IJ, Greene MT, Boerwinkle E, Chu J, Turner ST, Kardia SL: Association of polymorphisms in NOS3 with the ankle-brachial index in hypertensive adults. Atherosclerosis. 2008, 196 (2): 905-912. 10.1016/j.atherosclerosis.2007.02.008.Popov AF, Hinz J, Schulz EG, Schmitto JD, Wiese CH, Quintel M, Seipelt R, Schoendube FA: The eNOS 786C/T polymorphism in cardiac surgical patients with cardiopulmonary bypass is associated with renal dysfunction. Eur J Cardiothorac Surg. 2009, 36 (4): 651-656. 10.1016/j.ejcts.2009.04.049.Wang CH, Li F, Hiller S, Kim HS, Maeda N, Smithies O, Takahashi N: A modest decrease in endothelial NOS in mice comparable to that associated with human NOS3 variants exacerbates diabetic nephropathy. Proc Natl Acad Sci U S A. 2011, 108 (5): 2070-2075. 10.1073/pnas.1018766108.Desmet FO, Hamroun D, Lalande M, Collod-Beroud G, Claustres M, Beroud C: Human Splicing Finder: an online bioinformatics tool to predict splicing signals. Nucleic Acids Res. 2009, 37 (9): e67-10.1093/nar/gkp215.Sironi M, Menozzi G, Riva L, Cagliani R, Comi GP, Bresolin N, Giorda R, Pozzoli U: Silencer elements as possible inhibitors of pseudoexon splicing. Nucleic Acids Res. 2004, 32 (5): 1783-1791. 10.1093/nar/gkh341.Perneger TV: What's wrong with Bonferroni adjustments. BMJ. 1998, 316 (7139): 1236-1238. 10.1136/bmj.316.7139.1236.Sterne JA, Davey Smith G: Sifting the evidence-what's wrong with significance tests?. BMJ. 2001, 322 (7280): 226-231. 10.1136/bmj.322.7280.226

    A Built-In Mechanism to Mitigate the Spread of Insect-Resistance and Herbicide-Tolerance Transgenes into Weedy Rice Populations

    Get PDF
    BACKGROUND: The major challenge of cultivating genetically modified (GM) rice (Oryza sativa) at the commercial scale is to prevent the spread of transgenes from GM cultivated rice to its coexisting weedy rice (O. sativa f. spontanea). The strategic development of GM rice with a built-in control mechanism can mitigate transgene spread in weedy rice populations. METHODOLOGY/PRINCIPAL FINDINGS: An RNAi cassette suppressing the expression of the bentazon detoxifying enzyme CYP81A6 was constructed into the T-DNA which contained two tightly linked transgenes expressing the Bt insecticidal protein Cry1Ab and the glyphosate tolerant 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS), respectively. GM rice plants developed from this T-DNA were resistant to lepidopteran pests and tolerant to glyphosate, but sensitive to bentazon. The application of bentazon of 2000 mg/L at the rate of 40 mL/m(2), which is approximately the recommended dose for the field application to control common rice weeds, killed all F(2) plants containing the transgenes generated from the Crop-weed hybrids between a GM rice line (CGH-13) and two weedy rice strains (PI-63 and PI-1401). CONCLUSIONS/SIGNIFICANCE: Weedy rice plants containing transgenes from GM rice through gene flow can be selectively killed by the spray of bentazon when a non-GM rice variety is cultivated alternately in a few-year interval. The built-in control mechanism in combination of cropping management is likely to mitigate the spread of transgenes into weedy rice populations

    Regulation of the let-7a-3 Promoter by NF-κB

    Get PDF
    Changes in microRNA expression have been linked to a wide array of pathological states. However, little is known about the regulation of microRNA expression. The let-7 microRNA is a tumor suppressor that inhibits cellular proliferation and promotes differentiation, and is frequently lost in tumors. We investigated the transcriptional regulation of two let-7 family members, let-7a-3 and let-7b, which form a microRNA cluster and are located 864 bp apart on chromosome 22q13.31. Previous reports present conflicting data on the role of the NF-κB transcription factor in regulating let-7. We cloned three fragments upstream of the let-7a-3/let-7b miRNA genomic region into a plasmid containing a luciferase reporter gene. Ectopic expression of subunits of NF-κB (p50 or p65/RelA) significantly increased luciferase activity in HeLa, 293, 293T and 3T3 cells, indicating that the let-7a-3/let-7b promoter is highly responsive to NF-κB. Mutation of a putative NF-κB binding site at bp −833 reduced basal promoter activity and decreased promoter activity in the presence of p50 or p65 overexpression. Mutation of a second putative binding site, at bp −947 also decreased promoter activity basally and in response to p65 induction, indicating that both sites contribute to NF-κB responsiveness. While the levels of the endogenous primary let-7a and let-7b transcript were induced in response to NF-κB overexpression in 293T cells, the levels of fully processed, mature let-7a and let-7b miRNAs did not increase. Instead, levels of Lin-28B, a protein that blocks let-7 maturation, were induced by NF-κB. Increased Lin-28B levels could contribute to the lack of an increase in mature let-7a and let-7b. Our results suggest that the final biological outcome of NF-κB activation on let-7 expression may vary depending upon the cellular context. We discuss our results in the context of NF-κB activity in repressing self-renewal and promoting differentiation
    corecore