| 11. |
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| 12. |
- Winkler, K, et al.
(författare)
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Repulsively bound atom pairs in an optical lattice.
- 2006
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 441:7095, s. 853-6
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Tidskriftsartikel (refereegranskat)abstract
- Throughout physics, stable composite objects are usually formed by way of attractive forces, which allow the constituents to lower their energy by binding together. Repulsive forces separate particles in free space. However, in a structured environment such as a periodic potential and in the absence of dissipation, stable composite objects can exist even for repulsive interactions. Here we report the observation of such an exotic bound state, which comprises a pair of ultracold rubidium atoms in an optical lattice. Consistent with our theoretical analysis, these repulsively bound pairs exhibit long lifetimes, even under conditions when they collide with one another. Signatures of the pairs are also recognized in the characteristic momentum distribution and through spectroscopic measurements. There is no analogue in traditional condensed matter systems of such repulsively bound pairs, owing to the presence of strong decay channels. Our results exemplify the strong correspondence between the optical lattice physics of ultracold bosonic atoms and the Bose-Hubbard model-a link that is vital for future applications of these systems to the study of strongly correlated condensed matter and to quantum information.
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| 13. |
- Bauer, K., et al.
(författare)
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Welcome message from the PADE chairs
- 2013
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Ingår i: Welcome message from the PADE chairs (Editorial). - : IEEE Computer Society. - 9781479905379 ; , s. lxi-lxii
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 14. |
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| 15. |
- Chang, Hong, et al.
(författare)
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Identification of a Bipolar Disorder Vulnerable Gene CHDH at 3p21.1.
- 2017
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Ingår i: Molecular neurobiology. - : Springer Science and Business Media LLC. - 1559-1182 .- 0893-7648. ; 54:7, s. 5166-5176
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Tidskriftsartikel (refereegranskat)abstract
- Genome-wide analysis (GWA) is an effective strategy to discover extreme effects surpassing genome-wide significant levels in studying complex disorders; however, when sample size is limited, the true effects may fail to achieve genome-wide significance. In such case, there may be authentic results among the pools of nominal candidates, and an alternative approach is to consider nominal candidates but are replicable across different samples. Here, we found that mRNA expression of the choline dehydrogenase gene (CHDH) was uniformly upregulated in the brains of bipolar disorder (BPD) patients compared with healthy controls across different studies. Follow-up genetic analyses of CHDH variants in multiple independent clinical datasets (including 11,564 cases and 17,686 controls) identified a risk SNP rs9836592 showing consistent associations with BPD (P meta=5.72×10(-4)), and the risk allele indicated an increased CHDH expression in multiple neuronal tissues (lowest P=6.70×10(-16)). These converging results may identify a nominal but true BPD susceptibility gene CHDH. Further exploratory analysis revealed suggestive associations of rs9836592 with childhood intelligence (P=0.044) and educational attainment (P=0.0039), a "proxy phenotype" of general cognitive abilities. Intriguingly, the CHDH gene is located at chromosome 3p21.1, a risk region implicated in previous BPD genome-wide association studies (GWAS), but CHDH is lying outside of the core GWAS linkage disequilibrium (LD) region, and our studied SNP rs9836592 is ∼1.2Mb 3' downstream of the previous GWAS loci (e.g., rs2251219) with no LD between them; thus, the association observed here is unlikely a reflection of previous GWAS signals. In summary, our results imply that CHDH may play a previously unknown role in the etiology of BPD and also highlight the informative value of integrating gene expression and genetic code in advancing our understanding of its biological basis.
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| 16. |
- Enfors, Sven-Olof, et al.
(författare)
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Physiological responses to mixing in large scale bioreactors
- 2001
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Ingår i: Journal of Biotechnology. - 0168-1656 .- 1873-4863. ; 85:2, s. 175-185
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Tidskriftsartikel (refereegranskat)abstract
- Escherichia coli fed-batch cultivations at 22 m(3) scale were compared to corresponding laboratory scale processes and cultivations using a scale-down reactor furnished with a high-glucose concentration zone to mimic the conditions in a feed zone of the large bioreactor. Formate accumulated in the large reactor, indicating the existence of oxygen limitation zones. It is suggested that the reduced biomass yield at large scale partly is due to repeated production/reassimilation of acetate from overflow metabolism and mixed acid fermentation products due to local moving zones with oxygen limitation. The conditions that generated mixed-acid fermentation in the scale-down reactor also induced a number of stress responses, monitored by analysis of mRNA of selected stress induced genes. The stress responses were relaxed when the cells returned to the substrate limited and oxygen sufficient compartment of the reactor. Corresponding analysis in the large reactor showed that the concentration of mRNA of four stress induced genes was lowest at the sampling port most distant from the feed zone. It is assumed that repeated induction/relaxation of stress responses in a large bioreactor may contribute to altered physiological properties of the cells grown in large-scale bioreactor. Flow cytometric analysis revealed reduced damage with respect to cytoplasmic membrane potential and integrity in cells grown in the dynamic environments of the large scale reactor and the scale-down reactor.
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| 17. |
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| 18. |
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| 19. |
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| 20. |
- Oppeneer, Peter M., et al.
(författare)
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A novel spectroscopy : X-ray magneto-optical spectroscopy of buried antiferromagnetic films-Theory and experiment
- 2002
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Ingår i: Highlights of the Leibniz-Institute Dresden. ; , s. 7-10
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Forskningsöversikt (populärvet., debatt m.m.)abstract
- X-ray magneto-optical (MO) spectroscopies have developed into extremelypowerful tools for the investigation of both fundamental and applied magnetism.In particular the x-ray magnetic circular dichroism (XMCD) has become widelyused during the last decade. A disadvantage of the XMCD and related techniquesis that these can be applied only to study ferromagnetic (FM) materials. Thereexists currently an increasing interest in antiferromagnetic (AFM) materialswhich call for different x-ray spectroscopic techniques. A novel, versatilemagneto-x-ray spectroscopy has been developed, that can be applied to AFM’s.This magneto-x-ray spectroscopy may be measured in reflection and is relatedto the x-ray Voigt effect and the x-ray magnetic linear dichroism (XMLD), whichboth involve a transmission geometry. Using the newly developed technique,element-selective x-ray MO spectra of AFM materials have been measured forthe first time in reflection. The XMLD-type reflection spectroscopy has beenapplied to buried AFM layers, which was demonstrated by spectra obtained fromexchange-biased microstructures of current technological importance: NiO/Coand NiMn/Co, containing the insulating AFM NiO, and the metallic AFM NiMn,respectively. The measured spectrum provides information about the exchangesplitd-density of states of the AFM atom.
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