63 research outputs found
Manipulating Fock states of a harmonic oscillator while preserving its linearity
We present a new scheme for controlling the quantum state of a harmonic
oscillator by coupling it to an anharmonic multilevel system (MLS) with first
to second excited state transition frequency on-resonance with the oscillator.
In this scheme that we call "ef-resonant", the spurious oscillator Kerr
non-linearity inherited from the MLS is very small, while its Fock states can
still be selectively addressed via an MLS transition at a frequency that
depends on the number of photons. We implement this concept in a circuit-QED
setup with a microwave 3D cavity (the oscillator, with frequency 6.4 GHz and
quality factor QO=2E-6) embedding a frequency tunable transmon qubit (the MLS).
We characterize the system spectroscopically and demonstrate selective
addressing of Fock states and a Kerr non-linearity below 350 Hz. At times much
longer than the transmon coherence times, a non-linear cavity response with
driving power is also observed and explained.Comment: 8 pages, 5 figure
A Systematic Review of Atypical Teratoid Rhabdoid Tumor in Adults
Background: Atypical teratoid/rhabdoid tumor in adults is a relatively rare malignant neoplasm. It is characterized by the presence of rhabdoid cells in combination with loss of either the INI1 or BRG1protein from the tumor cells.Methods: A systematic review was conducted using MEDLINE using the terms “atypical teratoid rhabdoid tumor” AND “adult.” The systematic review was supplemented with relevant articles from the references. Cases were included if the pathology was confirmed by loss of INI1 or BRG1. We included a case from our institution. The dataset was analyzed using descriptive statistics and log-rank test.Results: A total of 50 cases from 29 articles were included in this study. The average age at diagnosis was 36.7 years. The most common locations reported are the sellar region and cerebral hemispheres (without deep gray matter involvement). Of the 50 cases, 14 were reported to show evidence of dissemination. The average overall survival was 20 months. There was a significant difference in survival between the adjuvant therapy groups (p = < 0.0001).Conclusion: Atypical teratoid rhabdoid tumor of the central nervous system in adults is a rare neoplasm associated with a poor prognosis in a majority of patients. The treatment and clinical course are highly variable, and it remains unclear which factors impact prognosis
Protein Kinase CK2 Regulates Nerve/Glial Antigen (NG)2-Mediated Angiogenic Activity of Human Pericytes
Protein kinase CK2 is a crucial regulator of endothelial cell proliferation, migration and
sprouting during angiogenesis. However, it is still unknown whether this kinase additionally affects
the angiogenic activity of other vessel-associated cells. In this study, we investigated the effect of
CK2 inhibition on primary human pericytes. We found that CK2 inhibition reduces the expression of
nerve/glial antigen (NG)2, a crucial factor which is involved in angiogenic processes. Reporter gene
assays revealed a 114 bp transcriptional active region of the human NG2 promoter, whose activity
was decreased after CK2 inhibition. Functional analyses demonstrated that the pharmacological
inhibition of CK2 by CX-4945 suppresses pericyte proliferation, migration, spheroid sprouting and
the stabilization of endothelial tubes. Moreover, aortic rings of NG2−/− mice showed a significantly
reduced vascular sprouting when compared to rings of NG2+/+ mice, indicating that NG2 is an
important regulator of the angiogenic activity of pericytes. In vivo, implanted Matrigel plugs
containing CX-4945-treated pericytes exhibited a lower microvessel density when compared to
controls. These findings demonstrate that CK2 regulates the angiogenic activity of pericytes through
NG2 gene expression. Hence, the inhibition of CK2 represents a promising anti-angiogenic strategy,
because it does not only target endothelial cells, but also vessel-associated pericytes
Observation of the lowest energy gamma-ray in any superdeformed nucleus : 196Bi
New results on the superdeformed Bi nucleus a re reported. We have
observed with the EUROBALL IV -ray spectrometer array a superdeformed
trans ition of 124 keV which is the lowest observed energy -ray in any
superdeformed nucleus. We have de velopped microscopic cranked
Hartree-Fock-Bogoliubov calculations using the SLy4 effective force and a
realistic surface p airing which strongly support the
([651]1/2[752]5/2) assignment of this su
perdeformed band
A polyyne toxin produced by an antagonistic bacterium blinds and lyses a Chlamydomonad alga
Algae are key contributors to global carbon fixation and form the basis of many food webs. In nature, their growth is often supported or suppressed by microorganisms. The bacterium Pseudomonas protegens Pf-5 arrests the growth of the green unicellular alga Chlamydomonas reinhardtii, deflagellates the alga by the cyclic lipopeptide orfamide A, and alters its morphology [P. Aiyar et al., Nat. Commun. 8, 1756 (2017)]. Using a combination of Raman microspectroscopy, genome mining, and mutational analysis, we discovered a polyyne toxin, protegencin, which is secreted by P. protegens, penetrates the algal cells, and causes destruction of the carotenoids of their primitive visual system, the eyespot. Together with secreted orfamide A, protegencin thus prevents the phototactic behavior of C. reinhardtii. A mutant of P. protegens deficient in protegencin production does not affect growth or eyespot carotenoids of C. reinhardtii. Protegencin acts in a direct and destructive way by lysing and killing the algal cells. The toxic effect of protegencin is also observed in an eyeless mutant and with the colony-forming Chlorophyte alga Gonium pectorale. These data reveal a two-pronged molecular strategy involving a cyclic lipopeptide and a conjugated tetrayne used by bacteria to attack select Chlamydomonad algae. In conjunction with the bloom-forming activity of several chlorophytes and the presence of the protegencin gene cluster in over 50 different Pseudomonas genomes [A. J. Mullins et al., bioRxiv [Preprint] (2021). https://www.biorxiv.org/content/10.1101/2021.03.05.433886v1 (Accessed 17 April 2021)], these data are highly relevant to ecological interactions between Chlorophyte algae and Pseudomonadales bacteria
Improvement of islet transplantation by the fusion of islet cells with functional blood vessels
Pancreatic islet transplantation still represents a promising therapeutic strategy for curative treatment of type 1 diabetes mellitus. However, a limited number of organ donors and insufficient vascularization with islet engraftment failure restrict the successful transfer of this approach into clinical practice. To overcome these problems, we herein introduce a novel strategy for the generation of prevascularized islet organoids by the fusion of pancreatic islet cells with functional native microvessels. These insulin-secreting organoids exhibit a significantly higher angiogenic activity compared to freshly isolated islets, cultured islets, and non-prevascularized islet organoids. This is caused by paracrine signaling between the β-cells and the microvessels, mediated by insulin binding to its corresponding receptor on endothelial cells. In vivo, the prevascularized islet organoids are rapidly blood-perfused after transplantation by the interconnection of their autochthonous microvasculature with surrounding blood vessels. As a consequence, a lower number of islet grafts are required to restore normoglycemia in diabetic mice. Thus, prevascularized islet organoids may be used to improve the success rates of clinical islet transplantation
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