Virtual Black Holes from Generalized Uncertainty Principle and Proton Decay

We investigate the formation of virtual black holes in the context of generalized uncertainty principle (GUP), as a mediator for a proton decay process which is forbidden by the standard model. Then, we calculate the lower bounds of the GUP deformation parameter by the experimental bound on the half life of the proton.Comment: 13 pages, 1 figure. Minor typos corrected. Published in EP

Over-expression of pumpkin GA-oxidases in Arabidopsis thaliana

Gibberellins (GAs) form a complex family of diterpenoid compounds, some of which are potent endogenous regulators of plant growth and development. Pumpkin seeds contain GA-oxidases with unique catalytic properties resulting in GAs of unknown function for plant development. In order to understand their potential to achieve changes in GA levels and their role for plant development, we produced transgenic Arabidopsis expressing sense or antisense copies of pumpkin genes encoding GA-oxidases; CmGA7ox, CmGA3ox1, and CmGA2ox1 as well as sense copies of CmGA20ox1. Arabidopsis plants were transformed with the pumpkin genes downstream of a strong constitutive promoter cassette (E12-35S-Omega). The expression levels of pumpkin GA-oxidases were determined by competitive RT-PCR. Over-expression of CmGA7ox in Arabidopsis resulted in seedlings with elongated roots, taller plants that flower earlier and developed more siliques in long day. Similarly, over-expression of CmGA3ox1 resulted in elongated phenotypes and an increase in bioactive GA4, indicating that both enzymes catalyse limiting steps in the GA biosynthesis of Arabidopsis. In contrast, over-expression of CmGA20ox1 in Arabidopsis resulted in shorter hypocotyls and internodes, less siliques and flowering was delayed with reduced GA4 levels and increased levels of the inactive GA17 and GA25. Severe dwarfed plants were obtained by over-expressing CmGA2ox1 in Arabidopsis and associated with a decrease in the levels of bioactive GA4 and an increase inactive product GA34 in comparison to control plants. The phenotype of plants expressing antisense copies did not change compared to the wild type plants. Modifying GA-biosynthesis using this approach may be useful for controlling plant development in agricultural and horticultural important species.Gibberelline (GAs) bilden eine komplexe Familie von Diterpenverbindungen, von denen einige wirkungsvolle endogene Regulatoren des Wachstums und der Entwicklung von Pflanzen darstellen. Kürbissamen enthalten GA-Oxidasen mit einzigartigen katalytischen Eigenschaften, die zu Gibberellinen führen mit oft nicht bekannten Funktionen für die pflanzliche Entwicklung. Um ihren Einfluss auf eine Veränderung der GA Gehalte und ihre Rolle für die pflanzliche Entwicklung besser zu verstehen, haben wir transgene Arabidopsis Pflanzen hergestellt, die sense oder antisense Kopien von Kürbis GA-Oxidase kodierenden Genen exprimieren; die CmGA7ox, CmGA3ox1, und die CmGA2ox1, sowie sense Kopien von der CmGA20ox1. Die Arabidopsis Pflanzen wurden transformiert mit Kürbis Genen downstream einer starken konstitutiven Promotor Kassette (E12-35S-Omega). Die Expressionslevel der Kürbis GA-Oxidasen wurde mit Hilfe der kompetitiven RT-PCR bestimmt. Die Überexpression des CmGA7ox in Arabidopsis resultiere in Keimlingen mit verlängerten Wurzeln, in größere Pflanzen, die früher blühen, und mehr Schoten im Langtag bilden und die erhöhte GA Gehalte aufwiesen im Vergleich zu Wildtyp Pflanzen. Ähnlich bewirkte die Überexpression von CmGA3ox1 erhöhtes Wachstum und einen erhöhten bioaktiven GA4 Gehalt. Diese Ergebnisse deuten darauf hin, dass die von beiden Enzyme (CmGA7ox und CmGA3ox1) katalysierten Schritte limitierend in der GA-Biosynthese von Arabidopsis sind. Im Gegensatz dazu resultierte Überexpression von CmGA20ox1 in Pflanzen mit kürzeren Hypokotylen und Internodien, weniger Schoten und einer verzögerten Blütenbildung bei verringerten GA4 Gehalten und erhöhten Gehalten an inaktiven GA17 und GA25. Starkes Zwergwachstum wurde durch die Überexpression von CmGA2ox1 erzielt. Im Vergleich zu Kontrollpflanzen wurde bei diesen Pflanzen eine Abnahme von bioaktivem GA4 und eine Zunahme des Abbauproduktes GA34 festgestellt. Die Phänotypen von Pflanzen, die antisense Kopien exprimieren, veränderten sich nicht im Vergleich zu den Kontrollpflanzen. Die Veränderung der GA-Biosynthese durch die vorgestellten Strategien könnte nutzbringend zur Kontrolle der pflanzlichen Entwicklung bei landwirtschaftlichen und gärtnerisch bedeutsamen Spezies eingesetzt werden

Proton Decay and the Quantum Structure of Spacetime

Virtual black holes in noncommutative spacetime are investigated using coordinate coherent state formalism such that the event horizon of black hole is manipulated by smearing it with a Gaussian of width $\sqrt \theta$, where $\theta$ is the noncommutativity parameter. Proton lifetime, the main associated phenomenology of the noncommutative virtual black holes, has been studied: first in $4$ dimensional spacetime and then generalized to $D$ dimensions. The lifetime depends on $\theta$ and the number of spacetime dimensions such that it emphasizes on the measurement of proton lifetime as a potential probe for the micro-structure of spacetime.Comment: 8 pages, 4 figure

Bioactive Glass Nanoparticles as a New Delivery System for Sustained 5-Fluorouracil Release: Characterization and Evaluation of Drug Release Mechanism

Bioactive glass nanoparticles were synthesized and tested for the first time as a new delivery system for sustained 5-fluorouracil (5-FU) release. They were characterized by TEM, DTA, TGA, and FT-IR. The porosity % and specific surface area of glass nanoparticles were 85.59% and 378.36 m2/g, respectively. The in vitro bioactivity evaluation confirmed that bioactive glass disks prepared from these nanoparticles could induce hydroxyapatite layer over their surfaces in simulated body fluid. The in vitro drug release experiment indicated that glass nanoparticles could serve as long-term local delivery vehicles for sustained 5-FU release. The release profile of 5-FU showed an initial fast release stage followed by a second stage of slower release. The initial burst release of 5-FU in the first day was about 23% (28.92 mg·L−1) of the total amount of loaded 5-FU, while the final cumulative percentage of the 5-FU released after 32 days was about 45.6% (57.31 mg·L−1) of the total amount of loaded 5-FU. The application of different mathematical models indicated that 5-FU was released by diffusion controlled mechanism and suggested that its release rate was dependent on glass particles dissolution, changes of surface area as well as diameter of glass particles, and concentration of loaded drug

4-Chloro-2-(6-nitro-1H-benzimidazol-2-yl)phenol N,N-dimethyl­form­amide solvate

In the title compound, C13H8ClN3O3·C3H7NO, the benzimidazole and benzene rings make a dihedral angle of 0.63 (11)°. An intra­molecular O—H⋯N hydrogen bond generates an S(6) ring motif. The solvent mol­ecule is hydrogen-bonded to the benzimidazole mol­ecule by inter­molecular N—H⋯O and C—H⋯O hydrogen bonds, generating an R 1 2(7) ring motif. In the crystal, the mol­ecules are arranged into parallel layers perpendicular to the c axis and stabilized by weak π–π inter­actions [centroid–centroid distances in the range 3.4036 (18)–3.5878 (16) Å]

The Therapeutic Potential of Human Umbilical Cord Blood Hematopoietic Stem Cells in Cyclophosphamide-Induced Ovarian Dysfunction in Rats

Millions of young women are rendered sterile by chemotherapy-associated oocyte loss. Recently some studies linked stem-cell transplantations to a spontaneous and unexplained return of ovarian function in some women rendered prematurely menopausal by high-dose chemotherapy or irradiatio

2-[(E)-(3-Carb­oxy-4-hy­droxy­phen­yl)iminiometh­yl]-4-chloro­phenolate

The title Schiff base compound, C14H10ClNO4, has been synthesized by the reaction of 5-amino-2-hy­droxy­benzoic acid and 5-chloro-2-hy­droxy­benzaldehyde. The mol­ecule is a zwitterion in the crystal, with the phenolic hy­droxy group deprotonated and the imine N atom protonated. It adopts an E configuration about the central C=N double bond. The dihedral angle between the two benzene rings is 3.83 (7)°. Intra­molecular N—H⋯O and O—H⋯O hydrogen bonding generates S(6) ring motifs. In the crystal, mol­ecules are connected by inter­molecular O—H⋯O and C—H⋯Cl hydrogen bonds, forming a supra­molecular chain

N 2-(4-Chloro­benzyl­idene)-4-nitro­benzene-1,2-diamine

In the title compound, C13H10ClN3O2, the dihedral angle between the two benzene rings is 3.61 (6)°. In the crystal structure, mol­ecules are linked by weak inter­molecular C—H⋯O hydrogen bonds, forming layers parallel to the bc plane. Short inter­molecular Cl⋯Cl contacts [3.491 (1) Å] are also observed

catena-Poly[[[aqua­manganese(III)]-μ-(E)-5-bromo-N-[2-(5-bromo-2-oxidobenzyl­idene­amino)-4-nitro­phen­yl]-2-oxidobenzamidato] N,N-dimethyl­fomamide monosolvate]

The asymmetric unit of the title complex, {[Mn(C20H10Br2N3O5)(H2O)]·(CH3)2NCHO}n, consists of one MnIII ion, one (E)-5-bromo-N-[2-(5-bromo-2-oxidobenzyl­idene­amino)-4-nitro­phen­yl]-2-oxidobenzamidate ligand (Schiff base), one water mol­ecule and an N,N-dimethyl­formamide mol­ecule. The coordination geometry around the MnIII ion is a distorted octa­hedron, being surrounded by two O and two N atoms from the Schiff base, which are positioned in the equatorial plane. The water mol­ecule and the O atom of the carbonyl group from the adjacent MnIII complex are situated at the axial positions, leading to a polymeric chain along the c axis. In the crystal, the complex and N,N-dimethyl­formamide mol­ecules are connected via O—H⋯O, C—H⋯O and C—H⋯Br hydrogen bonds, forming a three-dimensional network