Investigation of grain orientations of melt-textured HTSC with addition of uranium oxide, Y2O3 and Y2BaCuO5

Local grain orientations were studied in melt-textured YBCO samples processed with various amounts of depleted uranuim oxide (DU) and Y 2O3 by means of electron backscatter diffraction (EBSD) analysis. The addition of DU leads to the formation of Ucontaining nanoparticles (Y2Ba4CuUOx) with sizes of around 200 nm, embedded in the superconducting Y-123 matrix. The orientation of the Y 2BaCuO5 (Y-211) particles, which are also present in the YBCO bulk microstructure, is generally random as is the case in other melttextured Y-123 samples. The presence of Y-211 particles, however, also affects the orientation of the Y-123 matrix in these samples

An Effective Construction for Cut-And-Project Rhombus Tilings with Global n-Fold Rotational Symmetry

We give an explicit and effective construction for rhombus cut-and-project tilings with global n-fold rotational symmetry for any n. This construction is based on the dualization of regular n-fold multigrids. The main point is to prove the regularity of these multigrids, for this we use a result on trigonometric diophantine equations. A SageMath program that computes these tilings and outputs svg files is publicly available in [Lutfalla, 2021]

Trim17, novel E3 ubiquitin-ligase, initiates neuronal apoptosis

Accumulating data indicate that the ubiquitin-proteasome system controls apoptosis by regulating the level and the function of key regulatory proteins. In this study, we identified Trim17, a member of the TRIM/RBCC protein family, as one of the critical E3 ubiquitin ligases involved in the control of neuronal apoptosis upstream of mitochondria. We show that expression of Trim17 is increased both at the mRNA and protein level in several in vitro models of transcription-dependent neuronal apoptosis. Expression of Trim17 is controlled by the PI3K/Akt/GSK3 pathway in cerebellar granule neurons (CGN). Moreover, the Trim17 protein is expressed in vivo, in apoptotic neurons that naturally die during post-natal cerebellar development. Overexpression of active Trim17 in primary CGN was sufficient to induce the intrinsic pathway of apoptosis in survival conditions. This pro-apoptotic effect was abolished in Bax(-/-) neurons and depended on the E3 activity of Trim17 conferred by its RING domain. Furthermore, knock-down of endogenous Trim17 and overexpression of dominant-negative mutants of Trim17 blocked trophic factor withdrawal-induced apoptosis both in CGN and in sympathetic neurons. Collectively, our data are the first to assign a cellular function to Trim17 by showing that its E3 activity is both necessary and sufficient for the initiation of neuronal apoptosis. Cell Death and Differentiation (2010) 17, 1928-1941; doi: 10.1038/cdd.2010.73; published online 18 June 201

Polygonal corona limit on multigrid dual tilings

The growth pattern of an invasive cell-to-cell propagation (called the successive coronas) on the square grid is a tilted square. On the triangular and hexagonal grids, it is an hexagon. It is remarkable that, on the aperiodic structure of Penrose tilings, this cell-to-cell diffusion process tends to a regular decagon (at the limit). In this article we generalize this result to any regular multigrid dual tiling, by defining the characteristic polygon of a multigrid and its dual tiling. Exploiting this elegant duality allows to fully understand why such surprising phenomena, of seeing highly regular polygonal shapes emerge from aperiodic underlying structures, happen.Comment: 1 theorem, 13 figures, 19 pages, 17 references, 7 fundings aknowledge

Methotrexate Toxicity Induced Pancytopenia and Oral Ulcerations

Authors: Brooke McVaney, DO; Salim Lutfallah, MS3; Ashley Misky, DO; Najy Masri, MD Louisiana State University Internal Medicine, New Orleans, LA Case: A 65-year-old male presented to the emergency department with painful oral ulcerations for 10 days and a generalized rash for 6 days. His medical history was significant for coronary artery disease, seropositive rheumatoid arthritis on MTX, and paroxysmal atrial fibrillation. Vital signs were within normal limits upon presentation. On exam he was noted to have scattered petechiae with central erosions and excoriations to the bilateral upper and lower extremities, palms, back and trunk. He had oral mucosal lesions with punched out erosions and ulcers. His left dorsal hand had a large, hemorrhagic and yellow crusted plaque. His lab workup was significant for pancytopenia. The patient had been on MTX for four months and had undergone a dosage increase one month ago. He was initially on 15 mg weekly and had increased to 20 mg weekly approximately one month prior to presentation. The patient was incarcerated at the time, and it was discovered that he had been taking 40 mg of MTX weekly per infirmary records. The case was discussed with dermatology and it was determined that his presentation was consistent with MTX toxicity. Leucovorin rescue therapy was initiated in the hospital. Upon follow up one month after discharge, the patient had full count recovery and improvement in skin lesions. Discussion: We present a case of methotrexate toxicity presenting with skin lesions, oral ulcerations, and pancytopenia secondary to incorrect drug administration. Methotrexate (MTX) is a folic acid antagonist that is used for the treatment of rheumatologic and neoplastic diseases. It has both antiinflammatory and immunosuppressive effects. Common side effects associated with low-dose MTX use include nausea, stomatitis, elevated transaminases, cutaneous eruptions of the extremities, headache, fatigue, alopecia, fever, or macrocytosis. The typical dosage range for MTX when used for treatment of rheumatoid arthritis is 7.5-25 mg weekly, while our patient was taking 40 mg weekly. The most common causes of MTX toxicity include incorrect dosage, renal impairment leading to decreased excretion, or concomitant use of drugs that may inhibit excretion of MT

Geometrical Penrose Tilings are characterized by their 1-atlas

Rhombus Penrose tilings are tilings of the plane by two decorated rhombi such that the decoration match at the junction between two tiles (like in a jigsaw puzzle). In dynamical terms, they form a tiling space of finite type. If we remove the decorations, we get, by definition, a sofic tiling space that we here call geometrical Penrose tilings. Here, we show how to compute the patterns of a given size which appear in these tilings by two different method: one based on the substitutive structure of the Penrose tilings and the other on their definition by the cut and projection method. We use this to prove that the geometrical Penrose tilings are characterized by a small set of patterns called vertex-atlas, i.e., they form a tiling space of finite type. Though considered as folk, no complete proof of this result has been published, to our knowledge

Planar Rosa : a family of quasiperiodic substitution discrete plane tilings with 2n2n-fold rotational symmetry

We present Planar Rosa, a family of rhombus tilings with a $2n$-fold rotational symmetry that are generated by a primitive substitution and that are also discrete plane tilings, meaning that they are obtained as a projection of a higher dimensional discrete plane. The discrete plane condition is a relaxed version of the cut-and-project condition. We also prove that the Sub Rosa substitution tilings with $2n$-fold rotational symmetry defined by Kari and Rissanen do not satisfy even the weaker discrete plane condition. We prove these results for all even $n\geq 4$. This completes our previously published results for odd values of $n$

Substitution discrete plane tilings with 2n2n-fold rotational symmetry for odd n

We study substitution tilings that are also discrete plane tilings, that is, satisfy a relaxed version of cut-and-projection. We prove that the Sub Rosa substitution tilings with a 2n-fold rotational symmetry for odd n greater than 5 defined by Kari and Rissanen are not discrete planes, and therefore not cut-and-project tilings either. We then define new Planar Rosa substitution tilings with a 2n-fold rotational symmetry for any odd n, and show that these satisfy the discrete plane condition. The tilings we consider are edge-to-edge rhombus tilings. We give an explicit construction for the 10-fold case, and provide a construction method for the general case of any odd n

Synthesis, antitubercular activity and mechanism of resistance of highly effective thiacetazone analogues

Defining the pharmacological target(s) of currently used drugs and developing new analogues with greater potency are both important aspects of the search for agents that are effective against drug-sensitive and drug-resistant Mycobacterium tuberculosis. Thiacetazone (TAC) is an anti-tubercular drug that was formerly used in conjunction with isoniazid, but removed from the antitubercular chemotherapeutic arsenal due to toxic side effects. However, several recent studies have linked the mechanisms of action of TAC to mycolic acid metabolism and TAC-derived analogues have shown increased potency against M. tuberculosis. To obtain new insights into the molecular mechanisms of TAC resistance, we isolated and analyzed 10 mutants of M. tuberculosis that were highly resistant to TAC. One strain was found to be mutated in the methyltransferase MmaA4 at Gly101, consistent with its lack of oxygenated mycolic acids. All remaining strains harbored missense mutations in either HadA (at Cys61) or HadC (at Val85, Lys157 or Thr123), which are components of the bhydroxyacyl-ACP dehydratase complex that participates in the mycolic acid elongation step. Separately, a library of 31 new TAC analogues was synthesized and evaluated against M. tuberculosis. Two of these compounds, 15 and 16, exhibited minimal inhibitory concentrations 10-fold lower than the parental molecule, and inhibited mycolic acid biosynthesis in a dose-dependent manner. Moreover, overexpression of HadAB HadBC or HadABC in M. tuberculosis led to high level resistance to these compounds, demonstrating that their mode of action is similar to that of TAC. In summary, this study uncovered new mutations associated with TAC resistance and also demonstrated that simple structural optimization of the TAC scaffold was possible and may lead to a new generation of TAC-derived drug candidates for the potential treatment of tuberculosis as mycolic acid inhibitors

Antiarrhythmic effect of human bone marrow-dereived CD271+ mesenchymal stem cells tested in vivo using a new infarction-re-infarction mouse model

This experiment showed the safety and antiarrhythmic effect of human bone marrow-derived CD271+ MSC. This was performed in immune deficient mice (Rag2-/-γc-/--mice) with electrocardiogram monitoring through Implantation of telemtry system. The induction of ventricular arrhythmias has been achieved via a permanent re-infarction through left anterior descending artery (LAD) ligation one week after a 30-minute ischemia-reperfusion. The time between 2 infarctions gave the stem cells the required period to entgraft themselves after their intramyocardial injection with the first infarction