Two stochastic models for simulation of correlated random processes

Mathematical models for simulation of correlated stochastic processes with stationary Gaussian propertie

Palladium-Catalyzed Amination of Unprotected Five-Membered Heterocyclic Bromides

An efficient method for the palladium-catalyzed amination of unprotected bromoimidazoles and bromopyrazoles is presented. The transformation is facilitated by the use of our newly developed Pd precatalyst based on the bulky biarylphosphine ligand tBuBrettPhos (L4). The mild reaction conditions employed allow for the preparation of a broad scope of aminoimidazoles and aminopyrazoles in moderate to excellent yields.National Institutes of Health (U.S.) (Award GM58160)Astellas USA Foundation (Fellowship)Japan Society for the Promotion of Science (Young Scientist Research Fellowship

Hard x-ray photoemission spectroscopic investigation of palladium catalysts immobilized on a GaAs(001) surface

We present studies on the structure and chemical states of a catalyst developed by immobilizing palladium on S-terminated GaAs(001). Hard x-ray photoelectron spectroscopy (HX-PES) of core-level and valence band photoemission consistently indicates that the organopalladium molecules are reduced on the surface yielding Pd nanoparticles with a metallic nature. This finding is supported by high-resolution observations using scanning electron microscopy and backscattered electron image. HX-PES results also reveal that a portion of S atoms forming the S-termination is oxidized during the formation of Pd nanoparticles

Uniform resolvent and orthonormal Strichartz estimates for repulsive Hamiltonian

We consider the uniform resolvent and orthonormal Strichartz estimates for the Schrödinger operator. First we prove the Keel-Tao type theorem for the orthonormal Strichartz estimates, which means that the dispersive estimates yield the orthonormal Strichartz estimates for strongly continuous unitary groups. This result applies to many Schrödinger propagators which are difficult to treat by the smooth perturbation theory, for example, local-in-time estimates for the Schrödinger operator with unbounded electromagnetic potentials, the $(k, a)$-generalized Laguerre operators and global-in-time estimates for the Schrödinger operator with scaling critical magnetic potentials including the Aharonov-Bohm potentials. Next we observe mapping properties of resolvents for the repulsive Hamiltonian and apply to the orthonormal Strichartz estimates. We prove the Kato-Yajima type uniform resolvent estimates with logarithmic decaying weight functions. This is new even when without perturbations. The proof is dependent on the microlocal analysis and the Mourre theory. We also discuss mapping properties on the Schwartz class and the Lebesgue space

Re-engineering an alphoid-HAC-based vector to enable high-throughput analyses of gene function

Human artificial chromosome (HAC)-based vectors represent an alternative technology for gene delivery and expression with a potential to overcome the problems caused by the use of viral-based vectors. The recently developed alphoid(tetO)-HAC has an advantage over other HAC vectors because it can be easily eliminated from cells by inactivation of the HAC kinetochore via binding of tTS chromatin modifiers to its centromeric tetO sequences. This provides unique control for phenotypes induced by genes loaded into the alphoid(tetO)-HAC. However, inactivation of the HAC kinetochore requires transfection of cells by a retrovirus vector, a step that is potentially mutagenic. Here, we describe an approach to re-engineering the alphoid(tetO)-HAC that allows verification of phenotypic changes attributed to expression of genes from the HAC without a transfection step. In the new HAC vector, a tTS-EYFP cassette is inserted into a gene-loading site along with a gene of interest. Expression of the tTS generates a self-regulating fluctuating heterochromatin on the alphoid(tetO)-HAC that induces fast silencing of the genes on the HAC without significant effects on HAC segregation. This silencing of the HAC-encoded genes can be readily recovered by adding doxycycline. The newly modified alphoid(tetO)-HAC-based system has multiple applications in gene function studies

Classification of three generation models by orbifolding magnetized T2×T2T^2 \times T^2

We study orbifolding by the $\mathbb{Z}_2^{\rm (per)}$ permutaion of $T^2_1 \times T^2_2$ with magnetic fluxes and its twisted orbifolds. We classify the possible three generation models which lead to non-vanishing Yukawa couplings on the magnetized $T^2_1 \times T^2_2$ and orbifolds including the $\mathbb{Z}_2^{\rm (per)}$ permutation and $\mathbb{Z}_2^{\rm (t)}$ twist. We also study the modular symmetry on such orbifold models. As an illustrating model, we examine the realization of quark masses and mixing angles.Comment: 31 page

Repurposing HFC-125 to tetrafluoroethylene: A step toward a more sustainable fluoropolymer feedstock strategy

The urgency to reduce hydrofluorocarbon (HFC) emissions, particularly HFC-125 (pentafluoroethane, CF3CF2H), has driven efforts to develop sustainable alternatives. Herein, we present a method for converting HFC-125 into tetrafluoroethylene (TFE), an industrially valuable monomer for fluoropolymer production. Our approach uses potassium hexamethyldisilazide (KHMDS), optimizing reaction conditions at -50 °C to achieve high TFE yields without any observable byproducts. This low-temperature method offers a safer and more sustainable alternative to traditional high-temperature processes for TFE production, which involve hazardous byproducts and complex handling. We also demonstrated that various chemical reactions using freshly generated TFE, including thiol addition, trifluorovinylation, radical addition, amination, alcohol addition, and polymerization, can be performed, extending the utility of this approach. Moreover, a continuous flow process for the conversion of HFC-125 to TFE at room temperature was achieved without cryogenic equipment. This dual-purpose solution addresses both environmental sustainability of fluorochemicals and the growing demand for fluoropolymers in various industries

Spontaneous Extraskeletal Osteosarcoma in the Stomach of an Aged F344 Rat

Extraskeletal osteosarcoma is a very rare tumor in humans and animals including rats. This paper describes a case of extraskeletal osteosarcoma observed in the glandular stomach of an aged female Fischer 344 rat. Grossly, a whitish solid mass was observed at the greater curvature of the glandular stomach. Histologically, the tumor consisted of both atypical polygonal and pleomorphic spindle-shaped cells, with pleomorphic nuclei, and it contained variable amounts of osteoids and small clumps of mature bone tissue. In addition, mitotic figures were frequently observed. Neither invasion of the muscle layer or vessels in the stomach nor metastasis to distant organs was detected. There were no skeletal tumors in the body. Immunohistochemically, the tumor cells were positive for osteocalcin, osteonectin, vimentin and S-100 protein. Judging from these results, the present tumor was diagnosed as extraskeletal osteosarcoma. This is the first report of spontaneous extraskeletal osteosarcoma arising from the stomach in a rat