11 research outputs found
Controlling Ferromagnetic Easy Axis in a Layered MoS2 Single Crystal
We report the effective methods to induce weak ferromagnetism in pristine MoS2 persisting up to room temperature with the improved transport property, which would lead to new spintronics devices. The hydrogenation of MoS2 by heating at 300 degrees C for 1 h leads to the easy axis out of plane, while the irradiation of proton with a dose of 1 x 10(13) P/cm(2) leads to the easy axis in plane. The theoretical modeling supports such magnetic easy axes.open16
Controlling ferromagnetic easy axis in a layered MoS2 single crystal
We report the effective methods to induce weak ferromagnetism in pristine MoS2 persisting up to room temperature with the improved transport property, which would lead to new spintronics devices. The hydrogenation of MoS2 by heating at 300 degrees C for 1 h leads to the easy axis out of plane, while the irradiation of proton with a dose of 1 x 10(13) P/cm(2) leads to the easy axis in plane. The theoretical modeling supports such magnetic easy axes.open116160Nsciescopu
Homozygote CRIM1 variant is associated with thiopurine-induced neutropenia in leukemic patients with both wildtype NUDT15 and TPMT
Abstract
Background
NUDT15 and TPMT variants are strong genetic determinants of thiopurine-induced hematological toxicity that results in therapeutic failure in pediatric acute lymphoblastic leukemia (ALL). However, many patients with both wild-type (WT) NUDT15 and TPMT still suffer from thiopurine toxicity and therapeutic failure.
Methods
Whole-exome sequencing was done for discovery (N = 244) and replication (N = 76) cohorts. Age- and sex-adjusted multiple regression analyses of both WT patients were performed to identify (p < 0.01, N = 188 for discovery) and validate (p < 0.05, N = 52 for replication) candidate variants for the tolerated last-cycle 6-mercaptopurine (6-MP) dose intensity percentage (DIP). Both independent and additive effects of the candidate variants on well-known NUDT15 and TPMT were evaluated by multigene prediction models.
Results
Among the 12 candidate variants from the discovery phase, the rs3821169 variant of the gene encoding Cysteine-Rich Transmembrane BMP Regulator 1 (CRIM1) was successfully replicated (p < 0.05). It showed high interethnic variability with an impressively high allele frequency in East Asians (T = 0.255) compared to Africans (0.001), Americans (0.02), Europeans (0.009), and South Asians (0.05). Homozygote carriers of the CRIM1 rs3821169 variant (N = 12, 5%) showed significantly lower last-cycle 6-MP DIPs in the discovery, replication, and combined cohorts (p = 0.025, 0.013, and 0.001, respectively). The traditional two-gene model (NUDT15 and TPMT) for predicting 6-MP DIP < 25% was outperformed by the three-gene model that included CRIM1, in terms of the area under the receiver operating characteristic curve (0.734 vs. 0.665), prediction accuracy (0.759 vs. 0.756), sensitivity (0.636 vs. 0.523), positive predictive value (0.315 vs. 0.288), and negative predictive value (0.931 vs. 0.913).
Conclusions
The CRIM1 rs3821169 variant is suggested to be an independent and/or additive genetic determinant of thiopurine toxicity beyond NUDT15 and TPMT in pediatric ALL
Facile Tailoring of Contact Layer Characteristics of the Triboelectric Nanogenerator Based on Portable Imprinting Device
Renewable energy harvesting technologies have been actively studied in recent years for replacing rapidly depleting energies, such as coal and oil energy. Among these technologies, the triboelectric nanogenerator (TENG), which is operated by contact-electrification, is attracting close attention due to its high accessibility, light weight, high shape adaptability, and broad applications. The characteristics of the contact layer, where contact electrification phenomenon occurs, should be tailored to enhance the electrical output performance of TENG. In this study, a portable imprinting device is developed to fabricate TENG in one step by easily tailoring the characteristics of the polydimethylsiloxane (PDMS) contact layer, such as thickness and morphology of the surface structure. These characteristics are critical to determine the electrical output performance. All parts of the proposed device are 3D printed with high-strength polylactic acid. Thus, it has lightweight and easy customizable characteristics, which make the designed system portable. Furthermore, the finger tapping-driven TENG of tailored PDMS contact layer with microstructures is fabricated and easily generates 350 V of output voltage and 30 μA of output current with a simple finger tapping motion-related biomechanical energy
Hole doping effect of MoS2 via electron capture of He+ ion irradiation
Beyond the general purpose of noble gas ion sputtering, which is to achieve functional defect engineering of two-dimensional (2D) materials, we herein report another positive effect of low-energy (100 eV) He+ ion irradiation: converting n-type MoS2 to p-type by electron capture through the migration of the topmost S atoms. The electron capture ability via He+ ion irradiation is valid for supported bilayer MoS2; however, it is limited at supported monolayer MoS2 because the charges on the underlying substrates transfer into the monolayer under the current condition for He+ ion irradiation. Our technique provides a stable and universal method for converting n-type 2D transition metal dichalcogenides (TMDs) into p-type semiconductors in a controlled fashion using low-energy He+ ion irradiation.11Nsciescopu
Emetine Promotes von Hippel-Lindau-Independent Degradation of Hypoxia-Inducible Factor-2α in Clear Cell Renal Carcinoma
Inactivating mutations of the von Hippel-Lindau (VHL) tumor suppressor gene are associated with inherited VHL syndrome, which is characterized by susceptibility to a variety of neoplasms, including central nervous system hemangioblastoma and clear cell renal cell carcinoma (CCRCC). Mutations in the VHL gene are also found in the majority of sporadic clear cell renal carcinoma, the most common malignant neoplasm of the human kidney. Inactivation of VHL ubiquitin ligase is associated with normoxic stabilization of hypoxia-inducible factor-1α and 2-α (HIF-1α and HIF-2α), transcriptional regulators of tumor angiogenesis, invasion, survival, and glucose utilization. HIF-2α has been particularly implicated in the development of CCRCC. Although several inhibitors of HIF-1α have been described, these drugs typically have a minimal affect on HIF-2α. 786-O is a VHL-deficient CCRCC cell line that constitutively expresses only HIF-2α and is therefore suitable for the screening of novel HIF-2α inhibitors. Using this cell line, we have identified emetine as a specific inhibitor of HIF-2α protein stability and transcriptional activity. Without altering HIF-2α mRNA level, emetine rapidly and dramatically down-regulated HIF-2α protein expression in 786-O cells. HIF-2α down-regulation was accompanied by HIF-2α ubiquitination and was reversed by protea-some inhibition. Emetine-induced HIF-2α down-regulation was confirmed in three additional VHL-renal cancer cell lines, was insensitive to the prolyl hydroxylase inhibitor dimethyloxaloyl glycine, and did not require neural precursor cell expressed developmentally down-regulated-8, suggesting that emetine accesses a previously undescribed cullin-independent protea-some degradation pathway for HIF-2α. These data support the use of emetine or structurally related compounds as useful leads for the identification of novel HIF-2α inhibitors