Controlling the Intrinsic Josephson Junction Number in a Bi2Sr2CaCu2O8+δ\mathbf{Bi_2Sr_2CaCu_2O_{8+\delta}} Mesa

In fabricating $\mathrm{Bi_2Sr_2CaCu_2O_{8+\delta}}$ intrinsic Josephson junctions in 4-terminal mesa structures, we modify the conventional fabrication process by markedly reducing the etching rates of argon ion milling. As a result, the junction number in a stack can be controlled quite satisfactorily as long as we carefully adjust those factors such as the etching time and the thickness of the evaporated layers. The error in the junction number is within $\pm 1$. By additional ion etching if necessary, we can controllably decrease the junction number to a rather small value, and even a single intrinsic Josephson junction can be produced.Comment: to bu published in Jpn. J. Appl. Phys., 43(7A) 200

Survey of methadone-drug interactions among patients of methadone maintenance treatment program in Taiwan

<p>Abstract</p> <p>Background</p> <p>Although methadone has been used for the maintenance treatment of opioid dependence for decades, it was not introduced in China or Taiwan until 2000s. Methadone-drug interactions (MDIs) have been shown to cause many adverse effects. However, such effects have not been scrutinized in the ethnic Chinese community.</p> <p>Methods</p> <p>The study was performed in two major hospitals in southern Taiwan. A total of 178 non-HIV patients aged ≥ 20 years who had participated in the Methadone Maintenance Treatment Program (MMTP) ≥ 1 month were recruited. An MDI is defined as concurrent use of drug(s) with methadone that may result in an increase or decrease of effectiveness and/or adverse effect of methadone. To determine the prevalence and clinical characteristics of MDIs, credible data sources, including the National Health Insurance (NHI) database, face-to-face interviews, medical records, and methadone computer databases, were linked for analysis. Socio-demographic and clinical factors associated with MDIs and co-medications were also examined.</p> <p>Results</p> <p>128 (72%) MMTP patients took at least one medication. Clinically significant MDIs included withdrawal symptoms, which were found among MMTP patients co-administered with buprenorphine or tramadol; severe QTc prolongation effect, which might be associated with use of haloperidol or droperidol; and additive CNS and respiratory depression, which could result from use of methadone in combination with chlorpromazine or thioridazine. Past amphetamine use, co-infection with hepatitis C, and a longer retention in the MMTP were associated with increased odds of co-medication. Among patients with co-medication use, significant correlates of MDIs included the male gender and length of co-medication in the MMTP.</p> <p>Conclusions</p> <p>The results demonstrate clinical evidence of significant MDIs among MMTP patients. Clinicians should check the past medical history of MMTP clients carefully before prescribing medicines. Because combinations of methadone with other psychotropic or opioid medications can affect treatment outcomes or precipitate withdrawal symptoms, clinicians should be cautious when prescribing these medications to MMTP patients and monitor the therapeutic effects and adverse drug reactions. Although it is difficult to interconnect medical data from different sources for the sake of privacy protection, the incumbent agency should develop pharmacovigilant measures to prevent the MDIs from occurring. Physicians are also advised to check more carefully on the medication history of their MMTP patients.</p

MethylC-analyzer: A comprehensive downstream pipeline for the analysis of genome-wide DNA methylation

DNA methylation is a crucial epigenetic modification involved in multiple biological processes and diseases. Current approaches for measuring genome-wide DNA methylation via bisulfite sequencing (BS-seq) include whole-genome bisulfite sequencing (WGBS), reduced representation bisulfite sequencing (RRBS), and enzymatic methyl-seq (EM-seq). The computational analysis tools available for BS-seq data include customized aligners for mapping bisulfite-converted reads and computational pipelines for downstream data analysis. Current post-alignment methylation tools are specialized for the interpretation of CG methylation, which is known to dominate mammalian genomes, however, non-CG methylation (CHG and CHH, where H refers to A, C, or T) is commonly observed in plants and fungi and is closely associated with gene regulation, transposon silencing, and plant development. Thus, we have developed a MethylC-analyzer to analyze and visualize post-alignment WGBS, RRBS, and EM-seq data focusing on CG. The tool is able to also analyze non-CG sites to enhance deciphering genomes of plants and fungi. By processing aligned data and gene location files, MethylC-analyzer generates a genome-wide view of methylation levels and methylation in user-specified genomic regions. The meta-plot, for example, allows the investigation of DNA methylation within specific genomic elements. Moreover, our tool identifies differentially methylated regions (DMRs) and investigates the enrichment of genomic features associated with variable methylation. MethylC-analyzer functionality is not limited to specific genomes, and we demonstrated its performance on both plant and human BS-seq data. MethylC-analyzer is a Python- and R-based program designed to perform comprehensive downstream analyses of methylation data, providing an intuitive analysis platform for scientists unfamiliar with DNA methylation analysis. It is available as either a standalone version for command-line uses or a graphical user interface (GUI) and is publicly accessible at https://github.com/RitataLU/MethylC-analyzer

A controllable superconducting electromechanical oscillator with a suspended membrane

We fabricate a microscale electromechanical system, in which a suspended superconducting membrane, treated as a mechanical oscillator, capacitively couples to a superconducting microwave resonator. As the microwave driving power increases, nonmonotonic dependence of the resonance frequency of the mechanical oscillator on the driving power has been observed. We also demonstrate the optical switching of the resonance frequency of the mechanical oscillator. Theoretical models for qualitative understanding of our experimental observations are presented. Our experiment may pave the way for the application of a mechanical oscillator with its resonance frequency controlled by the electromagnetic and/or optical fields, such as a microwave-optical interface and a controllable element in a superqubit-mechanical oscillator hybrid system.Comment: 8 pages,4 figure

PT{\cal PT} Symmetry and PT{\cal PT}-Enhanced Quantum Sensing in a Spin-Boson System

Open systems, governed by non-Hermitian Hamiltonians, evolve fundamentally differently from their Hermitian counterparts and facilitate many unusual applications. Although non-Hermitian but parity-time (${\cal PT}$) symmetric dynamics has been realized in a variety of classical or semiclassical systems, its fully quantum-mechanical demonstration is still lacking. Here we ingeniously engineer a highly controllable anti-Hermitian spin-boson model in a circuit quantum-electrodynamical structure composed of a decaying artificial atom (pseudospin) interacting with a bosonic mode stored in a microwave resonator. Besides observing abrupt changes in the spin-boson entanglement evolution and bifurcation transition in quantum Rabi splitting, we demonstrate super-sensitive quantum sensing by mapping the observable of interest to a hitherto unobserved ${\cal PT}$-manifested entanglement evolution. These results pave the way for exploring non-Hermitian entanglement dynamics and ${\cal PT}$-enhanced quantum sensing empowered by nonclassical correlations.Comment: 25 pages, 19 figure

Nitrogen isotope composition of ammonium in PM 2.5 in the Xiamen, China: impact of non-agricultural ammonia

Abstract(#br)Since NH 3 is a significant precursor to ammonium in PM 2.5 and contributes significantly to atmospheric nitrogen deposition but largely remains unregulated in China, the insight into the source of NH 3 emissions by the isotopic investigation is important in controlling NH 3 emissions. In this study, atmospheric concentrations of NH 3 and water-soluble ion composition in PM 2.5 as well as nitrogen isotope ratios in NH 4 + (δ 15 N-NH 4 + ) in Xiamen, China, were measured. Results showed that average NH 3 concentration for the five sites in Xiamen was 7.9 μg m −3 with distinct higher values in the warm season and lower values in the cold season, and PM 2.5 concentration for the two sites (urban and suburban) was 59.2 μg m −3 with lowest values in summer. In the PM 2.5 , NH 4 +..

Nitrogen isotope composition of ammonium in PM2.5 in the Xiamen, China: impact of non-agricultural ammonia.

Since NH3 is a significant precursor to ammonium in PM2.5 and contributes significantly to atmospheric nitrogen deposition but largely remains unregulated in China, the insight into the source of NH3 emissions by the isotopic investigation is important in controlling NH3 emissions. In this study, atmospheric concentrations of NH3 and water-soluble ion composition in PM2.5 as well as nitrogen isotope ratios in NH4+ (δ15N-NH4+) in Xiamen, China, were measured. Results showed that average NH3 concentration for the five sites in Xiamen was 7.9 μg m-3 with distinct higher values in the warm season and lower values in the cold season, and PM2.5 concentration for the two sites (urban and suburban) was 59.2 μg m-3 with lowest values in summer. In the PM2.5, NH4+ concentrations were much lower than NH3 and showed a stronger positive correlation with NO3- than that with SO42- suggesting the formation of NH4NO3 and equilibrium between NH3 and NH4+. Although the concentrations of NH3 at the urban site were significantly higher than those at the suburban site, no significant spatial difference in NH4+ and δ15N-NH4+ was obtained. The distinct heavier δ15N-NH4+ values in summer than in other seasons correlated well with the equilibrium isotopic effects between NH3 and NH4+ which depend on temperature. The initial δ15N-NH3 values were in the range of waste treatment (- 25.42‰) and fossil fuel combustion (- 2.5‰) after accounting for the isotope fractionation. The stable isotope mixing model showed that fossil fuel-related NH3 emissions (fossil fuel combustion and NH3 slip) contributed more than 70% to aerosol NH4+. This finding suggested that the reduction of NH3 emissions from urban transportation and coal combustion should be a priority in the abatement of PM2.5 pollution in Xiamen