Shiba states and zero-bias anomalies in the hybrid normal-superconductor Anderson model

We determine the phase diagram of an Anderson impurity in contact with superconducting and normal-state leads for arbitrary ratio of the gap $\Delta$ to the Kondo temperature $T_K$. We observe a considerable effect of even very weak coupling to the normal lead that is usually considered as a non-perturbing tunneling probe. The numerical renormalization group results are analyzed in the context of relevant experimental scenarios such as parity crossing (doublet-singlet) quantum phase transitions induced by a gap reduction as well as novel Kondo features induced by the normal lead. We point out the important role of finite temperatures and magnetic fields. Overall, we find a very rich behavior of spectral functions with zero-bias anomalies which can emerge irrespective of whether the ground state is a doublet or a singlet. Our findings are pertinent to the tunnelling-spectroscopy experiments aiming at detecting Majorana modes in nanowires.Comment: Final version, 18 pages, 17 figure

Tunable Kondo effect in double quantum dots coupled to ferromagnetic contacts

We investigate the effects induced by spin polarization in the contacts attached to a serial double quantum dot. The polarization generates effective magnetic fields and suppresses the Kondo effect in each dot. The super-exchange interaction ($J_{\mathrm{AFM}}$), tuned by the inter-dot tunnelling rate $t$, can be used to compensate the effective fields and restore the Kondo resonance when the contact polarizations are aligned. As a consequence, the direction of the spin conductance can be controlled and even reversed using electrostatic gates alone. Furthermore, we study the associated two-impurity Kondo model and show that a ferromagnetic exchange coupling ($J_{\mathrm{FM}}$) leads to an effective spin-1 exchange-anisotropic Kondo model which exhibits a quantum phase transition in the presence of partially polarized contacts.Comment: 5 pages, 4 figure

Human AP Endonuclease 1: A Potential Marker for the Prediction of Environmental Carcinogenesis Risk

Human apurinic/apyrimidinic endonuclease 1 (APE1) functions mainly in DNA repair as an enzyme removing AP sites and in redox signaling as a coactivator of various transcription factors. Based on these multifunctions of APE1 within cells, numerous studies have reported that the alteration of APE1 could be a crucial factor in development of human diseases such as cancer and neurodegeneration. In fact, the study on the combination of an individual’s genetic make-up with environmental factors (gene-environment interaction) is of great importance to understand the development of diseases, especially lethal diseases including cancer. Recent reports have suggested that the human carcinogenic risk following exposure to environmental toxicants is affected by APE1 alterations in terms of gene-environment interactions. In this review, we initially outline the critical APE1 functions in the various intracellular mechanisms including DNA repair and redox regulation and its roles in human diseases. Several findings demonstrate that the change in expression and activity as well as genetic variability of APE1 caused by environmental chemical (e.g., heavy metals and cigarette smoke) and physical carcinogens (ultraviolet and ionizing radiation) is likely associated with various cancers. These enable us to ultimately suggest APE1 as a vital marker for the prediction of environmental carcinogenesis risk

Significance of p27kip1 as potential biomarker for intracellular oxidative status

Our previous proteomic study demonstrated that oxidative stress and antioxidant delphinidin regulated the cellular level of p27kip1 (referred to as p27) as well as some heat shock proteins in human colon cancer HT 29 cells. Current study was conducted to validate and confirm the regulation of these proteins using both in vitro and in vivo systems. The level of p27 was decreased by hydrogen peroxide in a dose-dependent manner in human colon carcinoma HCT 116 (p53-positive) cells while it was increased upon exposure to hydrogen peroxide in HT 29 (p53-negative) cells. However, high concentration of hydrogen peroxide (100 µM) downregulated p27 in both cell lines, but delphindin, one of antioxidative anthocyanins, enhanced the level of p27 suppressed by 100 µM hydrogen peroxide. ICR mice were injected with varying concentrations of hydrogen peroxide, delphinidin and both. Western blot analysis for the mouse large intestinal tissue showed that the expression of p27 was upregulated by 25 mg/kg BW hydrogen peroxide. To investigate the association of p27 regulation with hypoxia-inducible factor 1-beta (HIF-1β), the level of p27 was analyzed in wild-type mouse hepatoma hepa1c1c7 and Aryl Hydrocarbon Nuclear Translocator (arnt, HIF-1β)-defective mutant BPRc1 cells in the absence and presence of hydrogen peroxide and delphinidin. While the level of p27 was responsive to hydrogen peroxide and delphinidin, it remained unchanged in BPRc1, suggesting that the regulation of p27 requires functional HIF-1β. We also found that hydrogen peroxide and delphinidin affected PI3K/Akt/mTOR signaling pathway which is one of upstream regulators of HIFs. In conclusion, hydrogen peroxide and antioxidant delphinidin seem to regulate intracellular level of p27 through regulating HIF-1 level which is, in turn, governed by its upstream regulators comprising of PI3K/Akt/mTOR signaling pathway. The results should also encourage further study for the potential of p27 as a biomarker for intracellular oxidative or antioxidant status

Minimal information for studies of extracellular vesicles (MISEV2023): From basic to advanced approaches

Extracellular vesicles (EVs), through their complex cargo, can reflect the state of their cell of origin and change the functions and phenotypes of other cells. These features indicate strong biomarker and therapeutic potential and have generated broad interest, as evidenced by the steady year-on-year increase in the numbers of scientific publications about EVs. Important advances have been made in EV metrology and in understanding and applying EV biology. However, hurdles remain to realising the potential of EVs in domains ranging from basic biology to clinical applications due to challenges in EV nomenclature, separation from non-vesicular extracellular particles, characterisation and functional studies. To address the challenges and opportunities in this rapidly evolving field, the International Society for Extracellular Vesicles (ISEV) updates its 'Minimal Information for Studies of Extracellular Vesicles', which was first published in 2014 and then in 2018 as MISEV2014 and MISEV2018, respectively. The goal of the current document, MISEV2023, is to provide researchers with an updated snapshot of available approaches and their advantages and limitations for production, separation and characterisation of EVs from multiple sources, including cell culture, body fluids and solid tissues. In addition to presenting the latest state of the art in basic principles of EV research, this document also covers advanced techniques and approaches that are currently expanding the boundaries of the field. MISEV2023 also includes new sections on EV release and uptake and a brief discussion of in vivo approaches to study EVs. Compiling feedback from ISEV expert task forces and more than 1000 researchers, this document conveys the current state of EV research to facilitate robust scientific discoveries and move the field forward even more rapidly

Shiba states of an Anderson impurity in hybrid normal-superconducting systems

Paper presented at the XXXVIII International Conference of Theoretical Physics - Correlations and Coherence at Different Scales, which took place in Ustrón (Poland) during 5-10th September 2014.Many schemes for detecting the presence of Majorana zero-energy states in semiconductor nanowires coupled to superconductors involve a weakly coupled normal-state electrode for performing the tunneling spectroscopy. Since the normal-state electrode can lead to zero-bais anomalies associated with Kondo screening. It is important to better understand the phase diagram and spectral features of an Anderson impurity coupled to both superconducting and normal-state leads, in particular in the presence of magnetic field. I will also present detailed results for the Shiba doublet state splitting in magnetic field, which reveal a surprisingly linear dependence between the field of singlet-doublet crossing and the hybridization strength

Report on the side-effects of Pharmacopuncture Lubricants(CF, JsD)

Objectives : This study aims to report inflammatory reactions of Pharmacopuncture lubricants (CF and JsD) when administered on GB21, GB20, and TE23 in clinical trials. Methods : Follow-up studies were made on each patient's clinical observation and specific managemen. Results : 1. Inflammation induced by pharmacopuncture lubricants were limited to local area of administration. 2. Intensity of inflammation was depended on the patient's condition. 3. Inflammation caused pain, skin flare, and discomfort on the patient. Inflammation subsided when dissipating technique was rendered with the conventional acupuncture needle. Conclusions : It appears that prolonged usage of pharmacopuncture lubricant on the specific point can induce inflammation, thus using alternative pharmacopuncture is recommended