Charging induced asymmetry in molecular conductors

We investigate the origin of asymmetry in various measured current-voltage (I-V) characteristics of molecules with no inherent spatial asymmetry, with particular focus on a recent break junction measurement. We argue that such asymmetry arises due to unequal coupling with the contacts and a consequent difference in charging effects, which can only be captured in a self-consistent model for molecular conduction. The direction of the asymmetry depends on the sign of the majority carriers in the molecule. For conduction through highest occupied molecular orbitals (i.e. HOMO or p-type conduction), the current is smaller for positive voltage on the stronger contact, while for conduction through lowest unoccupied molecular orbitals (i.e. LUMO or n-type conduction), the sense of the asymmetry is reversed. Within an extended Huckel description of the molecular chemistry and the contact microstructure (with two adjustable parameters, the position of the Fermi energy and the sulphur-gold bond length), an appropriate description of Poisson's equation, and a self-consistently coupled non-equilibrium Green's function (NEGF) description of transport, we achieve good agreement between theoretical and experimental I-V characteristics, both in shape as well as overall magnitude.Comment: length of the paper has been extended (4 pages to 6 pages), two new figures have been added (3 figures to 5 figures), has been accepted for PR

Pump-probe scheme for optical coherence tomography using indocyanine green mixed with albumin or human plasma

Use of indocyanine green (ICG) in a pump-probe scheme for OCT is proposed. The study illustrates that ICG in protein solution shows unusual pump-probe imaging potential, indicating its usefulness as a contrast agent for OCT

Study of Subclinical Mastitis Control on Dry Cow Therapy (DCT) during the Dry Period

This aim of study was to indentify the variables supporting the dairy farmers on dry cow therapy (DCT) for contoling subclinical mastitis and impact of the treatment impact on milk production at KPSBU, Lembang, West Java Province. The study was conducted by interviewing the farmers using questionnaires and testing subclinical mastitis using IPB-1 reagen. This study showed that variables supporting the dairy farmers to apply DCT were the attending farmers meeting Odds Ratio (OR) = 4.05; Confidence Interval (CI) = 95% (1.36-12.04) and number of productive dairy OR =5.3; CI 95% (1.43-19.58). The DCT programs were able to improve milk production. The milk production increased 620.5 (76.3-1164.7) litre per cow per year

Quantum master equation scheme of time-dependent density functional theory to time-dependent transport in nano-electronic devices

In this work a practical scheme is developed for the first-principles study of time-dependent quantum transport. The basic idea is to combine the transport master-equation with the well-known time-dependent density functional theory. The key ingredients of this paper include: (i) the partitioning-free initial condition and the consideration of the time-dependent bias voltages which base our treatment on the Runge-Gross existence theorem; (ii) the non-Markovian master equation for the reduced (many-body) central system (i.e. the device); and (iii) the construction of Kohn-Sham master equation for the reduced single-particle density matrix, where a number of auxiliary functions are introduced and their equations of motion (EOM) are established based on the technique of spectral decomposition. As a result, starting with a well-defined initial state, the time-dependent transport current can be calculated simultaneously along the propagation of the Kohn-Sham master equation and the EOM of the auxiliary functions.Comment: 9 pages, no figure

Herpes Zoster During Immunosuppressive Therapy For Autoimmune Diseases

Background: Patients on immunosuppressive therapy are at a greater risk for herpes zoster reactivation and are more likely to have adverse outcomes. Propylactic antivrials and vaccinations may potentially prevent these complications.Methods: Medical literature addressing the clinical course and therapy of herpes zoster in patients receiving immunosuppressive therapy for autoimmune disorders, and the roles of anti-viral prophylaxis and vaccination was reviewed. Research databases including PubMed, Ovid, Medline, Google Scholar and Cochrane were utilized.Results: Acyclovir and its derivatives are most commonly used in this setting for treatment and reduction of post-zoster complications. Foscarnet may be used for acyclovir-resistant strains. At both conventional and ultralow doses, acyclovir has proven effective when used as prophylaxis, reducing the incidence of zoster and its complications in immunosuppressed patients. Additionally, ultra-low doses are associated with significantly reduced side effects. The zoster vaccine, Zostavax, a live-attenuated vaccine has shown promising results in several clinical trials. However, live-attenuated vaccines should be cautiously used in immunosuppressed patients. For patients who require immunosuppressive therapy, vaccination 2-3 months prior to therapy may be appropriate.CONCLUSIONS: Prophylactic antiviral therapy and vaccination help significantly reduce morbidity and mortality from zoster reactivation in patients receiving immunosuppressive therapy

Rest-frame Optical Emission Lines in Far-Infrared Selected Galaxies at z<1.7 from the FMOS-COSMOS Survey

We have used FMOS on Subaru to obtain near-infrared spectroscopy of 123 far-infrared selected galaxies in COSMOS and obtain the key rest-frame optical emission lines. This is the largest sample of infrared galaxies with near-infrared spectroscopy at these redshifts. The far-infrared selection results in a sample of galaxies that are massive systems that span a range of metallicities in comparison with previous optically selected surveys, and thus has a higher AGN fraction and better samples the AGN branch. We establish the presence of AGN and starbursts in this sample of (U)LIRGs selected as Herschel-PACS and Spitzer-MIPS detections in two redshift bins (z~0.7 and z~1.5) and test the redshift dependence of diagnostics used to separate AGN from star-formation dominated galaxies. In addition, we construct a low redshift (z~0.1) comparison sample of infrared selected galaxies and find that the evolution from z~1.5 to today is consistent with an evolving AGN selection line and a range of ISM conditions and metallicities from the models of Kewley et al. (2013b). We find that a large fraction of (U)LIRGs are BPT-selected AGN using their new, redshift-dependent classification line. We compare the position of known X-ray detected AGN (67 in total) with the BPT selection and find that the new classification line accurately selects most of these objects (> 70%). Furthermore, we identify 35 new (likely obscured) AGN not selected as such by their X-ray emission. Our results have direct implications for AGN selection at higher redshift with either current (MOSFIRE, KMOS) or future (PFS, MOONS) spectroscopic efforts with near-infrared spectral coverage.Comment: 7 pages, 3 figures, 2 tables. Accepted for publication in The Astrophysical Journal Letter

Transverse Priority Phase Sensitive Optical Coherence Tomography

A variation on the standard time domain optical coherence tomography (TDOCT) system is presented. Using an inexpensive piezoelectric stack to modulate the reference mirror position, the amplitude and phase of the sample reflection is determined without scanning. With the primary scan in the transverse direction, en face and B-scan OCT images can be readily produced with phase information. This project plans to use the dynamic phase information to add an extra level of contrast to the images, based on the motion of the scatterers

Bulk crystal growth and electronic characterization of the 3D Dirac Semimetal Na3Bi

High quality hexagon plate-like Na3Bi crystals with large (001) plane surfaces were grown from a molten Na flux. The freshly cleaved crystals were analyzed by low temperature scanning tunneling microscopy (STM) and angle-resolved photoemission spectroscopy (ARPES), allowing for the characterization of the three-dimensional (3D) Dirac semimetal (TDS) behavior and the observation of the topological surface states. Landau levels (LL) were observed, and the energy-momentum relations exhibited a linear dispersion relationship, characteristic of the 3D TDS nature of Na3Bi. In transport measurements on Na3Bi crystals the linear magnetoresistance and Shubnikov-de Haas (SdH) quantum oscillations are observed for the first time.Comment: To be published in a special issue of APL Material