Loop Corrections in Double Field Theory: Non-trivial Dilaton Potentials

It is believed that the invariance of the generalised diffeomorphisms prevents any non-trivial dilaton potential from double field theory. It is therefore difficult to include loop corrections in the formalism. We show that by redefining a non-local dilaton field, under strong constraint which is necessary to preserve the gauge invariance of double field theory, the theory does permit non-constant dilaton potentials and loop corrections. If the fields have dependence on only one single coordinate, the non-local dilaton is identical to the ordinary one with an additive constant.Comment: V3, 11 pages, references added, typos corrected, version to appear in JHE

4,4′-Bipyridine–dimethyl­glyoxime (1/1)

In the title compound, C10H8N2·C4H8N2O2, both the dimethyl­glyoxime and the 4,4′-bipyridine mol­ecules have crystallographic C i symmetry. The mol­ecules stack along the a-axis direction with a dihedral angle of 20.4 (8)° between their planes. In the crystal, the components are linked by O—H⋯N hydrogen bonds into alternating chains along [120] and [10]

The Effects of Warfarin on the Pharmacokinetics of Senkyunolide I in a Rat Model of Biliary Drainage After Administration of Chuanxiong

The aim of this study was to elucidate the effects of warfarin on senkyunolide I in a rat model of biliary drainage after oral administration Chuanxiong extract based on pharmacokinetics. Thirty-two rats were randomly divided into four groups: CN, healthy rats after a single administration of Chuanxiong; CO, rats with biliary drainage after a single administration of Chuanxiong; WCN, healthy rats after the administration of Chuanxiong and warfarin; WCO, rats with biliary drainage after the administration of Chuanxiong and warfarin. A series of blood samples were collected at different time points before and after oral administration. An ultra-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS) method for quantification of the main components of Chuanxiong and methyclothiazide (internal standard) have been established. The validated method was successfully applied to a comparative pharmacokinetics study. After calculated by the DAS 2.1.1 software, the pharmacokinetics parameters of senkyunolide I showed a significant difference between the CN and CO groups, the AUC0−t, and Cmax of CO group increased by 5.45, 4.02 folds, respectively. There was a significant difference between the WCO and WCN groups, the Tmax of WCO group prolonged 67%; compared to the CN group, the AUC0−t, and Cmax of WCN group raised 4.84, 3.49 folds, respectively; the Tmax and Cmax between the CO and WCO groups also showed a significant difference. The drug warfarin significantly affected the senkyunolide I disposition, which partly due to its enterohepatic circulation process in rat plasma after oral administration of Chuanxiong. The present study highlights an urgent evidence for drug-herb interactions

Effects of powder morphology on stereolithography additive manufactured Al2O3 ceramic

The digital light processing (DLP) for the preparation of alumina ceramics (Al2O3) is characterized by high molding accuracy and fast rates, making it show great promise for applications in high-end ceramic manufacturing. However, its forming process is greatly influenced by the photosensitive slurry. Although a large number of studies have been conducted to investigate the influence of different variables of the slurry on photo curing, the mechanism of the influence of the powder morphology of the Al2O3 raw material is still unclear. In this study, two kinds of slurry were prepared from spherical and laminated Al2O3 powders and DLP was carried out. The results showed that some of the spherical Al2O3 powder would break down after ball milling, resulting in a reduced flow-ability of the slurry. The relative density of the ceramic was 91.1 % and strength was 92.1 MPa. In contrast, the laminated Al2O3 could be oriented in the flow direction during flow, showing a lower viscosity. At the same time, the orientation allowed the lamellar powder to build up more tightly. The relative density of the ceramic was 93.2 % and strength was 165.5 MPa

A Ratiometric Fluorescent Sensor for Cd2+ Based on Internal Charge Transfer

This work reports on a novel fluorescent sensor 1 for Cd2+ ion based on the fluorophore of tetramethyl substituted bis(difluoroboron)-1,2-bis[(1H-pyrrol-2-yl)methylene]hydrazine (Me4BOPHY), which is modified with an electron donor moiety of N,N-bis(pyridin-2-ylmethyl)benzenamine. Sensor 1 has absorption and emission in visible region, at 550 nm and 675 nm, respectively. The long wavelength spectral response makes it easier to fabricate the fluorescence detector. The sensor mechanism is based on the tunable internal charge transfer (ICT) transition of molecule 1. Binding of Cd2+ ion quenches the ICT transition, but turns on the π − π transition of the fluorophore, thus enabling ratiometric fluorescence sensing. The limit of detection (LOD) was projected down to 0.77 ppb, which is far below the safety value (3 ppb) set for drinking water by World Health Organization. The sensor also demonstrates a high selectivity towards Cd2+ in comparison to other interferent metal ions

Visual, Label-Free Telomerase Activity Monitor via Enzymatic Etching of Gold Nanorods

Early diagnosis and life-long surveillance are clinically important to improve the long-term survival of cancer patients. Telomerase activity is a valuable biomarker for cancer diagnosis, but its measurement often used complex label procedures. Herein, we designed a novel, simple, visual and label-free method for telomerase detection by using enzymatic etching of gold nanorods (GNRs). First, repeating (TTAGGG)_<i>x</i> sequences were extented on telomerase substrate (TS) primer. It formed G-quadruplex under the help of Hemin and K⁺. Second, the obtained horseradish peroxidase mimicking hemin/G-quadruplex catalyzed the H₂O₂-mediated etching of GNRs to the short GNRs, even to gold nanoparticles (GNPs), generating a series of distinct color changes due to their plasmon-related optical response. Thus, this enzymatic reaction can be easily coupled to telomerase activity, allowing for the detection of telomerase activity based on vivid colors. This can be differentiated sensitively by naked eyes because human eyes are more sensitive to color variations rather than the optical density variations. As a result, telomerase activity can be quantitatively detected ranging from 200 to 15000 HeLa cells mL^–1. The detection limit was 90 HeLa cells mL^–1 (<i>S</i>/<i>N</i> = 3). Importantly, the application of this method in bladder cancer samples was in agreement with the clinical results. Thus, this method was considerably suitable for point-of-care diagnostics in resource-constrained regions because of the easy readout of results without the use of sophisticated apparatus