Isostructural metal-insulator transition in VO2

The metal-insulator transition in correlated materials is usually coupled to a symmetry-lowering structural phase transition. This coupling not only complicates the understanding of the basic mechanism of this phenomenon but also limits the speed and endurance of prospective electronic devices. We demonstrate an isostructural, purely electronically driven metal-insulator transition in epitaxial heterostructures of an archetypal correlated material, vanadium dioxide. A combination of thin-film synthesis, structural and electrical characterizations, and theoretical modeling reveals that an interface interaction suppresses the electronic correlations without changing the crystal structure in this otherwise correlated insulator. This interaction stabilizes a nonequilibrium metallic phase and leads to an isostructural metal-insulator transition. This discovery will provide insights into phase transitions of correlated materials and may aid the design of device functionalities.

An in vivo demonstration of efficacy and acute safety of burst wave lithotripsy using a porcine model

Burst wave lithotripsy (BWL) is a new non-invasive method for stone comminution using bursts of sub-megahertz ultrasound. A porcine model of urolithiasis and techniques to implement BWL treatment has been developed to evaluate its effectiveness and acute safety. Six human calcium oxalate monohydrate stones (6-7 mm) were hydrated, weighed, and surgically implanted into the kidneys of three pigs. Transcutaneous stone treatments were performed with a BWL transducer coupled to the skin via an external water bath. Stone targeting and treatment monitoring were performed with a co-aligned ultrasound imaging probe. Treatment exposures were applied in three 10-minute intervals for each stone. If sustained cavitation in the parenchyma was observed by ultrasound imaging feedback, treatment was paused and the pressure amplitude was decreased for the remaining time. Peak negative focal pressures between 6.5 and 7 MPa were applied for all treatments. After treatment, stone fragments were removed from the kidneys. At least 50% of each stone was reduced to <2 mm fragments. 100% of four stones were reduced to <4 mm fragments. Magnetic resonance imaging showed minimal injury to the functional renal volume. This study demonstrated that BWL could be used to effectively fragment kidney stones with minimal injury.

A new software scheme for scatter correction based on a simple radiographic scattering model

In common radiography, image contrast is often limited due mainly to scattered x-rays and noise, decreasing the quantitative usefulness of x-ray images. Several scatter reduction methods based on software correction schemes have been extensively investigated in an attempt to overcome these difficulties, most of which are based on measurement, mathematical-physical modeling, or a combination of both. However, those methods require special equipment, system geometry, and extra manual work to measure scatter characteristics. In this study, we investigated a new software scheme for scatter correction based on a simple radiographic scattering model where the intensity of the scattered x-rays was directly estimated from a single x-ray image using a weighted l¹-norm contextual regularization framework. We implemented the proposed algorithm and performed a systematic simulation and experiment to demonstrate its viability. We also conducted some clinical image studies using patient's image data of breast and L-spine to verify the clinical effectiveness of the proposed scheme. Our results indicate that the degradation of image characteristics by scattered x-rays and noise was effectively recovered by using the proposed software scheme, thus improving radiographic visibility considerably. Graphical abstract The schematic illustrations of scatter suppression methods by using a an antiscatter grid and b a scatter estimation algorithm.

Clastic cells are absent around the root surface in pulp-exposed periapical periodontitis lesions in mice

INTRODUCTION

Clastic cells, originating from the monocyte-macrophage lineage, resorb mineralized tissues. In periapical periodontitis, alveolar bone around the tooth apex becomes resorbed; however, the roots of the teeth are often left intact by yet unknown mechanisms. Here, we examined the status of clastic cells in a periapical periodontitis model in mice.

METHODS

Periapical periodontitis was induced by performing pulp exposure on the maxillary first molar. The contralateral maxillary first molar was used as a control. The maxillae were harvested, fixed, and subjected to μCT scanning and three-dimensional volumetric analysis. TRAP staining was performed, and osteoclasts were quantified. Immunohistochemical staining was performed for RANKL, OPG, and F4/80, a marker for macrophages.

RESULTS

At the apex of the tooth, pulp exposure resulted in periapical radiolucency with mineralized tissues at the surrounding bone surfaces but not on the root surfaces. Histologically, clastic cells were present on the bone surfaces but absent around the root surfaces. Expression of F4/80 and RANKL was not found at close proximity to the root surfaces, but OPG was globally expressed.

CONCLUSION

The absence of clastic cells around the root surface of pulp-exposed teeth, in part, is associated with the lack of macrophages and RANKL expression.

Randomized controlled trials define shape of dose response for Pollinex Quattro Birch allergoid immunotherapy

BACKGROUND

The Birch Allergoid, Tyrosine Adsorbate, Monophosphoryl Lipid A (POLLINEX^® Quattro Plus 1.0 ml Birch 100%) is an effective, well-tolerated short course subcutaneous immunotherapy. We performed 2 phase II studies to determine its optimal cumulative dose.

METHODS

The studies were conducted in Germany, Austria and Poland (EudraCT numbers: 2012-004336-28 PQBirch203 and 2015-000984-15 PQBirch204) using a wide range of cumulative doses. In both studies, subjects were administered 6 therapy injections weekly outside the pollen season. Conjunctival Provocation Tests were performed at screening, baseline and 3-4 weeks after completing treatment, to quantify the reduction in Total Symptom Scores (as the primary endpoint) with each cumulative dose. Multiple Comparison Procedure and Modeling analysis was used to test for the dose response, shape of the curve and estimation of the median effective dose (ED₅₀ ), a measure of potency.

RESULTS

Statistically significant dose responses (P < .01 & .001) were seen, respectively. The highest cumulative dose in PQBirch204 (27 300 standardized units [SU]) approached a plateau. Potency of the PQBirch was demonstrated by an ED₅₀ 2723 SU, just over half the current dose. Prevalence of treatment-emergent adverse events was similar for active doses, most being short-lived and mild. Compliance was over 85% in all groups.

CONCLUSION

Increasing the cumulative dose of PQBirch 5.5-fold from 5100 to 27 300 SU achieved an absolute point difference from placebo of 1.91, a relative difference 32.3% and an increase in efficacy of 50%, without compromising safety. The cumulative dose response was confirmed to be curvilinear in shape.