Adsorption of HO_x on Aerosol Surfaces: Implications for the Atmosphere of Mars

The potential impact of heterogeneous chemistry on the abundance and distribution of HO_x in the atmosphere of Mars has been assessed by combining observational data of dust and ice aerosol distributions with an updated photochemical model. Critical parameters include the altitude distributions of aerosols, and the surface loss coefficients (γ) of HO_2 on dust and ice in the lower atmosphere, and H on ice above 40 km. We find that adsorption of HO_2 on dust (γHO_2 ≥ 0.01), or ice near 30 km (γHO_2 ≥ 0.1), can deplete OH abundances in the lower atmosphere by 10% or more. Such depletions approach those obtained by lowering the water vapor abundance by an order of magnitude below the global average observed by Viking (≈ 25%). Since the oxidation of CO is catalyzed by HO_x in the lower atmosphere via the reaction CO + OH → CO_2 + H, loss of OH due to adsorption of HO_2 on dust or ice at low altitudes could have a significant effect on the ratio CO : CO_2. The adsorption of H on ice at 50 km (γ_H ≥ 0.01) can result in even larger OH depletions. However, this effect is localized to altitudes > 40 km, where CO oxidation is relatively unimportant. Laboratory data suggest that γHO_2 ≈ 0.01 is a reasonable estimate for adsorption on dust. Larger values are plausible, but are not strongly supported by experimental evidence. The reactivity of HO_2 on ice is unknown, while γH on ice appears to be < 0.001. There is a need for measurements of HO_x adsorption on surfaces representative of Martian aerosols at temperatures < 220 K

Focusing of quantum gate interactions using dynamical decoupling

In 1995, Cirac and Zoller proposed the first concrete implementation of a small-scale quantum computer, using laser beams focused to micron spot sizes to address individual trapped ions in a linear crystal. Here we propose a method to focus entangling gate interactions, but driven by microwave fields, to micron-sized zones, corresponding to $10^{-5}$ microwave wavelengths. We demonstrate the ability to suppress the spin-dependent force using a single ion, and find the required interaction introduces $3.7(4)\times 10^{-4}$ error per emulated gate in a single-qubit benchmarking sequence. We model the scheme for a 17-qubit ion crystal, and find that any pair of ions should be addressable with an average crosstalk error of $\sim 10^{-5}$

In-situ characterization of qubit drive-phase distortions

Reducing errors in quantum gates is critical to the development of quantum computers. To do so, any distortions in the control signals should be identified, however, conventional tools are not always applicable when part of the system is under high vacuum, cryogenic, or microscopic. Here, we demonstrate a method to detect and compensate for amplitude-dependent phase changes, using the qubit itself as a probe. The technique is implemented using a microwave-driven trapped ion qubit, where correcting phase distortions leads to a three-fold improvement in single-qubit gate error, to attain state-of-the-art performance benchmarked at $1.6(4)\times 10^{-6}$ error per Clifford gate

Eggshell membrane: A possible new natural therapeutic for joint and connective tissue disorders. Results from two open-label human clinical studies

Kevin J Ruff1, Dale P DeVore2, Michael D Leu3, Mark A Robinson41ESM Technologies, LLC, Carthage, MO, USA; 2Membrell, LLC, Carthage, MO, USA; 3Private Practice, Jenks, OK, USA; 4Robinson Family Health Center, Carthage, MO, USABackground: Natural Eggshell Membrane (NEM&reg;) is a novel dietary supplement that contains naturally occurring glycosaminoglycans and proteins essential for maintaining healthy joint and connective tissues. Two single center, open-label human clinical studies were conducted to evaluate the efficacy and safety of NEM&reg; as a treatment for pain and inflexibility associated with joint and connective tissue disorders. Methods: Eleven (single-arm trial) and 28 (double-arm trial) patients received oral NEM&reg; 500 mg once daily for four weeks. The primary outcome measure was to evaluate the change in general pain associated with the treatment joints/areas (both studies). In the single-arm trial, range of motion (ROM) and related ROM-associated pain was also evaluated. The primary treatment response endpoints were at seven and 30 days. Both clinical assessments were performed on the intent-to-treat (ITT) population within each study.Results: Single-arm trial: Supplementation with NEM&reg; produced a significant treatment&nbsp;response at seven days for flexibility (27.8% increase; P = 0.038) and at 30 days for general pain (72.5% reduction; P = 0.007), flexibility (43.7% increase; P = 0.006), and ROM-associated pain (75.9% reduction; P = 0.021). Double-arm trial: Supplementation with NEM&reg; produced a significant treatment response for pain at seven days for both treatment arms (X: 18.4% reduction; P = 0.021. Y: 31.3% reduction; P = 0.014). There was no clinically meaningful difference between treatment arms at seven days, so the Y arm crossed over to the X formulation for the remainder of the study. The significant treatment response continued through 30 days for pain (30.2% reduction; P = 0.0001). There were no adverse events reported during either study and the treatment was reported to be well tolerated by study participants. Conclusions: Natural Eggshell Membrane (NEM&reg;) is a possible new effective and safe therapeutic option for the treatment of pain and inflexibility associated with joint and connective tissue (JCT) disorders. Supplementation with NEM&reg;, 500 mg taken once daily, significantly reduced pain, both rapidly (seven days) and continuously (30 days). It also showed clinically meaningful results from a brief responder analysis, demonstrating that significant proportions of treated patients may be helped considerably from NEM&reg; supplementation. The Clinical Trial Registration numbers for these trials are: NCT00750230 and NCT00750854.Keywords: arthritis, pain, stiffness, eggshell membrane, joint, connective tissue, complimentary, alternativ

3D Bioprinting of Stem Cells and Polymer/Bioactive Glass Composite Scaffolds for Bone Tissue Engineering

A major limitation of using synthetic scaffolds in tissue engineering applications is insufficient angiogenesis in scaffold interior. Bioactive borate glasses have been shown to promote angiogenesis. There is a need to investigate the biofabrication of polymer composites by incorporating borate glass to increase the angiogenic capacity of the fabri-cated scaffolds. In this study, we investigated the bioprinting of human adipose stem cells (ASCs) with a polycaprolac-tone (PCL)/bioactive borate glass composite. Borate glass at the concentration of 10 to 50 weight %, was added to a mixture of PCL and organic solvent to make an extrudable paste. ASCs suspended in Matrigel were ejected as droplets using a second syringe. Scaffolds measuring 10 x 10 x 1 mm3 in overall dimensions with pore sizes ranging from 100 - 300 µm were fabricated. Degradation of the scaffolds in cell culture medium showed a controlled release of bioactive glass for up to two weeks. The viability of ASCs printed on the scaffold was investigated during the same time period. This 3D bioprinting method shows a high potential to create a bioactive, highly angiogenic three-dimensional environ-ment required for complex and dynamic interactions that govern the cell\u27s behavior in vivo

Influence of Magnetism on Phonons in CaFe2As2 Via Inelastic X-ray Scattering

In the iron pnictides, the strong sensitivity of the iron magnetic moment to the arsenic position suggests a significant relationship between phonons and magnetism. We measured the phonon dispersion of several branches in the high temperature tetragonal phase of CaFe2As2 using inelastic x-ray scattering on single-crystal samples. These measurements were compared to ab initio calculations of the phonons. Spin polarized calculations imposing the antiferromagnetic order present in the low temperature orthorhombic phase dramatically improve agreement between theory and experiment. This is discussed in terms of the strong antiferromagnetic correlations that are known to persist in the tetragonal phase.Comment: 4 pages, 3 figures; added additional information and references about spin fluctuation

A study protocol to investigate the relationship between dietary fibre intake and fermentation, colon cell turnover, global protein acetylation and early carcinogenesis: the FACT study

Background: A number of studies, notably EPIC, have shown a descrease in colorectal cancer risk associated with increased fibre consumption. Whilst the underlying mechanisms are likely to be multifactorial, production of the short-chain fatty-acid butyrate fro butyratye is frequently cited as a major potential contributor to the effect. Butyrate inhibits histone deacetylases, which work on a wide range of proteins over and above histones. We therefore hypothesized that alterations in the acetylated proteome may be associated with a cancer risk phenotype in the colorectal mucosa, and that such alterations are candidate biomarkers for effectiveness of fibre interventions in cancer prevention. Methods an design: There are two principal arms to this study: (i) a cross-sectional study (FACT OBS) of 90 subjects recruited from gastroenterology clinics and; (ii) an intervention trial in 40 subjects with an 8 week high fibre intervention. In both studies the principal goal is to investigate a link between fibre intake, SCFA production and global protein acetylation. The primary measure is level of faecal butyrate, which it is hoped will be elevated by moving subjects to a high fibre diet. Fibre intakes will be estimated in the cross-sectional group using the EPIC Food Frequency Questionnaire. Subsidiary measures of the effect of butyrate on colon mucosal function and precancerous phenotype will include measures of apoptosis, apoptotic regulators cell cycle and cell division. Discussion: This study will provide a new level of mechanistic data on alterations in the functional proteome in response to the colon microenvironment which may underwrite the observed cancer preventive effect of fibre. The study may yield novel candidate biomarkers of fibre fermentation and colon mucosal function

Solvent Based 3D Printing of Biopolymer/Bioactive Glass Composite and Hydrogel for Tissue Engineering Applications

Three-dimensional (3D) bioprinting is an emerging technology in which scaffolding materials and cell-laden hydrogels may be deposited in a pre-determined fashion to create 3D porous constructs. A major challenge in 3D bioprinting is the slow degradation of melt deposited biopolymer. In this paper, we describe a new method for printing poly-caprolactone (PCL)/bioactive borate glass composite as a scaffolding material and Pluronic F127 hydrogel as a cell suspension medium. Bioactive borate glass was added to a mixture of PCL and organic solvent to make an extrudable paste using one syringe while hydrogel was extruded and deposited in between the PCL/borate glass filaments using a second syringe. The degradation of the PCL/borate glass composite scaffold with and without the presence of hydrogel was investigated by soaking the scaffold in minimum essential medium. The weight loss of the scaffold together with formation of a hydroxyapatite-like layer on the surface shows the excellent bioactivity of the scaffold

Low field hysteresis in disordered ferromagnets

We analyze low field hysteresis close to the demagnetized state in disordered ferromagnets using the zero temperature random-field Ising model. We solve the demagnetization process exactly in one dimension and derive the Rayleigh law of hysteresis. The initial susceptibility a and the hysteretic coefficient b display a peak as a function of the disorder width. This behavior is confirmed by numerical simulations d=2,3 showing that in limit of weak disorder demagnetization is not possible and the Rayleigh law is not defined. These results are in agreement with experimental observations on nanocrystalline magnetic materials.Comment: Extended version, 18 pages, 5 figures, to appear in Phys. Rev.