Interobserver Reliability in Describing Radiographic Lung Changes After Stereotactic Body Radiation Therapy

Purpose Radiographic lung changes after stereotactic body radiation therapy (SBRT) vary widely between patients. Standardized descriptions of acute (≤6 months after treatment) and late (\u3e6 months after treatment) benign lung changes have been proposed but the reliable application of these classification systems has not been demonstrated. Herein, we examine the interobserver reliability of classifying acute and late lung changes after SBRT. Methods and materials A total of 280 follow-up computed tomography scans at 3, 6, and 12 months post-treatment were analyzed in 100 patients undergoing thoracic SBRT. Standardized descriptions of acute lung changes (3- and 6-month scans) include diffuse consolidation, patchy consolidation and ground glass opacity (GGO), diffuse GGO, patchy GGO, and no change. Late lung change classifications (12-month scans) include modified conventional pattern, mass-like pattern, scar-like pattern, and no change. Five physicians scored the images independently in a blinded fashion. Fleiss\u27 kappa scores quantified the interobserver agreement. Results The Kappa scores were 0.30 at 3 months, 0.20 at 6 months, and 0.25 at 12 months. The proportion of patients in each category at 3 and 6 months was as follows: Diffuse consolidation 11% and 21%; patchy consolidation and GGO 15% and 28%; diffuse GGO 10% and 11%; patchy GGO 15% and 15%; and no change 49% and 25%, respectively. The percentage of patients in each category at 12 months was as follows: Modified conventional 46%; mass-like 16%; scar-like 26%; and no change 12%. Uniform scoring between the observers occurred in 26, 8, and 14 cases at 3, 6, and 12 months, respectively. Conclusions Interobserver reliability scores indicate a fair agreement to classify radiographic lung changes after SBRT. Qualitative descriptions are insufficient to categorize these findings because most patient scans do not fit clearly into a single classification. Categorization at 6 months may be the most difficult because late and acute lung changes can arise at that time

Beyond icosahedral symmetry in packings of proteins in spherical shells

The formation of quasi-spherical cages from protein building blocks is a remarkable self-assembly process in many natural systems, where a small number of elementary building blocks are assembled to build a highly symmetric icosahedral cage. In turn, this has inspired synthetic biologists to design de novo protein cages. We use simple models, on multiple scales, to investigate the self-assembly of a spherical cage, focusing on the regularity of the packing of protein-like objects on the surface. Using building blocks, which are able to pack with icosahedral symmetry, we examine how stable these highly symmetric structures are to perturbations that may arise from the interplay between flexibility of the interacting blocks and entropic effects. We find that, in the presence of those perturbations, icosahedral packing is not the most stable arrangement for a wide range of parameters; rather disordered structures are found to be the most stable. Our results suggest that (i) many designed, or even natural, protein cages may not be regular in the presence of those perturbations, and (ii) that optimizing those flexibilities can be a possible design strategy to obtain regular synthetic cages with full control over their surface properties.Comment: 8 pages, 5 figure

Plasma flows in the Alcator C-Mod scrape-off layer

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Nuclear Science and Engineering, February 2010.Cataloged from PDF version of thesis.Includes bibliographical references (p. 227-234).Near-sonic parallel plasma flows are persistently observed in the scrape-off layer (SOL) of tokamaks, at locations far from material surfaces. Ballooning-like transport asymmetries are thought to be a principal driver for the strong parallel flows, a hypothesis supported by the observation of steep high-field side pressure profiles in double-null discharges. Yet parallel flow can also arise as a result of toroidal plasma rotation and/or neoclassical Pfirsch-Schliiter currents. In addition, the mechanism that closes the mass-flow loop back onto itself has remained elusive. To investigate these phenomena, a novel magnetically-actuated scanning probe has been deployed on the high-field side in Alcator C-Mod. This probe, along with two other scanning probes on the low-field side, measure the total plasma flow vector at these locations: parallel flows, perpendicular E_r x B drifts and radial fluctuation-induced particle fluxes. Boundary layer flows have been systematically examined as magnetic topology (upper versus lower-null) and plasma density were changed. It is found that the plasma flow pattern can be decomposed into two principal parts: (1) a drift-driven component, which lies within a magnetic flux surface and is divergence-free and (2) a transport-driven component which gives rise to parallel flows on the high-field side scrape-off layer.(cont.) Toroidal rotation, Pfirsch-Schlilter and transport-driven contributions are unambiguously identified. Parallel flows are found to dominate the high-field particle fluxes; the total poloidally-directed flow carries one half of the particle flux arriving on the inner divertor. As a result, convection is also found to be an important player in high-field side heat transport. In contrast, E_r x B plus parallel flows yield a mostly-toroidal flow component in the low-field SOL. The magnitude of the transport-driven flow component is found to be quantitatively consistent with radial fluctuation-induced particle fluxes measured on the low-field side, identifying this as the primary driver. In contrast, fluctuation-induced flux measurements on the high-field side midplane are found to be essentially zero, thereby excluding an 'inward pinch' effect as the mechanism that closes the mass-flow loop in this region.by Noah M. Smick.Ph.D

Development of vegetable oil-based emulsion liquid membrane for downstream processing of bio-succinic acid

Succinic acid has been recognized as a useful platform chemical that can be applied in various industries. The application of bio-based succinic acid is still limited due to high downstream processing cost. In this study, vegetable oil-based emulsion liquid membrane (ELM) process is proposed to recover succinic acid from fermentation broth. The ELM system consists of three main liquid phases; external feed, membrane, and internal stripping. The liquid membrane phase was prepared by dissolving Amberlite LA2 and Span 80 in palm oil, while, the internal phase comprises of sodium carbonate solution, Na2CO3. The influence of feed, stripping agent and carrier concentration, treat ratio, as well as liquid membrane recycling on ELM performance were studied. The results showed 10 g/L of initial concentration, 1.0 M of Na2CO3, 0.7 M of Amberlite LA2, and treat ratio of 1:5 is the best condition with almost 100% recovery and enrichment of 21 times. The recycled liquid membrane concentrates the succinic acid up to 12 times. Therefore, the proposed ELM is a potential technology to extract bio-succinic acid

Precious metals enrichment from wastewater solution using emulsion liquid membrane process

Recovery of precious metals including palladium and silver from liquid waste solutions is vital, in order to sustain the resources and to conserve the environment from hazardous materials, particularly heavy metals. Many methods were studied for precious metal recovery, but constrained by several limitations. One of the promising methods for industrial wastes treatment and precious metals recovery is emulsion liquid membrane (ELM). This method able to selectively separate and concentrate the target metals through a very thin layer of liquid membrane with large surface area. In this study, an attempt was made to recover palladium and silver from liquid waste solution using bis (2,4,4-trimethylpentyl) monothiophosphinic acid (Cyanex 302) as a mobile carrier. Several important parameters affecting the ELM recovery process such as extractant/carrier and stripping agent concentration, phase treatment ratio between emulsion and feed phase were studied. The results showed that at optimum process conditions of 0.03 M Cyanex 302 carrier concentration, 1.0 M of thiourea in 1.0 M of H2SO4(1.0 M acidic thiourea) stripping agent concentration and 1:4 treat ratio, almost 100% of silver was extracted and recovered with 11 times of enrichment. Whilst for the palladium treatment, almost 100% of palladium was extracted and recovered with 3 times enrichment in the receiving phase at 0.2 M of Cyanex 302, 1.0 M acidic thioureaof striping agent and 1:3 treat ratio. Therefore, it can be concluded that the ELM system is very promising and has high potential in removal and recovery of precious metals

Casimir Effects in Renormalizable Quantum Field Theories

We review the framework we and our collaborators have developed for the study of one-loop quantum corrections to extended field configurations in renormalizable quantum field theories. We work in the continuum, transforming the standard Casimir sum over modes into a sum over bound states and an integral over scattering states weighted by the density of states. We express the density of states in terms of phase shifts, allowing us to extract divergences by identifying Born approximations to the phase shifts with low order Feynman diagrams. Once isolated in Feynman diagrams, the divergences are canceled against standard counterterms. Thus regulated, the Casimir sum is highly convergent and amenable to numerical computation. Our methods have numerous applications to the theory of solitons, membranes, and quantum field theories in strong external fields or subject to boundary conditions.Comment: 27 pp., 11 EPS figures, LaTeX using ijmpa1.sty; email correspondence to R.L. Jaffe ; based on talks presented by the authors at the 5th workshop `QFTEX', Leipzig, September 200

Neutral Hydrogen Mapping of Virgo Cluster Blue Compact Dwarf Galaxies

A new installment of neutral hydrogen mappings of Blue Compact Dwarf galaxies, as defined by optical morphology, in and near the Virgo cluster is presented. The primary motivation was to search for outlying clouds of HI as potential interactive triggers of the enhanced star formation, and therefore the mapped galaxies were selected for large HI} mass, large optical diameter, and large velocity profile width. Approximately half the sample proved to have one or more small, low column density star-free companion clouds, either detached or appearing as an appendage in our maps, at resolution of order 4 kpc. Comparison is made to a sample of similarly mapped field BCD galaxies drawn from the literature; however, the Virgo cluster sample of mapped BCDs is still too small for conclusive comparisons to be made. We found, on the one hand, little or no evidence for ram pressure stripping nor, on the other, for extremely extended low column density HI envelopes. The HI rotation curves in most cases rise approximately linearly, and slowly, as far out as we can trace the gas.Comment: To appear in AJ, Dec. 200

Optimal Entanglement Enhancement for Mixed States

We consider the actions of protocols involving local quantum operations and classical communication (LQCC) on a single system consisting of two separated qubits. We give a complete description of the orbits of the space of states under LQCC and characterise the representatives with maximal entanglement of formation. We thus obtain a LQCC entanglement concentration protocol for a single given state (pure or mixed) of two qubits which is optimal in the sense that the protocol produces, with non-zero probability, a state of maximal possible entanglement of formation. This defines a new entanglement measure, the maximum extractable entanglement.Comment: Final version: to appear in Phys. Rev. Let

Emulsion stability of palladium extraction containing cyanex 302 as a mobile carrier in emulsion liquid membrane process

Emulsion Liquid Membrane (ELM) process is one of the alternative techniques to extract solutes from wastewater. It has been given considerable attention due to its advantages such as simultaneous extraction and recovery in a single step operation, non-equilibrium mass transfer, high fluxes, low energy consumption, reusability and high selectivity. The main concern in order to achieve high stability in the process is the size of internal droplets of primary emulsion. This study aims to investigate the affecting parameters such as concentration of surfactant, emulsification speed and emulsification time. ELM process containing bis(2,4,4-Trimethylpentyl) monothiophosphinic acid (Cyanex 302) as a mobile carrier in kerosene and acidic thiourea as stripping agent was used. The stability results showed that 2.8 μm of droplet diameter was formed at favorable condition of 2 % w/v surfactant concentration, 12,000 rpm of emulsification within 3 min of emulsification time. At this condition, 84 % of Palladium was extracted

The smallest refrigerators can reach maximal efficiency

We investigate whether size imposes a fundamental constraint on the efficiency of small thermal machines. We analyse in detail a model of a small self-contained refrigerator consisting of three qubits. We show analytically that this system can reach the Carnot efficiency, thus demonstrating that there exists no complementarity between size and efficiency.Comment: 9 pages, 1 figure. v2: published versio