We report the results of resonant x-ray diffraction at sulfur $K$-edge performed upon free-standing films a thiobenzoate liquid-crystal compound. Our data provide first direct structural evidence distinct periodicities in several chiral Sm-C phases, including 2-layer, 3-layer, and 4-layer superlattices $\mathrm{Sm}\ensuremath{-}{C}_{A}^{*}$, $\mathrm{Sm}\ensuremath{-}{C}_{\mathrm{FI}1}^{*}$, $\mathrm{Sm}\ensuremath{-}{C}_{\mathrm{FI}2}^{*}$, respectively. In...

FastSPECT II is a recently commissioned 16-camera small-animal SPECT imager built with modular scintillation cameras and list-mode data-acquisition electronics. The instrument housed in lead-shielded enclosure has exchangeable aperture assemblies adjustable camera positions for selection of magnification, pinhole size, field view. calibration individual measurement an overall system imaging matrix (1 mm(3) voxels) are supported via five-axis motion-control system.Details the integration...

In any gamma-ray detector, each event produces electrical signals on one or more circuit elements. From these signals, we may wish to determine the presence of an interaction; whether multiple interactions occurred; spatial coordinates in two three dimensions at least primary total energy deposited that interaction. We also want compute listmode probabilities for tomographic reconstruction. Maximum-likelihood methods provide a rigorous and some senses optimal approach extracting this...

It has been reported that hyaluronic acid (HA) with a 35 kDa molecular weight (HA35) acts biologically to protect tissue from injury, but its biological properties are not yet fully characterized. This study aimed evaluate the cellular effects and biodistribution of HA35 compared HA 1600 (HA1600). We assessed HA1600 on cell migration, NO ROS generation, gene expression in cultured macrophages, microglia, lymphocytes. was separately radiolabeled

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCrystallographic and EXAFS studies of conformationally designed nonplanar nickel(II) porphyrinsKathleen M. Barkigia, Mark W. Renner, Lars R. Furenlid, Craig J. Medforth, Kevin Smith, Jack FajerCite this: Am. Chem. Soc. 1993, 115, 9, 3627–3635Publication Date (Print):May 1, 1993Publication History Published online1 May 2002Published inissue 1 1993https://pubs.acs.org/doi/10.1021/ja00062a029https://doi.org/10.1021/ja00062a029research-articleACS...

We report polarization-analyzed, resonant x-ray diffraction at the sulfur K edge performed upon free-standing liquid-crystal films. Our studies of thiobenzoate enantiomer 10OTBBB1M7 yield polarization states satellite peaks arising from characteristic superlattices in chiral smectic-C $(\mathrm{Sm}{C}^{*})$ variant phases, including antiferroelectric $\mathrm{Sm}{C}_{A}^{{}^{*}},$ ferrielectric $\mathrm{Sm}{C}_{\mathrm{FI}1}^{*}$ and $\mathrm{Sm}{C}_{\mathrm{FI}2}^{*},$ as well...

The first full single‐photon emission computed tomography (SPECT) imager to exploit eight compact high‐intrinsic‐resolution cadmium zinc telluride (CZT) detectors, called SemiSPECT, has been completed. Each detector consists of a CZT crystal and customized application‐specific integrated circuit (ASIC). is slab with continuous top electrode bottom patterned into array by photolithography. ASIC attached the indium‐bump bonding. A bias voltage applied electrode. detectors are arranged in an...

A fast search algorithm capable of operating in multi-dimensional spaces is introduced. As a sample application, we demonstrate its utility the 2D and 3D maximum-likelihood position-estimation problem that arises processing PMT signals to derive interaction locations compact gamma cameras. We can be parallelized pipelines, thereby efficiently implemented specialized hardware, such as field-programmable gate arrays (FPGAs). implementation achieved Cell/BE processors, resulting speeds above...

Adaptive imaging systems alter their data-acquisition configuration or protocol in response to the image information received. An adaptive pinhole single-photon emission computed tomography (SPECT) system might acquire an initial scout obtain preliminary about radiotracer distribution and then adjust sizes of pinholes, magnifications, projection angles order improve performance. This paper briefly describes two small-animal SPECT that allow this flexibility presents a framework for...

Previously performed studies have shown that alfalfa shoot biomass can bind an appreciable amount of nickel(II) and chromium(III) ions from aqueous solution. Direct indirect approaches were applied to study the possible mechanisms involved in metal binding by biomass. The direct approach involves investigations metal-bound X-ray absorption spectroscopic analysis (XANES EXAFS). Results these suggest mostly occurs through coordination with oxygen ligands. Indirect consist chemical modification...

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTDirect XANES Evidence for Charge Transfer in Co−CO2 ComplexesEtsuko Fujita, Lars R. Furenlid, and Mark W. RennerView Author Information Chemistry Department, National Synchrotron Light Source, Department of Applied Science, Brookhaven Laboratory, Upton, New York 11973-5000 Cite this: J. Am. Chem. Soc. 1997, 119, 19, 4549–4550Publication Date (Web):May 14, 1997Publication History Received17 January 1997Published online14 May inissue 1...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTEXAFS studies of nickel(II), nickel(I), and Ni(I)-CO tetraazamacrocycles the crystal structure (5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene)nickel(I) perchlorateLars R. Furenlid, Mark W. Renner, David J. Szalda, Etsuko FujitaCite this: Am. Chem. Soc. 1991, 113, 3, 883–892Publication Date (Print):January 1, 1991Publication History Published online1 May 2002Published inissue 1 January...

We report herein the use of Medicago sativa alfalfa shoot biomass for removal gold from aqueous solutions. The accumulation process involves reduction Au(III) to colloidal Au(0) and is shown increase at elevated temperatures lower pH. X-ray absorption spectroscopy (XAS) was used determine that gold(III) reduced form gold(0) colloids, which varied in size depending on pH initial solution. cluster radius 6.2 ± 1 Å 5 9.0 2. Our findings indicate essentially another layer atoms deposited onto...

We have developed a dual-modality CT/SPECT imaging system for small-animal applications. The X-ray comprises commercially available micro-focus tube and CCD-based camera. transmission measurements are performed based on cone-beam geometry. Individual projections acquired by rotating the animal about vertical axis in front of CCD detector. A high-resolution CT image is obtained after reconstruction using an ordered subsets-expectation maximization (OS-EM) algorithm. SPECT utilizes compact...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTModels of factor 430. Structural and spectroscopic studies nickel(II) nickel(I) hydroporphyrinsMark W. Renner, Lars R. Furenlid, Kathleen M. Barkigia, Arthur Forman, Hyun Kwan Shim, Daniel J. Simpson, Kevin Smith, Jack FajerCite this: Am. Chem. Soc. 1991, 113, 18, 6891–6898Publication Date (Print):August 1, 1991Publication History Published online1 May 2002Published inissue 1 August 1991https://doi.org/10.1021/ja00018a027RIGHTS & PERMISSIONSArticle...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStructural consequences of nickel versus macrocycle reductions in F430 models: EXAFS studies a Ni(I) anion and Ni(II) .pi. radicalsLars R. Furenlid, Mark W. Renner, Kevin M. Smith, Jack FajerCite this: J. Am. Chem. Soc. 1990, 112, 4, 1634–1635Publication Date (Print):February 1, 1990Publication History Published online1 May 2002Published inissue 1 February...

High-energy (> 100 keV) photon detectors are often made thick relative to their lateral resolution in order improve photon-detection efficiency. To avoid issues of parallax and increased signal variance that result from random interaction depth, we must determine the 3D position imaging detector. With this goal mind, examine a method calibrating response statistics thick-detector gamma camera produce maximum-likelihood estimate position. We parameterize mean detector as function position,...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTEXAFS studies of nickel(II) and nickel(I) factor 430M. Conformational flexibility the F430 skeletonLars R. Furenlid, Mark W. Renner, Jack FajerCite this: J. Am. Chem. Soc. 1990, 112, 24, 8987–8989Publication Date (Print):November 1, 1990Publication History Published online1 May 2002Published inissue 1 November 1990https://pubs.acs.org/doi/10.1021/ja00180a058https://doi.org/10.1021/ja00180a058research-articleACS PublicationsRequest reuse...

The authors have designed and constructed a small‐animal adaptive SPECT imaging system as prototype for quantifying the potential benefit of over traditional fixed geometry approach. optical design is based on filling detector with region interest each viewing angle, maximizing sensitivity, optimizing resolution in projection images. Additional feedback rules determining optimal can be easily added to existing control software. Preliminary data been taken phantom small, hot, offset lesion...

Superparamagnetic iron oxide nanoparticles with well-integrated multimodality imaging properties have generated increasing research interest in the past decade, especially when it comes to targeted of tumors. Bevacizumab (BCZM) on other hand is a well-known and widely applied monoclonal antibody recognizing VEGF-A, which overexpressed angiogenesis. The aim this proof-of-concept study was develop dual-modality nanoplatform for vivo single photon emission tomography (SPET) magnetic resonance...

That guest atoms donate electrons to framework is a generally accepted concept. Nevertheless, evidence for the presence of neutral in thermoelectric clathrate structures presented form experimental X-ray charge density analysis and absorption near-edge structure (XANES) data. The picture shows deformation (DD) determined by maximum entropy method Ba8Ga16Ge30; DD that both Ba are disordered.