ONGUARD

PURPOSE: The purpose of the study was to determine whether computer-aided detection (CAD) can improve a radiologist's ability to detect lung cancers previously missed on a chest radiograph (CXR). MATERIALS AND METHODS: Eighty-one cases of lung cancer previously missed on CXR were collected, along with the CXRs of 215 age-matched and emphysema-matched controls without lung cancer. Tumor subtlety was scored from 1 (very subtle) to 5 (very obvious) by expert thoracic radiologists...

RATIONALE: Isotope analysis of carbohydrates is important for improved understanding of plant carbon metabolism and plant physiological response to the environment. High-performance liquid chromatography/isotope ratio mass spectrometry (HPLC/IRMS) for direct compound-specific δ(13)C measurements of soluble carbohydrates has recently been developed, but the still challenging sample preparation and the fact that no single method is capable of separating all compounds of interest hinder its wide-spread application...

A method for the determination of glyphosate in human blood by ion chromatography was established. The protein in heart blood from a corpse was precipitated with acetonitrile. The large molecules and Cl(-) in the supernatant were removed by a Dionex OnGuard II RP column and a Dionex OnGuard II Ag column, respectively. The filtrate was separated on an IonPac AS-19 column with KOH solution as eluent produced online by an eluent generator (EG). A suppressor with external water mode and a conductivity detector for the detection were used...

A new method for the determination of five cations (sodium, ammonium, potassium, magnesium and calcium) in wines and beverages was developed and validated based on capillary ion chromatography. With a capillary ion exchange column (IonPac CS12A, 250 mm x 0.4 mm, 8 microm) and 18 mmol/L methanesulfonic acid (MSA) elution, the five cations can be well separated in 15 min. After suppression with a capillary suppressor (CCES 300), the background was much decreased, and the sensitivities of the cations were greatly improved...

Stomatal guard cells play a key role in gas exchange for photosynthesis while minimizing transpirational water loss from plants by opening and closing the stomatal pore. Foliar gas exchange has long been incorporated into mathematical models, several of which are robust enough to recapitulate transpirational characteristics at the whole-plant and community levels. Few models of stomata have been developed from the bottom up, however, and none are sufficiently generalized to be widely applicable in predicting stomatal behavior at a cellular level...

The dynamics of stomatal movements and their consequences for photosynthesis and transpirational water loss have long been incorporated into mathematical models, but none have been developed from the bottom up that are widely applicable in predicting stomatal behavior at a cellular level. We previously established a systems dynamic model incorporating explicitly the wealth of biophysical and kinetic knowledge available for guard cell transport, signaling, and homeostasis. Here we describe the behavior of the model in response to experimentally documented changes in primary pump activities and malate (Mal) synthesis imposed over a diurnal cycle...

A simple, rapid and accurate method for the determination of monoethanolamine (MEA) in PHWR steam-water circuits has been developed. MEA is added in the feed water to provide protection against corrosion while hydrazine is added to scavenge dissolved oxygen. The quantitative determination of MEA in presence of hydrazine was accomplished using derivatization ion chromatography with conductometric detection in nonsuppressed mode. A Metrosep cation 1-2 analytical column and a Metrosep cartridge were used for cation separation...

OBJECTIVE: The primary objective of our study was to compare the effect of a chest radiography computer-aided detection (CAD) system on the follow-up recommendations of chest radiologists, general radiologists, and pulmonologists. MATERIALS AND METHODS: A chest radiography CAD system (RapidScreen 1.1) that has been approved by the U.S. Food and Drug Administration (FDA) and a second-generation version of the system (OnGuard 3.0) not yet approved by the FDA were applied to single frontal radiographs of 200 patients at high risk for lung cancer...

PURPOSE: There are few computer-aided detection (CAD) systems that are available for the detection of nodules on chest radiographs. We evaluated the performance of a Food and Drug Administration-approved system and 3 of its subsequent versions to determine their potential to improve readers' accuracy. MATERIALS AND METHODS: We tested the performance of 4 generations of CAD software programs, RapidScreen 1.1 and OnGuard 3.0, 4.0, and 5.0 (Riverain Medical), for their ability to detect lung cancer on a sample of 100 patients with and 100 patients without nodules...

The contents of iodide and thiocyanate are important detection items in powdered milk quality testing. Due to the complexity of the powdered milk matrix, chromatographic analysis is easily subjected to interference. Acclaim Mixed-Mode WAX-1 column incorporated both hydrophobic and weak anion-exchange properties was used to separate iodide and thiocyanate from interfering substances in powdered milk matrix, and detected by Ultraviolet (UV) detection. After powdered milk was dissolved in water, the protein was precipitated by acetonitrile...

A method was developed for the quantitative determination of inorganic cations and anions present in liquid crystal materials pretreated with ultraviolet irradiation by ion chromatography. The samples were irradiated at less than 20+/-2 degrees C and then pretreated with OnGuard RP and P cartridges to remove the interferential organic compounds prior to ion chromatographic analysis for both cations and anions. With a high capacity and very hydrophilic anion exchange column, four anions (fluoride, chloride, bromide, iodide) were determined in 20 min with gradient of sodium hydroxide...

A simple, rapid and accurate method for the determination of iodate in iodized common salts has been developed. The quantitative determination of iodate was accomplished by anion exchange chromatography with conductimetric detection. The method requires a sample pretreatment for the removal of large excess of chloride from the sample matrix. Onguard silver cartridges were found most suitable for this purpose. The sulphate content in the salt was simultaneously determined. The lower limits for the determination of iodate and sulphate in solution are 0...

A method for the determination of anions in the degradation products of C. I. Reactive Red 120 by ozonation was investigated. The sample can be pretreated with a Dionex OnGuard P column, which has high selectivity for removing phenols, azo group-contaning compounds, aromatic carboxylic aicds etc. For the separation of organic and inorganic anions in the products, the anion exchange chromatograhy with gradient elution of NaOH was used. All the species were detected by both suppressed conductivity and UV absorbance detectors...

A new method for the determination of nine haloacetic acids (HAAs) with ion chromatography (IC) coupled to inductively coupled plasma mass spectrometry (ICP-MS) was developed. With the very hydrophilic anion-exchange column and steep gradient of sodium hydroxide, the nine HAAs could be well separated in 15 min. After suppression with an ASRS suppressor that was introduced in between IC and ICP-MS, the background was much decreased, the interference caused by sodium ion present in eluent was removed, and the sensitivities of HAAs were greatly improved...

Based on selective sorption of bromide, bromoacetic acids (BAA) and bromomethanes on solid-phase extraction (SPE) cartridges, a sensitive and convenient method was developed for the determination of bromate in waters by inductively coupled plasma mass spectrometry (ICP-MS). Dionex OnGuard Ag and reversed-phase (RP) cartridges were tested for retention characteristics for bromide, BAA and bromomethanes. When a sample acidified with nitric acid was passed through an RP cartridge, BAA and bromomethanes were retained, afterwards bromide was absorbed as a precipitate of silver bromide and bromate was unretained when the nearly neutral sample passed a combination of Ag and H cartridges...

A new method for the determination of anions in liquid crystal samples by UV-photolysis-ion chromatography was developed. The sample pretreatment method, the photolytic conditions and the chromatographic parameters were optimized. The results indicate that there have five anions (F-, Cl-, NO2-, Br-, I-) in the liquid crystal sample. By the filtration with the Dionex OnGuard RP and P cartridges, most of the organic compounds in the photolyzed sample solution can be removed. In the process of photolysis, the efficiency can be remarkably enhanced by the adding of H2O2...

A simple sample preconcentration technique for the determination of trace level of bromate and perchlorate in drinking water with ion chromatography is presented. With the hydrophobic anion-exchange column and a sodium hydroxide eluent in linear gradient, bromate and perchlorate can be determined in a single injection within 35 min. Prior to ion chromatographic analysis, the drinking water sample was treated with the OnGuard Ag cartridge to remove the superfluous chloride and concentrated in 20-fold with poly(tetrafluoroethylene)(PTFE) beaker in a domestic microwave oven in 15 min...

An ion chromatographic method for determining chloride and trace anions, such as F-, Br-, I- and SO4(2-) in natural gas field water with high chloride concentration was studied. The separation of the anions was achieved on an IonPac AS11 column with NaOH as gradient eluent, and the detection was performed by a conductivity detection mode (self-regenerated suppression). The pre-treatment of the samples was through a filter of 0.45 micron and a Dionex OnGuard RP C18 column. The method is simple and useful, and has good linearity with correlation coefficients between 0...

A simple sample preconcentration technique employing microwave-based evaporation for the determination of trace level bromate and perchlorate in drinking water with ion chromatography is presented. With a hydrophilic anion-exchange column and a sodium hydroxide eluent in linear gradient, bromate and perchlorate can be determined in one injection within 35 min. Prior to ion chromatographic analysis, the drinking water sample was treated with an OnGuard-Ag cartridge to remove the superfluous chloride and concentrated 20-fold using a PTFE beaker in a domestic microwave oven for 15 min...

In spite of the good accuracy and precision of ion chromatographic methods for the determination of mono- and divalent cations in human serum, the major drawback with these methods were problems with the membrane suppressor's performance. Here, we describe experiments undertaken to solve these problems. We address in particular the use of histidine-sulfuric acid eluents, sample purification with OnGuard-A cartridges and chromatographic "front-cut" for divalent cations. The latter two adaptations, resulting in removal of the anionic species from the sample, were successful in solving the observed suppressor problems...