S.‐Y. Lee  G. Scharfenberger  W.&#x;H. Meyer  G. Wegner 《Advanced materials (Deerfield Beach, Fla.)》2005,17(5):626-630

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  总被引：15，自引：0，他引：15  

Lindsey ME  Meyer TM  Thurman EM 《Analytical chemistry》2001,73(19):4640-4646

A method has been developed for the trace analysis of two classes of antimicrobials consisting of six sulfonamides (SAs) and five tetracyclines (TCs), which commonly are used for veterinary purposes and agricultural feed additives and are suspected to leach into ground and surface water. The method used solid-phase extraction and liquid chromatography/mass spectrometry (LC/MS) with positive ion electrospray. The unique combination of a metal chelation agent (Na2EDTA) with a macroporous copolymer resulted in quantitative recoveries by solid-phase extraction (mean recovery, 98 +/- 12%) at submicrogramper-liter concentrations. An ammonium formate/formic acid buffer with a methanol/water gradient was used to separate the antimicrobials and to optimize the signal intensity. Mass spectral fragmentation and ionization characteristics were determined for each class of compounds for unequivocal identification. For all SAs, a characteristic m/z 156 ion representing the sulfanilyl fragment was identified. TCs exhibited neutral losses of 17 amu resulting from the loss of ammonia and 35 amu from the subsequent loss of water. Unusual matrix effects were seen only for TCs in this first survey of groundwater and surface water samples from sites around the United States, requiring that TCs be quantitated using the method of standard additions.  相似文献   

    

A. Bruinink  J.‐P. Kaiser  D.&#x;C. Meyer 《Advanced Engineering Materials》2005,7(5):411-418

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Eisenberg JM  Foster NE  Meyer G  Holland H 《The Joint Commission journal on quality improvement》2001,27(2):93-100

FORMATION OF THE QUIC: The Quality Interagency Coordination Task Force (QuIC) was established in 1998 to enable the participating federal agencies to coordinate their activities to study, measure, and improve the quality of care delivered by federal health programs; provide people with information to help them in making more informed choices about their care; and develop the research base and infrastructure needed to improve the health care system, including knowledgeable and empowered workers, well-designed systems of care, and useful information systems. STUDY, MEASURE, AND IMPROVE CARE: The QuIC's initial efforts to improve the care delivered in federal health care programs have focused on diabetes, depression, and the effect of working conditions on quality of care. More recently, patient safety efforts are under way to establish a coordinating center that will enable those who are testing methods of reducing errors to share information across their projects and with experts in error reduction. DEVELOP A RESEARCH BASE AND INFRASTRUCTURE: The QuIC has coordinated efforts in credentialing, information on measures of quality, a taxonomy of quality improvement methods, and errors data collection. PROVIDE INFORMATION TO AMERICANS ABOUT HEALTH CARE QUALITY: The QuIC agencies are developing products that will enhance their ability to communicate with the American people about their health care choices: improved gateways for consumer information available from federal agencies, a glossary of commonly used terms, and guidance for producing report cards on quality of care. MOVING THE QUALITY IMPROVEMENT AGENDA FORWARD: Federal efforts to improve quality of care are moving forward in a more integrated fashion on a wide number of fronts.  相似文献   

    

Marcos Meyer  L. E. Lagoeiro  L. M. Graça  C. J. Silva 《Mineral Processing and Extractive Metallurgy Review》2016,37(5):295-304

In the production of the pellets, phase identification for specific sintering condition is of prime importance in understanding the basis for the production and the required properties. The application of a methodology involving optical and scanning electron microscope equipped with an EBSD opened a broad possibility to establish a base for the relationship between heat-treated pellet microstructural features and cold crushing strength. The first results from the conjoined application of these techniques show that the cold crushing strength of the pellet increase with the decrease of porosity, the appearance of the fayalite, as well as the presence of magnetite-unoxidized.  相似文献   

    

DM Parker  JR Lishman  J Hughes 《Canadian Metallurgical Quarterly》1996,22(6):1448-1466

In 4 experiments the role of coarse (low-pass filtered) and fine (high-pass filtered) spatial information in guiding visual processing was studied in a same-different task. The second of a pair of sequential patterns was either a normal image or the first 100 ms was restricted either coarse or fine information before a normal image was shown for the rest of the presentation. This 100-ms cue could be from the immediately succeeding image (relevant) or from other images in the set (irrelevant). Analysis of response times and errors showed relevant coarse- and fine-scale cues were usually equally effective, but any differences favored fine-scale versions. Irrelevant fine-scale cuing was significantly more disruptive than coarse-scale cuing. No evidence of preferential cuing by coarse-scale information occurred in any experiment.  相似文献   

    

S Bhasin  K Ma  DM de Kretser 《Canadian Metallurgical Quarterly》1997,29(4):261-263

OBJECTIVE: To develop a simple assay using the silica wool filtration (SIFT) procedure to estimate percentage of acrosome-reacted (AR) sperm. SETTING: Private andrology laboratory. MATERIALS AND METHODS: Capacitated sperm processed by the SIFT procedure to remove nonviable sperm and those with broken membrane were acrosome reacted by induction with a calcium ionophore. Following the acrosome reaction, the sample was processed by the SIFT procedure. Sperm concentration and acrosomal status were also determined before and after the SIFT procedure. RESULTS: The SIFT procedure prevented AR sperm from filtering (mean +/- SD, 22.2 +/- 1.9 vs. 9.8 +/- 4.9%). The mean percent of sperm retained in the filter (SIFT assay: 61.8 +/- 21.5%) was significantly higher than the percent of AR sperm estimated by a staining technique (26.4 +/- 7.3%), but they were significantly correlated (r = .34) with each other. The filtration of capacitated sperm prior to induction of the acrosome reaction eliminated, or at least minimized, the possibility of falsely increasing the percent of AR sperm estimated by the SIFT assay. The higher estimate obtained by SIFT assay, therefore, suggests that it may be estimating sperm at various stages that are undergoing the acrosome reaction. CONCLUSION: The findings suggest that the SIFT assay could be used to estimate the percentage of AR spermatozoa.  相似文献   

    

LJ Oshinskie  DM Waitzman 《Canadian Metallurgical Quarterly》1996,67(8):481-495

BACKGROUND: Computed tomography (CT) and magnetic resonance imaging (MR) are commonly used neuroimaging modalities for patients with signs or symptoms of neuro-ophthalmic disorders. Understanding the technology and clinical uses of these modalities is vital in patient management. METHODS/RESULTS: Basic instrument design and technology are presented together with a discussion of indications and contraindications to the use of these imaging techniques. Case reports are presented to illustrate the usefulness in diagnosis of orbital and neuro-ophthalmic disease. CONCLUSIONS: A basic knowledge of CT and MR helps the optometrist correlate imaging with clinical signs and symptoms of disease. This understanding also results in more effective communication with other health care providers and patients.  相似文献   

    

JM Rusted  L Graupner  A Tennant  DM Warburton 《Canadian Metallurgical Quarterly》1998,138(3-4):362-368

We report two studies examining the effects of nicotine on memory in minimally deprived smokers. In experiment 1, semantically related words were recalled significantly better than unrelated words following nicotine, even when volunteers were explicitly instructed to target the unrelated word set for recall. Experiment 2 examined the effect of nicotine on two different types of lexical association: association by joint category membership (semantically related items), and association by derived meaning (\"encapsulated\" word pairs). Nicotine-induced improvements in recall were observed only for category associates and not for encapsulated word pairs. This implies that explicit, effortful processing of material in the presence of nicotine is necessary for improved recall performance to be observed.  相似文献   

    

DM Avila  SA Fuqua  FW George  MJ McPhaul 《Canadian Metallurgical Quarterly》1998,159(3):403-411

In mammals, testosterone and 5alpha-dihydrotestosterone (DHT) are the principal male hormones (androgens). Testosterone is the most abundant circulating androgen, and is converted in specific tissues to DHT by the 5alpha-reductase enzymes. Although each of these androgens binds to the same receptor protein (androgen receptor, AR), each exerts biologically distinct effects. Theories to explain the specific effects of testosterone and DHT have centered on kinetic differences of binding of androgens to the receptor or differences in the metabolic fates of the two hormones. In the current experiments, differential display PCR (ddPCR) was used to identify genes regulated differently by testosterone and DHT. Adult male rats were treated as follows: castrated, treated with Finasteride (an inhibitor of 5alpha-reductase) or left intact for ten days. RNA was prepared from the dissected prostates of these animals and used for ddPCR. Genes exhibiting four distinct patterns of regulation were observed among the mRNAs. Class 1 genes showed equivalent expression in intact and Finasteride-treated animals, but were absent in castrated animals (mRNAs D1, D2, D6, D10). Class 2 genes showed higher expression in intact animals, intermediate levels following Finasteride treatment, but were absent in castrated animals (mRNA D8). Two classes of gene were particularly intriguing: class 3 showed gene expression only in the intact animal (mRNA D7, D9) and class 4 showed increased gene expression following Finasteride treatment (mRNA D3). While the patterns observed for some of these genes (e.g. D8) suggest that the different biological effects of testosterone and DHT may be due to the lower affinity of the AR for testosterone and limiting tissue concentrations of androgen, our results also suggest that some genes expressed in the rat prostate may be regulated in fundamentally different ways in response to testosterone and DHT.  相似文献