DCU 250 Arabic dependency bank: an LFG gold standard resource for the Arabic Penn treebank

OpenAIRE

Al-Raheb, Yafa; Akrout, Amine; van Genabith, Josef; Dichy, J.

2006-01-01

This paper describes the construction of a dependency bank gold standard for Arabic, DCU 250 Arabic Dependency Bank (DCU 250), based on the Arabic Penn Treebank Corpus (ATB) (Bies and Maamouri, 2003; Maamouri and Bies, 2004) within the theoretical framework of Lexical Functional Grammar (LFG). For parsing and automatically extracting grammatical and lexical resources from treebanks, it is necessary to evaluate against established gold standard resources. Gold standards for various languages h...

Progression-free survival: gaining on overall survival as a gold standard and accelerating drug development.

Science.gov (United States)

Lebwohl, David; Kay, Andrea; Berg, William; Baladi, Jean Francois; Zheng, Ji

2009-01-01

In clinical trials of oncology drugs, overall survival (OS) is a direct measure of clinical efficacy and is considered the gold standard primary efficacy end point. The purpose of this study was to discuss the difficulties in using OS as a primary efficacy end point in the setting of evolving cancer therapies. We suggest that progression-free survival is an appropriate efficacy end point in many types of cancer, specifically those for which OS is expected to be prolonged and for which subsequent treatments are expected to affect OS.

An ROC-type measure of diagnostic accuracy when the gold standard is continuous-scale.

Science.gov (United States)

Obuchowski, Nancy A

2006-02-15

ROC curves and summary measures of accuracy derived from them, such as the area under the ROC curve, have become the standard for describing and comparing the accuracy of diagnostic tests. Methods for estimating ROC curves rely on the existence of a gold standard which dichotomizes patients into disease present or absent. There are, however, many examples of diagnostic tests whose gold standards are not binary-scale, but rather continuous-scale. Unnatural dichotomization of these gold standards leads to bias and inconsistency in estimates of diagnostic accuracy. In this paper, we propose a non-parametric estimator of diagnostic test accuracy which does not require dichotomization of the gold standard. This estimator has an interpretation analogous to the area under the ROC curve. We propose a confidence interval for test accuracy and a statistical test for comparing accuracies of tests from paired designs. We compare the performance (i.e. CI coverage, type I error rate, power) of the proposed methods with several alternatives. An example is presented where the accuracies of two quick blood tests for measuring serum iron concentrations are estimated and compared.

Gold Nanotheranostics: Proof-of-Concept or Clinical Tool?

Directory of Open Access Journals (Sweden)

Pedro Pedrosa

2015-11-01

Full Text Available Nanoparticles have been making their way in biomedical applications and personalized medicine, allowing for the coupling of diagnostics and therapeutics into a single nanomaterial—nanotheranostics. Gold nanoparticles, in particular, have unique features that make them excellent nanomaterials for theranostics, enabling the integration of targeting, imaging and therapeutics in a single platform, with proven applicability in the management of heterogeneous diseases, such as cancer. In this review, we focus on gold nanoparticle-based theranostics at the lab bench, through pre-clinical and clinical stages. With few products facing clinical trials, much remains to be done to effectively assess the real benefits of nanotheranostics at the clinical level. Hence, we also discuss the efforts currently being made to translate nanotheranostics into the market, as well as their commercial impact.

Task-based evaluation of segmentation algorithms for diffusion-weighted MRI without using a gold standard

International Nuclear Information System (INIS)

Jha, Abhinav K; Kupinski, Matthew A; Rodríguez, Jeffrey J; Stephen, Renu M; Stopeck, Alison T

2012-01-01

In many studies, the estimation of the apparent diffusion coefficient (ADC) of lesions in visceral organs in diffusion-weighted (DW) magnetic resonance images requires an accurate lesion-segmentation algorithm. To evaluate these lesion-segmentation algorithms, region-overlap measures are used currently. However, the end task from the DW images is accurate ADC estimation, and the region-overlap measures do not evaluate the segmentation algorithms on this task. Moreover, these measures rely on the existence of gold-standard segmentation of the lesion, which is typically unavailable. In this paper, we study the problem of task-based evaluation of segmentation algorithms in DW imaging in the absence of a gold standard. We first show that using manual segmentations instead of gold-standard segmentations for this task-based evaluation is unreliable. We then propose a method to compare the segmentation algorithms that does not require gold-standard or manual segmentation results. The no-gold-standard method estimates the bias and the variance of the error between the true ADC values and the ADC values estimated using the automated segmentation algorithm. The method can be used to rank the segmentation algorithms on the basis of both the ensemble mean square error and precision. We also propose consistency checks for this evaluation technique. (paper)

Low friction arthroplasty and dual mobility cup: a new gold standard.

Science.gov (United States)

Prudhon, Jean Louis; Verdier, Régis; Caton, Jacques H

2017-03-01

Low friction arthroplasty (LFA) introduced by Sir John Charnley was the gold standard for many years. Dislocation and infection are the first causes for early revision. Late failures are polyethylene (PE) wear and loosening. Due to dislocation risk we slowly switched to the use of LFA with dual mobility cups (DMC). The purposes of this study are (1) to assess whether our changes have improved outcomes and (2) what is the new gold standard? We selected from an observational registry of 1,091 cases of hybrid Charnley total hip arthroplasty (THA). The acetabular component was either DMC in 455 cases or fixed cup (FC) in 636 cases. Three dislocations (0.6%) occurred in the DMC group (none revised). In the FC group 54 dislocated (8.49%) and 20 were recurrent and underwent revision (revision rate 3.14%). In the DMC group, five acetabular and three femoral revisions were performed (revision rate for loosening 1.7%). In the FC group 19 cases underwent acetabular revision, and five cases had femoral component revised (revision rate for loosening 3.7%). Charnley's LFA has proven over 50 years of excellent survivorship. To decrease dislocation risk, one suggested increasing femoral head diameter. Gilles Bousquet proposed another way, namely, the DMC concept. Dislocation is no longer a critical issue with DMC as demonstrated in our series and main series. DMC in primary THA is still a subject of debate. Mid-term results do not demonstrate a higher rate of wear than LFA. What is the current gold standard? LFA was and is our current gold standard in association with a DMC.

Democratic Constraints and Adherence to the Classical Gold Standard

NARCIS (Netherlands)

Kramer, Bert S.; Milionis, Petros

We study how domestic politics affected the decisions of countries to adhere to the classical gold standard. Using a variety of econometric techniques and controlling for a wide range of economic factors, we demonstrate that political constraints were important in the decision of countries to adopt

The gold standard: gold nanoparticle libraries to understand the nano-bio interface.

Science.gov (United States)

Alkilany, Alaaldin M; Lohse, Samuel E; Murphy, Catherine J

2013-03-19

Since the late 1980s, researchers have prepared inorganic nanoparticles of many types--including elemental metals, metal oxides, metal sulfides, metal selenides, and metal tellurides--with excellent control over size and shape. Originally many researchers were primarily interested in exploring the quantum size effects predicted for such materials. Applications of inorganic nanomaterials initially centered on physics, optics, and engineering but have expanded to include biology. Many current nanomaterials can serve as biochemical sensors, contrast agents in cellular or tissue imaging, drug delivery vehicles, or even as therapeutics. In this Account we emphasize that the understanding of how nanomaterials will function in a biological system relies on the knowledge of the interface between biological systems and nanomaterials, the nano-bio interface. Gold nanoparticles can serve as excellent standards to understand more general features of the nano-bio interface because of its many advantages over other inorganic materials. The bulk material is chemically inert, and well-established synthetic methods allow researchers to control its size, shape, and surface chemistry. Gold's background concentration in biological systems is low, which makes it relatively easy to measure it at the part-per-billion level or lower in water. In addition, the large electron density of gold enables relatively simple electron microscopic experiments to localize it within thin sections of cells or tissue. Finally, gold's brilliant optical properties at the nanoscale are tunable with size, shape, and aggregation state and enable many of the promising chemical sensing, imaging, and therapeutic applications. Basic experiments with gold nanoparticles and cells include measuring the toxicity of the particles to cells in in vitro experiments. The species other than gold in the nanoparticle solution can be responsible for the apparent toxicity at a particular dose. Once the identity of the toxic

Effectiveness of the Gold Standard Programme compared with other smoking cessation interventions in Denmark

DEFF Research Database (Denmark)

Rasmussen, Mette; Fernández, Esteve; Tønnesen, Hanne

2017-01-01

Objectives: We compared the effectiveness of the Gold Standard Programme (a comprehensive smoking cessation intervention commonly used in Denmark) with other face-to-face smoking cessation programmes in Denmark after implementation in real life, and we identified factors associated with successful...... did not want further contact, who intentionally were not followed up or who lacked information about the intervention they received were excluded. A total of 46 287 smokers were included. Interventions: Various real-life smoking cessation interventions were identified and compared: The Gold Standard...... smokers. The follow-up rate was 74%. Women were less likely to remain abstinent, OR 0.83 (CI 0.79 to 0.87). Short interventions were more effective among men. After adjusting for confounders, the Gold Standard Programme was the only intervention with significant results across sex, increasing the odds...

Gold-standard for computer-assisted morphological sperm analysis.

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Chang, Violeta; Garcia, Alejandra; Hitschfeld, Nancy; Härtel, Steffen

2017-04-01

Published algorithms for classification of human sperm heads are based on relatively small image databases that are not open to the public, and thus no direct comparison is available for competing methods. We describe a gold-standard for morphological sperm analysis (SCIAN-MorphoSpermGS), a dataset of sperm head images with expert-classification labels in one of the following classes: normal, tapered, pyriform, small or amorphous. This gold-standard is for evaluating and comparing known techniques and future improvements to present approaches for classification of human sperm heads for semen analysis. Although this paper does not provide a computational tool for morphological sperm analysis, we present a set of experiments for comparing sperm head description and classification common techniques. This classification base-line is aimed to be used as a reference for future improvements to present approaches for human sperm head classification. The gold-standard provides a label for each sperm head, which is achieved by majority voting among experts. The classification base-line compares four supervised learning methods (1- Nearest Neighbor, naive Bayes, decision trees and Support Vector Machine (SVM)) and three shape-based descriptors (Hu moments, Zernike moments and Fourier descriptors), reporting the accuracy and the true positive rate for each experiment. We used Fleiss' Kappa Coefficient to evaluate the inter-expert agreement and Fisher's exact test for inter-expert variability and statistical significant differences between descriptors and learning techniques. Our results confirm the high degree of inter-expert variability in the morphological sperm analysis. Regarding the classification base line, we show that none of the standard descriptors or classification approaches is best suitable for tackling the problem of sperm head classification. We discovered that the correct classification rate was highly variable when trying to discriminate among non-normal sperm

The Trouble with the Gold Standard: School Libraries & Research

Science.gov (United States)

Gordon, Carol

2007-01-01

Although science has provided empirical evidence for centuries, it's only as recently as the 1940s that a scientific method called randomized controlled trials (RCT) emerged as a technique to test the efficacy of drugs and medical procedures. Since RCT is unique in that it can claim causality, it's considered the "gold standard" of research…

Postcholecystectomy benign biliary stricture: Surgery is the gold standard

Directory of Open Access Journals (Sweden)

Sadiq S Sikora

2012-01-01

Full Text Available Post cholecystectomy bile duct strictures present a challenge to the treating physicians. Advancement in skills and technology offers alternative treatment modalities to the standard surgical repair. Contemporary series of surgical repair by experienced surgeons report excellent long-term results with <5% restricture rates. Endoscopic therapy is conceptually flawed, is not applicable to all patients, requires prolonged duration of treatment with multiple interventions. Surgical repair by an experienced surgeon is the "Gold Standard" of care in management of postcholecystectomy bile duct strictures.

CHRONIC OBSTRUCTIVE PULMONARY DISEASE: DEFINITION, EPIDEMIOLOGY, PATHOPHYSIOLOGY, CLINICAL PICTURE AND TREATMENT (GOLD 2013

Directory of Open Access Journals (Sweden)

M. T. Vatutin

2015-01-01

Full Text Available Chronic obstructive pulmonary disease: definition, epidemiology, pathophysiology, clinical picture (GOLD 2013. Vatutin M.T., Smyrnova G.S., Taradin G.G. The represented translation of the new international guidelines (GOLD 2013 reflected the epidemiology, pathophysiology, clinical picture and treatment of chronic obstructive pulmonary disease.

Partial verification bias and incorporation bias affected accuracy estimates of diagnostic studies for biomarkers that were part of an existing composite gold standard.

Science.gov (United States)

Karch, Annika; Koch, Armin; Zapf, Antonia; Zerr, Inga; Karch, André

2016-10-01

To investigate how choice of gold standard biases estimates of sensitivity and specificity in studies reassessing the diagnostic accuracy of biomarkers that are already part of a lifetime composite gold standard (CGS). We performed a simulation study based on the real-life example of the biomarker "protein 14-3-3" used for diagnosing Creutzfeldt-Jakob disease. Three different types of gold standard were compared: perfect gold standard "autopsy" (available in a small fraction only; prone to partial verification bias), lifetime CGS (including the biomarker under investigation; prone to incorporation bias), and "best available" gold standard (autopsy if available, otherwise CGS). Sensitivity was unbiased when comparing 14-3-3 with autopsy but overestimated when using CGS or "best available" gold standard. Specificity of 14-3-3 was underestimated in scenarios comparing 14-3-3 with autopsy (up to 24%). In contrast, overestimation (up to 20%) was observed for specificity compared with CGS; this could be reduced to 0-10% when using the "best available" gold standard. Choice of gold standard affects considerably estimates of diagnostic accuracy. Using the "best available" gold standard (autopsy where available, otherwise CGS) leads to valid estimates of specificity, whereas sensitivity is estimated best when tested against autopsy alone. Copyright © 2016 Elsevier Inc. All rights reserved.

Determination of gold and silver in geological standard samples MGI by instrument neutron activation analysis

International Nuclear Information System (INIS)

Lu Huijiuan; Zhou; Yunlu

1987-01-01

Gold and silver in geological standard samples MGI were determined by instrument neutron activation analysis. The various interferences of nuclides were considered. Corrected factors of the geometry in different positions have been determined. Using the geological standard sample MGM and radiochemical separation neutron activation method as reference, the reliability of this method is proved. Gold content in samples is 0.4-0.009 g/t, silver content is 9-0.3 g/t. Standard deviation is less than 3.5%, the precision of the measurement is 4.8-11.6%

A multilingual gold-standard corpus for biomedical concept recognition: the Mantra GSC.

Science.gov (United States)

Kors, Jan A; Clematide, Simon; Akhondi, Saber A; van Mulligen, Erik M; Rebholz-Schuhmann, Dietrich

2015-09-01

To create a multilingual gold-standard corpus for biomedical concept recognition. We selected text units from different parallel corpora (Medline abstract titles, drug labels, biomedical patent claims) in English, French, German, Spanish, and Dutch. Three annotators per language independently annotated the biomedical concepts, based on a subset of the Unified Medical Language System and covering a wide range of semantic groups. To reduce the annotation workload, automatically generated preannotations were provided. Individual annotations were automatically harmonized and then adjudicated, and cross-language consistency checks were carried out to arrive at the final annotations. The number of final annotations was 5530. Inter-annotator agreement scores indicate good agreement (median F-score 0.79), and are similar to those between individual annotators and the gold standard. The automatically generated harmonized annotation set for each language performed equally well as the best annotator for that language. The use of automatic preannotations, harmonized annotations, and parallel corpora helped to keep the manual annotation efforts manageable. The inter-annotator agreement scores provide a reference standard for gauging the performance of automatic annotation techniques. To our knowledge, this is the first gold-standard corpus for biomedical concept recognition in languages other than English. Other distinguishing features are the wide variety of semantic groups that are being covered, and the diversity of text genres that were annotated. © The Author 2015. Published by Oxford University Press on behalf of the American Medical Informatics Association.

Assessing validity of a depression screening instrument in the absence of a gold standard.

Science.gov (United States)

Gelaye, Bizu; Tadesse, Mahlet G; Williams, Michelle A; Fann, Jesse R; Vander Stoep, Ann; Andrew Zhou, Xiao-Hua

2014-07-01

We evaluated the extent to which use of a hypothesized imperfect gold standard, the Composite International Diagnostic Interview (CIDI), biases the estimates of diagnostic accuracy of the Patient Health Questionnaire-9 (PHQ-9). We also evaluate how statistical correction can be used to address this bias. The study was conducted among 926 adults where structured interviews were conducted to collect information about participants' current major depressive disorder using PHQ-9 and CIDI instruments. First, we evaluated the relative psychometric properties of PHQ-9 using CIDI as a gold standard. Next, we used a Bayesian latent class model to correct for the bias. In comparison with CIDI, the relative sensitivity and specificity of the PHQ-9 for detecting major depressive disorder at a cut point of 10 or more were 53.1% (95% confidence interval: 45.4%-60.8%) and 77.5% (95% confidence interval, 74.5%-80.5%), respectively. Using a Bayesian latent class model to correct for the bias arising from the use of an imperfect gold standard increased the sensitivity and specificity of PHQ-9 to 79.8% (95% Bayesian credible interval, 64.9%-90.8%) and 79.1% (95% Bayesian credible interval, 74.7%-83.7%), respectively. Our results provided evidence that assessing diagnostic validity of mental health screening instrument, where application of a gold standard might not be available, can be accomplished by using appropriate statistical methods. Copyright © 2014 Elsevier Inc. All rights reserved.

Comparison of EHR-based diagnosis documentation locations to a gold standard for risk stratification in patients with multiple chronic conditions.

Science.gov (United States)

Martin, Shelby; Wagner, Jesse; Lupulescu-Mann, Nicoleta; Ramsey, Katrina; Cohen, Aaron; Graven, Peter; Weiskopf, Nicole G; Dorr, David A

2017-08-02

To measure variation among four different Electronic Health Record (EHR) system documentation locations versus 'gold standard' manual chart review for risk stratification in patients with multiple chronic illnesses. Adults seen in primary care with EHR evidence of at least one of 13 conditions were included. EHRs were manually reviewed to determine presence of active diagnoses, and risk scores were calculated using three different methodologies and five EHR documentation locations. Claims data were used to assess cost and utilization for the following year. Descriptive and diagnostic statistics were calculated for each EHR location. Criterion validity testing compared the gold standard verified diagnoses versus other EHR locations and risk scores in predicting future cost and utilization. Nine hundred patients had 2,179 probable diagnoses. About 70% of the diagnoses from the EHR were verified by gold standard. For a subset of patients having baseline and prediction year data (n=750), modeling showed that the gold standard was the best predictor of outcomes on average for a subset of patients that had these data. However, combining all data sources together had nearly equivalent performance for prediction as the gold standard. EHR data locations were inaccurate 30% of the time, leading to improvement in overall modeling from a gold standard from chart review for individual diagnoses. However, the impact on identification of the highest risk patients was minor, and combining data from different EHR locations was equivalent to gold standard performance. The reviewer's ability to identify a diagnosis as correct was influenced by a variety of factors, including completeness, temporality, and perceived accuracy of chart data.

PET/CT in cancer: moderate sample sizes may suffice to justify replacement of a regional gold standard

DEFF Research Database (Denmark)

Gerke, Oke; Poulsen, Mads Hvid; Bouchelouche, Kirsten

2009-01-01

PURPOSE: For certain cancer indications, the current patient evaluation strategy is a perfect but locally restricted gold standard procedure. If positron emission tomography/computed tomography (PET/CT) can be shown to be reliable within the gold standard region and if it can be argued that PET...... of metastasized prostate cancer. RESULTS: An added value in accuracy of PET/CT in adjacent areas can outweigh a downsized target level of accuracy in the gold standard region, justifying smaller sample sizes. CONCLUSIONS: If PET/CT provides an accuracy benefit in adjacent regions, then sample sizes can be reduced....../CT also performs well in adjacent areas, then sample sizes in accuracy studies can be reduced. PROCEDURES: Traditional standard power calculations for demonstrating sensitivities of both 80% and 90% are shown. The argument is then described in general terms and demonstrated by an ongoing study...

Effectiveness of the Gold Standard Programme compared with other smoking cessation interventions in Denmark: a cohort study.

Science.gov (United States)

Rasmussen, Mette; Fernández, Esteve; Tønnesen, Hanne

2017-02-27

We compared the effectiveness of the Gold Standard Programme (a comprehensive smoking cessation intervention commonly used in Denmark) with other face-to-face smoking cessation programmes in Denmark after implementation in real life, and we identified factors associated with successful quitting. Prospective cohort study. A total of 423 smoking cessation clinics from different settings reported data from 2001 to 2013. In total, 82 515 patients were registered. Smokers ≥15 years old and attending a programme with planned follow-up were included. Smokers who did not want further contact, who intentionally were not followed up or who lacked information about the intervention they received were excluded. A total of 46 287 smokers were included. Various real-life smoking cessation interventions were identified and compared: The Gold Standard Programme, Come & Quit, crash courses, health promotion counselling (brief intervention) and other interventions. Self-reported continuous abstinence for 6 months. Overall, 33% (11 184) were continuously abstinent after 6 months; this value was 24% when non-respondents were considered smokers. The follow-up rate was 74%. Women were less likely to remain abstinent, OR 0.83 (CI 0.79 to 0.87). Short interventions were more effective among men. After adjusting for confounders, the Gold Standard Programme was the only intervention with significant results across sex, increasing the odds of abstinence by 69% for men and 31% for women. In particular, compliance, and to a lesser degree, mild smoking, older age and not being disadvantaged were associated with positive outcomes for both sexes. Compliance increased the odds of abstinence more than 3.5-fold. Over time, Danish smoking cessation interventions have been effective in real life. Compliance is the main predictor of successful quitting. Interestingly, short programmes seem to have relatively strong effects among men, but the absolute numbers are very small. Only the

Gold standard program for heavy smokers in a real-life setting

DEFF Research Database (Denmark)

Neumann, Tim; Rasmussen, Mette; Heitmann, Berit L

2013-01-01

Background: High-intensity smoking cessation programs generally lead to more continuous abstinence, however, lower rates of success have been reported among heavy smokers. The aim was to evaluate continuous abstinence among heavy smokers during the intensive 6-week Gold Standard Program (GSP......) and to identify modifiable factors associated with continuous abstinence. Methods: In this nationwide clinical study based on 36,550 smokers attending an intensive cessation program in Denmark. Heavy smoking was defined as ≥7 points in the Fagerström Nicotine Dependency Test, smoking ≥20 cigarettes daily or ≥20...... pack-years. Results: Overall, 28% had a Fagerström score ≥7 points, 58% smoked ≥20 cigarettes daily and 68% smoked ≥20 pack-years. Continuous abstinence was 33% in responders (6-months response rate: 78%); however, abstinence was approximately 1-6% lower in the heavy smokers than the overall population...

75 FR 28227 - National Emission Standards for Hazardous Air Pollutants: Gold Mine Ore Processing and Production...

Science.gov (United States)

2010-05-20

...-AP48 National Emission Standards for Hazardous Air Pollutants: Gold Mine Ore Processing and Production... published a proposed rule for mercury emissions from the gold mine ore processing and production area source... Environmental protection, Air pollution control, Hazardous substances, Incorporations by reference, Reporting...

Does the Gold Standard label hold its promise in delivering higher Sustainable Development benefits? A multi-criteria comparison of CDM projects

International Nuclear Information System (INIS)

Drupp, Moritz A.

2011-01-01

The Clean Development Mechanism (CDM) has a twin objective: to help developed countries reduce GHG emissions, and to support developing countries in achieving Sustainable Development (SD). As a response to the widespread criticism of the CDM's unsatisfactory SD record, initiatives have developed premium labels like the Gold Standard, which applies two additional 'screens' to filter CDM projects for higher SD benefits. In order to determine whether Gold Standard projects can be associated with higher local SD benefits, this paper evaluates the potential benefits of 48 CDM projects using a multi-criteria method and building on existing work. The 18 evaluated Gold Standard projects are compared to a 'representative portfolio' of 30 unlabeled CDM projects in order to capture the 'full' effect of the additional Gold Standard requirements, which is further decomposed into the two 'screen' effects. The results suggest that Gold Standard Certified Emission Reductions can be associated with higher potential local SD benefits when compared to the 'representative portfolio' of unlabeled CDM projects, while the comparison of projects of the same type remains inconclusive. The results support previous findings showing that renewable energy projects may deliver comparatively high SD benefits. - Research highlights: → This study evaluates and compares the potential contribution of unlabeled- and Gold Standard labeled CDM projects to Sustainable Development (SD), extending the previously assessed projects as well as the methodological approach. → Gold Standard labeled Certified Emission Reductions (CER) can be associated with higher potential SD benefits compared to unlabeled projects. → A decomposition analysis shows that the Gold Standard s SD surplus must be primarily attributed to the favorable contribution of renewable energy projects to SD. → Policy makers might thus shift incentives towards renewable energy projects and buyers of CERs may shift their offset

Gold standard capture cross section from 100 keV to 15 MeV

International Nuclear Information System (INIS)

Ryves, T.B.

1982-01-01

The capture cross section of gold is now generally accepted as the principal reference standard, and therefore in this review only gold is considered. Recent measurements of the gold capture cross section in the unresolved region are discussed and compared with the ENDF/B-V evaluation. It is concluded that in the energy interval 100 to 2000 keV the present uncertainty in the evaluation is +-8%, in the interval 2 to 3.5 MeV the uncertainty is +-4%, in ther interval 3.5 to 14 MeV more measurements are needed before a realistic error can be assigned, and from 14 to 15 MeV the uncertainty is +-10%. Several recommendations for future work have been made

Changing organizational culture: using the CEO cancer gold standard policy initiatives to promote health and wellness at a school of public health.

Science.gov (United States)

Towne, Samuel D; Anderson, Kelsey E; Smith, Matthew Lee; Dahlke, Deborah Vollmer; Kellstedt, Debra; Purcell, Ninfa Pena; Ory, Marcia G

2015-09-03

Worksite wellness initiatives for health promotion and health education have demonstrated effectiveness in improving employee health and wellness. We examined the effects of a multifaceted health promotion campaign on organizational capacity to meet requirements to become CEO Cancer Gold Standard Accredited. We conducted an online survey to assess perceived organizational values and support for the five CEO Cancer Gold Standard Pillars for cancer prevention: tobacco cessation; physical activity; nutrition; cancer screening and early detection; and accessing information on cancer clinical trials. Baseline and follow-up surveys were sent 6-months apart to faculty, staff, and students at a school of public health to test the impact of a multifaceted health promotion campaign on perceived organizational change. Descriptive analyses were used to characterize percent improvement. Multivariate logistic regression analyses were used to control for participants' university status. The current organizational culture highly supported tobacco cessation at both time points. Significant improvements (p screening, and early detection of cancer' and 'accessing cancer treatment and clinical trials'. Health promotion and education efforts using multiple approaches were effective to improve perceived organizational values and support for cancer prevention and early detection, and increase access to information about cancer clinical trials. Future studies are needed to examine broader impacts of implementing worksite health promotion initiatives.

Usage of Latent Class Analysis in Diagnostic Microbiology in the Absence of Gold Standard Test

Directory of Open Access Journals (Sweden)

Gul Bayram Abiha

2016-12-01

Full Text Available The evaluation of performance of various tests diagnostic tests in the absence of gold standard is an important problem. Latent class analysis (LCA is a statistical analysis method known for many years, especially in the absence of a gold standard for evaluation of diagnostic tests so that LCA has found its wide application area. During the last decade, LCA method has widely used in for determining sensivity and specifity of different microbiological tests. It has investigated in the diagnosis of mycobacterium tuberculosis, mycobacterium bovis, human papilloma virus, bordetella pertussis, influenza viruses, hepatitis E virus (HEV, hepatitis C virus (HCV and other various viral infections. Researchers have compared several diagnostic tests for the diagnosis of different pathogens with LCA. We aimed to evaluate performance of latent class analysis method used microbiological diagnosis in various diseases in several researches. When we took into account all of these tests' results, we suppose that LCA is a good statistical analysis method to assess different test performances in the absence of gold standard. [Archives Medical Review Journal 2016; 25(4.000: 467-488

Validating Automated Essay Scoring: A (Modest) Refinement of the "Gold Standard"

Science.gov (United States)

Powers, Donald E.; Escoffery, David S.; Duchnowski, Matthew P.

2015-01-01

By far, the most frequently used method of validating (the interpretation and use of) automated essay scores has been to compare them with scores awarded by human raters. Although this practice is questionable, human-machine agreement is still often regarded as the "gold standard." Our objective was to refine this model and apply it to…

Carbon finance and pro-poor co-benefits: The Gold Standard and Climate, Community and Biodiversity Standards

Energy Technology Data Exchange (ETDEWEB)

Wood, Rachel

2011-04-15

This paper assesses the practical contribution of the Gold Standard (GS) and Climate Community and Biodiversity (CCB) Standards to local development through the identification of high quality carbon offset projects and ensuring high standards of consultation with local communities during project development and implementation. It is based on desk research, involving analysis of the GS and CCB Standards' project databases, project design documents, and secondary literature. In addition, over 20 representatives of the two standards systems, project developers, NGO representatives, and researchers were interviewed. The paper concludes that both standard systems successfully reward high quality projects which have a demonstrated commitment to local consultations and sustainable development benefits. Moreover, they serve to give well-meaning project developers frameworks with which to ensure that a wide range of criteria are considered in planning and implementing projects. As voluntary standards, it is unrealistic to expect either the GS or CCB Standards to improve poor-quality or unsustainable projects.

Carbon finance and pro-poor co-benefits: The Gold Standard and Climate, Community and Biodiversity Standards

Energy Technology Data Exchange (ETDEWEB)

Wood, Rachel

2011-04-15

This paper assesses the practical contribution of the Gold Standard (GS) and Climate Community and Biodiversity (CCB) Standards to local development through the identification of high quality carbon offset projects and ensuring high standards of consultation with local communities during project development and implementation. It is based on desk research, involving analysis of the GS and CCB Standards' project databases, project design documents, and secondary literature. In addition, over 20 representatives of the two standards systems, project developers, NGO representatives, and researchers were interviewed. The paper concludes that both standard systems successfully reward high quality projects which have a demonstrated commitment to local consultations and sustainable development benefits. Moreover, they serve to give well-meaning project developers frameworks with which to ensure that a wide range of criteria are considered in planning and implementing projects. As voluntary standards, it is unrealistic to expect either the GS or CCB Standards to improve poor-quality or unsustainable projects.

International Reserves Crises, Monetary Integration and the Payments System during the International Gold Standard

OpenAIRE

Paula Hernandez-Verme

2009-01-01

I model an international payments system with a financial center and periphery to reproduce various aspects of the International Gold Standard. This period was characterized by frequent crises associated with scarce stocks of reserves, high short-term interest rates with subsequent gold inflows and transmission of output contractions across countries. I find that a common international currency and no legal restrictions on exchange help the periphery share reserves with the financial center, ...

Quantitative Rapid Assessment of Leukoaraiosis in CT : Comparison to Gold Standard MRI.

Science.gov (United States)

Hanning, Uta; Sporns, Peter Bernhard; Schmidt, Rene; Niederstadt, Thomas; Minnerup, Jens; Bier, Georg; Knecht, Stefan; Kemmling, André

2017-10-20

The severity of white matter lesions (WML) is a risk factor of hemorrhage and predictor of clinical outcome after ischemic stroke; however, in contrast to magnetic resonance imaging (MRI) reliable quantification for this surrogate marker is limited for computed tomography (CT), the leading stroke imaging technique. We aimed to present and evaluate a CT-based automated rater-independent method for quantification of microangiopathic white matter changes. Patients with suspected minor stroke (National Institutes of Health Stroke scale, NIHSS < 4) were screened for the analysis of non-contrast computerized tomography (NCCT) at admission and compared to follow-up MRI. The MRI-based WML volume and visual Fazekas scores were assessed as the gold standard reference. We employed a recently published probabilistic brain segmentation algorithm for CT images to determine the tissue-specific density of WM space. All voxel-wise densities were quantified in WM space and weighted according to partial probabilistic WM content. The resulting mean weighted density of WM space in NCCT, the surrogate of WML, was correlated with reference to MRI-based WML parameters. The process of CT-based tissue-specific segmentation was reliable in 79 cases with varying severity of microangiopathy. Voxel-wise weighted density within WM spaces showed a noticeable correlation (r = -0.65) with MRI-based WML volume. Particularly in patients with moderate or severe lesion load according to the visual Fazekas score the algorithm provided reliable prediction of MRI-based WML volume. Automated observer-independent quantification of voxel-wise WM density in CT significantly correlates with microangiopathic WM disease in gold standard MRI. This rapid surrogate of white matter lesion load in CT may support objective WML assessment and therapeutic decision-making during acute stroke triage.

Use of gold and silver standards based on phenol-formalde-hyde resin in assay-activation analysis of geological samples

International Nuclear Information System (INIS)

Aliev, A.I.; Drynkin, V.I.; Lejpunskaya, D.I.; Nedostup, T.V.

1976-01-01

Using standards on phenol-formaldehyde resin base for assaying-activation analysis of geological specimens for gold and silver has bee the advantage of uniformly distributing Au and Ag in spesimens and possible preparing tablets of practically any form or size. The validity and accuracy of these standards have been studied for the cases of short irradiation. Conventional point standards were used as reference standards. The experiments carried out have shown that tablet resol standards are suitable for a mass assaying-activation analysis for gold and silver at practically any concentrations

Seeking a Valid Gold Standard for an Innovative, Dialect-Neutral Language Test

Science.gov (United States)

Pearson, Barbara Zurer; Jackson, Janice E.; Wu, Haotian

2014-01-01

Purpose: In this study, the authors explored alternative gold standards to validate an innovative, dialect-neutral language assessment. Method: Participants were 78 African American children, ages 5;0 (years;months) to 6;11. Twenty participants had previously been identified as having language impairment. The Diagnostic Evaluation of Language…

Population Health Metrics Research Consortium gold standard verbal autopsy validation study: design, implementation, and development of analysis datasets

Directory of Open Access Journals (Sweden)

Ohno Summer

2011-08-01

Full Text Available Abstract Background Verbal autopsy methods are critically important for evaluating the leading causes of death in populations without adequate vital registration systems. With a myriad of analytical and data collection approaches, it is essential to create a high quality validation dataset from different populations to evaluate comparative method performance and make recommendations for future verbal autopsy implementation. This study was undertaken to compile a set of strictly defined gold standard deaths for which verbal autopsies were collected to validate the accuracy of different methods of verbal autopsy cause of death assignment. Methods Data collection was implemented in six sites in four countries: Andhra Pradesh, India; Bohol, Philippines; Dar es Salaam, Tanzania; Mexico City, Mexico; Pemba Island, Tanzania; and Uttar Pradesh, India. The Population Health Metrics Research Consortium (PHMRC developed stringent diagnostic criteria including laboratory, pathology, and medical imaging findings to identify gold standard deaths in health facilities as well as an enhanced verbal autopsy instrument based on World Health Organization (WHO standards. A cause list was constructed based on the WHO Global Burden of Disease estimates of the leading causes of death, potential to identify unique signs and symptoms, and the likely existence of sufficient medical technology to ascertain gold standard cases. Blinded verbal autopsies were collected on all gold standard deaths. Results Over 12,000 verbal autopsies on deaths with gold standard diagnoses were collected (7,836 adults, 2,075 children, 1,629 neonates, and 1,002 stillbirths. Difficulties in finding sufficient cases to meet gold standard criteria as well as problems with misclassification for certain causes meant that the target list of causes for analysis was reduced to 34 for adults, 21 for children, and 10 for neonates, excluding stillbirths. To ensure strict independence for the validation of

Human papillomavirus testing as a cytology gold standard : comparing Surinam with the Netherlands

NARCIS (Netherlands)

Wachtel, MS; Boon, ME; Korporaal, H; Kok, LP

Polymerase chain reaction to detect high- risk human papillomavirus has been suggested as a gold standard for cytology. The Netherlands and Surinam were prospectively compared in regard to the proportions of Negative, Atypical Squamous Cells of Undetermined Significance, and Squamous Intraepithelial

Reassessing RCTs as the "Gold Standard": Synergy Not Separatism in Evaluation Designs

Science.gov (United States)

Hanley, Pam; Chambers, Bette; Haslam, Jonathan

2016-01-01

Randomised controlled trials (RCTs) are increasingly used to evaluate educational interventions in the UK. However, RCTs remain controversial for some elements of the research community. This paper argues that the widespread use of the term "gold standard" to describe RCTs is problematic, as it implies that other research methods are…

After the Gold Rush: Questioning the "Gold Standard" and Reappraising the Status of Experiment and Randomized Controlled Trials in Education

Science.gov (United States)

Thomas, Gary

2016-01-01

The past few years have seen a resurgence of faith in experimentation in education inquiry, and particularly in randomized controlled trials (RCTs). Proponents of such research have succeeded in bringing into common parlance the term "gold standard," which suggests that research emerging from any other design frame fails to achieve the…

Gold Returns

OpenAIRE

Robert J. Barro; Sanjay P. Misra

2013-01-01

From 1836 to 2011, the average real rate of price change for gold in the United States is 1.1% per year and the standard deviation is 13.1%, implying a one-standard-deviation confidence band for the mean of (0.1%, 2.1%). The covariances of gold's real rate of price change with consumption and GDP growth rates are small and statistically insignificantly different from zero. These negligible covariances suggest that gold's expected real rate of return--which includes an unobserved dividend yiel...

Proteomic Analysis Reveals the Leaf Color Regulation Mechanism in Chimera Hosta "Gold Standard" Leaves.

Science.gov (United States)

Yu, Juanjuan; Zhang, Jinzheng; Zhao, Qi; Liu, Yuelu; Chen, Sixue; Guo, Hongliang; Shi, Lei; Dai, Shaojun

2016-03-08

Leaf color change of variegated leaves from chimera species is regulated by fine-tuned molecular mechanisms. Hosta "Gold Standard" is a typical chimera Hosta species with golden-green variegated leaves, which is an ideal material to investigate the molecular mechanisms of leaf variegation. In this study, the margin and center regions of young and mature leaves from Hosta "Gold Standard", as well as the leaves from plants after excess nitrogen fertilization were studied using physiological and comparative proteomic approaches. We identified 31 differentially expressed proteins in various regions and development stages of variegated leaves. Some of them may be related to the leaf color regulation in Hosta "Gold Standard". For example, cytosolic glutamine synthetase (GS1), heat shock protein 70 (Hsp70), and chloroplastic elongation factor G (cpEF-G) were involved in pigment-related nitrogen synthesis as well as protein synthesis and processing. By integrating the proteomics data with physiological results, we revealed the metabolic patterns of nitrogen metabolism, photosynthesis, energy supply, as well as chloroplast protein synthesis, import and processing in various leaf regions at different development stages. Additionally, chloroplast-localized proteoforms involved in nitrogen metabolism, photosynthesis and protein processing implied that post-translational modifications were crucial for leaf color regulation. These results provide new clues toward understanding the mechanisms of leaf color regulation in variegated leaves.

Testing Pneumonia Vaccines in the Elderly: Determining a Case Definition for Pneumococcal Pneumonia in the Absence of a Gold Standard.

Science.gov (United States)

Jokinen, Jukka; Snellman, Marja; Palmu, Arto A; Saukkoriipi, Annika; Verlant, Vincent; Pascal, Thierry; Devaster, Jeanne-Marie; Hausdorff, William P; Kilpi, Terhi M

2017-12-15

Clinical assessments of vaccines to prevent pneumococcal (Pnc) community-acquired pneumonia (CAP) require sensitive and specific case definitions, but there is no gold standard diagnostic test. To develop a new case definition suitable for vaccine efficacy studies, we applied latent class analysis (LCA) to the results from seven diagnostic tests for Pnc etiology on clinical specimens from 323 elderly radiologically-confirmed pneumonia cases enrolled in The Finnish Community-Acquired Pneumonia Epidemiology study during 2005-2007. Compared to the conventional use of LCA, which is mainly to determine sensitivities and specificities of different tests, we instead used LCA as an appropriate instrument to predict the probability of Pnc etiology for each CAP case based on their test profiles, and utilized the predictions to minimize the sample size that would be needed for a vaccine efficacy trial. When compared to the conventional laboratory criteria of encapsulated Pnc in blood culture or in high-quality sputum culture or urine antigen positivity, our optimized case definition for PncCAP resulted in a trial sample size which was almost 20,000 subjects smaller. We believe that our novel application of LCA detailed here to determine a case definition for PncCAP could also be similarly applied to other diseases without a gold standard. © The Author(s) 2017. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health.

PIXE studies on gold standards by protons of energy 3.3 Me V

International Nuclear Information System (INIS)

Joseph, Daisy; Saxena, A.; Gupta, S.K.; Kailas, S.

2005-01-01

Proton Induced X-ray Emission Technique (PIXE) has been used in analysing Gold standards of 22, 20, 18, and 14 karats with a proton beam of energy 3.3 MeV at the newly commissioned Folded Tandem Ion Accelerator (FOTIA). Well resolved Au and Ag X-rays were detected at a current of 3 nA. Percentage values of gold and silver were calculated and were checked with those obtained by Energy Dispersive X-ray Fluorescence Method and were found to be in agreement with the certified values as well as those obtained by XRF. (author)

Gold monetization and gold discipline

OpenAIRE

Robert P. Flood; Peter M. Garber

1981-01-01

The paper is a study of the price level and relative price effects of a policy to monetize gold and fix its price at a given future time and at the then prevailing nominal price. Price movements are analyzed both during the transition to the gold standard and during the post-monetization period. The paper also explores the adjustments to fiat money which are necessary to ensure that this type of gold monetization is non-inflationary. Finally, some conditions which produce a run on the governm...

A studentized permutation test for three-arm trials in the 'gold standard' design.

Science.gov (United States)

Mütze, Tobias; Konietschke, Frank; Munk, Axel; Friede, Tim

2017-03-15

The 'gold standard' design for three-arm trials refers to trials with an active control and a placebo control in addition to the experimental treatment group. This trial design is recommended when being ethically justifiable and it allows the simultaneous comparison of experimental treatment, active control, and placebo. Parametric testing methods have been studied plentifully over the past years. However, these methods often tend to be liberal or conservative when distributional assumptions are not met particularly with small sample sizes. In this article, we introduce a studentized permutation test for testing non-inferiority and superiority of the experimental treatment compared with the active control in three-arm trials in the 'gold standard' design. The performance of the studentized permutation test for finite sample sizes is assessed in a Monte Carlo simulation study under various parameter constellations. Emphasis is put on whether the studentized permutation test meets the target significance level. For comparison purposes, commonly used Wald-type tests, which do not make any distributional assumptions, are included in the simulation study. The simulation study shows that the presented studentized permutation test for assessing non-inferiority in three-arm trials in the 'gold standard' design outperforms its competitors, for instance the test based on a quasi-Poisson model, for count data. The methods discussed in this paper are implemented in the R package ThreeArmedTrials which is available on the comprehensive R archive network (CRAN). Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

A no-gold-standard technique for objective assessment of quantitative nuclear-medicine imaging methods.

Science.gov (United States)

Jha, Abhinav K; Caffo, Brian; Frey, Eric C

2016-04-07

The objective optimization and evaluation of nuclear-medicine quantitative imaging methods using patient data is highly desirable but often hindered by the lack of a gold standard. Previously, a regression-without-truth (RWT) approach has been proposed for evaluating quantitative imaging methods in the absence of a gold standard, but this approach implicitly assumes that bounds on the distribution of true values are known. Several quantitative imaging methods in nuclear-medicine imaging measure parameters where these bounds are not known, such as the activity concentration in an organ or the volume of a tumor. We extended upon the RWT approach to develop a no-gold-standard (NGS) technique for objectively evaluating such quantitative nuclear-medicine imaging methods with patient data in the absence of any ground truth. Using the parameters estimated with the NGS technique, a figure of merit, the noise-to-slope ratio (NSR), can be computed, which can rank the methods on the basis of precision. An issue with NGS evaluation techniques is the requirement of a large number of patient studies. To reduce this requirement, the proposed method explored the use of multiple quantitative measurements from the same patient, such as the activity concentration values from different organs in the same patient. The proposed technique was evaluated using rigorous numerical experiments and using data from realistic simulation studies. The numerical experiments demonstrated that the NSR was estimated accurately using the proposed NGS technique when the bounds on the distribution of true values were not precisely known, thus serving as a very reliable metric for ranking the methods on the basis of precision. In the realistic simulation study, the NGS technique was used to rank reconstruction methods for quantitative single-photon emission computed tomography (SPECT) based on their performance on the task of estimating the mean activity concentration within a known volume of interest

A no-gold-standard technique for objective assessment of quantitative nuclear-medicine imaging methods

International Nuclear Information System (INIS)

Jha, Abhinav K; Frey, Eric C; Caffo, Brian

2016-01-01

The objective optimization and evaluation of nuclear-medicine quantitative imaging methods using patient data is highly desirable but often hindered by the lack of a gold standard. Previously, a regression-without-truth (RWT) approach has been proposed for evaluating quantitative imaging methods in the absence of a gold standard, but this approach implicitly assumes that bounds on the distribution of true values are known. Several quantitative imaging methods in nuclear-medicine imaging measure parameters where these bounds are not known, such as the activity concentration in an organ or the volume of a tumor. We extended upon the RWT approach to develop a no-gold-standard (NGS) technique for objectively evaluating such quantitative nuclear-medicine imaging methods with patient data in the absence of any ground truth. Using the parameters estimated with the NGS technique, a figure of merit, the noise-to-slope ratio (NSR), can be computed, which can rank the methods on the basis of precision. An issue with NGS evaluation techniques is the requirement of a large number of patient studies. To reduce this requirement, the proposed method explored the use of multiple quantitative measurements from the same patient, such as the activity concentration values from different organs in the same patient. The proposed technique was evaluated using rigorous numerical experiments and using data from realistic simulation studies. The numerical experiments demonstrated that the NSR was estimated accurately using the proposed NGS technique when the bounds on the distribution of true values were not precisely known, thus serving as a very reliable metric for ranking the methods on the basis of precision. In the realistic simulation study, the NGS technique was used to rank reconstruction methods for quantitative single-photon emission computed tomography (SPECT) based on their performance on the task of estimating the mean activity concentration within a known volume of interest

Evaluation of the accuracy of diagnostic scales for a syndrome in Chinese medicine in the absence of a gold standard.

Science.gov (United States)

Wang, Xiao Nan; Zhou, Vanessa; Liu, Qiang; Gao, Ying; Zhou, Xiao-Hua

2016-01-01

The concept of syndromes (zhengs) is unique to Chinese medicine (CM) and difficult to measure. Expert consensus is used as a gold standard to identify zhengs and evaluate the accuracy of existing diagnostic scales for zhengs. But, the use of expert consensus as a gold standard is problematic because the diagnosis of zhengs by expert consensus is not 100 % accurate. This study aimed to evaluate the accuracy of standardized diagnostic scales for a syndrome zhengs in the absence of a gold standard, with application to internal wind (nei feng) syndrome in ischemic stroke patients. A total of 204 participants (age 41-84 years) with ischemic stroke were assessed by the stroke syndrome differentiation diagnostic criterion (SSDC), ischemic stroke TCM syndrome diagnostic scale (ISDS), and expert syndrome differentiation (ESD). The diagnostic tests and data collection process were conducted over a 10-month period (February 2008 to November 2008) in 10 hospitals across nine cities in China. The Bayesian method was used to estimate the accuracy of the SSDC, ISDS, and ESD. For internal wind syndrome, the estimated sensitivities and specificities of the SSDC, ISDS, and ESD without use of a gold standard were respectively: [Formula: see text], [Formula: see text]; [Formula: see text], [Formula: see text]; and [Formula: see text], [Formula: see text]. After adjusting for imperfect gold standard bias, we found that both the sensitivity and specificity of the ISDS were higher than those of the SSDC for diagnosis of internal wind syndrome in ischemic stroke patients.

A study of prostate delineation referenced against a gold standard created from the visible human data

International Nuclear Information System (INIS)

Gao Zhanrong; Wilkins, David; Eapen, Libni; Morash, Christopher; Wassef, Youssef; Gerig, Lee

2007-01-01

Purpose: To measure inter- and intra-observer variation and systematic error in CT based prostate delineation, where individual delineations are referenced against a gold standard produced from photographic anatomical images from the Visible Human Project (VHP). Materials and methods: The CT and anatomical images of the VHP male form the basic data set for this study. The gold standard was established based on 1 mm thick anatomical photographic images. These were registered against the 3 mm thick CT images that were used for target delineation. A total of 120 organ delineations were performed by six radiation oncologists. Results: The physician delineated prostate volume was on average 30% larger than the 'true' prostate volume, but on average included only 84% of the gold standard volume. Our study found a systematic delineation error such that posterior portions of the prostate were always missed while anteriorly some normal tissue was always defined as target. Conclusions: Our data suggest that radiation oncologists are more concerned with the unintentional inclusion of rectal tissue than they are in missing prostate volume. In contrast, they are likely to overextend the anterior boundary of the prostate to encompass normal tissue such as the bladder

Voluntary pulmonary function screening with GOLD standard: an effective and simple approach to detect lung obstruction.

Science.gov (United States)

Wang, Shengyu; Gong, Wei; Tian, Yao; Yang, Min

2015-11-01

The prevalence of lung obstruction is probably underestimated. Early detection and screening may alter the course and prognosis associated with lung disease. We investigated the effectiveness of voluntary lung function screening program and the agreement between the Global Initiative for Chronic Obstructive Lung Disease (GOLD) and the lower limit of normal (LLN) standard for public screening in Xi'an China. Pulmonary function testing was conducted on volunteers recruited from eight community centers in Xi'an, China between July and August 2012. Participants underwent three forced vital capacity (FVC) maneuvers. The maneuver with the best FEV1 was retained. Participants filled out a medical history survey before undergoing pulmonary function testing. Patients that self-reported lung disease on the health survey were excluded from the analysis. A total of 803 volunteers participated in this study. And 722 participants (93.8%) did not self-report chronic lung disease and were analyzed. Of these participants, 143 subjects (19.8%) were diagnosed by GOLD standard and 134 subjects (18.6%) had obstruction with LLN definition. GOLD definition can identify more asymptomatic subjects (19.1%) with respect to LLN. GOLD definition can detect more lung obstruction in elder subjects compared with young people, the difference is significant (P=0.0007). The overall agreement between the 2 methods was good: the kappa estimate was 0.822. The agreement in subjects aged 40-49, 50-59 and 60-69 years was good: the kappa estimate was 0.82, 0.936 and 0.907 respectively and the agreement in subjects aged 18-29 was inferior: the kappa estimate was only 0.555. Voluntary lung function screening program with GOLD standard may be a simple and effective approach to ensuring high yield detection of lung obstruction in subjects aged 40-69.

Estimation of economic consequences of GOLD guidelines adoption in the Italian clinical practice

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Orietta Zaniolo

2011-03-01

Full Text Available Background: Chronic Obstructive Pulmonary Disease (COPD affects about 4.5% of the Italian population, representing one of most burdensome public health problems. Literature data report an annual health care expenditure ranging between € 1,300 and € 4,500 per patient, of which drug costs are a limited share. In 1998 the WHO started GOLD program in order to ameliorate COPD patient management. As a part of his program, periodically updated guidelines are produced with the aim of defining an efficient diagnostic-therapeutic pathway managed by a multidisciplinary team and based on the optimization of the use of drugs and diagnostic tests and the reduction of exposure to risk factors.Objective: to estimate the economic consequences of GOLD guidelines adoption in the Italian clinical practice.Methods: a decision analytic model capable of calculating the impact on the National Health Service budget of an ameliorated adherence to GOLD guidelines (GOLD GL strategy, basing on the needed variations in health care strategies on a defined patient cohort treated with the current approach (CURRENT strategy. The simulation runs on a cohort representing Italian COPD patients over 45 years who transit through 5 Markov health states (4 GOLD stages and death, according to patient characteristics (age, gender, FEV1, with a time horizon of 3 years. Stage-specific drug consumption of the CURRENT strategy is based on data of 3,113 patients collected by three Health Local Units involved in a larger clinical audit project. The consumption of other health resources, i.e. medical visits and inpatient care, is estimated based on a multicentre observational Italian study. The GOLD GL strategy includes spirometry-based staging on the totality of the simulated patients, the development of a therapeutic strategy including the redefinition of pharmacological therapy based on guideline recommendations and experts opinion, and variation of other health resources consumption

Median sternotomy - gold standard incision for cardiac surgeons

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Radu Matache

2016-05-01

Full Text Available Sternotomy is the gold standard incision for cardiac surgeons but it is also used in thoracic surgery especially for mediastinal, tracheal and main stem bronchus surgery. The surgical technique is well established and identification of the correct anatomic landmarks, midline tissue preparation, osteotomy and bleeding control are important steps of the procedure. Correct sternal closure is vital for avoiding short- and long-term morbidity and mortality. The two sternal halves have to be well approximated to facilitate healing of the bone and to avoid instability, which is a risk factor for wound infection. New suture materials and techniques would be expected to be developed to further improve the patients evolution, in respect to both immediate postoperative period and long-term morbidity and mortality

Endoscopic ultrasound, endoscopic sonoelastography, and strain ratio evaluation of lymph nodes with histology as gold standard

DEFF Research Database (Denmark)

Larsen, Michael Hareskov; Fristrup, Claus Wilki; Hansen, Tine Plato

2012-01-01

. Endoscopic sonoelastography (ESE) assesses the elasticity of lymph nodes and has been used to differentiate lymph nodes with promising results. The aim of this study was to evaluate the use of EUS, EUS - FNA, ESE, and ESE-strain ratio using histology as the gold standard. PATIENTS AND METHODS: Patients......, EUS - FNA and EUS - FNM were performed. The marked lymph node was isolated during surgery for histological examination. RESULTS: The marked lymph node was isolated for separate histological examination in 56 patients, of whom 22 (39 %) had malignant lymph nodes and 34 (61 %) had benign lymph nodes...... - FNM technique enabled the identification of a specific lymph node and thereby the use of histology as gold standard. ESE and ESE-strain ratio were no better than standard EUS in differentiating between malignant and benign lymph nodes in patients with resectable upper gastrointestinal cancer....

Evaluation of diagnostic tests when there is no gold standard. A review of methods

NARCIS (Netherlands)

Rutjes, A. W. S.; Reitsma, J. B.; Coomarasamy, A.; Khan, K. S.; Bossuyt, P. M. M.

2007-01-01

OBJECTIVE: To generate a classification of methods to evaluate medical tests when there is no gold standard. METHODS: Multiple search strategies were employed to obtain an overview of the different methods described in the literature, including searches of electronic databases, contacting experts

Gold-Mining

DEFF Research Database (Denmark)

Raaballe, J.; Grundy, B.D.

2002-01-01

  Based on standard option pricing arguments and assumptions (including no convenience yield and sustainable property rights), we will not observe operating gold mines. We find that asymmetric information on the reserves in the gold mine is a necessary and sufficient condition for the existence...... of operating gold mines. Asymmetric information on the reserves in the mine implies that, at a high enough price of gold, the manager of high type finds the extraction value of the company to be higher than the current market value of the non-operating gold mine. Due to this under valuation the maxim of market...

Underestimation of Self-Reported Smoking Prevalence in Korean Adolescents: Evidence from Gold Standard by Combined Method.

Science.gov (United States)

Hwang, Jun Hyun; Kim, Jong Yeon; Lee, Do Hoon; Jung, Hye Gyoun; Park, Soon-Woo

2018-04-05

The objective of this study was to evaluate the validity of self-reported smoking prevalence in Korean adolescents by using an improved gold standard by a combined method. Using a stratified sampling method, we selected 13 schools from among 397 high schools that participated in the 2015 Korean Youth Health Risk Behavior Web-Based Survey (KYRBS). A second survey (repeated self-reporting questionnaire and urinary cotinine test) was conducted on 1058 students who completed the KYRBS. The gold standard of current smoker was defined as those either self-reporting as a smoker in the second survey or having a urinary cotinine concentration ≥50 ng/mL. The current smoking prevalence in the first survey (KYRBS) was 7.9% (boys 16.5% and girls 1.8%), which was lower than the results based on gold standard (11.3% total, boys 21.9% and girls 3.7%). The sensitivity and specificity of self-reported smoking status was 62.5% and 99.0%, respectively. In particular, the sensitivity of girls (43.5%) was lower than that of boys (67.0%). The self-reported smoking prevalence in Korean adolescents was underestimated, particularly among girls. Careful attention should be paid to interpreting adolescents' smoking prevalence, and supplementary surveys or periodic validity tests need to be considered in Asian countries.

Fungus-mediated synthesis of gold nanoparticles and standardization of parameters for its biosynthesis.

Science.gov (United States)

Tidke, Pritish R; Gupta, Indarchand; Gade, Aniket K; Rai, Mahendra

2014-12-01

We report the extracellular biosynthesis of gold nanoparticles (AuNPs) using a fungus Fusarium acuminatum. Mycosynthesis of Au-NPs was carried out by challenging the fungal cells filtrate with HAuCl 4 solution (1 mM), as nanoparticles synthesizing enzyme secrete extracellularly by the fungi. The AuNPs were characterized with the help of UV-Visible spectrophotometer, Fourier Transform Infrared spectroscopy, Zeta Potential, X-ray diffraction (XRD) and Transmission electron microscopy (TEM). We observed absorbance peak in between 520 nm-550 nm corresponding to the surface plasmon absorbance of the gold nanoparticles. The nanoparticles synthesized in the present investigation were found to be capped by proteins. XRD results showed that the distinctive formation of crystalline gold nanoparticles in the solution. The spherical and polydispersed AuNPs in the range 8 to 28 nm with average size of 17 nm were observed by TEM analysis. We also standardized the parameters like the effect of pH, temperature and salt concentration on the biosynthesis of gold nanoparticles. It was found that acidic pH, 1 mM salt concentration and 37 (°)C temperature were found to be optimum for the synthesis of Au-NPs. Therefore, the present study introduces the easy, better and cheaper method for biosynthesis of AuNPs.

Reconsidering the H&E stain as the gold standard in assessing the depth of burn wounds.

Science.gov (United States)

Rosenberg, Arlene S

2017-12-01

While histological examination is considered by most as the gold standard for burn depth assessment, it has no practical use in the clinical setting. It has, however, been used in the research setting, as a mean for evaluating emerging techniques of depth measurement. Due to the limitations of the H&E stain, other stains have also been explored, such as lactate dehydrogenase (LDH), as presented in this issue, in "Improving the Histologic Characterization of Burn Depth." As the determination of burn depth is not a typical subject in dermatopathology, a summary of selected techniques and the possible role for the LDH stain in future research, is described herein. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Assessing operating characteristics of CAD algorithms in the absence of a gold standard

International Nuclear Information System (INIS)

Roy Choudhury, Kingshuk; Paik, David S.; Yi, Chin A.; Napel, Sandy; Roos, Justus; Rubin, Geoffrey D.

2010-01-01

Purpose: The authors examine potential bias when using a reference reader panel as ''gold standard'' for estimating operating characteristics of CAD algorithms for detecting lesions. As an alternative, the authors propose latent class analysis (LCA), which does not require an external gold standard to evaluate diagnostic accuracy. Methods: A binomial model for multiple reader detections using different diagnostic protocols was constructed, assuming conditional independence of readings given true lesion status. Operating characteristics of all protocols were estimated by maximum likelihood LCA. Reader panel and LCA based estimates were compared using data simulated from the binomial model for a range of operating characteristics. LCA was applied to 36 thin section thoracic computed tomography data sets from the Lung Image Database Consortium (LIDC): Free search markings of four radiologists were compared to markings from four different CAD assisted radiologists. For real data, bootstrap-based resampling methods, which accommodate dependence in reader detections, are proposed to test of hypotheses of differences between detection protocols. Results: In simulation studies, reader panel based sensitivity estimates had an average relative bias (ARB) of -23% to -27%, significantly higher (p-value <0.0001) than LCA (ARB -2% to -6%). Specificity was well estimated by both reader panel (ARB -0.6% to -0.5%) and LCA (ARB 1.4%-0.5%). Among 1145 lesion candidates LIDC considered, LCA estimated sensitivity of reference readers (55%) was significantly lower (p-value 0.006) than CAD assisted readers' (68%). Average false positives per patient for reference readers (0.95) was not significantly lower (p-value 0.28) than CAD assisted readers' (1.27). Conclusions: Whereas a gold standard based on a consensus of readers may substantially bias sensitivity estimates, LCA may be a significantly more accurate and consistent means for evaluating diagnostic accuracy.

Gold standards and expert panels: a pulmonary nodule case study with challenges and solutions

Science.gov (United States)

Miller, Dave P.; O'Shaughnessy, Kathryn F.; Wood, Susan A.; Castellino, Ronald A.

2004-05-01

Comparative evaluations of reader performance using different modalities, e.g. CT with computer-aided detection (CAD) vs. CT without CAD, generally require a "truth" definition based on a gold standard. There are many situations in which a true invariant gold standard is impractical or impossible to obtain. For instance, small pulmonary nodules are generally not assessed by biopsy or resection. In such cases, it is common to use a unanimous consensus or majority agreement from an expert panel as a reference standard for actionability in lieu of the unknown gold standard for disease. Nonetheless, there are three major concerns about expert panel reference standards: (1) actionability is not synonymous with disease (2) it may be possible to obtain different conclusions about which modality is better using different rules (e.g. majority vs. unanimous consensus), and (3) the variability associated with the panelists is not formally captured in the p-values or confidence intervals that are generally produced for estimating the extent to which one modality is superior to the other. A multi-reader-multi-case (MRMC) receiver operating characteristic (ROC) study was performed using 90 cases, 15 readers, and a reference truth based on 3 experienced panelists. The primary analyses were conducted using a reference truth of unanimous consensus regarding actionability (3 out of 3 panelists). To assess the three concerns noted above: (1) additional data from the original radiology reports were compared to the panel (2) the complete analysis was repeated using different definitions of truth, and (3) bootstrap analyses were conducted in which new truth panels were constructed by picking 1, 2, or 3 panelists at random. The definition of the reference truth affected the results for each modality (CT with CAD and CT without CAD) considered by itself, but the effects were similar, so the primary analysis comparing the modalities was robust to the choice of the reference truth.

From plastic to gold: a unified classification scheme for reference standards in medical image processing

Science.gov (United States)

Lehmann, Thomas M.

2002-05-01

Reliable evaluation of medical image processing is of major importance for routine applications. Nonetheless, evaluation is often omitted or methodically defective when novel approaches or algorithms are introduced. Adopted from medical diagnosis, we define the following criteria to classify reference standards: 1. Reliance, if the generation or capturing of test images for evaluation follows an exactly determined and reproducible protocol. 2. Equivalence, if the image material or relationships considered within an algorithmic reference standard equal real-life data with respect to structure, noise, or other parameters of importance. 3. Independence, if any reference standard relies on a different procedure than that to be evaluated, or on other images or image modalities than that used routinely. This criterion bans the simultaneous use of one image for both, training and test phase. 4. Relevance, if the algorithm to be evaluated is self-reproducible. If random parameters or optimization strategies are applied, reliability of the algorithm must be shown before the reference standard is applied for evaluation. 5. Significance, if the number of reference standard images that are used for evaluation is sufficient large to enable statistically founded analysis. We demand that a true gold standard must satisfy the Criteria 1 to 3. Any standard only satisfying two criteria, i.e., Criterion 1 and Criterion 2 or Criterion 1 and Criterion 3, is referred to as silver standard. Other standards are termed to be from plastic. Before exhaustive evaluation based on gold or silver standards is performed, its relevance must be shown (Criterion 4) and sufficient tests must be carried out to found statistical analysis (Criterion 5). In this paper, examples are given for each class of reference standards.

A Bayesian method for comparing and combining binary classifiers in the absence of a gold standard

Directory of Open Access Journals (Sweden)

Keith Jonathan M

2012-07-01

Full Text Available Abstract Background Many problems in bioinformatics involve classification based on features such as sequence, structure or morphology. Given multiple classifiers, two crucial questions arise: how does their performance compare, and how can they best be combined to produce a better classifier? A classifier can be evaluated in terms of sensitivity and specificity using benchmark, or gold standard, data, that is, data for which the true classification is known. However, a gold standard is not always available. Here we demonstrate that a Bayesian model for comparing medical diagnostics without a gold standard can be successfully applied in the bioinformatics domain, to genomic scale data sets. We present a new implementation, which unlike previous implementations is applicable to any number of classifiers. We apply this model, for the first time, to the problem of finding the globally optimal logical combination of classifiers. Results We compared three classifiers of protein subcellular localisation, and evaluated our estimates of sensitivity and specificity against estimates obtained using a gold standard. The method overestimated sensitivity and specificity with only a small discrepancy, and correctly ranked the classifiers. Diagnostic tests for swine flu were then compared on a small data set. Lastly, classifiers for a genome-wide association study of macular degeneration with 541094 SNPs were analysed. In all cases, run times were feasible, and results precise. The optimal logical combination of classifiers was also determined for all three data sets. Code and data are available from http://bioinformatics.monash.edu.au/downloads/. Conclusions The examples demonstrate the methods are suitable for both small and large data sets, applicable to the wide range of bioinformatics classification problems, and robust to dependence between classifiers. In all three test cases, the globally optimal logical combination of the classifiers was found to be

The Clinical Test of Nano gold Cosmetic for Recovering Skin Damage Due to Chemicals: Special Case

Science.gov (United States)

Taufikurohmah, T.; Wardana, A. P.; Tjahjani, S.; Sanjaya, I. G. M.; Baktir, A.; Syahrani, A.

2018-01-01

Manufacturing of Nano gold cosmetics was done at PT. Gizi Indonesia. Clinical trials to cosmetics data supported that cosmetics are able to treat skin health which has been reported partially. For special cases, the recovery process of facial skin damage should also receive attention including cases of facial skin damage caused by chemicals such as phenol, HCl, aqua regia or other harsh chemicals. The problem determined whether the Nano gold is able to recover skin damage due to the harsh chemicals. This clinical trial data on the forms of early skin damage caused by phenol was delivered in the forms of facial photos patients. The recovery progress of facial skin condition was obtained every week for two months. The data included the forms of widespread wounds during the recovery process. This statement supported by anova statistical analysis of the widespread wound changing every week for 8 times. The conclusion is skin damage due to Phenol impregnation can be recovered with the use of Nano gold cosmetics for 8 weeks. This results support the manufacturing of Nano gold cosmetics for the needs of society. It also suggest that Nano gold material can be used for medicine manufacturing in the future.

Still no single gold standard for using cementless femoral stems routinely in total hip arthroplasty

Directory of Open Access Journals (Sweden)

Joseph T. Moskal, MD

2016-12-01

Conclusions: Using evidence-based data should be better guidance in selecting the most reliable implants for THA. Although cementless femoral fixation for THA has evolved to the “new standard,” it has not been proven to be the “gold standard” for all patients.

Effectiveness of the gold standard programmes (GSP) for smoking cessation in pregnant and non-pregnant women

DEFF Research Database (Denmark)

Rasmussen, Mette; Heitmann, Berit Lilienthal; Tønnesen, Hanne

2013-01-01

Smoking is considered the most important preventable risk factor in relation to the development of complications during pregnancy and delivery. The aim of this study was to evaluate the effectiveness of an intensive 6-week gold standard programme (GSP) on pregnant women in real life....

Characterization of scale contrast of gold nanoparticles with the use of clinical computed tomography

International Nuclear Information System (INIS)

Badelli, Juliana C.; Miquellin, Charlie A.; Bezerra, Arandi G.; Orsato, Alexandre; Woiski, Thiago D.; Figueiredo, Bonald C.

2015-01-01

Binding nanoparticles with antibodies that have protein with affinity cancer cells, then insert them into a diseased tissue, the antibodies will lead the nanoparticles to the region with malignant cells. Being possible to see the committed region, the size of tissue involvement and if is occurring metastasis with diagnostic imaging methods. This study aimed to evaluate how you distributed the contrast range of a set of concentrations of gold nanoparticles (NP) using existing protocols in clinical computed tomography equipment. For the irradiation of NP was made a support in HDPE . Different concentrations of NP form prepared ranging from 0.01 to 10 mg / ml , and samples of distilled water , and calcium. The standard protocols of cranium and abdomen of a Toshiba equipment Aquillion 64 were used for obtaining the CT numbers (HU). The theoretical HU value of Gold nanoparticles for beam energy used was 47.4 HU calculated and compared with the values found . Of the results was not possible to notice a growing response from the HU NP as a function of increasing concentration, however you can view a range of HU according to these concentrations . Of different concentrations of 5 mg / mL is the one closest to the theoretical value obtained. These results are promising and demonstrate that there is a need for further experiments with the NP and the tomograph. (author)

Characterization of scale contrast of gold nanoparticles with the use of clinical computed tomography

Energy Technology Data Exchange (ETDEWEB)

Badelli, Juliana C.; Miquellin, Charlie A.; Bezerra, Arandi G., E-mail: jubadellin@gmail.com, E-mail: charlie@utfpr.edu.br, E-mail: arandi@utfpr.edu.br [Universidade Tecnologica Federal do Parana (CPGEI/UTFPR), Curitiba, PR (Brazil); Orsato, Alexandre; Woiski, Thiago D.; Figueiredo, Bonald C., E-mail: orsato_ale@yahoo.co.uk, E-mail: Thiagodw@ibest.com.br [Instituto de Pesquisa Pele Pequeno Principe, Curitiba PR (Brazil)

2015-07-01

Binding nanoparticles with antibodies that have protein with affinity cancer cells, then insert them into a diseased tissue, the antibodies will lead the nanoparticles to the region with malignant cells. Being possible to see the committed region, the size of tissue involvement and if is occurring metastasis with diagnostic imaging methods. This study aimed to evaluate how you distributed the contrast range of a set of concentrations of gold nanoparticles (NP) using existing protocols in clinical computed tomography equipment. For the irradiation of NP was made a support in HDPE . Different concentrations of NP form prepared ranging from 0.01 to 10 mg / ml , and samples of distilled water , and calcium. The standard protocols of cranium and abdomen of a Toshiba equipment Aquillion 64 were used for obtaining the CT numbers (HU). The theoretical HU value of Gold nanoparticles for beam energy used was 47.4 HU calculated and compared with the values found . Of the results was not possible to notice a growing response from the HU NP as a function of increasing concentration, however you can view a range of HU according to these concentrations . Of different concentrations of 5 mg / mL is the one closest to the theoretical value obtained. These results are promising and demonstrate that there is a need for further experiments with the NP and the tomograph. (author)

Diagnostic accuracy of tuberculous lymphadenitis fine needle aspiration biopsy confirmed by PCR as gold standard

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DSuryadi; Delyuzar; Soekimin

2018-03-01

Indonesia is the second country with the TB (tuberculosis) burden in the world. Improvement in controlling TB and reducing the complications can accelerate early diagnosis and correct treatment. PCR test is a gold standard. However, it is quite expensive for routine diagnosis. Therefore, an accurate and cheaper diagnostic method such as fine needle aspiration biopsy is needed. The study aimsto determine the accuracy of fine needle aspiration biopsy cytology in the diagnosis of tuberculous lymphadenitis. A cross-sectional analytic study was conducted to the samples from patients suspected with tuberculous lymphadenitis. The fine needle aspiration biopsy (FNAB)test was performed and confirmed by PCR test.There is a comparison to the sensitivity, specificity, accuracy, positive predictive value and negative predictive value of both methods. Sensitivity (92.50%), specificity (96.49%), accuracy (94.85%), positive predictive value (94.87%) and negative predictive value (94.83%) were in FNAB test compared to gold standard. We concluded that fine needle aspiration biopsy is a recommendation for a cheaper and accurate diagnostic test for tuberculous lymphadenitis diagnosis.

Twenty years after Erich Muhe: Persisting controversies with the gold standard of laparoscopic cholecystectomy

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Jani Kalpesh

2006-01-01

Full Text Available This review article is a tribute to the genius of Professor Erich Muhe, a man ahead of his times. We trace the development of laparoscopic cholecystectomy and detail the tribulations faced by Muhe. On the occasion of the twentieth anniversary of the first laparoscopic cholecystectomy, we take another look at some of the controversies surrounding this gold standard in the management of gallbladder disease

Twenty years after Erich Muhe: Persisting controversies with the gold standard of laparoscopic cholecystectomy.

Science.gov (United States)

Jani, Kalpesh; Rajan, P S; Sendhilkumar, K; Palanivelu, C

2006-06-01

This review article is a tribute to the genius of Professor Erich Muhe, a man ahead of his times. We trace the development of laparoscopic cholecystectomy and detail the tribulations faced by Muhe. On the occasion of the twentieth anniversary of the first laparoscopic cholecystectomy, we take another look at some of the controversies surrounding this gold standard in the management of gallbladder disease.

Twenty years after Erich Muhe: Persisting controversies with the gold standard of laparoscopic cholecystectomy

OpenAIRE

Jani, Kalpesh; Rajan, P S; Sendhilkumar, K; Palanivelu, C

2006-01-01

This review article is a tribute to the genius of Professor Erich Muhe, a man ahead of his times. We trace the development of laparoscopic cholecystectomy and detail the tribulations faced by Muhe. On the occasion of the twentieth anniversary of the first laparoscopic cholecystectomy, we take another look at some of the controversies surrounding this gold standard in the management of gallbladder disease

Practical no-gold-standard evaluation framework for quantitative imaging methods: application to lesion segmentation in positron emission tomography.

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Jha, Abhinav K; Mena, Esther; Caffo, Brian; Ashrafinia, Saeed; Rahmim, Arman; Frey, Eric; Subramaniam, Rathan M

2017-01-01

Recently, a class of no-gold-standard (NGS) techniques have been proposed to evaluate quantitative imaging methods using patient data. These techniques provide figures of merit (FoMs) quantifying the precision of the estimated quantitative value without requiring repeated measurements and without requiring a gold standard. However, applying these techniques to patient data presents several practical difficulties including assessing the underlying assumptions, accounting for patient-sampling-related uncertainty, and assessing the reliability of the estimated FoMs. To address these issues, we propose statistical tests that provide confidence in the underlying assumptions and in the reliability of the estimated FoMs. Furthermore, the NGS technique is integrated within a bootstrap-based methodology to account for patient-sampling-related uncertainty. The developed NGS framework was applied to evaluate four methods for segmenting lesions from F-Fluoro-2-deoxyglucose positron emission tomography images of patients with head-and-neck cancer on the task of precisely measuring the metabolic tumor volume. The NGS technique consistently predicted the same segmentation method as the most precise method. The proposed framework provided confidence in these results, even when gold-standard data were not available. The bootstrap-based methodology indicated improved performance of the NGS technique with larger numbers of patient studies, as was expected, and yielded consistent results as long as data from more than 80 lesions were available for the analysis.

The Gold Standard Program for Smoking Cessation is Effective for Participants Over 60 Years of Age

DEFF Research Database (Denmark)

Flamand, Mette Kehlet; Schroeder, Torben V; Tønnesen, Hanne

2015-01-01

BACKGROUND: Tobacco smoking is more prevalent among the elderly than among the young, and the elderly also have the most frequent contact with the health care system. The aim of this study was to evaluate the effectiveness of the Gold Standard Program, which is an intensive six-week smoking...

Efficiency of a solid-phase chemiluminescence immunoassay for detection of antinuclear and cytoplasmic autoantibodies compared with gold standard immunoprecipitation.

Science.gov (United States)

Gelpí, Carmen; Pérez, Elena; Roldan, Cristina

2014-09-01

The aim of this study was to compare the degree of agreement of a novel Zenit RA chemiluminescent immunoassay (CLIA) from A. Menarini Diagnostics (Florence, Italy) and the gold standard immunoprecipitation assay to screen for the presence of specific anti-U1snRNP, anti-Sm, anti-Ro/SS-A, anti-La/SS-B, anti-Jo-1((his)tRNA-Synthetase) and anti-Scl-70(Topo I) antibodies. We studied 114 sera, 98 from patients with well-defined autoimmune connective tissue diseases and 16 from blood donor volunteers. All samples were fully characterized using the new chemiluminescent immunoassay and immunoprecipitation. In addition, all the samples were analyzed by indirect immunofluorescence (IIF) and anti-Scl-70(Topo I) antibodies were analyzed by immunoblot (IB) assay. Discrepant samples were analyzed using a commercial dot blot technique (Recomline from Mikrogen). The simple Kappa coefficient was used to measure the level of agreement between the results of Zenit RA CLIA and the gold standard. The Kappa agreement between Zenit RA CLIA and gold standard immunoprecipitation, as well as IB and IIFassays for the presence of anti-Scl-70(Topo I)(0.948) was excellent. The concordance between Zenit RA CLIA and gold standard immunoprecipitation for the presence of anti-U1snRNP (0.883), anti-Ro/SS-A (0.878), anti-Jo-1((his)tRNA-Synthetase) (0.791) and anti-Sm (0.786) was good, and excellent when the cut-off was raised to 14 U/ml (arbitrary units/ml). Between Zenit RA CLIA and gold standard immunoprecipitation for the presence of anti-La/SS-B, the Kappa agreement had a value of 0.689, but this improved to 0.775 when the cut-off was raised to14 U/ml. Precision was good based on the evaluation of replicate samples. Inter-assay coefficient variation was lower than 3.4 % (CV in %) in all the kits and <1.2 % (CV in  %) for intra-assay measurements. Our findings show that Zenit RA CLIA was specific and sensitive to detect anti-U1snRNP, anti-Sm, anti-Ro/SS-A, anti-La/SS-B, anti-Jo-1((his

Gold-standard evaluation of a folksonomy-based ontology learning model

Science.gov (United States)

Djuana, E.

2018-03-01

Folksonomy, as one result of collaborative tagging process, has been acknowledged for its potential in improving categorization and searching of web resources. However, folksonomy contains ambiguities such as synonymy and polysemy as well as different abstractions or generality problem. To maximize its potential, some methods for associating tags of folksonomy with semantics and structural relationships have been proposed such as using ontology learning method. This paper evaluates our previous work in ontology learning according to gold-standard evaluation approach in comparison to a notable state-of-the-art work and several baselines. The results show that our method is comparable to the state-of the art work which further validate our approach as has been previously validated using task-based evaluation approach.

Evaluating the Gold Standard: A Review and Meta-Analysis of the Structured Interview of Reported Symptoms

Science.gov (United States)

Green, Debbie; Rosenfeld, Barry

2011-01-01

The Structured Interview of Reported Symptoms (SIRS; Rogers, Bagby, & Dickens, 1992) is often touted as the gold standard of measures of feigning. This label likely arises in part out of the impressive accuracy rates reported in the extensive validation research that preceded its publication. However, since its publication, researchers not only…

Biomonitoring of trace-element air pollution in a gold mining area in Ghana using the generalized k0-standardization NAA method

International Nuclear Information System (INIS)

Nyarko, B.J.B.; Kyere, A.W.K.; Serfor-Armah, Y.; Akaho, E.H.K.

2003-01-01

Full text: Mining activities contribute immensely to trace element atmospheric pollution. In Ghana, air pollution due to gold mining is the least investigated. In order to obtain preliminary information on air quality in the mining areas, the generalized k o- Standardization neutron activation analysis (NAA) method for nuclides following '1/v' and non-'1/v' (n,γ) reactions was used to analyse lichen samples from Prestea, a gold mining area in Ghana. Using the computed EPI values of both the Hogdahl-convention and the modified Westcott-formalism with gold as comparator standard, the IAEA lichen 336 certified reference material (CRM) and the lichen samples were irradiated in the inner irradiation site of the Ghana Research Reactor-1 (GHARR-1) operating at a thermal neutron flux of 5.0x10 11 ns -1 cm -2 . Comparison of the results with samples obtained from a non-mining (control) area, indicates that values of some metal pollutants such as As, Cr, Sb, and V were found to be higher in the lichens from the mining area than those in the non-mining area (control area); signifying accumulation of these metal pollutant due to gold - mining activities. (author)

Moessbauer study of the chemical state of gold in gold ores

International Nuclear Information System (INIS)

Wagner, F.E.; Marion, P.H.; Regnard, J.-R.

1986-01-01

Information on the chemical state of gold in gold ores has been obtained by 197 Au Moessbauer spectroscopy in cases where the state of this element cannot be determined by such standard methods as optical or electron microscopy. Ore concentrates consisting mainly of pyrite or arsenopyrite and roasted ore and matte samples were studied. The results yielded directly the respective amounts of metallic and chemically bound gold. Unless the gold is metallic, its chemical state in the ores turns out to be different from that in the minerals studied so far as reference materials. The chemical processes taking place during various treatments of the ores, such as roasting or leaching, can also be followed by Moessbauer spectroscopy. It is hoped that Moessbauer spectroscopy will eventually facilitate the development of more efficient methods of gold extraction

Scattering resonances in bimolecular collisions between NO radicals and H2 challenge the theoretical gold standard

Science.gov (United States)

Vogels, Sjoerd N.; Karman, Tijs; Kłos, Jacek; Besemer, Matthieu; Onvlee, Jolijn; van der Avoird, Ad; Groenenboom, Gerrit C.; van de Meerakker, Sebastiaan Y. T.

2018-02-01

Over the last 25 years, the formalism known as coupled-cluster (CC) theory has emerged as the method of choice for the ab initio calculation of intermolecular interaction potentials. The implementation known as CCSD(T) is often referred to as the gold standard in quantum chemistry. It gives excellent agreement with experimental observations for a variety of energy-transfer processes in molecular collisions, and it is used to calibrate density functional theory. Here, we present measurements of low-energy collisions between NO radicals and H2 molecules with a resolution that challenges the most sophisticated quantum chemistry calculations at the CCSD(T) level. Using hitherto-unexplored anti-seeding techniques to reduce the collision energy in a crossed-beam inelastic-scattering experiment, a resonance structure near 14 cm-1 is clearly resolved in the state-to-state integral cross-section, and a unique resonance fingerprint is observed in the corresponding differential cross-section. This resonance structure discriminates between two NO-H2 potentials calculated at the CCSD(T) level and pushes the required accuracy beyond the gold standard.

The accuracy of k1-standardized INAA applied to a gold-lined well-type detector

International Nuclear Information System (INIS)

Blaauw, M.

2000-01-01

The k 1 -method for standardization in INAA specifically tackles the problem of the interpretation of gamma-ray spectra as obtained with highly efficient detectors, as opposed to the k 0 -method. Results obtained from three NIST reference materials, measured after neutron activation with a gold-lined well-type detector, are presented. It is concluded that the accuracy of the method is better than 1%. (author)

Comparing image search behaviour in the ARRS GoldMiner search engine and a clinical PACS/RIS.

Science.gov (United States)

De-Arteaga, Maria; Eggel, Ivan; Do, Bao; Rubin, Daniel; Kahn, Charles E; Müller, Henning

2015-08-01

underrepresented, therefore RadLex was considered to be the best option for this task. The results show a surprising similarity between the usage behaviour in the two systems, but several subtle differences can also be noted. The average number of terms per query is 2.21 for GoldMiner and 2.07 for radTF, the used axes of RadLex (anatomy, pathology, findings, …) have almost the same distribution with clinical findings being the most frequent and the anatomical entity the second; also, combinations of RadLex axes are extremely similar between the two systems. Differences include a longer length of the sessions in radTF than in GoldMiner (3.4 and 1.9 queries per session on average). Several frequent search terms overlap but some strong differences exist in the details. In radTF the term "normal" is frequent, whereas in GoldMiner it is not. This makes intuitive sense, as in the literature normal cases are rarely described whereas in clinical work the comparison with normal cases is often a first step. The general similarity in many points is likely due to the fact that users of the two systems are influenced by their daily behaviour in using standard web search engines and follow this behaviour in their professional search. This means that many results and insights gained from standard web search can likely be transferred to more specialized search systems. Still, specialized log files can be used to find out more on reformulations and detailed strategies of users to find the right content. Copyright © 2015 Elsevier Inc. All rights reserved.

Nondestructive analysis of the gold quarter liras

International Nuclear Information System (INIS)

Cakir, C.; Guerol, A.; Demir, L.; Sahin, Y.

2009-01-01

In this study, we have prepared seven Au-Cu standards in the concentration range of 18-24 (as carat) for nondestructive control of gold quarter liras. Some calibration curves for quantitative analysis of Au in the gold quarter liras that commercially present in Turkey have been plotted using these standard samples. The characteristic X-rays of Au and Cu emitted from these standard samples and the test sample with known composition are recorded by using a Ge(Li) detector. These calibration curves provide a nondestructive analysis of gold quarter liras with the uncertainties about 1.18%. (author)

Role of hydrogen ions in standard and activation heap leaching of gold

Science.gov (United States)

Rubtsov, YuI

2017-02-01

The role of hydrogen ions in activation heap leaching of gold from rebellious ore has been studied, which has allowed enhancing gold recovery. The author puts forward a gold leaching circuit with the use of activated oxygen-saturated solutions acidified to pH = 6-9.

Grading School Choice: Evaluating School Choice Programs by the Friedman Gold Standard. School Choice Issues in Depth

Science.gov (United States)

Enlow, Robert C.

2008-01-01

In 2004, The Friedman Foundation for Educational Choice published a report titled "Grading Vouchers: Ranking America's School Choice Programs." Its purpose was to measure every existing school choice program against the gold standard set by Milton and Rose Friedman: that the most effective way to improve K-12 education and thus ensure a stable…

A Gold Standards Approach to Training Instructors to Evaluate Crew Performance

Science.gov (United States)

Baker, David P.; Dismukes, R. Key

2003-01-01

The Advanced Qualification Program requires that airlines evaluate crew performance in Line Oriented Simulation. For this evaluation to be meaningful, instructors must observe relevant crew behaviors and evaluate those behaviors consistently and accurately against standards established by the airline. The airline industry has largely settled on an approach in which instructors evaluate crew performance on a series of event sets, using standardized grade sheets on which behaviors specific to event set are listed. Typically, new instructors are given a class in which they learn to use the grade sheets and practice evaluating crew performance observed on videotapes. These classes emphasize reliability, providing detailed instruction and practice in scoring so that all instructors within a given class will give similar scores to similar performance. This approach has value but also has important limitations; (1) ratings within one class of new instructors may differ from those of other classes; (2) ratings may not be driven primarily by the specific behaviors on which the company wanted the crews to be scored; and (3) ratings may not be calibrated to company standards for level of performance skill required. In this paper we provide a method to extend the existing method of training instructors to address these three limitations. We call this method the "gold standards" approach because it uses ratings from the company's most experienced instructors as the basis for training rater accuracy. This approach ties the training to the specific behaviors on which the experienced instructors based their ratings.

“Gold Standards,” Plurality and Monocultures: The Need for Diversity in Psychotherapy

Directory of Open Access Journals (Sweden)

Falk Leichsenring

2018-04-01

Full Text Available For psychotherapy of mental disorders, presently several approaches are available, such as interpersonal, humanistic, systemic, psychodynamic or cognitive behavior therapy (CBT. Pointing to the available evidence, proponents of CBT claim that CBT is the gold standard. Some authors even argue for an integrated CBT-based form of psychotherapy as the only form of psychotherapy. CBT undoubtedly has its strengths and CBT researchers have to be credited for developing and testing treatments for many mental disorders. A critical review, however, shows that the available evidence for the theoretical foundations of CBT, assumed mechanisms of change, quality of studies, and efficacy is not as robust as some researchers claim. Most important, there is no consistent evidence that CBT is more efficacious than other evidence-based approaches. These findings do not justify regarding CBT as the gold standard psychotherapy. They even provide less justification for the idea that the future of psychotherapy lies in one integrated CBT-based form of psychotherapy as the only type of psychotherapy. For the different psychotherapeutic approaches a growing body of evidence is available. These approaches have their strengths because of differences in their respective focus on interpersonal relationships, affects, cognitions, systemic perspectives, experiential, or unconscious processes. Different approaches may be suitable to different patients and therapists. As generally assumed, progress in research results from openness to new ideas and learning from diverse perspectives. Thus, different forms of evidence-based psychotherapy are required. Plurality is the future of psychotherapy, not a uniform “one fits all” approach.

“Gold Standards,” Plurality and Monocultures: The Need for Diversity in Psychotherapy

Science.gov (United States)

Leichsenring, Falk; Abbass, Allan; Hilsenroth, Mark J.; Luyten, Patrick; Munder, Thomas; Rabung, Sven; Steinert, Christiane

2018-01-01

For psychotherapy of mental disorders, presently several approaches are available, such as interpersonal, humanistic, systemic, psychodynamic or cognitive behavior therapy (CBT). Pointing to the available evidence, proponents of CBT claim that CBT is the gold standard. Some authors even argue for an integrated CBT-based form of psychotherapy as the only form of psychotherapy. CBT undoubtedly has its strengths and CBT researchers have to be credited for developing and testing treatments for many mental disorders. A critical review, however, shows that the available evidence for the theoretical foundations of CBT, assumed mechanisms of change, quality of studies, and efficacy is not as robust as some researchers claim. Most important, there is no consistent evidence that CBT is more efficacious than other evidence-based approaches. These findings do not justify regarding CBT as the gold standard psychotherapy. They even provide less justification for the idea that the future of psychotherapy lies in one integrated CBT-based form of psychotherapy as the only type of psychotherapy. For the different psychotherapeutic approaches a growing body of evidence is available. These approaches have their strengths because of differences in their respective focus on interpersonal relationships, affects, cognitions, systemic perspectives, experiential, or unconscious processes. Different approaches may be suitable to different patients and therapists. As generally assumed, progress in research results from openness to new ideas and learning from diverse perspectives. Thus, different forms of evidence-based psychotherapy are required. Plurality is the future of psychotherapy, not a uniform “one fits all” approach. PMID:29740361

An investigation into the validity of cervical spine motion palpation using subjects with congenital block vertebrae as a 'gold standard'

Directory of Open Access Journals (Sweden)

Peterson Cynthia K

2004-06-01

Full Text Available Abstract Background Although the effectiveness of manipulative therapy for treating back and neck pain has been demonstrated, the validity of many of the procedures used to detect joint dysfunction has not been confirmed. Practitioners of manual medicine frequently employ motion palpation as a diagnostic tool, despite conflicting evidence regarding its utility and reliability. The introduction of various spinal models with artificially introduced 'fixations' as an attempt to introduce a 'gold standard' has met with frustration and frequent mechanical failure. Because direct comparison against a 'gold standard' allows the validity, specificity and sensitivity of a test to be calculated, the identification of a realistic 'gold standard' against which motion palpation can be evaluated is essential. The objective of this study was to introduce a new, realistic, 'gold standard', the congenital block vertebra (CBV to assess the validity of motion palpation in detecting a true fixation. Methods Twenty fourth year chiropractic students examined the cervical spines of three subjects with single level congenital block vertebrae, using two commonly employed motion palpation tests. The examiners, who were blinded to the presence of congenital block vertebrae, were asked to identify the most hypomobile segment(s. The congenital block segments included two subjects with fusion at the C2–3 level and one with fusion at C5-6. Exclusion criteria included subjects who were frankly symptomatic, had moderate or severe degenerative changes in their cervical spines, or displayed signs of cervical instability. Spinal levels were marked on the subject's skin overlying the facet joints from C1 to C7 bilaterally and the motion segments were then marked alphabetically with 'A' corresponding to C1-2. Kappa coefficients (K were calculated to determine the validity of motion palpation to detect the congenitally fused segments as the 'most hypomobile' segments. Sensitivity

Increased apoptotic potential and dose-enhancing effect of gold nanoparticles in combination with single-dose clinical electron beams on tumor-bearing mice

International Nuclear Information System (INIS)

Chang Mengya; Chen Yuhung; Chang Chihjui; Chen Helen H-W; Wu Chaoliang; Shiau Aili

2008-01-01

High atomic number material, such as gold, may be used in conjunction with radiation to provide dose enhancement in tumors. In the current study, we investigated the dose-enhancing effect and apoptotic potential of gold nanoparticles in combination with single-dose clinical electron beams on B16F10 melanoma tumor-bearing mice. We revealed that the accumulation of gold nanoparticles was detected inside B16F10 culture cells after 18 h of incubation, and moreover, the gold nanoparticles were shown to be colocalized with endoplasmic reticulum and Golgi apparatus in cells. Furthermore, gold nanoparticles radiosensitized melanoma cells in the colony formation assay (P=0.02). Using a B16F10 tumor-bearing mouse model, we further demonstrated that gold nanoparticles in conjunction with ionizing radiation significantly retarded tumor growth and prolonged survival compared to the radiation alone controls (P<0.05). Importantly, an increase of apoptotic signals was detected inside tumors in the combined treatment group (P<0.05). Knowing that radiation-induced apoptosis has been considered a determinant of tumor responses to radiation therapy, and the length of tumor regrowth delay correlated with the extent of apoptosis after single-dose radiotherapy, these results may suggest the clinical potential of gold nanoparticles in improving the outcome of melanoma radiotherapy. (author)

Clinical quality standards for radiotherapy

Science.gov (United States)

2012-01-01

Aim of the study The technological progress that is currently being witnessed in the areas of diagnostic imaging, treatment planning systems and therapeutic equipment has caused radiotherapy to become a high-tech and interdisciplinary domain involving staff of various backgrounds. This allows steady improvement in therapy results, but at the same time makes the diagnostic, imaging and therapeutic processes more complex and complicated, requiring every stage of those processes to be planned, organized, controlled and improved so as to assure high quality of services provided. The aim of this paper is to present clinical quality standards for radiotherapy as developed by the author. Material and methods In order to develop the quality standards, a comparative analysis was performed between European and Polish legal acts adopted in the period of 1980-2006 and the universal industrial ISO 9001:2008 standard, defining requirements for quality management systems, and relevant articles published in 1984-2009 were reviewed, including applicable guidelines and recommendations of American, international, European and Polish bodies, such as the American Association of Physicists in Medicine (AAPM), the European Society for Radiotherapy & Oncology (ESTRO), the International Atomic Energy Agency (IAEA), and the Organisation of European Cancer Institutes (OECI) on quality assurance and management in radiotherapy. Results As a result, 352 quality standards for radiotherapy were developed and categorized into the following three groups: 1 – organizational standards; 2 – physico-technical standards and 3 – clinical standards. Conclusion Proposed clinical quality standards for radiotherapy can be used by any institution using ionizing radiation for medical purposes. However, standards are of value only if they are implemented, reviewed, audited and improved, and if there is a clear mechanism in place to monitor and address failure to meet agreed standards. PMID:23788854

Detection of Echinococcus multilocularis by MC-PCR: evaluation of diagnostic sensitivity and specificity without gold standard

Directory of Open Access Journals (Sweden)

Helene Wahlström

2016-03-01

Full Text Available Introduction: A semi-automated magnetic capture probe-based DNA extraction and real-time PCR method (MC-PCR, allowing for a more efficient large-scale surveillance of Echinococcus multilocularis occurrence, has been developed. The test sensitivity has previously been evaluated using the sedimentation and counting technique (SCT as a gold standard. However, as the sensitivity of the SCT is not 1, test characteristics of the MC-PCR was also evaluated using latent class analysis, a methodology not requiring a gold standard. Materials and methods: Test results, MC-PCR and SCT, from a previous evaluation of the MC-PCR using 177 foxes shot in the spring (n=108 and autumn 2012 (n=69 in high prevalence areas in Switzerland were used. Latent class analysis was used to estimate the test characteristics of the MC-PCR. Although it is not the primary aim of this study, estimates of the test characteristics of the SCT were also obtained. Results and discussion: This study showed that the sensitivity of the MC-PCR was 0.88 [95% posterior credible interval (PCI 0.80–0.93], which was not significantly different than the SCT, 0.83 (95% PCI 0.76–0.88, which is currently considered as the gold standard. The specificity of both tests was high, 0.98 (95% PCI 0.94–0.99 for the MC-PCR and 0.99 (95% PCI 0.99–1 for the SCT. In a previous study, using fox scats from a low prevalence area, the specificity of the MC-PCR was higher, 0.999% (95% PCI 0.997–1. One reason for the lower estimate of the specificity in this study could be that the MC-PCR detects DNA from infected but non-infectious rodents eaten by foxes. When using MC-PCR in low prevalence areas or areas free from the parasite, a positive result in the MC-PCR should be regarded as a true positive. Conclusion: The sensitivity of the MC-PCR (0.88 was comparable to the sensitivity of SCT (0.83.

A Preliminary Study on Detecting Fake Gold Bars Using Prompt Gamma Activation Analysis: Simulation of Neutron Transmission in Gold Bar

Energy Technology Data Exchange (ETDEWEB)

Lee, K. M.; Sun, G. M. [KAERI, Daejeon (Korea, Republic of)

2016-05-15

The purpose of this study is to develop fake gold bar detecting method by using Prompt-gamma activation analysis (PGAA) facility at the Korea Atomic Energy Research Institute (KAERI). PGAA is an established nuclear analytical technique for non-destructive determination of elemental and isotopic compositions. For a preliminary study on detecting fake gold bar, Monte Carlo simulation of neutron transmission in gold bar was conducted and the possibility for detecting fake gold bar was confirmed. Under the gold bullion standard, it guaranteed the government would redeem any amount of currency for its value in gold. After the gold bullion standard ended, gold bars have been the target for investment as ever. But it is well known that fake gold bar exist in the gold market. This cannot be identified easily without performing a testing as it has the same appearance as the pure gold bar. In order to avoid the trading of fake gold bar in the market, they should be monitored thoroughly. Although the transmissivity of cold neutrons are low comparing that of thermal neutrons, the slower neutrons are more apt to be absorbed in a target, and can increase the prompt gamma emission rate. Also the flux of both thermal and cold neutron beam is high enough to activate thick target. If the neutron beam is irradiated on the front and the reverse side of gold bar, all insides of it can be detected.

A Preliminary Study on Detecting Fake Gold Bars Using Prompt Gamma Activation Analysis: Simulation of Neutron Transmission in Gold Bar

International Nuclear Information System (INIS)

Lee, K. M.; Sun, G. M.

2016-01-01

The purpose of this study is to develop fake gold bar detecting method by using Prompt-gamma activation analysis (PGAA) facility at the Korea Atomic Energy Research Institute (KAERI). PGAA is an established nuclear analytical technique for non-destructive determination of elemental and isotopic compositions. For a preliminary study on detecting fake gold bar, Monte Carlo simulation of neutron transmission in gold bar was conducted and the possibility for detecting fake gold bar was confirmed. Under the gold bullion standard, it guaranteed the government would redeem any amount of currency for its value in gold. After the gold bullion standard ended, gold bars have been the target for investment as ever. But it is well known that fake gold bar exist in the gold market. This cannot be identified easily without performing a testing as it has the same appearance as the pure gold bar. In order to avoid the trading of fake gold bar in the market, they should be monitored thoroughly. Although the transmissivity of cold neutrons are low comparing that of thermal neutrons, the slower neutrons are more apt to be absorbed in a target, and can increase the prompt gamma emission rate. Also the flux of both thermal and cold neutron beam is high enough to activate thick target. If the neutron beam is irradiated on the front and the reverse side of gold bar, all insides of it can be detected

Gold-coated copper cone detector as a new standard detector for F2 laser radiation at 157 nm

International Nuclear Information System (INIS)

Kueck, Stefan; Brandt, Friedhelm; Taddeo, Mario

2005-01-01

A new standard detector for high-accuracy measurements of F2 laser radiation at 157 nm is presented. This gold-coated copper cone detector permits the measurement of average powers up to 2 W with an uncertainty of ∼1%. To the best of our knowledge, this is the first highly accurate standard detector for F2 laser radiation for this power level. It is fully characterized according to Guide to the Expression of Uncertainty in Measurement of the International Organization for Standardization and is connected to the calibration chain for laser radiation established by the German National Metrology Institute

Real-time PCR versus viral culture on urine as a gold standard in the diagnosis of congenital cytomegalovirus infection

NARCIS (Netherlands)

de Vries, Jutte J. C.; van der Eijk, Annemiek A.; Wolthers, Katja C.; Rusman, Lisette G.; Pas, Suzan D.; Molenkamp, Richard; Claas, Eric C.; Kroes, Aloys C. M.; Vossen, Ann C. T. M.

2012-01-01

Background: Cytomegalovirus (CMV) infection is the most common cause of congenital infection. Whereas CMV PCR has replaced viral culture and antigen detection in immunocompromised patients because of higher sensitivity, viral culture of neonatal urine is still referred to as the gold standard in the

The Cox-maze IV procedure in its second decade: still the gold standard?

Science.gov (United States)

Ruaengsri, Chawannuch; Schill, Matthew R; Khiabani, Ali J; Schuessler, Richard B; Melby, Spencer J; Damiano, Ralph J

2018-04-01

Atrial fibrillation (AF) is the most common cardiac arrhythmia and the treatment options include medical treatment and catheter-based or surgical interventions. AF is a major cause of stroke, and its prevalence is increasing. The surgical treatment of AF has been revolutionized over the past 2 decades through surgical innovation and improvements in endoscopic imaging, ablation technology and surgical instrumentation. The Cox-maze (CM) procedure, which was developed by James Cox and introduced clinically in 1987, is a procedure in which multiple incisions are created in both the left and the right atria to eliminate AF while allowing the sinus impulse to reach the atrioventricular node. This procedure became the gold standard for the surgical treatment of AF. Its latest iteration is termed the CM IV and was introduced in 2002. The CM IV replaced the previous cut-and-sew method (CM III) by replacing most of the incisions with a combination of bipolar radiofrequency and cryoablation. The use of ablation technologies, made the CM IV technically easier, faster and more amenable to minimally invasive approaches. The aims of this article are to review the indications and preoperative planning for the CM IV, to describe the operative technique and to review the literature including comparisons of the CM IV with the previous cut-and-sew method. Finally, this review explores future directions for the surgical treatment of patients with AF.

Estimation of Sensitivity and Specificity of Three Conditionally Dependent Diagnostic Tests in the Absence of a Gold Standard

NARCIS (Netherlands)

Engel, B.; Swildens, B.; Stegeman, J.A.; Buist, W.G.; Jong, de M.

2006-01-01

This article presents a model to evaluate the accuracy of diagnostic tests. Data from three tests for the detection of EF-positive Streptococcus suis serotype 2 strains in sows were analyzed. The data were collected in a field study in the absence of a gold standard, that is, the true disease status

MR imaging of the articular cartilage of the knee with arthroscopy as gold standard: assessment of methodological quality of clinical studies

International Nuclear Information System (INIS)

Duchateau, Florence; Berg, Bruno C. vande

2002-01-01

The purpose of this study was to assess the methodological quality of articles addressing the value of MR imaging of the knee cartilage with arthroscopy as a standard. Relevant papers were selected after Medline review (MEDLINE database search including the terms ''cartilage'' ''knee'', ''MR'' and ''arthroscopy''). Two observers reviewed independently 29 selected articles to determine how each study had met 15 individual standards that had been previously developed to assess the methodological quality of clinical investigations. The following criteria were met in variable percentage of articles including adequate definition of purpose (100%), statistical analysis (90%), avoidance of verification bias (86%), patient population description (83%), reference standard (79%), review bias (79%), study design (66%), inclusion criteria (41%) and method of analysis (41.5%), avoidance of diagnostic-review bias (24%), exclusion criteria (21%), indeterminate examination results (17%), analysis criteria (14%), interobserver reliability (14%) and intraobserver reliability (7%). The assessment of the methodological quality of clinical investigations addressing the value of MR imaging in the evaluation of the articular cartilage of the knee with arthroscopy as the standard of reference demonstrated that several standards were rarely met in the literature. Efforts should be made to rely on clearly defined lesion criteria and to determine reliability of the observations. (orig.)

Low-energy ED-XRF spectrometry application in gold assaying

International Nuclear Information System (INIS)

Marucco, Alessandra

2004-01-01

The performances of a low-energy dispersive XRF spectrometer in gold assaying are evaluated by a series of analysis on international standards and other certified gold alloys with. Results of standard-free analysis based on fundamental parameters method compared to results of multi-standard method, demonstrate a large gain of accuracy by drawing appropriate calibration curves with use of 1 to 16 matrix-specific standards. The accuracy of gold assaying has improved by a factor of 10, as compared to the conventional touchstone test. This rather economical technique satisfies then numerous precious alloys analyst needs, representing an excellent alternative to the traditional method for quick anti-fraud controls

Clinical investigation of 14C-urea breath test

International Nuclear Information System (INIS)

Yu Yongli; Zhu Ruisen; Ji Hong; Luo Quanyong

2000-01-01

To investigate clinical value of 14 C-urea breath test ( 14 C-UBT) for the diagnosis of Helicobacter pylori(Hp), 70 patients were both performed gastroscopy (taking gastric mucosae biopsy for rapid urease test and histology) and 14 C-UBT (some patients by Hp-IgG or DNAHp test also) within two days. The positive cases of both rapid urease test and histology was defined as 'gold standard' of Hp-positive, whereas the negative cases of both rapid urease test and histology as 'gold standard' of Hp-negative. The sensitivity of 14 C-UBT was 93.2%, the specificity 73.1%, and the diagnostic accuracy 85.7%. The difference (comparing with 'gold standard') was not marked (x 2 = 0.9 0.05(1) 2 = 3.84, P>0.05). But the diagnostic accuracy of 14 C-UBT (85.7%) and Hp-IgG (50%) had a marked difference (x 2 13.80>x 0.01(1) 2 = 6.64, P 14 C-UBT was easy to operate, reliable and suitable for clinical application

Nanoscale radiation transport and clinical beam modeling for gold nanoparticle dose enhanced radiotherapy (GNPT) using X-rays.

Science.gov (United States)

Zygmanski, Piotr; Sajo, Erno

2016-01-01

We review radiation transport and clinical beam modelling for gold nanoparticle dose-enhanced radiotherapy using X-rays. We focus on the nanoscale radiation transport and its relation to macroscopic dosimetry for monoenergetic and clinical beams. Among other aspects, we discuss Monte Carlo and deterministic methods and their applications to predicting dose enhancement using various metrics.

Physical Activity Characteristics across GOLD Quadrants Depend on the Questionnaire Used.

Directory of Open Access Journals (Sweden)

Heleen Demeyer

Full Text Available The GOLD multidimensional classification of COPD severity combines the exacerbation risk with the symptom experience, for which 3 different questionnaires are permitted. This study investigated differences in physical activity (PA in the different GOLD quadrants and patient's distribution in relation to the questionnaire used.136 COPD patients (58±21% FEV1 predicted, 34F/102M completed COPD assessment test (CAT, clinical COPD questionnaire (CCQ and modified Medical Research Council (mMRC questionnaire. Exacerbation history, spirometry and 6MWD were collected. PA was objectively measured for 2 periods of 1 week, 6 months apart, in 5 European centres; to minimise seasonal and clinical variation the average of these two periods was used for analysis.GOLD quadrants C+D had reduced PA compared with A+B (3824 [2976] vs. 5508 [4671] steps.d-1, p<0.0001. The choice of questionnaire yielded different patient distributions (agreement mMRC-CAT κ = 0.57; CCQ-mMRC κ = 0.71; CCQ-CAT κ = 0.72 with different clinical characteristics. PA was notably lower in patients with an mMRC score ≥2 (3430 [2537] vs. 5443 [3776] steps.d-1, p <0.001 in both the low and high risk quadrants.Using different questionnaires changes the patient distribution and results in different clinical characteristics. Therefore, standardization of the questionnaire used for classification is critical to allow comparison of different studies using this as an entry criterion.ClinicalTrials.gov NCT01388218.

Gold internal standard correction for elemental imaging of soft tissue sections by LA-ICP-MS: element distribution in eye microstructures.

Science.gov (United States)

Konz, Ioana; Fernández, Beatriz; Fernández, M Luisa; Pereiro, Rosario; González, Héctor; Alvarez, Lydia; Coca-Prados, Miguel; Sanz-Medel, Alfredo

2013-04-01

Laser ablation coupled to inductively coupled plasma mass spectrometry has been developed for the elemental imaging of Mg, Fe and Cu distribution in histological tissue sections of fixed eyes, embedded in paraffin, from human donors (cadavers). This work presents the development of a novel internal standard correction methodology based on the deposition of a homogeneous thin gold film on the tissue surface and the use of the (197)Au(+) signal as internal standard. Sample preparation (tissue section thickness) and laser conditions were carefully optimized, and internal normalisation using (197)Au(+) was compared with (13)C(+) correction for imaging applications. (24)Mg(+), (56)Fe(+) and (63)Cu(+) distributions were investigated in histological sections of the anterior segment of the eye (including the iris, ciliary body, cornea and trabecular meshwork) and were shown to be heterogeneously distributed along those tissue structures. Reproducibility was assessed by imaging different human eye sections from the same donor and from ten different eyes from adult normal donors, which showed that similar spatial maps were obtained and therefore demonstrate the analytical potential of using (197)Au(+) as internal standard. The proposed analytical approach could offer a robust tool with great practical interest for clinical studies, e.g. to investigate trace element distribution of metals and their alterations in ocular diseases.

Characteristics of COPD patients according to GOLD classification and clinical phenotypes in the Russian Federation: the SUPPORT trial

Directory of Open Access Journals (Sweden)

Arkhipov V

2017-11-01

Full Text Available Vladimir Arkhipov,1 Daria Arkhipova,2 Marc Miravitlles,3 Andrey Lazarev,4 Ekaterina Stukalina5 1Clinical Pharmacology and Therapy Department, Russian Medical Academy of Postgraduate Education, Moscow, Russian Federation; 2Clinical Pharmacology and Propaedeutic Internal Diseases Department, First Moscow State Medical University, Moscow, Russian Federation; 3Pneumology Department, Hospital Universitari Vall d’Hebron, Ciber de Enfermedades Respiratorias (CIBERES, Barcelona, Spain; 4AstraZeneca Pharmaceuticals, Moscow, Russian Federation; 5AstraZeneca LP, Gaithersburg, MD, USA Background: The high prevalence of COPD in the Russian Federation has been demonstrated in several epidemiological studies. However, there are still no data on the clinical characteristics of these patients according to Global Initiative for Chronic Obstructive Lung Disease (GOLD groups and phenotypes, which could provide additional understanding of the burden of COPD, routine clinical practice, and ways to improve the treatment of patients with COPD in Russia.Patients and methods: SUPPORT was an observational multicenter study designed to obtain data about the distribution of patients with previously diagnosed COPD according to the severity of bronchial obstruction, symptom severity, risk of exacerbation, COPD phenotypes, and treatment of COPD. We included patients with a previous diagnosis of COPD who visited one of 33 primary-care centers for any reason in 23 cities in Russia.Results: Among the 1,505 patients with a previous diagnosis of COPD who attended the primary-care centers and were screened for the study, 1,111 had a spirometry-confirmed diagnosis and were included in the analysis. Up to 53% of the patients had severe or very severe COPD (GOLD stages III–IV, and 74.3% belonged to the GOLD D group. The majority of patients were frequent exacerbators (exacerbators with chronic bronchitis [37.3%], exacerbators without chronic bronchitis [14%], while 35.8% were

Can context justify an ethical double standard for clinical research in developing countries?

Directory of Open Access Journals (Sweden)

Landes Megan

2005-07-01

Full Text Available Abstract Background The design of clinical research deserves special caution so as to safeguard the rights of participating individuals. While the international community has agreed on ethical standards for the design of research, these frameworks still remain open to interpretation, revision and debate. Recently a breach in the consensus of how to apply these ethical standards to research in developing countries has occurred, notably beginning with the 1994 placebo-controlled trials to reduce maternal to child transmission of HIV-1 in Africa, Asia and the Caribbean. The design of these trials sparked intense debate with the inclusion of a placebo-control group despite the existence of a 'gold standard' and trial supporters grounded their justifications of the trial design on the context of scarcity in resource-poor settings. Discussion These 'contextual' apologetics are arguably an ethical loophole inherent in current bioethical methodology. However, this convenient appropriation of 'contextual' analysis simply fails to acknowledge the underpinnings of feminist ethical analysis upon which it must stand. A more rigorous analysis of the political, social, and economic structures pertaining to the global context of developing countries reveals that the bioethical principles of beneficence and justice fail to be met in this trial design. Conclusion Within this broader, and theoretically necessary, understanding of context, it becomes impossible to justify an ethical double standard for research in developing countries.

SHORT- AND LONG-TERM BOND STRENGTHS OF A GOLD STANDARD

Directory of Open Access Journals (Sweden)

Safa TUNCER

2015-04-01

Full Text Available Purpose: The aim of this study was to investigate the micro tensile bond strength of a self-etch adhesive system following 1 year storage in water. Materials and Methods: 10 sound human molar teeth were used for micro tensile bond strength test. Twostep self-etch dentin adhesive (Clearfil SE Bond® was applied to the flat dentin surfaces according to the manufacturer’s instructions. Composite blocks (Z- 250; 3M ESPE of 5 mm in height have been prepared by using layering technique. Teeth were stored in water for 24 hours at 37°C and longitudinally sectioned to obtain dentin sticks of 1 mm2.Randomly selected samples from half of the teeth were immediately subjected to micro tensile test and. Remaining specimens were tested after 1 year storage in water. Bond strengths were calculated in megapascal (MPa. Results: Means and standard deviations of the Clearfil SE Bond® micro tensile bond strength values were, respectively, 37.31 ± 13.77 MPa and 24.78 ± 2.99 MPa after 24 h and 1 year of storage in water. The difference was statistically significant (p=0.031. Conclusion: Long-term storage in water decreased the micro tensile bond strength values of the twostep self-etch adhesive which has been accepted as the gold standard in bond strength tests.

Thrombelastography detects dabigatran at therapeutic concentrations in vitro to the same extent as gold-standard tests

DEFF Research Database (Denmark)

Solbeck, Sacha; Ostrowski, Sisse R; Stensballe, Jakob

2016-01-01

BACKGROUND/OBJECTIVES: Dabigatran is an oral anticoagulant approved for treatment of non-valvular atrial fibrillation, deep venous thrombosis (DVT), pulmonary embolism and prevention of DVT following orthopedic surgery. Monitoring of the dabigatran level is essential in trauma and bleeding patien...... to the current gold-standard tests Hemoclot and ECT, for assessing dabigatran. TEG R is applicable as a rapid and precise whole blood monitoring test for dabigatran treated patients in the emergency setting....

Physical Activity Characteristics across GOLD Quadrants Depend on the Questionnaire Used

Science.gov (United States)

Demeyer, Heleen; Gimeno-Santos, Elena; Rabinovich, Roberto A.; Hornikx, Miek; Louvaris, Zafeiris; de Boer, Willem I.; Karlsson, Niklas; de Jong, Corina; Van der Molen, Thys; Vogiatzis, Ioannis; Janssens, Wim; Garcia-Aymerich, Judith; Troosters, Thierry; Polkey, Michael I.

2016-01-01

Background The GOLD multidimensional classification of COPD severity combines the exacerbation risk with the symptom experience, for which 3 different questionnaires are permitted. This study investigated differences in physical activity (PA) in the different GOLD quadrants and patient’s distribution in relation to the questionnaire used. Methods 136 COPD patients (58±21% FEV1 predicted, 34F/102M) completed COPD assessment test (CAT), clinical COPD questionnaire (CCQ) and modified Medical Research Council (mMRC) questionnaire. Exacerbation history, spirometry and 6MWD were collected. PA was objectively measured for 2 periods of 1 week, 6 months apart, in 5 European centres; to minimise seasonal and clinical variation the average of these two periods was used for analysis. Results GOLD quadrants C+D had reduced PA compared with A+B (3824 [2976] vs. 5508 [4671] steps.d-1, p<0.0001). The choice of questionnaire yielded different patient distributions (agreement mMRC-CAT κ = 0.57; CCQ-mMRC κ = 0.71; CCQ-CAT κ = 0.72) with different clinical characteristics. PA was notably lower in patients with an mMRC score ≥2 (3430 [2537] vs. 5443 [3776] steps.d-1, p <0.001) in both the low and high risk quadrants. Conclusions Using different questionnaires changes the patient distribution and results in different clinical characteristics. Therefore, standardization of the questionnaire used for classification is critical to allow comparison of different studies using this as an entry criterion. Clinical Trial Registration ClinicalTrials.gov NCT01388218 PMID:26974332

Substoichiometric neutron activation determination of gold

International Nuclear Information System (INIS)

Mitchell, J.W.; Riley, J.E. Jr.; Payne, V.

1978-01-01

A highly precise and selective method is described for the determination of traces of gold by substoichiometric extraction from hydrochloric acid with tri-n-octylphosphine sulfide in cyclohexane following thermal neutron activation. Fundamental aspects of the extraction system are discussed and results are reported for the determination of gold in an effluent from a recovery process containing a complexed species of gold and unknown amounts of cyanide, citrate, phosphate, potassium and sodium. Other constituents of the effluent stream include traces of the transition elements Co, Ni, Fe, Cu, Zn, Pb and Sn at concentrations less than 50 ppm. One hour was allowed for the Au 3+ carrier and the 198 Au complexed species in samples and standards to oxidize, exchange, and reach chemical equilibrium. Samples were then equilibrated by shaking with the organic phase for thirty min. The percentage extractions (%E) for the substoichiometric separation of gold from the effluent and from the corresponding comparison standards were monitored. The mean percentage extractions for the substoichiometric separations of carrier from the effluent, and its corresponding standard were 75.3 and 59.3, respectively. These data are estimated to be accurate within +-2.0%. (T.G.)

GOLD NANOPARTICLES: A REVIVAL IN PRECIOUS METAL ADMINISTRATION TO PATIENTS

Science.gov (United States)

Thakor, AS; Jokerst, J; Zaveleta, C; Massoud, TF; Gambhir, SS

2011-01-01

Gold has been used as a therapeutic agent to treat a wide variety of rheumatic diseases including psoriatic arthritis, juvenile arthritis and discoid lupus erythematosus. Although the use of gold has been largely superseded by newer drugs, gold nanoparticles are being used effectively in laboratory based clinical diagnostic methods whilst concurrently showing great promise in vivo either as a diagnostic imaging agent or a therapeutic agent. For these reasons, gold nanoparticles are therefore well placed to enter mainstream clinical practice in the near future. Hence, the present review summarizes the chemistry, pharmacokinetics, bio-distribution, metabolism and toxicity of bulk gold in humans based on decades of clinical observation and experiments in which gold was used to treat patients with rheumatoid arthritis. The beneficial attributes of gold nanoparticles, such as their ease of synthesis, functionalization and shape control are also highlighted demonstrating why gold nanoparticles are an attractive target for further development and optimization. The importance of controlling the size and shape of gold nanoparticles to minimize any potential toxic side effects is also discussed. PMID:21846107

Imatinib mesylate--gold standards and silver linings.

Science.gov (United States)

Peggs, K

2004-09-01

Imatinib mesylate represents the first of a new generation of molecularly targeted therapies engineered to disrupt signal transduction pathways. It is a tyrosine kinase inhibitor with relatively selective activity against the Abelson (ABL) proto-oncogene, platelet-derived growth factor receptor, and c-KIT receptor. Deregulated tyrosine kinase activity has been implicated as a central pathogenic event in a number of human malignancies, most notably chronic myeloid leukemia. In this myeloproliferative disorder the t(9;22) reciprocal translocation results in the generation of a novel fusion oncoprotein, BCR-ABL, with constitutive tyrosine kinase activity. Imatinib inhibits this activity, inducing remarkable rates of hematological and cytogenetic remission in excess of those seen with alternative medical therapies. Following a large phase III study comparing its efficacy with the combination of interferon alpha and low-dose cytarabine, it has emerged as the current gold standard therapy for patients with chronic-phase disease without a potential bone marrow donor and those considered unsuitable for bone marrow transplantation. Its integration into the management of those patients who might be considered for transplantation, which has historically been considered the only potentially curative approach, remains a major challenge. The increasing recognition and subsequent molecular characterization of resistance mechanisms has reinforced the need to exercise caution against deferring a proven curative therapy in favor of a treatment approach that is still investigational, with the spectre of increased numbers of patients progressing to sudden-onset blast crisis remaining the potential dark cloud in the silver lining for imatinib.

42 CFR 493.1457 - Standard; Clinical consultant responsibilities.

Science.gov (United States)

2010-10-01

... HUMAN SERVICES (CONTINUED) STANDARDS AND CERTIFICATION LABORATORY REQUIREMENTS Personnel for Nonwaived Testing Laboratories Performing High Complexity Testing § 493.1457 Standard; Clinical consultant... 42 Public Health 5 2010-10-01 2010-10-01 false Standard; Clinical consultant responsibilities. 493...

Metallic gold beads in hyaluronic acid

DEFF Research Database (Denmark)

Pedersen, Dan Sonne; Tran, Thao Phuong; Smidt, Kamille

2013-01-01

. In conclusion, our findings support that bio-liberation of gold from metallic gold surfaces have anti-inflammatory properties similar to classic gold compounds, warranting further studies into the pharmacological potential of this novel gold-treatment and the possible synergistic effects of hyaluronic acid....... by exploiting macrophage-induced liberation of gold ions (dissolucytosis) from gold surfaces. Injecting gold beads in hyaluronic acid (HA) as a vehicle into the cavities of the brain can delay clinical signs of disease progression in the MS model, experimental autoimmune encephalitis (EAE). This study...... investigates the anti-inflammatory properties of metallic gold/HA on the gene expression of tumor necrosis factor (Tnf-α), Interleukin (Il)-1β, Il-6, Il-10, Colony-stimulating factor (Csf)-v2, Metallothionein (Mt)-1/2, Bcl-2 associated X protein (Bax) and B cell lymphoma (Bcl)-2 in cultured J774 macrophages...

Gold and Silver Extraction from Leach Solutions

OpenAIRE

Bagdaulet K. Kenzhaliyev; Renata R. Iskhakova; Zamzagul D. Dosymbaeva; Esen N. Sulejmenov

2014-01-01

There has been carried out an investigation on the extraction of gold and silver from thiosulfate solutions: standard test and technological solutions of chemical and electrochemical leaching. The influence of related metals on the process of extracting gold from solution was studied. There has been conducted a comparative study of the IR spectra of solutions after the sorption of gold, silver and related metals.

Gold and Silver Extraction from Leach Solutions

Directory of Open Access Journals (Sweden)

Bagdaulet K. Kenzhaliyev

2014-03-01

Full Text Available There has been carried out an investigation on the extraction of gold and silver from thiosulfate solutions: standard test and technological solutions of chemical and electrochemical leaching. The influence of related metals on the process of extracting gold from solution was studied. There has been conducted a comparative study of the IR spectra of solutions after the sorption of gold, silver and related metals.

42 CFR 493.1419 - Standard; Clinical consultant responsibilities.

Science.gov (United States)

2010-10-01

... Testing Laboratories Performing Moderate Complexity Testing § 493.1419 Standard; Clinical consultant... clinical consultation to the laboratory's clients; (b) Be available to assist the laboratory's clients in... 42 Public Health 5 2010-10-01 2010-10-01 false Standard; Clinical consultant responsibilities. 493...

When do latent class models overstate accuracy for diagnostic and other classifiers in the absence of a gold standard?

Science.gov (United States)

Spencer, Bruce D

2012-06-01

Latent class models are increasingly used to assess the accuracy of medical diagnostic tests and other classifications when no gold standard is available and the true state is unknown. When the latent class is treated as the true class, the latent class models provide measures of components of accuracy including specificity and sensitivity and their complements, type I and type II error rates. The error rates according to the latent class model differ from the true error rates, however, and empirical comparisons with a gold standard suggest the true error rates often are larger. We investigate conditions under which the true type I and type II error rates are larger than those provided by the latent class models. Results from Uebersax (1988, Psychological Bulletin 104, 405-416) are extended to accommodate random effects and covariates affecting the responses. The results are important for interpreting the results of latent class analyses. An error decomposition is presented that incorporates an error component from invalidity of the latent class model. © 2011, The International Biometric Society.

Diagnostic tests for Helicobacter pylori : A prospective evaluation of their accuracy, without selecting a single test as the gold standard

NARCIS (Netherlands)

Thijs, J C; van Zwet, A A; Thijs, W J; Oey, H B; Karrenbeld, A; Stellaard, F; Luijt, D S; Meyer, B C; Kleibeuker, J H

1996-01-01

OBJECTIVE: To assess the accuracy of six commonly used diagnostic tests for Helicobacter pylori in a prospective study without using any specific test as the gold standard (the patient was regarded as H. pylori-infected if two or more tests, whatever their nature, were positive). METHODS: In 105

Gold - Old Drug with New Potentials.

Science.gov (United States)

Faa, Gavino; Gerosa, Clara; Fanni, Daniela; Lachowicz, Joanna I; Nurchi, Valeria M

2018-01-01

Research into gold-based drugs for a range of human diseases has seen a revival in recent years. This article reviews the most important applications of gold products in different fields of human pathology. Au(I) and Au(III) compounds have been re-introduced in clinical practice for targeting the cellular components involved in the onset and progression of viral and parasitic diseases, rheumatoid arthritis and cancer. After some brief historical notes, this article takes into account the applications of gold compounds against Mycobacterium tuberculosis, and also in tuberculosis and in rheumatoid arthritis treatment. The use of gold containing drugs in the cure of cancer are then considered, with special emphasis to the use of nanoparticles and to the photo-thermal cancer therapy. The use of colloidal gold in diagnostics, introduced in the last decade is widely discussed. As a last point a survey on the adverse effects and on the toxicity of the various gold derivatives in use in medicine is presented. In this review, we described the surprisingly broad spectrum of possible uses of gold in diagnostics and in therapeutic approaches to multiple human diseases, ranging from degenerative to infectious diseases, and to cancer. In particular, gold nanoparticles appear as attractive elements in modern clinical medicine, combining high therapeutic properties, high selectivity in targeting cancer cells and low toxicity. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Reverse translated and gold standard continuous performance tests predict global cognitive performance in schizophrenia.

Science.gov (United States)

Bismark, Andrew W; Thomas, Michael L; Tarasenko, Melissa; Shiluk, Alexandra L; Rackelmann, Sonia Y; Young, Jared W; Light, Gregory A

2018-04-12

Attentional dysfunction contributes to functional impairments in schizophrenia (SZ). Sustained attention is typically assessed via continuous performance tasks (CPTs), though many CPTs have limited cross-species translational validity and place demands on additional cognitive domains. A reverse-translated 5-Choice Continuous Performance Task (5C-CPT) for human testing-originally developed for use in rodents-was designed to minimize demands on perceptual, visual learning, processing speed, or working memory functions. To-date, no studies have validated the 5C-CPT against gold standard attentional measures nor evaluated how 5C-CPT scores relate to cognition in SZ. Here we examined the relationship between the 5C-CPT and the CPT-Identical Pairs (CPT-IP), an established and psychometrically robust measure of vigilance from the MATRICS Consensus Cognitive Battery (MCCB) in a sample of SZ patients (n = 35). Relationships to global and individual subdomains of cognition were also assessed. 5C-CPT and CPT-IP measures of performance (d-prime) were strongly correlated (r = 0.60). In a regression model, the 5C-CPT and CPT-IP collectively accounted for 54% of the total variance in MCCB total scores, and 27.6% of overall cognitive variance was shared between the 5C-CPT and CPT-IP. These results indicate that the reverse translated 5C-CPT and the gold standard CPT-IP index a common attentional construct that also significantly overlaps with variance in general cognitive performance. The use of simple, cross-species validated behavioral indices of attentional/cognitive functioning such as the 5C-CPT could accelerate the development of novel generalized pro-cognitive therapeutics for SZ and related neuropsychiatric disorders.

A gold standard method for the evaluation of antibody-based materials functionality: Approach to forced degradation studies.

Science.gov (United States)

Coussot, Gaëlle; Le Postollec, Aurélie; Faye, Clément; Dobrijevic, Michel

2018-04-15

The scope of this paper is to present a gold standard method to evaluate functional activity of antibody (Ab)-based materials during the different phases of their development, after their exposure to forced degradations or even during routine quality control. Ab-based materials play a central role in the development of diagnostic devices, for example, for screening or therapeutic target characterization, in formulation development, and in novel micro(nano)technology approaches to develop immunosensors useful for the analysis of trace substances in pharmaceutical and food industries, clinical and environmental fields. A very important aspect in diagnostic device development is the construction of its biofunctional surfaces. These Ab surfaces require biocompatibility, homogeneity, stability, specificity and functionality. Thus, this work describes the validation and applications of a unique ligand binding assay to directly perform the quantitative measurement of functional Ab binding sites immobilized on the solid surfaces. The method called Antibody Anti-HorseRadish Peroxidase (A2HRP) method, uses a covalently coated anti-HRP antibody (anti-HRP Ab) and does not need for a secondary Ab during the detection step. The A2HRP method was validated and gave reliable results over a wide range of absorbance values. Analyzed validation criteria were fulfilled as requested by the food and drug administration (FDA) and European Medicines Agency (EMA) guidance for the validation of bioanalytical methods with 1) an accuracy mean value within +15% of the nominal value; 2) the within-assay precision less than 7.1%, and 3) the inter-day variability under 12.1%. With the A2HRP method, it is then possible to quantify from 0.04 × 10 12 to 2.98 × 10 12 functional Ab binding sites immobilized on the solid surfaces. A2HRP method was validated according to FDA and EMA guidance, allowing the creation of a gold standard method to evaluate Ab surfaces for their resistance under

Transvaginal duplex ultrasonography appears to be the gold standard investigation for the haemodynamic evaluation of pelvic venous reflux in the ovarian and internal iliac veins in women.

Science.gov (United States)

Whiteley, M S; Dos Santos, S J; Harrison, C C; Holdstock, J M; Lopez, A J

2015-12-01

To assess the suitability of transvaginal duplex ultrasonography to identify pathological reflux in the ovarian and internal iliac veins in women. A retrospective study of patients treated in 2011 and 2012 was performed in a specialised vein clinic. Diagnostic transvaginal duplex ultrasonography in women presenting with symptoms or signs of pelvic vein reflux were compared with the outcomes of treatment from pelvic vein embolisation. A repeat transvaginal duplex ultrasonography was performed 6 weeks later by a blinded observer and any residual reflux was identified. Results from 100 sequential patients were analysed. Mean age 44.2 years (32-69) with mode average parity of 3 (0-5 deliveries). Pre-treatment, 289/400 veins were refluxing (ovarian - 29 right, 81 left; internal iliac - 93 right, 86 left). Coil embolisation was successful in 86/100 patients and failed partially in 14/100 - 5 due to failure to cannulate the target vein. One false-positive diagnosis was made. Currently there is no accepted gold standard for pelvic vein incompetence. Comparing transvaginal duplex ultrasonography with the outcome from selectively treating the veins identified as having pathological reflux with coil embolisation, there were no false-negative diagnoses and only one false-positive. This study suggests that transvaginal duplex ultrasonography could be the gold standard in assessing pelvic vein reflux. © The Author(s) 2014.

Outpatient laparoscopic cholecystectomy: A new gold standard for cholecystectomy?

Directory of Open Access Journals (Sweden)

J. Bueno Lledó

Full Text Available Objective: to contribute our experience for five years in the implemetation of outpatient laparoscopic cholecystectomy (LC. Patients: between January 1999 and March 2004 we performed 504 outpatient LCs. We applied both exclusion and inclusion criteria, an anesthetic and surgical protocol, and discharge-specific criteria. Postoperative management in "fast track" regime. Postoperative period controlled by protocol, including phone calls after cholecystectomy. Results: the ambulatory percentage in the global series was 88.8%, and mean hospital stay was 6.1 hours. Fifty-one patients required overnight stays (10.1%, most of them for "social" causes. Five patients required admission (between 24 and 48 hours for different causes (conversion to laparotomy, intraoperative neumothorax, and postoperative medical complications. Six patients (1.1% were readmitted, and we observed 11.6% postoperative complications in the global series, with abdominal parietal pain being most frequent. Phone localization by 22.00 p.m. in the same day of surgery was 100% complete for outpatient cases. Postoperative surveillance within the first month after surgery was completed in 93.9%, and within th first year in 86.7% of patients. Conclusions: outpatient LC is safe and feasible, and probably represents a new "gold standard" in the treatment of symptomatic cholelithiasis.

Preparation, Physicochemical Characterization and Performance Evaluation of Gold Nanoparticles in Radiotherapy

Directory of Open Access Journals (Sweden)

Ali Kamiar

2013-08-01

Full Text Available Purpose: The aim of the present study was preparation, physicochemical characterization and performance evaluation of gold nanoparticles (GNPs in radiotherapy. Another objective was the investigation of anti-bacterial efficacy of gold nanoparticle against E. coli clinical strains. Methods: Gold nanoparticles prepared by controlled reduction of an aqueous HAuCl4 solution using Tri sodium citrate. Particle size analysis and Transmission electron microscopy were used for physicochemical characterization. Polymer gel dosimetry was used for evaluation of the enhancement of absorbed dose. Diffusion method in agar media was used for investigation of anti-bacterial effect. Results: Gold nanoparticles synthesized in size range from 57 nm to 346 nm by planning different formulation. Gold nanoparticle in 57 nm size increased radiation dose effectiveness with the magnitude of about 21 %. At the concentration of 400 ppm, Nano gold exhibited significant anti-bacterial effect against E. coli clinical strains. Conclusion: It is concluded that gold nanoparticles can be applied as dose enhancer in radiotherapy. The Investigation of anti-bacterial efficacy showed that gold nanoparticle had significant effect against E. coli clinical strains.

Decision Making in the Management of Extracapsular Fractures of the Proximal Femur - is the Dynamic Hip Screw the Prevailing Gold Standard?

Science.gov (United States)

Jacob, Joshua; Desai, Ankit; Trompeter, Alex

2017-01-01

Currently, approximately half of all hip fractures are extracapsular, with an incidence as high as 50 in 100,000 in some countries. The common classification systems fail to explain the logistics of fracture classification and whether they all behave in the same manner. The Muller AO classification system is a useful platform to delineate stable and unstable fractures. The Dynamic hip screw (DHS) however, has remained the 'gold standard' implant of choice for application in all extracapsular fractures. The DHS relies on the integrity and strength of the lateral femoral wall as well as the postero-medial fragment. An analysis of several studies indicates significant improvements in design and techniques to ensure a better outcome with intramedullary nails. This article reviews the historical trends that helped to evolve the DHS implant as well as discussing if the surgeon should remain content with this implant. We suggest that the gold standard surgical management of extracapsular fractures can, and should, evolve.

Can We Create a "Gold Standard of Education" for Our Children through the "Advancement via Independent Determination (AVID) Program"?

Science.gov (United States)

Gaskins, Darlene

2014-01-01

We need to come together as a team and become one system of total quality improvement regarding the education of our nation's children. In order to achieve a gold standard in the education of our nation's children, leadership has to be willing to go against the status quo and build bridges for long-term sustainable change. In order to survive,…

Gold--a controversial sensitizer

DEFF Research Database (Denmark)

Bruze, M; Andersen, Klaus Ejner

1999-01-01

allergy to gold sodium thiosulfate were published at the beginning of the 1990s, the allergic nature of the reported positive patch test reactions to gold was questioned. The major argument for such questioning was the lack of demonstrable clinical relevance in most positive reactors. A major reason......Until recently, gold allergy was considered to be extremely rare. Gold has been used and worshipped for thousands of years without any obvious complaints of skin problems, either in those participating in mining and other ways of prospecting, or in those wearing jewellery. When studies on contact...... for the questioning may have been confusion in differentiating between contact allergy and allergic contact dermatitis. To arrive at a diagnosis of allergic contact dermatitis, 3 steps have, in principle, to be fulfilled: (i) establishment of contact allergy; (ii) demonstration of present exposure; (iii) assessment...

A radiochemical study of gold electrodeposition kinetics in alkaline cyanide solutions

International Nuclear Information System (INIS)

Poshkus, D.; Agafonovas, G.; Zhebrauskas, A.

1995-01-01

Kinetics of gold electrodeposition from alkaline cyanide solutions was investigated by the use of labelled gold 195 atoms. The absorption of cyanide containing species from alkaline cyanide and dicyanoaurate solutions on a gold electrode by the use of labelled carbon atoms was investigated. Polarization curves of anodic dissolution and cathodic deposition of gold in alkaline cyanide solutions were obtained. The values of standard potential, exchange current density, transfer coefficient and standard polarization rate were determined from polarization curves. The errors in current density caused by the nuclear disintegration statistics were evaluated. 28 refs., 1 tab., 4 figs

Immobilization of gold nanoparticles on cell culture surfaces for safe and enhanced gold nanoparticle-mediated laser transfection

Science.gov (United States)

Kalies, Stefan; Heinemann, Dag; Schomaker, Markus; Gentemann, Lara; Meyer, Heiko; Ripken, Tammo

2014-01-01

Abstract. In comparison to standard transfection methods, gold nanoparticle-mediated laser transfection has proven to be a versatile alternative. This is based on its minor influence on cell viability and its high efficiency, especially for the delivery of small molecules like small interfering RNA. However, in order to transfer it to routine usage, a safety aspect is of major concern: The avoidance of nanoparticle uptake by the cells is desired. The immobilization of the gold nanoparticles on cell culture surfaces can address this issue. In this study, we achieved this by silanization of the appropriate surfaces and the binding of gold nanoparticles to them. Comparable perforation efficiencies to the previous approaches of gold nanoparticle-mediated laser transfection with free gold nanoparticles are demonstrated. The uptake of the immobilized particles by the cells is unlikely. Consequently, these investigations offer the possibility of bringing gold nanoparticle-mediated laser transfection closer to routine usage. PMID:25069006

Gold ions bio-released from metallic gold particles reduce inflammation and apoptosis and increase the regenerative responses in focal brain injury

DEFF Research Database (Denmark)

Larsen, Agnete; Kolind, Kristian; Pedersen, Dan Sonne

2008-01-01

neural stem cell response. We conclude that bio-liberated gold ions possess pronounced anti-inflammatory and neuron-protective capacities in the brain and suggest that metallic gold has clinical potentials. Intra-cerebral application of metallic gold as a pharmaceutical source of gold ions represents......Traumatic brain injury results in loss of neurons caused as much by the resulting neuroinflammation as by the injury. Gold salts are known to be immunosuppressive, but their use are limited by nephrotoxicity. However, as we have proven that implants of pure metallic gold release gold ions which do...... not spread in the body, but are taken up by cells near the implant, we hypothesize that metallic gold could reduce local neuroinflammation in a safe way. Bio-liberation, or dissolucytosis, of gold ions from metallic gold surfaces requires the presence of disolycytes i.e. macrophages and the process...

Some developments in the extraction of gold from Witwatersrand ores

International Nuclear Information System (INIS)

Laxen, P.A.

1975-01-01

The extraction of gold from most ores of the Witwatersrand has been consistently high - approximately 95 per cent - for many years. The present high price of gold has stimulated research and development into potential improvements of the standard procedures. The occurrence of the gold and its association with other minerals is described briefly. The Witwatersrand reefs also contain uranium and pyrite, and some of the improvements to the standard gold-extraction process are associated with the recovery or concentration of one or both of these valuable constituents. For instance, the 'reverse-leach' process, in which acid treatment for the extraction of uranium precedes cyanidation, results in improved gold extraction. Some concentration techniques used on the present residues from cyanidation offer promise in improving the overall gold recoveries. Thucholite is an important carrier of residual gold, and its recovery from some residues by flotation appears to be economically justifiable. Wet high-intensity magnetic separation has given promising results, in the laboratory and on the pilot plant, for the recovery of both uranium and gold from a number of cyanide tailings. The benefits of gravity concentration and of the application of empirical modelling to the gold-extraction process have been demonstrated by a mining group. Some developments in instrumentation for control during cyanidation are discussed briefly [af

Realism and Imagination in Child Foreign-Language Productions: Three Reasons for an Early Exit from the "Gold Standard" of Personal Experience

Science.gov (United States)

Hong, Seongeun; Kellogg, David

2016-01-01

Teachers often assume that personal experience is a rich resource for classroom chat and a gold standard for meaningful exchange of information. But in this paper, we first present three kinds of reasons for suspecting that primary intersubjectivity--the "me and you" relationship in which personal experiences are directly exchanged…

Event Rates in Randomized Clinical Trials Evaluating Cardiovascular Interventions and Devices

NARCIS (Netherlands)

Mahmoud, Karim D.; Lennon, Ryan J.; Holmes, David R.

2015-01-01

Randomized clinical trials (RCTs) are considered the gold standard for evidence-based medicine. However, an accurate estimation of the event rate is crucial for their ability to test clinical hypotheses. Overestimation of event rates reduces the required sample size but can compromise the

The determination, by x-ray-fluorescence spectrometry, of gold in activated charcoal

International Nuclear Information System (INIS)

Austen, C.E.

1977-01-01

A rapid method is described for the determination of gold in activated charcoal by X-ray-fluorescence spectrometry. Compensation for matrix effects is achieved by means of platinum that is added for use as an internal standard. Calibration is achieved by use of a series of synthetic standards that are made by the spiking of barren charcoal with gold and platinum. The limit of determination is about 8 p.p.m. of gold, and the relative standard deviation is 1,2 per cent at a concentration level of 2300 p.p.m

Impact of using the new GOLD classification on the distribution of COPD severity in clinical practice

Directory of Open Access Journals (Sweden)

Hernández M

2018-01-01

Full Text Available Marcos Hernández, Gabriel García, Jimena Falco, Agustín R García, Vanina Martín, Manuel Ibarrola, Silvia Quadrelli Department of Respiratory Medicine, Güemes Foundation, Buenos Aires, Argentina Objective: The objective of this study was to examine how COPD patients were classified by the Global Initiative for Chronic Obstructive Lung Disease (GOLD spirometry-based severity system and the distribution of COPD severity using the new GOLD 2011 assessment framework.Materials and methods: This was an observational, retrospective cohort study conducted in a single tertiary center on a prospective database, which aimed to evaluate the prevalence, incidence, severity, and comorbidities of COPD. Inclusion criteria were age ≥40 years and COPD diagnosis according to GOLD 2007 classification. Clinical factors were compared between the categories in GOLD 2007 and 2011 groups by using the χ2 test for categorical data and the analysis of variance for continuous data.Results: In total, 420 COPD patients were included in the analysis. The distribution of patients into GOLD 2007 categories was as follows: 6.4% (n=27 of them were classified into subgroup I, 42.1% (n=177 into subgroup II, 37.9% (n=159 into subgroup III, and 13.6% (n=57 into subgroup IV. The distribution of patients into GOLD 2011 categories was as follows: 16.4% (n=69 of them were classified into subgroup A (low risk and fewer symptoms, 32.1% (n=135 into subgroup B (low risk and more symptoms, 21.6% (n=91 into subgroup C (high risk and fewer symptoms, and 29.7% (n=125 into subgroup D (high risk and more symptoms. After the application of the new GOLD 2011 (modified Medical Research Council [mMRC] system, 22% (n=94 of patients were upgraded to a higher level than their spirometry level, and 16.2% (n=68 of them were downgraded in their severity category, meaning that almost 40% of patients changed their severity assessment category. In total, 22% of patients in stage I were allocated to

Validation for 2D/3D registration II: The comparison of intensity- and gradient-based merit functions using a new gold standard data set

International Nuclear Information System (INIS)

Gendrin, Christelle; Markelj, Primoz; Pawiro, Supriyanto Ardjo; Spoerk, Jakob; Bloch, Christoph; Weber, Christoph; Figl, Michael; Bergmann, Helmar; Birkfellner, Wolfgang; Likar, Bostjan; Pernus, Franjo

2011-01-01

Purpose: A new gold standard data set for validation of 2D/3D registration based on a porcine cadaver head with attached fiducial markers was presented in the first part of this article. The advantage of this new phantom is the large amount of soft tissue, which simulates realistic conditions for registration. This article tests the performance of intensity- and gradient-based algorithms for 2D/3D registration using the new phantom data set. Methods: Intensity-based methods with four merit functions, namely, cross correlation, rank correlation, correlation ratio, and mutual information (MI), and two gradient-based algorithms, the backprojection gradient-based (BGB) registration method and the reconstruction gradient-based (RGB) registration method, were compared. Four volumes consisting of CBCT with two fields of view, 64 slice multidetector CT, and magnetic resonance-T1 weighted images were registered to a pair of kV x-ray images and a pair of MV images. A standardized evaluation methodology was employed. Targets were evenly spread over the volumes and 250 starting positions of the 3D volumes with initial displacements of up to 25 mm from the gold standard position were calculated. After the registration, the displacement from the gold standard was retrieved and the root mean square (RMS), mean, and standard deviation mean target registration errors (mTREs) over 250 registrations were derived. Additionally, the following merit properties were computed: Accuracy, capture range, number of minima, risk of nonconvergence, and distinctiveness of optimum for better comparison of the robustness of each merit. Results: Among the merit functions used for the intensity-based method, MI reached the best accuracy with an RMS mTRE down to 1.30 mm. Furthermore, it was the only merit function that could accurately register the CT to the kV x rays with the presence of tissue deformation. As for the gradient-based methods, BGB and RGB methods achieved subvoxel accuracy (RMS m

VALIDATION OF MITRAL VALVE ANNULUS DIMENSIONS MEASURED BY 2D TRANS-THORACIC ECHOCARDIOGRAPHY WITH GOLD STANDARD DIRECT INTRA-OPERATIVE MEASUREMENT

OpenAIRE

Praveen; Yadav; Ankur; Saket; Kaushal

2014-01-01

CONTEXT: Precise estimation of Mitral valve annulus dimensions preoperatively through Echocardiography is of paramount importance in replacement/repair surgeries. However a frequent disagreement was experienced between anticipated size of prosthetic valve based on echocardiography and actual valve size. This fact encouraged the authors to validate the measurements through echocardiography with gold-standard direct intra operative measurement. AIM: To compare the mitral val...

Determination of Commercial Karats on Gold Alloys for Jewellery

International Nuclear Information System (INIS)

Morales, S.E.A.

1986-12-01

An XRF method for the gold content determination in gold alloys was proposed and tested. Gold coins and ingot samples were analyzed. Monoelemental standards and two pint regression curves calculated with the NBSGSC program, Cd-109 annular source, Si-Li detector, 4096 channels analyzer and AXIL deconvolution software were employed. Good precision better than 1.5% and accuracy better than 2% were obtained. (author)

Validation of different measures of insulin sensitivity of glucose metabolism in dairy cows using the hyperinsulinemic euglycemic clamp test as the gold standard.

Science.gov (United States)

De Koster, J; Hostens, M; Hermans, K; Van den Broeck, W; Opsomer, G

2016-10-01

The aim of the present research was to compare different measures of insulin sensitivity in dairy cows at the end of the dry period. To do so, 10 clinically healthy dairy cows with a varying body condition score were selected. By performing hyperinsulinemic euglycemic clamp (HEC) tests, we previously demonstrated a negative association between the insulin sensitivity and insulin responsiveness of glucose metabolism and the body condition score of these animals. In the same animals, other measures of insulin sensitivity were determined and the correlation with the HEC test, which is considered as the gold standard, was calculated. Measures derived from the intravenous glucose tolerance test (IVGTT) are based on the disappearance of glucose after an intravenous glucose bolus. Glucose concentrations during the IVGTT were used to calculate the area under the curve of glucose and the clearance rate of glucose. In addition, glucose and insulin data from the IVGTT were fitted in the minimal model to derive the insulin sensitivity parameter, Si. Based on blood samples taken before the start of the IVGTT, basal concentrations of glucose, insulin, NEFA, and β-hydroxybutyrate were determined and used to calculate surrogate indices for insulin sensitivity, such as the homeostasis model of insulin resistance, the quantitative insulin sensitivity check index, the revised quantitative insulin sensitivity check index and the revised quantitative insulin sensitivity check index including β-hydroxybutyrate. Correlation analysis revealed no association between the results obtained by the HEC test and any of the surrogate indices for insulin sensitivity. For the measures derived from the IVGTT, the area under the curve for the first 60 min of the test and the Si derived from the minimal model demonstrated good correlation with the gold standard. Copyright © 2016 Elsevier Inc. All rights reserved.

Assessing FDG-PET diagnostic accuracy studies to develop recommendations for clinical use in dementia.

Science.gov (United States)

Boccardi, Marina; Festari, Cristina; Altomare, Daniele; Gandolfo, Federica; Orini, Stefania; Nobili, Flavio; Frisoni, Giovanni B

2018-04-30

FDG-PET is frequently used as a marker of synaptic damage to diagnose dementing neurodegenerative disorders. We aimed to adapt the items of evidence quality to FDG-PET diagnostic studies, and assess the evidence available in current literature to assist Delphi decisions for European recommendations for clinical use. Based on acknowledged methodological guidance, we defined the domains, specific to FDG-PET, required to assess the quality of evidence in 21 literature searches addressing as many Population Intervention Comparison Outcome (PICO) questions. We ranked findings for each PICO and fed experts making Delphi decisions for recommending clinical use. Among the 1435 retrieved studies, most lacked validated measures of test performance, an adequate gold standard, and head-to-head comparison of FDG-PET and clinical diagnosis, and only 58 entered detailed assessment. Only two studies assessed the accuracy of the comparator (clinical diagnosis) versus any kind of gold-/reference-standard. As to the index-test (FDG-PET-based diagnosis), an independent gold-standard was available in 24% of the examined papers; 38% used an acceptable reference-standard (clinical follow-up); and 38% compared FDG-PET-based diagnosis only to baseline clinical diagnosis. These methodological limitations did not allow for deriving recommendations from evidence. An incremental diagnostic value of FDG-PET versus clinical diagnosis or lack thereof cannot be derived from the current literature. Many of the observed limitations may easily be overcome, and we outlined them as research priorities to improve the quality of current evidence. Such improvement is necessary to outline evidence-based guidelines. The available data were anyway provided to expert clinicians who defined interim recommendations.

The evolution of a clinical database: from local to standardized clinical languages.

OpenAIRE

Prophet, C. M.

2000-01-01

For more than twenty years, the University of Iowa Hospitals and Clinics Nursing Informatics (UIHC NI) has been developing a clinical database to support patient care planning and documentation in the INFORMM NIS (Information Network for Online Retrieval & Medical Management Nursing Information System). Beginning in 1992, the database content was revised to standardize orders and to incorporate the Standardized Nursing Languages (SNLs) of the North American Nursing Diagnosis Association (NAND...

42 CFR 493.1276 - Standard: Clinical cytogenetics.

Science.gov (United States)

2010-10-01

... SERVICES (CONTINUED) STANDARDS AND CERTIFICATION LABORATORY REQUIREMENTS Quality System for Nonwaived Testing Analytic Systems § 493.1276 Standard: Clinical cytogenetics. (a) The laboratory must have policies and procedures for ensuring accurate and reliable patient specimen identification during the process...

Gold film with gold nitride - A conductor but harder than gold

International Nuclear Information System (INIS)

Siller, L.; Peltekis, N.; Krishnamurthy, S.; Chao, Y.; Bull, S.J.; Hunt, M.R.C.

2005-01-01

The formation of surface nitrides on gold films is a particularly attractive proposition, addressing the need to produce harder, but still conductive, gold coatings which reduce wear but avoid the pollution associated with conventional additives. Here we report production of large area gold nitride films on silicon substrates, using reactive ion sputtering and plasma etching, without the need for ultrahigh vacuum. Nanoindentation data show that gold nitride films have a hardness ∼50% greater than that of pure gold. These results are important for large-scale applications of gold nitride in coatings and electronics

Histopathological examination of nail clippings using PAS staining (HPE-PAS): gold standard in diagnosis of Onychomycosis.

Science.gov (United States)

Jeelani, Shazia; Ahmed, Qazi Masood; Lanker, Audil Mohmad; Hassan, Iffat; Jeelani, Nasir; Fazili, Tawheeda

2015-01-01

Onychomycosis is fungal infection of one or more of the nail units. However, because fungi cause only about half of all nail dystrophies, the use of appropriate diagnostic techniques is important to ensure correct diagnosis and treatment. Aim of the present study was to compare direct microscopy, culture and HPE-PAS for diagnosis of onychomycosis by evaluating their sensitivity and various other relevant statistical parameters. A prospective, hospital-based, cross-sectional study was conducted on 216 patients with a high degree of clinical suspicion of onychomycosis. Nail specimens were evaluated using three diagnostic methods, i.e. direct microscopy using 20% Potassium hydroxide (KOH) & 40% Di-methyl-suphoxide (DMSO), culture and histopathological examination using PAS stain (HPE-PAS). Of 216 patients direct microscopy was positive in 138 (63.9%), culture in 147 (68%) and HPE-PAS in 164 patients (76%). One hundred and seventy-nine patients fitted into the criteria set for confirmed diagnosis of onychomycosis. Using this as a denominator; direct microscopy, culture and HPE-PAS had sensitivities of 77.1%, 70% and 91.6% respectively. Also, HPE-PAS showed the highest sensitivity of 94.7% in 19 cases with prediagnostic antimycotic treatment compared to direct microscopy (42.1%) or culture (57.9%). HPE-PAS shows high sensitivity for diagnosis of onychomycosis and can be considered as a gold standard in the diagnosis of onychomycosis. © 2014 Blackwell Verlag GmbH.

Determination of gold coating thickness measurement by using EDXRF

International Nuclear Information System (INIS)

Meor Yusoff Meor Sulaian; Masliana Muslimin; Fadlullah Jili Fursani

2005-01-01

The paper relates a study on the development of an analysis procedure for measuring the gold coating thickness using EDXRF technique. Gold coating thickness was measured by relating the counts under the Au L? peak its thickness value. In order to get a reasonably accurate result, a calibration graph was plotted using five gold-coated reference standards of different thickness. The calibration graph shows a straight line for thin coating measurement until 0.9 μm. Beyond this the relationship was not linear and this may be resulted from the self-absorption effect. Quantitative analysis was also performed on two different samples of gold coated jewelry and a phone connector. Result from the phone connector analysis seems to agree with the manufacturer gold coating value. From the analysis of gold-coated jewelry it had been able to differentiate the two articles as gold wash and gold electroplated. (Author)

Low-pass whole-genome sequencing in clinical cytogenetics

DEFF Research Database (Denmark)

Dong, Zirui; Zhang, Jun; Hu, Ping

2016-01-01

Purpose: Chromosomal microarray analysis is the gold standard for copy-number variant (CNV) detection in prenatal and postnatal diagnosis. We aimed to determine whether next-generation sequencing (NGS) technology could be an alternative method for CNV detection in routine clinical application. Me...

Consent for routine neonatal procedures: A study of practices in Irish neonatal units. How do we compare with the gold standard BAPM guidelines?

Science.gov (United States)

Ryan, M A; Ryan, C A; Dempsey, E; O'Connell, R

2017-06-09

The Irish National Consent Policy (NCP) proposes that the legal requirement for consent extends to all forms of interventions, investigations and treatment, carried out on or behalf of the Health Service Executive (HSE). This study employs a quantitative descriptive approach to investigate the practices for obtaining consent for an identified group of routine neonatal procedures in neonatal facilities throughout Ireland. The BAPM (British Association of Perinatal Medicine) guidelines were identified as 'gold standard' for the purposes of this study. The results indicated a lack of consistency between participating units pertaining to the modes of consent utilised and notable variances from 'gold standard' guidelines. Unanimity was evident for 3 procedures only (administering BCG, 6-in-1, and donor breast milk to infant). Significant findings related to EEG with video recordings, MRI/CT and gastro intestinal imaging, screening of an infant with suspected substance abuse or retinopathy of prematurity screening (ROP), administration of Vitamin K, and the carrying out of a lumbar puncture.

[Accreditation of clinical laboratories based on ISO standards].

Science.gov (United States)

Kawai, Tadashi

2004-11-01

International Organization for Standardization (ISO) have published two international standards (IS) to be used for accreditation of clinical laboratories; ISO/IEC 17025:1999 and ISO 15189:2003. Any laboratory accreditation body must satisfy the requirements stated in ISO/IEC Guide 58. In order to maintain the quality of the laboratory accreditation bodies worldwide, the International Laboratory Accreditation Cooperation (ILAC) has established the mutual recognition arrangement (MRA). In Japan, the International Accreditation Japan (IAJapan) and the Japan Accreditation Board for Conformity Assessment (JAB) are the members of the ILAC/MRA group. In 2003, the Japanese Committee for Clinical Laboratory Standards (JCCLS) and the JAB have established the Development Committee of Clinical Laboratory Accreditation Program (CLAP), in order to establish the CLAP, probably starting in 2005.

Roadmap to Clinical Use of Gold Nanoparticles for Radiation Sensitization

Energy Technology Data Exchange (ETDEWEB)

Schuemann, Jan, E-mail: jschuemann@mgh.harvard.edu [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (United States); Berbeco, Ross [Department of Radiation Oncology, Brigham and Women' s Hospital, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts (United States); Chithrani, Devika B. [Department of Physics, Ryerson University, Toronto, Ontario (Canada); Cho, Sang Hyun [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Kumar, Rajiv [Nanomedicine Science and Technology Center, Northeastern University, Boston, Massachusetts (United States); Department of Radiation Oncology, Harvard Medical School, Boston, Massachusetts (United States); McMahon, Stephen J. [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (United States); Centre for Cancer Research and Cell Biology, Queen' s University Belfast, Belfast, Northern Ireland (United Kingdom); Sridhar, Srinivas [Nanomedicine Science and Technology Center, Northeastern University, Boston, Massachusetts (United States); Department of Radiation Oncology, Harvard Medical School, Boston, Massachusetts (United States); Krishnan, Sunil [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

2016-01-01

The past decade has seen a dramatic increase in interest in the use of gold nanoparticles (GNPs) as radiation sensitizers for radiation therapy. This interest was initially driven by their strong absorption of ionizing radiation and the resulting ability to increase dose deposited within target volumes even at relatively low concentrations. These early observations are supported by extensive experimental validation, showing GNPs' efficacy at sensitizing tumors in both in vitro and in vivo systems to a range of types of ionizing radiation, including kilovoltage and megavoltage X rays as well as charged particles. Despite this experimental validation, there has been limited translation of GNP-mediated radiation sensitization to a clinical setting. One of the key challenges in this area is the wide range of experimental systems that have been investigated, spanning a range of particle sizes, shapes, and preparations. As a result, mechanisms of uptake and radiation sensitization have remained difficult to clearly identify. This has proven a significant impediment to the identification of optimal GNP formulations which strike a balance among their radiation sensitizing properties, their specificity to the tumors, their biocompatibility, and their imageability in vivo. This white paper reviews the current state of knowledge in each of the areas concerning the use of GNPs as radiosensitizers, and outlines the steps which will be required to advance GNP-enhanced radiation therapy from their current pre-clinical setting to clinical trials and eventual routine usage.

[Scientific, practical and educational aspects of clinical epidemiology].

Science.gov (United States)

Briko, N I

2012-01-01

This article defines clinical epidemiology and describes its goal and objectives. The author claims that clinical epidemiology is a section of epidemiology which underlies the development of evidence-based standards for diagnostics, treatment and prevention and helps to select the appropriate algorithm for each clinical case. The study provides a comprehensive overview of the relationship between clinical epidemiology and evidence-based medicine. Epidemiological research is shown to be methodological basis of clinical epidemiology and evidence-based medicine with randomized controlled trials being the "gold standard" for obtaining reliable data. The key stages in the history of clinical epidemiology are discussed and further development of clinical epidemiology and the integration of courses on clinical epidemiology in education is outlined for progress in medical research and health care practice.

Comparison of the novel Partec rapid malaria test to the conventional Giemsa stain and the gold standard real-time PCR.

Science.gov (United States)

Nkrumah, Bernard; Agyekum, Alex; Acquah, Samuel E K; May, Jürgen; Tannich, Egbert; Brattig, Norbert; Nguah, Samuel Blay; von Thien, Heidrun; Adu-Sarkodie, Yaw; Huenger, Frank

2010-08-01

Malaria remains the single most frequent cause of death in Africa, killing one child every 30 s, but treatment decisions are often made only on clinical diagnosis, as laboratory techniques to confirm the clinical suspicion are labor intensive and costly. In this study, we evaluated the recently developed Partec rapid malaria test (PM) for the detection of Plasmodium spp. in human blood from patients in an area where malaria is endemic and compared the results with those of thick blood film Giemsa stain (GS) in terms of its performance and operational characteristics, using real-time (RT) PCR as the gold standard. The sensitivities of the PM and the GS were 62.2% (95% CI, 56.3 to 67.8) and 61.8% (95% CI, 55.9 to 67.4), respectively, while the specificities were 96.0% (95% CI, 92.3 to 98.3) and 98% (95% CI, 95.0 to 99.5), respectively. There was an excellent agreement between the results for the PM and those of the GS (k [level of agreement] = 0.96; P < 0.001). The results for the PM were obtained more quickly and at less cost than those for the GS. The performance characteristics of the PM were almost equal to those of the GS, but the operational characteristics were better, and the PM can therefore be considered as an alternative method for GS.

Standardized training in nurse model travel clinics.

Science.gov (United States)

Sofarelli, Theresa A; Ricks, Jane H; Anand, Rahul; Hale, Devon C

2011-01-01

International travel plays a significant role in the emergence and redistribution of major human diseases. The importance of travel medicine clinics for preventing morbidity and mortality has been increasingly appreciated, although few studies have thus far examined the management and staff training strategies that result in successful travel-clinic operations. Here, we describe an example of travel-clinic operation and management coordinated through the University of Utah School of Medicine, Division of Infectious Diseases. This program, which involves eight separate clinics distributed statewide, functions both to provide patient consult and care services, as well as medical provider training and continuing medical education (CME). Initial training, the use of standardized forms and protocols, routine chart reviews and monthly continuing education meetings are the distinguishing attributes of this program. An Infectious Disease team consisting of one medical doctor (MD) and a physician assistant (PA) act as consultants to travel nurses who comprise the majority of clinic staff. Eight clinics distributed throughout the state of Utah serve approximately 6,000 travelers a year. Pre-travel medical services are provided by 11 nurses, including 10 registered nurses (RNs) and 1 licensed practical nurse (LPN). This trained nursing staff receives continuing travel medical education and participate in the training of new providers. All nurses have completed a full training program and 7 of the 11 (64%) of clinic nursing staff serve more than 10 patients a week. Quality assurance measures show that approximately 0.5% of charts reviewed contain a vaccine or prescription error which require patient notification for correction. Using an initial training program, standardized patient intake forms, vaccine and prescription protocols, preprinted prescriptions, and regular CME, highly trained nurses at travel clinics are able to provide standardized pre-travel care to

Determination of gold in gold ores

International Nuclear Information System (INIS)

Keedy, C.R.; Parson, L.; Shen, J.

1989-01-01

The gold content of placer gold flakes and gold bearing ores was determined by instrumental and radiochemical neutron activation analysis, respectively. It was discovered that significant errors result in the instrumental method for gold flakes as small as 10 mg due to sample self-absorption of neutrons during irradiation. Reliable results were obtained for both ore samples and gold flakes by dissolving the samples in aqua regia prior to irradiation. (author) 7 refs.; 3 tabs

Phonon assisted thermophoretic motion of gold nanoparticles inside carbon nanotubes

DEFF Research Database (Denmark)

Schoen, Philipp A.E.; Walther, Jens Honore; Poulikakos, Dimos

2007-01-01

The authors investigate the thermally driven mass transport of gold nanoparticles confined inside carbon nanotubes using molecular dynamics simulations. The observed thermophoretic motion of the gold nanoparticles correlates with the phonon dispersion exhibited by a standard carbon nanotube and...

Effect of Gold Marker Seeds on Magnetic Resonance Spectroscopy of the Prostate

Energy Technology Data Exchange (ETDEWEB)

Hossain, Murshed, E-mail: Murshed.Hossain@fccc.edu [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA (United States); Schirmer, Timo [Global MR Applied Science Laboratory, GE Healthcare, Munich (Germany); Richardson, Theresa; Chen, Lili; Buyyounouski, Mark K.; Ma Changming [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA (United States)

2012-05-01

Purpose: Magnetic resonance stereoscopic imaging (MRSI) of the prostate is an emerging technique that may enhance targeting and assessment in radiotherapy. Current practices in radiotherapy invariably involve image guidance. Gold seed fiducial markers are often used to perform daily prostate localization. If MRSI is to be used in targeting prostate cancer and therapy assessment, the impact of gold seeds on MRSI must be investigated. The purpose of this study was to quantify the effects of gold seeds on the quality of MRSI data acquired in phantom experiments. Methods and Materials: A cylindrical plastic phantom with a spherical cavity 10 centimeters in diameter wss filled with water solution containing choline, creatine, and citrate. A gold seed fiducial marker was put near the center of the phantom mounted on a plastic stem. Spectra were acquired at 1.5 Tesla by use of a clinical MRSI sequence. The ratios of choline + creatine to citrate (CC/Ci) were compared in the presence and absence of gold seeds. Spectra in the vicinity of the gold seed were analyzed. Results: The maximum coefficient of variation of CC/Ci induced by the gold seed was found to be 10% in phantom experiments at 1.5 T. Conclusion: MRSI can be used in prostate radiotherapy in the presence of gold seed markers. Gold seeds cause small effects (in the order of the standard deviation) on the ratio of the metabolite's CC/Ci in the phantom study done on a 1.5-T scanner. It is expected that gold seed markers will have similar negligible effect on spectra from prostate patients. The maximum of 10% of variation in CC/Ci found in the phantom study also sets a limit on the threshold accuracy of CC/Ci values for deciding whether the tissue characterized by a local spectrum is considered malignant and whether it is a candidate for local boost in radiotherapy dose.

Effect of Gold Marker Seeds on Magnetic Resonance Spectroscopy of the Prostate

International Nuclear Information System (INIS)

Hossain, Murshed; Schirmer, Timo; Richardson, Theresa; Chen, Lili; Buyyounouski, Mark K.; Ma Changming

2012-01-01

Purpose: Magnetic resonance stereoscopic imaging (MRSI) of the prostate is an emerging technique that may enhance targeting and assessment in radiotherapy. Current practices in radiotherapy invariably involve image guidance. Gold seed fiducial markers are often used to perform daily prostate localization. If MRSI is to be used in targeting prostate cancer and therapy assessment, the impact of gold seeds on MRSI must be investigated. The purpose of this study was to quantify the effects of gold seeds on the quality of MRSI data acquired in phantom experiments. Methods and Materials: A cylindrical plastic phantom with a spherical cavity 10 centimeters in diameter wss filled with water solution containing choline, creatine, and citrate. A gold seed fiducial marker was put near the center of the phantom mounted on a plastic stem. Spectra were acquired at 1.5 Tesla by use of a clinical MRSI sequence. The ratios of choline + creatine to citrate (CC/Ci) were compared in the presence and absence of gold seeds. Spectra in the vicinity of the gold seed were analyzed. Results: The maximum coefficient of variation of CC/Ci induced by the gold seed was found to be 10% in phantom experiments at 1.5 T. Conclusion: MRSI can be used in prostate radiotherapy in the presence of gold seed markers. Gold seeds cause small effects (in the order of the standard deviation) on the ratio of the metabolite's CC/Ci in the phantom study done on a 1.5-T scanner. It is expected that gold seed markers will have similar negligible effect on spectra from prostate patients. The maximum of 10% of variation in CC/Ci found in the phantom study also sets a limit on the threshold accuracy of CC/Ci values for deciding whether the tissue characterized by a local spectrum is considered malignant and whether it is a candidate for local boost in radiotherapy dose.

Analysis of gold in jewellery articles by energy dispersive XRF

International Nuclear Information System (INIS)

Meor Yusoff Meor Sulaiman; Latifah Amin

2001-01-01

The value of a precious metal article is much related to its fineness. For gold assay, conventional fire assay technique has been used as the standard technique for more than 500 years. Alternative modern techniques like energy dispersive x-ray fluorescence can also be used in the determination of gold purity. Advantages of this technique compared to the conventional method including non-destructive analysis, does not use any toxic or hazardous chemicals, automatic computer control and is user friendly, requires minimum number of personnel, shorter analysis time and able to determine associated elements in the metal. Analysis was performed on different sizes and purity of gold. Comparison results for the analysis using different reference standards show small differences between technique and its certified value. The technique also gives small standard deviation value in its repeatability test. (Author)

Implementing Home Health Standards in Clinical Practice.

Science.gov (United States)

Gorski, Lisa A

2016-02-01

In 1986, the American Nurses Association (ANA) published the first Standards of Home Health Practice. Revised in 1992 and expanded in 1999 to become Home Health Nursing: Scope and Standards of Practice, it was revised in 2008 and again in 2014. In the 2014 edition, there are 6 standards of home healthcare nursing practice and 10 standards of professional performance for home healthcare nursing. The focus of this article is to describe the home healthcare standards and to provide guidance for implementation in clinical practice. It is strongly encouraged that home healthcare administrators, educators, and staff obtain a copy of the standards and fully read this essential home healthcare resource.

40 CFR 440.140 - Applicability; description of the gold placer mine subcategory.

Science.gov (United States)

2010-07-01

... separation methods for recovering gold from placer deposits. (b) The provisions of this subpart M are not... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Applicability; description of the gold... AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORE MINING AND DRESSING POINT SOURCE CATEGORY Gold...

[Clinical investigation of basophil activation test as a complementary test for house dust mite allergen].

Science.gov (United States)

Ren, H L; Li, J D; Miao, Y H; Xu, T

2018-03-01

Objective: To investigate the clinical application of glass micro fiber basophil activation test (BAT) used as a complementary test for house dust mite allergen. Method: Forty patients with clinical diagnosed allergic rhinitis was test by three methods for house dust mite allergen, skin prick test(SPT),Immuno CAP sIgE, and BAT in vitro. The sensitivity and specificity of glass micro fiber were accessed, and the consistency between BAT, SPT, and Immuno sIgE was analyzed. As in vivo provocation was not performed, gold standard is regarded as the combination of medical history and positive reports of SPT and/or ImmunoCAP sIgE test. Result: Twentythree patients are diagnosed as house dust mite allergic rhinitis by gold standard. The sensitivity and specificity of glass micro fiber BAT were 60.9% and 88.2%, the sensitivity of SPT and sIgE was 87.0% and sIgE 73.9%. The correlation rates between BAT with SPT is 0.67( P house dust mite allergic rhinitis, BAT have a good consistency with SPT and sIgE, while as it has only moderate consistency with "gold standard", further studies are needed to prove its clinical significance. Copyright© by the Editorial Department of Journal of Clinical Otorhinolaryngology Head and Neck Surgery.

Imaging of the optic disk in caring for patients with glaucoma: ophthalmoscopy and photography remain the gold standard.

Science.gov (United States)

Spaeth, George L; Reddy, Swathi C

2014-01-01

Optic disk imaging is integral to the diagnosis and treatment of patients with glaucoma. We discuss the various forms of imaging the optic nerve, including ophthalmoscopy, photography, and newer imaging modalities, including optical coherence tomography (OCT), confocal scanning laser ophthalmoscopy (HRT), and scanning laser polarimetry (GDx), specifically highlighting their benefits and disadvantages. We argue that ophthalmoscopy and photography remain the gold standard of imaging due to portability, ease of interpretation, and the presence of a large database of images for comparison. Copyright © 2014 Elsevier Inc. All rights reserved.

The Modern Monetary System and Gold

Directory of Open Access Journals (Sweden)

N N Rubtsov

2013-12-01

Full Text Available The article considers the nature of modern money, analyzes the mechanism of its creation, showing that it is basically generated by credit and the principle of partial bank reserve. The article draws comparative parallels between trade money based on gold and contemporary, credit money; the author quotes leading bankers and finance experts on the need for partial return to the principles of functioning of the gold standard as the most effective institute of regulating the monetary system in society.

Development of job standards for clinical nutrition therapy for dyslipidemia patients.

Science.gov (United States)

Kang, Min-Jae; Seo, Jung-Sook; Kim, Eun-Mi; Park, Mi-Sun; Woo, Mi-Hye; Ju, Dal-Lae; Wie, Gyung-Ah; Lee, Song-Mi; Cha, Jin-A; Sohn, Cheong-Min

2015-04-01

Dyslipidemia has significantly contributed to the increase of death and morbidity rates related to cardiovascular diseases. Clinical nutrition service provided by dietitians has been reported to have a positive effect on relief of medical symptoms or reducing the further medical costs. However, there is a lack of researches to identify key competencies and job standard for clinical dietitians to care patients with dyslipidemia. Therefore, the purpose of this study was to analyze the job components of clinical dietitian and develop the standard for professional practice to provide effective nutrition management for dyslipidemia patients. The current status of clinical nutrition therapy for dyslipidemia patients in hospitals with 300 or more beds was studied. After duty tasks and task elements of nutrition care process for dyslipidemia clinical dietitians were developed by developing a curriculum (DACUM) analysis method. The developed job standards were pretested in order to evaluate job performance, difficulty, and job standards. As a result, the job standard included four jobs, 18 tasks, and 53 task elements, and specific job description includes 73 basic services and 26 recommended services. When clinical dietitians managing dyslipidemia patients performed their practice according to this job standard for 30 patients the job performance rate was 68.3%. Therefore, the job standards of clinical dietitians for clinical nutrition service for dyslipidemia patients proposed in this study can be effectively used by hospitals.

Characterisation of a thiosulphate-sulphite gold electrodeposition process

International Nuclear Information System (INIS)

J-Liew, M.; Sobri, S.; Roy, S.

2005-01-01

Electrodeposition of soft gold is an important process in the fabrication of micro devices for electronics, optics etc. Traditional gold electroplating is based on a gold cyanide process which is not applicable for the stringent requirements in state of the art micro device manufacture. Newcastle University has been involved in the development of an industrial process based on a mixed ligand electrolyte-the gold thiosulphate-sulphite system. Here we present methods for the formulation of this electrolyte in the laboratory which ensure bath stability and process compatibility. In addition, we have carried out spectrophotometry to elucidate the possible reasons of its chemical stability. Standard rotating disk and cyclic voltammetry has been carried out to determine the electrochemical behaviour of the gold thiosulphate-sulphite system. The changes in electrochemical behaviour as the bath ages are also discussed

Subchronic inhalation toxicity of gold nanoparticles

Directory of Open Access Journals (Sweden)

Chung Yong

2011-05-01

Full Text Available Abstract Background Gold nanoparticles are widely used in consumer products, including cosmetics, food packaging, beverages, toothpaste, automobiles, and lubricants. With this increase in consumer products containing gold nanoparticles, the potential for worker exposure to gold nanoparticles will also increase. Only a few studies have produced data on the in vivo toxicology of gold nanoparticles, meaning that the absorption, distribution, metabolism, and excretion (ADME of gold nanoparticles remain unclear. Results The toxicity of gold nanoparticles was studied in Sprague Dawley rats by inhalation. Seven-week-old rats, weighing approximately 200 g (males and 145 g (females, were divided into 4 groups (10 rats in each group: fresh-air control, low-dose (2.36 × 104 particle/cm3, 0.04 μg/m3, middle-dose (2.36 × 105 particle/cm3, 0.38 μg/m3, and high-dose (1.85 × 106 particle/cm3, 20.02 μg/m3. The animals were exposed to gold nanoparticles (average diameter 4-5 nm for 6 hours/day, 5 days/week, for 90-days in a whole-body inhalation chamber. In addition to mortality and clinical observations, body weight, food consumption, and lung function were recorded weekly. At the end of the study, the rats were subjected to a full necropsy, blood samples were collected for hematology and clinical chemistry tests, and organ weights were measured. Cellular differential counts and cytotoxicity measurements, such as albumin, lactate dehydrogenase (LDH, and total protein were also monitored in a cellular bronchoalveolar lavage (BAL fluid. Among lung function test measurements, tidal volume and minute volume showed a tendency to decrease comparing control and dose groups during the 90-days of exposure. Although no statistically significant differences were found in cellular differential counts, histopathologic examination showed minimal alveoli, an inflammatory infiltrate with a mixed cell type, and increased macrophages in the high-dose rats. Tissue

The 'Thin film of gold': monetary rules and policy credibility

OpenAIRE

Niall Ferguson; Moritz Schularick

2012-01-01

This paper asks whether developing countries can reap credibility gains from submitting policy to a strict monetary rule. Following earlier work, we look at the gold standard era (1880-1914) as a "natural experiment" to test whether adoption of a rule-based monetary framework such as the gold standard increased policy credibility. On the basis of the largest possible dataset covering almost sixty independent and colonial borrowers in the London market, we challenge the traditional view that g...

Biosynthesis of gold nanoparticles using diatoms-silica-gold and EPS-gold bionanocomposite formation

OpenAIRE

Schröfel, Adam; Kratošová, Gabriela; Bohunická, Markéta; Dobročka, Edmund; Vávra, Ivo

2011-01-01

Novel synthesis of gold nanoparticles, EPS-gold, and silica-gold bionanocomposites by biologically driven processes employing two diatom strains (Navicula atomus, Diadesmis gallica) is described. Transmission electron microscopy (TEM) and electron diffraction analysis (SAED) revealed a presence of gold nanoparticles in the experimental solutions of the diatom culture mixed with tetrachloroaureate. Nature of the gold nanoparticles was confirmed by X-ray diffraction studies. Scanning electron m...

COPD, stage and treatment in a large outpatient clinic

DEFF Research Database (Denmark)

Holm, Claire Præst; Holm, Jakob; Nørgaard, Annette

2017-01-01

of exacerbations. Our aim was to describe COPD patient characteristics and compare roflumilast treatment eligible to non-eligible patients. An observational cross-section study was conducted. Patients were included from a large COPD outpatient clinic. Information regarding COPD patient characteristics...... was registered on a standardized form and lung function was measured. Patients were categorized according to the GOLD classification. Eligibility for roflumilast treatment was assessed and patient characteristics compared between groups. 547 patients were included. Most patients (54%) were in GOLD group D. 62...

Comparison of the Novel Partec Rapid Malaria Test to the Conventional Giemsa Stain and the Gold Standard Real-Time PCR ▿

Science.gov (United States)

Nkrumah, Bernard; Agyekum, Alex; Acquah, Samuel E. K.; May, Jürgen; Tannich, Egbert; Brattig, Norbert; Nguah, Samuel Blay; von Thien, Heidrun; Adu-Sarkodie, Yaw; Huenger, Frank

2010-01-01

Malaria remains the single most frequent cause of death in Africa, killing one child every 30 s, but treatment decisions are often made only on clinical diagnosis, as laboratory techniques to confirm the clinical suspicion are labor intensive and costly. In this study, we evaluated the recently developed Partec rapid malaria test (PM) for the detection of Plasmodium spp. in human blood from patients in an area where malaria is endemic and compared the results with those of thick blood film Giemsa stain (GS) in terms of its performance and operational characteristics, using real-time (RT) PCR as the gold standard. The sensitivities of the PM and the GS were 62.2% (95% CI, 56.3 to 67.8) and 61.8% (95% CI, 55.9 to 67.4), respectively, while the specificities were 96.0% (95% CI, 92.3 to 98.3) and 98% (95% CI, 95.0 to 99.5), respectively. There was an excellent agreement between the results for the PM and those of the GS (k [level of agreement] = 0.96; P < 0.001). The results for the PM were obtained more quickly and at less cost than those for the GS. The performance characteristics of the PM were almost equal to those of the GS, but the operational characteristics were better, and the PM can therefore be considered as an alternative method for GS. PMID:20554822

A locking compression plate versus the gold-standard non-locking plate with lag screw for first metatarsophalangeal fusion: A biomechanical comparison.

Science.gov (United States)

Mandell, Daniel; Karbassi, John; Zhou, Hanbing; Burroughs, Brian; Aurigemma, Philip; Patel, Abhay R

2018-03-01

The treatment of end-stage first metatarso-phalangeal joint (MTP) arthritis has been arthrodesis. A dorsal non-locking plate with a lag screw has been the standard traditional fixation method. This study compares the biomechanical strength of a locking compression plate (LCP) with and without internal compression versus this known gold standard. In group 1, six matched pairs of cadaver great toes were used to compare the standard non-locking dorsal plate and 3.5mm lag screw to an anatomic locking compression plate in which a lag screw was utilized rather than the internal compression features of the plate. In group 2, another six matched pairs of cadaver great toes were used to compare the gold standard to the locking compression plate, utilizing the plate's internal compression feature instead of a lag screw. A material testing system (MTS) machine applied loads to the MTP joints and measured displacement and stiffness of the constructs. The stiffness of the constructs (Young's modulus) was calculated from the force-displacement curves, and the displacement was measured. The locking compression plate group that used the compression features of the plate, without the lag screw, had less joint displacement and higher stiffness than control (p<0.05). The same plating construct in which a lag screw was used rather than internal compression of the plate was found to be stiffer than the control (p<0.05), but displacement was not statistically significant. The results suggest that a locking compression plate alone provides the stiffest construct for a first MTP joint fusion. Copyright © 2017 Elsevier Ltd. All rights reserved.

Agreement in the diagnosis of dental fluorosis in central incisors performed by a standardized photographic method and clinical examination Concordância no diagnóstico da fluorose dentária em incisivos centrais realizado por um método fotográfico padronizado e pelo exame clínico

OpenAIRE

Carolina Castro Martins; Loliza Chalub; Ynara Bosco Lima-Arsati; Isabela Almeida Pordeus; Saul Martins Paiva

2009-01-01

The aim of this study was to assess agreement in the diagnosis of dental fluorosis performed by a standardized digital photographic method and a clinical examination (gold standard). 49 children (aged 7-9 years) were clinically evaluated by a trained examiner for the assessment of dental fluorosis. Central incisors were evaluated for the presence or absence of dental fluorosis and were photographed with a digital camera. Photographs were presented to three pediatric dentists, who examined the...

Hallmarking as an essential need of gold industry

International Nuclear Information System (INIS)

Mahmood, K.; Alam, S.; Ahmed, T.

2006-01-01

As gold is a soft metal, for Jewellery making it is alloyed with Silver or Copper so that its strength may increase. Other main alloying elements include; Zinc, Cadmium and Nickel. These alloying elements help to reduce cost, improve appearance and to improve chemical properties of gold. The percentage of alloying elements determines the caratages of gold. The gold Jewellery sold in local market is often under-carated. In order to improve the quality of product sold, complete quality assessment of gold should be done. A complete quality assessment includes both Assaying and Hallmarking. Assaying is the analysis of an individual sample of gold from a customer to find out it's composition and Hallmarking refers to physically marking: a piece of Jewellery according to specific laws to certify the purity of metal. In this paper we have assessed and compared the quality of locally manufactured gold ornaments and its alloying components with international market as well as standards of gold and its alloys. And as Hallmarking is one of the main strategic initiatives to improve the quality of product sold for domestic and export consumption, this paper discusses the necessary steps leading to Hallmarking. We have used micro-XRF spectrometer for assaying and Laser Engraving machine for the purpose of Hallmarking. (author)

Lamellar multilayer hexadecylaniline-modified gold nanoparticle ...

Indian Academy of Sciences (India)

standard Wilhelmy plate was used for surface pressure sensing. Multilayer ... carried out on a JEOL model 1200EX instrument operated at an accelerating voltage of ... the gold nanoparticles within domains (and reorganization of the domains ...

Annotated chemical patent corpus: a gold standard for text mining.

Directory of Open Access Journals (Sweden)

Saber A Akhondi

Full Text Available Exploring the chemical and biological space covered by patent applications is crucial in early-stage medicinal chemistry activities. Patent analysis can provide understanding of compound prior art, novelty checking, validation of biological assays, and identification of new starting points for chemical exploration. Extracting chemical and biological entities from patents through manual extraction by expert curators can take substantial amount of time and resources. Text mining methods can help to ease this process. To validate the performance of such methods, a manually annotated patent corpus is essential. In this study we have produced a large gold standard chemical patent corpus. We developed annotation guidelines and selected 200 full patents from the World Intellectual Property Organization, United States Patent and Trademark Office, and European Patent Office. The patents were pre-annotated automatically and made available to four independent annotator groups each consisting of two to ten annotators. The annotators marked chemicals in different subclasses, diseases, targets, and modes of action. Spelling mistakes and spurious line break due to optical character recognition errors were also annotated. A subset of 47 patents was annotated by at least three annotator groups, from which harmonized annotations and inter-annotator agreement scores were derived. One group annotated the full set. The patent corpus includes 400,125 annotations for the full set and 36,537 annotations for the harmonized set. All patents and annotated entities are publicly available at www.biosemantics.org.

Multidetector CT: a new gold standard in the diagnosis of pulmonary embolism? State of the art and diagnostic algorithms

International Nuclear Information System (INIS)

Russo, Vincenzo; Piva, Tommaso; Lovato, Luigi; Fattori, Rossella; Gavelli, Giampaolo

2005-01-01

Purpose: From the early 90s, spiral CT technology has considerably changed the diagnostic capability of Pulmonary Embolism (PE), giving a direct vision of intravascular thrombi. Further technological progress has straightened its diagnostic impact leading to an essential role in clinical practice. The advent of Multi-Detector CT (MDCT) has subsequently increased the reliability of this technique to the point of undermining the role of pulmonary angiography as the gold standard and occupying a central position in diagnostic algorithms. The aim of this paper is to appraise this evolution by means of a meta-analysis of the relevant literature from 1995 to 2004. Results: The review of the literature showed the sensitivity and specificity of CT to have increased from 37-94% and 91-100% (single detector CT) to 87-94% and 94-100% (4-channel multidetector CT), especially thanks to the possibility of depicting subsegmental clots, with an interobserver agreement of 0.63-0.94 (k). Conclusions: CT is one of the most reliable and effective methods in the diagnosis is PE, with the advantage of being extremely fast and providing alternative diagnoses. Recent improvements in MDCT technology confers the highest value of diagnostic accuracy with respect to other imaging modalities such as scintigraphy, angiography, MRI, D-dimer essay and Doppler US [it

The Clinical Utility of ASRS-v1.1 for Identifying ADHD in Alcoholics Using PRISM as the Reference Standard.

Science.gov (United States)

Reyes, Maria M; Schneekloth, Terry D; Hitschfeld, Mario J; Geske, Jennifer R; Atkinson, David L; Karpyak, Victor M

2016-05-02

The objective was to assess the clinical utility of the Adult ADHD Self-Report Scale (ASRS-v1.1) in identifying ADHD in alcoholics using the Psychiatric Research Interview for Substance and Mental Disorders (PRISM) as the diagnostic "gold standard." We performed a secondary analysis of data from 379 treatment-seeking alcoholics who completed the ASRS-v1.1 and the ADHD module of the PRISM. Data analysis included descriptive statistics. The prevalence of ADHD was 7.7% (95% CI = [5.4, 10.8]). The positive predictive value (PPV) of the ASRS-v1.1 was 18.1% (95% CI = [12.4, 25.7]) and the negative predictive value (NPV) was 97.6% (95% CI = [94.9, 98.9]). The ASRS-v1.1 demonstrated a sensitivity of 79.3% (95% CI = [61.6, 90.2]) and a specificity of 70.3% (95% CI = [65.3, 74.8]). The ASRS-v1.1 demonstrated acceptable sensitivity and specificity in a sample of treatment-seeking alcoholics when compared with the PRISM as the reference standard for ADHD diagnosis. © The Author(s) 2016.

Multidetector CT: a new gold standard in the diagnosis of pulmonary embolism? State of the art and diagnostic algorithms; La TC multitettore: il nuovo gold standard nella diagnosi di embolia polmonare? Stato dell'arte e algoritmi diagnostici

Energy Technology Data Exchange (ETDEWEB)

Russo, Vincenzo; Piva, Tommaso; Lovato, Luigi; Fattori, Rossella; Gavelli, Giampaolo [Policlinico S. Orsola, Bologna (Italy). Dipartimento di Radiologia Radiologia III

2005-02-01

Purpose: From the early 90s, spiral CT technology has considerably changed the diagnostic capability of Pulmonary Embolism (PE), giving a direct vision of intravascular thrombi. Further technological progress has straightened its diagnostic impact leading to an essential role in clinical practice. The advent of Multi-Detector CT (MDCT) has subsequently increased the reliability of this technique to the point of undermining the role of pulmonary angiography as the gold standard and occupying a central position in diagnostic algorithms. The aim of this paper is to appraise this evolution by means of a meta-analysis of the relevant literature from 1995 to 2004. Results: The review of the literature showed the sensitivity and specificity of CT to have increased from 37-94% and 91-100% (single detector CT) to 87-94% and 94-100% (4-channel multidetector CT), especially thanks to the possibility of depicting subsegmental clots, with an interobserver agreement of 0.63-0.94 (k). Conclusions: CT is one of the most reliable and effective methods in the diagnosis is PE, with the advantage of being extremely fast and providing alternative diagnoses. Recent improvements in MDCT technology confers the highest value of diagnostic accuracy with respect to other imaging modalities such as scintigraphy, angiography, MRI, D-dimer essay and Doppler US. [Italian] Scopo: Dall'inizio degli anni '90, la tecnologia TC spirale (TCS) ha cambiato notevolmente la capacita' diagnostica di Embolia Polmonare (EP), fornendo una visione diretta dei trombi endoluminali. Successivi progressi tecnologici hanno fortificato il suo impatto diagnostico a tal punto che questa metodica e' ora essenziale nella pratica clinica. L'avvento della TC Multi-Detettore (TCMD) ha aumentato di conseguenza l'affidabilita' di questa tecnica fino a tal punto da scalzare l'angiopneumografia dal ruolo di Gold Standard ed occupare una posizione cantrale negli algoritmi diagnostici

Management of ADHD in children and adolescents: clinical audit in ...

African Journals Online (AJOL)

We undertook to measure compliance in a South African setting using the National Institute for Clinical Excellence (NICE) guidelines for ADHD as the gold standard to compare compliance and socio-demographic characteristics between two treatment locations in Cape Town and to generate an audit checklist for ...

The development of clinical document standards for semantic interoperability in china.

Science.gov (United States)

Yang, Peng; Pan, Feng; Liu, Danhong; Xu, Yongyong; Wan, Yi; Tu, Haibo; Tang, Xuejun; Hu, Jianping

2011-12-01

This study is aimed at developing a set of data groups (DGs) to be employed as reusable building blocks for the construction of the eight most common clinical documents used in China's general hospitals in order to achieve their structural and semantic standardization. The Diagnostics knowledge framework, the related approaches taken from the Health Level Seven (HL7), the Integrating the Healthcare Enterprise (IHE), and the Healthcare Information Technology Standards Panel (HITSP) and 1,487 original clinical records were considered together to form the DG architecture and data sets. The internal structure, content, and semantics of each DG were then defined by mapping each DG data set to a corresponding Clinical Document Architecture data element and matching each DG data set to the metadata in the Chinese National Health Data Dictionary. By using the DGs as reusable building blocks, standardized structures and semantics regarding the clinical documents for semantic interoperability were able to be constructed. Altogether, 5 header DGs, 48 section DGs, and 17 entry DGs were developed. Several issues regarding the DGs, including their internal structure, identifiers, data set names, definitions, length and format, data types, and value sets, were further defined. Standardized structures and semantics regarding the eight clinical documents were structured by the DGs. This approach of constructing clinical document standards using DGs is a feasible standard-driven solution useful in preparing documents possessing semantic interoperability among the disparate information systems in China. These standards need to be validated and refined through further study.

Elemental analysis of gold coins by particle induced X-ray emission (PIXE)

International Nuclear Information System (INIS)

Ferreira, G.P.; Gil, F.B.

1981-01-01

A Van de Graaff accelerator of 2 MeV energy was used for quantitative analysis of gold coins of the eighteenth and nineteenth centuries by the PIXE method. The results reproduce well the known legal title of the coins. However, for confirmation, a small set of Au-Ag-Cu and Au-Cu standards was also analysed. Again, the known composition of the standards was reasonably reproduced. In this way the authors think that the PIXE method is quite adequate for absolutely non-destructive analysis of gold alloy artifacts with no need of standards. (author)

Increased cellular uptake of peptide-modified PEGylated gold nanoparticles.

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He, Bo; Yang, Dan; Qin, Mengmeng; Zhang, Yuan; He, Bing; Dai, Wenbing; Wang, Xueqing; Zhang, Qiang; Zhang, Hua; Yin, Changcheng

2017-12-09

Gold nanoparticles are promising drug delivery vehicles for nucleic acids, small molecules, and proteins, allowing various modifications on the particle surface. However, the instability and low bioavailability of gold nanoparticles compromise their clinical application. Here, we functionalized gold nanoparticles with CPP fragments (CALNNPFVYLI, CALRRRRRRRR) through sulfhydryl PEG to increase their stability and bioavailability. The resulting gold nanoparticles were characterized with transmission electron microscopy (TEM), dynamic light scattering (DLS), UV-visible spectrometry and X-ray photoelectron spectroscopy (XPS), and the stability in biological solutions was evaluated. Comparing to PEGylated gold nanoparticles, CPP (CALNNPFVYLI, CALRRRRRRRR)-modified gold nanoparticles showed 46 folds increase in cellular uptake in A549 and B16 cell lines, as evidenced by the inductively coupled plasma atomic emission spectroscopy (ICP-AES). The interactions between gold nanoparticles and liposomes indicated CPP-modified gold nanoparticles bind to cell membrane more effectively than PEGylated gold nanoparticles. Surface plasmon resonance (SPR) was used to measure interactions between nanoparticles and the membrane. TEM and uptake inhibitor experiments indicated that the cellular entry of gold nanoparticles was mediated by clathrin and macropinocytosis. Other energy independent endocytosis pathways were also identified. Our work revealed a new strategy to modify gold nanoparticles with CPP and illustrated the cellular uptake pathway of CPP-modified gold nanoparticles. Copyright © 2017 Elsevier Inc. All rights reserved.

Outpatient laparoscopic cholecystectomy: A new gold standard for cholecystectomy? Colecistectomía laparoscópica ambulatoria: ¿El nuevo "gold standard" de la colecistectomía?

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J. Bueno Lledó

2006-01-01

Full Text Available Objective: to contribute our experience for five years in the implemetation of outpatient laparoscopic cholecystectomy (LC. Patients: between January 1999 and March 2004 we performed 504 outpatient LCs. We applied both exclusion and inclusion criteria, an anesthetic and surgical protocol, and discharge-specific criteria. Postoperative management in "fast track" regime. Postoperative period controlled by protocol, including phone calls after cholecystectomy. Results: the ambulatory percentage in the global series was 88.8%, and mean hospital stay was 6.1 hours. Fifty-one patients required overnight stays (10.1%, most of them for "social" causes. Five patients required admission (between 24 and 48 hours for different causes (conversion to laparotomy, intraoperative neumothorax, and postoperative medical complications. Six patients (1.1% were readmitted, and we observed 11.6% postoperative complications in the global series, with abdominal parietal pain being most frequent. Phone localization by 22.00 p.m. in the same day of surgery was 100% complete for outpatient cases. Postoperative surveillance within the first month after surgery was completed in 93.9%, and within th first year in 86.7% of patients. Conclusions: outpatient LC is safe and feasible, and probably represents a new "gold standard" in the treatment of symptomatic cholelithiasis.Objetivo: aportar nuestra experiencia durante cinco años en la implantación de la colecistectomía laparoscópica (CL en un programa de cirugía mayor ambulatoria (CMA. Pacientes: entre enero de 1999 y marzo de 2004, se realizaron 504 CL consecutivas en régimen ambulatorio. Se aplicaron criterios de exclusión e inclusión, un procedimiento anestésico-quirurgico protocolizado, y criterios específicos al alta hospitalaria. El manejo postoperatorio se realizó en régimen de "fast track" o de recuperación rápida. Seguimiento postoperatorio estricto mediante protocolo de revisiones, incluido localizaci

Clinical aspects of MR colonography as a diagnostic tool

DEFF Research Database (Denmark)

Achiam, Michael

2010-01-01

and that polypectomy might be curative. Colonoscopy remains the gold standard for full colon evaluation. However, the result of our studies can justify clinical use of MRC on selected indications, e.g. in the cases where colonoscopy is incomplete or technically difficult. Since up to 54% of all preoperative colon...

Leishmania Infection: Laboratory Diagnosing in the Absence of a “Gold Standard”

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Rodríguez-Cortés, Alhelí; Ojeda, Ana; Francino, Olga; López-Fuertes, Laura; Timón, Marcos; Alberola, Jordi

2010-01-01

There is no gold standard for diagnosing leishmaniases. Our aim was to assess the operative validity of tests used in detecting Leishmania infection using samples from experimental infections, a reliable equivalent to the classic definition of gold standard. Without statistical differences, the highest sensitivity was achieved by protein A (ProtA), immunoglobulin (Ig)G2, indirect fluorescenece antibody test (IFAT), lymphocyte proliferation assay, quantitative real-time polymerase chain reaction of bone marrow (qPCR-BM), qPCR-Blood, and IgG; and the highest specificity by IgG1, IgM, IgA, qPCR-Blood, IgG, IgG2, and qPCR-BM. Maximum positive predictive value was obtained simultaneously by IgG2, qPCR-Blood, and IgG; and maximum negative predictive value by qPCR-BM. Best positive and negative likelihood ratios were obtained by IgG2. The test having the greatest, statistically significant, area under the receiver operating characteristics curve was IgG2 enzyme-linked immunosorbent assay (ELISA). Thus, according to the gold standard used, IFAT and qPCR are far from fulfilling the requirements to be considered gold standards, and the test showing the highest potential to detect Leishmania infection is Leishmania-specific ELISA IgG2. PMID:20134001

Basic electrochemical properties of sputtered gold film electrodes

International Nuclear Information System (INIS)

Libansky, Milan; Zima, Jiri; Barek, Jiri; Reznickova, Alena; Svorcik, Vaclav; Dejmkova, Hana

2017-01-01

Gold nanolayers made by sputtering of pure gold (physical vapour deposition) are commonly used for many biophysical and material applications. However, the use of sputtering method for fabrication of working electrodes for electroanalytical purposes is less common. This paper focuses on the testing and characterization of sputtered working roughened gold nanostructured film electrodes, which fall into category of upcoming desirable new generation of nanostructured gold working electrodes. Gold nanostructured films (80 nm thin) were sputtered onto 50 μm thin PTFE substrates with three different types of treatment: pristine, plasma treated, and plasma treated and subsequently spontaneously grafted with biphenyl-4,4′-dithiol. The characterization of gold nanostructured film electrodes was carried out by examination of the electrode reaction of standard redox probes (ferrocyanide/ferricyanide, hydroquinone/benzoquinone) in different types of supporting electrolytes (BR buffers of various pH, KCl, KNO 3 , H 2 SO 4 ), by exploration of the electrode surface by scanning electron microscopy, by atomic force microscopy accompanied by elementary analysis and contact angle measurements. The testing of electrodes was complemented by an attempt to calculate their real surface areas from Randles-Sevcik equation. All results were compared to conventional bulk gold electrode. The practical applicability of the nanostructured gold electrodes as sensors for the determination of environmental pollutants was verified by voltammetric determination of hydroquinone as a model electrochemically oxidisable organic environmental pollutant.

[Possible relation between clinical guidelines and legal standard of medicine].

Science.gov (United States)

Furukawa, Toshiharu; Kitagawa, Yuko

2010-10-01

Legal standard of medicine is not equal across the all kinds of medical institutions. Each medical institution is required its respective standard of medicine in which its doctors are expected to have studied medical informations, which have been spread among medical institutions with similar characteristics. Therefore, in principle, clinical guidelines for the treatment of a disease formed by public committees do not directly become the medical standards of respective disease treatment. However, doctors would be legally required to practice medicine with reference to the clinical guidelines because medical informations, mediated by internet or many kinds of media, have been spread very fast to all medical institutions these days. Moreover, doctors would be required to inform their patients of non-standardized new treatments, even if such treatments are not listed in clinical guidelines in case patients have special concern about new treat-

Annotating risk factors for heart disease in clinical narratives for diabetic patients.

Science.gov (United States)

Stubbs, Amber; Uzuner, Özlem

2015-12-01

The 2014 i2b2/UTHealth natural language processing shared task featured a track focused on identifying risk factors for heart disease (specifically, Cardiac Artery Disease) in clinical narratives. For this track, we used a "light" annotation paradigm to annotate a set of 1304 longitudinal medical records describing 296 patients for risk factors and the times they were present. We designed the annotation task for this track with the goal of balancing annotation load and time with quality, so as to generate a gold standard corpus that can benefit a clinically-relevant task. We applied light annotation procedures and determined the gold standard using majority voting. On average, the agreement of annotators with the gold standard was above 0.95, indicating high reliability. The resulting document-level annotations generated for each record in each longitudinal EMR in this corpus provide information that can support studies of progression of heart disease risk factors in the included patients over time. These annotations were used in the Risk Factor track of the 2014 i2b2/UTHealth shared task. Participating systems achieved a mean micro-averaged F1 measure of 0.815 and a maximum F1 measure of 0.928 for identifying these risk factors in patient records. Copyright © 2015 Elsevier Inc. All rights reserved.

Radiochemical neutron activation analysis of gold in geochemical samples

International Nuclear Information System (INIS)

Zilliacus, R.

1983-01-01

A fast method for the radiochemical neutron activation analysis of gold in geochemical samples is described. The method is intended for samples having background concentrations of gold. The method is based on the dissolution of samples with hydrofluoric acid and aqua regia followed by the dissolution of the fluorides with boric acid and hydrochloric acid. Gold is then adsorbed on activated carbon by filtrating the solution through a thin carbon layer. The activity measurements are carried out using a Ge(Li)-detector and a multichannel analyzer. The chemical yields of the separation determined by reirradiation vary between 60 and 90%. The detection limit of the method is 0.2 ng/g gold in rock samples. USGS standard rocks and exploration reference materials are analyzed and the results are presented and compared with literature data. (author)

Gold-Based Medicine: A Paradigm Shift in Anti-Cancer Therapy?

Science.gov (United States)

Yeo, Chien Ing; Ooi, Kah Kooi; Tiekink, Edward R T

2018-06-11

A new era of metal-based drugs started in the 1960s, heralded by the discovery of potent platinum-based complexes, commencing with cisplatin [(H₃N)₂PtCl₂], which are effective anti-cancer chemotherapeutic drugs. While clinical applications of gold-based drugs largely relate to the treatment of rheumatoid arthritis, attention has turned to the investigation of the efficacy of gold(I) and gold(III) compounds for anti-cancer applications. This review article provides an account of the latest research conducted during the last decade or so on the development of gold compounds and their potential activities against several cancers as well as a summary of possible mechanisms of action/biological targets. The promising activities and increasing knowledge of gold-based drug metabolism ensures that continued efforts will be made to develop gold-based anti-cancer agents.

Terminalia chebula mediated green and rapid synthesis of gold nanoparticles

Science.gov (United States)

Mohan Kumar, Kesarla; Mandal, Badal Kumar; Sinha, Madhulika; Krishnakumar, Varadhan

2012-02-01

Biologically inspired experimental process in synthesising nanoparticles is of great interest in present scenario. Biosynthesis of nanoparticles is considered to be one of the best green techniques in synthesising metal nanoparticles. Here, an in situ green biogenic synthesis of gold nanoparticles using aqueous extracts of Terminalia chebula as reducing and stabilizing agent is reported. Gold nanoparticles were confirmed by surface plasmon resonance in the range of 535 nm using UV-visible spectrometry. TEM analysis revealed that the morphology of the particles thus formed contains anisotropic gold nanoparticles with size ranging from 6 to 60 nm. Hydrolysable tannins present in the extract of T. chebula are responsible for reductions and stabilization of gold nanoparticles. Antimicrobial activity of gold nanoparticles showed better activity towards gram positive S. aureus compared to gram negative E. coli using standard well diffusion method.

Granulomatous prostatitis: clinical and histomorphologic survey of the disease in a tertiary care hospital

Directory of Open Access Journals (Sweden)

Prakriti Shukla

2017-03-01

Conclusion: Despite present-day advances in imaging modalities and serological investigations, it is virtually impossible to identify granulomatous prostatitis clinically. Histopathology remains the gold standard in diagnosing the disease. However, assigning an etiologic cause to the wide spectrum of granulomas in granulomatous prostatitis requires a pathologist’s expertise and proper clinical correlation for appropriate patient management.

Biometry and intraocular lens power calculation results with a new optical biometry device: comparison with the gold standard.

Science.gov (United States)

Kaswin, Godefroy; Rousseau, Antoine; Mgarrech, Mohamed; Barreau, Emmanuel; Labetoulle, Marc

2014-04-01

To evaluate the agreement in axial length (AL), keratometry (K), anterior chamber depth (ACD) measurements; intraocular lens (IOL) power calculations; and predictability using a new partial coherence interferometry (PCI) optical biometer (AL-Scan) and a reference (gold standard) PCI optical biometer (IOLMaster 500). Service d'Ophtalmologie, Hopital Bicêtre, APHP Université, Paris, France. Evaluation of a diagnostic device. One eye of consecutive patients scheduled for cataract surgery was measured. Biometry was performed with the new biometer and the reference biometer. Comparisons were performed for AL, average K at 2.4 mm, ACD, IOL power calculations with the Haigis and SRK/T formulas, and postoperative predictability of the devices. A P value less than 0.05 was statistically significant. The study enrolled 50 patients (mean age 72.6 years±4.2 SEM). There was a good correlation between biometers for AL, K, and ACD measurements (r=0.999, r=0.933, and r=0.701, respectively) and between IOL power calculation with the Haigis formula (r=0.972) and the SRK/T formula (r=0.981). The mean absolute error (MAE) in IOL power prediction was 0.42±0.08 diopter (D) with the new biometer and 0.44±0.08 D with the reference biometer. The MAE was 0.20 D with the Haigis formula and 0.19 with the SRK/T formula (P=.36). The new PCI biometer provided valid measurements compared with the current gold standard, indicating that the new device can be used for IOL power calculations for routine cataract surgery. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2014 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Highly sensitive detection of influenza virus in saliva by real-time PCR method using sugar chain-immobilized gold nanoparticles; application to clinical studies

Directory of Open Access Journals (Sweden)

Yasuo Suda

2015-09-01

Full Text Available A highly sensitive and convenient method for detecting influenza virus was developed using modified end-point melt curve analysis of a RT-qPCR SYBR Green method and influenza virus-binding sugar chain-immobilized gold-nanoparticles (SGNP. Because SGNPs capture influenza viruses, the virus-SGNP complex was separated easily by centrifugation. Viral RNA was detected at very low concentrations, suggesting that SGNP increased sensitivity compared with standard methods. This method was applied to clinical studies. Influenza viruses were detected in saliva of patients or inpatients who had been considered influenza-free by a rapid diagnostic assay of nasal swabs. Furthermore, the method was applied to a human trial of prophylactic anti-influenza properties of yogurt containing Lactobacillus acidophilus L-92. The incidence of influenza viruses in saliva of the L-92 group was found to be significantly lower compared to the control group. Thus, this method was useful for monitoring the course of anti-influenza treatment or preventive measures against nosocomial infection.

Decision Making in the Management of Extracapsular Fractures of the Proximal Femur – is the Dynamic Hip Screw the Prevailing Gold Standard?

Science.gov (United States)

Jacob, Joshua; Desai, Ankit; Trompeter, Alex

2017-01-01

Currently, approximately half of all hip fractures are extracapsular, with an incidence as high as 50 in 100,000 in some countries. The common classification systems fail to explain the logistics of fracture classification and whether they all behave in the same manner. The Muller AO classification system is a useful platform to delineate stable and unstable fractures. The Dynamic hip screw (DHS) however, has remained the ‘gold standard’ implant of choice for application in all extracapsular fractures. The DHS relies on the integrity and strength of the lateral femoral wall as well as the postero-medial fragment. An analysis of several studies indicates significant improvements in design and techniques to ensure a better outcome with intramedullary nails. This article reviews the historical trends that helped to evolve the DHS implant as well as discussing if the surgeon should remain content with this implant. We suggest that the gold standard surgical management of extracapsular fractures can, and should, evolve. PMID:29290858

Coal-gold agglomeration: an alternative separation process in gold recovery

Energy Technology Data Exchange (ETDEWEB)

Akcil, A.; Wu, X.Q.; Aksay, E.K. [Suleyman Demirel University, Isparta (Turkey). Dept. of Mining Engineering

2009-07-01

Considering the increasing environmental concerns and the potential for small gold deposits to be exploited in the future, the uses of environmentally friendly processes are essential. Recent developments point to the potential for greatly increased plant performance through a separation process that combines the cyanide and flotation processes. In addition, this kind of alternative treatment processes to the traditional gold recovery processes may reduce the environmental risks of present small-scale gold mining. Gold recovery processes that applied to different types of gold bearing ore deposits show that the type of deposits plays an important role for the selection of mineral processing technologies in the production of gold and other precious metals. In the last 25 years, different alternative processes have been investigated on gold deposits located in areas where environmental issues are a great concern. In 1988, gold particles were first recovered by successful pilot trial of coal-gold agglomeration (CGA) process in Australia. The current paper reviews the importance of CGA in the production of gold ore and identifies areas for further development work.

Phage based green chemistry for gold ion reduction and gold retrieval.

Science.gov (United States)

Setyawati, Magdiel I; Xie, Jianping; Leong, David T

2014-01-22

The gold mining industry has taken its toll on the environment, triggering the development of more environmentally benign processes to alleviate the waste load release. Here, we demonstrate the use of bacteriophages (phages) for biosorption and bioreduction of gold ions from aqueous solution, which potentially can be applied to remediate gold ions from gold mining waste effluent. Phage has shown a remarkably efficient sorption of gold ions with a maximum gold adsorption capacity of 571 mg gold/g dry weight phage. The product of this phage mediated process is gold nanocrystals with the size of 30-630 nm. Biosorption and bioreduction processes are mediated by the ionic and covalent interaction between gold ions and the reducing groups on the phage protein coat. The strategy offers a simple, ecofriendly and feasible option to recover of gold ions to form readily recoverable products of gold nanoparticles within 24 h.

Silver and gold in the Protein Data Bank.

Science.gov (United States)

Carugo, Oliviero

2017-10-01

The structural features of the silver and gold sites in protein crystal structures extracted from the Protein Data Bank have been investigated. It is observed that both cations have nearly always low oxidations states (+1) and low coordination numbers, adopt standard stereochemistries, and interact preferentially (particularly gold) with sulfur donor atoms of cysteine and methionine side-chains. Interestingly, gold cation have been very often refined with occupancy minor than 1.0 and are very often "naked", in the sense that no donor atoms are sufficiently close to the metal cation. This apparently strange observation points out towards the need to develop specific and efficient validation tools for these elements when they are coordinated to proteins. Copyright © 2017 Elsevier Inc. All rights reserved.

31 CFR 100.4 - Gold coin and gold certificates in general.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Gold coin and gold certificates in... EXCHANGE OF PAPER CURRENCY AND COIN In General § 100.4 Gold coin and gold certificates in general. Gold coins, and gold certificates of the type issued before January 30, 1934, are exchangeable, as provided...

Antibacterial properties and mechanisms of gold-silver nanocages

Science.gov (United States)

Wang, Yulan; Wan, Jiangshan; Miron, Richard J.; Zhao, Yanbin; Zhang, Yufeng

2016-05-01

Despite the number of antibiotics used in routine clinical practice, bacterial infections continue to be one of the most important challenges faced in humans. The main concerns arise from the continuing emergence of antibiotic-resistant bacteria and the difficulties faced with the pharmaceutical development of new antibiotics. Thus, advancements in the avenue of novel antibacterial agents are essential. In this study, gold (Au) was combined with silver (Ag), a well-known antibacterial material, to form silver nanoparticles producing a gold-silver alloy structure with hollow interiors and porous walls (gold-silver nanocage). This novel material was promising in antibacterial applications due to its better biocompatibility than Ag nanoparticles, potential in photothermal effects and drug delivery ability. The gold-silver nanocage was then tested for its antibacterial properties and the mechanism involved leading to its antibacterial properties. This study confirms that this novel gold-silver nanocage has broad-spectrum antibacterial properties exerting its effects through the destruction of the cell membrane, production of reactive oxygen species (ROS) and induction of cell apoptosis. Therefore, we introduce a novel gold-silver nanocage that serves as a potential nanocarrier for the future delivery of antibiotics.

Real-time cardiac magnetic resonance cine imaging with sparse sampling and iterative reconstruction for left-ventricular measures: Comparison with gold-standard segmented steady-state free precession.

Science.gov (United States)

Camargo, Gabriel C; Erthal, Fernanda; Sabioni, Leticia; Penna, Filipe; Strecker, Ralph; Schmidt, Michaela; Zenge, Michael O; Lima, Ronaldo de S L; Gottlieb, Ilan

2017-05-01

Segmented cine imaging with a steady-state free-precession sequence (Cine-SSFP) is currently the gold standard technique for measuring ventricular volumes and mass, but due to multi breath-hold (BH) requirements, it is prone to misalignment of consecutive slices, time consuming and dependent on respiratory capacity. Real-time cine avoids those limitations, but poor spatial and temporal resolution of conventional sequences has prevented its routine application. We sought to examine the accuracy and feasibility of a newly developed real-time sequence with aggressive under-sampling of k-space using sparse sampling and iterative reconstruction (Cine-RT). Stacks of short-axis cines were acquired covering both ventricles in a 1.5T system using gold standard Cine-SSFP and Cine-RT. Acquisition parameters for Cine-SSFP were: acquisition matrix of 224×196, temporal resolution of 39ms, retrospective gating, with an average of 8 heartbeats per slice and 1-2 slices/BH. For Cine-RT: acquisition matrix of 224×196, sparse sampling net acceleration factor of 11.3, temporal resolution of 41ms, prospective gating, real-time acquisition of 1 heart-beat/slice and all slices in one BH. LV contours were drawn at end diastole and systole to derive LV volumes and mass. Forty-one consecutive patients (15 male; 41±17years) in sinus rhythm were successfully included. All images from Cine-SSFP and Cine-RT were considered to have excellent quality. Cine-RT-derived LV volumes and mass were slightly underestimated but strongly correlated with gold standard Cine-SSFP. Inter- and intra-observer analysis presented similar results between both sequences. Cine-RT featuring sparse sampling and iterative reconstruction can achieve spatial and temporal resolution equivalent to Cine-SSFP, providing excellent image quality, with similar precision measurements and highly correlated and only slightly underestimated volume and mass values. Copyright © 2017 Elsevier Inc. All rights reserved.

Gold and gold working in Late Bronze Age Northern Greece

Science.gov (United States)

Vavelidis, M.; Andreou, S.

2008-04-01

Numerous objects of gold displaying an impressive variety of types and manufacturing techniques are known from the Late Bronze Age (LBA) contexts of Mycenaean Greece, but very little is known about the origin and processing of gold during the second millennium b.c. Ancient literature and recent research indicate that northern Greece is probably the richest gold-bearing region in Greece, and yet, very little evidence exists regarding the exploitation of its deposits and the production as well as use of gold in the area during prehistory. The unusual find of a group of small stone crucibles at the prehistoric settlement of Thessaloniki Toumba, one with visible traces of gold melting, proves local production and offers a rare opportunity to examine the process of on-site gold working. Furthermore, the comparison of the chemical composition of prehistoric artefacts from two settlements with those of gold deposits in their immediate areas supports the local extraction of gold and opens up the prospect for some of the Mycenaean gold to have originated in northern Greece. The scarcity of gold items in northern Greek LBA contexts may not represent the actual amount of gold produced and consumed, but could be a result of the local social attitudes towards the circulation and deposition of artefacts from precious metals.

Open Partial Nephrectomy in Renal Cancer: A Feasible Gold Standard Technique in All Hospitals

Directory of Open Access Journals (Sweden)

J. M. Cozar

2008-01-01

Full Text Available Introduction. Partial nephrectomy (PN is playing an increasingly important role in localized renal cell carcinoma (RCC as a true alternative to radical nephrectomy. With the greater experience and expertise of surgical teams, it has become an alternative to radical nephrectomy in young patients when the tumor diameter is 4 cm or less in almost all hospitals since cancer-specific survival outcomes are similar to those obtained with radical nephrectomy. Materials and Methods. The authors comment on their own experience and review the literature, reporting current indications and outcomes including complications. The surgical technique of open partial nephrectomy is outlined. Conclusions. Nowadays, open PN is the gold standard technique to treat small renal masses, and all nonablative techniques must pass the test of time to be compared to PN. It is not ethical for patients to undergo radical surgery just because the urologists involved do not have adequate experience with PN. Patients should be involved in the final treatment decision and, when appropriate, referred to specialized centers with experience in open or laparoscopic partial nephrectomies.

Comparison of the gold standard of hemoglobin measurement with the clinical standard (BGA) and noninvasive hemoglobin measurement (SpHb) in small children: a prospective diagnostic observational study.

Science.gov (United States)

Wittenmeier, Eva; Bellosevich, Sophia; Mauff, Susanne; Schmidtmann, Irene; Eli, Michael; Pestel, Gunther; Noppens, Ruediger R

2015-10-01

Collecting a blood sample is usually necessary to measure hemoglobin levels in children. Especially in small children, noninvasively measuring the hemoglobin level could be extraordinarily helpful, but its precision and accuracy in the clinical environment remain unclear. In this study, noninvasive hemoglobin measurement and blood gas analysis were compared to hemoglobin measurement in a clinical laboratory. In 60 healthy preoperative children (0.2-7.6 years old), hemoglobin was measured using a noninvasive method (SpHb; Radical-7 Pulse Co-Oximeter), a blood gas analyzer (clinical standard, BGAHb; ABL 800 Flex), and a laboratory hematology analyzer (reference method, labHb; Siemens Advia). Agreement between the results was assessed by Bland-Altman analysis and by determining the percentage of outliers. Sixty SpHb measurements, 60 labHb measurements, and 59 BGAHb measurements were evaluated. In 38% of the children, the location of the SpHb sensor had to be changed more than twice for the signal quality to be sufficient. The bias/limits of agreement between SpHb and labHb were -0.65/-3.4 to 2.1 g·dl(-1) . Forty-four percent of the SpHb values differed from the reference value by more than 1 g·dl(-1) . Age, difficulty of measurement, and the perfusion index (PI) had no influence on the accuracy of SpHb. The bias/limits of agreement between BGAHb and labHb were 1.14/-1.6 to 3.9 g·dl(-1) . Furthermore, 66% of the BGAHb values differed from the reference values by more than 1 g·dl(-1) . The absolute mean difference between SpHb and labHb (1.1 g·dl(-1) ) was smaller than the absolute mean difference between BGAHb and labHb (1.5 g·dl(-1) /P = 0.024). Noninvasive measurement of hemoglobin agrees more with the reference method than the measurement of hemoglobin using a blood gas analyzer. However, both methods can show clinically relevant differences from the reference method (ClinicalTrials.gov: NCT01693016). © 2015 John Wiley & Sons Ltd.

Performances of Four Helicobacter pylori Serological Detection Kits Using Stool Antigen Test as Gold Standard.

Science.gov (United States)

Biranjia-Hurdoyal, Susheela D; Seetulsingh-Goorah, Sharmila P

2016-01-01

The aim was to determine the performances of four Helicobacter pylori serological detection kits in different target groups, using Amplified IDEIA™ Hp StAR™ as gold standard. Kits studied were Rapid Immunochromatoghraphic Hexagon, Helicoblot 2.1, an EIA IgG kit and EIA IgA kit. Stool and blood samples were collected from 162 apparently healthy participants (control) and 60 Type 2 diabetes mellitus (T2DM) patients. The performances of the four serological detection kits were found to be affected by gender, age, health status and ethnicity of the participants. In the control group, the Helicoblot 2.1 kit had the best performance (AUC = 0.85; ppoor performances. In the T2DM subgroup, the kits H2.1 and EIA IgG had best performances, with accuracies of 96.5% and 93.1% respectively. The performance of EIA IgG improved with adjustment of its cut-off value. The performances of the detection kits were affected by various factors which should be taken into consideration.

The euro and the recent European crisis vis-à-vis the gold standard and the great depression: institutionalities, specificities and interfaces

Directory of Open Access Journals (Sweden)

GIULIANO CONTENTO DE OLIVEIRA

Full Text Available ABSTRACT The paper aims to establish interfaces between the Great Depression of the 1930s under the Gold Standard and the recent European Crisis under the Euro. It is argued that, despite their specificities, both crises revealed the potentially harmful effects, in economic and social terms, of institutional arrangements that considerably reduce the autonomy of monetary, fiscal and exchange rate policies of participating countries, without being accompanied by increased cooperation between them, which should be led by a global (in the case of the Great Depression or regional (in the case of the European Crisis hegemonic power, which is not only capable of, but is also willing to act as a buyer and lender of last resort, especially in circumstances characterized by increased uncertainty, the deterioration of the general state of expectations and increased liquidity preference. In fact, central European countries in the past and peripheral European countries nowadays were effectively pushed toward deflationary adjustments in which a reduction of prices and wages was accompanied by a reduction of output and employment levels. Thus, in the absence of the possibility of restoring the autonomy of economic policy, the overcome of the crisis necessarily requires, both before - under the Gold Standard - and nowadays - under the Euro -, joint actions aimed to assure that the responsibility for the adjustment will be equally distributed among all the economies, in order to avoid that some of them benefit at the expense of the others in this process.

Artisanal and Small-Scale Gold Mining Without Mercury

Science.gov (United States)

Mercury-free techniques are safer for miners, their families and local communities. They can also help miners qualify for certification under fair-mined standards, potentially allowing them to market their gold at higher prices.

RESULTS OF AN OPEN CLINICAL STUDY OF THE EFFICACY OF LEFLUNOMIDE IN RHEUMATOID ARTHRITIS

Directory of Open Access Journals (Sweden)

I M Marusenko

2009-06-01

Conclusion. The new basic drug leflunomide is as effective as the gold standard methotrexate, at the same time it allows clinical improvement to be more rapidly achieved. Leflunomide also slows down the rate of progression of erosive arthritis and it is well tolerated.

Organizational, technical, physical and clinical quality standards for radiotherapy

Science.gov (United States)

Bogusz-Czerniewicz, Marta; Kaźmierczak, Daniel

2012-01-01

Background Indisputably, radiotherapy has become an entirely interdisciplinary specialty. This situation requires efficient planning, verification, monitoring, quality control and constant improvement of all aspects of service delivery, referring both to patients’ (including diagnosis, prescription and method of treatment, its justification, realization and follow up) and organizational, technical and physics matters. Aim The aim of this work was to develop technical, physics and clinical quality standards for radiotherapy. This paper presents chosen standards for each of the aforementioned category. Materials and methods For the development of quality standards the comparison analysis of EU and Polish acts of law passed between 1980 and 2010 was conducted, the universal industrial ISO norm 9001:2008 referring to quality management system was reviewed. Recommendations of this norm were completed with detailed quality standards based on the author's 11 year work experience and the review of articles on quality assurance and quality control standards for radiotherapy published between 1984 and 2009 and the review of current recommendations and guidelines of American, International, European and National bodies (associations, societies, agencies such as AAPM, ESTRO, IAEA, and OECI) for quality assurance and quality management in radiotherapy. Results As a result 352 quality standards for radiotherapy were developed and categorized into the following three groups: (1) organizational standards, (2) physics and technical standards and (3) clinical standards. Conclusions Proposed quality standards for radiotherapy, can be used by any institution using ionizing radiation for medical procedures. Nevertheless standards are only of value if they are implemented, reviewed, audited and improved and if there is a clear mechanism in place to monitor and address failure to meet agreed standards. PMID:24377023

Validation of assessment of intraoral digital photography for evaluation of dental restorations in clinical research.

Science.gov (United States)

Signori, Cácia; Collares, Kauê; Cumerlato, Catarina B F; Correa, Marcos B; Opdam, Niek J M; Cenci, Maximiliano S

2018-04-01

The aim of this study was to investigate the validity of assessment of intraoral digital photography in the evaluation of dental restorations. Intraoral photographs of anterior and posterior restorations were classified based on FDI criteria according to the need for intervention: no intervention, repair and replacement. Evaluations were performed by an experienced expert in restorative dentistry (gold standard evaluator) and 3 trained dentists (consensus). The clinical inspection was the reference standard method. The prevalence of failures was explored. Cohen's kappa statistic was used. Validity was accessed by sensitivity, specificity, likelihood ratio and predictives values. Higher prevalence of failed restorations intervention was identified by the intraoral photography (17.7%) in comparison to the clinical evaluation (14.1%). Moderate agreement in the diagnosis of total failures was shown between the methods for the gold standard evaluator (kappa = 0.51) and consensus of evaluators (kappa = 0.53). Gold standard evaluator and consensus showed substantial and moderate agreement for posterior restorations (kappa = 0.61; 0.59), and fair and moderate agreement for anterior restorations (kappa = 0.36; 0.43), respectively. The accuracy was 84.8% in the assessment by intraoral photographs. Sensitivity and specificity values of 87.5% and 89.3% were found. Under the limits of this study, the assessment of digital photography performed by intraoral camera is an indirect diagnostic method valid for the evaluation of dental restorations, mainly in posterior teeth. This method should be employed taking into account the higher detection of defects provided by the images, which are not always clinically relevant. Copyright © 2018 Elsevier Ltd. All rights reserved.

[Gold salt alveolitis in 3 patients with rheumatoid arthritis].

Science.gov (United States)

Music, E; Tomsic, M; Logar, D

1995-06-01

When the characteristic symptoms for an interstitial pulmonary disease arise in patients with rheumatoid arthritis, a drug-induced alveolitis should be considered in the differential diagnosis. In such cases, the administration of the drug and gold salts should be stopped. The cases of three patients with rheumatoid arthritis (RA) who had been treated with gold salts for 2 months (A), 23 months (B), and 36 months (C) are presented. The total dose of sodium aureothiomalate amounted to 280 mg for patient A, 1150 mg for patient B, and 2190 mg for patient C. Clinical signs, X-rays of the lungs, pulmonary function tests, and laboratory tests were evaluated for the three patients while, for patient A BAL as well as provocation tests were additionally performed before and after therapy. In this case, the histological picture of the lungs is presented; biopsies were taken during the first BAL. The clinical complaints of all 3 patients were similar, with the alveolitis being observed as diffuse in one case and above all in the upper regions in two cases on radiology. This led to differing degrees of diffusion disorders in the lungs. In patient A, the diagnosis was made in the stage of progressive fibrotic alveolitis and was treated with D-penicillamine. All 3 patients received steroids over 3-6 months and the gold salts were stopped. Because of the long duration and doubtful differential diagnosis for patient A with either rheumatoid lung or gold salt alveolitis, a provocation test with sodium aureothiomalate was performed. All 3 patients had blood eosinophilia while, in case A, a thrombopenia was also found. A gold salt alveolitis can occur as a side effect of gold salts in addition to skin vasculitis and hematological disorders. When the gold salt administration is not stopped a fibrotic alveolitis can develop. The provocation test can be diagnostically useful to distinguish between a rheumatoid lung and gold salt alveolitis.

Forward and backscatter dose profile to diagnostic X-rays at gold/tissue interfaces

International Nuclear Information System (INIS)

Rosa, Luiz A.R. da; Seidenbusch, Michael; Regulla, Dieter F.

1997-01-01

The radiological and clinical significance of dose distributions in the vicinity of media interfaces in radiotherapy and the complex nature of these dose distributions have long been recognised. A possible dosimetry method for dose profile assessment near interfaces is the use of the so-called thermally stimulated exoelectron emission (TSEE) dosemeter. In this work the possibility of using Be O/TSEE dosimeters to assess the forward and backscatter dose profile at the interface soft tissue/gold was investigated for diagnostic heavily filtered X-rays spectrum A-60 of ISO Standard A-quality. Dose and range profiles are presented. (author). 14 refs., 3 figs

Application of the Fundamental Parameter Method for X-ray fluorescence analysis of gold jewellery alloys

International Nuclear Information System (INIS)

Le Hong Khiem

2004-01-01

The Fundamental Parameter Method has been used for the correction of the matrix effects for determination of the fineness of gold in the ternary Au-Ag-Cu yellow jewellery alloys. A computer code GOLDANA based on this algorithm has been developed for both data taking and on-line determining the fineness of gold jewellery. Only one ternary Au-Ag-Cu standard sample is required. The analysis performance has been tested by measurements conducted on certified gold reference materials, with the use of the fundamental method, could be used for quickly determining the gold concentration in gold jewellery alloys with an acceptable accuracy for the gold jewellery producers. (author)

The clinical practice of intraoperative neurophysiological monitoring in Shanghai Huashan Hospital

Directory of Open Access Journals (Sweden)

WU Jin-song

2012-12-01

Full Text Available Intraoperative neurophysiological monitoring (IONM is the gold standard of the intraoperative functional brain mapping. It employs various electrophysiological methods such as awake craniotomy, intraoperative somatosensory and motor evoked potentials monitoring, intraoperative cortical stimulation and sub-cortical stimulation to accurately map the cortical and sub-cortical nervous pathways so that the continuous assessment and real -time protection of the functional integrity of certain neural structures can be achieved during surgery. Based on decades of clinical practice, the Department of Neurosurgery of Shanghai Huashan Hospital has set up an "IONM clinical practice guideline" used in the institute. The clinical practice guideline covers technical and operation standards of IONM in all kinds of common neurosurgery diseases and does improve the clinical efficacy in neurosurgical procedures.

Gold Nanoparticles Obtained by Bio-precipitation from Gold(III) Solutions

International Nuclear Information System (INIS)

Gardea-Torresdey, J.L.; Tiemann, K.J.; Gamez, G.; Dokken, K.; Tehuacanero, S.; Jose-Yacaman, M.

1999-01-01

The use of metal nanoparticles has shown to be very important in recent industrial applications. Currently gold nanoparticles are being produced by physical methods such as evaporation. Biological processes may be an alternative to physical methods for the production of gold nanoparticles. Alfalfa biomass has shown to be effective at passively binding and reducing gold from solutions containing gold(III) ions and resulting in the formation of gold(0) nanoparticles. High resolution microscopy has shown that five different types of gold particles are present after reaction with gold(III) ions with alfalfa biomass. These particles include: fcc tetrahedral, hexagonal platelet, icosahedral multiple twinned, decahedral multiple twinned, and irregular shaped particles. Further analysis on the frequency of distribution has shown that icosahedral and irregular particles are more frequently formed. In addition, the larger particles observed may be formed through the coalescence of smaller particles. Through modification of the chemical parameters, more uniform particle size distribution may be obtained by the alfalfa bio-reduction of gold(III) from solution

Neutron activation analysis of geological samples for gold and accessory elements power reactor

International Nuclear Information System (INIS)

Burmistrenko, Yu.N.; Medvedev, A.A.; Kovalenko, V.V.; Markov, A.V.

1986-01-01

Possibility of using a power reactor for neutron activation analysis to detect gold and accompanying elements in geological samples of a region was investigated. Specimens (gold-containing samples and standards) were irradiated in a spare channel for ionization chambers located outside the core in graphite reflector. Spectrometry was conducted with the help of a semiconducting detector with LP 4900 multichannel analizer. Sensitivity threshold for gold was (1-3)10 -6 % - (1-2)10 -5 %. It is shown that this method can be used not only for gold detection but for high-sensitive multielement analysis of geological samples

Staging Hemodynamic Failure With Blood Oxygen-Level-Dependent Functional Magnetic Resonance Imaging Cerebrovascular Reactivity: A Comparison Versus Gold Standard (15O-)H2O-Positron Emission Tomography.

Science.gov (United States)

Fierstra, Jorn; van Niftrik, Christiaan; Warnock, Geoffrey; Wegener, Susanne; Piccirelli, Marco; Pangalu, Athina; Esposito, Giuseppe; Valavanis, Antonios; Buck, Alfred; Luft, Andreas; Bozinov, Oliver; Regli, Luca

2018-03-01

Increased stroke risk correlates with hemodynamic failure, which can be assessed with ( 15 O-)H 2 O positron emission tomography (PET) cerebral blood flow (CBF) measurements. This gold standard technique, however, is not established for routine clinical imaging. Standardized blood oxygen-level-dependent (BOLD) functional magnetic resonance imaging+CO 2 is a noninvasive and potentially widely applicable tool to assess whole-brain quantitative cerebrovascular reactivity (CVR). We examined the agreement between the 2 imaging modalities and hypothesized that quantitative CVR can be a surrogate imaging marker to assess hemodynamic failure. Nineteen data sets of subjects with chronic cerebrovascular steno-occlusive disease (age, 60±11 years; 4 women) and unilaterally impaired perfusion reserve on Diamox-challenged ( 15 O-)H 2 O PET were studied and compared with a standardized BOLD functional magnetic resonance imaging+CO 2 examination within 6 weeks (8±19 days). Agreement between quantitative CBF- and CVR-based perfusion reserve was assessed. Hemodynamic failure was staged according to PET findings: stage 0: normal CBF, normal perfusion reserve; stage I: normal CBF, decreased perfusion reserve; and stage II: decreased CBF, decreased perfusion reserve. The BOLD CVR data set of the same subjects was then matched to the corresponding stage of hemodynamic failure. PET-based stage I versus stage II could also be clearly separated with BOLD CVR measurements (CVR for stage I 0.11 versus CVR for stage II -0.03; P the affected hemisphere and middle cerebral artery territory ( P the affected hemisphere and middle cerebral artery territory and for identifying hemodynamic failure stage II. BOLD CVR may, therefore, be considered for prospective studies assessing stroke risk in patients with chronic cerebrovascular steno-occlusive disease, in particular because it can potentially be implemented in routine clinical imaging. © 2018 American Heart Association, Inc.

Neutron activation for logging the distribution of gold in bore-hole cores

International Nuclear Information System (INIS)

Rahmanian, H.; Watterson, J.I.W.

1992-01-01

A new method for the non-destructive determination of gold in bore-hole cores has been developed using instrumental neutron activation analysis with a 252 Cf source. The procedure obtains the distribution and concentration of gold along the longitudinal axis of the core i.e. a log of the gold concentration. The accuracy of the method is comparable to fire assay at a level of 2 ppm and has a detection limit of 1 ppm under the conditions used. The assay of the gold is carried out by employing a novel variation of the conventional comparator method using gold wires as both standard and flux monitor. A method is described for logging gold in bore-hole cores using neutron activation with a 160 μg 252 Cf neutron source. The method has a limit of detection of about 1 ppm under the described conditions. (author)

Size fraction assaying of gold bearing rocks (for gold extraction) by ...

African Journals Online (AJOL)

A novel method has been developed for processing and extraction of gold from gold bearing rocks for use by small-scale gold miners in Ghana. The methodology involved crushing of gold bearing hard rocks to fine particles to form a composite sample and screening at a range of sizes. Gold distribution in the composite ...

Geostatistical Approach to Estimating the Gold Ore Characteristics and Gold Reserves: A Case Study Daksa Area, Quang Nam Province, Viet Nam

Science.gov (United States)

Luan Truong, Xuan; Luong Le, Van; Quang Truong, Xuan

2015-04-01

Daksa gold deposit is the biggest gold deposits in Vietnam. The Daksa geological structure complicated, distributed mainly metamorphosed sedimentary NuiVu formation (PR3-?1nv2). The sulfide gold ore bodies distributed in quartz schist, quartz - biotite related to faut and distribution wing anticline. The gold ore bodies form circuits, network circuits, circuits lenses; fill the cup surface layer of the developing northeast - southwest; is the less than or west longitude north - SE. The results show that, Au and accompanying elements (Ag, Pb and Zn) have correlated pretty closely. All of its consistent with the logarithmic distribution standard, in accordance with the law of distribution of content mineral rare. The structure functions have nugget effect and spherical models with show that Au and accompanying elements special variation are changes. Au contents shown local anisotropy, no clearly anisotropy (K=1,17) and weakly anisotropy (K=1,4). Intensity mineralization of the ore bodies are quite high with demand spherical conversion coefficient ranging from 0.49 to 0.75 and from 0.66 to 0.97 (for other body). With nugget effects, ore bodies shown that it is consistent with mineralization in the ore bodies study, ore erasable, micro vein, infilling fractures in quartz vein. All of variogram presents local anisotropy, indicated gold mineralization at study area has least two-mineralization stages, consistent with the analysis of mineralography samples. By the results of the structure function study, the authors present the system optimization for exploration deposit and used to evaluate gold reserves by Ordinary Kriging. High accuracy of Kriging estimation results are expressed in the minimum Kriging variance, by compare the results calculated by some other methods (such as distance inverse weighting method, ..) and specially compare to the results of a some blocks have been exploited. Key words: Geostat and gold deposits VN. Daksa and gold mineralization. Geostat

"Heidelberg standard examination" and "Heidelberg standard procedures" - Development of faculty-wide standards for physical examination techniques and clinical procedures in undergraduate medical education.

Science.gov (United States)

Nikendei, C; Ganschow, P; Groener, J B; Huwendiek, S; Köchel, A; Köhl-Hackert, N; Pjontek, R; Rodrian, J; Scheibe, F; Stadler, A-K; Steiner, T; Stiepak, J; Tabatabai, J; Utz, A; Kadmon, M

2016-01-01

The competent physical examination of patients and the safe and professional implementation of clinical procedures constitute essential components of medical practice in nearly all areas of medicine. The central objective of the projects "Heidelberg standard examination" and "Heidelberg standard procedures", which were initiated by students, was to establish uniform interdisciplinary standards for physical examination and clinical procedures, and to distribute them in coordination with all clinical disciplines at the Heidelberg University Hospital. The presented project report illuminates the background of the initiative and its methodological implementation. Moreover, it describes the multimedia documentation in the form of pocketbooks and a multimedia internet-based platform, as well as the integration into the curriculum. The project presentation aims to provide orientation and action guidelines to facilitate similar processes in other faculties.

Evaluation of image quality and radiation dose using gold nanoparticles and other clinical contrast agents in dual-energy Computed Tomography (CT): CT abdomen phantom

Science.gov (United States)

Zukhi, J.; Yusob, D.; Tajuddin, A. A.; Vuanghao, L.; Zainon, R.

2017-05-01

The aim of this study was to evaluate the image quality and radiation dose using commercial gold nanoparticles and clinical contrast agents in dual-energy Computed Tomography (CT). Five polymethyl methacrylate (PMMA) tubes were used in this study, where four tubes were filled with different contrast agents (barium, iodine, gadolinium, and gold nanoparticles). The fifth tube was filled with water. Two optically stimulated luminescence dosimeters (OSLD) were placed in each tube to measure the radiation dose. The tubes were placed in a fabricated adult abdominal phantom of 32 cm in diameter using PMMA. The phantom was scanned using a DECT at low energy (80 kV) and high energy (140 kV) with different pitches (0.6 mm and 1.0 mm) and different slice thickness (3.0 mm and 5.0 mm). The tube current was applied automatically using automatic exposure control (AEC) and tube current modulation recommended by the manufacturer (CARE Dose 4D, Siemens, Germany). The contrast-to-noise ratio (CNR) of each contrast agent was analyzed using Weasis software. Gold nanoparticles has highest atomic number (Z = 79) than barium (Z = 56), iodine (Z = 53) and gadolinium (Z = 64). The CNR value of each contrast agent increases when the slice thickness increases. The radiation dose obtained from this study decreases when the pitch increases. The optimal imaging parameters for gold nanoparticles and other clinical contrast agents is obtained at pitch value of 1.0 mm and slice thickness of 5.0 mm. Low noise and low radiation dose obtained at these imaging parameters. The optimal imaging parameters obtained in this study can be applied in multiple contrast agents imaging.

Evaluation of image quality and radiation dose using gold nanoparticles and other clinical contrast agents in dual-energy Computed Tomography (CT): CT abdomen phantom

International Nuclear Information System (INIS)

Zukhi, J; Yusob, D; Vuanghao, L; Zainon, R; Tajuddin, A A

2017-01-01

The aim of this study was to evaluate the image quality and radiation dose using commercial gold nanoparticles and clinical contrast agents in dual-energy Computed Tomography (CT). Five polymethyl methacrylate (PMMA) tubes were used in this study, where four tubes were filled with different contrast agents (barium, iodine, gadolinium, and gold nanoparticles). The fifth tube was filled with water. Two optically stimulated luminescence dosimeters (OSLD) were placed in each tube to measure the radiation dose. The tubes were placed in a fabricated adult abdominal phantom of 32 cm in diameter using PMMA. The phantom was scanned using a DECT at low energy (80 kV) and high energy (140 kV) with different pitches (0.6 mm and 1.0 mm) and different slice thickness (3.0 mm and 5.0 mm). The tube current was applied automatically using automatic exposure control (AEC) and tube current modulation recommended by the manufacturer (CARE Dose 4D, Siemens, Germany). The contrast-to-noise ratio (CNR) of each contrast agent was analyzed using Weasis software. Gold nanoparticles has highest atomic number (Z = 79) than barium (Z = 56), iodine (Z = 53) and gadolinium (Z = 64). The CNR value of each contrast agent increases when the slice thickness increases. The radiation dose obtained from this study decreases when the pitch increases. The optimal imaging parameters for gold nanoparticles and other clinical contrast agents is obtained at pitch value of 1.0 mm and slice thickness of 5.0 mm. Low noise and low radiation dose obtained at these imaging parameters. The optimal imaging parameters obtained in this study can be applied in multiple contrast agents imaging. (paper)

Self-absorption of neutron capture gamma-rays in gold samples

International Nuclear Information System (INIS)

Wisshak, K.; Walter, G.; Kaeppeler, F.

1983-06-01

The self absorption of neutron capture gamma rays in gold samples has been determined experimentally for two standard setups used in measurements of neutron capture cross sections. One makes use of an artificially collimated neutron beam and two C 6 D 6 detectors, the other of kinematically collimated neutrons and three Moxon-Rae detectors. Correction factors for an actual measurement of a neutron capture cross section using a gold standard of 1 mm thickness up to 12% were found for the first setup while they are only 4% for the second setup. The present data allow to determine the correction in an actual measurement with an accuracy of 0.5-1%. (orig.) [de

Exploring the feasibility and synergistic value of the One Health approach in clinical research

DEFF Research Database (Denmark)

Cordoba Currea, Gloria Cristina; Sørensen, Tina Møller; Holm, Anne

2015-01-01

diagnostic pathways (i.e., 16 possiblecombinations of diagnostic tools) to gold standard in human and veterinary primary care practice in Denmark.Fifty primary care practices and 100 veterinary clinics will each consecutively include 20 human patients or 8–10dogs, respectively. Data will be collected...

Nanomolar Trace Metal Analysis of Copper at Gold Microband Arrays

Science.gov (United States)

Wahl, A.; Dawson, K.; Sassiat, N.; Quinn, A. J.; O'Riordan, A.

2011-08-01

This paper describes the fabrication and electrochemical characterization of gold microband electrode arrays designated as a highly sensitive sensor for trace metal detection of copper in drinking water samples. Gold microband electrodes have been routinely fabricated by standard photolithographic methods. Electrochemical characterization were conducted in 0.1 M H2SO4 and found to display characteristic gold oxide formation and reduction peaks. The advantages of gold microband electrodes as trace metal sensors over currently used methods have been investigated by employing under potential deposition anodic stripping voltammetry (UPD-ASV) in Cu2+ nanomolar concentrations. Linear correlations were observed for increasing Cu2+ concentrations from which the concentration of an unknown sample of drinking water was estimated. The results obtained for the estimation of the unknown trace copper concentration in drinking was in good agreement with expected values.

Nanomolar Trace Metal Analysis of Copper at Gold Microband Arrays

International Nuclear Information System (INIS)

Wahl, A; Dawson, K; Sassiat, N; Quinn, A J; O'Riordan, A

2011-01-01

This paper describes the fabrication and electrochemical characterization of gold microband electrode arrays designated as a highly sensitive sensor for trace metal detection of copper in drinking water samples. Gold microband electrodes have been routinely fabricated by standard photolithographic methods. Electrochemical characterization were conducted in 0.1 M H 2 SO 4 and found to display characteristic gold oxide formation and reduction peaks. The advantages of gold microband electrodes as trace metal sensors over currently used methods have been investigated by employing under potential deposition anodic stripping voltammetry (UPD-ASV) in Cu 2+ nanomolar concentrations. Linear correlations were observed for increasing Cu 2+ concentrations from which the concentration of an unknown sample of drinking water was estimated. The results obtained for the estimation of the unknown trace copper concentration in drinking was in good agreement with expected values.

Patterning of oxide-hardened gold black by photolithography and metal lift-off

Science.gov (United States)

Panjwani, Deep; Yesiltas, Mehmet; Nath, Janardan; Maukonen, D. E.; Rezadad, Imen; Smith, Evan M.; Peale, R. E.; Hirschmugl, Carol; Sedlmair, Julia; Wehlitz, Ralf; Unger, Miriam; Boreman, Glenn

2014-01-01

A method to pattern infrared-absorbing gold black by conventional photolithography and lift-off is described. A photo-resist pattern is developed on a substrate by standard photolithography. Gold black is deposited over the whole by thermal evaporation in an inert gas at ˜1 Torr. SiO2 is then deposited as a protection layer by electron beam evaporation. Lift-off proceeds by dissolving the photoresist in acetone. The resulting sub-millimeter size gold black patterns that remain on the substrate retain high infrared absorption out to ˜5 μm wavelength and exhibit good mechanical stability. This technique allows selective application of gold black coatings to the pixels of thermal infrared imaging array detectors.

The accuracy and efficiency of electronic screening for recruitment into a clinical trial on COPD.

Science.gov (United States)

Schmickl, Christopher N; Li, Man; Li, Guangxi; Wetzstein, Marnie M; Herasevich, Vitaly; Gajic, Ognjen; Benzo, Roberto P

2011-10-01

Participant recruitment is an important process in successful conduct of randomized controlled trials. To facilitate enrollment into a National Institutes of Health-sponsored clinical trial involving patients with chronic obstructive pulmonary disease (COPD), we developed and prospectively validated an automated electronic screening tool based on boolean free-text search of admission notes in electronic medical records. During a 2-week validation period, all patients admitted to prespecified general medical services were screened for eligibility by both the electronic screening tool and a COPD nurse. Group discussion was the gold standard for confirmation of true-positive results. Compared with the gold standard, electronic screening yielded 100% sensitivity, 92% specificity, 100% negative predictive value, and 72% positive predictive value. Compared with traditional manual screening, electronic screening demonstrated time-saving potential of 76%. Thus, the electronic screening tool accurately identifies potential study subjects and improves efficiency of patient accrual for a clinical trial on COPD. This method may be expanded into other institutional and clinical settings. Copyright © 2011 Elsevier Ltd. All rights reserved.

Neutron activation determination of gold and palladium using extraction by organic sulfides

International Nuclear Information System (INIS)

Gil'berg, Eh.N.; Torgov, V.G.; Verevkin, G.V.; AN SSSR, Novosibirsk. Inst. Neorganicheskoj Khimii)

1978-01-01

Compared are methods of gold determination in standard rock samples of the USA National Geological Service: a) extraction by solutions of dioctylsulfide and oil sulfides from irradiated samples; b) preliminary extraction by the above solfides with the following extract radiation; c) the method of isotope dilution with substoichiometry extraction. A possibility is studied to determine palladium in the sulfide extract with gold using the NaI(Tl) thin crystal scintillators. It is established that joint palladium and gold extraction permits to determine them in many natural products simultaneously

Multifunctional gold nanoparticles for photodynamic therapy of cancer

Science.gov (United States)

Khaing Oo, Maung Kyaw

As an important and growing branch of photomedicine, photodynamic therapy (PDT) is being increasingly employed in clinical applications particularly for the treatment of skin cancer. This dissertation focuses on the synthesis, characterization and deployment of gold nanoparticles for enhanced PDT of fibrosarcoma cancer cells. We have developed robust strategies and methods in fabrication of gold nanoparticles with positively- and negatively-tethered surface charges by photo-reduction of gold chloride salt using branched polyethyleneimine and sodium citrate respectively. An optimal concentration window of gold salt has been established to yield the most stable and monodispersed gold nanoparticles. 5-aminolevulinic acid (5-ALA), a photosensitizing precursor, has been successfully conjugated on to positively charged gold nanoparticles through electrostatic interactions. The 5-ALA/gold nanoparticle conjugates are biocompatible and have shown to be preferably taken up by cancer cells. Subsequent light irradiation results in the generation of reactive oxygen species (ROS) in cancer cells, leading to their destruction without adverse effects on normal fibroblasts. We have demonstrated for the first time that gold nanoparticles can enhance PDT efficacy by 50% compared to the treatment with 5-ALA alone. Collected evidence has strongly suggested that this enhancement stems from the elevated formation of ROS via the strongly localized electric field of gold nanoparticles. Through single cell imaging using surface-enhanced Raman scattering enabled by the very same gold nanoparticles, we have shown that multifunctionality of gold nanoparticles can be harvested concurrently for biomedical applications in general and for PDT in specific. In other words, gold nanoparticles can be used not only for targeted drug delivery and field-enhanced ROS formation, but also for monitoring cell destructions during PDT. Finally, our COMSOL Multiphysics simulation of the size-dependent electric

Gold prices

OpenAIRE

Joseph G. Haubrich

1998-01-01

The price of gold commands attention because it serves as an indicator of general price stability or inflation. But gold is also a commodity, used in jewelry and by industry, so demand and supply affect its pricing and need to be considered when gold is a factor in monetary policy decisions.

A taxonomy of multinational ethical and methodological standards for clinical trials of therapeutic interventions

Science.gov (United States)

Ashton, Carol M; Wray, Nelda P; Jarman, Anna F; Kolman, Jacob M; Wenner, Danielle M; Brody, Baruch A

2013-01-01

Background If trials of therapeutic interventions are to serve society’s interests, they must be of high methodological quality and must satisfy moral commitments to human subjects. The authors set out to develop a clinical-trials compendium in which standards for the ethical treatment of human subjects are integrated with standards for research methods. Methods The authors rank-ordered the world’s nations and chose the 31 with >700 active trials as of 24 July 2008. Governmental and other authoritative entities of the 31 countries were searched, and 1004 English-language documents containing ethical and/or methodological standards for clinical trials were identified. The authors extracted standards from 144 of those: 50 designated as ‘core’, 39 addressing trials of invasive procedures and a 5% sample (N=55) of the remainder. As the integrating framework for the standards we developed a coherent taxonomy encompassing all elements of a trial’s stages. Findings Review of the 144 documents yielded nearly 15 000 discrete standards. After duplicates were removed, 5903 substantive standards remained, distributed in the taxonomy as follows: initiation, 1401 standards, 8 divisions; design, 1869 standards, 16 divisions; conduct, 1473 standards, 8 divisions; analysing and reporting results, 997 standards, four divisions; and post-trial standards, 168 standards, 5 divisions. Conclusions The overwhelming number of source documents and standards uncovered in this study was not anticipated beforehand and confirms the extraordinary complexity of the clinical trials enterprise. This taxonomy of multinational ethical and methodological standards may help trialists and overseers improve the quality of clinical trials, particularly given the globalisation of clinical research. PMID:21429960

Nanobubble trouble on gold surfaces

DEFF Research Database (Denmark)

Holmberg, Maria; Kuhle, A.; Garnaes, J.

2003-01-01

When analyzing surfaces related to biosensors with in situ atomic force microscopy (AFM), the existence of nanobubbles called for our attention. The bubbles seem to form spontaneously when gold surfaces are immersed in clean water and are probably a general phenomenon at water-solid interfaces....... Besides from giving rise to undesired effects in, for example, biosensors, nanobubbles can also cause artifacts in AFM imaging. We have observed nanobubbles on unmodified gold surfaces, immersed in clean water, using standard silicon AFM probes. Nanobubbles can be made to disappear from contact mode AFM...... images and then to reappear by changing the scanning force. By combining contact mode AFM imaging and local force measurements, the interaction between the nanobubbles and the probe can be analyzed and give information about the characteristics of nanobubbles. A model of the forces between the AFM probe...

Determination of trace gold in rocks and minerals by neutron activation analysis

International Nuclear Information System (INIS)

Zhao Yunlong; Zhou Suqing; Liang Yutang

1988-05-01

The determination of trace gold in rocks and minerals by neutron activation analysis is described. Two methods are used for pre-separating and concentrating the trace gold in geological samples. one of the methods is that the samples are dissolved in aqua regia solution; activated carbon paper pulp filter is used for pre-separating and concentrating trace gold by dynamic adsorption method; then the activated carbon containing gold was ashed at 650 ∼ 700 deg c. The other method is that the samples are dissolved in aqua regia solution; the polyurethane foam plastic filled with activated carbon is used for pre-separating and concentrating trace gold by dynamic adsorption method; then the foam plastic containing gold was ashed at 650 deg c. The gold in ashes is determinated by neutron activation analysis. The detection limit is 0.004ng/g. The accuracy of the method is examined by gold in reference standard material. The results of this method are in good agreement with the recommended value. For analysis of the trace gold by the methods of instrumental neutron activation analysis and epithermal neutron activation analysis, the interference of 411.8 keV γ-ray from 153 Sm, 152 Eu and fission products of uranium and the correction methods are discussed

Unreliability and error in the military's "gold standard" measure of sexual harassment by education and gender.

Science.gov (United States)

Murdoch, Maureen; Pryor, John B; Griffin, Joan M; Ripley, Diane Cowper; Gackstetter, Gary D; Polusny, Melissa A; Hodges, James S

2011-01-01

The Department of Defense's "gold standard" sexual harassment measure, the Sexual Harassment Core Measure (SHCore), is based on an earlier measure that was developed primarily in college women. Furthermore, the SHCore requires a reading grade level of 9.1. This may be higher than some troops' reading abilities and could generate unreliable estimates of their sexual harassment experiences. Results from 108 male and 96 female soldiers showed that the SHCore's temporal stability and alternate-forms reliability was significantly worse (a) in soldiers without college experience compared to soldiers with college experience and (b) in men compared to women. For men without college experience, almost 80% of the temporal variance in SHCore scores was attributable to error. A plain language version of the SHCore had mixed effects on temporal stability depending on education and gender. The SHCore may be particularly ill suited for evaluating population trends of sexual harassment in military men without college experience.

International Standardization of the Clinical Dosimetry of Beta Radiation Brachytherapy Sources: Progress of an ISO Standard

Science.gov (United States)

Soares, Christopher

2006-03-01

In 2004 a new work item proposal (NWIP) was accepted by the International Organization for Standardization (ISO) Technical Committee 85 (TC85 -- Nuclear Energy), Subcommittee 2 (Radiation Protection) for the development of a standard for the clinical dosimetry of beta radiation sources used for brachytherapy. To develop this standard, a new Working Group (WG 22 - Ionizing Radiation Dosimetry and Protocols in Medical Applications) was formed. The standard is based on the work of an ad-hoc working group initiated by the Dosimetry task group of the Deutsches Insitiut für Normung (DIN). Initially the work was geared mainly towards the needs of intravascular brachytherapy, but with the decline of this application, more focus has been placed on the challenges of accurate dosimetry for the concave eye plaques used to treat ocular melanoma. Guidance is given for dosimetry formalisms, reference data to be used, calibrations, measurement methods, modeling, uncertainty determinations, treatment planning and reporting, and clinical quality control. The document is currently undergoing review by the ISO member bodies for acceptance as a Committee Draft (CD) with publication of the final standard expected by 2007. There are opportunities for other ISO standards for medical dosimetry within the framework of WG22.

Clinical Case Vignettes: A Promising Tool to Assess Competence in the Management of Agitation.

Science.gov (United States)

Sowden, Gillian L; Vestal, Heather S; Stoklosa, Joseph B; Valcourt, Stephanie C; Peabody, John W; Keary, Christopher J; Nejad, Shamim H; Caminis, Argyro; Huffman, Jeff C

2017-06-01

While standardized patients (SPs) remain the gold standard for assessing clinical competence in a standardized setting, clinical case vignettes that allow free-text, open-ended written responses are more resource- and time-efficient assessment tools. It remains unknown, however, whether this is a valid method for assessing competence in the management of agitation. Twenty-six psychiatry residents partook in a randomized controlled study evaluating a simulation-based teaching intervention on the management of agitated patients. Competence in the management of agitation was assessed using three separate modalities: simulation with SPs, open-ended clinical vignettes, and self-report questionnaires. Performance on clinical vignettes correlated significantly with SP-based assessments (r = 0.59, p = 0.002); self-report questionnaires that assessed one's own ability to manage agitation did not correlate with SP-based assessments (r = -0.06, p = 0.77). Standardized clinical vignettes may be a simple, time-efficient, and valid tool for assessing residents' competence in the management of agitation.

Extraction of gold (Au) particles from sea water by Delftia Acidovorans microbes

Science.gov (United States)

Yusoff, A. H. M.; Nading, M. E.; Salimi, M. N.

2017-10-01

Gold-mining activities have been an issue, especially when it involves in contamination of chemicals, for example arsenic and mercury. However, despite of these hazards, gold-mining activities are still being conducted. This is because the gold is worth, regardless of the problems. Gold-mining, as known needs a very large area of land, or site plant. Vast amount of labor force, mechanical force and fund are a must in order for the mining process to be continued. High demand of gold, made gold-mining industries as ones of the most profitable industries in the world. Thus, this has encouraged another alternative way to extract gold. At the mining site, researchers found that biomineralization of gold by Delftia acidovorans can be conducted. How it is done still cannot be understood. It is said that the bacteria secretes secondary metabolites, Delftibactin as a defensive mechanism against the toxicity of the soluble gold. Researchers try to find another source of elemental gold besides of the earth’s core. The options are either lava of a volcano or ocean. Here, the focus is seawater. The problem of seawater is that its composition still not yet to be proved. Dissolve gold existed as gold chloride in seawater, but in a very small amount. So, the gold separation should be focused, in order to make this process to be a successful one. Factors such as depth, climate, region, temperature need to be considered. If this difference affecting the separating process, standardized seawater composition have to be proposed.

Update on clinical trials in Dysphagia.

Science.gov (United States)

Logemann, Jeri A

2006-04-01

Randomized clinical trials (RCTs) are often known as the gold standard in treatment efficacy studies. This article defines the characteristics of RCTs and the factors that investigators must consider in designing clinical trials in dysphagia. Design issues unique to behavioral treatments often used in dysphagia are discussed. Ongoing RCTs in dysphagia are described including studies of (1) the effectiveness of the Shaker exercise versus standardized treatment in patients with severe dysphagia resulting from stroke or treatment for head and neck cancer who have been nonoral for at least three months; (2) the comparative effects of nectar- and honey-thickened liquids versus chin tuck posture and in patients with dementia or Parkinson's disease with or without dementia who aspirate on thin liquids; and (3) the comparative effects of muscle exercise versus sensory postural therapy for dysphagia resulting from treatment for head and neck cancer. Issues in generalizing from the results of clinical trials are also described.

The diagnosis of silicone breast-implant rupture: clinical findings compared with findings at magnetic resonance imaging

DEFF Research Database (Denmark)

Hölmich, Lisbet Rosenkrantz; Fryzek, Jon P; Kjøller, Kim

2005-01-01

The objective was to evaluate the usefulness of clinical examination in the evaluation of breast-implant integrity, using the diagnosis at magnetic resonance imaging (MRI) as the "gold standard." Fifty-five women with 109 implants underwent a breast examination either just before or shortly after...

Emerging advances in nanomedicine with engineered gold nanostructures.

Science.gov (United States)

Webb, Joseph A; Bardhan, Rizia

2014-03-07

Gold nanostructures possess unique characteristics that enable their use as contrast agents, as therapeutic entities, and as scaffolds to adhere functional molecules, therapeutic cargo, and targeting ligands. Due to their ease of synthesis, straightforward surface functionalization, and non-toxicity, gold nanostructures have emerged as powerful nanoagents for cancer detection and treatment. This comprehensive review summarizes the progress made in nanomedicine with gold nanostructures (1) as probes for various bioimaging techniques including dark-field, one-photon and two-photon fluorescence, photothermal optical coherence tomography, photoacoustic tomography, positron emission tomography, and surface-enhanced Raman scattering based imaging, (2) as therapeutic components for photothermal therapy, gene and drug delivery, and radiofrequency ablation, and (3) as a theranostic platform to simultaneously achieve both cancer detection and treatment. Distinct from other published reviews, this article also discusses the recent advances of gold nanostructures as contrast agents and therapeutic actuators for inflammatory diseases including atherosclerotic plaque and arthritis. For each of the topics discussed above, the fundamental principles and progress made in the past five years are discussed. The review concludes with a detailed future outlook discussing the challenges in using gold nanostructures, cellular trafficking, and translational considerations that are imperative for rapid clinical viability of plasmonic nanostructures, as well as the significance of emerging technologies such as Fano resonant gold nanostructures in nanomedicine.

Molecular testing for viral and bacterial enteric pathogens: gold standard for viruses, but don't let culture go just yet?

Science.gov (United States)

Bloomfield, Maxim G; Balm, Michelle N D; Blackmore, Timothy K

2015-04-01

Contemporary diagnostic microbiology is increasingly adopting molecular methods as front line tests for a variety of samples. This trend holds true for detection of enteric pathogens (EP), where nucleic acid amplification tests (NAAT) for viruses are well established as the gold standard, and an increasing number of commercial multi-target assays are now available for bacteria and parasites. NAAT have significant sensitivity and turnaround time advantages over traditional methods, potentially returning same-day results. Multiplex panels offer an attractive 'one-stop shop' that may provide workflow and cost advantages to laboratories processing large sample volumes. However, there are a number of issues which need consideration. Reflex culture is required for antibiotic susceptibility testing and strain typing when needed for food safety and other epidemiological investigations. Surveillance systems will need to allow for differences in disease incidence due to the enhanced sensitivity of NAAT. Laboratories should be mindful of local epidemiology when selecting which pathogens to include in multiplex panels, and be thoughtful regarding which pathogens will not be detected. Multiplex panels may not be appropriate in certain situations, such as hospital-onset diarrhoea, where Clostridium difficile testing might be all that is required, and laboratories may wish to retain the flexibility to run single tests in such situations. The clinical impact of rapid results is also likely to be relatively minor, as infective diarrhoea is a self-limiting illness in the majority of cases. Laboratories will require strategies to assist users in the interpretation of the results produced by NAAT, particularly where pathogens are detected at low levels with uncertain clinical significance. These caveats aside, faecal NAAT are increasingly being used and introduce a new era of diagnosis of gastrointestinal infection.

Computerized tomography magnified bone windows are superior to standard soft tissue windows for accurate measurement of stone size: an in vitro and clinical study.

Science.gov (United States)

Eisner, Brian H; Kambadakone, Avinash; Monga, Manoj; Anderson, James K; Thoreson, Andrew A; Lee, Hang; Dretler, Stephen P; Sahani, Dushyant V

2009-04-01

We determined the most accurate method of measuring urinary stones on computerized tomography. For the in vitro portion of the study 24 calculi, including 12 calcium oxalate monohydrate and 12 uric acid stones, that had been previously collected at our clinic were measured manually with hand calipers as the gold standard measurement. The calculi were then embedded into human kidney-sized potatoes and scanned using 64-slice multidetector computerized tomography. Computerized tomography measurements were performed at 4 window settings, including standard soft tissue windows (window width-320 and window length-50), standard bone windows (window width-1120 and window length-300), 5.13x magnified soft tissue windows and 5.13x magnified bone windows. Maximum stone dimensions were recorded. For the in vivo portion of the study 41 patients with distal ureteral stones who underwent noncontrast computerized tomography and subsequently spontaneously passed the stones were analyzed. All analyzed stones were 100% calcium oxalate monohydrate or mixed, calcium based stones. Stones were prospectively collected at the clinic and the largest diameter was measured with digital calipers as the gold standard. This was compared to computerized tomography measurements using 4.0x magnified soft tissue windows and 4.0x magnified bone windows. Statistical comparisons were performed using Pearson's correlation and paired t test. In the in vitro portion of the study the most accurate measurements were obtained using 5.13x magnified bone windows with a mean 0.13 mm difference from caliper measurement (p = 0.6). Measurements performed in the soft tissue window with and without magnification, and in the bone window without magnification were significantly different from hand caliper measurements (mean difference 1.2, 1.9 and 1.4 mm, p = 0.003, window settings with magnification. For uric acid calculi the measurement error was observed only in standard soft tissue window settings. In vivo 4.0x

Separation of polythionates and the gold thiosulfate complex in gold thiosulfate leach solutions by ion-interaction chromatography.

Science.gov (United States)

O'Reilly, John W; Shaw, Matthew J; Dicinoski, Greg W; Grosse, Andrew C; Miura, Yasuyuki; Haddad, Paul R

2002-07-01

A method for the separation of the polythionates (SxO6(2-), x = 3-5) in gold thiosulfate leach solutions using ion-interaction chromatography with conductivity and ultraviolet (UV) detection is described. Polythionates were eluted within 18 min using an eluent comprising an acetonitrile step gradient at 0.0 min from 15% v/v to 28% v/v, 3 mM TBAOH, and 2.5 mM sodium carbonate, operated using a Dionex NS1-5 micron column with guard. The developed method was capable of separating the gold thiosulfate complex ion in standard solutions, but quantification of this species in realistic leach solutions proved impractical due to a self-elution effect that caused the gold peak to be eluted as a broad band. Detection limits for polythionates using a 10 microL injection volume ranged between 1-6 mg L(-1) (5-23 microM) for conductivity and 0.8-13 mg L(-1) (4-68 microM) for UV detection, based on a signal-to-noise ratio of 2. Calibration was linear over the ranges 5-2000, 10-2000 and 25-2500 mg L(-1) for trithionate, tetrathionate and pentathionate, respectively. The technique was applied successfully to leach liquors containing 0.5 M ammonium thiosulfate, 2 M ammonia, 0.05 M copper sulfate and 20 % m/v gold ore.

Enhancing translation: guidelines for standard pre-clinical experiments in mdx mice.

Science.gov (United States)

Willmann, Raffaella; De Luca, Annamaria; Benatar, Michael; Grounds, Miranda; Dubach, Judith; Raymackers, Jean-Marc; Nagaraju, Kanneboyina

2012-01-01

Duchenne Muscular Dystrophy is an X-linked disorder that affects boys and leads to muscle wasting and death due to cardiac involvement and respiratory complications. The cause is the absence of dystrophin, a large structural protein indispensable for muscle cell function and viability. The mdx mouse has become the standard animal model for pre-clinical evaluation of potential therapeutic treatments. Recent years have seen a rapid increase in the number of experimental compounds being evaluated in the mdx mouse. There is, however, much variability in the design of these pre-clinical experimental studies. This has made it difficult to interpret and compare published data from different laboratories and to evaluate the potential of a treatment for application to patients. The authors therefore propose the introduction of a standard study design for the mdx mouse model. Several aspects, including animal care, sampling times and choice of tissues, as well as recommended endpoints and methodologies are addressed and, for each aspect, a standard procedure is proposed. Testing of all new molecules/drugs using a widely accepted and agreed upon standard experimental protocol would greatly improve the power of pre-clinical experimentations and help identifying promising therapies for the translation into clinical trials for boys with Duchenne Muscular Dystrophy. Copyright © 2011 Elsevier B.V. All rights reserved.

Utilization of electrodeposition for electrothermal atomic absorption spectrometry determination of gold

International Nuclear Information System (INIS)

Konecna, Marie; Komarek, Josef

2007-01-01

Gold was determined by electrothermal atomic absorption spectrometry after electrochemical preconcentration on the graphite ridge probe used as a working electrode and sample support. The probe surface was electrochemically modified with Pd, Re and the mixture of both. The electrolysis of gold was performed under galvanostatic control at 0.5 mA. Maximum pyrolysis temperature for the probe surface modified with Pd was 1200 deg. C, with Re 1300 deg. C. The relative standard deviation for the determination of 2 μg l -1 Au was not higher than 5.6% (n = 8) for 2 min electrodeposition. The sensitivity of gold determination was reproducible for 300 electrodeposition and atomization cycles. When the probe surface was modified with a mixture of Pd and Re the detection limit was 31 ng l -1 for 2 min electrodeposition, 3.7 ng l -1 for 30 min, 1.5 ng l -1 for 1 h and 0.4 ng l -1 for 4 h electrodeposition, respectively. The procedure was applied to the determination of gold in river water samples. The relative standard deviation for the determination of 2.5 ng l -1 Au at 4 h electrodeposition time at 0.5 mA was 7.5%

Gold 100: proceedings of the international conference on gold. V. 2

International Nuclear Information System (INIS)

Fivaz, C.E.; King, R.P.

1986-01-01

The proceedings of Gold 100 have been published in three separate volumes. The first deals with the mining of gold, the second with the extractive metallurgy of gold, and the third with industrial uses of gold. In this second volume, the papers on extractive metallurgy presented at the Conference reflect most of the problems that are currently of significant technical interest to the industry. This volume is divided in six main parts covering plant design, carbon-in-pulp technology, refractory gold, new technology, grinding and concentration, and leaching. The part on new technology includes papers on x-ray fluorescence analyzers, Moessbauer spectroscopy and leaching processes for uranium, while the part on grinding and concentration includes papers on nuclear and radiotracer techniques for the recovery of gold as well as various flotation parameters in the flotation behaviour of gold and uranium

Synoviorthesis with radioactive gold in hemophiliacs

International Nuclear Information System (INIS)

Ahlberg, Aa.; Petterson, H.

1979-01-01

Twenty-seven patients with hemophilia treated with intra-articular injection of radioactive gold were followed up clinically and radiologically for 3 to 9 years after treatment. To assess the radiological changes, a new classification was designed, with a score describing the severity of the changes in a more accurate manner than the methods previously used. The treatment decreased the bleeding frequency and stopped the progress of the arthropathy if applied at an early stage when the arthropathy was still reversible. If the treatment was begun at a later stage, the arthropathy seemed to progress independently of the effect on the bleeding frequency. No negative effect of the radioactive gold was observed on the joint or the growing zone. (author)

A clinical investigation of motivation to change standards and cognitions about failure in perfectionism.

Science.gov (United States)

Egan, Sarah J; Piek, Jan P; Dyck, Murray J; Rees, Clare S; Hagger, Martin S

2013-10-01

Clinical perfectionism is a transdiagnostic process that has been found to maintain eating disorders, anxiety disorders and depression. Cognitive behavioural models explaining the maintenance of clinical perfectionism emphasize the contribution of dichotomous thinking and resetting standards higher following both success and failure in meeting their goals. There has been a paucity of research examining the predictions of the models and motivation to change perfectionism. Motivation to change is important as individuals with clinical perfectionism often report many perceived benefits of their perfectionism; they are, therefore, likely to be ambivalent regarding changing perfectionism. The aim was to compare qualitative responses regarding questions about motivation to change standards and cognitions regarding failure to meet a personal standard in two contrasting groups with high and low negative perfectionism. Negative perfectionism refers to concern over not meeting personal standards. A clinical group with a range of axis 1 diagnoses who were elevated on negative perfectionism were compared to a group of athletes who were low on negative perfectionism. Results indicated that the clinical group perceived many negative consequences of their perfectionism. They also, however, reported numerous benefits and the majority stated that they would prefer not to change their perfectionism. The clinical group also reported dichotomous thinking and preferring to either keep standards the same or reset standards higher following failure, whilst the athlete group reported they would keep standards the same or set them lower. The findings support predictions of the cognitive behavioural model of clinical perfectionism.

GOLD IS EARNED FROM THE PRODUCTION OF THAI GOLD LEAF

Directory of Open Access Journals (Sweden)

Dirk Bax

2010-06-01

Full Text Available Thai people like to cover sacred objects or things dear to them with gold leaf.. Statues of Buddha are sometimes covered with so many layers of gold leaf that they become formless figures, that can hardly be recognized. Portraits of beloved ancestors, statues of elephants and grave tombs are often covered with gold leaf. If one considers the number of Thai people and the popularity of the habit, the amount of gold involved could be considerable.

Indacaterol/glycopyrronium in symptomatic patients with COPD (GOLD B and GOLD D versus salmeterol/fluticasone: ILLUMINATE/LANTERN pooled analysis

Directory of Open Access Journals (Sweden)

Vogelmeier C

2016-12-01

Full Text Available Claus Vogelmeier,1 Nanshan Zhong,2 Michael J Humphries,3 Karen Mezzi,4 Robert Fogel,5 Giovanni Bader,4 Francesco Patalano,4 Donald Banerji5 1Department of Medicine, Pulmonary and Critical Care Medicine, University Medical Center Giessen and Marburg, Philipps-University Marburg, Member of the German Center for Lung Research (DZL, Marburg, Germany; 2State Key Laboratory, Guangzhou Institute of Respiratory Diseases, First Affiliated Hospital, Guangzhou Medical University, Guangzhou, 3Beijing Novartis Pharma Co. Ltd., Shanghai, People’s Republic of China; 4Novartis Pharma AG, Basel, Switzerland; 5Novartis Pharmaceuticals Corporation, East Hanover, NJ, USA Background: Indacaterol/glycopyrronium (IND/GLY is approved for maintenance treatment of adult patients with COPD. This post hoc analysis explored the efficacy and safety of IND/GLY versus salmeterol/fluticasone (SFC in symptomatic (Global Initiative for Chronic Obstructive Lung Disease [GOLD] B and GOLD D patients with moderate-to-severe COPD.Patients and methods: Data from LANTERN and ILLUMINATE studies were pooled and analyzed. In both studies, symptomatic COPD patients were randomized to once-daily IND/GLY 110 µg/50 µg or twice-daily SFC 50 µg/500 µg. End points were pre-dose trough forced expiratory volume in one second (FEV1, standardized area under the curve for FEV1 from 0 to 12 hours (FEV1 AUC0–12 hours, peak FEV1, peak forced vital capacity (FVC, pre-dose trough FVC, Transition Dyspnea Index (TDI total score, St George’s Respiratory Questionnaire total score, rescue medication use and safety.Results: A total of 1,263 patients were classified as either GOLD B (n=809 or GOLD D (n=454. At week 26, IND/GLY demonstrated statistically significant improvement in all lung function parameters versus SFC in patients in both the GOLD B and GOLD D subgroups. TDI total score and rescue medication use were significantly improved with IND/GLY versus SFC in the overall population and in the

Changes in definition lead to changes in the clinical characteristics across COPD categories according to GOLD 2017: a national cross-sectional survey in China

Directory of Open Access Journals (Sweden)

Sun LN

2017-10-01

Full Text Available Lina Sun,* Yahong Chen,* Rui Wu, Ming Lu, Wanzhen Yao Department of Pulmonary and Critical Care Medicine, Peking University Third Hospital, Beijing, China *These authors contributed equally to this work Purpose: To investigate how the changes of definition in assessment of Global Initiative for Chronic Obstructive Lung Disease (GOLD stratification 2017 lead to changes of chronic obstructive pulmonary disease (COPD patient clinical characteristics across categories in China.Patients and methods: COPD patients from 11 medical centers in China were stratified into old and new groups A–D twice according to the GOLD 2011 and 2017 comprehensive assessment. Demography and clinical characteristics were compared between old and new groups A–D.Results: In 1,532 COPD patients, the distribution from group A to D was 330 (21.5%, 132 (8.6%, 411 (26.8%, 659 (43.0% and 557 (36.4%, 405 (26.4%, 184 (12.0%, 386 (25.2%, respectively according to GOLD 2011 and 2017. 46.7% (500/1,070 patients in high-risk groups were regrouped to low-risk groups. Compared to the old groups A and B, the new groups A and B had a higher proportion of males, lower body mass index, higher modified Medical Research Council (mMRC grade, poor pulmonary function, more patients with chronic bronchitis, and fewer patients with coronary heart disease and hypertension disease. Compared to the old groups C and D, the new groups C and D had older patients, fewer men, better pulmonary functions, frequent acute exacerbations in the previous year, and more patients with chronic bronchitis, coronary heart disease, or diabetes mellitus. The new group D had more patients with stroke than the old group D.Conclusion: In China, GOLD 2017 shifted the overall COPD comprehensive assessments distribution to more low-risk groups. The new high-risk groups had more characteristics associated with high risk of acute exacerbation and mortality. Some of the changes in demography and clinical characteristics of

Minimum reporting standards for clinical research on groin pain in athletes

DEFF Research Database (Denmark)

Delahunt, Eamonn; Thorborg, Kristian; Khan, Karim M

2015-01-01

Groin pain in athletes is a priority area for sports physiotherapy and sports medicine research. Heterogeneous studies with low methodological quality dominate research related to groin pain in athletes. Low-quality studies undermine the external validity of research findings and limit the ability...... to generalise findings to the target patient population. Minimum reporting standards for research on groin pain in athletes are overdue. We propose a set of minimum reporting standards based on best available evidence to be utilised in future research on groin pain in athletes. Minimum reporting standards...... are provided in relation to: (1) study methodology, (2) study participants and injury history, (3) clinical examination, (4) clinical assessment and (5) radiology. Adherence to these minimum reporting standards will strengthen the quality and transparency of research conducted on groin pain in athletes...

Standard requirements for GCP-compliant data management in multinational clinical trials

LENUS (Irish Health Repository)

Ohmann, Christian

2011-03-22

Abstract Background A recent survey has shown that data management in clinical trials performed by academic trial units still faces many difficulties (e.g. heterogeneity of software products, deficits in quality management, limited human and financial resources and the complexity of running a local computer centre). Unfortunately, no specific, practical and open standard for both GCP-compliant data management and the underlying IT-infrastructure is available to improve the situation. For that reason the "Working Group on Data Centres" of the European Clinical Research Infrastructures Network (ECRIN) has developed a standard specifying the requirements for high quality GCP-compliant data management in multinational clinical trials. Methods International, European and national regulations and guidelines relevant to GCP, data security and IT infrastructures, as well as ECRIN documents produced previously, were evaluated to provide a starting point for the development of standard requirements. The requirements were produced by expert consensus of the ECRIN Working group on Data Centres, using a structured and standardised process. The requirements were divided into two main parts: an IT part covering standards for the underlying IT infrastructure and computer systems in general, and a Data Management (DM) part covering requirements for data management applications in clinical trials. Results The standard developed includes 115 IT requirements, split into 15 separate sections, 107 DM requirements (in 12 sections) and 13 other requirements (2 sections). Sections IT01 to IT05 deal with the basic IT infrastructure while IT06 and IT07 cover validation and local software development. IT08 to IT015 concern the aspects of IT systems that directly support clinical trial management. Sections DM01 to DM03 cover the implementation of a specific clinical data management application, i.e. for a specific trial, whilst DM04 to DM12 address the data management of trials across the unit

Performance evaluation of grid-enabled registration algorithms using bronze-standards

CERN Document Server

Glatard, T; Montagnat, J

2006-01-01

Evaluating registration algorithms is difficult due to the lack of gold standard in most clinical procedures. The bronze standard is a real-data based statistical method providing an alternative registration reference through a computationally intensive image database registration procedure. We propose in this paper an efficient implementation of this method through a grid-interfaced workflow enactor enabling the concurrent processing of hundreds of image registrations in a couple of hours only. The performances of two different grid infrastructures were compared. We computed the accuracy of 4 different rigid registration algorithms on longitudinal MRI images of brain tumors. Results showed an average subvoxel accuracy of 0.4 mm and 0.15 degrees in rotation.

The need for international standardization in clinical beta dosimetry for brachytherapy

International Nuclear Information System (INIS)

Quast, U.; Boehm, J.; Kaulich, T.W.

2002-01-01

Beta radiation has found increasing interest in radiotherapy. Besides the curative treatment of small and medium-sized intraocular tumors by means of ophthalmic beta radiation plaques, intravascular brachytherapy has proven to successfully overcome the severe problem of restenosis after interventional treatment of arterial stenosis in coronaries and peripheral vessels in many clinical trials with a large number of patients. Prior to initiating procedures applying beta radiation in radiotherapy, however, there is a common need to specify methods for the determination and specification of the absorbed dose to water or tissue and their spatial distributions. The IAEA-TECDOC-1274 Calibration of photon and beta ray sources used in brachytherapy (2002) is a help for photon brachytherapy calibration. But, for beta seed and line sources, IAEA recommends well type ionization chambers as working standards which are far from measuring absorbed dose to water of the radiation clinically used. Although the application of such working standards seems to be more precise, large errors can occur when the medical physicist has to convert the calibration data to absorbed dose to water of the beta radiation emitted. The user must believe that the source is equally activated and that the manufacturer did not change the design and construction of the source encapsulation. With the DGMP Report 16 (2001) Guidelines for medical physical aspects of intravascular brachytherapy a very detailed code of practice is given, especially for the calibration and clinical dosimetry of intravascular beta radiation sources. As there is a global need for standardization in clinical dosimetry for intravascular brachytherapy utilizing beta radiation, the DIN-NAR, the German committee on standardization in radiology, task group dosimetry, has initiated an international adhoc working group for a new ISO work item proposal on the standardization of procedures in clinical dosimetry to guarantee reliable

Gold(I)-selenolate complexes: Synthesis, characterization and ...

Indian Academy of Sciences (India)

known that the gold(I) drugs rapidly bind to the most abundant plasma protein serum albumin (Alb-SH) after ... Aldrich. The experiments were carried out under dry and oxygen-free nitrogen using standard Schlenk tech- ... To a deoxygenated aqueous solution of the disele- nide 11 (30.0mg, 0.094mmol) was added sodium.

The clinical value of planar thallium-201 myocardial perfusion scintigraphy

International Nuclear Information System (INIS)

Niemeyer, M.G.

1989-01-01

The clinical value of planar thalium-201 myocardial perfusion scintigraphy was examined, using visual and quantitative analysis, for the detection of presence, localization and extent of coronary disease, using coronary arteriography as gold standard. The indremental diagnostic yield of different noninvasive tests for the diagnosis and the severity of coronary artery disease was quantified by using multivariate discriminant analysis. (author). 284 refs.; 14 figs.; 37 tabs

Standardized cardiovascular data for clinical research, registries, and patient care: a report from the Data Standards Workgroup of the National Cardiovascular Research Infrastructure project.

Science.gov (United States)

Anderson, H Vernon; Weintraub, William S; Radford, Martha J; Kremers, Mark S; Roe, Matthew T; Shaw, Richard E; Pinchotti, Dana M; Tcheng, James E

2013-05-07

Relatively little attention has been focused on standardization of data exchange in clinical research studies and patient care activities. Both are usually managed locally using separate and generally incompatible data systems at individual hospitals or clinics. In the past decade there have been nascent efforts to create data standards for clinical research and patient care data, and to some extent these are helpful in providing a degree of uniformity. Nonetheless, these data standards generally have not been converted into accepted computer-based language structures that could permit reliable data exchange across computer networks. The National Cardiovascular Research Infrastructure (NCRI) project was initiated with a major objective of creating a model framework for standard data exchange in all clinical research, clinical registry, and patient care environments, including all electronic health records. The goal is complete syntactic and semantic interoperability. A Data Standards Workgroup was established to create or identify and then harmonize clinical definitions for a base set of standardized cardiovascular data elements that could be used in this network infrastructure. Recognizing the need for continuity with prior efforts, the Workgroup examined existing data standards sources. A basic set of 353 elements was selected. The NCRI staff then collaborated with the 2 major technical standards organizations in health care, the Clinical Data Interchange Standards Consortium and Health Level Seven International, as well as with staff from the National Cancer Institute Enterprise Vocabulary Services. Modeling and mapping were performed to represent (instantiate) the data elements in appropriate technical computer language structures for endorsement as an accepted data standard for public access and use. Fully implemented, these elements will facilitate clinical research, registry reporting, administrative reporting and regulatory compliance, and patient care

Acute toxicity and pharmacokinetics of 13 nm-sized PEG-coated gold nanoparticles

International Nuclear Information System (INIS)

Cho, Wan-Seob; Cho, Minjung; Jeong, Jinyoung; Choi, Mina; Cho, Hea-Young; Han, Beom Seok; Kim, Sheen Hee; Kim, Hyoung Ook; Lim, Yong Taik; Chung, Bong Hyun; Jeong, Jayoung

2009-01-01

In general, gold nanoparticles are recognized as being as nontoxic. Still, there have been some reports on their toxicity, which has been shown to depend on the physical dimension, surface chemistry, and shape of the nanoparticles. In this study, we carry out an in vivo toxicity study using 13 nm-sized gold nanoparticles coated with PEG (MW 5000). In our findings the 13 nm sized PEG-coated gold nanoparticles were seen to induce acute inflammation and apoptosis in the liver. These nanoparticles were found to accumulate in the liver and spleen for up to 7 days after injection and to have long blood circulation times. In addition, transmission electron microscopy showed that numerous cytoplasmic vesicles and lysosomes of liver Kupffer cells and spleen macrophages contained the PEG-coated gold nanoparticles. These findings of toxicity and kinetics of PEG-coated gold nanoparticles may have important clinical implications regarding the safety issue as PEG-coated gold nanoparticles are widely used in biomedical applications

Neutron activation analysis of gold and prospectiveness of its application

International Nuclear Information System (INIS)

Tong Chunhan.

1988-01-01

NAA of gold is a method of high sensitivity and high percision, especially when epithermal neutron activation is applied. NAA is particularly emphasized in the process of gold reference standards preparation. In addition to the pure instrumental NAA, the NAA with pre-enrichment before sctivation is developed. This technque has been successfully used in assessment of micro and fine grained Au-Ag-phlymetal ores in Guixian, Guangxi. Through this example, prospectiveness of NAA application in Au-Ag-prospecting, fast assessment and trace element geochemistry investigation is seen

Toward Clarity in Clinical Vitamin D Status Assessment: 25(OH)D Assay Standardization.

Science.gov (United States)

Binkley, Neil; Carter, Graham D

2017-12-01

Widespread variation in 25-hydroxyvitamin D (25(OH)D) assays continues to compromise efforts to develop clinical and public health guidelines regarding vitamin D status. The Vitamin D Standardization Program helps alleviate this problem. Reference measurement procedures and standard reference materials have been developed to allow current, prospective, and retrospective standardization of 25(OH)D results. Despite advances in 25(OH)D measurement, substantial variability in clinical laboratory 25(OH)D measurement persists. Existing guidelines have not used standardized data and, as a result, it seems unlikely that consensus regarding definitions of vitamin D deficiency, inadequacy, sufficiency, and excess will soon be reached. Until evidence-based consensus is reached, a reasonable clinical approach is advocated. Copyright © 2017 Elsevier Inc. All rights reserved.

Clinical Image Evaluation of Film Mammograms in Korea: Comparison with the ACR Standard

International Nuclear Information System (INIS)

Gwak, Yeon Joo; Kim, Hye Jung; Kwak, Jin Young; Son, Eun Ju; Ko, Kyung Hee; Lee, Jin Hwa; Lim, Hyo Soon; Lee, You Jin; Park, Ji Won; Shin, Kyung Min; Jang, Yun-Jin

2013-01-01

The goal of this study is to compare the overall quality of film mammograms taken according to the Korean standards with the American College of Radiology (ACR) standard for clinical image evaluation and to identify means of improving mammography quality in Korea. Four hundred and sixty eight sets of film mammograms were evaluated with respect to the Korean and ACR standards for clinical image evaluation. The pass and failure rates of mammograms were compared by medical facility types. Average scores in each category of the two standards were evaluated. Receiver operating characteristic curve analysis was used to identify an optimal Korean standard pass mark by taking the ACR standard as the reference standard. 93.6% (438/468) of mammograms passed the Korean standard, whereas only 80.1% (375/468) passed the ACR standard (p < 0.001). Non-radiologic private clinics had the lowest pass rate (88.1%: Korean standard, 71.8%: ACR standard) and the lowest total score (76.0) by the Korean standard. Average scores of positioning were lowest (19.3/29 by the Korean standard and 3.7/5 by the ACR standard). A cutoff score of 77.0 for the Korean standard was found to correspond to a pass level when the ACR standard was applied. We suggest that tighter regulations, such as, raising the Korean pass mark, subtracting more for severe deficiencies, or considering a very low scores in even a single category as failure, are needed to improve the quality of mammography in Korea

Optimization of Standard In-House 24-Locus Variable-Number Tandem-Repeat Typing for Mycobacterium tuberculosis and Its Direct Application to Clinical Material

NARCIS (Netherlands)

de Beer, Jessica L.; Akkerman, Onno W.; Schurch, Anita C.; Mulder, Arnout; van der Werf, Tjip S.; van der Zanden, Adri G. M.; van Ingen, Jakko; van Soolingen, Dick

Variable-number tandem-repeat (VNTR) typing with a panel of 24 loci is the current gold standard in the molecular typing of Mycobacterium tuberculosis complex isolates. However, because of technical problems, a part of the loci often cannot be amplified by multiplex PCRs. Therefore, a considerable

Enhancement of gold recovery using bioleaching from gold concentrate

Science.gov (United States)

Choi, S. H.; Cho, K. H.; Kim, B. J.; Choi, N. C.; Park, C. Y.

2012-04-01

The gold in refractory ores is encapsulated as fine particles (sometimes at a molecular level) in the crystal structure of the sulfide (typically pyrite with or without arsenopyrite) matrix. This makes it impossible to extract a significant amount of refractory gold by cyanidation since the cyanide solution cannot penetrate the pyrite/arsenopyrite crystals and dissolve gold particles, even after fine grinding. To effectively extract gold from these ores, an oxidative pretreatment is necessary to break down the sulfide matrix. The most popular methods of pretreatment include nitric acid oxidation, roasting, pressure oxidation and biological oxidation by microorganisms. This study investigated the bioleaching efficiency of Au concentrate under batch experimental conditions (adaptation cycles and chemical composition adaptation) using the indigenous acidophilic bacteria collected from gold mine leachate in Sunsin gold mine, Korea. We conducted the batch experiments at two different chemical composition (CuSO4 and ZnSO4), two different adaptation cycles 1'st (3 weeks) and 2'nd (6 weeks). The results showed that the pH in the bacteria inoculating sample decreased than initial condition and Eh increased. In the chemical composition adaptation case, the leached accumulation content of Fe and Pb was exhibited in CuSO4 adaptation bacteria sample more than in ZnSO4 adaptation bacteria samples, possibly due to pre-adaptation effect on chalcopyrite (CuFeS2) in gold concentrate. And after 21 days on the CuSO4 adaptation cycles case, content of Fe and Pb was appeared at 1'st adaptation bacteria sample(Fe - 1.82 and Pb - 25.81 times per control sample) lower than at 2'nd adaptation bacteria sample(Fe - 2.87 and Pb - 62.05 times per control sample). This study indicates that adaptation chemical composition and adaptation cycles can play an important role in bioleaching of gold concentrate in eco-/economic metallurgy process.

Non-traumatic rhabdomyolysis: Background, laboratory features, and acute clinical management.

Science.gov (United States)

Cervellin, Gianfranco; Comelli, Ivan; Benatti, Mario; Sanchis-Gomar, Fabian; Bassi, Antonella; Lippi, Giuseppe

2017-08-01

Rhabdomyolysis is a relatively rare condition, but its clinical consequences are frequently dramatic in terms of both morbidity and mortality. Although no consensus has been reached so far about the precise definition of this condition, the term rhabdomyolysis describes a rapid breakdown of striated, or skeletal, muscle. It is hence characterized by the rupture and necrosis of muscle fibers, resulting in release of cell degradation products and intracellular elements within the bloodstream and extracellular space. Notably, the percentage of patients with rhabdomyolysis who develop acute kidney injury, the most dramatic consequence, varies from 13% to over 50% according to both the cause and the clinical and organizational setting where they are diagnosed. Despite direct muscle injury (i.e., traumatic rhabdomyolysis) remains the most common cause, additional causes, frequently overlapping, include hypoxic, physical, chemical or biological factors. The conventional triad of symptoms includes muscle pain, weakness and dark urine. The laboratory diagnosis is essentially based on the measurement of biomarkers of muscle injury, being creatine kinase (CK) the biochemical "gold standard" for diagnosis, and myoglobin the "gold standard" for prognostication, especially in patients with non-traumatic rhabdomyolysis. The essential clinical management in the emergency department is based on a targeted intervention to manage the underlying cause, combined with infusion of fluids and eventually sodium bicarbonate. We will present and discuss in this article the pathophysiological and clinical features of non-traumatic rhabdomyolysis, focusing specifically on Emergency Department (ED) management. Copyright © 2017 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Sensitive electrochemical immunosensor based on three-dimensional nanostructure gold electrode

Directory of Open Access Journals (Sweden)

Zhong G

2015-03-01

Full Text Available Guangxian Zhong,1,2,* Ruilong Lan,3,* Wenxin Zhang,1,4 Feihuan Fu,5 Yiming Sun,1,4 Huaping Peng,1,4 Tianbin Chen,3 Yishan Cai,6 Ailin Liu,1,4 Jianhua Lin,2 Xinhua Lin1,4 1Department of Pharmaceutical Analysis, Faculty of Pharmacy, Fujian Medical University, 2Department of Orthopaedics, 3The Centralab, First Affiliated Hospital of Fujian Medical University, 4Nano Medical Technology Research Institute, Fujian Medical University, Fuzhou, 5Department of Endocrinology, The County Hospital of Anxi, Anxi, 6Fujian International Travel Healthcare Center, Fujian Entry-Exit Inspection and Quarantine Bureau, Fuzhou, People’s Republic of China *These authors contributed equally to this work Abstract: A sensitive electrochemical immunosensor was developed for detection of alpha-fetoprotein (AFP based on a three-dimensional nanostructure gold electrode using a facile, rapid, “green” square-wave oxidation-reduction cycle technique. The resulting three-dimensional gold nanocomposites were characterized by scanning electron microscopy and cyclic voltammetry. A “sandwich-type” detection strategy using an electrochemical immunosensor was employed. Under optimal conditions, a good linear relationship between the current response signal and the AFP concentrations was observed in the range of 10–50 ng/mL with a detection limit of 3 pg/mL. This new immunosensor showed a fast amperometric response and high sensitivity and selectivity. It was successfully used to determine AFP in a human serum sample with a relative standard deviation of <5% (n=5. The proposed immunosensor represents a significant step toward practical application in clinical diagnosis and monitoring of prognosis. Keywords: electrochemical immunosensors, three-dimensional nanostructure gold electrode, square-wave oxidation-reduction cycle, alpha-fetoprotein 

Low rate of asymptomatic cerebral embolism and improved procedural efficiency with the novel pulmonary vein ablation catheter GOLD: results of the PRECISION GOLD trial.

Science.gov (United States)

De Greef, Yves; Dekker, Lukas; Boersma, Lucas; Murray, Stephen; Wieczorek, Marcus; Spitzer, Stefan G; Davidson, Neil; Furniss, Steve; Hocini, Mélèze; Geller, J Christoph; Csanádi, Zoltan

2016-05-01

This prospective, multicentre study (PRECISION GOLD) evaluated the incidence of asymptomatic cerebral embolism (ACE) after pulmonary vein isolation (PVI) using a new gold multi-electrode radiofrequency (RF) ablation catheter, pulmonary vein ablation catheter (PVAC) GOLD. Also, procedural efficiency of PVAC GOLD was compared with ERACE. The ERACE study demonstrated that a low incidence of ACE can be achieved with a platinum multi-electrode RF catheter (PVAC) combined with procedural manoeuvres to reduce emboli. A total of 51 patients with paroxysmal atrial fibrillation (AF) (age 57 ± 9 years, CHA2DS2-VASc score 1.4 ± 1.4) underwent AF ablation with PVAC GOLD. Continuous oral anticoagulation using vitamin K antagonists, submerged catheter introduction, and heparinization (ACT ≥ 350 s prior to ablation) were applied. Cerebral magnetic resonance imaging (MRI) scans were performed within 48 h before and 16-72 h post-ablation. Cognitive function assessed by the Mini-Mental State Exam at baseline and 30 days post-ablation. New post-procedural ACE occurred in only 1 of 48 patients (2.1%) and was not detectable on MRI after 30 days. The average number of RF applications per patient to achieve PVI was lower in PRECISION GOLD (20.3 ± 10.0) than in ERACE (28.8 ± 16.1; P = 0.001). Further, PVAC GOLD ablations resulted in significantly fewer low-power (GOLD in combination with established embolic lowering manoeuvres results in a low incidence of ACE. Pulmonary vein ablation catheter GOLD demonstrates improved biophysical efficiency compared with platinum PVAC. ClinicalTrials.gov NCT01767558. © The Author 2016. Published by Oxford University Press on behalf of the European Society of Cardiology.

Enrichment of Gold in Antimony Matte by Direct Smelting of Refractory Gold Concentrate

Science.gov (United States)

Yang, Tianzu; Xie, Boyi; Liu, Weifeng; Zhang, Duchao; Chen, Lin

2018-06-01

Conventional cyanidation technology achieves low gold recovery when used to process refractory gold concentrate. Based on the geochemical characteristics of gold deposit mineralization, a new method is proposed herein for gold enrichment in antimony matte by smelting of refractory gold concentrate. The effects of the FeO/SiO2 and CaO/SiO2 ratios, smelting temperature, and smelting time on the gold recovery were investigated in detail. The optimum conditions were determined to be FeO/SiO2 ratio of 1.2, CaO/SiO2 ratio of 0.4, smelting temperature of 1200°C, and smelting time of 45 min. The gold content in antimony matte and smelting slag was 96.68 and 1.13 g/t, respectively. The gold, antimony, and arsenic recovery was 97.72%, 26.89%, and 6.56%, respectively, with most of the antimony and arsenic volatilized into dust. Mineral liberation analyzer results showed that the antimony matte mainly consisted of FeS and FeO, with three phases, viz. FeAs, SbAs, and AuSb, embedded between them, indicating that gold was easily enriched with antimony and arsenic during smelting of refractory gold concentrate.

Enrichment of Gold in Antimony Matte by Direct Smelting of Refractory Gold Concentrate

Science.gov (United States)

Yang, Tianzu; Xie, Boyi; Liu, Weifeng; Zhang, Duchao; Chen, Lin

2018-04-01

Conventional cyanidation technology achieves low gold recovery when used to process refractory gold concentrate. Based on the geochemical characteristics of gold deposit mineralization, a new method is proposed herein for gold enrichment in antimony matte by smelting of refractory gold concentrate. The effects of the FeO/SiO2 and CaO/SiO2 ratios, smelting temperature, and smelting time on the gold recovery were investigated in detail. The optimum conditions were determined to be FeO/SiO2 ratio of 1.2, CaO/SiO2 ratio of 0.4, smelting temperature of 1200°C, and smelting time of 45 min. The gold content in antimony matte and smelting slag was 96.68 and 1.13 g/t, respectively. The gold, antimony, and arsenic recovery was 97.72%, 26.89%, and 6.56%, respectively, with most of the antimony and arsenic volatilized into dust. Mineral liberation analyzer results showed that the antimony matte mainly consisted of FeS and FeO, with three phases, viz. FeAs, SbAs, and AuSb, embedded between them, indicating that gold was easily enriched with antimony and arsenic during smelting of refractory gold concentrate.

Radiological versus clinical evidence of malrotation, a tortuous tale--10-year review.

LENUS (Irish Health Repository)

Stephens, Linda Ruth

2012-06-01

Malrotation is a common abnormality, often diagnosed in the neonatal period. Symptoms may be nonspecific and clinical signs of volvulus are often only seen in the late stages when there has been significant ischemic insult to the bowel. The gold standard diagnostic investigation is the upper gastrointestinal (UGI) contrast study. This study was designed to assess the incidence of negative laparotomy in patients with malrotation diagnosed on UGI contrast study and to identify the clinical signs and symptoms at presentation.

Setting up a randomized clinical trial in the UK: approvals and process.

Science.gov (United States)

Greene, Louise Eleanor; Bearn, David R

2013-06-01

Randomized clinical trials are considered the 'gold standard' in primary research for healthcare interventions. However, they can be expensive and time-consuming to set up and require many approvals to be in place before they can begin. This paper outlines how to determine what approvals are required for a trial, the background of each approval and the process for obtaining them.

The geology of the gold deposits of Prestea gold belt of Ghana ...

African Journals Online (AJOL)

This paper presents the geology of the gold deposits along the Prestea gold belt of Ghana to assist exploration work for new orebodies along the belt. Prestea district is the third largest gold producer in West Africa after Obuasi and Tarkwa districts (over 250 metric tonnes Au during the last century). The gold deposits are ...

Gold Leaching Characteristics and Intensification of a High S and As-Bearing Gold Concentrate

Science.gov (United States)

Yang, Yong-bin; Liu, Xiao-liang; Jiang, Tao; Li, Qian; Xu, Bin; Zhang, Yan

Some high sulfur and arsenic-bearing gold concentrate has a gold leaching rate less than 80% by oxidation roasting-pickling-cyanidation process. The characteristics and intensification of gold leaching were studied systemically. By combining chemical composition and phase analysis, the low gold leaching rate was found to lie in the capsulation of gold by iron-containing phases including iron oxides, arsenopyrite and pyrite. 96.66% of gold in the industrial leaching residue was capsulated and 95.88% of the capsulated turned out to be in the iron-containing phases. The results of laboratory pickling-cyanidation experiments on the calcine and industrial leaching residue presented further demonstration for the fact that gold capsulated in the iron-containing phases was hard to be leached. However, the gold cyanide leaching rate of calcine could be raised over 95% by a reduction roasting-pickling pretreatment which played such a significant role in exposing the capsulated gold that gold leaching was intensified remarkably.

Oxidation state of gold and arsenic in gold-bearing arsenian pyrite

Energy Technology Data Exchange (ETDEWEB)

Simon, G.; Huang, H.; Penner-Hahn, J.E.; Kesler, S.E.; Kao, L.S. [Univ. of Michigan, Ann Arbor, MI (United States)

1999-07-01

XANES measurements on gold-bearing arsenian pyrite from the Twin Creeks Carlin-type gold deposits show that gold is present as both Au{sup 0} and Au{sup 1+} and arsenic is present as As{sup 1{minus}}. Au{sup 0} is attributed to sub-micrometer size inclusions of free gold, whereas Au{sup 1+} is attributed to gold in the lattice of the arsenian pyrite. STEM observations suggest that As{sup 1{minus}} is probably concentrated in angstrom-scale, randomly distributed layers with a marcasite or arsenopyrite structure. Ionic gold (Au{sup 1+}) could be concentrated in these layers as well, and is present in both twofold- and fourfold-coordinated forms, with fourfold-coordinated Au{sup 1+} more abundant. Twofold-coordinated Au{sup 1+} is similar to gold in Au{sub 2}S in which it is linearly coordinated to two sulfur atoms. The nature of fourfold-coordinated Au{sup 1+} is not well understood, although it might be present as an Au-As-S compound where gold is bonded in fourfold coordination to sulfur and arsenic atoms, or in vacancy positions on a cation site in the arsenian pyrite. Au{sup 1+} was probably incorporated into arsenian pyrite by adsorption onto pyrite surfaces during crystal growth. The most likely compound in the case of twofold-coordinated Au{sup 1+} was probably a tri-atomic surface complex such as S{sub pyrite}-Au{sup 1+}-S{sub bi-sulfide}H or Au{sup 1+}-S-Au{sup 1+}. The correlation between gold and arsenic might be related to the role of arsenic in enhancing the adsorption of gold complexes of this type on pyrite surfaces, possibly through semiconductor effects.

Prediction of the clinical course of chronic obstructive pulmonary disease, using the new GOLD classification

DEFF Research Database (Denmark)

Lange, Peter; Marott, Jacob Louis; Vestbo, Jørgen

2012-01-01

The new Global Initiative for Obstructive Lung Disease (GOLD) stratification of chronic obstructive pulmonary disease (COPD) into categories A, B, C, and D is based on symptoms, level of lung function, and history of exacerbations.......The new Global Initiative for Obstructive Lung Disease (GOLD) stratification of chronic obstructive pulmonary disease (COPD) into categories A, B, C, and D is based on symptoms, level of lung function, and history of exacerbations....

Standards for Clinical Trials in Male and Female Sexual Dysfunction: I. Phase I to Phase IV Clinical Trial Design.

Science.gov (United States)

Fisher, William A; Gruenwald, Ilan; Jannini, Emmanuele A; Lev-Sagie, Ahinoam; Lowenstein, Lior; Pyke, Robert E; Reisman, Yakov; Revicki, Dennis A; Rubio-Aurioles, Eusebio

2016-12-01

This series of articles outlines standards for clinical trials of treatments for male and female sexual dysfunctions, with a focus on research design and patient-reported outcome assessment. These articles consist of revision, updating, and integration of articles on standards for clinical trials in male and female sexual dysfunction from the 2010 International Consultation on Sexual Medicine developed by the authors as part of the 2015 International Consultation on Sexual Medicine. We are guided in this effort by several principles. In contrast to previous versions of these guidelines, we merge discussion of standards for clinical trials in male and female sexual dysfunction in an integrated approach that emphasizes the common foundational practices that underlie clinical trials in the two settings. We present a common expected standard for clinical trial design in male and female sexual dysfunction, a common rationale for the design of phase I to IV clinical trials, and common considerations for selection of study population and study duration in male and female sexual dysfunction. We present a focused discussion of fundamental principles in patient- (and partner-) reported outcome assessment and complete this series of articles with specific discussions of selected aspects of clinical trials that are unique to male and to female sexual dysfunction. Our consideration of standards for clinical trials in male and female sexual dysfunction attempts to embody sensitivity to existing and new regulatory guidance and to address implications of the evolution of the diagnosis of sexual dysfunction that have been brought forward in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. The first article in this series focuses on phase I to phase IV clinical trial design considerations. Subsequent articles in this series focus on the measurement of patient-reported outcomes, unique aspects of clinical trial design for men, and unique aspects of clinical

“Heidelberg standard examination” and “Heidelberg standard procedures” – Development of faculty-wide standards for physical examination techniques and clinical procedures in undergraduate medical education

Science.gov (United States)

Nikendei, C.; Ganschow, P.; Groener, J. B.; Huwendiek, S.; Köchel, A.; Köhl-Hackert, N.; Pjontek, R.; Rodrian, J.; Scheibe, F.; Stadler, A.-K.; Steiner, T.; Stiepak, J.; Tabatabai, J.; Utz, A.; Kadmon, M.

2016-01-01

The competent physical examination of patients and the safe and professional implementation of clinical procedures constitute essential components of medical practice in nearly all areas of medicine. The central objective of the projects “Heidelberg standard examination” and “Heidelberg standard procedures”, which were initiated by students, was to establish uniform interdisciplinary standards for physical examination and clinical procedures, and to distribute them in coordination with all clinical disciplines at the Heidelberg University Hospital. The presented project report illuminates the background of the initiative and its methodological implementation. Moreover, it describes the multimedia documentation in the form of pocketbooks and a multimedia internet-based platform, as well as the integration into the curriculum. The project presentation aims to provide orientation and action guidelines to facilitate similar processes in other faculties. PMID:27579354

Certifying a university ENT clinic using the ISO 9001:2000 international standard.

Science.gov (United States)

Helbig, Matthias; Helbig, Silke; Kahla-Witzsch, Heike A; Kroll, Tobias; May, Angelika

2010-01-01

Against statutory duties to introduce quality management systems, the increased importance of this subject has led to numerous activities in various public health institutions. Following the International Standardization Organization (ISO 9001:2000) prerequisites, Frankfurt Goethe University Hospital ENT clinic staff introduced a quality management system. This paper aims to investigate this process. Designing, planning and implementing the quality management system is described. Under the supervision of an executive quality management board, clinic quality goals were defined. Thereafter, several quality management teams performed an actual state analysis as well as developing and realising improvement proposals. Finally a quality management manual containing binding standards and working instructions concerning all patient care, research and teaching aspects was written. Successful certification by a neutral body ascertained that the clinic's quality management system conformed to current national and international standards while restructuring and reform improved procedural efficiency. The paper shows that mplementing the quality management system requires considerable effort but patients as well as staff profit considerably from the innovation. On the whole, the positive impact on structure and workflow in a specialist clinic predominates. Therefore, implementing a quality management system in all the clinic's wards and departments is recommended.

Quantification of captopril in urine through surface-assisted laser desorption/ionization mass spectrometry using 4-mercaptobenzoic acid-capped gold nanoparticles as an internal standard.

Science.gov (United States)

Chen, Wen-Tsen; Chiang, Cheng-Kang; Lin, Yang-Wei; Chang, Huan-Tsung

2010-05-01

We have developed a new internal standard method for the determination of the concentration of captopril (CAP) through surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS) using gold nanoparticles (Au NPs). This approach provided linearity for CAP over the concentration range 2.5-25 microM (R(2) = 0.987), with a limit of detection (signal-to-noise ratio = 3) of 1.0 microM. The spot-to-spot variations in the concentration of CAP through SALDI-MS analyses performed in the absence and presence of the internal standard were 26% and 9%, respectively (15 measurements). This approach provides simplicity, accuracy, precision, and great reproducibility to the determination of the levels of CAP in human urine samples. Copyright 2010 American Society for Mass Spectrometry. Published by Elsevier Inc. All rights reserved.

Coal-oil gold agglomeration assisted flotation to recover gold from refractory ore

Science.gov (United States)

Otsuki, A.; Yue, C.

2017-07-01

This study aimed to investigate the applicability of coal-oil gold agglomeration (CGA) assisted flotation to recover gold from a refractory ore. The ore with the grade of 2-5 g/t was tested with the CGA-flotation process in six different size fractions from 38 to 300 urn using different collector types and dosages. In addition, the flotation without CGA was performed under the same condition for comparison. The results showed that the higher gold grade and recovery were achieved by applying the CGA-flotation, compared with the flotation without CGA. More than 20-60 times grade increase from the head grade was obtained with CGA-flotation. The elemental analysis of gold and sulphur explained their relationship with gold recovery. The results well indicated the applicability of CGA to upgrade the refractory gold ore.

Validity of ultrasonography and measures of adult shoulder function and reliability of ultrasonography in detecting shoulder synovitis in patients with rheumatoid arthritis using magnetic resonance imaging as a gold standard.

LENUS (Irish Health Repository)

Bruyn, G A W

2010-08-01

To assess the intra- and interobserver reproducibility of musculoskeletal ultrasonography (US) in detecting inflammatory shoulder changes in patients with rheumatoid arthritis, and to determine the agreement between US and the Shoulder Pain and Disability Index (SPADI) and the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire, using magnetic resonance imaging (MRI) as a gold standard.

Recent progress in theranostic applications of hybrid gold nanoparticles.

Science.gov (United States)

Gharatape, Alireza; Salehi, Roya

2017-09-29

A significant area of research is theranostic applications of nanoparticles, which involves efforts to improve delivery and reduce side effects. Accordingly, the introduction of a safe, effective, and, most importantly, renewable strategy to target, deliver and image disease cells is important. This state-of-the-art review focuses on studies done from 2013 to 2016 regarding the development of hybrid gold nanoparticles as theranostic agents in the diagnosis and treatment of cancer and infectious disease. Several syntheses (chemical and green) methods of gold nanoparticles and their applications in imaging, targeting, and delivery are reviewed; their photothermal efficiency is discussed as is the toxicity of gold nanoparticles. Owing to the unique characterizations of hybrid gold nanoparticles and their potential to be developed as multifunctional, we predict they will present an undeniable role in clinical studies and provide treatment platforms for various diseases. Thus, their clearance and interactions with extra- and intra-cellular molecules need to be considered in future projects. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Medical Paraclinical Standards, Political Economy of Clinic, and Patients’ Clinical Dependency; A Critical Conversation Analysis of Clinical Counseling in South of Iran

Science.gov (United States)

Kalateh Sadati, Ahmad; Iman, Mohammad Taghi; Bagheri Lankarani, Kamran

2014-01-01

Background: Despite its benefits and importance, clinical counseling affects the patient both psychosocially and socially. Illness labeling not only leads to many problems for patient and his/her family but also it imposes high costs to health care system. Among various factors, doctor-patient relationship has an important role in the clinical counseling and its medical approach. The goal of this study is to evaluate the nature of clinical counseling based on critical approach. Methods: The context of research is the second major medical training center in Shiraz, Iran. In this study, Critical Conversation Analysis was used based on the methodologies of critical theories. Among about 50 consultation meetings digitally recorded, 33 were selected for this study. Results: Results show that the nature of doctor-patient relationship in these cases is based on paternalistic model. On the other hand, in all consultations, the important values that were legitimated with physicians were medical paraclinical standards. Paternalism in one hand and standardization on the other leads to dependency of patients to the clinic. Conclusion: Although we can’t condone the paraclinical standards, clinical counseling and doctor-patient relationship need to reduce its dominance over counseling based on interpretation of human relations, paying attention to social and economical differences of peoples and biosocial and biocultural differences, and focusing on clinical examinations. Also, we need to accept that medicine is an art of interaction that can’t reduce it to instrumental and linear methods of body treatment. PMID:25349858

Medical paraclinical standards, political economy of clinic, and patients' clinical dependency; a critical conversation analysis of clinical counseling in South of iran.

Science.gov (United States)

Kalateh Sadati, Ahmad; Iman, Mohammad Taghi; Bagheri Lankarani, Kamran

2014-07-01

Despite its benefits and importance, clinical counseling affects the patient both psychosocially and socially. Illness labeling not only leads to many problems for patient and his/her family but also it imposes high costs to health care system. Among various factors, doctor-patient relationship has an important role in the clinical counseling and its medical approach. The goal of this study is to evaluate the nature of clinical counseling based on critical approach. The context of research is the second major medical training center in Shiraz, Iran. In this study, Critical Conversation Analysis was used based on the methodologies of critical theories. Among about 50 consultation meetings digitally recorded, 33 were selected for this study. RESULTS show that the nature of doctor-patient relationship in these cases is based on paternalistic model. On the other hand, in all consultations, the important values that were legitimated with physicians were medical paraclinical standards. Paternalism in one hand and standardization on the other leads to dependency of patients to the clinic. Although we can't condone the paraclinical standards, clinical counseling and doctor-patient relationship need to reduce its dominance over counseling based on interpretation of human relations, paying attention to social and economical differences of peoples and biosocial and biocultural differences, and focusing on clinical examinations. Also, we need to accept that medicine is an art of interaction that can't reduce it to instrumental and linear methods of body treatment.

[History of gold--with danish contribution to tuberculosis and rheumatoid arthritis].

Science.gov (United States)

Norn, Svend; Permin, Henrik; Kruse, Poul R; Kruse, Edith

2011-01-01

Gold has a long history as a therapeutic agent, first as gold particles and colloidal gold, then as a soluble salt made by the alchemists, and potable gold was recommended almost as a panacea against different diseases. Gold compounds were introduced in the treatment of tuberculosis, based initially on the reputation of Robert Koch, who found gold cyanide effective against Mycobacterium tuberculosis in cultures. Although several investigations of gold salts showed no convincing effect in experimental tuberculosis in guinea pigs, the idea of using gold compounds as chemotherapy was furthermore encouraged from the work of Paul Ehrlich with arsenicals. The enthusiasm and the craving desperately for a remedy for tuberculosis forced Danish physicians, in the mid-1920s to treat tuberculosis with Sanocrysin (gold sodium thiosulfate). Professor Holger Møllgaard, in collaboration with the clinicians the professors Knud Secher and Knud Faber, was the theoretical promoter of the project. He recommended sanocrysin-antiserum therapy, since sanocrysin caused serious reactions in tuberculosis animals, possible by releasing toxins from tubercle bacilli "killed" by sanocrysin. However the enthusiastic response to sanocrysin in Europe declined along by controlled trials and reports on toxicity in the 1930s. The belief that rheumatoid arthritis was a form of tuberculosis caused a renaissance in chrysotherapy. In France Jacques Forestier obtained encouraging results in the treatment of rheumatoid arthritis with myochrysine and other gold salts, and he pointed out the disease modifying effect of chrysotherapy. In Denmark Knud Secher, who was the clinical initiator of Sanocrysin therapy in tuberculosis, now became the founder of chrysotherapy in rheumatoid arthritis. Although new potential agents are now taking over in the treatment of arthritis, it is still believed, that there is a place for the chrysotherapy. However a new future for gold, in the form of nanoparticles, appears on

Gold and gold-copper nanoparticles in 2-propanol: A radiation chemical study

International Nuclear Information System (INIS)

Dey, G.R.

2011-01-01

The studies on the reduction of Au 3+ to gold nanoparticles in presence and absence of Cu 2+ under deoxygenated conditions in 2-propanol by radiolytic method have been carried out. On γ-radiolysis, preliminary yellow colored solution of Au 3+ changed to purple color owing to gold nanoparticles formation, which exhibits an absorption peak at around 540 nm. In the presence of Cu 2+ , absorption of gold-copper nanoparticles, which was also produced during γ-radiolysis, was red shifted in contrast to the system containing no Cu 2+ . Under DLS studies the sizes of gold nanoparticles in the absence and the presence of Cu 2+ were found to be larger (>400 nm). However, in presence of polyethylene glycol, a stabilizer the nanoparticle sizes became smaller, sizes measured for gold and gold-copper nanoparticles are 40 and 140 nm, respectively. Moreover, the change in UV-vis spectra in the Cu 2+ and Au 3+ mixed system highlights the formation of gold-copper nanoparticles in core-shell type arrangement. - Highlights: → Present radiation chemical study highlights high reactivity of Au ·2+ with Cu 2+ . → Absorption of gold-copper nanoparticles is blue shifted as compared to copper nanoparticles. → Change in UV-vis spectra with dose emphasizes core-shell type arrangement of Au-Cu nanoparticles.

Gold in plants

International Nuclear Information System (INIS)

Girling, C.A.; Peterson, P.J.

1980-01-01

Many plants have the ability to take up gold from the soil and to accumulate it in their tisssue. Advances have been made in understanding these processes to the point where their exploitation in the field of prospecting for gold appears practically feasible. Neutron activation analysis is used for the determination of the small quantities of gold in plants

Standardizing data exchange for clinical research protocols and case report forms: An assessment of the suitability of the Clinical Data Interchange Standards Consortium (CDISC) Operational Data Model (ODM).

Science.gov (United States)

Huser, Vojtech; Sastry, Chandan; Breymaier, Matthew; Idriss, Asma; Cimino, James J

2015-10-01

Efficient communication of a clinical study protocol and case report forms during all stages of a human clinical study is important for many stakeholders. An electronic and structured study representation format that can be used throughout the whole study life-span can improve such communication and potentially lower total study costs. The most relevant standard for representing clinical study data, applicable to unregulated as well as regulated studies, is the Operational Data Model (ODM) in development since 1999 by the Clinical Data Interchange Standards Consortium (CDISC). ODM's initial objective was exchange of case report forms data but it is increasingly utilized in other contexts. An ODM extension called Study Design Model, introduced in 2011, provides additional protocol representation elements. Using a case study approach, we evaluated ODM's ability to capture all necessary protocol elements during a complete clinical study lifecycle in the Intramural Research Program of the National Institutes of Health. ODM offers the advantage of a single format for institutions that deal with hundreds or thousands of concurrent clinical studies and maintain a data warehouse for these studies. For each study stage, we present a list of gaps in the ODM standard and identify necessary vendor or institutional extensions that can compensate for such gaps. The current version of ODM (1.3.2) has only partial support for study protocol and study registration data mainly because it is outside the original development goal. ODM provides comprehensive support for representation of case report forms (in both the design stage and with patient level data). Inclusion of requirements of observational, non-regulated or investigator-initiated studies (outside Food and Drug Administration (FDA) regulation) can further improve future revisions of the standard. Published by Elsevier Inc.

Distribution and composition of gold in porphyry gold systems: example from the Biely Vrch deposit, Slovakia

Science.gov (United States)

Koděra, Peter; Kozák, Jaroslav; Brčeková, Jana; Chovan, Martin; Lexa, Jaroslav; Jánošík, Michal; Biroň, Adrián; Uhlík, Peter; Bakos, František

2018-03-01

The Biely Vrch deposit in the Western Carpathians is assigned to the shallow, sulfide-poor porphyry gold deposit type and has an exceptionally low Cu/Au ratio. According to 3-D geochemical models, there is a limited spatial correlation between Au and Cu due to the primary introduction of gold by a salt melt and Cu by low-density vapor. Despite a rough spatial correlation of gold grades with quartz stockwork intensity, gold is hosted mostly by altered rock, exclusively in native form. Three main gold mineral assemblages were recognized here. In the deepest parts of the system, the K- and Ca-Na silicate gold assemblage is associated with minerals of high-temperature alteration (plagioclase, K-feldspar, actinolite), with gold grades and fineness depending on depth and potassium content of the host rock: K-silicate alteration hosts the lowest fineness gold ( 914), whereas Ca-Na silicate alteration has the highest ( 983). The intermediate argillic gold assemblage is the most widespread, with gold hosted mainly by chlorite, illite, smectite, and interstratified illite-chlorite-smectite minerals. The gold fineness is mostly variable (875-990) and inherited from the former gold mineral assemblages. The latest advanced argillic gold assemblage has its gold mostly in kaolinite. The extremely high fineness ( 994) results from gold remobilization by late-stage aqueous magmatic-hydrothermal fluids. Uncommon bonanza-grade appears where the earlier gold mineral assemblages were further enriched by this remobilized gold. Primary precipitation of gold occurred during ascent and cooling of salt melts at 450 to 309 °C, mostly during retrograde quartz solubility.

40 CFR 440.104 - New source performance standards (NSPS).

Science.gov (United States)

2010-07-01

... GUIDELINES AND STANDARDS ORE MINING AND DRESSING POINT SOURCE CATEGORY Copper, Lead, Zinc, Gold, Silver, and... copper, lead, zinc, gold, silver, or molybdenum bearing ores or any combination of these ores from open... discharge of process wastewater to navigable waters from mills that use the froth-flotation process alone...

Determination of the occurrence of gold in an unoxidized Carlin-type ore sample using synchrotron radiation

International Nuclear Information System (INIS)

Chen, J.R.; Chao, E.C.T.; Minkin, J.A.; Back, J.M.; Bagby, W.C.; Rivers, M.L.; Sutton, S.R.; Hanson, A.L.; Jones, K.W.

1986-01-01

The occurrence of the so-called invisible gold in two unoxidized Carlin-type gold samples from Nevada have been determined using synchrotron x-ray fluorescence (SXRF) analysis at the National Sychrotron Light Source, Brookhaven National Laboratory. The samples were a bedded sample from the east ore zone of the Carlin deposit and a breccia sample from Horse Canyon. Preliminary results show that gold is found only in the Horse Canyon breccia sample. Experimental details including other x-ray line and diffraction peak interferences, standards used, and minimum detection limits (MDLs) are discussed. Gold was not detected in euhedral pyrite crystals except in the interior porous portion of one grain with MDLs of 0.8 to 3 ppM. Gold was detected in some parts of the matrix. The phase which contains gold has not yet been identified. The highest content of gold so far analyzed is about 40 ppM. Implications of these new findings are discussed. 2 figs

The restoration of the gold standard after the US Civil War : A volatility analysis

NARCIS (Netherlands)

Meulemann, Max; Uebele, Martin; Wilfling, Bernd

This paper presents a new view on the gold price of greenbacks during and after the American Civil War by analyzing exchange-rate volatility rather than exchange-rate levels. Our empirical investigation detects regimes of high and low volatility alternating in a way that is consistent with a

A comparative analysis of quality management standards for contract research organisations in clinical trials.

Science.gov (United States)

Murray, Elizabeth; McAdam, Rodney

2007-01-01

This article compares and contrasts the main quality standards in the highly regulated pharmaceutical industry with specific focus on Good Clinical Practice (GCP), the standard for designing, conducting, recording and reporting clinical trials involving human participants. Comparison is made to ISO quality standards, which can be applied to all industries and types of organisation. The study is then narrowed to that of contract research organisations (CROs) involved in the conduct of clinical trials. The paper concludes that the ISO 9000 series of quality standards can act as a company-wide framework for quality management within such organisations by helping to direct quality efforts on a long-term basis without any loss of compliance. This study is valuable because comparative analysis in this domain is uncommon.

Silver, gold, and alloyed silver-gold nanoparticles: characterization and comparative cell-biologic action

Science.gov (United States)

Mahl, Dirk; Diendorf, Jörg; Ristig, Simon; Greulich, Christina; Li, Zi-An; Farle, Michael; Köller, Manfred; Epple, Matthias

2012-10-01

Silver, gold, and silver-gold-alloy nanoparticles were prepared by citrate reduction modified by the addition of tannin during the synthesis, leading to a reduction in particle size by a factor of three. Nanoparticles can be prepared by this easy water-based synthesis and subsequently functionalized by the addition of either tris(3-sulfonatophenyl)phosphine or poly( N-vinylpyrrolidone). The resulting nanoparticles of silver (diameter 15-25 nm), gold (5-6 nm), and silver-gold (50:50; 10-12 nm) were easily dispersable in water and also in cell culture media (RPMI + 10 % fetal calf serum), as shown by nanoparticle tracking analysis and differential centrifugal sedimentation. High-resolution transmission electron microscopy showed a polycrystalline nature of all nanoparticles. EDX on single silver-gold nanoparticles indicated that the concentration of gold is higher inside a nanoparticle. The biologic action of the nanoparticles toward human mesenchymal stem cells (hMSC) was different: Silver nanoparticles showed a significant concentration-dependent influence on the viability of hMSC. Gold nanoparticles showed only a small effect on the viability of hMSC after 7 days. Surprisingly, silver-gold nanoparticles had no significant influence on the viability of hMSC despite the silver content. Silver nanoparticles and silver-gold nanoparticles in the concentration range of 5-20 μg mL-1 induced the activation of hMSC as indicated by the release of IL-8. In contrast, gold nanoparticles led to a reduction of the release of IL-6 and IL-8.

Standardized Patients Provide a Reliable Assessment of Athletic Training Students' Clinical Skills

Science.gov (United States)

Armstrong, Kirk J.; Jarriel, Amanda J.

2016-01-01

Context: Providing students reliable objective feedback regarding their clinical performance is of great value for ongoing clinical skill assessment. Since a standardized patient (SP) is trained to consistently portray the case, students can be assessed and receive immediate feedback within the same clinical encounter; however, no research, to our…

Prehospital Emergencies in Illegal Gold Mining Sites in French Guiana.

Science.gov (United States)

Egmann, Gérald; Tattevin, Pierre; Palancade, Renaud; Nacher, Matthieu

2018-03-01

Illegal gold mining is flourishing in French Guiana, existing outside the law due to both the high cost of gold mining permits and the challenges of law enforcement within the Amazon forest. We report the characteristics of, and the medical responses to, medical emergencies in illegal gold mining sites. We performed a retrospective study of all medical emergencies reported from illegal gold mining sites to the centralized call office of SAMU 973 from 1998 through 2000 and from 2008 through 2010. According to the national health care system, any medical emergency within the territory is handled by the prehospital emergency medical service (SAMU 973), irrespective of the patients' legal status. Data were extracted from the SAMU 973 notebook registry (1998-2000) or the SAMU 973 computerized database (2008-2010) and werre collected using a standardized questionnaire. Of 71,932 calls for medical emergencies in French Guiana during the study periods, 340 (0.5%) originated from illegal gold mining sites. Of these, 196 (58%) led to medical evacuation by helicopter, whereas the overall rate of evacuation by helicopter after placing a call to SAMU 973 was only 4% (3020/71,932; PAmazon forest mostly include infectious diseases, followed by trauma, and often require medical evacuation by helicopter. Our study suggests that implementation of preventive medicine within gold mining sites, irrespective of their legal status, could be cost-effective and reduce morbidity. Copyright © 2017 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.

A quality assessment tool for markup-based clinical guidelines.

Science.gov (United States)

Shalom, Erez; Shahar, Yuval; Taieb-Maimon, Meirav; Lunenfeld, Eitan

2008-11-06

We introduce a tool for quality assessment of procedural and declarative knowledge. We developed this tool for evaluating the specification of mark-up-based clinical GLs. Using this graphical tool, the expert physician and knowledge engineer collaborate to perform scoring, using pre-defined scoring scale, each of the knowledge roles of the mark-ups, comparing it to a gold standard. The tool enables scoring the mark-ups simultaneously at different sites by different users at different locations.

Banana peel extract mediated synthesis of gold nanoparticles.

Science.gov (United States)

Bankar, Ashok; Joshi, Bhagyashree; Kumar, Ameeta Ravi; Zinjarde, Smita

2010-10-01

Gold nanoparticles were synthesized by using banana peel extract (BPE) as a simple, non-toxic, eco-friendly 'green material'. The boiled, crushed, acetone precipitated, air-dried peel powder was used to reduce chloroauric acid. A variety of nanoparticles were formed when the reaction conditions were altered with respect to pH, BPE content, chloroauric acid concentration and temperature of incubation. The reaction mixtures displayed vivid colors and UV-vis spectra characteristic of gold nanoparticles. Dynamic light scattering (DLS) studies revealed that the average size of the nanoparticles under standard synthetic conditions was around 300nm. Scanning electron microscopy and energy dispersive spectrometry (EDS) confirmed these results. A coffee ring phenomenon, led to the aggregation of the nanoparticles into microcubes and microwire networks towards the periphery of the air-dried samples. X-ray diffraction studies of the samples revealed spectra that were characteristic for gold. Fourier transform infra red (FTIR) spectroscopy indicated the involvement of carboxyl, amine and hydroxyl groups in the synthetic process. The BPE mediated nanoparticles displayed efficient antimicrobial activity towards most of the tested fungal and bacterial cultures.

Establishment of quality assessment standard for mammographic equipment: evaluation of phantom and clinical images

International Nuclear Information System (INIS)

Lee, Sung Hoon; Choe, Yeon Hyeon; Chung, Soo Young

2005-01-01

The purpose of this study was to establish a quality standard for mammographic equipment Korea and to eventually improve mammographic quality in clinics and hospitals throughout Korea by educating technicians and clinic personnel. For the phantom test and on site assessment, we visited 37 sites and examined 43 sets of mammographic equipment. Items that were examined include phantom test, radiation dose measurement, developer assessment, etc. The phantom images were assessed visually and by optical density measurements. For the clinical image assessment, clinical images from 371 sites were examined following the new Korean standard for clinical image evaluation. The items examined include labeling, positioning, contrast, exposure, artifacts, collimation among others. Quality standard of mammographic equipment was satisfied in all equipment on site visits. Average mean glandular dose was 114.9 mRad. All phantom image test scores were over 10 points (average, 10.8 points). However, optical density measurements were below 1.2 in 9 sets of equipment (20.9%). Clinical image evaluation revealed appropriate image quality in 83.5%, while images from non-radiologist clinics were adequate in 74.6% (91/122), which was the lowest score of any group. Images were satisfactory in 59.0% (219/371) based on evaluation by specialists following the new Korean standard for clinical image evaluation. Satisfactory images had a mean score of 81.7 (1 S.D. =8.9) and unsatisfactory images had a mean score of 61.9 (1 S.D = 11). The correlation coefficient between the two observers was 0.93 (ρ < 0.01) in 49 consecutive cases. The results of the phantom tests suggest that optical density measurements should be performed as part of a new quality standard for mammographic equipment. The new clinical evaluation criteria that was used in this study can be implemented with some modifications for future mammography quality control by the Korean government

Standardized Methods for Detection of Poliovirus Antibodies.

Science.gov (United States)

Weldon, William C; Oberste, M Steven; Pallansch, Mark A

2016-01-01

Testing for neutralizing antibodies against polioviruses has been an established gold standard for assessing individual protection from disease, population immunity, vaccine efficacy studies, and other vaccine clinical trials. Detecting poliovirus specific IgM and IgA in sera and mucosal specimens has been proposed for evaluating the status of population mucosal immunity. More recently, there has been a renewed interest in using dried blood spot cards as a medium for sample collection to enhance surveillance of poliovirus immunity. Here, we describe the modified poliovirus microneutralization assay, poliovirus capture IgM and IgA ELISA assays, and dried blood spot polio serology procedures for the detection of antibodies against poliovirus serotypes 1, 2, and 3.

Gold deposit styles and placer gold characterisation in northern and east-central Madagascar

Science.gov (United States)

Pitfield, Peter E. J; Styles, Michael T.; Taylor, Cliff D.; Key, Roger M.; Bauer,; Ralison, A

2009-01-01

Microchemical characterisation of bedrock and placer gold grains from six gold districts within the Archaean domains and intervening Neoproterozoic Anaboriana-Manampotsy belt of northern and east-central Madagascar show few opaque inclusions (e.g pyrrhotite, Bi tellurides) but wide range of Ag contents (40wt%). Some districts exhibit multiple source populations of grains. The ‘greenstone belt’ terranes have an orogenic gold signature locally with an intrusion-related to epithermal overprint. Proterozoic metasediments with felsic to ultramafic bodies yield dominantly intrusion-related gold. A high proportion of secondary gold (<0.5wt% Ag) is related to recycling of paleoplacers and erosion of post-Gondwana planation surfaces and indicates that some mesothermal gold systems were already partially to wholly removed by erosion by the PermoTriassic.

Diagnosing dehydration? Blend evidence with clinical observations.

Science.gov (United States)

Armstrong, Lawrence E; Kavouras, Stavros A; Walsh, Neil P; Roberts, William O

2016-11-01

The purpose of the review is to provide recommendations to improve clinical decision-making based on the strengths and weaknesses of commonly used hydration biomarkers and clinical assessment methods. There is widespread consensus regarding treatment, but not the diagnosis of dehydration. Even though it is generally accepted that a proper clinical diagnosis of dehydration can only be made biochemically rather than relying upon clinical signs and symptoms, no gold standard biochemical hydration index exists. Other than clinical biomarkers in blood (i.e., osmolality and blood urea nitrogen/creatinine) and in urine (i.e., osmolality and specific gravity), blood pressure assessment and clinical symptoms in the eye (i.e., tear production and palpitating pressure) and the mouth (i.e., thirst and mucous wetness) can provide important information for diagnosing dehydration. We conclude that clinical observations based on a combination of history, physical examination, laboratory values, and clinician experience remain the best approach to the diagnosis of dehydration.

Analysis of gold and silver concentration on gold mining tailings by neutron activation analysis

International Nuclear Information System (INIS)

Sadikov, I.I.; Salimov, M.I.; Sadykova, Z.O.

2014-01-01

Full text: Instrumental neutron-activation analysis without radiochemical separation is one of most applicable and often used methods to analyze the concentration of gold, silver and other rare and noble metals in gold ores. This method is not suitable for analyzing low concentration of gold and silver in gold mining tailings due to rather high concentration of some elements. Samples are dissolved by boiling in a mixture of concentrated hydrochloric and nitric acids to extract gold and silver into the solution. Chemical yield of gold and silver after dissolution of the sample and further chromatographic separation is between 92 and 95 percent respectively

Gold nanoparticle formation in diamond-like carbon using two different methods: Gold ion implantation and co-deposition of gold and carbon

International Nuclear Information System (INIS)

Salvadori, M. C.; Teixeira, F. S.; Araújo, W. W. R.; Sgubin, L. G.; Cattani, M.; Spirin, R. E.; Brown, I. G.

2012-01-01

We describe work in which gold nanoparticles were formed in diamond-like carbon (DLC), thereby generating a Au-DLC nanocomposite. A high-quality, hydrogen-free DLC thin film was formed by filtered vacuum arc plasma deposition, into which gold nanoparticles were introduced using two different methods. The first method was gold ion implantation into the DLC film at a number of decreasing ion energies, distributing the gold over a controllable depth range within the DLC. The second method was co-deposition of gold and carbon, using two separate vacuum arc plasma guns with suitably interleaved repetitive pulsing. Transmission electron microscope images show that the size of the gold nanoparticles obtained by ion implantation is 3-5 nm. For the Au-DLC composite obtained by co-deposition, there were two different nanoparticle sizes, most about 2 nm with some 6-7 nm. Raman spectroscopy indicates that the implanted sample contains a smaller fraction of sp 3 bonding for the DLC, demonstrating that some sp 3 bonds are destroyed by the gold implantation.

Dosimetric implications of inter- and intrafractional prostate positioning errors during tomotherapy : Comparison of gold marker-based registrations with native MVCT.

Science.gov (United States)

Wust, Peter; Joswig, Marc; Graf, Reinhold; Böhmer, Dirk; Beck, Marcus; Barelkowski, Thomasz; Budach, Volker; Ghadjar, Pirus

2017-09-01

For high-dose radiation therapy (RT) of prostate cancer, image-guided (IGRT) and intensity-modulated RT (IMRT) approaches are standard. Less is known regarding comparisons of different IGRT techniques and the resulting residual errors, as well as regarding their influences on dose distributions. A total of 58 patients who received tomotherapy-based RT up to 84 Gy for high-risk prostate cancer underwent IGRT based either on daily megavoltage CT (MVCT) alone (n = 43) or the additional use of gold markers (n = 15) under routine conditions. Planned Adaptive (Accuray Inc., Madison, WI, USA) software was used for elaborated offline analysis to quantify residual interfractional prostate positioning errors, along with systematic and random errors and the resulting safety margins after both IGRT approaches. Dosimetric parameters for clinical target volume (CTV) coverage and exposition of organs at risk (OAR) were also analyzed and compared. Interfractional as well as intrafractional displacements were determined. Particularly in the vertical direction, residual interfractional positioning errors were reduced using the gold marker-based approach, but dosimetric differences were moderate and the clinical relevance relatively small. Intrafractional prostate motion proved to be quite high, with displacements of 1-3 mm; however, these did not result in additional dosimetric impairments. Residual interfractional positioning errors were reduced using gold marker-based IGRT; however, this resulted in only slightly different final dose distributions. Therefore, daily MVCT-based IGRT without markers might be a valid alternative.

Fire-assay determination of small amounts of gold in mineral raw materials

International Nuclear Information System (INIS)

Kuligin, V.M.; Zdorova, Eh.P.; Popova, N.N.; Rakovskij, Eh.V.

1976-01-01

Gold is concentrated in 0.1-1.0 g of a lead alloy obtained in fire assay and cupellation and can be used for the analysis of a number of geological samples. The procedure makes it possible to determine gold with a limit of detection of 0.02 g/ton from a representative sample of 50-100 g. The use of lead acetate ensures the limit of detection of 0.002 g/ton, the relative standard deviation being greater than 0.01

Silver, gold, and alloyed silver-gold nanoparticles: characterization and comparative cell-biologic action

Energy Technology Data Exchange (ETDEWEB)

Mahl, Dirk; Diendorf, Joerg; Ristig, Simon [University of Duisburg-Essen, Department of Inorganic Chemistry, Center for Nanointegration Duisburg-Essen (CeNIDE) (Germany); Greulich, Christina [Ruhr-University of Bochum, Bergmannsheil University Hospital/Surgical Research (Germany); Li Zian; Farle, Michael [University of Duisburg-Essen, Faculty of Physics, Center for Nanointegration Duisburg-Essen (CeNIDE) (Germany); Koeller, Manfred [Ruhr-University of Bochum, Bergmannsheil University Hospital/Surgical Research (Germany); Epple, Matthias, E-mail: matthias.epple@uni-due.de [University of Duisburg-Essen, Department of Inorganic Chemistry, Center for Nanointegration Duisburg-Essen (CeNIDE) (Germany)

2012-10-15

Silver, gold, and silver-gold-alloy nanoparticles were prepared by citrate reduction modified by the addition of tannin during the synthesis, leading to a reduction in particle size by a factor of three. Nanoparticles can be prepared by this easy water-based synthesis and subsequently functionalized by the addition of either tris(3-sulfonatophenyl)phosphine or poly(N-vinylpyrrolidone). The resulting nanoparticles of silver (diameter 15-25 nm), gold (5-6 nm), and silver-gold (50:50; 10-12 nm) were easily dispersable in water and also in cell culture media (RPMI + 10 % fetal calf serum), as shown by nanoparticle tracking analysis and differential centrifugal sedimentation. High-resolution transmission electron microscopy showed a polycrystalline nature of all nanoparticles. EDX on single silver-gold nanoparticles indicated that the concentration of gold is higher inside a nanoparticle. The biologic action of the nanoparticles toward human mesenchymal stem cells (hMSC) was different: Silver nanoparticles showed a significant concentration-dependent influence on the viability of hMSC. Gold nanoparticles showed only a small effect on the viability of hMSC after 7 days. Surprisingly, silver-gold nanoparticles had no significant influence on the viability of hMSC despite the silver content. Silver nanoparticles and silver-gold nanoparticles in the concentration range of 5-20 {mu}g mL{sup -1} induced the activation of hMSC as indicated by the release of IL-8. In contrast, gold nanoparticles led to a reduction of the release of IL-6 and IL-8.

Silver, gold, and alloyed silver–gold nanoparticles: characterization and comparative cell-biologic action

International Nuclear Information System (INIS)

Mahl, Dirk; Diendorf, Jörg; Ristig, Simon; Greulich, Christina; Li Zian; Farle, Michael; Köller, Manfred; Epple, Matthias

2012-01-01

Silver, gold, and silver–gold-alloy nanoparticles were prepared by citrate reduction modified by the addition of tannin during the synthesis, leading to a reduction in particle size by a factor of three. Nanoparticles can be prepared by this easy water-based synthesis and subsequently functionalized by the addition of either tris(3-sulfonatophenyl)phosphine or poly(N-vinylpyrrolidone). The resulting nanoparticles of silver (diameter 15–25 nm), gold (5–6 nm), and silver–gold (50:50; 10–12 nm) were easily dispersable in water and also in cell culture media (RPMI + 10 % fetal calf serum), as shown by nanoparticle tracking analysis and differential centrifugal sedimentation. High-resolution transmission electron microscopy showed a polycrystalline nature of all nanoparticles. EDX on single silver–gold nanoparticles indicated that the concentration of gold is higher inside a nanoparticle. The biologic action of the nanoparticles toward human mesenchymal stem cells (hMSC) was different: Silver nanoparticles showed a significant concentration-dependent influence on the viability of hMSC. Gold nanoparticles showed only a small effect on the viability of hMSC after 7 days. Surprisingly, silver–gold nanoparticles had no significant influence on the viability of hMSC despite the silver content. Silver nanoparticles and silver–gold nanoparticles in the concentration range of 5–20 μg mL −1 induced the activation of hMSC as indicated by the release of IL-8. In contrast, gold nanoparticles led to a reduction of the release of IL-6 and IL-8.

Immense random colocalization, revealed by automated high content image cytometry, seriously questions FISH as gold standard for detecting EML4-ALK fusion.

Science.gov (United States)

Smuk, Gábor; Tornóczky, Tamás; Pajor, László; Chudoba, Ilse; Kajtár, Béla; Sárosi, Veronika; Pajor, Gábor

2018-05-19

EML4-ALK gene fusion (inv2(p21p23)) of non-small cell lung cancer (NSCLC) predisposes to tyrosine kinase inhibitor treatment. One of the gold standard diagnostics is the dual color (DC) break-apart (BA) FISH technique, however, the unusual closeness of the involved genes has been suggested to raise likelihood of random co-localization (RCL) of signals. Although this is suspected to decrease sensitivity (often to as low as 40-70%), the exact level and effect of RCL has not been revealed thus far. Signal distances were analyzed to the 0.1 µm precision in more than 25,000 nuclei, via automated high content-image cytometry. Negative and positive controls were created using conventional DC BA-, and inv2(p21p23) mimicking probe-sets, respectively. Average distance between red and green signals was 9.72 pixels (px) (±5.14px) and 3.28px (±2.44px), in positives and negatives, respectively; overlap in distribution being 41%. Specificity and sensitivity of correctly determining ALK status was 97% and 29%, respectively. When investigating inv2(p21p23) with DC BA FISH, specificity is high, but seven out of ten aberrant nuclei are inevitably falsely classified as negative, due to the extreme level of RCL. Together with genetic heterogeneity and dilution effect of non-tumor cells in NSCLC, this immense analytical false negativity is the primary cause behind the often described low diagnostic sensitivity. These results convincingly suggest that if FISH is to remain a gold standard for detecting the therapy relevant inv(2), either a modified evaluation protocol, or a more reliable probe-design should be considered than the current DC BA one. © 2018 International Society for Advancement of Cytometry. © 2018 International Society for Advancement of Cytometry.

Performances of Four Helicobacter pylori Serological Detection Kits Using Stool Antigen Test as Gold Standard.

Directory of Open Access Journals (Sweden)

Susheela D Biranjia-Hurdoyal

Full Text Available The aim was to determine the performances of four Helicobacter pylori serological detection kits in different target groups, using Amplified IDEIA™ Hp StAR™ as gold standard. Kits studied were Rapid Immunochromatoghraphic Hexagon, Helicoblot 2.1, an EIA IgG kit and EIA IgA kit.Stool and blood samples were collected from 162 apparently healthy participants (control and 60 Type 2 diabetes mellitus (T2DM patients.The performances of the four serological detection kits were found to be affected by gender, age, health status and ethnicity of the participants. In the control group, the Helicoblot 2.1 kit had the best performance (AUC = 0.85; p<0.05, accuracy = 86.4%, followed by EIA IgG (AUC = 0.75; p<0.05, accuracy = 75.2%. The Rapid Hexagon and EIA IgA kits had relatively poor performances. In the T2DM subgroup, the kits H2.1 and EIA IgG had best performances, with accuracies of 96.5% and 93.1% respectively. The performance of EIA IgG improved with adjustment of its cut-off value.The performances of the detection kits were affected by various factors which should be taken into consideration.

The need for European professional standards and the challenges facing clinical microbiology.

Science.gov (United States)

Humphreys, H; Nagy, E; Kahlmeter, G; Ruijs, G J H M

2010-06-01

Microorganisms spread across national boundaries and the professional activities of clinical (medical) microbiologists are critical in minimising their impact. Clinical microbiologists participate in many activities, e.g. diagnosis, antibiotic therapy, and there is a need for a set of professional standards for Europe with a common curriculum, to build upon the current strengths of the specialty and to facilitate the free movement of specialists within the European Union. Such standards will also better highlight the important contribution of clinical microbiologists to healthcare. There is a move to larger centralised microbiology laboratories often located off-site from an acute hospital, driven by the concentration of resources, amalgamation of services, outsourcing of diagnostics, automation, an explosion in the range of staff competencies and accreditation. Large off-site centralised microbiology laboratories are often distant to the patient and may not facilitate the early detection of microbial spread. Ultimately, the needs of patients and the public are paramount in deciding on the future direction of clinical microbiology. Potential conflicts between integration on an acute hospital site and centralisation can be resolved by a common set of professional standards and a team-based approach that puts patients first.

A review of standardized patients in clinical education: Implications for speech-language pathology programs.

Science.gov (United States)

Hill, Anne E; Davidson, Bronwyn J; Theodoros, Deborah G

2010-06-01

The use of standardized patients has been reported as a viable addition to traditional models of professional practice education in medicine, nursing and allied health programs. Educational programs rely on the inclusion of work-integrated learning components in order to graduate competent practitioners. Allied health programs world-wide have reported increasing difficulty in attaining sufficient traditional placements for students within the workplace. In response to this, allied health professionals are challenged to be innovative and problem-solving in the development and maintenance of clinical education placements and to consider potential alternative learning opportunities for students. Whilst there is a bank of literature describing the use of standardized patients in medicine and nursing, reports of its use in speech-language pathology clinical education are limited. Therefore, this paper aims to (1) provide a review of literature reporting on the use of standardized patients within medical and allied health professions with particular reference to use in speech-language pathology, (2) discuss methodological and practical issues involved in establishing and maintaining a standardized patient program and (3) identify future directions for research and clinical programs using standardized patients to build foundation clinical skills such as communication, interpersonal interaction and interviewing.

For the love of gold

International Nuclear Information System (INIS)

Young, J.E.

1993-01-01

Gold is found in minute quantities and gold mining generates enormous amounts of waste materials and long history of environmental destruction: mercury in tailing, eroded land, and acid mine drainage are legacies of the past. The problem has become worse in recent years in North America, Australia, the Amazon basin, Philippines. This paper describes the economics of gold and the changes in the world economy which has precipitated the new gold rushes. Current technology uses a cyanide solution for leaching small amounts of gold from tons of waste, and mercury remains a toxic waste of gold mining. Both short and long term results of gold mining, on the environment and on indiginous populations are described

Moving metal artifact reduction in cone-beam CT scans with implanted cylindrical gold markers

International Nuclear Information System (INIS)

Toftegaard, Jakob; Fledelius, Walther; Worm, Esben S.; Poulsen, Per R.; Seghers, Dieter; Huber, Michael; Brehm, Marcus; Elstrøm, Ulrik V.

2014-01-01

Purpose: Implanted gold markers for image-guided radiotherapy lead to streaking artifacts in cone-beam CT (CBCT) scans. Several methods for metal artifact reduction (MAR) have been published, but they all fail in scans with large motion. Here the authors propose and investigate a method for automatic moving metal artifact reduction (MMAR) in CBCT scans with cylindrical gold markers. Methods: The MMAR CBCT reconstruction method has six steps. (1) Automatic segmentation of the cylindrical markers in the CBCT projections. (2) Removal of each marker in the projections by replacing the pixels within a masked area with interpolated values. (3) Reconstruction of a marker-free CBCT volume from the manipulated CBCT projections. (4) Reconstruction of a standard CBCT volume with metal artifacts from the original CBCT projections. (5) Estimation of the three-dimensional (3D) trajectory during CBCT acquisition for each marker based on the segmentation in Step 1, and identification of the smallest ellipsoidal volume that encompasses 95% of the visited 3D positions. (6) Generation of the final MMAR CBCT reconstruction from the marker-free CBCT volume of Step 3 by replacing the voxels in the 95% ellipsoid with the corresponding voxels of the standard CBCT volume of Step 4. The MMAR reconstruction was performed retrospectively using a half-fan CBCT scan for 29 consecutive stereotactic body radiation therapy patients with 2–3 gold markers implanted in the liver. The metal artifacts of the MMAR reconstructions were scored and compared with a standard MAR reconstruction by counting the streaks and by calculating the standard deviation of the Hounsfield units in a region around each marker. Results: The markers were found with the same autosegmentation settings in 27 CBCT scans, while two scans needed slightly changed settings to find all markers automatically in Step 1 of the MMAR method. MMAR resulted in 15 scans with no streaking artifacts, 11 scans with 1–4 streaks, and 3 scans

Frontiers in Gold Chemistry

OpenAIRE

Ahmed A. Mohamed

2015-01-01

Basic chemistry of gold tells us that it can bond to sulfur, phosphorous, nitrogen, and oxygen donor ligands. The Frontiers in Gold Chemistry Special Issue covers gold complexes bonded to the different donors and their fascinating applications. This issue covers both basic chemistry studies of gold complexes and their contemporary applications in medicine, materials chemistry, and optical sensors. There is a strong belief that aurophilicity plays a major role in the unending applications of g...

Non-standard patch test

Directory of Open Access Journals (Sweden)

Astri Adelia

2018-06-01

Full Text Available In managing contact dermatitis, identification of the causative agent is essential to prevent recurrent complaints. Patch test is the gold standard to identify the causative agent. Nowadays, there are many patch test standard materials available in the market, but do not include all the materials that potentially cause contact dermatitis. Patch test using patient’s own products or later we refer to as non-standard materials, is very helpful in identifying the causative agents of contact dermatitis. Guidance is needed in producing non-standard patch test materials in order to avoid test results discrepancy.

Applicability Evaluation of Job Standards for Diabetes Nutritional Management by Clinical Dietitian.

Science.gov (United States)

Baek, Young Jin; Oh, Na Gyeong; Sohn, Cheong-Min; Woo, Mi-Hye; Lee, Seung Min; Ju, Dal Lae; Seo, Jung-Sook

2017-04-01

This study was conducted to evaluate applicability of job standards for diabetes nutrition management by hospital clinical dietitians. In order to promote the clinical nutrition services, it is necessary to present job standards of clinical dietitian and to actively apply these standardized tasks to the medical institution sites. The job standard of clinical dietitians for diabetic nutrition management was distributed to hospitals over 300 beds. Questionnaire was collected from 96 clinical dietitians of 40 tertiary hospitals, 47 general hospitals, and 9 hospitals. Based on each 5-point scale, the importance of overall duty was 4.4 ± 0.5, performance was 3.6 ± 0.8, and difficulty was 3.1 ± 0.7. 'Nutrition intervention' was 4.5 ± 0.5 for task importance, 'nutrition assessment' was 4.0 ± 0.7 for performance, and 'nutrition diagnosis' was 3.4 ± 0.9 for difficulty. These 3 items were high in each category. Based on the grid diagram, the tasks of both high importance and high performance were 'checking basic information,' 'checking medical history and therapy plan,' 'decision of nutritional needs,' 'supply of foods and nutrients,' and 'education of nutrition and self-management.' The tasks with high importance but low performance were 'derivation of nutrition diagnosis,' 'planning of nutrition intervention,' 'monitoring of nutrition intervention process.' The tasks of both high importance and high difficulty were 'derivation of nutrition diagnosis,' 'planning of nutrition intervention,' 'supply of foods and nutrients,' 'education of nutrition and self-management,' and 'monitoring of nutrition intervention process.' The tasks of both high performance and high difficulty were 'documentation of nutrition assessment,' 'supply of foods and nutrients,' and 'education of nutrition and self-management.'

Gold removal rate by ion sputtering as a function of ion-beam voltage and raster size using Auger electron spectroscopy. Final report

International Nuclear Information System (INIS)

Boehning, C.W.

1983-01-01

Gold removal rate was measured as a function of ion beam voltage and raster size using Auger electron spectroscopy (AES). Three different gold thicknesses were developed as standards. Two sputter rate calibration curves were generated by which gold sputter rate could be determined for variations in ion beam voltage or raster size

Gold clusters sliding on graphite: a possible quartz crystal microbalance experiment?

International Nuclear Information System (INIS)

Pisov, S; Tosatti, E; Tartaglino, U; Vanossi, A

2007-01-01

A large measured two-dimensional (2D) diffusion coefficient of gold nanoclusters on graphite has been known experimentally and theoretically for about a decade. When subjected to a lateral force, these clusters should slide with an amount of friction that can be measured. We examine the hypothetical possibility of measuring by quartz crystal microbalance (QCM) the phononic sliding friction of gold clusters in the size range around 250 atoms on a graphite substrate between 300 and 600 K. Assuming the validity of Einstein's relations of ordinary Brownian motion and making use of the experimentally available activated behaviour of the diffusion coefficients, we can predict the sliding friction and slip times as a function of temperature. It is found that a prototypical deposited gold cluster could yield slip times at the standard measurable size of 10 -9 s for temperatures around 450-500 K, or 200 0 C. Since gold nanoclusters may also melt at around these temperatures, QCM could offer the additional chance of observing this phenomenon through a frictional change

Effects of soldering methods on tensile strength of a gold-palladium metal ceramic alloy.

Science.gov (United States)

Ghadhanfari, Husain A; Khajah, Hasan M; Monaco, Edward A; Kim, Hyeongil

2014-10-01

The tensile strength obtained by conventional postceramic application soldering and laser postceramic welding may require more energy than microwave postceramic soldering, which could provide similar tensile strength values. The purpose of the study was to compare the tensile strength obtained by microwave postceramic soldering, conventional postceramic soldering, and laser postceramic welding. A gold-palladium metal ceramic alloy and gold-based solder were used in this study. Twenty-seven wax specimens were cast in gold-palladium noble metal and divided into 4 groups: laser welding with a specific postfiller noble metal, microwave soldering with a postceramic solder, conventional soldering with the same postceramic solder used in the microwave soldering group, and a nonsectioned control group. All the specimens were heat treated to simulate a normal porcelain sintering sequence. An Instron Universal Testing Machine was used to measure the tensile strength for the 4 groups. The means were analyzed statistically with 1-way ANOVA. The surface and fracture sites of the specimens were subjectively evaluated for fracture type and porosities by using a scanning electron microscope. The mean (standard deviation) ultimate tensile strength values were as follows: nonsectioned control 818 ±30 MPa, microwave 516 ±34 MPa, conventional 454 ±37 MPa, and laser weld 191 ±39 MPa. A 1-way ANOVA showed a significant difference in ultimate tensile strength among the groups (F3,23=334.5; Ptensile strength for gold and palladium noble metals than either conventional soldering or laser welding. Conventional soldering resulted in a higher tensile strength than laser welding. Under the experimental conditions described, either microwave or conventional postceramic soldering would appear to satisfy clinical requirements related to tensile strength. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

The Genomes OnLine Database (GOLD) v.5: a metadata management system based on a four level (meta)genome project classification

Science.gov (United States)

Reddy, T.B.K.; Thomas, Alex D.; Stamatis, Dimitri; Bertsch, Jon; Isbandi, Michelle; Jansson, Jakob; Mallajosyula, Jyothi; Pagani, Ioanna; Lobos, Elizabeth A.; Kyrpides, Nikos C.

2015-01-01

The Genomes OnLine Database (GOLD; http://www.genomesonline.org) is a comprehensive online resource to catalog and monitor genetic studies worldwide. GOLD provides up-to-date status on complete and ongoing sequencing projects along with a broad array of curated metadata. Here we report version 5 (v.5) of the database. The newly designed database schema and web user interface supports several new features including the implementation of a four level (meta)genome project classification system and a simplified intuitive web interface to access reports and launch search tools. The database currently hosts information for about 19 200 studies, 56 000 Biosamples, 56 000 sequencing projects and 39 400 analysis projects. More than just a catalog of worldwide genome projects, GOLD is a manually curated, quality-controlled metadata warehouse. The problems encountered in integrating disparate and varying quality data into GOLD are briefly highlighted. GOLD fully supports and follows the Genomic Standards Consortium (GSC) Minimum Information standards. PMID:25348402

The Genomes OnLine Database (GOLD) v.5: a metadata management system based on a four level (meta)genome project classification

Energy Technology Data Exchange (ETDEWEB)

Reddy, Tatiparthi B. K. [USDOE Joint Genome Institute (JGI), Walnut Creek, CA (United States); Thomas, Alex D. [USDOE Joint Genome Institute (JGI), Walnut Creek, CA (United States); Stamatis, Dimitri [USDOE Joint Genome Institute (JGI), Walnut Creek, CA (United States); Bertsch, Jon [USDOE Joint Genome Institute (JGI), Walnut Creek, CA (United States); Isbandi, Michelle [USDOE Joint Genome Institute (JGI), Walnut Creek, CA (United States); Jansson, Jakob [USDOE Joint Genome Institute (JGI), Walnut Creek, CA (United States); Mallajosyula, Jyothi [USDOE Joint Genome Institute (JGI), Walnut Creek, CA (United States); Pagani, Ioanna [USDOE Joint Genome Institute (JGI), Walnut Creek, CA (United States); Lobos, Elizabeth A. [USDOE Joint Genome Institute (JGI), Walnut Creek, CA (United States); Kyrpides, Nikos C. [USDOE Joint Genome Institute (JGI), Walnut Creek, CA (United States); King Abdulaziz Univ., Jeddah (Saudi Arabia)

2014-10-27

The Genomes OnLine Database (GOLD; http://www.genomesonline.org) is a comprehensive online resource to catalog and monitor genetic studies worldwide. GOLD provides up-to-date status on complete and ongoing sequencing projects along with a broad array of curated metadata. Within this paper, we report version 5 (v.5) of the database. The newly designed database schema and web user interface supports several new features including the implementation of a four level (meta)genome project classification system and a simplified intuitive web interface to access reports and launch search tools. The database currently hosts information for about 19 200 studies, 56 000 Biosamples, 56 000 sequencing projects and 39 400 analysis projects. More than just a catalog of worldwide genome projects, GOLD is a manually curated, quality-controlled metadata warehouse. The problems encountered in integrating disparate and varying quality data into GOLD are briefly highlighted. Lastly, GOLD fully supports and follows the Genomic Standards Consortium (GSC) Minimum Information standards.

Direct formation of gold nanorods on surfaces using polymer-immobilised gold seeds

Directory of Open Access Journals (Sweden)

Majid K. Abyaneh

2016-06-01

Full Text Available Herein, we present the formation of gold nanorods (GNRs on novel gold–poly(methyl methacrylate (Au–PMMA nanocomposite substrates with unprecedented growth control through the polymer molecular weight (Mw and gold-salt-to-polymer weight ratio. For the first time, GNRs have been produced by seed-mediated direct growth on surfaces that were pre-coated with polymer-immobilised gold seeds. A Au–PMMA nanocomposite formed by UV photoreduction has been used as the gold seed. The influence of polymer Mw and gold concentration on the formation of GNRs has been investigated and discussed. The polymer nanocomposite formed with a lower Mw PMMA and 20 wt % gold salt provides a suitable medium for growing well-dispersed GNRs. In this sample, the average dimension of produced GNRs is 200 nm in length with aspect ratios up to 10 and a distribution of GNRs to nanoparticles of nearly 22%. Suitable characterization techniques such as AFM and SEM have been used to support concept of the proposed growth method.

Moessbauerspectroscopy on Gold Ruby Glass

International Nuclear Information System (INIS)

Haslbeck, S.

2005-01-01

In this thesis, the chemical states of gold and the physical mechanisms of the growing process of the particles under the influence of additional ingredients like tin, lead, antimony and selenium before, during and after the colouring process are investigated by using the Moessbauer spectroscopy on 197 Au, 119 Sn and 121 Sb, optical spectroscopy and X-ray-diffraction. Gold in an unnealed, colourless state of the glasses consists of monovalent forming linear bonds to two neighbouring oxygen atoms. The Lamb-Moessbauer factor of these gold oxide bondings is observed as 0.095 at 4.2 K. The gold in it's oxide state transforms to gold particles with a diameter of 3 nm to 60 nm. The size of the gold particles is quite definable within the optical spectra and certain sizes are also discernable within the Moessbauer spectra. One component of the Moessbauer spectra is assigned to the surface layer of the gold particles. By comparing this surface component with the amount of the bulk metallic core, one can calculate the size of the gold particles. In the Moessbauer spectra of the colourless glass one also can find parts of bulk metallic gold. Investigations with X-ray diffraction show that these are gold particles with a diameter of 100 nm to 300 nm and therefore have no additional colouring effect within the visible spectrum. The Moessbauer spectra on gold of the remelt glasses are similar to those which have been measured on the initial colourless glasses

Aluminium-gold reference material for the k0-standardisation of neutron activation analysis

International Nuclear Information System (INIS)

Ingelbrecht, C.; Peetermans, F.; Corte, F. de; Wispelaere, A. de; Vandecasteele, C.; Courtijn, E.; Hondt, P. d'

1991-01-01

Gold is an excellent comparator material for the k 0 -standardisation of neutron activation analysis because of its convenient and well defined nuclear properties. The most suitable form for a reference material is a dilute aluminium-gold alloy, for which the self-shielding effect for neutrons is small. Castings of composition Al-0.1 wt.% Au were prepared by crucible-less levitation melting, which gives close control of ingot composition with minimal contamination of the melt. The alloy composition was checked using induction-coupled plasma source emission spectrometry. The homogeneity of the alloy was measured by neutron activation analysis and a relative standard deviation of the gold content of 0.30% was found (10 mg samples). Metallography revealed a homogeneous distribution of AuAl 2 particles. The alloy was certified as Reference Materials CBNM-530, with certified gold mass fraction 0.100±0.002 wt.%. (orig.)

Immunological properties of gold nanoparticles.

Science.gov (United States)

Dykman, Lev A; Khlebtsov, Nikolai G

2017-03-01

In the past decade, gold nanoparticles have attracted strong interest from the nanobiotechnological community owing to the significant progress made in robust and easy-to-make synthesis technologies, in surface functionalization, and in promising biomedical applications. These include bioimaging, gene diagnostics, analytical sensing, photothermal treatment of tumors, and targeted delivery of various biomolecular and chemical cargos. For the last-named application, gold nanoparticles should be properly fabricated to deliver the cargo into the targeted cells through effective endocytosis. In this review, we discuss recent progress in understanding the selective penetration of gold nanoparticles into immune cells. The interaction of gold nanoparticles with immune cell receptors is discussed. As distinct from other published reviews, we present a summary of the immunological properties of gold nanoparticles. This review also summarizes what is known about the application of gold nanoparticles as an antigen carrier and adjuvant in immunization for the preparation of antibodies in vivo . For each of the above topics, the basic principles, recent advances, and current challenges are discussed. Thus, this review presents a detailed analysis of data on interaction of gold nanoparticles with immune cells. Emphasis is placed on the systematization of data over production of antibodies by using gold nanoparticles and adjuvant properties of gold nanoparticles. Specifically, we start our discussion with current data on interaction of various gold nanoparticles with immune cells. The next section describes existing technologies to improve production of antibodies in vivo by using gold nanoparticles conjugated with specific ligands. Finally, we describe what is known about adjuvant properties of bare gold or functionalized nanoparticles. In the Conclusion section, we present a short summary of reported data and some challenges and perspectives.

Measurement of the isotope effect of the diffusion of silver and gold in gold and of silver in silver-gold alloys

International Nuclear Information System (INIS)

Wolter, D.

1974-01-01

The silver isotopes Ag 105 and Agsup(110m) and the gold isotopes Au 195 and Au 199 were used for isotope effect measurements. The isotope effect of the gold self-diffusion was measured on four monocrystals samples at about 850 0 C, that of silver in gold monocrystals at five different temperatures between 731 0 C and 1050 0 C. Furthermore, the isotope effect for silver at 904 0 C was measured on seven silver-gold alloys of varying silver concentration. The correlation factor was determined from the measurements. (HPOE/LH) [de

The giant Jiaodong gold province: The key to a unified model for orogenic gold deposits?

Directory of Open Access Journals (Sweden)

David I. Groves

2016-05-01

Full Text Available Although the term orogenic gold deposit has been widely accepted for all gold-only lode-gold deposits, with the exception of Carlin-type deposits and rare intrusion-related gold systems, there has been continuing debate on their genesis. Early syngenetic models and hydrothermal models dominated by meteoric fluids are now clearly unacceptable. Magmatic-hydrothermal models fail to explain the genesis of orogenic gold deposits because of the lack of consistent spatially – associated granitic intrusions and inconsistent temporal relationships. The most plausible, and widely accepted, models involve metamorphic fluids, but the source of these fluids is hotly debated. Sources within deeper segments of the supracrustal successions hosting the deposits, the underlying continental crust, and subducted oceanic lithosphere and its overlying sediment wedge all have their proponents. The orogenic gold deposits of the giant Jiaodong gold province of China, in the delaminated North China Craton, contain ca. 120 Ma gold deposits in Precambrian crust that was metamorphosed over 2000 million years prior to gold mineralization. The only realistic source of fluid and gold is a subducted oceanic slab with its overlying sulfide-rich sedimentary package, or the associated mantle wedge. This could be viewed as an exception to a general metamorphic model where orogenic gold has been derived during greenschist- to amphibolite-facies metamorphism of supracrustal rocks: basaltic rocks in the Precambrian and sedimentary rocks in the Phanerozoic. Alternatively, if a holistic view is taken, Jiaodong can be considered the key orogenic gold province for a unified model in which gold is derived from late-orogenic metamorphic devolatilization of stalled subduction slabs and oceanic sediments throughout Earth history. The latter model satisfies all geological, geochronological, isotopic and geochemical constraints but the precise mechanisms of auriferous fluid release, like many

Using Hashimoto thyroiditis as gold standard to determine the upper limit value of thyroid stimulating hormone in a Chinese cohort.

Science.gov (United States)

Li, Yu; Chen, Dong-Ning; Cui, Jing; Xin, Zhong; Yang, Guang-Ran; Niu, Ming-Jia; Yang, Jin-Kui

2016-11-06

Subclinical hypothyroidism, commonly caused by Hashimoto thyroiditis (HT), is a risk factor for cardiovascular diseases. This disorder is defined as merely having elevated serum thyroid stimulating hormone (TSH) levels. However, the upper limit of reference range for TSH is debated recently. This study was to determine the cutoff value for the upper normal limit of TSH in a cohort using the prevalence of Hashimoto thyroiditis as "gold" calibration standard. The research population was medical staff of 2856 individuals who took part in health examination annually. Serum free triiodothyronine (FT3), free thyroxine (FT4), TSH, thyroid peroxidase antibody (TPAb), thyroglobulin antibody (TGAb) and other biochemistry parameters were tested. Meanwhile, thyroid ultrasound examination was performed. The diagnosis of HT was based on presence of thyroid antibodies (TPAb and TGAb) and abnormalities of thyroid ultrasound examination. We used two different methods to estimate the cutoff point of TSH based on the prevalence of HT. Joinpoint regression showed the prevalence of HT increased significantly at the ninth decile of TSH value corresponding to 2.9 mU/L. ROC curve showed a TSH cutoff value of 2.6 mU/L with the maximized sensitivity and specificity in identifying HT. Using the newly defined cutoff value of TSH can detect patients with hyperlipidemia more efficiently, which may indicate our approach to define the upper limit of TSH can make more sense from the clinical point of view. A significant increase in the prevalence of HT occurred among individuals with a TSH of 2.6-2.9 mU/L made it possible to determine the cutoff value of normal upper limit of TSH.

Facts and Fantasies about Gold

OpenAIRE

Klement, Joachim

2015-01-01

Due to the increasing popularity of gold as an investment the demand for effective risk management techniques for gold investments has increased as well. In this paper we analyze several drivers of the price of gold that have been proposed in the past. Our analysis indicates that short-term volatility of the price of gold remains rather unpredictable with many of the explanations like the fund flows in physical gold ETF either unreliable or unstable over time. Our analysis suggests that there...

The Bland-Altman analysis: Does it have a role in assessing radiation dosimeter performance relative to an established standard?

International Nuclear Information System (INIS)

Hill, R.F.; Tofts, P.S.; Baldock, C.

2010-01-01

Bland-Altman analysis is used to compare two different methods of measurement and to determine whether a new method of measurement may replace an existing accepted 'gold standard' method. In this work, Bland-Altman analysis has been applied to radiation dosimetry to compare the PTW Markus and Roos parallel plate ionisation chambers and a PTW PinPoint chamber against a Farmer type ionisation chamber which is accepted as the gold standard for radiation dosimetry in the clinic. Depth doses for low energy x-rays beams with energies of 50, 75 and 100 kVp were measured using each of the ionisation chambers. Depth doses were also calculated by interpolation of the data in the British Journal of Radiology (BJR) Report 25. From the Bland-Altman analysis, the mean dose difference between the two parallel plate chambers and the Farmer chambers was 1% over the range of depths measured. The PinPoint chamber gave significant dose differences compared to the Farmer chamber. There were also differences of up to 12% between the BJR Report 25 depth doses and the measured data. For the Bland-Altman plots, the lines representing the limits of agreement were selected to be a particular percentage agreement e.g. 1 or 2%, instead of being based on the standard deviation (σ) of the differences. The Bland-Altman statistical analysis is a powerful tool for making comparisons of ionisation chambers with an ionisation chamber that has been accepted as a 'gold standard'. Therefore we conclude that Bland-Altman analysis does have a role in assessing radiation dosimeter performance relative to an established standard.

Occurrences of dendritic gold at the McLaughlin Mine hot-spring gold deposit

Science.gov (United States)

Sherlock, R. L.; Lehrman, N. J.

1995-06-01

Two styles of gold dendrites are variably developed at the McLaughlin Mine. The most abundant occurrence is hosted by amber-coloured hydrocarbon-rich opal. Silica likely precipitated from a boiling hydrothermal fluid and complexed with immiscible hydrocarbons forming an amorphous hydrocarbon-silica phase. This phase likely scavenged particulate gold by electrostatic attraction to the hydrocarbon-silica phase. The dendritic nature of the gold is secondary and is the result of dewatering of the amorphous hydrocarbon-silica phase and crystallization of gold into syneresis fractures. The second style of dendritic gold is hosted within vein swarms that focused large volumes of fluid flow. The dendrites occur along with hydrocarbon-rich silica at the upper contact of the vein margins which isolated the dendrites allowing sufficient time for them to grow. In a manner similar to the amber-coloured opal, the dendrites may have formed by scavenging particulate gold by electrostatic attraction to the hydrocarbon-silica phase.

Electrocatalytic glucose oxidation at gold and gold-carbon nanoparticulate film prepared from oppositely charged nanoparticles

International Nuclear Information System (INIS)

Karczmarczyk, Aleksandra; Celebanska, Anna; Nogala, Wojciech; Sashuk, Volodymyr; Chernyaeva, Olga; Opallo, Marcin

2014-01-01

Graphical abstract: - Highlights: • Gold nanoparticulate film electrodes were prepared by layer-by-layer method from oppositely charged nanoparticles. • Positively charged nanoparticles play dominant role in glucose oxidation in alkaline solution. • Gold and gold-carbon nanoparticulate film electrodes exhibit similar glucose oxidation current and onset potential. - Abstract: Electrocatalytic oxidation of glucose was studied at nanoparticulate gold and gold-carbon film electrodes. These electrodes were prepared by a layer-by-layer method without application of any linker molecules. Gold nanoparticles were stabilized by undecane thiols functionalized by trimethyl ammonium or carboxylate groups, whereas the carbon nanoparticles were covered by phenylsulfonate functionalities. The gold nanoparticulate electrodes were characterized by UV-vis and XPS spectroscopy, atomic force microscopy and voltammetry, before and after heat-treatment. Heat-treatment facilitates the aggregation of the nanoparticles and affects the structure of the film. The comparison of the results obtained with film electrodes prepared from gold nanoparticles with the same charge and with gold-carbon nanoparticulate electrodes, proved that positively charged nanoparticles are responsible for the high electrocatalytic activity, whereas negatively charged ones act rather as a linker of the film

Fact Sheet - Final Air Toxics Rule for Gold Mine Ore Processing and Production

Science.gov (United States)

Fact sheet summarizing main points of National Emissions Standards for Hazardous Air Pollutants for gold ore processing and production facilities, the seventh largest source of mercury air emission in the United States.

A non-diazo approach to α-oxo gold carbenes via gold-catalyzed alkyne oxidation.

Science.gov (United States)

Zhang, Liming

2014-03-18

For the past dozen years, homogeneous gold catalysis has evolved from a little known topic in organic synthesis to a fully blown research field of significant importance to synthetic practitioners, due to its novel reactivities and reaction modes. Cationic gold(I) complexes are powerful soft Lewis acids that can activate alkynes and allenes toward efficient attack by nucleophiles, leading to the generation of alkenyl gold intermediates. Some of the most versatile aspects of gold catalysis involve the generation of gold carbene intermediates, which occurs through the approach of an electrophile to the distal end of the alkenyl gold moiety, and their diverse transformations thereafter. On the other hand, α-oxo metal carbene/carbenoids are highly versatile intermediates in organic synthesis and can undergo various synthetically challenging yet highly valuable transformations such as C-H insertion, ylide formation, and cyclopropanation reactions. Metal-catalyzed dediazotizations of diazo carbonyl compounds are the principle and most reliable strategy to access them. Unfortunately, the substrates contain a highly energetic diazo moiety and are potentially explosive. Moreover, chemists need to use energetic reagents to prepare them, putting further constrains on operational safety. In this Account, we show that the unique access to the gold carbene species in homogeneous gold catalysis offers an opportunity to generate α-oxo gold carbenes if both nucleophile and electrophile are oxygen. Hence, this approach would enable readily available and safer alkynes to replace hazardous α-diazo carbonyl compounds as precursors in the realm of gold carbene chemistry. For the past several years, we have demonstrated that alkynes can indeed effectively serve as precursors to versatile α-oxo gold carbenes. In our initial study, we showed that a tethered sulfoxide can be a suitable oxidant, which in some cases leads to the formation of α-oxo gold carbene intermediates. The

A Non-Diazo Approach to α-Oxo Gold Carbenes via Gold-Catalyzed Alkyne Oxidation

Science.gov (United States)

2015-01-01

For the past dozen years, homogeneous gold catalysis has evolved from a little known topic in organic synthesis to a fully blown research field of significant importance to synthetic practitioners, due to its novel reactivities and reaction modes. Cationic gold(I) complexes are powerful soft Lewis acids that can activate alkynes and allenes toward efficient attack by nucleophiles, leading to the generation of alkenyl gold intermediates. Some of the most versatile aspects of gold catalysis involve the generation of gold carbene intermediates, which occurs through the approach of an electrophile to the distal end of the alkenyl gold moiety, and their diverse transformations thereafter. On the other hand, α-oxo metal carbene/carbenoids are highly versatile intermediates in organic synthesis and can undergo various synthetically challenging yet highly valuable transformations such as C–H insertion, ylide formation, and cyclopropanation reactions. Metal-catalyzed dediazotizations of diazo carbonyl compounds are the principle and most reliable strategy to access them. Unfortunately, the substrates contain a highly energetic diazo moiety and are potentially explosive. Moreover, chemists need to use energetic reagents to prepare them, putting further constrains on operational safety. In this Account, we show that the unique access to the gold carbene species in homogeneous gold catalysis offers an opportunity to generate α-oxo gold carbenes if both nucleophile and electrophile are oxygen. Hence, this approach would enable readily available and safer alkynes to replace hazardous α-diazo carbonyl compounds as precursors in the realm of gold carbene chemistry. For the past several years, we have demonstrated that alkynes can indeed effectively serve as precursors to versatile α-oxo gold carbenes. In our initial study, we showed that a tethered sulfoxide can be a suitable oxidant, which in some cases leads to the formation of α-oxo gold carbene intermediates. The

Surface-stabilized gold nanocatalysts

Science.gov (United States)

Dai, Sheng [Knoxville, TN; Yan, Wenfu [Oak Ridge, TN

2009-12-08

A surface-stabilized gold nanocatalyst includes a solid support having stabilizing surfaces for supporting gold nanoparticles, and a plurality of gold nanoparticles having an average particle size of less than 8 nm disposed on the stabilizing surfaces. The surface-stabilized gold nanocatalyst provides enhanced stability, such as at high temperature under oxygen containing environments. In one embodiment, the solid support is a multi-layer support comprising at least a first layer having a second layer providing the stabilizing surfaces disposed thereon, the first and second layer being chemically distinct.

Neurorestorative clinical application standards for the culture and quality control of olfactory ensheathing cells

Directory of Open Access Journals (Sweden)

Xiao J

2017-09-01

Full Text Available Juan Xiao,1,2 Lin Chen,3 Gengsheng Mao,1 Wenyong Gao,1,2 Ming Lu,4 Xijing He,5 Hongyun Huang1,2 On behalf of the Neurorestoratology Professional Committee of Chinese Medical Doctors Association (Chinese Association of Neurorestoratology 1Institute of Neurorestoratology, The General Hospital of Chinese People’s Armed Police Forces, Beijing, People’s Republic of China; 2Cell Therapy Center, Beijing Hongtianji Neuroscience Academy, Beijing, People’s Republic of China; 3Department of Neurosurgery, Tsinghua University Yuquan Hospital, Beijing, People’s Republic of China; 4Department of Neurosurgery, 163 Hospital of PLA (Second Affiliated Hospital of Hunan Normal University, Changsha, Hunan Province, People’s Republic of China; 5Department of Orthopedics, Second Affiliated Hospital of Xi’an Jiaotong University, Xian, Shanxi Provine, People’s Republic of China Abstract: Olfactory ensheathing cells (OECs are a novel type of glial cell that can perform and promote many neurorestorative processes in vivo after transplant. To date, dozens of preclinical and clinical studies have confirmed that OECs have unique restoring effects in animal models and human subjects with neurological degeneration or damage, such as spinal cord injury, stroke, cerebral palsy, traumatic brain injury, and motor neuron disease (amyotrophic lateral sclerosis. To ensure the safety and effectiveness of clinical applications utilizing this type of cell, it is important to standardize cell-culture and quality-control processes. Based on a comprehensive review of published clinical studies, as well as existing methods of OEC culture and quality control currently utilized by hospitals and biomedical enterprises, the Chinese Association of Neurorestoratology has developed a set of standards for the culture and quality control of olfactory ensheathing cells for use in clinical applications. These guidelines include standardized training and management procedures for

Preparation of gold nanoparticles and determination of their particles size via different methods

International Nuclear Information System (INIS)

Iqbal, Muhammad; Usanase, Gisele; Oulmi, Kafia; Aberkane, Fairouz; Bendaikha, Tahar; Fessi, Hatem; Zine, Nadia; Agusti, Géraldine; Errachid, El-Salhi; Elaissari, Abdelhamid

2016-01-01

Graphical abstract: Preparation of gold nanoparticles via NaBH_4 reduction method, and determination of their particle size, size distribution and morphology by using different techniques. - Highlights: • Gold nanoparticles were synthesized by NaBH_4 reduction method. • Excess of reducing agent leads to tendency of aggregation. • The particle size, size distribution and morphology were investigated. • Particle size was determined both experimentally as well as theoretically. - Abstract: Gold nanoparticles have been used in various applications covering both electronics, biosensors, in vivo biomedical imaging and in vitro biomedical diagnosis. As a general requirement, gold nanoparticles should be prepared in large scale, easy to be functionalized by chemical compound of by specific ligands or biomolecules. In this study, gold nanoparticles were prepared by using different concentrations of reducing agent (NaBH_4) in various formulations and their effect on the particle size, size distribution and morphology was investigated. Moreover, special attention has been dedicated to comparison of particles size measured by various techniques, such as, light scattering, transmission electron microscopy, UV spectrum using standard curve and particles size calculated by using Mie theory and UV spectrum of gold nanoparticles dispersion. Particle size determined by various techniques can be correlated for monodispersed particles and excess of reducing agent leads to increase in the particle size.

A halogen-free synthesis of gold nanoparticles using gold(III) oxide

International Nuclear Information System (INIS)

Sashuk, Volodymyr; Rogaczewski, Konrad

2016-01-01

Gold nanoparticles are one of the most used nanomaterials. They are usually synthesized by the reduction of gold(III) chloride. However, the presence of halide ions in the reaction mixture is not always welcome. In some cases, these ions have detrimental influence on the morphology and structure of resulting nanoparticles. Here, we present a simple and halogen-free procedure to prepare gold nanoparticles by reduction of gold(III) oxide in neat oleylamine. The method provides the particles with an average size below 10 nm and dispersity of tens of percent. The process of nanoparticle formation was monitored using UV–Vis spectroscopy. The structure and chemical composition of the nanoparticles was determined by SEM, XPS and EDX. We also proposed the mechanism of reduction of gold(III) oxide based on MS, IR and NMR data. Importantly, the synthetic protocol is general and applicable for the preparation of other coinage metal nanoparticles from the corresponding metal oxides. For instance, we demonstrated that the absence of halogen enables efficient alloying of metals when preparing gold–silver bimetallic nanoparticles.

Gas-Stabilizing Gold Nanocones for Acoustically Mediated Drug Delivery.

Science.gov (United States)

Mannaris, Christophoros; Teo, Boon M; Seth, Anjali; Bau, Luca; Coussios, Constantin; Stride, Eleanor

2018-04-25

The efficient penetration of drugs into tumors is a major challenge that remains unmet. Reported herein is a strategy to promote extravasation and enhanced penetration using inertial cavitation initiated by focused ultrasound and cone-shaped gold nanoparticles that entrap gas nanobubbles. The cones are capable of initiating inertial cavitation under pressures and frequencies achievable with existing clinical ultrasound systems and of promoting extravasation and delivery of a model large therapeutic molecule in an in vitro tissue mimicking flow phantom, achieving penetration depths in excess of 2 mm. Ease of functionalization and intrinsic imaging capabilities provide gold with significant advantages as a material for biomedical applications. The cones show neither cytotoxicity in Michigan Cancer Foundation (MCF)-7 cells nor hemolytic activity in human blood at clinically relevant concentrations and are found to be colloidally stable for at least 5 d at 37 °C and several months at 4 °C. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Determination of phosphorus in gold or silver brazing alloys

International Nuclear Information System (INIS)

Antepenko, R.J.

1976-01-01

A spectrophotometric method has been devised for measuring microgram levels of phosphorus in brazing alloys of gold or silver alloys is normally measured by solid mass spectrometry, but the high nickel concentration produces a double ionized nickel spectral interference. The described procedures is based upon the formation of molybdovandophosphoric acid when a molybdate solution is added to an acidic solution containing orthophosphate and vanadate ions. The optimum acidity for forming the yellow colored product is 0.5 N hydrochloric acid. The working concentration range is from 0.1 to 1 ppm phosphorus using 100-mm cells and measuring the absorbance at 460 nm. The sample preparation procedure employs aqua regia to dissolve the alloy oxidize the phosphorus to orthophosphate. Cation-exchange chromatography is used to remove nickel ions and anion-exchange and chromatography to remove gold ions as the chloride complex. Excellent recoveries are obtained for standard phosphorus solutions run through the sample procedure. The procedure is applicable to a variety of gold or silver braze alloys requiring phosphorus analysis

Gold nanoparticles in breast cancer treatment: Promise and potential pitfalls

Science.gov (United States)

Lee, Jihyoun; Chatterjee, Dev Kumar; Lee, Min Hyuk; Krishnan, Sunil

2014-01-01

Despite remarkable achievements in the treatment of breast cancer, some obstacles still remain. Gold nanoparticles may prove valuable in addressing these problems owing to their unique characteristics, including their enhanced permeability and retention in tumor tissue, their light absorbance and surface plasmon resonance in near-infrared light, their interaction with radiation to generate secondary electrons, and their ability to be conjugated with drugs or other agents. Herein, we discuss some basic concepts of gold nanoparticles, and early results from studies regarding their use in breast cancer, including toxicity and side effects. We also discuss these particles’ potential clinical applications. PMID:24556077

Structure and bonding in gold compounds

International Nuclear Information System (INIS)

Parish, R.V.

1988-01-01

Recent developments in chemical applications of 197 Au Moessbauer spectroscopy are reviewed. For gold(I) and gold(III), systematic variations in isomer shift and quadrupole splitting are seen as the ligands are changed; the effects of change in coordination number of the gold atoms are also systematic. Data for gold(II) systems involving gold-gold bonds lie between those for corresponding gold(I) and gold(III) materials, showing a small increase in isomer shift and a larger increase in quadrupole splitting as the oxidation state decreases; these trends are explained in terms of the structures. Data for mixed-metal cluster compounds are much more sensitive to structural effects than in homonuclear clusters. Both sets of data show systematic changes with increase in the number of metal atoms to which the gold atom is bound. The connectivity also influences the recoil-free fraction. (orig.)

E-textiles in Clinical Rehabilitation: A Scoping Review

Directory of Open Access Journals (Sweden)

Amanda Fleury

2015-02-01

Full Text Available Electronic textiles have potential for many practical uses in clinical rehabilitation. This scoping review appraises recent and emerging developments of textile-based sensors with applications to rehabilitation. Contributions published from 2009 to 2013 are appraised with a specific focus on the measured physiological or biomechanical phenomenon, current measurement practices, textile innovations, and their merits and limitations. While fabric-based signal quality and sensor integration have advanced considerably, overall system integration (including circuitry and power has not been fully realized. Validation against clinical gold standards is inconsistent at best, and feasibility with clinical populations remains to be demonstrated. The overwhelming focus of research and development has been on remote sensing but the opportunity for textile-mediated feedback to the wearer remains unexplored. Recommendations for future research are provided.

Utilising magnetic resonance imaging as the gold-standard in management of suspected scaphoid fractures in the emergency department setting

LENUS (Irish Health Repository)

Ramasubbu, B

2017-02-01

Scaphoid fractures are the most common carpal bone fracture. Up to 40% of scaphoid fractures can be missed at initial presentation and investigation. Follow-up plain film radiograph has overall poor sensitivity and reliability. MRI has been shown to have an almost 100% sensitivity and specificity and so is the gold standard in scaphoid fracture diagnosis. Additionally, early specialist involvement is recommended. We proposed that following a designated pathway, there would be no significant increase in MRI requests. Following implementation of a pathway for the management of suspected scaphoid fractures in St James’s Hospital in 2012 re-auditing demonstrated that management changed to either MRI directly after initial x-ray (16\\/145, 11%), MRI after second x-ray (9\\/28, 32%) or orthopaedic follow-up (19\\/28, 68%). The number of MRIs requested was consistent with our predictors of demand. Thus, our new protocol maximises diagnostics, cost effectiveness and quality of patient care.

Knowledge-driven GIS modeling technique for gold exploration, Bulghah gold mine area, Saudi Arabia

Directory of Open Access Journals (Sweden)

Ahmed A. Madani

2011-12-01

Full Text Available This research aims to generate a favorability map for gold exploration at the Bulghah gold mine area using integration of geo-datasets within a GIS environment. Spatial data analyses and integration of different geo-datasets are carried out based on knowledge-driven and weighting technique. The integration process involves the weighting and scoring of different layers affecting the gold mineralization at the study area using the index overlay method within PCI Geomatica environment. Generation of the binary predictor maps for lithology, lineaments, faults and favorable contacts precede the construction of the favorability map. About 100 m buffer zones are generated for favorable contacts, lineaments and major faults layers. Internal weighting is assigned to each layer based on favorability for gold mineralization. The scores for lithology, major faults, lineaments and favorable contacts layers in the constructed favorability map are 50%, 25%, 10% and 15%, respectively. Final favorability map for the Bulghah gold mine area shows the recording of two new sites for gold mineralization located at the northern and southern extensions of tonalite–diorite intrusions. The northern new site is now exploited for gold from the Bulghah North mine. The southern new site is narrow and small; its rocks resemble those of the Bulghah gold mine.

Dosimetric impact of gold markers implanted closely to lung tumors: a Monte Carlo simulation.

Science.gov (United States)

Shiinoki, Takehiro; Sawada, Akira; Ishihara, Yoshitomo; Miyabe, Yuki; Matsuo, Yukinori; Mizowaki, Takashi; Kokubo, Masaki; Hiraoka, Masahiro

2014-05-08

We are developing an innovative dynamic tumor tracking irradiation technique using gold markers implanted around a tumor as a surrogate signal, a real-time marker detection system, and a gimbaled X-ray head in the Vero4DRT. The gold markers implanted in a normal organ will produce uncertainty in the dose calculation during treatment planning because the photon mass attenuation coefficient of a gold marker is much larger than that of normal tissue. The purpose of this study was to simulate the dose variation near the gold markers in a lung irradiated by a photon beam using the Monte Carlo method. First, the single-beam and the opposing-beam geometries were simulated using both water and lung phantoms. Subsequently, the relative dose profiles were calculated using a stereotactic body radiotherapy (SBRT) treatment plan for a lung cancer patient having gold markers along the anterior-posterior (AP) and right-left (RL) directions. For the single beam, the dose at the gold marker-phantom interface laterally along the perpendicular to the beam axis increased by a factor of 1.35 in the water phantom and 1.58 in the lung phantom, respectively. Furthermore, the entrance dose at the interface along the beam axis increased by a factor of 1.63 in the water phantom and 1.91 in the lung phantom, while the exit dose increased by a factor of 1.00 in the water phantom and 1.12 in the lung phantom, respectively. On the other hand, both dose escalations and dose de-escalations were canceled by each beam for opposing portal beams with the same beam weight. For SBRT patient data, the dose at the gold marker edge located in the tumor increased by a factor of 1.30 in both AP and RL directions. In clinical cases, dose escalations were observed at the small area where the distance between a gold marker and the lung tumor was ≤ 5 mm, and it would be clinically negligible in multibeam treatments, although further investigation may be required.

Separation and enrichment of gold(III) from environmental samples prior to its flame atomic absorption spectrometric determination

International Nuclear Information System (INIS)

Senturk, Hasan Basri; Gundogdu, Ali; Bulut, Volkan Numan; Duran, Celal; Soylak, Mustafa; Elci, Latif; Tufekci, Mehmet

2007-01-01

A simple and accurate method was developed for separation and enrichment of trace levels of gold in environmental samples. The method is based on the adsorption of Au(III)-diethyldithiocarbamate complex on Amberlite XAD-2000 resin prior to the analysis of gold by flame atomic absorption spectrometry after elution with 1 mol L -1 HNO 3 in acetone. Some parameters including nitric acid concentration, eluent type, matrix ions, sample volume, sample flow rate and adsorption capacity were investigated on the recovery of gold(III). The recovery values for gold(III) and detection limit of gold were greater than 95% and 16.6 μg L -1 , respectively. The preconcentration factor was 200. The relative standard deviation of the method was -1 . The validation of the presented procedure was checked by the analysis of CRM-SA-C Sandy Soil certified reference material. The presented procedure was applied to the determination of gold in some environmental samples

Novel solid phase extraction procedure for gold(III) on Dowex M 4195 prior to its flame atomic absorption spectrometric determination

International Nuclear Information System (INIS)

Tuzen, Mustafa; Saygi, Kadriye O.; Soylak, Mustafa

2008-01-01

A method for solid phase extraction (SPE) of gold(III) using Dowex M 4195 chelating resin has been developed. The optimum experimental conditions for the quantitative sorption of gold(III), pH, effect of flow rates, eluent types, sorption capacity and the effect of diverse ions on the sorption of gold(III) have been investigated. The chelating resin can be reused for more than 100 cycles of sorption-desorption without any significant change in sorption of gold(III) ions. The recovery values for gold(III) and detection limit (LOD) of gold were greater than 95% and 1.61 μg L -1 , respectively. The preconcentration factor was 31. The relative standard deviation of the method was -1 . The proposed method has been applied for the determination of gold(III) in some real samples including water, soil and sediment samples

National Accreditation and Its Role in Early Education: An Analysis of Florida's Gold Seal Quality Child-Care Program and Licensing Standards

Science.gov (United States)

Winterbottom, Christian; Jones, Ithel

2014-01-01

This article reports on the first Florida statewide assessment of the Gold Seal Quality Care program, accreditation, and the relationship with licensing violations. This study analyzed the differences between the Department of Children and Families Gold Seal-Accredited facilities and nonaccredited facilities by comparing the facilities and the…

Dental Hygiene Faculty Calibration Using Two Accepted Standards for Calculus Detection: A Pilot Study.

Science.gov (United States)

Santiago, Lisa J; Freudenthal, Jacqueline J; Peterson, Teri; Bowen, Denise M

2016-08-01

Faculty calibration studies for calculus detection use two different standards for examiner evaluation, yet the only therapeutic modality that can be used for nonsurgical periodontal treatment is scaling/root debridement or planing. In this study, a pretest-posttest design was used to assess the feasibility of faculty calibration for calculus detection using two accepted standards: that established by the Central Regional Dental Testing Service, Inc. (CRDTS; readily detectible calculus) and the gold standard for scaling/root debridement (root roughness). Four clinical dental hygiene faculty members out of five possible participants at Halifax Community College agreed to participate. The participants explored calculus on the 16 assigned teeth (64 surfaces) of four patients. Calculus detection scores were calculated before and after training. Kappa averages using CRDTS criteria were 0.561 at pretest and 0.631 at posttest. Kappa scores using the scaling/root debridement or planing standard were 0.152 at pretest and 0.271 at posttest. The scores indicated improvement from moderate (Kappa=0.41-0.60) to substantial agreement (Kappa=0.61-0.80) following training using the CRDTS standard. Although this result differed qualitatively and Kappas were significantly different from 0, the differences for pre- to post-Kappas for patient-rater dyads using CRDTS were not statistically significant (p=0.778). There was no difference (p=0.913) in Kappa scores pre- to post-training using the scaling/root debridement standard. Despite the small number of participants in this study, the results indicated that training to improve interrater reliability to substantial agreement was feasible using the CRDTS standard but not using the gold standard. The difference may have been due to greater difficulty in attaining agreement regarding root roughness. Future studies should include multiple training sessions with patients using the same standard for scaling/root debridement used for

Determination of Gold from Gold Matrix of North Western Nigeria ...

African Journals Online (AJOL)

The research paper presents analytical results of Au, Mn and V concentrations of some Nigerian gold ores using two techniques: epithermal neutron activation analysis (ENAA) and proton induced X-ray emission (PIXE). Fourteen samples were collected from gold fields of North Western Nigeria, prepared separately to a ...

A multisite study of the clinical diagnosis of different autism spectrum disorders.

Science.gov (United States)

Lord, Catherine; Petkova, Eva; Hus, Vanessa; Gan, Weijin; Lu, Feihan; Martin, Donna M; Ousley, Opal; Guy, Lisa; Bernier, Raphael; Gerdts, Jennifer; Algermissen, Molly; Whitaker, Agnes; Sutcliffe, James S; Warren, Zachary; Klin, Ami; Saulnier, Celine; Hanson, Ellen; Hundley, Rachel; Piggot, Judith; Fombonne, Eric; Steiman, Mandy; Miles, Judith; Kanne, Stephen M; Goin-Kochel, Robin P; Peters, Sarika U; Cook, Edwin H; Guter, Stephen; Tjernagel, Jennifer; Green-Snyder, Lee Anne; Bishop, Somer; Esler, Amy; Gotham, Katherine; Luyster, Rhiannon; Miller, Fiona; Olson, Jennifer; Richler, Jennifer; Risi, Susan

2012-03-01

Best-estimate clinical diagnoses of specific autism spectrum disorders (autistic disorder, pervasive developmental disorder-not otherwise specified, and Asperger syndrome) have been used as the diagnostic gold standard, even when information from standardized instruments is available. To determine whether the relationships between behavioral phenotypes and clinical diagnoses of different autism spectrum disorders vary across 12 university-based sites. Multisite observational study collecting clinical phenotype data (diagnostic, developmental, and demographic) for genetic research. Classification trees were used to identify characteristics that predicted diagnosis across and within sites. Participants were recruited through 12 university-based autism service providers into a genetic study of autism. A total of 2102 probands (1814 male probands) between 4 and 18 years of age (mean [SD] age, 8.93 [3.5] years) who met autism spectrum criteria on the Autism Diagnostic Interview-Revised and the Autism Diagnostic Observation Schedule and who had a clinical diagnosis of an autism spectrum disorder. Best-estimate clinical diagnoses predicted by standardized scores from diagnostic, cognitive, and behavioral measures. Although distributions of scores on standardized measures were similar across sites, significant site differences emerged in best-estimate clinical diagnoses of specific autism spectrum disorders. Relationships between clinical diagnoses and standardized scores, particularly verbal IQ, language level, and core diagnostic features, varied across sites in weighting of information and cutoffs. Clinical distinctions among categorical diagnostic subtypes of autism spectrum disorders were not reliable even across sites with well-documented fidelity using standardized diagnostic instruments. Results support the move from existing subgroupings of autism spectrum disorders to dimensional descriptions of core features of social affect and fixated, repetitive behaviors

Sleep apnea detection by a cardiac resynchronization device integrated thoracic impedance sensor: A validation study against the gold standard polysomnography.

Science.gov (United States)

Barbieri, Fabian; Dichtl, Wolfgang; Heidbreder, Anna; Brandauer, Elisabeth; Stefani, Ambra; Adukauskaite, Agne; Senoner, Thomas; Schgör, Wilfried; Hintringer, Florian; Högl, Birgit

2018-01-01

Sleep disordered breathing is a common but often undiagnosed comorbidity in heart failure patients. Cardiac implantable electronic devices used for cardiac resynchronization therapy (CRT) may detect sleep apnea by use of a transthoracic impedance sensor. Validation of the AP scan® algorithm (Boston Scientific®) was performed by using the diagnostic gold standard polysomnography (PSG). Forty-one patients with impaired left ventricular ejection fraction, frequent right ventricular pacing due to atrioventricular block and heart failure symptoms despite optimal medical therapy underwent upgrading to biventricular pacing. Within one month after left ventricular lead implantation, sleep apnea was assessed by single-night PSG and AP scan® measurements. AP scan® measurements were valid in only 21 of 41 (51.2%) patients in the index night of the PSG. The PSG determined apnea-hypopnea index did not correlate statistically significant with the AP scan® measurements (r = 0.41, 95% confidence interval -0.05-0.72, p = 0.07). The degree of overestimation is displayed by using the Bland-Altman method: mean difference -12.4, standard deviation ± 15.8, 95% confidence interval -43.3-18.6. In heart failure patients receiving CRT upgrading, the AP scan® algorithm may need further improvement before it can be recommended for sleep apnea detection.

Interaction between manufactured gold nanoparticles and naturally occurring organic macromolecules

International Nuclear Information System (INIS)

Diegoli, Sara; Manciulea, Adriana L.; Begum, Shakiela; Jones, Ian P.; Lead, Jamie R.; Preece, Jon A.

2008-01-01

The increasing exploitation of nanomaterials into many consumer and other products is raising concerns as these nanomaterials are likely to be released into the environment. Due to our lack of knowledge about the environmental chemistry, transport and ecotoxicology of nanomaterials, it is of paramount importance to study how natural aquatic colloids can interact with manufactured gold nanoparticles as these interactions will determine their environmental fate and behaviour. In this context, our work aims to quantify the effect of naturally occurring riverine macromolecules - International Humic Substances Society (IHSS) Suwannee River Humic Acid Standard (SRHA) - on citrate- and acrylate-stabilized gold nanoparticles. The influence of SRHA on the stability of the gold colloids was studied as a function of pH by UV-visible absorption spectroscopy, dynamic light scattering (DLS) and transmission electron microscopy (TEM). At high ionic strengths (0.1 M), extensive and rapid aggregation occurred, while more subtle effects were observed at lower ionic strength values. Evidence was found that SRHA enhances particle stability at extreme pH values (ionic strength < 0.01 M) by substituting and/or over-coating the original stabilizer on the gold nanoparticle surface, thus affecting surface charge and chemistry. These findings have important implications for the fate and behaviour of nanoparticles in the environment and their ecotoxicity

Analysis of gold(I/III)-complexes by HPLC-ICP-MS demonstrates gold(III) stability in surface waters.

Science.gov (United States)

Ta, Christine; Reith, Frank; Brugger, Joël; Pring, Allan; Lenehan, Claire E

2014-05-20

Understanding the form in which gold is transported in surface- and groundwaters underpins our understanding of gold dispersion and (bio)geochemical cycling. Yet, to date, there are no direct techniques capable of identifying the oxidation state and complexation of gold in natural waters. We present a reversed phase ion-pairing HPLC-ICP-MS method for the separation and determination of aqueous gold(III)-chloro-hydroxyl, gold(III)-bromo-hydroxyl, gold(I)-thiosulfate, and gold(I)-cyanide complexes. Detection limits for the gold species range from 0.05 to 0.30 μg L(-1). The [Au(CN)2](-) gold cyanide complex was detected in five of six waters from tailings and adjacent monitoring bores of working gold mines. Contrary to thermodynamic predictions, evidence was obtained for the existence of Au(III)-complexes in circumneutral, hypersaline waters of a natural lake overlying a gold deposit in Western Australia. This first direct evidence for the existence and stability of Au(III)-complexes in natural surface waters suggests that Au(III)-complexes may be important for the transport and biogeochemical cycling of gold in surface environments. Overall, these results show that near-μg L(-1) enrichments of Au in environmental waters result from metastable ligands (e.g., CN(-)) as well as kinetically controlled redox processes leading to the stability of highly soluble Au(III)-complexes.

Analysis on the Impact of the Fluctuation of the International Gold Prices on the Chinese Gold Stocks

Directory of Open Access Journals (Sweden)

Jiankang Jin

2014-01-01

Full Text Available Five gold stocks in Chinese Shanghai and Shenzhen A-share and Comex gold futures are chosen to form the sample, for the purpose of analysing the impact of the fluctuation of the international gold prices on the gold stocks in Chinese Shanghai and Shenzhen A-share. Using the methods of unit root test, Granger causality test, VAR model, and impulse response function, this paper has analysed the relationship between the price change of the international gold futures and the price fluctuation of gold stocks in Chinese Shanghai and Shenzhen comprehensively. The results suggest the fluctuation of the international gold futures has a strong influence on the domestic futures.

Nanotoxicity of gold and iron nanoparticles.

Science.gov (United States)

Maiti, Souvik

2011-02-01

The extensive use of potentially hazardous nanoparticles in industrial applications suggest that their biological effects need to be evaluated following clinical testing practices as applicable for any new pharmaceutical. It was rationalized that a non hypothesis-driven approach is best suited for discovering the biological effects of nanoparticles. Gold nanoparticles (approximately 18 nm), showed no drastic effect on gene expression in cells but iron nanoparticles showed perturbations in the expression of a set of functional genes.

Paper-based tuberculosis diagnostic devices with colorimetric gold nanoparticles

International Nuclear Information System (INIS)

Tsai, Tsung-Ting; Shen, Shu-Wei; Chen, Chien-Fu; Cheng, Chao-Min

2013-01-01

A colorimetric sensing strategy employing gold nanoparticles and a paper assay platform has been developed for tuberculosis diagnosis. Unmodified gold nanoparticles and single-stranded detection oligonucleotides are used to achieve rapid diagnosis without complicated and time-consuming thiolated or other surface-modified probe preparation processes. To eliminate the use of sophisticated equipment for data analysis, the color variance for multiple detection results was simultaneously collected and concentrated on cellulose paper with the data readout transmitted for cloud computing via a smartphone. The results show that the 2.6 nM tuberculosis mycobacterium target sequences extracted from patients can easily be detected, and the turnaround time after the human DNA is extracted from clinical samples was approximately 1 h. (paper)

Formation of gold nanorods and gold nanorod films for surface-enhanced Raman scattering spectroscopy

International Nuclear Information System (INIS)

Trotsyuk, L.L.; Kulakovich, O.S.; Shabunya-Klyachkovskaya, E.V.; Gaponenko, S.V.; Vashchenko, S.V.

2016-01-01

The formation of gold nanorods as well as thin films prepared via electrostatic deposition of gold nanorods has been investigated. The obtained gold nanorods films have been used as substrates for the surface-enhanced Raman scattering analysis of sulfur-free organic molecules mitoxantrone and malachite green as well as inorganic malachite microcrystals for the first time. The additional modification of films with L-cysteine allows one to significantly extend the use of gold nanorods for the surface-enhanced Raman scattering analysis. (authors)

Standardized Representation of Clinical Study Data Dictionaries with CIMI Archetypes.

Science.gov (United States)

Sharma, Deepak K; Solbrig, Harold R; Prud'hommeaux, Eric; Pathak, Jyotishman; Jiang, Guoqian

2016-01-01

Researchers commonly use a tabular format to describe and represent clinical study data. The lack of standardization of data dictionary's metadata elements presents challenges for their harmonization for similar studies and impedes interoperability outside the local context. We propose that representing data dictionaries in the form of standardized archetypes can help to overcome this problem. The Archetype Modeling Language (AML) as developed by the Clinical Information Modeling Initiative (CIMI) can serve as a common format for the representation of data dictionary models. We mapped three different data dictionaries (identified from dbGAP, PheKB and TCGA) onto AML archetypes by aligning dictionary variable definitions with the AML archetype elements. The near complete alignment of data dictionaries helped map them into valid AML models that captured all data dictionary model metadata. The outcome of the work would help subject matter experts harmonize data models for quality, semantic interoperability and better downstream data integration.

MR arthrography: pharmacology, efficacy and safety in clinical trials

International Nuclear Information System (INIS)

Schulte-Altedorneburg, G.; Gebhard, M.; Wohlgemuth, W.A.; Fischer, W.; Zentner, J.; Bohndorf, K.; Wegener, R.; Balzer, T.

2003-01-01

A meta-analysis was carried out of clinical trials published between 1987 and 2001 in respect of the clinical pharmacology and safety as well as the diagnostic efficacy of gadolinium-DTPA (Gd-DTPA) for direct intra-articular injection before MRI examination.Design. Scientific papers (clinical, postmortem and experimental studies) and information from the manufacturer regarding intra-articular injection of Gd-DTPA that addressed questions of mode of action, optimal concentration and dose, elimination and safety were reviewed. Clinical studies were classified according to their study design. The sensitivity, specificity and accuracy of MR arthrography (MRA) were compared with a ''gold standard'' (arthroscopy, arthrotomy) and other radiological evidence for different joints.Results. Fifty-two clinical studies of the overall 112 studies addressed aspects of diagnostic efficacy of MRA in patients or in healthy volunteers. The shoulder was the most assessed joint (29 of 52 studies). Good (>80%) or even excellent (90-100%) sensitivity, specificity and accuracy were found for MRA in most indications, especially for the shoulder and knee joints and induced extension of rotator cuff lesions, labrum abnormalities and postoperative meniscal tears. Two millimoles per liter has proven to be the best concentration for intra-articular administration of Gd-DTPA. After passive complete diffusion from the joint within 6-24 h, complete and rapid renal elimination takes place after intra-articular injection. Local safety proved to be excellent after intra-articular administration of Gd-DTPA. Regarding systemic tolerance almost no side effects have been reported, but the same safety considerations apply for intra-articular administration of Gd-DTPA as for intravenous injection.Conclusions. The diagnostic efficacy of intra-articular MRA in most clinical conditions affecting major joints is greater than that of plain MRI. In some diagnostic problems MRA achieves almost the same

Mercury use in small scale gold mining in Ghana: an assessment of its impact on miners

International Nuclear Information System (INIS)

Biagya, Robert Yakubu

2002-12-01

Small scale gold mining is responsible for about 5% of Ghana’s annual gold production. It is estimated that between 80,000 and 100,000 people are engaged in small scale gold mining either on part-time or permanent basis. Amalgamation is the preferred method used by small scale gold miners for extracting free gold from its ores. The rate at which mercury, an important input in this method, is discharged into the atmosphere and water bodies is alarming. This research describes the various mining and processing methods in small scale gold mining and the extent of mercury use and releases to the environment. It discusses mercury and its human and environmental effects. It defines the various forms of mercury, routes of exposure, toxic effects. The levels of exposure to mercury by all groups of small scale gold miners are determined, and the impacts on the miners and the environment are assessed. It concludes that: • Mercury is mainly released into the environment as a result of small scale gold mining through spillage of elemental mercury and evaporation of mercury from the amalgam and sponge gold when they are heated on open fire. • Mercury in environmental samples from small scale gold mining areas is well above standard limit values. • Mercury released into the environment through small scale gold mining impacts negatively on the miners themselves and the general environment. Finally, it recommends the need for the adoption of mercury emission reduction strategies for dealing with the mercury problem. (au)

A study on gold detection in Wenyu gold mine with XRF techniques

International Nuclear Information System (INIS)

Liu Liuchun

1988-01-01

A portable X ray fluorescence analyzer was used for detecting fluorcescent X rays from the elements associated with gold ores. Fe, As and Ni were chosen to be the indicator elements to analyse rock samples in Wenyu gold mine. Optimum indicators were determined, and it had proved to be successful to detect gold indirectly by measuring the yields of characteristic X rays of the elements. The method provided also valuable information on geology mapping and deposits forming environment

Coal gold agglomeration: an innovative approach to the recovery of gold in environmentally sensitive areas

Energy Technology Data Exchange (ETDEWEB)

Wall, N.C.; Hughes-Narborough, C.; Willey, G. [Davy (Stockton) Ltd., Stockton-on-Tees (United Kingdom)

1994-11-01

Coal Gold Agglomeration (CGA) was developed by BP Minerals and involves the selective recovery of oleophilic gold particles from an aqueous slurry into coal-oil agglomerates. These agglomerates are allowed to build up to a high gold loading and are then separated from the slurry. The loaded agglomerates are burned and the gold is finally recovered from the ash residue by dissolution and precipitation or by direct smelting. 6 figs.

Comparison of anthropometry with photogrammetry based on a standardized clinical photographic technique using a cephalostat and chair.

Science.gov (United States)

Han, Kihwan; Kwon, Hyuk Joon; Choi, Tae Hyun; Kim, Jun Hyung; Son, Daegu

2010-03-01

The aim of this study was to standardize clinical photogrammetric techniques, and to compare anthropometry with photogrammetry. To standardize clinical photography, we have developed a photographic cephalostat and chair. We investigated the repeatability of the standardized clinical photogrammetric technique. Then, with 40 landmarks, a total of 96 anthropometric measurement items was obtained from 100 Koreans. Ninety six photogrammetric measurements from the same subjects were also obtained from standardized clinical photographs using Adobe Photoshop version 7.0 (Adobe Systems Corporation, San Jose, CA, USA). The photogrammetric and anthropometric measurement data (mm, degree) were then compared. A coefficient was obtained by dividing the anthropometric measurements by the photogrammetric measurements. The repeatability of the standardized photography was statistically significantly high (p=0.463). Among the 96 measurement items, 44 items were reliable; for these items the photogrammetric measurements were not different to the anthropometric measurements. The remaining 52 items must be classified as unreliable. By developing a photographic cephalostat and chair, we have standardized clinical photogrammetric techniques. The reliable set of measurement items can be used as anthropometric measurements. For unreliable measurement items, applying a suitable coefficient to the photogrammetric measurement allows the anthropometric measurement to be obtained indirectly.

Standards for the culture and quality control of umbilical cord mesenchymal stromal cells for neurorestorative clinical application (2017

Directory of Open Access Journals (Sweden)

Ao Q

2017-12-01

Full Text Available Qiang Ao,1,* Juan Xiao,2,3,* Yanqiu Yu,4 Gengsheng Mao,2 Qingyan Zou,5 Wenyong Gao,2,3 Hongyun Huang2,3 On behalf of Neurorestoratology Professional Committee of Chinese Medical Doctor Association (Chinese Association of Neurorestoratology 1Department of Tissue Engineering, China Medical University, Shen Yang, 2Institute of Neurorestoratology, General Hospital of Armed Police Forces, Beijing, 3Cell Therapy Center, Beijing Hongtianji Neuroscience Academy, Beijing, 4Department of Pathophysiology, China Medical University, Shen Yang, 5Guangdong 999 Brain Hospital, Guangzhou, People’s Republic of China *These authors contributed equally to this work Abstract: Formulating common standards for the culture and quality control of umbilical cord mesenchymal stromal cells (MSCs is crucial for the standardization of clinical neurorestorative therapy. But to date, there have been no standardized guidelines for the culture and quality control of MSCs in neurorestorative clinical application. Based on a relatively comprehensive review of published clinical studies as well as the existing methods of MSC culture and quality control, the Chinese Association of Neurorestoratology has developed standards for the culture and quality control of umbilical cord MSCs which possess the potential in neurorestorative clinical application. These guidelines include standardized training and management procedures for laboratory operators; standardized use and management of materials and equipment; standardized collection, culture and proliferation of umbilical cord MSCs; standardized management for cell preservation, transport and related safeguard measures; as well as standardization of a clean environment, routine maintenance and related tests and examinations and so on. These guidelines represent the minimum required standards for the culture and quality control of umbilical cord MSCs for potential use in current neurorestorative clinical therapy, and will be further

Gold-catalyzed aerobic epoxidation of trans-stilbene in methylcyclohexane. Part I: Design of a reference catalyst

KAUST Repository

Guillois, Kevin

2012-02-01

The kinetics of the heterogeneous gold-catalyzed aerobic epoxidation of stilbene in the liquid phase has been shown to be hindered by diffusion limitations, due to the use of supports which are unsuitable to apolar reaction media. The choice of these supports is generally dictated by the ability of standard methods of preparation to stabilize highly dispersed gold nanoparticles on them. Hence, new methods need to be designed in order to produce catalytically active gold nanoparticles on hydrophobic supports in general and on passivated silicas in particular. By investigating Tsukuda\\'s method to produce colloidal solutions of gold nanoparticles upon reduction of the triphenylphosphine gold chloride complex in solution, we found that direct reduction of AuPPh3Cl in the presence of a commercially available silica support functionalized with dimethylsiloxane, Aerosil R972, leads, in a highly reproducible and potentially scalable way, to the best catalyst ever reported for this reaction. (C) 2011 Elsevier BM. All rights reserved.

Gold-catalyzed aerobic epoxidation of trans-stilbene in methylcyclohexane. Part I: Design of a reference catalyst

KAUST Repository

Guillois, Kevin; Burel, Laurence; Tuel, Alain; Caps, Valerie

2012-01-01

The kinetics of the heterogeneous gold-catalyzed aerobic epoxidation of stilbene in the liquid phase has been shown to be hindered by diffusion limitations, due to the use of supports which are unsuitable to apolar reaction media. The choice of these supports is generally dictated by the ability of standard methods of preparation to stabilize highly dispersed gold nanoparticles on them. Hence, new methods need to be designed in order to produce catalytically active gold nanoparticles on hydrophobic supports in general and on passivated silicas in particular. By investigating Tsukuda's method to produce colloidal solutions of gold nanoparticles upon reduction of the triphenylphosphine gold chloride complex in solution, we found that direct reduction of AuPPh3Cl in the presence of a commercially available silica support functionalized with dimethylsiloxane, Aerosil R972, leads, in a highly reproducible and potentially scalable way, to the best catalyst ever reported for this reaction. (C) 2011 Elsevier BM. All rights reserved.

Preparation of gold nanoparticles and determination of their particles size via different methods

Energy Technology Data Exchange (ETDEWEB)

Iqbal, Muhammad; Usanase, Gisele [University of Lyon, University Lyon-1, CNRS, UMR-5007, LAGEP, F-69622 Villeurbanne (France); Oulmi, Kafia; Aberkane, Fairouz; Bendaikha, Tahar [Laboratory of Chemistry and Environmental Chemistry(LCCE), Faculty of Science, Material Science Department, University of Batna, 05000 (Algeria); Fessi, Hatem [University of Lyon, University Lyon-1, CNRS, UMR-5007, LAGEP, F-69622 Villeurbanne (France); Zine, Nadia [Institut des Sciences Analytiques (ISA), Université Lyon, Université Claude Bernard Lyon-1, UMR-5180, 5 rue de la Doua, F-69100 Villeurbanne (France); Agusti, Géraldine [University of Lyon, University Lyon-1, CNRS, UMR-5007, LAGEP, F-69622 Villeurbanne (France); Errachid, El-Salhi [Institut des Sciences Analytiques (ISA), Université Lyon, Université Claude Bernard Lyon-1, UMR-5180, 5 rue de la Doua, F-69100 Villeurbanne (France); Elaissari, Abdelhamid, E-mail: elaissari@lagep.univ-lyon1.fr [University of Lyon, University Lyon-1, CNRS, UMR-5007, LAGEP, F-69622 Villeurbanne (France)

2016-07-15

Graphical abstract: Preparation of gold nanoparticles via NaBH{sub 4} reduction method, and determination of their particle size, size distribution and morphology by using different techniques. - Highlights: • Gold nanoparticles were synthesized by NaBH{sub 4} reduction method. • Excess of reducing agent leads to tendency of aggregation. • The particle size, size distribution and morphology were investigated. • Particle size was determined both experimentally as well as theoretically. - Abstract: Gold nanoparticles have been used in various applications covering both electronics, biosensors, in vivo biomedical imaging and in vitro biomedical diagnosis. As a general requirement, gold nanoparticles should be prepared in large scale, easy to be functionalized by chemical compound of by specific ligands or biomolecules. In this study, gold nanoparticles were prepared by using different concentrations of reducing agent (NaBH{sub 4}) in various formulations and their effect on the particle size, size distribution and morphology was investigated. Moreover, special attention has been dedicated to comparison of particles size measured by various techniques, such as, light scattering, transmission electron microscopy, UV spectrum using standard curve and particles size calculated by using Mie theory and UV spectrum of gold nanoparticles dispersion. Particle size determined by various techniques can be correlated for monodispersed particles and excess of reducing agent leads to increase in the particle size.

Standardization of radiochemical techniques aiming the study of Hg volatilization and methylation in water and sediment of gold mining areas in the Amazon region

International Nuclear Information System (INIS)

Guimaraes, Jean Remy Davee

1992-09-01

Methylation of inorganic Hg in aquatic systems is a key process in the environmental cycling of this metal, not yet studied in tropical conditions. Radiochemical techniques were adapted and simplified, aiming at the study of Hg volatilization and methylation in water and sediment of gold mining areas in the Amazon region. Preliminary experiments showed, in 35 days volatilization of up to 32 % of 203 Hg 2+ added to aqueous solutions. Acid K 2 Cr 2 0 7 0.1 M solutions were not effective in 203 Hg 0 trapping and the latter was highly and irreversibly absorbed by a variety of synthetic materials commonly used in laboratory work. Considerably simplified versions of the Furutani and Rudd (1980) radiochemical technique for the determination of methylation rates in environmental samples were developed and showed efficiencies close to 90 % in tests with methyl- 2 0 3 H g standards. In-situ incubations of surface sediments were performed in the Madeira River gold mining region, Rondonia State, Brazil, and potential net Hg methylation rates (MR) of up to 1 %.g-1.h-1 were found in black-water affluent like the Mutum-Parana and Jamari rivers and in the Samuel reservoir. MRs in the Madeira River sediments were lower, ranging 10-5 to 10-3 %.g-1.h-1 . MRs obtained in incubations of samples some weeks after collection were one or two orders of magnitude lower than those resulting from in-situ incubations. Methylation in autoclaved samples was close to minimum detectable rates. MRs in surface water samples was in all cases < 7.10-7 %.ml-1.h-1. The determination of the predominant methylation sites will allow a better standardization of the technique described herein, suitable for MR determinations even under the unfavorable conditions prevailing in the Amazon region. (author)

Phosphorus-31 NMR (nuclear magnetic resonance) analysis of gold plating baths

Energy Technology Data Exchange (ETDEWEB)

Smith, R.E.

1990-01-01

This report describes the nuclear magnetic resonance (NMR) analysis of the gold plating baths in the Micro-Miniature Electronic Assembly department of Allied-Signal Inc., Kansas City Division (KCD). The baths were analyzed for phosphorylated components. In freshly prepared gold plating baths, a 50-percent aqueous solution of aminotrimethylphosphonate (ATMP) is the principal compound observed. As the bath is used in production, the ATMP breaks down and new materials (phosphate, ADMP, and AMMP) are identified. The NMR method was used to monitor the concentrations of the ATMP and breakdown products for a nine-month period. The 225-liter bath had plated approximately 100 square feet of gold during the nine-month period. These results can be used to predict the performance of baths as they are used in production. The accuracy of the analysis is 96 percent for ATMP and 92 percent for phosphate. The precision (relative standard deviation) is 5.2 percent for ATMP and 4.5 percent for phosphate. 1 ref., 5 figs., 2 tabs.

Annealing relaxation of ultrasmall gold nanostructures

Science.gov (United States)

Chaban, Vitaly

2015-01-01

Except serving as an excellent gift on proper occasions, gold finds applications in life sciences, particularly in diagnostics and therapeutics. These applications were made possible by gold nanoparticles, which differ drastically from macroscopic gold. Versatile surface chemistry of gold nanoparticles allows coating with small molecules, polymers, biological recognition molecules. Theoretical investigation of nanoscale gold is not trivial, because of numerous metastable states in these systems. Unlike elsewhere, this work obtains equilibrium structures using annealing simulations within the recently introduced PM7-MD method. Geometries of the ultrasmall gold nanostructures with chalcogen coverage are described at finite temperature, for the first time.

Fingerprinting ancient gold by measuring Pt with spatially resolved high energy Sy-XRF

International Nuclear Information System (INIS)

Guerra, M.F.; Calligaro, T.; Radtke, M.; Reiche, I.; Riesemeier, H.

2005-01-01

Trace elements of ancient gold such as Pt, give fundamental information on the circulation of the metal in the past. In the case of objects from the cultural heritage, the determination of trace elements requires non-destructive point analysis in general. These conditions and the need of good detection limits restrain the number of applicable analytical techniques. After the development of a PIXE set-up with a selective Cu or Zn filter of 75 μm and of a PIXE-XRF set-up using a primary target of As, we tested the possibilities of spatially resolved Sy-XRF to determine Pt in gold alloys. With a Zn filter, PIXE showed a detection limit of 1000 ppm in gold while PIXE-XRF lowers this detection limit down to 80 ppm. This last value being constrained by the resonant Raman effect produced on gold. In order to improve the detection limit of Pt keeping the non-destructiveness and access to point analysis, we developed an analytical protocol for XRF with synchrotron radiation at BESSY II, using the BAMline set-up. The L-lines of Pt were excited by a beam of energy above and below 11.564 keV and measured using a Si(Li) detector with a 50 μm Cu filter. A μ-beam of 100-250 μm 2 was used according to the size of the sample. The determination of the Pt content in the samples was carried out by Monte-Carlo simulation and subtraction of Au and Pt spectra obtained on pure standards. The limit of detection for Pt of 20 ppm was determined by using certified standards. The detection limits of a small set of other characteristic elements of gold were also measured using an incident energy of 33 keV

Gold grade variation and particle microchemistry in exploration pits of the Batouri gold district, SE Cameroon

Science.gov (United States)

Vishiti, A.; Suh, C. E.; Lehmann, B.; Egbe, J. A.; Shemang, E. M.

2015-11-01

The Batouri area hosts lode-gold mineralization under several-m-thick lateritic cover. Pitting to bed rock on a geochemical Au anomaly defined from previous reconnaissance soil sampling identified five horizons ranging from saprock at the base to laterite at the top. Analysis of bulk samples from each horizon by fire assay shows that most of the horizons are barren although 119 ppb and 48 ppb Au values were obtained from one laterite horizon and one saprolite horizon, respectively, from two separate pits. All the horizons were panned and particulate gold was also recovered only from these two horizons. The gold grains from both horizons are morphologically and compositionally indistinguishable with rare quartz, pyrite and galena inclusions. The grains have irregular, sub-rounded, bean to elongated shapes and they show a remarkable core-rim zonation. Electron microprobe analysis of the grains recorded high gold content in the rims (86.3-100 wt%) and along fissures within the grains (95.1-100 wt%). The cores are relatively Ag rich (11.8-14 wt% Ag) while the rims (0.63-13.7 wt% Ag, most of the values fall within the lower limit of this range) and fissures (0.03-5.02 wt% Ag) are poor in Ag. The low Ag concentration in the rims and along fissures is attributed to preferential leaching of Ag; a process recognized in gold grains and platiniferous alloys from alluvia. The core composition of the grains is similar to that of primary gold composition in the bedrock. These results show that gold in the soil is relic particulate gold derived from the primary source with no evidence of secondary gold precipitation in the weathering cycle. In all the pits no horizon was systematically enriched in gold suggesting there has been no chemical remobilization of gold in this environment. Rather the dispersion of gold here is in the particulate form. Therefore combining particulate gold features with assay data is relevant to exploration in such tropical environments.

Size fraction assaying of gold bearing rocks (for gold extraction) by instrumental neutron activation analysis

International Nuclear Information System (INIS)

Ahmed, K.; Dampare, S.B.; Addo, M.A.; Osae, S.; Adotey, D.K.; Adomako, D.

2005-01-01

A novel method has been developed for processing and extraction of gold from gold bearing rocks for use by small-scale gold miners in Ghana. The methodology involved crushing of gold bearing hard rocks to fine particles to form a composite sample and screening at a range of sizes. Gold distribution in the composite sample was determined as a function of particle size by using Instrumental Neutron Activation Analysis. The concentrations of gold for the corresponding particle sizes were 16.4 ± 0.17mg/kg for sizes <63μm; 161± 0.75 mg/kg for 63 - 125 μm, 0.53 + 0.03 mg/kg for 125 - 250 μm, 4.66± 0.07 mg/kg for 250 - 355 μm, 1.55 ± 0.06 for 355 - 425 μm, 0.80 ± 0.008 mg/kg for 425 -1000 μm, and 1.27 + 0.05 mg/kg for 1000-2000 μm. The average gold content in a 7.127 kg composite sample based on particle size found to be 3.08 mg/kg. (au)

Gold and uranium extraction

International Nuclear Information System (INIS)

James, G.S.; Davidson, R.J.

1977-01-01

A process for extracting gold and uranium from an ore containing them both comprising the steps of pulping the finely comminuted ore with a suitable cyanide solution at an alkaline pH, acidifying the pulp for uranium dissolution, adding carbon activated for gold recovery to the pulp at a suitable stage, separating the loaded activated carbon from the pulp, and recovering gold from the activated carbon and uranium from solution

Shape-controlled synthesis of NIR absorbing branched gold nanoparticles and morphology stabilization with alkanethiols

International Nuclear Information System (INIS)

Van de Broek, B; Frederix, F; Bonroy, K; Jans, H; Jans, K; Borghs, G; Maes, G

2011-01-01

Gold nanoparticles are ideal candidates for clinical applications if their plasmon absorption band is situated in the near infrared region (NIR) of the electromagnetic spectrum. Various parameters, including the nanoparticle shape, strongly influence the position of this absorption band. The aim of this study is to produce stabilized NIR absorbing branched gold nanoparticles with potential for biomedical applications. Hereto, the synthesis procedure for branched gold nanoparticles is optimized varying the different synthesis parameters. By subsequent electroless gold plating the plasmon absorption band is shifted to 747.2 nm. The intrinsic unstable nature of the nanoparticles' morphology can be clearly observed by a spectral shift and limits their use in real applications. However, in this article we show how the stabilization of the branched structure can be successfully achieved by exchanging the initial capping agent for different alkanethiols and disulfides. Furthermore, when using alkanethiols/disulfides with poly(ethylene oxide) units incorporated, an increased stability of the gold nanoparticles is achieved in high salt concentrations up to 1 M and in a cell culture medium. These achievements open a plethora of opportunities for these stabilized branched gold nanoparticles in nanomedicine.

Providing support to nursing students in the clinical environment: a nursing standard requirement.

Science.gov (United States)

Anderson, Carina; Moxham, Lorna; Broadbent, Marc

2016-10-01

This discussion paper poses the question 'What enables or deters Registered Nurses to take up their professional responsibility to support undergraduate nursing students through the provision of clinical education?'. Embedded within many nursing standards are expectations that Registered Nurses provide support and professional development to undergraduate nursing students undertaking clinical placements. Expectations within nursing standards that Registered Nurses provide support and professional development to nursing students are important because nursing students depend on Registered Nurses to help them to become competent practitioners. Contributing factors that enable and deter Registered Nurses from fulfilling this expectation to support nursing students in their clinical learning include; workloads, preparedness for the teaching role, confidence in teaching and awareness of the competency requirement to support students. Factors exist which can enable or deter Registered Nurses from carrying out the licence requirement to provide clinical education and support to nursing students.

Free gold recovery by coal-oil agglomeration

Energy Technology Data Exchange (ETDEWEB)

Kotze, W.; Petersen, F.W. [Cape Technikon Cape Town (South Africa). Dept. of Chemical Engineering

2000-02-01

The gold mining industry has mainly relied upon the use of highly polluting chemicals, such as mercury and cyanide to recover gold from its ores. The Coal Gold Agglomeration (CGA) process was developed some years ago and has the advantage in that gold is recovered by a procedure which has little or no negative impact on the environment. A gold ore containing liberated gold particles is contacted with coal-oil agglomerates, whereby the gold is recovered into the coal/oil phase. Laboratory scale batch tests were performed on an artificial mixture gold slurry and gold recoveries of up to 85% were found under optimized conditions. By recycling the coal/oil phase, it was found that the gold loading onto the agglomerates was increased. Tests performed on an industrial ore yielded slightly lower gold recoveries, and X-ray Diffraction (XRD) analysis on the coal/oil phase showed that minerals other than gold were recovered into this phase. A comparative study was conducted whereby the CGA process was compared to mercury amalgamation. Gold recoveries obtained through amalgamation were 15% lower than by the agglomeration process, which indicates that this process can be considered favourably as an alternative to amalgamation. 16 refs., 2 figs., 6 tabs.

Spectroscopic diagnostic of gold plasma

Energy Technology Data Exchange (ETDEWEB)

Busquet, M.

1986-06-01

Results of a simulation of a gold-aluminium alloy target irradiated by laser are presented. FCI code has been used with a processing out of LTE of atomic physics of gold and of multigroup photonics. Emission and reabsorption of gold and aluminium lines are included.

Activation analysis in gold industry

International Nuclear Information System (INIS)

Kist, A. A.

2003-01-01

Nuclear techniques and methods were, are, and will be very important for many fields of science, agriculture, industry, etc. Among other examples one can remember role of the nuclear medicine (radiotherapy and radiodiagnostic methods) or semiconductors (communication, computing, information, etc.) which industrial production has been on initial stage based on activation analysis. One of very illustrative examples is application of nuclear methods in gold industry. This is given by favorable nuclear properties of gold. Uzbekistan is one of the main producers of gold. Open-cast mining and hydro metallurgic extraction (using leaching by cyanide and sorption by ion-exchange resin) is the mostly used technology. The typical gold ores are sulfide and contain elevated concentration of As and Sb. That needs special technology of gold extraction. Importance of gold for Uzbekistan economy is a reason why for many years there are carried out studies concerning to gold production. These studies include also nuclear methods and their results are successfully used in gold industry. The present paper gives a brief overview for period of 25 years. For many reasons most of these studies were not published before completely. Despite some results are obtained decades ago we decided to present the overview as an example how nuclear methods can cover requirements of the whole process. We are trying to sort these studies according to methods and applications

[The challenges of standardization in clinical diagnostic laboratories of medical organizations].

Science.gov (United States)

Men'shikov, V V

2013-04-01

The generalized data concerning the conditions of application of regulations of national standards in clinical diagnostic laboratories of medical organizations is presented. The primary information was provided by 14 regions of 6 federal administrative okrugs of Russia. The causes of challenges of application of requirements of standards are presented. They are mostly related with insufficient financial support, lacking of manpower, difficulties with reagents supply, inadequate technical maintenance of devices and absence of support of administration of medical organizations. The recommendations are formulated concerning the necessity of publishing the document of Minzdrav of Russia to determine the need in application of standards in laboratory practice.

Metamorphic Rock-Hosted Orogenic Gold Deposit Type as a Source of Langkowala Placer Gold, Bombana, Southeast Sulawesi

Directory of Open Access Journals (Sweden)

Arifudin Idrus

2014-06-01

Full Text Available DOI: 10.17014/ijog.v6i1.114In 2008, placer gold was discovered in Langkowala area (Bombana Regency, Southeast Sulawesi, Indonesia, and more than 60,000 traditional gold miners in the early 2009 have been operating by digging vertical pits and panning active stream sediments. The grade of placer gold ranges from 50 to 140 g/t. Local geological framework indicates that the placer gold is not related to volcanic rock-related hydrothermal gold deposit, e.g. epithermal, skarn or porphyry. This paper describes a preliminary study on possible primary deposit type as a source of the Langkowala (Bombana secondary placer gold. A field study indicates that the Langkowala (Bombana placer/paleoplacer gold is possibly related to gold-bearing quartz veins/veinlets hosted by metamorphic rocks particularly mica schist and metasediments in the area. These quartz veins/veinlets are currently recognized in metamorphic rocks at Wumbubangka Mountains, a northern flank of Rumbia Mountain Range. Sheared, segmented quartz veins/veinlets are of 2 cm to 2 m in width and contain gold in a grade varying between 2 and 61 g/t. At least, there are two generations of the quartz veins. The first generation of quartz vein is parallel to foliation of mica schist and metasediments with general orientation of N 300oE/60o; the second quartz vein generation crosscut the first quartz vein and the foliation of the wallrock. The first quartz veins are mostly sheared/deformed, brecciated, and occasionally sigmoidal, whereas the second quartz veins are relatively massive. The similar quartz veins/veinlets types are also probably present in Mendoke Mountain Range, in the northern side of Langkowala area. This primary gold deposit is called as ‘orogenic gold type’. The orogenic gold deposit could be a new target of gold exploration in Indonesia in the future.

Spectrophotometric Evaluation of Polyetheretherketone (PEEK as a Core Material and a Comparison with Gold Standard Core Materials

Directory of Open Access Journals (Sweden)

Bogna Stawarczyk

2016-06-01

Full Text Available This study investigated the colorimetric properties of different veneering materials on core materials. Standardized specimens (10 mm × 10 mm × 1.5 mm reflecting four core (polyetheretherketone (PEEK, zirconia (ZrO2, cobalt–chromium–molybdenum alloy (CoCrMo, and titanium oxide (TiO2; thickness: 1.5 mm and veneering materials (VITA Mark II, IPS e.max CAD, LAVA Ultimate and VITA Enamic, all in shade A3; thickness: 0.5, 1.0, 1.5 and 2 mm, respectively were fabricated. Specimens were superimposed to assemblies, and the color was determined with a spectrophotometer (CieLab-System or a chair-side color measurement device (VITA EasyShade, respectively. Data were analyzed using three-, two-, and one-way ANOVA, a Chi2-test, and a Wilson approach (p < 0.05. The measurements with EasyShade showed A2 for VITA Mark II, A3.5 for VITA Enamic, B2 for LAVA Ultimate, and B3 for IPS e.max CAD. LabE-values showed significant differences between the tested veneering materials (p < 0.001. CieLab-System and VITA EasyShade parameters of the different assemblies showed a significant impact of core (p < 0.001, veneering material (p < 0.001, and thickness of the veneering material (p < 0.001. PEEK as core material showed comparable outcomes as compared to ZrO2 and CoCrMo, with respect to CieLab-System parameters for each veneering material. The relative frequency of the measured VITA EasyShade parameters regarding PEEK cores also showed comparable results as compared to the gold standard CoCrMo, regardless of the veneering material used.

DNA biosensor for detection of Salmonella typhi from blood sample of typhoid fever patient using gold electrode modified by self-assembled monolayers of thiols

Science.gov (United States)

Suryapratiwi, Windha Novita; Paat, Vlagia Indira; Gaffar, Shabarni; Hartati, Yeni Wahyuni

2017-05-01

Electrochemical biosensors are currently being developed in order to handle various clinical problems in diagnosing infectious diseases caused by pathogenic bacteria, or viruses. On this research, voltammetric DNA biosensor using gold electrode modified by thiols with self-assembled monolayers had been developed to detect a certain sequence of Salmonella typhi DNA from blood sample of typhoid fever patient. Thiol groups of cysteamines (Cys) and aldehyde groups from glutaraldehydes (Glu) were used as a link to increase the performance of gold electrode in detecting guanine oxidation signal of hybridized S. typhi DNA and ssDNA probe. Standard calibration method was used to determine analytical parameters from the measurements. The result shown that, the detection of S. typhi DNA from blood sample of typhoid fever patient can be carried out by voltammetry using gold electrode modified by self-assembled monolayers of thiols. A characteristic oxidation potential of guanine using Au/Cys/Gluwas obtained at +0.17 until +0.20 V. Limit of detection and limit of quantification from this measurements were 1.91μg mL-1 and 6.35 μg mL-1. The concentration of complement DNA from sample was 6.96 μg mL-1.

Medicinal gold compounds

International Nuclear Information System (INIS)

Parish, R.V.; Cottrill, S.M.

1987-01-01

A major use of gold compounds in the pharmaceutical industry is for anti-arthritic agents. The disease itself is not understood and little is known about the way in which the drugs act, but detailed pictures of the distribution of gold in the body are available, and some of the relevant biochemistry is beginning to emerge. The purpose of this article is to give a survey of the types of compounds presently employed in medicine, of the distribution of gold in the body which results from their use, and of some relevant chemistry. Emphasis is placed on results obtained in the last few years

Spectroscopic diagnostic of gold plasma

International Nuclear Information System (INIS)

Busquet, M.

1986-01-01

Results of a simulation of a gold-aluminium alloy target irradiated by laser are presented. FCI code has been used with a processing out of LTE of atomic physics of gold and of multigroup photonics. Emission and reabsorption of gold and aluminium lines are included [fr

Application of K0-NAA in the Determination of Gold and other Trace Elements in Mineralized Rocks from El-Sid Gold District, Eastern Desert, Egypt

International Nuclear Information System (INIS)

El Abd, A.; Hamdy, M.; Mostafa, M.; El-Amir, M.

2009-01-01

K 0 - neutron activation analysis is an important method for multi-element analysis . The NAA k - 0 was used to determine the concentration of gold and some other trace elements in the mineralized mafic (gabro) and ultramafic (serpentinite) rocks from El-Sid gold district, Central Eastern Desert, Egypt . The samples were properly prepared together with the standards Au, Zr and Ni and simultaneously irradiated in the irradiation position 2, which is characterized with the neutron spectrum parameters a = -0.01 and f =20. After activation, the samples were subjected to gamma-ray spectrometry, using a high-purity germanium detection system and computerized multichannel analyzer. The concentrations of 25 elements, beside gold were determined. The results showed that the concentrations of incompatible elements including rare earth elements, large-ion lithophile elements (Rb, Sr, Th, Ba, Cs and Na) and high field strength elements (Ta, Hf and Zr), and the compatible elements (transition elements Co and Cr) are different from one sample to another. The results were briefly discussed within the text of this research work.

Low Z target switching to increase tumor endothelial cell dose enhancement during gold nanoparticle-aided radiation therapy

Energy Technology Data Exchange (ETDEWEB)

Berbeco, Ross I., E-mail: rberbeco@partners.org; Detappe, Alexandre [Department of Radiation Oncology, Brigham and Women’s Hospital, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts 02115 (United States); Tsiamas, Panogiotis [Department of Radiation Oncology, St. Jude Children’s Hospital, Memphis, Tennessee 38105 (United States); Parsons, David; Yewondwossen, Mammo; Robar, James [Department of Radiation Oncology and Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia B3H 1V7 (Canada)

2016-01-15

Purpose: Previous studies have introduced gold nanoparticles as vascular-disrupting agents during radiation therapy. Crucial to this concept is the low energy photon content of the therapy radiation beam. The authors introduce a new mode of delivery including a linear accelerator target that can toggle between low Z and high Z targets during beam delivery. In this study, the authors examine the potential increase in tumor blood vessel endothelial cell radiation dose enhancement with the low Z target. Methods: The authors use Monte Carlo methods to simulate delivery of three different clinical photon beams: (1) a 6 MV standard (Cu/W) beam, (2) a 6 MV flattening filter free (Cu/W), and (3) a 6 MV (carbon) beam. The photon energy spectra for each scenario are generated for depths in tissue-equivalent material: 2, 10, and 20 cm. The endothelial dose enhancement for each target and depth is calculated using a previously published analytic method. Results: It is found that the carbon target increases the proportion of low energy (<150 keV) photons at 10 cm depth to 28% from 8% for the 6 MV standard (Cu/W) beam. This nearly quadrupling of the low energy photon content incident on a gold nanoparticle results in 7.7 times the endothelial dose enhancement as a 6 MV standard (Cu/W) beam at this depth. Increased surface dose from the low Z target can be mitigated by well-spaced beam arrangements. Conclusions: By using the fast-switching target, one can modulate the photon beam during delivery, producing a customized photon energy spectrum for each specific situation.

Separation and enrichment of gold(III) from environmental samples prior to its flame atomic absorption spectrometric determination

Energy Technology Data Exchange (ETDEWEB)

Senturk, Hasan Basri; Gundogdu, Ali [Department of Chemistry, Faculty of Arts and Sciences, Karadeniz Technical University, 61080 Trabzon (Turkey); Bulut, Volkan Numan [Department of Chemistry, Faculty of Arts and Sciences, Karadeniz Technical University, 28049 Giresun (Turkey); Duran, Celal [Department of Chemistry, Faculty of Arts and Sciences, Karadeniz Technical University, 61080 Trabzon (Turkey); Soylak, Mustafa [Department of Chemistry, Faculty of Arts and Sciences, Erciyes University, 38039 Kayseri (Turkey)], E-mail: soylak@erciyes.edu.tr; Elci, Latif [Department of Chemistry, Faculty of Arts and Sciences, Pamukkale University, 20020 Denizli (Turkey); Tufekci, Mehmet [Department of Chemistry, Faculty of Arts and Sciences, Karadeniz Technical University, 61080 Trabzon (Turkey)

2007-10-22

A simple and accurate method was developed for separation and enrichment of trace levels of gold in environmental samples. The method is based on the adsorption of Au(III)-diethyldithiocarbamate complex on Amberlite XAD-2000 resin prior to the analysis of gold by flame atomic absorption spectrometry after elution with 1 mol L{sup -1} HNO{sub 3} in acetone. Some parameters including nitric acid concentration, eluent type, matrix ions, sample volume, sample flow rate and adsorption capacity were investigated on the recovery of gold(III). The recovery values for gold(III) and detection limit of gold were greater than 95% and 16.6 {mu}g L{sup -1}, respectively. The preconcentration factor was 200. The relative standard deviation of the method was <6%. The adsorption capacity of the resin was 12.3 mg g{sup -1}. The validation of the presented procedure was checked by the analysis of CRM-SA-C Sandy Soil certified reference material. The presented procedure was applied to the determination of gold in some environmental samples.

Novel solid phase extraction procedure for gold(III) on Dowex M 4195 prior to its flame atomic absorption spectrometric determination

Energy Technology Data Exchange (ETDEWEB)

Tuzen, Mustafa [Gaziosmanpasa University, Faculty of Science and Arts, Chemistry Department, 60250 Tokat (Turkey)], E-mail: mtuzen@gop.edu.tr; Saygi, Kadriye O. [Gaziosmanpasa University, Faculty of Science and Arts, Chemistry Department, 60250 Tokat (Turkey); Soylak, Mustafa [Erciyes University, Faculty of Science and Arts, Chemistry Department, 38039 Kayseri (Turkey)

2008-08-15

A method for solid phase extraction (SPE) of gold(III) using Dowex M 4195 chelating resin has been developed. The optimum experimental conditions for the quantitative sorption of gold(III), pH, effect of flow rates, eluent types, sorption capacity and the effect of diverse ions on the sorption of gold(III) have been investigated. The chelating resin can be reused for more than 100 cycles of sorption-desorption without any significant change in sorption of gold(III) ions. The recovery values for gold(III) and detection limit (LOD) of gold were greater than 95% and 1.61 {mu}g L{sup -1}, respectively. The preconcentration factor was 31. The relative standard deviation of the method was <5%. The adsorption capacity of the resin was 8.1 mg g{sup -1}. The proposed method has been applied for the determination of gold(III) in some real samples including water, soil and sediment samples.

Antimicrobial activity of silver and gold in toothpastes: A comparative analysis.

Science.gov (United States)

Junevičius, Jonas; Žilinskas, Juozas; Česaitis, Kęstutis; Česaitienė, Gabrielė; Gleiznys, Darius; Maželienė, Žaneta

2015-01-01

In this study, we compared the antimicrobial activity of identical toothpastes differing only in silver or gold nanoparticles against the activity of one of the common toothpastes containing a chemical active ingredient. We also compared the active concentrations of the toothpastes. For this study, we selected "Royal Denta" toothpastes containing silver and gold particles, and the "Blend-A-Med Complete" toothpaste containing zinc citrate as the active ingredient. We used 8 standard microorganism cultures on the basis of their individual mechanisms of protection. The antimicrobial activity of each studied preparation was evaluated at 9 concentrations. Most effective against gram-positive bacteria (Staphylococcus aureus and Enterococcus faecalis) was the "Silver Technology" – MIC was 0.004-0.0015 g/mL. Neither "Silver Technology" nor "Orange and Gold Technology" had any effect on Escherichia coli or Proteus mirabilis. Antimicrobial activity against the motile bacterium Proteus mirabilis was observed in "Silver Technology", "Orange and Gold Technology", and "Blend-A-Med Complete" – the MIC was 0.015 g/mL or lower. No antimicrobial activity against Candida albicans fungus at the studied concentrations was observed in the "Orange and Gold Technology". The toothpaste "Blend-A-Med" demonstrated the most effective antimicrobial activity - the MIC of 0.0015 g/mL and 0.015 g/mL inhibited Staphylococcus aureus and Enterococcus faecalis, respectively, and the MIC of 0.15 g/mL inhibited the growth of the bacteria Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, and fungus Candida albicans. Silver in toothpaste has a greater antimicrobial effect than gold, but its effect is still inferior to that of a chemical antimicrobial agent.

Spherical aggregates composed of gold nanoparticles

International Nuclear Information System (INIS)

Chen, C-C; Kuo, P-L; Cheng, Y-C

2009-01-01

Alkylated triethylenetetramine (C12E3) was synthesized and used as both a reductant in the preparation of gold nanoparticles by the reduction of HAuCl 4 and a stabilizer in the subsequent self-assembly of the gold nanoparticles. In acidic aqueous solution, spherical aggregates (with a diameter of about 202 ± 22 nm) of gold nanoparticles (with the mean diameter of ∼18.7 nm) were formed. The anion-induced ammonium adsorption of the alkylated amines on the gold nanoparticles was considered to provide the electrostatic repulsion and steric hindrance between the gold nanoparticles, which constituted the barrier that prevented the individual particles from coagulating. However, as the amino groups became deprotonated with increasing pH, the ammonium adsorption was weakened, and the amino groups were desorbed from the gold surface, resulting in discrete gold particles. The results indicate that the morphology of the reduced gold nanoparticles is controllable through pH-'tunable' aggregation under the mediation of the amino groups of alkylated amine to create spherical microstructures.

Methodological aspects of clinical trials in tinnitus: A proposal for an international standard

Science.gov (United States)

Landgrebe, Michael; Azevedo, Andréia; Baguley, David; Bauer, Carol; Cacace, Anthony; Coelho, Claudia; Dornhoffer, John; Figueiredo, Ricardo; Flor, Herta; Hajak, Goeran; van de Heyning, Paul; Hiller, Wolfgang; Khedr, Eman; Kleinjung, Tobias; Koller, Michael; Lainez, Jose Miguel; Londero, Alain; Martin, William H.; Mennemeier, Mark; Piccirillo, Jay; De Ridder, Dirk; Rupprecht, Rainer; Searchfield, Grant; Vanneste, Sven; Zeman, Florian; Langguth, Berthold

2013-01-01

Chronic tinnitus is a common condition with a high burden of disease. While many different treatments are used in clinical practice, the evidence for the efficacy of these treatments is low and the variance of treatment response between individuals is high. This is most likely due to the great heterogeneity of tinnitus with respect to clinical features as well as underlying pathophysiological mechanisms. There is a clear need to find effective treatment options in tinnitus, however, clinical trials differ substantially with respect to methodological quality and design. Consequently, the conclusions that can be derived from these studies are limited and jeopardize comparison between studies. Here, we discuss our view of the most important aspects of trial design in clinical studies in tinnitus and make suggestions for an international methodological standard in tinnitus trials. We hope that the proposed methodological standard will stimulate scientific discussion and will help to improve the quality of trials in tinnitus. PMID:22789414

The Performance of Standardized Patients in Portraying Clinical Scenarios in Speech-Language Therapy

Science.gov (United States)

Hill, Anne E.; Davidson, Bronwyn J.; Theodoros, Deborah G.

2013-01-01

Background: Standardized patients (SPs) are frequently included in the clinical preparation of students in the health sciences. An acknowledged benefit of using SPs is the opportunity to provide a standardized method by which students can demonstrate and develop their competency. Relatively little is known, however, about the capacity of SPs to…

41 CFR 101-45.002 - Gold.

Science.gov (United States)

2010-07-01

... 41 Public Contracts and Property Management 2 2010-07-01 2010-07-01 true Gold. 101-45.002 Section... PERSONAL PROPERTY § 101-45.002 Gold. (a) Gold will be sold in accordance with this section and part 102-38 of the Federal Management Regulation. (b) Sales of gold shall be processed to— (1) Use the sealed bid...

Omentoplasty in Perforated Peptic Ulcer Surgery: Is it Still the Gold ...

African Journals Online (AJOL)

multiruka1

the stimulus for fibrin formation. Very often surgeons mention „using a Graham patch‟, but what they actually. Omentoplasty in Perforated Peptic Ulcer Surgery: Is it Still the Gold Standard? Paul Ochieng‟ Odula. School of Medicine, University of Nairobi. Correspondence to: Dr. Paul Odula, P.O. Box 19762 – 00202, Nairobi, ...

Micro-Computed Tomography Detection of Gold Nanoparticle-Labelled Mesenchymal Stem Cells in the Rat Subretinal Layer

Science.gov (United States)

Mok, Pooi Ling; Leow, Sue Ngein; Koh, Avin Ee-Hwan; Mohd Nizam, Hairul Harun; Ding, Suet Lee Shirley; Luu, Chi; Ruhaslizan, Raduan; Wong, Hon Seng; Halim, Wan Haslina Wan Abdul; Ng, Min Hwei; Idrus, Ruszymah Binti Hj.; Chowdhury, Shiplu Roy; Bastion, Catherine Mae-Lynn; Subbiah, Suresh Kumar; Higuchi, Akon; Alarfaj, Abdullah A.; Then, Kong Yong

2017-01-01

Mesenchymal stem cells are widely used in many pre-clinical and clinical settings. Despite advances in molecular technology; the migration and homing activities of these cells in in vivo systems are not well understood. Labelling mesenchymal stem cells with gold nanoparticles has no cytotoxic effect and may offer suitable indications for stem cell tracking. Here, we report a simple protocol to label mesenchymal stem cells using 80 nm gold nanoparticles. Once the cells and particles were incubated together for 24 h, the labelled products were injected into the rat subretinal layer. Micro-computed tomography was then conducted on the 15th and 30th day post-injection to track the movement of these cells, as visualized by an area of hyperdensity from the coronal section images of the rat head. In addition, we confirmed the cellular uptake of the gold nanoparticles by the mesenchymal stem cells using transmission electron microscopy. As opposed to other methods, the current protocol provides a simple, less labour-intensive and more efficient labelling mechanism for real-time cell tracking. Finally, we discuss the potential manipulations of gold nanoparticles in stem cells for cell replacement and cancer therapy in ocular disorders or diseases. PMID:28208719

Micro-Computed Tomography Detection of Gold Nanoparticle-Labelled Mesenchymal Stem Cells in the Rat Subretinal Layer.

Science.gov (United States)

Mok, Pooi Ling; Leow, Sue Ngein; Koh, Avin Ee-Hwan; Mohd Nizam, Hairul Harun; Ding, Suet Lee Shirley; Luu, Chi; Ruhaslizan, Raduan; Wong, Hon Seng; Halim, Wan Haslina Wan Abdul; Ng, Min Hwei; Idrus, Ruszymah Binti Hj; Chowdhury, Shiplu Roy; Bastion, Catherine Mae-Lynn; Subbiah, Suresh Kumar; Higuchi, Akon; Alarfaj, Abdullah A; Then, Kong Yong

2017-02-08

Mesenchymal stem cells are widely used in many pre-clinical and clinical settings. Despite advances in molecular technology; the migration and homing activities of these cells in in vivo systems are not well understood. Labelling mesenchymal stem cells with gold nanoparticles has no cytotoxic effect and may offer suitable indications for stem cell tracking. Here, we report a simple protocol to label mesenchymal stem cells using 80 nm gold nanoparticles. Once the cells and particles were incubated together for 24 h, the labelled products were injected into the rat subretinal layer. Micro-computed tomography was then conducted on the 15th and 30th day post-injection to track the movement of these cells, as visualized by an area of hyperdensity from the coronal section images of the rat head. In addition, we confirmed the cellular uptake of the gold nanoparticles by the mesenchymal stem cells using transmission electron microscopy. As opposed to other methods, the current protocol provides a simple, less labour-intensive and more efficient labelling mechanism for real-time cell tracking. Finally, we discuss the potential manipulations of gold nanoparticles in stem cells for cell replacement and cancer therapy in ocular disorders or diseases.

The free electron laser: a system capable of determining the gold standard in laser vision correction