bluuebunny/crossref_metadata_2025 huggingface dataset:
In-vitro evaluation of an experimental method for bonding of orthodontic brackets with self-adhesive resin cements
Authors: Ramazanzadeh Barat Ali , Merati Mohsen , Shafaee Hooman , Dogon Leon , Sohrabi Keyvan
Published: August 2013

Background: Self-adhesive resin cements do not require the surface treatment of teeth and are said to release fluoride, which makes them suitable candidates for bonding of orthodontic brackets. The objectives of this study was to investigate the shear bond strength (SBS) of self-adhesive resin cements on etched on non-etched surfaces in vitro and to assess their fluoride release features. Materials and Methods: Four fluoride-releasing dual-cure self-adhesive resin cements were investigated. For SBS experiment, 135 freshly extracted human maxillary premolars were used and divided into nine groups of 15 teeth. In the control group, brackets were cemented by Transbond XT (3M Unitek, USA), in four groups self-adhesive resin cements were used without acid-etching and in four groups self-adhesive cements were applied on acid-etched surfaces and the brackets were then deboned in shear with a testing machine. Adhesive remnant index (ARI) scores were also calculated. For fluoride release investigation, 6 discs were prepared for each self-adhesive cement. Transbond XT and Fuji Ortho LC (GC, Japan) served as negative and positive control groups, respectively. The fluoride release of each disc into 5 ml of de-ionized water was measured at days 1, 2, 3, 7, 14, 28, and 56 using a fluoride ion-selective electrode connected to an ion analyzer. To prevent cumulative measurements, the storage solutions were changed daily. Results: The SBS of brackets cemented with Transbond XT were significantly higher compared to self-adhesives applied on non-etched surfaces (P<0.001). However, when the self-adhesive resin cements were used with enamel etching, no significant differences was found in the SBS compared to Transbond XT, except for Breeze. The comparisons of the ARI scores indicated that bracket failure modes were significantly different between the etched and non-etched groups. All self-adhesive cements released clinically sufficient amounts of fluoride for an extended period of time. Conclusion: For the tested cements, the strongest bonds were obtained by enamel acid-etching prior to bracket bonding. All the self-adhesive resin cements had significant long-term fluoride release and could be recommended as suitable fluoride-releasing orthodontic bonding materials.
Dental anxiety: Prevalence and associated factors
Authors: Hawamdeh Sana , Awad Manal
Published: August 2013

Objectives: This study aimed to estimate the prevalence of dental anxiety and examine the socio-demographic associations of dental anxiety among a representative sample of UAE college populations. Materials and Methods: Four hundred and thirteen college students of Sharjah University in the UAE completed Modified Corah’s Dental Anxiety Scale (MDAS) (47% males and 53% females). The survey also included questions in a yes/no format with which respondents rated attributions for their anxiety. Results: Prevalence of dental anxiety (MDAS score of 13 or more) was 36%, with overall severity represented by a mean score of 11.52 (SD: 4.88). Students who visited their dentist more than two years ago had significantly higher MDAS scores compared with those who visited their dentist less than two years ago (t-test, P=0.02). Compared with female students, a significantly higher proportion of males indicated that their last visit to the dentist was more than two years ago (17% vs. 30%, respectively, χ2-test, P=0.002). In addition, more than half of the students (55%) perceived a need for a checkup and 54% indicated that they visited the dentist because of problems with their teeth. Conclusions: The findings of this study indicate that although dental anxiety was not associated with gender and frequency of dental visits, feeling of lack of control and pain anticipation were strong predictors of anxiety. These results highlight the important role that dental healthcare providers could play in counseling anxious patients to reduce the impact of these factors on seeking dental care.
A comparison of the wear resistance and hardness of two different indirect composite resins with a ceramic material, opposed to human enamel
Authors: Culhaoglu Ahmet Kursad , Park Joonge
Published: August 2013

Objectives: The aim of this study was to compare the two-body wear resistance of two different indirect composites and lithium disilicate porcelain versus human enamel antagonists. Materials and Methods: Ten specimens of each material (BelleGlass NG, Kerr Corp.; SR Adoro, Ivoclar Vivadent AG; IPS e.max, Ivoclar Vivadent AG) were fabricated. Indirect dental composites and all-ceramic restoration were compared by an in vitro tribological test against human teeth antagonist. Wear loss of antagonist was calculated using an image analyzer (Leica) Wear behavior of restorative materials was investigated with a profilometer after each individual tribological test. A scanning microscope was used to examine the crystal morphology of the samples; the crystal phases were identified by an X-ray diffractometer. Microhardness test results were analyzed using ANOVA. Kruskal Wallis multi-comparison test was used for evaluating the corrosion data. In order to understand whether there is a relationship between mean friction co-efficients, wear rate, and hardness, the statistical non-parametric relation test was used. Results: The indirect composites showed lower wear rate and friction co-efficient than all-ceramic dental materials against enamel. As for the wear loss of the enamel antagonists, the all-ceramic restorations were more harmful to human teeth than the dental composites. Conclusion: Indirect dental composite is relatively more wear-friendly than all-ceramic restoration. Furthermore, indirect composites are favorable and less offensive. Therefore, the second generation of indirect composites is promising in long-life dental restorations.
Initial boundary value problems for the two-component shallow water systems
Authors: Yan Kai , Yin Zhaoyang
Published: August 2013

In this paper we study initial boundary value problems of three types of two-component shallow water systems on the half line subject to homogeneous Dirichlet boundary conditions. We first prove local well-possedness of the two-component Camassa–Holm system, the modified two-component Camassa–Holm system, and the two-component Degasperis–Procesi system in the Besov spaces. Then, we are able to specify certain conditions on the initial data which on the one hand guarantee global existence and on the other hand produce solutions with a finite lifespan. Moreover, in the case of finite time singularities we are able to describe the precise blow-up scenario for breaking waves. Finally we investigate global weak solutions for the two-component Camassa–Holm system and the modified two-component Camassa–Holm system on the half line, respectively. Our approach is based on sharp extension results for functions on the half line and several symmetry preserving properties of the systems under discussion.
Monodromy zeta function formula for embedded $\mathbf{Q}$-resolutions
Authors: Martín-Morales Jorge
Published: August 2013

In previous work we have introduced the notion of an embedded

\mathbf{Q}

-resolution, which essentially consists in allowing the final ambient space to contain abelian quotient singularities. Here we give a generalization to this setting of N. A’Campo’s formula for the monodromy zeta function of a singularity. Some examples of its application are shown.
Density of Lipschitz functions and equivalence of weak gradients in metric measure spaces
Authors: Ambrosio Luigi , Gigli Nicola , Savaré Giuseppe
Published: August 2013

We compare several notions of weak (modulus of) gradients in metric measure spaces and prove their equivalence. Using tools from optimal transportation theory we prove density in energy of Lipschitz maps independently of doubling and Poincaré assumptions on the metric measure space.
Single annulus $L^p$ estimates for Hilbert transforms along vector fields
Authors: Bateman Michael
Published: August 2013

We prove

L^p

estimates,

p\in (1,\infty)

, on the Hilbert transform along a one variable vector field acting on functions with frequency support in an annulus. Estimates when

p>2

were proved by Lacey and Li. This paper also contains key technical ingredients for a companion paper with Christoph Thiele in which

L^p

estimates are established for the full Hilbert transform. The operators considered here are singular integral variants of maximal operators arising in the study of planar differentiation problems.
Analysis of passive-sampler monitored atmospheric ammonia at 74 sites across southern Ontario, Canada
Authors: Yao X. H. , Zhang L.
Published: August 2013

Abstract. Weekly/biweekly concentrations of atmospheric NH3 were collected using passive samplers at 74 sites across southern Ontario, Canada during the period from June 2006 to March 2007 with tens of sites running as early as March 2006. The annual average of NH3 (AAN) at all the sites across southwestern Ontario was over 1 µg m–3, a value that was recently proposed as the new critical level for protecting vegetation. High ANN values (3.6–6.1 µg m–3) were observed at eight sites located inside the intensive livestock production zones. The AAN values at the sites across southeastern Ontario were generally less than 1 µg m–3 and the values were less than 0.4 µg m–3 at non-agricultural sites. Regional transport from the southwest region to the southeast region was identified to be the main contributor to the observed NH3 at the southeastern non-agricultural sites. However, different transport mechanisms were proposed in different seasons. The transport of NH3 produced through bi-directional air-surface exchange along air mass trajectories was believed to be the main mechanism in the hot seasons while the transport of NH4NO3 produced at source locations followed by its evaporation at receptor sites was thought to be dominant in the cold seasons. A sharp increase in NH3 concentration was surprisingly observed at 20 out of the 74 sites during the coldest two weeks when ambient temperature was lower than −7 °C, and cannot be explained by known sources or with existing knowledge. Recently developed NH3 emission inventory for southern Ontario was also evaluated with the measurement data and emissions within two small zones were identified to be potentially underestimated.
Model study of the circulation of the Miocene Mediterranean Sea and Paratethys: closure of the Indian Gateway
Authors: de la Vara A. , Meijer P. Th. , Wortel M. J. R.
Published: August 2013

Abstract. The early Mediterranean Sea and the Paratethys were both connected to the Indian Ocean until the Early/Middle Miocene, when the convergence of the Eurasian and African-Arabian plates caused the constriction and final closure of the Indian Gateway. Although little is certain concerning the timing of the closure and the consequences that it entailed, it is broadly accepted that it had a large effect on water properties and ocean dynamics on the regional and global scales and, in that way, may have also played a role in the evolution of climate. The purpose of this work is to investigate the palaeocirculation of the Mediterranean Sea and the Paratethys during different stages of closure and the impact of this event on the water exchange between the Mediterranean and the adjacent Indian and Atlantic oceans. To this extent we use a regional ocean model and an Early Miocene palaeogeographic map. In addition to varying the depth of the Indian Gateway, different sets of values for the atmospheric forcing have been applied in order to check the robustness of our results and to understand the role of the temperature and net evaporation on the marine circulation and the strait dynamics. The series of experiments performed shows that, with an Indian Gateway ranging from 1000 to 460 m deep, the Mediterranean accommodates anti-estuarine exchange to the Indian and Atlantic oceans. The shoaling of the Indian Gateway results in a progressive decrease in the water exchanged between the Indian Ocean and the Mediterranean basin, and increases the spatial extension of the Atlantic inflow. When the gateway is as shallow as 220 m, there is no effective water exchange between the Indian Ocean and the Mediterranean basin, suggesting that the gateway may have been closed in an oceanographical sense, even while a water passage was still in existence. On a basinal scale, closure results in a rearrangement of the circulation pattern which leads to changes in salinity and temperature in both the Paratethys and the Mediterranean Sea. On the global scale, closure implies the disappearance of a source of dense outflow into the Indian Ocean which could have played a role in the development of the East Antarctic Ice Sheet. The additional experiments show that the response to gateway shoaling is largely independent of the assumed atmospheric forcing.
Maximum entropy production: can it be used to constrain conceptual hydrological models?
Authors: Westhoff M. C. , Zehe E.
Published: August 2013

Abstract. In recent years, optimality principles have been proposed to constrain hydrological models. The principle of maximum entropy production (MEP) is one of the proposed principles and is subject of this study. It states that a steady state system is organized in such a way that entropy production is maximized. Although successful applications have been reported in literature, generally little guidance has been given on how to apply the principle. The aim of this paper is to use the maximum power principle – which is closely related to MEP – to constrain parameters of a simple conceptual (bucket) model. Although, we had to conclude that conceptual bucket models could not be constrained with respect to maximum power, this study sheds more light on how to use and how not to use the principle. Several of these issues have been correctly applied in other studies, but have not been explained or discussed as such. While other studies were based on resistance formulations, where the quantity to be optimized is a linear function of the resistance to be identified, our study shows that the approach also works for formulations that are only linear in the log-transformed space. Moreover, we showed that parameters describing process thresholds or influencing boundary conditions cannot be constrained. We furthermore conclude that, in order to apply the principle correctly, the model should be (1) physically based; i.e. fluxes should be defined as a gradient divided by a resistance, (2) the optimized flux should have a feedback on the gradient; i.e. the influence of boundary conditions on gradients should be minimal, (3) the temporal scale of the model should be chosen in such a way that the parameter that is optimized is constant over the modelling period, (4) only when the correct feedbacks are implemented the fluxes can be correctly optimized and (5) there should be a trade-off between two or more fluxes. Although our application of the maximum power principle did not work, and although the principle is a hypothesis that should still be thoroughly tested, we believe that the principle still has potential in advancing hydrological science.
High-Throughput Analytical Techniques for Multiresidue, Multiclass Determination of 653 Pesticides and Chemical Pollutants in Tea—Part III: Evaluation of the Cleanup Efficiency of an SPE Cartridge Newly Developed for Multiresidues in Tea
Authors: Pang Guo-Fang , Fan Chun-Lin , Chang Qiao-Ying , Li Yan , Kang Jian , Wang Wen-Wen , Cao Jing , Zhao Yan-Bing , Li Nan , Li Zeng-Yin , Chen Zong-Mao , Luo Feng-Jian , Lou Zheng-Yun
Published: August 2013

A comparative study was conducted over three stages on the cleanup efficiency of SPE cartridge Cleanert TPT, newly developed for multigroups of pesticide residues in tea. In Stage I, different SPE cartridges C18, graphite carbon black (GCB), primary secondary amine (PSA), and amino (NH2) were purchased and combined into 12 different sequences. Through the comparative test on cleanup efficiency of 84 representative pesticides in tea, Envi-Carb GCB + PSA with a good cleanup effect was selected. In Stage II, GC/MS test results from the comparative study of the extraction efficiency of 201 pesticides spiked into green tea and Woolong tea with Cleanert TPT and Envi-Carb + PSA SPE showed that average recoveries fell within 70–110% and RSD <20% for 193 and 184 pesticides, respectively, for green tea, accounting for 96.0 and 91.0% of the total number, respectively. GC/MS/MS test results also found 193 and 184 pesticides, respectively, meeting the recovery and RSD conditions, accounting for 96.0 and 91.5%, respectively, of the total number. For Woolong tea samples, GC/MS results showed that with Cleanert TPT and Envi-Carb + PSA SPE for cleanup, there were 192 and 177 pesticides, respectively, meeting the conditions, accounting for 95.5 and 88.1% of the total number, respectively. GC/MS/MS results demonstrated that there were 195 and 184 pesticides, respectively, meeting the conditions, accounting for 97.0 and 91.5% of the total number, respectively. It was seen that Cleanert TPT was superior to Envi-Carb + PSA in cleanup efficiency, whether for green or Woolong tea samples, or GC/MS or GC/MS/MS determination. In Stage III, 61 104 results of the average content value of pesticides and RSD (two teas × two Youden pair concentrations × two kinds of SPE cartridges × two instruments × 19 tests × 201 pesticides) were derived from the 19 times stability tests over 3 months by paralleling three samples every 5 days via two instruments with two kinds of SPE cartridges for cleanup, respectively, against Youden Pair samples of the 201 incurred pesticides from green and Woolong teas. The statistical analysis found that detected values from the target pesticides of the incurred Youden pair samples showed no marked differences with cleanup by either Cleanert TPT or Envi-Carb + PSA, whether for green or Woolong tea, or GC/MS or GC/MS/MS. The test results using the two aforementioned kinds of SPE cleanup for above 93% pesticides had a tolerance less than 15%, which testifies that both cartridge cleanups met the requirement for pesticide residue analysis.
Development and Validation of an Analytical Method for Quantification of Arsenic and Antimony in Liposomes Using Inductively Coupled Plasma-Optical Emission Spectrometry
Authors: Reis Priscila G , Abreu Adriana T , Guimarães Andrea G , Teixeira Mônica C , de Souza Jacqueline , Silva-Barcellos Neila M
Published: August 2013

Arsenic and antimony compounds are used to treat endemic diseases, such as cancer, leishmaniasis, and schistosomiasis, in spite of their toxicity. Several studies seeking the development and characterization of nanocarrier systems such as liposomes are being carried out with the aim of developing new drug delivery systems and minimizing the toxicity of these drugs. However, the lack of reference methods to quantify these semimetals within a liposomal matrix hinders the QC of these formulations. Therefore, the validation of an analytical method for arsenic and antimony quantification in liposomal matrix by inductively coupled plasma-optical emission spectrometry is presented here. The linearity, specificity, LOD, LOQ, accuracy, and precision were determined according to the International Conference on Harmonization norms and the Brazilian Health Surveillance Agency (Resolution 899). The LOD values were 0.02 and 0.06 mg/L for antimony and arsenic, respectively. The LOQ for both was 3.0 mg/L, with an adequate accuracy within 98.26 and 101.32% for different levels of antimony and 99.98 and 100.36% for arsenic. Precision (CV) was lower than 5.0%. The developed and validated method was shown to be reproducible for quantification of arsenic and antimony in liposome pharmaceutical dosage forms.
Extractive Spectrophotometric Determination of Some Nonsteroidal Anti-Inflammatory Drugs Using Methylene Blue
Authors: El-Kommos Michael E , Mohamed Niveen A , Abdel Hakiem Ahmed F
Published: August 2013

A simple, rapid, sensitive, and accurate extractive spectrophotometric method has been developed for the determination of seven nonsteroidal anti-inflammatory drugs (NSAIDs)—namely diclofenac sodium, ibuprofen, indomethacin, ketoprofen, ketorolac tromethamine, mefenamic acid, and naproxen—in pure forms as well as their pharmaceutical dosage forms (tablets, capsules, effervescent granules, syrups, oral drops, ampules, eye drops, gels, and suppositories). The method depends on the formation of an intensely colored ion-pair complex between the acidic drug and methylene blue in alkaline medium. The complex is stable and extractable into methylene chloride. All parameters were optimized. Beer-Lambert's law was obeyed in concentrations ranging from 0.04 to 9 μg/mL. Statistical analysis of the calibration data was carried out, and correlation coefficients were in the range from 0.9996 to 0.9998. The developed method was fully validated according to International Conference on Harmonization guidelines, and complied with U.S. Pharmacopeia guidelines. The proposed method was applied to the analysis of the investigated drugs in their pharmaceutical formulations, and good recoveries were obtained. The results obtained were compared with those of reported and official methods, and no significant differences were found with t- and F-tests. Interference effects of some compounds usually present in combination with NSAIDs were studied, and the tolerance limits of these compounds were determined.
Multivariate Optimization of Separation Conditions for Simultaneous Determination of Acemetacin and Chlorzoxazone in a Pharmaceutical Preparation by HPLC Using Response Surface Methodology
Authors: Aybaba Cigdem , Palabiyik Ismail Murat , Caglayan Mehmet Gokhan , Onur Feyyaz
Published: August 2013

A new, fast, accurate, precise, and sensitive RP-HPLC method for the simultaneous determination of acemetacin and chlorzoxazone has been developed. Response surface methodology with a central composite design was used to optimize the acetonitrile and ammonium acetate percentage in the mobile phase and pH of ammonium acetate. The optimum separation was achieved on a C18 column (250 × 4.6 mm id, 5 μm particle size) using the mobile phase methanol–acetonitrile–0.02 M ammonium acetate, pH 9.4 (25 + 35 + 40, v/v/v) at a flow rate of 1.5 mL/min; UV detection at 270 nm, and cyanocobalamin as an internal standard. This developed method was validated and successfully applied to a coated tablet pharmaceutical preparation.
Method Development andValidation for the Simultaneous Determination of Organochlorine and Organophosphorus Pesticides in a Complex Sediment Matrix
Authors: Alcántara-Concepción Victor , Cram Silke , Gibson Richard , de León Claudia Ponce , Mazari-Hiriart Marisa
Published: August 2013

The Xochimilco area in the southeastern part of Mexico City has a variety of socioeconomic activities, such as periurban agriculture, which is of great importance in the Mexico City metropolitan area. Pesticides are used extensively, some being legal, mostly chlorpyrifos and malathion, and some illegal, mostly DDT. Sediments are a common sink for pesticides in aquatic systems near agricultural areas, and Xochimilco sediments have a complex composition with high contents of organic matter and clay that are ideal adsorption sites for organochlorine (OC) and organophosphorus (OP) pesticides. Therefore, it is important to have a quick, affordable, and reliable method to determine these pesticides. Conventional methods for the determination of OC and OP pesticides are long, laborious, and costly owing to the high volume of solvents and adsorbents. The present study developed and validated a method for determining 18 OC and five OP pesticides in sediments with high organic and clay contents. In contrast with other methods described in the literature, this method allows isolation of the 23 pesticides with a 12 min microwave-assisted extraction (MAE) and one-step cleanup of pesticides. The method developed is a simpler, time-saving procedure that uses only 3.5 g of dry sediment. The use of MAE eliminates excessive handling and the possible loss of analytes. It was shown that the use of LC-Si cartridges with hexane–ethyl acetate (75 + 25, v/v) in the cleanup procedure recovered all pesticides with rates between 70 and 120%. The validation parameters demonstrated good performance of the method, with intermediate precision ranging from 7.3 to 17.0%, HorRat indexes all below 0.5, and tests of accuracy with the 23 pesticides at three concentration levels demonstrating recoveries ranging from 74 to 114% and RSDs from 3.3 to 12.7%.
Determination of Chloramphenicol Residues in Aquatic Products Using Immunoaffinity Column Cleanup and High Performance Liquid Chromatography with Ultraviolet Detection
Authors: Zhang Qing-Jie , Peng Tao , Chen Dong-Dong , Xie Jie , Wang Xiong , Wang Guo-Min , Nie Chang-Ming
Published: August 2013

A method based on HPLC with UV detection was developed for the quantitative determination of chloramphenicol (CAP) residues in aquatic products. The samples were extracted with ethyl acetate–ammonium hydroxide (98 + 2, v/v), followed by a cleanup step using an immunoaffinity column. The analytes were determined by HPLC-UV. Optimal conditions for the extraction and cleanup procedures are described. The linear regression equation was y = 91.47x – 8.60 with R2 = 0.9998 (y = peak area and x = CAP concentration) and showed a good reproducibility. The LOQ was 0.25 μg/kg for determining CAP spiked in the aquatic products. The mean recoveries of CAP from fish and shrimp samples fortified at 0.25–1.0 μg/kg were 88.7–93.1 and 92.0–97.3%, respectively; the repeatability RSDs were less than 8.1%. It was concluded that the method is simple, highly sensitive, and low cost for quantitatively measuring CAP residues in aquatic products. Analyte identification was confirmed by HPLC/MS/MS analysis.
Immunoaffinity Column Cleanup with LC/MS/MS for the Determination of Chloramphenicol in Honey and Prawns: Single-Laboratory Validation
Authors: Mackie Jennifer , Marley Elaine , Donnelly Carold
Published: August 2013

A single-laboratory validation was conducted to establish the effectiveness of an immunoaffinity column (IAC) cleanup procedure followed by LC/MS/MS for the determination of chloramphenicol (CAP) in honey and prawns. Honey is dissolved in buffer solution and centrifuged, and an aliquot applied to an IAC. For prawns, a portion of the homogenized sample is shaken with buffer and centrifuged, and an aliquot similarly applied to an IAC. For both matrix extracts, CAP is removed from the IAC with neat methanol, then directly analyzed by electrospray LC/MS/MS in the negative ionization mode using m/z 321 as a precursor ion and m/z 257 and 152 as qualifier and quantifier ions, respectively. Test portions of blank honey and prawns were fortified with CAP to give levels of 0.3, 1.0, and 5.0 μg/kg. Recoveries of CAP on 3 consecutive days ranged from 83–103% for honey and 84–108% for prawns. Based on results for fortified blank matrixes (triplicate at three levels), the RSD for repeatability (RSDr) averaged 8.4% for honey and 4.8% for prawns. The method LOD was 0.05 for prawns and 0.16 μg/kg for honey, both well below the minimum required method performance limit for CAP. The accuracy of the method was demonstrated by participation in proficiency testing, where satisfactory Z-scores were obtained for CAP in incurred samples of both honey and prawns. The method was shown to be applicable to a wide range of other matrixes, including milk, egg, royal jelly, meat, and seafood products.
Atlas™ Salmonella Detection Method Using Transcription Mediated Amplification (TMA) to Detect Salmonella enterica in a Variety of Foods and Select Surfaces
Authors: Kwong William , Livezey Kristin , Reshatoff Michael , Vaughn Steve , Freed Anna , Puente Celina , Hu Ernie , Zukowski Alexis , Schweis Franz , Yang Hua , Fleischer Chad , Kamantigue Edgar , Morgan Jarrod , Koehler Robert , Maroni Brett , Becker Michael , Wisniewski Michele
Published: August 2013

The Atlas™ Salmonella detection assay was compared to the reference culture methods for 12 foods and three surfaces. Comparison of the Atlas method to the U.S. Food and Drug Administration Bacteriological Analytical Manual (FDA/BAM) and U.S. Department of Agriculture-Food Safety and Inspection Service/Microbiology Laboratory Guidebook (USDA-FSIS/MLG) reference methods required an unpaired approach. Each method had a total of 320 samples inoculated with an S. enterica strain. Each food and surface was inoculated with a different strain of S. enterica at two different levels/method. Meat and egg products were compared to the USDA-FSIS/MLG 4.05 method. All other foods were compared to the FDA/BAM-5 method. The Atlas method had 148 positives out of 320 total inoculated samples, compared to 119 positives for the reference methods. Overall, the probability of detection analysis of the results showed equivalent or better performance by the Atlas Salmonella detection method compared to the reference methods. The Atlas Salmonella detection assay detected all 100 inclusive organisms and none of the 30 exclusive organisms. The lot-to-lot and kit stability studies showed no statistical differences between lots or over the term of the shelf-life. Instrument-to-instrument testing showed no statistical difference between instruments. Finally, the robustness study showed no difference when the sample volume added to the Atlas Salmonella detection assay varied by 10%, storage time was extended up to 5 days before analysis, or enrichment times were varied from 12 to 24 h.
Method for the Determination of Total Selenium in a Wide Variety of Foods Using Inductively Coupled Plasma/Mass Spectrometry
Authors: Sullivan Darryl , Zywicki Richard , Yancey Mark
Published: August 2013

An optimized method for use in a high volume laboratory was developed and validated for the determination of total selenium in a wide variety of food products including infant formula. The method utilizes a single-stage, closed-vessel microwave digestion procedure with nitric acid. Upon completion of digestion, the solution is brought to volume with water. A dilution is prepared for analysis by adding methanol (MeOH) to an aliquot and then brought to volume by nitric acid diluent resulting in a 3% MeOH concentration. The amount of selenium is determined by inductively coupled plasma (ICP)/MS with the capability of removing argon-based polyatomic interferences. Experiments were conducted to validate the method by determining precision, accuracy, linearity, specificity, ruggedness, and robustness. The calculated practical reporting level for this method was 25.0 μg/kg. The method provided an average RSD of 2.03% during analysis of a wheat flour reference material and 2.73% during analysis of a powdered infant formula. The accuracy of the method for these materials was 98.6 and 105%, respectively. The method has also been used successfully on a variety of foods from various categories including fruits, grains, vegetables, protein, and dairy.
Determination and Confirmation of Narasin and Monensin in Chicken, Swine, and Bovine Tissues by LC/MS/MS: Final Action 2011.24
Authors: Lombardi Kimberly R , Burnett Thomas J , Brunelle Sharon L , Ulrey W Dennis , Coleman Mark R ,   Collaborators:, Boison J , Connolly P , Danaher M , D’Angelo D , MacDougall J , Matus J , Rodewald J M , Ruiz S , Spilsbury L , Stephenson C , Song H , Zuidema T
Published: August 2013

A multilaboratory study was conducted to validate the reproducibility of AOAC Official MethodSM 2011.24 for determination of narasin and monensin in chicken, swine, and bovine tissues. This study was intended to satisfy requirements for Final Action status through the AOAC Expert Review Panel process. Ten laboratories participated in the study, analyzing blind duplicates of five incurred residue materials for each analyte. After removal of invalid data sets, the method reproducibility (RSDR 12.8–60.6%, HorRat 0.45–1.47) was within AOAC acceptance criteria. The method was awarded Final Action status by the Official Methods Board on October 4, 2012.
Determination and Confirmation of Parent and Total Ractopamine in Bovine, Swine, and Turkey Tissues by Liquid Chromatography with Tandem Mass Spectrometry: Final Action 2011.23
Authors: Ulrey W Dennis , Burnett Thomas J , Brunelle Sharon L , Lombardi Kimberly R , Coleman Mark R
Published: August 2013

A multilaboratory study of AOAC Official MethodSM 2011.23 was performed to satisfy requirements for Final Action status through the AOAC expert review panel process. The study included nine collaborating laboratories from the United States, Canada, Brazil, and The Netherlands. Five incurred residue materials (bovine muscle, bovine liver, swine muscle, swine liver, and turkey muscle) were analyzed by each laboratory as blind duplicates for parent and total ractopamine content. After removal of invalid data, the parent and total ractopamine methods demonstrated acceptable reproducibility (RSDR 11.4–42.4%, HorRatR 0.34–2.01) based on AOAC criteria. The method was awarded Final Action status by the Official Methods Board on October 4, 2012.
Flavanol and Procyanidin Content (by Degree of Polymerization 1–10) of Chocolate, Cocoa Liquors, Cocoa Powders, and Cocoa Extracts: First Action 2012.24
Authors: Robbins Rebecca J , Leonczak Jadwiga , Li Julia , Johnson J Christopher , Collins Tom , Kwik-Uribe Catherine , Schmitz Harold H ,   Collaborators:, Austad J , Bhandari S , Cifuentes T , Derck V , Ellem S , Ellingson D , Gallegos T , Groves M , Grypa R , Gu L , Hongyu W , Huang D , Johnson J C , Jones M , Kremers B , Kuhnle G , Li J , Mateos A R , Ottaviani J , Schaneberg B , Spencer J , Sullivan D , Vidts K , Wang W , Williamson G , Zapf M
Published: August 2013

An international collaborative study was conducted on an HPLC method with fluorescent detection for the determination of flavanols and procyanidins in chocolate and cocoa-containing materials. The sum of the oligomeric fractions with degree of polymerization 1–10 was the determined content value. Sample materials included dark and milk chocolates, cocoa powder, cocoa liquors, and cocoa extracts. The content ranged from approximately 2 to 500 mg/g (defatted basis). Thirteen laboratories—representing commercial, industrial, and academic institutions in six countries—participated in this interlaboratory study. Fourteen samples were sent as blind duplicates to the collaborators. Results for 12 laboratories yielded repeatability RSD (RSDr) values below 10% for all materials analyzed, ranging from 4.17 to 9.61%. Reproducibility RSD (RSDR) values ranged from 5.03 to 12.9% for samples containing 8.07 to 484.7 mg/g material analyzed. In one sample containing a low content of flavanols and procyanidins (approximately 2 mg/g), the RSDR was 17.68%.
ComparativeValidation Study To Demonstrate the Equivalence of a Minor Modification to AOAC Official Method 2005.04 Assurance GDS® E. coli O157:H7 Method to the Reference Culture Method: 375 Gram Sample Size
Authors: Feldsine Philip T , Montgomery-Fullerton Megan , Roa Nerie , Kaur Mandeep , Lienau Andrew H , Jucker Markus , Kerr David E
Published: August 2013

The Assurance GDS® Escherichia coli (E. coli) O157:H7, AOAC Official MethodSM 2005.04, has been modified to include a larger sample size of 375 g. A methods comparison study was conducted to demonstrate the equivalence of this modification to the reference culture method. Ninety samples and controls, representing three foods, were analyzed. Results show no statistically detectable difference between the Assurance GDS E. coli O157:H7 assay and the reference culture methods for the detection of E. coli O157:H7, other than the low level of inoculation for leaf lettuce, for which the GDS gave noticeably higher recovery [difference in probability of detection between candidate methods (dPODc = +0.45)]. There were also suggestions of moderate differences (dPODc = +0.15 to +0.20) for ground beef and the high level of leaf lettuce, but the study size was too small to detect differences of this size. Results showed that the Assurance GDS E. coli O157:H7 method is equivalent to reference culture methods for the detection of E. coli O157:H7.
Comparative Validation Study to Demonstrate the Equivalence of a Minor Modification to AOAC Official Method 2005.05 Assurance GDS® Shiga Toxin Genes (O157) Method to the Reference Culture Method: 375 Gram Sample Size
Authors: Feldsine Philip T , Montgomery-Fullerton Megan , Roa Nerie , Kaur Mandeep , Kerr David E , Lienau Andrew H , Jucker Markus
Published: August 2013

The Assurance GDS® Shiga Toxin Genes (O157), AOAC Official MethodSM 2005.05, has been modified to include a larger sample size of 375 g. A methods comparison study was conducted to demonstrate the equivalence of this modification to the reference culture method. Ninety samples and controls, representing three foods, were analyzed. Results show no statistically detectable difference between the Assurance GDS Escherichia coli O157:H7 assay and the reference culture methods for the detection of E. coli O157:H7, other than the low level of inoculation for leaf lettuce for which the GDS gave noticeably higher recovery [difference in Probability of Detection between candidate methods (dPODc = +0.45)]. There were also suggestions of moderate differences (dPODc = +0.15 to +0.20) for ground beef and the high level of leaf lettuce, but the study size was too small to detect differences of this size. Results showed that the Assurance GDS Shiga Toxin Genes (O157) method is equivalent to the reference culture methods for the detection of Shiga toxigenic E. coli O157:H7.
Why Health is a Planning Issue
Authors: Letts Lori , Milroy Beth Moore
Published: August 2013

Health is moving back onto the planning agenda. It used to be an issue closely associated with planning early in the century. Then it was scooped away as the preserve of medical care providers and rarely discussed in planning. Now it is appearing again as a planning issue.
Negative parenting behavior and childhood oppositional defiant disorder: Differential moderation by positive and negative peer regard
Authors: Tung Irene , Lee Steve S.
Published: August 2013

Although negative parenting behavior and peer status are independently associated with childhood conduct problems (e.g., oppositional defiant disorder (ODD)), relatively little is known about their interplay, particularly in relation to differentiated measures of positive and negative peer regard. To improve the specificity of the association of negative parenting behavior and peer factors with ODD, we explored the potential interaction of parenting and peer status in a sample of 169 five‐to ten‐year‐old ethnically diverse children with and without attention‐deficit/hyperactivity disorder (ADHD) assessed using multiple measures (i.e., rating scales, interview) and informants (i.e., parents, teachers). Controlling for children's age, sex, number of ADHD symptoms, and parents' race‐ethnicity, peer acceptance inversely predicted and inconsistent discipline, harsh punishment, and peer rejection were each positively associated with ODD symptom severity. Interactive influences were also evident such that inconsistent discipline and harsh punishment each predicted elevated ODD but only among children experiencing low peer acceptance or high peer rejection. These findings suggest that supportive environments, including peer acceptance, may protect children from negative outcomes associated with inconsistent discipline and harsh punishment. Findings are integrated with theories of social support, and we additionally consider implications for intervention and prevention. Aggr. Behav. 40:79–90, 2014. © 2013 Wiley Periodicals, Inc.
Ultrastrongly Coupled Exciton–Polaritons in Metal‐Clad Organic Semiconductor Microcavities
Authors: Kéna‐Cohen Stéphane , Maier Stefan A. , Bradley Donal D. C.
Published: August 2013

Ultrastrong exciton–photon coupling of Frenkel molecular excitons is demonstrated at room temperature in a metal‐clad microcavity containing a thin film of 2,7‐bis[9,9‐di(4‐methylphenyl)‐fluoren‐2‐yl]‐9,9‐di(4‐methylphenyl)fluorene. A giant Rabi splitting of Ω ∼ 1 eV is measured using angle‐resolved reflectivity and bright photoluminescence is observed from the lower polariton branch. To obtain the virtual photon and exciton content of the polariton ground state, the results are interpreted in terms of the full Hopfield Hamiltonian, including anti‐resonant terms. Also included is an analytical treatment of the often ignored and sometimes misinterpreted TM‐polarized metal–insulator–metal plasmon–polariton.
Associations between allergies and risk of hematologic malignancies: Results from the VITamins and lifestyle cohort study
Authors: Shadman Mazyar , White Emily , De Roos Anneclaire J. , Walter Roland B.
Published: August 2013

Immune dysregulations associated with allergies may affect cancer cell biology but studies on the relationship between allergies and risk of hematologic malignancies (HM) yielded inconsistent results. Herein, we used the vitamins and Lifestyle (VITAL) cohort to examine this association. From 2000 to 2002, 66,212 participants, aged 50–76, completed a baseline questionnaire on cancer risk factors, medical conditions, allergies, and asthma. Through 2009, incident HMs (n = 681) were identified via linkage to the surveillance, epidemiology, and end results cancer registry. After adjustment for factors possibly associated with HMs, a history of airborne allergy was associated with increased risk of HMs (hazard ratio [HR] = 1.19 [95% confidence interval: 1.01–1.41], P = 0.039) in Cox proportional hazards models. This association was limited to allergies to plants/grass/trees (HR = 1.26 [1.05–1.50], P = 0.011) and was strongest for some mature B‐cell lymphomas (HR = 1.50 [1.14–2.00], P = 0.005). Gender‐stratified analyses revealed that the associations between airborne allergies overall and those to plants, grass, and trees were only seen in women (HR = 1.47 [1.14–1.91], P = 0.004; and HR = 1.73 [1.32–2.25], P < 0.001) but not men (HR = 1.03 [0.82–1.29], P = 0.782; and HR = 0.99 [0.77–1.27], P = 0.960). Together, our study indicates a moderately increased risk of HMs in women but not men with a history of allergies to airborne allergens, especially to plant, grass, or trees. Am. J. Hematol. 88:1050–1054, 2013. © 2013 Wiley Periodicals, Inc.
A distinct mitochondrial myopathy, lactic acidosis and sideroblastic anemia (MLASA) phenotype associates with YARS2 mutations
Authors: Shahni Rojeen , Wedatilake Yehani , Cleary Maureen A. , Lindley Keith J. , Sibson Keith R. , Rahman Shamima
Published: August 2013

Nuclear‐encoded disorders of mitochondrial translation are clinically and genetically heterogeneous. Genetic causes include defects of mitochondrial aminoacyl‐tRNA synthetases, and factors required for initiation, elongation and termination of protein synthesis as well as ribosome recycling. We report on a new case of myopathy, lactic acidosis and sideroblastic anemia (MLASA) syndrome caused by defective mitochondrial tyrosyl aminoacylation. The patient presented at 1 year with anemia initially attributed to iron deficiency. Bone marrow aspirate at 5 years revealed ringed sideroblasts but transfusion dependency did not occur until 11 years. Other clinical features included lactic acidosis, poor weight gain, hypertrophic cardiomyopathy and severe myopathy leading to respiratory failure necessitating ventilatory support. Long‐range PCR excluded mitochondrial DNA rearrangements. Clinical diagnosis of MLASA prompted direct sequence analysis of the YARS2 gene encoding the mitochondrial tyrosyl‐tRNA synthetase, which revealed homozygosity for a known pathogenic mutation, c.156C>G;p.F52L. Comparison with four previously reported cases demonstrated remarkable clinical homogeneity. First line investigation of MLASA should include direct sequence analysis of YARS2 and PUS1 (encoding a tRNA modification factor) rather than muscle biopsy. Early genetic diagnosis is essential for counseling and to facilitate appropriate supportive therapy. Reasons for segregation of specific clinical phenotypes with particular mitochondrial aminoacyl tRNA‐synthetase defects remain unknown. © 2013 Wiley Periodicals, Inc.
Molecular etiology of hearing impairment associated with nonsyndromic enlarged vestibular aqueduct in East China
Authors: Chai Yongchuan , Huang Zhiwu , Tao Zheng , Li Xiaohua , Li Lei , Li Yun , Wu Hao , Yang Tao
Published: August 2013

Recessive mutations in SLC26A4 and in rarer cases double heterozygous mutations of FOXI1/SLC26A4 and KCNJ10/SLC26A4 lead to hearing impairment associated with enlarged vestibular aqueduct (EVA), the most common inner ear malformation. In our large cohort study, we addressed several important questions to the molecular etiology of this disorder. The overall prevalence of SLC26A4 mutations in nonsyndromic childhood sensorineural hearing loss (11.2%, 37/330) were determined by sequencing of SLC26A4 in 330 hearing impaired children who did not undergo inner ear radiologic imaging prior to their genetic test. The penetrance of EVA in bi‐allelic SLC26A4 mutation carriers (100%, 37/37) was determined by follow‐up computed tomography scanning. Combined with the study of 140 additional probands diagnosed with nonsyndromic EVA, we characterized the mutation spectrum of SLC26A4 in East China, which consisted of 19 novel SLC26A4 mutations and differed from those reported in other regions of China. © 2013 Wiley Periodicals, Inc.
Learning and memory in children with Noonan syndrome
Authors: Pierpont Elizabeth I. , Tworog‐Dube Erica , Roberts Amy E.
Published: August 2013

Genetic syndromes resulting from molecular alterations of the RAS–MAPK signaling cascade have become the focus of heightened interest among behavioral scientists due to discoveries that proteins within this pathway play an important role in memory formation and consolidation. Individuals with Noonan syndrome (NS), caused by germline mutations in the RAS–MAPK pathway, exhibit wide variability in cognitive and memory skills. The current study aimed to characterize memory deficits that occur in some affected individuals as a key step toward understanding the neurocognitive effects of dysregulated Ras signaling. Learning and memory skills were assessed among 29 children and adolescents with NS using the Wide Range Assessment of Memory and Learning, Second Edition. Performance across subdomains (verbal memory, visual memory and working memory) was compared, as well as the effect of response type (free recall vs. recognition). For immediate memory, children with NS performed significantly better on verbal memory tasks than on visual memory or working memory tasks. For delayed memory, verbal free recall tasks that depend heavily on prefrontal‐hippocampal networks were more challenging than recognition tasks that rely on more distributed temporal cortical regions. Additionally, verbal information presented in context was more easily retained than that presented in a rote format. The current study contributes to our knowledge of the effects of dysregulated RAS–MAPK signaling on the brain and behavior. Continued research on neurocognitive skills in NS has the potential to generate a novel conceptualization of how learning disabilities can arise from altered molecular processes within a specific biological pathway. © 2013 Wiley Periodicals, Inc.