bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of phenoxyacetic acid herbicides as biomarkers in human urine using liquid chromatography/triple quadrupole mass spectrometry
Authors: Lindh Christian H. , Littorin Margareta , Amilon Åsa , Jönsson Bo A. G. 
Published: December 2007

AbstractPhenoxyacetic acids are widely used herbicides. The toxicity of phenoxyacetic acids is debated, but high‐level exposure has been shown to be hepatotoxic as well as nephrotoxic in animal studies. An inter‐species difference in toxic effects has been found, with dogs particularly susceptible. In this study a method using liquid chromatography/triple quadrupole mass spectrometry (LC/MS/MS) is described for the analysis of 4‐chloro‐2‐methylphenoxyacetic acid (MCPA), and its metabolite 4‐chloro‐2‐hydroxymethylphenoxyacetic acid (HMCPA), 2,4‐dichlorophenoxyacetic acid (2,4‐D), and 2,4,5‐trichlorophenoxyacetic acid (2,4,5‐T) in human urine. The urine samples were treated by acid hydrolysis to degrade possible conjugations. The sample preparation was performed using solid‐phase extraction. Analysis was carried out using selected reaction monitoring (SRM) in the negative ion mode. Quantification of the phenoxyacetic acids was performed using [2H3]‐labeled MCPA and 2,4‐D as internal standards. The method was linear in the range 0.05–310 ng/mL urine and has a within‐run precision of 2–5%. The between‐run precision in lower concentration ranges was between 6–15% and between 2–8% in higher concentration ranges. The limit of detection was determined to 0.05 ng/mL. The metabolites in urine were found to be stable during storage at −20°C. To validate the phenoxyacetic acids as biomarkers of exposure, the method was applied in a human experimental oral exposure to MCPA, 2,4‐D and 2,4,5‐T. Two healthy volunteers received 200 µg of each phenoxyacetic acid in a single oral dose followed by urine sampling for 72 h post‐exposure. After exposure, between 90 and 101% of the dose was recovered in the urine. In the female subject, 23%, and in the male subject 17%, of MCPA was excreted as HMCPA. Copyright © 2007 John Wiley & Sons, Ltd.
Exploring Taiwanese high school students' conceptions of and approaches to learning science through a structural equation modeling analysis
Authors: Lee Min‐Hsien , Johanson Robert E. , Tsai Chin‐Chung 
Published: December 2007

AbstractPrevious research has established a close link between students' conceptions of learning and approaches to learning. Until recently, only a few quantitative studies have investigated the relationship between high school students' conceptions of learning science and the approaches they adopt to learning science. This study sought to address this gap in the literature by assessing these possible relationships empirically through the development of two questionnaires: The Conceptions of Learning Science (COLS) questionnaire and the Approaches to Learning Science (ALS) questionnaire. Four hundred and seventy‐four Taiwanese high school students were administered the COLS questionnaire and the ALS questionnaire. Results were entered into a structural equation model to elicit structural relations between students' conceptions of and their approaches to learning science. Overall, findings revealed that students holding constructivist conceptions of learning science tended to employ deep approaches to learning science. Conceptions of learning science such as “testing” and “calculate and practice” were also found to have effects on the surface approaches to learning science; the conceptions of learning science as “applying” and “understanding and seeing in a new way” had noticeable effects on deep approaches to learning science. This study employed quantitative methods to confirm further the structural relations existing between conceptions of learning science and the motives and strategies employed in learning science. Implications for implementing the study's findings into the context of the real‐world classroom are discussed. © 2007 Wiley Periodicals, Inc. Sci Ed, 92:191–220, 2008.
Making (electrical) connections: Exploring student agency in a school in India
Authors: Sharma Ajay 
Published: December 2007

AbstractStudents studying in government‐run schools in rural India possess much experiential knowledge of the world around them. This paper presents a narrative account of an ethnographic exploration of such students as they attempted to learn about electricity in an eighth‐grade classroom in a government‐run schools in a village in India. The paper shows how students having a rich experience with household electric circuits attempt, in a contingent and situated manner, to negotiate their role as students and participate in the school science discourse. The students' actions expressed agency that was contingent, situated, and aimed at selective appropriation of school science discourse for their own purposes. Such expressions of student agency indicate rich possibilities for meaningful learning of science in rural schools in India provided school science is made relevant for their lives and concerns. © 2007 Wiley Periodicals, Inc. Sci Ed 92:297–319, 2008
“A sketch is like a sentence”: Curriculum structures that support teaching epistemic practices of science
Authors: Enfield Mark , Smith Edward L. , Grueber David J. 
Published: December 2007

AbstractThis research reports on a study of curriculum materials development and use compared with the use of existing curriculum materials in an elementary classroom. The research explored the effect of explicit attention to epistemic practices in curriculum materials and the enactment of those materials. Epistemic practices include asking questions, collecting data, making descriptions of observations, finding patterns in the data, and developing scientific reasoning. Scaffolding considered the function, role, and purpose of epistemic practices in the community of science and the production of scientific knowledge. The designed curriculum was compared with an existing pedagogically similar curriculum to consider whether the scaffolding and explicitness affected enactment. Findings lead to the conclusion that enactment was impacted. Specifically, findings show that scaffolding in materials created more instances of students engaging in scientific reasoning. Similarly, the explicit description of epistemic practices supported the teacher in explicitly providing opportunities for children to learn about and use epistemic practices of science. Finally, when using the designed curriculum, teacher modifications during enactment showed to be more consistent with the intended instructional approach and also helpful for children in learning epistemic practices of science. © 2007 Wiley Periodicals, Inc.Sci Ed92:608–630, 2008
Hochreflektierende Beschichtungen auf Kunststoffoptiken
Authors: Munzert P. , Schulz U. , Kaiser N. 
Published: December 2007

AbstractDie Herstellung von Metallbeschichtungen mit höchster Reflexion auf Substraten aus Kunststoff gehört heutzutage noch nicht zum Stand der Technik. Bei der Beschichtung organischer Substratmaterialien treten nach wie vor vielfältige Probleme auf, deren Ursachen zumeist nicht bekannt sind. Eines der Hauptprobleme ist dabei die unzureichende Haftfestigkeit der Schicht auf dem Kunststoffsubstrat. In Versuchen konnte gezeigt werden, dass Aluminium‐ und Silberschichten durch Vakuumbedampfung auf vielen verschiedenen Kunststoffen durchaus haftfest abscheidbar sind, wenn bestimmte Prozessparameter eingehalten werden.Weitere Probleme sind das Erreichen hoher Reflexionswerte sowie die Klimastabilität der Metallschichten. Durch Rauigkeitsmessungen an verschiedenen Kunststoffproben und einem Vergleich mit den nach Beschichtung erzielten Reflexionswerten konnte der Einfluss der Oberflächenqualität des Substrats auf die Reflexion der Metallbeschichtung ermittelt werden. Besonders hohe Reflexionswerte von über 97% im sichtbaren Spektralbereich wurden sowohl mit geschützten Silberspiegeln als auch mit dielektrisch verstärktem Aluminium erreicht. Bei diesen Systemen wurde zwischen der Beschichtung auf Glas und Kunststoff kein Reflexionsunterschied festgestellt. Die dielektrischen Verstärkungsschichten erhöhen zudem die Klimastabilität der Aluminiumbeschichtung.
Nichtinvasive Elektronendichtemessungen an technischen Plasmen mittels 26,5 GHz‐Mikrowellen‐Interferometrie
Authors: Selenin V. , Schwabedissen A. , Bunse D. 
Published: December 2007

AbstractDie Diagnostik von technischen Plasmen mittels Mikrowellen‐Interferometrie wird insbesondere im Vergleich zur traditionellen Langmuir‐Sondendiagnostik diskutiert. Ein neuartiges Mikrowellen‐Interferometer (MWI 2650) der JE PlasmaConsult GmbH wird vorgestellt, das auf starre Hohlleiter im Referenzarm verzichtet und stattdessen ein flexibles Koaxialkabel verwendet. Die direkte Anzeige der Elektronendichte sowie ein kalibrierter Ausgang zu einem Oszilloskop erleichtern die Bedienung des Gerätes. Neben Messungen der Plasmadichte an chemisch reaktiven bzw. schichtabscheidenen Plasmen, bei denen Langmuirsonden prinzipbedingt Begrenzungen haben, können mit dem MWI 2650 auch zeitaufgelöste Messungen der Elektronendichte an gepulsten Plasmen mit hoher Empfindlichkeit durchgeführt werden. Mit diesem Gerät gelang es, einen Peak der Elektronendichte im Afterglow von elektronegativen bzw. staubigen Plasmen experimentell nachzuweisen. Eine spezielle Version des MWI 2650 ist auch für die Diagnostik von Atmosphärendruck‐Plasmen geeignet.
Project New Hope: Volunteers Caring for Children in Need
Authors: Landis Kit L. , Loar Christine W. 
Published: December 2007

ABSTRACTPROJECT NEW HOPE is an ongoing, collaborative, community program that provides no‐cost surgical procedures to uninsured children in the Reno, Nevada, region.CHILDREN WITH PHYSICAL ABNORMALITIES who cannot otherwise afford surgery are referred to the program by clinics, schools, and social workers.VOLUNTEERS FROM THE HEALTH CARE sector and the community participate in the program and have treated almost 150 children since the program started in 1997.STRUCTURED, FREE‐SURGERY programs can be set up in other health care facilities using guidelines outlined in this article. AORN J 86 (November 2007) 769–779.
Reuse and Recycling Practices in a Colombian Hospital
Authors: Arévalo Lyda C. , Carrillo‐Martínez César Manuel 
Published: December 2007

ABSTRACTREUSE AND RECYCLING of donated and purchased items can allow health care facilities in developing countries to remain financially viable and provide services to those who could not otherwise afford them.IN ONE BOGOTÁ, COLOMBIA, HOSPITAL, surgical instrumentation professionals and other clinicians developed reuse and recycling protocols for the OR.ALTHOUGH NOT ALL OF THE PRACTICES described would be acceptable in the United States, these practices are a direct consequence of the impact of poverty on health care systems in a developing country. AORN J 86 (November 2007) 791–797.
Cognitive control in autism spectrum disorders
Authors: Solomon Marjorie , Ozonoff Sally J. , Cummings Neil , Carter Cameron S. 
Published: December 2007

AbstractCognitive control refers to the ability to flexibly allocate mental resources to guide thoughts and actions in light of internal goals. Given the behavioral inflexibility exhibited by individuals with autism spectrum disorders (ASDs), it would appear they experience cognitive control deficits. Cognitive correlates of this behavioral inflexibility have been elusive in previous investigations. Study goals were to investigate deficits in cognitive control in ASDs; to explore its developmental trajectory; and to test whether control deficits are related to symptoms of inflexible thoughts and/or behaviors, and attention symptoms. Thirty‐one children and adolescents aged 8–17 with ASDs and 32 age, IQ, and gender matched control subjects completed cognitive, diagnostic, and behavorial assessments, as well as a measure of cognitive control involving overcoming a prepotent response tendency. Compared with typically developing control subjects, individuals with ASDs exhibited deficits in cognitive control. Younger children with ASDs did not demonstrate age‐related improvements in cognitive control. Modest relationships between cognitive control, IQ, and attention problems were found for the sample. Only the relationship between cognitive control and full‐scale IQ survived correction for multiple comparisons.
Linking learning and effective process implementation to mass customization capability
Authors: Huang Xiaowen , Kristal Mehmet Murat , Schroeder Roger G. 
Published: December 2007

AbstractThis study investigates the role of learning and effective process implementation in the development of mass customization capability. Building upon the knowledge‐based view of the firm, we argue that internal and external learning are two knowledge‐generation routines that contribute to effective process implementation. Effective process implementation, in turn, is a knowledge‐based manufacturing capability, which, as a function of internal and external learning, leads to mass customization capability. We employ structural equation modeling to empirically test the effects of learning on mass customization capability, mediated by effective process implementation, using survey data collected from 100 manufacturing plants in 3 industries and 6 countries. Our results provide empirical evidence supporting the proposed model of the effect of internal and external learning on mass customization capability, fully mediated by effective process implementation. This research is one of the first studies to integrate insights from the knowledge‐based view of the firm and mass customization. It complements the OM view of mass customization, which to date has largely focused on the technical side, by demonstrating the role of managerial practices and learning in cultivating mass customization capability in a manufacturing environment.
Iodine requirements during pregnancy, lactation and the neonatal period and indicators of optimal iodine nutrition
Authors: Delange François 
Published: December 2007

AbstractObjective:This paper re-evaluates the requirements for iodine during pregnancy, lactation and the neonatal period, and formulates original proposals for the median concentrations of urinary iodine (UI) that indicate optimal iodine nutrition during these three critical periods of life. This paper also discusses the measurements that are used to explore thyroid functions during the same periods.Design:An extensive and critical review of the literature on thyroid physiopathology during the perinatal period.Setting:Human studies conducted in various regions throughout the world.Subjects:Pregnant women, lactating women, and newborns.Results:The following proposals are made after extensive review of the literature: the requirement for iodine by the mother during pregnancy is 250-300 μg day-1; during lactation the requirement is 225-350 μg day-1; and during the neonatal period the requirement of the infant is 90 μg day-1. The median UI that indicates an optimal iodine nutrition during these three periods should be in the range of 150-230 μg day-1. These figures are higher than recommended to date by the international agencies.Conclusions:Pregnant women and young infants, but especially the second group, are more sensitive to the effects of an iodine deficiency (ID) than the general population because their serum thyroid-stimulating hormone (TSH) and thyroxine are increased and decreased, respectively, for degrees of ID that do not seem to affect thyroid function in the general population. Systematic neonatal thyroid screening using primary TSH could be the most sensitive indicator to monitor the process of ID control.
Effect of Communication Errors During Calls to an Antimicrobial Stewardship Program
Authors: Linkin Darren R. , Fishman Neil O. , Landis J. Richard , Barton Todd D. , Gluckman Steven , Kostman Jay , Metlay Joshua P. 
Published: December 2007

Objective.To determine how inaccurate communication of patient data by clinicians in telephone calls to the prior-approval antimicrobial stewardship program (ASP) staff affects the incidence of inappropriate antimicrobial recommendations made by ASP practitioners.Design.A retrospective cohort design was used. The accuracy of the patient data communicated was evaluated against patients' medical records to identify predetermined, clinically significant inaccuracies. Inappropriate antimicrobial recommendations were defined having been made if an expert panel unanimously rated the actual recommendations as inappropriate after reviewing vignettes derived from inpatients' medical records.Setting.The setting was an academic medical center with a prior-approval ASP.Patients.All inpatient subjects of ASP prior-approval calls were eligible for inclusion.Results.Of 200 ASP telephone calls, the panel agreed about whether or not antimicrobial recommendations were inappropriate for 163 calls (82%); these 163 calls were then used as the basis for further analyses. After controlling for confbunders, inaccurate communication was found to be associated with inappropriate antimicrobial recommendations (odds ratio [OR], of 2.2; P = .03). In secondary analyses of specific data types, only inaccuracies in microbiological data were associated with the study outcome (OR, 7.5; P = .002). The most common reason panelists gave for rating a recommendation as inappropriate was that antimicrobial therapy was not indicated.Conclusions.Inaccurate communication of patient data, particularly microbiological data, during prior-approval calls is associated with an increased risk of inappropriate antimicrobial recommendations from the ASP. Clinicians and ASP practitioners should work to confirm that critical data has been communicated accurately prior to use of that data in prescribing decisions.
Case-Control Study of Antibiotic Use and Subsequent Clostridium difficile–Associated Diarrhea in Hospitalized Patients
Authors: Baxter Roger , Ray G. Thomas , Fireman Bruce H. 
Published: December 2007

Objective.To determine which antibiotics increase or decrease the risk of Clostridium difficile-associated diarrhea (CDAD).Design.Retrospective case-control study.Setting.Nonprofit, integrated healthcare delivery system in Northern California.Patients.Study participants included patients with cases of hospital-acquired CDAD that occurred during the period from 1999 through 2005 (n = 1,142) and control patients (n = 3,351) matched for facility, calendar quarter during which hospitalization occurred, diagnosis related group for the index hospitalization, and length of hospital stay. All case and control patients had received antibiotics in the 60 days before the index date. For each antibiotic, the risk of CDAD was examined in relation to whether the patient received the antibiotic, after adjustment for use of other antibiotics, demographic characteristics, selected health conditions, and use of healthcare services.Results.The following antibiotics were associated with a significantly increased risk of acquiring CDAD: imipenem-cilastin (odds ratio [OR], 2.77), clindamycin (OR, 2.31), cefuroxime (OR, 2.16), moxifloxacin (OR, 1.88), ceftazidime (OR, 1.82), cefpodoxime (OR, 1.58), ceftizoxime (OR, 1.57), and ceftriaxone (OR, 1.49). Metronidazole and doxycycline were associated with a significantly reduced risk of CDAD (OR for metronidazole, 0.67; OR for doxycycline, 0.41). Other factors associated with an increased risk of CDAD were older age, longer hospital stays, use of proton pump inhibitors, prior gastrointestinal disease, and prior infection (not including C. difficile infection.)Conclusions.Some antibiotics appear to increase the risk of acquiring CDAD, notably clindamycin, third-generation cephalosporins, and carbapenems, whereas metronidazole and doxycycline appear to be protective, compared with other antibiotics.
Budget Impact Analysis of Rapid Screening for Staphylococcus aureus Colonization Among Patients Undergoing Elective Surgery in US Hospitals
Authors: Noskin Gary A. , Rubin Robert J. , Schentag Jerome J. , Kluytmans Jan , Hedblom Edwin C. , Jacobson Cassie , Smulders Maartje , Gemmen Eric , Bharmal Murtuza 
Published: December 2007

Objective.To evaluate the economic impact of performing rapid testing for Staphylococcus aureus colonization before admission for all inpatients who are scheduled to undergo elective surgery and providing subsequent decolonization therapy for those patients found to be colonized with S. aureus.Methods.A budget impact model that used probabilistic sensitivity analysis to account for the uncertainties in the input variables was developed. Primary input variables included the marginal effect of S. aureus infection on patient outcomes among patients who underwent elective surgery, patient demographic characteristics, the prevalence of nasal carriage of S. aureus, the sensitivity and specificity of the rapid diagnostic test for S. aureus colonization, the efficacy of decolonization therapy for nasal carriage of S. aureus, and cost data. Data sources for the input variables included the 2003 Nationwide Inpatient Sample data and the published literature.Results.In 2003, there were an estimated 7,181,484 patients admitted to US hospitals for elective surgery. Our analysis indicated preadmission testing and subsequent decolonization therapy for patients colonized with S. aureus would have produced a mean annual cost savings to US hospitals of $231,538,400 (95% confidence interval [CI], -$300 million to $1.3 billion). The mean annual number of hospital-days that could have been eliminated was estimated at 364,919 days (95% CI, 67,893-926,983 days), and a mean of 935 in-hospital deaths (95% CI, 88-3,691) could have been avoided per year. Sensitivity analysis indicated a 64.5% probability that there would be cost savings to US hospitals as a result of preadmission testing and subsequent decolonization therapy.Conclusion.The addition of preadmission testing and decolonization therapy to standard care would result in significant cost savings, even after accounting for variations in the model input values.