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Sample records for objetivo estructurado osce

  1. Optical network management with OSC

    NASA Astrophysics Data System (ADS)

    Liu, Fengqing; Zeng, QingJi; Xiao, Shilin; Zhu, Xu; Xu, Jie

    2001-10-01

    How to transport the control and management information of optical networking is a major concern these days. We compare several means and arrive at a conclusion that OSC (optical supervisory channel) is a better choice. The content of OSC is given and OSC channel wavelength, bit rate and coding method are discussed. An OSC example of WDM metro network are illuminated, which demonstrates the processing operation of overheads in OSC, FDI behavior for three types of failure, and Self-management of OSC subsystem. To fulfill the demand of intelligent and distributed management of optical transport network, an OSC of OC-3 (155Mbps) channel bit rate may be needed in the near future.

  2. Does student performance on preclinical OSCEs relate to clerkship grades?

    PubMed Central

    Chima, Margot; Dallaghan, Gary Beck

    2016-01-01

    Background Objective structured clinical examinations (OSCEs) have been used to assess the clinical competence and interpersonal skills of healthcare professional students for decades. However, the relationship between preclinical (second year or M2) OSCE grades and clerkship performance had never been evaluated, until it was explored to provide information to educators at the University of Nebraska Medical Center (UNMC). In addition, the relationship between M2 OSCE communication scores (which is a portion of the total score) and third-year (M3) Internal Medicine (IM) clerkship OSCE scores was also explored. Lastly, conflicting evidence exists about the relationship between the amount of previous clinical experience and OSCE performance. Therefore, the relationship between M3 IM clerkship OSCE scores and the timing of the clerkship in the academic year was explored. Methods Data from UNMC M2 OSCEs and M3 IM clerkship OSCEs were obtained for graduates of the 2013 and 2014 classes. Specifically, the following data points were collected: M2 fall OSCE total, M2 fall OSCE communication; M2 spring OSCE total, M2 spring OSCE communication; and M3 IM clerkship OSCE total percentages. Data were organized by class, M3 IM clerkship OSCE performance, and timing of the clerkship. Microsoft Excel and SPSS were used for data organization and analysis. Results Of the 245 records, 229 (93.5%) had data points for all metrics of interest. Significant differences between the classes of 2013 and 2014 existed for average M2 spring total, M2 spring communication, and M3 IM clerkship OSCEs. Retrospectively, there were no differences in M2 OSCE performances based on how students scored on the M3 IM clerkship OSCE. M3 IM clerkship OSCE performance improved for those students who completed the clerkship last in the academic year. Conclusions There were inconsistencies in OSCE performances between the classes of 2013 and 2014, but more information is needed to determine if this is because of

  3. The emperor's new clothes: the OSCE reassessed.

    PubMed

    Mavis, B E; Henry, R C; Ogle, K S; Hoppe, R B

    1996-05-01

    In response to increasing concerns about the prevalence of knowledge- based assessments of medical student competency, leaders in medical education have emphasized the importance of methods that quantify student performance. As a result, the use of objective structured clinical examinations (OSCEs) is viewed by many as the newest and most promising technique for assessing students' abilities. In considering the implementation of a fourth-year OSCE, faculty at the College of Human Medicine at Michigan State University became uncomfortable with some of the technical limitations of the method (limited generalizability; weak linkages to the curriculum; little opportunity provided for improvement in examinees' skills; and others), as well as the possible ramifications of such an innovation within their school's specific curricular and organizational contexts. This essay is offered as a reflection of the challenges and possible alternatives that have emerged as the faculty have considered how best to design and implement performance-based assessment within their institution. Rather than using the OSCE as a milestone marker of student performance, they consider the possibility of smaller assessment events, closely tied to the curriculum and consistent with the guiding principles of the medical school. PMID:9114860

  4. In the Minds of OSCE Examiners: Uncovering Hidden Assumptions

    ERIC Educational Resources Information Center

    Chahine, Saad; Holmes, Bruce; Kowalewski, Zbigniew

    2016-01-01

    The Objective Structured Clinical Exam (OSCE) is a widely used method of assessment in medical education. Rater cognition has become an important area of inquiry in the medical education assessment literature generally, and in the OSCE literature specifically, because of concerns about potential compromises of validity. In this study, a novel…

  5. Increased Authenticity in Practical Assessment Using Emergency Case OSCE Stations

    ERIC Educational Resources Information Center

    Ruesseler, Miriam; Weinlich, Michael; Byhahn, Christian; Muller, Michael P.; Junger, Jana; Marzi, Ingo; Walcher, Felix

    2010-01-01

    In case of an emergency, a fast and structured patient management is crucial for patient's outcome. The competencies needed should be acquired and assessed during medical education. The objective structured clinical examination (OSCE) is a valid and reliable assessment format to evaluate practical skills. However, traditional OSCE stations examine…

  6. Have OSCEs come of age in nursing education?

    PubMed

    Traynor, Marian; Galanouli, Despina

    This article is intended to contribute to the current debate as to whether the objective structured clinical examination (OSCE) should become a standard assessment tool for undergraduate nursing education as they currently are for medicine. The authors describe how one UK university developed an OSCE for a nursing undergraduate programme with the aim of emphasising the need for nursing students to be competent in clinical skills and offering a means of standardising the assessment of these skills. There has been an increasing number of research studies carried out in this area at international level and this article's main contribution to the literature is the description of the Angoff standard-setting procedure that was used to calibrate the OSCE at this University and which makes it the first nursing OSCE in the UK to incorporate a scientific standard-setting procedure. PMID:25849236

  7. Objective structured clinical examination (OSCE) in pharmacy education - a trend

    PubMed Central

    Shirwaikar, Annie

    2015-01-01

    Pharmacy education has undergone a radical change as it evolves towards becoming a more patient oriented profession. With a greater emphasis on problem based teaching and competency, the Objective Structured Clinical Examination (OSCE), supported by its reliability and validity became the gold standard for the evaluation of clinical skills of undergraduate students of medicine and pharmacy worldwide. Core competency evaluation has become a mandatory and critical norm for accountability of educational objectives as the traditional testing tools cannot evaluate clinical competence. Interpersonal and communication skills, professional judgment, skills of resolution etc., may be best assessed through a well- structured OSCE in comparison to oral examinations, multiple choice tests and other methods of assessment. Though OSCEs as an objective method of evaluation offer several advantages to both students and teachers, it also has disadvantages and pitfalls in implementation. This article reviews the OSCE as a trend in pharmacy education. PMID:26759616

  8. Item Analysis to Improve Reliability for an Internal Medicine Undergraduate OSCE

    ERIC Educational Resources Information Center

    Auewarakul, Chirayu; Downing, Steven M.; Praditsuwan, Rungnirand; Jaturatamrong, Uapong

    2005-01-01

    Utilization of objective structured clinical examinations (OSCEs) for final assessment of medical students in Internal Medicine requires a representative sample of OSCE stations. The reliability and generalizability of OSCE scores provides validity evidence for OSCE scores and supports its contribution to the final clinical grade of medical…

  9. The influence of examiner type on dental students' OSCE scores.

    PubMed

    Park, Sang E; Kim, Arthur; Kristiansen, Joshua; Karimbux, Nadeem Y

    2015-01-01

    The purpose of this study was to evaluate the difference in grading of objective structured clinical examinations (OSCEs) at Harvard School of Dental Medicine (HSDM) by full-time faculty examiners, part-time faculty examiners, and postgraduate resident examiners. The OSCE is an evaluation of clinical competence and is used as a multidisciplinary examination at HSDM. Two examiners are selected for each of ten disciplines. Evaluators meet to review the case before the OSCE is given, and faculty examiners are given the opportunity to write exam questions based on the students' expected level of knowledge and ability. All examiners also meet on the day of the OSCE to review the case and discuss relevant issues. Students are randomly assigned to examiners and meet with one examiner at a time in each discipline during the examination. Analysis of OSCE scores on four exams given to HSDM students between 2012 and 2013 suggests that part-time faculty members tended to score students significantly higher than full-time faculty members or postgraduate residents. This may be a result of reduced contact time between students and the part-time faculty although it may also point to a need for more efforts in calibration of the part-time faculty members who take part in the OSCE. PMID:25576557

  10. In the minds of OSCE examiners: uncovering hidden assumptions.

    PubMed

    Chahine, Saad; Holmes, Bruce; Kowalewski, Zbigniew

    2016-08-01

    The Objective Structured Clinical Exam (OSCE) is a widely used method of assessment in medical education. Rater cognition has become an important area of inquiry in the medical education assessment literature generally, and in the OSCE literature specifically, because of concerns about potential compromises of validity. In this study, a novel approach to mixed methods that combined Ordinal Logistic Hierarchical Linear Modeling and cognitive interviews was used to gain insights about what examiners were thinking during an OSCE. This study is based on data from the 2010 to 2014 administrations of the Clinician Assessment for Practice Program OSCE for International Medical Graduates (IMGs) in Nova Scotia. An IMG is a physician trained outside of Canada who was a licensed practitioner in a different country. The quantitative data were examined alongside four follow-up cognitive interviews of examiners conducted after the 2014 administration. The quantitative results show that competencies of (1) Investigation and Management and (2) Counseling were highly predictive of the Overall Global score. These competencies were also described in the cognitive interviews as the most salient parts of OSCE. Examiners also found Communication Skills and Professional Behavior to be relevant but the quantitative results revealed these to be less predictive of the Overall Global score. The interviews also reveal that there is a tacit sequence by which IMGs are expected to proceed in an OSCE, starting with more basic competencies such as History Taking and building up to Investigation Management and Counseling. The combined results confirm that a hidden pattern exists with respect to how examiners rate candidates. This study has potential implications for research into rater cognition, and the design and scoring of practice-ready OSCEs. PMID:26661783

  11. Standard Setting for OSCEs: Trial of Borderline Approach

    ERIC Educational Resources Information Center

    Kilminster, Sue; Roberts, Trudie

    2004-01-01

    OSCE examinations were held in May and June 2002 for all third and fourth year and some fifth year medical students at the University of Leeds. There has been an arbitrary pass mark of 65% for these examinations. However, we recognise that it is important to adopt a systematic approach towards standard setting in all examinations so held a trial…

  12. Studying Teacher Behavior with the OScAR Technique.

    ERIC Educational Resources Information Center

    Medley, Donald M.

    Educational Testing Service is involved in a measurement approach to research in teaching with a goal of developing procedures for obtaining objective quantitive descriptions of teacher behavior, in terms of a minimum number of dimensions, on the basis of direct observation. The Observation Schedule and Record (OScAR), a card which contains a list…

  13. Evaluating an Objective Structured Clinical Examination (OSCE) Adapted for Social Work

    ERIC Educational Resources Information Center

    Bogo, Marion; Regehr, Cheryl; Katz, Ellen; Logie, Carmen; Tufford, Lea; Litvack, Andrea

    2012-01-01

    Objectives: To evaluate an objective structured clinical examination (OSCE) adapted for social work in a lab course and examine the degree to which it predicts competence in the practicum. Method: 125 Masters students participated in a one-scenario OSCE and wrote responses to standardized reflection questions. OSCE performance and reflections were…

  14. Brief Analysis of Application of Objective Structured Clinical Examination (OSCE) in Graduation Exams of Clinical Medical Students

    ERIC Educational Resources Information Center

    Du, Yihua; Yu, Ke; Li, Xiaohong; Wang, Feng; Wang, Tingting

    2011-01-01

    This article gives a brief introduction to the Objective Structured Clinical Examination (OSCE) and analyzes developmental progress of OSCE at both home and abroad and standardized patients' application in OSCE. Also, this article expounds application of OSCE in graduation exam of clinical medical students. Finally, this article summarizes…

  15. Reviewing the nursing students’ views toward OSCE test

    PubMed Central

    Hosseini, Seyyed Abbas; Fatehi, Nahideh; Eslamian, Jalil; Zamani, Mehrangiz

    2011-01-01

    BACKGROUND: One of the essential components of learning and educational program is evaluation or examination. There are various methods for evaluating clinical skills among which objective structured clinical examination (OSCE) has been recognized as the most reliable method for evaluation of the clinical skills. METHODS: This was a one-step single-group descriptive study which was conducted through a researcher-made questionnaire. RESULTS: Results indicated that the view of most of the students in OSCE test has been good in terms of equipment and facilities with relative frequency of 59.2 percent, conditions of holding the examination with relative frequency of 50.9% and total test with relative frequency of 55.1%; in terms of physical environment, students’ view was moderate with relative frequency of 469%. CONCLUSIONS: The results of the study showed that appropriateness of physical environment and equipment and facilities to hold OSCE can directly be involved in enhancing the quality of this test. PMID:23450218

  16. Quality Control of an OSCE Using Generalizability Theory and Many-Faceted Rasch Measurement

    ERIC Educational Resources Information Center

    Iramaneerat, Cherdsak; Yudkowsky, Rachel; Myford, Carol M.; Downing, Steven M.

    2008-01-01

    An Objective Structured Clinical Examination (OSCE) is an effective method for evaluating competencies. However, scores obtained from an OSCE are vulnerable to many potential measurement errors that cases, items, or standardized patients (SPs) can introduce. Monitoring these sources of errors is an important quality control mechanism to ensure…

  17. A Comparative Analysis of the Costs of Administration of an OSCE.

    ERIC Educational Resources Information Center

    Cusimano, Michael D.; And Others

    1994-01-01

    A study compared the costs of a six-station structured oral examination and an objective structured clinical examination (OSCE) for a surgery clerkship, assessing both faculty and materials costs. The OSCE was found to be more time consuming and expensive. Cost-cutting measures and guidelines to assist medical schools in selecting test type are…

  18. Assessing the Organizational Social Context (OSC) of Child Welfare Systems: Implications for Research and Practice

    ERIC Educational Resources Information Center

    Glisson, Charles; Green, Philip; Williams, Nathaniel J.

    2012-01-01

    Objective: The study: (1) provides the first assessment of the a "priori" measurement model and psychometric properties of the Organizational Social Context (OSC) measurement system in a US nationwide probability sample of child welfare systems; (2) illustrates the use of the OSC in constructing norm-based organizational culture and climate…

  19. Psychiatric OSCE Performance of Students with and without a Previous Core Psychiatry Clerkship

    ERIC Educational Resources Information Center

    Goisman, Robert M.; Levin, Robert M.; Krupat, Edward; Pelletier, Stephen R.; Alpert, Jonathan E.

    2010-01-01

    Objective: The OSCE has been demonstrated to be a reliable and valid method by which to assess students' clinical skills. An OSCE station was used to determine whether or not students who had completed a core psychiatry clerkship demonstrated skills that were superior to those who had not taken the clerkship and which areas discriminated between…

  20. Construct Validity of an Objective Structured Clinical Examination (OSCE) in Psychiatry: Associations with the Clinical Skills Examination and Other Indicators

    ERIC Educational Resources Information Center

    Park, Robin S.; Chibnall, John T.; Blaskiewicz, Robert J.; Furman, Gail E.; Powell, Jill K.; Mohr, Clinton J.

    2004-01-01

    Objective: The construct validity of checklist and global process scores for an objective structured clinical examination (OSCE) in psychiatry was assessed. Multiple regression analysis was used to predict psychiatry OSCE scores from the clinical skills examination, an obstetrics/gynecology (OB/GYN) OSCE, and the National Board of Medical…

  1. How high are the personnel costs for OSCE? A financial report on management aspects

    PubMed Central

    Rau, Thea; Fegert, Jörg; Liebhardt, Hubert

    2011-01-01

    Objective: The OSCE (objective structured clinical examination) was put to the test in order to assess the clinical practical skills of students in medical studies in the medical faculties. For the implementation of an OSCE, a large number of personnel is necessary. In particular for subjects with limited resources, therefore, efficient cost planning is required. In the winter semester 09/10, the Department of Neurology at the Medical Faculty of the University of Ulm introduced the OSCE as a pilot project. A financial report retrospectively shows the personnel expenses. The report is intended as an example for an insight into the resources needed for the OSCE with simulated patients. Method: Included in the calculation of the financial costs of the OSCE were: employment, status of staff involved in the OSCE, subject-matter and temporal dimension of the task. After the exam, acceptance of the examination format was reviewed by a focus group interview with the teachers and students. Result: The total expenses for the personnel involved in the OSCE amounted to 12,468 €. The costing of the clinic’s share was calculated at 9,576 €. Tuition fees from the students have been used to the amount of 2.892 €. For conversion of total expenditure to the number of examines the sum of 86 € per student was calculated. Both students and teachers confirmed the validity of the OSCE and recognised the added value in the learning effects. Conclusion: The high acceptance of the OSCE in neurology by both students and teachers favours maintaining the test format. Against the background of the high financial and logistical costs, however, in individual cases it should be assessed how in the long-term efficient examination procedure will be possible. PMID:21818228

  2. The reliability, validity, and usefulness of the Objective Structured Clinical Examination (OSCE) in dental education

    NASA Astrophysics Data System (ADS)

    Graham, Roseanna

    This study evaluated the reliability, validity, and educational usefulness of a comprehensive, multidisciplinary Objective Structured Clinical Examination (OSCE) in dental education. The OSCE was administered to dental students at the Columbia University College of Dental Medicine (CDM) before they entered clinical training. Participants in this study included CDM's class of 2010 which consisted of 78 students. The overall reliability of the examination was measured via calculation of Cronbach's alpha. Content validity was examined through evaluation of the OSCE by three experienced clinical faculty members. Predictive validity was evaluated by correlating student grades on the OSCE to future clinical performance as measured by number of clinical points achieved during the third year of training. Student perceptions regarding the educational usefulness of the examination were evaluated through a 12-question Liken-type survey and focus group interviews analyzed using a phenomenological approach. Findings of the study indicated the OSCE was a highly reliable examination (alpha=0.86) with high content validity and a moderately high correlation to future clinical performance (r=.614, p<.0001). Overall, student perceptions of the educational usefulness of the OSCE were positive as based on their responses to a 5-point Likert scale (1=strongly disagree and 5=strongly agree). They reported that the exam required the ability to think critically and problem-solve (4.0 +/- 0.85), assessed clinically relevant skills (4.59 +/- 0.69), helped identify clinical weaknesses (4.16 +/- 0.90), and was a learning experience (4.58 +/- 0.84). Findings from the qualitative portion of the study identified four main themes including the student perception that the OSCE is a unique assessment experience that required integration and application of knowledge. Recommendations for the use of the OSCE to improve clinical teaching and the implications of this study relating to the expanded use of

  3. OSC in the 1970s: a springboard for a career in optical engineering

    NASA Astrophysics Data System (ADS)

    Harvey, James E.

    2014-09-01

    Anecdotes and recollections from a graduate student at the Optical Sciences Center (OSC) in the late 1960s and early 1970s. The early faculty of the OCS fostered an exciting environment where even graduate students served significant roles on major government research contracts. Teamwork and collaboration between research groups was often required to meet the contract goals. This unique learning experience at the OSC almost 50 years ago served as a springboard for a satisfying and rewarding career in Optical Engineering.

  4. Noise and resolution in images reconstructed with FBP and OSC algorithms for CT

    SciTech Connect

    Ziegler, A.; Koehler, Th.; Proksa, R.

    2007-02-15

    This paper presents a comparison between an analytical and a statistical iterative reconstruction algorithm for computed transmission tomography concerning their noise and resolution performance. The reconstruction of two-dimensional images from simulated fan-beam transmission data is performed with a filtered back-projection (FBP) type reconstruction and an iterative ordered subsets convex (OSC) maximum-likelihood method. A special software phantom, which allows measuring the resolution and noise in a nonambiguous way, is used to simulate transmission tomography scans with different signal-to-noise ratios (SNR). The noise and modulation transfer function is calculated for FBP and OSC reconstruction at several positions, distributed over the field-of-view (FOV). The reconstruction with OSC using different numbers of subsets shows an inverse linear relation to the number of iterations that are necessary to reach a certain resolution and SNR, i.e., increasing the number of subsets by a factor x reduces the number of required iterations by the same factor. The OSC algorithm is able to achieve a nearly homogeneous high resolution over the whole FOV, which is not achieved with FBP. The OSC method achieves a lower level of noise compared with FBP at the same resolution. The reconstruction with OSC can save a factor of up to nine of x-ray dose compared with FBP in the investigated range of noise levels.

  5. Characterization of stress and methylglyoxal inducible triose phosphate isomerase (OscTPI) from rice

    PubMed Central

    Sharma, Shweta; Mustafiz, Ananda; Singla-Pareek, Sneh L.; Shankar Srivastava, Prem; Sopory, Sudhir Kumar

    2012-01-01

    As compared with plant system, triose phosphate isomerase (TPI), a crucial enzyme of glycolysis, has been well studied in animals. In order to characterize TPI in plants, a full-length cDNA encoding OscTPI was cloned from rice and expressed in E. coli. The recombinant OscTPI was purified to homogeneity and it showed Km value of 0.1281 ± 0.025 µM, and the Vmax value of 138.7 ± 16 µmol min−1mg−1 which is comparable to the kinetic values studied in other plants. The OscTPI was found to be exclusively present in the cytoplasm when checked with the various methods. Functional assay showed that OscTPI could complement a TPI mutation in yeast. Real time PCR analysis revealed that OscTPI transcript level was regulated in response to various abiotic stresses. Interestingly, it was highly induced under different concentration of methylglyoxal (MG) stress in a concentration dependent manner. There was also a corresponding increase in the protein and the enzyme activity of OscTPI both in shoot and root tissues under MG stress. Our result shows that increases in MG leads to the increase in TPI which results in decrease of DHAP and consequently decrease in the level of toxic MG. PMID:22902706

  6. Power of the policy: how the announcement of high-stakes clinical examination altered OSCE implementation at institutional level

    PubMed Central

    2013-01-01

    Background The Objective Structured Clinical Examination (OSCE) has been widely applied as a high-stakes examination for assessing physicians’ clinical competency. In 1992, OSCE was first introduced in Taiwan, and the authorities announced that passing the OSCE would be a prerequisite for step-2 medical licensure examination in 2013. This study aimed to investigate the impacts of the announced national OSCE policy on implementation of OSCE at the institutional level. Further, the readiness and the recognition of barriers toward a high-stakes examination were explored. Methods In 2007 and 2010, the year before and after the announcement of high-stakes OSCE policy in 2008, respectively, questionnaires on the status of OSCE implementation were distributed to all hospitals with active OSCE programs in Taiwan. Information on OSCE facilities, equipment, station length, number of administrations per year, and the recognition of barriers to the success of implementing an OSCE were collected. The missing data were completed by telephone interviews. The OSCE format, administration, and facilities before and after the announcement of the nationwide OSCE policy were compared. Results The data were collected from 17 hospitals in 2007 and 21 in 2010. Comparing the OSCE formats between 2007 and 2010, the number of stations increased and the station length decreased. The designated space and the equipment for OSCE were also found to have been improved. As for the awareness of OSCE implementation barriers, the hospital representatives concerned mostly about the availability and quality of standardized patients in 2007, as well as space and facilities in 2010. Conclusions The results of this study underscored an overall increase in the number of OSCE hospitals and changes in facilities and formats. While recruitment and training of standardized patients were the major concerns before the official disclosure of the policy, space and facilities became the focus of attention after

  7. A pilot test of WebOSCE: a system for assessing trainees' clinical skills via teleconference.

    PubMed

    Novack, Dennis H; Cohen, Diane; Peitzman, Steven J; Beadenkopf, Scott; Gracely, Ed; Morris, John

    2002-09-01

    WebOSCE is a computer-based system that allows a student at an affiliate site to participate in a 10-station standardized patient-based exam using a videoconference interface, while nine other students take the exam on-site. We pilot-tested this system during a required year-end objective structured clinical exam. We compared performance data between the 26 distance students taking the exam via WebOSCE with 221 on-site students. We also compared both student groups' responses on a post-exam questionnaire, and conducted a post-exam structured interview to elicit the Pittsburgh students' perspectives on the WebOSCE experience. Students taking the exam via WebOSCE scored significantly lower in most categories except for physical exam and information-giving skills, on which the groups did not differ. There were no differences between groups in students' overall evaluation of the exam experiences. In general, Pittsburgh students rated WebOSCE highly and offered many helpful comments to improve the technology and the experience. PMID:12474813

  8. Evaluation of the OSC-TV iterative reconstruction algorithm for cone-beam optical CT

    SciTech Connect

    Matenine, Dmitri Mascolo-Fortin, Julia; Goussard, Yves

    2015-11-15

    Purpose: The present work evaluates an iterative reconstruction approach, namely, the ordered subsets convex (OSC) algorithm with regularization via total variation (TV) minimization in the field of cone-beam optical computed tomography (optical CT). One of the uses of optical CT is gel-based 3D dosimetry for radiation therapy, where it is employed to map dose distributions in radiosensitive gels. Model-based iterative reconstruction may improve optical CT image quality and contribute to a wider use of optical CT in clinical gel dosimetry. Methods: This algorithm was evaluated using experimental data acquired by a cone-beam optical CT system, as well as complementary numerical simulations. A fast GPU implementation of OSC-TV was used to achieve reconstruction times comparable to those of conventional filtered backprojection. Images obtained via OSC-TV were compared with the corresponding filtered backprojections. Spatial resolution and uniformity phantoms were scanned and respective reconstructions were subject to evaluation of the modulation transfer function, image uniformity, and accuracy. The artifacts due to refraction and total signal loss from opaque objects were also studied. Results: The cone-beam optical CT data reconstructions showed that OSC-TV outperforms filtered backprojection in terms of image quality, thanks to a model-based simulation of the photon attenuation process. It was shown to significantly improve the image spatial resolution and reduce image noise. The accuracy of the estimation of linear attenuation coefficients remained similar to that obtained via filtered backprojection. Certain image artifacts due to opaque objects were reduced. Nevertheless, the common artifact due to the gel container walls could not be eliminated. Conclusions: The use of iterative reconstruction improves cone-beam optical CT image quality in many ways. The comparisons between OSC-TV and filtered backprojection presented in this paper demonstrate that OSC-TV can

  9. OscSNS: A Precision Short-Baseline Neutrino Oscillation Experiment

    NASA Astrophysics Data System (ADS)

    Louis, William

    2012-03-01

    Short baseline neutrino experiments are consistent with neutrino oscillations at a δm^2 of approximately 1 eV^2, and world neutrino and antineutrino data fit reasonably well to a 3+2 (active+sterile) neutrino oscillation model with CP violation. The OscSNS experiment at ORNL would be able to make precision short-baseline neutrino oscillation measurements and prove that sterile neutrinos exist. The OscSNS experiment will be described and the corresponding neutrino oscillation sensitivities will be discussed.

  10. Modification of an OSCE format to enhance patient continuity in a high-stakes assessment of clinical performance

    PubMed Central

    2011-01-01

    Background Traditional Objective Structured Clinical Examinations (OSCEs) are psychometrically sound but have the limitation of fragmenting complex clinical cases into brief stations. We describe a pilot study of a modified OSCE that attempts to balance a typical OSCE format with a semblance of a continuous, complex, patient case. Methods Two OSCE scenarios were developed. Each scenario involved a single standardized patient and was subdivided into three sequential 10 minute sections that assessed separate content areas and competencies. Twenty Canadian PGY-4 internal medicine trainees were assessed by trained examiner pairs during each OSCE scenario. Paired examiners rated participant performance independent of each other, on each section of each scenario using a validated global rating scale. Inter-rater reliabilities and Pearson correlations between ratings of the 3 sections of each scenario were calculated. A generalizability study was conducted. Participant and examiner satisfaction was surveyed. Results There was no main effect of section or scenario. Inter-rater reliability was acceptable. The g-coefficient was 0.68; four scenarios would achieve 0.80. Moderate correlations between sections of a scenario suggest a possible halo effect. The majority of examiners and participants felt that the modified OSCE provided a sense of patient continuity. Conclusions The modified OSCE provides another approach to the assessment of clinical performance. It attempts to balance the advantages of a traditional OSCE with a sense of patient continuity. PMID:21609486

  11. Effect of Clinically Discriminating, Evidence-Based Checklist Items on the Reliability of Scores from an Internal Medicine Residency OSCE

    ERIC Educational Resources Information Center

    Daniels, Vijay J.; Bordage, Georges; Gierl, Mark J.; Yudkowsky, Rachel

    2014-01-01

    Objective structured clinical examinations (OSCEs) are used worldwide for summative examinations but often lack acceptable reliability. Research has shown that reliability of scores increases if OSCE checklists for medical students include only clinically relevant items. Also, checklists are often missing evidence-based items that high-achieving…

  12. Identifying strengths and weaknesses in the utilization of Objective Structured Clinical Examination (OSCE) in a nursing program.

    PubMed

    McWilliam, Paula L; Botwinski, Carol A

    2012-01-01

    Objective Structured Clinical Examination (OSCE) is used in nursing to assess students' transfer of classroom and laboratory learning experiences into simulated clinical practice. OSCE is a performance-based exam in which students are observed demonstrating a multitude of clinical behaviors. The purpose of this study was to identify strengths and weaknesses in the utilization of OSCE in this nursing program with 60 full-time students ages 21 to 23. An evaluation methodology was used for this study. Interviews were conducted with two groups: faculty facilitators of OSCE and standardized patients (SPs). Areas of focus were: data collection of students' performance, SP selection and training, and modification of the Nursing Interview Interaction Scale (NIIS). It was found that with appropriate SP selection and training, utilization of appropriate tools, and good data collection, OSCE can offer a valid and reliable means of testing nursing students' clinical competencies. PMID:22416539

  13. 40 CFR 300.145 - Special teams and other assistance available to OSCs/RPMs.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... support of the OSC during a response to or a threat of a worst case discharge of oil. (iii) Review of the... evaluation; risk assessment; multimedia sampling and analysis program; on-site safety, including development... available in radiation monitoring, radionuclide analysis, radiation health physics, and risk...

  14. 40 CFR 300.145 - Special teams and other assistance available to OSCs/RPMs.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 29 2013-07-01 2013-07-01 false Special teams and other assistance available to OSCs/RPMs. 300.145 Section 300.145 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SUPERFUND, EMERGENCY PLANNING, AND COMMUNITY RIGHT-TO-KNOW PROGRAMS NATIONAL OIL AND HAZARDOUS SUBSTANCES POLLUTION CONTINGENCY...

  15. 40 CFR 300.145 - Special teams and other assistance available to OSCs/RPMs.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 28 2014-07-01 2014-07-01 false Special teams and other assistance available to OSCs/RPMs. 300.145 Section 300.145 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SUPERFUND, EMERGENCY PLANNING, AND COMMUNITY RIGHT-TO-KNOW PROGRAMS NATIONAL OIL AND HAZARDOUS SUBSTANCES POLLUTION CONTINGENCY...

  16. Functions of OsDof25 in regulation of OsC4PPDK.

    PubMed

    Zhang, Y; Verhoeff, N I; Chen, Z; Chen, S; Wang, Mei; Zhu, Zhen; Ouwerkerk, P B F

    2015-10-01

    Relative little is known about the functions of the so-called Dof zinc factors in plants. Here we report on the analysis of OsDof25 and show a function in regulation of the important C4 photosynthesis gene, OsC4PPDK in rice. Over-expression of OsDof25 enhanced the expression of OsC4PPDK in transient expression experiments by binding in a specific way to a conserved Dof binding site which was confirmed by yeast and in vitro binding studies. Expression studies using promoter GUS plants as well as qPCR experiments showed that OsDof25 expressed in different tissues including both photosynthetic and non-photosynthetic organs and that expression of OsDof25 was partially overlapping with the OsC4PPDK gene. Conclusive evidence for a role of OsDof25 in regulation of C4PPDK came from loss-of-function and gain-of-function experiments with transgenic rice, which showed that down-regulation or over-expression of OsDof25 correlated with OsC4PPDK expression and that OsDof25 has functions as transcriptional activator. PMID:26337938

  17. Geriatric Medicine Fellows' Experiences and Attitudes toward an Objective Structured Clinical Examination (OSCE)

    ERIC Educational Resources Information Center

    Bagri, Anita S.; Zaw, Khin M.; Milanez, Marcos N.; Palacios, Juan J.; Qadri, Syeda S.; Bliss, Linda A.; Roos, Bernard A.; Ruiz, Jorge G.

    2009-01-01

    A total of 8 geriatric medicine fellows participated in an objective structured clinical examination (OSCE) assessing communication skills and clinical reasoning in common geriatric syndromes. To determine their perceptions about the experience, we conducted surveys and semistructured interviews. We analyzed the survey data using descriptive…

  18. 40 CFR 300.145 - Special teams and other assistance available to OSCs/RPMs.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 29 2012-07-01 2012-07-01 false Special teams and other assistance available to OSCs/RPMs. 300.145 Section 300.145 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SUPERFUND, EMERGENCY PLANNING, AND COMMUNITY RIGHT-TO-KNOW PROGRAMS NATIONAL OIL AND HAZARDOUS SUBSTANCES POLLUTION CONTINGENCY...

  19. A Procedural Skills OSCE: Assessing Technical and Non-Technical Skills of Internal Medicine Residents

    ERIC Educational Resources Information Center

    Pugh, Debra; Hamstra, Stanley J.; Wood, Timothy J.; Humphrey-Murto, Susan; Touchie, Claire; Yudkowsky, Rachel; Bordage, Georges

    2015-01-01

    Internists are required to perform a number of procedures that require mastery of technical and non-technical skills, however, formal assessment of these skills is often lacking. The purpose of this study was to develop, implement, and gather validity evidence for a procedural skills objective structured clinical examination (PS-OSCE) for internal…

  20. Undesired Variance Due to Examiner Stringency/Leniency Effect in Communication Skill Scores Assessed in OSCEs

    ERIC Educational Resources Information Center

    Harasym, Peter H.; Woloschuk, Wayne; Cunning, Leslie

    2008-01-01

    Physician-patient communication is a clinical skill that can be learned and has a positive impact on patient satisfaction and health outcomes. A concerted effort at all medical schools is now directed at teaching and evaluating this core skill. Student communication skills are often assessed by an Objective Structure Clinical Examination (OSCE).…

  1. Design and performance of radioisotope space power systems based on OSC multitube AMTEC converter designs

    SciTech Connect

    Schock, A.; Noravian, H.; Or, C.

    1997-12-31

    This paper extends the analytical procedure described in another paper in these proceedings to analyze a variety of compact and light-weight OSC-designed radioisotope-heated generators. Those generators employed General Purpose Heat Source (GPHS) modules and a converter containing sixteen AMTEC cells of OSC`s revised five-tube design with enhanced cell wall reflectivity described in a companion paper in these proceedings. OSC found that the performance of the generator is primarily a function of the thermal insulation between the outside of the generator`s 16 cells and the inside of its wall. After examining a variety of insulation options, it was found that the generator`s performance is optimized by employing a hybrid insulation system, in which the space between the cells is filled with fibrous Min-K insulation, and the generator walls are lined with tapered (i.e., graded-length) multifoil insulation. The OSC design results in a very compact generator, with eight AMTEC cells on each end of the heat source stack. The choice of the five-tube cells makes it possible to expand the BASE tube diameter without increasing the cell diameter. This is important because the eight cells mate well with the stacked GPHS modules. The OSC generator design includes a compliant heat source support and preload arrangement, to hold the heat source modules together during launch, and to maintain thermal contact conductance at the generator`s interfaces despite creep relaxation of its housing. The BOM and EOM (up to 15 years) performances of the revised generators were analyzed for two and three GPHS modules, both for fresh fuel and for aged fuel left over from a spare RTG (Radioisotope Thermoelectric Generator) fueled in 1982. The resulting power outputs were compared with JPL`s latest EOM power demand goals for the Pluto Express and Europa Orbiter missions, and with the generic goals of DOE`s Advanced Radioisotope Power System (ARPS) study. The OSC AMTEC designs yielded system

  2. Recommended OSC design and analysis of AMTEC power system for outer-planet missions

    SciTech Connect

    Schock, A.; Noravian, H.; Or, C.; Kumar, V.

    1999-01-01

    The paper describes OSC designs and analyses of AMTEC cells and radioisotope power systems for possible application to NASA{close_quote}s Europa Orbiter and Pluto Kuiper Express missions, and compares their predicted performance with JPL{close_quote}s preliminary mission goals. The latest cell and generator designs presented here were the culmination of studies covering a wide variety of generator configurations and operating parameters. The many steps and rationale leading to OSC{close_quote}s design evolution and materials selection were discussed in earlier publications and will not be repeated here except for a description of OSC{close_quote}s latest design, including a recent heat source support scheme and cell configuration that have not been described in previous publications. As shown, that heat source support scheme eliminates all contact between the heat source and the AMTEC (Alkali Metal Thermal-to-Electrical Conversion) cells, which simplifies the generator{close_quote}s structural design as well as its fabrication and assembly procedure. An additional purpose of the paper is to describe a revised cell design and fabrication procedure which represent a major departure from previous OSC designs. Previous cells had a uniform diameter, but in the revised design the cell wall beyond the BASE tubes has a greatly reduced diameter. The paper presents analytical performance predictions which show that the revised ({open_quotes}chimney{close_quotes}) cell design yields substantially higher efficiencies than the previous (cylindrical) design. This makes it possible to meet and substantially exceed the JPL-stipulated EOM power goal with four instead of six General Purpose Heat Source (GPHS) modules, resulting in a one-third reduction in the heat source mass, cost, and fuel requirements. OSC{close_quote}s performance predictions were based on its techniques for the coupled thermal, electrical, and fluid flow analyses of AMTEC generators. Those analytical techniques

  3. Probing the effect of OSCE checklist length on inter-observer reliability and observer accuracy

    PubMed Central

    Hurley, Katrina F.; Giffin, Nick A.; Stewart, Samuel A.; Bullock, Graham B.

    2015-01-01

    Purpose The Objective Structured Clinical Examination (OSCE) is a widely employed tool for measuring clinical competence. In the drive toward comprehensive assessment, OSCE stations and checklists may become increasingly complex. The objective of this study was to probe inter-observer reliability and observer accuracy as a function of OSCE checklist length. Method Study participants included emergency physicians and senior residents in Emergency Medicine at Dalhousie University. Participants watched an identical series of four, scripted, standardized videos enacting 10-min OSCE stations and completed corresponding assessment checklists. Each participating observer was provided with a random combination of two 40-item and two 20-item checklists. A panel of physicians scored the scenarios through repeated video review to determine the ‘gold standard’ checklist scores. Results Fifty-seven observers completed 228 assessment checklists. Mean observer accuracy ranged from 73 to 93% (14.6–18.7/20), with an overall accuracy of 86% (17.2/20), and inter-rater reliability range of 58–78%. After controlling for station and individual variation, no effect was observed regarding the number of checklist items on overall accuracy (p=0.2305). Consistency in ratings was calculated using intraclass correlation coefficient and demonstrated no significant difference in consistency between the 20- and 40-item checklists (ranged from 0.432 to 0.781, p-values from 0.56 to 0.73). Conclusions The addition of 20 checklist items to a core list of 20 items in an OSCE assessment checklist does not appear to impact observer accuracy or inter-rater reliability. PMID:26490948

  4. Investigation into the mechanism of action of the antimicrobial peptides Os and Os-C derived from a tick defensin.

    PubMed

    Taute, Helena; Bester, Megan J; Neitz, Albert W H; Gaspar, Anabella R M

    2015-09-01

    Os and Os-C are two novel antimicrobial peptides, derived from a tick defensin, which have been shown to have a larger range of antimicrobial activity than the parent peptide, OsDef2. The aim of this study was to determine whether the peptides Os and Os-C are mainly membrane acting, or if these peptides have possible additional intracellular targets in Escherichia coli and Bacillus subtilis. Transmission electron microscopy revealed that both peptides adversely affected intracellular structure of both bacteria causing different degrees of granulation of the intracellular contents. At the minimum bactericidal concentrations, permeabilization as determined with the SYTOX green assay seemed not to be the principle mode of killing when compared to melittin. However, fluorescent triple staining indicated that the peptides caused permeabilization of stationary phase bacteria and TEM indicated membrane effects. Studies using fluorescently labeled peptides revealed that the membrane penetrating activity of Os and Os-C was similar to buforin II. Os-C was found to associate with the septa of B. subtilis. Plasmid binding studies showed that Os and Os-C binds E. coli plasmid DNA at a similar charge ratio as melittin. These studies suggest membrane activity for Os and Os-C with possible intracellular targets such as DNA. The differences in permeabilization at lower concentrations and binding to DNA between Os and Os-C, suggest that the two peptides have dissimilar modes of action. PMID:26215047

  5. Experiences in adding multiple-choice questions to an objective structural clinical examination (OSCE) in undergraduate dental education.

    PubMed

    Näpänkangas, R; Harila, V; Lahti, S

    2012-02-01

    In the University of Oulu, the competencies of fourth-year dental students have traditionally been assessed with a written examination before they go to work for the first time as dentists outside the Institute of Dentistry. In 2009, the objective structural clinical examination (OSCE) modified with multiple-choice questions was introduced as a tool for assessing clinical competencies. The aim of the study was to evaluate the validity of the modified OSCE (m-OSCE) by measuring the attitude of examiners (teachers) and dental students towards the m-OSCE and to evaluate whether the OSCE is preferred to the written examination in the assessment of knowledge and clinical skills. Additionally, the aim was to evaluate the reliability of the multiple-choice examination. Altogether 30 students (86%) and 11/12 examiners (92%) responded to the questionnaire. Most of the students considered the multiple-choice questions easy, but complained about the complex formulation of the questions. The test stations were easy for 87% of the students, but the time allocated was too short. Most of the students (73%) and examiners (91%) preferred the m-OSCE to the written examination. All students and examiners found the immediate assessment of the tasks good. Based on the evaluations of m-OSCE, it could be concluded that both students and examiners preferred the m-OSCE to the pure written examination in assessment, which indicate that m-OSCE had good face validity. Combining multiple methods in assessment of knowledge and clinical skills whilst simultaneously taking into account the feasibility and available resources provides more valid results. PMID:22251338

  6. Assessment of photoselective vaporization of prostate skills during Urology Objective Structured Clinical Examinations (OSCE)

    PubMed Central

    Noureldin, Yasser A.; Elkoushy, Mohamed A.; Fahmy, Nader; Carrier, Serge; Elhilali, Mostafa M.; Andonian, Sero

    2015-01-01

    Introduction: We evaluated the use of the GreenLight Simulator (GL-SIM) (American Medical Systems, Guelph, ON) in the skill assessment of postgraduate trainees (PGTs) in photoselective vaporization of the prostate (PVP). We also sought to determine whether previous PVP experience or GL-SIM practice improved performance. Methods: PGTs in postgraduate years (PGY-3 to PGY-5) from all 4 Quebec urology training programs were recruited during 2 annual Objective Structured Clinical Examinations (OSCEs). During a 20-minute OSCE station, PGTs were asked to perform 2 exercises: (1) identification of endoscopic landmarks and (2) a PVP of a 30-g normal prostate. Grams vaporized, global scores, and number of correct anatomical landmarks were recorded and correlated with PGY level, practice on the GL-SIM, and previous PVP experience. Results: In total, 25 PGTs were recruited at each OSCE, with 13 PGTs participating in both OSCEs. When comparing scores from the first and second OSCEs, there was a significant improvement in the number of grams vaporized (2.9 vs. 4.3 g; p = 0.003) and global score (100 vs. 165; p = 0.03). There was good correlation between the number of previously performed PVPs and the global score (r = 0.4, p = 0.04). Similarly, PGTs with previous practice on the GL-SIM had significantly higher global score (100.6 vs. 162.6; p = 0.04) and grams vaporized (3.1 vs. 4.1 g; p = 0.04) when compared with those who did not practice on GL-SIM. Furthermore, there were significantly more competent PGTs among those who had previously practiced on the GL-SIM (32.7% vs. 10.2%; p = 0.009). PGY level did not significantly affect grams vaporized or global score (p > 0.05). Conclusion: Performance on the GL-SIM at OSCEs significantly correlated with previous practice on the GL-SIM and previous PVP experience rather than PGY level. Furthermore, there were significantly more competent PGTs among those who had previously practiced on the GL-SIM. PMID:25737763

  7. Composition of OSCS-contaminated heparin occurring in 2008 in batches on the German market.

    PubMed

    Beyer, Tanja; Matz, Magnus; Brinz, Daniela; Rädler, Oliver; Wolf, Bernhard; Norwig, Jochen; Baumann, Knut; Alban, Susanne; Holzgrabe, Ulrike

    2010-07-11

    In 2008, some 900 cases of adverse events associated with the use of heparin were reported to the Food and Drug Administration of USA and the Federal Institute of Drugs and Medical Devices in Germany. 238 patients died from heparin in the USA. In March 2008, oversulfated chondroitin sulfate (OSCS) was identified to be responsible for these cases. NMR spectroscopic evaluation of heparin samples revealed OSCS, dermatan sulfate (DS), chondroitin sulfate A and C as well as various residual solvents to be present in heparin batches, which could not be identified by means of conventional methods described in various pharmacopoeias at that time. In order to evaluate the situation on the German market, 145 representative samples were collected in 2008 and analyzed by means of 1H NMR spectroscopy, water determination, optical rotation and sheep plasma clotting assay. 66 samples were found to contain pure heparin, 51 samples heparin plus DS, 5 samples heparin plus OSCS, and 23 samples heparin, DS and OSCS, each in varying amounts. In 94 out of 145 batches especially ethanol was found in strongly varying amounts up to about 9.5%. Traces of acetone and formic acid were found with concentrations up to 0.04%, as well as sodium acetate and methanol up to 0.5%. Additionally, in many batches the content of water was found to be relatively high. Whereas the optical rotation was able to identify samples with a high contamination of OCSC, all samples tested fulfilled the requirements of the anticoagulation potency assay of the European Pharmacopoeia 6.0. The presented analysis of a representative set of heparin samples proves the suitability of 1H NMR spectroscopy for the quality control of heparin of both glycosaminoglycans and residual solvents. PMID:20399266

  8. Osteopathia striata with cranial sclerosis (OSCS): review of the literature and case report demonstrating challenges of spinal fusion after trauma.

    PubMed

    Katsevman, Gennadiy A; Turner, Ryan C; Lucke-Wold, Brandon P; Sedney, Cara L; Bhatia, Sanjay

    2016-06-01

    Osteopathia striata with cranial sclerosis (OSCS) is a rare but well-described pathology characterized by abnormalities in bone deposition in the axial and cranial skeleton as well as other abnormalities and associated deficits. These skeletal abnormalities can lead to significant intra-operative challenges for the surgeon and influence outcomes for the patient. In this report, we present a case of a patient with OSCS who was involved in a traumatic motor vehicle crash and underwent posterior cervico-thoracic fusion for a T4 chance fracture. Bony abnormalities in the cervico-thoracic spine presented a significant operative challenge due to alterations in bony anatomy and bone architecture. This case serves as an example of the challenges that the spine surgeon faces when dealing with OSCS, and highlights the differences between OSCS and commoner skeletal hyperplasias such as osteopetrosis. PMID:27068044

  9. Assessing Communication Skills of Medical Students in Objective Structured Clinical Examinations (OSCE) - A Systematic Review of Rating Scales

    PubMed Central

    Cömert, Musa; Zill, Jördis Maria; Christalle, Eva; Dirmaier, Jörg; Härter, Martin; Scholl, Isabelle

    2016-01-01

    Background Teaching and assessment of communication skills have become essential in medical education. The Objective Structured Clinical Examination (OSCE) has been found as an appropriate means to assess communication skills within medical education. Studies have demonstrated the importance of a valid assessment of medical students’ communication skills. Yet, the validity of the performance scores depends fundamentally on the quality of the rating scales used in an OSCE. Thus, this systematic review aimed at providing an overview of existing rating scales, describing their underlying definition of communication skills, determining the methodological quality of psychometric studies and the quality of psychometric properties of the identified rating scales. Methods We conducted a systematic review to identify psychometrically tested rating scales, which have been applied in OSCE settings to assess communication skills of medical students. Our search strategy comprised three databases (EMBASE, PsycINFO, and PubMed), reference tracking and consultation of experts. We included studies that reported psychometric properties of communication skills assessment rating scales used in OSCEs by examiners only. The methodological quality of included studies was assessed using the COnsensus based Standards for the selection of health status Measurement INstruments (COSMIN) checklist. The quality of psychometric properties was evaluated using the quality criteria of Terwee and colleagues. Results Data of twelve studies reporting on eight rating scales on communication skills assessment in OSCEs were included. Five of eight rating scales were explicitly developed based on a specific definition of communication skills. The methodological quality of studies was mainly poor. The psychometric quality of the eight rating scales was mainly intermediate. Discussion Our results reveal that future psychometric evaluation studies focusing on improving the methodological quality are needed

  10. Objective Structured Clinical Examination (OSCE)-based Assessment of the Advanced Trauma Life Support (ATLS) Course in Iran

    PubMed Central

    Abbasi, Hamid Reza; Amini, Mitra; Bolandparvaz, Shahram; Paydar, Shahram; Ali, Jameel; Sefidbakht, Sepideh

    2016-01-01

    Objective: To evaluate the effect of advance trauma life support (ATLS®) training on general surgery residents clinical reasoning skills using the national boards-style objective structured clinical examination (OSCE). Methods: This cross-sectional single-center study was conducted in Shiraz University of Medical Sciences including 51 surgery residents that participated in a mandatory national board style OSCE between May 2014 and May 2015. OSCE scores of two groups of general surgery residents including 23 ATLS® trained and 28 non-ATLS® trained were compared using Mann-Whitney U test. The exam was graded out of 20 points and the passing score was ≥14 including 40% trauma cases. Results: There were 8(15.7%) women and 43(84.3%) men among the participants with mean age of 31.12 ± 2.69 and 33.67 ± 4.39 years in women and men respectively. Overall 7 (87.5%) women and 34 (79.07%) men passed the OSCE. The trauma section OSCE score was significantly higher in the ATLS® trained participants when compared to non-ATLS®(7.79 ± 0.81vs.6.90 ± 1.00; p=0.001). In addition, the total score was also significantly higher in ATLS® trained residents (16.07 ± 1.41 vs. 14.60 ± 1.40; p=0.001). There was no association between gender and ATLS® score (p=0.245) or passing the OSCE (p=0.503). Conclusion: ATLS® training is associated with improved overall OSCE scores of general surgery residents completing the board examinations suggesting a positive transfer of ATLS learned skills to management of simulated surgical patients including trauma cases. PMID:27331063

  11. Implementation of OSCE Test to Develop Appropriate Tool to Measure Mothers’ Parenting Skills

    PubMed Central

    Norouzi, Saiideh; Moghaddam, Mohammad H. Baghiani; Sharifabad, Mohammad A. Morowwaty; Norouzi, Ali; Jafari, Ali R.; Zadeh, Hossein Fallah

    2015-01-01

    Introduction: Parents play a vital role throughout a child’s life. This role is very significant in the beginning years of a child’s life. In this period, the child encounters new experiences and these experiences make him or her to learn and grow. These days, in order to help the parents build a bright future for their children, different parenting programs have been designed. These programs provide a great opportunity for parents to enhance positive parenting skills. The aim of this study was to design a reliable and valid instrument for assessing the mothers’ parenting skills. Methodology: 44 mothers who had children aged 3–8 were invited to participate in this study. They took part in parenting-skills training sessions for more than two months. Then they were asked to attend the test center after six months to be tested on trained skills. In this study, mothers’ parenting skills were measured by the OSCE test. The reliability of the test was determined with three methods including split half, Cronbach alpha, and correlation between assessors’ scores in two similar stations. The construct validity of the test was determined with Explanatory Factor Analysis. Results: The total Cronbach alpha coefficient obtained was 0.83 which indicated that the test had a high internal reliability. The Spearman correlation coefficient obtained for two halves of the test was 0.76. The results of Explanatory Factor Analysis showed that nine stations of OSCE were focused on two factors. The first factor was named positive positions and the second factor was named negative positions. Conclusion: The designed OSCE test has the suitable psychometric features to be used by researchers to assess mothers’ parenting skills. PMID:25716400

  12. Using experiential learning and OSCEs to teach and assess tobacco dependence education with first-year dental students.

    PubMed

    Romito, Laura; Schrader, Stuart; Zahl, David

    2014-05-01

    Previous research has indicated that dentists do not routinely engage in tobacco cessation interventions with their patients due, in part, to a lack of training in the predoctoral curriculum. From 2010 to 2012, this study at one U.S. dental school evaluated the effectiveness of experiential learning and objective structured clinical examinations (OSCEs) to improve first-year dental students' knowledge and beliefs about tobacco dependence and cessation interventions. Analysis indicated acceptable reliability and student performance for the OSCE. In all three years, there were statistically significant increases in student knowledge (p<0.001). In each year, there were also statistically significant shifts in student perceptions of preparedness (p<0.001 to p=0.034) and willingness (p<0.001 to p=0.005) to provide tobacco dependence treatment to patients. Results suggest that OSCEs utilizing standardized patients may be an effective method for assessing tobacco dependence education. Preparing for and participating in an OSCE with a standardized patient may help increase student knowledge and shape the beliefs of early dental students about engaging in patient tobacco cessation interventions. Findings were mixed on the impact of experiential learning on OSCE performance, suggesting further research is needed. PMID:24789830

  13. Peer-assisted teaching student tutors as examiners in an orthopedic surgery OSCE station – pros and cons

    PubMed Central

    Melcher, Peter; Zajonz, Dirk; Roth, Andreas; Heyde, Christoph-E.; Ghanem, Mohamed

    2016-01-01

    Background: The OSCE (objective structured clinical examination) is composed of oral and practical examination in order to examine students’ abilities to imply clinical examination techniques and to interact with patients. The examiners for this procedure can be either lecturers or peers. The aim of this work is to evaluate the peer-assisted teaching student tutors as examiners in an orthopedic surgery OSCE station. Methods: We analyzed the OSCE data from 2013 to 2015. During this period over 300 medical students were examined each year. An evaluation was conducted at an orthopedic station and examined by peer students to assess the advantages and disadvantages of peer-assisted teaching student tutors as examiners. Results: We have noticed that student peers are more flexible regarding their schedule and they have been well trained for OSCE. Concerning the economic aspects, student peers are clearly of major economic advantage. Disadvantages were not reported in our study probably because peers were well trained and the checklists are monitored regularly. Conclusion: Student peers in OSCE are of major advantage due to their flexible time schedule and relatively low costs. They must be well trained and the checklists are to be monitored regularly. Our study shows that peer tutor examiners conducted the examination as competent as lecture examiners. However, legal restrictions on the employment of students should be considered. PMID:27500078

  14. Influence of Marital Status on Attitude of Midwives towards OSCE and Their Performance in the Examination in Akwa Ibom and Cross River States, Nigeria

    ERIC Educational Resources Information Center

    Duke, Emon Umoe; Mgbekem, Mary Achi; Nsemo, Alberta David; Ojong-Alacia, Mary Manyo; Nkwonta, Chigozie A.; Mobolaji-Olajide, O. M.

    2015-01-01

    This quantitative study investigated the influence of marital status on the midwives' attitude towards OSCE and how this affects their performance in the examination. Two hypotheses guided the study. HO 1 sort to find out if there exist a significant influence of marital status of midwives on their attitude towards OSCE as well as performance in…

  15. Assessment of percutaneous renal access skills during Urology Objective Structured Clinical Examinations (OSCE)

    PubMed Central

    Noureldin, Yasser A.; Elkoushy, Mohamed A.; Andonian, Sero

    2015-01-01

    Introduction: The first objective was to assess percutaneous renal access (PCA) skills of urology postgraduate trainees (PGTs) during the Objective Structured Clinical Examinations (OSCEs). The second objective was to determine whether previous experience with percutaneous nephrolithotomy (PCNL) improved performance. Methods: After obtaining ethics approval, we recruited PGTs from two urology programs in Quebec between postgraduate years (PGY-3 to PGY-5). Each trainee was asked to answer a short questionnaire regarding previous experience in endourologic procedures. After a 3-minute orientation on the PERC Mentor simulator (Simbionix, Cleveland, OH), each trainee was asked to perform task 4, where they had to correctly access all of the renal calyces and pop the balloons in a normal left kidney model. We collected and analyzed data from the questionnaire and the performance report generated by the simulator. Results: In total, 13 PGTs participated in this study. PGTs had performed a median of 200 (range: 50–1000) cystoscopies, 50 (range: 10–125) TURBTs, 30 (range: 0–100) TURPs, 5 (range: 0–50) laser prostatectomies, and 50 (range: 2–125) ureteroscopies prior to this OSCE. PGTs with previous PCNL experience (8/13) had performed a mean of 18.6 ± 6.3 PCNLs. PGTs with previous PCNL experience performed significantly better in terms of shorter fluoroscopy time (10 ± 1.5 vs. 5.1 ± 0.7 min; p = 0.04), fewer attempts required for successful puncture of the pelvi-calyceal system (PCS) (21 ± 2.3 vs. 13 ± 1.8; p = 0.02), and had significantly lower complications in terms of fewer infundibular injury (7.4 ± 1.5 vs. 2 ± 0.4; p = 0.004) and fewer PCS perforations (11 ± 1.7 vs. 4.5 ± 1.2; p = 0.01). Conclusion: It is feasible to use the PERC Mentor simulator during OSCEs to assess PCA skills of urology PGTs. PGTs who had previous PCNL experience performed significantly better with fewer complications. PMID:25844094

  16. ABA-induced CCCH tandem zinc finger protein OsC3H47 decreases ABA sensitivity and promotes drought tolerance in Oryza sativa.

    PubMed

    Wang, Wenyi; Liu, Bohan; Xu, Mengyun; Jamil, Muhammad; Wang, Guoping

    2015-08-14

    Water deficit causes multiple negative impacts on plants, such as reactive oxygen species (ROS) accumulation, abscisic acid (ABA) induction, stomatal closure, and decreased photosynthesis. Here, we characterized OsC3H47, which belongs to CCCH zinc-finger families, as a drought-stress response gene. It can be strongly induced by NaCl, PEG, ABA, and drought conditions. Overexpression of OsC3H47 significantly enhanced tolerance to drought and salt stresses in rice seedlings, which indicates that OsC3H47 plays important roles in post-stress recovery. However, overexpression of OsC3H47 reduced the ABA sensitivity of rice seedlings. This suggests that OsC3H47 is a newly discovered gene that can control rice drought-stress response, and it may play an important role in ABA feedback and post-transcription processes. PMID:26047696

  17. Training Family Medicine Residents in Effective Communication Skills While Utilizing Promotoras as Standardized Patients in OSCEs: A Health Literacy Curriculum

    PubMed Central

    Pagels, Patti; Kindratt, Tiffany; Arnold, Danielle; Brandt, Jeffrey; Woodfin, Grant; Gimpel, Nora

    2015-01-01

    Introduction. Future health care providers need to be trained in the knowledge and skills to effectively communicate with their patients with limited health literacy. The purpose of this study is to develop and evaluate a curriculum designed to increase residents' health literacy knowledge, improve communication skills, and work with an interpreter. Materials and Methods. Family Medicine residents (N = 25) participated in a health literacy training which included didactic lectures and an objective structured clinical examination (OSCE). Community promotoras acted as standardized patients and evaluated the residents' ability to measure their patients' health literacy, communicate effectively using the teach-back and Ask Me 3 methods, and appropriately use an interpreter. Pre- and postknowledge, attitudes, and postdidactic feedback were obtained. We compared OSCE scores from the group that received training (didactic group) and previous graduates. Residents reported the skills they used in practice three months later. Results. Family Medicine residents showed an increase in health literacy knowledge (p = 0.001) and scored in the adequately to expertly performed range in the OSCE. Residents reported using the teach-back method (77.8%) and a translator more effectively (77.8%) three months later. Conclusions. Our innovative health literacy OSCE can be replicated for medical learners at all levels of training. PMID:26491565

  18. Isomers of OCS{sub 2}: IR absorption spectra of OSCS and O(CS{sub 2}) in solid Ar

    SciTech Connect

    Lo, W.-J.; Chen, H.-F.; Chou, P.-H.; Lee, Y.-P.

    2004-12-22

    Irradiation of an Ar matrix sample containing O{sub 3} and CS{sub 2} with a KrF excimer laser at 248 nm yielded new lines at 1402.1 (1404.7), 1056.2 (1052.7), and 622.3 (620.5) cm-1; numbers in parentheses correspond to species in a minor matrix site. Secondary photolysis at 308 nm diminished these lines and produced mainly OCS and SO{sub 2}. Annealing of this matrix to 30 K yielded a second set of new lines at 1824.7 and 617.8 cm-1. The first set of lines are assigned to C=S stretching, O-S stretching, and S-C stretching modes of carbon disulfide S-oxide, OSCS; and the second set of lines are assigned to C=O stretching and OCS bending modes of dithiiranone, O(CS{sub 2}), respectively, based on results of {sup 34}S- and {sup 18}O-isotopic experiments and quantum-chemical calculations. These calculations using density-functional theory (B3LYP/aug-cc-pVTZ) predict four stable isomers of OCS{sub 2}: O(CS{sub 2}), SSCO, OSCS, and SOCS, listed in order of increasing energy. According to calculations, O(CS{sub 2}) has a cyclic CS{sub 2} moiety and is the most stable isomer of OCS{sub 2}. OSCS is planar, with bond angles anguprOSC congruent with 111.9 deg. and anguprSCS congruent with 177.3 deg.; it is less stable than SSCO and O(CS{sub 2}) by {approx}102 and 154 kJ mol-1, respectively, and more stable than SOCS by {approx}26 kJ mol-1. Calculated vibrational wave numbers, IR intensities, {sup 34}S- and {sup 18}O-isotopic shifts for OSCS and O(CS{sub 2}) fit satisfactorily with experimental results.

  19. OsC6, Encoding a Lipid Transfer Protein, Is Required for Postmeiotic Anther Development In Rice1[W][OA

    PubMed Central

    Zhang, Dasheng; Liang, Wanqi; Yin, Changsong; Zong, Jie; Gu, Fangwei; Zhang, Dabing

    2010-01-01

    Synthesis of lipidic components in anthers, including of the pollen exine, is essential for plant male reproductive development. Plant lipid transfer proteins (LTPs) are small, abundant lipid-binding proteins that have the ability to exchange lipids between membranes in vitro. However, their biological role in male reproductive development remains less understood. Here, we report the crucial role of OsC6 in regulating postmeiotic anther development in rice (Oryza sativa). Found in monocots, OsC6 belongs to a distinct clade from previously identified LTP1 and LTP2 family members found in both dicots and monocots. OsC6 expression is mainly detectable in tapetal cells and weakly in microspores from stage 9 to stage 11 of anther development. Immunological assays indicated that OsC6 is widely distributed in anther tissues such as the tapetal cytoplasm, the extracellular space between the tapetum and middle layer, and the anther locule and anther cuticle. Biochemical assays indicated that recombinant OsC6 has lipid binding activity. Moreover, plants in which OsC6 was silenced had defective development of orbicules (i.e. Ubisch bodies) and pollen exine and had reduced pollen fertility. Furthermore, additional evidence is provided that the expression of OsC6 is positively regulated by a basic helix-loop-helix transcription factor, Tapetum Degeneration Retardation (TDR). Extra granule-like structures were observed on the inner surface of the tdr tapetal layer when the expression of OsC6 was driven by the TDR promoter compared with the tdr mutant. These data suggest that OsC6 plays a crucial role in the development of lipidic orbicules and pollen exine during anther development in rice. PMID:20610705

  20. Team OSCE: A Teaching Modality for Promotion of Multidisciplinary Work in Mental Health Settings

    PubMed Central

    Sharma, Manoj Kumar; Chandra, Prabha S.; Chaturvedi, Santosh K.

    2015-01-01

    Objective: The objective structured clinical examination has been in use both as an assessment and a teaching modality within the mental health profession. It focuses on individual skill enhancement, the inter-professional understanding of role obligation is helpful in promoting competence as a team as well as role of other team members. The Team OSCE (TOSCE) is an effective way in promoting inter-professional learning. Materials and Methods: The present work assesses the trainee experience with TOSCE and its utility in clinical care. Twenty-two mental health trainees (17 male and 5 female from psychiatry, clinical psychology and psychiatric social work) got exposure to weekly OSCAF training as well as 2-3 Team OSCAFS on various aspects of clinical work as a part of their clinical training for 3 months. Rating from the trainees were taken on TOSCE feedback checklist. Results: TOSCE was helpful in promoting the understanding role of other team members; shared decision-making, problem-solving, handling unexpected events, giving feedback and closure. Conclusion: The TOSCE may be introduced as a way to work on clinical performance, shared decision-making and inter-professional understanding. PMID:26664082

  1. An innovative OSCE clinical log station: a quantitative study of its influence on Log use by medical students

    PubMed Central

    2012-01-01

    Background A Clinical Log was introduced as part of a medical student learning portfolio, aiming to develop a habit of critical reflection while learning was taking place, and provide feedback to students and the institution on learning progress. It was designed as a longitudinal self-directed structured record of student learning events, with reflection on these for personal and professional development, and actions planned or taken for learning. As incentive was needed to encourage student engagement, an innovative Clinical Log station was introduced in the OSCE, an assessment format with established acceptance at the School. This study questions: How does an OSCE Clinical Log station influence Log use by students? Methods The Log station was introduced into the formative, and subsequent summative, OSCEs with careful attention to student and assessor training, marking rubrics and the standard setting procedure. The scoring process sought evidence of educational use of the log, and an ability to present and reflect on key learning issues in a concise and coherent manner. Results Analysis of the first cohort’s Log use over the four-year course (quantified as number of patient visits entered by all students) revealed limited initial use. Usage was stimulated after introduction of the Log station early in third year, with some improvement during the subsequent year-long integrated community-based clerkship. Student reflection, quantified by the mean number of characters in the ‘reflection’ fields per entry, peaked just prior to the final OSCE (mid-Year 4). Following this, very few students continued to enter and reflect on clinical experience using the Log. Conclusion While the current study suggested that we can’t assume students will self-reflect unless such an activity is included in an assessment, ongoing work has focused on building learner and faculty confidence in the value of self-reflection as part of being a competent physician. PMID:23140250

  2. Heparin identification test and purity test for OSCS in heparin sodium and heparin calcium by weak anion-exchange high-performance liquid chromatography.

    PubMed

    Hashii, Noritaka; Kawasaki, Nana; Itoh, Satsuki; Qin, Yan; Fujita, Naho; Hattori, Toshiaki; Miyata, Kazuyoshi; Bando, Aya; Sekimoto, Yuko; Hama, Takeshi; Kashimura, Masaki; Tatsumi, Masashi; Mabuchi, Kazunori; Namekawa, Hiroshi; Sakai, Toru; Hirose, Mio; Dobashi, Sei; Shimahashi, Hirotoshi; Koyama, Sadatoshi; Herr, Susanne Odgaard; Kawai, Kenzo; Yoden, Hikaru; Yamaguchi, Teruhide

    2010-09-01

    Heparin sodium and heparin calcium, which are widely used as anti-coagulants, are known to potentially contain the natural impurity dermatan sulfate (DS). Recently serious adverse events occurred in patients receiving heparin sodium in the US, and a contaminant oversulfated chondroitin sulfate (OSCS) was found to be a cause of the events. To ensure the quality and safety of pharmaceutical heparins, there is need of a physicochemical identification test that can discriminate heparin from the heparin-related substances as well as a sensitive purity test for OSCS. Recently, HPLC with a strong-anion exchange column was proposed as the methods for identifying heparin and determination of OSCS in heparin sodium. Although this method is convenient and easy to perform, the only column suitable for this purpose is the Dionex IonPac AS11-HC column. In this study, we developed alternative identification test and test for OSCS in both heparin sodium and heparin calcium using a weak anion-exchange column. The identification test allowed for separation of heparin from the impurity DS and contaminant OSCS in a shorter time. The purity test provided enough sensitivity, specificity, linearity, recovery and repeatability for OSCS. We believe that our methods will be useful for quality control of pharmaceutical heparins. PMID:20452241

  3. Modifying the organic/electrode interface in Organic Solar Cells (OSCs) and improving the efficiency of solution-processed phosphorescent Organic Light-Emitting Diodes (OLEDs)

    SciTech Connect

    Xiao, Teng

    2012-01-01

    Organic semiconductors devices, such as, organic solar cells (OSCs), organic light-emitting diodes (OLEDs) and organic field-effect transistors (OFETs) have drawn increasing interest in recent decades. As organic materials are flexible, light weight, and potentially low-cost, organic semiconductor devices are considered to be an alternative to their inorganic counterparts. This dissertation will focus mainly on OSCs and OLEDs. As a clean and renewable energy source, the development of OSCs is very promising. Cells with 9.2% power conversion efficiency (PCE) were reported this year, compared to < 8% two years ago. OSCs belong to the so-called third generation solar cells and are still under development. While OLEDs are a more mature and better studied field, with commercial products already launched in the market, there are still several key issues: (1) the cost of OSCs/OLEDs is still high, largely due to the costly manufacturing processes; (2) the efficiency of OSCs/OLEDs needs to be improved; (3) the lifetime of OSCs/OLEDs is not sufficient compared to their inorganic counterparts; (4) the physics models of the behavior of the devices are not satisfactory. All these limitations invoke the demand for new organic materials, improved device architectures, low-cost fabrication methods, and better understanding of device physics. For OSCs, we attempted to improve the PCE by modifying the interlayer between active layer/metal. We found that ethylene glycol (EG) treated poly(3,4-ethylenedioxythiophene): polystyrenesulfonate (PEDOT: PSS) improves hole collection at the metal/polymer interface, furthermore it also affects the growth of the poly(3- hexylthiophene) (P3HT):phenyl-C61-butyric acid methyl ester (PCBM) blends, making the phase segregation more favorable for charge collection. We then studied organic/inorganic tandem cells. We also investigated the effect of a thin LiF layer on the hole-collection of copper phthalocyanine (CuPc)/C70-based small molecular OSCs. A

  4. Modifying the organic/electrode interface in Organic Solar Cells (OSCs) and improving the efficiency of solution-processed phosphorescent Organic Light-Emitting Diodes (OLEDs)

    NASA Astrophysics Data System (ADS)

    Xiao, Teng

    Organic semiconductors devices, such as, organic solar cells (OSCs), organic light-emitting diodes (OLEDs) and organic field-effect transistors (OFETs) have drawn increasing interest in recent decades. As organic materials are flexible, light weight, and potentially low-cost, organic semiconductor devices are considered to be an alternative to their inorganic counterparts. This dissertation will focus mainly on OSCs and OLEDs. As a clean and renewable energy source, the development of OSCs is very promising. Cells with 9.2% power conversion efficiency (PCE) were reported this year, compared to < 8% two years ago. OSCs belong to the so-called third generation solar cells and are still under development. While OLEDs are a more mature and better studied field, with commercial products already launched in the market, there are still several key issues: (1) the cost of OSCs/OLEDs is still high, largely due to the costly manufacturing processes; (2) the efficiency of OSCs/OLEDs needs to be improved; (3) the lifetime of OSCs/OLEDs is not sufficient compared to their inorganic counterparts; (4) the physics models of the behavior of the devices are not satisfactory. All these limitations invoke the demand for new organic materials, improved device architectures, low-cost fabrication methods, and better understanding of device physics. For OSCs, we attempted to improve the PCE by modifying the interlayer between active layer/metal. We found that ethylene glycol (EG) treated poly(3,4-ethylenedioxy-thiophene):polystyrenesulfonate (PEDOT: PSS) improves hole collection at the metal/polymer interface, furthermore it also affects the growth of the poly(3-hexylthiophene) (P3HT):phenyl-C 61-butyric acid methyl ester (PCBM) blends, making the phase segregation more favorable for charge collection. We then studied organic/inorganic tandem cells. We also investigated the effect of a thin LiF layer on the hole-collection of copper phthalocyanine (CuPc)/C70-based small molecular OSCs. A

  5. A wide-band low phase noise LC-tuned VCO with constant KVCO/ωosc for LTE PLL

    NASA Astrophysics Data System (ADS)

    Jiwei, Huang; Zhigong, Wang; Kuili, Li; Zhengping, Li; Yongping, Wang

    2012-02-01

    A wideband LC-tuned voltage-controlled oscillator (LC-VCO) applied in LTE PLL frequency synthesizers with constant KVCO/ωosc is described. In order to minimize the loop bandwidth variations of PLL, a varactor array is proposed, which consists of a series of differential variable capacitor pairs and a series of single-pole double-throw (SPDT) switches to connect Vtune or VDD. The switches are controlled by switching bits. With this scheme, the ratio of KV = ∂Cvar/∂Vtune and the capacitance value of the capacitor array maintains relatively constant; furthermore, the loop bandwidth of the PLL fluctuation is suppressed. The 3.2-4.6-GHz VCO for multi-band LTE PLL is fabricated in a 0.13-μm RF-CMOS process. The VCO exhibits a maximum variation of KVCO/ωosc of only ±4%. The VCO also exhibits a low phase-noise of-124 dBc/Hz at a 1-MHz offset frequency and a low current consumption of 18.0 mA with a 1.2-V power supply.

  6. Feedback promotes learning success! Which kind of feedback for the faculty is given by an interdisciplinary OSCE with focus on decision-making?

    PubMed Central

    Stibane, Tina; Sitter, Helmut; Neuhof, Despina; Wiechens, Helena; Schönbauer, Andrea; Bösner, Stefan; Baum, Erika

    2016-01-01

    Clinical skills such as history taking, diagnostic reasoning, therapy planning, and giving advice are even more complex than practical skills like lung auscultation and have to be applied in complex clinical situations. We judged this competence in an interdisciplinary formative OSCE conducted with students of Marburg University. Results of 218 students passing 643 OSCE stations composed of 37 different scenarios were analyzed. As a competence based examination that reflects the practical skills gained during clinical training, the here presented analysis serves also as a feedback instrument for clinical teachers, their respective disciplines and the medical faculty as a whole. PMID:27579353

  7. Standard Setting in a Small Scale OSCE: A Comparison of the Modified Borderline-Group Method and the Borderline Regression Method

    ERIC Educational Resources Information Center

    Wood, Timothy J.; Humphrey-Murto, Susan M.; Norman, Geoffrey R.

    2006-01-01

    When setting standards, administrators of small-scale OSCEs often face several challenges, including a lack of resources, a lack of available expertise in statistics, and difficulty in recruiting judges. The Modified Borderline-Group Method is a standard setting procedure that compensates for these challenges by using physician examiners and is…

  8. Long-term prospective teaching effectivity of practical skills training and a first OSCE in cranio maxillofacial surgery for dental students.

    PubMed

    Landes, Constantin A; Hoefer, Sebastian; Schuebel, Florian; Ballon, Alexander; Teiler, Anna; Tran, Andreas; Weber, Roxane; Walcher, Felix; Sader, Robert

    2014-07-01

    Basic skills in oral/CMF surgery should be taught effectively to dental students as surgical skills training is traditionally under-represented in the dental curriculum compared to its later need in daily clinical practice. Rigid curricular time frames and prospectively condensed professional education foster new effective teaching and examination formats. Transmitting and assessing clinical competence objectively (independent of subjective bias), reliably (repeatable, inter-rater consistency) and valid (representative, structured task selection) was intended and evaluated in oral/CMF surgery skills acquisition starting in summer 2009. A small-group practical skills training (PST) day initiated a one-week practical training course, covering previously formulated learning objectives. An objective structured clinical evaluation (OSCE) was held at the end of each semester. Theoretical background knowledge and clinical skills should have to be memorized within a representative number of practical tasks (test stations). A first semester (26 students) used classical practical training alone as controls, the following semesters (171 students) had PST, considered as a study group. All 197 students were assessed with OSCE's over a 3-year period. An instructor held PST based on presentations, videos and practical training, including mannequins, with pairs of students. This included history taking, communication and interpretation of laboratory/image diagnostics, structured clinical facial examination, fracture diagnosis, venipuncture, suturing, biopsy and wire loops on pig jaws for manual and clinical skills, which were later incorporated in OSCE stations. OSCE average results increased from 63.3 ± 9.7% before and to 75.5 ± 10% after the inclusion of PST (p < 0.05). Knowledge diffusion between sittings on the same test date and between consecutive semesters was insignificant. Students and faculty rated their learning/teaching experience "very good" to "good". PST was

  9. Patterns of nucleotide diversity and phenotypes of two domestication related genes (OsC1 and Wx) in indigenous rice varieties in Northeast India

    PubMed Central

    2014-01-01

    Background During the domestication of crops, individual plants with traits desirable for human needs have been selected from their wild progenitors. Consequently, genetic and nucleotide diversity of genes associated with these selected traits in crop plants are expected to be lower than their wild progenitors. In the present study, we surveyed the pattern of nucleotide diversity of two selected trait specific genes, Wx and OsC1, which regulate amylose content and apiculus coloration respectively in cultivated rice varieties. The analyzed samples were collected from a wide geographic area in Northeast (NE) India, and included contrasting phenotypes considered to be associated with selected genes, namely glutinous and nonglutinous grains and colored and colorless apiculus. Results No statistically significant selection signatures were detected in both Wx and OsC1gene sequences. However, low level of selection that varied across the length of each gene was evident. The glutinous type varieties showed higher levels of nucleotide diversity at the Wx locus (πtot = 0.0053) than nonglutinous type varieties (πtot = 0.0043). The OsC1 gene revealed low levels of selection among the colorless apiculus varieties with lower nucleotide diversity (πtot = 0.0010) than in the colored apiculus varieties (πtot = 0.0023). Conclusions The results revealed that functional mutations at Wx and OsC1genes considered to be associated with specific phenotypes do not necessarily correspond to the phenotypes in indigenous rice varieties in NE India. This suggests that other than previously reported genomic regions may also be involved in determination of these phenotypes. PMID:24935343

  10. The iOSC3 system: using ontologies and SWRL rules for intelligent supervision and care of patients with acute cardiac disorders.

    PubMed

    Martínez-Romero, Marcos; Vázquez-Naya, José M; Pereira, Javier; Pereira, Miguel; Pazos, Alejandro; Baños, Gerardo

    2013-01-01

    Physicians in the Intensive Care Unit (ICU) are specially trained to deal constantly with very large and complex quantities of clinical data and make quick decisions as they face complications. However, the amount of information generated and the way the data are presented may overload the cognitive skills of even experienced professionals and lead to inaccurate or erroneous actions that put patients' lives at risk. In this paper, we present the design, development, and validation of iOSC3, an ontology-based system for intelligent supervision and treatment of critical patients with acute cardiac disorders. The system analyzes the patient's condition and provides a recommendation about the treatment that should be administered to achieve the fastest possible recovery. If the recommendation is accepted by the doctor, the system automatically modifies the quantity of drugs that are being delivered to the patient. The knowledge base is constituted by an OWL ontology and a set of SWRL rules that represent the expert's knowledge. iOSC3 has been developed in collaboration with experts from the Cardiac Intensive Care Unit (CICU) of the Meixoeiro Hospital, one of the most significant hospitals in the northwest region of Spain. PMID:23476717

  11. OSC2 and CYP716A14v2 Catalyze the Biosynthesis of Triterpenoids for the Cuticle of Aerial Organs of Artemisia annua

    PubMed Central

    Moses, Tessa; Pollier, Jacob; Shen, Qian; Soetaert, Sandra; Reed, James; Erffelinck, Marie-Laure; Van Nieuwerburgh, Filip C.W.; Vanden Bossche, Robin; Osbourn, Anne; Thevelein, Johan M.; Deforce, Dieter; Tang, Kexuan

    2015-01-01

    Artemisia annua is widely studied for its ability to accumulate the antimalarial sesquiterpenoid artemisinin. In addition to producing a variety of sesquiterpenoids, A. annua also accumulates mono-, di-, and triterpenoids, the majority of which are produced in the glandular trichomes. A. annua also has filamentous trichomes on its aerial parts, but little is known of their biosynthesis potential. Here, through a comparative transcriptome analysis between glandular and filamentous trichomes, we identified two genes, OSC2 and CYP716A14v2, encoding enzymes involved in the biosynthesis of specialized triterpenoids in A. annua. By expressing these genes in Saccharomyces cerevisiae and Nicotiana benthamiana, we characterized the catalytic function of these proteins and could reconstitute the specialized triterpenoid spectrum of A. annua in these heterologous hosts. OSC2 is a multifunctional oxidosqualene cyclase that produces α-amyrin, β-amyrin, and δ-amyrin. CYP716A14v2 is a P450 belonging to the functionally diverse CYP716 family and catalyzes the oxidation of pentacyclic triterpenes, leading to triterpenes with a carbonyl group at position C-3, thereby providing an alternative biosynthesis pathway to 3-oxo triterpenes. Together, these enzymes produce specialized triterpenoids that are constituents of the wax layer of the cuticle covering the aerial parts of A. annua and likely function in the protection of the plant against biotic and abiotic stress. PMID:25576188

  12. The iOSC3 System: Using Ontologies and SWRL Rules for Intelligent Supervision and Care of Patients with Acute Cardiac Disorders

    PubMed Central

    Martínez-Romero, Marcos; Vázquez-Naya, José M.; Pereira, Javier; Pereira, Miguel; Pazos, Alejandro; Baños, Gerardo

    2013-01-01

    Physicians in the Intensive Care Unit (ICU) are specially trained to deal constantly with very large and complex quantities of clinical data and make quick decisions as they face complications. However, the amount of information generated and the way the data are presented may overload the cognitive skills of even experienced professionals and lead to inaccurate or erroneous actions that put patients' lives at risk. In this paper, we present the design, development, and validation of iOSC3, an ontology-based system for intelligent supervision and treatment of critical patients with acute cardiac disorders. The system analyzes the patient's condition and provides a recommendation about the treatment that should be administered to achieve the fastest possible recovery. If the recommendation is accepted by the doctor, the system automatically modifies the quantity of drugs that are being delivered to the patient. The knowledge base is constituted by an OWL ontology and a set of SWRL rules that represent the expert's knowledge. iOSC3 has been developed in collaboration with experts from the Cardiac Intensive Care Unit (CICU) of the Meixoeiro Hospital, one of the most significant hospitals in the northwest region of Spain. PMID:23476717

  13. How Do Medical Students Respond to Emotional Cues and Concerns Expressed by Simulated Patients during OSCE Consultations? – A Multilevel Study

    PubMed Central

    Zhou, Yuefang; Collinson, Alex; Laidlaw, Anita; Humphris, Gerry

    2013-01-01

    Objectives How medical students handle negative emotions expressed by simulated patients during Objective Structured Clinical Examinations (OSCE) has not been fully investigated. We aim to explore (i) whether medical students respond differently to different types of patients’ emotional cues; and (2) possible effects of patients’ progressive disclosure of emotional cues on students’ responses. Methods Forty OSCE consultations were video recorded and coded for patients’ expressions of emotional distress and students’ responses using a validated behavioural coding scheme (the Verona Coding Definitions of Emotional Sequence). Logistic multilevel regression was adopted to model the probability of the occurrence of student reduce space response behaviour as a function of the number of patients’ expressions of emotional cues. Results We found that medical students offered responses that differed to emotional cue types expressed by simulated patients. Students appeared to provide space to emotional cues when expressed in vague and unspecific words and reduce space to cues emphasizing physiological or cognitive correlates. We also found that medical students were less likely to explore patients’ emotional distress nearer the end of the consultation and when the duration of a patient speech turn got larger. Cumulative frequency of patients’ emotional cues also predicted students’ reduce space behaviour. Practical Implications Understanding how medical students manage negative emotions has significant implications for training programme development focusing on emotion recognition skills and patient-centred communication approach. In addition, the statistical approaches adopted by this study will encourage researchers in healthcare communication to search for appropriate analytical techniques to test theoretical propositions. PMID:24194960

  14. Fellow use of medical jargon correlates inversely with patient and observer perceptions of professionalism: results of a rheumatology OSCE (ROSCE) using challenging patient scenarios.

    PubMed

    Berman, Jessica R; Aizer, Juliet; Bass, Anne R; Blanco, Irene; Davidson, Anne; Dwyer, Edward; Fields, Theodore R; Huang, Wei-Ti; Kang, Jane S; Kerr, Leslie D; Krasnokutsky-Samuels, Svetlana; Lazaro, Deana M; Schwartzman-Morris, Julie S; Paget, Stephen A; Pillinger, Michael H

    2016-08-01

    The NYC Rheumatology Objective Structured Clinical Examination (NYC-ROSCE) is held annually to assess fellow competencies. We recently redesigned our OSCE to better assess subspecialty trainee communication skills and professionalism by developing scenarios in which the patients encountered were psychosocially or medically complex. The objective of this study is to identify which types of verbal and non-verbal skills are most important in the perception of professionalism in the patient-physician interaction. The 2012-2013 NYC-ROSCEs included a total of 53 fellows: 55 MD evaluators from 7 NYC rheumatology training programs (Hospital for Special Surgery-Weill Cornell (HSS), SUNY/Downstate, NYU, Einstein, Columbia, Mount Sinai, and North Shore/Long Island Jewish (NSLIJ)), and 55 professional actors/standardized patients participated in 5 stations. Quantitative fellow performance assessments were made on the following: maintaining composure; partnering with the patient; honesty; professionalism; empathy; and accountability. Free-text comments were solicited regarding specific strengths and weaknesses. A total of 53/53 eligible (100 %) fellows were evaluated. MD evaluators rated fellows lower for professionalism than did the standardized patients (6.8 ± 0.6 vs. 7.4 ± 0.8, p = 0.05), suggesting that physicians and patients view professionalism somewhat differently. Fellow self-evaluations for professionalism (6.6 ± 1.2) were concordant with those of the MD evaluators. Ratings of empathy by fellows themselves (6.6 ± 1.0), MD evaluators (6.6 ± 0.7), and standardized patients (6.6 ± 1.1) agreed closely. Jargon use, frequently cited by evaluators, showed a moderate association with lower professionalism ratings by both MD evaluators and patients. Psychosocially challenging patient encounters in the NYC-ROSCE permitted critical assessment of the patient-centered traits contributing to impressions of professionalism and indicate that

  15. Developments in the photonics program at OSC

    NASA Astrophysics Data System (ADS)

    Peyghambarian, N.

    2014-10-01

    The photonics program at the College of Optical Sciences started nearly 30 years ago. In 1984, the program was focused on development of femtosecond laser sources and their use in investigating semiconductor carrier dynamics. The program grew into polymer and organic optics in late 1989 and was strengthened by the winning of the CAMP MURI from ONR in 1995 that was focused on multifunctional polymers including photorefractive polymers, organic light emitting diodes and 3D direct laser writing. Also in 1995, the areas of glass waveguide and fiber optic materials and devices were added to the program. In 2008, the optical communication and future internet research was started through winning the CIAN NSF ERC. Expertise in thin films, optical storage and the fundamental aspects of light are elements of the overall research program. Holographic 3D display, autofocus lenses, bio-medical imaging and devices for vision have also been ongoing research areas.

  16. Materials Data on OsC4ClO4 (SG:19) by Materials Project

    SciTech Connect

    Kristin Persson

    2014-07-09

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  17. The Relationship between Checklist Scores on a Communication OSCE and Analogue Patients' Perceptions of Communication

    ERIC Educational Resources Information Center

    Mazor, Kathleen M.; Ockene, Judith K.; Rogers, H. Jane; Carlin, Michele M.; Quirk, Mark E.

    2005-01-01

    Many efforts to teach and evaluate physician-patient communication are based on two assumptions: first, that communication can be conceptualized as consisting of specific observable behaviors, and second, that physicians who exhibit certain behaviors are more effective in communicating with patients. These assumptions are usually implicit, and are…

  18. Students’ performance in the different clinical skills assessed in OSCE: what does it reveal?

    PubMed Central

    Sim, Joong Hiong; Abdul Aziz, Yang Faridah; Mansor, Azura; Vijayananthan, Anushya; Foong, Chan Choong; Vadivelu, Jamuna

    2015-01-01

    Introduction The purpose of this study was to compare students’ performance in the different clinical skills (CSs) assessed in the objective structured clinical examination. Methods Data for this study were obtained from final year medical students’ exit examination (n=185). Retrospective analysis of data was conducted using SPSS. Means for the six CSs assessed across the 16 stations were computed and compared. Results Means for history taking, physical examination, communication skills, clinical reasoning skills (CRSs), procedural skills (PSs), and professionalism were 6.25±1.29, 6.39±1.36, 6.34±0.98, 5.86±0.99, 6.59±1.08, and 6.28±1.02, respectively. Repeated measures ANOVA showed there was a significant difference in the means of the six CSs assessed [F(2.980, 548.332)=20.253, p<0.001]. Pairwise multiple comparisons revealed significant differences between the means of the eight pairs of CSs assessed, at p<0.05. Conclusions CRSs appeared to be the weakest while PSs were the strongest, among the six CSs assessed. Students’ unsatisfactory performance in CRS needs to be addressed as CRS is one of the core competencies in medical education and a critical skill to be acquired by medical students before entering the workplace. Despite its challenges, students must learn the skills of clinical reasoning, while clinical teachers should facilitate the clinical reasoning process and guide students’ clinical reasoning development. PMID:25697602

  19. 40 CFR 300.145 - Special teams and other assistance available to OSCs/RPMs.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...; (iii) The flight time to provide response to oil spills in all areas of the Coast Guard district with... responding in an oil spill emergency; and (v) Areas where large quantities of petroleum products are... (CONTINUED) SUPERFUND, EMERGENCY PLANNING, AND COMMUNITY RIGHT-TO-KNOW PROGRAMS NATIONAL OIL AND...

  20. Materials Data on OsC3IO3 (SG:11) by Materials Project

    SciTech Connect

    Kristin Persson

    2014-07-09

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  1. Materials Data on Sb2OsC6(OF2)6 (SG:128) by Materials Project

    SciTech Connect

    Kristin Persson

    2014-07-09

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  2. Materials Data on Sb2OsC4(OF3)4 (SG:33) by Materials Project

    SciTech Connect

    Kristin Persson

    2014-07-09

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  3. Materials Data on OsC4(ClO2)2 (SG:15) by Materials Project

    SciTech Connect

    Kristin Persson

    2014-07-09

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  4. Materials Data on OsC4(ClO2)2 (SG:136) by Materials Project

    SciTech Connect

    Kristin Persson

    2014-07-09

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  5. How Do Examiners and Examinees Think About Role-Playing of Standardized Patients in an OSCE Setting?

    ERIC Educational Resources Information Center

    Sadeghi, Majid; Taghva, Arsia; Mirsepassi, Gholamreza; Hassanzadeh, Mehdi

    2007-01-01

    Objective: The use of standardized patients in Objective Structured Clinical Examinations in the assessment of psychiatric residents has increased in recent years. The aim of this study is to investigate the experience of psychiatry residents and examiners with standardized patients in Iran. Method: Final-year residents in psychiatry participated…

  6. Knowing How and Showing How: Interdisciplinary Collaboration on Substance Abuse Skill OSCEs for Medical, Nursing and Social Work Students

    ERIC Educational Resources Information Center

    Baez, Annecy; Eckert-Norton, Margaret; Morrison, Ann

    2005-01-01

    The problem use of alcohol causes over 100,000 deaths in the United States per year and has substantial negative impact on family structure, the economy and the criminal justice system. Screening and early treatment of individuals with problem use of alcohol by health professionals can significantly reduce mortality and morbidity. Students from…

  7. Delimitacion de las Zonas Dialectales de Mexico: Objetivos y Problemas (Delimitation of Dialect Zones in Mexico: Objectives and Problems)

    ERIC Educational Resources Information Center

    Blanch, Juan M. Lope

    1975-01-01

    Before creating a linguistic map of Mexican dialects, it is necessary to determine the dialect regions of the country. An extensive questionnaire must be written and distributed to collect data from a representative sample of the population for an accurate picture of the language. (CK) (Text in Spanish.)

  8. 5 CFR 1820.1 - General provisions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... records is available on the FOIA page of OSC's Web site (http://www.osc.gov/foia.htm). Information... by the public affairs officer, records published on the agency's Web site (http://www.osc.gov),...

  9. An Objective Structured Clinical Examination to Assess Problem-Based Learning

    PubMed Central

    O'Connell, Mary Beth; Garwood, Candice L.; Lehr, Victoria Tutag; Abdallah, Karina

    2012-01-01

    Objectives. To compare pharmacy students’ performance on an objective structured clinical examination (OSCE) to their performance on a written examination for the assessment of problem-based learning (PBL); and to determine students’ and faculty members’ perceptions of OSCEs for PBL evaluations. Design. Four OSCEs were added to the written examination to assess 4 PBL cases in a third-year pharmacotherapy course. OSCE scores were compared to written examination scores. Faculty members evaluated student performance. Assessment. OSCE performance did not correlate with the written-examination scores. Most students (≥ 75%) agreed that OSCEs reflected their learning from PBL and measured knowledge, communication, and clinical skills. A majority of faculty members (≥75%) agreed that OSCEs should be part of PBL assessment. Conclusions. Addition of an OSCE to written examinations was valued and provided a more comprehensive assessment of the PBL experience. PMID:22544961

  10. Los retos de la educación bilingüe en inglés y español en las escuelas públicas de Nueva York: objetivos, modelos y currículos

    NASA Astrophysics Data System (ADS)

    Velasco, Patricia; Cancino, Herlinda

    2012-10-01

    The challenges of bilingual education in English and Spanish in public schools of New York: Objectives, models and curricula - The first section of this article describes the conceptual differences between educational objectives, educational model (context and structures) and curriculum (units of study or sequential study guides). The second section analyses how these three concepts were put into practice in five bilingual elementary schools serving immigrant students in New York City. The educational objectives reflect the leadership and work expectations which the principal establishes within the school and with the community. The educational model is translated into a clear language allocation policy that is reached by consensus between the principal and the teachers. The curriculum adaptations reflect the context and culture of the students, but without neglecting the educational objectives. The development of academic language (the language based on academic texts) is an element that attracts vast interest in American schools, but is ignored in many bilingual ones. The development of academic language occupies a central role in the curriculum of these five schools. This is, to a great extent, the result of the limited exposure to literacy that many students have had outside of the school environment. The final section of this article describes how these schools disregard the antagonism towards immigrants and bilingual education that is currently characteristic of the United States and focus on the quality of their programmes.

  11. 40 CFR 300.115 - Regional Response Teams.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... ACPs with the RCP and NCP. (b) The two principal components of the RRT mechanism are a standing team..., based on the RCP. The incident-specific RRT supports the designated OSC/RPM. The designated OSC/RPM... the resources of their agencies to the OSC/RPM as specified in the RCP and ACP. (g) RRT members...

  12. 78 FR 6347 - Agency Information Collection Activities Under Review: Related Unfair Employment Practices...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-30

    ... Special Counsel for Immigration- Related Unfair Employment Practices Charge Form (OSC Charge Form) ACTION... Employment Practices Charge Form [OSC Charge Form]. (3) The agency form number and applicable component of..., where reasonable cause is found, litigates charges alleging discrimination. OSC also...

  13. Cloning and Functional Characterization of Three Branch Point Oxidosqualene Cyclases from Withania somnifera (L.) Dunal*

    PubMed Central

    Dhar, Niha; Rana, Satiander; Razdan, Sumeer; Bhat, Wajid Waheed; Hussain, Aashiq; Dhar, Rekha S.; Vaishnavi, Samantha; Hamid, Abid; Vishwakarma, Ram; Lattoo, Surrinder K.

    2014-01-01

    Oxidosqualene cyclases (OSCs) positioned at a key metabolic subdividing junction execute indispensable enzymatic cyclization of 2,3-oxidosqualene for varied triterpenoid biosynthesis. Such branch points present favorable gene targets for redirecting metabolic flux toward specific secondary metabolites. However, detailed information regarding the candidate OSCs covering different branches and their regulation is necessary for the desired genetic manipulation. The aim of the present study, therefore, was to characterize members of OSC superfamily from Withania somnifera (Ws), a medicinal plant of immense repute known to synthesize a large array of biologically active steroidal lactone triterpenoids called withanolides. Three full-length OSC cDNAs, β-amyrin synthase (WsOSC/BS), lupeol synthase (WsOSC/LS), and cycloartenol synthase (WsOSC/CS), having open reading frames of 2289, 2268, and 2277 bp, were isolated. Heterologous expression in Schizosaccharomyces pombe, LC-MS analyses, and kinetic studies confirmed their monofunctionality. The three WsOSCs were found to be spatially regulated at transcriptional level with WsOSC/CS being maximally expressed in leaf tissue. Promoter analysis of three WsOSCs genes resulted in identification of distinct cis-regulatory elements. Further, transcript profiling under methyl jasmonate, gibberellic acid, and yeast extract elicitations displayed differential transcriptional regulation of each of the OSCs. Changes were also observed in mRNA levels under elicitations and further substantiated with protein expression levels by Western blotting. Negative regulation by yeast extract resulted in significant increase in withanolide content. Empirical evidence suggests that repression of competitive branch OSCs like WsOSC/BS and WsOSC/LS possibly leads to diversion of substrate pool toward WsOSC/CS for increased withanolide production. PMID:24770414

  14. Objective structured clinical examination in radiology

    PubMed Central

    Agarwal, Anurag; Batra, Bipin; Sood, AK; Ramakantan, Ravi; Bhargava, Satish K; Chidambaranathan, N; Indrajit, IK

    2010-01-01

    There is a growing need for introducing objective structured clinical examination (OSCE) as a part of radiology practical examinations in India. OSCE is an established, reliable, and effective multistation test for the assessment of practical professional skills in an objective and a transparent manner. In India, it has been successfully initiated and implemented in specialties like pediatrics, ophthalmology, and otolaryngology. Each OSCE station needs to have a pre-agreed “key-list” that contains a list of objective steps prepared for uniformly assessing the tasks given to students. Broadly, OSCE stations are classified as “manned” or “unmanned” stations. These stations may include procedure or pictorial or theory stations with clinical oriented contents. This article is one of a series of measures to initiate OSCE in radiology; it analyzes the attributes of OSCE stations and outlines the steps for implementing OSCE. Furthermore, important issues like the advantages of OSCE, its limitations, a strengths, weaknesses, opportunities, and threats (SWOT) analysis, and the timing of introduction of OSCE in radiology are also covered. The OSCE format in radiology and its stations needs to be validated, certified, and finalized before its use in examinations. This will need active participation and contribution from the academic radiology fraternity and inputs from faculty members of leading teaching institutions. Many workshops/meetings need to be conducted. Indeed, these collaborative measures will effectively sensitize universities, examiners, organizers, faculty, and students across India to OSCE and help successfully usher in this new format in radiology practical examinations. PMID:20607015

  15. Germline mosaicism in osteopathia striata with cranial sclerosis - recurrence in siblings.

    PubMed

    O'Byrne, James J; Phelan, Ethna; Steenackers, Ellen; van Hul, Wim; Reardon, William

    2016-04-01

    We report recurrence of osteopathia striata with cranial sclerosis (OSCS) in two full siblings conceived by unaffected parents. Molecular confirmation of OSCS in both siblings was achieved by identification of a novel heterozygous mutation in the WTX gene. Neither parent had clinical features of OSCS nor was the pathogenic mutation demonstrable in DNA extracted from both peripheral blood leucocytes and buccal cells. This case demonstrates germline mosaicism in OSCS and represents the third report of mosaicism affecting the germline in families with OSCS. Previous reports were of parental gonadosomal mosaicism, with one showing recurrence in multiple children. Our observation adds to a body of evidence that suggests that germline mosaicism in OSCS may occur more frequently than believed previously and may have implications for counselling families with OSCS. PMID:26886897

  16. Design and application of carbon nanomaterials for photoactive and charge transport layers in organic solar cells

    NASA Astrophysics Data System (ADS)

    Jin, Sunghwan; Jun, Gwang Hoon; Jeon, Seokwoo; Hong, Soon Hyung

    2016-04-01

    Commercialization of organic solar cell (OSC) has faltered due to their low power conversion efficiency (PCE) compared to inorganic solar cell. Low electrical conductivity, low charge mobility, and short-range light absorption of most organic materials limit the PCE of OSCs. Carbon nanomaterials, especially carbon nanotubes (CNTs) and graphenes, are of great interest for use in OSC applications due to their high electrical conductivity, mobility, and unique optical properties for enhancing the performance of OSCs. In this review, recent progress toward the integration of carbon nanomaterials into OSCs is described. The role of carbon nanomaterials and strategies for their integration into various layers of OSCs, including the photoactive layer and charge transport layer, are discussed. Based on these, we also discuss the prospects of carbon nanomaterials for specific OSC layers to maximize the PCE.

  17. Mental health and learning disability nursing students' perceptions of the usefulness of the objective structured clinical examination to assess their competence in medicine administration.

    PubMed

    Hemingway, Steve; Stephenson, John; Roberts, Bronwyn; McCann, Terence

    2014-08-01

    The aim of this study was to evaluate mental health and learning disability nursing students' perceptions of the usefulness of the objective structured clinical examination (OSCE) in assessing their administration of medicine competence. Learning disability (n = 24) and mental health (n = 46) students from a single cohort were invited to evaluate their experience of the OSCE. A 10-item survey questionnaire was used, comprising open- and closed-response questions. Twelve (50%) learning disability and 32 (69.6%) mental health nursing students participated. The OSCE was rated highly compared to other theoretical assessments; it was also reported as clinically real and as a motivational learning strategy. However, it did not rate as well as clinical practice. Content analysis of written responses identified four themes: (i) benefits of the OSCE; (ii) suggestions to improve the OSCE; (iii) concern about the lack of clinical reality of the OSCE; and (iv) OSCE-induced stress. The themes, although repeating some of the positive statistical findings, showed that participants were critical of the university setting as a place to conduct clinical assessment, highlighted OSCE-related stress, and questioned the validity of the OSCE as a real-world assessment. The OSCE has an important role in the development of student nurses' administration of medicine skills. However, it might hinder their performance as a result of the stress of being assessed in a simulated environment. PMID:25180411

  18. The opinion of post graduate students on objective structured clinical examination in Anaesthesiology: A preliminary report

    PubMed Central

    Jindal, Parul; Khurana, Gurjeet

    2016-01-01

    Background and Aims: The scenario in medical education is changing with objective structured clinical examination (OSCE) being introduced as an assessment tool. Its successful implementation in anaesthesiology postgraduate evaluation process is still limited. We decided to to evaluate the effectiveness of OSCE and compare it to conventional examinations as formative assessment tools in anaesthesiology. Methods: We conducted a cross-sectional comparative study in defined population of anaesthesiology postgraduate students to evaluate the effectiveness of OSCE as compared to conventional examination as formative assessment tool in anaesthesiology. Thirty-five students appeared for the conventional examination on the 1st day and viva voce on the 2nd day and OSCE on the last day. At the conclusion of the assessment, all the students were asked to respond to the perception evaluation questionnaire. We analysed the perception of OSCE among the students. Results: Results showed a positive perception of the objective structured physical examination (OSCE) as well as structured 9 (25.7%), fair 19 (54.2%) and unbiased 13 (37.1%) with more standardised scoring 9 (25.7%). The students perceived OSCE to be less stressful than other examination. Thirty-one (88.5%) students agreed that OSCE is easier to pass than conventional method and 29 (82.5%) commented that the degree of emotional stress is less in OSCE than traditional methods. Conclusion: OSCE is better evaluation tool when compared to conventional examination. PMID:27053779

  19. Synthesis and detection of N-sulfonated oversulfated chondroitin sulfate in marketplace heparin.

    PubMed

    Mans, Daniel J; Ye, Hongping; Dunn, Jamie D; Kolinski, Richard E; Long, Dianna S; Phatak, Nisarga L; Ghasriani, Houman; Buhse, Lucinda F; Kauffman, John F; Keire, David A

    2015-12-01

    N-sulfonated oversulfated chondroitin sulfate (NS-OSCS), recently reported as a potential threat to the heparin supply, was prepared along with its intermediate derivatives. All compounds were spiked into marketplace heparin and subjected to United States Pharmacopeia (USP) identification assays for heparin (proton nuclear magnetic resonance [(1)H NMR], chromatographic identity, % galactosamine [%GalN], anti-factor IIa potency, and anti-factor Xa/IIa ratio). The U.S. Food and Drug Administration (FDA) strong-anionic exchange high-performance liquid chromatography (SAX-HPLC) method resolved NS-OSCS from heparin and OSCS and had a limit of detection of 0.26% (w/w) NS-OSCS. The %GalN test was sensitive to the presence of NS-OSCS in heparin. Therefore, current USP heparin monograph tests (i.e., SAX-HPLC and %GalN) detect the presence of NS-OSCS in heparin. PMID:26278168

  20. The roles of metallic rectangular-grating and planar anodes in the photocarrier generation and transport of organic solar cells

    NASA Astrophysics Data System (ADS)

    Sha, Wei E. I.; Choy, Wallace C. H.; Cho Chew, Weng

    2012-11-01

    A multiphysics study carries out on organic solar cells (OSCs) by solving Maxwell's and semiconductor equations simultaneously. By introducing a metallic rectangular-grating as the anode, surface plasmons are excited resulting in nonuniform exciton generation. Meanwhile, the internal E-field of plasmonic OSCs is modified with the modulated anode boundary. The plasmonic OSC improves 13% of short-circuit current but reduces 7% of fill factor (FF) compared to the standard one with a planar anode. The uneven photocarrier generation and transport by the grating anode are physical origins of the dropped FF. This work provides fundamental multiphysics modeling and understanding for plasmonic OSCs.

  1. One-Stop Clinic Utilization in Plastic Surgery: Our Local Experience and the Results of a UK-Wide National Survey

    PubMed Central

    Gorman, Mark; Coelho, James; Gujral, Sameer; McKay, Alastair

    2015-01-01

    Introduction. “See and treat” one-stop clinics (OSCs) are an advocated NHS initiative to modernise care, reducing cancer treatment waiting times. Little studied in plastic surgery, the existing evidence suggests that though they improve care, they are rarely implemented. We present our experience setting up a plastic surgery OSC for minor skin surgery and survey their use across the UK. Methods. The OSC was evaluated by 18-week wait target compliance, measures of departmental capacity, and patient satisfaction. Data was obtained from 32 of the 47 UK plastic surgery departments to investigate the prevalence of OSCs for minor skin cancer surgery. Results. The OSC improved 18-week waiting times, from a noncompliant mean of 80% to a compliant 95% average. Department capacity increased 15%. 95% of patients were highly satisfied with and preferred the OSC to a conventional service. Only 25% of UK plastic surgery units run OSCs, offering varying reasons for not doing so, 42% having not considered their use. Conclusions. OSCs are underutilised within UK plastic surgery, where a significant proportion of units have not even considered their benefit. This is despite associated improvements in waiting times, department capacity, and levels of high patient satisfaction. We offer our considerations and local experience instituting an OSC service. PMID:26236502

  2. Improved piecewise orthogonal signal correction algorithm.

    PubMed

    Feudale, Robert N; Tan, Huwei; Brown, Steven D

    2003-10-01

    Piecewise orthogonal signal correction (POSC), an algorithm that performs local orthogonal filtering, was recently developed to process spectral signals. POSC was shown to improve partial leastsquares regression models over models built with conventional OSC. However, rank deficiencies within the POSC algorithm lead to artifacts in the filtered spectra when removing two or more POSC components. Thus, an updated OSC algorithm for use with the piecewise procedure is reported. It will be demonstrated how the mathematics of this updated OSC algorithm were derived from the previous version and why some OSC versions may not be as appropriate to use with the piecewise modeling procedure as the algorithm reported here. PMID:14639746

  3. Oversulfated chondroitin sulfate inhibits the complement classical pathway by potentiating C1 inhibitor.

    PubMed

    Zhou, Zhao-Hua; Rajabi, Mohsen; Chen, Trina; Karnaukhova, Elena; Kozlowski, Steven

    2012-01-01

    Oversulfated chondroitin sulfate (OSCS) has become the subject of multidisciplinary investigation as a non-traditional contaminant in the heparin therapeutic preparations that were linked to severe adverse events. In this study, it was found that OSCS inhibited complement fixation on bacteria and bacterial lysis mediated by the complement classical pathway. The inhibition of complement by OSCS is not due to interference with antibody/antigen interaction or due to consumption of C3 associated with FXII-dependent contact system activation. However, OSCS complement inhibition is dependent on C1 inhibitor (C1inh) since the depletion of C1inh from either normal or FXII-deficient complement plasma prevents OSCS inhibition of complement activity. Surface plasmon resonance measurements revealed that immobilized C1inhibitor bound greater than 5-fold more C1s in the presence of OSCS than in presence of heparin. Although heparin can also inhibit complement, OSCS and OSCS contaminated heparin are more potent inhibitors of complement. Furthermore, polysulfated glycosaminoglycan (PSGAG), an anti-inflammatory veterinary medicine with a similar structure to OSCS, also inhibited complement in the plasma of dogs and farm animals. This study provides a new insight that in addition to the FXII-dependent activation of contact system, oversulfated and polysulfated chondroitin-sulfate can inhibit complement activity by potentiating the classical complement pathway regulator C1inh. This effect on C1inh may play a role in inhibiting inflammation as well as impacting bacterial clearance. PMID:23077587

  4. Effects of Bending Radii on the Characteristics of Flexible Organic Solar Cells Investigated by Impedance Analysis.

    PubMed

    Kim, Hoonbae; Ye, Donghyun; Won, Beomhee; Yu, SeGi; Jung, Donggeun

    2016-05-01

    Flexible organic solar cells (OSCs) were fabricated on an indium-tin-oxide (ITO)/poly(ethylene terephthalate) (PET) substrate and were subjected to bending tests with various bending radii. We observed that the photovoltaic properties of the OSCs precipitously deteriorated at a bending radius ≤ 0.75 cm. In order to investigate the effects of the bending test, the changes in the surface morphology and the sheet resistance of the ITO-coated PET samples were investigated, and the photovoltaic properties of bent and unbent OSCs were evaluated. Thereafter, equivalent circuits for the OSCs were assumed and the change in their parameters, such as resistance and capacitance, was observed. PMID:27483935

  5. Theoretical studies of effects of 2D plasmonic grating on electrical properties of organic solar cells

    NASA Astrophysics Data System (ADS)

    Sha, Wei E. I.; Choy, Wallace C. H.; Chew, Weng Cho

    2012-09-01

    Although various optical designs and physical mechanisms have been studied both experimentally and theoretically to improve the optical absorption of organic solar cells (OSCs) by incorporating metallic nanostructures, the effects of plasmonic nanostructures on the electrical properties of OSCs is still not fully understood. Hence, it is highly desirable to study the changes of electrical properties induced by plasmonic structures and the corresponding physics for OSCs. In this work, we develop a multiphysics model for plasmonic OSCs by solving the Maxwell's equations and semiconductor equations (Poisson, continuity, and drift-diffusion equations) with unified finite-difference method. Both the optical and electrical properties of OSCs incorporating a 2D metallic grating anode are investigated. For typical active polymer materials, low hole mobility, which is about one magnitude smaller than electron mobility, dominates the electrical property of OSCs. Since surface plasmon resonances excited by the metallic grating will produce concentrated near-field penetrated into the active polymer layer and decayed exponentially away from the metal-polymer interface, a significantly nonuniform and extremely high exciton generation rate is obtained near the grating. Interestingly, the reduced recombination loss and the increased open-circuit voltage can be achieved in plasmonic OSCs. The physical origin of the phenomena lies at direct hole collections to the metallic grating anode with a short transport path. In comparison with the plasmonic OSC, the hole transport in a multilayer planar OSC experiences a long transport path and time because the standard planar OSC has a high exciton generation rate at the transparent front cathode. The unveiled multiphysics is particularly helpful for designing high-performance plasmonic OSCs.

  6. Reducing the variability in performance of organic solar cells containing vacuum deposited MoOx extraction layers

    NASA Astrophysics Data System (ADS)

    Williams, Graeme; Aziz, Hany

    2014-10-01

    Reproducibility in efficiency and lifetime of organic solar cells (OSCs) remains a major concern, especially with the development of more complex and modern multi-layer device architectures. In this work, OSCs are studied for their efficiency and photo-stability as a function of the quality of their thermally evaporated MoOx hole extraction layer (HEL). To this end, the characteristics of the MoOx film are demonstrated to change with repeat evaporation runs from the same source material. These variations have strong effects on polymer OSCs (p-OSCs), with an effective halving of the power conversion efficiency after only three MoO3 evaporation runs. In contrast, vacuum deposited small molecule OSCs (sm-OSCs) appear to be unaffected by the history of the MoO3 source material. sm- OSCs are instead shown to be prone to large changes in efficiency as a function of the delay time in between deposition of the MoOx HEL and subsequent photo-active materials. Increased delay time between these deposition steps is also demonstrated to decrease the sm-OSC photo-stability. The results thus emphasize subtleties in materials deposition processes that can play a significant role in obtaining reproducible and scientifically relevant data.

  7. Improvement in Isolation and Identification of Mouse Oogonial Stem Cells

    PubMed Central

    Lu, Zhiyong; Wu, Meng; Zhang, Jinjin; Xiong, Jiaqiang; Cheng, Jing; Shen, Wei; Luo, Aiyue; Fang, Li; Wang, Shixuan

    2016-01-01

    Female germline stem cells (FGSCs) or oogonial stem cells (OSCs) have the capacity to generate newborn oocytes and thus open a new door to fight ovarian aging and female infertility. However, the production and identification of OSCs are difficult for investigators. Rare amount of these cells in the ovary results in the failure of the acquisition of OSCs. Furthermore, the oocyte formation by OSCs in vivo was usually confirmed using tissue sections by immunofluorescence or immunohistochemistry in previous studies. STO or MEF feeder cells are derived from mouse, not human. In our study, we modified the protocol. The cells were digested from ovaries and cultured for 2-3 days and then were purified by magnetic-activated cell sorting (MACS). The ovaries and fetus of mice injected with EGFP-positive OSCs were prepared and put on the slides to directly visualize oocyte and progeny formation under microscope. Additionally, the human umbilical cord mesenchymal stem cells (hUC-MSCs) were also used as feeder cells to support the proliferation of OSCs. The results showed that all the modified procedures can significantly improve and facilitate the generation and characterization of OSCs, and hUC-MSCs as feeder will be useful for isolation and proliferation of human OSCs avoiding contamination from mouse. PMID:26635882

  8. 77 FR 24242 - Privacy Act of 1974; System of Records

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-23

    ...,'' last published in full in the Federal Register on July 12, 2001 (66 FR 36611), and corrected on October 5, 2001 (66 FR 51095). OSC proposes to modify this system of records to make necessary revisions to... OSC's regulations implementing the Privacy Act, published October 4, 2007 (72 FR 56617). The...

  9. 32 CFR 145.6 - Procedures.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) Allegations of improper or illegal conduct received from the OSC under 5 U.S.C. 1206(b)(2), (3), or (c)(3). (1) Allegations of improper or illegal conduct referred by the OSC to the Secretary of Defense or to a Defense agency (other than the DLA) shall be forwarded to the IG, DoD. (2) Allegations of improper or...

  10. 32 CFR 145.6 - Procedures.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) Allegations of improper or illegal conduct received from the OSC under 5 U.S.C. 1206(b)(2), (3), or (c)(3). (1) Allegations of improper or illegal conduct referred by the OSC to the Secretary of Defense or to a Defense agency (other than the DLA) shall be forwarded to the IG, DoD. (2) Allegations of improper or...

  11. 32 CFR 145.6 - Procedures.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) Allegations of improper or illegal conduct received from the OSC under 5 U.S.C. 1206(b)(2), (3), or (c)(3). (1) Allegations of improper or illegal conduct referred by the OSC to the Secretary of Defense or to a Defense agency (other than the DLA) shall be forwarded to the IG, DoD. (2) Allegations of improper or...

  12. 5 CFR 1820.1 - General provisions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 3 2014-01-01 2014-01-01 false General provisions. 1820.1 Section 1820.1... TESTIMONY § 1820.1 General provisions. This part contains rules and procedures followed by the Office of... records is available on the FOIA page of OSC's Web site (http://www.osc.gov/foia.htm)....

  13. 5 CFR 1820.1 - General provisions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 3 2012-01-01 2012-01-01 false General provisions. 1820.1 Section 1820.1... TESTIMONY § 1820.1 General provisions. This part contains rules and procedures followed by the Office of... records is available on the FOIA page of OSC's Web site (http://www.osc.gov/foia.htm)....

  14. 5 CFR 1820.1 - General provisions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 3 2013-01-01 2013-01-01 false General provisions. 1820.1 Section 1820.1... TESTIMONY § 1820.1 General provisions. This part contains rules and procedures followed by the Office of... records is available on the FOIA page of OSC's Web site (http://www.osc.gov/foia.htm)....

  15. 5 CFR 1820.1 - General provisions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 3 2011-01-01 2011-01-01 false General provisions. 1820.1 Section 1820.1... TESTIMONY § 1820.1 General provisions. This part contains rules and procedures followed by the Office of... records is available on the FOIA page of OSC's Web site (http://www.osc.gov/foia.htm)....

  16. HANDBOOK FOR OIL SPILL PROTECTION AND CLEANUP PRIORITIES

    EPA Science Inventory

    This handbook was developed in an easily accessible yet extensive field format for use by federally designated on-scene coordinators (OSC) to guide them in assessing priorities during all phases of an oil spill response. The guidelines presented will enable the OSC to (1) determi...

  17. Communication Skills in Standardized-Patient Assessment of Final-Year Medical Students: A Psychometric Study

    ERIC Educational Resources Information Center

    Guiton, Gretchen; Hodgson, Carol S.; Delandshere, Ginett; Wilkerson, Luann

    2004-01-01

    The purpose of this study is to investigate the content-specificity of communication skills. It investigates the reliability and dimensionality of standardized patient (SP) ratings of communication skills in an Objective Structured Clinical Examination(OSCE) for final year medical students. An OSCE consisting of seven standardized patient(SP)…

  18. Psychometric Structure of a Comprehensive Objective Structured Clinical Examination: A Factor Analytic Approach

    ERIC Educational Resources Information Center

    Volkan, Kevin; Simon, Steven R.; Baker, Harley; Todres, I. David

    2004-01-01

    Problem Statement and Background: While the psychometric properties of Objective Structured Clinical Examinations (OSCEs) have been studied, their latent structures have not been well characterized. This study examines a factor analytic model of a comprehensive OSCE and addresses implications for measurement of clinical performance. Methods: An…

  19. Implementation of an Electronic Objective Structured Clinical Exam for Assessing Practical Skills in Pre-Professional Physiotherapy and Occupational Therapy Programs: Examiner and Course Coordinator Perspectives

    ERIC Educational Resources Information Center

    Snodgrass, Suzanne J.; Ashby, Samantha E.; Rivett, Darren A.; Russell, Trevor

    2014-01-01

    Assessment of practical clinical skills is essential in the health fields. Objective Structured Clinical Exams (OSCEs), where examiners assess students performing clinical procedures on simulated patients (actors), are central to the evaluation of practical skills. However, traditional OSCEs require considerable time-investment to administer, and…

  20. 33 CFR 155.T150 - Temporary suspension of requirements to permit support of deepwater horizon spill response.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (OSC), as defined in 40 CFR 300.5, in support of the response to the Deepwater Horizon Spill of... oil spill removal organization (OSRO), as defined in § 155.1020 of this part, if the OSRO's response..., deployed in coordination with the OSC, as defined in 40 CFR 300.5, in support of the response to...

  1. Measuring Professional Behaviour in Canadian Physical Therapy Students' Objective Structured Clinical Examinations: An Environmental Scan

    PubMed Central

    Ellerton, Cindy; Evans, Cathy

    2015-01-01

    ABSTRACT Purpose: To identify professional behaviours measured in objective structured clinical examinations (OSCEs) by Canadian university physical therapy (PT) programs. Method: A cross-sectional telephone survey was conducted to review current practice and determine which OSCE items Canadian PT programs are using to measure PT students' professional behaviours. Telephone interviews using semi-structured questions were conducted with individual instructors responsible for courses that included an OSCE as part of the assessment component. Results: Nine PT programmes agreed to take part in the study, and all reported conducting at least one OSCE. The number and characteristics of OSCEs varied both within and across programs. Participants identified 31 professional behaviour items for use in an OSCE; these items clustered into four categories: communication (n=14), respect (n=10), patient safety (n=4), and physical therapists' characteristics (n=3). Conclusions: All Canadian entry-level PT programmes surveyed assess professional behaviours in OSCE-type examinations; however, the content and style of assessment is variable. The local environment should be considered when determining what professional behaviours are appropriate to assess in the OSCE context in individual programmes. PMID:25931656

  2. A focus group study of the use of video-recorded simulated objective structured clinical examinations in nurse practitioner education.

    PubMed

    Barratt, Julian

    2010-05-01

    The objective structured clinical examination (OSCE) is a common method of clinical skills assessment used for advanced nurse practitioner students across the United Kingdom. The purpose of an advanced nursing OSCE is to assess a nurse practitioner student's competence and safety in the performance of commonly used advanced clinical practice skills. Students often feel nervous when preparing for and participating in an OSCE. Consideration of these identified anxieties led to the development of an alternative method of meeting students' OSCE learning and preparation needs; namely video-recorded simulated OSCEs. Video-recording was appealing for the following reasons: it provides a flexible usage of staff resources and time; OSCE performance mistakes can be rectified; it is possible to use the same video-recordings with multiple cohorts of students, and the recordings can be made conveniently available for students with video streaming on internet-based video-sharing sites or virtual learning environments. The aim of the study was to explore the value of using such recordings amongst nurse practitioner students, via online and face-to-face focus groups, to see if they are a suitable OSCE educational preparation technique. The study findings indicate that simulated OSCE video-recordings are an effective method for supporting nurse practitioner educational development. PMID:20202909

  3. Influences of semiconductor morphology on the mechanical fatigue behavior of flexible organic electronics

    SciTech Connect

    Lee, Young-Joo; Yeon, Han-Wool; Shin, Hae-A-Seul; Joo, Young-Chang; Uk Lee, Yong; Evans, Louise A.

    2013-12-09

    The influence of crystalline morphology on the mechanical fatigue of organic semiconductors (OSCs) was investigated using 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-pentacene) as a crystalline OSC and poly(triarylamine) (PTAA) as an amorphous OSC. During cyclic bending, resistances of the OSCs were monitored using the transmission-line method on a metal-semiconductor-metal structure. The resistance of the TIPS-pentacene increased under fatigue damage in tensile-stress mode, but no such degradation was observed in the PTAA. Both OSCs were stable under compressive bending fatigue. The formation of intergranular cracks at the domain boundaries of the TIPS-pentacene was responsible for the degradation of its electrical properties under tensile bending fatigue.

  4. Limited Predictive Utility of Admissions Scores and Objective Structured Clinical Examinations for APPE Performance

    PubMed Central

    McLaughlin, Jacqueline E.; Khanova, Julia; Scolaro, Kelly; Rodgers, Philip T.

    2015-01-01

    Objective. To examine the relationship between admissions, objective structured clinical examination (OSCE), and advanced pharmacy practice experience (APPE) scores. Methods. Admissions, OSCE, and APPE scores were collected for students who graduated from the doctor of pharmacy (PharmD) program in spring of 2012 and spring of 2013 (n=289). Pearson correlation was used to examine relationships between variables, and independent t test was used to compare mean scores between groups. Results. All relationships among admissions data (undergraduate grade point average, composite PCAT scores, and interview scores) and OSCE and APPE scores were weak, with the strongest association found between the final OSCE and ambulatory care APPEs. Students with low scores on the final OSCE performed lower than others on the acute care, ambulatory care, and community APPEs. Conclusion. This study highlights the complexities of assessing student development of noncognitive professional skills over the course of a curriculum. PMID:26430271

  5. Orbit correction in an orbit separated cyclotron

    NASA Astrophysics Data System (ADS)

    Plostinar, C.; Rees, G. H.

    2014-04-01

    The orbit separated proton cyclotron (OSC) described in [1] differs in concept from that of a separated orbit cyclotron (SOC) [2]. Synchronous acceleration in an OSC is based on harmonic number jumps and orbit length adjustments via reverse bending. Four-turn acceleration in the OSC enables it to have four times fewer cryogenic-cavity systems than in a superconducting linac of the same high beam power and energy range. Initial OSC studies identified a progressive distortion of the spiral beam orbits by the off-axis, transverse deflecting fields in its accelerating cavities. Compensation of the effects of these fields involves the repeated use of a cavity field map, in a 3-D linac tracking code, to determine the modified arc bends required for the OSC ring. Subsequent tracking studies confirm the compensation scheme and show low emittance growth in acceleration.

  6. Teaching About Substance Abuse with Objective Structured Clinical Exams

    PubMed Central

    Parish, Sharon J; Ramaswamy, Megha; Stein, Melissa R; Kachur, Elizabeth K; Arnsten, Julia H

    2006-01-01

    BACKGROUND Although residents commonly manage substance abuse disorders, optimal approaches to teaching these specialized interviewing and intervention skills are unknown. OBJECTIVE We developed a Substance Abuse Objective Structured Clinical Exam (OSCE) to teach addiction medicine competencies using immediate feedback. In this study we evaluated OSCE performance, examined associations between performance and self-assessed interest and competence in substance abuse, and assessed learning during the OSCE. DESIGN Five-station OSCE, including different substance abuse disorders and readiness to change stages, administered during postgraduate year-3 ambulatory rotations for 2 years. PARTICIPANTS One hundred and thirty-one internal and family medicine residents. MEASUREMENTS Faculty and standardized patients (SPs) assessed residents' general communication, assessment, management, and global skills using 4-point scales. Residents completed a pre-OSCE survey of experience, interest and competence in substance abuse, and a post-OSCE survey evaluating its educational value. Learning during the OSCE was also assessed by measuring performance improvement from the first to the final OSCE station. RESULTS Residents performed better (P<.001) in general communication (mean ± SD across stations = 3.12 ± 0.35) than assessment (2.65 ± 0.32) or management (2.58 ± 0.44), and overall ratings were lowest in the contemplative alcohol abuse station (2.50 ± 0.83). Performance was not associated with residents' self-assessed interest or competence. Perceived educational value of the OSCE was high, and feedback improved subsequent performance. CONCLUSIONS Although internal and family medicine residents require additional training in specialized substance abuse skills, immediate feedback provided during an OSCE helped teach needed skills for assessing and managing substance abuse disorders. PMID:16704387

  7. Use of online clinical videos for clinical skills training for medical students: benefits and challenges

    PubMed Central

    2014-01-01

    Background Multimedia learning has been shown effective in clinical skills training. Yet, use of technology presents both opportunities and challenges to learners. The present study investigated student use and perceptions of online clinical videos for learning clinical skills and in preparing for OSCE (Objective Structured Clinical Examination). This study aims to inform us how to make more effective us of these resources. Methods A mixed-methods study was conducted for this study. A 30-items questionnaire was administered to investigate student use and perceptions of OSCE videos. Year 3 and 4 students from 34 Korean medical schools who had access to OSCE videos participated in the online survey. Additionally, a semi-structured interview of a group of Year 3 medical students was conducted for an in-depth understanding of student experience with OSCE videos. Results 411 students from 31 medical schools returned the questionnaires; a majority of them found OSCE videos effective for their learning of clinical skills and in preparing for OSCE. The number of OSCE videos that the students viewed was moderately associated with their self-efficacy and preparedness for OSCE (p < 0.05). One-thirds of those surveyed accessed the video clips using mobile devices; they agreed more with the statement that it was convenient to access the video clips than their peers who accessed the videos using computers (p < 0.05). Still, students reported lack of integration into the curriculum and lack of interaction as barriers to more effective use of OSCE videos. Conclusions The present study confirms the overall positive impact of OSCE videos on student learning of clinical skills. Having faculty integrate these learning resources into their teaching, integrating interactive tools into this e-learning environment to foster interactions, and using mobile devices for convenient access are recommended to help students make more effective use of these resources. PMID:24650290

  8. [In Process Citation].

    PubMed

    Sellés, Sergio; Fernández-Sáez, José; López-Lluch, Guillermo; Cejuela, Roberto

    2016-01-01

    El proceso de formación de futuros deportistas debe ser un trabajo estructurado y planificado para poder alcanzar el máximo nivel deportivo. Es fundamental en este periodo tener presentes los ritmos de desarrollo y maduración de los jóvenes deportistas para así adecuar las cargas de entrenamientos a sus estados evolutivos. El objetivo del estudio fue determinar y analizar la edad morfológica en nadadores y triatletas adolescentes, estableciendo diferencias entre su edad cronológica, grupos y género. A través del método antropométrico se determinó el estado de maduración biológica en un grupo de 37 deportistas jóvenes tecnificados. Los resultados muestran que la mayoría de la muestra (70,8%) se encuentra en un estado avanzado de desarrollo con respecto a su edad cronológica, siendo más notorio en el caso de los nadadores este estado de madurez avanzado. Tener una edad morfológica más avanzada respecto a su edad cronológica podría favorecer a los deportistas adolescentes a la hora de conseguir mejores marcas y resultados en las competiciones y de esta manera acceder con más facilidad a los programas de tecnificación. El índice de desarrollo corporal modificado (IDCm) se presenta como un método validado, fiable y no invasivo para tener presente el grado de desarrollo y maduración en la selección de talentos deportivos y adecuar las cargas de entrenamiento al estado evolutivo de los deportistas. PMID:27019253

  9. Fill factor in organic solar cells can exceed the Shockley-Queisser limit

    PubMed Central

    Trukhanov, Vasily A.; Bruevich, Vladimir V.; Paraschuk, Dmitry Yu.

    2015-01-01

    The ultimate efficiency of organic solar cells (OSC) is under active debate. The solar cell efficiency is calculated from the current-voltage characteristic as a product of the open-circuit voltage (VOC), short-circuit current (JSC), and the fill factor (FF). While the factors limiting VOC and JSC for OSC were extensively studied, the ultimate FF for OSC is scarcely explored. Using numerical drift-diffusion modeling, we have found that the FF in OSC can exceed the Shockley-Queisser limit (SQL) established for inorganic p–n junction solar cells. Comparing charge generation and recombination in organic donor-acceptor bilayer heterojunction and inorganic p–n junction, we show that such distinctive properties of OSC as interface charge generation and heterojunction facilitate high FF, but the necessary condition for FF exceeding the SQL in OSC is field-dependence of charge recombination at the donor-acceptor interface. These findings can serve as a guideline for further improvement of OSC. PMID:26095688

  10. Characterization of the apoptotic response of human leukemia cells to organosulfur compounds

    PubMed Central

    2010-01-01

    Background Novel therapeutic agents that selectively induce tumor cell death are urgently needed in the clinical management of cancers. Such agents would constitute effective adjuvant approaches to traditional chemotherapy regimens. Organosulfur compounds (OSCs), such as diallyl disulfide, have demonstrated anti-proliferative effects on cancer cells. We have previously shown that synthesized relatives of dysoxysulfone, a natural OSC derived from the Fijian medicinal plant, Dysoxylum richi, possess tumor-specific antiproliferative effects and are thus promising lead candidates. Methods Because our structure-activity analyses showed that regions flanking the disulfide bond mediated specificity, we synthesized 18 novel OSCs by structural modification of the most promising dysoxysulfone derivatives. These compounds were tested for anti-proliferative and apoptotic activity in both normal and leukemic cells. Results Six OSCs exhibited tumor-specific killing, having no effect on normal bone marrow, and are thus candidates for future toxicity studies. We then employed mRNA expression profiling to characterize the mechanisms by which different OSCs induce apoptosis. Using Gene Ontology analysis we show that each OSC altered a unique set of pathways, and that these differences could be partially rationalized from a transcription factor binding site analysis. For example, five compounds altered genes with a large enrichment of p53 binding sites in their promoter regions (p < 0.0001). Conclusions Taken together, these data establish OSCs derivatized from dysoxysulfone as a novel group of compounds for development as anti-cancer agents. PMID:20598143

  11. Evaluation of Clinical and Communication Skills of Pharmacy Students and Pharmacists with an Objective Structured Clinical Examination

    PubMed Central

    Attridge, Rebecca L.; Tovar, John M.; Witte, Amy P.

    2015-01-01

    Objective. To evaluate how effectively pharmacy students and practicing pharmacists communicate and apply knowledge to simulations of commonly encountered patient scenarios using an objective structured clinical examination (OSCE). Design. Second-, third-, and fourth-year pharmacy students completed an OSCE as part of their required courses in 2012 and 2013. All students in both years completed identical OSCE cases. Licensed pharmacists were recruited to complete the OSCE and serve as controls in 2012. A survey assessed student perception and acceptance of the OSCE as well as student confidence in performance. Assessment. Licensed pharmacists had significantly higher clinical and communication skills scores than did pharmacy students. Student progression in communication and clinical skills improved significantly over time. Survey results indicated that students felt the OSCE was well-structured and assessed clinical skills taught in pharmacy school; 86% of students felt confident they could provide these skills. Conclusion. Objective structured clinical examinations can evaluate clinical competence and communication skills among professional students. Implementation of OSCEs may be an effective tool for assessment of the Center for the Advancement of Pharmacy Education domains. PMID:26690286

  12. Simultaneous determination of penicillin G salts by infrared spectroscopy: Evaluation of combining orthogonal signal correction with radial basis function-partial least squares regression

    NASA Astrophysics Data System (ADS)

    Talebpour, Zahra; Tavallaie, Roya; Ahmadi, Seyyed Hamid; Abdollahpour, Assem

    2010-09-01

    In this study, a new method for the simultaneous determination of penicillin G salts in pharmaceutical mixture via FT-IR spectroscopy combined with chemometrics was investigated. The mixture of penicillin G salts is a complex system due to similar analytical characteristics of components. Partial least squares (PLS) and radial basis function-partial least squares (RBF-PLS) were used to develop the linear and nonlinear relation between spectra and components, respectively. The orthogonal signal correction (OSC) preprocessing method was used to correct unexpected information, such as spectral overlapping and scattering effects. In order to compare the influence of OSC on PLS and RBF-PLS models, the optimal linear (PLS) and nonlinear (RBF-PLS) models based on conventional and OSC preprocessed spectra were established and compared. The obtained results demonstrated that OSC clearly enhanced the performance of both RBF-PLS and PLS calibration models. Also in the case of some nonlinear relation between spectra and component, OSC-RBF-PLS gave satisfactory results than OSC-PLS model which indicated that the OSC was helpful to remove extrinsic deviations from linearity without elimination of nonlinear information related to component. The chemometric models were tested on an external dataset and finally applied to the analysis commercialized injection product of penicillin G salts.

  13. Fill factor in organic solar cells can exceed the Shockley-Queisser limit.

    PubMed

    Trukhanov, Vasily A; Bruevich, Vladimir V; Paraschuk, Dmitry Yu

    2015-01-01

    The ultimate efficiency of organic solar cells (OSC) is under active debate. The solar cell efficiency is calculated from the current-voltage characteristic as a product of the open-circuit voltage (VOC), short-circuit current (JSC), and the fill factor (FF). While the factors limiting VOC and JSC for OSC were extensively studied, the ultimate FF for OSC is scarcely explored. Using numerical drift-diffusion modeling, we have found that the FF in OSC can exceed the Shockley-Queisser limit (SQL) established for inorganic p-n junction solar cells. Comparing charge generation and recombination in organic donor-acceptor bilayer heterojunction and inorganic p-n junction, we show that such distinctive properties of OSC as interface charge generation and heterojunction facilitate high FF, but the necessary condition for FF exceeding the SQL in OSC is field-dependence of charge recombination at the donor-acceptor interface. These findings can serve as a guideline for further improvement of OSC. PMID:26095688

  14. Fill factor in organic solar cells can exceed the Shockley-Queisser limit

    NASA Astrophysics Data System (ADS)

    Trukhanov, Vasily A.; Bruevich, Vladimir V.; Paraschuk, Dmitry Yu.

    2015-06-01

    The ultimate efficiency of organic solar cells (OSC) is under active debate. The solar cell efficiency is calculated from the current-voltage characteristic as a product of the open-circuit voltage (VOC), short-circuit current (JSC), and the fill factor (FF). While the factors limiting VOC and JSC for OSC were extensively studied, the ultimate FF for OSC is scarcely explored. Using numerical drift-diffusion modeling, we have found that the FF in OSC can exceed the Shockley-Queisser limit (SQL) established for inorganic p-n junction solar cells. Comparing charge generation and recombination in organic donor-acceptor bilayer heterojunction and inorganic p-n junction, we show that such distinctive properties of OSC as interface charge generation and heterojunction facilitate high FF, but the necessary condition for FF exceeding the SQL in OSC is field-dependence of charge recombination at the donor-acceptor interface. These findings can serve as a guideline for further improvement of OSC.

  15. Quantitative capillary electrophoresis determination of oversulfated chondroitin sulfate as a contaminant in heparin preparations

    PubMed Central

    Volpi, Nicola; Maccari, Francesca; Linhardt, Robert J.

    2014-01-01

    A simple, accurate and robust quantitative CE method for the determination of oversulfated chondroitin sulfate (OSCS) as a contaminant in heparin (Hep) preparations is described. After degradation of the polysaccharides by acidic hydrolysis, the hexosamines produced, i.e., GlcN from Hep and GalN from OSCS, were derivatized with anthranilic acid (AA) and separated by means of CE in approx. 10 min with high sensitivity detection at 214 nm (limit of detection (LOD) of approx. 200 pg). Furthermore, AA-derivatized GlcN and GalN showed quite similar molar absorptivity allowing for direct and simple quantification of OSCS in Hep samples. Moreover, a preliminary step of specific enzymatic treatment by using chondroitin ABC lyase may be applied for the specific elimination of interference in the analysis due to the possible presence in Hep samples of natural chondroitin sulfate and dermatan sulfate impurities, making this analytical approach highly specific for OSCS contamination, since chondroitin ABC lyase is unable to act on this semi-synthetic polymer. The CE method was validated for specificity, linearity, accuracy, precision, LOD and limit of quantification (LOQ). Due to the very high sensitivity of CE, as little as 1% OSCS contaminant in Hep sample could be detected and quantified. Finally, a contaminated raw Hep sample was found to contain 38.9% OSCS while a formulated contaminated Hep was calculated to have 39.7% OSCS. PMID:19232311

  16. Perceptions of postgraduate trainees on the impact of objective structured clinical examinations on their study behavior and clinical practice

    PubMed Central

    Opoka, Robert O; Kiguli, Sarah; Ssemata, Andrew S; Govaerts, Marjan; Driessen, Erik W

    2015-01-01

    Background The objective structured clinical examination (OSCE) is a commonly used method of assessing clinical competence at various levels, including at the postgraduate level. How the OSCE impacts on learning in higher education is poorly described. In this study, we evaluated the perceptions of postgraduate trainees regarding the impact of the OSCE on their study and clinical behavior. Methods We employed an explorative qualitative research design by conducting focus group discussions with 41 pediatric postgraduate trainees at the College of Health Science, Makerere University. A semi-structured tool was used to obtain the views and experiences of the trainees. Transcripts from the discussion were analyzed in an iterative manner using thematic content analysis. Results The trainees reported the OSCEs as a fair and appropriate tool for assessing clinical competency at the postgraduate level. However, they noted that whereas OSCEs assess a broad range of skills and competencies relevant to their training, there were areas that they did not adequately assess. In particular, OSCEs did not adequately assess in-depth clinical knowledge or detailed history-taking skills. Overall, the majority of the trainees reported that the OSCEs inspired them to study widely and improve their procedural and communication skills. Conclusion OSCEs are a useful tool for assessing clinical competencies in postgraduate education. However, the perceived limitations in their ability to assess complex skills raises concerns about their use as a standalone mode of assessment at the postgraduate level. Future studies should evaluate how use of OSCEs in combination with other assessment tools impacts on learning. PMID:26082673

  17. Does Objective Structured Clinical Examinations Score Reflect the Clinical Reasoning Ability of Medical Students?

    PubMed Central

    Park, Wan Beom; Kang, Seok Hoon; Lee, Yoon-Seong

    2015-01-01

    Abstract: Background: Clinical reasoning ability is an important factor in a physician's competence and thus should be taught and tested in medical schools. Medical schools generally use objective structured clinical examinations (OSCE) to measure the clinical competency of medical students. However, it is unknown whether OSCE can also evaluate clinical reasoning ability. In this study, the authors investigated whether OSCE scores reflected students' clinical reasoning abilities. Methods: Sixty-five fourth-year medical students participated in this study. Medical students completed the OSCE with 4 cases using standardized patients. For assessment of clinical reasoning, students were asked to list differential diagnoses and the findings that were compatible or not compatible with each diagnosis. The OSCE score (score of patient encounter), diagnostic accuracy score, clinical reasoning score, clinical knowledge score and grade point average (GPA) were obtained for each student, and correlation analysis was performed. Results: Clinical reasoning score was significantly correlated with diagnostic accuracy and GPA (correlation coefficient = 0.258 and 0.380; P = 0.038 and 0.002, respectively) but not with OSCE score or clinical knowledge score (correlation coefficient = 0.137 and 0.242; P = 0.276 and 0.052, respectively). Total OSCE score was not significantly correlated with clinical knowledge test score, clinical reasoning score, diagnostic accuracy score or GPA. Conclusions: OSCE score from patient encounters did not reflect the clinical reasoning abilities of the medical students in this study. The evaluation of medical students' clinical reasoning abilities through OSCE should be strengthened. PMID:25647834

  18. A search for new open clusters hosting cepheids

    NASA Astrophysics Data System (ADS)

    Glushkova, E. V.; Zabolotskikh, M. V.; Rastorguev, A. S.; Grudskaya, A. V.; Koposov, S. E.

    We analyze yet-unknown genetic links between open star clusters (OSC) and galactic Cepheids and report the results of the new search for Cepheids -- probable OSC members. A sample of 25% of the stars from a new catalog by Berdnikov (published in Melnik et al. 2015) which lists 674 Cepheids with reliable parameters was investigated. Based on photometric and kinematic data, we selected 17 Cepheids that are likely to be related to star clusters, four of which being new OSCs discovered by us.

  19. Full-solution processed flexible organic solar cells using low-cost printable copper electrodes.

    PubMed

    Li, Kan; Zhen, Hongyu; Niu, Liyong; Fang, Xu; Zhang, Yaokang; Guo, Ruisheng; Yu, You; Yan, Feng; Li, Haifeng; Zheng, Zijian

    2014-11-12

    Full-solution-processed flexible organic solar cells (OSCs) are fabricated using low-cost and high-quality printable Cu electrodes, which achieve a power conversion efficiency as high as 2.77% and show remarkable stability upon 1000 bending cycles. This device performance is thought to be the best among all full-solution-processed OSCs reported in the literature using the same active materials. This printed Cu electrode is promising for application in roll-to-roll fabrication of flexible OSCs. PMID:25220216

  20. Stability of organic solar cells: challenges and strategies.

    PubMed

    Cheng, Pei; Zhan, Xiaowei

    2016-05-01

    Organic solar cells (OSCs) present some advantages, such as simple preparation, light weight, low cost and large-area flexible fabrication, and have attracted much attention in recent years. Although the power conversion efficiencies have exceeded 10%, the inferior device stability still remains a great challenge. In this review, we summarize the factors limiting the stability of OSCs, such as metastable morphology, diffusion of electrodes and buffer layers, oxygen and water, irradiation, heating and mechanical stress, and survey recent progress in strategies to increase the stability of OSCs, such as material design, device engineering of active layers, employing inverted geometry, optimizing buffer layers, using stable electrodes and encapsulation. Some research areas of device stability that may deserve further attention are also discussed to help readers understand the challenges and opportunities in achieving high efficiency and high stability of OSCs towards future industrial manufacture. PMID:26890341

  1. 5 CFR 1800.2 - Filing disclosures of information.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...-free), or (202) 653-9125 (in the Washington, DC area); or (iii) Online, at: http://www.osc.gov (to print out and complete on paper, or to complete online). (2) Filers may use another written format...

  2. Hybrid Transparent Conductive Films of Multilayer Graphene and Metal Grid for Organic Photovoltaics

    NASA Astrophysics Data System (ADS)

    Kim, Sung Man; Walker, Bright; Seo, Jung Hwa; Kang, Seong Jun

    2013-12-01

    Organic solar cells (OSCs) were fabricated on hybrid transparent conductive films consisting of multilayer graphene (MLG) and metal grids. MLG was transferred onto Ag grids to form hybrid transparent conductive films. The optical transmittance was found to be 87% at a wavelength of 550 nm, while the sheet resistance was measured to be 28 +/-7.9 Ω/square. The device characteristics of OSCs prepared on the hybrid films include an open circuit voltage of 0.58 V, a short circuit current of 8.05 mA/cm2, a fill factor of 51%, and a power conversion efficiency (PCE) of 2.38%. The PCE shows 11% improvement compared with that of OSCs fabricated using MLG films without Ag grids. This improvement can be attributed to the reduced sheet resistance of the hybrid film. These results indicate that hybrid films comprising MLG deposited on Ag grids constitute a promising transparent electrode for improving performance in OSCs.

  3. 40 CFR 300.910 - Authorization of use.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... substantially reduce a hazard to human life. Whenever the OSC authorizes the use of a product pursuant to this... product, including products not on the Schedule, as soon as possible. Once the threat to human life...

  4. 40 CFR 300.910 - Authorization of use.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... substantially reduce a hazard to human life. Whenever the OSC authorizes the use of a product pursuant to this... product, including products not on the Schedule, as soon as possible. Once the threat to human life...

  5. Development of a Single-Pass Amplifier for an Optical Stochastic Cooling Proof-of-Principle Experiment at Fermilab's IOTA Facility

    SciTech Connect

    Andorf, M. B.; Lebedev, V. A.; Piot, P.

    2015-06-01

    Optical stochastic cooling (OSC) is a method of beam cooling which is expected to provide cooling rates orders of magnitude larger than ordinary stochastic cooling. Light from an undulator (the pickup) is amplified and fed back onto the particle beam via another undulator (the kicker). Fermilab is currently exploring a possible proof-of-principle experiment of the OSC at the integrable-optics test accelerator (IOTA) ring. To implement effective OSC a good correction of phase distortions in the entire band of the optical amplifier is required. In this contribution we present progress in experimental characterization of phase distortions associated to a Titanium Sapphire crystal laser-gain medium (a possible candidate gain medium for the OSC experiment to be performed at IOTA). We also discuss a possible option for a mid-IR amplifier

  6. 5 CFR 1800.2 - Filing disclosures of information.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...-free), or (202) 653-9125 (in the Washington, DC area); or (iii) Online, at: http://www.osc.gov (to print out and complete on paper, or to complete online). (2) Filers may use another written format...

  7. 5 CFR 1820.4 - Timing of responses to requests.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... simple and more complex requests based on the amount of work and/or time needed to process the request... out of order and given expedited treatment whenever OSC has established to its satisfaction that:...

  8. 5 CFR 1820.4 - Timing of responses to requests.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... simple and more complex requests based on the amount of work and/or time needed to process the request... out of order and given expedited treatment whenever OSC has established to its satisfaction that:...

  9. Large-area formation of self-aligned crystalline domains of organic semiconductors on transistor channels using CONNECT

    PubMed Central

    Park, Steve; Giri, Gaurav; Shaw, Leo; Pitner, Gregory; Ha, Jewook; Koo, Ja Hoon; Gu, Xiaodan; Park, Joonsuk; Lee, Tae Hoon; Nam, Ji Hyun; Hong, Yongtaek; Bao, Zhenan

    2015-01-01

    The electronic properties of solution-processable small-molecule organic semiconductors (OSCs) have rapidly improved in recent years, rendering them highly promising for various low-cost large-area electronic applications. However, practical applications of organic electronics require patterned and precisely registered OSC films within the transistor channel region with uniform electrical properties over a large area, a task that remains a significant challenge. Here, we present a technique termed “controlled OSC nucleation and extension for circuits” (CONNECT), which uses differential surface energy and solution shearing to simultaneously generate patterned and precisely registered OSC thin films within the channel region and with aligned crystalline domains, resulting in low device-to-device variability. We have fabricated transistor density as high as 840 dpi, with a yield of 99%. We have successfully built various logic gates and a 2-bit half-adder circuit, demonstrating the practical applicability of our technique for large-scale circuit fabrication. PMID:25902502

  10. A nanoscale study of charge extraction in organic solar cells: the impact of interfacial molecular configurations

    NASA Astrophysics Data System (ADS)

    Tang, Fu-Ching; Wu, Fu-Chiao; Yen, Chia-Te; Chang, Jay; Chou, Wei-Yang; Gilbert Chang, Shih-Hui; Cheng, Horng-Long

    2014-11-01

    In the optimization of organic solar cells (OSCs), a key problem lies in the maximization of charge carriers from the active layer to the electrodes. Hence, this study focused on the interfacial molecular configurations in efficient OSC charge extraction by theoretical investigations and experiments, including small molecule-based bilayer-heterojunction (sm-BLHJ) and polymer-based bulk-heterojunction (p-BHJ) OSCs. We first examined a well-defined sm-BLHJ model system of OSC composed of p-type pentacene, an n-type perylene derivative, and a nanogroove-structured poly(3,4-ethylenedioxythiophene) (NS-PEDOT) hole extraction layer. The OSC with NS-PEDOT shows a 230% increment in the short circuit current density compared with that of the conventional planar PEDOT layer. Our theoretical calculations indicated that small variations in the microscopic intermolecular interaction among these interfacial configurations could induce significant differences in charge extraction efficiency. Experimentally, different interfacial configurations were generated between the photo-active layer and the nanostructured charge extraction layer with periodic nanogroove structures. In addition to pentacene, poly(3-hexylthiophene), the most commonly used electron-donor material system in p-BHJ OSCs was also explored in terms of its possible use as a photo-active layer. Local conductive atomic force microscopy was used to measure the nanoscale charge extraction efficiency at different locations within the nanogroove, thus highlighting the importance of interfacial molecular configurations in efficient charge extraction. This study enriches understanding regarding the optimization of the photovoltaic properties of several types of OSCs by conducting appropriate interfacial engineering based on organic/polymer molecular orientations. The ultimate power conversion efficiency beyond at least 15% is highly expected when the best state-of-the-art p-BHJ OSCs are combined with present arguments

  11. SUPERFUND TECHNICAL SUPPORT

    EPA Science Inventory

    Under this task, technical support is provided to Regional Remedial Project Managers (RPMs)/On-Scene Coordinators (OSCs) at Superfund, RCRA, and Brownfields sites contaminated with hazardous materials by the Technical Support Center (TSC) for Monitoring and Site Characterization....

  12. Organic photovoltaic with various plasmonic nanostructures using titanium nitride

    NASA Astrophysics Data System (ADS)

    Magdi, Sara; Gan, Qiaoqiang; Swillam, Mohamed A.

    2016-03-01

    We demonstrate absorption improvement in organic solar cells due to the incorporation of TiN nanopatterned back electrode. Organic solar cells (OSC) have already reached 10% power conversion efficiency (PCE), which made them comparable to commercial solar cells. Localizing light using plasmonic nanostructures has the potential to overcome OSC absorption limitations and thus further improve their PCE. Using a C-MOS compatible, cheap and abundant material for light trapping could facilitate the commercialization of OSC. This work theoretically shows that the replacement of Ag nanopatterned back electrode with TiN in plasmonic OSC gives enhanced performance. In addition, the incorporation of TiN nanoparticles inside the active layer has been studied and analyzed.

  13. Prevalence and Incidence of Traumatic Experiences Among Orphans in Institutional and Family-Based Settings in 5 Low- and Middle-Income Countries: A Longitudinal Study

    PubMed Central

    Pence, Brian W; Ostermann, Jan; Whetten, Rachel A; O’Donnell, Karen; Thielman, Nathan M; Whetten, Kathryn

    2015-01-01

    Background: Policy makers struggling to protect the 153 million orphaned and separated children (OSC) worldwide need evidence-based research on the burden of potentially traumatic events (PTEs) and the relative risk of PTEs across different types of care settings. Methods: The Positive Outcomes for Orphans study used a 2-stage, cluster-randomized sampling design to identify 1,357 institution-dwelling and 1,480 family-dwelling orphaned and separated children in 5 low- and middle-income countries (LMICs) in sub-Saharan Africa and Asia. We used the Life Events Checklist developed by the National Center for Posttraumatic Stress Disorder to examine self-reported PTEs among 2,235 OSC ages 10–13 at baseline. We estimated prevalence and incidence during 36-months of follow-up and compared the risk of PTEs across care settings. Data collection began between May 2006 and February 2008, depending on the site. Results: Lifetime prevalence by age 13 of any PTE, excluding loss of a parent, was 91.0% (95% confidence interval (CI) = 85.6, 94.5) in institution-dwelling OSC and 92.4% (95% CI = 90.3, 94.0) in family-dwelling OSC; annual incidence of any PTE was lower in institution-dwelling (23.6% [95% CI = 19.4, 28.7]) than family-dwelling OSC (30.0% [95% CI = 28.1, 32.2]). More than half of children in institutions (50.3% [95% CI = 42.5, 58.0]) and in family-based care (54.0% [95% CI = 50.2, 57.7]) had experienced physical or sexual abuse by age 13. Annual incidence of physical or sexual abuse was lower in institution-dwelling (12.9% [95% CI = 9.6, 17.3]) than family-dwelling OSC (19.4% [95% CI = 17.7, 21.3]), indicating statistically lower risk in institution-dwelling OSC (risk difference = 6.5% [95% CI = 1.4, 11.7]). Conclusion: Prevalence and incidence of PTEs were high among OSC, but contrary to common assumptions, OSC living in institutions did not report more PTEs or more abuse than OSC living with families. Current efforts to reduce

  14. Plasmonic nanostructures based on block copolymer templates for efficient organic solar cells

    NASA Astrophysics Data System (ADS)

    Go, Seung Jae; Lee, Dong-Eun; Lee, Dong Hyun; Chin, Byung Doo

    2016-01-01

    Plasmonic nanostructures fabricated from self-assembled patterns of block copolymers (BCPs) were applied for organic solar cells (OSCs). A thin film of a cylinder-forming polystrene- block-poly(2-vinylpyridine) copolymer (PS- b-P2VP) was spin-coated on the transparent electrode of the OSCs, where nanostructures such as dot, dot with mixed line, and line patterns emerged during different solvent annealing processes. Selective conversion of hydrogen tetrachloroaurate (III) (HAuCl4) in P2VP blocks yielded gold (Au) nanostructures, which were used to trigger the localized surface plasmonic resonance (LSPR) effect at the OSCs. Plasmonic nanostructures with almost similar scales of BCP patterns were formed at the anode/buffer interface at the OSC, showing no-table enhancements of the short circuit current ( J sc) and the power conversion efficiency (3.57% for the reference compared to 4.35% for the optimum LSPR-OSC) as the size and the anisotropy of Au patterns changed from a simple dot through an integrated dot-line pattern to a line pattern. Based on the experimental analyses of the light absorption, photoluminescence, and exciton lifetime of OSC, such an enhancement would be mainly attributed to size-dependent LSPR-induced scattering and absorption at the OSC's active layer, which is not in intimate contact with the Au nanostructures. Up to a 26% increase in the power conversion efficiency could be observed at the plasmonic structures from BCP template, providing an accurately tuning and powerful tailoring of the LSPR-enhancing patterns for the OSCs.

  15. Two Oxidosqualene Cyclases Responsible for Biosynthesis of Tomato Fruit Cuticular Triterpenoids1[C][W][OA

    PubMed Central

    Wang, Zhonghua; Guhling, Ortwin; Yao, Ruonan; Li, Fengling; Yeats, Trevor H.; Rose, Jocelyn K.C.; Jetter, Reinhard

    2011-01-01

    The first committed step in triterpenoid biosynthesis is the cyclization of epoxysqualene into various triterpene alcohol isomers, a reaction catalyzed by oxidosqualene cyclases (OSCs). The different OSCs have characteristic product specificities, which are mainly due to differences in the numbers of high-energy intermediates the enzymes can stabilize. The goal of this investigation was to clone and characterize OSCs from tomato (Solanum lycopersicum), a species known to accumulate δ-amyrin in its fruit cuticular wax, in order to gain insights into the enzymatic formation of this particular triterpenoid. We used a homology-based approach to isolate two tomato OSCs and tested their biochemical properties by heterologous expression in yeast as well as overexpression in tomato. One of the enzymes was found to be a product-specific β-amyrin synthase, while the other one was a multifunctional OSC synthesizing 48% δ-amyrin and six other products. The product spectra of both OSCs together account for both the range and the relative amounts of the triterpenoids found in the fruit cuticle. Both enzymes were expressed exclusively in the epidermis of the tomato fruit, indicating that their major function is to form the cuticular triterpenoids. The relative expression levels of both OSC genes, determined by quantitative reverse transcription-polymerase chain reaction, were consistent with product profiles in fruit and leaves of the tomato cultivar MicroTom. However, the transcript ratios were only partially consistent with the differences in amounts of product triterpenoids between the tomato cultivars MicroTom, M82, and Ailsa Craig; thus, transcriptional control of the two OSCs alone cannot explain the fruit triterpenoid profiles of the cultivars. PMID:21059824

  16. Small-molecule organic solar cells with multiple-layer donor

    NASA Astrophysics Data System (ADS)

    Arisawa, Kenta; Harafuji, Kenji

    2015-09-01

    Small-molecule organic solar cells (OSCs) with a multifunction three-layer donor are experimentally investigated to achieve higher power conversion efficiency. The proposed OSC has an indium tin oxide (ITO, anode)/three-layer donor/fullerene (C60, acceptor, 40 nm)/bathocuproine (BCP, cathode buffer, 10 nm)/Ag (cathode, 100 nm) structure. The three-layer donor is composed of 3-nm-thick pentacene/20-nm-thick copper phthalocyanine (CuPc)/5-nm-thick aluminum phthalocyanine chloride (ClAlPc). The OSC achieves a power conversion efficiency of 1.79%, which is 1.7 times as large as that for an OSC with a single-layer donor of 20-nm-thick CuPc. Atomic force microscopy observation is carried out to clarify in detail the surface morphology at typical organic layers. The acceptor C60 is in contact not only with ClAlPc but also with CuPc due to the vertical and wall-like growth of the ClAlPc layer. The open-circuit voltage for the OSC with the ClAlPc/C60 contact is 0.56 V, compared with 0.47 V for the OSC with the CuPc/C60 contact. The thin pentacene layer is uniformly grown on the ITO and serves to achieve a high short-circuit current density Jsc by lowering the barrier height for hole transport between ITO and CuPc. Jsc for the OSC with the thin pentacene layer is 5.60 mA/cm2, compared with 4.32 mA/cm2 for the OSC without the thin pentacene layer.

  17. Optimizing Sisal Compiler; Sisal Compiler and Running System

    SciTech Connect

    1992-11-12

    OSC is a compiler and runtime system for the functional language Sisal. Functional languages are based on mathematical principals, and may reduce the cost of parallel program development without sacrificing performance. OSC compiles Sisal source code to binary form, automatically inserting calls to the Sisal runtime system to manage parallel execution of independent tasks. Features include support for dynamic arrays, automatic vectorization, and automatic parallelization. At runtime, the user may specify the number of workers, the granularity of tasks, and other execution parameters.

  18. Interface design principles for high-performance organic semiconductor devices

    DOE PAGESBeta

    Nie, Wanyi; Gupta, Gautam; Crone, Brian K.; Liu, Feilong; Smith, Darryl L.; Ruden, P. Paul; Kuo, Cheng -Yu; Tsai, Hsinhan; Wang, Hsing -Lin; Li, Hao; et al

    2015-03-23

    Organic solar cells (OSCs) are a promising cost-effective candidate in next generation photovoltaic technology. However, a critical bottleneck for OSCs is the electron/hole recombination loss through charge transfer state at the interface, which greatly limits the power conversion efficiency. W. Nie, A. Mohite, and co-workers demonstrate a simple strategy of suppressing the recombination rate by inserting a spacer layer at the donor-acceptor interface, resulting in a dramatic increase in power conversion efficiency.

  19. Feedback Implementation of Zermelo's Optimal Control by Sugeno Approximation

    NASA Technical Reports Server (NTRS)

    Clifton, C.; Homaifax, A.; Bikdash, M.

    1997-01-01

    This paper proposes an approach to implement optimal control laws of nonlinear systems in real time. Our methodology does not require solving two-point boundary value problems online and may not require it off-line either. The optimal control law is learned using the original Sugeno controller (OSC) from a family of optimal trajectories. We compare the trajectories generated by the OSC and the trajectories yielded by the optimal feedback control law when applied to Zermelo's ship steering problem.

  20. Using the objective structured clinical examinations in undergraduate midwifery students

    PubMed Central

    Delavar, MA; Salmalian, H; Faramarzi, M; Pasha, H; Bakhtiari, A; Nikpour, M; Ledari, FM

    2013-01-01

    The Objective Structured Clinical Examination (OSCE) has been considered a modern type of examination for the assessment of clinical skills within nurse education, but it has been rarely applied in the teaching of midwifery. The aim of the present study was to assess the use of the OSCE as a tool to evaluate the abilities of undergraduate midwifery students and to compare the perspectives of the students regarding the OSCE and traditional examination. Fifty-two midwifery students participated in the study. The export trainer evaluated the internal consistency of the OSCE stations and it was tested by using Cronbach’s alpha. Successive groups of students completed a self-administered questionnaire immediately after the final examination. The students’ perspective regarding the traditional final examination ranked as unsatisfactory by more than two thirds of the students, while, the students’ perspective regarding the OSCE system was ranked as very satisfactory to satisfactory by more than half of the students (p=0.001). There was a significant difference in the students’ perspective between the OSCE system and the traditional final examination among the students (49.8±18.3 vs 25.3±18.1) (p=0.001). A significant difference was found in being credible (p=0.0001), consistent/reliable (p=0.001), enhances teaching level (p=0.011), and measures the course category (p=0.008) between two methods of the final examination. Around half of the students expressed their opinion that the OSCE test was a stressful assessment. Overall, students’ evaluation of the OSCE was remarkably encouraging. To this end, we recommend the consideration of the validity and reliability of the process for undergraduate midwifery students. PMID:23599825

  1. Multifunctional oxidosqualene cyclases and cytochrome P450 involved in the biosynthesis of apple fruit triterpenic acids.

    PubMed

    Andre, Christelle M; Legay, Sylvain; Deleruelle, Amélie; Nieuwenhuizen, Niels; Punter, Matthew; Brendolise, Cyril; Cooney, Janine M; Lateur, Marc; Hausman, Jean-François; Larondelle, Yvan; Laing, William A

    2016-09-01

    Apple (Malus × domestica) accumulates bioactive ursane-, oleanane-, and lupane-type triterpenes in its fruit cuticle, but their biosynthetic pathway is still poorly understood. We used a homology-based approach to identify and functionally characterize two new oxidosqualene cyclases (MdOSC4 and MdOSC5) and one cytochrome P450 (CYP716A175). The gene expression patterns of these enzymes and of previously described oxidosqualene cyclases were further studied in 20 apple cultivars with contrasting triterpene profiles. MdOSC4 encodes a multifunctional oxidosqualene cyclase producing an oleanane-type triterpene, putatively identified as germanicol, as well as β-amyrin and lupeol, in the proportion 82 : 14 : 4. MdOSC5 cyclizes 2,3-oxidosqualene into lupeol and β-amyrin at a ratio of 95 : 5. CYP716A175 catalyses the C-28 oxidation of α-amyrin, β-amyrin, lupeol and germanicol, producing ursolic acid, oleanolic acid, betulinic acid, and putatively morolic acid. The gene expression of MdOSC1 was linked to the concentrations of ursolic and oleanolic acid, whereas the expression of MdOSC5 was correlated with the concentrations of betulinic acid and its caffeate derivatives. Two new multifuntional triterpene synthases as well as a multifunctional triterpene C-28 oxidase were identified in Malus × domestica. This study also suggests that MdOSC1 and MdOSC5 are key genes in apple fruit triterpene biosynthesis. PMID:27214242

  2. Recent progress in degradation and stabilization of organic solar cells

    SciTech Connect

    Cao, Huanqi; He, Weidong; Mao, Yiwu; Lin, Xiao; Ishikawa, Ken; Dickerson, James H.; Hess, Wayne P.

    2014-10-15

    Stability is of paramount importance in organic semiconductor devices, especially in organic solar cells (OSCs). Serious degradation in air limits wide applications of these flexible, light-weight and low-cost power-generation devices. Studying the stability of organic solar cells will help us understand degradation mechanisms and further improve the stability of these devices. There are many investigations into the efficiency and stability of OSCs. The efficiency and stability of devices even of the same photoactive materials are scattered in different papers. In particular, the extrinsic degradation that mainly occurs near the interface between the organic layer and the cathode is a major stability concern. In the past few years, researchers have developed many new cathodes and cathode buffer layers, some of which have astonishingly improved the stability of OSCs. In this review article, we discuss the recent developments of these materials and summarize recent progresses in the study of the degradation/stability of OSCs, with emphasis on the extrinsic degradation/stability that is related to the intrusion of oxygen and water. The review provides detailed insight into the current status of research on the stability of OSCs and seeks to facilitate the development of highly-efficient OSCs with enhanced stability.

  3. Artificially MoO3 graded ITO anodes for acidic buffer layer free organic photovoltaics

    NASA Astrophysics Data System (ADS)

    Lee, Hye-Min; Kim, Seok-Soon; Kim, Han-Ki

    2016-02-01

    We report characteristics of MoO3 graded ITO anodes prepared by a RF/DC graded sputtering for acidic poly(3,4-ethylene dioxylene thiophene):poly(styrene sulfonic acid) (PEDOT:PSS)-free organic solar cells (OSCs). Graded sputtering of the MoO3 buffer layer on top of the ITO layer produced MoO3 graded ITO anodes with a sheet resistance of 12.67 Ω/square, a resistivity of 2.54 × 10-4 Ω cm, and an optical transmittance of 86.78%, all of which were comparable to a conventional ITO anode. In addition, the MoO3 graded ITO electrode showed a greater work function of 4.92 eV than that (4.6 eV) of an ITO anode, which is beneficial for hole extraction from an organic active layer. Due to the high work function of MoO3 graded ITO electrodes, the acidic PEDOT:PSS-free OSCs fabricated on the MoO3 graded ITO electrode exhibited a power conversion efficiency 3.60% greater than that of a PEDOT:PSS-free OSC on the conventional ITO anode. The successful operation of PEDOT:PSS-free OSCs indicates simpler fabrication steps for cost-effective OSCs and elimination of interfacial reactions caused by the acidic PEDOT:PSS layer for reliable OSCs.

  4. Designing the objective structured clinical examination to cover all major areas of physical medicine and rehabilitation over 3 yrs.

    PubMed

    Garstang, Susan; Altschuler, Eric L; Jain, Sheela; Delisa, Joel A

    2012-06-01

    The Accreditation Council for Graduate Medical Education requires that training programs comprehensively evaluate residents in the six core Accreditation Council for Graduate Medical Education competencies. One of the ways we do this in our residency is by administering a nine-station Objective Structured Clinical Examination (OSCE) at the end of each year, which evaluates tasks such as history taking, focused physical examination, communication, professionalism, procedural skills, management, prescription writing, and understanding systems-based practice. We have classified our OSCE stations into what we consider key areas in our field and assessed these on a rotating basis over 3 yrs. This results in the assessment of 27 areas over the 3 yrs of residency. Structuring the OSCE as a series of stations over 3 yrs is an efficient method to evaluate residents' competencies that are required by the Accreditation Council for Graduate Medical Education and certifying boards. An analysis of OSCE scores when compared with American Board of Physical Medicine & Rehabilitation parts 1 and 2 scores and final summative resident evaluation scores reveals that OSCE results correlate with part 1 scores and final evaluation scores but do not show the same strong correlations with part 2 scores. We discuss the way the OSCE can complete other assessment techniques and ways to improve cases in the future. PMID:22469878

  5. Extracting the Density of States of Copper Phthalocyanine at the SiO2 Interface with Electronic Sum Frequency Generation.

    PubMed

    Pandey, Ravindra; Moon, Aaron P; Bender, Jon A; Roberts, Sean T

    2016-03-17

    Organic semiconductors (OSCs) constitute an attractive platform for optoelectronics design due to the ease of their processability and chemically tunable properties. Incorporating OSCs into electrical circuits requires forming junctions between them and other materials, yet the change in dielectric properties about these junctions can strongly perturb the electronic structure of the OSC. Here we adapt an interface-selective optical technique, electronic sum frequency generation (ESFG), to the study of a model OSC thin-film system, copper phthalocyanine (CuPc) deposited on SiO2. We find that by modeling the thickness dependence of our measured spectra, we can identify changes in CuPc's electronic density of states at both its buried interface with SiO2 and air-exposed surface. Our work demonstrates that ESFG can be used to noninvasively probe the interfacial electronic structure of optically thick OSC films, indicating that it can be used for the study of OSC-based optoelectronics in situ. PMID:26938148

  6. Use of standardised patients in the evaluation of a residency mood disorders curriculum: a brief report

    PubMed Central

    2013-01-01

    Background and objectives The purpose of this paper is to describe the use of resident performance on an observed structured clinical examination (OSCE) as a tool to refine a mood disorders curriculum, and to disseminate a mood disorders OSCE for use in other residency settings. Methods A depression-focused OSCE and a direct observation evaluation tool were developed and implemented. A total of 24 first-year family medicine residents (PGY1) participated in the OSCE, and their performance was used to direct changes in a mood disorders curriculum. Results Residents performed well on general interview behaviours, and 67% were able to uncover depression in a patient presenting with headaches. Less than 50% of the residents asked about suicidal ideation and recreational drug use. Curriculum was added that addressed the latter deficiencies. Conclusions Tracking of resident performance on specific behaviours during OSCE sessions can be used for curriculum evaluation purposes. The mood disorders curriculum in additional family medicine residency programmes can now be evaluated using our depression-focused OSCE and Clinical Performance Checklist. PMID:24381654

  7. Ultrathin organic solar cells with graphene doped by ferroelectric polarization.

    PubMed

    Kim, Keumok; Bae, Sang-Hoon; Toh, Chee Tat; Kim, Hobeom; Cho, Jeong Ho; Whang, Dongmok; Lee, Tae-Woo; Özyilmaz, Barbaros; Ahn, Jong-Hyun

    2014-03-12

    Graphene has been employed as transparent electrodes in organic solar cells (OSCs) because of its good physical and optical properties. However, the electrical conductivity of graphene films synthesized by chemical vapor deposition (CVD) is still inferior to that of conventional indium tin oxide (ITO) electrodes of comparable transparency, resulting in a lower performance of OSCs. Here, we report an effective method to improve the performance and long-term stability of graphene-based OSCs using electrostatically doped graphene films via a ferroelectric polymer. The sheet resistance of electrostatically doped few layer graphene films was reduced to ∼70 Ω/sq at 87% optical transmittance. Such graphene-based OSCs exhibit an efficiency of 2.07% with a superior stability when compared to chemically doped graphene-based OSCs. Furthermore, OSCs constructed on ultrathin ferroelectric film as a substrate of only a few micrometers show extremely good mechanical flexibility and durability and can be rolled up into a cylinder with 7 mm diameter. PMID:24521002

  8. Garlic-derived natural polysulfanes as hydrogen sulfide donors: Friend or foe?

    PubMed

    Yagdi, Esma; Cerella, Claudia; Dicato, Mario; Diederich, Marc

    2016-09-01

    In vitro and in vivo studies reported the anti-cancer potential of organosulfur compounds (OSCs) as they trigger biological effects leading to cell cycle arrest with accumulation of cells in G2/M, alteration of the microtubular network, modulation of Bcl-2 family protein expression patterns and changes of the redox status. Despite these well-described effects, no OSC derivative is yet undergoing clinical trials even though their chemistry is well understood as OSCs act as hydrogen sulfide (H2S) donors. H2S is a biological mediator, synthesized through cysteine degradation and modulates vasodilation, cytoprotection, inflammation and angiogenesis. It is well accepted that H2S plays a biphasic pharmacological role: the inhibition of endogenous synthesis of H2S and paradoxically also the use of H2S donors to increase H2S concentration, induce both anti-cancer effects leading therefore to controversial discussions. Altogether, the role of H2S in the anti-cancer action of OSCs remains poorly understood. In this review, we hypothesize that OSCs act through H2S signaling pathways in cancer cells, and that a clearer understanding of the mechanism of action of H2S in OSC-mediated anti-cancer activity is required for further application of these compounds in translational medicine. PMID:27430419

  9. Fast charge separation in a non-fullerene organic solar cell with a small driving force

    NASA Astrophysics Data System (ADS)

    Liu, Jing; Chen, Shangshang; Qian, Deping; Gautam, Bhoj; Yang, Guofang; Zhao, Jingbo; Bergqvist, Jonas; Zhang, Fengling; Ma, Wei; Ade, Harald; Inganäs, Olle; Gundogdu, Kenan; Gao, Feng; Yan, He

    2016-07-01

    Fast and efficient charge separation is essential to achieve high power conversion efficiency in organic solar cells (OSCs). In state-of-the-art OSCs, this is usually achieved by a significant driving force, defined as the offset between the bandgap (Egap) of the donor/acceptor materials and the energy of the charge transfer (CT) state (ECT), which is typically greater than 0.3 eV. The large driving force causes a relatively large voltage loss that hinders performance. Here, we report non-fullerene OSCs that exhibit ultrafast and efficient charge separation despite a negligible driving force, as ECT is nearly identical to Egap. Moreover, the small driving force is found to have minimal detrimental effects on charge transfer dynamics of the OSCs. We demonstrate a non-fullerene OSC with 9.5% efficiency and nearly 90% internal quantum efficiency despite a low voltage loss of 0.61 V. This creates a path towards highly efficient OSCs with a low voltage loss.

  10. Conocimientos y autoeficacia asociados a la prevención del VIH y SIDA en mujeres chilenas

    PubMed Central

    Villegas Rodríguez, Natalia; Ferrer Lagunas, Lilian Marcela; Cianelli Acosta, Rosina; Miner, Sarah; Lara Campos, Loreto; Peragallo, Nilda

    2014-01-01

    Resumen Objetivo Evaluar la relación existente entre conocimientos y autoeficacia asociados al VIH/SIDA en mujeres chilenas en desventaja social. Metodología Estudio correlacional, que utiliza la medición basal del estudio “Testeando una intervención en VIH y SIDA en mujeres chilenas”, realizada entre 2006 y 2008, que tiene una muestra de 496 mujeres entre 18 y 49 años residentes en dos comunas de Santiago de Chile. Las participantes respondieron un cuestionario estructurado aplicado por entrevistadoras entrenadas. Este cuestionario incluyó preguntas sobre datos sociodemográficos, escala de conocimientos de conductas de riesgo y autoeficacia, entre otros. Resultados Edad promedio de 32.3±9.1 años, 72.2% vive con su pareja y 42.7% poseen educación media completa. La puntuación media de los conocimientos de la infección por el VIH fue de 8.9±2.5, mientras que para las tres escalas empleadas para medir autoeficacia fueron: “Normas de los pares” =9.8±3.6, “Intención de reducir conductas de riesgo” =12.2±3.6 y “Self Efficacy Form”=20.2±4.7. Los conocimientos tuvieron una correlación positiva débil con la “intención de reducir conductas de riesgo” (r=0.19; p<0.0001) y con la escala “Self Efficacy Form” (r=0.34; p<0.0001), pero no se relacionaron con las “normas de los pares en cuanto a relaciones sexuales seguras” (r=0.13; p=0.78). Conclusión Existe una débil correlación positiva entre el nivel de conocimientos sobre el VIH/SIDA y la autoeficacia en mujeres chilenas en desventaja social. PMID:25284914

  11. PREVENCION DE VIH PARA MUJERES HISPANAS DE 50 AÑOS Y MÁS

    PubMed Central

    Villegas, N.; Cianelli, R.; Ferrer, L.; Kaelber, L.; Peragallo, N.; Yaya, Alexandra O.

    2012-01-01

    Introducción Las mujeres Hispanas de 50 años y más (MHC) son una minoría en Estados Unidos que está a elevado riesgo de adquirir VIH y son el grupo menos estudiado en lo que respecta a salud, características sociales y de comportamiento sexual. Objetivo Investigar los factores que incrementan el riesgo de VIH en las MHC con el propósito de desarrollar o adaptar una intervención apropiada para la “edad y la cultura "de este grupo de mujeres. Metodología Estudio descriptivo de corte transversal con una muestra de 50 MHC, sexualmente activas y que residían en Miami, Florida, Estados Unidos. Se utilizó un cuestionario estructurado administrado por entrevistadores entrenados y bilingües (inglés/español). Las participantes fueron reclutadas en diferentes lugares en el Sur de Florida. Para el análisis de los datos se utilizó estadística descriptiva, tanto medidas de tendencia central como medidas de dispersión. Resultados La edad promedio de las MHC fue de 55,7 ± 6 años (rango 50–76 años). Todas las MHC estaban en la menopausia. Prevención del VIH Las MHC reportaron niveles medios de conocimientos sobre VIH y comunicación con la pareja. En la muestra se reportó la presencia de síntomas depresivos, violencia en la pareja, actitudes negativas hacia las personas viviendo con VIH y baja percepción de riesgo de adquirir VIH. Las MHC mencionaron necesidades de aprendizaje en tópicos relacionados con prevención de VIH y cambios de la edad. Conclusión Las MHC están a riesgo de adquirir VIH y tienen necesidades especiales en términos de educación sobre prevención de VIH. PMID:25242862

  12. Anti-inflammatory and anti-endotoxin properties of peptides derived from the carboxy-terminal region of a defensin from the tick Ornithodoros savignyi.

    PubMed

    Malan, Melissa; Serem, June C; Bester, Megan J; Neitz, Albert W H; Gaspar, Anabella R M

    2016-01-01

    Antimicrobial peptides are small cationic peptides that possess a large spectrum of bioactivities, including antimicrobial, anti-inflammatory and antioxidant activities. Several antimicrobial peptides are known to inhibit lipopolysaccharide (LPS)-induced inflammation in vitro and to protect animals from sepsis. In this study, the cellular anti-inflammatory and anti-endotoxin activities of Os and Os-C, peptides derived from the carboxy-terminal of a tick defensin, were investigated. Both Os and Os-C were found to bind LPS in vitro, albeit to a lesser extent than polymyxin B and melittin, known endotoxin-binding peptides. Binding to LPS was found to reduce the bactericidal activity of Os and Os-C against Escherichia coli confirming the affinity of both peptides for LPS. At a concentration of 25 µM, the nitric oxide (NO) scavenging activity of Os was higher than glutathione, a known NO scavenger. In contrast, Os-C showed no scavenging activity. Os and Os-C inhibited LPS/IFN-γ induced NO and TNF-α production in RAW 264.7 cells in a concentration-dependent manner, with no cellular toxicity even at a concentration of 100 µM. Although inhibition of NO and TNF-α secretion was more pronounced for melittin and polymyxin B, significant cytotoxicity was observed at concentrations of 1.56 µM and 25 µM for melittin and polymyxin B, respectively. In addition, Os, Os-C and glutathione protected RAW 264.7 cells from oxidative damage at concentrations as low as 25 µM. This study identified that besides previously reported antibacterial activity of Os and Os-C, both peptides have in addition anti-inflammatory and anti-endotoxin properties. PMID:26662999

  13. Identification of organic sulfur compounds in coal bitumen obtained by different extraction techniques using comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometric detection.

    PubMed

    Machado, Maria Elisabete; Fontanive, Fernando Cappelli; de Oliveira, José Vladimir; Caramão, Elina Bastos; Zini, Cláudia Alcaraz

    2011-11-01

    The determination of organic sulfur compounds (OSC) in coal is of great interest. Technically and operationally these compounds are not easily removed and promote corrosion of equipment. Environmentally, the burning of sulfur compounds leads to the emission of SO(x) gases, which are major contributors to acid rain. Health-wise, it is well known that these compounds have mutagenic and carcinogenic properties. Bitumen can be extracted from coal by different techniques, and use of gas chromatography coupled to mass spectrometric detection enables identification of compounds present in coal extracts. The OSC from three different bitumens were tentatively identified by use of three different extraction techniques: accelerated solvent extraction (ASE), ultrasonic extraction (UE), and supercritical-fluid extraction (SFE). Results obtained from one-dimensional gas chromatography (1D GC) coupled to quadrupole mass spectrometric detection (GC-qMS) and from two-dimensional gas chromatography with time-of-flight mass spectrometric detection (GC × GC-TOFMS) were compared. By use of 2D GC, a greater number of OSC were found in ASE bitumen than in SFE and UE bitumens. No OSC were identified with 1D GC-qMS, although some benzothiophenes and dibenzothiophenes were detected by use of EIM and SIM modes. GC × GC-TOFMS applied to investigation of OSC in bitumens resulted in analytical improvement, as more OSC classes and compounds were identified (thiols, sulfides, thiophenes, naphthothiophenes, benzothiophenes, and benzonaphthothiophenes). The roof-tile effect was observed for OSC and PAH in all bitumens. Several co-elutions among analytes and with matrix interferents were solved by use of GC × GC. PMID:21743984

  14. Evaluation of midwifery students’ competency in providing intrauterine device services using objective structured clinical examination

    PubMed Central

    Erfanian, Fatemeh; Khadivzadeh, Talaat

    2011-01-01

    BACKGROUND: Delivering IUD services is one of the important competencies that midwifery students must obtain during academic period. As Objective Structured Clinical Examination (OSCE) can be reasonably reliable, valid and objective method for clinical skills assessment, this study was conducted to assess midwifery students’ skill in delivering intrauterine device (IUD) services using a clinical examination and their satisfaction from the OSCE. METHODS: All of the 62 eligible Bachelor of Science midwifery students of Mashhad University of Medical Sciences participated in a ten-station OSCE about delivering IUD services for 50 minutes in 2006. Students performed technical skills or interacted with standard patients in 6 stations and in 4 stations they answered to the related questions. Students’ performance in 6 stations was rated by observer or standard patients using validated checklists. Students’ level of satisfaction and also their experience of participating in OSCE examination were gathered. RESULTS: Performance of 98.2% of students was poor. On average, the students gained 49% of total score in counseling and screening, 35.7% in inserting the IUD, 40% in IUD removal and 24.4% in management of IUD side effect. Eighty percent of students rated their satisfaction from the OSCE high and very high. Students reported the OSCE as an enjoying examination experience. CONCLUSIONS: Students’ skill in delivering IUD services was lower than expected level that shows the need to change the current teaching methods. OSCE is a valid evaluation method which provides valuable information which cannot be obtained by more traditional assessment modalities. Based on the finding of this study a workshop program on providing IUD services for midwifery students and family planning providers should be prepared. PMID:22224105

  15. Human microsomal cyttrochrome P450-mediated reduction of oxysophocarpine, an active and highly toxic constituent derived from Sophora flavescens species, and its intestinal absorption and metabolism in rat.

    PubMed

    Wu, Lili; Zhong, Wanping; Liu, Junjin; Han, Weichao; Zhong, Shilong; Wei, Qiang; Liu, Shuwen; Tang, Lan

    2015-09-01

    Oxysophocarpine (OSC), an active and toxic quinolizidine alkaloid, is highly valued in Sophora flavescens Ait. and Subprostrate sophora Root. OSC is used to treat inflammation and hepatitis for thousands of years in China. This study aims to investigate the CYP450-mediated reduction responsible for metabolizing OSC and to evaluate the absorption and metabolism of OSC in rat in situ. Four metabolites were identified, with sophocarpine (SC) as the major metabolite. SC formation was rapid in human and rat liver microsomes (HLMs and RLMs, respectively). The reduction rates in the liver are two fold higher than in the intestine, both in humans and rats. In HLMs, inhibitors of CYP2C9, 3A4/5, 2D6, and 2B6 had strong inhibitory effects on SC formation. Meanwhile, inhibitors of CYP3A and CYP2D6 had significant inhibition on SC formation in RLMs. Human recombinant CYP3A4/5, 2B6, 2D6, and 2C9 contributed significantly to SC production. The permeability in rat intestine and the excretion rates of metabolites were highest in the duodenum (p<0.05), and the absorbed amount of OSC in duodenum and jejunum was concentration-dependent. The metabolism could be significantly decreased by CYP3A inhibitor ketoconazole. In conclusion, the liver was the main organ responsible for OSC metabolism. First-pass metabolism via CYP3A4/5, 2B6, 2D6, and 2C9 may be the main reason for the poor OSC bioavailability. PMID:26045316

  16. Automated principal component-based orthogonal signal correction applied to fused near infrared-mid-infrared spectra of French olive oils.

    PubMed

    Harrington, Peter de B; Kister, Jacky; Artaud, Jacques; Dupuy, Nathalie

    2009-09-01

    An approach for automating the determination of the number of components in orthogonal signal correction (OSC) has been devised. In addition, a novel principal component OSC (PC-OSC) is reported that builds softer models for removing background from signals and is much faster than the partial least-squares (PLS) based OSC algorithm. These signal correction methods were evaluated by classifying fused near- and mid-infrared spectra of French olive oils by geographic origin. Two classification methods, partial least-squares-discriminant analysis (PLS-DA) and a fuzzy rule-building expert system (FuRES), were used to evaluate the signal correction of the fused vibrational spectra from the olive oils. The number of components was determined by using bootstrap Latin partitions (BLPs) in the signal correction routine and maximizing the average projected difference resolution (PDR). The same approach was used to select the number of latent variables in the PLS-DA evaluation and perfect classification was obtained. Biased PLS-DA models were also evaluated that optimized the number of latent variables to yield the minimum prediction error. Fuzzy or soft classification systems benefit from background removal. The FuRES prediction results did not differ significantly from the results that were obtained using either the unbiased or biased PLS-DA methods, but was an order of magnitude faster in the evaluations when a sufficient number of PC-OSC components were selected. The importance of bootstrapping was demonstrated for the automated OSC and PC-OSC methods. In addition, the PLS-DA algorithms were also automated using BLPs and proved effective. PMID:19655711

  17. Reliability analysis of the objective structured clinical examination using generalizability theory

    PubMed Central

    Trejo-Mejía, Juan Andrés; Sánchez-Mendiola, Melchor; Méndez-Ramírez, Ignacio; Martínez-González, Adrián

    2016-01-01

    Background The objective structured clinical examination (OSCE) is a widely used method for assessing clinical competence in health sciences education. Studies using this method have shown evidence of validity and reliability. There are no published studies of OSCE reliability measurement with generalizability theory (G-theory) in Latin America. The aims of this study were to assess the reliability of an OSCE in medical students using G-theory and explore its usefulness for quality improvement. Methods An observational cross-sectional study was conducted at National Autonomous University of Mexico (UNAM) Faculty of Medicine in Mexico City. A total of 278 fifth-year medical students were assessed with an 18-station OSCE in a summative end-of-career final examination. There were four exam versions. G-theory with a crossover random effects design was used to identify the main sources of variance. Examiners, standardized patients, and cases were considered as a single facet of analysis. Results The exam was applied to 278 medical students. The OSCE had a generalizability coefficient of 0.93. The major components of variance were stations, students, and residual error. The sites and the versions of the tests had minimum variance. Conclusions Our study achieved a G coefficient similar to that found in other reports, which is acceptable for summative tests. G-theory allows the estimation of the magnitude of multiple sources of error and helps decision makers to determine the number of stations, test versions, and examiners needed to obtain reliable measurements. PMID:27543188

  18. [Improving the Care Accuracy of Percutaneously Inserted Central Catheters Using Objective Structured Clinical Examination].

    PubMed

    Yang, Pei-Hsin; Hsu, Hsin-Chieh; Chiang, Chia-Chin; Tseng, Yun-Shan

    2016-06-01

    Approximately 9,800 adverse events related to medical tubing are reported in Taiwan every year. Most neonates in critical condition and premature infants acquire fluid, nutrition, and infusion solution using percutaneously inserted central catheters (PICCs). Objective structured clinical examination (OSCE) is an objective evaluative tool that may be used to measure the clinical competence of healthcare professionals. Very little is known about the effects of OSCE in Taiwan in terms of improving the accuracy of use of PICCs in nursing care and of reducing unexpected medical tubing removals. The present project aimed to explore the effects of an OSCE course on these two issues in the realms of standard operating procedures, care protocols, and training equipment at a neonatal intermediate unit in Taiwan. The duration of the present study ran from 2/20/2013 to 10/30/2013. The results showed that nurses' knowledge of PICCs improved from 87% to 91.5%; nurses' skill-care accuracy related to PICCs improved from 59.1% to 97.3%; and incidents of unexpected tube removals declined from 63.6% to 16.7%. This project demonstrated that OSCE courses improve the quality of PICC nursing care. Additionally, the instant feedback mechanism within the OSCE course benefited both teachers and students. PMID:27250965

  19. Organosulfur Compounds: Molecular and Isotopic Evolution from Biota to Oil and Gas

    NASA Astrophysics Data System (ADS)

    Amrani, Alon

    2014-05-01

    Organosulfur compounds (OSCs) play important roles in the formation, preservation, and thermal degradation of sedimentary organic matter and the associated petroleum generation. Improved analytical techniques for S isotope analysis have recently enhanced our understanding of the mechanisms for OSC formation and maturation and their associated S isotope distributions. The close interaction of OSCs with inorganic S species throughout their formation and maturation affects their 34S/32S isotopic ratio (δ34S), forming specific signatures for distinct sources and processes. Ultimately, thermal maturation homogenizes the δ34S values of different fractions and individual compounds. Reservoir processes such as thermochemical sulfate reduction (TSR) introduce exogenous and isotopically distinct S into hydrocarbons and can significantly change the δ34S of petroleum or kerogen. Specific OSCs react at different rates and thus can be used to evaluate the extent of processes such as TSR. This article reviews factors that affect the 34S/32S isotopic distribution of OSCs along pathways of formation, diagenesis, and thermal alteration.

  20. Highly transparent Nb-doped indium oxide electrodes for organic solar cells

    SciTech Connect

    Kim, Jun Ho; Seong, Tae-Yeon; Na, Seok-In; Chung, Kwun-Bum; Lee, Hye-Min; Kim, Han-Ki

    2014-03-15

    The authors investigated the characteristics of Nb-doped In{sub 2}O{sub 3} (INbO) films prepared by co-sputtering of Nb{sub 2}O{sub 5} and In{sub 2}O{sub 3} for use in transparent anodes for organic solar cells (OSCs). To optimize the Nb dopant composition in the In{sub 2}O{sub 3} matrix, the effect of the Nb doping power on the resistivity and transparency of the INbO films were examined. The electronic structure and microstructure of the INbO films were also investigated using synchrotron x-ray absorption spectroscopy and x-ray diffraction examinations in detail. At the optimized Nb co-sputtering power of 30 W, the INbO film exhibited a sheet resistance of 15 Ω/sq, and an optical transmittance of 86.04% at 550 nm, which are highly acceptable for the use as transparent electrodes in the fabrication of OSCs. More importantly, the comparable power conversion efficiency (3.34%) of the OSC with an INbO anode with that (3.31%) of an OSC with a commercial ITO anode indicates that INbO films are promising as a transparent electrode for high performance OSCs.

  1. Near-peer education: a novel teaching program

    PubMed Central

    Premnath, Daphne

    2016-01-01

    Objectives This study aims to: 1) Evaluate whether a near-peer program improves perceived OSCE performance; 2) Identify factors motivating students to teach; 3) Evaluate role of near-peer teaching in medical education. Methods A near-peer OSCE teaching program was implemented at Monash University’s Peninsula Clinical School over the 2013 academic year. Forty 3rd-year and thirty final-year medical students were recruited as near-peer learners and educators, respectively. A post-program questionnaire was completed by learners prior to summative OSCEs (n=31), followed by post-OSCE focus groups (n=10). Near-peer teachers were interviewed at the program’s conclusion (n=10). Qualitative data was analysed for emerging themes to assess the perceived value of the program. Results Learners felt peer-led teaching was more relevant to assessment, at an appropriate level of difficulty and delivered in a less threatening environment than other methods of teaching. They valued consistent practice and felt confident approaching their summative OSCEs. Educators enjoyed the opportunity to develop their teaching skills, citing mutual benefit and gratitude to past peer-educators as strong motivators to teach others. Conclusions Near-peer education, valued by near-peer learners and teachers alike, was a useful method to improve preparation and perceived performance in summative examinations. In particular, a novel year-long, student-run initiative was regarded as a valuable and feasible adjunct to faculty teaching. PMID:27239951

  2. Photocurrent generation through electron-exciton interaction at the organic semiconductor donor/acceptor interface.

    PubMed

    Chen, Lijia; Zhang, Qiaoming; Lei, Yanlian; Zhu, Furong; Wu, Bo; Zhang, Ting; Niu, Guoxi; Xiong, Zuhong; Song, Qunliang

    2013-10-21

    In this work, we report our effort to understand the photocurrent generation that is contributed via electron-exciton interaction at the donor/acceptor interface in organic solar cells (OSCs). Donor/acceptor bi-layer heterojunction OSCs, of the indium tin oxide/copper phthalocyanine (CuPc)/fullerene (C60)/molybdenum oxide/Al type, were employed to study the mechanism of photocurrent generation due to the electron-exciton interaction, where CuPc and C60 are the donor and the acceptor, respectively. It is shown that the electron-exciton interaction and the exciton dissociation processes co-exist at the CuPc/C60 interface in OSCs. Compared to conventional donor/acceptor bi-layer OSCs, the cells with the above configuration enable holes to be extracted at the C60 side while electrons can be collected at the CuPc side, resulting in a photocurrent in the reverse direction. The photocurrent thus observed is contributed to primarily by the charge carriers that are generated by the electron-exciton interaction at the CuPc/C60 interface, while charges derived from the exciton dissociation process also exist at the same interface. The mechanism of photocurrent generation due to electron-exciton interaction in the OSCs is further investigated, and it is manifested by the transient photovoltage characteristics and the external quantum efficiency measurements. PMID:24002235

  3. Relational Coordination and Organisational Social Capital Association with Characteristics of General Practice

    PubMed Central

    Knudsen, Thomas Bøllingtoft; Larsen, Pia Veldt; Søndergaard, Jens

    2014-01-01

    Background. Relational coordination (RC) and organisational social capital (OSC) are measures of novel aspects of an organisation's performance, which have not previously been analysed together, in general practice. Objectives. The aim of this study was to analyse the associations between RC and OSC, and characteristics of general practice. Methods. Questionnaire survey study comprising 2074 practices in Denmark. Results. General practitioners (GPs) rated both RC and OSC in their general practice higher than their secretaries and nurses. The practice form was statistically significantly associated with high RC and OSC. RC was positively associated with the number of patients listed with a practice per staff, where staff is defined as all members of a practice including both owners and employees. Conclusion. The study showed that RC and OSC were significantly associated with type of profession and practice type. RC was also found to be significantly positively associated with number of patients per staff. However, the low response rate must be taken into consideration when interpreting the self-reported results of this study. PMID:25045537

  4. An innovative method to assess negotiation skills necessary for quality improvement.

    PubMed

    Varkey, Prathibha; Gupta, Priyanka; Bennet, Kevin E

    2008-01-01

    Quality improvement (QI) initiatives require leaders who can facilitate change through negotiation. Although a few education programs teach these skills, there is no published literature on methods to assess competency in negotiation. This study's purpose was to determine the psychometric properties of an Objective Structured Clinical Examination (OSCE) to assess negotiation skills. The OSCE uses an actor trained to respond to the learner in a standardized fashion. The negotiation station was part of an 8-station QI OSCE piloted in the Mayo Clinic Endocrinology and Preventive Medicine fellowship programs. External experts judged the content validity to be excellent. Interrater reliability was outstanding for the global competency assessment (0.80) and moderate for checklist scores (0.53). All participating faculty strongly agreed (33.3%) or agreed (66.7%) that the OSCE station was an authentic assessment tool. Further research is needed to study the predictive validity of such an OSCE and its application to assessing other quality improvement competencies. PMID:18820139

  5. Relational coordination and organisational social capital association with characteristics of general practice.

    PubMed

    Lundstrøm, Sanne Lykke; Edwards, Kasper; Knudsen, Thomas Bøllingtoft; Larsen, Pia Veldt; Reventlow, Susanne; Søndergaard, Jens

    2014-01-01

    Background. Relational coordination (RC) and organisational social capital (OSC) are measures of novel aspects of an organisation's performance, which have not previously been analysed together, in general practice. Objectives. The aim of this study was to analyse the associations between RC and OSC, and characteristics of general practice. Methods. Questionnaire survey study comprising 2074 practices in Denmark. Results. General practitioners (GPs) rated both RC and OSC in their general practice higher than their secretaries and nurses. The practice form was statistically significantly associated with high RC and OSC. RC was positively associated with the number of patients listed with a practice per staff, where staff is defined as all members of a practice including both owners and employees. Conclusion. The study showed that RC and OSC were significantly associated with type of profession and practice type. RC was also found to be significantly positively associated with number of patients per staff. However, the low response rate must be taken into consideration when interpreting the self-reported results of this study. PMID:25045537

  6. Investigation of the organic solar cell characteristics for indoor LED light applications

    NASA Astrophysics Data System (ADS)

    Mori, Shigehiko; Gotanda, Takeshi; Nakano, Yoshihiko; Saito, Mitsunaga; Todori, Kenji; Hosoya, Masahiro

    2015-07-01

    We report an experimental study on the current-voltage characteristics of organic solar cells (OSCs) under indoor light illumination. A daylight color light-emitting diode (LED) was used as the indoor light source. We investigated the short circuit current density, open circuit voltage, and fill factor of the OSC under LED irradiation and compared them with those for a crystal silicon solar cell (c-Si-SC), which occupy a large part of the solar cell market. We found that compared with the c-Si-SC, the OSC had higher power conversion efficiency (PCE). We also derived the maximum feasible PCE of an OSC for indoor applications and calculated that a PCE value of 21.3% could be obtained under daylight color LED illumination at approximately 200 lx. From the results of the calculation, it became apparent that the open circuit voltage plays an important role in achieving a high PCE from OSCs, indicating they are promising as electrical energy harvesting module for indoor applications.

  7. The feasibility and acceptability of administering a telemedicine objective structured clinical exam as a solution for providing equivalent education to remote and rural learners

    PubMed Central

    Palmer, RT; Biagioli, FE; Mujcic, J; Schneider, BN; Spires, L; Dodson, LG

    2016-01-01

    Introduction Although many medical schools incorporate distance learning into their curricula, assessing students at a distance can be challenging. While some assessments are relatively simple to administer to remote students, other assessments, such as objective structured clinical exams (OSCEs) are not. This article describes a means to more effectively and efficiently assess distance learners and evaluate the feasibility and acceptability of the assessment. Methods We developed a teleOSCE, administered online in real time, to two cohorts of students on a rural clerkship rotation and assessed the feasibility and acceptability of using such an approach to assess medical students’ clinical skills at rural locations. Project feasibility was defined as having development and implementation costs of less than $5000. Project acceptability was determined by analyzing student interview transcripts. A qualitative case study design framework was chosen due to the novel nature of the activity. Results The implementation cost of the teleOSCE was approximately US$1577.20, making it a feasible educational endeavor. Interview data indicated the teleOSCE was also acceptable to students. Conclusions The teleOSCE format may be useful to other institutions as a method to centrally administer clinical skills exams for assessment of distance medical students. PMID:26632083

  8. Broadband absorption enhancement in organic solar cells with an antenna layer through surface-plasmon mediated energy transfer

    NASA Astrophysics Data System (ADS)

    Jin, Yu; Feng, Jing; Zhang, Xu-Lin; Xu, Ming; Chen, Qi-Dai; Wu, Zhi-Jun; Sun, Hong-Bo

    2015-06-01

    We demonstrated a strategy to realize broadband enhanced absorption in the top-incident inverted organic solar cells (OSCs) by employing an external antenna layer on top of the periodic corrugated metallic anode. Surface-plasmon polaritons (SPPs) are excited on the opposite interfaces of the periodic corrugated metallic anode, which mediate the energy transfer from the antenna layer to the active layer through the anode. The absorption of the OSCs is significantly broadened and enhanced by tuning the SPP resonance to coincide with both the emission of the antenna and the absorption of the active material. The power conversion efficiency exhibits an enhancement of 16% compared to that of the OSCs without the antenna layer.

  9. Practical clinical skills assessment for a cohort of 680 2nd year human medicine students. Is it feasible?

    PubMed

    Wagner-Menghin, Michaela; Preusche, Ingrid; Schmidts, Michael

    2015-03-01

    In clinical skills training objective structured clinical examinations (OSCEs) are the method of choice to foster learning. Hence, implementing them is challenging and expensive. Thus it is investigated how an alternative procedure that keeps OSCE's essential elements, but assigns less stations to each student, works in terms of validity and justifiability.Data of n = 694 students, each taking five tasks drawn semi-randomized out of a pool of 26 tasks, strictly aligned with learning objectives, are analyzed. Despite unsurprisingly low overall reliability, a justifiable pass/fail decision is possible for 480 students (69 %). The remaining group (n = 210, 30 %) is indeed larger than with longer OSCEs, and would need ongoing assessment. The tasks' psychometric quality contributes to exams construct validity. Resource preserving short practical skills assessment is educationally valid and feasible with MedUniVienna's human medicine cohorts of n = 680. PMID:25724462

  10. Isolation of Mammalian Oogonial Stem Cells by Antibody-Based Fluorescence-Activated Cell Sorting.

    PubMed

    Navaroli, Deanna M; Tilly, Jonathan L; Woods, Dori C

    2016-01-01

    The ability to isolate and subsequently culture mitotically active female germ cells from adult ovaries, referred to as either oogonial stem cells (OSCs) or adult female germline stem cells (aFGSCs), has provided a robust system to study female germ cell development under multiple experimental conditions, and in many species. Flow cytometry or fluorescence-activated cell sorting (FACS) is an integral part of many isolation and characterization protocols. Here, we provide methodological details for antibody-based flow cytometric isolation of OSCs using antibodies specific for external epitopes of the proteins Ddx4 or Ifitm3, alone or in combination with the use of fluorescent reporter mice. Beginning with sample preparation, we provide point-by-point instructions to guide researchers on how to isolate OSCs using flow cytometry. PMID:27557587

  11. Structure and oxygen storage/release capacities of Dy1-xYxMnO3+δ (0 <= x <= 1)

    NASA Astrophysics Data System (ADS)

    Remsen, S.; Dabrowski, B.; Chmaissem, O.; Kolesnik, S.; Mais, J.

    2010-03-01

    Synthesis, oxygen storage/release capacities (OSC), oxygen absorption/desorption rates, and structural properties of Dy1-xYxMnO3+δ (0 <= x <= 1) have been studied by x-ray and neutron powder diffraction, dilatometry, and thermogravimetric analysis. These materials have been found to have excellent reversible OSC at low-temperatures of 200 - 375 C and various oxygen partial-pressures, making them potential candidates for oxygen sorbents in novel gas separation methods such as thermal swing absorption and thermal-automatic recovery processes. The OSC of the Dy1-xYxMnO3+δ system relies on the difference in oxygen content of a reversible phase transitions between hexagonal P63cm (δ = 0) and a previously unreported stable phases of this system (0 < δ < 0.5) and pyrochlore Fd3m [δ = 0.50, Subramanian et al. J. Solid State Chem. 72, 24 (1988)].

  12. Dynamic infrared scene projectors based upon the DMD

    NASA Astrophysics Data System (ADS)

    Beasley, D. Brett; Bender, Matt; Crosby, Jay; Messer, Tim

    2009-02-01

    The Micromirror Array Projector System (MAPS) is an advanced dynamic scene projector system developed by Optical Sciences Corporation (OSC) for Hardware-In-the-Loop (HWIL) simulation and sensor test applications. The MAPS is based upon the Texas Instruments Digital Micromirror Device (DMD) which has been modified to project high resolution, realistic imagery suitable for testing sensors and seekers operating in the UV, visible, NIR, and IR wavebands. Since the introduction of the first MAPS in 2001, OSC has continued to improve the technology and develop systems for new projection and Electro-Optical (E-O) test applications. This paper reviews the basic MAPS design and performance capabilities. We also present example projectors and E-O test sets designed and fabricated by OSC in the last 7 years. Finally, current research efforts and new applications of the MAPS technology are discussed.

  13. High-performance ternary blend polymer solar cells involving both energy transfer and hole relay processes

    SciTech Connect

    Lu, Luyao; Chen, Wei; Xu, Tao; Yu, Luping

    2015-06-04

    The integration of multiple materials with complementary absorptions into a single junction device is regarded as an efficient way to enhance the power conversion efficiency (PCE) of organic solar cells (OSCs). However, because of increased complexity with one more component, only limited high-performance ternary systems have been demonstrated previously. Here we report an efficient ternary blend OSC with a PCE of 9.2%. We show that the third component can reduce surface trap densities in the ternary blend. Detailed studies unravel that the improved performance results from synergistic effects of enlarged open circuit voltage, suppressed trap-assisted recombination, enhanced light absorption, increased hole extraction, efficient energy transfer and better morphology. The working mechanism and high device performance demonstrate new insights and design guidelines for high-performance ternary blend solar cells and suggest that ternary structure is a promising platform to boost the efficiency of OSCs.

  14. Selective observation of photo-induced electric fields inside different material components in bulk-heterojunction organic solar cell

    SciTech Connect

    Chen, Xiangyu; Taguchi, Dai; Manaka, Takaaki; Iwamoto, Mitsumasa

    2014-01-06

    By using electric-field-induced optical second-harmonic generation (EFISHG) measurement at two laser wavelengths of 1000 nm and 860 nm, we investigated carrier behavior inside the pentacene and C{sub 60} component of co-deposited pentacene:C{sub 60} bulk-heterojunctions (BHJs) organic solar cells (OSCs). The EFISHG experiments verified the presence of two carrier paths for electrons and holes in BHJs OSCs. That is, two kinds of electric fields pointing in opposite directions are identified as a result of the selectively probing of SHG activation from C{sub 60} and pentacene. Also, under open-circuit conditions, the transient process of the establishment of open-circuit voltage inside the co-deposited layer has been directly probed, in terms of photovoltaic effect. The EFISHG provides an additional promising method to study carrier path of electrons and holes as well as dissociation of excitons in BHJ OSCs.

  15. Datamining and analysis of the key parameters in organic solar cells

    NASA Astrophysics Data System (ADS)

    Riede, Moritz K.; Liehr, Andreas W.; Glatthaar, Markus; Niggemann, Michael; Zimmermann, Birger; Ziegler, Tobias; Gombert, Andreas; Willeke, Gerhard

    2006-04-01

    The production process of organic solar cells (OSCs) is investigated and the effects of parameter variations on experimental results are analysed with the Principal Component Analysis (PCA). This statistical method is applied to an exemplar data set, in which the materials' concentration in the absorber solution and the spincoating speed of the absorber solution were varied intentionally. In addition to the remaining production parameters, the time intervals between the steps were included in the analysis. A large part of the variance in the experimental results can be explained with the evaporation conditions, the spincoating speed and the concentrations in the absorber solution. The PCA also confirms that the OSC is a complex and interdependent system, where one has to analyse the influence of several parameters at the same time in order to understand their effects on the OSC properties. The PCA results will be used to focus further experiments on the identified key parameters.

  16. Direct analytical method of contact position effects on the energy-level alignments at organic semiconductor/electrode interfaces using photoemission spectroscopy combined with Ar gas cluster ion beam sputtering

    NASA Astrophysics Data System (ADS)

    Yun, Dong-Jin; Chung, JaeGwan; Kim, Seong Heon; Kim, Yongsu; Park, SungHoon; Seol, Minsu; Heo, Sung

    2015-11-01

    Poly(3, 4-ethylenedioxythiophene) (PEDOT) polymerized with poly(4-styrenesulfonate) (PSS) is one of the most widely used conducting organic electrodes owing to its outstanding optical/electrical properties and high work function. Because its work function depends significantly on the molecular arrangements between PEDOT and PSS molecules on the surface, the contact position of PEDOT:PSS films on organic semiconductors (OSCs) must also be an essential consideration. However, existing analysis methods based on in situ deposition/analysis are limited in their ability to accurately investigate the electronic structures of the buried interface regions under the solution-processed electrode or OSC layer in organic devices. Therefore, to overcome such limitations, we propose a top-down method based on photoemission spectroscopy analysis combined with Ar gas cluster ion beam (GCIB) sputtering. Through this method, both energy-level alignments and molecular distributions at various OSC/electrode interfaces can be successfully characterized without reference to any deposition process.

  17. Use of the Abbe sine condition to quantify alignment aberrations in optical imaging systems

    NASA Astrophysics Data System (ADS)

    Burge, James H.; Zhao, Chunyu; Lu, Sheng Huei

    2010-08-01

    Violation of Abbe's sine condition is well-known to cause coma in axisymmetric imaging systems, and generally any offense against the sine condition (OSC) will cause aberrations that have linear dependence on the field angle. A well-corrected imaging system must obey the Abbe sine condition. A misaligned optical system can have particular forms of the OSC which are evaluated here. The lowest order non-trivial effects of misalignment have quadratic pupil dependence which causes a combination of astigmatism and focus that have linear field dependence. Higher order terms can arise from complex systems, but the effects of misalignment are nearly always dominated by the lowest order effects which can be fully characterized by measuring images on axis and the on-axis offense against the sine condition. By understanding the form of the on-axis images and the OSC, the state of alignment can be determined.

  18. Improved performances of CuPc/C60-based solar cell by using randomly and irregularly embossed PEDOT:PSS as anode buffer layer

    NASA Astrophysics Data System (ADS)

    Zhang, Haiqing; Hao, Yuying; Zhang, Fan; Sun, Qinjun; Li, Zhanfeng; Cui, Yanxia; Wang, Hua; Shi, Fang

    2015-07-01

    An unique organic solar cell (OSC) based on copper phthalocyanine (CuPc) and fullerene C60 as the electron donor and acceptor materials is demonstrated with randomly and irregularly embossed poly (3, 4-ethylenedioxythiophene) poly (styrenesulfonate) (PEDOT: PSS) as anode buffer layer. The effect of PEDOT:PSS nanostructure is characterized by optical and electrical measurements. The results indicate that introducing irregular nanostructure with random distribution into OSC leads to longer light paths by efficient scattering of the incident light and thus higher light absorption in active layer. Moreover, such a nanostructure increases the junction area, allowing more efficient exciton dissociation and charge carrier transfer/collection. These combined effects result in a prominent enhancement of 25.5% in average power conversion efficiency relative to the non-structured OSC due to the increases in short-circuit current and fill factor.

  19. High-performance ternary blend polymer solar cells involving both energy transfer and hole relay processes

    DOE PAGESBeta

    Lu, Luyao; Chen, Wei; Xu, Tao; Yu, Luping

    2015-06-04

    The integration of multiple materials with complementary absorptions into a single junction device is regarded as an efficient way to enhance the power conversion efficiency (PCE) of organic solar cells (OSCs). However, because of increased complexity with one more component, only limited high-performance ternary systems have been demonstrated previously. Here we report an efficient ternary blend OSC with a PCE of 9.2%. We show that the third component can reduce surface trap densities in the ternary blend. Detailed studies unravel that the improved performance results from synergistic effects of enlarged open circuit voltage, suppressed trap-assisted recombination, enhanced light absorption, increasedmore » hole extraction, efficient energy transfer and better morphology. The working mechanism and high device performance demonstrate new insights and design guidelines for high-performance ternary blend solar cells and suggest that ternary structure is a promising platform to boost the efficiency of OSCs.« less

  20. Continuous 1D-Metallic Microfibers Web for Flexible Organic Solar Cells.

    PubMed

    Hong, Kihyon; Ham, Juyoung; Kim, Byoung-Joon; Park, Jae Yong; Lim, Dong Chan; Lee, Joo Yul; Lee, Jong-Lam

    2015-12-16

    We report the use of a continuous 1D-metallic microfibers web (MFW) as transparent electrode for organic solar cells (OSCs). The MFW electrode can be produced with a process that involves simple electrospinning and wet etching of metal thin film. Au MFW exhibits a maximum optical transmittance of 90.8% (at 15 Ω/sq of the sheet resistance) and excellent mechanical flexibility. The MFW structure has an average width in the range from 4 to 6 μm and a junction-free structure, resulting in very smooth surface roughness. The OSCs with Au MFW electrode exhibited a higher power conversion efficiency (PCE) of 3.50% than the device with an indium tin oxide electrode (PCE = 3.20%). The optical modeling calculation showed that the Au MFW electrode induced light scattering and improved the light absorption in the active layer, resulting in an improved PCE in the OSCs. PMID:26580701

  1. Understanding the Electronic Structure of Metal/SAM/Organic−Semiconductor Heterojunctions

    PubMed Central

    2009-01-01

    Computational modeling is used to describe the mechanisms governing energy level alignment between an organic semiconductor (OSC) and a metal covered by various self-assembled monolayers (SAMs). In particular, we address the question to what extent and under what circumstances SAM-induced work-function modifications lead to an actual change of the barriers for electron and hole injection from the metal into the OSC layer. Depending on the nature of the SAM, we observe clear transitions between Fermi level pinning and vacuum-level alignment regimes. Surprisingly, although in most cases the pinning occurs only when the metal is present, it is not related to charge transfer between the electrode and the organic layer. Instead, charge rearrangements at the interface between the SAM and the OSC are observed, accompanied by a polarization of the SAM. PMID:19891441

  2. The cost of the objective structured clinical examination on an Italian nursing bachelor's degree course.

    PubMed

    Palese, A; Bulfone, G; Venturato, E; Urli, N; Bulfone, T; Zanini, A; Fabris, S; Tomietto, M; Comisso, I; Tosolini, C; Zuliani, S; Dante, A

    2012-05-01

    The OSCE (Objective Structured Clinical Examination) is considered the most valid and reliable method for assessing the clinical skills of students training for health professions, but its use is limited by the related high costs. We analyzed the cost retrospectively of using an OSCE designed for second-year students (2009) in our degree course, adopting the Reznick et al. guidelines (1993), which recommend assessing both high-end costs and low-end costs. The high-end costs adopting the OSCE amounted to € 145.23 per student, while the low-end costs were € 31.51 per student. Considering the economic crisis and the cost-containment measures applied also in nursing education, strategies for further reducing costs are discussed. PMID:21470724

  3. High-performance ternary blend polymer solar cells involving both energy transfer and hole relay processes.

    PubMed

    Lu, Luyao; Chen, Wei; Xu, Tao; Yu, Luping

    2015-01-01

    The integration of multiple materials with complementary absorptions into a single junction device is regarded as an efficient way to enhance the power conversion efficiency (PCE) of organic solar cells (OSCs). However, because of increased complexity with one more component, only limited high-performance ternary systems have been demonstrated previously. Here we report an efficient ternary blend OSC with a PCE of 9.2%. We show that the third component can reduce surface trap densities in the ternary blend. Detailed studies unravel that the improved performance results from synergistic effects of enlarged open circuit voltage, suppressed trap-assisted recombination, enhanced light absorption, increased hole extraction, efficient energy transfer and better morphology. The working mechanism and high device performance demonstrate new insights and design guidelines for high-performance ternary blend solar cells and suggest that ternary structure is a promising platform to boost the efficiency of OSCs. PMID:26041586

  4. High-performance ternary blend polymer solar cells involving both energy transfer and hole relay processes

    PubMed Central

    Lu, Luyao; Chen, Wei; Xu, Tao; Yu, Luping

    2015-01-01

    The integration of multiple materials with complementary absorptions into a single junction device is regarded as an efficient way to enhance the power conversion efficiency (PCE) of organic solar cells (OSCs). However, because of increased complexity with one more component, only limited high-performance ternary systems have been demonstrated previously. Here we report an efficient ternary blend OSC with a PCE of 9.2%. We show that the third component can reduce surface trap densities in the ternary blend. Detailed studies unravel that the improved performance results from synergistic effects of enlarged open circuit voltage, suppressed trap-assisted recombination, enhanced light absorption, increased hole extraction, efficient energy transfer and better morphology. The working mechanism and high device performance demonstrate new insights and design guidelines for high-performance ternary blend solar cells and suggest that ternary structure is a promising platform to boost the efficiency of OSCs. PMID:26041586

  5. Synergistic Effects of Binary-Solvent Annealing for Efficient Polymer-Fullerene Bulk Heterojunction Solar Cells.

    PubMed

    Wu, Fu-Chiao; Li, Yi-Hao; Tsou, Chieh-Jen; Tung, Kuo-Cheng; Yen, Chia-Te; Chou, Fang-Sheng; Tang, Fu-Ching; Chou, Wei-Yang; Ruan, Jrjeng; Cheng, Horng-Long

    2015-09-01

    Conjugated polymer-fullerene-based bulk-heterojunction (BHJ) organic solar cells (OSCs) have attracted tremendous attention over the past two decades because of their potential to develop low-cost and easy methods to produce energy from light. The complicated microstructure and morphology with randomly organized architecture of these polymer-fullerene-based active layers (ALs) is a key factor that limits photovoltaic performance. In this study, a binary-solvent annealing (BSA) approach was established to improve the poly(3-hexylthiophene):indene-C60 bisadduct-based AL for efficient BHJ-type OSCs by varying the second solvents with different boiling points (BP). Thus, we were able to change the evaporation behavior of cosolvents and consequently obtain the various microstructural properties of the AL. An in-depth study was conducted on the solvent-evaporation driven morphology of the active layer under various cosolvent conditions and its effect on the photovoltaic parameters of OSCs. Under the BSA processes, we found that the specimens with low-BP second solvents allows us to observe a more ideal AL for increasing photon absorption and efficient charge transport and collection at the respective electrodes, resulting in enhanced PCE of the corresponding OSCs. By contrast, the specimens with high-BP second solvents exhibit random microstructures, which are detrimental to charge transport and collection and lead to diminished PCE of the corresponding OSCs. By appropriately selecting the composition of a binary solvent, BSA can be employed as an easy method for the effective manipulation of the microstructures of ALs. BSA is a promising technique for the performance enhancement of not only OSCs but also other organic/polymeric-based electronic devices. PMID:26267758

  6. Characterization of the 2,3-Oxidosqualene Cyclase Gene from Antrodia cinnamomea and Enhancement of Cytotoxic Triterpenoid Compound Production.

    PubMed

    Lin, Yan-Liang; Lee, Yi-Ru; Tsao, Nai-Wen; Wang, Sheng-Yang; Shaw, Jei-Fu; Chu, Fang-Hua

    2015-07-24

    Antrodia cinnamomea is a scarce, epiphyte, host-specific, brown-rot fungus that produces diverse bioactive compounds with potent biological activity. Natural wild-type fruiting bodies of A. cinnamomea are rare and highly valued, but their artificial culture poses challenges. Triterpenoids are a group of secondary metabolites that contribute to the bioactivities of A. cinnamomea. 2,3-Oxidosqualene cyclase (OSC) is a key enzyme in triterpenoid biosynthesis, which converts 2,3-oxidosqualene (OS) into polycyclic triterpenoids. In this study, we isolated a 2,3-oxidosqualene cyclase gene from A. cinnamomea with degenerate primers and designated it as AcOSC. The full length AcOSC cDNA was subcloned into a yeast expression vector, and AcOSC activity was confirmed. RT-PCR results showed that AcOSC expression was highest in the wild-type fruiting body and correlated with a higher concentration of triterpenoids. Agrobacterium-mediated gene transformation was conducted to enhance the triterpenoid synthesis capacity of the cultured mycelium. Metabolite profiling was conducted by LC-MS/MS and principal component analysis (PCA). The compositions and contents of metabolites in the AcOSC transgenic lines were different from those in the wild-type mycelium and vector control. The levels of two important triterpenoids, dehydrosulphurenic acid (DSA) and dehydroeburicoic acid (DEA), were increased in A. cinnamomea oxidosqualene cyclase overexpression strains compared to controls. In summary an Agrobacterium-mediated gene transformation procedure was established that successfully increased the level of transgene expression and enhanced the triterpenoid content in cultured A. cinnamomea. PMID:26125648

  7. Near-field multiple scattering effects of plasmonic nanospheres embedded into thin-film organic solar cells

    NASA Astrophysics Data System (ADS)

    Sha, Wei E. I.; Choy, Wallace C. H.; Liu, Yang G.; Cho Chew, Weng

    2011-09-01

    We investigate near-field multiple scattering effects of plasmonic nanospheres (NSPs) embedded into organic solar cells (OSCs). When NSPs are embedded into a spacer layer, the near-field scattering from the NSPs shows strong direction-dependent features, which significantly affects the optical absorption. When NSPs are embedded into an active layer, the absorption enhancement is attributed to the interplay between longitudinal and transverse modes supported by the NSP chain. The breakdown of electrostatic scaling law is confirmed by our theoretical model and should be accounted for optical designs of OSCs. The work provides the fundamental physical understanding and design guidelines for plasmonic photovoltaics.

  8. Image science and image-quality research in the Optical Sciences Center

    NASA Astrophysics Data System (ADS)

    Barrett, Harrison H.; Myers, Kyle J.

    2014-09-01

    This paper reviews the history of research into imaging and image quality at the Optical Sciences Center (OSC), with emphasis on the period 1970-1990. The work of various students in the areas of psychophysical studies of human observers of images; mathematical model observers; image simulation and analysis, and the application of these methods to radiology and nuclear medicine is summarized. The rapid progress in computational power, at OSC and elsewhere, which enabled the steady advances in imaging and the emergence of a science of imaging, is also traced. The implications of these advances to ongoing research and the current Image Science curriculum at the College of Optical Sciences are discussed.

  9. New concept to break the intrinsic properties of organic semiconductors for optical sensing applications

    NASA Astrophysics Data System (ADS)

    Choy, Wallace C. H.

    2015-09-01

    As the intrinsic electrostatic limit, space charge limit (SCL) for photocurrent is a universal phenomenon which is fundamental important for organic semiconductors. We will demonstrate SCL breaking by a new plasmonic-electrical concept. As a proof-ofconcept, organic solar cells (OSCs) comprising metallic planar and grating electrodes are studied. Interestingly, although strong plasmonic resonances induce abnormally dense photocarriers around a grating anode, the grating incorporated inverted OSC is exempt from space charge accumulation (limit) and degradation of electrical properties. The plasmonic-electrical concept will open up a new way to manipulate both optical and electrical properties of semiconductor devices simultaneously.

  10. Data from thermal testing of the Open Source Cryostage.

    PubMed

    Buch, Johannes Lørup; Ramløv, Hans

    2016-09-01

    The data presented here is related to the research article "An open source cryostage and software analysis method for detection of antifreeze activity" (Buch and Ramløv, 2016) [1]. The design of the Open Source Cryostage (OSC) is tested in terms of thermal limits, thermal efficiency and electrical efficiency. This article furthermore includes an overview of the electrical circuitry and a flowchart of the software program controlling the temperature of the OSC. The thermal efficiency data is presented here as degrees per volt and maximum cooling capacity. PMID:27508238

  11. Optimizing Sisal Compiler; Sisal Compiler and Running System

    Energy Science and Technology Software Center (ESTSC)

    1992-11-12

    OSC is a compiler and runtime system for the functional language Sisal. Functional languages are based on mathematical principals, and may reduce the cost of parallel program development without sacrificing performance. OSC compiles Sisal source code to binary form, automatically inserting calls to the Sisal runtime system to manage parallel execution of independent tasks. Features include support for dynamic arrays, automatic vectorization, and automatic parallelization. At runtime, the user may specify the number of workers,more » the granularity of tasks, and other execution parameters.« less

  12. Development of a scanning time of flight microscope and its application to the study of charge transport in phase separated structured organic semiconductors

    NASA Astrophysics Data System (ADS)

    Paul, Sanjoy; Ellman, Brett; Tripathi, Suvagata; Singh, Gautam; Twieg, Robert J.

    2016-04-01

    We describe a tool for studying the two-dimensional spatial variation in electronic properties of organic semiconductors: the scanning time-of-flight microscope (STOFm). The STOFm simultaneously measures the transmittance of polarized light and time-of-flight current transients with a pixel size <30 μm, making it especially valuable for studies of the correlations of structure with charge generation and transport in liquid crystalline organic semiconductors (LC OSCs). Adapting a previously developed photopolymerization technique, we characterize the instrument using patterned samples of a LC OSC bounded by a non-semiconducting polymer matrix.

  13. Interfacial spectroscopic characterization of organic/ferromagnet hetero-junction of 3,4,9,10-perylene-teracarboxylic dianhydride-based organic spin valves

    NASA Astrophysics Data System (ADS)

    Hong, Jhen-Yong; Ou Yang, Kui-Hon; Wang, Bo-Yao; Li, Kai-Shin; Shiu, Hung-Wei; Chen, Chia-Hao; Chan, Yuet-Loy; Wei, Der-Hsin; Chang, Fan-Hsiu; Lin, Hong-Ji; Chiang, Wen-Chung; Lin, Minn-Tsong

    2014-02-01

    We report interfacial characterization of 3,4,9,10-perylene-teracarboxylic dianhydride (PTCDA)-based organic spin valves (OSV) dusted with a thin layer of partially oxidized alumina at the organic semiconductor (OSC)/ferromagnet (FM) interfaces. Up to 13.5% magnetoresistance is achieved at room temperature. X-ray photoelectron spectroscopy measurements reveal interfacial electronic interaction between PTCDA and FM while the application of a thin alumina layer at the PTCDA/FM interfaces prevents the electronic hybridization and effectively preserves the spin injection into the OSC spacer. This finding demonstrates the critical effect of interfacial structure on magnetotransport behavior in OSV.

  14. To what extent does the Health Professions Admission Test-Ireland predict performance in early undergraduate tests of communication and clinical skills? – An observational cohort study

    PubMed Central

    2013-01-01

    Background Internationally, tests of general mental ability are used in the selection of medical students. Examples include the Medical College Admission Test, Undergraduate Medicine and Health Sciences Admission Test and the UK Clinical Aptitude Test. The most widely used measure of their efficacy is predictive validity. A new tool, the Health Professions Admission Test- Ireland (HPAT-Ireland), was introduced in 2009. Traditionally, selection to Irish undergraduate medical schools relied on academic achievement. Since 2009, Irish and EU applicants are selected on a combination of their secondary school academic record (measured predominately by the Leaving Certificate Examination) and HPAT-Ireland score. This is the first study to report on the predictive validity of the HPAT-Ireland for early undergraduate assessments of communication and clinical skills. Method Students enrolled at two Irish medical schools in 2009 were followed up for two years. Data collected were gender, HPAT-Ireland total and subsection scores; Leaving Certificate Examination plus HPAT-Ireland combined score, Year 1 Objective Structured Clinical Examination (OSCE) scores (Total score, communication and clinical subtest scores), Year 1 Multiple Choice Questions and Year 2 OSCE and subset scores. We report descriptive statistics, Pearson correlation coefficients and Multiple linear regression models. Results Data were available for 312 students. In Year 1 none of the selection criteria were significantly related to student OSCE performance. The Leaving Certificate Examination and Leaving Certificate plus HPAT-Ireland combined scores correlated with MCQ marks. In Year 2 a series of significant correlations emerged between the HPAT-Ireland and subsections thereof with OSCE Communication Z-scores; OSCE Clinical Z-scores; and Total OSCE Z-scores. However on multiple regression only the relationship between Total OSCE Score and the Total HPAT-Ireland score remained significant; albeit the

  15. Contrary interfacial exciton dissociation at metal/organic interface in regular and reverse configuration organic solar cells

    SciTech Connect

    Wu, Bo; Wu, Zhenghui; Tam, Hoi Lam; Zhu, Furong

    2014-09-08

    An opposite interfacial exciton dissociation behavior at the metal (Al)/organic cathode interface in regular and inverted organic solar cells (OSCs) was analyzed using transient photocurrent measurements. It is found that Al/organic contact in regular OSCs, made with the blend layer of poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl] -[3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]-thiophenediyl

  16. Metal nanoparticles enhanced optical absorption in thin film solar cells

    NASA Astrophysics Data System (ADS)

    Xie, Wanlu; Liu, Fang; Qu, Di; Xu, Qi; Huang, Yidong

    2011-12-01

    The plasmonic enhanced absorption for thin film solar cells with silver nanoparticles (NPs) deposited on top of the amorphous silicon film (a-Si:H) solar cells and embedded inside the active layer of organic solar cells (OSCs) has been simulated and analyzed. Obvious optical absorption enhancement is obtained not only at vertical incidence but also at oblique incidence. By properly adjusting the period and size of NPs, an increased absorption enhancement of about 120% and 140% is obtained for a-Si:H solar cells and OSCs, respectively.

  17. Direct measurements of blood glucose concentration in the presence of saccharide interferences using slope and bias orthogonal signal correction and Fourier transform near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Abookasis, David; Workman, Jerome J.

    2011-02-01

    Saccharide interferences such as Dextran, Galactose, etc. have a great potential to interfere with near infrared (NIR) glucose analysis since they have a similar spectroscopic fingerprint and are present physiologically at large relative concentrations. These can lead to grossly inappropriate interpretation of patient glucose levels and resultant treatment in critical care and hospital settings. This study describes a methodology to reduce this effect on glucose analysis using an NIR Fourier transform spectroscopy method combined with a multivariate calibration technique (PLS) using preprocessing by orthogonal signal correction (OSC). A mathematical approach based on the use of a single calibration based bias and slope correction was applied in addition to a standard OSC was investigated. This approach is combined with a factorial interferent calibration design to accommodate for interference effects. We named this approach as a slope and bias OSC (sbOSC). sbOSC differs from OSC in the way it handles the prediction. In sbOSC, statistics on slope and bias obtained from a set of calibration samples are then used as a validation parameter in the prediction set. Healthy human volunteer blood with different glucose (80 to 200 mg/dL) and hematocrit (24 to 48 vol.%) levels containing high expected levels of inteferents have been measured with a transmittance near-infrared Fourier transform spectrometer operates in the broadband spectral range of 1.25-2.5 μm (4000-8000 cm-1). The effect of six interferents compounds used in intensive care and operating rooms, namely Dextran, Fructose, Galactose, Maltose, Mannitol, and Xylose, were tested on blood glucose. A maximum interference effect (MIE) parameter was used to rank the significance for the individual interferent type on measurement error relative to the total NIR whole blood glucose measurement error. For comparison, a YSI (Yellow Springs Instrument) laboratory reference glucose analyzer and NIR data were collected at

  18. Tailoring Functional Interlayers in Organic Field-Effect Transistor Biosensors.

    PubMed

    Magliulo, Maria; Manoli, Kyriaki; Macchia, Eleonora; Palazzo, Gerardo; Torsi, Luisa

    2015-12-01

    This review aims to provide an update on the development involving dielectric/organic semiconductor (OSC) interfaces for the realization of biofunctional organic field-effect transistors (OFETs). Specific focus is given on biointerfaces and recent technological approaches where biological materials serve as interlayers in back-gated OFETs for biosensing applications. Initially, to better understand the effects produced by the presence of biomolecules deposited at the dielectric/OSC interfacial region, the tuning of the dielectric surface properties by means of self-assembled monolayers is discussed. Afterward, emphasis is given to the modification of solid-state dielectric surfaces, in particular inorganic dielectrics, with biological molecules such as peptides and proteins. Special attention is paid on how the presence of an interlayer of biomolecules and bioreceptors underneath the OSC impacts on the charge transport and sensing performance of the device. Moreover, naturally occurring materials, such as carbohydrates and DNA, used directly as bulk gating materials in OFETs are reviewed. The role of metal contact/OSC interface in the overall performance of OFET-based sensors is also discussed. PMID:25429859

  19. 5 CFR 1820.7 - Fees.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 3 2012-01-01 2012-01-01 false Fees. 1820.7 Section 1820.7 Administrative Personnel OFFICE OF SPECIAL COUNSEL FREEDOM OF INFORMATION ACT REQUESTS; PRODUCTION OF RECORDS OR TESTIMONY § 1820.7 Fees. (a) In general. OSC shall charge for processing requests under the FOIA in accordance with paragraph (c) of this...

  20. Inverted Ultrathin Organic Solar Cells with a Quasi-Grating Structure for Efficient Carrier Collection and Dip-less Visible Optical Absorption

    PubMed Central

    In, Sungjun; Park, Namkyoo

    2016-01-01

    We propose a metallic-particle-based two-dimensional quasi-grating structure for application to an organic solar cell. With the use of oblate spheroidal nanoparticles in contact with an anode of inverted, ultrathin organic solar cells (OSCs), the quasi-grating structure offers strong hybridization between localized surface plasmons and plasmonic gap modes leading to broadband (300~800 nm) and uniform (average ~90%) optical absorption spectra. Both strong optical enhancement in extreme confinement within the active layer (90 nm) and improved hole collection are thus realized. A coupled optical-electrical multi-physics optimization shows a large (~33%) enhancement in the optical absorption (corresponding to an absorption efficiency of ~47%, AM1.5G weighted, visible) when compared to a control OSC without the quasi-grating structure. That translates into a significant electrical performance gain of ~22% in short circuit current and ~15% in the power conversion efficiency (PCE), leading to an energy conversion efficiency (~6%) which is comparable to that of optically-thick inverted OSCs (3–7%). Detailed analysis on the influences of mode hybridization to optical field distributions, exciton generation rate, charge carrier collection efficiency and electrical conversion efficiency is provided, to offer an integrated understanding on the coupled optical-electrical optimization of ultrathin OSCs. PMID:26902974

  1. Teacher Effectiveness: A Position.

    ERIC Educational Resources Information Center

    Scott, Myrtle

    1969-01-01

    This document summarizes the highlights of research on teacher effectiveness and concludes with recommendations based on a synthesis of this past work. The various methodologies that have been used are discussed, from rating scales to objective observation techniques, such as OScAR and the ecological studies. The major problems in teacher…

  2. HATCN-based charge recombination layers as effective interconnectors for tandem organic solar cells.

    PubMed

    Wang, Rong-Bin; Wang, Qian-Kun; Xie, Hao-Jun; Xu, Lu-Hai; Duhm, Steffen; Li, Yan-Qing; Tang, Jian-Xin

    2014-09-10

    A comprehensive understanding of the energy-level alignment at the organic heterojunction interfaces is of paramount importance to optimize the performance of organic solar cells (OSCs). Here, the detailed electronic structures of organic interconnectors, consisting of cesium fluoride-doped 4,7-diphenyl-1,10-phenanthroline and hexaazatriphenylene-hexacarbonitrile (HATCN), have been investigated via in situ photoemission spectroscopy, and their impact on the charge recombination process in tandem OSCs has been identified. The experimental determination shows that the HATCN interlayer plays a significant role in the interface energetics with a dramatic decrease in the reverse built-in potential for electrons and holes from stacked subcells, which is beneficial to the charge recombination between HATCN and the adjacent layer. In accordance with the energy-level alignments, the open-circuit voltage of tandem OSC incorporating a HATCN-based interconnector is almost 2 times that of a single-cell OSC, revealing the effectiveness of the HATCN-based interconnectors in tandem organic devices. PMID:25141159

  3. 5 CFR 1820.5 - Responses to requests.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 3 2012-01-01 2012-01-01 false Responses to requests. 1820.5 Section 1820.5 Administrative Personnel OFFICE OF SPECIAL COUNSEL FREEDOM OF INFORMATION ACT REQUESTS; PRODUCTION OF RECORDS OR TESTIMONY § 1820.5 Responses to requests. (a) General. Ordinarily, OSC shall have...

  4. 5 CFR 1820.5 - Responses to requests.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 3 2011-01-01 2011-01-01 false Responses to requests. 1820.5 Section 1820.5 Administrative Personnel OFFICE OF SPECIAL COUNSEL FREEDOM OF INFORMATION ACT REQUESTS; PRODUCTION OF RECORDS OR TESTIMONY § 1820.5 Responses to requests. (a) General. Ordinarily, OSC shall have...

  5. 5 CFR 1820.5 - Responses to requests.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 3 2013-01-01 2013-01-01 false Responses to requests. 1820.5 Section 1820.5 Administrative Personnel OFFICE OF SPECIAL COUNSEL FREEDOM OF INFORMATION ACT REQUESTS; PRODUCTION OF RECORDS OR TESTIMONY § 1820.5 Responses to requests. (a) General. Ordinarily, OSC shall have...

  6. The Implementation and Development of an Objective Structured Clinical Examination in the Community Pharmacy Course of a Select Gulf-Region Academic Institution (Ras Al Khaimah College of Pharmaceutical Sciences): A Pilot Study

    ERIC Educational Resources Information Center

    Al-Azzawi, Amad Mohammed Jamil; Nagavi, B.G.; Hachim, Mahmood Y.; Mossa, Omar H.

    2016-01-01

    Background: Objective Structured Clinical Examinations (OSCEs) were used to assess translational pharmacotherapeutic skills of a Gulf-region representative academic institution. Aim: The aim of the current study was to assess the clinical skills of students enrolled within the third year Bachelor of Pharmacy (BPharm) programme within Ras Al…

  7. 5 CFR 1800.1 - Filing complaints of prohibited personnel practices or other prohibited activities.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...: (800) 872-9855 (toll-free), or (202) 653-7188 (in the Washington, DC area); or (iii) Online, at: http://www.osc.gov (to print out and complete on paper, or to complete online). (5) A complainant can file...

  8. Open Source Communities in Technical Writing: Local Exigence, Global Extensibility

    ERIC Educational Resources Information Center

    Conner, Trey; Gresham, Morgan; McCracken, Jill

    2011-01-01

    By offering open-source software (OSS)-based networks as an affordable technology alternative, we partnered with a nonprofit community organization. In this article, we narrate the client-based experiences of this partnership, highlighting the ways in which OSS and open-source culture (OSC) transformed our students' and our own expectations of…

  9. Spatial Display of Agronomic Data While Preserving Grower Confidentiality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Data from 10 years of field inspections conducted by the Oregon Seed Certification Service (OSCS) were shared with us for analysis of spatial and temporal trends in weed severity in Oregon's grass seed industry under the provision that no confidential business information (CBI) would be released to ...

  10. 40 CFR 300.305 - Phase II-Preliminary assessment and initiation of action.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (CONTINUED) SUPERFUND, EMERGENCY PLANNING, AND COMMUNITY RIGHT-TO-KNOW PROGRAMS NATIONAL OIL AND HAZARDOUS... are promptly notified in the event of any discharge of oil, to the maximum extent practicable as..., investigations, and planning with respect to appropriate removal actions. The OSC shall consult with the...

  11. 32 CFR 145.6 - Procedures.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... agency (other than the DLA) shall be forwarded to the IG, DoD. (2) Allegations of improper or illegal... IG, DoD, or the GC of the Component concerned, as appropriate, shall ensure compliance with the Civil...) shall be forwarded by the General Counsel concerned to the IG, DoD. (b) OSC Investigations of...

  12. KSC Engineering Academy (KEA): Ares 1-X Overview

    NASA Technical Reports Server (NTRS)

    Ess, Bob

    2007-01-01

    The presentation provides an overview of the ARES 1-X program. Videos include avionics ATVC actuator testing, GS damper retractor, GS vortex shedding, RoCS hot fire at WSTF, RoCS Peacekeeper tests, RoCS installation, thrust OSC, amd Ares 1-X fly through.

  13. Sub-nanometer resolution of an organic semiconductor crystal surface using friction force microscopy in water

    NASA Astrophysics Data System (ADS)

    Pimentel, Carlos; Varghese, Shinto; Yoon, Seong-Jun; Park, Soo Young; Gierschner, Johannes; Gnecco, Enrico; Pina, Carlos M.

    2016-04-01

    Organic semiconductors (OSC) are attracting much interest for (opto)electronic applications, such as photovoltaics, LEDs, sensors or solid state lasers. In particular, crystals formed by small π -conjugated molecules have shown to be suitable for constructing OSC devices. However, the (opto)electronic properties are complex since they depend strongly on both the mutual orientation of molecules as well as the perfection of bulk crystal surfaces. Hence, there is an urgent need to control nano-topographic OSC features in real space. Here we show that friction force microscopy in water is a very suitable technique to image the free surface morphology of an OSC single crystal (TDDCS) with sub-nanometer resolution. We demonstrate the power of the method by direct correlation to the structural information extracted from combined single crystal (SC-) and specular (s-) XRD studies, which allows us to identify the pinning centers encountered in the stick-slip motion of the probing tip with the topmost methyl groups on the TDDCS surface.

  14. 40 CFR 300.155 - Public information and community relations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... responsible party. (b) An on-scene news office may be established to coordinate media relations and to issue... the lead agency. The OSC/RPM determines the location of the on-scene news office, but every effort... interest warrants the issuance of statements and an on-scene news office has not been established,...

  15. Three subsets of sequence complexity and their relevance to biopolymeric information.

    PubMed

    Abel, David L; Trevors, Jack T

    2005-01-01

    Genetic algorithms instruct sophisticated biological organization. Three qualitative kinds of sequence complexity exist: random (RSC), ordered (OSC), and functional (FSC). FSC alone provides algorithmic instruction. Random and Ordered Sequence Complexities lie at opposite ends of the same bi-directional sequence complexity vector. Randomness in sequence space is defined by a lack of Kolmogorov algorithmic compressibility. A sequence is compressible because it contains redundant order and patterns. Law-like cause-and-effect determinism produces highly compressible order. Such forced ordering precludes both information retention and freedom of selection so critical to algorithmic programming and control. Functional Sequence Complexity requires this added programming dimension of uncoerced selection at successive decision nodes in the string. Shannon information theory measures the relative degrees of RSC and OSC. Shannon information theory cannot measure FSC. FSC is invariably associated with all forms of complex biofunction, including biochemical pathways, cycles, positive and negative feedback regulation, and homeostatic metabolism. The algorithmic programming of FSC, not merely its aperiodicity, accounts for biological organization. No empirical evidence exists of either RSC of OSC ever having produced a single instance of sophisticated biological organization. Organization invariably manifests FSC rather than successive random events (RSC) or low-informational self-ordering phenomena (OSC). PMID:16095527

  16. Structural and energetic characteristics of silicas modified by organosilicon compounds.

    PubMed

    Gun'ko, V M; Sheeran, D J; Augustine, S M; Blitz, J P

    2002-05-01

    Silica gels Davisil 633 and 643, and fumed silica Cab-O-Sil HS-5 with grafted 3-aminopropyl dimethylsilyl (APDMS), butyl dimethylsilyl (BDMS), octadecyl dimethylsilyl (ODDMS), and trimethylsilyl (TMS) groups of different concentrations were studied using the nitrogen adsorption method. Changes in the textural and energetic characteristics of modified silicas depend on features of the oxide matrices and grafted OSC. PMID:16290577

  17. 5 CFR 1820.2 - Requirements for making FOIA requests.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 3 2012-01-01 2012-01-01 false Requirements for making FOIA requests... REQUESTS; PRODUCTION OF RECORDS OR TESTIMONY § 1820.2 Requirements for making FOIA requests. (a) How made and addressed. A request for OSC records under the FOIA should be made by writing to the agency....

  18. 5 CFR 1820.2 - Requirements for making FOIA requests.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 3 2011-01-01 2011-01-01 false Requirements for making FOIA requests... REQUESTS; PRODUCTION OF RECORDS OR TESTIMONY § 1820.2 Requirements for making FOIA requests. (a) How made and addressed. A request for OSC records under the FOIA should be made by writing to the agency....

  19. 5 CFR 1820.7 - Fees.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 3 2011-01-01 2011-01-01 false Fees. 1820.7 Section 1820.7 Administrative Personnel OFFICE OF SPECIAL COUNSEL FREEDOM OF INFORMATION ACT REQUESTS; PRODUCTION OF RECORDS OR TESTIMONY § 1820.7 Fees. (a) In general. OSC shall charge for processing requests under the FOIA in accordance with paragraph (c) of this...

  20. 5 CFR 1820.5 - Responses to requests.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 3 2014-01-01 2014-01-01 false Responses to requests. 1820.5 Section 1820.5 Administrative Personnel OFFICE OF SPECIAL COUNSEL FREEDOM OF INFORMATION ACT REQUESTS; PRODUCTION OF RECORDS OR TESTIMONY § 1820.5 Responses to requests. (a) General. Ordinarily, OSC shall have...

  1. 5 CFR 1820.2 - Requirements for making FOIA requests.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ..., both the request letter and envelope or any fax cover sheet should be clearly marked “FOIA Request.” Whether sent by mail or by fax, a FOIA request will not be considered to have been received by OSC...

  2. 5 CFR 1820.2 - Requirements for making FOIA requests.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ..., both the request letter and envelope or any fax cover sheet should be clearly marked “FOIA Request.” Whether sent by mail or by fax, a FOIA request will not be considered to have been received by OSC...

  3. 5 CFR 1820.2 - Requirements for making FOIA requests.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., both the request letter and envelope or any fax cover sheet should be clearly marked “FOIA Request.” Whether sent by mail or by fax, a FOIA request will not be considered to have been received by OSC...

  4. 32 CFR 145.6 - Procedures.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... agency (other than the DLA) shall be forwarded to the IG, DoD. (2) Allegations of improper or illegal... IG, DoD, or the GC of the Component concerned, as appropriate, shall ensure compliance with the Civil...) shall be forwarded by the General Counsel concerned to the IG, DoD. (b) OSC Investigations of...

  5. 77 FR 19322 - Daniel B. Brubaker, D.O.; Decision and Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-30

    ... California, where marijuana may legally be prescribed for medical purposes, a doctor must first establish a... medical purpose and with ``extreme deviations from the standard of care.'' The OSC further alleges that... toxicology results revealed the presence of the controlled substances marijuana, modafinil, oxazepam...

  6. 40 CFR 300.120 - On-scene coordinators and remedial project managers: general responsibilities.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., and the CERCLA cost recovery activity. When a removal and remedial action occur at the same site, the... through design and remedial action and the CERCLA cost recovery activity. The OSC and RPM shall ensure... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SUPERFUND, EMERGENCY PLANNING, AND COMMUNITY RIGHT-TO-KNOW...

  7. Exploring the underperformance of male and minority ethnic medical students in first year clinical examinations.

    PubMed

    Woolf, Katherine; Haq, Inam; McManus, I Chris; Higham, Jenny; Dacre, Jane

    2008-12-01

    Evidence shows that medical students from Minority Ethnic (ME) backgrounds and male medical students underperform in undergraduate examinations. Our study confirmed these findings in first year clinical (year 3) medical students, and further explored this disparity in performance. We conducted a series of meta-analyses to measure the effects of sex and ethnic group on the written examination and Objective Structured Clinical Examination (OSCE) scores of three groups of year 3 medical students at two London UK medical schools (n = 1,051; 46.0% male; 48.7% White). Male and ME students scored lower on written and OSCE assessments. Both assessments were statistically significantly correlated (mean r = 0.45) and therefore the effects of sex and ethnic group were measured on each exam after being adjusted for the effect of the other. Although sex and ethnic differences remained on the OSCE when adjusted for written performance, these differences disappeared on the written when it was adjusted for OSCE performance. These findings may reflect a relative deficit in practical clinical knowledge in male and ME year 3 students. Results were unlikely to be due to examiner bias, as the machine-marked unadjusted written exam results showed significant sex and ethnic differences. PMID:17487565

  8. Alkaline earth metal doped tin oxide as a novel oxygen storage material

    SciTech Connect

    Dong, Qiang; Yin, Shu; Yoshida, Mizuki; Wu, Xiaoyong; Liu, Bin; Miura, Akira; Takei, Takahiro; Kumada, Nobuhiro; Sato, Tsugio

    2015-09-15

    Alkaline earth metal doped tin oxide (SnO{sub 2}) hollow nanospheres with a diameter of 50 nm have been synthesized successfully via a facial solvothermal route in a very simple system composed of only ethanol, acetic acid, SnCl{sub 4}·5H{sub 2}O and A(NO{sub 3}){sub 2}·xH{sub 2}O (A = Mg, Ca, Sr, Ba). The synthesized undoped SnO{sub 2} and A-doped SnO{sub 2} hollow nanospheres were characterized by the oxygen storage capacity (OSC), X-ray diffraction, transmission electron microscopy and the Brunauer–Emmet–Teller (BET) technique. The OSC values of all samples were measured using thermogravimetric-differential thermal analysis. The incorporation of alkaline earth metal ion into tin oxide greatly enhanced the thermal stability and OSC. Especially, Ba-doped SnO{sub 2} hollow nanospheres calcined at 1000 °C for 20 h with a BET surface area of 61 m{sup 2} g{sup −1} exhibited the considerably high OSC of 457 μmol-O g{sup −1} and good thermal stability. Alkaline earth metal doped tin oxide has the potential to be a novel oxygen storage material.

  9. 5 CFR 1800.1 - Filing complaints of prohibited personnel practices or other prohibited activities.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...: (800) 872-9855 (toll-free), or (202) 653-7188 (in the Washington, DC area); or (iii) Online, at: http://www.osc.gov (to print out and complete on paper, or to complete online). (5) A complainant can file...

  10. 32 CFR 145.4 - Policy.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... CFR 1250, the Privacy Act, and Civil Service Rule V. (e) Close coordination between DoD and OSC... litigation, release of information shall be accomplished pursuant to MSPB rules of discovery (5 CFR 1201... responsibility of each DoD management official to take vigorous corrective action and, when appropriate,...

  11. 32 CFR 145.4 - Policy.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... CFR 1250, the Privacy Act, and Civil Service Rule V. (e) Close coordination between DoD and OSC... litigation, release of information shall be accomplished pursuant to MSPB rules of discovery (5 CFR 1201... responsibility of each DoD management official to take vigorous corrective action and, when appropriate,...

  12. 32 CFR 145.4 - Policy.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... CFR 1250, the Privacy Act, and Civil Service Rule V. (e) Close coordination between DoD and OSC... litigation, release of information shall be accomplished pursuant to MSPB rules of discovery (5 CFR 1201... responsibility of each DoD management official to take vigorous corrective action and, when appropriate,...

  13. Efficient and ultraviolet durable inverted organic solar cells based on an aluminum-doped zinc oxide transparent cathode

    NASA Astrophysics Data System (ADS)

    Liu, Hanxiao; Wu, Zhenghui; Hu, Jianqiao; Song, Qunliang; Wu, Bo; Lam Tam, Hoi; Yang, Qingyi; Hong Choi, Wing; Zhu, Furong

    2013-07-01

    High performance inverted bulk heterojunction organic solar cells (OSCs), based on the blend of poly[[4,8-bis[(2-ethylhexyl)oxy] benzo [1,2-b:4,5-b'] dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl

  14. Students' Reactions to Three Typical Examinations in Health Sciences

    ERIC Educational Resources Information Center

    Sarid, Orly; Anson, Ofra; Bentov, Yaakov

    2005-01-01

    Objective: A search for universal and particular changes in emotional, behavioral and cognitive assessments in relation to three types of examinations: an oral presentation, an objective structured clinical examination (OSCE) and a pencil and paper examination. Methods: One hundred and two students of health professions completed the Profile of…

  15. Time domain reflectometry waveform analysis with second order bounded mean oscillation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tangent-line methods and adaptive waveform interpretation with Gaussian filtering (AWIGF) have been proposed for determining reflection positions of time domain reflectometry (TDR) waveforms. However, the accuracy of those methods is limited for short probe TDR sensors. Second order bounded mean osc...

  16. Inverted Ultrathin Organic Solar Cells with a Quasi-Grating Structure for Efficient Carrier Collection and Dip-less Visible Optical Absorption

    NASA Astrophysics Data System (ADS)

    in, Sungjun; Park, Namkyoo

    2016-02-01

    We propose a metallic-particle-based two-dimensional quasi-grating structure for application to an organic solar cell. With the use of oblate spheroidal nanoparticles in contact with an anode of inverted, ultrathin organic solar cells (OSCs), the quasi-grating structure offers strong hybridization between localized surface plasmons and plasmonic gap modes leading to broadband (300~800 nm) and uniform (average ~90%) optical absorption spectra. Both strong optical enhancement in extreme confinement within the active layer (90 nm) and improved hole collection are thus realized. A coupled optical-electrical multi-physics optimization shows a large (~33%) enhancement in the optical absorption (corresponding to an absorption efficiency of ~47%, AM1.5G weighted, visible) when compared to a control OSC without the quasi-grating structure. That translates into a significant electrical performance gain of ~22% in short circuit current and ~15% in the power conversion efficiency (PCE), leading to an energy conversion efficiency (~6%) which is comparable to that of optically-thick inverted OSCs (3-7%). Detailed analysis on the influences of mode hybridization to optical field distributions, exciton generation rate, charge carrier collection efficiency and electrical conversion efficiency is provided, to offer an integrated understanding on the coupled optical-electrical optimization of ultrathin OSCs.

  17. The correlation of student performance in preclinical and clinical prosthodontic assessments.

    PubMed

    Curtis, Donald A; Lind, Samuel L; Brear, Sheila; Finzen, Frederick C

    2007-03-01

    Tracking student performance in preclinical and clinical courses can be helpful in developing and refining a curriculum. Our objective was to correlate student performance on three fixed prosthodontic examinations taken by eighty junior dental students. Examinations included a knowledge-based objective structured clinical examination (OSCE), a manual skills exercise completed on a typodont (Typodont), and a competency casting exam (Casting CE) on a patient. Multiple regression analysis indicated that the OSCE and Typodont exam scores, as independent variables, were not statistically significant predictors (P=0.07; P=0.87, respectively) of Casting CE exam performance, which was the dependent variable. Correlations were weak for the OSCE (r=0.21) and nearly nonexistent for the Typodont exam(r=0.03) when compared to the Casting CE. Our results indicate a weak correlation between an OSCE-based knowledge exam measuring students' knowledge of critical errors in preparations and castings and a competency exam involving the preparation of a full veneer crown. Results also indicate virtually no correlation between a typodont preparation examination designed to provide a measure of students' clinical skill and a clinical competency exam involving the preparation of a full crown. PMID:17389571

  18. Scholarly Communication: ARL as a Catalyst for Change

    ERIC Educational Resources Information Center

    Case, Mary M.

    2009-01-01

    With the creation of the Office of Scholarly Communication (OSC) in 1990, the Association of Research Libraries (ARL) launched an initiative to focus widespread attention on the dysfunctions in the scholarly publishing system. Through the collection and dissemination of data documenting the serials crisis, a bias for action that led to the…

  19. 40 CFR 300.155 - Public information and community relations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 29 2013-07-01 2013-07-01 false Public information and community... responsible party. (b) An on-scene news office may be established to coordinate media relations and to issue... the lead agency. The OSC/RPM determines the location of the on-scene news office, but every...

  20. Solution processable organic polymers and small molecules for bulk-heterojunction solar cells: A review

    SciTech Connect

    Sharma, G. D.

    2011-10-20

    Solution processed bulk heterojunction (BHJ) organic solar cells (OSCs) have gained wide interest in past few years and are established as one of the leading next generation photovoltaic technologies for low cost power production. Power conversion efficiencies up to 6% and 6.5% have been reported in the literature for single layer and tandem solar cells, respectively using conjugated polymers. A recent record efficiency about 8.13% with active area of 1.13 cm{sup 2} has been reported. However Solution processable small molecules have been widely applied for photovoltaic (PV) devices in recent years because they show strong absorption properties, and they can be easily purified and deposited onto flexible substrates at low cost. Introducing different donor and acceptor groups to construct donor--acceptor (D--A) structure small molecules has proved to be an efficient way to improve the properties of organic solar cells (OSCs). The power conversion efficiency about 4.4 % has been reported for OSCs based on the small molecules. This review deals with the recent progress of solution processable D--A structure small molecules and discusses the key factors affecting the properties of OSCs based on D--A structure small molecules: sunlight absorption, charge transport and the energy level of the molecules.

  1. CHARACTERIZING SOILS FOR HAZAROUDS WASTE SITE ASSESSMENTS

    EPA Science Inventory

    The purpose of this paper is to provide guidance to Remedial Project Managers (RPM) and On-Scene Coordinators (OSC) concerning soil characterization data types required for decision-making in the CERCLA RI/FS process related to risk assessment and remedial alternative evaluation ...

  2. Mainstreaming Open Textbooks: Educator Perspectives on the Impact of OpenStax College Open Textbooks

    ERIC Educational Resources Information Center

    Pitt, Rebecca

    2015-01-01

    This paper presents the results of collaborative research between open textbook provider OpenStax College (OSC) and the OER Research Hub (OERRH), a Hewlett funded mixed methods open research project examining the impact of open educational resources (OER) on learning and teaching. The paper focuses primarily on the results of two surveys that were…

  3. Characterization of sulfur and nitrogen compounds in Brazilian petroleum derivatives using ionic liquid capillary columns in comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometric detection.

    PubMed

    Cappelli Fontanive, Fernando; Souza-Silva, Érica Aparecida; Macedo da Silva, Juliana; Bastos Caramão, Elina; Alcaraz Zini, Claudia

    2016-08-26

    Diesel and naphtha samples were analyzed using ionic liquid (IL) columns to evaluate the best column set for the investigation of organic sulfur compounds (OSC) and nitrogen(N)-containing compounds analyses with comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry detector (GC×GC/TOFMS). Employing a series of stationary phase sets, namely DB-5MS/DB-17, DB-17/DB-5MS, DB-5MS/IL-59, and IL-59/DB-5MS, the following parameters were systematically evaluated: number of tentatively identified OSC, 2D chromatographic space occupation, number of polyaromatic hydrocarbons (PAH) and OSC co-elutions, and percentage of asymmetric peaks. DB-5MS/IL-59 was chosen for OSC analysis, while IL59/DB-5MS was chosen for nitrogen compounds, as each stationary phase set provided the best chromatographic efficiency for these two classes of compounds, respectively. Most compounds were tentatively identified by Lee and Van den Dool and Kratz retention indexes, and spectra-matching to library. Whenever available, compounds were also positively identified via injection of authentic standards. PMID:27488721

  4. 32 CFR Appendix to Part 145 - Legal Representation

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 1 2011-07-01 2011-07-01 false Legal Representation Appendix to Part 145... Part 145—Legal Representation 1. An employee or member of the Armed Forces asked to provide information (testimonial or documentary) to the OSC in the course of an investigation by that office may obtain...

  5. Correlating high power conversion efficiency of PTB7:PC71BM inverted organic solar cells with nanoscale structures.

    PubMed

    Das, Sanjib; Keum, Jong K; Browning, James F; Gu, Gong; Yang, Bin; Dyck, Ondrej; Do, Changwoo; Chen, Wei; Chen, Jihua; Ivanov, Ilia N; Hong, Kunlun; Rondinone, Adam J; Joshi, Pooran C; Geohegan, David B; Duscher, Gerd; Xiao, Kai

    2015-10-14

    Advances in material design and device engineering led to inverted organic solar cells (i-OSCs) with superior power conversion efficiencies (PCEs) compared to their "conventional" counterparts, in addition to the well-known better ambient stability. Here, we report an in-depth morphology study of the i-OSC active and cathode modifying layers, employing a model system with a well-established bulk-heterojunction, PTB7:PC71BM as the active layer and poly-[(9,9-bis(3'-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)] (PFN) as the cathode surface modifying layer. We have also identified the role of a processing additive, 1,8-diiodooctane (DIO), used in the spin-casting of the active layer to increase PCE. Using various characterization techniques, we demonstrate that the high PCEs of i-OSCs are due to the diffusion of electron-accepting PC71BM into the PFN layer, resulting in improved electron transport. The diffusion occurs when residual solvent molecules in the spun-cast film act as a plasticizer. Addition of DIO to the casting solution results in more PC71BM diffusion and therefore more efficient electron transport. This work provides important insight and guidance to further enhancement of i-OSC performance by materials and interface engineering. PMID:26220775

  6. Construct Validity of Three Clerkship Performance Assessments

    ERIC Educational Resources Information Center

    Lee, Ming; Wimmers, Paul F.

    2010-01-01

    This study examined construct validity of three commonly used clerkship performance assessments: preceptors' evaluations, OSCE-type clinical performance measures, and the NBME [National Board of Medical Examiners] medicine subject examination. Six hundred and eighty-six students taking the inpatient medicine clerkship from 2003 to 2007…

  7. Simple Calculation of Power Conversion Efficiency of PC61BM and PC71 BM Based Organic Solar Cells--Good Agreement with Experiments in Donor Materials with Different Band Gap Energies.

    PubMed

    Otsura, Takanori; Nakatsuka, Emi; Nagase, Takashi; Kobayashi, Takashi; Naito, Hiroyoshi

    2016-04-01

    The power conversion efficiencies (PCEs) as a function of band gap energies and the lowest unoccupied molecular orbital (LUMO) levels of donor materials are studied in bulk-heterojunction organic solar cells (OSCs) fabricated from donor materials and fullerene acceptors. The PCEs of [6,6]-pheynl-C61-butyric acid methyl ester (PC61BM) and [6,6]-pheynl-C71-butyric acid methyl ester (PC71 BM) based OSCs blended with donor materials under the Air Mass 1.5 (AM1.5) spectrum are calculated. In the calculation, the short circuit current densities are determined by band gap energies of donor materials and the open circuit voltages are derived from the difference between the highest occupied molecular orbital (HOMO) levels of donor materials and LUMO levels of PC61BM and PC71 BM. The calculation is in good agreement with the experiments. The PCEs under a fluorescent lamp are also calculated. The calculated PCEs of PC71 BM based OSCs under a fluorescent lamp are higher than those under the AM1.5 spectrum by a factor of 2. The PCEs of thieno [3,4-b] thiophene and benzodithiophene (PTB7):PC71BM based OSCs are studied under the AM1.5 spectrum and a fluorescent lamp spectrum and are consistent with the calculation. PMID:27451630

  8. Transmission Techniques For Vamos GSM In Downlink

    NASA Astrophysics Data System (ADS)

    Enache, Bianca

    2015-07-01

    In this paper is presented a study of the transmission techniques for Vamos GSM. Are presented the advantages and disadvantages. The study was performed for the second generation:GSM(Global System for Mobile Communications). In order to observe the performance of the BTS equipment was performed a study of the DARP (Downlink Advanced Receiver Performance) techniques and OSC(Orthogonal Sub Channel) influence.

  9. Sub-nanometer resolution of an organic semiconductor crystal surface using friction force microscopy in water.

    PubMed

    Pimentel, Carlos; Varghese, Shinto; Yoon, Seong-Jun; Park, Soo Young; Gierschner, Johannes; Gnecco, Enrico; Pina, Carlos M

    2016-04-01

    Organic semiconductors (OSC) are attracting much interest for (opto)electronic applications, such as photovoltaics, LEDs, sensors or solid state lasers. In particular, crystals formed by small π-conjugated molecules have shown to be suitable for constructing OSC devices. However, the (opto)electronic properties are complex since they depend strongly on both the mutual orientation of molecules as well as the perfection of bulk crystal surfaces. Hence, there is an urgent need to control nano-topographic OSC features in real space. Here we show that friction force microscopy in water is a very suitable technique to image the free surface morphology of an OSC single crystal (TDDCS) with sub-nanometer resolution. We demonstrate the power of the method by direct correlation to the structural information extracted from combined single crystal (SC-) and specular (s-) XRD studies, which allows us to identify the pinning centers encountered in the stick-slip motion of the probing tip with the topmost methyl groups on the TDDCS surface. PMID:26931487

  10. Organization and Management of Non-Profit Private Higher Education in a Multi-Ethnic and Multi-Lingual Environment

    ERIC Educational Resources Information Center

    Farrington, Dennis; Abazi, Alajdin

    2009-01-01

    The South East European University (SEEU) was founded in 2001 as a non-profit university established by co-operation between OSCE, USAID, the European Commission and the Government of the Republic of Macedonia (or FYROM) as a contribution towards conflict prevention. There has been a gradual transition from a centrally managed project to a modern…

  11. 5 CFR 1820.5 - Responses to requests.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Responses to requests. 1820.5 Section 1820.5 Administrative Personnel OFFICE OF SPECIAL COUNSEL FREEDOM OF INFORMATION ACT REQUESTS; PRODUCTION OF RECORDS OR TESTIMONY § 1820.5 Responses to requests. (a) General. Ordinarily, OSC shall have...

  12. Thin air-plasma-treated alkali fluoride layers for improved hole extraction in copper phthalocyanine/C70-based solar cells

    SciTech Connect

    Xiao, Teng; Cui, Weipan; Cai, Min; Liu, Rui; Anderegg, James W.; Shinar, Joseph; Shinar, Ruth

    2012-03-12

    Alkali fluorides, mostly LiF and CsF, are well-known to improve electron injection/extraction in organic light-emitting diodes (OLEDs) and organic solar cells (OSCs). They are also utilized, though to a lesser extent, for hole injection in OLEDs. Here we demonstrate a new role for such fluorides in enhancing OSCs’ hole extraction.We show that an ultrathin air-plasmatreated alkali fluoride layer between the indium tin oxide (ITO) anode and the active layer in copper phthalocyanine ðCuPcÞ∕C70-based OSCs increases the short circuit current by up to ∼17% for cells with LiF and ∼7% for cells with NaF or CsF. The effects of the fluoride layer thickness and treatment duration were evaluated, as were OSCs with oxidized and plasma-treated Li and UV-ozone treated LiF. Measurements included current voltage, absorption, external quantum efficiency (EQE), atomic force microscopy, and x-ray photoelectron spectroscopy, which showed the presence of alkali atoms F and O at the treated ITO/fluoride surface. The EQE of optimized devices with LiF increased at wavelengths >560 nm, exceeding the absorption increase. Overall, the results indicate that the improved performance is due largely to enhanced hole extraction, possibly related to improved energy-level alignment at the fluorinated ITO/CuPc interface, reduced OSC series resistance, and in the case of LiF, improved absorption.

  13. Rational design of multifunctional star-shaped molecules with a 1,3,5-triazine core and different arms for application in organic light-emitting diodes and organic solar cells.

    PubMed

    Jin, Ruifa

    2015-08-01

    A series of star-shaped 1,3,5-triazine derivatives for intended application in organic light-emitting diodes (OLEDs) and organic solar cells (OSCs) were investigated theoretically to explore their optical, electronic, and charge-transport properties. Analysis of their frontier molecular orbitals (FMOs) indicated that vertical electronic transitions associated with absorption and emission by these derivatives can be characterized as intramolecular charge-transfer (ICT) processes. The calculated results show that the optical, electronic, and charge-transport properties of the derivatives are influenced by the end groups and π-bridges present. Our results suggest that the molecules under investigation could serve as donor materials in OSCs and/or luminescent materials in OLEDs. In addition, all of the molecules are expected to be promising candidates for hole- and electron-transport materials. Based on our results, we were able to propose a rational method of designing multifunctional materials for application in OLEDs and OSCs. Graphical abstract A series of multifunctional star-shaped small molecules were investigated as charge-transport and luminescent materials for OLEDs as well as charge-transport and donor materials for OSCs. PMID:26232184

  14. Do quality indicators for general practice teaching practices predict good outcomes for students?

    PubMed

    Bartlett, Maggie; Potts, Jessica; McKinley, Bob

    2016-07-01

    Keele medical students spend 113 days in general practices over our five-year programme. We collect practice data thought to indicate good quality teaching. We explored the relationships between these data and two outcomes for students; Objective Structured Clinical Examination (OSCE) scores and feedback regarding the placements. Though both are surrogate markers of good teaching, they are widely used. We collated practice and outcome data for one academic year. Two separate statistical analyses were carried out: (1) to determine how much of the variation seen in the OSCE scores was due to the effect of the practice and how much to the individual student. (2) to identify practice characteristics with a relationship to student feedback scores. (1) OSCE performance: 268 students in 90 practices: six quality indicators independently influenced the OSCE score, though without linear relationships and not to statistical significance. (2) Student satisfaction: 144 students in 69 practices: student feedback scores are not influenced by practice characteristics. The relationships between the quality indicators we collect for practices and outcomes for students are not clear. It may be that neither the quality indicators nor the outcome measures are reliable enough to inform decisions about practices' suitability for teaching. PMID:27117344

  15. Incorporating Active Learning into a Psychiatry Clerkship: Does It Make a Difference?

    ERIC Educational Resources Information Center

    Morreale, Mary; Arfken, Cynthia; Bridge, Patrick; Balon, Richard

    2012-01-01

    Objective: Medical students' satisfaction with the psychiatry clerkship, sense of preparedness for an institutional Objective Structured Clinical Exam (OSCE), expressed likelihood of choosing psychiatry as a specialty, and National Board of Medical Examiners (NBME) psychiatry shelf-examination scores were compared after a curriculum based on…

  16. 43 CFR 11.23 - Preassessment screen-general.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... or OSC Report, unless doing so would unnecessarily delay the preassessment screen. (3) Where a... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Preassessment screen-general. 11.23... ASSESSMENTS Preassessment Phase § 11.23 Preassessment screen—general. (a) Requirement. Before beginning...

  17. 43 CFR 11.23 - Preassessment screen-general.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... or OSC Report, unless doing so would unnecessarily delay the preassessment screen. (3) Where a... 43 Public Lands: Interior 1 2011-10-01 2011-10-01 false Preassessment screen-general. 11.23... ASSESSMENTS Preassessment Phase § 11.23 Preassessment screen—general. (a) Requirement. Before beginning...

  18. 77 FR 36328 - Agency Information Collection Activities; Request for Comment

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-18

    ... these forms was published in the Federal Register on April 16, 2012 at 77 FR 22614 and on May 15, 2012 at 77 FR 28638. DATES: Comments should be received on or before July 26, 2012. ADDRESSES: Comments... Notice at 78 FR 24242 (April 23, 2012). The Consent Statement for Form OSC-12 is also revised....

  19. Emulsion-Based RIR-MAPLE Deposition of Conjugated Polymers: Primary Solvent Effect and Its Implications on Organic Solar Cell Performance.

    PubMed

    Ge, Wangyao; Li, Nan K; McCormick, Ryan D; Lichtenberg, Eli; Yingling, Yaroslava G; Stiff-Roberts, Adrienne D

    2016-08-01

    Emulsion-based, resonant infrared matrix-assisted pulsed laser evaporation (RIR-MAPLE) has been demonstrated as an alternative technique to deposit conjugated polymer films for photovoltaic applications; yet, a fundamental understanding of how the emulsion target characteristics translate into film properties and solar cell performance is unclear. Such understanding is crucial to enable the rational improvement of organic solar cell (OSC) efficiency and to realize the expected advantages of emulsion-based RIR-MAPLE for OSC fabrication. In this paper, the effect of the primary solvent used in the emulsion target is studied, both experimentally and theoretically, and it is found to determine the conjugated polymer cluster size in the emulsion as well as surface roughness and internal morphology of resulting polymer films. By using a primary solvent with low solubility-in-water and low vapor pressure, the surface roughness of deposited P3HT and PCPDTBT polymer films was reduced to 10 nm, and the efficiency of P3HT:PC61BM OSCs was increased to 3.2% (∼100 times higher compared to the first MAPLE OSC demonstration [ Caricato , A. P. ; Appl. Phys. Lett. 2012 , 100 , 073306 ]). This work unveils the mechanism of polymer film formation using emulsion-based RIR-MAPLE and provides insight and direction to determine the best ways to take advantage of the emulsion target approach to control film properties for different applications. PMID:27414167

  20. 33 CFR 154.T150 - Temporary suspension of requirements to permit support of deepwater horizon spill response.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... CFR 300.5, in support of the response to the Deepwater Horizon Spill of National Significance. (b... described in § 154.100 of this part, that has contracted with any oil spill removal organization (OSRO), as... part, are deployed in coordination with the On-Scene Coordinator (OSC), as defined in 40 CFR 300.5,...

  1. Adapting Objective Structured Clinical Examinations to Assess Social Work Students' Performance and Reflections

    ERIC Educational Resources Information Center

    Bogo, Marion; Regehr, Cheryl; Logie, Carmen; Katz, Ellen; Mylopoulos, Maria; Regehr, Glenn

    2011-01-01

    The development of standardized, valid, and reliable methods for assessment of students' practice competence continues to be a challenge for social work educators. In this study, the Objective Structured Clinical Examination (OSCE), originally used in medicine to assess performance through simulated interviews, was adapted for social work to…

  2. Role of the Charge-Transfer State in Reduced Langevin Recombination in Organic Solar Cells: A Theoretical Study

    PubMed Central

    2015-01-01

    Reduced Langevin recombination has been observed in organic solar cells (OSCs) for many years, but its origin is still unclear. A recent work by Burke et al. (Adv. Energy Mater.2015, 5, 1500123-1) was inspired by this reduced Langevin recombination, and they proposed an equilibrium model of charge-transfer (CT) states that correlates the open-circuit voltage of OSCs with experimentally available device parameters. In this work, we extend Burke et al.’s CT model further and for the first time directly correlate the reduced Langevin recombination with the energetic and dynamic behavior of the CT state. Recombination through CT states leads in a straightforward manner to a decrease in the Langevin reduction factor with increasing temperature, without explicit consideration of the temperature dependence of the mobility. To verify the correlation between the CT states and reduced Langevin recombination, we incorporated this CT model and the reduced Langevin model into drift-diffusion simulations of a bilayer OSC. The simulations not only successfully reproduced realistic current–voltage (J–V) characteristics of the bilayer OSC, but also demonstrate that the two models consistently lead to same value of the apparent Langevin reduction factor. PMID:26640611

  3. Control of Subsurface Contaminant Migration by Vertical Engineered Barriers

    EPA Science Inventory

    This Fact Sheet is intended to provide remedial project managers (RPMs), on-scene coordinators (OSCs), contractors, and other remediation stakeholders with a basic overview of hazardous waste containment systems constructed to prevent or limit the migration of contamination in gr...

  4. How do students with dyslexia perform in extended matching questions, short answer questions and observed structured clinical examinations?

    PubMed

    Gibson, Sandra; Leinster, Samuel

    2011-08-01

    There are an increasing number of students with learning difficulties attending university, and currently much debate about the suitability and ability of students with dyslexia at both medical school and once they graduate into clinical practice. In this study we describe the performance of students with dyslexia compared to fellow students in extended matching questions (EMQ), short answer question (SAQ) and observed structured clinical examinations (OSCE) and discuss the implications of differences identified. End of year assessment results for 5 cohorts of medical students were analysed. Students with dyslexia did less well overall in all assessment types in year 1 but this difference was not evident in later years. Dyslexic students who were allowed extra time in written assessments did better than dyslexic students who did not have their assessment concessions in place. When station type within OSCE assessments was analysed students with dyslexia did less well in both examination skills and data interpretation stations in years 1, 2 & 3. In conclusion, differences in performance in written assessments are only evident early in training and may be partly due to delayed adjustment to medical school or implementation of assessment concessions. Performance in individual OSCE stations is dependent on station type. Why students with specific learning difficulties (SpLDs) perform less well in examination skills and data analysis OSCE stations requires further investigation. PMID:21249518

  5. The male phenotype in osteopathia striata congenita with cranial sclerosis.

    PubMed

    Holman, Sarah K; Daniel, Phil; Jenkins, Zandra A; Herron, Rachel L; Morgan, Tim; Savarirayan, Ravi; Chow, C W; Bohring, Axel; Mosel, Annette; Lacombe, Didier; Steiner, Bernhard; Schmitt-Mechelke, Thomas; Schroter, Barbara; Raas-Rothschild, Annick; Miñaur, Sixto Garcia; Porteous, Mary; Parker, Michael; Quarrell, Oliver; Tapon, Dagmar; Cormier-Daire, Valérie; Mansour, Sahar; Nash, Ruth; Bindoff, Laurence A; Fiskerstrand, Torunn; Robertson, Stephen P

    2011-10-01

    Osteopathia striata with cranial sclerosis (OSCS) is an X-linked disease caused by truncating mutations in WTX. Females exhibit sclerotic striations on the long bones, cranial sclerosis, and craniofacial dysmorphism. Males with OSCS have significant skeletal sclerosis, do not have striations but do display a more severe phenotype commonly associated with gross structural malformations, patterning defects, and significant pre- and postnatal lethality. The recent description of mutations in WTX underlying OSCS has led to the identification of a milder, survivable phenotype in males. Individuals with this presentation can have, in addition to skeletal sclerosis, Hirschsprung disease, joint contractures, cardiomyopathy, and neuromuscular anomalies. A diagnosis of OSCS should be considered in males with macrocephaly, skeletal sclerosis that is most marked in the cranium and the absence of metaphyseal striations. The observation of striations in males may be indicative of a WTX mutation in a mosaic state supporting the contention that this sign in females is indicative of the differential lyonization of cells in the osteoblastic lineage. PMID:22043478

  6. Development of a Content-Valid Standardized Orthopedic Assessment Tool (SOAT)

    ERIC Educational Resources Information Center

    Lafave, Mark; Katz, Larry; Butterwick, Dale

    2008-01-01

    Content validation of an instrument that measures student performance in OSCE-type practical examinations is a critical step in a tool's overall validity and reliability [Hopkins (1998), "Educational and Psychological Measurement and Evaluation" (8th ed.). Toronto: Allyn & Bacon]. The purpose of the paper is to outline the process employed to…

  7. Development, Impact, and Measurement of Enhanced Physical Diagnosis Skills

    ERIC Educational Resources Information Center

    Smith, Miriam A.; Burton, William B.; Mackay, Meggan

    2009-01-01

    Evidence suggests that the quality and frequency of bedside clinical examination have declined. We undertook the study to (1) determine whether intensive instruction in physical examination enhances medical student skills and (2) develop a tool to evaluate those skills using a modified observed structured clinical examination (OSCE). This was a…

  8. Optical scanning cryptography

    NASA Astrophysics Data System (ADS)

    Poon, Ting-Chung

    2004-01-01

    We introduce a technique called optical scanning cryptography (OSC). The technique can perform encryption on-the-fly using laser beams and can be implemented using an optical heterodyne scanning. We shall first describe the optical heterodyne scanning system and then provide some computer simulations to clarify and confirm the idea of encryption and decryption.

  9. Direct laser patterning of transparent ITO-Ag-ITO multilayer anodes for organic solar cells

    NASA Astrophysics Data System (ADS)

    Kim, Hyo-Joong; Seo, Ki-Won; Kim, Yong Hyeon; Choi, Jiyeon; Kim, Han-Ki

    2015-02-01

    Direct laser patterning of transparent ITO-Ag-ITO (IAI) multilayer anodes is investigated using a femtosecond fiber laser for application in organic solar cells (OSC) fabrication. By adjusting laser fluence and scan speed, we successfully patterned the IAI multilayer anode without changing the electrical or optical properties. At an optimized laser fluence of 0.6 J/cm2 and a scan speed of 200 mm/s, the patterned IAI multilayer was electrically isolated with a clean edge. The metallic Ag interlayer of the IAI multilayer plays an important role in direct laser patterning because it absorbed the laser and increases the maximum temperature in the IAI multilayer. In addition, the Ag layer could effectively decrease the temperature of the IAI multilayer after irradiation of laser. The OSC fabricated on the laser patterned IAI multilayer showed power conversion efficiencies of 3.12% (Ag 8 nm) and 2.85% (Ag 12 nm). Successful operation of the OSC indicates that direct laser patterning of IAI multilayer anodes is a promising, simple patterning technology for fabrication of IAI-based OSCs.

  10. Continuous Practice-Based Research on the Use of Standardized Patients: Experience from Shanghai Medical College of Fudan University

    ERIC Educational Resources Information Center

    Zeng, Yong; Wu, Yan; Lai, Yanni; Lu, Yingqing; Zou, Hejian; Feng, Xueshan

    2014-01-01

    In the past ten years, the objective structured clinical examination (OSCE) project team of the Shanghai Medical College of Fudan University has continuously conducted further study on the development and maintenance of standardized patients and their application in teaching. The team carried out a series of randomized controlled studies on the…

  11. Preparation of flexible organic solar cells with highly conductive and transparent metal-oxide multilayer electrodes based on silver oxide.

    PubMed

    Yun, Jungheum; Wang, Wei; Bae, Tae Sung; Park, Yeon Hyun; Kang, Yong-Cheol; Kim, Dong-Ho; Lee, Sunghun; Lee, Gun-Hwan; Song, Myungkwan; Kang, Jae-Wook

    2013-10-23

    We report that significantly more transparent yet comparably conductive AgOx films, when compared to Ag films, are synthesized by the inclusion of a remarkably small amount of oxygen (i.e., 2 or 3 atom %) in thin Ag films. An 8 nm thick AgOx (O/Ag=2.4 atom %) film embedded between 30 nm thick ITO films (ITO/AgOx/ITO) achieves a transmittance improvement of 30% when compared to a conventional ITO/Ag/ITO electrode with the same configuration by retaining the sheet resistance in the range of 10-20 Ω sq(-1). The high transmittance provides an excellent opportunity to improve the power-conversion efficiency of organic solar cells (OSCs) by successfully matching the transmittance spectral range of the electrode to the optimal absorption region of low band gap photoactive polymers, which is highly limited in OSCs utilizing conventional ITO/Ag/ITO electrodes. An improvement of the power-conversion efficiency from 4.72 to 5.88% is achieved from highly flexible organic solar cells (OSCs) fabricated on poly(ethylene terephthalate) polymer substrates by replacing the conventional ITO/Ag/ITO electrode with the ITO/AgOx/ITO electrode. This novel transparent electrode can facilitate a cost-effective, high-throughput, room-temperature fabrication solution for producing large-area flexible OSCs on heat-sensitive polymer substrates with excellent power-conversion efficiencies. PMID:24060352

  12. Do Clinical Clerks Provide Candidates with Adequate Formative Assessment during Objective Structured Clinical Examinations?

    ERIC Educational Resources Information Center

    Reiter, Harold I.; Rosenfeld, Jack; Nandagopal, Kiruthiga; Eva, Kevin W.

    2004-01-01

    Context: Various research studies have examined the question of whether expert or non-expert raters, faculty or students, evaluators or standardized patients, give more reliable and valid summative assessments of performance on Objective Structured Clinical Examinations (OSCEs). Less studied has been the question of whether or not non-faculty…

  13. 5 CFR 1800.3 - Advisory opinions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 3 2013-01-01 2013-01-01 false Advisory opinions. 1800.3 Section 1800.3... opinions. The Special Counsel is authorized to issue advisory opinions only about political activity of..., subchapter III). A person can seek an advisory opinion from OSC by any of the following methods: (a) By...

  14. 5 CFR 1800.3 - Advisory opinions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 3 2012-01-01 2012-01-01 false Advisory opinions. 1800.3 Section 1800.3... opinions. The Special Counsel is authorized to issue advisory opinions only about political activity of..., subchapter III). A person can seek an advisory opinion from OSC by any of the following methods: (a) By...

  15. 5 CFR 1800.3 - Advisory opinions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 3 2011-01-01 2011-01-01 false Advisory opinions. 1800.3 Section 1800.3... opinions. The Special Counsel is authorized to issue advisory opinions only about political activity of..., subchapter III). A person can seek an advisory opinion from OSC by any of the following methods: (a) By...

  16. 5 CFR 1800.3 - Advisory opinions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Advisory opinions. 1800.3 Section 1800.3... opinions. The Special Counsel is authorized to issue advisory opinions only about political activity of..., subchapter III). A person can seek an advisory opinion from OSC by any of the following methods: (a) By...

  17. 5 CFR 1800.3 - Advisory opinions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 3 2014-01-01 2014-01-01 false Advisory opinions. 1800.3 Section 1800.3... opinions. The Special Counsel is authorized to issue advisory opinions only about political activity of..., subchapter III). A person can seek an advisory opinion from OSC by any of the following methods: (a) By...

  18. Glutathione-garlic sulfur conjugates: slow hydrogen sulfide releasing agents for therapeutic applications.

    PubMed

    Bhuiyan, Ashif Iqbal; Papajani, Vilma Toska; Paci, Maurizio; Melino, Sonia

    2015-01-01

    Natural organosulfur compounds (OSCs) from Allium sativum L. display antioxidant and chemo-sensitization properties, including the in vitro inhibition of tumor cell proliferation through the induction of apoptosis. Garlic water- and oil-soluble allyl sulfur compounds show distinct properties and the capability to inhibit the proliferation of tumor cells. In the present study, we optimized a new protocol for the extraction of water-soluble compounds from garlic at low temperatures and the production of glutathionyl-OSC conjugates during the extraction. Spontaneously, Cys/GSH-mixed-disulfide conjugates are produced by in vivo metabolism of OSCs and represent active molecules able to affect cellular metabolism. Water-soluble extracts, with (GSGaWS) or without (GaWS) glutathione conjugates, were here produced and tested for their ability to release hydrogen sulfide (H2S), also in the presence of reductants and of thiosulfate:cyanide sulfurtransferase (TST) enzyme. Thus, the TST catalysis of the H2S-release from garlic OSCs and their conjugates has been investigated by molecular in vitro experiments. The antiproliferative properties of these extracts on the human T-cell lymphoma cell line, HuT 78, were observed and related to histone hyperacetylation and downregulation of GAPDH expression. Altogether, the results presented here pave the way for the production of a GSGaWS as new, slowly-releasing hydrogen sulfide extract for potential therapeutic applications. PMID:25608858

  19. Theoretical Investigation of Donor-Acceptor Copolymers Based on C-, Si-, and Ge-Bridged Thieno[3,2-b]dithiophene for Organic Solar Cell Applications

    NASA Astrophysics Data System (ADS)

    Liu, Xiaorui; Huang, Chengzhi; Shen, Wei; He, Rongxing; Li, Ming

    2016-06-01

    The aim of this work is to modify the electron-donating block in donor-acceptor (D-A) copolymers to improve their electronic and photophysical properties for organic solar cell (OSC) applications. Based on the reported polymer PCPDTTTTz (Pa1), which includes electron-rich cyclopenta[2,1-b:3,4-b']dithiophene (CPDT), electron-withdrawing tetrazine, and bridge thiophene, we substituted CPDT with electron-rich dithienocyclopentadithiophene, dithienosiloledithiophene, and dithienogermolodithiophene to design three D-A copolymers (Pa2 to Pa4). The calculation results indicate that Pa3 and Pa4 show lower highest occupied molecular orbital (HOMO)/lowest unoccupied molecular orbital (LUMO) energy levels and larger open-circuit voltage (V oc) than Pa1. Polymers Pa2 to Pa4 exhibit better performance with stronger and wider optical absorption and good hole transport properties in comparison with Pa1. The predicted power conversion efficiencies for the designed polymers Pa2 to Pa4 in OSC applications are ˜5.7%, ˜5.9%, and 6.0%, respectively. These results clearly indicate that modifying the electron-donating block in D-A copolymers can effectively improve their electronic and photophysical properties and OSC performance. The designed polymers Pa2 to Pa4 may be promising donor candidates for OSC applications.

  20. Potentially traumatic experiences and sexual health among orphaned and separated adolescents in five low- and middle-income countries

    PubMed Central

    Gray, Christine L.; Whetten, Kathryn; Messer, Lynne C.; Whetten, Rachel A.; Ostermann, Jan; O'Donnell, Karen; Thielman, Nathan M.; Pence, Brian W.

    2016-01-01

    ABSTRACT Orphans and separated children (OSC) are a vulnerable population whose numbers are increasing, particularly in sub-Saharan Africa and Asia. Over 153 million children worldwide have lost one or both parents, including 17 million orphaned by AIDS, and millions more have been separated from their parents. As younger orphans enter adolescence, their sexual health and HIV-related risk behaviors become key considerations for their overall health. Importantly, their high prevalence of exposure to potentially traumatic events (PTEs) may put OSC at additional risk for adverse sexual health outcomes. The Positive Outcomes for Orphans study followed OSC randomly sampled from institution-based care and from family-based care, as well as a convenience sample of non-OSC, at six sites in five low-and middle-income countries. This analysis focused on the 90-month follow-up, during which adolescents 16 and older were assessed for sexual health, including age at sexual debut, past-year sex, past-year condom use, and perceptions of condom use. We specifically examined the relationship between PTEs and sexual health outcomes. Of the 1258 OSC and 138 non-OSC assessed, 11% reported ever having sex. Approximately 6% of participants reported recent sex and 5% reported having recent unprotected sex. However, 70% of those who had recent sex reported that they did not use a condom every time, and perceptions of condom use tended to be unfavorable for protection against sexual risk behavior. Nearly all (90%) of participants reported experiencing at least one lifetime PTE. For those who experienced “any” PTE, we found increased prevalence of recent sex (PR = 1.39 [0.47, 4.07]) and of recent unprotected sex (PR = 3.47 [0.60, 19.91]). This study highlights the need for caregivers, program managers, and policymakers to promote condom use for sexually active OSC and identify interventions for trauma support services. Orphans living in family-based care may also be particularly

  1. Potentially traumatic experiences and sexual health among orphaned and separated adolescents in five low- and middle-income countries.

    PubMed

    Gray, Christine L; Whetten, Kathryn; Messer, Lynne C; Whetten, Rachel A; Ostermann, Jan; O'Donnell, Karen; Thielman, Nathan M; Pence, Brian W

    2016-07-01

    Orphans and separated children (OSC) are a vulnerable population whose numbers are increasing, particularly in sub-Saharan Africa and Asia. Over 153 million children worldwide have lost one or both parents, including 17 million orphaned by AIDS, and millions more have been separated from their parents. As younger orphans enter adolescence, their sexual health and HIV-related risk behaviors become key considerations for their overall health. Importantly, their high prevalence of exposure to potentially traumatic events (PTEs) may put OSC at additional risk for adverse sexual health outcomes. The Positive Outcomes for Orphans study followed OSC randomly sampled from institution-based care and from family-based care, as well as a convenience sample of non-OSC, at six sites in five low-and middle-income countries. This analysis focused on the 90-month follow-up, during which adolescents 16 and older were assessed for sexual health, including age at sexual debut, past-year sex, past-year condom use, and perceptions of condom use. We specifically examined the relationship between PTEs and sexual health outcomes. Of the 1258 OSC and 138 non-OSC assessed, 11% reported ever having sex. Approximately 6% of participants reported recent sex and 5% reported having recent unprotected sex. However, 70% of those who had recent sex reported that they did not use a condom every time, and perceptions of condom use tended to be unfavorable for protection against sexual risk behavior. Nearly all (90%) of participants reported experiencing at least one lifetime PTE. For those who experienced "any" PTE, we found increased prevalence of recent sex (PR = 1.39 [0.47, 4.07]) and of recent unprotected sex (PR = 3.47 [0.60, 19.91]). This study highlights the need for caregivers, program managers, and policymakers to promote condom use for sexually active OSC and identify interventions for trauma support services. Orphans living in family-based care may also be particularly vulnerable

  2. Oligomer Molecules for Efficient Organic Photovoltaics.

    PubMed

    Lin, Yuze; Zhan, Xiaowei

    2016-02-16

    Solar cells, a renewable, clean energy technology that efficiently converts sunlight into electricity, are a promising long-term solution for energy and environmental problems caused by a mass of production and the use of fossil fuels. Solution-processed organic solar cells (OSCs) have attracted much attention in the past few years because of several advantages, including easy fabrication, low cost, lightweight, and flexibility. Now, OSCs exhibit power conversion efficiencies (PCEs) of over 10%. In the early stage of OSCs, vapor-deposited organic dye materials were first used in bilayer heterojunction devices in the 1980s, and then, solution-processed polymers were introduced in bulk heterojunction (BHJ) devices. Relative to polymers, vapor-deposited small molecules offer potential advantages, such as a defined molecular structure, definite molecular weight, easy purification, mass-scale production, and good batch-to-batch reproducibility. However, the limited solubility and high crystallinity of vapor-deposited small molecules are unfavorable for use in solution-processed BHJ OSCs. Conversely, polymers have good solution-processing and film-forming properties and are easily processed into flexible devices, whereas their polydispersity of molecular weights and difficulty in purification results in batch to batch variation, which may hamper performance reproducibility and commercialization. Oligomer molecules (OMs) are monodisperse big molecules with intermediate molecular weights (generally in the thousands), and their sizes are between those of small molecules (generally with molecular weights <1000) and polymers (generally with molecular weights >10000). OMs not only overcome shortcomings of both vapor-deposited small molecules and solution-processed polymers, but also combine their advantages, such as defined molecular structure, definite molecular weight, easy purification, mass-scale production, good batch-to-batch reproducibility, good solution processability

  3. Use of DEAD-box polypeptide-4 (Ddx4) gene promoter-driven fluorescent reporter mice to identify mitotically active germ cells in post-natal mouse ovaries.

    PubMed

    Park, Eun-Sil; Tilly, Jonathan L

    2015-01-01

    Several laboratories have independently isolated mitotically active germ cells, termed female germline stem cells or oogonial stem cells (OSCs), from adult mouse ovaries. However, a recent study using Ddx4-Cre;Rosa26 reporter mice concluded that such germ cells do not exist. Given the disparity in conclusions drawn in this study compared with others, we felt it was important to re-assess the utility of Ddx4-Cre;Rosa26 reporter mice for identification of OSCs in adult mouse ovaries. Transgenic Ddx4-Cre mice were crossed with Rosa26(tdTm/tdTm) mice to drive restricted tomato red (tdTm) gene expression in cells in which the Ddx4 gene promoter has been activated. Crude dispersion of ovaries from recombined offspring generated cell fractions containing tdTm-positive immature oocytes, which are incapable of proliferation and thus probably represent the uncharacterized reporter-positive ovarian cells identified in the paper Zhang et al. (2012) as being mitotically inactive. Dispersed ovaries further subjected to fluorescence-activated cell sorting yielded a large population of non-germline tdTm-positive cells, indicative of promoter 'leakiness' in the Ddx4-Cre mouse line. Nonetheless, a small percentage of these tdTm-positive cells exhibited externalized (extracellular, ec) expression of Ddx4 protein (ecDdx4-positive), expressed markers of primitive germ cells but not of oocytes, and actively proliferated in culture, all of which are characteristic features of OSCs. Thus, crude dispersion of ovaries collected from Ddx4 gene promoter-driven reporter mice is not, by itself, a reliable approach to identify OSCs, whereas the same ovarian dispersates further subjected to cell sorting strategies yield purified OSCs that can be expanded in culture. PMID:25147160

  4. Cloning and characterization of oxidosqualene cyclases from Kalanchoe daigremontiana: enzymes catalyzing up to 10 rearrangement steps yielding friedelin and other triterpenoids.

    PubMed

    Wang, Zhonghua; Yeats, Trevor; Han, Hong; Jetter, Reinhard

    2010-09-24

    The first committed step in triterpenoid biosynthesis is the cyclization of oxidosqualene to polycyclic alcohols or ketones C(30)H(50)O. It is catalyzed by single oxidosqualene cyclase (OSC) enzymes that can carry out varying numbers of carbocation rearrangements and, thus, generate triterpenoids with diverse carbon skeletons. OSCs from diverse plant species have been cloned and characterized, the large majority of them catalyzing relatively few rearrangement steps. It was recently predicted that special OSCs must exist that can form friedelin, the pentacyclic triterpenoid whose formation involves the maximum possible number of rearrangement steps. The goal of the present study, therefore, was to clone a friedelin synthase from Kalanchoe daigremontiana, a plant species known to accumulate this triterpenoid in its leaf surface waxes. Five OSC cDNAs were isolated, encoding proteins with 761-779 amino acids and sharing between 57.4 and 94.3% nucleotide sequence identity. Heterologous expression in yeast and GC-MS analyses showed that one of the OSCs generated the steroid cycloartenol together with minor side products, whereas the other four enzymes produced mixtures of pentacyclic triterpenoids dominated by lupeol (93%), taraxerol (60%), glutinol (66%), and friedelin (71%), respectively. The cycloartenol synthase was found expressed in all leaf tissues, whereas the lupeol, taraxerol, glutinol, and friedelin synthases were expressed only in the epidermis layers lining the upper and lower surfaces of the leaf blade. It is concluded that the function of these enzymes is to form respective triterpenoid aglycones destined to coat the leaf exterior, probably as defense compounds against pathogens or herbivores. PMID:20610397

  5. Cloning and Characterization of Oxidosqualene Cyclases from Kalanchoe daigremontiana

    PubMed Central

    Wang, Zhonghua; Yeats, Trevor; Han, Hong; Jetter, Reinhard

    2010-01-01

    The first committed step in triterpenoid biosynthesis is the cyclization of oxidosqualene to polycyclic alcohols or ketones C30H50O. It is catalyzed by single oxidosqualene cyclase (OSC) enzymes that can carry out varying numbers of carbocation rearrangements and, thus, generate triterpenoids with diverse carbon skeletons. OSCs from diverse plant species have been cloned and characterized, the large majority of them catalyzing relatively few rearrangement steps. It was recently predicted that special OSCs must exist that can form friedelin, the pentacyclic triterpenoid whose formation involves the maximum possible number of rearrangement steps. The goal of the present study, therefore, was to clone a friedelin synthase from Kalanchoe daigremontiana, a plant species known to accumulate this triterpenoid in its leaf surface waxes. Five OSC cDNAs were isolated, encoding proteins with 761–779 amino acids and sharing between 57.4 and 94.3% nucleotide sequence identity. Heterologous expression in yeast and GC-MS analyses showed that one of the OSCs generated the steroid cycloartenol together with minor side products, whereas the other four enzymes produced mixtures of pentacyclic triterpenoids dominated by lupeol (93%), taraxerol (60%), glutinol (66%), and friedelin (71%), respectively. The cycloartenol synthase was found expressed in all leaf tissues, whereas the lupeol, taraxerol, glutinol, and friedelin synthases were expressed only in the epidermis layers lining the upper and lower surfaces of the leaf blade. It is concluded that the function of these enzymes is to form respective triterpenoid aglycones destined to coat the leaf exterior, probably as defense compounds against pathogens or herbivores. PMID:20610397

  6. E-learning module on chronic low back pain in older adults: evidence of effect on medical student objective structured clinical examination performance.

    PubMed

    Weiner, Debra K; Morone, Natalia E; Spallek, Heiko; Karp, Jordan F; Schneider, Michael; Washburn, Carol; Dziabiak, Michael P; Hennon, John G; Elnicki, D Michael

    2014-06-01

    The Institute of Medicine has highlighted the urgent need to close undergraduate and graduate educational gaps in treating pain. Chronic low back pain (CLBP) is one of the most common pain conditions, and older adults are particularly vulnerable to potential morbidities associated with misinformed treatment. An e-learning case-based interactive module was developed at the University of Pittsburgh Center of Excellence in Pain Education, one of 12 National Institutes of Health-designated centers, to teach students important principles for evaluating and managing CLBP in older adults. A team of six experts in education, information technology, pain management, and geriatrics developed the module. Teaching focused on common errors, interactivity, and expert modeling and feedback. The module mimicked a patient encounter using a standardized patient (the older adult with CLBP) and a pain expert (the patient provider). Twenty-eight medical students were not exposed to the module (Group 1) and 27 were exposed (Group 2). Their clinical skills in evaluating CLBP were assessed using an objective structured clinical examination (OSCE). Mean scores were 62.0 ± 8.6 for Group 1 and 79.5 ± 10.4 for Group 2 (P < .001). Using an OSCE pass-fail cutoff score of 60%, 17 of 28 Group 1 students (60.7%) and 26 of 27 Group 2 students (96.3%) passed. The CLBP OSCE was one of 10 OSCE stations in which students were tested at the end of a Combined Ambulatory Medicine and Pediatrics Clerkship. There were no between-group differences in performance on eight of the other nine OSCE stations. This module significantly improved medical student clinical skills in evaluating CLBP. Additional research is needed to ascertain the effect of e-learning modules on more-advanced learners and on improving the care of older adults with CLBP. PMID:24833496

  7. Criterion validity of a competency-based assessment center in medical education – a 4-year follow-up study

    PubMed Central

    Rotthoff, Thomas; Ostapczuk, Martin S.; Kröncke, Klaus D.; Zimmerhofer, Alexander; Decking, Ulrich; Schneider, Matthias; Ritz-Timme, Stefanie

    2014-01-01

    Introduction Core competencies have progressively gained importance in medical education. In other contexts, especially personnel selection and development, assessment centers (ACs) are used to assess competencies, but there is only a limited number of studies on competency-based ACs in medical education. To the best of our knowledge, the present study provides the first data on the criterion-related validity of a competency-based AC in medical education. Methods We developed an AC tailored to measure core competencies relevant to medical education (social-ethical, communicative, self, and teaching) and tested its validity in n=30 first-year medical students using 3- to 4-year follow-up measures such as (a) objective structured clinical examinations (OSCE) on basic clinical skills (n=26), (b) OSCE on communication skills (n=21), and (c) peer feedback (n=18). The AC contained three elements: interview, group discussion, and role play. Additionally, a self-report questionnaire was provided as a basis for the interview. Results Baseline AC average score and teaching competency correlated moderately with the communication OSCE average score (r=0.41, p=0.03, and r=0.38, p=0.04, respectively). Social-ethical competency in the AC showed a very strong convergent association with the communication OSCE average score (r=0.60, p<0.01). The AC total score also showed a moderate correlation with the overall peer feedback score provided in Year 4 (r=0.38, p=0.06). In addition, communicative competency correlated strongly with the overall peer feedback (r=0.50, p=0.02). We found predominantly low and insignificant correlations between the AC and the OSCE on basic clinical skills (r=−0.33 to 0.30, all p's>0.05). Conclusion The results showed that competency-based ACs can be used at a very early stage of medical training to successfully predict future performance in core competencies. PMID:25219931

  8. Aluminum-doped ceria-zirconia solid solutions with enhanced thermal stability and high oxygen storage capacity

    PubMed Central

    2012-01-01

    A facile solvothermal method to synthesize aluminum-doped ceria-zirconia (Ce0.5Zr0.5-xAlxO2-x/2, x = 0.1 to 0.4) solid solutions was carried out using Ce(NH4)2(NO3)6, Zr(NO3)3·2H2O Al(NO3)3·9H2O, and NH4OH as the starting materials at 200°C for 24 h. The obtained solid solutions from the solvothermal reaction were calcined at 1,000°C for 20 h in air atmosphere to evaluate the thermal stability. The synthesized Ce0.5Zr0.3Al0.2O1.9 particle was characterized for the oxygen storage capacity (OSC) in automotive catalysis. For the characterization, X-ray diffraction, transmission electron microscopy, and the Brunauer-Emmet-Teller (BET) technique were employed. The OSC values of all samples were measured at 600°C using thermogravimetric-differential thermal analysis. Ce0.5Zr0.3Al0.2O1.9 solid solutions calcined at 1,000°C for 20 h with a BET surface area of 18 m2 g−1 exhibited a considerably high OSC of 427 μmol-O g−1 and good OSC performance stability. The same synthesis route was employed for the preparation of the CeO2 and Ce0.5Zr0.5O2. The incorporation of aluminum ion in the lattice of ceria-based catalyst greatly enhanced the thermal stability and OSC. PMID:23025588

  9. One-hour screening of adulterated heparin by simplified peroxide digestion and fast RPIP-LC-MS(2).

    PubMed

    Li, Hongli; Wickramasekara, Samanthi; Nemes, Peter

    2015-08-18

    Early detection of potential contaminants in heparin, an extensively used anticoagulant in drug formulations and medical devices, is critical to ensuring public health. In response to heparin adulteration by oversulfated chondroitin sulfates (OSCS) that was associated with adverse events including deaths in 2007-2008, many methods have been developed to detect OSCS in heparin. However, an analytical challenge for quality screenings has been to speed up these measurements to address the complex distribution scheme of heparin in today's global market. Here an approach based on mass spectrometry is described that enables the measurement of adulterated heparin in 1 h, significantly shortening the time frame of screening for potential contaminants. The methodology is based on simplified peroxide digestion that rapidly depolymerizes large polysaccharide chains to small oligosaccharides followed by fast liquid chromatography mass spectrometry to determine sample purity. We find that rapid peroxide digestion generates abundant C- and Y-type oligosaccharides that can be used to differentiate parent glycosaminoglycans via unsupervised multivariate analysis, including heparin, chondroitin sulfate A, dermatan sulfate, and the infamous OSCS. With quantitation demonstrated at 1% (w/w), or 50 ng, OSCS in heparin and the lower limit of detection estimated at ∼0.20% (w/w), or ∼10 ng, OSCS in heparin, the technology was sufficiently sensitive to differentiate real-life, "authentic" adulterated heparin samples and to quantify this contaminant with an error <10% relative standard deviation. The methodologies presented here are deliberately simple to foster adoption and increase the analytical throughput of mass spectrometric screening in the routine quality assessment of heparin and other types of compounds of this molecular family. PMID:26168275

  10. Fast iterative reconstructions for animal CT

    NASA Astrophysics Data System (ADS)

    Huang, H.-M.; Hsiao, I.-T.; Jan, M.-L.

    2009-06-01

    For iterative x-ray computed tomography (CT) reconstruction, the convex algorithm combined with ordered subset (OSC) [1] is a relatively fast algorithm and has shown its potential for low-dose situations. But it needs one forward projection and two backprojections per iteration. Unlike convex algorithm, the gradient algorithm only requires one forward projection and one backprojection per iteration. Here, we applied ordered subsets of projection data to a modified gradient algorithm. In order to further reduce computation time, the new algorithm, the ordered subset gradient (OSG) algorithm, can be adjusted with a step size. We also implemented another OS-type algorithm called OSTR. The OSG algorithm is compared with OSC algorithm and OSTR algorithm using three-dimensional simulated helical cone-beam CT data. The performance is evaluated in terms of log-likelihood, contrast recovery, and bias-variance studies. Results show that images of OSG has compatible visual image quality to those of OSC and OSTR, but in the resolution and bias-variance studies, OSG seems to reach stable values with faster speed. In particular, OSTR has better recovery in a smoother region, but both OSG and OSC have better recovery in the high-frequency regions. Moreover, in terms of log likelihood with respect to computation time, OSG has faster convergence rate than that of OSC and similar to that of OSTR. We conclude that OSG has potential to provide comparable image quality and is more computationally efficient, and thus could be suitable for low-dose, helical cone-beam CT image reconstruction.

  11. Small radioisotope thermophotovoltaic (RTPV) generators

    NASA Astrophysics Data System (ADS)

    Schock, A.; Or, C.; Kumar, V.

    1996-02-01

    The National Aeronautics and Space Administration's recently inaugurated New Millennium program, with its emphasis on miniaturized spacecraft, has generated interest in a low-power (10- to 30-watt), low-mass, high-efficiency RTPV power system. This led to a Department of Energy (DOE)-sponsored design study by OSC (formerly Fairchild) personnel, who had previously conducted very encouraging studies of 75-watt RTPV systems based on two 250-watt General Purpose Heat Source (GPHS) modules. Since these modules were too large for the small RTPVs described in this paper, OSC generated derivative designs for 125-watt and 62.5-watt heat source modules. To minimize the need for new development and safety verification studies, these contained identical fuel pellets, clads, impact shell, and thermal insulation as the previously developed and safety-qualified 250-watt units. OSC also generated a novel heat source support scheme to reduce the heat losses through the structural supports, and a new and much simpler radiator structure, employing no honeycombs or heat pipes. OSC's previous RTPV study had been based on the use of GaSb PV cells and spectrally selective Infra-Red (IR) filters that had been partially developed and characterized by Boeing (now EDTEK) personnel. The present study was based on greatly improved selective filters developed and performance-mapped by EDTEK under an OSC-initiated subcontract. The paper describes illustrative small-RTPV designs and analyzes their mass, size, power output, system efficiency, and specific power, and illustrates their integration with a miniaturized New Millennium spacecraft.

  12. Regulation of the perilymphatic-endolymphatic water shunt in the cochlea by membrane translocation of aquaporin-5.

    PubMed

    Eckhard, A; Dos Santos, A; Liu, W; Bassiouni, M; Arnold, H; Gleiser, C; Hirt, B; Harteneck, C; Müller, M; Rask-Andersen, H; Löwenheim, H

    2015-12-01

    Volume homeostasis of the cochlear endolymph depends on radial and longitudinal endolymph movements (LEMs). LEMs measured in vivo have been exclusively recognized under physiologically challenging conditions, such as experimentally induced alterations of perilymph osmolarity or endolymph volume. The regulatory mechanisms that adjust LEMs to the physiological requirements of endolymph volume homeostasis remain unknown. Here, we describe the formation of an aquaporin (AQP)-based "water shunt" during the postnatal development of the mouse cochlea and its regulation by different triggers. The final complementary expression pattern of AQP5 (apical membrane) and AQP4 (basolateral membrane) in outer sulcus cells (OSCs) of the cochlear apex is acquired at the onset of hearing function (postnatal day (p)8-p12). In vitro, hyperosmolar perfusion of the perilymphatic fluid spaces or the administration of the muscarinic agonist pilocarpine in cochlear explants (p14) induced the translocation of AQP5 channel proteins into the apical membranes of OSCs. AQP5 membrane translocation was blocked by the muscarinic antagonist atropine. The muscarinic M3 acetylcholine (ACh) receptor (M3R) was identified in murine OSCs via mRNA expression, immunolabeling, and in vitro binding studies using an M3R-specific fluorescent ligand. Finally, the water shunt elements AQP4, AQP5, and M3R were also demonstrated in OSCs of the human cochlea. The regulation of the AQP4/AQP5 water shunt in OSCs of the cochlear apex provides a molecular basis for regulated endolymphatic volume homeostasis. Moreover, its dysregulation or disruption may have pathophysiologic implications for clinical conditions related to endolymphatic hydrops, such as Ménière's disease. PMID:26208470

  13. Comparison of the problem based learning-driven with the traditional didactic-lecture-based curricula

    PubMed Central

    Varghese, Ramani; Mohammed, Ahmed M.; Ayed, Adel K.

    2016-01-01

    Objectives To compare the Problem-based learning (PBL) with the traditional lecture-based curricula. Methods The single best answer Multiple Choice Questions (MCQ) and the Objective Structured Clinical Examination (OSCE) were used to compare performance of the lecture-based curriculum with the PBL medical student groups. The reliability for the MCQs and OSCE was calculated with Kuder-Richardson formula and Cronbach’s alpha, respectively. The content validity of the MCQs and OSCE were tested by the Independent Subject Experts (ISE). The Student’s t-test for independent samples was used to compare the item difficulty of the MCQs and OSCE’s, and the Chi-square test was used to compare the grades between the two student groups. Results The PBL students outperformed the old curriculum students in overall grades, theoretical knowledge base (tested with K2 type MCQs) and OSCE. The number of the PBL students with scores between 80-90% (grade B) was significantly (p=0.035) higher while their number with scores between 60 to 69% (grade C) was significantly p=0.001) lower than the old curriculum students. Similarly, the mean MCQ and the OSCE scores of the new curriculum students were significantly higher (p = 0.001 and p = 0.025, respectively) than the old curriculum students. Lastly, the old curriculum students found the K2-MCQs to be more (p = 0.001) difficult than the single correct answer (K1 type) MCQs while no such difference was found by the new curriculum students. Conclusions Suitably designed MCQs can be used to tap the higher cognitive knowledge base acquired in the PBL setting.  PMID:27289331

  14. E-Learning Module on Chronic Low Back Pain in Older Adults: Evidence of Effect on Medical Student Objective Structured Clinical Examination Performance

    PubMed Central

    Weiner, Debra K.; Morone, Natalia E.; Spallek, Heiko; Karp, Jordan F.; Schneider, Michael; Washburn, Carol; Dziabiak, Michael P.; Hennon, John G.; Elnicki, D. Michael

    2015-01-01

    The Institute of Medicine has highlighted the urgent need to close undergraduate and graduate educational gaps in treating pain. Chronic low back pain (CLBP) is one of the most common pain conditions, and older adults are particularly vulnerable to potential morbidities associated with misinformed treatment. An e-learning case-based interactive module was developed at the University of Pittsburgh Center of Excellence in Pain Education, one of 12 National Institutes of Health–designated centers, to teach students important principles for evaluating and managing CLBP in older adults. A team of six experts in education, information technology, pain management, and geriatrics developed the module. Teaching focused on common errors, interactivity, and expert modeling and feedback. The module mimicked a patient encounter using a standardized patient (the older adult with CLBP) and a pain expert (the patient provider). Twenty-eight medical students were not exposed to the module (Group 1) and 27 were exposed (Group 2). Their clinical skills in evaluating CLBP were assessed using an objective structured clinical examination (OSCE). Mean scores were 62.0 ± 8.6 for Group 1 and 79.5 ± 10.4 for Group 2 (P < .001). Using an OSCE pass–fail cutoff score of 60%, 17 of 28 Group 1 students (60.7%) and 26 of 27 Group 2 students (96.3%) passed. The CLBP OSCE was one of 10 OSCE stations in which students were tested at the end of a Combined Ambulatory Medicine and Pediatrics Clerkship. There were no between-group differences in performance on eight of the other nine OSCE stations. This module significantly improved medical student clinical skills in evaluating CLBP. Additional research is needed to ascertain the effect of e-learning modules on more-advanced learners and on improving the care of older adults with CLBP. PMID:24833496

  15. Ag-Pd-Cu alloy inserted transparent indium tin oxide electrodes for organic solar cells

    SciTech Connect

    Kim, Hyo-Joong; Seo, Ki-Won; Kim, Han-Ki; Noh, Yong-Jin; Na, Seok-In

    2014-09-01

    The authors report on the characteristics of Ag-Pd-Cu (APC) alloy-inserted indium tin oxide (ITO) films sputtered on a glass substrate at room temperature for application as transparent anodes in organic solar cells (OSCs). The effect of the APC interlayer thickness on the electrical, optical, structural, and morphological properties of the ITO/APC/ITO multilayer were investigated and compared to those of ITO/Ag/ITO multilayer electrodes. At the optimized APC thickness of 8 nm, the ITO/APC/ITO multilayer exhibited a resistivity of 8.55 × 10{sup −5} Ω cm, an optical transmittance of 82.63%, and a figure-of-merit value of 13.54 × 10{sup −3} Ω{sup −1}, comparable to those of the ITO/Ag/ITO multilayer. Unlike the ITO/Ag/ITO multilayer, agglomeration of the metal interlayer was effectively relieved with APC interlayer due to existence of Pd and Cu elements in the thin region of the APC interlayer. The OSCs fabricated on the ITO/APC/ITO multilayer showed higher power conversion efficiency than that of OSCs prepared on the ITO/Ag/ITO multilayer below 10 nm due to the flatness of the APC layer. The improved performance of the OSCs with ITO/APC/ITO multilayer electrodes indicates that the APC alloy interlayer prevents the agglomeration of the Ag-based metal interlayer and can decrease the thickness of the metal interlayer in the oxide-metal-oxide multilayer of high-performance OSCs.

  16. Gender (in) differences in prevalence and incidence of traumatic experiences among orphaned and separated children living in five low- and middle-income countries

    PubMed Central

    Gray, C. L.; Pence, B. W.; Ostermann, J.; Whetten, R. A.; O’Donnell, K.; Thielman, N. M.; Whetten, K.

    2015-01-01

    Background Approximately 153 million children worldwide are orphaned and vulnerable to potentially traumatic events (PTEs). Gender differences in PTEs in low- and middle-income countries (LMIC) are not well-understood, although support services and prevention programs often primarily involve girls. Methods The Positive Outcomes for Orphans study used a two-stage, cluster-randomized sampling design to identify 2837 orphaned and separated children (OSC) in five LMIC in sub-Saharan Africa and Asia. We examined self-reported prevalence and incidence of several PTE types, including physical and sexual abuse, among 2235 children who were ≥10 years at baseline or follow-up, with a focus on gender comparisons. Results Lifetime prevalence by age 13 of any PTE other than loss of a parent was similar in both boys [91.7% (95% confidence interval (CI) (85.0–95.5)] and girls [90.3% CI (84.2–94.1)] in institutional-based care, and boys [92.0% (CI 89.0–94.2)] and girls [92.9% CI (89.8–95.1)] in family-based care; annual incidence was similarly comparable between institution dwelling boys [23.6% CI (19.1, –29.3)] and girls [23.6% CI (18.6, –30.0)], as well as between family-dwelling boys [30.7% CI (28.0, –33.6)] and girls [29.3% CI (26.8,-32.0)]. Physical and sexual abuse had the highest overall annual incidence of any trauma type for institution-based OSC [12.9% CI (9.6–17.4)] and family-based OSC [19.4% CI (14.5–26.1)], although estimates in each setting were no different between genders. Conclusion Prevalence and annual incidence of PTEs were high among OSC in general, but gender-specific estimates were comparable. Although support services and prevention programs are essential for female OSC, programs for male OSC are equally important. PMID:26085939

  17. Sulfur and temperature effects on the spatial distribution of reactions inside a lean NOx trap and resulting changes in global performance

    SciTech Connect

    Choi, Jae-Soon; Partridge Jr, William P; Pihl, Josh A; Daw, C Stuart

    2008-01-01

    We experimentally studied the influence of temperature and sulfur loading on the axial distribution of reactions inside a commercial lean NOx trap (LNT) catalyst to better understand the global performance trends. Our measurements were made on a monolith core, bench-flow reactor under cycling conditions (60-s lean/5-s rich) at 200, 325, and 400 C with intra-catalyst and reactor-outlet gas speciation. Postmortem elemental and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) analyses of the catalyst also supplemented our gas species measurements. For the unsulfated catalyst, the NOx storage/reduction (NSR) reactions were localized in the front (upstream) portion of the monolith, whereas oxygen storage/reduction reactions were distributed more evenly along the entire catalyst length. As a result, two axially distinct reaction zones were developed inside the working catalyst: an upstream 'NSR zone' where both NOx and oxygen storage/reduction took place and a downstream oxygen storage capacity (OSC)-only zone where the NSR reactions did not penetrate. The NSR zone involved less than half the LNT at 325 and 400 C, but it included almost the entire length at 200 C. Sulfation poisoned both the NSR and OSC reactions beginning at the catalyst upstream edge, with the NSR degradation occurring more rapidly and distinctly than the OSC. As sulfation proceeded, a third zone (the sulfated zone) developed and the NSR zone moved downstream, with a concomitant decrease in both the OSC-only zone and global NOx conversion. The sulfation impact on NOx conversion was greatest at 200 C, when the NSR zone was largest. Ammonia selectivity increased with sulfation, which we attributed to a shortened OSC-only zone and resultantly reduced consumption of NH{sub 3}, slipping from the NSR zone, by downstream OSC. Lower temperatures also increased NH{sub 3} selectivity. Nitrous oxide selectivity also increased with decreasing temperature but showed little dependence on

  18. Structural evolution of the East Pacific Rise axis from 13°10'N to 10°35'N: interpretations from SeaMARC I data

    NASA Astrophysics Data System (ADS)

    Crane, Kathleen

    1987-05-01

    In 1983 the SeaMARC I and the Sea Beam systems imaged the East Pacific Rise (EPR) and the Clipperton Transform Fault from 13°10'N to 9°50'N revealing both magmatic and tectonic segmentation along the rise axis. Tectonic segments are defined by an undulating axial zone of extension which widens and narrows at an average wavelength of 45 km. In addition, axial fissure-fault-density and -length curves reveal wavelengths of 30 and 56 km. The narrowest axial zones, < 0.5 km in width, correspond to regions of hydrothermal activity and are located atop regional morphologic highs quasi-harmonically spaced at 155 km. These highs define the major magma centers on the rise axis about which seamounts cluster. Superimposed on the intermediate-wavelength highs are smaller highs (from 10 to 50 km in length) which are truncated by overlapping spreading centers (OSC's) at their distal edges. The rise axis widens near OSC's while it narrows and disappears near the Clipperton Transform Fault suggesting that transforms and OSC's have different origins. Imagery on and adjacent to a few OSC's reveals that in some cases OSC's migrate along the axis forming relict off-axial structural traces at oblique angles (285°-330°) to the axis. Off-axial fault density and length curves have wavelengths similar to the axial curves. However, fault densities to the west of the axis are somewhat antisymmetric to fissure-fault densities on the axis. In contrast, faults to the east of the axis nearly mimic fissure-fault density and length curves on the axis suggesting that the fracture pattern is controlled by the state of deviatoric stress in the adjacent Cocos Plate to the east. The data suggest that large deep-seated magma diapirs may dominate the magmatic segmentation of the EPR generating dynamically supported 155 km wavelength highs. Smaller, shallower magma cupulas may rise as fingers to the seafloor above the large diapirs. Where the magma erupts may be a factor of the thin skin tectonic

  19. United States Coast Guard portable salvage computer. Final report

    SciTech Connect

    Allen, S.J.

    1986-07-01

    The US Coast Guard's interest in marine salvage arises from its responsibility under the Federal Water Pollution Control Act and other laws dealing with oil spills. At vessel stranding situations, which could result in significant environmental damage through the release of oil or hazardous chemicals, the Coast Guard is represented by an On-Scene Coordinator (OSC), who must evaluate whether or not appropriate salvage techniques are applied to the stranded vessel by commercial salvors. To assist the OSC, who may not be trained in marine salvage, and other Coast Guard personnel assigned to such salvage operations, a portable salvage computer has been programmed to accomplish salvage calculations in a user-friendly manner. In this final report, the development of the salvage program and selection of a portable computer are described along with results of field testing with actual stranding situations.

  20. Design, development and optimization of self-microemulsifying drug delivery system of an anti-obesity drug.

    PubMed

    Desai, Jagruti; Khatri, Nirav; Chauhan, Sachin; Seth, Avinash

    2012-03-01

    The aim of the present work was to formulate a self-microemulsifying drug delivery system (SMEDDS) containing orlistat. The oil, surfactant and co-surfactant were decided based on the solubility studies. Pseudoternary phase diagrams were plotted, microemulsification area was determined and different formulations were prepared. Particle size, zeta potential, dispersibility test and thermodynamic stability studies were measured. In-vitro dissolution test of thermodynamically stable formulations OS-B and OS-C were carried and results were compared with those of plain drug and suspension formulation. Stability studies performed indicated that formulation OS-C remained stable over 12 months period. Thus this investigation concluded that hydrophobic drugs like orlistat can be delivered effectively through the formulation of SMEDDS. PMID:23066191

  1. Design, development and optimization of self-microemulsifying drug delivery system of an anti-obesity drug

    PubMed Central

    Desai, Jagruti; Khatri, Nirav; Chauhan, Sachin; Seth, Avinash

    2012-01-01

    The aim of the present work was to formulate a self-microemulsifying drug delivery system (SMEDDS) containing orlistat. The oil, surfactant and co-surfactant were decided based on the solubility studies. Pseudoternary phase diagrams were plotted, microemulsification area was determined and different formulations were prepared. Particle size, zeta potential, dispersibility test and thermodynamic stability studies were measured. In-vitro dissolution test of thermodynamically stable formulations OS-B and OS-C were carried and results were compared with those of plain drug and suspension formulation. Stability studies performed indicated that formulation OS-C remained stable over 12 months period. Thus this investigation concluded that hydrophobic drugs like orlistat can be delivered effectively through the formulation of SMEDDS. PMID:23066191

  2. Correlating high power conversion efficiency of PTB7:PC71BM inverted organic solar cells with nanoscale structures

    NASA Astrophysics Data System (ADS)

    Das, Sanjib; Keum, Jong K.; Browning, James F.; Gu, Gong; Yang, Bin; Dyck, Ondrej; Do, Changwoo; Chen, Wei; Chen, Jihua; Ivanov, Ilia N.; Hong, Kunlun; Rondinone, Adam J.; Joshi, Pooran C.; Geohegan, David B.; Duscher, Gerd; Xiao, Kai

    2015-09-01

    Advances in material design and device engineering led to inverted organic solar cells (i-OSCs) with superior power conversion efficiencies (PCEs) compared to their ``conventional'' counterparts, in addition to the well-known better ambient stability. Here, we report an in-depth morphology study of the i-OSC active and cathode modifying layers, employing a model system with a well-established bulk-heterojunction, PTB7:PC71BM as the active layer and poly-[(9,9-bis(3'-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)] (PFN) as the cathode surface modifying layer. We have also identified the role of a processing additive, 1,8-diiodooctane (DIO), used in the spin-casting of the active layer to increase PCE. Using various characterization techniques, we demonstrate that the high PCEs of i-OSCs are due to the diffusion of electron-accepting PC71BM into the PFN layer, resulting in improved electron transport. The diffusion occurs when residual solvent molecules in the spun-cast film act as a plasticizer. Addition of DIO to the casting solution results in more PC71BM diffusion and therefore more efficient electron transport. This work provides important insight and guidance to further enhancement of i-OSC performance by materials and interface engineering.Advances in material design and device engineering led to inverted organic solar cells (i-OSCs) with superior power conversion efficiencies (PCEs) compared to their ``conventional'' counterparts, in addition to the well-known better ambient stability. Here, we report an in-depth morphology study of the i-OSC active and cathode modifying layers, employing a model system with a well-established bulk-heterojunction, PTB7:PC71BM as the active layer and poly-[(9,9-bis(3'-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)] (PFN) as the cathode surface modifying layer. We have also identified the role of a processing additive, 1,8-diiodooctane (DIO), used in the spin-casting of the active

  3. The Telecommunications and Data Acquisition Report

    NASA Technical Reports Server (NTRS)

    Yuen, Joseph H. (Editor)

    1994-01-01

    This quarterly publication provides archival reports on developments in programs managed by JPL's Office of Telecommunications and Data Acquisition (TDA). In space communications, radio navigation, radio science, and ground-based radio and radar astronomy, it reports on activities of the Deep Space Network (DSN) in planning, supporting research and technology, implementation, and operations. Also included are standards activity at JPL for space data and information systems and reimbursable DSN work performed for other space agencies through NASA. The preceding work is all performed for NASA's Office of Space Communications (OSC). The TDA Office also performs work funded by other NASA program offices through and with the cooperation of OSC. Finally, tasks funded under the JPL Director's Discretionary Fund and the Caltech President's Fund that involve the TDA Office are included.

  4. MoO3 as a Cathode Buffer Layer Material for the Improvement of Planar pn-Heterojunction Organic Solar Cell Performance

    NASA Astrophysics Data System (ADS)

    Kageyama, Hiroshi; Kajii, Hirotake; Ohmori, Yutaka; Shirota, Yasuhiko

    2011-03-01

    The use of MoO3 as a cathode buffer layer inserted between LiF and Al improved the power conversion efficiency (PCE) of planar pn-heterojunction organic solar cells (OSCs) by reducing exciton quenching at the interface between the n-type organic active layer and the electrode. The cell using an amorphous molecular material, tris[4-(5-phenylthiophen-2-yl)phenyl]amine, as a p-type organic semiconductor, C70 as an n-type organic semiconductor and MoO3 as a cathode buffer layer exhibited a PCE of 3.3% under AM1.5G illumination (100 mW cm-2), which is of the highest level among those for planar pn-heterojunction OSCs using amorphous molecular materials as donor materials.

  5. Determination of the interface δ-hole density in a blue-emitting organic semiconductor diode by electromodulated absorption spectroscopy

    NASA Astrophysics Data System (ADS)

    Zhou, Mi; Png, Rui-Qi; Sivaramakrishnan, Sankaran; Chia, Perq-Jon; Yong, Chaw-Keong; Chua, Lay-Lay; Ho, Peter K. H.

    2010-09-01

    The hole density at the interface of a poly(fluorene-alt-triarylamine) (TFB) with p-doped poly(3,4-ethylenedioxythiophene) (PEDT) anodes has been determined from electromodulation of the TFB subgap polaron band. At 295 K, this δ-hole density σOSC is approximately 1×1012 cm-2, for which the current-voltage characteristics indicate an Ohmic contact. However at 30 K, σOSC falls to 2×1011 cm-2, and the contact characteristics approach the injecting-blocking boundary. The PEDT/TFB vacuum offset inside the device is inferred to be 0.1 eV, and so the Fermi level is not as deeply pinned in the TFB gap as suggested by ultraviolet photoemission measurements.

  6. Advancements in the micromirror array projector technology II

    NASA Astrophysics Data System (ADS)

    Beasley, D. B.; Bender, Matt; Crosby, Jay; McCall, Sean; Messer, Tim; Saylor, Daniel A.

    2005-05-01

    The Micromirror Array Projector System (MAPS) is a state-of-the-art dynamic scene projector developed by Optical Sciences Corporation (OSC) for Hardware-In-the-Loop (HWIL) simulation and sensor test applications. Since the introduction of the first MAPS in 2001, OSC has continued to improve the technology and develop systems for new projection and test applications. The MAPS is based upon the Texas Instruments Digital Micromirror Device (DMD) which has been modified to project high resolution, realistic imagery suitable for testing sensors and seekers operating in the UV, visible, NIR, and IR wavebands. This paper reviews the basic design and describes recent developments and new applications of the MAPS technology. Recent developments for the MAPS include increasing the format of the micromirror array to 1280x1024, increasing the video frame rate to >230 Hz, development of a DMD active cooling system, and development of a high-temperature illumination blackbody.

  7. A theoretical study of charge-transport parameters for a hydrogen-bonded organic semiconductor: the indigo and s-indaceno [1,2-b:5,6-b‧] dithiophene-4,9-dione derivatives

    NASA Astrophysics Data System (ADS)

    Wei, Hui-Ling; Shi, Ya-Rui; Liu, Yu-Fang

    2016-06-01

    The properties of synthesized ambipolar organic semiconductor (OSC) materials, containing hydrogen bonding, i.e. the 6,6‧-dibromoindigo and the three s-indaceno [1, 2-b:5, 6-b‧] dithiophene-4,9-dione derivatives, have been systematically studied using a density functional theory. The hydrogen bonding formed between the interlayer molecules, though it does not affect the charge mobility in the same layer, influences the interorbital overlapping of HOMO and LUMO states between the layers, and influences the charge mobility directly. In addition, the hydrogen bonding between the layers may reinforce the π-π stacking and make the center-to-center distance closer, which indirectly enhances charge mobility, and can turn a monopole OSC into an ambipolar one.

  8. Study of the Chemotactic Response of Multicellular Spheroids in a Microfluidic Device.

    PubMed

    Ayuso, Jose M; Basheer, Haneen A; Monge, Rosa; Sánchez-Álvarez, Pablo; Doblaré, Manuel; Shnyder, Steven D; Vinader, Victoria; Afarinkia, Kamyar; Fernández, Luis J; Ochoa, Ignacio

    2015-01-01

    We report the first application of a microfluidic device to observe chemotactic migration in multicellular spheroids. A microfluidic device was designed comprising a central microchamber and two lateral channels through which reagents can be introduced. Multicellular spheroids were embedded in collagen and introduced to the microchamber. A gradient of fetal bovine serum (FBS) was established across the central chamber by addition of growth media containing serum into one of the lateral channels. We observe that spheroids of oral squamous carcinoma cells OSC-19 invade collectively in the direction of the gradient of FBS. This invasion is more directional and aggressive than that observed for individual cells in the same experimental setup. In contrast to spheroids of OSC-19, U87-MG multicellular spheroids migrate as individual cells. A study of the exposure of spheroids to the chemoattractant shows that the rate of diffusion into the spheroid is slow and thus, the chemoattractant wave engulfs the spheroid before diffusing through it. PMID:26444904

  9. OrbView-3 Initial On-Orbit Characterization

    NASA Technical Reports Server (NTRS)

    Ross, Kent; Blonski, Slawomir; Holekamp, Kara; Pagnutti, Mary; Zanoni, Vicki; Carver, David; Fendley, Debbie; Smith, Charles

    2004-01-01

    NASA at Stennis Space Center (SSC) established a Space Act Agreement with Orbital Sciences Corporation (OSC) and ORBIMAGE Inc. to collaborate on the characterization of the OrbView-3 system and its imagery products and to develop characterization techniques further. In accordance with the agreement, NASA performed an independent radiometric, spatial, and geopositional accuracy assessment of OrbView-3 imagery acquired before completion of the system's initial on-orbit checkout. OSC acquired OrbView-3 imagery over SSC from July 2003 through January 2004, and NASA collected ground reference information coincident with many of these acquisitions. After evaluating all acquisitions, NASA deemed two multispectral images and five panchromatic images useful for characterization. NASA then performed radiometric, spatial, and geopositional characterizations.

  10. Perspective in infertility: the ovarian stem cells.

    PubMed

    Silvestris, Erica; D'Oronzo, Stella; Cafforio, Paola; D'Amato, Giuseppe; Loverro, Giuseppe

    2015-01-01

    Infertility is a medical and social condition that affects millions of women worldwide and is today considered so far as a new disease. A considerable progress has been recently pursued in the field of the reproductive medicine and the infertility treatment may account for novel and modern procedures such as in vitro oocyte fertilization, egg donation, pregnancy surrogacy and preimplantation diagnosis. However, great interest has lately been reserved to the ovarian stem cells (OSCs) whose existence in woman ovaries has been proven. OSCs are thus suitable for developmental studies in infertility and in other clinical applications as endocrine derangements due to premature ovarian failure, or for infertility treatment after cancer chemotherapies, as well as in restoring the hormonal balance in postmenopausal age. PMID:26250560

  11. Offshore space center (offshore launch site)

    SciTech Connect

    Harvey, D.G.

    1980-07-01

    Any activity requiring the development of the HLLV can benefit by operations from an offshore space center (OSC) since operating near the equator provides a twenty percent increase in payload in an ecliptic plan orbit. Some OSC concepts considered include a moored floating (semisubmersible) design, a stationary design supported by fixed piles, and a combination of these two. The facility supports: a 15,000 foot long, 300 foot wide runway, designed to accommodate a two staged winged launch vehicle, with a one million pound payload capacity to low earth orbit, an industrial area for HLLV maintenance, an airport terminal, control and operation center, and observation tower, liquid hydrogen and liquid oxygen production and storage, and fuel storage platforms, a power generation station, docks with an unloading area, two separate launch sites, and living accommodations for 10,000 people. Potential sites include the Paramount Seamount in the Pacific Ocean off the north coast of South America. Cost estimates are considered.

  12. An onboard star identification algorithm

    NASA Astrophysics Data System (ADS)

    Ha, Kong; Femiano, Michael

    The paper presents the autonomous Initial Stellar Acquisition (ISA) algorithm developed for the X-Ray Timing Explorer for prividing the attitude quaternion within the desired accuracy, based on the one-axis attitude knowledge (through the use of the Digital Sun Sensor, CCD Star Trackers, and the onboard star catalog, OSC). Mathematical analysis leads to an accurate measure of the performance of the algorithm as a function of various parameters, such as the probability of a tracked star being in the OSC, the sensor noise level, and the number of stars matched. It is shown that the simplicity, tractability, and robustness of the ISA algorithm, compared to a general three-axis attiude determination algorithm, make it a viable on-board solution.

  13. A facile approach to a silver conductive ink with high performance for macroelectronics

    NASA Astrophysics Data System (ADS)

    Tao, Yu; Tao, Yuxiao; Wang, Biaobing; Wang, Liuyang; Tai, Yanlong

    2013-06-01

    An unusual kind of transparent and high-efficiency organic silver conductive ink (OSC ink) was synthesized with silver acetate as silver carrier, ethanolamine as additive, and different kinds of aldehyde-based materials as reduction agents and was characterized by using a thermogravimetric analyzer, X-ray diffraction, a scanning electron microscope, and a four-point probe. The results show that different reduction agents all have an important influence on the conductive properties of the ink through a series of complex chemical reactions, and especially when formic acid or dimethylformamide was used as the reduction agent and sintered at 120°C for 30 s, the resistivity can be lowered to 6 to 9 μΩ·cm. Furthermore, formula mechanism, conductive properties, temperature, and dynamic fatigue properties were investigated systematically, and the feasibility of the OSC ink was also verified through the preparation of an antenna pattern.

  14. Cancer chemoprevention by garlic and its organosulfur compounds-panacea or promise?

    PubMed

    Nagini, Siddavaram

    2008-04-01

    Of late medicinal plants and functional foods rich in bioactive phytochemicals have received growing attention as potential agents for cancer chemoprevention. Accumulating evidence from epidemiological studies as well as laboratory data supports the anticancer properties of garlic widely used as a medicinal herb and spice. Garlic and its organosulfur compounds (OSCs) appear to exert their anticarcinogenic effects through multiple mechanisms that include modulation of carcinogen metabolism, inhibition of DNA adduct formation, upregulation of antioxidant defences and DNA repair systems, and suppression of cell proliferation by blocking cell cycle progression and/or inducing apoptosis. Since multiple signaling pathways are dysfunctional in cancer and new oncogenic mutations accumulate with carcinogenic progression, dietary agents such as garlic with its rich array of bioactive OSCs that modulate cancer cascades offer promise as potential chemopreventive and chemotherapeutic agents. PMID:18393790

  15. Rapid identification of soil cadmium pollution risk at regional scale based on visible and near-infrared spectroscopy.

    PubMed

    Chen, Tao; Chang, Qingrui; Clevers, J G P W; Kooistra, L

    2015-11-01

    Soil heavy metal pollution due to long-term sewage irrigation is a serious environmental problem in many irrigation areas in northern China. Quickly identifying its pollution status is an important basis for remediation. Visible-near-infrared reflectance spectroscopy (VNIRS) provides a useful tool. In a case study, 76 soil samples were collected and their reflectance spectra were used to estimate cadmium (Cd) concentration by partial least squares regression (PLSR) and back propagation neural network (BPNN). To reduce noise, six pre-treatments were compared, in which orthogonal signal correction (OSC) was first used in soil Cd estimation. Spectral analysis and geostatistics were combined to identify Cd pollution hotspots. Results showed that Cd was accumulated in topsoil at the study area. OSC can effectively remove irrelevant information to improve prediction accuracy. More accurate estimation was achieved by applying a BPNN. Soil Cd pollution hotspots could be identified by interpolating the predicted values obtained from spectral estimates. PMID:26188912

  16. A way for studying the impact of PEDOT:PSS interface layer on carrier transport in PCDTBT:PC71BM bulk hetero junction solar cells by electric field induced optical second harmonic generation measurement

    NASA Astrophysics Data System (ADS)

    Ahmad, Zubair; Abdullah, Shahino Mah; Taguchi, Dai; Sulaiman, Khaulah; Iwamoto, Mitsumasa

    2015-04-01

    Electric-field-induced optical second-harmonic generation (EFISHG) measurement was employed to study the impact of poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate (PEDOT:PSS) interface layer on the carrier transport mechanism of the PCDTBT:PC71BM bulk heterojunction (BHJ) organic solar cells (OSCs). We revealed that the electric fields in the PCDTBT and PC71BM were allowed to be measured individually by choosing fundamental laser wavelengths of 1000 nm and 1060 nm, respectively, in dark and under illumination. The results showed that the direction of the internal electric fields in the PCDTBT:PC71BM BHJ layer is reversed by introducing the PEDOT:PSS layer, and this results in longer electron transport time in the BHJ layer. We conclude that TR-EFISHG can be used as a novel way for studying the impact of interfacial layer on the transport of electrons and holes in the bulk-heterojunction OSCs.

  17. Advanced Measurement Devices for the Microgravity Electromagnetic Levitation Facility EML

    NASA Technical Reports Server (NTRS)

    Brillo, Jurgen; Fritze, Holger; Lohofer, Georg; Schulz, Michal; Stenzel, Christian

    2012-01-01

    This paper reports on two advanced measurement devices for the microgravity electromagnetic levitation facility (EML), which is currently under construction for the use onboard the "International Space Station (ISS)": the "Sample Coupling Electronics (SCE)" and the "Oxygen Sensing and Control Unit (OSC)". The SCE measures by a contactless, inductive method the electrical resistivity and the diameter of a spherical levitated metallic droplet by evaluating the voltage and electrical current applied to the levitation coil. The necessity of the OSC comes from the insight that properties like surface tension or, eventually, viscosity cannot seriously be determined by the oscillating drop method in the EML facility without knowing the conditions of the surrounding atmosphere. In the following both measurement devices are explained and laboratory test results are presented.

  18. A Standardized Patient Counseling Rubric for a Pharmaceutical Care and Communications Course

    PubMed Central

    Payne, Kenna D.; Jernigan, Michelle; Frost, Jill; Wise, Stephen; Klein, Mary; Epps, Joel; Anderson, H. Glenn

    2013-01-01

    Objective. To restructure a required pharmaceutical care and communications course to place greater emphasis on communication skills and include a high-stakes assessment. Design. A standardized counseling rubric was developed for use throughout the pharmacy curriculum and the counseling laboratory practicals were changed to high-stakes assessments. Assessment. An annual mid-semester and end-of-semester high-stakes patient-counseling objective structured clinical examination (OSCE) conducted prior to and after revision of the course and counseling rubric documented improvements in students’ scores. Performance on the post-course annual assessment patient counseling OSCE improved compared to that on the pre-course (p<0.001). Conclusion. The 2010 course revision improved students’ medication counseling abilities and readiness to practice. Major course revisions should be undertaken only after input from all stakeholders and with data to support the need for change. PMID:24052655

  19. Favorable electronic structure for organic solar cells induced by strong interaction at interface

    SciTech Connect

    Wang, Shenghao Hao, Xia; Fu, Wei; Akimoto, Katsuhiro; Sakurai, Takeaki; Masuda, Shigeru

    2013-11-14

    To clarify the role of buffer layer in organic solar cells (OSCs), the electronic properties of bathocuproine (BCP)/Mg interface were systematically investigated by using ultraviolet photoemissions spectroscopy, high-resolution X-ray photoemission spectroscopy, angle-resolved X-ray photoemission spectroscopy and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. The results show there are gap states at the interface, which are caused by the interaction between BCP and Mg. The formation of Mg-N bond was found at the interface. The NEXAFS measurements show that BCP molecules for 1-2 monolayers are lying-down on the substrate, whereas orient randomly for thick BCP layer. It was supposed that the gap states and the highly-ordered orientation of thin BCP layer are the reasons for improving the performance of OSC with BCP buffer layer and low work function metal cathode.

  20. Women and managed care.

    PubMed

    England, M J; Muchnick-Baku, S

    1997-01-01

    The nation's health care system is undergoing a period of rapid change that will profoundly affect women's health care services and, ultimately, women's health. Although managed care is quickly becoming the predominant mode of health care delivery in the United States, a new, more consumer-focused, and accountable model known as organized systems of care (OSC) is emerging. OSC development has been driven by large private and public employers seeking to purchase the highest quality health care for the best price. The changes in health care delivery encouraged by these innovative employers will provide women with optimal care and attention, which will in turn help them attract and retain a competitive and productive workforce. PMID:9127999

  1. Offshore Space Center (offshore launch site)

    NASA Technical Reports Server (NTRS)

    Harvey, D. G.

    1980-01-01

    Any activity requiring the development of the HLLV can benefit by operations from an offshore space center (OSC) since operating near the equator provides a twenty percent increase in payload in an ecliptic plan orbit. Some OSC concepts considered include a moored floating (semisubmersible) design, a stationary design supported by fixed piles, and a combination of these two. The facility supports: a 15,000 foot long, 300 foot wide runway, designed to accommodate a two staged winged launch vehicle, with a one million pound payload capacity to low earth orbit; an industrial area for HLLV maintenance; an airport terminal, control and operation center, and observation tower; liquid hydrogen and liquid oxygen production and storage, and fuel storage platforms; a power generation station, docks with an unloading area; two separate launch sites; and living accommodations for 10,000 people. Potential sites include the Paramount Seamount in the Pacific Ocean off the north coast of South America. Cost estimates are considered.

  2. Carbon oxidation state as a metric for describing the chemistry of atmospheric organic aerosol

    SciTech Connect

    Massachusetts Institute of Technology; Kroll, Jesse H.; Donahue, Neil M.; Jimenez, Jose L.; Kessler, Sean H.; Canagaratna, Manjula R.; Wilson, Kevin R.; Altieri, Katye E.; Mazzoleni, Lynn R.; Wozniak, Andrew S.; Bluhm, Hendrik; Mysak, Erin R.; Smith, Jared D.; Kolb, Charles E.; Worsnop, Douglas R.

    2010-11-05

    A detailed understanding of the sources, transformations, and fates of organic species in the environment is crucial because of the central roles that organics play in human health, biogeochemical cycles, and Earth's climate. However, such an understanding is hindered by the immense chemical complexity of environmental mixtures of organics; for example, atmospheric organic aerosol consists of at least thousands of individual compounds, all of which likely evolve chemically over their atmospheric lifetimes. Here we demonstrate the utility of describing organic aerosol (and other complex organic mixtures) in terms of average carbon oxidation state (OSC), a quantity that always increases with oxidation, and is readily measured using state-of-the-art analytical techniques. Field and laboratory measurements of OSC , using several such techniques, constrain the chemical properties of the organics and demonstrate that the formation and evolution of organic aerosol involves simultaneous changes to both carbon oxidation state and carbon number (nC).

  3. Using peer-assisted learning to teach and evaluate residents' musculoskeletal skills.

    PubMed

    Martinez, Johanna; Harris, Christina; Jalali, Cathy; Tung, Judy; Meyer, Robert

    2015-01-01

    Although direct observation and corrective feedback are established methods of increasing select aspects of residents' musculoskeletal (MSK) clinical skills, the evaluation and management of patients with MSK complaints remains an underemphasized part of internal medicine training. This paper reports on the development of an innovative peer-assisted learning (PAL) model to teach five MSK areas (back, knee, shoulder, neck, or hip pain). Based on data from 42 participating interns and 44 senior residents from an urban US academic medical center, results from an objective structured clinical exam (OSCE) demonstrate gains in both knowledge and self-reported confidence in MSK skills. Moreover, subsequent focus group results reveal a strong preference for the PAL model. In conclusion, an educational module that utilizes the OSCE format holds much promise for teaching MSK skills to both intern and senior residents. PMID:26028495

  4. Oogonial stem cells as a model to study age-associated infertility in women.

    PubMed

    Garg, Neha; Sinclair, David A

    2015-07-01

    Fertility is the first biological process to break down during aging, thereby making it a useful tool to understand fundamental processes of aging. Reproductive aging in females is associated with a loss of ovarian function characterised by a reduction in the number and quality of oocytes. The central dogma, namely that females are born with a fixed pool of oocytes that progressively decline with increasing maternal age, has been challenged by evidence supporting postnatal oogenesis in mammals. Reports demonstrating formation of new oocytes from newly discovered germline stem cells, referred to as oogonial stem cells (OSCs), has opened new avenues for treatment of female infertility. In this review we discuss why the OSCs possibly lose their regenerative potential over time, and focus specifically on the aging process in germline stem cells as a possible mechanism for understanding female age-related infertility and how we can slow or delay ovarian aging. PMID:25897831

  5. Influence of transition metal electronegativity on the oxygen storage capacity of perovskite oxides.

    PubMed

    Liu, Lu; Taylor, Daniel D; Rodriguez, Efrain E; Zachariah, Michael R

    2016-08-16

    The selection of highly efficient oxygen carriers (OCs) is a key step necessary for the practical development of chemical looping combustion (CLC). In this study, a series of ABO3 perovskites, where A = La, Ba, Sr, Ca and B = Cr, Mn, Fe, Co, Ni, Cu, are synthesized and tested in a fixed bed reactor for reactivity and stability as OCs with CH4 as the fuel. We find that the electronegativity of the transition metal on the B-site (λB), is a convenient descriptor for oxygen storage capacity (OSC) of our perovskite samples. By plotting OSC for total methane oxidation against λB, we observe an inverted volcano plot relationship. These results could provide useful guidelines for perovskite OC design and their other energy related applications. PMID:27478888

  6. Optical Sciences Center/College of Optical Sciences: 50 years of excellence

    NASA Astrophysics Data System (ADS)

    Wyant, James C.

    2014-09-01

    Aden B. Meinel established the University of Arizona Optical Sciences Center, now known as the College of Optical Sciences, in 1964 to fulfill a national need for more highly trained engineers and physicists in the optical sciences. Throughout its 50-year history, OSC has grown and evolved in response to industrial demand. It now includes a worldclass faculty and an international student body, and its academic programs offer more than 100 graduate and undergraduate courses, an ABET-accredited undergraduate optical sciences and engineering degree program, and outstanding M.S. and Ph.D. graduate programs with extensive distance learning options. Its graduates are in great demand and are employed by national and international governments, businesses and universities. This paper will describe the formation of OSC and its 50 years of excellence.

  7. Aluminium doped ceria–zirconia supported palladium-alumina catalyst with high oxygen storage capacity and CO oxidation activity

    SciTech Connect

    Dong, Qiang; Yin, Shu Guo, Chongshen; Wu, Xiaoyong; Kimura, Takeshi; Sato, Tsugio

    2013-12-15

    Graphical abstract: Ce{sub 0.5}Zr{sub 0.3}Al{sub 0.2}O{sub 1.9}/Pd/γ-Al{sub 2}O{sub 3} possessed high OSC and CO oxidation activity at low temperature. - Highlights: • A new OSC material of Ce{sub 0.5}Zr{sub 0.3}Al{sub 0.2}O{sub 1.9}/Pd/γ-Al{sub 2}O{sub 3} is prepared via a mechanochemical method. • Ce{sub 0.5}Zr{sub 0.3}Al{sub 0.2}O{sub 1.9}/Pd/γ-Al{sub 2}O{sub 3} showed high OSC even after calcination at 1000 °C for 20 h. • Ce{sub 0.5}Zr{sub 0.3}Al{sub 0.2}O{sub 1.9}/Pd/γ-Al{sub 2}O{sub 3} exhibited the highest CO oxidation activity at low temperature correlates with enhanced OSC. - Abstract: The Ce{sub 0.5}Zr{sub 0.3}Al{sub 0.2}O{sub 1.9}/Pd-γ-Al{sub 2}O{sub 3} catalyst prepared by a mechanochemical route and calcined at 1000 °C for 20 h in air atmosphere to evaluate the thermal stability. The prepared Ce{sub 0.5}Zr{sub 0.3}Al{sub 0.2}O{sub 1.9}/Pd-γ-Al{sub 2}O{sub 3} catalyst was characterized for the oxygen storage capacity (OSC) and CO oxidation activity in automotive catalysis. For the characterization, X-ray diffraction, transmission electron microscopy and the Brunauer–Emmet–Teller (BET) technique were employed. The OSC values of all samples were measured at 600 °C using thermogravimetric-differential thermal analysis. Ce{sub 0.5}Zr{sub 0.3}Al{sub 0.2}O{sub 1.9}/Pd-γ-Al{sub 2}O{sub 3} catalyst calcined at 1000 °C for 20 h with a BET surface area of 41 m{sup 2} g{sup −1} exhibited the considerably high OSC of 583 μmol-O g{sup −1} and good OSC performance stability. The same synthesis route was employed for the preparation of the CeO{sub 2}/Pd-γ-Al{sub 2}O{sub 3} and Ce{sub 0.5}Zr{sub 0.5}O{sub 2}/Pd-γ-Al{sub 2}O{sub 3} for comparison.

  8. The Telecommunications and Data Acquisition Report

    NASA Technical Reports Server (NTRS)

    Posner, Edward C. (Editor)

    1993-01-01

    This quarterly publication provides archival reports on developments in programs managed by JPL's Office of Telecommunications and Data Acquisition (TDA) in the following areas: space communications, radio navigation, radio science, and ground-based radio and radar astronomy. This document also reports on the activities of the Deep Space Network (DSN) in planning, supporting research and technology, implementation, and operations. Also included are standards activity at JPL for space data and information systems and reimbursable DSN work performed for other space agencies through NASA. The preceding work is all performed for NASA's Office of Space Communications (OSC). The TDA Office also performs work funded by another NASA program office through and with the cooperation of OSC. This is the Orbital Debris Radar Program with the Office of Space Systems Development.

  9. Efficient optical absorption enhancement in organic solar cells by using a 2-dimensional periodic light trapping structure

    SciTech Connect

    Zu, Feng-Shuo; Shi, Xiao-Bo; Liang, Jian; Xu, Mei-Feng; Wang, Zhao-Kui E-mail: zkwang@suda.edu.cn Liao, Liang-Sheng E-mail: zkwang@suda.edu.cn; Lee, Chun-Sing E-mail: zkwang@suda.edu.cn

    2014-06-16

    We have investigated the effects induced by periodic nanosphere arrays on the performance of organic solar cells (OSCs). Two-dimensional periodic arrays of polystyrene nanospheres were formed by using a colloidal lithography method together with plasma etching to trim down the size to various degrees on the substrates of OSCs. It is found that the devices prepared on such substrates can have improved light harvesting, resulting in as high as 35% enhancement in power conversion efficiency over that of the reference devices. The measured external quantum efficiency and finite-difference time-domain simulation reveal that the controlled periodic morphology of the substrate can efficiently increase light scattering in the device and thus enhance the absorption of incident light.

  10. Evaluating the objective structured long examination record for nurse education.

    PubMed

    Traynor, Marian; Galanouli, Despina; Rice, Billiejoan; Lynn, Fiona

    2016-06-23

    An objective structured long examination record (OSLER) is a modification of the long-case clinical examination and is mainly used in medical education. This study aims to obtain nursing students' views of the OSLER compared with the objective structured clinical examination (OSCE), which is used to assess discrete clinical skills. A sample of third-year undergraduate nursing students (n=21) volunteered to participate from a cohort of 230 students. Participants undertook the OSLER under examination conditions. Pre-and post-test questionnaires gathered the students' views on the assessments and these were analysed from a mainly qualitative perspective. Teachers' and simulated patient views were also used for data triangulation. The findings indicate that the OSLER ensures more holistic assessment of a student's clinical skills and particularly essential skills such as communication, and that the OSLER, together with the OSCE, should be used to supplement the assessment of clinical competence in nursing education. PMID:27345072

  11. An ADI extrapolated Crank-Nicolson orthogonal spline collocation method for nonlinear reaction-diffusion systems

    NASA Astrophysics Data System (ADS)

    Fernandes, Ryan I.; Fairweather, Graeme

    2012-08-01

    An alternating direction implicit (ADI) orthogonal spline collocation (OSC) method is described for the approximate solution of a class of nonlinear reaction-diffusion systems. Its efficacy is demonstrated on the solution of well-known examples of such systems, specifically the Brusselator, Gray-Scott, Gierer-Meinhardt and Schnakenberg models, and comparisons are made with other numerical techniques considered in the literature. The new ADI method is based on an extrapolated Crank-Nicolson OSC method and is algebraically linear. It is efficient, requiring at each time level only O(N) operations where N is the number of unknowns. Moreover, it is shown to produce approximations which are of optimal global accuracy in various norms, and to possess superconvergence properties.

  12. An onboard star identification algorithm

    NASA Technical Reports Server (NTRS)

    Ha, Kong; Femiano, Michael

    1993-01-01

    The paper presents the autonomous Initial Stellar Acquisition (ISA) algorithm developed for the X-Ray Timing Explorer for prividing the attitude quaternion within the desired accuracy, based on the one-axis attitude knowledge (through the use of the Digital Sun Sensor, CCD Star Trackers, and the onboard star catalog, OSC). Mathematical analysis leads to an accurate measure of the performance of the algorithm as a function of various parameters, such as the probability of a tracked star being in the OSC, the sensor noise level, and the number of stars matched. It is shown that the simplicity, tractability, and robustness of the ISA algorithm, compared to a general three-axis attiude determination algorithm, make it a viable on-board solution.

  13. A facile approach to a silver conductive ink with high performance for macroelectronics

    PubMed Central

    2013-01-01

    An unusual kind of transparent and high-efficiency organic silver conductive ink (OSC ink) was synthesized with silver acetate as silver carrier, ethanolamine as additive, and different kinds of aldehyde-based materials as reduction agents and was characterized by using a thermogravimetric analyzer, X-ray diffraction, a scanning electron microscope, and a four-point probe. The results show that different reduction agents all have an important influence on the conductive properties of the ink through a series of complex chemical reactions, and especially when formic acid or dimethylformamide was used as the reduction agent and sintered at 120°C for 30 s, the resistivity can be lowered to 6 to 9 μΩ·cm. Furthermore, formula mechanism, conductive properties, temperature, and dynamic fatigue properties were investigated systematically, and the feasibility of the OSC ink was also verified through the preparation of an antenna pattern. PMID:23799897

  14. A novel reductive amination method with isotopic formaldehydes for the preparation of internal standard and standards for determining organosulfur compounds in garlic.

    PubMed

    Tsai, De-Cheng; Liu, Meng-Chieh; Lin, Yi-Reng; Huang, Mei-Fang; Liang, Shih-Shin

    2016-04-15

    Garlic (Allium sativum) is a long-cultivated plant that is widely utilized in cooking and has been employed as a medicine for over 4000 years. In this study, we fabricated standards and internal standards (ISs) for absolute quantification via reductive amination with isotopic formaldehydes. Garlic has four abundant organosulfur compounds (OSCs): S-allylcysteine, S-allylcysteinine sulfoxide, S-methylcysteine, and S-ethylcysteine are abundant in garlic. OSCs with primary amine groups were reacted with isotopic formaldehydes to synthesize ISs and standards. Cooked and uncooked garlic samples were compared, and we utilized tandem mass spectrometry equipped with a selective reaction monitoring technique to absolutely quantify the four organosulfur compounds. PMID:26617005

  15. Squalene-Hopene Cyclases▿

    PubMed Central

    Siedenburg, Gabriele; Jendrossek, Dieter

    2011-01-01

    Hopanoids and sterols are members of a large group of cyclic triterpenoic compounds that have important functions in many prokaryotic and eukaryotic organisms. They are biochemically synthesized from linear precursors (squalene, 2,3-oxidosqualene) in only one enzymatic step that is catalyzed by squalene-hopene cyclase (SHC) or oxidosqualene cyclase (OSC). SHCs and OSCs are related in amino acid sequences and probably are derived from a common ancestor. The SHC reaction requires the formation of five ring structures, 13 covalent bonds, and nine stereo centers and therefore is one of the most complex one-step enzymatic reactions. We summarize the knowledge of the properties of triterpene cyclases and details of the reaction mechanism of Alicyclobacillus acidocaldarius SHC. Properties of other SHCs are included. PMID:21531832

  16. Oogonial stem cells as a model to study age-associated infertility in women

    PubMed Central

    Garg, Neha; Sinclair, David A.

    2016-01-01

    Fertility is the first biological process to break down during aging, thereby making it a useful tool to understand fundamental processes of aging. Reproductive aging in females is associated with a loss of ovarian function characterised by a reduction in the number and quality of oocytes. The central dogma, namely that females are born with a fixed pool of oocytes that progressively decline with increasing maternal age, has been challenged by evidence supporting postnatal oogenesis in mammals. Reports demonstrating formation of new oocytes from newly discovered germline stem cells, referred to as oogonial stem cells (OSCs), has opened new avenues for treatment of female infertility. In this review we discuss why the OSCs possibly lose their regenerative potential over time, and focus specifically on the aging process in germline stem cells as a possible mechanism for understanding female age-related infertility and how we can slow or delay ovarian aging. PMID:25897831

  17. The future of airborne sulfur-containing particles in the absence of fossil fuel sulfur dioxide emissions

    PubMed Central

    Perraud, Véronique; Horne, Jeremy R.; Martinez, Andrew S.; Kalinowski, Jaroslaw; Meinardi, Simone; Dawson, Matthew L.; Wingen, Lisa M.; Dabdub, Donald; Blake, Donald R.; Gerber, R. Benny; Finlayson-Pitts, Barbara J.

    2015-01-01

    Sulfuric acid (H2SO4), formed from oxidation of sulfur dioxide (SO2) emitted during fossil fuel combustion, is a major precursor of new airborne particles, which have well-documented detrimental effects on health, air quality, and climate. Another precursor is methanesulfonic acid (MSA), produced simultaneously with SO2 during the atmospheric oxidation of organosulfur compounds (OSCs), such as dimethyl sulfide. In the present work, a multidisciplinary approach is used to examine how contributions of H2SO4 and MSA to particle formation will change in a large coastal urban area as anthropogenic fossil fuel emissions of SO2 decline. The 3-dimensional University of California Irvine–California Institute of Technology airshed model is used to compare atmospheric concentrations of gas phase MSA, H2SO4, and SO2 under current emissions of fossil fuel-associated SO2 and a best-case futuristic scenario with zero fossil fuel sulfur emissions. Model additions include results from (i) quantum chemical calculations that clarify the previously uncertain gas phase mechanism of formation of MSA and (ii) a combination of published and experimental estimates of OSC emissions, such as those from marine, agricultural, and urban processes, which include pet waste and human breath. Results show that in the zero anthropogenic SO2 emissions case, particle formation potential from H2SO4 will drop by about two orders of magnitude compared with the current situation. However, particles will continue to be generated from the oxidation of natural and anthropogenic sources of OSCs, with contributions from MSA and H2SO4 of a similar order of magnitude. This could be particularly important in agricultural areas where there are significant sources of OSCs. PMID:26483454

  18. One-step synthesis of carbon nanosheets converted from a polycyclic compound and their direct use as transparent electrodes of ITO-free organic solar cells

    NASA Astrophysics Data System (ADS)

    Son, Su-Young; Noh, Yong-Jin; Bok, Changsuk; Lee, Sungho; Kim, Byoung Gak; Na, Seok-In; Joh, Han-Ik

    2013-12-01

    Through a catalyst- and transfer-free process, we fabricated indium tin oxide (ITO)-free organic solar cells (OSCs) using a carbon nanosheet (CNS) with properties similar to graphene. The morphological and electrical properties of the CNS derived from a polymer of intrinsic microporosity-1 (PIM-1), which is mainly composed of several aromatic hydrocarbons and cycloalkanes, can be easily controlled by adjusting the polymer concentration. The CNSs, which are prepared by simple spin-coating and heat-treatment on a quartz substrate, are directly used as the electrodes of ITO-free OSCs, showing a high efficiency of approximately 1.922% under 100 mW cm-2 illumination and air mass 1.5 G conditions. This catalyst- and transfer-free approach is highly desirable for electrodes in organic electronics.Through a catalyst- and transfer-free process, we fabricated indium tin oxide (ITO)-free organic solar cells (OSCs) using a carbon nanosheet (CNS) with properties similar to graphene. The morphological and electrical properties of the CNS derived from a polymer of intrinsic microporosity-1 (PIM-1), which is mainly composed of several aromatic hydrocarbons and cycloalkanes, can be easily controlled by adjusting the polymer concentration. The CNSs, which are prepared by simple spin-coating and heat-treatment on a quartz substrate, are directly used as the electrodes of ITO-free OSCs, showing a high efficiency of approximately 1.922% under 100 mW cm-2 illumination and air mass 1.5 G conditions. This catalyst- and transfer-free approach is highly desirable for electrodes in organic electronics. Electronic supplementary information (ESI) available: Detailed experimental methods; chemical structure and 1H NMR spectra; AFM images; TGA spectra; shunt and series resistances; Raman spectra and optical images; atomic contents of the CNSs. See DOI: 10.1039/c3nr04828d

  19. Microwave-assisted of dispersive liquid-liquid microextraction and spectrophotometric determination of uranium after optimization based on Box-Behnken design and chemometrics methods

    NASA Astrophysics Data System (ADS)

    Niazi, Ali; Khorshidi, Neda; Ghaemmaghami, Pegah

    2015-01-01

    In this study an analytical procedure based on microwave-assisted dispersive liquid-liquid microextraction (MA-DLLME) and spectrophotometric coupled with chemometrics methods is proposed to determine uranium. In the proposed method, 4-(2-pyridylazo) resorcinol (PAR) is used as a chelating agent, and chloroform and ethanol are selected as extraction and dispersive solvent. The optimization strategy is carried out by using two level full factorial designs. Results of the two level full factorial design (24) based on an analysis of variance demonstrated that the pH, concentration of PAR, amount of dispersive and extraction solvents are statistically significant. Optimal condition for three variables: pH, concentration of PAR, amount of dispersive and extraction solvents are obtained by using Box-Behnken design. Under the optimum conditions, the calibration graphs are linear in the range of 20.0-350.0 ng mL-1 with detection limit of 6.7 ng mL-1 (3δB/slope) and the enrichment factor of this method for uranium reached at 135. The relative standard deviation (R.S.D.) is 1.64% (n = 7, c = 50 ng mL-1). The partial least squares (PLS) modeling was used for multivariate calibration of the spectrophotometric data. The orthogonal signal correction (OSC) was used for preprocessing of data matrices and the prediction results of model, with and without using OSC, were statistically compared. MA-DLLME-OSC-PLS method was presented for the first time in this study. The root mean squares error of prediction (RMSEP) for uranium determination using PLS and OSC-PLS models were 4.63 and 0.98, respectively. This procedure allows the determination of uranium synthesis and real samples such as waste water with good reliability of the determination.

  20. Assessing clinical communication skills in physicians: are the skills context specific or generalizable

    PubMed Central

    Baig, Lubna A; Violato, Claudio; Crutcher, Rodney A

    2009-01-01

    Background Communication skills are essential for physicians to practice Medicine. Evidence for the validity and domain specificity of communication skills in physicians is equivocal and requires further research. This research was conducted to adduce evidence for content and context specificity of communication skills and to assess the usefulness of a generic instrument for assessing communication skills in International Medical Graduates (IMGs). Methods A psychometric design was used for identifying the reliability and validity of the communication skills instruments used for high-stakes exams for IMG's. Data were collected from 39 IMGs (19 men – 48.7%; 20 women – 51.3%; Mean age = 41 years) assessed at 14 station OSCE and subsequently in supervised clinical practice with several instruments (patient surveys; ITERs; Mini-CEX). Results All the instruments had adequate reliability (Cronbach's alpha: .54 – .96). There were significant correlations (r range: 0.37 – 0.70, p < .05) of communication skills assessed by examiner with standardized patients, and of mini-CEX with patient surveys, and ITERs. The intra-item reliability across all cases for the 13 items was low (Cronbach's alpha: .20 – .56). The correlations of communication skills within method (e.g., OSCE or clinical practice) were significant but were non-significant between methods (e.g., OSCE and clinical practice). Conclusion The results provide evidence of context specificity of communication skills, as well as convergent and criterion-related validity of communication skills. Both in OSCEs and clinical practice, communication checklists need to be case specific, designed for content validity. PMID:19445685

  1. Al-TiO₂ composite-modified single-layer graphene as an efficient transparent cathode for organic solar cells.

    PubMed

    Zhang, Di; Xie, Fengxian; Lin, Peng; Choy, Wallace C H

    2013-02-26

    While there are challenges in tuning the properties of graphene (surface wettability, work function alignment, and carrier transport) for realizing an efficient graphene cathode in organic solar cells (OSCs), we propose and demonstrate using an Al-TiO₂ composite to modify single-layer graphene as an efficient cathode for OSCs. To unveil the contributions of the composite in addressing the aforementioned challenges, the evaporated aluminum nanoclusters in the composite benefit the graphene cathode by simultaneously achieving two roles of improving its surface wettability for subsequent TiO₂ deposition and reducing its work function to offer better energy alignment. To address challenges related to charge transport, solution-processed TiO₂ with excellent electron transport can offer charge extraction enhancement to the graphene cathode, which is essential to efficient devices. However, it is a well-known issue for methods such as spin-coating to produce uniform films on the initially hydrophobic graphene, even with improved wettability. The undesirable morphology of TiO₂ by such methods considerably inhibits its effectiveness in enhancing charge extraction. We propose a self-assembly method to deposit the solution-processed TiO₂ on the Al-covered graphene for forming the Al-TiO₂ composite. Compared with spin-coating, the self-assembly method is found to achieve more uniform coating on the graphene surface, with highly controllable thickness. Consequently, the graphene cathode modified with the Al-TiO₂ composite in inverted OSCs gives rise to enhanced power conversion efficiency of 2.58%, which is 2-fold of the previously best reported efficiency (1.27%) for graphene cathode OSCs, reaching ∼75% performance of control devices using indium tin oxide. PMID:23327464

  2. Patterned Growth of Organic Semiconductors: Selective Nucleation of Perylene on Self-Assembled Monolayers.

    PubMed

    Pick, André; Witte, Gregor

    2016-08-16

    Organic semiconductors (OSC) have received a large amount of attention because they afford the fabrication of flexible electronic devices. However, the limited resistance to radiation and etching of such materials does not permit their patterning by photolithography, which has been a driving force for the development of integrated circuits and therefore requires alternative structuring techniques. One approach is based on precoating the substrate with self-assembled monolayers (SAMs) to control the nucleation of subsequently deposited OSC layers, but the underlying mechanism is barely understood. Here, we used alkanethiols with different chemical terminations to prepare SAMs on gold substrates serving as model systems to identify the mechanism of selective nucleation for the case of the OSC perylene. Using atomic force microscopy and fluorescence microscopy, we demonstrate that the chemical functionalization of the SAMs determines the adhesion forces for the OSC that are smallest for CF3-terminated and largest for OH-terminated SAMs, hence yielding distinctly different sticking probabilities upon perylene deposition at room temperature. Microcontact printing and immersion were employed to prepare SAM patterns that enable the selective growth of polycrystalline perylene films. A quite different situation is found upon printing long-chain thiols with low vapor pressure, which leads to the transfer of multilayers and favors the growth of perylene single crystallites. In a more abstract scenario, patterns of silicone oil droplets were printed on a gold substrate, which was previously covered with a repelling fluorinated SAM. Such droplets provide nucleation centers for liquid-mediated growth, often yielding platelet-shaped perylene single crystallites without unwanted perylene nucleation on the remaining surface. PMID:27441921

  3. Correlating High Power Conversion Efficiency of PTB7:PC71BM Inverted Organic Solar Cells with Nanoscale Structures

    SciTech Connect

    Das, Sanjib; Keum, Jong Kahk; Browning, Jim; Gu, Gong; Yang, Bin; Do, Changwoo; Chen, Wei; Chen, Jihua; Ivanov, Ilia N; Hong, Kunlun; Rondinone, Adam J.; Joshi, Pooran C.; Geohegan, David B.; Xiao, Kai

    2015-01-01

    Advances in materials design and device engineering led to inverted organic solar cells (i-OSCs) with superior power conversion efficiencies (PCEs) to their conventional counterparts, in addition to the well-known better ambient stability. Despite the significant progress, however, it has so far been unclear how the morphologies of the photoactive layer and its interface with the cathode modifying layer impact device performance. Here, we report an in-depth morphology study of the i-OSC active and cathode modifying layers, employing a model system with the well-established bulk-heterojunction, PTB7:PC71BM as the active layer and poly-[(9,9-bis(3 -(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)] (PFN) as the cathode surface modifying layer. We have also identified the role of a processing additive, 1,8-diiodooctane (DIO), used in the spin-casting of the active layer to increase PCE. Using a variety of characterization techniques, we demonstrate that the high PCEs of i-OSCs are due to the smearing (diffusion) of electron-accepting PC71BM into the PFN layer, resulting in improved electron transport. The PC71BM diffusion occurs after spin-casting the active layer onto the PFN layer, when residual solvent molecules act as a plasticizer. The DIO additive, with a higher boiling point than the host solvent, has a longer residence time in the spin-cast active layer, resulting in more PC71BM smearing and therefore more efficient electron transport. This work provides important insight and guidance to further enhancement of i-OSC performance by materials and interface engineering.

  4. Co-functionalized organic/inorganic hybrid ZnO nanorods as electron transporting layers for inverted organic solar cells.

    PubMed

    Ambade, Swapnil B; Ambade, Rohan B; Eom, Seung Hun; Baek, Myung-Jin; Bagde, Sushil S; Mane, Rajaram S; Lee, Soo-Hyoung

    2016-03-01

    In an unprecedented attempt, we present an interesting approach of coupling solution processed ZnO planar nanorods (NRs) by an organic small molecule (SM) with a strong electron withdrawing cyano moiety and the carboxylic group as binding sites by a facile co-functionalization approach. Direct functionalization by SMs (SM-ZnO NRs) leads to higher aggregation owing to the weaker solubility of SMs in solutions of ZnO NRs dispersed in chlorobenzene (CB). A prior addition of organic 2-(2-methoxyethoxy)acetic acid (MEA) over ZnO NRs not only inhibits aggregation of SMs over ZnO NRs, but also provides enough sites for the SM to strongly couple with the ZnO NRs to yield transparent SM-MEA-ZnO NRs hybrids that exhibited excellent capability as electron transporting layers (ETLs) in inverted organic solar cells (iOSCs) of P3HT:PC60BM bulk-heterojunction (BHJ) photoactive layers. A strongly coupled SM-MEA-ZnO NR hybrid reduces the series resistance by enhancing the interfacial area and tunes the energy level alignment at the interface between the (indium-doped tin oxide, ITO) cathode and BHJ photoactive layers. A significant enhancement in power conversion efficiency (PCE) was achieved for iOSCs comprising ETLs of SM-MEA-ZnO NRs (3.64%) advancing from 0.9% for pristine ZnO NRs, while the iOSCs of aggregated SM-ZnO NRs ETL exhibited a much lower PCE of 2.6%, thus demonstrating the potential of the co-functionalization approach. The superiority of the co-functionalized SM-MEA-ZnO NRs ETL is also evident from the highest PCE of 7.38% obtained for the iOSCs comprising BHJ of PTB7-Th:PC60BM compared with extremely poor 0.05% for non-functionalized ZnO NRs. PMID:26864170

  5. US space commerce, 1991

    NASA Technical Reports Server (NTRS)

    Pace, Scott

    1992-01-01

    The topics are presented in viewgraph form and include the following: the US share of commercial payloads in comparison with Ariane's share; world communications satellite orders; the US share of prime contracts for construction of commercial communications satellites; emerging markets; space activities at the Commerce Department (DOC); Office of Space Commerce (OSC) mission description; key drivers for commercial space; and general DOC space policy themes.

  6. Lifestyle medicine curriculum for a preventive medicine residency program: implementation and outcomes

    PubMed Central

    Nawaz, Haq; Petraro, Paul V.; Via, Christina; Ullah, Saif; Lim, Lionel; Wild, Dorothea; Kennedy, Mary; Phillips, Edward M.

    2016-01-01

    Background The vast majority of the healthcare problems burdening our society today are caused by disease-promoting lifestyles (e.g., physical inactivity and unhealthy eating). Physicians report poor training and lack of confidence in counseling patients on lifestyle changes. Objective To evaluate a new curriculum and rotation in lifestyle medicine for preventive medicine residents. Methods Training included didactics (six sessions/year), distance learning, educational conferences, and newly developed lifestyle medicine rotations at the Institute of Lifestyle Medicine, the Yale-Griffin Prevention Research Center, and the Integrative Medicine Center. We used a number of tools to assess residents’ progress including Objective Structured Clinical Examinations (OSCEs), self-assessments, and logs of personal health habits. Results A total of 20 residents participated in the lifestyle medicine training between 2010 and 2013. There was a 15% increase in residents’ discussions of lifestyle issues with their patients based on their baseline and follow-up surveys. The performance of preventive medicine residents on OSCEs increased each year they were in the program (average OSCE score: PGY1 73%, PGY2 83%, PGY3 87%, and PGY4 91%, p=0.01). Our internal medicine and preliminary residents served as a control, since they did participate in didactics but not in lifestyle medicine rotations. Internal medicine and preliminary residents who completed the same OSCEs had a slightly lower average score (76%) compared with plural for resident, preventive medicine residents (80%). However, this difference did not reach statistical significance (p=0.11). Conclusion Incorporating the lifestyle medicine curriculum is feasible for preventive medicine training allowing residents to improve their health behavior change discussions with patients as well as their own personal health habits. PMID:27507540

  7. High-Mass Star Formation in the Outer Scutum-Centaurus Arm

    NASA Astrophysics Data System (ADS)

    Armentrout, William P.; Anderson, Loren D.; Balser, Dana S.; Bania, Thomas M.; Dame, Thomas M.; Wenger, Trey

    2016-01-01

    The HII Region Discovery Survey (HRDS; Bania et al., 2010) has discovered nearly 1000 HII regions by detecting their radio recombination line (RRL) emission using the Green Bank Telescope (GBT) and the Arecibo Observatory. Observations of RRLs allow us to measure source velocities and determine positions within the Galaxy using a rotation curve model, but until recently our sample in the far outer Galaxy was incomplete. Using HI and CO data, Dame & Thaddeus (2011) identified an extension of the Scutum-Centaurus spiral arm, deemed the Outer Scutum-Centaurus arm, or OSC. This arm offers a new laboratory for the study of Galactic structure, high-mass star formation, and chemistry of the outer Galaxy. We searched for new Galactic HII regions in the OSC by targeting infrared-identified candidates that have an (l,b) location consistent with this arm. We have discovered 10 OSC HII regions thus far, using observations of: (1) VLA 9 GHz continuum to identify thermally emitting sources, (2) GBT RRLs to detect evolved HII regions, and (3) GBT NH3 to detect younger HII regions. Detected regions lie at an average Heliocentric distance of 20.0 ± 1.4 kpc and an average Galactocentric distance of 14.5 ± 1.4 kpc. The most distant region detected has a Heliocentric distance of 23.5 kpc and a Galactocentric distance of 17.0 kpc. These are the most distant known Galactic high-mass star formation regions. We will present the results of ongoing NH3 observations with the GBT, which will likely increase the sample of OSC HII regions further.

  8. GPU-accelerated regularized iterative reconstruction for few-view cone beam CT

    SciTech Connect

    Matenine, Dmitri; Goussard, Yves

    2015-04-15

    Purpose: The present work proposes an iterative reconstruction technique designed for x-ray transmission computed tomography (CT). The main objective is to provide a model-based solution to the cone-beam CT reconstruction problem, yielding accurate low-dose images via few-views acquisitions in clinically acceptable time frames. Methods: The proposed technique combines a modified ordered subsets convex (OSC) algorithm and the total variation minimization (TV) regularization technique and is called OSC-TV. The number of subsets of each OSC iteration follows a reduction pattern in order to ensure the best performance of the regularization method. Considering the high computational cost of the algorithm, it is implemented on a graphics processing unit, using parallelization to accelerate computations. Results: The reconstructions were performed on computer-simulated as well as human pelvic cone-beam CT projection data and image quality was assessed. In terms of convergence and image quality, OSC-TV performs well in reconstruction of low-dose cone-beam CT data obtained via a few-view acquisition protocol. It compares favorably to the few-view TV-regularized projections onto convex sets (POCS-TV) algorithm. It also appears to be a viable alternative to full-dataset filtered backprojection. Execution times are of 1–2 min and are compatible with the typical clinical workflow for nonreal-time applications. Conclusions: Considering the image quality and execution times, this method may be useful for reconstruction of low-dose clinical acquisitions. It may be of particular benefit to patients who undergo multiple acquisitions by reducing the overall imaging radiation dose and associated risks.

  9. Carrier density effect on recombination in PTB7-based solar cell

    NASA Astrophysics Data System (ADS)

    Moritomo, Yutaka; Yonezawa, Kouhei; Yasuda, Takeshi

    2015-09-01

    Organic solar cells (OSCs) are promising alternatives to the conventional inorganic solar cells due to their low-cost processing and compatibility with flexible substrates. The development of low band-gap polymer, e.g., poly-[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b’]dithiophene-2,6-diyl] [3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3]thiophenediyl

  10. The Role of Self- and Peer Assessment in Dental Students' Reflective Practice Using Standardized Patient Encounters.

    PubMed

    Quick, Karin K

    2016-08-01

    The aim of this study was to gain insight into the nature of the role played by self- and peer assessment in the development of dental students' reflective practice skills and the value gained through structured encounters with standardized patients. Four standardized patient encounters in an objective structured clinical exam (OSCE) format served as a learning experience for students to demonstrate decision making and communication skills in complex scenarios regarding issues of ethics. Self- and peer assessment and peer-to-peer discourse were used to enhance student reflection. A sample of 16 peer pairs was randomly selected from the population of 108 fourth-year students who participated in the 2014 Clinical Dental Ethics OSCE. Data were collected from self- and peer assessment forms. Five overall performance themes (personal affect, verbal communication, professional demeanor, relationship-building, and patient management) and three student learning themes (application and knowledge, ways to change, and impressed with peer/increased confidence in self) were identified. The results showed that peer assessment ratings were consistently higher than those in the self-assessments, but overall the students deemed both their peers' and their own decision making and communication skills to be quite good. These students rated their experience with the OSCE and self- and peer assessments as positive, appreciating the importance of reflection and learning from their peers. These results provide support for the continued formative use of standardized patient OSCEs and self- and peer assessment to help students develop skills in decision making, communication, professionalism, and reflection. PMID:27480703

  11. Resident Ratings of Communication Skills Using the Kalamazoo Adapted Checklist

    PubMed Central

    Porcerelli, John H.; Brennan, Simone; Carty, Jennifer; Ziadni, Maisa; Markova, Tsveti

    2015-01-01

    Background The Kalamazoo Essential Elements Communication Checklist–Adapted (KEECC-A) is a well-regarded instrument for evaluating communication and interpersonal skills. To date, little research has been conducted that assesses the accuracy of resident self-ratings of their communication skills. Objective To assess whether residents can accurately self-rate communication skills, using the KEECC-A, during an objective structured clinical examination (OSCE). Methods A group of 104 residents from 8 specialties completed a multistation OSCE as part of an institutional communication skills curriculum conducted at a single institution. Standardized patients (SPs) and observers were trained in rating communication skills using the KEECC-A. Standardized patient ratings and resident self-ratings were completed immediately following each OSCE encounter, and trained observers rated archived videotapes of the encounters. Results Resident self-ratings and SP ratings using the KEECC-A were significantly correlated (r104 = 0.238, P = .02), as were resident self-ratings and observer ratings (r104 = 0.284, P = .004). The correlation between the SP ratings and observer (r104 = 0.378, P = .001) ratings were larger in magnitude, but not significantly different (P > .05) from resident/SP or resident/observer correlations. Conclusions The results suggest that residents, with a modicum of training using the KEECC-A, can accurately rate their own communication and interpersonal skills during an OSCE. Using trained observers to rate resident communication skills provides a unique opportunity for evaluating SP and resident self-ratings. Our findings also lend further support for the reliability and validity of the KEECC-A. PMID:26457156

  12. Dermatology – a compulsory part of the UK medical school curriculum?

    PubMed Central

    Shah, Hemal; Pozo-Garcia, Lucia; Koulouroudias, Marinos

    2015-01-01

    Dermatological conditions form a significant number of consultations seen by general practitioners on a daily basis. There is a lack of training and formal assessment of dermatology during medical school and we propose that there should be a mandatory component in OSCEs for dermatology during medical school to enhance one's diagnostic and clinical reasoning skills which will ultimately lead to better care for the patient and efficacious use of NHS resources. PMID:26701607

  13. Carrier density effect on recombination in PTB7-based solar cell

    PubMed Central

    Moritomo, Yutaka; Yonezawa, Kouhei; Yasuda, Takeshi

    2015-01-01

    Organic solar cells (OSCs) are promising alternatives to the conventional inorganic solar cells due to their low-cost processing and compatibility with flexible substrates. The development of low band-gap polymer, e.g., poly-[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2–b:4,5–b’]dithiophene-2,6-diyl] [3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3]thiophenediyl

  14. The future of airborne sulfur-containing particles in the absence of fossil fuel sulfur dioxide emissions.

    PubMed

    Perraud, Véronique; Horne, Jeremy R; Martinez, Andrew S; Kalinowski, Jaroslaw; Meinardi, Simone; Dawson, Matthew L; Wingen, Lisa M; Dabdub, Donald; Blake, Donald R; Gerber, R Benny; Finlayson-Pitts, Barbara J

    2015-11-01

    Sulfuric acid (H2SO4), formed from oxidation of sulfur dioxide (SO2) emitted during fossil fuel combustion, is a major precursor of new airborne particles, which have well-documented detrimental effects on health, air quality, and climate. Another precursor is methanesulfonic acid (MSA), produced simultaneously with SO2 during the atmospheric oxidation of organosulfur compounds (OSCs), such as dimethyl sulfide. In the present work, a multidisciplinary approach is used to examine how contributions of H2SO4 and MSA to particle formation will change in a large coastal urban area as anthropogenic fossil fuel emissions of SO2 decline. The 3-dimensional University of California Irvine-California Institute of Technology airshed model is used to compare atmospheric concentrations of gas phase MSA, H2SO4, and SO2 under current emissions of fossil fuel-associated SO2 and a best-case futuristic scenario with zero fossil fuel sulfur emissions. Model additions include results from (i) quantum chemical calculations that clarify the previously uncertain gas phase mechanism of formation of MSA and (ii) a combination of published and experimental estimates of OSC emissions, such as those from marine, agricultural, and urban processes, which include pet waste and human breath. Results show that in the zero anthropogenic SO2 emissions case, particle formation potential from H2SO4 will drop by about two orders of magnitude compared with the current situation. However, particles will continue to be generated from the oxidation of natural and anthropogenic sources of OSCs, with contributions from MSA and H2SO4 of a similar order of magnitude. This could be particularly important in agricultural areas where there are significant sources of OSCs. PMID:26483454

  15. Correlating High Power Conversion Efficiency of PTB7:PC71BM Inverted Organic Solar Cells with Nanoscale Structures

    DOE PAGESBeta

    Das, Sanjib; Keum, Jong Kahk; Browning, Jim; Gu, Gong; Yang, Bin; Do, Changwoo; Chen, Wei; Chen, Jihua; Ivanov, Ilia N; Hong, Kunlun; et al

    2015-01-01

    Advances in materials design and device engineering led to inverted organic solar cells (i-OSCs) with superior power conversion efficiencies (PCEs) to their conventional counterparts, in addition to the well-known better ambient stability. Despite the significant progress, however, it has so far been unclear how the morphologies of the photoactive layer and its interface with the cathode modifying layer impact device performance. Here, we report an in-depth morphology study of the i-OSC active and cathode modifying layers, employing a model system with the well-established bulk-heterojunction, PTB7:PC71BM as the active layer and poly-[(9,9-bis(3 -(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)] (PFN) as the cathode surface modifying layer. Wemore » have also identified the role of a processing additive, 1,8-diiodooctane (DIO), used in the spin-casting of the active layer to increase PCE. Using a variety of characterization techniques, we demonstrate that the high PCEs of i-OSCs are due to the smearing (diffusion) of electron-accepting PC71BM into the PFN layer, resulting in improved electron transport. The PC71BM diffusion occurs after spin-casting the active layer onto the PFN layer, when residual solvent molecules act as a plasticizer. The DIO additive, with a higher boiling point than the host solvent, has a longer residence time in the spin-cast active layer, resulting in more PC71BM smearing and therefore more efficient electron transport. This work provides important insight and guidance to further enhancement of i-OSC performance by materials and interface engineering.« less

  16. An immersive “simulation week” enhances clinical performance of incoming surgical interns improved performance persists at 6 months follow-up

    PubMed Central

    Singh, Pritam; Aggarwal, Rajesh; Pucher, Philip H.; Hashimoto, Daniel A.; Beyer-Berjot, Laura; Bharathan, Rasiah; Middleton, Katherine E.; Jones, Joanne; Darzi, Ara

    2015-01-01

    Background The transition from student to intern can be challenging. The “August” or “July effect” describes increased errors and reduced patient safety during this transition. The study objectives were to develop, pilot, and evaluate clinical performance after an immersive simulation course for incoming interns. Methods Graduating students were recruited for a 1-week immersive simulation course. Controls received no simulation training. Primary outcome (at baseline, and 1 and 6 months) was clinical performance on Objective Structured Clinical Examinations (OSCE) of clinical procedures and surgical technical skills. Secondary outcomes were self-reported confidence and clinical procedure logbook data. Results Nineteen students were recruited. Sixteen completed the 6-month follow-up, 10 in the intervention group and 6 in the control group. No differences were demonstrated between interventions and controls at baseline (OSCE [median, 66 vs 78; P = .181], technical skills [48 vs 52.5; P = .381], and confidence [101 vs 96; P = .368]). Interventions outperformed controls at 1 month (OSCE [111 vs 82; P = .001], technical skills [78.5 vs 63; P = .030], and confidence [142 vs 119; P < .001]), and 6 months (OSCE [107 vs 93; P = .007], technical skills [92.5 vs 69; P = .044], and confidence [148 vs 129; P = .022]). No differences were observed in numbers of clinical procedures performed at 1 (P = .958), 4 (P = .093), or 6 months (P = .713). Conclusion The immersive simulation course objectively improved subjects’ clinical skills, technical skills, and confidence. Despite similar clinical experience as controls, the intervention group’s improved performance persisted at 6 months follow-up. This feasible and effective intervention to ease transition from student to intern could reduce errors and enhance patient safety. PMID:25633735

  17. Microwave-assisted of dispersive liquid-liquid microextraction and spectrophotometric determination of uranium after optimization based on Box-Behnken design and chemometrics methods.

    PubMed

    Niazi, Ali; Khorshidi, Neda; Ghaemmaghami, Pegah

    2015-01-25

    In this study an analytical procedure based on microwave-assisted dispersive liquid-liquid microextraction (MA-DLLME) and spectrophotometric coupled with chemometrics methods is proposed to determine uranium. In the proposed method, 4-(2-pyridylazo) resorcinol (PAR) is used as a chelating agent, and chloroform and ethanol are selected as extraction and dispersive solvent. The optimization strategy is carried out by using two level full factorial designs. Results of the two level full factorial design (2(4)) based on an analysis of variance demonstrated that the pH, concentration of PAR, amount of dispersive and extraction solvents are statistically significant. Optimal condition for three variables: pH, concentration of PAR, amount of dispersive and extraction solvents are obtained by using Box-Behnken design. Under the optimum conditions, the calibration graphs are linear in the range of 20.0-350.0 ng mL(-1) with detection limit of 6.7 ng mL(-1) (3δB/slope) and the enrichment factor of this method for uranium reached at 135. The relative standard deviation (R.S.D.) is 1.64% (n=7, c=50 ng mL(-1)). The partial least squares (PLS) modeling was used for multivariate calibration of the spectrophotometric data. The orthogonal signal correction (OSC) was used for preprocessing of data matrices and the prediction results of model, with and without using OSC, were statistically compared. MA-DLLME-OSC-PLS method was presented for the first time in this study. The root mean squares error of prediction (RMSEP) for uranium determination using PLS and OSC-PLS models were 4.63 and 0.98, respectively. This procedure allows the determination of uranium synthesis and real samples such as waste water with good reliability of the determination. PMID:25062051

  18. Dentine oxygen isotopes (δ (18)O) as a proxy for odontocete distributions and movements.

    PubMed

    Matthews, Cory J D; Longstaffe, Fred J; Ferguson, Steven H

    2016-07-01

    Spatial variation in marine oxygen isotope ratios (δ (18)O) resulting from differential evaporation rates and precipitation inputs is potentially useful for characterizing marine mammal distributions and tracking movements across δ (18)O gradients. Dentine hydroxyapatite contains carbonate and phosphate that precipitate in oxygen isotopic equilibrium with body water, which in odontocetes closely tracks the isotopic composition of ambient water. To test whether dentine oxygen isotope composition reliably records that of ambient water and can therefore serve as a proxy for odontocete distribution and movement patterns, we measured δ (18)O values of dentine structural carbonate (δ (18) OSC) and phosphate (δ (18) OP) of seven odontocete species (n = 55 individuals) from regional marine water bodies spanning a surface water δ (18)O range of several per mil. Mean dentine δ (18) OSC (range +21.2 to +25.5‰ VSMOW) and δ (18) OP (+16.7 to +20.3‰) values were strongly correlated with marine surface water δ (18)O values, with lower dentine δ (18) OSC and δ (18) OP values in high-latitude regions (Arctic and Eastern North Pacific) and higher values in the Gulf of California, Gulf of Mexico, and Mediterranean Sea. Correlations between dentine δ (18) OSC and δ (18) OP values with marine surface water δ (18)O values indicate that sequential δ (18)O measurements along dentine, which grows incrementally and archives intra- and interannual isotopic composition over the lifetime of the animal, would be useful for characterizing residency within and movements among water bodies with strong δ (18)O gradients, particularly between polar and lower latitudes, or between oceans and marginal basins. PMID:27547302

  19. Effect of respiration on Korotkoff sounds and oscillometric cuff pressure pulses during blood pressure measurement.

    PubMed

    Zheng, Dingchang; Di Marco, Luigi Yuri; Murray, Alan

    2014-05-01

    Blood pressure (BP) measurement accuracy depends on consistent changes in Korotkoff sounds (KorS) for manual measurement and oscillometric pulses for automated measurement, yet little is known about the direct effect of respiration on these physiological signals. The aim of this research was to quantitatively assess the modulation effect of respiration on Korotkoff sounds and oscillometric pulses. Systolic and diastolic blood pressures were measured manually from 30 healthy subjects (age 41 ± 12 years). Three static cuff pressure conditions were studied for two respiratory rates. Cuff pressure [with oscillometric pulses (OscP)], ECG, chest motion respiration [respiration signal (Resp), from magnetometer] and Korotkoff sounds (KorS, from digital stethoscope) were recorded twice for 20 s. The physiological data were evenly resampled. Respiratory frequency was calculated from Resp (fR), OscP (fO) and KorS (fK) from peak spectral frequency. There was no statistically significant difference between fR and fO or fK. Respiratory modulation was observed in all subjects. OscP amplitude modulation changed significantly between the two respiratory rates (p < 0.05) and between the three cuff pressures (p < 0.0001), and decreased significantly with decreasing cuff pressure (p < 0.05). The phase shift between Resp and modulation of OscP was statistically significant with respiratory rates (p < 0.05), but not with cuff pressures. It is accepted that BP in individuals is variable and that this relates to respiration; we now show that this respiration modulates oscillometric pulse and Korotkoff sound amplitudes from which BP is measured. PMID:24668326

  20. Effect of novel patient interaction on students’ performance of pregnancy options counseling

    PubMed Central

    Shaddeau, Angela; Nimz, Abigail; Sheeder, Jeanelle; Tocce, Kristina

    2015-01-01

    Background Although options counseling is a fundamental skill for medical providers, previous research has identified gaps in medical school reproductive health education. Purpose To determine if a 1-h novel patient interaction (NPI) improves student performance when caring for a standardized patient with an unintended pregnancy. Methods From September 2012 to June 2013 we randomized third-year medical students at the University of Colorado School of Medicine to the standard curriculum plus an NPI, or the standard curriculum only. The NPI consisted of a 1-h small-group session with a patient who discussed her experiences with options counseling and her decision to terminate her pregnancy. Students completed an Objective Structured Clinical Examination (OSCE) at the rotation's end, which included options counseling. The primary outcome was the proportion of participants achieving ‘excellence’ on the OSCE checklist. ‘Excellence’ was defined as a score ≥90%. Examinations were flagged as ‘unsatisfactory encounters’ if core competencies were not addressed. OSCE standardized patients and evaluators were blinded to group assignment. Results In total, 135 students were eligible and randomized: 75 to NPI; 60 to control. During the OSCE, few students achieved ‘excellence’ (24% NPI vs. 28% control, p=0.57). There were no differences between scores for components of options counseling. More students in the control group ‘appeared somewhat uncomfortable’ delivering the pregnancy test results (5% NPI vs. 18% control, p=0.006). More than half (54%) of the intervention group and 67% of controls had ‘unsatisfactory encounters’ (p=0.16), almost exclusively due to omission of adoption. Most students addressed abortion (96% NPI vs. 92% control, p=0.29). Conclusions A 1-h NPI does not improve medical students’ performance of pregnancy options counseling and the option of adoption is routinely omitted. Adoption is clearly an area that needs greater attention

  1. Solution-Processable Small Molecules for High-Performance Organic Solar Cells with Rigidly Fluorinated 2,2'-Bithiophene Central Cores.

    PubMed

    Wang, Zhenguo; Li, Zuojia; Liu, Jiang; Mei, Jun; Li, Kai; Li, Ying; Peng, Qiang

    2016-05-11

    Small molecules containing an oligothiophene backbone are simple but effective donor materials for organic solar cells (OSCs). In this work, we incorporated rigid 2,2'-bithiophene (BT) or fluorinated 2,2'-bithiophene (FBT) as the central unit and synthesized two novel small molecules (TTH-D3TRh and TTF-D3TRh) with an oligothiophene backbone and 3-ethylrhodanine end groups. Both molecules exhibit good thermal stability as well as strong and broad absorption. The fluorination of the BT central unit made TTF-D3TRh possess a relatively lower-lying HOMO energy level, better molecular stacking, and higher mobility in comparison with those of TTH-D3TRh. Conventional OSCs were fabricated to evaluate the photovoltaic property of these two molecules. Without extra post-treatments, the conventional devices based on TTH-D3TRh and TTF-D3TRh showed high PCEs of 5.00 and 5.80%, respectively. The TTF-D3TRh device exhibited a higher performance, which can be attributed to the improved Voc of 0.92 V, Jsc of 10.04 mA cm(-2), and FF of 62.8%. Using an inverted device structure, the OSCs based on TTH-D3TRh and TTF-D3TRh showed largely elevated PCEs of 5.89 and 7.14%, respectively. The results indicated that the structurally simple TTH-D3TRh and TTF-D3TR molecules are potential donor candidates for achieving highly efficient OSCs. The strategy of fluorination and rigidity designation is an effective approach to develop oligothiophene-based small molecular donors for highly efficient solar cell applications. PMID:27097642

  2. Test of Optical Stochastic Cooling in the IOTA Ring

    SciTech Connect

    Lebedev, V. A.; Tokpanov, Yu.; Zolotorev, M. S.

    2013-09-26

    A new 150 MeV electron storage ring is being built at Fermilab. The construction of a new machine pursues two goals a test of highly non-linear integrable optics and a test of optical stochastic cooling. This paper discusses details of OSC arrangements, choice of major parameters of the cooling scheme and incoming experimental tests of the optical amplifier prototype which uses highly doped Ti-sapphire crystal as amplification medium.

  3. Porphyromonas gingivalis increases the invasiveness of oral cancer cells by upregulating IL-8 and MMPs.

    PubMed

    Ha, Na Hee; Park, Dae Gun; Woo, Bok Hee; Kim, Da Jeong; Choi, Jeom Il; Park, Bong Soo; Kim, Yong Deok; Lee, Ji Hye; Park, Hae Ryoun

    2016-10-01

    Recent studies indicate that chronic inflammation promotes the aggressiveness of cancers. However, the direct molecular mechanisms underlying a functional link between chronic periodontitis, the most common form of oral inflammatory diseases, and the malignancy of oral cancer remain unknown. To elucidate the role of chronic periodontitis in progression of oral cancer, we examined the effect of Porphyromonas gingivalis (P. gingivalis), a major pathogen that causes chronic periodontitis, on the invasiveness of oral squamous cell carcinoma (OSCC) cells, including SCC-25, OSC-20 and SAS cells. Exposures to P. gingivalis promoted the invasive ability of OSC-20 and SAS cells via the upregulation of matrix metalloproteinases (MMPs), specifically MMP-1 and MMP-2. However, P. gingivalis-infected SCC-25 cells did not exhibit changes in their invasive properties or the low expression levels of MMPs. In an effort to delineate the molecular players that control the invasiveness, we first assessed the level of interleukin-8 (IL-8), a well-known inflammatory cytokine, in P. gingivalis-infected OSCC cells. IL-8 secretion was substantially increased in the OSC-20 and SAS cells, but not in the SCC-25 cells, following P. gingivalis infection. When IL-8 was directly applied to SCC-25 cells, their invasive ability and MMP level were significantly increased. Furthermore, the downregulation of IL-8 in P. gingivalis-infected OSC-20 and SAS cells attenuated their invasive potentials and MMP levels. Taken together, our findings strongly suggest that P. gingivalis infection plays an important role in the promotion of the invasive potential of OSCC cells via the upregulation of IL-8 and MMPs. PMID:27468958

  4. Objective structured clinical examination for pharmacy students in Qatar: cultural and contextual barriers to assessment.

    PubMed

    Wilby, K J; Black, E K; Austin, Z; Mukhalalati, B; Aboulsoud, S; Khalifa, S I

    2016-04-01

    This study aimed to evaluate the feasibility and psychometric defensibility of implementing a comprehensive objective structured clinical examination (OSCE) on the complete pharmacy programme for pharmacy students in a Middle Eastern context, and to identify facilitators and barriers to implementation within new settings. Eight cases were developed, validated, and had standards set according to a blueprint, and were assessed with graduating pharmacy students. Assessor reliability was evaluated using inter-class coefficients (ICCs). Concurrent validity was evaluated by comparing OSCE results to professional skills course grades. Field notes were maintained to generate recommendations for implementation in other contexts. The examination pass mark was 424 points out of 700 (60.6%). All 23 participants passed. Mean performance was 74.6%. Low to moderate inter-rater reliability was obtained for analytical and global components (average ICC 0.77 and 0.48, respectively). In conclusion, OSCE was feasible in Qatar but context-related validity and reliability concerns must be addressed prior to future iterations in Qatar and elsewhere. PMID:27432407

  5. Challenges associated with the sampling and analysis of organosulfur compounds in air using real-time PTR-ToF-MS and offline GC-FID

    NASA Astrophysics Data System (ADS)

    Perraud, Véronique; Meinardi, Simone; Blake, Donald R.; Finlayson-Pitts, Barbara J.

    2016-03-01

    Organosulfur compounds (OSCs) are naturally emitted via various processes involving phytoplankton and algae in marine regions, from animal metabolism, and from biomass decomposition inland. These compounds are malodorant and reactive. Their oxidation to methanesulfonic and sulfuric acids leads to the formation and growth of atmospheric particles, which are known to influence clouds and climate, atmospheric chemical processes. In addition, particles in air have been linked to negative impacts on visibility and human health. Accurate measurements of the OSC precursors are thus essential to reduce uncertainties in their sources and contributions to particle formation in air. Two different approaches, proton-transfer reaction time-of-flight mass spectrometry (PTR-ToF-MS) and canister sampling coupled to gas chromatography with flame ionization detector (GC-FID), are compared for both laboratory standards (dimethyl sulfide, DMS; dimethyl disulfide, DMDS; dimethyl trisulfide, DMTS; and methanethiol, MTO) and for a complex sample. Results show that both techniques produce accurate quantification of DMS. While PTR-ToF-MS provides real-time measurements of all four OSCs individually, significant fragmentation of DMDS and DMTS occurs, which can complicate their identification in complex mixtures. Canister sampling coupled with GC-FID provides excellent sensitivity for DMS, DMDS, and DMTS. However, MTO was observed to react on metal surfaces to produce DMDS and, in the presence of hydrogen sulfide, even DMTS. Avoiding metal in sampling systems seems to be necessary for measuring all but dimethyl sulfide in air.

  6. Morphological study on small molecule acceptor-based organic solar cells with efficiencies beyond 7% (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Ma, Wei; Yan, He

    2015-10-01

    Despite the essential role of fullerenes in achieving best-performance organic solar cells (OSCs), fullerene acceptors have several drawbacks including poor light absorption, high-cost production and purification. For this reason, small molecule acceptor (SMA)-based OSCs have attracted much attention due to the easy tunability of electronic and optical properties of SMA materials. In this study, polymers with temperature dependent aggregation behaviors are combined with various small molecule acceptor materials, which lead to impressive power conversion efficiencies of up to 7.3%. The morphological and aggregation properties of the polymer:small molecule blends are studied in details. It is found that the temperature-dependent aggregation behavior of polymers allows for the processing of the polymer solutions at moderately elevated temperature, and more importantly, controlled aggregation and strong crystallization of the polymer during the film cooling and drying process. This results in a well-controlled and near-ideal polymer:small molecule morphology that is controlled by polymer aggregation during warm casting and thus insensitive to the choice of small molecules. As a result, several cases of highly efficient (PCE between 6-7.3%) SMA OSCs are achieved. The second part of this presentation will describe the morphology of a new small molecule acceptor with a unique 3D structure. The relationship between molecular structure and morphology is revealed.

  7. Study of the structure and oxygen storage/release capacities of Dy1-xYxMnO3+δ (0 <= x <= 1)

    NASA Astrophysics Data System (ADS)

    Remsen, Steven; Dabrowski, Bogdan; Chmaissem, Omar; Kolesnik, Stanislaw; Mais, James

    2009-11-01

    Synthesis, oxygen storage/release capacities (OSC), oxygen absorption/desorption rates, and preliminary structural properties of Dy1-xYxMnO3+δ(0 <= x <= 1) have been studied by x-ray and neutron powder diffraction, dilatometry, and thermogravimetric analysis. This system has been found to have excellent reversible OSC at low-temperatures of 200 - 375 C and oxygen content of these structures have also been found to be sensitive to changes of partial-pressures of oxygen in this low-temperature range, making them potential candidates for oxygen sorbents in novel gas separation methods such as thermal swing absorption and thermal-automatic recovery processes. The OSC of the Dy1-xYxMnO3+δsystem relies on the difference in oxygen content of a reversible phase transition between hexagonal P63cm (δ = 0) and a previously unreported phase of this system (δ = 0.25, currently under investigation) and pyrochlore Fd3m (δ = 0.50, Subramanian et al. J. Solid State Chem. 72 (1988) 24).

  8. Broadband light absorption enhancement in moth's eye nanostructured organic solar cells

    NASA Astrophysics Data System (ADS)

    Lan, Weixia; Cui, Yanxia; Yang, Qingyi; Lo, Ming-Fai; Lee, Chun-Sing; Zhu, Furong

    2015-05-01

    A comprehensive study on inverted organic solar cells (OSCs) with a moth's eye nanostructured (MEN) active layer was carried out. Performance of the MEN-based OSCs and the corresponding control planar cells, fabricated with blend of poly[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-bA] dithiophene-2, 6-diyl][3-fluoro-2-[(2- ethylhexyl) carbonyl]thieno[3,4-b]-thiophenediyl] (PTB7):[6,6]- phenyl-C70- butyric-acid-methyl-ester (PC70BM) was analyzed. The efficiency of the MEN-based OSCs was optimized by adjusting the height of MEN pattern in the active layer. Our experimental and theoretical results reveal that the MEN pattern enhances light absorption in the PTB7:PC70BM active layer, especially over the long wavelength region. This leads to a 7.8% increase in short circuit current density and a 6.1% increase in power conversion efficiency over those of the control planar cell.

  9. Rational Design of Diketopyrrolopyrrole-Based Small Molecules as Donating Materials for Organic Solar Cells

    PubMed Central

    Jin, Ruifa; Wang, Kai

    2015-01-01

    A series of diketopyrrolopyrrole-based small molecules have been designed to explore their optical, electronic, and charge transport properties as organic solar cell (OSCs) materials. The calculation results showed that the designed molecules can lower the band gap and extend the absorption spectrum towards longer wavelengths. The designed molecules own the large longest wavelength of absorption spectra, the oscillator strength, and absorption region values. The optical, electronic, and charge transport properties of the designed molecules are affected by the introduction of different π-bridges and end groups. We have also predicted the mobility of the designed molecule with the lowest total energies. Our results reveal that the designed molecules are expected to be promising candidates for OSC materials. Additionally, the designed molecules are expected to be promising candidates for electron and/or hole transport materials. On the basis of our results, we suggest that molecules under investigation are suitable donors for [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) and its derivatives as acceptors of OSCs. PMID:26343640

  10. Plasmonically sensitized metal-oxide electron extraction layers for organic solar cells

    PubMed Central

    Trost, S.; Becker, T.; Zilberberg, K.; Behrendt, A.; Polywka, A.; Heiderhoff, R.; Görrn, P.; Riedl, T.

    2015-01-01

    ZnO and TiOx are commonly used as electron extraction layers (EELs) in organic solar cells (OSCs). A general phenomenon of OSCs incorporating these metal-oxides is the requirement to illuminate the devices with UV light in order to improve device characteristics. This may cause severe problems if UV to VIS down-conversion is applied or if the UV spectral range (λ < 400 nm) is blocked to achieve an improved device lifetime. In this work, silver nanoparticles (AgNP) are used to plasmonically sensitize metal-oxide based EELs in the vicinity (1–20 nm) of the metal-oxide/organic interface. We evidence that plasmonically sensitized metal-oxide layers facilitate electron extraction and afford well-behaved highly efficient OSCs, even without the typical requirement of UV exposure. It is shown that in the plasmonically sensitized metal-oxides the illumination with visible light lowers the WF due to desorption of previously ionosorbed oxygen, in analogy to the process found in neat metal oxides upon UV exposure, only. As underlying mechanism the transfer of hot holes from the metal to the oxide upon illumination with hν < Eg is verified. The general applicability of this concept to most common metal-oxides (e.g. TiOx and ZnO) in combination with different photoactive organic materials is demonstrated. PMID:25592174

  11. Improving charge transport of P3HT:PCBM organic solar cell using MoO3 nanoparticles as an interfacial buffer layer

    NASA Astrophysics Data System (ADS)

    Kim, Jae-Hyoung; Park, Eung-Kyu; Kim, Ji-Hwan; Cho, Hyeong Jun; Lee, Dong-Hoon; Kim, Yong-Sang

    2016-05-01

    In this work, P3HT:PCBM based organic solar cells (OSCs) were fabricated. We investigated the protection of PEDOT:PSS from active layer using the solution processed molybdenum oxide nanoparticles layer (MoO3 NPs, ≤100 nm). The device structure was ITO/ZnO/P3HT: PCBM/MoO3/PEDOT:PSS/Ag. A thin film MoO3 NPs was spin-coated and it acts as a hole transporting layer between the active layer and PEDOT:PSS. The MoO3 NPs based device showed an improved short circuit current compared without MoO3 NP layer. The pristine OSCs showed short circuit current density ( J sc ) of 11.56 mA/cm2 and PCE of 3.70% under AM 1.5G (100 mW/cm2). MoO3 NPs based device showed an increased PCE of 4.11% with J sc of 12.74 mA/cm2. MoO3 NPs also decreased the charge recombination and resistance of the OSCs. [Figure not available: see fulltext.

  12. An implementation of SISAL for distributed-memory architectures

    SciTech Connect

    Beard, P.C.

    1995-06-01

    This thesis describes a new implementation of the implicitly parallel functional programming language SISAL, for massively parallel processor supercomputers. The Optimizing SISAL Compiler (OSC), developed at Lawrence Livermore National Laboratory, was originally designed for shared-memory multiprocessor machines and has been adapted to distributed-memory architectures. OSC has been relatively portable between shared-memory architectures, because they are architecturally similar, and OSC generates portable C code. However, distributed-memory architectures are not standardized -- each has a different programming model. Distributed-memory SISAL depends on a layer of software that provides a portable, distributed, shared-memory abstraction. This layer is provided by Split-C, a dialect of the C programming language developed at U.C. Berkeley, which has demonstrated good performance on distributed-memory architectures. Split-C provides important capabilities for good performance: support for program-specific distributed data structures, and split-phase memory operations. Distributed data structures help achieve good memory locality, while split-phase memory operations help tolerate the longer communication latencies inherent in distributed-memory architectures. The distributed-memory SISAL compiler and run-time system takes advantage of these capabilities. The results of these efforts is a compiler that runs identically on the Thinking Machines Connection Machine (CM-5), and the Meiko Computing Surface (CS-2).

  13. Using digital flow cytometry to assess the degradation of three cyanobacteria species after oxidation processes.

    PubMed

    Wert, Eric C; Dong, Mei Mei; Rosario-Ortiz, Fernando L

    2013-07-01

    Depending on drinking water treatment conditions, oxidation processes may result in the degradation of cyanobacteria cells causing the release of toxic metabolites (microcystin), odorous metabolites (MIB, geosmin), or disinfection byproduct precursors. In this study, a digital flow cytometer (FlowCAM(®)) in combination with chlorophyll-a analysis was used to evaluate the ability of ozone, chlorine, chlorine dioxide, and chloramine to damage or lyse cyanobacteria cells added to Colorado River water. Microcystis aeruginosa (MA), Oscillatoria sp. (OSC) and Lyngbya sp. (LYN) were selected for the study due to their occurrence in surface water supplies, metabolite production, and morphology. Results showed that cell damage was observed without complete lysis or fragmentation of the cell membrane under many of the conditions tested. During ozone and chlorine experiments, the unicellular MA was more susceptible to oxidation than the filamentous OSC and LYN. Rate constants were developed based on the loss of chlorophyll-a and oxidant exposure, which showed the oxidants degraded MA, OSC, and LYN according to the order of ozone > chlorine ~ chlorine dioxide > chloramine. Digital and binary images taken by the digital flow cytometer provided qualitative insight regarding cell damage. When applying this information, drinking water utilities can better understand the risk of cell damage or lysis during oxidation processes. PMID:23726712

  14. Reactivation of an aged commercial three-way catalyst by oxalic and citric acid washing.

    PubMed

    Christou, Stavroula Y; Birgersson, Henrik; Fierro, José L G; Efstathiou, Angelos M

    2006-03-15

    The efficiency of dilute oxalic and citric acid solutions on improving the oxygen storage capacity (OSC) and catalytic activity of a severely aged (83,000 km) commercial three-way catalyst (TWC) has been investigated. Washing procedures applied after optimization of experimental parameters, namely, temperature, flow-rate, and concentration of acid solution, led to significant improvements of OSC and catalytic activity (based on dynamometer test measurements) of the aged TWC. The latterwas made possible due to the removal of significant amounts of various contaminants accumulated on the catalyst surface (e.g., P, S, Pb, Ca, Zn, Si, Fe, Cu, and Ni) during driving conditions, as revealed by Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES) and X-ray Photoelectron Spectroscopy (XPS) analyses. For the first time, it is demonstrated that dilute oxalic acid solution significantly improves the catalytic activity of an aged commercial TWC toward CO, Cx,Hy, and NOx conversions under real exhaust gas conditions (dynamometer tests) by two to eight times in the 250-450 degrees C range and the OSC quantity by up to 50%. Oxalic acid appears to be more efficient than citric acid in removing specifically P- and S-containing compounds from the catalyst surface, whereas citric acid in removing Pb- and Zn-containing compounds, thus uncovering surface active catalytic sites. PMID:16570632

  15. Transposable element dynamics and PIWI regulation impacts lncRNA and gene expression diversity in Drosophila ovarian cell cultures

    PubMed Central

    Sytnikova, Yuliya A.; Rahman, Reazur; Chirn, Gung-wei; Clark, Josef P.

    2014-01-01

    Piwi proteins and Piwi-interacting RNAs (piRNAs) repress transposable elements (TEs) from mobilizing in gonadal cells. To determine the spectrum of piRNA-regulated targets that may extend beyond TEs, we conducted a genome-wide survey for transcripts associated with PIWI and for transcripts affected by PIWI knockdown in Drosophila ovarian somatic sheet (OSS) cells, a follicle cell line expressing the Piwi pathway. Despite the immense sequence diversity among OSS cell piRNAs, our analysis indicates that TE transcripts are the major transcripts associated with and directly regulated by PIWI. However, several coding genes were indirectly regulated by PIWI via an adjacent de novo TE insertion that generated a nascent TE transcript. Interestingly, we noticed that PIWI-regulated genes in OSS cells greatly differed from genes affected in a related follicle cell culture, ovarian somatic cells (OSCs). Therefore, we characterized the distinct genomic TE insertions across four OSS and OSC lines and discovered dynamic TE landscapes in gonadal cultures that were defined by a subset of active TEs. Particular de novo TEs appeared to stimulate the expression of novel candidate long noncoding RNAs (lncRNAs) in a cell lineage-specific manner, and some of these TE-associated lncRNAs were associated with PIWI and overlapped PIWI-regulated genes. Our analyses of OSCs and OSS cells demonstrate that despite having a Piwi pathway to suppress endogenous mobile elements, gonadal cell TE landscapes can still dramatically change and create transcriptome diversity. PMID:25267525

  16. Effect of fluorine plasma treatment with chemically reduced graphene oxide thin films as hole transport layer in organic solar cells

    NASA Astrophysics Data System (ADS)

    Yu, Youn-Yeol; Kang, Byung Hyun; Lee, Yang Doo; Lee, Sang Bin; Ju, Byeong-Kwon

    2013-12-01

    The inorganic materials such as V2O5, MoO3 and WO3 were investigated to replace PEDOT:PSS as hole transport layer (HTL) in organic electronic devices such as organic solar cells (OSCs) and organic lighting emission diodes. However, these methods require vacuum techniques that are long time process and complex. Here, we report about plasma treatment with SF6 and CF4 using reactive ion etching on reduced graphene oxide (rGO) thin films that are obtained using an eco-friendly method with vitamin C. The plasma treated rGO thin films have dipoles since they consist of covalent bonds with fluorine on the surface of rGO. This means it is possible to increase the electrostatic potential energy than bare rGO. Increased potential energy on the surface of rGO films is worth applying organic electronic devices as HTL such as OSCs. Consequently, the power conversion efficiency of OSCs increased more than the rGO films without plasma treatment.

  17. 1H Nuclear Magnetic Resonance (NMR) Metabolomic Study of Chronic Organophosphate Exposure in Rats

    PubMed Central

    Alam, Todd M.; Neerathilingam, Muniasamy; Alam, M. Kathleen; Volk, David E.; Ansari, G. A. Shakeel; Sarkar, Swapna; Luxon, Bruce A.

    2012-01-01

    1H NMR spectroscopy and chemometric analysis were used to characterize rat urine obtained after chronic exposure to either tributyl phosphate (TBP) or triphenyl phosphate (TPP). In this study, the daily dose exposure was 1.5 mg/kg body weight for TBP, or 2.0 mg/kg body weight for TPP, administered over a 15-week period. Orthogonal signal correction (OSC) -filtered partial least square discriminant analysis (OSC-PLSDA) was used to predict and classify exposure to these organophosphates. During the development of the model, the classification error was evaluated as a function of the number of latent variables. NMR spectral regions and corresponding metabolites important for determination of exposure type were identified using variable importance in projection (VIP) coefficients obtained from the OSC-PLSDA analysis. As expected, the model for classification of chronic (1.5–2.0 mg/kg body weight daily) TBP or TPP exposure was not as strong as the previously reported model developed for identifying acute (15–20 mg/kg body weight) exposure. The set of majorly impacted metabolites identified for chronic TBP or TPP exposure was slightly different than those metabolites previously identified for acute exposure. These metabolites were then mapped to different metabolite pathways and ranked, allowing the metabolic response to chronic organophosphate exposure to be addressed. PMID:24957643

  18. Self-oscillation of standing spin wave in ring resonator with proportional-integral-derivative control

    SciTech Connect

    Peng, B.; Urazuka, Y.; Chen, H.; Oyabu, S.; Otsuki, H.; Tanaka, T. Matsuyama, K.

    2014-05-07

    We report on numerical analysis on self-oscillation of standing spin wave excited in a nanostructured active ring resonator, consists of a ferromagnetic nanowire with perpendicular anisotropy. The confined resonant modes are along the nanowire length. A positive feedback with proportional-integral-derivative gain control was adopted in the active ring. Stable excitation of the 1st order standing spin wave has been demonstrated with micromagnetic simulations, taking into account the thermal effect with a random field model. The stationary standing spin wave with a pre-determined set variable of precession amplitude was attained within 20 ns by optimizing the proportional-integral-derivative gain control parameters. The result indicates that a monochromatic oscillation frequency f{sub osc} is extracted from the initial thermal fluctuation state and selectively amplified with the positive feedback loop. The obtained f{sub osc} value of 5.22 GHz practically agrees with the theoretical prediction from dispersion relation of the magneto static forward volume wave. It was also confirmed that the f{sub osc} change due to the temperature rise can be compensated with an external perpendicular bias field H{sub b}. The observed quick compensation time with an order of nano second suggests the fast operation speed in the practical device application.

  19. High-Performance Electron Acceptor with Thienyl Side Chains for Organic Photovoltaics.

    PubMed

    Lin, Yuze; Zhao, Fuwen; He, Qiao; Huo, Lijun; Wu, Yang; Parker, Timothy C; Ma, Wei; Sun, Yanming; Wang, Chunru; Zhu, Daoben; Heeger, Alan J; Marder, Seth R; Zhan, Xiaowei

    2016-04-13

    We develop an efficient fused-ring electron acceptor (ITIC-Th) based on indacenodithieno[3,2-b]thiophene core and thienyl side-chains for organic solar cells (OSCs). Relative to its counterpart with phenyl side-chains (ITIC), ITIC-Th shows lower energy levels (ITIC-Th: HOMO = -5.66 eV, LUMO = -3.93 eV; ITIC: HOMO = -5.48 eV, LUMO = -3.83 eV) due to the σ-inductive effect of thienyl side-chains, which can match with high-performance narrow-band-gap polymer donors and wide-band-gap polymer donors. ITIC-Th has higher electron mobility (6.1 × 10(-4) cm(2) V(-1) s(-1)) than ITIC (2.6 × 10(-4) cm(2) V(-1) s(-1)) due to enhanced intermolecular interaction induced by sulfur-sulfur interaction. We fabricate OSCs by blending ITIC-Th acceptor with two different low-band-gap and wide-band-gap polymer donors. In one case, a power conversion efficiency of 9.6% was observed, which rivals some of the highest efficiencies for single junction OSCs based on fullerene acceptors. PMID:27015115

  20. Increased Efficiency in Small Molecule Organic Solar Cells Through the Use of a 56-π Electron Acceptor – Methano Indene Fullerene

    PubMed Central

    Ryan, James W.; Matsuo, Yutaka

    2015-01-01

    Organic solar cells (OSCs) offer the possibility of harnessing the sun's ubiquitous energy in a low-cost, environmentally friendly and renewable manner. OSCs based on small molecule semiconductors (SMOSCs) – have made a substantial improvement in recent years and are now achieving power conversion efficiencies (PCEs) that match those achieved for polymer:fullerene OSCs. To date, all efficient SMOSCs have relied on the same fullerene acceptor, PCBM, in order to achieve high performance. The use of PCBM however, is unfavourable due to its low lying LUMO level, which limits the open-circuit voltage (VOC). Alternative fullerene derivatives with higher lying LUMOs are thus required to improve the VOC. The challenge, however, is to prevent the typical concomitant decrease in the short circuit current density (JSC) when using a higher LUMO fullerene. In this communication, we address the issue by applying methano indene fullerene, MIF, a bis-functionalised C60 fullerene that has a LUMO level 140 mV higher than PCBM, in solution processed SMOSCs with a well known small molecule donor, DPP(TBFu)2. MIF-based devices show an improved VOC of 140 mV over PC61BM and only a small decrease in the JSC, with the PCE increasing to 5.1% (vs. 4.5% for PC61BM). PMID:25661976

  1. FACS-sorted putative oogonial stem cells from the ovary are neither DDX4-positive nor germ cells

    PubMed Central

    Zarate-Garcia, Larissa; Lane, Simon I. R.; Merriman, Julie A.; Jones, Keith T.

    2016-01-01

    Whether the adult mammalian ovary contains oogonial stem cells (OSCs) is controversial. They have been isolated by a live-cell sorting method using the germ cell marker DDX4, which has previously been assumed to be cytoplasmic, not surface-bound. Furthermore their stem cell and germ cell characteristics remain disputed. Here we show that although OSC-like cells can be isolated from the ovary using an antibody to DDX4, there is no good in silico modelling to support the existence of a surface-bound DDX4. Furthermore these cells when isolated were not expressing DDX4, and did not initially possess germline identity. Despite these unremarkable beginnings, they acquired some pre-meiotic markers in culture, including DDX4, but critically never expressed oocyte-specific markers, and furthermore were not immortal but died after a few months. Our results suggest that freshly isolated OSCs are not germ stem cells, and are not being isolated by their DDX4 expression. However it may be that culture induces some pre-meiotic markers. In summary the present study offers weight to the dogma that the adult ovary is populated by a fixed number of oocytes and that adult de novo production is a rare or insignificant event. PMID:27301892

  2. FACS-sorted putative oogonial stem cells from the ovary are neither DDX4-positive nor germ cells.

    PubMed

    Zarate-Garcia, Larissa; Lane, Simon I R; Merriman, Julie A; Jones, Keith T

    2016-01-01

    Whether the adult mammalian ovary contains oogonial stem cells (OSCs) is controversial. They have been isolated by a live-cell sorting method using the germ cell marker DDX4, which has previously been assumed to be cytoplasmic, not surface-bound. Furthermore their stem cell and germ cell characteristics remain disputed. Here we show that although OSC-like cells can be isolated from the ovary using an antibody to DDX4, there is no good in silico modelling to support the existence of a surface-bound DDX4. Furthermore these cells when isolated were not expressing DDX4, and did not initially possess germline identity. Despite these unremarkable beginnings, they acquired some pre-meiotic markers in culture, including DDX4, but critically never expressed oocyte-specific markers, and furthermore were not immortal but died after a few months. Our results suggest that freshly isolated OSCs are not germ stem cells, and are not being isolated by their DDX4 expression. However it may be that culture induces some pre-meiotic markers. In summary the present study offers weight to the dogma that the adult ovary is populated by a fixed number of oocytes and that adult de novo production is a rare or insignificant event. PMID:27301892

  3. Activation of K+ channel by 1-EBIO rescues the head and neck squamous cell carcinoma cells from Ca2+ ionophore-induced cell death

    PubMed Central

    Yin, Ming Zhe; Park, Seok-Woo; Kang, Tae Wook; Kim, Kyung Soo; Yoo, Hae Young; Lee, Junho; Hah, J. Hun; Sung, Myung Hun

    2016-01-01

    Ion channels in carcinoma and their roles in cell proliferation are drawing attention. Intracellular Ca2+ ([Ca2+]i)-dependent signaling affects the fate of cancer cells. Here we investigate the role of Ca2+-activated K+ channel (SK4) in head and neck squamous cell carcinoma cells (HNSCCs) of different cell lines; SNU-1076, OSC-19 and HN5. Treatment with 1 µM ionomycin induced cell death in all the three cell lines. Whole-cell patch clamp study suggested common expressions of Ca2+-activated Cl- channels (Ano-1) and Ca2+-activated nonselective cation channels (CAN). 1-EBIO, an activator of SK4, induced outward K+ current (ISK4) in SNU-1076 and OSC-19. In HN5, ISK4 was not observed or negligible. The 1-EBIO-induced current was abolished by TRAM-34, a selective SK4 blocker. Interestingly, the ionomycin-induced cell death was effectively prevented by 1-EBIO in SNU-1076 and OSC-19, and the rescue effect was annihilated by combined TRAM-34. Consistent with the lower level of ISK4, the rescue by 1-EBIO was least effective in HN5. The results newly demonstrate the role of SK4 in the fate of HNSCCs under the Ca2+ overloaded condition. Pharmacological modulation of SK4 might provide an intriguing novel tool for the anti-cancer strategy in HNSCC. PMID:26807020

  4. Evaluating the anti-neuroinflammatory capacity of raw and steamed garlic as well as five organosulfur compounds.

    PubMed

    Ho, Su-Chen; Su, Min-Sheng

    2014-01-01

    The anti-neuroinflammatory capacities of raw and steamed garlic extracts as well as five organosulfur compounds (OSCs) were examined in lipopolysaccharide (LPS)-stimulated BV2 microglia. According to those results, steaming pretreatment blocked the formation of alliinase-catalyzed OSCs such as allicin and diallyl trisulfide (DATS) in crushed garlic. Raw garlic, but not steamed garlic, dose-dependently attenuated the production of LPS-induced nitric oxide (NO), interleukin-1β (IL-1β), tumor necrosis factor (TNF)-α, and monocyte chemoattractant protein-1 (MCP-1). DATS and diallyl disulfide at 200 and 400 μM, respectively, displayed significant anti-neuroinflammatory activity. Meanwhile, even at 1 mM, diallyl sulfide, S-allyl cysteine and alliin did not display such activity. Inhibition of nuclear factor-κB activation was the mechanism underlying this protective effect of raw garlic and DATS. Analysis results indicated that the anti-neuroinflammatory capacity of raw garlic is due to the alliin-derived OSCs. Importantly, DATS is a highly promising therapeutic candidate for treating inflammation-related neurodegenerative diseases. PMID:25365295

  5. Varying the apparent conduction mechanism in polymer semiconductors

    NASA Astrophysics Data System (ADS)

    Bittle, Emily G.; Ro, Hyun Wook; Basham, James I.; Delongchamp, Dean; Gundlach, David; Jurchescu, Oana

    The weak van der Waals inter-molecular interactions in organic semiconductors (OSCs) result in large variations in transport behavior ranging from hopping to band-like. Accurately measuring and modelling charge transport is a prerequisite to establishing robust transport-microstructure correlations and developing predictive structure-function relationships for optimized materials design and processing. Field-effect transistors have become a favored test structure for parameterizing and benchmarking the electronic properties of OSCs due to their ease of fabrication, measurement, and possible use in commercial applications. However, correctly analyzing transistor current-voltage measurements to extract material properties has proven difficult, as parasitic effects influence the device electrical properties and mask intrinsic material properties. Here, we use impedance spectroscopy to evaluate the effects of contacts on device operation and extract the properties of the channel which we compare with conventional DC measurements. We apply this approach to model systems of the widely studied polymer regioregular poly(3-hexylthiophene-2,5-diyl) which we engineer through different solidification kinetics to achieve distinct, well characterized degrees of molecular order. When increasing the order we find that the transport changes from field enhanced to field independent. This study addresses the origins of transport behavior seen in OSCs while discerning non-linear contact effects from field dependent transport.

  6. Activation of K(+) channel by 1-EBIO rescues the head and neck squamous cell carcinoma cells from Ca(2+) ionophore-induced cell death.

    PubMed

    Yin, Ming Zhe; Park, Seok-Woo; Kang, Tae Wook; Kim, Kyung Soo; Yoo, Hae Young; Lee, Junho; Hah, J Hun; Sung, Myung Hun; Kim, Sung Joon

    2016-01-01

    Ion channels in carcinoma and their roles in cell proliferation are drawing attention. Intracellular Ca(2+) ([Ca(2+)]i)-dependent signaling affects the fate of cancer cells. Here we investigate the role of Ca(2+)-activated K(+) channel (SK4) in head and neck squamous cell carcinoma cells (HNSCCs) of different cell lines; SNU-1076, OSC-19 and HN5. Treatment with 1 µM ionomycin induced cell death in all the three cell lines. Whole-cell patch clamp study suggested common expressions of Ca(2+)-activated Cl(-) channels (Ano-1) and Ca(2+)-activated nonselective cation channels (CAN). 1-EBIO, an activator of SK4, induced outward K(+) current (ISK4) in SNU-1076 and OSC-19. In HN5, ISK4 was not observed or negligible. The 1-EBIO-induced current was abolished by TRAM-34, a selective SK4 blocker. Interestingly, the ionomycin-induced cell death was effectively prevented by 1-EBIO in SNU-1076 and OSC-19, and the rescue effect was annihilated by combined TRAM-34. Consistent with the lower level of ISK4, the rescue by 1-EBIO was least effective in HN5. The results newly demonstrate the role of SK4 in the fate of HNSCCs under the Ca(2+) overloaded condition. Pharmacological modulation of SK4 might provide an intriguing novel tool for the anti-cancer strategy in HNSCC. PMID:26807020

  7. Challenges associated with the sampling and analysis of organosulfur compounds in air using real-time PTR-ToF-MS and off-line GC-FID

    NASA Astrophysics Data System (ADS)

    Perraud, V.; Meinardi, S.; Blake, D. R.; Finlayson-Pitts, B. J.

    2015-12-01

    Organosulfur compounds (OSC) are naturally emitted via various processes involving phytoplankton and algae in marine regions, from animal metabolism and from biomass decomposition inland. These compounds are malodorant and reactive. Their oxidation to methanesulfonic and sulfuric acids leads to the formation and growth of atmospheric particles, which are known to have negative effects on visibility, climate and human health. In order to predict particle formation events, accurate measurements of the OSC precursors are essential. Here, two different approaches, proton-transfer reaction time-of-flight mass spectrometry (PTR-ToF-MS) and canister sampling coupled with GC-FID are compared for both laboratory standards [dimethyl sulfide (DMS), dimethyl disulfide (DMDS), dimethyl trisulfide (DMTS) and methanethiol (MTO)] and for a complex sample. Results show that both techniques produce accurate quantification of DMS. While PTR-ToF-MS provides real-time measurements of all four OSCs individually, significant fragmentation of DMDS and DMTS occurs, which can complicate their identification in complex mixtures. Canister sampling coupled with GC-FID provides excellent sensitivity for DMS, DMDS and DMTS. However, MTO was observed to react on metal surfaces to produce DMDS and, in the presence of hydrogen sulfide, even DMTS. Avoiding metal in sampling systems seems to be necessary for measuring all but dimethyl sulfide in air.

  8. Clinical simulation training improves the clinical performance of Chinese medical students

    PubMed Central

    Zhang, Ming-ya; Cheng, Xin; Xu, An-ding; Luo, Liang-ping; Yang, Xuesong

    2015-01-01

    Background Modern medical education promotes medical students’ clinical operating capacity rather than the mastery of theoretical knowledge. To accomplish this objective, clinical skill training using various simulations was introduced into medical education to cultivate creativity and develop the practical ability of students. However, quantitative analysis of the efficiency of clinical skill training with simulations is lacking. Methods In the present study, we compared the mean scores of medical students (Jinan University) who graduated in 2013 and 2014 on 16 stations between traditional training (control) and simulative training groups. In addition, in a clinical skill competition, the objective structured clinical examination (OSCE) scores of participating medical students trained using traditional and simulative training were compared. The data were statistically analyzed and qualitatively described. Results The results revealed that simulative training could significantly enhance the graduate score of medical students compared with the control. The OSCE scores of participating medical students in the clinical skill competition, trained using simulations, were dramatically higher than those of students trained through traditional methods, and we also observed that the OSCE marks were significantly increased for the same participant after simulative training for the clinical skill competition. Conclusions Taken together, these data indicate that clinical skill training with a variety of simulations could substantially promote the clinical performance of medical students and optimize the resources used for medical education, although a precise analysis of each specialization is needed in the future. PMID:26478142

  9. Wavelet representation of plasma particle dynamics in stationary electrostatic waves

    SciTech Connect

    Tanriverdi, Sevim; Psimopoulos, Michalis

    2005-10-01

    The dynamics of plasma particles in the presence of a stationary electrostatic wave is studied by expanding the motion of each particle in powers of the wave amplitude. The coefficients of this expansion are wavelets in velocity space that gradually transform into well-behaved singular functions for t>>t{sub o}; t{sub o}=(m/k{sup 2}T){sup 1/2}. The force exerted on the plasma and the rate of kinetic energy transferred to the plasma by the wave are obtained by averaging the amplitude expansion over initial conditions. Higher-order terms show that nonlinear wave-plasma interactions are governed by a universal function M({tau}) which is independent of the velocity distribution and depends only on {tau}=t/t{sub osc}; t{sub osc}=(m/kqE{sub o}){sup 1/2}. It is found that the short-time (t{approx_equal}t{sub osc}) behavior of M({tau}) describing the transition between linear and nonlinear regimes is given by M({tau})=1-({tau}{sup 4}/2{sup 3}4{exclamation_point})+(41{tau}{sup 8}/2{sup 7}8{exclamation_point}). Also, using an implicit expansion of the particle motion, a global component M{sub o}({tau})=(4/{tau}{sup 2})J{sub 1}({tau}{sup 2}/2), 0{<=}{tau}<{infinity}, of the universal function is obtained.

  10. Can disclosure of scoring rubric for basic clinical skills improve objective structured clinical examination?

    PubMed Central

    2016-01-01

    Purpose: To determine whether disclosure of scoring rubric for objective basic clinical skills can improve the scores on the objective structured clinical examination (OSCE) in medical students. Methods: Clinical performance score results of one university medical students (study group, n=345) were compared to those of another university (control group, n=1,847). Both groups took identical OSCE exam. OSCE rubric was not revealed to the study group until they were in the last 2 years of medical school. Results: There was no significant difference between before and after disclosure of rubric. However, history taking and physical examination scores of the study group were lower than those of the control group before the disclosure of rubric. After disclosure of rubric, the scores were either unchanged or slightly increased in the control group. Trend analysis of scores demonstrated that history taking and physical examination scores after the disclosure were significantly increased in the study group for 2 years. Conclusion: This study revealed that disclosure of basic clinical skills rubric to medical students could enhance their clinical performance, particularly in history taking and physical examination scores. PMID:27240891

  11. Increased Efficiency in Small Molecule Organic Solar Cells Through the Use of a 56-π Electron Acceptor - Methano Indene Fullerene

    NASA Astrophysics Data System (ADS)

    Ryan, James W.; Matsuo, Yutaka

    2015-02-01

    Organic solar cells (OSCs) offer the possibility of harnessing the sun's ubiquitous energy in a low-cost, environmentally friendly and renewable manner. OSCs based on small molecule semiconductors (SMOSCs) - have made a substantial improvement in recent years and are now achieving power conversion efficiencies (PCEs) that match those achieved for polymer:fullerene OSCs. To date, all efficient SMOSCs have relied on the same fullerene acceptor, PCBM, in order to achieve high performance. The use of PCBM however, is unfavourable due to its low lying LUMO level, which limits the open-circuit voltage (VOC). Alternative fullerene derivatives with higher lying LUMOs are thus required to improve the VOC. The challenge, however, is to prevent the typical concomitant decrease in the short circuit current density (JSC) when using a higher LUMO fullerene. In this communication, we address the issue by applying methano indene fullerene, MIF, a bis-functionalised C60 fullerene that has a LUMO level 140 mV higher than PCBM, in solution processed SMOSCs with a well known small molecule donor, DPP(TBFu)2. MIF-based devices show an improved VOC of 140 mV over PC61BM and only a small decrease in the JSC, with the PCE increasing to 5.1% (vs. 4.5% for PC61BM).

  12. Rational Design of Diketopyrrolopyrrole-Based Small Moleculesas Donating Materials for Organic Solar Cells.

    PubMed

    Jin, Ruifa; Wang, Kai

    2015-01-01

    A series of diketopyrrolopyrrole-based small molecules have been designed to explore their optical, electronic, and charge transport properties as organic solar cell(OSCs) materials. The calculation results showed that the designed molecules can lower the band gap and extend the absorption spectrum towards longer wavelengths.The designed molecules own the large longest wavelength of absorption spectra,the oscillator strength, and absorption region values. The optical, electronic, and charge transport properties of the designed molecules are affected by the introduction of different π-bridges and end groups. We have also predicted the mobility of the designed molecule with the lowest total energies. Our results reveal that the designed molecules are expected to be promising candidates for OSC materials. Additionally, the designed molecules are expected to be promising candidates for electron and/or hole transport materials. On the basis of our results, we suggest that molecules under investigation are suitable donors for[6,6]-phenyl-C61-butyric acid methyl ester (PCBM) and its derivatives as acceptors of OSCs. PMID:26343640

  13. New Geochemical Analyses Reveal Crustal Accretionary Processes at The Overlapping Spreading Center Near 3 N East Pacific Rise

    NASA Astrophysics Data System (ADS)

    Smithka, I. N.; Perfit, M. R.

    2013-12-01

    Mid-ocean ridges (MORs) are the sites of oceanic lithosphere creation and construction. Ridge discontinuities are a global phenomenom but are not as well understood as ridge axes. Geochemical analyses provide insights into upper mantle processes since elements fractionate with melting and freezing as well as reside in material to retain source signature. Lavas collected from ridge discontinuities consist of greater chemical diversity and represent variations in source, melting parameters, and local crustal processes. The small overlapping spreading center (OSC) near the third parallel north on the East Pacific Rise has been superficially analyzed previously, but here we present new isotope analyses and expand our understanding of MOR processes and processes near OSCs. Initial analyses of lavas collected in 2000 on AHA-NEMO2 revealed normal MOR basalt trends in rare earth element enrichments as well as in major element concentrations. Crystal fractionation varies along the tips of both axes, with MgO and TiO2 concentrations increasing towards the OSC basin. Newly analyzed Sr, Nd, and Pb isotope ratios will further constrain the nature of geochemical diversity along axis. As the northern tip seems to be propagating and the southern tip dying, lavas collected from each may reflect two different underlying mantle melting and magma storage processes.

  14. Competency-based simulation assessment of resuscitation skills in emergency medicine postgraduate trainees – a Canadian multi-centred study

    PubMed Central

    Dagnone, J. Damon; Hall, Andrew K.; Sebok-Syer, Stefanie; Klinger, Don; Woolfrey, Karen; Davison, Colleen; Ross, John; McNeil, Gordon; Moore, Sean

    2016-01-01

    Background The use of high-fidelity simulation is emerging as a desirable method for competency-based assessment in postgraduate medical education. We aimed to demonstrate the feasibility and validity of a multi-centre simulation-based Objective Structured Clinical Examination (OSCE) of resuscitation competence with Canadian Emergency Medicine (EM) trainees. Method EM postgraduate trainees (n=98) from five Canadian academic centres participated in a high fidelity, 3-station simulation-based OSCE. Expert panels of three emergency physicians evaluated trainee performances at each centre using the Queen’s Simulation Assessment Tool (QSAT). Intraclass correlation coefficients were used to measure the inter-rater reliability, and analysis of variance was used to measure the discriminatory validity of each scenario. A fully crossed generalizability study was also conducted for each examination centre. Results Inter-rater reliability in four of the five centres was strong with a median absolute intraclass correlation coefficient (ICC) across centres and scenarios of 0.89 [0.65–0.97]. Discriminatory validity was also strong (p < 0.001 for scenarios 1 and 3; p < 0.05 for scenario 2). Generalizability studies found significant variations at two of the study centres. Conclusions This study demonstrates the successful pilot administration of a multi-centre, 3-station simulation-based OSCE for the assessment of resuscitation competence in post-graduate Emergency Medicine trainees. PMID:27103954

  15. Effect of Fluorine Substitution on Photovoltaic Properties of Alkoxyphenyl Substituted Benzo[1,2-b:4,5-b']dithiophene-Based Small Molecules.

    PubMed

    Qiu, Beibei; Yuan, Jun; Xiao, Xuxian; He, Dingjun; Qiu, Lixia; Zou, Yingping; Zhang, Zhi-guo; Li, Yongfang

    2015-11-18

    Two new small molecules, C3T-BDTP and C3T-BDTP-F with alkoxyphenyl-substituted benzo[1,2-b:4,5-b']dithiophene (BDT) and meta-fluorinated-alkoxyphenyl-substituted BDT as the central donor blocks, respectively, have been synthesized and used as donor materials in organic solar cells (OSCs). With the addition of 0.4% v/v 1,8-diiodooctane (DIO), the blend of C3T-BDTP-F/PC71BM showed a higher hole mobility of 8.67 × 10(-4) cm(2) V(-1) s(-1) compared to that of the blend of C3T-BDTP/PC71BM. Two types of interlayers, zirconium acetylacetonate (ZrAcac) and perylene diimide (PDI) derivatives (PDINO and PDIN), were used to further optimize the performance of OSCs. With a device structure of ITO/PEDOT:PSS/donor:PC71BM/PDIN/Al, the OSCs based on C3T-BDTP delivered a satisfying power conversion efficiency (PCE) of 5.27% with an open circuit voltage (V(oc)) of 0.91 V, whereas the devices based on C3T-BDTP-F showed an enhanced PCE of 5.42% with a higher V(oc) of 0.97 V. PMID:26517574

  16. Assessment of email communication skills of rheumatology fellows: a pilot study

    PubMed Central

    Dhuper, Sonal; Siva, Chokkalingam; Fresen, John L; Petruc, Marius; Velázquez, Celso R

    2010-01-01

    Physician–patient email communication is gaining popularity. However, a formal assessment of physicians' email communication skills has not been described. We hypothesized that the email communication skills of rheumatology fellows can be measured in an objective structured clinical examination (OSCE) setting using a novel email content analysis instrument which has 18 items. During an OSCE, we asked 50 rheumatology fellows to respond to a simulated patient email. The content of the responses was assessed using our instrument. The majority of rheumatology fellows wrote appropriate responses scoring a mean (±SD) of 10.6 (±2.6) points (maximum score 18), with high inter-rater reliability (0.86). Most fellows were concise (74%) and courteous (68%) but not formal (22%). Ninety-two percent of fellows acknowledged that the patient's condition required urgent medical attention, but only 30% took active measures to contact the patient. No one encrypted their messages. The objective assessment of email communication skills is possible using simulated emails in an OSCE setting. The variable email communication scores and incidental patient safety gaps identified, suggest a need for further training and defined proficiency standards for physicians' email communication skills. PMID:20962134

  17. Pyrrolidinone derivatives as processing additives for solution processed organic solar cells

    NASA Astrophysics Data System (ADS)

    Vongsaysy, Uyxing; Pavageau, Bertrand; Servant, Laurent; Aziz, Hany

    2014-10-01

    Processing additives are widely used to increase the efficiency of solution processed organic solar cells. We use the Hansen solubility parameters (HSPs) to investigate novel processing additives. The HSPs predict pyrrolidinone derivatives to be efficient processing additives for OSC systems based on poly(3-hexylthiophene)/[6,6]-phenyl-C61- butyric acid methyl ester (P3HT/PCBM). Two pyrrolidinone derivatives are identified: 1-methyl-2-pyrrolidinone and 1- benzyl-2-pyrrolidinone. The processing additives are introduced with various concentrations in the formulation of P3HT and PCBM solution. The electrical characterizations show that the two processing additives significantly increase the short circuit current and thus the power conversion efficiency of the OSCs. The results thus highlight HSPs as an effective and relatively straightforward tool that can be employed to optimize OSC morphology from a theoretical standpoint. Such a tool will be invaluable for identifying additives for novel high efficiency polymer species as they are synthesized, and thus to streamline the device fabrication and device optimization process.

  18. Optical metrology at the Optical Sciences Center: an historical review

    NASA Astrophysics Data System (ADS)

    Creath, Katherine; Parks, Robert E.

    2014-10-01

    The Optical Sciences Center (OSC) begun as a graduate-level applied optics teaching institution to support the US space effort. The making of optics representative of those used in other space programs was deemed essential. This led to the need for optical metrology: at first Hartmann tests, but almost immediately to interferometric tests using the newly invented HeNe laser. Not only were new types of interferometers needed, but the whole infrastructure that went with testing, fringe location methods, aberration removal software and contour map generation to aid the opticians during polishing needed to be developed. Over the last half century more rapid and precise methods of interferogram data reduction, surface roughness measurement, and methods of instrument calibration to separate errors from those in the optic have been pioneered at OSC. Other areas of research included null lens design and the writing of lens design software that led into the design of computer generated holograms for asphere testing. More recently work has been done on the reduction of speckle noise in interferograms, methods to test large convex aspheres, and a return to slope measuring tests to increase the dynamic range of the types of aspheric surfaces amenable to optical testing including free-form surfaces. This paper documents the history of the development of optical testing projects at OSC and highlights the contributions some of the individuals associated with new methods of testing and the infrastructure needed to support the testing. We conclude with comments about the future trends optical metrology.

  19. Large optics fabrication and testing at the College of Optical Sciences

    NASA Astrophysics Data System (ADS)

    Burge, James H.

    2014-10-01

    The origin of the Optical Sciences Center (OSC) at the University of Arizona was closely tied to the need to expand the national capability for manufacturing large optics. This connection allowed OSC to grow quickly to become a truly unique place where new technologies are born and applied and where students have opportunities to apply academic lessons to real-world projects. In the decades that follow, OSC has grown to become a leader in many other optical disciplines, including photonics, imaging, optical engineering, and optical physics. But the core capability of optical fabrication and testing has remained as a unique University of Arizona asset. The last decade has seen explosive growth in development and implementation of new technologies for manufacturing and measuring large optics at the College of Optical Sciences. The classic polishing techniques have given way to advanced computer controlled machines and highly engineered laps. New measuring methods have enabled accurate metrology of steeply aspheric surfaces, concave and convex, symmetric and freeform. This paper discusses the history of optical fabrication and testing at University of Arizona and reviews some recent major projects and the technical developments that have enabled their success.

  20. Solvothermal synthesis and characterization of ceria-zirconia mixed oxides for catalytic applications.

    PubMed

    Devaraju, M K; Liu, Xiangwen; Yusuke, Kikuchi; Yin, S; Sato, T

    2009-10-01

    Solvothermal synthesis under supercritical conditions (400 degrees C) and high autogenous pressure (about 40 MPa), has been carried out for the direct preparation of nanocrystalline powders of CeO2, Ce(0.85)Zr(0.15)O2, Ce(0.75)Zr(0.25)O2, Ce(0.65)Zr(0.35)O2 and Ce(0.5)Zr(0.5)O2 which are characterized for applications as catalysts for oxygen storage in automotive catalysis. The synthesis was carried out in the presence of polyethylene glycol and water. For the characterization, x-ray diffraction (XRD), transmission electron microscopy (TEM), dynamic light scattering (DLS) and the Brunauer-Emmet-Teller (BET) technique were employed. The oxygen storage capacity (OSC) of as-prepared and calcined samples without loading of noble metals was measured using thermogravimetric-differential thermal analysis (TG-DTA) at 600 degrees C with a continuous flow of CO-N2 gas and air alternately. Ce(0.5)Zr(0.5)O2 nanoparticles with a BET surface area of 102 m(2) g(-1) exhibited the highest OSC of 0.073 50 mol-O2/mol-CeO2. The OSC values obtained increased with increasing the amount of ZrO2 doping in the samples. PMID:19738312

  1. Post-natal oogenesis: a concept for controversy that intensified during the last decade.

    PubMed

    Esmaeilian, Yashar; Atalay, Arzu; Erdemli, Esra

    2015-06-01

    For decades, scientists have considered that female mammals are born with a lifetime reserve of oocytes in the ovary, irrevocably fated to decline after birth. However, controversy in the matter of the possible presence of oocytes and granulosa cells that originate from stem cells in the adult mammalian ovaries has been expanded. The restricted supply of oocytes in adult female mammals has been disputed in recent years by supporters of neo-oogenesis, who claim that germline stem cells (GSCs) exist in the ovarian surface epithelium (OSE) or the bone marrow (BM). Differentiation of ovarian stem cells (OSCs) into oocytes, fibroblast-like cells, granulosa phenotype, neural and mesenchymal type cells and generation of germ cells from OSCs under the contribution of an OSC niche that consists of immune system-related cells and hormonal signalling has been claimed. Although these arguments have met with intense suspicion, their confirmation would necessitate the revision of the current classic knowledge of female reproductive biology. PMID:24355650

  2. Uncovering the role of cathode buffer layer in organic solar cells

    NASA Astrophysics Data System (ADS)

    Qi, Boyuan; Zhang, Zhi-Guo; Wang, Jizheng

    2015-01-01

    Organic solar cells (OSCs) as the third generation photovoltaic devices have drawn intense research, for their ability to be easily deposited by low-cost solution coating technologies. However the cathode in conventional OSCs, Ca, can be only deposited by thermal evaporation and is highly unstable in ambient. Therefore various solution processible cathode buffer layers (CBLs) are synthesized as substitute of Ca and show excellent effect in optimizing performance of OSCs. Yet, there is still no universal consensus on the mechanism that how CBL works, which is evidently a critical scientific issue that should be addressed. In this article detailed studies are targeted on the interfacial physics at the interface between active layer and cathode (with and without treatment of a polar CBL) by using ultraviolet photoelectron spectroscopy, capacitance-voltage measurement, and impedance spectroscopy. The experimental data demonstrate that CBL mainly takes effect in three ways: suppressing surface states at the surface of active layer, protecting the active layer from being damaged by thermally evaporated cathode, and changing the energy level alignment by forming dipole moments with active layer and/or cathode. Our findings here provide a comprehensive picture of interfacial physics in devices with and without CBL.

  3. Uncovering the role of cathode buffer layer in organic solar cells.

    PubMed

    Qi, Boyuan; Zhang, Zhi-Guo; Wang, Jizheng

    2015-01-01

    Organic solar cells (OSCs) as the third generation photovoltaic devices have drawn intense research, for their ability to be easily deposited by low-cost solution coating technologies. However the cathode in conventional OSCs, Ca, can be only deposited by thermal evaporation and is highly unstable in ambient. Therefore various solution processible cathode buffer layers (CBLs) are synthesized as substitute of Ca and show excellent effect in optimizing performance of OSCs. Yet, there is still no universal consensus on the mechanism that how CBL works, which is evidently a critical scientific issue that should be addressed. In this article detailed studies are targeted on the interfacial physics at the interface between active layer and cathode (with and without treatment of a polar CBL) by using ultraviolet photoelectron spectroscopy, capacitance-voltage measurement, and impedance spectroscopy. The experimental data demonstrate that CBL mainly takes effect in three ways: suppressing surface states at the surface of active layer, protecting the active layer from being damaged by thermally evaporated cathode, and changing the energy level alignment by forming dipole moments with active layer and/or cathode. Our findings here provide a comprehensive picture of interfacial physics in devices with and without CBL. PMID:25588623

  4. Nanoscale characterization of the electrical properties of oxide electrodes at the organic semiconductor-oxide electrode interface in organic solar cells

    NASA Astrophysics Data System (ADS)

    MacDonald, Gordon Alex

    This dissertation focuses on characterizing the nanoscale and surface averaged electrical properties of transparent conducting oxide electrodes such as indium tin oxide (ITO) and transparent metal-oxide (MO) electron selective interlayers (ESLs), such as zinc oxide (ZnO), the ability of these materials to rapidly extract photogenerated charges from organic semiconductors (OSCs) used in organic photovoltaic (OPV) cells, and evaluating their impact on the power conversion efficiency (PCE) of OPV devices. In Chapter 1, we will introduce the fundamental principles, benefits, and the key innovations that have advanced this technology. In Chapter 2 of this dissertation, we demonstrate an innovative application of conductive probe atomic force microscopy (CAFM) to map the nanoscale electrical heterogeneity at the interface between ITO, and a well-studied OSC, copper phthalocyanine (CuPc).(MacDonald et al. (2012) ACS Nano, 6, p. 9623) In this work we collected arrays of current-voltage (J-V) curves, using a CAFM probe as the top contact of CuPc/ITO systems, to map the local J-V responses. By comparing J-V responses to known models for charge transport, we were able to determine if the local rate-limiting-step for charge transport is through the OSC (ohmic) or the CuPc/ITO interface (non-ohmic). Chapter 3 focus on the electrical property characterization of RF-magnetron sputtered ZnO (sp-ZnO) ESL films on ITO substrates. We have shown that the energetic alignment of ESLs and the OSC active materials plays a critical role in determining the PCE of OPV devices and UV light soaking sensitivity. We have used a combination of device testing, modeling, and impedance spectroscopy to characterize the effects that energetic alignment has on the charge carrier transport and distribution within the OPV device. In Chapter 4 we demonstrate that the local properties of sp-ZnO films varies as a function of the underlying ITO crystal face. We show that the local ITO crystal face determines

  5. Correlation of Seafloor Surface Features and Underlying Melt Bodies at the 9° N Overlapping Spreading Center, East Pacific Rise

    NASA Astrophysics Data System (ADS)

    Nunnery, A.; Klein, E. M.; Perfit, M. R.; White, S.; Mason, J.; Zaino, A. J.

    2008-12-01

    Recent seismic surveys of the 9°N Overlapping Spreading Center (OSC) have imaged the complex geometry of melt sills in the mid to upper crust beneath the east and west limbs of the OSC (Kent 2000). Photographic data were collected in Spring 2007 using the ROV Jason II (~7000 digital photographs) and the WHOI TowCam (~10,000 digital photographs) to explore possible connections between seafloor features and underlying melt bodies. Photographic analyses of relative seafloor age and tectonic features along both limbs of the OSC and the overlap basin has been utilized to determine their relationships to underlying melt sills. Photographs were analyzed for relative seafloor age using a classification system based on percentage of sediment cover, pillow ornamentation, presence of glass, rock relief and rock fracture. At the 9°N OSC apparently youngest seafloor is located primarily along the bathymetrically high east limb. An active hydrothermal vent site was found along the ridge at 9°8.3' N. Moving south on the east limb, where the paths of the ridge crest and the underlying melt sill diverge, young ocean crust is imaged only along bathymetrically elevated ridge crest, and only old crust is observed over the plunging melt sill to its east. It is possible that magma erupted along the southern ridge crest was supplied by a source originating in the north via dikes rather than the plunging melt sill to its east. Fault scarps and fissures are abundant along the east limb oriented approximately parallel to the ridge axis. Surprisingly, relatively recent volcanism is present in the northern portion of the overlap basin above the off- axis melt lens. A wide range of lava morphologies is present, including pillows, lobates, and sheet flows. Fault scarps and fissures are abundant in this region, overlying the location of the off-axis melt sill. Orientations of these features appear to be ~orthogonal to spreading direction. Along the west limb, where the melt sill lies beneath

  6. Regulation of microRNA biosynthesis and expression in 2102Ep embryonal carcinoma stem cells is mirrored in ovarian serous adenocarcinoma patients

    PubMed Central

    2009-01-01

    Background Tumours with high proportions of differentiated cells are considered to be of a lower grade to those containing high proportions of undifferentiated cells. This property may be linked to the differentiation properties of stem cell-like populations within malignancies. We aim to identify molecular mechanism associated with the generation of tumours with differing grades from malignant stem cell populations with different differentiation potentials. In this study we assessed microRNA (miRNA) regulation in two populations of malignant Embryonal Carcinoma (EC) stem cell, which differentiate (NTera2) or remain undifferentiated (2102Ep) during tumourigenesis, and compared this to miRNA regulation in ovarian serous carcinoma (OSC) patient samples. Methods miRNA expression was assessed in NTera2 and 2102Ep cells in the undifferentiated and differentiated states and compared to that of OSC samples using miRNA qPCR. Results Our analysis reveals a substantial overlap between miRNA regulation in 2102Ep cells and OSC samples in terms of miRNA biosynthesis and expression of mature miRNAs, particularly those of the miR-17/92 family and clustering to chromosomes 14 and 19. In the undifferentiated state 2102Ep cells expressed mature miRNAs at up to 15,000 fold increased levels despite decreased expression of miRNA biosynthesis genes Drosha and Dicer. 2102Ep cells avoid differentiation, which we show is associated with consistent levels of expression of miRNA biosynthesis genes and mature miRNAs while expression of miRNAs clustering to chromosomes 14 and 19 is deemphasised. OSC patient samples displayed decreased expression of miRNA biosynthesis genes, decreased expression of mature miRNAs and prominent clustering to chromosome 14 but not 19. This indicates that miRNA biosynthesis and levels of miRNA expression, particularly from chromosome 14, are tightly regulated both in progenitor cells and in tumour samples. Conclusion miRNA biosynthesis and expression of mature mi

  7. Deformation in the hanging wall of Cretaceous HP rocks (Austroalpine Ötztal-Stubai Complex, European Eastern Alps): constraints on timing, conditions and kinematics

    NASA Astrophysics Data System (ADS)

    Habler, Gerlinde; Thöni, Martin; Grasemann, Bernhard; Sölva, Helmuth; Cotza, Gianluca

    2010-05-01

    The position and nature of the tectonic boundary between the Cretaceous eclogite facies metamorphic Texel Complex (Sölva et al. 2005, TC) and the Ötztal-Stubai Complex sensu stricto (OSC) with predominantly pre-Cretaceous tectonometamorphic imprint remained a matter of discussion (Fügenschuh et al. 2009). Sölva et al (2005) described the Cretaceous Schneeberg Normal Fault Zone (SNFZ) as the major tectonic boundary between the exhuming TC and the OSC, where the major portion of ductile deformation was partitioned into the rheologically weak Schneeberg/Monteneve Unit (SMU). In contrast, other authors proposed a model of a coherent vertical crustal section in the southern OSC (Schmid and Haas 1989), which was rotated and exhumed by erosion due to Oligocene large scale refolding (Fügenschuh et al. 2009). Here, new Rb-Sr data of muscovite and biotite from para- and orthogneisses from the Ferwalltal and Timmelsjoch areas (Austria/Italy) were correlated with mineral chemical and structural data in order to constrain the age and kinematics of the predominant deformational imprint in the OSC representing the hanging wall of the SNFZ. In the Ferwalltal the undisturbed OSC/SMU boundary is exposed. Above that boundary an amphibolite facies mylonitic foliation (Sc1) represented by the compositional layering of coarse grained Qtz, Bt and dynamically recrystallized Pl interferes with an overprinting mylonitic foliation (Sc2) with spatially heterogeneous intensity. Sc1-planes were syn-tectonically overgrown by euhedral Grt with single phase continuous prograde chemical zoning and Bt-porphyroblasts. Dc2 postdated garnet growth and caused the formation of SCC' fabrics in Bt-Pl gneisses. Still Qtz recrystallized dynamically, whereas Ms and Bt newly crystallized during Dc2. In the study area, the lithological boundaries in the OSC mainly are subparallel to the predominant foliation Sc1. These planes dip with 45-50° to the NW-NNW and show a WNW-plunging stretching lineation (LSc1

  8. Design of RTPV generators integrated with new millennium spacecraft for outer solar system

    NASA Astrophysics Data System (ADS)

    Schock, A.; Or, C.; Kumar, V.

    1996-03-01

    The National Aeronautics and Space Administration's recently inaugurated New Millennium program, with its emphasis on miniaturized spacecraft, has generated interest in a low-power (10- to 30-watt), low-mass, high-efficiency RTPV (Radioisotope Thermophotovoltaic) power system. This led to a Department of Energy (DOE)-sponsored design study of such a system, which was assigned to OSC (formerly Fairchild) personnel, who have been conducting similar studies of a 75-watt RTPV system with very encouraging results. The 75-watt design employed two 250-watt General Purpose Heat Source (GPHS) modules that DOE had previously developed and safety-qualified for various space missions. These modules were too large for the small RTPVs described in this paper. To minimize the need for new development and safety verification studies, OSC generated derivative designs for 125-watt and 62.5-watt heat source modules containing identical fuel pellets, clads, impact shell, and thermal insulation. OSC also generated a novel heat source support scheme to reduce the heat losses through the structural supports, and a new and much simpler radiator structure, employing no honeycombs or heat pipes. OSC's previous RTPV study had been based on the use of GaSb PV cells and spectrally selective IR filters that had been partially developed and characterized by Boeing (now EDTEK) personnel, who had supplied us with spectral data on filter reflectivities and cell quantum efficiencies. Because of the very encouraging results of our system design studies, OSC in the fall of 1994 initiated an experimental program at EDTEK to develop improved filters and cells, to demonstrate how much improvement can actually be achieved. OSC requested that first priority be given to filter improvements, because our system studies indicated that improved filters would have a much greater effect on system performance than cell improvements. By September 1995 EDTEK had achieved about 94% of the filter performance

  9. Linking Microearthquakes and Seismic Tomography on the Endeavour Segment of the Juan de Fuca Ridge: Implications for Hydrothermal Circulation

    NASA Astrophysics Data System (ADS)

    Wilcock, W. S.; Weekly, R. T.; Hooft, E. E.; Toomey, D. R.; Kim, E.

    2013-12-01

    We report on a remarkable correlation between the patterns of microearthquakes and three-dimensional upper crustal velocity anomalies on the Endeavour segment of the Juan de Fuca Ridge. Microearthquakes were monitored from 2003-2006 by a small seismic network deployed on the central part of the segment. The velocity model was obtained from a tomography experiment comprising over 5500 shots from a large airgun array that were recorded by ocean bottom seismometers deployed at 64 sites along the Endeavour segment and the adjacent overlapping spreading centers (OSCs). On the segment scale, upper crustal velocities are low in the OSCs indicating that the crust is highly fractured. These low velocities persist off-axis and record the history of ridge propagation. In 2005, two swarm sequences that were interpreted in terms of magmatic intrusions on the limbs of the Endeavour-West Valley OSC were accompanied by extensive seismicity within the overlap basin. Throughout the microearthquake experiment earthquakes were concentrated in a region surrounding the southern tip of the West Valley propagator that coincides closely with the southern limit of the low velocities imaged around the OSC. Beneath the hydrothermal vent fields in the center of the Endeavour segment, the earthquakes were mostly located in a 500-m-thick band immediately above the axial magma chamber. There was a close correlation between the rates of seismicity beneath each vent field and their thermal output. The highest rates of seismicity were observed beneath the High Rise and Main Endeavour fields that each have power outputs of several hundred megawatts. Seismic velocities are generally high beneath the vent fields relative to velocities along the ridge axis immediately to the north and south. However, the High Rise and Main Endeavour fields are underlain by a low velocity region at 2 km depth that coincides with the seismically active region. This is consistent with a region of increased fracturing and

  10. Morphological and Immunohistochemical Reevaluation of Tumors Initially Diagnosed as Ovarian Endometrioid Carcinoma With Emphasis on High-grade Tumors.

    PubMed

    Lim, Diana; Murali, Rajmohan; Murray, Melissa P; Veras, Emanuela; Park, Kay J; Soslow, Robert A

    2016-03-01

    Ovarian endometrioid carcinomas (OEC) of low grade have characteristic morphologic features, but high-grade tumors can mimic high-grade serous and undifferentiated carcinomas. We reviewed tumors initially diagnosed as OEC to determine whether a combination of pathologic and immunohistochemical features can improve histologic subclassification. Tumors initially diagnosed as OEC were reviewed using World Health Organization criteria. We also noted the presence of associated confirmatory endometrioid features (CEFs): (i) squamous metaplasia; (ii) endometriosis; (iii) adenofibromatous background; and (iv) borderline endometrioid or mixed Mullerian component. A tissue microarray was constructed from 27 representative tumors with CEF and 14 without CEF, and sections were stained for WT-1, p16, and p53. Of 109 tumors initially diagnosed as OEC, 76 (70%) tumors were classified as OEC. The median patient age was 55 years, and 75% of patients were younger than 60 years. Ninety-two percent presented with disease confined to the pelvis, and 87% of tumors were unilateral. The median tumor size was 11.8 cm. Only 3% of tumors were high grade (grade 3of 3). Eighty percent of cases had at least 1 CEF, and 59% had at least 2 CEFs. Eleven percent overexpressed p16, 0% overexpressed p53, and 3% expressed WT-1. Only 10% of patients died of disease at last follow-up. Thirty-three (33) tumors, or 30% of tumors originally classified as endometrioid, were reclassified as serous carcinoma (OSC). The median patient age was 54.5 years, and 59% of patients were younger than 60 years of age. Only 27% had disease confined to the pelvis at presentation, 52% of tumors were unilateral, and the median tumor size was 8 cm. Associated squamous differentiation, endometrioid adenofibroma, and endometrioid or mixed Mullerian borderline tumor (CEFs) were not present in any case, but 6% of patients had endometriosis. Approximately one half of the reclassified OSC demonstrated SET-pattern morphology

  11. Immunoregulation of follicular renewal, selection, POF, and menopause in vivo, vs. neo-oogenesis in vitro, POF and ovarian infertility treatment, and a clinical trial

    PubMed Central

    2012-01-01

    The immune system plays an important role in the regulation of tissue homeostasis ("tissue immune physiology"). Function of distinct tissues during adulthood, including the ovary, requires (1) Renewal from stem cells, (2) Preservation of tissue-specific cells in a proper differentiated state, which differs among distinct tissues, and (3) Regulation of tissue quantity. Such morphostasis can be executed by the tissue control system, consisting of immune system-related components, vascular pericytes, and autonomic innervation. Morphostasis is established epigenetically, during morphogenetic (developmental) immune adaptation, i.e., during the critical developmental period. Subsequently, the tissues are maintained in a state of differentiation reached during the adaptation by a “stop effect” of resident and self renewing monocyte-derived cells. The later normal tissue is programmed to emerge (e.g., late emergence of ovarian granulosa cells), the earlier its function ceases. Alteration of certain tissue differentiation during the critical developmental period causes persistent alteration of that tissue function, including premature ovarian failure (POF) and primary amenorrhea. In fetal and adult human ovaries the ovarian surface epithelium cells called ovarian stem cells (OSC) are bipotent stem cells for the formation of ovarian germ and granulosa cells. Recently termed oogonial stem cells are, in reality, not stem but already germ cells which have the ability to divide. Immune system-related cells and molecules accompany asymmetric division of OSC resulting in the emergence of secondary germ cells, symmetric division, and migration of secondary germ cells, formation of new granulosa cells and fetal and adult primordial follicles (follicular renewal), and selection and growth of primary/preantral, and dominant follicles. The number of selected follicles during each ovarian cycle is determined by autonomic innervation. Morphostasis is altered with advancing age, due

  12. Oxygen storage properties of La1-xSrxFeO3- for chemical-looping reactions an in-situ neutron and synchrotron X-ray study

    SciTech Connect

    Taylor, Daniel; Schreiber, Nathaniel; Levitas, Benjamin; Xu, Wenqian; Rodriguez, Efrain E

    2016-01-01

    Oxygen storage materials (OSMs) provide lattice oxygen for a number of chemical-looping reactions including natural gas combustion and methane reforming. La1 xSrxFeO3 has shown promise for use as an OSM in methane reforming reactions due to its high product selectivity, fast oxide diffusion, and cycle stability. Here, we investigate the structural evolution of the series La1 xSrxFeO3 for x = 0, 1/3, 1/2, 2/3, and 1, using in situ synchrotron X-ray and neutron diffraction, as it is cycled under the conditions of a chemical-looping reactor (methane and oxygen atmospheres). In the compositions x = 1/3, 1/2, 2/3, and 1, we discover an envelope , or temperature range, of oxygen storage capacity (OSC), where oxygen can easily and reversibly be inserted and removed from the OSM. Our in situ X-ray and neutron diffraction results reveal that while samples with higher Sr contents had a higher OSC, those same samples suffered from slower reaction kinetics and some, such as the x = 1/2 and x = 2/3 compositions, had local variations in Sr content, which led to inhomogeneous regions with varying reaction rates. Therefore, we highlight the importance of in situ diffraction studies, and we propose that these measurements are required for the thorough evaluation of future candidate OSMs. We recommend La2/3Sr1/3FeO3 as the optimal OSM in the series because its structure remains homogeneous throughout the reaction, and its OSC envelope is similar to that of the higher doped materials.

  13. Can near-peer medical students effectively teach a new curriculum in physical examination?

    PubMed Central

    2013-01-01

    Background Students in German medical schools frequently complain that the subject ‘clinical examination’ is not taught in a satisfying manner due to time constraints and lack of personnel resources. While the effectiveness and efficiency of practice-oriented teaching in small groups using near-peer teaching has been shown, it is rarely used in German medical schools. We investigated whether adding a new near-peer teaching course developed with student input plus patient examination under supervision in small groups improves basic clinical examination skills in third year medical students compared to a traditional clinical examination course alone. Methods Third year medical students registered for the mandatory curricular clinical examination course at the medical faculty of the Technische Universität München were invited to participate in a randomised trial with blinded outcome assessment. Students were randomised to the control group participating in the established curricular physical examination course or to the intervention group, which received additional near-peer teaching for the same content. The learning success was verified by a voluntary objective structured clinical examination (OSCE). Results A total of 84 students were randomised and 53 (63%) participated in the final OSCE. Students in the control group scored a median of 57% (25th percentile 47%, 75th percentile 61%) of the maximum possible total points of the OSCE compared to 77% (73%, 80%; p < 0.001) for students in the intervention group. Only two students in the intervention group received a lower score than the best student in the control group. Conclusion Adding a near-peer teaching course to the routine course significantly improved the clinical examination skills of medical students in an efficient manner in the context of a resource-constrained setting. PMID:24325639

  14. Finding Distant Galactic HII Regions

    NASA Astrophysics Data System (ADS)

    Anderson, L. D.; Armentrout, W. P.; Johnstone, B. M.; Bania, T. M.; Balser, Dana S.; Wenger, Trey V.; Cunningham, V.

    2015-12-01

    The WISE Catalog of Galactic H ii Regions contains ˜2000 H ii region candidates lacking ionized gas spectroscopic observations. All candidates have the characteristic H ii region mid-infrared morphology of WISE 12 μ {{m}} emission surrounding 22 μ {{m}} emission, and additionally have detected radio continuum emission. We here report Green Bank Telescope hydrogen radio recombination line and radio continuum detections in the X-band (9 GHz; 3 cm) of 302 WISE H ii region candidates (out of 324 targets observed) in the zone 225^\\circ ≥slant {\\ell }≥slant -20^\\circ , | {\\text{}}b| ≤slant 6^\\circ . Here we extend the sky coverage of our H ii region Discovery Survey, which now contains nearly 800 H ii regions distributed across the entire northern sky. We provide LSR velocities for the 302 detections and kinematic distances for 131 of these. Of the 302 new detections, 5 have ({\\ell },{\\text{}}b,v) coordinates consistent with the Outer Scutum-Centaurus Arm (OSC), the most distant molecular spiral arm of the Milky Way. Due to the Galactic warp, these nebulae are found at Galactic latitudes >1° in the first Galactic quadrant, and therefore were missed in previous surveys of the Galactic plane. One additional region has a longitude and velocity consistent with the OSC but lies at a negative Galactic latitude (G039.183-01.422 -54.9 {km} {{{s}}}-1). With Heliocentric distances >22 kpc and Galactocentric distances >16 kpc, the OSC H ii regions are the most distant known in the Galaxy. We detect an additional three H ii regions near {\\ell }≃ 150^\\circ whose LSR velocities place them at Galactocentric radii >19 kpc. If their distances are correct, these nebulae may represent the limit to Galactic massive star formation.

  15. HNF1β drives glutathione (GSH) synthesis underlying intrinsic carboplatin resistance of ovarian clear cell carcinoma (OCCC).

    PubMed

    Lopes-Coelho, Filipa; Gouveia-Fernandes, Sofia; Gonçalves, Luís G; Nunes, Carolina; Faustino, Inês; Silva, Fernanda; Félix, Ana; Pereira, Sofia A; Serpa, Jacinta

    2016-04-01

    Chemoresistance to platinum-based antineoplastic agents is a consistent feature among ovarian carcinomas; however, whereas high-grade serous carcinoma (OSC) acquires resistance during chemotherapy, ovarian clear cell carcinoma (OCCC) is intrinsically resistant. The main objective of this study was to explore, in vitro and in vivo, if hepatocyte nuclear factor 1β (HNF1β) and glutaminolysis contribute for the resistance of OCCC to carboplatin through the intrinsically increased GSH bioavailability. To disclose the role of HNF1β, experiments were also performed in an OSC cell line, which does not express HNF1β. Metabolic profiles, GSH quantification, HNF1β, and γ-glutamylcysteine ligase catalytic subunit (GCLC) and modifier subunit (GCLM) expression, cell cycle, and death were assessed in ES2 cell line (OCCC) and OVCAR3 cell line (OSC); HNF1β knockdown was performed in ES2 and murine model of subcutaneous and peritoneal OCCC tumors was established to test buthionine sulphoxamine (BSO), as a sensitizer to carboplatin. Glutaminolysis is activated in ES2 and OVCAR3, though ES2 exclusively synthesizes amino acids and GSH. ES2 cells are more resistant to carboplatin than OVCAR3 and the abrogation of GSH production by BSO sensitizes ES2 to carboplatin. HNF1β regulates the expression of GCLC, but not GCLM, and consequently GSH production in ES2. In vivo, BSO prior to carboplatin reduces dramatically subcutaneous tumor size and GSH levels, as well as peritoneal dissemination. Our study discloses HNF1β as the mediator of intrinsic OCCC chemoresistance and sheds a light to re-explore a cancer adjuvant therapeutic approach using BSO to overcome the lack of efficient therapy in OCCC. PMID:26520442

  16. Sterol Synthesis in Diverse Bacteria.

    PubMed

    Wei, Jeremy H; Yin, Xinchi; Welander, Paula V

    2016-01-01

    Sterols are essential components of eukaryotic cells whose biosynthesis and function has been studied extensively. Sterols are also recognized as the diagenetic precursors of steranes preserved in sedimentary rocks where they can function as geological proxies for eukaryotic organisms and/or aerobic metabolisms and environments. However, production of these lipids is not restricted to the eukaryotic domain as a few bacterial species also synthesize sterols. Phylogenomic studies have identified genes encoding homologs of sterol biosynthesis proteins in the genomes of several additional species, indicating that sterol production may be more widespread in the bacterial domain than previously thought. Although the occurrence of sterol synthesis genes in a genome indicates the potential for sterol production, it provides neither conclusive evidence of sterol synthesis nor information about the composition and abundance of basic and modified sterols that are actually being produced. Here, we coupled bioinformatics with lipid analyses to investigate the scope of bacterial sterol production. We identified oxidosqualene cyclase (Osc), which catalyzes the initial cyclization of oxidosqualene to the basic sterol structure, in 34 bacterial genomes from five phyla (Bacteroidetes, Cyanobacteria, Planctomycetes, Proteobacteria, and Verrucomicrobia) and in 176 metagenomes. Our data indicate that bacterial sterol synthesis likely occurs in diverse organisms and environments and also provides evidence that there are as yet uncultured groups of bacterial sterol producers. Phylogenetic analysis of bacterial and eukaryotic Osc sequences confirmed a complex evolutionary history of sterol synthesis in this domain. Finally, we characterized the lipids produced by Osc-containing bacteria and found that we could generally predict the ability to synthesize sterols. However, predicting the final modified sterol based on our current knowledge of sterol synthesis was difficult. Some bacteria

  17. Sterol Synthesis in Diverse Bacteria

    PubMed Central

    Wei, Jeremy H.; Yin, Xinchi; Welander, Paula V.

    2016-01-01

    Sterols are essential components of eukaryotic cells whose biosynthesis and function has been studied extensively. Sterols are also recognized as the diagenetic precursors of steranes preserved in sedimentary rocks where they can function as geological proxies for eukaryotic organisms and/or aerobic metabolisms and environments. However, production of these lipids is not restricted to the eukaryotic domain as a few bacterial species also synthesize sterols. Phylogenomic studies have identified genes encoding homologs of sterol biosynthesis proteins in the genomes of several additional species, indicating that sterol production may be more widespread in the bacterial domain than previously thought. Although the occurrence of sterol synthesis genes in a genome indicates the potential for sterol production, it provides neither conclusive evidence of sterol synthesis nor information about the composition and abundance of basic and modified sterols that are actually being produced. Here, we coupled bioinformatics with lipid analyses to investigate the scope of bacterial sterol production. We identified oxidosqualene cyclase (Osc), which catalyzes the initial cyclization of oxidosqualene to the basic sterol structure, in 34 bacterial genomes from five phyla (Bacteroidetes, Cyanobacteria, Planctomycetes, Proteobacteria, and Verrucomicrobia) and in 176 metagenomes. Our data indicate that bacterial sterol synthesis likely occurs in diverse organisms and environments and also provides evidence that there are as yet uncultured groups of bacterial sterol producers. Phylogenetic analysis of bacterial and eukaryotic Osc sequences confirmed a complex evolutionary history of sterol synthesis in this domain. Finally, we characterized the lipids produced by Osc-containing bacteria and found that we could generally predict the ability to synthesize sterols. However, predicting the final modified sterol based on our current knowledge of sterol synthesis was difficult. Some bacteria

  18. Effect of oxidant exposure on the release of intracellular microcystin, MIB, and geosmin from three cyanobacteria species.

    PubMed

    Wert, Eric C; Korak, Julie A; Trenholm, Rebecca A; Rosario-Ortiz, Fernando L

    2014-04-01

    The release of intracellular microcystin-LR (MC-LR), 2-methylisoborneol (MIB), and geosmin was investigated after the oxidation of three cyanobacteria (Microcystis aeruginosa (MA), Oscillatoria sp. (OSC), and Lyngbya sp. (LYN)). During the oxidation of 200,000 cells/mL of MA, release of intracellular MC-LR exceeded the World Health Organization (WHO) guideline of 1 μg/L during the lowest oxidant exposures (CT) tested: ozone (0 mg-min/L, below the ozone demand), chlorine (<40 mg-min/L), chlorine dioxide (<560 mg-min/L), and chloramine (<640 mg-min/L). As the CT increased, ozone, chlorine, and chlorine dioxide were able to oxidize the released MC-LR. During the oxidation of OSC (2800 cells/mL) and LYN (1600 cells/mL), release of intracellular MIB and geosmin exceeded reported threshold odor values after exposure to chlorine, chlorine dioxide, and chloramine, which have low reactivity with these taste and odor compounds. Ozone oxidation of OSC yielded an increase in MIB concentration at lower exposures (≤2.9 mg-min/L), likely due to insufficient oxidation by hydroxyl radicals. The release of intracellular organic matter (IOM) was also measured to determine the potential of bulk measurements to act as a surrogate for cyanotoxins and metabolite release. In all cases, the dissolved organic carbon (DOC) release was less than 0.25 mgC/L, which lacked the sensitivity to indicate the release of MC-LR, MIB, or geosmin. The fluorescence index proved to be a more sensitive indicator of intracellular organic matter release than DOC for MA. These results illustrate that toxic or odorous compounds may be released from cyanobacteria cells during oxidation processes with minimal changes in the DOC concentration. PMID:24289950

  19. A prospective, blinded evaluation of a video-assisted ‘4-stage approach’ during undergraduate student practical skills training

    PubMed Central

    2014-01-01

    Background The 4-stage approach (4-SA) is used as a didactic method for teaching practical skills in international courses on resuscitation and the structured care of trauma patients. The aim of this study was to evaluate objective and subjective learning success of a video-assisted 4-SA in teaching undergraduate medical students. Methods The participants were medical students learning the principles of the acute treatment of trauma patients in their multidiscipline course on emergency and intensive care medicine. The participants were quasi- randomly divided into two groups. The 4-SA was used in both groups. In the control group, all four steps were presented by an instructor. In the study group, the first two steps were presented as a video. At the end of the course a 5-minute objective, structured clinical examination (OSCE) of a simulated trauma patient was conducted. The test results were divided into objective results obtained through a checklist with 9 dichotomous items and the assessment of the global performance rated subjectively by the examiner on a Likert scale from 1 to 6. Results 313 students were recruited; the results of 256 were suitable for analysis. The OSCE results were excellent in both groups and did not differ significantly (control group: median 9, interquantil range (IQR) 8–9, study group: median 9, IQR 8–9; p = 0.29). The global performance was rated significantly better for the study group (median 1, IQR 1–2 vs. median 2, IQR 1–3; p < 0.01). The relative knowledge increase, stated by the students in their evaluation after the course, was greater in the study group (85% vs. 80%). Conclusion It is possible to employ video assistance in the classical 4-SA with comparable objective test results in an OSCE. The global performance was significantly improved with use of video assistance. PMID:24885140

  20. Does Emotional Intelligence at Medical School Admission Predict Future Academic Performance?

    PubMed Central

    Leddy, John J.; Wood, Timothy J.; Puddester, Derek; Moineau, Geneviève

    2014-01-01

    Purpose Medical school admissions committees are increasingly considering noncognitive measures like emotional intelligence (EI) in evaluating potential applicants. This study explored whether scores on an EI abilities test at admissions predicted future academic performance in medical school to determine whether EI could be used in making admissions decisions. Method The authors invited all University of Ottawa medical school applicants offered an interview in 2006 and 2007 to complete the Mayer–Salovey–Caruso EI Test (MSCEIT) at the time of their interview (105 and 101, respectively), then again at matriculation (120 and 106, respectively). To determine predictive validity, they correlated MSCEIT scores to scores on written examinations and objective structured clinical examinations (OSCEs) administered during the four-year program. They also correlated MSCEIT scores to the number of nominations for excellence in clinical performance and failures recorded over the four years. Results The authors found no significant correlations between MSCEIT scores and written examination scores or number of failures. The correlations between MSCEIT scores and total OSCE scores ranged from 0.01 to 0.35; only MSCEIT scores at matriculation and OSCE year 4 scores for the 2007 cohort were significantly correlated. Correlations between MSCEIT scores and clinical nominations were low (range 0.12–0.28); only the correlation between MSCEIT scores at matriculation and number of clinical nominations for the 2007 cohort were statistically significant. Conclusions EI, as measured by an abilities test at admissions, does not appear to reliably predict future academic performance. Future studies should define the role of EI in admissions decisions. PMID:24556771

  1. An Obvious Improvement in the Performance of Ternary Organic Solar Cells with "Guest" Donor Present at the "Host" Donor/Acceptor Interface.

    PubMed

    Bi, Peng-Qing; Wu, Bo; Zheng, Fei; Xu, Wei-Long; Yang, Xiao-Yu; Feng, Lin; Zhu, Furong; Hao, Xiao-Tao

    2016-09-01

    A small-molecule material, 7,7-(4,4-bis(2-ethylhexyl)-4H-silolo[3,2-b:4,5-b']dithiophene-2,6-diyl)bis(6-fluoro-4-(5'-hexyl-[2,2'-bithiophen]-5-yl)benzo-[c] [1,2,5]thiadiazole) (p-DTS(FBTTH2)2), was used to modify the morphology and electron-transport properties of the polymer blend of poly(3-hexythiophene) (P3HT) and [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) bulk heterojunctions. As a result, a 24% increase in the power-conversion efficiency (PCE) of the p-DTS(FBTTH2)2:P3HT:PC71BM ternary organic solar cells (OSCs) is obtained. The improvement in the performance of OSCs is attributed to the constructive energy cascade path in the ternary system that benefits an efficient Förster resonance energy/charge transfer process between P3HT and p-DTS(FBTTH2)2, thereby improving photocurrent generation. It is shown that p-DTS(FBTTH2)2 molecules engage themselves at the P3HT/PC71BM interface. A combination of absorption enhancement, efficient energy transfer process, and ordered nanomorphology in the ternary system favors exciton dissociation and charge transportation in the polymer bulk heterojunction. The finding of this work reveals that distribution of the appropriate "guest" donor at the "host" donor/acceptor interface is an effective approach for attaining high-performance OSCs. PMID:27525544

  2. Assessment of first-year veterinary students' communication skills using an objective structured clinical examination: the importance of context.

    PubMed

    Hecker, Kent G; Adams, Cindy L; Coe, Jason B

    2012-01-01

    Communication skills are considered to be a core clinical skill in veterinary medicine and essential for practice success, including outcomes of care for patients and clients. While veterinary schools include communication skills training in their programs, there is minimal knowledge on how best to assess communication competence throughout the undergraduate program. The purpose of this study was to further our understanding of the reliability, utility, and suitability of a communication skills Objective Structured Clinical Examination (OSCE). Specifically we wanted to (1) identify the greatest source of variability (student, rater, station, and track) within a first-year, four station OSCE using exam scores and scores from videotape review by two trained raters, and (2) determine the effect of different stations on students' communication skills performance. Reliability of the scores from both the exam data and the two expert raters was 0.50 and 0.46 respectively, with the greatest amount of variance attributable to student by station. The percentage of variance due to raters in the exam data was 16.35%, whereas the percentage of variance for the two expert raters was 0%. These results have three important implications. First, the results reinforce the need for communication educators to emphasize that use of communication skills is moderated by the context of the clinical interaction. Second, by increasing rater training the amount of error in the scores due to raters can be reduced and inter-rater reliability increases. Third, the communication assessment method (in this case the OSCE checklist) should be built purposefully, taking into consideration the context of the case. PMID:22951466

  3. Comparison between pre-fractionation and fractionation process of heavy gas oil for determination of sulfur compounds using comprehensive two-dimensional gas chromatography.

    PubMed

    Machado, Maria Elisabete; Bregles, Lucas Panizzi; de Menezes, Eliana Weber; Caramão, Elina Bastos; Benvenutti, Edilson Valmir; Zini, Cláudia Alcaraz

    2013-01-25

    The separation of the organic sulfur compounds (OSC) of petroleum or its heavy fractions is a critical step and is essential for the correct characterization of these compounds, especially due to similar physical and chemical properties of polycyclic aromatic sulfur heterocycles (PASH) and polycyclic aromatic hydrocarbons (PAH). This similarity results in coelutions among PAH and PASH and for this reason former steps of fractionation are required before gas chromatographic analysis. The objective of this study was to evaluate the potential of GC×GC for the separation and identification of OSC in a heavy gas oil sample without fractionation, after pre-fractionation in an alumina column and also after fractionation process. This last one was performed with a modified stationary phase manufactured and characterized in the laboratory, called Pd(II)-MPSG, where palladium is chemically linked to silica through mercaptopropyl groups. The fractions obtained from both procedures were analyzed by GC×GC/TOFMS, which was effective to separate and identify various classes of OSC. A hundred and thirty-five compounds were tentatively identified in the sample that was only pre-fractionated. However, when the fractionation was also performed with the Pd(II)-MPSG phase, a larger number of sulfur compounds were found (317). Results have shown that the analysis of a pre-fractionated sample by GC×GC/TOFMS is suitable when the goal is a general characterization of classes of compounds in the sample, while a more detailed analysis of PASH can be performed, using also the fractionation Pd(II)-MPSG phase. GC×GC/TOFMS played a major role in the comparison of samples obtained from pre-fractionation and fractionation steps due to its high peak capacity, selectivity, organized distribution of chromatographic peaks and resolution. PMID:23298843

  4. Oxygen storage properties of La1-xSrxFeO3-δ for chemical-looping reactions–An in-situ neutron and synchrotron X-ray study

    DOE PAGESBeta

    Taylor, Daniel D.; Schreiber, Nathaniel J.; Levitas, Benjamin D.; Xu, Wenqian; Rodriguez, Efrain E.; Whitfield, Pamela S.

    2016-05-16

    Oxygen storage materials (OSMs) provide lattice oxygen for a number of chemical-looping reactions including natural gas combustion and methane reforming. La1–xSrxFeO3-δ has shown promise for use as an OSM in methane reforming reactions due to its high product selectivity, fast oxide diffusion, and cycle stability. Here, we investigate the structural evolution of the series La1–xSrxFeO3-δ for x = 0, 1/3, 1/2, 2/3, and 1, using in situ synchrotron X-ray and neutron diffraction, as it is cycled under the conditions of a chemical-looping reactor (methane and oxygen atmospheres). In the compositions x = 1/3, 1/2, 2/3, and 1, we discover anmore » envelope , or temperature range, of oxygen storage capacity (OSC), where oxygen can easily and reversibly be inserted and removed from the OSM. Our in situ X-ray and neutron diffraction results reveal that while samples with higher Sr contents had a higher OSC, those same samples suffered from slower reaction kinetics and some, such as the x = 1/2 and x = 2/3 compositions, had local variations in Sr content, which led to inhomogeneous regions with varying reaction rates. Therefore, we highlight the importance of in situ diffraction studies, and we propose that these measurements are required for the thorough evaluation of future candidate OSMs. Furthermore, we recommend La2/3Sr1/3FeO3-δ as the optimal OSM in the series because its structure remains homogeneous throughout the reaction, and its OSC envelope is similar to that of the higher doped materials.« less

  5. Do medical students’ scores using different assessment instruments predict their scores in clinical reasoning using a computer-based simulation?

    PubMed Central

    Fida, Mariam; Kassab, Salah Eldin

    2015-01-01

    Purpose The development of clinical problem-solving skills evolves over time and requires structured training and background knowledge. Computer-based case simulations (CCS) have been used for teaching and assessment of clinical reasoning skills. However, previous studies examining the psychometric properties of CCS as an assessment tool have been controversial. Furthermore, studies reporting the integration of CCS into problem-based medical curricula have been limited. Methods This study examined the psychometric properties of using CCS software (DxR Clinician) for assessment of medical students (n=130) studying in a problem-based, integrated multisystem module (Unit IX) during the academic year 2011–2012. Internal consistency reliability of CCS scores was calculated using Cronbach’s alpha statistics. The relationships between students’ scores in CCS components (clinical reasoning, diagnostic performance, and patient management) and their scores in other examination tools at the end of the unit including multiple-choice questions, short-answer questions, objective structured clinical examination (OSCE), and real patient encounters were analyzed using stepwise hierarchical linear regression. Results Internal consistency reliability of CCS scores was high (α=0.862). Inter-item correlations between students’ scores in different CCS components and their scores in CCS and other test items were statistically significant. Regression analysis indicated that OSCE scores predicted 32.7% and 35.1% of the variance in clinical reasoning and patient management scores, respectively (P<0.01). Multiple-choice question scores, however, predicted only 15.4% of the variance in diagnostic performance scores (P<0.01), while students’ scores in real patient encounters did not predict any of the CCS scores. Conclusion Students’ scores in OSCE are the most important predictors of their scores in clinical reasoning and patient management using CCS. However, real patient

  6. Direct Uniaxial Alignment of a Donor-Acceptor Semiconducting Polymer Using Single-Step Solution Shearing.

    PubMed

    Shaw, Leo; Hayoz, Pascal; Diao, Ying; Reinspach, Julia Antonia; To, John W F; Toney, Michael F; Weitz, R Thomas; Bao, Zhenan

    2016-04-13

    The alignment of organic semiconductors (OSCs) in the active layers of electronic devices can confer desirable properties, such as enhanced charge transport properties due to better ordering, charge transport anisotropy for reduced device cross-talk, and polarized light emission or absorption. The solution-based deposition of highly aligned small molecule OSCs has been widely demonstrated, but the alignment of polymeric OSCs in thin films deposited directly from solution has typically required surface templating or complex pre- or postdeposition processing. Therefore, single-step solution processing and the charge transport enhancement afforded by alignment continue to be attractive. We report here the use of solution shearing to tune the degree of alignment in poly(diketopyrrolopyrrole-terthiophene) thin films by controlling the coating speed. A maximum dichroic ratio of ∼7 was achieved on unpatterned substrates without any additional pre- or postdeposition processing. The degree of polymer alignment was found to be a competition between the shear alignment of polymer chains in solution and the complex thin film drying process. Contrary to previous reports, no charge transport anisotropy was observed because of the small crystallite size relative to the channel length, a meshlike morphology, and the likelihood of increased grain boundaries in the direction transverse to coating. In fact, the lack of aligned morphological structures, coupled with observed anisotropy in X-ray diffraction data, suggests the alignment of polymer molecules in both the crystalline and the amorphous regions of the films. The shear speed at which maximum dichroism is achieved can be controlled by altering deposition parameters such as temperature and substrate treatment. Modest changes in molecular weight showed negligible effects on alignment, while longer polymer alkyl side chains were found to reduce the degree of alignment. This work demonstrates that solution shearing can be used

  7. Oxygen storage properties of La1-xSrxFeO3- for chemical-looping reactions an in-situ neutron and synchrotron X-ray study

    DOE PAGESBeta

    Taylor, Daniel; Schreiber, Nathaniel; Levitas, Benjamin; Xu, Wenqian; Rodriguez, Efrain E

    2016-01-01

    Oxygen storage materials (OSMs) provide lattice oxygen for a number of chemical-looping reactions including natural gas combustion and methane reforming. La1 xSrxFeO3 has shown promise for use as an OSM in methane reforming reactions due to its high product selectivity, fast oxide diffusion, and cycle stability. Here, we investigate the structural evolution of the series La1 xSrxFeO3 for x = 0, 1/3, 1/2, 2/3, and 1, using in situ synchrotron X-ray and neutron diffraction, as it is cycled under the conditions of a chemical-looping reactor (methane and oxygen atmospheres). In the compositions x = 1/3, 1/2, 2/3, and 1, wemore » discover an envelope , or temperature range, of oxygen storage capacity (OSC), where oxygen can easily and reversibly be inserted and removed from the OSM. Our in situ X-ray and neutron diffraction results reveal that while samples with higher Sr contents had a higher OSC, those same samples suffered from slower reaction kinetics and some, such as the x = 1/2 and x = 2/3 compositions, had local variations in Sr content, which led to inhomogeneous regions with varying reaction rates. Therefore, we highlight the importance of in situ diffraction studies, and we propose that these measurements are required for the thorough evaluation of future candidate OSMs. We recommend La2/3Sr1/3FeO3 as the optimal OSM in the series because its structure remains homogeneous throughout the reaction, and its OSC envelope is similar to that of the higher doped materials.« less

  8. Guidance for use of the oil spill liability trust fund

    SciTech Connect

    1997-02-01

    This guidance document has been prepared to assist On-Scene Coordinators (OSCs) and financial management personnel in accessing and using the Oil Spill Liability Trust Fund (OSLTF) in orders to conduct oil pollution removal actions under Section 311(c) of the Clean Water Act (CWA) and Section 1012 of the Oil Pollution Act of 1990 (OPA), and fully accounting for OSLTF funds. This document details the requirments and procedures for use of the OSLTF that are described in the Memorandum of Understanding between the U.S. Environmental Protection Agency and the U.S. Coast Guard for use of the Oil Spill Liability Trust Fund (MOU).

  9. Effects of ray profile modeling on resolution recovery in clinical CT

    SciTech Connect

    Hofmann, Christian; Knaup, Michael; Kachelrieß, Marc

    2014-02-15

    Purpose: Iterative image reconstruction gains more and more interest in clinical routine, as it promises to reduce image noise (and thereby patient dose), to reduce artifacts, or to improve spatial resolution. However, among vendors and researchers, there is no consensus of how to best achieve these goals. The authors are focusing on the aspect of geometric ray profile modeling, which is realized by some algorithms, while others model the ray as a straight line. The authors incorporate ray-modeling (RM) in nonregularized iterative reconstruction. That means, instead of using one simple single needle beam to represent the x-ray, the authors evaluate the double integral of attenuation path length over the finite source distribution and the finite detector element size in the numerical forward projection. Our investigations aim at analyzing the resolution recovery (RR) effects of RM. Resolution recovery means that frequencies can be recovered beyond the resolution limit of the imaging system. In order to evaluate, whether clinical CT images can benefit from modeling the geometrical properties of each x-ray, the authors performed a 2D simulation study of a clinical CT fan-beam geometry that includes the precise modeling of these geometrical properties. Methods: All simulations and reconstructions are performed in native fan-beam geometry. A water phantom with resolution bar patterns and a Forbild thorax phantom with circular resolution patterns representing calcifications in the heart region are simulated. An FBP reconstruction with a Ram–Lak kernel is used as a reference reconstruction. The FBP is compared to iterative reconstruction techniques with and without RM: An ordered subsets convex (OSC) algorithm without any RM (OSC), an OSC where the forward projection is modeled concerning the finite focal spot and detector size (OSC-RM) and an OSC with RM and with a matched forward and backprojection pair (OSC-T-RM, T for transpose). In all cases, noise was matched to

  10. Problem on the United States Continental Shelf - measuring the environmental {open_quotes}effectiveness{close_quotes} of the Outer Continental Shelf Act (OCSA)

    SciTech Connect

    Dubner, B.H.

    1994-12-31

    This article reviews the interplay of environmental standard with oil and gas leasing on the Outer Continental Shelf (OSC) in order to determine if the marine environment is really protected by the interplay of domestic legislation. The 1982 LOS treaty leaves environmental protection to State (domestic) regulation. There is no customary law regarding this type of domestic shelf regulation. The main problem is measuring the {open_quotes}effectiveness{close_quotes} of our domestic shelf legislation. For example, do we simply review effectiveness in terms of controlling operational damage or in terms of environmental injury caused by catastrophic accidents?

  11. Charge Transport and Transfer at the Nanoscale Between Metals and Novel Conjugated Materials

    NASA Astrophysics Data System (ADS)

    Worne, Jeffrey Howard

    Organic semiconductors (OSCs) and graphene are two classes of conjugated materials that hold promise to create flexible electronic displays, high speed transistors, and low-cost solar cells. Crucial to understanding the behavior of these materials is understanding the effects metallic contacts have on the local charge environment. Additionally, characterizing the charge carrier transport behavior within these materials sheds light on the physical mechanisms behind transport. The first part of this thesis examines the origin of the low-temperature, high electric field transport behavior of OSCs. Two chemically distinct OSCs are used, poly-3(hexylthiophene) (P3HT) and 6,13-bis(triisopropyl-silylethynyl) (TIPS) pentacene. Several models explaining the low-temperature behavior are presented, with one using the Tomonaga-Luttinger liquid (TLL) insulator-to-metal transition model and one using a field-emission hopping model. While the TLL model is only valid for 1-dimensional systems, it is shown to work for both P3HT (1D) and TIPS-pentacene (2D), suggesting the TLL model is not an appropriate description of these systems. Instead, a cross-over from thermally-activated hopping to field-emission hopping is shown to explain the data well. The second part of this thesis focuses on the interaction between gold and platinum contacts and graphene using suspended graphene over sub-100 nanometer channels. Contacts to graphene can strongly dominate charge transport and mobility as well as significantly modify the charge environment local to the contacts. Platinum electrodes are discovered to be strong dopants to graphene at short length scales while gold electrodes do not have the same effect. By increasing the separation distance between the electrodes, this discrepancy is shown to disappear, suggesting an upper limit on charge diffusion from the contacts. Finally, this thesis will discuss a novel technique to observe the high-frequency behavior in OSCs using two microwave

  12. Performance tuned radioisotope thermophotovoltaic space power system

    NASA Astrophysics Data System (ADS)

    Horne, W. E.; Morgan, M. D.; Saban, S. B.

    1998-01-01

    The trend in space exploration is to use many small, low-cost, special-purpose satellites instead of the large, high-cost, multipurpose satellites used in the past. As a result of this new trend, there is a need for lightweight, efficient, and compact radioisotope fueled electrical power generators. This paper presents an improved design for a radioisotope thermophotovoltaic (RTPV) space power system in the 10 W to 20 W class which promises up to 37.6 watts at 30.1% efficiency and 25 W/kg specific power. The RTPV power system concept has been studied and compared to radioisotope thermoelectric generators (RTG) radioisotope, Stirling generators and alkali metal thermal electric conversion (AMTEC) generators (Schock, 1995). The studies indicate that RTPV has the potential to be the lightest weight, most efficient and most reliable of the three concepts. However, in spite of the efficiency and light weight, the size of the thermal radiator required to eliminate excess heat from the PV cells and the lack of actual system operational performance data are perceived as obstacles to RTPV acceptance for space applications. Between 1994 and 1997 EDTEK optimized the key converter components for an RTPV generator under Department of Energy (DOE) funding administered via subcontracts to Orbital Sciences Corporation (OSC) and EG&G Mound Applied Technologies Laboratory (Horne, 1995). The optimized components included a resonant micromesh infrared bandpass filter, low-bandgap GaSb PV cells and cell arrays. Parametric data from these components were supplied to OSC who developed and analyzed the performance of 100 W, 20 W, and 10 W RTPV generators. These designs are described in references (Schock 1994, 1995 and 1996). Since the performance of each class of supply was roughly equivalent and simply scaled with size, this paper will consider the OSC 20 W design as a baseline. The baseline 20-W RTPV design was developed by Schock, et al of OSC and has been presented elsewhere. The

  13. Seismic Structure of the Shallow Mantle Beneath the Endeavor Segment of the Juan de Fuca Ridge

    NASA Astrophysics Data System (ADS)

    VanderBeek, B. P.; Toomey, D. R.; Hooft, E. E.; Wilcock, W. S.; Weekly, R. T.; Soule, D. C.

    2013-12-01

    We present tomographic images of the seismic structure of the shallow mantle beneath the intermediate-spreading Endeavor segment of the Juan de Fuca ridge. Our results provide insight into the relationship between magma supply from the mantle and overlying ridge crest processes. We use seismic energy refracted below the Moho (Pn), as recorded by the Endeavor tomography (ETOMO) experiment, to image the anisotropic and isotropic P wave velocity structure. The ETOMO experiment was an active source seismic study conducted in August 2009 as part of the RIDGE2000 science program. The experimental area extends 100 km along- and 60 km across-axis and encompasses active hydrothermal vent fields near the segment center, the eastern end of the Heck seamount chain, and two overlapping spreading centers (OSCs) at either end of the segment. Previous tomographic analyses of seismic arrivals refracted through the crust (Pg), and reflected off the Moho (PmP), constrain a three-dimensional starting model of crustal velocity and thickness. These Pg and PmP arrivals are incorporated in our inversion of Pn travel-time data to further constrain the isotropic and anisotropic mantle velocity structure. Preliminary results reveal three distinct mantle low-velocity zones, inferred as regions of mantle melt delivery to the base of the crust, that are located: (i) off-axis near the segment center, (ii) beneath the Endeavor-West Valley OSC, and (iii) beneath the Cobb OSC near Split Seamount. The mantle anomalies are located at intervals of ~30 to 40 km along-axis and the low velocity anomalies beneath the OSCs are comparable in magnitude to the one located near the segment center. The direction of shallow mantle flow is inferred from azimuthal variations in Pn travel-time residuals relative to a homogeneous isotropic mantle. Continuing analysis will focus on constraining spatial variations in the orientation of azimuthal anisotropy. On the basis of our results, we will discuss the transport of

  14. The IXTOC I oil spill: the Federal Scientific Response. Special report

    SciTech Connect

    Hooper, C.H.

    1981-12-01

    On 3 June 1979, a Petroleos Mexicanos (PEMEX) exploratory well, IXTOC I, blew out in the Bay of Campeche, about 80 km northwest of Ciudad del Carmen, Mexico. The spill, not brought under control until 27 March 1980, became the largest oil spill in history. The following summary described the numerous operation support activities and scientific studies performed under the purview of the Federal Scientific Support Coordinator. The primary purpose of the physical, chemical, and biological activities described herein was to provide the Federal On-Scene Coordinator (OSC) with timely information concerning the location, toxicity, and potential ecological impact of the oil on the Texas coastline.

  15. The Telecommunications and Data Acquisition

    NASA Technical Reports Server (NTRS)

    Posner, Edward C. (Editor)

    1992-01-01

    This quarterly publication provides archival reports on developments in programs managed by JPL's Office of Telecommunications and Data Acquisition (TDA). In space communications, radio navigation, radio science, and ground-based radio and radar astronomy, it reports on activities of the Deep Space Network (DSN) in planning, supporting research and technology, implementation, and operations. Also included are standards activity at JPL for space data and information systems and reimbursable DSN work performed for other space agencies through NASA. The preceding work is all performed for NASA's Office of Space Communications (OSC).

  16. A simple method to adjust the morphology of gradient three-dimensional PTB7-Th:PC71BM polymer solar cells

    NASA Astrophysics Data System (ADS)

    Zhao, Ling; Zhao, Suling; Xu, Zheng; Yang, Qianqian; Huang, Di; Xu, Xurong

    2015-03-01

    Multiple interfaces are necessary for exciton separation in bulk heterojunction (BHJ) solar cells and continuous pathways for carrier transportation in donor : acceptor blend films, especially along the vertical direction, for efficient charge collection. Therefore film morphology is critically important to satisfy both in the construction of high performance organic solar cells (OSCs). In this work, the cooperative effect of solvent additives and solvent flux treatment on film morphology was confirmed. Furthermore, the correlation between a single processing parameter and the resulting morphology has been investigated. Our results show that film morphology can be tuned by changing the volume fraction of the solvent additive. Beyond that, after methanol fluxing, the OSC performance improves significantly, as short circuit current density (JSC) increases from 13.85 mA cm-2 to 15.17 mA cm-2 and fill factor (FF) from 62.9% to 65.7%, simultaneously. As a result, power conversion efficiency (PCE) increases from 6.79% to 7.67%. The favorable morphology was further investigated using time-of-flight secondary-ion mass spectroscopy (TOF-SIMS), and atomic force microscopy (AFM).Multiple interfaces are necessary for exciton separation in bulk heterojunction (BHJ) solar cells and continuous pathways for carrier transportation in donor : acceptor blend films, especially along the vertical direction, for efficient charge collection. Therefore film morphology is critically important to satisfy both in the construction of high performance organic solar cells (OSCs). In this work, the cooperative effect of solvent additives and solvent flux treatment on film morphology was confirmed. Furthermore, the correlation between a single processing parameter and the resulting morphology has been investigated. Our results show that film morphology can be tuned by changing the volume fraction of the solvent additive. Beyond that, after methanol fluxing, the OSC performance improves

  17. A "roller-wheel" Pt-containing small molecule that outperforms its polymer analogs in organic solar cells

    DOE PAGESBeta

    He, Wenhan; Wu, Qin; Livshits, Maksim Y.; Dickie, Diane A.; Yang, Jianzhong; Quinnett, Rachel; Rack, Jeffrey R.; Qin, Yang

    2016-05-23

    A novel Pt-bisacetylide small molecule (Pt-SM) featuring “roller-wheel” geometry was synthesized and characterized. When compared with conventional Pt-containing polymers and small molecules having “dumbbell” shaped structures, Pt-SM displays enhanced crystallinity and intermolecular π–π interactions, as well as favorable panchromatic absorption behaviors. Furthermore, organic solar cells (OSCs) employing Pt-SM achieve power conversion efficiencies (PCEs) up to 5.9%, the highest reported so far for Pt-containing polymers and small molecules.

  18. Effect of OSHA's bloodborne pathogens standard on hazardous waste cleanup activities. Fact sheet

    SciTech Connect

    Not Available

    1993-08-01

    Bloodborne pathogens are microorganisms that are present in human blood and can cause disease in humans. These pathogens include, but are not limited to, hepatitis B virus (HBV) and human immunodeficiency virus (HIV). In addition to healthcare workers, the standard also may affect workers who handle waste potentially contaminated with blood or other potentially infectious material during response actions at uncontrolled hazardous waste sites. The purpose of the Fact Sheet is to describe the additional planning, training, and medical surveillance requirements that the new OSHA standard on bloodborne pathogens imposes upon On-Scene Coordinators (OSCs) and Remedial Project Managers (RPMs) during a Superfund response action.

  19. The Telecommunications and Data Acquisition Report

    NASA Technical Reports Server (NTRS)

    Yuen, Joseph H. (Editor)

    1995-01-01

    This quarterly publication provides archival reports on developments in programs managed by JPL's Telecommunications and Mission Operations Directorate (TMOD), which now includes the former Telecommunications and Data Acquisition (TDA) Office. In space communications, radio navigation, radio science, and ground-based radio and radar astronomy, it reports on activities of the Deep Space Network (DSN) in planning, supporting research and technology, implementation, and operations. Also included are standards activity at JPL for space data and information systems and reimbursable DSN work performed for other space agencies through NASA. The preceding work is all performed for NASA's Office of Space Communications (OSC).

  20. Advances in osteosarcoma stem cell research and opportunities for novel therapeutic targets.

    PubMed

    Yan, Guang-Ning; Lv, Yang-Fan; Guo, Qiao-Nan

    2016-01-28

    Osteosarcoma is the most common type of bone cancer, especially in children and young adults. The primary treatment for osteosarcoma is a combination of surgery and chemotherapy, however prognoses remain poor due to chemoresistance and early metastases. Osteosarcoma stem cells appear to play central roles in tumor recurrence, metastases and chemoresistance via self-renewal and differentiation. Targeting these cells may provide a novel strategy in the treatment of osteosarcoma. This review summarizes current knowledge of this rare phenotype and recent advances in understanding the functions OSCs (osteosarcoma stem cells) in osteosarcoma, with the aim of improving therapies in the future. PMID:26571463

  1. Three-Year Change in the Wellbeing of Orphaned and Separated Children in Institutional and Family-Based Care Settings in Five Low- and Middle-Income Countries

    PubMed Central

    Whetten, Kathryn; Ostermann, Jan; Pence, Brian W.; Whetten, Rachel A.; Messer, Lynne C.; Ariely, Sumedha; O'Donnell, Karen; Wasonga, Augustine I.; Vann, Vanroth; Itemba, Dafrosa; Eticha, Misganaw; Madan, Ira; Thielman, Nathan M.

    2014-01-01

    Background With more than 2 million children living in group homes, or “institutions”, worldwide, the extent to which institution-based caregiving negatively affects development and wellbeing is a central question for international policymakers. Methods A two-stage random sampling methodology identified community representative samples of 1,357 institution-dwelling orphaned and separated children (OSC) and 1,480 family-dwelling OSC aged 6–12 from 5 low and middle income countries. Data were collected from children and their primary caregivers. Survey-analytic techniques and linear mixed effects models describe child wellbeing collected at baseline and at 36 months, including physical and emotional health, growth, cognitive development and memory, and the variation in outcomes between children, care settings, and study sites. Findings At 36-month follow-up, institution-dwelling OSC had statistically significantly higher height-for-age Z-scores and better caregiver-reported physical health; family-dwelling OSC had fewer caregiver-reported emotional difficulties. There were no statistically significant differences between the two groups on other measures. At both baseline and follow-up, the magnitude of the differences between the institution- and family-dwelling groups was small. Relatively little variation in outcomes was attributable to differences between sites (11–27% of total variation) or care settings within sites (8–14%), with most variation attributable to differences between children within settings (60–75%). The percent of variation in outcomes attributable to the care setting type, institution- versus family-based care, ranged from 0–4% at baseline, 0–3% at 36-month follow-up, and 0–4% for changes between baseline and 36 months. Interpretation These findings contradict the hypothesis that group home placement universally adversely affects child wellbeing. Without substantial improvements in and support for family settings, the removal of

  2. World Climate Research Programme (WCRP) Open Science Conference Final Report

    SciTech Connect

    Amy Honchar

    2012-11-07

    Travel support was provided for a range of invited speakers, students, early-career, and developing-country, and key scientists who required financial assistance to participate, and would otherwise be unable to attend, to contribute to, and benefit from, this important event. This support also allowed participants to present their research findings, provide input to WCRP planning and plans, and encourage collaboration with other research scientists. In particular, the participation and engagement of regional scientists in the OSC helped to ensure communication and advocacy in identifying the climate research needs of the region and their inclusion in the WCRP long-range research priorities.

  3. RHIC spin flipper commissioning results

    SciTech Connect

    Bai M.; Roser, T.; Dawson, C.; Kewisch, J.; Makdisi, Y.; Oddo, P.; Pai, C.; Pile, P.

    2012-05-20

    The five AC dipole RHIC spin flipper design in the RHIC Blue ring was first tested during the RHIC 2012 polarized proton operation. The advantage of this design is to eliminate the vertical coherent betatron oscillations outside the spin flipper. The closure of each ac dipole vertical bump was measured with orbital response as well as spin. The effect of the rotating field on the spin motion by the spin flipper was also confirmed by measuring the suppressed resonance at Q{sub s} = 1 - Q{sub osc}.

  4. DOPS (Direct Observation of Procedural Skills) in undergraduate skills-lab: Does it work? Analysis of skills-performance and curricular side effects

    PubMed Central

    Profanter, Christoph; Perathoner, Alexander

    2015-01-01

    Objective: Sufficient teaching and assessing clinical skills in the undergraduate setting becomes more and more important. In a surgical skills-lab course at the Medical University of Innsbruck fourth year students were teached with DOPS (direct observation of procedural skills). We analyzed whether DOPS worked or not in this setting, which performance levels could be reached compared to tutor teaching (one tutor, 5 students) and which curricular side effects could be observed. Methods: In a prospective randomized trial in summer 2013 (April – June) four competence-level-based skills were teached in small groups during one week: surgical abdominal examination, urethral catheterization (phantom), rectal-digital examination (phantom), handling of central venous catheters. Group A was teached with DOPS, group B with a classical tutor system. Both groups underwent an OSCE (objective structured clinical examination) for assessment. 193 students were included in the study. Altogether 756 OSCE´s were carried out, 209 (27,6%) in the DOPS- and 547 (72,3%) in the tutor-group. Results: Both groups reached high performance levels. In the first month there was a statistically significant difference (p<0,05) in performance of 95% positive OSCE items in the DOPS-group versus 88% in the tutor group. In the following months the performance rates showed no difference anymore and came to 90% in both groups. In practical skills the analysis revealed a high correspondence between positive DOPS (92,4%) and OSCE (90,8%) results. Discussion: As shown by our data DOPS furnish high performance of clinical skills and work well in the undergraduate setting. Due to the high correspondence of DOPS and OSCE results DOPS should be considered as preferred assessment tool in a students skills-lab. The approximation of performance-rates within the months after initial superiority of DOPS could be explained by an interaction between DOPS and tutor system: DOPS elements seem to have improved

  5. The Telecommunications and Data Acquisition Report

    NASA Technical Reports Server (NTRS)

    Yuen, Joseph H. (Editor)

    1994-01-01

    This quarterly publication provides archival reports on developments in programs managed by JPL's Telecommunications and Mission Operations Directorate (TMOD), which now includes the former Telecommunications and Data Acquisition (TDA) Office. In space communications, radio navigation, radio science, and ground-based radio and radar astronomy, it reports on activities of the Deep Space Network (DS) in planning, supporting research and technology, implementation, and operations. Also included are standards activity at JPL for space data and information systems and reimbursable DSN work performed for other space agencies through NASA. The preceding work is all performed for NASA's Office of Space Communications (OSC).

  6. Case-control study of paternal occupation and social class with risk of childhood central nervous system tumours in Great Britain, 1962–2006

    PubMed Central

    Keegan, T J; Bunch, K J; Vincent, T J; King, J C; O'Neill, K A; Kendall, G M; MacCarthy, A; Fear, N T; Murphy, M F G

    2013-01-01

    Background: Paternal occupational exposures have been proposed as a risk factor for childhood central nervous system (CNS) tumours. This study investigates possible associations between paternal occupational exposure and childhood CNS tumours in Great Britain. Methods: The National Registry of Childhood Tumours provided all cases of childhood CNS tumours born and diagnosed in Great Britain from 1962 to 2006. Controls without cancer were matched on sex, period of birth and birth registration sub-district. Fathers' occupations were assigned to one or more of 33 exposure groups. A measure of social class was also derived from father's occupation at the time of the child's birth. Results: Of 11 119 cases of CNS tumours, 5 722 (51%) were astrocytomas or other gliomas, 2 286 (21%) were embryonal and 985 (9%) were ependymomas. There was an increased risk for CNS tumours overall with exposure to animals, odds ratio (OR) 1.40 (95% confidence intervals (CIs) 1.01, 1.94) and, after adjustment for occupational social class (OSC), with exposure to lead, OR 1.18 (1.01, 1.39). Exposure to metal-working oil mists was associated with reduced risk of CNS tumours, both before and after adjustment for OSC, OR 0.87 (0.75, 0.99). Risk of ependymomas was raised for exposure to solvents, OR 1.73 (1.02,2.92). For astrocytomas and other gliomas, risk was raised with high social contact, although this was only statistically significant before adjustment for OSC, OR 1.15 (1.01,1.31). Exposure to paints and metals appeared to reduce the risk of astrocytomas and embryonal tumours, respectively. However, as these results were the result of a number of statistical tests, it is possible they were generated by chance. Higher social class was a risk factor for all CNS tumours, OR 0.97 (0.95, 0.99). This was driven by increased risk for higher social classes within the major subtype astrocytoma, OR 0.95 (0.91, 0.98). Conclusion: Our results provide little evidence that paternal occupation is a

  7. Status of NASA's commercial cargo and crew transportation initiative

    NASA Astrophysics Data System (ADS)

    Lindenmoyer, Alan; Stone, Dennis

    2010-03-01

    To stimulate the commercial space transportation industry, the National Aeronautics and Space Administration (NASA) is facilitating the demonstration of Commercial Orbital Transportation Services (COTS) to Low Earth Orbit (LEO) by private-sector companies. In 2006, NASA entered into funded agreements with two such companies to share NASA's 500 million investment, Space Exploration Technologies (SpaceX) and Rocketplane Kistler (RpK), each of which proposed to obtain the additional private financing needed to complete its flight demonstrations. In 2007, NASA terminated the agreement with RpK because it failed to meet a series of technical and financial milestones which were necessary to receive the incremental NASA payments. In 2008, NASA conducted another competition for the remaining 170 million of NASA funding and entered into a funded agreement with Orbital Sciences Corporation (OSC). This paper provides an overview of the COTS approach of SpaceX and OSC and the status of their efforts to develop reliable and cost-effective commercial transportation to serve the LEO marketplace.

  8. Teaching and assessing procedural skills: a qualitative study

    PubMed Central

    2013-01-01

    Background Graduating Internal Medicine residents must possess sufficient skills to perform a variety of medical procedures. Little is known about resident experiences of acquiring procedural skills proficiency, of practicing these techniques, or of being assessed on their proficiency. The purpose of this study was to qualitatively investigate resident 1) experiences of the acquisition of procedural skills and 2) perceptions of procedural skills assessment methods available to them. Methods Focus groups were conducted in the weeks following an assessment of procedural skills incorporated into an objective structured clinical examination (OSCE). Using fundamental qualitative description, emergent themes were identified and analyzed. Results Residents perceived procedural skills assessment on the OSCE as a useful formative tool for direct observation and immediate feedback. This positive reaction was regularly expressed in conjunction with a frustration with available assessment systems. Participants reported that proficiency was acquired through resident directed learning with no formal mechanism to ensure acquisition or maintenance of skills. Conclusions The acquisition and assessment of procedural skills in Internal Medicine programs should move toward a more structured system of teaching, deliberate practice and objective assessment. We propose that directed, self-guided learning might meet these needs. PMID:23672617

  9. Determining the value of simulation in nurse education: study design and initial results.

    PubMed

    Alinier, Guillaume; Hunt, William B; Gordon, Ray

    2004-09-01

    Nowadays simulation is taking an important place in training and education of healthcare professionals. The University of Hertfordshire is carrying out a study which aims to determine the effect of realistic scenario-based simulation on nursing students' competence and confidence. This project is sponsored by the British Heart Foundation and takes place in the Hertfordshire Intensive Care and Emergency Simulation Centre (HICESC), a simulated three adult beds Intensive Care Unit. The simulation platform used is a Laerdal SimMan Universal Patient Simulator. A unique and robust study design, and results of the study are presented in this article. Consecutive cohorts of students are being assessed and reassessed after six months using an Objective Structured Clinical Examination (OSCE). Students are randomly divided into a control and experimental group for the period intervening between the two examinations. The experimental group is exposed to simulation training while the other students follow their usual nursing courses. Comparison is made between the OSCE results of the two groups of students. The experimental group had a greater improvement in performance than the control group (13.43% compared with 6.76% (p<0.05)). The results and feedback received from students and lecturers suggest that simulation training in nursing education is beneficial. PMID:19038158

  10. Evaluation of a training model to teach veterinary students a technique for injecting the jugular vein in horses.

    PubMed

    Eichel, Jane-Carolin; Korb, Werner; Schlenker, Antje; Bausch, Gerold; Brehm, Walter; Delling, Uta

    2013-01-01

    In this study, a newly-developed model for training veterinary students to inject the jugular vein in horses was evaluated as an additional tool to supplement the current method of teaching. The model was first validated by 19 experienced equine veterinarians, who judged the model to be a realistic and valuable tool for learning the technique. Subsequently, it was assessed using 24 students who were divided randomly into two groups. The injection technique was taught conventionally in a classroom lecture and a live demonstration to both groups, but only group 1 received additional training on the new model. All participants filled out self-assessment questionnaires before and after group 1 received training on the model. Finally, the proficiency of both groups was assessed using an objective structured clinical evaluation (OSCE) on live horses. Students from group 1 showed significantly improved confidence after their additional training on the model and also showed greater confidence when compared to group 2 students. In the OSCE, group 1 had a significantly better score compared to group 2: the median (with inter-quartile range) was 15 (0.7) vs. 11.5 (2.8) points out of 15, respectively. The training model proved to be a useful tool to teach veterinary students how to perform jugular vein injections in horses in a controlled environment, without time limitations or animal welfare concerns. The newly developed training model offers an inexpensive, efficient, animal-sparing way to teach this clinical skill to veterinary students. PMID:23975072

  11. Breaking the Space Charge Limit in Organic Solar Cells by a Novel Plasmonic-Electrical Concept

    NASA Astrophysics Data System (ADS)

    Sha, Wei E. I.; Li, Xuanhua; Choy, Wallace C. H.

    2014-08-01

    As a fundamental electrostatic limit, space charge limit (SCL) for photocurrent is a universal phenomenon and of paramount importance for organic semiconductors with unbalanced photocarriers mobility and high exciton generation. Here we proposed a new plasmonic-electrical concept to manipulate electrical properties of organic devices including photocarriers recombination, transport and collection. As a proof-of-concept, organic solar cells (OSCs) comprising metallic planar and grating electrodes are systematically investigated with normal and inverted device structures. Interestingly, although strong plasmonic resonances induce abnormally dense photocarriers around a grating anode, the grating-inverted OSC is exempt from space charge accumulation (limit) and degradation of electrical properties in contrast to the planar-inverted and planar-normal ones. The particular reason is that plasmonically induced photocarriers redistribution shortens the transport path of low-mobility holes, which are collected by the grating anode. The work demonstrated and explained the SCL breaking with the plasmonic-electrical effect. Most importantly, the plasmonic-electrical concept will open up a new way to manipulate both optical and electrical properties of semiconductor devices simultaneously.

  12. Nitrogen lasers, optical devices of variable gain coefficient: Theoretical considerations

    NASA Astrophysics Data System (ADS)

    Sarikhani, S.; Hariri, A.

    2010-01-01

    Based on our previous measurements on the gain values by employing an oscillator amplifier (OSC-AMP) N2-laser system of variable AMP electrode lengths, a calculation has been made for evaluation of the gain coefficient using rate equations. It is shown both numerically and analytically that small signal gain, g0, is following our experimental observations of g0=m+n/lAMP, where m and n are some constants, and l AMP is the length of the amplifier. For simplifying the calculation in the OCS-AMP circuit, an experimental condition of imposing the OSC-open-circuit operation has been applied, where the voltage waveforms from the relevant sections of the Blumlein circuit have been used for evaluation of the circuit parameters. Due to the fact that during the past years different cross-sections for the electron-impact excitations from the ground to the upper, N2( C), and lower, N2( B), have been introduced, our experimental observations have also been applied to examine the effect of introduced electron impact-excitation cross-sections on the g0(lAMP) behavior.

  13. Spacecraft and launch systems for TACSAT applications

    NASA Astrophysics Data System (ADS)

    Schade, Chris; Rye, Gilbert D.; Meurer, Robert H.

    1993-02-01

    The ability of a tactical communication satellite (TACSAT) space system to fulfill its mission application with the desired capability, responsiveness, reliability, and survivability, while at the same time achieving low cost objectives, is a tremendous challenge that can only be met if all of the system segments - launch, space, and ground - contribute to meeting mission unique requirements. The emerging concepts for the development, deployment, and operation of cost-effective TACSAT space systems are especially dependent on the flexibility and operability of their launch vehicle and spacecraft bus systems. Orbital Sciences Corporation (OSC) has privately developed two flexible yet cost-effective space launch vehicles--Pegasus (TM) and Taurus (TM)--with significant and unique operational capabilities that enable TACSAT space systems to meet these challenges. The Defense Advanced Research Projects Agency (DARPA) has sponsored the first launch of both systems, with follow-on launches scheduled in support of U.S. Air Force, NASA, SDIO, and commercial programs. In addition, OSC has developed a flexible, cost-effective, spacecraft bus--PegaStar (TM)--that makes common use of the Pegasus or Taurus final stage avionics and structure in an integrated systems approach, thereby optimizing the mass and volume available for payload sensors. PegaStar spacecraft for the Air Force and NASA are now in engineering and production.

  14. Training medical students to manage a chronic pain patient: both knowledge and communication skills are needed.

    PubMed

    Leila, Niemi-Murola; Pirkko, Heasman; Eeva, Pyörälä; Eija, Kalso; Reino, Pöyhiä

    2006-02-01

    Most studies concerning pain education of undergraduate medical students focus on knowledge, but little is known about the interviewing skills and pain evaluation. At the end of the fifth study year and at the beginning of the sixth year the students were asked to answer an electronical questionnaire to evaluate how the IASP curriculum on pain had been covered during the studies. In addition, the interviewing skills of the fifth year medical students were assessed using an objective structured clinical examination (OSCE). The students met a standardized patient suffering from postherpetic neuralgia, who was instructed to express depressive and exhausted feelings. A total of 97 students received the questionnaire and 35% responded with identification. All students answering the IASP questionnaire evaluated teaching of postherpetic pain and antidepressant treatment as sufficient. OSCE appeared as a feasible instrument in the assessment of chronic pain education. Eighty-eight percent of the students made the correct diagnosis. However, only 35% asked about sleep disturbances and 16% about depression. When developing a curriculum on pain education, attention should be paid to pedagogic methods about helping the students to implement the learned knowledge in their practice. Formative assessment of both knowledge and skills is essential for the development of a functional pain curriculum. PMID:16310721

  15. Packing effects in charge transfer dynamics in organic molecular heterojunctions consisting of TFB and F8BT

    NASA Astrophysics Data System (ADS)

    Fujii, Mikiya; Yamashita, Koichi

    2013-03-01

    Organic semiconductors have been widely investigated for photovoltaic and light emitting devices. Especially, further improvements for more efficient organic solar cells (OSCs) are desired. Thus, we explored computationally possibilities to make OSCs more efficient by adjusting the packing of molecular heterojunctions. We analyzed a molecular heterojunction that consists of poly(9,9-dioctylfluorene-co-N-(4-butylphenyl)diphenylenediamine) (TFB) and poly(9,9-dioctylfluorene-co-benzothiadiazole) (F8BT). Geometrical optimization of TFB(monomer)/F8BT(monomer) complex was carried out with DFT-D/B3LYP/6-31G*. Excited states were also calculated with CIS/6-31G*. To analyze packing effects, we rotated TFB around a principal axis. Then, charge transfer dynamics is analyzed with a quantum master equation (QME) approach in each packing From the excited states calculations, it is clarified that the packing strongly affects the energy level of the charge transfer state only. This packing dependency arises from a packing dependency of the exciton binding energy that is Coulomb interaction between an electron localized to F8BT and a hole localized to TFB. From the QME approach, it is confirmed that qualitative different electronic relaxation dynamics occurs in each different packing.

  16. Light Manipulation for Organic Optoelectronics Using Bio-inspired Moth's Eye Nanostructures

    NASA Astrophysics Data System (ADS)

    Zhou, Lei; Ou, Qing-Dong; Chen, Jing-De; Shen, Su; Tang, Jian-Xin; Li, Yan-Qing; Lee, Shuit-Tong

    2014-02-01

    Organic-based optoelectronic devices, including light-emitting diodes (OLEDs) and solar cells (OSCs) hold great promise as low-cost and large-area electro-optical devices and renewable energy sources. However, further improvement in efficiency remains a daunting challenge due to limited light extraction or absorption in conventional device architectures. Here we report a universal method of optical manipulation of light by integrating a dual-side bio-inspired moth's eye nanostructure with broadband anti-reflective and quasi-omnidirectional properties. Light out-coupling efficiency of OLEDs with stacked triple emission units is over 2 times that of a conventional device, resulting in drastic increase in external quantum efficiency and current efficiency to 119.7% and 366 cd A-1 without introducing spectral distortion and directionality. Similarly, the light in-coupling efficiency of OSCs is increased 20%, yielding an enhanced power conversion efficiency of 9.33%. We anticipate this method would offer a convenient and scalable way for inexpensive and high-efficiency organic optoelectronic designs.

  17. Light Manipulation for Organic Optoelectronics Using Bio-inspired Moth's Eye Nanostructures

    PubMed Central

    Zhou, Lei; Ou, Qing-Dong; Chen, Jing-De; Shen, Su; Tang, Jian-Xin; Li, Yan-Qing; Lee, Shuit-Tong

    2014-01-01

    Organic-based optoelectronic devices, including light-emitting diodes (OLEDs) and solar cells (OSCs) hold great promise as low-cost and large-area electro-optical devices and renewable energy sources. However, further improvement in efficiency remains a daunting challenge due to limited light extraction or absorption in conventional device architectures. Here we report a universal method of optical manipulation of light by integrating a dual-side bio-inspired moth's eye nanostructure with broadband anti-reflective and quasi-omnidirectional properties. Light out-coupling efficiency of OLEDs with stacked triple emission units is over 2 times that of a conventional device, resulting in drastic increase in external quantum efficiency and current efficiency to 119.7% and 366 cd A−1 without introducing spectral distortion and directionality. Similarly, the light in-coupling efficiency of OSCs is increased 20%, yielding an enhanced power conversion efficiency of 9.33%. We anticipate this method would offer a convenient and scalable way for inexpensive and high-efficiency organic optoelectronic designs. PMID:24509524

  18. Flexible indium zinc oxide/Ag/indium zinc oxide multilayer electrode grown on polyethersulfone substrate by cost-efficient roll-to-roll sputtering for flexible organic photovoltaics

    SciTech Connect

    Park, Yong-Seok; Kim, Han-Ki

    2010-01-15

    The authors describe the preparation and characteristics of flexible indium zinc oxide (IZO)-Ag-IZO multilayer electrodes grown on flexible polyethersulfone (PES) substrates using a roll-to-roll sputtering system for use in flexible organic photovoltaics. By the continuous roll-to-roll sputtering of the bottom IZO, Ag, and top IZO layers at room temperature, they were able to fabricate a high quality IZO-Ag-IZO multilayer electrode with a sheet resistance of 6.15 {epsilon}/square, optical transmittance of 87.4%, and figure of merit value of 42.03x10{sup -3} {Omega}{sup -1} on the PES substrate. In addition, the IZO-Ag-IZO multilayer electrode exhibited superior flexibility to the roll-to-roll sputter grown single ITO electrode due to the existence of a ductile Ag layer between the IZO layers and stable amorphous structure of the IZO film. Furthermore, the flexible organic solar cells (OSCs) fabricated on the roll-to-roll sputter grown IZO-Ag-IZO electrode showed higher power efficiency (3.51%) than the OSCs fabricated on the roll-to-roll sputter grown single ITO electrode (2.67%).

  19. Advancements in the micromirror array projector technology

    NASA Astrophysics Data System (ADS)

    Beasley, David B.; Bender, Matt W.; Crosby, Jay; Messer, Tim; Saylor, Daniel A.

    2003-09-01

    The Micromirror Array Projector System (MAPS) is a state-of-the-art dynamic scene projector developed by Optical Sciences Corporation (OSC) for Hardware-In-the-Loop (HWIL) simulation and sensor test applications. Since the introduction of the first MAPS in 2001, OSC has continued to improve the technology and develop systems for new projection and test applications. The MAPS is based upon the Texas Instruments Digital Micromirror Device (DMD) which has been modified to project high resolution, realistic imagery suitable for testing sensors and seekers operating in the UV, visible, NIR, and IR wavebands. This paper reviews the basic design and describes recent developments and new applications of the MAPS technology. Recent developments for the MAPS include increasing the format of the micromirror array to 1024x768 and increasing the binary frame rate to 10KHz. The MAPS technology has also been applied to the design of a Mobile Extended Spectrum Electro-Optical Test Set (MESEOTS). This test set is designed for testing UV, visible, NIR and IR sensors as well as laser rangefinders, laser trackers, and laser designators. The design and performance of the improved MAPS and the MESEOTS are discussed in paper.

  20. Dispersibility of vapor phase oxygen and nitrogen functionalized multi-walled carbon nanotubes in various organic solvents

    NASA Astrophysics Data System (ADS)

    Khazaee, Maryam; Xia, Wei; Lackner, Gerhard; Mendes, Rafael G.; Rümmeli, Mark; Muhler, Martin; Lupascu, Doru C.

    2016-05-01

    The synthesis and characterization of gas phase oxygen- and nitrogen-functionalized multi-walled carbon nanotubes (OMWCNTs and NMWCNTs) and the dispersibility of these tubes in organic solvents were investigated. Recently, carbon nanotubes have shown supreme capacity to effectively enhance the efficiency of organic solar cells (OSCs). A critical challenge is to individualize tubes from their bundles in order to provide homogenous nano-domains in the active layer of OSCs. OMWCNTs and NMWCNTs were synthesized via HNO3 vapor and NH3 treatments, respectively. Surface functional groups and the structure of the tubes were analyzed by temperature-programmed desorption, Fourier transform infrared spectroscopy, transmission electron microscopy, and Raman spectroscopy which confirmed the formation of functional groups on the tube surface and the enhancement of surface defects. Elemental analysis demonstrated that the oxygen and nitrogen content increased with increasing treatment time of the multi-walled carbon nanotube (MWCNT) in HNO3 vapor. According to ultra-violet visible spectroscopy, modification of the MWCNT increased the extinction coefficients of the tubes owing to enhanced compatibility of the functionalized tubes with organic matrices.

  1. SCUBA: The Self-Contained Unified Bass Augmenter

    NASA Astrophysics Data System (ADS)

    Cceres, Juan Pablo; Mysore, Gautham J.; Trevio, Jeffrey

    2005-04-01

    The Self-Contained Unified Bass Augmenter (SCUBA) is a new augmentative OSC (Open Sound Control) controller for the tuba. SCUBA allows new expressive possibilities by adding onboard continuous and discrete sensors to provide user-controlled parametric data for the processing of the instruments natural sound in Pd. SCUBA endows acoustic instruments with parametric control of virtual instruments and provides a means of integrating the output of a virtual instrument with the natural sound of the tuba. The user sends controller data from the augmented tuba interface to the virtual instrument via FSRs (Force-Sensitive Resistors) and buttons mounted on the existing instrument interface. An AVRMini microcontroller converts raw sensor data to OSC (Open Sound Control) messages, which are mapped in Pd to control virtual instrument parameters. Virtual instrument output is integrated into the solo instrument interface via satellite speakers mounted in the bell; this allows for mixing of the instruments natural sound with that of the virtual instrument to create the impression of a single instrument. This integration is the goal of the SCUBA project: by providing a flexible but unified control interface and acoustic output, traditional acoustic instrument interfaces can be augmented and paired with virtual musical instruments. [We would like to thank Michael Gurevich, Max Matthews, Bill Verplank, Pascal Stang, and classmates from Music 250 (Fall 04) for assistance in the realization of this project.

  2. Lattice design of the integrable optics test accelerator and optical stochastic cooling experiment at Fermilab

    SciTech Connect

    Kafka, Gene

    2015-05-01

    The Integrable Optics Test Accelerator (IOTA) storage ring at Fermilab will serve as the backbone for a broad spectrum of Advanced Accelerator R&D (AARD) experiments, and as such, must be designed with signi cant exibility in mind, but without compromising cost e ciency. The nonlinear experiments at IOTA will include: achievement of a large nonlinear tune shift/spread without degradation of dynamic aperture; suppression of strong lattice resonances; study of stability of nonlinear systems to perturbations; and studies of di erent variants of nonlinear magnet design. The ring optics control has challenging requirements that reach or exceed the present state of the art. The development of a complete self-consistent design of the IOTA ring optics, meeting the demands of all planned AARD experiments, is presented. Of particular interest are the precise control for nonlinear integrable optics experiments and the transverse-to-longitudinal coupling and phase stability for the Optical Stochastic Cooling Experiment (OSC). Since the beam time-of- ight must be tightly controlled in the OSC section, studies of second order corrections in this section are presented.

  3. Performance of third-year primary-care-track students in an integrated curriculum at Case Western Reserve University.

    PubMed

    Lewin, L O; Papp, K K; Hodder, S L; Workings, M G; Wolfe, L; Glover, P; Headrick, L A

    1999-01-01

    In 1994, Case Western Reserve University School of Medicine established a Primary Care Track (PCT) with an integrated curriculum as part of The Robert Wood Johnson Foundation's Generalist Physician Initiative. This study compared the performance of the first cohort of students to participate in the PCT third year with that of their classmates and determined student attitudes toward their experiences. The performances of 24 PCT and 81 traditional students on the Medical School Admissions Test (MCAT) and the United States Medical Licensure Examination (USMLE) Step 1 and 2 were compared using analysis of variance. Grades on the six core clerkships were compared using chi-square analysis. Performances of the PCT students and a subset of traditional students on the generalist school's objective structured clinical exam (OSCE) were compared using multivariate analysis. The students reported their perceptions on a questionnaire. The traditional students had significantly higher scores on the physical science section of the MCAT and on the USMLE Step 1, but at the end of year three, their USMLE Step 2 scores did not differ. Grade distributions in the core clerkships did not differ, except in psychiatry, where the PCT students received honors significantly more often. The PCT students had a lower mean score on the internal medicine National Board of Medicine Examiners shelf exam but performed better on the generalist OSCE exam. A majority of PCT students reported that they would choose the integrated third year again and recommend it to others. PMID:9934315

  4. The effectiveness of immediate feedback during the objective structured clinical examination.

    PubMed

    Hodder, R V; Rivington, R N; Calcutt, L E; Hart, I R

    1989-03-01

    Using eight different physical examination or technical stations, 400 examinations were conducted to evaluate the effectiveness of immediate feedback during the Objective Structured Clinical Examination (OSCE). The test group comprised 50 medical students who underwent a standard 4-minute examination followed by 2 minutes of feedback. Immediately following feedback the students repeated an identical 4-minute examination scored by the same examiners. The control group consisted of 50 students from the same class who underwent an identical testing sequence, but instead of receiving feedback, they were instructed to continue their examinations for an additional 2 minutes before repeating the stations. Simple repetition of the task did not significantly improve score (mean increase 2.0%, NS). Extending the testing period from 4 to 6 minutes resulted in a small but significant increase in score (mean 6.7%, P less than 0.001). However, there was a much larger increase in the scores obtained following 2 minutes of immediate feedback compared to pre-feedback performance (mean 26.3%, P less than 0.0001). The majority of students and examiners felt that feedback, as administered in this study, was valuable both as a learning and teaching experience. Short periods of immediate feedback during an OSCE are practical and can improve competency in the performance of criterion-based tasks, at least over the short term. In addition, such feedback provides students with valuable self-assessment that may stimulate further learning. PMID:2716557

  5. Upregulation of isoprenoid pathway genes during enhanced saikosaponin biosynthesis in the hairy roots of Bupleurum falcatum.

    PubMed

    Kim, Young Soon; Cho, Jung Hyun; Ahn, Juncheul; Hwang, Baik

    2006-12-31

    In order to characterize saikosaponin biosynthesis in Bupleurum falcatum, the expression of five isoprenoid pathway genes and their relationship to saikosaponin accumulation in the hairy roots were analyzed. The hairy roots exhibited a rapid accumulation of saikosaponins when incubated in a root culture medium (3XRCM). Homology-based RT-PCR was used to isolate core fragments of five genes, HMGR, IPPI, FPS, SS, and OSC, from the hairy roots. The deduced amino acid sequences exhibited amino acid identities of more than 85% to previously reported genes. Using the fragments as probes, the expression of these five genes in the hairy roots during incubation in 3XRCM medium was examined. Expression of all five genes in the hairy roots increased soon after incubation. In particular, the SS and OSC genes were coordinately induced at 8 days of incubation, and their expression persisted throughout the incubation period. A quantitative HPLC analysis showed that the saikosaponin content of the hairy root culture also began to increase at 8 days of culture. The correlation between SS transcript level and saikosaponin content in the hairy roots suggests that transcriptional regulation plays a regulatory role in saikosaponin biosynthesis. PMID:17202854

  6. Role of Clinical Images Based Teaching as a Supplement to Conventional Clinical Teaching in Dermatology

    PubMed Central

    Kumar, Gurumoorthy Rajesh; Madhavi, Sankar; Karthikeyan, Kaliaperumal; Thirunavakarasu, MR

    2015-01-01

    Introduction: Clinical Dermatology is a visually oriented specialty, where visually oriented teaching is more important than it is in any other specialty. It is essential that students must have repeated exposure to common dermatological disorders in the limited hours of Dermatology clinical teaching. Aim: This study was conducted to assess the effect of clinical images based teaching as a supplement to the patient based clinical teaching in Dermatology, among final year MBBS students. Methods: A clinical batch comprising of 19 students was chosen for the study. Apart from the routine clinical teaching sessions, clinical images based teaching was conducted. This teaching method was evaluated using a retrospective pre-post questionnaire. Students’ performance was assessed using Photo Quiz and an Objective Structured Clinical Examination (OSCE). Feedback about the addition of images based class was collected from students. Results: A significant improvement was observed in the self-assessment scores following images based teaching. Mean OSCE score was 6.26/10, and that of Photo Quiz was 13.6/20. Conclusion: This Images based Dermatology teaching has proven to be an excellent supplement to routine clinical cases based teaching. PMID:26677267

  7. Direct characterization of the energy level alignments and molecular components in an organic hetero-junction by integrated photoemission spectroscopy and reflection electron energy loss spectroscopy analysis

    NASA Astrophysics Data System (ADS)

    Yun, Dong-Jin; Shin, Weon-Ho; Bulliard, Xavier; Park, Jong Hwan; Kim, Seyun; Chung, Jae Gwan; Kim, Yongsu; Heo, Sung; Kim, Seong Heon

    2016-08-01

    A novel, direct method for the characterization of the energy level alignments at bulk-heterojunction (BHJ)/electrode interfaces on the basis of electronic spectroscopy measurements is proposed. The home-made in situ photoemission system is used to perform x-ray/ultraviolet photoemission spectroscopy (XPS/UPS), reflection electron energy loss spectroscopy (REELS) and inverse photoemission spectroscopy of organic-semiconductors (OSCs) deposited onto a Au substrate. Through this analysis system, we are able to obtain the electronic structures of a boron subphthalocyanine chloride:fullerene (SubPC:C60) BHJ and those of the separate OSC/electrode structures (SubPC/Au and C60/Au). Morphology and chemical composition analyses confirm that the original SubPC and C60 electronic structures remain unchanged in the electrodes prepared. Using this technique, we ascertain that the position and area of the nearest peak to the Fermi energy (EF = 0 eV) in the UPS (REELS) spectra of SubPC:C60 BHJ provide information on the highest occupied molecular orbital level (optical band gap) and combination ratio of the materials, respectively. Thus, extracting the adjusted spectrum from the corresponding SubPC:C60 BHJ UPS (REELS) spectrum reveals its electronic structure, equivalent to that of the C60 materials. This novel analytical approach allows complete energy-level determination for each combination ratio by separating its electronic structure information from the BHJ spectrum.

  8. A nonradial pulsation model for the rapidly rotating Delta Scuti star Kappa(2) Bootis

    NASA Technical Reports Server (NTRS)

    Kennelly, E. J.; Walker, G. A. H.; Hubeny, I.

    1991-01-01

    A sectorial nonradial pulsation model is used to construct theoretical line profiles which mimic the variations for Kappa(2) Boo. Synthetic spectra generated with the appropriate Teff and log g are used as input. It is found that the data can be reproduced by the combination of a high-degree l is approximately equal to 12 mode with P(osc) aproximately equal to 0.071 d, and a low-degree mode, l is approximately equal to 0-2 with P(osc) approximately equal to 0.071-0.079 d. The projected rotational velocity (v sin i - 115 +/-5 km/s) was determined by fitting synthetic line profiles to the observed spectra. The velocity amplitude of the high-degree oscillations is estimated to be about 3.5 km/s. It is found that the ratio of the horizontal and radial pulsation amplitudes is small (about 0.02) and consistent with p-mode oscillations. Comparisons are made with models invoking starspots, and it is impossible to fit the observations of Kappa(2) Boo by a starspot model without assuming unrealistic values of radius or equatorial velocity.

  9. Non-Patient-Based Clinical Licensure Examination for Dentistry in Minnesota: Significance of Decision and Description of Process.

    PubMed

    Mills, Eric A

    2016-06-01

    In recent years in the United States, there has been heightened interest in offering clinical licensure examination (CLE) alternatives to the live patient-based method in dentistry. Fueled by ethical concerns of faculty members at the University of Minnesota School of Dentistry, the state of Minnesota's Board of Dentistry approved a motion in 2009 to provide two CLE options to the school's future predoctoral graduates: a patient-based one, administered by the Central Regional Dental Testing Service, and a non-patient-based one administered by the National Dental Examining Board of Canada (NDEB). The validity of the NDEB written exam and objective structured clinical exam (OSCE) has been verified in a multi-year study. Via five-option, one-best-answer, multiple-choice questions in the written exam and extended match questions with up to 15 answer options in the station-based OSCE, competent candidates are distinguished from those who are incompetent in their didactic knowledge and clinical critical thinking and judgment across all dental disciplines. The action had the additional effects of furthering participation of Minnesota Board of Dentistry members in the University of Minnesota School of Dentistry's competency-based curriculum, of involving the school's faculty in NDEB item development workshops, and, beginning in 2018, of no longer permitting the patient-based CLE option on site. The aim of this article is to describe how this change came about and its effects. PMID:27251345

  10. CsmA Protein is Associated with BChl a in the Baseplate Subantenna of Chlorosomes of the Photosynthetic Green Filamentous Bacterium Oscillochloris trichoides belonging to the Family Oscillochloridaceae

    PubMed Central

    Zobova, Anastasiya; Taisova, Alexandra; Lukashev, Eugeny; Fedorova, Nataliya; Baratova, Ludmila; Fetisova, Zoya

    2011-01-01

    The baseplate subantenna in chlorosomes of green anoxygenic photosynthetic bacteria, belonging to the families Chloroflexaceae and Chlorobiaceae, is known to represent a complex of bacteriochlorophyll (BChl) a with the ~6 kDa CsmA proteins. Earlier, we showed the existence of a similar BChl a subantenna in chlorosomes of the photosynthetic green bacterium Oscillochloris trichoides, member of Oscillochloridaceae, the third family of green photosynthetic bacteria. However, this BChl a subantenna was not visually identified in absorption spectra of isolated Osc. trichoides chlorosomes in contrast to those of Chloroflexaceae and Chlorobiaceae. In this work, using room and low-temperature absorbance and fluorescence spectroscopy and sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis of alkaline-treated and untreated chlorosomes of Osc. trichoides, we showed that the baseplate BChl a subantenna does exist in Oscillochloridaceae chlorosomes as a complex of BChl a with the 5.7 kDa CsmA protein. The present results support the idea that the baseplate subantenna, representing a complex of BChl a with a ~6 kDa CsmA protein, is a universal interface between the BChl c subantenna of chlorosomes and the nearest light-harvesting BChl a subantenna in all three known families of green anoxygenic photosynthetic bacteria. PMID:21941538

  11. Intracellular organic matter from cyanobacteria as a precursor for carbonaceous and nitrogenous disinfection byproducts.

    PubMed

    Wert, Eric C; Rosario-Ortiz, Fernando L

    2013-06-18

    The formation of total organic halogen (TOX), carbonaceous disinfection byproducts (DBPs) (trihalomethanes (THMs) and haloacetic acids (HAAs)), and nitrogenous DBPs (trichloronitromethane (TCNM) or chloropicrin, haloacetonitriles (HANs), and nitrosamines) was examined during the chlorination or chloramination of intracellular organic matter (IOM) extracted from Microcystis aeruginosa, Oscillatoria sp. (OSC), and Lyngbya sp. (LYN). The percentage of unknown TOX (22-38%) during chlorination indicated that the majority of DBPs were identified among THMs, HAAs, TCNM, and HANs. Bromide was readily incorporated into DBPs with speciation shifting slightly from dihalogenated species to trihalogenated species. During formation potential testing with chloramines, nitrosamine yields from IOM were measured for N-nitrosodimethylamine (NDMA, 10-52 ng/mgC), N-nitrosopyrrolidine (NPYR, 14 ng/mgC), N-nitrosopiperidine (NPIP, 3.7-5.5 ng/mgC), and N-nitrosomethylethylamine (NMEA, 2.1-2.6 ng/mgC). When IOM was added to a natural water matrix, the nitrosamine yields were not realized likely due to competition from natural organic matter. Ozonation increased NDMA and NMEA formation and reduced NPYR and NPIP formation during subsequent chloramination. In addition, ozone oxidation of IOM formed detectable concentrations of aldehydes, which may contribute to DBP formation. Finally, bioluminescence-based test results showed that >99% of the IOM extracted from OSC and LYN was biodegradable. Therefore, a biological treatment process could minimize this source of DBP precursor material during drinking water treatment. PMID:23675656

  12. Does medical students’ clinical performance affect their actual performance during medical internship?

    PubMed Central

    Han, Eui-Ryoung; Chung, Eun-Kyung

    2016-01-01

    INTRODUCTION This study examines the relationship between the clinical performance of medical students and their performance as doctors during their internships. METHODS This retrospective study involved 63 applicants of a residency programme conducted at Chonnam National University Hospital, South Korea, in November 2012. We compared the performance of the applicants during their internship with their clinical performance during their fourth year of medical school. The performance of the applicants as interns was periodically evaluated by the faculty of each department, while their clinical performance as fourth-year medical students was assessed using the Clinical Performance Examination (CPX) and the Objective Structured Clinical Examination (OSCE). RESULTS The performance of the applicants as interns was positively correlated with their clinical performance as fourth-year medical students, as measured by the CPX and OSCE. The performance of the applicants as interns was moderately correlated with the patient-physician interaction items addressing communication and interpersonal skills in the CPX. CONCLUSION The clinical performance of medical students during their fourth year in medical school was related to their performance as medical interns. Medical students should be trained to develop good clinical skills through actual encounters with patients or simulated encounters using manikins, to enable them to become more competent doctors. PMID:26768172

  13. Technology Directions for the 21st Century. Vol. 2

    NASA Technical Reports Server (NTRS)

    Crimi, Giles F.; Verheggen, Henry; Malinowski, John; Malinowski, Robert; Botta, Robert

    1996-01-01

    The Office of Space Communications (OSC) is tasked by NASA to conduct a planning process to meet NASA's science mission and other communications and data processing requirements. A set of technology trend studies was undertaken by Science Applications International Corporation (SAIC) for OSC to identify quantitative data that can be used to predict performance of electronic equipment in the future to assist in the planning process. Only commercially available, off-the-shelf technology was included. For each technology area considered, the current state of the technology is discussed, future applications that could benefit from use of the technology are identified, and likely future developments of the technology are described. The impact of each technology area on NASA operations is presented together with a discussion of the feasibility and risk associated with its development. An approximate timeline is given for the next 15 to 25 years to indicate the anticipated evolution of capabilities within each of the technology areas considered. This volume contains four chapters: one each on technology trends for database systems, computer software, neural and fuzzy systems, and artificial intelligence. The principal study results are summarized at the beginning of each chapter.

  14. A simple method to adjust the morphology of gradient three-dimensional PTB7-Th:PC71BM polymer solar cells.

    PubMed

    Zhao, Ling; Zhao, Suling; Xu, Zheng; Yang, Qianqian; Huang, Di; Xu, Xurong

    2015-03-12

    Multiple interfaces are necessary for exciton separation in bulk heterojunction (BHJ) solar cells and continuous pathways for carrier transportation in donor : acceptor blend films, especially along the vertical direction, for efficient charge collection. Therefore film morphology is critically important to satisfy both in the construction of high performance organic solar cells (OSCs). In this work, the cooperative effect of solvent additives and solvent flux treatment on film morphology was confirmed. Furthermore, the correlation between a single processing parameter and the resulting morphology has been investigated. Our results show that film morphology can be tuned by changing the volume fraction of the solvent additive. Beyond that, after methanol fluxing, the OSC performance improves significantly, as short circuit current density (JSC) increases from 13.85 mA cm(-2) to 15.17 mA cm(-2) and fill factor (FF) from 62.9% to 65.7%, simultaneously. As a result, power conversion efficiency (PCE) increases from 6.79% to 7.67%. The favorable morphology was further investigated using time-of-flight secondary-ion mass spectroscopy (TOF-SIMS), and atomic force microscopy (AFM). PMID:25739074

  15. 1,8-Naphthalimide-Based Planar Small Molecular Acceptor for Organic Solar Cells.

    PubMed

    Zhang, Jicheng; Zhang, Xuejuan; Xiao, Hongmei; Li, Guangwu; Liu, Yahui; Li, Cuihong; Huang, Hui; Chen, Xuebo; Bo, Zhishan

    2016-03-01

    Four small molecular acceptors (SM1-4) comprising a central benzene core, two thiophene bridges and two 1,8-naphthalimide (NI) terminal groups were designed and synthesized by direct C-H activation. SM1 has a planar chemical structure and forms H-aggregation as films. By attachment of different substituents on the central benzene ring, the dihedral angles between the two NI end groups of SM1-4 gradually increased, leading to a gradual decrease of planarity. SM1-4 all possess a high-lying LUMO level, matching with wide band gap (WBG) polymer donors which usually have a high-lying LUMO level. When used in OSCs, devices based on SM1 and WBG donor PCDTBT-C12 gave higher electron mobility, superior film morphology and better photovoltaic performance. After optimization, a PCE of 2.78% with a V(oc) of 1.04 V was achieved for SM1 based devices, which is among the highest PCEs with a V(oc) higher than 1 V. Our results have demonstrated that NI based planar small molecules are potential acceptors for WBG polymer based OSCs. PMID:26845638

  16. Investigating the efficacy of practical skill teaching: a pilot-study comparing three educational methods.

    PubMed

    Maloney, Stephen; Storr, Michael; Paynter, Sophie; Morgan, Prue; Ilic, Dragan

    2013-03-01

    Effective education of practical skills can alter clinician behaviour, positively influence patient outcomes, and reduce the risk of patient harm. This study compares the efficacy of two innovative practical skill teaching methods, against a traditional teaching method. Year three pre-clinical physiotherapy students consented to participate in a randomised controlled trial, with concealed allocation and blinded participants and outcome assessment. Each of the three randomly allocated groups were exposed to a different practical skills teaching method (traditional, pre-recorded video tutorial or student self-video) for two specific practical skills during the semester. Clinical performance was assessed using an objective structured clinical examination (OSCE). The students were also administered a questionnaire to gain the participants level of satisfaction with the teaching method, and their perceptions of the teaching methods educational value. There were no significant differences in clinical performance between the three practical skill teaching methods as measured in the OSCE, or for student ratings of satisfaction. A significant difference existed between the methods for the student ratings of perceived educational value, with the teaching approaches of pre-recorded video tutorial and student self-video being rated higher than 'traditional' live tutoring. Alternative teaching methods to traditional live tutoring can produce equivalent learning outcomes when applied to the practical skill development of undergraduate health professional students. The use of alternative practical skill teaching methods may allow for greater flexibility for both staff and infrastructure resource allocation. PMID:22354336

  17. Optimum Compromise Between Optical Absorption and Electrical Property of the Planar Multi-Heterojunction Organic Solar Cells Based with New Thiazol Derivative, the (2-THIOXO-3-N-(2-METHOXYPHENYL) THIAZOLIDIN-4-ONE), as Electron Donor

    NASA Astrophysics Data System (ADS)

    Toumi, A. Lakhdar; Khelil, A.; Bernède, J. C.; Mouchaal, Y.; Djafri, A.; Toubal, K.; Hellal, N.; Cattin, L.

    2015-03-01

    The synthesis of a new thiazol derivative, the (2-thioxo-3-N-(2-methoxyphenyl) thiazolidin-4-one) (called TH-2) is described. After characterization of the TH-2, the cyclic voltammetry study coupled with optical absorbance measurements show that its LUMO and HOMO are -3.5 and -5.5 respectively. Then the TH-2 is used as electron donor (ED) in organic solar cells (OSCs). The anode buffer layer being CuI the devices are based on the planar heterojunction TH-2/fullerene. Homogeneous amorphous films of TH-2 are obtained when it is deposited onto CuI. For an optimum TH-2 thickness of 20 nm, a power conversion efficiency of 0.42% is obtained. Then, in order to broaden the absorption range of the OSCs, it is coupled with the tetraphenyl-dibenzoperiflanthene, whose band structure matches the band structure of TH-2. Such new multilayer structure allows achieving a power conversion efficiency of 0.49%.

  18. Pharmacy practice simulations: performance of senior pharmacy students at a University in southern Brazil

    PubMed Central

    Galato, Dayani; Alano, Graziela M.; Trauthman, Silvana C.; França, Tainã F.

    Objective A simulation process known as objective structured clinical examination (OSCE) was applied to assess pharmacy practice performed by senior pharmacy students. Methods A cross-sectional study was conducted based on documentary analysis of performance evaluation records of pharmacy practice simulations that occurred between 2005 and 2009. These simulations were related to the process of self-medication and dispensing, and were performed with the use of patients simulated. The simulations were filmed to facilitate the evaluation process. It presents the OSCE educational experience performed by pharmacy trainees of the University of Southern Santa Catarina and experienced by two evaluators. The student general performance was analyzed, and the criteria for pharmacy practice assessment often identified trainees in difficulty. Results The results of 291 simulations showed that students have an average yield performance of 70.0%. Several difficulties were encountered, such as the lack of information about the selected/prescribed treatment regimen (65.1%); inadequate communication style (21.9%); lack of identification of patients’ needs (7.7%) and inappropriate drug selection for self-medication (5.3%). Conclusions These data show that there is a need for reorientation of clinical pharmacy students because they need to improve their communication skills, and have a deeper knowledge of medicines and health problems in order to properly orient their patients. PMID:24367467

  19. Ultrasonic ablation as a novel technique for producing pure aluminium nanoparticles dispersed in different liquids for different applications

    NASA Astrophysics Data System (ADS)

    Ismail, Yasser A. M.; Kishi, Naoki; Soga, Tetsuo

    2015-07-01

    In this paper, we introduce a novel physical method for producing surfactant-free aluminium nanoparticles (Al NPs) by irradiating ultrasonic waves on Al thin films immersed in different liquids used for different applications. We suggest naming this technique “ultrasonic ablation”. Our method has many advantages compared with other chemical and physical methods such as (1) fabrication of Al NPs using low-cost and easy procedures, (2) fabrication of pure Al NPs without any chemical additives, (3) fabrication of Al NPs dispersed in different liquids used for different applications, and (4) fabrication of individual Al NPs without aggregations. We have prepared Al NPs in 1,2-dichlorobenzene, which is used as a solvent for preparing active layer solutions of organic solar cells (OSCs), poly(3,4-ethylenedioxythiophene)-blend-poly(styrene sulfonate) (PEDOT:PSS), which is a representative aqueous solution used as a buffer layer in OSCs, and ethanol, which is a representative polar solvent used for different applications. Scanning electron microscopy (SEM) and optical absorption techniques have verified the fabrication of individual and surfactant-free Al NPs dispersed in different liquids that can be safely used in different applications.

  20. The longitudinal curriculum "social and communicative competencies" within Bologna-reformed undergraduate medical education in Basel

    PubMed Central

    Kiessling, Claudia; Langewitz, Wolf

    2013-01-01

    Background: Within the Bologna reform, a longitudinal curriculum of “social and communicative competencies” (SOKO) was implemented into the new Bachelor-Master structure of undergraduate medical education in Basel (Switzerland). Project description: The aim of the SOKO curriculum is to enable students to use techniques of patient-centred communication to elicit and provide information to patients in order to involve them as informed partners in decision making processes. The SOKO curriculum consists of 57 lessons for the individual student from the first bachelor year to the first master year. Teaching encompasses lectures and small group learning. Didactic methods include role play, video feedback, and consultations with simulated and real patients. Summative assessment takes place in objective structured clinical examinations (OSCE). Conclusion: In Basel, a longitudinal SOKO curriculum based on students’ cumulative learning was successfully implemented. Goals and contents were coordinated with the remaining curriculum and are regularly assessed in OSCEs. At present, most of the workload rests on the shoulders of the department of psychosomatic medicine at the university hospital. For the curriculum to be successful in the long-term, sustainable structures need to be instituted at the medical faculty and the university hospital to guarantee high quality teaching and assessment. PMID:24062811