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Sample records for objetivo estructurado osce

  1. Developing and implementing an OSCE in dentistry.

    PubMed

    Manogue, M; Brown, G

    1998-05-01

    The processes of development, implementation and perceived usefulness of an objective structured clinical examination in restorative dentistry (OSCE(D)) are reported. An OSCE is a system of assessment. It consists of a set of standardised 'stations'. At each station, a student is tested on a specific clinical task. Each student moves from one station to the next so that by the end of the OSCE, every student has completed every station. The primary purpose of this OSCE was to provide feedback to 49 4th year students on their performance in the clinical areas of conservative dentistry, periodontology and prosthetics. Individual profiles were provided to students and the overall results discussed by staff. There were no significant differences in overall performance between genders or between students in the morning and afternoon examinations. There was a significant difference between performance in prosthetics and the other areas and there were some significant differences among the skill clusters of clinical knowledge, procedures, clinical reasoning, history-taking, techniques and communication. Students and staff perceived the OSCE(D) as a valuable tool for providing feedback. The development of the OSCE and the findings described in this paper will be of value to clinical staff who are developing OSCEs in all areas of dentistry.

  2. Objective Structured Clinical Examination (OSCE) Revisited.

    PubMed

    Gupta, Piyush; Dewan, Pooja; Singh, Tejinder

    2010-11-01

    Objective structured clinical examination (OSCE) was introduced in 1975 as a standardized tool for objectively assessing clinical competencies - including history-taking, physical examination, communication skills, data interpretation etc. It consists of a circuit of stations connected in series, with each station devoted to assessment of a particular competency using pre-determined guidelines or checklists. OSCE has been used as a tool for both formative and summative evaluation of medical graduate and postgraduate students across the globe. The use of OSCE for formative assessment has great potential as the learners can gain insights into the elements making up clinical competencies as well as feedback on personal strengths and weaknesses. However, the success of OSCE is dependent on adequacy of resources, including the number of stations, construction of stations, method of scoring (checklists and or global scoring), the number of students assessed, and adequate time and money. Lately, OSCE has drawn some criticism for its lack of validity, feasibility, practicality, and objectivity. There is evidence to show that many OSCEs may be too short to achieve reliable results. There are also currently no clear cut standards set for passing an OSCE. It is perceived that OSCEs test the students knowledge and skills in a compartmentalized fashion, rather than looking at the patient as a whole. This article focuses on the issues of validity, objectivity, reliability, and standard setting of OSCE. Presently, the Indian experiences with OSCE are limited and there is a need to sensitise the Indian faculty and students. A cautious approach is desired before it is considered as a supplementary tool to other methods of assessment for the summative examinations in Indian settings.

  3. Cheating in OSCEs: The Impact of Simulated Security Breaches on OSCE Performance.

    PubMed

    Gotzmann, Andrea; De Champlain, André; Homayra, Fahmida; Fotheringham, Alexa; de Vries, Ingrid; Forgie, Melissa; Pugh, Debra

    2017-01-01

    Construct: Valid score interpretation is important for constructs in performance assessments such as objective structured clinical examinations (OSCEs). An OSCE is a type of performance assessment in which a series of standardized patients interact with the student or candidate who is scored by either the standardized patient or a physician examiner.

  4. The validity and reliability of an OSCE in dentistry.

    PubMed

    Brown, G; Manogue, M; Martin, M

    1999-08-01

    The validity and reliability of a newly-developed objective structured clinical examination for 4th year dental students (OSCE(D)) were estimated by a range of quantitative and qualitative methods. The OSCE(D) consisted of 17 stations in conservation, periodontology and prosthetics. A blueprint was used to match the OSCE stations to clinical subject areas and to 7 skill clusters of clinical competence. Repeat measures of skills were undertaken in the OSCE(D) to maximise its validity and reliability. The primary purposes of the OSCE(D) were to assess clinical competence and to provide feedback to students. The results indicate that the OSCE(D) was intrinsically valid and a better predictor of performance in the final examination than either a concurrent 4th-year examination or Advanced-level university entry grades. The OSCE(D) scored relatively highly on internal consistency (Cronbach's alpha = 0.68). Intra-domain and inter-domain correlations were high and inter-examiner reliability was relatively high (eta 2 coefficients ranged from 0.00 to 0.10). There were no significant differences between performances in the morning and afternoon sessions of the examination so reproducibility is assumed to be high. Some improvement in individual stations and in inter-examiner reliability are required. A set of recommendations based on the experience of designing and testing a dental OSCE are provided.

  5. Surveying Students' Attitudes During the OSCE.

    PubMed

    Allen, Ruth; Heard, Jeanne; Savidge, Mildred; Bittergle, Joseph; Cantrell, Mary; Huffmaster, Tim

    1998-01-01

    This study assessed students' attitudes, students' level of confidence and the importance of faculty feedback during an Objective Structured Clinical Examination (OSCE). A survey was administered as one of 15 OSCE stations to 138 sophomore medical students. Eight of the twelve survey items were Likert type items with a follow-up open-ended question. The remaining four items required only an open-ended response. The five surveyors participated in the design of the questionnaire and in training to insure reliable information acquisition and recording. The OSCE was given in five identical tracks in a single day. Each surveyor interviewed either 27 or 28 students during the four-hour period of the track. The Likert responses to the eight items were analyzed and statistical comparisons made for each question. The open-ended responses were analyzed using qualitative summary techniques and compared to the Likert responses.Statistical analyses of the Likert based items showed students had high levels of confidence in their ability to conduct physical examinations and histories, found faculty feedback helpful and informative, but were nervous throughout the examination. The qualitative analysis provided additional information regarding students' feelings about the OSCE, their levels of confidence, their stress levels and the importance of faculty feedback during the examination.Results of the survey suggest curricular changes which could be made in preparation for the OSCE and for a new Introduction to Clinical Medicine course currently in its first year in the College of Medicine.

  6. Taking OSCE examiner training on the road: reaching the masses

    PubMed Central

    Reid, Katharine; Smallwood, David; Collins, Margo; Sutherland, Ruth; Dodds, Agnes

    2016-01-01

    Background To ensure the rigour of objective structured clinical examinations (OSCEs) in assessing medical students, medical school educators must educate examiners with a view to standardising examiner assessment behaviour. Delivering OSCE examiner training is a necessary yet challenging part of the OSCE process. A novel approach to implementing training for current and potential OSCE examiners was trialled by delivering large-group education sessions at major teaching hospitals. Methods The ‘OSCE Roadshow’ comprised a short training session delivered in the context of teaching hospital ‘Grand Rounds’ to current and potential OSCE examiners. The training was developed to educate clinicians about OSCE processes, clarify the examiners’ role and required behaviours, and to review marking guides and mark allocation in an effort to standardise OSCE processes and encourage consistency in examiner marking behaviour. A short exercise allowed participants to practise marking a mock OSCE to investigate examiner marking behaviour after the training. Results OSCE Roadshows at four metropolitan and one rural teaching hospital were well received and well attended by 171 clinicians across six sessions. Unexpectedly, medical students also attended in large numbers (n=220). After training, participants’ average scores for the mock OSCE clustered closely around the ideal score of 28 (out of 40), and the average scores did not differ according to the levels of clinical experience. Conclusion The OSCE Roadshow demonstrated the potential of brief familiarisation training in reaching large numbers of current and potential OSCE examiners in a time and cost-effective manner to promote standardisation of OSCE processes. PMID:27687287

  7. Using OSCE-based evaluation: curricular impact over time.

    PubMed

    Zartman, Rosemarie R; McWhorter, Alton G; Seale, N Sue; Boone, William John

    2002-12-01

    The Objective Structured Clinical Examination (OSCE) is becoming more widely used for performance assessment in dentistry. The department of pediatric dentistry at Baylor College of Dentistry (BCD) began incorporating the OSCE into its curriculum in 1995. This article describes the evolution of the department's use of the OSCE and its impact on teaching and the curriculum. The discussion focuses on logistics and station design, curricular content and order, student anxiety, writing and scoring exams, and curriculum assessment. BCD has found that using an OSCE-based testing format is time-consuming and labor-intensive, but provides unprecedented feedback about students' understanding and pinpoints areas of confusion. The demands of an OSCE-based testing format reveal that students can master, to the level of competency, only a finite amount of information in a given time period. The timed, interactive aspects of the OSCE create high levels of student anxiety that must be addressed. Writing and scoring OSCE items are different from traditional test items. The OSCE is a valuable mechanism to assess the students' progress toward competency. This review of the process of incorporating OSCEs into a curriculum is the foundation for future assessment of the OSCE and its use for curricular improvement.

  8. Electronic acquisition of OSCE performance using tablets.

    PubMed

    Hochlehnert, Achim; Schultz, Jobst-Hendrik; Möltner, Andreas; Tımbıl, Sevgi; Brass, Konstantin; Jünger, Jana

    2015-01-01

    Hintergrund: OSCE-Prüfungen sind oft mit einem erheblichen Material- und Organisationsaufwand verbunden, da die Leistungserfassung üblicherweise auf Papier durchgeführt wird. Eine elektronisch unterstützte Durchführung stellt hierzu eine Alternative dar, mit der der Verbrauch materieller Ressourcen reduziert werden kann. Insbesondere erscheint hier der Einsatz von Tablets sinnvoll, da diese zudem leicht zu transportieren sind und damit flexibel eingesetzt werden können. Zielsetzung: Die Nutzerakzeptanz der Verwendung von Tablets bei OSCE-Prüfungen wurde bislang allerdings nur wenig untersucht. Ziel dieser Studie war daher eine Evaluation Tablet-basierter OSCE-Prüfungen aus Sicht der Benutzer (Prüfer) und der geprüften Studierenden.Methodik: Bei zwei OSCE-Prüfungen des Faches Innere Medizin der Universität Heidelberg wurde die Nutzerakzeptanz einer Tablet-basierten Durchführung (Zufriedenheit mit der Funktionalität) und die subjektive Anstrengung aus Sicht der Prüfer untersucht. Hierzu wurden standardisierte Fragebögen und halbstandardisierte Interviews eingesetzt (Vollerfassung aller teilnehmenden Prüfer). Zudem wurde bei einer der Prüfungen die subjektive Bewertung dieser Prüfungsvariante an einer Stichprobe teilnehmender Studierender mittels halbstandardisierter Interviews erhoben.Ergebnisse: Die Prüfer waren mit der Tablet-Prüfungsvariante insgesamt sehr zufrieden. Die subjektive Anstrengung der Bedienung der Tablets wurde im Mittel als „kaum anstrengend“ empfunden. In den Interviews wurden insbesondere die einfache Handhabung und die geringe Fehleranfälligkeit von den Prüfern als Vorteile dieser Prüfungsvariante genannt. In der Befragung der geprüften Studierenden zeigte sich ebenfalls eine Akzeptanz der Tablet-Prüfungsvariante. Diskussion: Insgesamt hat sich gezeigt, dass der Einsatz von Tablets in OSCE-Prüfungen sowohl von Prüfern als auch Studierenden gut angenommen wird. Es wird erwartet, dass diese Prüfungsvariante auch

  9. 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…

  10. 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…

  11. Implementation of an OSCE at Kaohsiung Medical University.

    PubMed

    Huang, Yu-Sheng; Liu, Min; Huang, Chun-Hsiung; Liu, Keh-Min

    2007-04-01

    The Objective Structured Clinical Examination (OSCE), a tool to objectively and fairly assess medical students' clinical competences, has become widely used in medical education worldwide. However, most medical schools in Taiwan have just begun to adopt this assessment method. In 2003, Kaohsiung Medical University (KMU) established the first standardized patient (SP) program in Taiwan and applied SPs with an OSCE. This study reports the process of the implementation of an OSCE at KMU, which includes collecting information, visiting leading clinical skills centers, consulting medical educators from other countries, holding international conferences, establishing an OSCE committee, writing cases, training SPs, administrating the OSCE, and receiving feedback from medical students. Most students were satisfied with the assessment and appreciated the learning experience. Based on the experience in 2003, the OSCE committee decided to incorporate the OSCE into the medical curriculum as a measure to assess medical students' clinical competences. In addition to assessing medical students' clinical competence, the OSCE can also be applied to other professional health education, such as dentistry, nursing, and pharmacy. We are currently sharing our experience with other colleges at KMU.

  12. 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

  13. Why do physicians volunteer to be OSCE examiners?

    PubMed

    Humphrey-Murto, Susan; Wood, Timothy J; Touchie, Claire

    2005-03-01

    Recruitment of physician examiners for an objective structured clinical examination (OSCE) can be difficult. The following study will explore reasons why physicians volunteer their time to be OSCE examiners. A questionnaire was collected from 110 examiners including a fourth year formative student OSCE (SO) (n=49), formative internal medicine OSCE (IM) (n=21) and the Medical Council of Canada Qualifying Exam Part II (MCCQE II) (n=40). A 5-point Likert scale was used. Statements with high mean ratings overall included: enjoy being an examiner (4.05), gain insights into learners' skills and knowledge (4.27), and examine out of a sense of duty (4.10). The MCC participants produced higher ratings (p<0.05). Overall, OSCE examiners volunteer their time because they enjoy the experience, feel a sense of duty and gain insight into learners' skills and knowledge. The MCC examiners appear to value the experience more. The ability to provide feedback and the provision of CME credits were not significant factors for increasing examiner satisfaction.

  14. [Using Objective Structured Clinical Examination (OSCE) across different levels of pediatric training].

    PubMed

    Di Lalla, Sandra; Manjarin, Mercedes; Torres, Fernando; Ossorio, María Fabiana; Wainsztein, Raquel; Ferrero, Fernando

    2014-01-01

    Antecedentes:Evaluar competencias profesionales es objetivo principal de todo programa de capacitación; el examen clínico objetivo estructurado (ECOE) es una herramienta útil para explorarlas. Objetivo:Describimos la implementación del ECOE en tres instancias de enseñanza de la pediatría (carrera de especialista, módulo pediatría del internado anual rotatorio, materia pediatría en el grado). Métodos: En relación con situaciones y patologías frecuentes en pediatría, se evaluaron conocimiento aplicado, juicio clínico y habilidad comunicacional. Resultados: En el posgrado el ECOE se aplica desde hace 8 años, examinando 330 alumnos, con 60%-82% de aprobación. En el Internado Anual Rotatorio el ECOE se emplea desde hace 2 años, examinando 12 alumnos, con 84% de aprobación. En el grado el ECOE se empleó sólo en una oportunidad, examinando 15 alumnos, con 93,4% de aprobación. Conclusión:En nuestra experiencia, a pesar de desafíos logísticos, la implementación del ECOE fue factible en distintas instancias de enseñanza de la pediatría.

  15. OSCE vs. TEM: Different Approaches to Assess Clinical Skills of Nursing Students

    PubMed Central

    Jelly, Prasuna; Sharma, Rakesh

    2017-01-01

    Introduction: Nurses are trained with specific clinical skills, and objective structured clinical examination (OSCE) could be a better approach to assess clinical skills of nursing students. Materials and Methods: A comparative study was conducted by observational checklist regarding antenatal care and opinionnaire on the usefulness of OSCE and tradition evaluation method (TEM) was used to assess the clinical skills and to get opinion. Results: The mean score of OSCE was more than TEM and the difference was statistically significant (P < 0.001). The opinion of students regarding the usefulness of OSCE was higher than TEM. Conclusions: The study concluded that implementing OSCE will overweigh the advantages of the TEM.

  16. 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…

  17. 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…

  18. The use of objective structured clinical examination (OSCE) for evaluation and instruction in graduate medical education.

    PubMed

    Sloan, D A; Donnelly, M B; Schwartz, R W; Felts, J L; Blue, A V; Strodel, W E

    1996-06-01

    This study had two purposes: determining the reliability and validity of the Objective Structured Clinical Examination (OSCE) in assessing performance by trainees at all levels, including medical students and chief residents; and estimating the impact of providing OSCE participants with immediate feedback about their performance. A comprehensive 210-min OSCE was administered to 53 surgical residents and 6 junior medical students. Faculty experts proctored all patient stations and provided immediate feedback to participants after the patient interaction segments (Part A). The participants then answered questions about the patients seen (Part B). The reliability of the OSCE was high (.91), identical to that of a previous resident OSCE with no feedback. The standard error of measurement for both parts was approximately 4%. At the 95% confidence interval, each participant's actual level of clinical performance (Part A) and clinical knowledge (Part B) could be estimated with an error of +/-8%. Participants showed significant differences in clinical performance (Part A, P < 0.01) and knowledge (Part B, P < 0.01) by level of training. Most participants (74%) rated the OSCE as an above average or outstanding educational method. The OSCE is a valid and reliable test of residents' clinical skills. Feedback to participants during the OSCE was positively received and did not perturb test reliability.

  19. 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…

  20. The Reliability, Validity, and Usefulness of the Objective Structured Clinical Examination (OSCE) in Dental Education

    ERIC Educational Resources Information Center

    Graham, Roseanna

    2010-01-01

    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…

  1. [Quality assurance of assessments using the example of the OSCE examination format: experiences of the Medical School of Heidelberg University].

    PubMed

    Schultz, Jobst-Hendrik; Nikendei, Christoph; Weyrich, Peter; Möltner, Andreas; Fischer, Martin R; Jünger, Jana

    2008-01-01

    Quality management of assessment in medical education plays a key role in Germany--owing to, among other factors, the new medical licensing regulations ("Approbationsordnung"). OSCE (Objective Structured Clinical Examination) is a widespread tool to assess clinical competencies. However, the quality of OSCE in terms of reliability as a criterion of a good test is highly debated in the current literature. To improve the reliability of the OSCE three accompanying measures have been implemented at the Faculty of Medicine of the University of Heidelberg since the summer of 2006: 1. the application of a checklist for pre- and post-reviews of OSCEs, 2. a specific training of OSCE examiners, 3. an advanced psychometric OSCE test report giving feedback to the item developer. The reliability of the Internal Medicine OSCE at the University of Heidelberg has increased since. Currently Cronbach's alpha of the final OSCE in the summer of 2007 was 0.829.

  2. Medical Students' Perception of OSCE at the Department of Internal Medicine, College of Medicine, King Khalid University, Abha, KSA.

    PubMed

    Elfaki, Omer Abdelgadir; Al-Humayed, Suliman

    2016-02-01

    The aim of this study was to explore the students' acceptance of Objective Structured Clinical Examination (OSCE) as a method of assessment of clinical competence in internal medicine. This cross sectional study was conducted from June to August 2013, at King Khalid University, Abha, KSA, through a self-administered questionnaire which was completed by fourth year medical students, immediately after the OSCE. Student feedback confirmed their acceptance of OSCE. This was encouraging to the department to consider implementing OSCE for graduating students.

  3. 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…

  4. 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

  5. Standardization of Clinical Skill Evaluation in Physical/Occupational Therapist Education -Effects of Introduction of an Education System Using OSCE-.

    PubMed

    Sakurai, Hiroaki; Kanada, Yoshikiyo; Sugiura, Yoshito; Motoya, Ikuo; Yamada, Masayuki; Tomita, Masao; Naka, Toru; Teranishi, Toshio; Tanabe, Shigeo; Tsujimura, Toru; Okanishi, Tetsuo

    2013-09-01

    [Purpose] A major issue in physical/occupational therapist education is the improvement of students' clinical techniques. In this study, we introduced an education system using an Objective Structured Clinical Examination (OSCE), and made an attempt at standardization of its evaluation. [Subjects] The subjects were 227 students in the classes of 2008 to 2010 who enrolled at our university between 2004 and 2006, before the introduction of the education system using OSCE, and 221 students in the classes of 2011 to 2013 who enrolled between 2007 and 2009, after the introduction. [Methods] Performances in attitude and skills (performance in clinical training and OSCE) were compared between before and after the introduction of OSCE. OSCE results were compared between before and after clinical trainings at each OSCE Level; and the correlation of between performances in clinical training and OSCE was examined. [Results] Performances in OSCE and clinical training (attitude, skills) were improved by the introduction of the education system using OSCE, but no significant correlation was observed in the relationship between performances in OSCE and clinical training. [Conclusion] Further studies should be conducted aiming at the standardization of clinical skill evaluation in postgraduate education to establish an education system using OSCE.

  6. [Assessment of communication skills with an OSCE among first year medical students].

    PubMed

    Fischbeck, Sabine; Mauch, Marianne; Leschnik, Elisabeth; Beutel, Manfred E; Laubach, Wilfried

    2011-11-01

    In order to determine if first year medical students of a Medical Psychology and Medical Sociology course have adopted basic physician patient communication skills, we developed an appropriate Objective Structured Clinical Examination (OSCE). The parcours took place in a pretest condition (n=182) and in the following semester under test condition, now relevant for passing the course (n=181). Reliability of the OSCE reached a medium degree (α=0.55/0.50). Results of written examinations and OSCE scores were weakly correlated. The correlation between task competence and patient-centeredness was higher in the pretest than under test condition. Female students mostly achieved higher scores than male students. Nearly all of the students (92%/97%) were in favor of continuing this examination. Physician-patient communication is a process of high complexity, but it can be tested by OSCE. Relevance for passing the course seems to enhance the learning behaviour.

  7. Competency-based training: objective structured clinical exercises (OSCE) in marriage and family therapy.

    PubMed

    Miller, John K

    2010-07-01

    The field of marriage and family therapy (MFT) has recently engaged in the process of defining core competencies for the profession. Many MFT training programs are adapting their curriculum to develop more competency-based training strategies. The Objective Structured Clinical Examination (OSCE) is widely used in the medical profession to assess clinical competence. These examinations involve using simulated clinical situations as a tool in conducting summative evaluations of trainee competence. This article describes an adaptation of the OSCE procedures for competency-based training of MFT students. Instead of using the procedures as a summative examination as is typical in medical education, this article proposes how to use them as formative exercises in the development of student competence. The development of the OSCE is discussed, including "blueprinting," focused competencies, procedures, and feedback protocols. The article concludes with suggestions of how to continue the development of the OSCE for evaluation in MFT education.

  8. A procedural skills OSCE: assessing technical and non-technical skills of internal medicine residents.

    PubMed

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

    2015-03-01

    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 medicine (IM) residents to assess their technical and non-technical skills when performing procedures. Thirty-five first to third-year IM residents participated in a 5-station PS-OSCE, which combined partial task models, standardized patients, and allied health professionals. Formal blueprinting was performed and content experts were used to develop the cases and rating instruments. Examiners underwent a frame-of-reference training session to prepare them for their rater role. Scores were compared by levels of training, experience, and to evaluation data from a non-procedural OSCE (IM-OSCE). Reliability was calculated using Generalizability analyses. Reliabilities for the technical and non-technical scores were 0.68 and 0.76, respectively. Third-year residents scored significantly higher than first-year residents on the technical (73.5 vs. 62.2%) and non-technical (83.2 vs. 75.1%) components of the PS-OSCE (p < 0.05). Residents who had performed the procedures more frequently scored higher on three of the five stations (p < 0.05). There was a moderate disattenuated correlation (r = 0.77) between the IM-OSCE and the technical component of the PS-OSCE scores. The PS-OSCE is a feasible method for assessing multiple competencies related to performing procedures and this study provides validity evidence to support its use as an in-training examination.

  9. 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.

  10. 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

  11. The introduction and perception of an OSCE with an element of self- and peer-assessment.

    PubMed

    Larsen, T; Jeppe-Jensen, D

    2008-02-01

    The purpose of the present study was to encourage reflective dental students by performing an educational Objective Structured Clinical Examination (OSCE) with an element of self- and peer-assessment. An interdisciplinary OSCE comprising cariology, endodontics and microbiology was set up for all third-year students. A blueprint secured representation of the skills to be tested, i.e. knowledge, interdisciplinary knowledge, communication, clinical reasoning and practical procedures. At each station positive and constructive feedback was given to the students based on predefined criteria. Further, the students received written marks after completion of the OSCE. At one station the feedback and marks were replaced by self- and peer-assessment performed by the students in groups after the OSCE. Afterwards, the 68 students and 8 teachers participating in the OSCE answered a questionnaire on their opinion and perception of the examination. The results showed good correlation between the marks given and the students' perception of task difficulty. Generally, there were no systematic variations in the marks given during the week or by individual assessors at the same station, except for one, as well as agreement with marks of the ordinary clinical assessment. The marks given during self- and peer-assessment differed widely, indicating a need for training in this aspect. The questionnaires revealed a very positive perception of the OSCE from both students and teachers. Thus, the majority found the examination relevant and of educational benefit, capable of improving the learning of the students and useful for assessment purposes. Also, the self- and peer-assessment was found useful by the students. In conclusion, this interdisciplinary OSCE stressing constructive feedback to the students was perceived very positively by students and teachers and recognised for its beneficial possibilities in education and assessment.

  12. Development of computer-based OSCE re-examination system for minimizing inter-examiner discrepancy.

    PubMed

    Abe, Shinichi; Kawada, Eiji

    2008-02-01

    The validity of objective structured clinical examination (OSCE) in evaluating clinical skills has been confirmed in a number of studies. However, inter-examiner reliability has been noted as a concern by many educators. To minimize discrepancy between examiners, in application of the OSCE, we have developed an OSCE attitude and skill test re-examination system. Student performance was digitally, filmed and stored as electronic files. When results showed inter-examiner discrepancy, those items were automatically extracted in the form of a re-examination sheet to allow student re-evaluation by a third examiner in reference to the relevant film files. This system facilitates feedback to each examiner and examinee, offering a potentially useful tool for attitude and skill education.

  13. 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

  14. 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…

  15. 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…

  16. M-OSCE as a method to measure dental hygiene students' critical thinking: a pilot study.

    PubMed

    McComas, Martha J; Wright, Rebecca A; Mann, Nancy K; Cooper, Mary D; Jacks, Mary E

    2013-04-01

    Educators in all academic disciplines have been encouraged to utilize assessment strategies to evaluate students' critical thinking. The purpose of this study was to assess the viability of the modified objective structured clinical examination (m-OSCE) to evaluate critical thinking in dental hygiene education. This evaluation utilized a convenience sample of senior dental hygiene students. Students participated in the m-OSCE in which portions of a patient case were revealed at four stations. The exam consisted of multiple-choice questions intended to measure students' ability to utilize critical thinking skills. Additionally, there was one fill-in-the-blank question and a treatment plan that was completed at the fifth station. The results of this study revealed that the m-OSCE did not reliably measure dental hygiene students' critical thinking. Statistical analysis found no satisfactory reliability within the multiple-choice questions and moderately reliable results within the treatment planning portion of the examination. In addition, the item analysis found gaps in students' abilities to transfer clinical evidence/data to basic biomedical knowledge as demonstrated through the multiple-choice questioning results. This outcome warrants further investigation of the utility of the m-OSCE, with a focus on modifications to the evaluation questions, grading rubric, and patient case.

  17. 40 CFR 300.145 - Special teams and other assistance available to OSCs/RPMs.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... regional emergency coordinator. (c) Scientific Support Coordinators (SSCs) may be designated by the OSC (and RPM in the case of EPA SSCs) as the principal advisors for scientific issues, communication with the scientific community, and coordination of requests for assistance from state and federal...

  18. 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.

  19. Use of the OSCE to evaluate brief communication skills training for dental students.

    PubMed

    Cannick, Gabrielle F; Horowitz, Alice M; Garr, David R; Reed, Susan G; Neville, Brad W; Day, Terry A; Woolson, Robert F; Lackland, Daniel T

    2007-09-01

    Although communications competency is recommended by the American Dental Education Association, only a few (n=5) dental schools report evaluating students' skills using a competency examination for communication. This study used an objective structured clinical examination (OSCE) to evaluate dental students' competency in interpersonal and tobacco cessation communication skills. All students were evaluated on their interpersonal communication skills at baseline and at six months post-OSCE by standardized patients and on their tobacco cessation communication skills by two independent raters. First- and second-year dental students (n=104) were randomized to a control or intervention group. One month after the baseline OSCE, students in the intervention group participated in a two-hour training session in which faculty members communicated with a standardized patient during a head and neck examination and counseled the patient about tobacco cessation. There were no statistically significant differences from baseline to post-test between the intervention and control group students as measured by the OSCE. However, among first-year students, both the intervention (n=23) and control (n=21) groups significantly increased in tobacco cessation communication scores. Second-year students in both intervention (n=24) and control (n=28) groups declined in interpersonal communication skills from baseline to post-test. Overall, this one-shot intervention was not successful, and results suggest that a comprehensive communication skills training course may be more beneficial than a single, brief training session for improving dental students' communication skills.

  20. 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…

  1. Competency-Based Training: Objective Structured Clinical Exercises (OSCE) in Marriage and Family Therapy

    ERIC Educational Resources Information Center

    Miller, John K.

    2010-01-01

    The field of marriage and family therapy (MFT) has recently engaged in the process of defining core competencies for the profession. Many MFT training programs are adapting their curriculum to develop more competency-based training strategies. The Objective Structured Clinical "Examination" (OSCE) is widely used in the medical profession to assess…

  2. Dental student perceptions of the educational value of a comprehensive, multidisciplinary OSCE.

    PubMed

    Graham, Roseanna; Zubiaurre Bitzer, Laureen A; Mensah, Felicia Moore; Anderson, O Roger

    2014-05-01

    The aim of this study was to examine student perceptions of the educational value of a comprehensive, multidisciplinary objective structured clinical examination (OSCE). The examination is administered after the second year of the curriculum, prior to the beginning of clinical training at the Columbia University College of Dental Medicine. The quantitative component of the study consisted of a survey administered to students who had taken the OSCE (N=78). Due to the ordinal level of data produced by the Likert-scale survey, statistical analysis was performed through calculation of the median and interquartile range (IQR). Overall, student perceptions of the educational value of the OSCE, as measured using a five-point scale (1=strongly disagree to 5=strongly agree) were positive, demonstrating students' agreement that the exam required the ability to think critically and problem-solve (median=4, IQR=1), assessed clinically relevant skills (median=5, IQR=1), and was a learning experience (median=5, IQR=1). A statistically significant chi-square value (p<0.001) was found for all questions. The qualitative component consisted of phenomenological examination of student focus group interviews (N=15). Four main themes were identified including that the OSCE was an authentic assessment that required integration and application of knowledge.

  3. 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).…

  4. 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

  5. Finding reality: the use of objective structured clinical examination (OSCE) in the assessment of mental health nursing students interpersonal skills.

    PubMed

    Anderson, Martin; Stickley, Theodore

    2002-09-01

    This paper presents the implementation of an objective structured clinical examination (OSCE) in the assessment of mental health nursing students' interpersonal skills. It begins by providing a rationale for the use of this instrument to assess such ski lls and offers a brief discussion of the development of OSCEs. The preparation and implementation of the OSCE is explored and both students' and tutors' reflections of the process are highlighted. The strengths and problems, particularly the use of an ac tor and video tape recordings are examined, in the light of other studies. The paper concludes by advocating the use of such an assessment tool as a formative exercise.

  6. 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.

  7. Standardised clients as assessors in a veterinary communication OSCE: a reliability and validity study.

    PubMed

    Artemiou, E; Adams, C L; Hecker, K G; Vallevand, A; Violato, C; Coe, J B

    2014-11-22

    In human medicine, standardised patients (SP) have been shown to reliably and accurately assess learners' communication performance in high-stakes certification Objective Structured Clinical Examinations (OSCE), offering a feasible way to reduce the need for recruitment, time commitment and coordination of faculty assessors. In this study, we evaluated the use of standardised clients (SC) as a viable option for assessing veterinary students' communication performance. We designed a four-station, two-track communication skills OSCE. SC assessors used an adapted nine-item Liverpool Undergraduate Communication Assessment Scale (LUCAS). Faculty used a 21-item checklist derived from the Calgary-Cambridge Guide (CCG) and a five-point global rating scale. Participants were second year veterinary students (n=96). For the four stations, intrastation reliability (α) ranged from 0.63 to 0.82 for the LUCAS, and 0.73 to 0.87 for the CCG. The interstation reliability coefficients were 0.85 for the LUCAS and 0.89 for the CGG. The calculated Generalisability (G) coefficients were 0.62 for the LUCAS and 0.60 for the CGG. Supporting construct validity, SC and faculty assessors showed a significant correlation between the LUCAS and CCG total percent scores (r=0.45, P<0.001), and likewise between the LUCAS and global rating scores (r=0.49, P<0.001).Study results support that SC assessors offer a reliable and valid approach for assessing veterinary communication OSCE.

  8. A mini-OSCE for formative assessment of diagnostic and radiographic skills at a dental college in India.

    PubMed

    Lele, Shailesh M

    2011-12-01

    The objective structured clinical examination (OSCE) is being widely used for assessment of skills in dental education around the world. In India, OSCE awareness is rising, and a few exploratory attempts have been made in its implementation. This article describes use of a five-station mini-OSCE for formative assessment of dental diagnostic and radiographic skills in an undergraduate curriculum. Besides gaining experience in OSCEs, the purpose of this project was to study their validity, objectivity, feasibility, acceptability to students and faculty, and impact on student performance. The mini-OSCE was found to be a fairly valid and reliable tool for formative assessment, though it required more planning, preparation, and resources than other means of assessment. A specially developed orientation module improved its feasibility. The nineteen students perceived it to be a meaningful examination and a fair method due to uniformity of tasks and time allocation; they found the scoring to be transparent and objective. The specific and immediate feedback received was appreciated by both students and faculty members.

  9. Key challenges for implementing a Canadian-based objective structured clinical examination (OSCE) in a Middle Eastern context

    PubMed Central

    Wilby, Kyle John; Diab, Mohammad

    2016-01-01

    Globalization of medical education is occurring at a rapid pace and many regions of the world are adapting curricula, teaching methods, and assessment tools from established programs. In the Middle East, the use of Objective Structured Clinical Examinations (OSCEs) is rare. The College of Pharmacy at Qatar University recently partnered with the University of Toronto and the Supreme Council of Health in Qatar to adapt policies and procedures of a Canadian-based OSCE as an exit-from-degree assessment for pharmacy students in Qatar. Despite many cultural and contextual barriers, the OSCE was implemented successfully and is now an integrated component of the pharmacy curriculum. This paper aims to provide insight into the adoption and implementation process by identifying four major cultural and contextual challenges associated with OSCEs: assessment tools, standardized actors, assessor calibration, and standard setting. Proposed solutions to the challenges are also given. Findings are relevant to international programs attempting to adapt OSCEs into their contexts, as well as Canadian programs facing increasing rates of cultural diversity within student and assessor populations. PMID:28344703

  10. Key challenges for implementing a Canadian-based objective structured clinical examination (OSCE) in a Middle Eastern context.

    PubMed

    Wilby, Kyle John; Diab, Mohammad

    2016-12-01

    Globalization of medical education is occurring at a rapid pace and many regions of the world are adapting curricula, teaching methods, and assessment tools from established programs. In the Middle East, the use of Objective Structured Clinical Examinations (OSCEs) is rare. The College of Pharmacy at Qatar University recently partnered with the University of Toronto and the Supreme Council of Health in Qatar to adapt policies and procedures of a Canadian-based OSCE as an exit-from-degree assessment for pharmacy students in Qatar. Despite many cultural and contextual barriers, the OSCE was implemented successfully and is now an integrated component of the pharmacy curriculum. This paper aims to provide insight into the adoption and implementation process by identifying four major cultural and contextual challenges associated with OSCEs: assessment tools, standardized actors, assessor calibration, and standard setting. Proposed solutions to the challenges are also given. Findings are relevant to international programs attempting to adapt OSCEs into their contexts, as well as Canadian programs facing increasing rates of cultural diversity within student and assessor populations.

  11. 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

  12. Undesired variance due to examiner stringency/leniency effect in communication skill scores assessed in OSCEs.

    PubMed

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

    2008-12-01

    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). However, it is unknown what sources of error variance are introduced into examinee communication scores by various OSCE components. This study primarily examined the effect different examiners had on the evaluation of students' communication skills assessed at the end of a family medicine clerkship rotation. The communication performance of clinical clerks from Classes 2005 and 2006 were assessed using six OSCE stations. Performance was rated at each station using the 28-item Calgary-Cambridge guide. Item Response Theory analysis using a Multifaceted Rasch model was used to partition the various sources of error variance and generate a "true" communication score where the effects of examiner, case, and items are removed. Variance and reliability of scores were as follows: communication scores (.20 and .87), examiner stringency/leniency (.86 and .91), case (.03 and .96), and item (.86 and .99), respectively. All facet scores were reliable (.87-.99). Examiner variance (.86) was more than four times the examinee variance (.20). About 11% of the clerks' outcome status shifted using "true" rather than observed/raw scores. There was large variability in examinee scores due to variation in examiner stringency/leniency behaviors that may impact pass-fail decisions. Exploring the benefits of examiner training and employing "true" scores generated using Item Response Theory analyses prior to making pass/fail decisions are recommended.

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

    PubMed

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

    2016-01-01

    Hintergrund: Ein OSCE (objective structured clinical examination) ist zusammengestellt aus mündlichen und praktischen Prüfungen um die studentischen Fähigkeiten der klinischen Untersuchung und des Umgangs mit den Patienten zu beurteilen. Als Prüfer können dabei Peers und Dozenten eingesetzt werden. In dieser Arbeit werden studentische „Skills-Lab“-Tutoren als Prüfer einer OSCE-Station Orthopädie evaluiert.Methoden: Wir analysierten die Zahlen der OSCEs von 2013 bis 2015. In jedem Jahr wurden mehr als 300 Studenten geprüft. Die Prüfungsergebnisse nach Einsatz von studentischen „Skills-Lab“-Tutoren als Prüfer einer OSCE-Station Orthopädie werden ausgewertet.Ergebnisse: Die Auswertung der studentischen Peers in unserer Studie zeigt, dass sie flexibler in der zeitlichen Planung sind und gut auf den OSCE vorbereitet waren. Zudem haben studentische Peers einen klaren ökonomischen Vorteil.Nachteile wurden in unserer Untersuchung nicht festgestellt, was mit dem Fakt zusammenhängen kann, dass die Peers gut vorbreitet wurden und die Checklisten regelmäßig überprüft werden. Schlussfolgerung: Studentische Peers im OSCE haben große Vorteile durch ihre zeitliche Flexibilität und relativ geringe Kosten. Sie müssen gut vorbereitet werden und die Checklisten müssen regelmäßig geprüft werden. In den ausgewerteten Prüfungsergebnissen zeigt sich kein Unterschied zwischen studentischen und ärztlichen Prüfern. Die gesetzlichen Grundlagen für den Einsatz von Studenten sollten bedacht werden.

  14. Improved OSC Amtec generator design to meet goals of JPL's candidate Europa Orbiter mission

    SciTech Connect

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

    1998-07-01

    The preceding paper (Paper IECEC.98.244) described OSC's initial designs of AMTEC (Alkali Metal Thermal-to-Electrical Conversion) power systems, consisting of one or two generators, each with 2, 3, or 4 General Purpose Heat Source (GPHS) modules and with 16 refractory AMTEC cells containing 5 Beta Alumina Solid Electrolyte (BASE) tubes; and presented the effect of heat input and voltage output on the generator's BOM evaporator and clad temperatures and on its EOM system efficiency and power output. Comparison of the computed results with JPL's goals for the Europa Orbiter mission showed that all of the initial 16-cell design options yielded either excessive evaporator and clad temperatures or insufficient EOM power to satisfy the JPL-specified mission goals. The present paper describes modified OSC generator designs with different numbers of AMTEC cells, cell diameters, cell lengths, cell materials, BASE tube lengths, and number of tubes per cell. These efforts succeeded in identifying generator designs with only half the number of AMTEC cells which -- for the same assumptions -- can produce EOM power outputs substantially in excess of JPL's goals for NASA's Europa Orbiter mission while operating well below the prescribed BOM limits on evaporator and clad temperature; and revealed that lowering the emissivity of the generator's housing to raise the cells' condenser temperatures can achieve substantial additional performance improvement. Finally, the paper culminates in programmatic recommendations.

  15. 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…

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

    PubMed

    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.

  17. Exploration of Nursing Faculty Members' Lived Experiences of Objective Structured Clinical Examination (OSCE) in Undergraduate Nursing Education

    ERIC Educational Resources Information Center

    Obizoba, Cordelia O.

    2014-01-01

    The purpose of this phenomenological study was to gain an understanding of nursing faculty members' lived experiences of Objective Structured Clinical Examination (OSCE) in undergraduate nursing education. As owners of their programs' curriculum, nursing faculties are charged with the responsibility of providing needed knowledge, skills, and…

  18. [Testing objective structured clinical evaluation (OSCE) for nursing students experience developed during the years 1995-2009].

    PubMed

    Sola Pola, Montserrat; Martínez Castela, Daniel; Molins I Mesalles, Ainhoa; Pulpón Segura, Anna M

    2011-01-01

    The objective structured clinical examination (OSCE) has been recognized as an effective evaluation tool in the health area and has been implemented by an important sector of educational institutions, the Faculty of Medicine and School of Nursing. The present article describes the OSCE organized by the Institute of Health Studies in collaboration with the University Schools of Catalan Nursing. Between the years of 2002 and 2009, OSCE annual exams took place with the participation of 1.803 students. The global results remained stable with a median grade of slightly less than 60%, and the competence component that evaluated communicative capacity was the one in which students obtained the best results. The reliability obtained surpassed the minimum recommended by international standards. It's important underline the positive value to the students of all aspects of the test. From this experience it seems evident that it would be useful to take advantage of the OSCE tests in order to show the students their strong points and ways to improve. We should highlight, not only as a goal but also as an opportunity the assessment by competencies that the European space of higher Education provides at the end of studies for a Nursing degree.

  19. 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.

  20. Performance of OSC's initial Amtec generator design, and comparison with JPL's Europa Orbiter goals

    SciTech Connect

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

    1998-07-01

    The procedure for the analysis (with overpotential correction) of multitube AMTEC (Alkali Metal Thermal-to-Electrical Conversion) cells described in Paper IECEC 98-243 was applied to a wide range of multicell radioisotope space power systems. System design options consisting of one or two generators, each with 2, 3, or 4 stacked GPHS (General Purpose Heat Source) modules, identical to those used on previous NASA missions, were analyzed and performance-mapped. The initial generators analyzed by OSC had 8 AMTEC cells on each end of the heat source stack, with five beta-alumina solid electrolyte (BASE) tubes per cell. The heat source and converters in the Orbital generator designs are embedded in a thermal insulation system consisting of Min-K fibrous insulation surrounded by graded-length molybdenum multifoils. Detailed analyses in previous Orbital studies found that such an insulation system could reduce extraneous heat losses to about 10%. For the above design options, the present paper presents the system mass and performance (i.e., the EOM system efficiency and power output and the BOM evaporator and clad temperatures) for a wide range of heat inputs and load voltages, and compares the results with JPL's preliminary goals for the Europa Orbiter mission to be launched in November 2003. The analytical results showed that the initial 16-cell generator designs resulted in either excessive evaporator and clad temperatures and/or insufficient power outputs to meet the JPL-specified mission goals. The computed performance of modified OSC generators with different numbers of AMTEC cells, cell diameters, cell lengths, cell materials, BASE tube lengths, and number of tubes per cell are described in Paper IECEC.98.245 in these proceedings.

  1. The use of global rating scales for OSCEs in veterinary medicine.

    PubMed

    Read, Emma K; Bell, Catriona; Rhind, Susan; Hecker, Kent G

    2015-01-01

    OSCEs (Objective Structured Clinical Examinations) are widely used in health professions to assess clinical skills competence. Raters use standardized binary checklists (CL) or multi-dimensional global rating scales (GRS) to score candidates performing specific tasks. This study assessed the reliability of CL and GRS scores in the assessment of veterinary students, and is the first study to demonstrate the reliability of GRS within veterinary medical education. Twelve raters from two different schools (6 from University of Calgary [UCVM] and 6 from Royal (Dick) School of Veterinary Studies [R(D)SVS] were asked to score 12 students (6 from each school). All raters assessed all students (video recordings) during 4 OSCE stations (bovine haltering, gowning and gloving, equine bandaging and skin suturing). Raters scored students using a CL, followed by the GRS. Novice raters (6 R(D)SVS) were assessed independently of expert raters (6 UCVM). Generalizability theory (G theory), analysis of variance (ANOVA) and t-tests were used to determine the reliability of rater scores, assess any between school differences (by student, by rater), and determine if there were differences between CL and GRS scores. There was no significant difference in rater performance with use of the CL or the GRS. Scores from the CL were significantly higher than scores from the GRS. The reliability of checklist scores were .42 and .76 for novice and expert raters respectively. The reliability of the global rating scale scores were .7 and .86 for novice and expert raters respectively. A decision study (D-study) showed that once trained using CL, GRS could be utilized to reliably score clinical skills in veterinary medicine with both novice and experienced raters.

  2. 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

  3. 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

  4. 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

  5. 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

  6. The Objective Structured Clinical Examination (OSCE) as a strategy for assessing clinical competence in midwifery education in Ireland: a critical review.

    PubMed

    Smith, Valerie; Muldoon, Kathryn; Biesty, Linda

    2012-09-01

    In Ireland, to register as a midwife, all student midwives must be deemed competent to practice with the assessment of competence an essential component of midwifery education. A variety of assessment strategies, including observed practice, clinical interviews, portfolios of reflection, the Objective Structured Clinical Examination (OSCE) and written examination papers, are utilised to assess midwifery students' clinical competence. In this paper, a critical review of the OSCE as a strategy for assessing clinical competence in one third level institution in Ireland is offered. Although utilised for assessing competence across a range of areas (e.g. obstetric emergencies and pharmacology/drug administration), the use of the OSCE for assessing midwifery students' competence in lactation and infant feeding practices, as an example for this paper, is described. The advantages, disadvantages, validity and reliability of the OSCE, as an assessment strategy, are critically explored. Recognising that no single assessment strategy can provide all the information required to assess something as complex as clinical performance, the OSCE, when viewed alongside other forms of assessment, and with relevance to the topic under examination, may be considered a valuable strategy for enhancing the assessment of students' clinical competence, and for embracing diversity within midwifery education and training.

  7. Allelic diversification at the C (OsC1) locus of wild and cultivated rice: nucleotide changes associated with phenotypes.

    PubMed

    Saitoh, Kumi; Onishi, Kazumitsu; Mikami, Ichiho; Thidar, Khin; Sano, Yoshio

    2004-10-01

    Divergent phenotypes are often detected in domesticated plants despite the existence of invariant phenotypes in their wild forms. One such example in rice is the occurrence of varying degrees of apiculus coloration due to anthocyanin pigmentation, which was previously reported to be caused by a series of alleles at the C locus. The present study reveals, on the basis of comparison of its maps, that the C gene appears to be the rice homolog (OsC1) of maize C1, which belongs to the group of R2R3-Myb factors. Two different types of deletions causing a frameshift were detected in the third exon, and both of the deleted nucleotides corresponded to the positions of putative base-contacting residues, suggesting that the Indica and Japonica types carry loss-of-function mutations with independent origins. In addition, replacement substitutions were frequently detected in OsC1 of strains carrying the previously defined C alleles. Molecular population analysis revealed that 17 haplotypes were found in 39 wild and cultivated rices, and the haplotypes of most cultivated forms could be classified into one of three distinct groups, with few shared haplotypes among taxa, including Indica and Japonica types. The genealogy of the OsC1 gene suggests that allelic diversification causing phenotypic change might have resulted from mutations in the coding region rather than from recombination between preexisting alleles. The McDonald and Kreitman test revealed that the changes in amino acids might be associated with selective forces acting on the lineage of group A whose haplotypes were carried by most Asian cultivated forms. The results regarding a significant implication for genetic diversity in landraces of rice are also discussed.

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

    PubMed

    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.

  9. 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

  10. 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

  11. Design and analysis of O-S-C triple band wavelength division demultiplexer using cascaded MMI couplers

    NASA Astrophysics Data System (ADS)

    Chack, Devendra; Kumar, V.; Raghuwanshi, Sanjeev Kumar; Singh, Dev Prakash

    2017-01-01

    Compact triple O-S-C band wavelength demultiplexer, which consists of series cascaded multimode interference (MMI) couplers has been carried out in this paper. The MMI coupler has been used to drop the wavelengths of 1510 nm and 1550 nm at bar port while the wavelength 1300 nm into the cross port. Then another MMI coupler has been designed to separate the wavelength 1510 nminto one port and wavelength 1550 nm into another port. The triple wavelength demultiplexer function has been performed by choosing a suitable refractive index of the guiding region and geometrical parameters such as the width and length of MMI coupler. Numerical simulation with finite difference beam propagation method (BPM) has been utilized to design and optimize the operation of the proposed triple wavelength demultiplexer. The simulation results show that insertion losses of wavelength O, S and C, bands are 1.884 dB, 1.452 dB and 2.568 dB, respectively, with isolations for each output waveguide ranging from 10 dB to 28.72 dB. The 3-dB bandwidth of insertion loss for 1300 nm, 1510 nm and 1550 nm are 80 nm, 20 nm and 10 nm, respectively.

  12. 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

  13. 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

  14. An exploration of student nurses' thoughts and experiences of using a video-recording to assess their performance of cardiopulmonary resuscitation (CPR) during a mock objective structured clinical examination (OSCE).

    PubMed

    Paul, Fiona

    2010-09-01

    Cardiopulmonary resuscitation (CPR) is an essential skill taught within undergraduate nursing programmes. At the author's institution, students must pass the CPR objective structured clinical examination (OSCE) before progressing to second year. However, some students have difficulties developing competence in CPR and evidence suggests that resuscitation skills may only be retained for several months. This has implications for practice as nurses are required to be competent in CPR. Therefore, further opportunities for students to develop these skills are necessary. An action research project was conducted with six students who were assessed by an examiner at a video-recorded mock OSCE. Students self-assessed their skills using the video and a checklist. Semi-structured interviews were conducted to compare checklist scores, and explore students' thoughts and experiences of the OSCE. The findings indicate that students may need to repeat this exercise by comparing their previous and current performances to develop both their self-assessment and CPR skills. Although there were some differences between the examiner's and student's checklist scores, all students reported the benefits of participating in this project, e.g. discussion and identification of knowledge and skills deficits, thus emphasising the benefits of formative assessments to prepare students for summative assessments and ultimately clinical practice.

  15. 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

  16. G-CLEAN OSC-1809

    EPA Pesticide Factsheets

    Technical product bulletin: aka OIL SPILL CLEANUP, this surface washing agent may be applied liberally to heavily weathered oil on rocks or beaches/sand, vegetation, or at full strength on tar balls. Best results if allowed to soak, agitated, or reapplied.

  17. EPA's On-Scene Coordinators (OSCs)

    EPA Pesticide Factsheets

    These are the federal officials responsible for monitoring or directing responses to all oil spills and hazardous substance releases reported to the government. They are responsible for assessment, monitoring, response assistance, and evaluation.

  18. 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.

  19. Democratization in Albania: The OSCE, NATO and the European Union

    DTIC Science & Technology

    2010-06-01

    for Albania, one of transition from communism to democracy . In addition to undertaking domestic political and economic reforms, Albania began to...establish political and economic relations with European and Euro- Atlantic organizations as a means of making the transition to democracy irreversible...the establishment of political pluralism marked the beginning of a new era for Albania, one of transition from communism to democracy . In addition

  20. Materials Data on Sc3OsC4 (SG:12) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-07-31

    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. 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

  2. Materials Data on OsC2 (SG:187) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-09-19

    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 H21OsC9NO7 (SG:14) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-02-11

    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 OsC (SG:194) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-05-24

    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. Materials Data on OsC (SG:187) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-02-10

    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

  6. 40 CFR 300.145 - Special teams and other assistance available to OSCs/RPMs.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... treatment technology, biology, chemistry, hydrology, geology, and engineering. (2) The ERT can provide... SUPSALV. Formal requests are routed through the Chief of Naval Operations (N312). (e) For marine salvage... proper actions are taken. Marine salvage operations generally fall into five categories: afloat...

  7. 40 CFR 300.145 - Special teams and other assistance available to OSCs/RPMs.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... treatment technology, biology, chemistry, hydrology, geology, and engineering. (2) The ERT can provide... SUPSALV. Formal requests are routed through the Chief of Naval Operations (N312). (e) For marine salvage... proper actions are taken. Marine salvage operations generally fall into five categories: afloat...

  8. 40 CFR 300.145 - Special teams and other assistance available to OSCs/RPMs.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... treatment technology, biology, chemistry, hydrology, geology, and engineering. (2) The ERT can provide... SUPSALV. Formal requests are routed through the Chief of Naval Operations (N312). (e) For marine salvage... proper actions are taken. Marine salvage operations generally fall into five categories: afloat...

  9. 40 CFR 300.145 - Special teams and other assistance available to OSCs/RPMs.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... treatment technology, biology, chemistry, hydrology, geology, and engineering. (2) The ERT can provide... SUPSALV. Formal requests are routed through the Chief of Naval Operations (N312). (e) For marine salvage... proper actions are taken. Marine salvage operations generally fall into five categories: afloat...

  10. 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

  11. 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

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

    PubMed

    Sim, Joong Hiong; Aziz, Yang Faridah Abdul; 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.

  13. 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…

  14. Feedback in formative OSCEs: comparison between direct observation and video-based formats

    PubMed Central

    Junod Perron, Noëlle; Louis-Simonet, Martine; Cerutti, Bernard; Pfarrwaller, Eva; Sommer, Johanna; Nendaz, Mathieu

    2016-01-01

    Introduction Medical students at the Faculty of Medicine, University of Geneva, Switzerland, have the opportunity to practice clinical skills with simulated patients during formative sessions in preparation for clerkships. These sessions are given in two formats: 1) direct observation of an encounter followed by verbal feedback (direct feedback) and 2) subsequent review of the videotaped encounter by both student and supervisor (video-based feedback). The aim of the study was to evaluate whether content and process of feedback differed between both formats. Methods In 2013, all second- and third-year medical students and clinical supervisors involved in formative sessions were asked to take part in the study. A sample of audiotaped feedback sessions involving supervisors who gave feedback in both formats were analyzed (content and process of the feedback) using a 21-item feedback scale. Results Forty-eight audiotaped feedback sessions involving 12 supervisors were analyzed (2 direct and 2 video-based sessions per supervisor). When adjusted for the length of feedback, there were significant differences in terms of content and process between both formats; the number of communication skills and clinical reasoning items addressed were higher in the video-based format (11.29 vs. 7.71, p=0.002 and 3.71 vs. 2.04, p=0.010, respectively). Supervisors engaged students more actively during the video-based sessions than during direct feedback sessions (self-assessment: 4.00 vs. 3.17, p=0.007; active problem-solving: 3.92 vs. 3.42, p=0.009). Students made similar observations and tended to consider that the video feedback was more useful for improving some clinical skills. Conclusion Video-based feedback facilitates discussion of clinical reasoning, communication, and professionalism issues while at the same time actively engaging students. Different time and conceptual frameworks may explain observed differences. The choice of feedback format should depend on the educational goal. PMID:27834170

  15. Feedback in formative OSCEs: comparison between direct observation and video-based formats.

    PubMed

    Perron, Noëlle Junod; Louis-Simonet, Martine; Cerutti, Bernard; Pfarrwaller, Eva; Sommer, Johanna; Nendaz, Mathieu

    2016-01-01

    Introduction Medical students at the Faculty of Medicine, University of Geneva, Switzerland, have the opportunity to practice clinical skills with simulated patients during formative sessions in preparation for clerkships. These sessions are given in two formats: 1) direct observation of an encounter followed by verbal feedback (direct feedback) and 2) subsequent review of the videotaped encounter by both student and supervisor (video-based feedback). The aim of the study was to evaluate whether content and process of feedback differed between both formats. Methods In 2013, all second- and third-year medical students and clinical supervisors involved in formative sessions were asked to take part in the study. A sample of audiotaped feedback sessions involving supervisors who gave feedback in both formats were analyzed (content and process of the feedback) using a 21-item feedback scale. Results Forty-eight audiotaped feedback sessions involving 12 supervisors were analyzed (2 direct and 2 video-based sessions per supervisor). When adjusted for the length of feedback, there were significant differences in terms of content and process between both formats; the number of communication skills and clinical reasoning items addressed were higher in the video-based format (11.29 vs. 7.71, p=0.002 and 3.71 vs. 2.04, p=0.010, respectively). Supervisors engaged students more actively during the video-based sessions than during direct feedback sessions (self-assessment: 4.00 vs. 3.17, p=0.007; active problem-solving: 3.92 vs. 3.42, p=0.009). Students made similar observations and tended to consider that the video feedback was more useful for improving some clinical skills. Conclusion Video-based feedback facilitates discussion of clinical reasoning, communication, and professionalism issues while at the same time actively engaging students. Different time and conceptual frameworks may explain observed differences. The choice of feedback format should depend on the educational goal.

  16. Materials Data on OsC (SG:221) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-09-21

    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. Materials Data on OsC (SG:225) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-09-21

    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

  18. Materials Data on OsC (SG:216) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-09-21

    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

  19. 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.)

  20. Designing, implementing and assessing a new formative OSCE for ENT higher surgical trainees: our experience in the North West region.

    PubMed

    Khwaja, Sadie; Khwaja, Nadeem; Kumar, Nirmal; Stobbs, Nicola

    2017-04-09

    Currently Otolaryngology trainees have a six or seven year gap between formal summative assessments, which comprise of the Membership of the Royal College if Surgeons exams (MRCS) during core training and the Fellowship of the Royal Colleges of Surgeons exams (FRCS) at the end of higher surgical training. In between these examinations, trainees undergo formative Work-Place Based Assessments (WPBA) and a summative Annual Review of Competency and Progression (ARCP) however there are no other tests or formal assessments of knowledge and skills to ensure that they are developing and progressing at the required rate. This article is protected by copyright. All rights reserved.

  1. Materials Data on P3H18OsC6(SO)6 (SG:15) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-07-29

    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 Sb4OsC6(O3F11)2 (SG:14) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-02-04

    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. 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…

  4. The Development of Strategies for the Assignment of Semantic Information to Unknown Lexemes in Text. Lenguas para Objetivos Especificas (Languages for Special Purposes), No. 5.

    ERIC Educational Resources Information Center

    Alderson, Charles; Alvarez, Guadalupe

    An English for Special Purposes (ESP) course being developed aims to give the students a series of techniques to help them handle vocabulary in a text, and teach them strategies for identifying meaning in context. Traditional strategies, such as the study of morphology, use of grammatical information, and exercises in dictionary usage, are…

  5. 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),...

  6. 5 CFR 1820.1 - General provisions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 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),...

  7. [Using GA-dOSC method to eliminate interference of peel with prediction of apple firmness based on near infrared diffuse reflection spectra].

    PubMed

    Shi, Bo-Lin; Qing, Zhao-Shen; Ji, Bao-Ping; Tu, Zhen-Hua; Zhu, Da-Zhou; Yin, Jing-Yuan

    2009-03-01

    In the present work, "Fuji" apples from Shandong Yantai were used to take the diffuse reflection spectra by FT-NIR PLS components (i.e., factors) were computed by nonlinear iterative partial least squares (NIPALS) and the number of latent factors (LV) was optimized by a leave-one-out cross-validation procedure on the calibration set. On the basis of partial least square (PLS) regression, the models for apples' firmness before and after peeling were compared. In order to eliminate the effect of apple peel on prediction, spectral pretreatments such as multiplicative scatter correction (MSC), derivative, direct orthogonal signal correction (DOSC) and wavelengths selection based on genetic algorithms (GA) were used. Finally, the results of different spectral treatments were compared. In conclusion, the RSDp of models for apples before and after peeling was 16.71% and 12.36%, respectively, suggesting that the apple peel played a negative role in constructing good predictive models. Moreover, the traditional spectral pretreatments (such as MSC, derivative) can hardly resolve the problem. In this research, GA-DOSC played an important role in reducing the interference of apple peel. It not only reduced the wavelength variables from 1480 to 36, but also reduced the latent variables from 5 to 1. The correlation coefficient (r) was improved from 0.753 to 0.805, and the RMSECV and RMESP were reduced from 1.019 kgf x cm(-2) and 1.197 kgf x cm(-2) to 0.919 kgf x cm(-2) and 0.924 kgf x cm(-2), respectively. Especially, the RSDp was decreased remarkably from 16.71% to 12.89%. The performance of the model after GA-DOSC treatment was similar to the model using spectra of apple flesh (12.36%). It was concluded that the prediction precision based on GA-DOSC satisfied the requirement of NIR non-destruction determination of apples firmness.

  8. The development and evaluation of a computer-based resource to assist pre-registration nursing students with their preparation for objective structured clinical examinations (OSCEs).

    PubMed

    Bloomfield, Jacqueline; Fordham-Clarke, Carol; Pegram, Anne; Cunningham, Brent

    2010-02-01

    This paper presents a narrative discussion of an innovative, computer-based resource developed, implemented and evaluated by a small project team at a school of nursing and midwifery in London. The interactive resource was designed to assist first and second year pre-registration nursing students with both their clinical skills revision and formative preparation for Objective Structured Clinical Examinations and involved a small range of clinical skills. These included: skin assessment; hand hygiene; reading a drug prescription chart, weighing a baby and assessment of an intravenous cannulae site. The processes involved in the development of the tool are described and, the key drivers informing its development are identified. Although a formal research approach was not adopted a summary of feedback obtained from anonymous student evaluations is included. This provides important insights into the perceived usefulness of the tool and is discussed in light of the challenges and practicalities associated with the content development and technical issues. The paper concludes by identifying proposed future developments and wider applications of this innovative clinical skills education initiative within nursing and healthcare education.

  9. 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.

  10. Introducing a Model for Optimal Design of Sequential Objective Structured Clinical Examinations

    ERIC Educational Resources Information Center

    Mortaz Hejri, Sara; Yazdani, Kamran; Labaf, Ali; Norcini, John J.; Jalili, Mohammad

    2016-01-01

    In a sequential OSCE which has been suggested to reduce testing costs, candidates take a short screening test and who fail the test, are asked to take the full OSCE. In order to introduce an effective and accurate sequential design, we developed a model for designing and evaluating screening OSCEs. Based on two datasets from a 10-station…

  11. Assessment of the DoD Establishment of the Office of Security Cooperation -- Iraq

    DTIC Science & Technology

    2012-03-16

    Engineering) • J8 (Finance) • J9 (Strategic Communications) • Deputy Commanding General for Advising and Training o Executive Director o ITAM ...Ministry of Defense o ITAM Ministry of Interior o ITAM Police o ITAM Army/OSC-I Army o ITAM Army Aviation/OSC-I Army Aviation o ITAM Navy/OSC-I Navy o ITAM

  12. 40 CFR 300.115 - Regional Response Teams.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 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...

  13. 40 CFR 300.115 - Regional Response Teams.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 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...

  14. 40 CFR 300.115 - Regional Response Teams.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 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...

  15. 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.

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

    PubMed

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

    2016-01-01

    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. Can the exercise mode determine lipid profile improvements in obese patients?

    PubMed

    Romero Moraleda, Blanca; Morencos, Esther; Peinado, Ana Belén; Bermejo, Laura; Gómez Candela, Carmen; Benito, Pedro José

    2013-01-01

    Introducción y objetivo: El perfil lipídico desfavorable se asocia con el desarrollo de enfermedades cardiovasculares. Para reducir este factor es necesario estudiar el impacto que los diferentes modos de ejercicio con dieta tienen sobre el perfil lipídico. Por ello, el objetivo de este trabajo fue investigar, en hombres y mujeres obesos, el efecto sobre el perfil lipídico de la dieta hipocalórica combinada con programas de ejercicios estructurados o recomendaciones de actividad física. Métodos: Noventa y seis participantes con obesidad (edad entre 18-50; IMC > 30 and < 34.9 kg/m(2)) fueron repartidos en 4 grupos: fuerza (S; n = 24), aeróbico (E; n = 26), combinado de fuerza y aeróbico (SE; n = 24), los cuales entrenaron 3 veces/semana durante 22 semanas, y el grupo de recomendaciones de actividad física (PA; n = 22). A todos se les asigno una dieta equilibrada con un 35% de restricción. Antes y después de la intervención todos los grupos fueron evaluados de los cambios en el perfil lipídico, la composición corporal y la ingesta diaria. Resultados: El perfil lipídico mejoró en todos los grupos. No se observaron diferencias significativas en los valores basales y tras la intervención entre los grupos. El HDL no mostró cambios. Para los valores de LDL se observó una disminución significativa en todos los grupos (S: 11,2%, E: 10,8%, SE: 7,9%, PA: 10,8%). Los sujetos S, E y PA mostraron una disminución en los triglicéridos (S: 14,9%, E: 15,8%, PA: 15,7%; p < 0,01). El colesterol total disminuyó significativamente en todos los grupos (S: 8,4%, E: 8,8%, SE: 4,9%, PA: 8,3%). Conclusiones: Todos los protocolos propuestos en nuestro estudio mejoraron el perfil lipídico en personas obesas. No hubo diferencias significativas en cuanto al efecto sobre el perfil lipídico entre la aplicación de un protocolo de entrenamiento estructurado que seguir las recomendaciones de actividad física.

  18. 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.

  19. The understanding, attitude and use of nutrition label among consumers (China).

    PubMed

    Song, Jiangen; Huang, Junxia; Chen, Yujuan; Zhu, Yu; Li, Haibo; Wen, Yufeng; Yuan, Hui; Liang, Yali

    2015-06-01

    Objetivo: el objetivo de este estudio fue investigar el conocimiento, la actitud y el uso de la etiqueta nutricional entre los consumidores en China. Métodos: estudio transversal con un cuestionario estructurado que fue realizada entre 1.153 consumidores, que fueron reclutados a partir de diferentes supermercados durante marzo a mayo de 2014 en la ciudad de Wuhu de China. Resultados: el resultado muestra que la comprensión subjetiva de las etiquetas nutricionales fue moderada (el 62,8% de los encuestados), pero el objetivo entendimiento fue variado. Las actitudes hacia la etiqueta nutricional fueron positivas en aquellos participantes con mayor confianza y satisfacción en las mismas. Respecto a la lectura de las etiquetas, el 59,2 % de los encuestados contestó que “a veces” y el 28,7 % que “siempre”. La lectura de la etiqueta nutricional de alimentos que con mayor frecuencia se realizó fue la de la leche (57,5%), seguida por la alimentación infantil (33,3%), proteínas y nutrientes (51,5%), vitaminas (49,8%) y grasas (29,4%). Ninguna de las características demográficas se asoció con el conocimiento, la actitud y el uso de la etiqueta nutricional, excepto la educación. Conclusiones: Las personas que participaron en nuestro estudio tenían una comprensión moderada, mostrando una actitud más positiva aquellos que la utilizan con más frecuencia. Aunque la etiqueta nutricional se convirtió en obligatoria, aún son necesarias estrategias adicionales, así como fomentar su conocimiento por parte de los consumidores.

  20. Validation of a computer based objective structured clinical examination in the assessment of undergraduate dermatology courses.

    PubMed

    Kaliyadan, Feroze; Khan, Abdul Sattar; Kuruvilla, Joel; Feroze, Kaberi

    2014-01-01

    Many teaching centers have now adopted objective structured clinical examination (OSCE) as an assessment method for undergraduate dermatology courses. A modification of the standard OSCE in dermatology is computer based or electronic OSCE (eOSCE). We attempted to validate the use of a computer-based OSCE in dermatology in a group of fifth year medical students. The scores of the students in the computer-based OSCE showed a strong positive correlation with the scores on the clinical presentation (Pearson's co-efficient - 0.923, P value <0.000, significant at the 0.01 level) and a good correlation with overall scores of the student (Pearson's co-efficient - 0.728, P value <0.000, significant at the 0.01 level), indicating that this is a reliable method for assessment in dermatology. Generally, the students' feedback regarding the methods was positive.

  1. Eosinophils in human oral squamous carcinoma; role of prostaglandin D2.

    PubMed

    Davoine, Francis; Sim, Adrian; Tang, Charlie; Fisher, Sibina; Ethier, Caroline; Puttagunta, Lakshmi; Wu, Yingqi; McGaw, W Tim; Yu, Donald; Cameron, Lisa; Adamko, Darryl J; Moqbel, Redwan

    2013-01-31

    Eosinophils are often predominant inflammatory leukocytes infiltrating oral squamous carcinoma (OSC) sites. Prostaglandins are secreted by oral carcinomas and may be involved in eosinophil infiltration. The objective of this study was to determine the factors contributing to eosinophil migration and potential anti-neoplastic effects on OSC. Eosinophil degranulation was evaluated by measuring release of eosinophil peroxidase (EPO). Eosinophil chemotaxis towards OSC cells was assessed using artificial basement membrane. Eosinophil infiltration was prominent within the tissue surrounding the OSC tumor mass. We observed growth inhibition of the OSC cell line, SCC-9, during co-culture with human eosinophils, in vitro, which correlated with EPO activity that possesses growth inhibitory activity. The PGD2 synthase inhibitor, HQL-79, abrogated migration towards SCC-9. Our data suggest that OSC-derived PGD2 may play an important role via CRTH2 (the PGD2 receptor on eosinophils) in eosinophil recruitment and subsequent anti-tumor activity through the action of eosinophil cationic proteins.

  2. 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.

  3. 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.

  4. Assessing registered nurses' clinical skills in orthopaedics.

    PubMed

    Clarke, Sonya; McDonald, Sinead; Rainey, Debbie

    The aim of this article is to explore the views of registered nurses undertaking the new Objective Structured Clinical Examination (OSCE), incorporating an integrated preparatory skills workshop. The workshop and the OSCE were audited with particular regard to the student experience. This article describes the audit process and the results of three questionnaires: one carried out before the OSCE assessment, a second immediately after the workshop and a third four days after the assessment. The results provide an insight into the student experience.

  5. Centralization or Decentralization in Iraq? In Search of the Elusive Sweet Spot

    DTIC Science & Technology

    2008-12-01

    example, see Open Source Center (OSC), Iraqi PM Pushes Tribal Councils Over Local Officials’ Objections, OSC Analysis (Washington, DC: OSC...Foreign Affairs, July/August 2006; Edward P. Joseph and Michael E. O’Hanlon, The Case for Soft Partition in Iraq, Analysis Paper No. 12 (Washington, DC...or it may ignite the tinder of Iraq’s many unresolved internal conflicts and destroy the semblance of stability achieved so far. Is there a safe

  6. Functional Flow and Event-Driven Methods for Predicting System Performance

    DTIC Science & Technology

    2015-09-01

    21. 2. SAR Mission initiates; SAR Assets conduct search but no objects of interest are found; SAR assets continue to scan but OSC aborts mission...be related to the SAR, so the OSC aborts mission and all Assets RTB. 45 4. SAR Mission initiates; SAR Assets conduct search and find an object of...interest; the object of interest is determined to be wreckage so the OSC aborts mission and all Assets RTB. 5. SAR Mission initiates; SAR Assets

  7. Assessment of the Office of Security Cooperation-Iraq Mission Capabilities

    DTIC Science & Technology

    2013-09-18

    of Department of Defense support for executing security cooperation programs in Iraq and whether the Office of Security Cooperation–Iraq ( OSC -I...plans, and guidance for executing security cooperation programs in Iraq through the OSC -I performing under U.S. Department of State/Chief of Mission...authority are issued and sufficiently operative; • determined whether the OSC -I is adequately structured and resourced to accomplish its

  8. Status and prospects for ternary organic photovoltaics

    NASA Astrophysics Data System (ADS)

    Lu, Luyao; Kelly, Mary Allison; You, Wei; Yu, Luping

    2015-08-01

    In the past few years, ternary organic solar cells (OSCs) featuring multiple donor or acceptor materials in the active layer have emerged as a promising structure to simultaneously improve all solar cell parameters compared with traditional binary OSCs. Power conversion efficiencies around 10% have been achieved for conjugated polymers in a ternary structure, showing the great potential of ternary systems. In this review, we summarize progress in developing ternary OSCs and discuss many of the designs, chemistries and mechanisms that have been investigated. We conclude by highlighting the challenges and future directions for further development in the field of ternary blend OSCs.

  9. Expanding the role of objectively structured clinical examinations in nephrology training.

    PubMed

    Prince, Lisa K; Abbott, Kevin C; Green, Felicidad; Little, Dustin; Nee, Robert; Oliver, James D; Bohen, Erin M; Yuan, Christina M

    2014-06-01

    Objectively structured clinical examinations (OSCEs) are widely used in medical education, but we know of none described that are specifically for nephrology fellowship training. OSCEs use simulation to educate and evaluate. We describe a technically simple, multidisciplinary, low-cost OSCE developed by our program that contains both examination and training features and focuses on management and clinical knowledge of rare hemodialysis emergencies. The emergencies tested are venous air embolism, blood leak, dialysis membrane reaction, and hemolysis. Fifteen fellows have participated in the OSCE as examinees and/or preceptors since June 2010. All have passed the exercise. Thirteen responded to an anonymous survey in July 2013 that inquired about their confidence in managing each of the 4 tested emergencies pre- and post-OSCE. Fellows were significantly more confident in their ability to respond to the emergencies after the OSCE. Those who subsequently saw such an emergency reported that the OSCE experience was somewhat or very helpful in managing the event. The OSCE tested and trained fellows in the recognition and management of rare hemodialysis emergencies. OSCEs and simulation generally deserve greater use in nephrology subspecialty training; however, collaboration between training programs would be necessary to validate such exercises.

  10. 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.

  11. 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

  12. Divergent interactions involving the oxidosqualene cyclase and the steroid-3-ketoreductase in the sterol biosynthetic pathway of mammals and yeasts.

    PubMed

    Taramino, Silvia; Teske, Brian; Oliaro-Bosso, Simonetta; Bard, Martin; Balliano, Gianni

    2010-11-01

    In mammals and yeasts, oxidosqualene cyclase (OSC) catalyzes the formation of lanosterol, the first cyclic intermediate in sterol biosynthesis. We used a murine myeloma cell line (NS0), deficient in the 17β-hydroxysteroid dehydrogenase type 7 (HSD17B7), as a model to study the potential interaction of the HSD17B7 with the OSC in mammals. HSD17B7 is the orthologue of the yeast steroid-3-ketoreductase (ERG27), an enzyme of ergosterol biosynthesis that plays a protective role towards OSC. Tracer experiments with NS0 cells showed that OSC is fully active in these mammalian cells, suggesting that in mammals the ketosteroid reductase is not required for OSC activity. Mouse and human HSD17B7 were overexpressed in ERG27-deletant yeast cells, and recombinant strains were tested for (i) the ability to grow on different media, (ii) steroid-3-ketoreductase activity, and (iii) OSC activity. Recombinant strains grew more slowly than the control yeast ERG27-overexpressing strain on sterol-deficient media, whereas the growth rate was normal on media supplemented with a 3-ketoreductase substrate. The full enzymatic functionality of mammalian steroid-3-ketoreductase expressed in yeast along with the lack of (yeast) OSC activity point to an inability of the mammalian reductase to assist yeast OSC. Results demonstrate that in mammals, unlike in yeast, OSC and steroid-3-ketoreductase are non-interacting proteins.

  13. Protective effects of garlic sulfur compounds against DNA damage induced by direct- and indirect-acting genotoxic agents in HepG2 cells.

    PubMed

    Belloir, C; Singh, V; Daurat, C; Siess, M H; Le Bon, A M

    2006-06-01

    The aim of this study was to assess the antigenotoxic activity of several garlic organosulfur compounds (OSC) in the human hepatoma cell line HepG2, using comet assay. The OSC selected were allicin (DADSO), diallyl sulfide (DAS), diallyl disulfide (DADS), S-allyl cysteine (SAC) and allyl mercaptan (AM). To explore their potential mechanisms of action, two approaches were performed: (i) a pre-treatment protocol which allowed study of the possible modulation of drug metabolism enzymes by OSC before treatment of the cells with the genotoxic agent; (ii) a co-treatment protocol by which the ability of OSC to scavenge direct-acting compounds was assessed. Preliminary studies showed that, over the concentration range tested (5-100 microM), the studied OSC neither affected cell viability nor induced DNA damage by themselves. In the pre-treatment protocol, aflatoxin B1 genotoxicity was significantly reduced by all the OSC tested except AM. DADS was the most efficient OSC in reducing benzo(a)pyrene genotoxicity. SAC and AM significantly decreased DNA breaks in HepG2 cells treated with dimethylnitrosamine. Additionally, all the OSC studied were shown to decrease the genotoxicity of the direct-acting compounds, hydrogen peroxide and methyl methanesulfonate. This study demonstrated that garlic OSC displayed antigenotoxic activity in human metabolically competent cells.

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

    PubMed

    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.

  15. An exploration of student midwives' experiences of the Objective Structured Clinical Examination assessment process.

    PubMed

    Barry, Maebh; Noonan, Maria; Bradshaw, Carmel; Murphy-Tighe, Sylvia

    2012-08-01

    This paper reports on a qualitative descriptive study that explored student midwives' experiences of the Objective Structured Clinical Examination assessment process for obstetric emergencies within a university setting. The development of fundamental clinical skills is an important component in preparing students to meet the responsibilities of a midwife. There is an international concern that the transfer of midwifery education into universities may impact on the development of midwifery clinical skills. Objective Structured Clinical Examinations (OSCEs) have the potential to promote integration and consolidation of skills prior to clinical placement. Twenty six students (n=36) from two midwifery programmes (BSc and Higher Diploma) participated in four focus groups and Burnard's (2006) framework was used for data analysis. Three main themes emerged following analysis: preparation for the OSCE assessment, the OSCE process and learning through simulating practice. Preparation for the OSCE's which included lectures, demonstrations, and practice of OSCE's facilitated by lecturers and by the students themselves, was considered central to the process. Learning via OSCEs was perceived to be more effective in comparison to other forms of assessment and prepared students for clinical practice. Positive aspects of the process and areas for improvement were identified. Using OSCE's increased the depth of learning for the students with the steps taken in preparation for the OSCE's proving to be a valuable learning tool. This study adds to the evidence on the use of OSCE's in midwifery education.

  16. 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.

  17. 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…

  18. Fullerene-based Schottky-junction organic solar cells: a brief review

    NASA Astrophysics Data System (ADS)

    Sutty, Sibi; Williams, Graeme; Aziz, Hany

    2014-01-01

    Recent advances in fullerene-based Schottky organic solar cells (OSCs) are presented, with a focus on the current understanding of device physics. Fullerene-based Schottky OSCs attain high open-circuit voltages due to the n-type Schottky junction formed between fullerene and an adjacent high work function anode. Small concentrations of donor material doped into the fullerene matrix serve as efficient exciton dissociation and hole transport agents that can substantially bolster short-circuit currents and fill factors. As a consequence, fullerene-based Schottky OSCs have been demonstrated to provide some of the highest-performance vacuum-deposited small molecule OSCs, with power conversion efficiencies up to 8.1%. Fullerene-based Schottky OSCs constructed using different donor materials and varying cathode buffer layers, as studied by a number of different research groups, are presented. To elucidate the differences between Schottky OSCs and more traditional bulk-heterojunction OSCs, we discuss the photophysics of fullerenes, the role of the donor material, and charge transport in low donor concentration active layers. Fullerene-based Schottky OSCs possess considerable advantages because they can reach high efficiencies with a simple structure using readily available and cost-effective materials. The impact and applicability of the Schottky device architecture on the field of organic photovoltaics at large are discussed.

  19. 5 CFR 1820.2 - Requirements for making FOIA requests.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... at the number provided on the FOIA page of OSC's web site (see § 1820.1). For the quickest handling... records about an OSC case file, the case file number, name, and type (for example, prohibited personnel..., such as the date, title or name, author, recipient, and subject matter. (c) Agreement to pay...

  20. Department of the Navy FY 1992/FY 1993 Budget Estimates Descriptive Summaries Submitted to Congress February 1991, Research, Development, Test and Evaluation, Navy

    DTIC Science & Technology

    1991-02-01

    SPE), Operational Systems Control (OSC), and Technical Control (TECHCON) required to deploy, operate, and restore the Marine Corps tactical...Control (OSC), and (3) Technical Control (TECHCON). These functions are required to deploy, operate, and restore Marine Corps tactical communications...Electro-Optical performance models. C. (U) Completed Navy Operational Gulf Stream Forecasting System. 2. (U) FY 1991 PROGRAM: Develop advanced feature

  1. The Flight of Flexible Aircraft in Turbulence - State-of-the-Art in the Description and Modelling of Atmospheric Turbulence: Meeting of the Structures and Materials Panel of AGARD (64th) Held in Athens (Greece) on 28 September-3 October 1986

    DTIC Science & Technology

    1987-12-01

    Flights. Le Groupe de I’AGARD charge de I’etude des Structures et des Materiaux etudie actuellement le vol des avions flexibles dans les turbulences...D.O.F. FORCED OSC. ANGULAR OSCILLATION TRANSL. OSCILLATION SINGLE D.O.F. FREE OSC. FREE FLIGHT SEMI-FREE CONTROLLED MAGNETIC SUSPENSION

  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.

  3. 78 FR 26332 - 36(b)(1) Arms Sales Notification

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-06

    ... systems. The AN/ ALE-47 uses threat data received over the aircraft interfaces to assess the threat... environment may be dispensed using one of four operational modes. The hardware, technical data, and... Converter (OSC) units, a Computer Processor (CP) and a Control Indicator (CI). The set of OSC units,...

  4. Supervisor Use of Observation Systems.

    ERIC Educational Resources Information Center

    Medley, Donald M.

    This paper discusses the supervisory use of one observational system -- Observation Schedule and Record, Form 5V (OScAR 5V). OScAR 5V refers to a series of observation schedules to develop techniques for obtaining an objective, quantitative record of observed classroom behavior that could be scored on dimensions of teacher behavior. Under this…

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

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., Complaints Examining Unit, 1730 M Street NW., Suite 218, Washington, DC 20036-4505; (ii) By calling OSC, at...://www.osc.gov (to print out and complete on paper, or to complete online). (5) A complainant can file a..., Complaints Examining Unit, 1730 M Street NW., Suite 218, Washington, DC 20036-4505; (ii) By fax, to:...

  6. 5 CFR 1209.2 - Jurisdiction.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...)(8). Example 3: Citing alleged misconduct, an agency proposes Employee Y's removal. While that removal action is pending, Y files a complaint with OSC alleging that the proposed removal was initiated... of Federal law and regulation. OSC subsequently issues a letter notifying Y that it has...

  7. The Anti-Inflammatory and Vasodilating Effects of Three Selected Dietary Organic Sulfur Compounds from Allium Species

    PubMed Central

    Chu, Chin-Chen; Wu, Wen-Shiann; Shieh, Ja-Ping; Chu, Heuy-Ling; Lee, Chia-Pu; Duh, Pin-Der

    2017-01-01

    The anti-inflammatory and vasodilating effects of three selected dietary organic sulfur compounds (OSC), including diallyl disulfide (DADS), dimethyl disulfide (DMDS), and propyl disulfide (PDS), from Allium species were investigated. In the anti-inflammatory activity assay, the three OSC demonstrated significant inhibition of nitric oxide (NO) and prostaglandin E2 (PGE2) production in LPS-induced RAW 264.7 cells. The expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX-2) in activated RAW 264.7 cells was inhibited by the three OSC, indicating that the three OSC prevented the LPS-induced inflammatory response in RAW 264.7 cells. For the vasodilative assay, the three OSC were ineffective in producing NO in SVEC4-10 cells, but they did enhance prostacyclin (PGI2) production. The expression of COX-2 in SVEC4-10 cells was activated by DADS and DMDS. Pretreatment of SVEC4-10 cells with the three OSC decreased ROS generation in H2O2-induced SVEC4-10 cells. In addition, the three OSC significantly inhibited angiotensin-I converting enzyme (ACE). The up-regulation of PGI2 production and COX-2 expression by DADS and DMDS and the reduction of ROS generation by DADS, DMDS, and PDS in SVEC4-10 cells contributed to the vasodilative effect of the three OSC. Collectively, these findings suggest that DADS, DMDS, and PDS are potential anti-inflammatory and vasodilative mediators. PMID:28134777

  8. 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 personnel during an OSC investigation is encouraged to eliminate duplication of effort, and to avoid... litigation, release of information shall be accomplished pursuant to MSPB rules of discovery (5 CFR...

  9. 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)…

  10. 15 CFR 990.26 - Emergency restoration.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...) NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE OIL POLLUTION ACT REGULATIONS... response actions. Emergency restoration may not address residual oil unless: (1) The OSC's response is complete; or (2) The OSC has determined that the residual oil identified by the trustee as part of...

  11. 15 CFR 990.26 - Emergency restoration.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...) NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE OIL POLLUTION ACT REGULATIONS... response actions. Emergency restoration may not address residual oil unless: (1) The OSC's response is complete; or (2) The OSC has determined that the residual oil identified by the trustee as part of...

  12. 15 CFR 990.26 - Emergency restoration.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...) NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE OIL POLLUTION ACT REGULATIONS... response actions. Emergency restoration may not address residual oil unless: (1) The OSC's response is complete; or (2) The OSC has determined that the residual oil identified by the trustee as part of...

  13. 15 CFR 990.26 - Emergency restoration.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...) NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE OIL POLLUTION ACT REGULATIONS... response actions. Emergency restoration may not address residual oil unless: (1) The OSC's response is complete; or (2) The OSC has determined that the residual oil identified by the trustee as part of...

  14. 15 CFR 990.26 - Emergency restoration.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...) NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE OIL POLLUTION ACT REGULATIONS... response actions. Emergency restoration may not address residual oil unless: (1) The OSC's response is complete; or (2) The OSC has determined that the residual oil identified by the trustee as part of...

  15. Using Simulation in Assessment and Teaching: OSCE Adapted for Social Work

    ERIC Educational Resources Information Center

    Bogo, Marion; Rawlings, Mary; Katz, Ellen; Logie, Carmen

    2014-01-01

    This detailed book by the most experienced authors in the field describes how to develop and implement the objective structured clinical examination (OSCE) for social work education. In addition to a wealth of practical material in the appendices, two videos produced especially for this book (accessible online) show the OSCE process step-by-step.…

  16. 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.

  17. 40 CFR 300.315 - Phase IV-Documentation and cost recovery.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... parties, and impacts and potential impacts to public health and welfare and the environment. Documentation... technology. Funding for these actions is restricted by section 6002 of the OPA. (c) OSCs shall submit OSC... necessary collection and safeguarding of information, samples, and reports. Samples and information shall...

  18. 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

  19. Designing and implementing the objective structured clinical examination in anesthesiology.

    PubMed

    Hastie, Maya Jalbout; Spellman, Jessica L; Pagano, Parwane P; Hastie, Jonathan; Egan, Brian J

    2014-01-01

    Since its description in 1974, the Objective Structured Clinical Examination (OSCE) has gained popularity as an objective assessment tool of medical students, residents, and trainees. With the development of the anesthesiology residents' milestones and the preparation for the Next Accreditation System, there is an increased interest in OSCE as an evaluation tool of the six core competencies and the corresponding milestones proposed by the Accreditation Council for Graduate Medical Education.In this article the authors review the history of OSCE and its current application in medical education and in different medical and surgical specialties. They also review the use of OSCE by anesthesiology programs and certification boards in the United States and internationally. In addition, they discuss the psychometrics of test design and implementation with emphasis on reliability and validity measures as they relate to OSCE.

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    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.

  1. Used protocols for isolation and propagation of ovarian stem cells, different cells with different traits.

    PubMed

    Yazdekhasti, Hossein; Rajabi, Zahra; Parvari, Soraya; Abbasi, Mehdi

    2016-10-20

    Although existence of ovarian stem cells (OSCs) in mammalian postnatal ovary is still under controversy, however, it has been almost accepted that OSCs are contributing actively to folliculogenesis and neo-oogenesis. Recently, various methods with different efficacies have been employed for OSCs isolation from ovarian tissue, which these methods could be chosen depends on aim of isolation and accessible equipments and materials in lab. Although isolated OSCs from different methods have various traits and characterizations, which might become from their different nature and origin, however these stem cells are promising source for woman infertility treatment or source of energy for women with a history of repeat IVF failure in near future. This review has brought together and summarized currently used protocols for isolation and propagation of OSCs in vitro.

  2. Students' feedback of objectively structured clinical examination: a private medical college experience.

    PubMed

    Khursheed, Iram; Usman, Yaseen; Usman, Jawaid

    2007-03-01

    The aim of the study was to evaluate undergraduate students' perceptions regarding Objectively Structured Clinical Examination (OSCE) to be used as a feedback to improve the assessment technique. At the end of OSCE, students were provided with a feedback questionnaire related to OSCE to obtain their views and comments. The feedback was obtained from two consecutive batches of third year medical students and was utilized to incorporate the improvements in the process, wherever possible. A great majority of students (93% from group 'A' and 95% from group 'B') regarded OSCE as a practical and useful assessment tool in early years of medical education. In this study, students appreciated OSCE and offered constructive feedback on structure and organization of the process. However, at some stations they felt that instructions were ambiguous and time allocation was inadequate for the assigned tasks. The overall feedback was very useful and facilitated a critical review of the process.

  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. 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

  5. An unusual plant triterpene synthase with predominant α-amyrin-producing activity identified by characterizing oxidosqualene cyclases from Malus × domestica.

    PubMed

    Brendolise, Cyril; Yauk, Yar-Khing; Eberhard, Ellen D; Wang, Mindy; Chagne, David; Andre, Christelle; Greenwood, David R; Beuning, Lesley L

    2011-07-01

    The pentacyclic triterpenes, in particular ursolic acid and oleanolic acid and their derivatives, exist abundantly in the plant kingdom, where they are well known for their anti-inflammatory, antitumour and antimicrobial properties. α-Amyrin and β-amyrin are the precursors of ursolic and oleanolic acids, respectively, formed by concerted cyclization of squalene epoxide by a complex synthase reaction. We identified three full-length expressed sequence tag sequences in cDNA libraries constructed from apple (Malus × domestica 'Royal Gala') that were likely to encode triterpene synthases. Two of these expressed sequence tag sequences were essentially identical (> 99% amino acid similarity; MdOSC1 and MdOSC3). MdOSC1 and MdOSC2 were expressed by transient expression in Nicotiana benthamiana leaves and by expression in the yeast Pichia methanolica. The resulting products were analysed by GC and GC-MS. MdOSC1 was shown to be a mixed amyrin synthase (a 5 : 1 ratio of α-amyrin to β-amyrin). MdOSC1 is the only triterpene synthase so far identified in which the level of α-amyrin produced is > 80% of the total product and is, therefore, primarily an α-amyrin synthase. No product was evident for MdOSC2 when expressed either transiently or in yeast, suggesting that this putative triterpene synthase is either encoded by a pseudogene or does not express well in these systems. Transcript expression analysis in Royal Gala indicated that the genes are mostly expressed in apple peel, and that the MdOSC2 expression level was much lower than that of MdOSC1 and MdOSC3 in all the tissues tested. Amyrin content analysis was undertaken by LC-MS, and demonstrated that levels and ratios differ between tissues, but that the true consequence of synthase activity is reflected in the ursolic/oleanolic acid content and in further triterpenoids derived from them. Phylogenetic analysis placed the three triterpene synthase sequences with other triterpene synthases that encoded either

  6. [Pyramid training model in laparoscopic surgery].

    PubMed

    Usón-Gargallo, Jesús; Pérez-Merino, Eva María; Usón-Casaús, Jesús María; Sánchez-Fernández, Javier; Sánchez-Margallo, Francisco Miguel

    2013-01-01

    Antecedentes: la práctica de la cirugía de mínima invasión necesita que el aprendizaje sea estructurado y progresivo. Material y métodos: estudio prospectivo efectuado en el Centro de Cirugía de Mínima Invasión Jesús Usón que propone un modelo de formación piramidal con cuatro niveles: adquisición de habilidades básicas en simulador (nivel 1), desarrollo de técnicas quirúrgicas específicas en modelos animales (nivel 2), telemedicina y telementorización (nivel 3), y aplicación al paciente con supervisión experimentada (nivel 4). Objetivo: describir los niveles 1 y 2 que se practican en el Centro y evaluar la formación impartida. Resultados: 4,284 alumnos han recibido formación en cirugía laparoscópica: 95.5% médicos: cirujanos del aparato digestivo (49%), urólogos (30%) y ginecólogos (14%). En 77% de los cursos celebrados disponen de 20 horas de adiestramiento, 8 en el nivel 1, y 12 en el nivel 2. El 94.37% considera altamente apropiado el modelo de formación piramidal, calificándolo con 9.58 sobre 10 y con 9.5 a la calidad de la simulación. El 82.75% percibe que ha avanzado notablemente en sus destrezas y 99.56% recomendaría a otros cirujanos la realización de actividades en el Centro. Conclusión: el modelo de formación propuesto permite alcanzar las habilidades necesarias para efectuar correctamente procedimientos avanzados en cirugía de mínima invasión.

  7. PubMed

    Plaza Moral, V; Carrillo, T; Delgado, J; Entrenas, L M; Martinez Moragón, E; Olaguibel, J M; Pérez de Llano, L; Perpiñá, M; Sastre, J; Valero, A; Quirce, S

    2016-11-21

      Fundamento. Numerosos estudios constatan que aproximadamente la mitad de la población asmática no está bien controlada. El objetivo de este trabajo fue analizar entre expertos las causas, consecuencias y las posibles soluciones del asma no controlada (ANC).  Material y métodos. Debate entre expertos en asma de las especialidades de Neumología, Alergología y Atención Primaria, estructurado en tres fases 1) Cuestionario para pulsar la opinión de los participantes en los diferentes elementos implicados del ANC; 2) Reunión presencial de los expertos, en la que se discutieron los resultados de la encuesta y se presentaron y debatieron ponencias sobre el diagnóstico, tratamiento y seguimiento del ANC; 3) Formulación de 83 ítems que fueron sometidos a consenso entre todos los participantes mediante el método Delphi.  Resultados. El 86,7% de los ítems del cuestionario Delphi fue consensuado, mayoritariamente en términos de acuerdo.  Conclusiones. El análisis de los resultados sobre el ANC señala la necesidad de mejora futura en: incorporar en las Guías de Práctica Clínica de asma un protocolo de actuación clínico para identificar agravantes y comorbilidades; desarrollar una herramienta barata y de fácil utilización que permita identificar la adherencia al tratamiento; establecer el fenotipo del paciente; analizar los efectos secundarios del tratamiento y ofrecer un tratamiento personalizado, valorando especialmente la eficacia y seguridad (control de síntomas y riesgo futuro). Se precisa generar nuevas evidencias (estudios) que determinen exploraciones complementarias a emplear en el seguimiento de estos pacientes.

  8. [In Process Citation].

    PubMed

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

    2016-02-16

    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.

  9. Interfacial Materials for Organic Solar Cells: Recent Advances and Perspectives.

    PubMed

    Yin, Zhigang; Wei, Jiajun; Zheng, Qingdong

    2016-08-01

    Organic solar cells (OSCs) have shown great promise as low-cost photovoltaic devices for solar energy conversion over the past decade. Interfacial engineering provides a powerful strategy to enhance efficiency and stability of OSCs. With the rapid advances of interface layer materials and active layer materials, power conversion efficiencies (PCEs) of both single-junction and tandem OSCs have exceeded a landmark value of 10%. This review summarizes the latest advances in interfacial layers for single-junction and tandem OSCs. Electron or hole transporting materials, including metal oxides, polymers/small-molecules, metals and metal salts/complexes, carbon-based materials, organic-inorganic hybrids/composites, and other emerging materials, are systemically presented as cathode and anode interface layers for high performance OSCs. Meanwhile, incorporating these electron-transporting and hole-transporting layer materials as building blocks, a variety of interconnecting layers for conventional or inverted tandem OSCs are comprehensively discussed, along with their functions to bridge the difference between adjacent subcells. By analyzing the structure-property relationships of various interfacial materials, the important design rules for such materials towards high efficiency and stable OSCs are highlighted. Finally, we present a brief summary as well as some perspectives to help researchers understand the current challenges and opportunities in this emerging area of research.

  10. 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.

  11. Coordinate patterns of estrogen receptor, progesterone receptor, and Wilms tumor 1 expression in the histopathologic distinction of ovarian from endometrial serous adenocarcinomas.

    PubMed

    Fadare, Oluwole; James, Samuel; Desouki, Mohamed M; Khabele, Dineo

    2013-10-01

    The purpose of this study is to assess whether composite or coordinate immunoexpression patterns of estrogen receptor (ER), progesterone receptor (PR), and Wilms tumor 1 (WT1) gene can significantly distinguish between endometrial serous carcinoma (ESC) and ovarian serous carcinoma (OSC). Immunohistochemical analyses were performed on whole tissue sections from 22 uterus-confined ESCs and on a tissue microarray of 140 high-grade, pan-stage OSCs, using antibodies to ER, PR, and WT-1. Estrogen receptor, PR, and WT1 expressions were present in 37%, 49%, and 81% of OSC, respectively, but these markers were also present in 18%, 27%, and 36% of ESC. The ER+/PR+/WT1+ coordinate profile was identified in 33.6% of OSC but in none of ESC (P = .0006), resulting in a calculated sensitivity and specificity of this profile for OSC of 33.6% and 100%, respectively. By contrast, the ER-/PR-/WT1- coordinate profile was identified in 41% of ESC but in only 6.4% of OSC (P = .0001), resulting in a calculated sensitivity and specificity of this profile for ESC of 50% and 94%. In summary, in the differential diagnosis between OSC and ESC, positivity for all 3 markers favors an extrauterine origin, whereas negativity for all 3 markers is supportive of an endometrial origin. The use of single markers for this purpose is not recommended, as each lacks optimal discriminatory power. Coordinate profiles, in general, have a high specificity but low sensitivity in this differential diagnosis.

  12. Interfacial Materials for Organic Solar Cells: Recent Advances and Perspectives

    PubMed Central

    Yin, Zhigang; Wei, Jiajun

    2016-01-01

    Organic solar cells (OSCs) have shown great promise as low‐cost photovoltaic devices for solar energy conversion over the past decade. Interfacial engineering provides a powerful strategy to enhance efficiency and stability of OSCs. With the rapid advances of interface layer materials and active layer materials, power conversion efficiencies (PCEs) of both single‐junction and tandem OSCs have exceeded a landmark value of 10%. This review summarizes the latest advances in interfacial layers for single‐junction and tandem OSCs. Electron or hole transporting materials, including metal oxides, polymers/small‐molecules, metals and metal salts/complexes, carbon‐based materials, organic‐inorganic hybrids/composites, and other emerging materials, are systemically presented as cathode and anode interface layers for high performance OSCs. Meanwhile, incorporating these electron‐transporting and hole‐transporting layer materials as building blocks, a variety of interconnecting layers for conventional or inverted tandem OSCs are comprehensively discussed, along with their functions to bridge the difference between adjacent subcells. By analyzing the structure–property relationships of various interfacial materials, the important design rules for such materials towards high efficiency and stable OSCs are highlighted. Finally, we present a brief summary as well as some perspectives to help researchers understand the current challenges and opportunities in this emerging area of research. PMID:27812480

  13. 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

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

    PubMed

    Urteaga, Elizabeth M; Attridge, Rebecca L; Tovar, John M; Witte, Amy P

    2015-10-25

    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.

  16. Bulk-Heterojunction Organic Solar Cells: Five Core Technologies for Their Commercialization.

    PubMed

    Kang, Hongkyu; Kim, Geunjin; Kim, Junghwan; Kwon, Sooncheol; Kim, Heejoo; Lee, Kwanghee

    2016-09-01

    The past two decades of vigorous interdisciplinary approaches has seen tremendous breakthroughs in both scientific and technological developments of bulk-heterojunction organic solar cells (OSCs) based on nanocomposites of π-conjugated organic semiconductors. Because of their unique functionalities, the OSC field is expected to enable innovative photovoltaic applications that can be difficult to achieve using traditional inorganic solar cells: OSCs are printable, portable, wearable, disposable, biocompatible, and attachable to curved surfaces. The ultimate objective of this field is to develop cost-effective, stable, and high-performance photovoltaic modules fabricated on large-area flexible plastic substrates via high-volume/throughput roll-to-roll printing processing and thus achieve the practical implementation of OSCs. Recently, intensive research efforts into the development of organic materials, processing techniques, interface engineering, and device architectures have led to a remarkable improvement in power conversion efficiencies, exceeding 11%, which has finally brought OSCs close to commercialization. Current research interests are expanding from academic to industrial viewpoints to improve device stability and compatibility with large-scale printing processes, which must be addressed to realize viable applications. Here, both academic and industrial issues are reviewed by highlighting historically monumental research results and recent state-of-the-art progress in OSCs. Moreover, perspectives on five core technologies that affect the realization of the practical use of OSCs are presented, including device efficiency, device stability, flexible and transparent electrodes, module designs, and printing techniques.

  17. Bioinformatics analysis of the oxidosqualene cyclase gene and the amino acid sequence in mangrove plants

    NASA Astrophysics Data System (ADS)

    Basyuni, M.; Wati, R.

    2017-01-01

    This study described the bioinformatics methods to analyze seven oxidosqualene cyclase (OSC) genes from mangrove plants on DDBJ/EMBL/GenBank as well as predicted the structure, composition, similarity, subcellular localization and phylogenetic. The physical and chemical properties of seven mangrove OSC showed variation among the genes. The percentage of the secondary structure of seven mangrove OSC genes followed the order of a helix > random coil > extended chain structure. The values of chloroplast or signal peptide were too low, indicated that no chloroplast transit peptide or signal peptide of secretion pathway in mangrove OSC genes. The target peptide value of mitochondria varied from 0.163 to 0.430, indicated it was possible to exist. These results suggested the importance of understanding the diversity and functional of properties of the different amino acids in mangrove OSC genes. To clarify the relationship among the mangrove OSC gene, a phylogenetic tree was constructed. The phylogenetic tree shows that there are three clusters, Kandelia KcMS join with Bruguiera BgLUS, Rhizophora RsM1 was close to Bruguiera BgbAS, and Rhizophora RcCAS join with Kandelia KcCAS. The present study, therefore, supported the previous results that plant OSC genes form distinct clusters in the tree.

  18. 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

  19. Determination of oversulfated chondroitin sulfate and dermatan sulfate impurities in heparin by capillary electrophoresis.

    PubMed

    Somsen, Govert W; Tak, Yvonne H; Toraño, Javier Sastre; Jongen, Peter M J M; de Jong, Gerhardus J

    2009-05-01

    Recently, oversulfated chondroitin sulfate (OSCS) present in certain lots of heparin was identified as the toxic contaminant responsible for severe side effects following intravenous heparin administration. The United States Pharmacopeia (USP) and European Pharmacopeia (Eur.Ph.) announced an immediate revision of their monographs for heparin sodium by adding two US Food and Drugs Administration-recommended tests for OSCS based on nuclear magnetic resonance and capillary electrophoresis (CE). However, the proposed CE method provides only partial separation of the OSCS contaminant from heparin, thereby hindering appropriate impurity profiling. Here we present an improved CE method that is especially useful for the reliable quantification of OSCS in heparin samples, but also allows determination of the common impurity dermatan sulfate (DS). Parameters such as type and concentration of background electrolyte, capillary temperature, sample concentration and injection volume were investigated and optimized. Enhancement of the OSCS-heparin separation was achieved by using high concentrations of Tris phosphate (pH 3.0) as background electrolyte. High currents and excessive Joule heating were prevented by employing fused-silica capillaries with an internal diameter of 25 microm. Good separations of OSCS, heparin and DS are obtained within 17 min. The method permits injection of relatively high heparin concentrations (up to 50 mg/ml) and large sample volumes (up to 5% of the capillary volume) allowing OSCS and DS determination in heparin down to the 0.05% and 0.5% (w/w) level, respectively. The CE method is shown to be repeatable and linear (R(2)>0.99) for OSCS, heparin and DS. CE analyses of OSCS-contaminated heparin samples and different heparin standards further demonstrate the utility of the method.

  20. The emerging multiple metal nanostructures for enhancing the light trapping of thin film organic photovoltaic cells.

    PubMed

    Choy, Wallace C H

    2014-10-18

    Recently, various metal nanostructures have been introduced into organic solar cells (OSCs) for performance enhancement. Here, we review the recent progress in OSCs incorporated with multiple metal nanostructures including various metal nanopatterns and metal nanomaterials. Multiple physical effects arise from these incorporated nanostructures, which require careful distinction. Changes induced by the metal nanostructures are examined in detail from the optical and electrical aspects. With the comprehensive understanding of the physical mechanisms for various metal nanostructures, further improvement in device performance and emerging applications can be expected for the new class of nanostructure-incorporated OSCs.

  1. 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.

  2. High performance n-type and ambipolar small organic semiconductors for organic thin film transistors.

    PubMed

    Zhou, Ke; Dong, Huanli; Zhang, Hao-li; Hu, Wenping

    2014-11-07

    Remarkable progress has recently been achieved in n-type and ambipolar OFETs. In this mini review, we will highlight the representative development of high performance n-type and ambipolar organic semiconductors (OSCs) especially for those n-type small OSCs with thin film mobilities >1 cm(2) V(-1) s(-1), and ambipolar small OSCs with both hole and electron mobilities of over 0.1 cm(2) V(-1) s(-1). This overview shall provide a meaningful guideline for further development of high performance n-type and ambipolar materials and devices.

  3. Mechanism of optical absorption enhancement in thin film organic solar cells with plasmonic metal nanoparticles.

    PubMed

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

    2011-11-21

    The optical absorption enhancement in thin film organic solar cells (OSCs) with plasmonic metal nanoparticles (NPs) has been studied by means of finite element method with a three-dimension model. It is found that significant plasmonic enhancement of above 100% can be obtained by introducing Ag-NPs at the interface between P3HT:PCBM active layer and PEDOT:PSS anode layer. This enhancement is even larger than that with Ag-NPs totally embedded in the P3HT:PCBM active layer of thin film OSCs. Furthermore, the enhancement mechanism of Ag-NPs at different positions of thin film OSCs is investigated.

  4. Highly Efficient Organic Solar Cells Consisting of Double Bulk Heterojunction Layers.

    PubMed

    Huang, Jiang; Wang, Hanyu; Yan, Kangrong; Zhang, Xiaohua; Chen, Hongzheng; Li, Chang-Zhi; Yu, Junsheng

    2017-03-15

    An organic solar cell (OSCs) containing double bulk heterojunction (BHJ) layers, namely, double-BHJ OSCs is constructed via stamp transferring of low bandgap BHJ atop of mediate bandgap active layers. Such devices allow a large gain in photocurrent to be obtained due to enhanced photoharvest, without suffering much from the fill factor drop usually seen in thick-layer-based devices. Overall, double-BHJ OSC with optimal ≈50 nm near-infrared PDPP3T:PC71 BM layer atop of ≈200 nm PTB7-Th:PC71 BM BHJ results in high power conversion efficiencies over 12%.

  5. Generation and Modulation of a Millimeter-Wave Subcarrier on an Optical Frequency Generated via Optical Injection (Postprint)

    DTIC Science & Technology

    2013-01-01

    the measured output power of the laser, is the damping rate, and osc is the oscillation frequency defined in (7) dPout ðtÞ ¼ dPout ð1Þ 1 et=2cosð...osctÞ 2 osc et=2sinðosctÞ (6) osc ¼fr ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi 1...A, Atom.,Mol., Opt. Phys., vol. 51, no. 5, pp. 4181–4185,May 1995. [25] T. B. Simpson, BMapping the nonlinear dynamics of a distributed feedback

  6. Solution-processed Ag-nanowire/ZnO-nanoparticle composite transparent electrode for flexible organic solar cells.

    PubMed

    Wei, Bin; Pan, Saihu; Wang, Taohong; Tian, Zhenghao; Chen, Guo; Xu, Tao

    2016-12-16

    This paper demonstrates a hybrid transparent electrode composed of a solution-processed silver-nanowire (AgNW) film coated by zinc oxide nanoparticles (ZnO-NPs) acting as a modified buffer layer. The effect of the ZnO-NPs' coating ratio on the performances of indium tin oxide (ITO)-free organic solar cells (OSCs) has been systematically investigated. The optimized ITO-free OSCs achieved a power conversion efficiency (PCE) of 2.85%, while flexible OSCs using the AgNW/ZnO-NP composite transparent electrode grown on a polyethylene terephthalate (PET) substrate showed a PCE of 2.2%.

  7. Solution-processed Ag-nanowire/ZnO-nanoparticle composite transparent electrode for flexible organic solar cells

    NASA Astrophysics Data System (ADS)

    Wei, Bin; Pan, Saihu; Wang, Taohong; Tian, Zhenghao; Chen, Guo; Xu, Tao

    2016-12-01

    This paper demonstrates a hybrid transparent electrode composed of a solution-processed silver-nanowire (AgNW) film coated by zinc oxide nanoparticles (ZnO-NPs) acting as a modified buffer layer. The effect of the ZnO-NPs’ coating ratio on the performances of indium tin oxide (ITO)-free organic solar cells (OSCs) has been systematically investigated. The optimized ITO-free OSCs achieved a power conversion efficiency (PCE) of 2.85%, while flexible OSCs using the AgNW/ZnO-NP composite transparent electrode grown on a polyethylene terephthalate (PET) substrate showed a PCE of 2.2%.

  8. 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.

  9. Pharmacotherapy follow-up of patients under treatment with biologic agents for chronic inflammatory systemic conditions: an agreement among hospital pharmacists for the standardized collection of a minimum set of data.

    PubMed

    Calleja Hernández, Miguel Ángel; Herrero Ambrosio, Alicia; Lamas Díaz, María Jesús; Martínez Cutillas, Julio; Poveda Andrés, Jose Luis; Aragón, Belén

    2017-01-01

    Fundamento y objetivo: El objetivo de este estudio fue consensuar un conjunto mínimo de datos cuya recopilación sistemática y estandarizada, mediante una herramienta electrónica en la farmacia hospitalaria, permitiera optimizar el seguimiento farmacoterapéutico de los pacientes tratados con agentes biológicos por enfermedades sistémicas inflamatorias crónicas. Material y método: Se constituyó un comité científico (n = 5 farmacéuticos hospitalarios). Se empleó la técnica Delphi, 2 rondas de consulta, por correo electrónico entre farmacéuticos hospitalarios. Se utilizó un cuestionario estructurado basado en una revisión bibliográfica y en recomendaciones del comité científico, valorándose 37 afirmaciones en una escala Likert de 5 puntos (1 = “En total desacuerdo”; 5 = “Totalmente de acuerdo”). Se alcanzó consenso cuando el 75% o más de los panelistas puntuaron 1-2 (consenso-rechazo) o 4-5 (consenso- acuerdo) la cuestión planteada. Se realizaron análisis estadísticos descriptivos. Resultados: Participaron 21 farmacéuticos hospitalarios (70 invitados, 70% respuesta). Se logró consenso en el 100% de las afirmaciones. Se acordó el conjunto mínimo de datos y de recomendaciones que el farmacéutico debe recoger y hacer en las visitas; documentar el estado de salud, la calidad de vida relacionada con la salud, los cambios en la adherencia al tratamiento y en la autonomía de los pacientes, así como las condiciones para hacer factible la recopilación sistemática del conjunto mínimo de datos. Conclusiones: Existe consenso entre los farmacéuticos hospitalarios en un conjunto mínimo de datos cuya recopilación, mediante una herramienta electrónica, ordenará, estandarizará y sistematizará el seguimiento farmacoterapéutico de los pacientes con enfermedades inflamatorias crónicas en tratamiento con agentes biológicos en el entorno sanitario público español.

  10. RISK AND PROTECTIVE FACTORS FOR GASTRIC METAPLASIA AND CANCER: A HOSPITAL-BASED CASE-CONTROL STUDY IN ECUADOR.

    PubMed

    Salvador, Iván; Mercado, Andrés; Bravo, Gabriela Liliana; Baldeón, Manuel; Fornasini, Marco

    2015-09-01

    Introducción: el cáncer de estómago ocupa la quinta posición entre los cánceres más frecuentes en el mundo, con 952.000 casos diagnosticados en el 2012. El Ecuador ocupa el 15º lugar entre los países con la incidencia más alta de cáncer gástrico en ambos sexos. Objetivo: el objetivo del presente estudio fue evaluar los factores de protección y de riesgo para cáncer/metaplasia gástrico. Métodos: se realizó un estudio hospitalario de casos y controles en la ciudad de Quito, Ecuador. Se definieron como casos a los pacientes con diagnóstico histológico confirmado de cáncer gástrico (N = 60) o con metaplasia gástrica incompleta (N = 53). Se definieron como controles a los pacientes sin cáncer gástrico o lesiones premalignas (N = 144). A todos los pacientes se les realizó una entrevista personalizada utilizando un cuestionario estructurado para recoger datos sobre hábitos dietéticos, estilo de vida e historia clínica. Resultados: los factores de riesgo asociados significativamente con el diagnóstico de cáncer gástrico/metaplasia fueron el consumo de alimentos recalentados al menos tres veces a la semana, (AOR: 4,57; CI: 2,2 – 9,5) y añadir sal a más del 50% de las comidas (AOR: 1,32; CI: 1,04 – 1,67). Los factores de protección asociados significativamente para no desarrollar cáncer/metaplasia gástrico fueron el uso de antiinflamatorios no esteroideos (AOR: 0,39; CI 0,19 – 0,83), edad menor a 58 años (AOR: 0,38; CI: 0,18 – 0,79) y haber recibido tratamiento para la infección por H. Pylori (AOR: 0,33; CI: 0,16 – 0,71). Conclusiones: este estudio reporta por primera vez los factores de riesgo y de protección asociados con el cáncer/ metaplasia gástrico en Ecuador.

  11. Teaching core competencies of reconstructive microsurgery with the use of standardized patients.

    PubMed

    Son, Ji; Zeidler, Kamakshi R; Echo, Anthony; Otake, Leo; Ahdoot, Michael; Lee, Gordon K

    2013-04-01

    The Accreditation Council of Graduate Medical Education has defined 6 core competencies that residents must master before completing their training. Objective structured clinical examinations (OSCEs) using standardized patients are effective educational tools to assess and teach core competencies. We developed an OSCE specific for microsurgical head and neck reconstruction. Fifteen plastic surgery residents participated in the OSCE simulating a typical new patient consultation, which involved a patient with oral cancer. Residents were scored in all 6 core competencies by the standardized patients and faculty experts. Analysis of participant performance showed that although residents performed well overall, many lacked proficiency in systems-based practice. Junior residents were also more likely to omit critical elements of the physical examination compared to senior residents. We have modified our educational curriculum to specifically address these deficiencies. Our study demonstrates that the OSCE is an effective assessment tool for teaching and assessing all core competencies in microsurgery.

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

    PubMed

    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

    2015-05-05

    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.

  13. Nonlinear Phase Distortion in a Ti:Sapphire Optical Amplifier for Optical Stochastic Cooling

    SciTech Connect

    Andorf, Matthew; Lebedev, Valeri; Piot, Philippe; Ruan, Jinhao

    2016-06-01

    Optical Stochastic Cooling (OSC) has been considered for future high-luminosity colliders as it offers much faster cooling time in comparison to the micro-wave stochastic cooling. The OSC technique relies on collecting and amplifying a broadband optical signal from a pickup undulator and feeding the amplified signal back to the beam. It creates a corrective kick in a kicker undulator. Owing to its superb gain qualities and broadband amplification features, Titanium:Sapphire medium has been considered as a gain medium for the optical amplifier (OA) needed in the OSC*. A limiting factor for any OA used in OSC is the possibility of nonlinear phase distortions. In this paper we experimentally measure phase distortions by inserting a single-pass OA into one leg of a Mach-Zehnder interferometer. The measurement results are used to estimate the reduction of the corrective kick a particle would receive due to these phase distortions in the kicker undulator.

  14. Analysis and optimization of surface plasmon-enhanced organic solar cells with a metallic crossed grating electrode.

    PubMed

    Lee, Eungkyu; Kim, Changsoon

    2012-09-10

    We perform a systematic analysis of enhanced short-circuit current density (J(sc) in organic solar cells (OSCs) where one metallic electrode is optically thick and the other consists of a two-dimensional metallic crossed grating. By examining a model device representative of such surface plasmon (SP)-enhanced OSCs by the Fourier modal and finite-element methods for electromagnetic and exciton diffusion calculations, respectively, we provide general guidelines to maximize J(sc) of the SP-enhanced OSCs. Based on this study, we optimize the performance of a small-molecule OSC employing a copper phthalocyanine-fullerene donor-acceptor pair, demonstrating that the optimized SP-enhanced device has J(sc) that is 75 % larger than that of the optimized device with an ITO-based conventional structure.

  15. 43 CFR 11.20 - Notification and detection.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... CERCLA requires prompt notification of Federal and State natural resource trustees of potential damages..., and planning under section 104 of CERCLA with such trustees. (2) The NCP provides for the OSC or...

  16. 40 CFR 300.140 - Multi-regional responses.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... shall be only one OSC and/or RPM at any time during the course of a response operation. Should a..., shall give prime consideration to the area vulnerable to the greatest threat, in determining...

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

    PubMed

    Cheng, Pei; Zhan, Xiaowei

    2016-05-03

    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.

  18. Optical and electrical study of organic solar cells with a 2D grating anode.

    PubMed

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

    2012-01-30

    We investigate both optical and electrical properties of organic solar cells (OSCs) incorporating 2D periodic metallic back grating as an anode. Using a unified finite-difference approach, the multiphysics modeling framework for plasmonic OSCs is established to seamlessly connect the photon absorption with carrier transport and collection by solving the Maxwell's equations and semiconductor equations (Poisson, continuity, and drift-diffusion equations). Due to the excited surface plasmon resonance, the significantly nonuniform and extremely high exciton generation rate near the metallic grating are strongly confirmed by our theoretical model. Remarkably, the nonuniform exciton generation indeed does not induce more recombination loss or smaller open-circuit voltage compared to 1D multilayer standard OSC device. The increased open-circuit voltage and reduced recombination loss by the plasmonic OSC are attributed to direct hole collections at the metallic grating anode with a short transport path. The work provides an important multiphysics understanding for plasmonic organic photovoltaics.

  19. Study of efficiency enhancement in layered geometry of excitonic-plasmonic solar cell

    NASA Astrophysics Data System (ADS)

    Pathak, Nilesh K.; Ji, Alok; Sharma, R. P.

    2014-06-01

    The nano-plasmonic effect on the organic solar cell (OSC) considering different materials, thickness, configurations and geometry has been considered. A theoretical modelling based on exciton-plasmon coupling using first principle approach was done to see the effect of incident photon to current collection efficiency of OSC in the direction to achieve efficient light trapping. For the present numerical model, uniform sized silver Nanoparticle were considered to be embedded in the active layer poly-(4'-(1", 4", 7"-trioaoctyl) phenyl) thiophanyl (PEOPT) of OSC. The coupling of local electromagnetic field due to metallic nano-plasmonic antenna resulted in the enhanced overall performance of the OSC. Optimized efficiency calculations suggested that there is nearly 1.6 % of enhancement in the efficiency (IPCE) due to plasmonic coupling to excitonic cell.

  20. 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.

  1. 43 CFR 11.20 - Notification and detection.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... CERCLA requires prompt notification of Federal and State natural resource trustees of potential damages..., and planning under section 104 of CERCLA with such trustees. (2) The NCP provides for the OSC or...

  2. National Response Team (NRT) Member Roles and Responsibilities

    EPA Pesticide Factsheets

    EPA personnel chair the NRT and cochair all Regional Response Teams (RRTs). They provide On-Scene Coordinators (OSCs), scientific support coordinators for inland spills, and Remedial Project Managers for hazardous waste remedial actions under Superfund.

  3. High-Performance Long-Term-Stable Dopant-Free Perovskite Solar Cells and Additive-Free Organic Solar Cells by Employing Newly Designed Multirole π-Conjugated Polymers.

    PubMed

    Kranthiraja, Kakaraparthi; Gunasekar, Kumarasamy; Kim, Hyunji; Cho, An-Na; Park, Nam-Gyu; Kim, Seonha; Kim, Bumjoon J; Nishikubo, Ryosuke; Saeki, Akinori; Song, Myungkwan; Jin, Sung-Ho

    2017-04-10

    Perovskite solar cells (PSCs) and organic solar cells (OSCs) are promising renewable light-harvesting technologies with high performance, but the utilization of hazardous dopants and high boiling additives is harmful to all forms of life and the environment. Herein, new multirole π-conjugated polymers (P1-P3) are developed via a rational design approach through theoretical hindsight, further successfully subjecting them into dopant-free PSCs as hole-transporting materials and additive-free OSCs as photoactive donors, respectively. Especially, P3-based PSCs and OSCs not only show high power conversion efficiencies of 17.28% and 8.26%, but also display an excellent ambient stability up to 30 d (for PSCs only), owing to their inherent superior optoelectronic properties in their pristine form. Overall, the rational approach promises to support the development of environmentally and economically sustainable PSCs and OSCs.

  4. 40 CFR 300.910 - Authorization of use.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 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. 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...

  6. 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

  7. 20 CFR 655.1316 - Job Service Complaint System; enforcement of work contracts.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... violations involving the same, may be referred to the U.S. Department of Justice, Civil Rights Division, Office of Special Counsel for Unfair Immigration Related Employment Practices (OSC), in addition to...

  8. 77 FR 67025 - Agency Information Collection Activities: Proposed Collection; Comments Requested: Office of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-08

    ... Immigration-Related Unfair Employment Practices (OSC), Civil Rights Division, United States Department of.... If additional information is required contact: Jerri Murray, Department Clearance Officer, United States Department of Justice, Justice Management Division, Policy and Planning Staff, Two...

  9. 78 FR 36223 - Extension and Redesignation of Syria for Temporary Protected Status

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-17

    ... emails are accepted in English and many other languages including Arabic. For questions about avoiding..., Spanish and many other languages including Arabic. Employees or applicants may also call the OSC...

  10. M Times Photon Subtraction-Addition Coherent Superposition Operated Odd-Schrődinger-cat State: Nonclassicality and Decoherence

    NASA Astrophysics Data System (ADS)

    Huang, Li; Guo, Qin; Jiang, Li-ying; Chen, Ge; Xu, Xue-xiang; Yuan, Wen

    2015-08-01

    We introduce a new non-Gaussian state (MCSO-OSCS), generated by m times coherent superposition operation acos θ + a †sin θ (MCSO) on odd-Schrődinger-cat state | α 0> - | - α 0>(OSCS), whose normalized constant is shown to be related to Hermite polynomials. We investigate the nonclassical properties of the MCSO-OSCS through Mandel's Q-parameter, quadrature squeezing, the photocount distribution and Wigner function (WF), which is turned out to be influenced by parameters m, θ and α 0. Especially the volume of negative region of WF could increase through controlling the parameters m, θ and α 0. We also investigate the decoherence of the MCSO-OSCS in terms of the fadeaway of the negativity of WF in a thermal environment.

  11. Developing a successful nursing Objective Structured Clinical Examination.

    PubMed

    McWilliam, Paula; Botwinski, Carol

    2010-01-01

    The evaluation of nursing students' clinical competencies is essential to the educational process. The Objective Structured Clinical Examination (OSCE) program was designed to assess students in a variety of health topics that may not be experienced during the assigned clinical rotation. Building on prior work, the purpose of this study was to examine specific aspects of the nursing OSCE toward developing a reliable and valid tool for evaluating selected students' clinical competencies.The following areas were investigated using an assessment design: the development of case scenarios and updates, the role and training of the standardized patient, and students' perceptions of the nursing OSCE experience. Recommendations are made for the variety of case scenarios, frequency of updates, methods by which standardized patients should be trained, remediation, and program requirements. Students were overwhelmingly favorable to perceived benefits of participation in OSCEs during their nursing education.

  12. 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

  13. Regulation of Injury-Induced Ovarian Regeneration by Activation of Oogonial Stem Cells.

    PubMed

    Erler, Piril; Sweeney, Alexandra; Monaghan, James R

    2017-01-01

    Some animals have the ability to generate large numbers of oocytes throughout life. This raises the question whether persistent adult germline stem cell populations drive continuous oogenesis and whether they are capable of mounting a regenerative response after injury. Here we demonstrate the presence of adult oogonial stem cells (OSCs) in the adult axolotl salamander ovary and show that ovarian injury induces OSC activation and functional regeneration of the ovaries to reproductive capability. Cells that have morphological similarities to germ cells were identified in the developing and adult ovaries via histological analysis. Genes involved in germ cell maintenance including Vasa, Oct4, Sox2, Nanog, Bmp15, Piwil1, Piwil2, Dazl, and Lhx8 were expressed in the presumptive OSCs. Colocalization of Vasa protein with H3 mitotic marker showed that both oogonial and spermatogonial adult stem cells were mitotically active. Providing evidence of stemness and viability of adult OSCs, enhanced green fluorescent protein (EGFP) adult OSCs grafted into white juvenile host gonads gave rise to EGFP OSCs, and oocytes. Last, the axolotl ovaries completely regenerated after partial ovariectomy injury. During regeneration, OSC activation resulted in rapid differentiation into new oocytes, which was demonstrated by Vasa(+) /BrdU(+) coexpression. Furthermore, follicle cell proliferation promoted follicle maturation during ovarian regeneration. Overall, these results show that adult oogenesis occurs via proliferation of endogenous OSCs in a tetrapod and mediates ovarian regeneration. This study lays the foundations to elucidate mechanisms of ovarian regeneration that will assist regenerative medicine in treating premature ovarian failure and reduced fertility. Stem Cells 2017;35:236-247.

  14. A tetraphenylethylene core-based 3D structure small molecular acceptor enabling efficient non-fullerene organic solar cells.

    PubMed

    Liu, Yuhang; Mu, Cheng; Jiang, Kui; Zhao, Jingbo; Li, Yunke; Zhang, Lu; Li, Zhengke; Lai, Joshua Yuk Lin; Hu, Huawei; Ma, Tingxuan; Hu, Rongrong; Yu, Demei; Huang, Xuhui; Tang, Ben Zhong; Yan, He

    2015-02-01

    A tetraphenylethylene core-based small molecular acceptor with a unique 3D molecular structure is developed. Bulk-heterojunction blend films with a small feature size (≈20 nm) are obtained, which lead to non-fullerene organic solar cells (OSCs) with 5.5% power conversion efficiency. The work provides a new molecular design approach to efficient non-fullerene OSCs based on 3D-structured small-molecule acceptors.

  15. Order effects in high stakes undergraduate examinations: an analysis of 5 years of administrative data in one UK medical school

    PubMed Central

    Barclay, Matt; Evans, Robert; Benson, John; Gurnell, Mark

    2016-01-01

    Objective To investigate the association between student performance in undergraduate objective structured clinical examinations (OSCEs) and the examination schedule to which they were assigned to undertake these examinations. Design Analysis of routinely collected data. Setting One UK medical school. Participants 2331 OSCEs of 3 different types (obstetrics OSCE, paediatrics OSCE and simulated clinical encounter examination OSCE) between 2009 and 2013. Students were not quarantined between examinations. Outcomes (1) Pass rates by day examination started, (2) pass rates by day station undertaken and (3) mean scores by day examination started. Results We found no evidence that pass rates differed according to the day on which the examination was started by a candidate in any of the examinations considered (p>0.1 for all). There was evidence (p=0.013) that students were more likely to pass individual stations on the second day of the paediatrics OSCE (OR 1.27, 95% CI 1.05 to 1.54). In the cases of the simulated clinical encounter examination and the obstetrics and gynaecology OSCEs, there was no (p=0.42) or very weak evidence (p=0.099), respectively, of any such variation in the probability of passing individual stations according to the day they were attempted. There was no evidence that mean scores varied by day apart from the paediatric OSCE, where slightly higher scores were achieved on the second day of the examination. Conclusions There is little evidence that different examination schedules have a consistent effect on pass rates or mean scores: students starting the examinations later were not consistently more or less likely to pass or score more highly than those starting earlier. The practice of quarantining students to prevent communication with (and subsequent unfair advantage for) subsequent examination cohorts is unlikely to be required. PMID:27729351

  16. PKCι regulates nuclear YAP1 localization and ovarian cancer tumorigenesis

    PubMed Central

    Wang, Yin; Justilien, Verline; Brennan, Katharyn I.; Jamieson, Lee; Murray, Nicole R.; Fields, Alan P.

    2016-01-01

    Atypical protein kinase Cι (PKCι) is an oncogene in lung and ovarian cancer. The PKCι gene PRKCI is targeted for frequent tumor-specific copy number gain (CNG) in both lung squamous cell carcinoma (LSCC) and ovarian serous carcinoma (OSC). We recently demonstrated that in LSCC cells PRKCI CNG functions to drive transformed growth and tumorigenicity by activating PKCι-dependent cell autonomous Hedgehog (Hh) signaling. Here, we assessed whether OSC cells harboring PRKCI CNG exhibit similar PKCι-dependent Hh signaling. Surprisingly, we find that whereas PKCι is required for the transformed growth for OSC cells harboring PRKCI CNG, these cells do not exhibit PKCι-dependent Hh signaling or Hh-dependent proliferation. Rather, transformed growth of OSC cells is regulated by PKCι-dependent nuclear localization of the oncogenic transcription factor, YAP1. Lentiviral shRNA-mediated knock down (KD) of PKCι leads to decreased nuclear YAP1 and increased YAP1 binding to angiomotin (AMOT), which sequesters YAP1 in the cytoplasm. Biochemical analysis reveals that PKCι directly phosphorylates AMOT at a unique site, Thr750, whose phosphorylation inhibits YAP1 binding. Pharmacologic inhibition of PKCι decreases YAP1 nuclear localization and blocks OSC tumor growth in vitro and in vivo. Immunohistochemical analysis reveals a strong positive correlation between tumor PKCι expression and nuclear YAP1 in primary OSC tumor samples, indicating the clinical relevance of PKCι-YAP1 signaling. Our results uncover a novel PKCι-AMOT-YAP1 signaling axis that promotes OSC tumor growth, and provide a rationale for therapeutic targeting of this pathway for treatment of OSC. PMID:27321186

  17. Central Asia: Regional Developments and Implications for U.S. Interests

    DTIC Science & Technology

    2008-07-10

    headquarters for the main pro-government party, Nur- Otan (Fatherland’s Ray of Light), on July 2, Nazarbayev appeared to endorse a predominant role for...Nur- Otan CRS-17 40 OSCE. Office for Democratic Institutions and Human Rights. Republic of Kazakhstan Parliamentary Elections, 18 August 2007: OSCE...which is an opposition party. Local legislative elections also took place, but these involved voting for individuals rather than party lists. Nur- Otan

  18. Past, present, and future of optical design at the College of Optical Sciences

    NASA Astrophysics Data System (ADS)

    Sasián, José

    2014-09-01

    The College of Optical Sciences, OSC, has seen three periods of optical design teaching and development. The first years 1964-1969; the golden years 1970-1999; and the new millennia years. Today the college offers a comprehensive and professional curriculum in optical design learning, and enjoys a strong heritage in optical design. This paper provides a perspective into the history and future prospects in optical design at the OSC.

  19. 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.

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

    DOE PAGES

    Nie, Wanyi; Gupta, Gautam; Crone, Brian K.; ...

    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.

  1. Factors Affecting Coast Guard SAR Unit Visual Detection Performance.

    DTIC Science & Technology

    1981-08-01

    and outer search legs were one-half the track spacing (S) inside the perimeter of the search area. cuP r MINOR AXIS SKETCH 1. PARALLEL SEARCH PATTERN...SRU. Wind speed and direction were recorded using a hand-held anemometer onboard the OSC vessel and an installed anemometer or an estimate onboard the...Surface wind measurements or estimates were made at various heights between the anemometer located at 90 feet and the sea surface (OSC at 10 feet

  2. Ternary Organic Solar Cells Based on Two Compatible Nonfullerene Acceptors with Power Conversion Efficiency >10.

    PubMed

    Liu, Tao; Guo, Yuan; Yi, Yuanping; Huo, Lijun; Xue, Xiaonan; Sun, Xiaobo; Fu, Huiting; Xiong, Wentao; Meng, Dong; Wang, Zhaohui; Liu, Feng; Russell, Thomas P; Sun, Yanming

    2016-12-01

    Two different nonfullerene acceptors and one copolymer are used to fabricate ternary organic solar cells (OSCs). The two acceptors show unique interactions that reduce crystallinity and form a homogeneous mixed phase in the blend film, leading to a high efficiency of ≈10.3%, the highest performance reported for nonfullerene ternary blends. This work provides a new approach to fabricate high-performance OSCs.

  3. 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.

  4. Microeconomics, Private Security, and the Significance to Operational Planning

    DTIC Science & Technology

    2013-05-23

    like to thank Major Ryan Bulger who provided significant peer feedback on the organization and flow of what unfolds in the following pages. I...Philippines OIF Operation Iraqi Freedom OSC -I Office of Security Cooperation-Iraq PACOM Pacific Command PMC Private Military Contractor PMF Private...unknown but a model established in Iraq under the Office of Security 8 Cooperation-Iraq ( OSC -I) provides a framework to maintain strategic

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

    PubMed

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

    2015-01-07

    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.

  6. 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.

  7. Albania’s Counter-Terrorism Policy Options: Finding a Strategy of Common Sense

    DTIC Science & Technology

    2004-06-01

    Hoxha, Banner of Struggle for Freedom and Socialism (Tirana, N.p., 1985), 107. 15 Aleks Luarasi, Historia e Institucioneve Juridike Shqiptare...minority villages and neighborhoods. The rampage left nineteen dead; nearly 900 injured; 700 Serb, Ashkali and Roma homes, up to 10 public buildings, 30...OSCE, February 2004. http://www.osce.org/documents/pia/2004/02/2117_en.pdf (accessed 20 March 2004). Luarasi, Aleks. Historia e Institucioneve

  8. Toward Highly Efficient Large-Area ITO-Free Organic Solar Cells with a Conductance-Gradient Transparent Electrode.

    PubMed

    Zuo, Lijian; Zhang, Shuhua; Li, Hanying; Chen, Hongzheng

    2015-11-18

    Highly efficient large-area organic solar cells (OSCs) with power conversion efficiency up to 7.09%, and device area of 4 cm(2) are demonstrated on flexible substrates. A conductance- or thickness-gradient ultra-thin Ag-based transparent electrode is developed to better balance the light trapping and energy loss, owing to the inhomogeneous energy-loss density on the large OSC sheet.

  9. Introduction to Orbital Sciences Corporation

    NASA Technical Reports Server (NTRS)

    1991-01-01

    A general overview of the Orbital Sciences Corporation (OSC) is presented. The following topics are covered: (1) manpower, facilities, and financial growth; (2) organization and management team; (3) the Space Data Division organization; (4) the Chandler facility; (5) Space Data-Products and Services; (6) space transportation systems; (7) spacecraft and space support systems; (8) turn-key suborbital launch services and support systems; and (9) OSC suborbital booster performance.

  10. Nonfullerene Tandem Organic Solar Cells with High Open-Circuit Voltage of 1.97 V.

    PubMed

    Liu, Wenqing; Li, Shuixing; Huang, Jiang; Yang, Shida; Chen, Jiehuan; Zuo, Lijian; Shi, Minmin; Zhan, Xiaowei; Li, Chang-Zhi; Chen, Hongzheng

    2016-11-01

    Small-molecule nonfullerene-based tandem organic solar cells (OSCs) are fabricated for the first time by utilizing P3HT:SF(DPPB)4 and PTB7-Th:IEIC bulk heterojunctions as the front and back subcells, respectively. A power conversion efficiency of 8.48% is achieved with an ultrahigh open-circuit voltage of 1.97 V, which is the highest voltage value reported to date among efficient tandem OSCs.

  11. 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.

  12. Chemopreventive functions and molecular mechanisms of garlic organosulfur compounds.

    PubMed

    Trio, Phoebe Zapanta; You, Sixiang; He, Xi; He, Jianhua; Sakao, Kozue; Hou, De-Xing

    2014-05-01

    Garlic (Allium sativum L.) has long been used both for culinary and medicinal purposes by many cultures. Population and preclinical investigations have suggested that dietary garlic intake has health benefits, such as lowering the risk of esophageal, stomach and prostate cancers. Extensive studies from laboratory and animal models have revealed that garlic has a wide range of biological activities, and garlic organosulfur compounds (OSCs) are responsible for the biological activities. However, the presence and potency of garlic OSCs vary with respect to the mode of garlic preparation and extraction. Cooked or processed garlic products showed different kinds of garlic OSCs, some of which are highly unstable and instantly decomposed. These facts, possibly gave paradoxical results on the garlic effects. In this review, we first summarized the biotransformation processes of garlic alliin into different garlic OSCs as well as the garlic OSCs compositions from different garlic preparations. Next, we reviewed the chemopreventive functions and molecular mechanisms focusing on the anti-inflammation, antioxidation, anti-diabetes and anticancer activity behind different garlic OSCs.

  13. Organic solar cells using CVD-grown graphene electrodes

    NASA Astrophysics Data System (ADS)

    Kim, Hobeom; Bae, Sang-Hoon; Han, Tae-Hee; Lim, Kyung-Geun; Ahn, Jong-Hyun; Lee, Tae-Woo

    2014-01-01

    We report on the development of flexible organic solar cells (OSCs) incorporating graphene sheets synthesized by chemical vapor deposition (CVD) as transparent conducting electrodes on polyethylene terephthalate (PET) substrates. A key barrier that must be overcome for the successful fabrication of OSCs with graphene electrodes is the poor-film properties of water-based poly(3,4-ethylenedioxythiphene):poly(styrenesulfonate) (PEDOT:PSS) when coated onto hydrophobic graphene surfaces. To form a uniform PEDOT:PSS film on a graphene surface, we added perfluorinated ionomers (PFI) to pristine PEDOT:PSS to create ‘GraHEL’, which we then successfully spin coated onto the graphene surface. We systematically investigated the effect of number of layers in layer-by-layer stacked graphene anode of an OSC on the performance parameters including the open-circuit voltage (Voc), short-circuit current (Jsc), and fill factor (FF). As the number of graphene layers increased, the FF tended to increase owing to lower sheet resistance, while Jsc tended to decrease owing to the lower light absorption. In light of this trade-off between sheet resistance and transmittance, we determined that three-layer graphene (3LG) represents the best configuration for obtaining the optimal power conversion efficiency (PCE) in OSC anodes, even at suboptimal sheet resistances. We finally developed efficient, flexible OSCs with a PCE of 4.33%, which is the highest efficiency attained so far by an OSC with CVD-grown graphene electrodes to the best of our knowledge.

  14. Mixing plasmonic Au nanoparticles into all polymer layers for improving the efficiency of organic solar cells

    NASA Astrophysics Data System (ADS)

    Choy, Wallace C. H.; Wang, Charlie C. D.; Fung, Dixon D. S.; Sha, Wei E. I.; Xie, Feng-Xian

    2012-09-01

    To enhance the light trapping of organic solar cells (OSCs), metallic (e.g. Au, Ag) nanoparticles (NPs) have been incorporated into the polymer layers conveniently in solution process. Although power conversion efficiency (PCE) of OSCs has been shown to improve by incorporating metallic NPs in either the buffer layer such as poly-(3,4-ethylenedioxythiophene) :poly(styrenesulfonate) (PEDOT:PSS)[1] or the active layer[2], the understanding on the changes is still not quite clear. Moreover, there are very limited studies on incorporating metallic NPs in more than one organic layer and investigating their effects on the optical and electrical properties as well as the performances of OSCs. In this work, monofunctional poly(ethylene glycol) (PEG)-capped Au NPs of sizes 18 nm and 35 nm are doped in the PEDOT:PSS and poly(3-hexylthiophene) (P3HT): phenyl-C61-butyric acid methyl ester (PCBM) layers respectively, leading to an improvement of PCE by ~22% compared to the optimized control device. We will firstly identify the impact of NPs in each polymer layer on OSC characteristics by doping Au NPs in either the PEDOT:PSS or P3HT:PCBM layer. Then, we will investigate Au NPs incorporated in all polymer layers. We demonstrate that the accumulated benefits of incorporating Au NPs in all organic layers of OSCs can achieve larger improvements in OSC performances.

  15. 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.

  16. 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

  17. 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.

  18. The Oxidosqualene Cyclase from the Oomycete Saprolegnia parasitica Synthesizes Lanosterol as a Single Product

    PubMed Central

    Dahlin, Paul; Srivastava, Vaibhav; Bulone, Vincent; McKee, Lauren S.

    2016-01-01

    The first committed step of sterol biosynthesis is the cyclisation of 2,3-oxidosqualene to form either lanosterol (LA) or cycloartenol (CA). This is catalyzed by an oxidosqualene cyclase (OSC). LA and CA are subsequently converted into various sterols by a series of enzyme reactions. The specificity of the OSC therefore determines the final composition of the end sterols of an organism. Despite the functional importance of OSCs, the determinants of their specificity are not well understood. In sterol-synthesizing oomycetes, recent bioinformatics, and metabolite analysis suggest that LA is produced. However, this catalytic activity has never been experimentally demonstrated. Here, we show that the OSC of the oomycete Saprolegnia parasitica, a severe pathogen of salmonid fish, has an uncommon sequence in a conserved motif important for specificity. We present phylogenetic analysis revealing that this sequence is common to sterol-synthesizing oomycetes, as well as some plants, and hypothesize as to the evolutionary origin of some microbial sequences. We also demonstrate for the first time that a recombinant form of the OSC from S. parasitica produces LA exclusively. Our data pave the way for a detailed structural characterization of the protein and the possible development of specific inhibitors of oomycete OSCs for disease control in aquaculture. PMID:27881978

  19. 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

  20. [Food-related lifestyles and eating habits inside and outside the home in the Metropolitan Region of Santiago, Chile].

    PubMed

    Schnettler, Berta; Peña, Juan Pablo; Mora, Marcos; Miranda, Horacio; Sepúlveda, José; Denegri, Marianela; Lobos, Germán

    2013-01-01

    Objetivo: Distinguir tipologías de consumidores en base a su estilo de vida en relación a la alimentación en las principales comunas de la Región Metropolitana de Santiago, Chile, y caracterizarlas según sus hábitos de consumo de alimentos dentro y fuera del hogar, características sociodemográficas y su nivel de satisfacción con su alimentación. Material y método: Se aplicó un cuestionario estructurado a una muestra de 951 personas en las principales comunas de la Región Metropolitana de Santiago (más de 100.000 habitantes). El instrumento de recogida de información incluyó una adaptación del cuestionario de estilos de vida en relación a la alimentación (FRL) y la escala SWFL (Satisfaction with Food-related Life). Se consultaron los hábitos de consumo de alimentos dentro y fuera del hogar y variables de clasificación sociodemográfica de los encuestados. Resultados: Mediante análisis cluster se distinguieron cinco tipologías con diferencias significativas en los cinco componentes obtenidos del FRL, con análisis factorial de componentes principales. Las tipologías presentaron distinto perfil de género, edad y nivel socioeconómico y difirieron en los puntajes obtenidos en la SWFL. Se diferenciaron en la frecuencia en que la persona almuerza, toma once y cena en su hogar. Respecto a las comidas fuera del hogar, las tipologías se distinguieron según la frecuencia de comidas en restaurantes, locales de comida rápida y en la compra de comida preparada. Conclusiones: Un estilo de vida en relación a la alimentación con baja implicación y disfrute de los alimentos se asocia con un mayor nivel socioeconómico y menor edad de las personas. Adicionalmente, se asocia con comportamientos alimentarios poco saludables y no beneficiosos para las personas, como una mayor frecuencia de comidas en restaurantes y de compra de comida preparada, junto a una menor frecuencia de comidas en el hogar, lo que estaría influyendo en un nivel inferior de

  1. Metabolic syndrome and associated factors in children and adolescents of a Brazilian municipality.

    PubMed

    Dias Pitangueira, Jacqueline Costa; Rodrigues Silva, Luciana; Portela de Santana, Mônica Leila; Monteiro da Silva, Maria da Conceição; de Farias Costa, Priscila Ribas; D'Almeida, Vânia; de Oliveira Assis, Ana Marlúcia

    2014-04-01

    Introducción: Los factores asociados al Síndrome metabólico (SM) han sido ampliamente estudiados en adultos, pero aún son poco explorado en niños y adolescentes Objetivo: Identificar la superioridad de SM y los factores asociados en niños y adolescentes. Métodos: Se trata de estudio transversal, con 540 niños de 7 a 14 años de edad. Los datos socioeconómicos, demográficos, estilo de vida e historia familiar de enfermedades crónicas fueron informados por la persona y/o responsable y registrados en cuestionario estructurado. Fueron realizadas dosificaciones bioquímicas (glicemia en ayuno, triglicérides, lipoproteína de alta densidad reducida, lipoproteína de muy baja densidad, homocisteina y cisteina), evaluación antropométrica y verificación de la presión arterial. La SM fue definida de acuerdo con los criterios del The National Cholesterol Education Program Adult Treatment Panel III adaptado por Ferranti. Se utilizó regresión de Poisson como técnica estadística para identificar los factores asociados a la SM. Resultados: La superioridad de la SM fue del 12,8%, siendo a lipoproteína de alta densidad reducida (58,2%) el componente más frecuente, seguido por la hipertrigliceridemia (41,8%), presión arterial aumentada (29,1%), circunferencia de la cintura aumentada (26,7%) e hiperglicemia (7,2%). Fue observada asociación entre SM y exceso de peso (RP: 2,2 [1,22-3,95]), escolaridad paterna (RP: 2,19 [1,10-4,37]), concentración sérica de la lipoproteína de muy baja densidad (RP: 1,08 [1,04-1,11]) y concentraciones séricas simultáneamente aumentadas de homocisteina y cisteina (RP: 2,58 [1,32-5,04]). Conclusiones: La superioridad de SM es elevada en niños y adolescentes y se encuentra aumentada en paciente con exceso de peso, mayor escolaridad paterna, concentraciones séricas aumentadas de la lipoproteína de muy baja densidad, y elevación simultánea de los niveles séricos de homocisteína y cisteína.

  2. Restriction of dairy products; a reality in inflammatory bowel disease patients.

    PubMed

    Brasil Lopes, Mirella; Rocha, Raquel; Castro Lyra, André; Rosa Oliveira, Vanessa; Gomes Coqueiro, Fernanda; Silveira Almeida, Naiade; Santos Valois, Sandra; Oliveira Santana, Genoile

    2014-03-01

    Introducción: Se considera que la deficiencia de calcio es un factor de riesgo para el desarrollo de osteoporosis en pacientes con enfermedad inflamatoria intestinal (EII). En estos pacientes se han notificado diversas restricciones dietéticas. Objetivo: Evaluar la ingesta de productos lácteos y calcio de la dieta en pacientes con EII. Métodos: En este estudio cruzado se reclutaron 65 pacientes ambulatorios con EII procedentes de un centro de referencia para EII. Se administraron un cuestionario semi-estructurado (que recogía datos demográficos, socio- económicos y clínicos) y un cuestionario de frecuencia de consumo de alimento. Con respecto a los datos clínicos, evaluamos el estado nutricional antropométrico, la clasificación de la enfermedad, el índice de actividad de la enfermedad y la presencia de síntomas gastrointestinales. Se evaluaron las modificaciones auto-notificadas en el uso de los productos lácteos. Resultados: Las edades de los pacientes con EII variaban entre los 20 y 75 años y el 67,0% fueron diagnosticados de colitis ulcerosa. La mayoría (64,7 %) notificaban una restricción de los productos lácteos. La frecuencia de síntomas gastrointestinales fue mayor en los pacientes con enfermedad de Crohn que restringían los productos lácteos que en aquellos que no lo hacían (100% frente a 42,9%; p = 0,013); este resultado no se observó en los pacientes con colitis ulcerosa CU. La actividad de la enfermedad también fue más frecuente en los pacientes con EII que restringían los productos lácteos que en aquellos sin restricción (23,8% frente a 4,5%; p = 0,031) y, en los pacientes con CU, la enfermedad extensa fue más habitual en pacientes que restringían los productos lácteos que en aquellos que no lo hacían (42,9 % frente a 20,0%; p = 0,03). Conclusión: La restricción de productos lácteos es habitual en pacientes con EII, posiblemente debido a la actividad de la enfermedad, la presencia de síntomas gastrointestinales y la

  3. [Eating habits and subjective well-being among university students in southern Chile].

    PubMed

    Schnettler, Berta; Denegri, Marianela; Miranda, Horacio; Sepúlveda, José; Orellana, Ligia; Paiva, Galo; Grunert, Klaus G

    2013-11-01

    Objetivo: Distinguir tipologías de estudiantes universitarios en el sur de Chile, en base a su nivel de satisfacción con la vida y la alimentación, y caracterizarlas según sus hábitos alimentarios dentro y fuera del lugar de residencia, aspectos asociados a la salud y características demográficas. Material y método: Se aplicó un cuestionario estructurado a una muestra no probabilística de 347 estudiantes de la Universidad de La Frontera, Temuco-Chile. El instrumento de recogida de información incluyó las escalas SWLS (Satisfaction with Life Scale), SWFL (Satisfaction with Food-related Life) y el ICVRS (Índice de calidad de vida relativo a la salud). Se consultaron los hábitos de consumo de alimentos dentro y fuera del lugar de residencia, el peso y estatura aproximada y, variables de clasificación demográfica. Resultados: Mediante análisis clúster se distinguieron tres tipologías de estudiantes con diferencias significativas en los puntajes de la SWLS y SWFL. Las tipologías difirieron en el número de días afectados por problemas de salud emocional, clasificación de su estado nutricional (IMC), auto percepción de su estado de salud, importancia de la alimentación para el bienestar personal, lugar de residencia durante el periodo de estudios, frecuencia de alimentación en el lugar donde vive y frecuencia de comidas a deshora. Conclusiones: La posibilidad de vivir con los padres durante el periodo de estudios universitarios se asocia con mejores hábitos de alimentación, mejor salud emocional y auto percepción de la salud, menor prevalencia de sobre peso y obesidad y, con una mayor satisfacción con la vida y la alimentación.

  4. NUTRITIONAL STATUS AND PERIOPERATIVE FASTING TIME VERSUS COMPLICATIONS AND HOSPITAL STAY OF SURGICAL PATIENTS.

    PubMed

    de Amorim, Ana Carolina Ribeiro; Costa, Milena Damasceno de Souza; Nunes, Francisca Leide da Silva; da Silva, Maria da Guia Bezerra; de Souza Leão, Cristiano; Gadelha, Patrícia Calado Ferreira Pinheiro

    2015-08-01

    Introducción: muchos factores pueden influir negativamente en los resultados quirúrgicos, tales como el estado nutricional deteriorado y la extensión del tiempo de ayuno perioperatorio. Objetivo: evaluar la influencia del estado nutricional y el tiempo de ayuno perioperatorio en la aparición de complicaciones quirúrgicas y la duración de la estancia hospitalaria en pacientes sometidos a cirugía del tracto gastrointestinal y/o la pared abdominal, que fueron sometidos a protocolo de atención nutricional. Métodos: estudio de cohorte, realizado con 84 pacientes, de junio a noviembre de 2014. La recolección de datos se realizó mediante la aplicación de un cuestionario estructurado, búsqueda en los registros y prescripción médica y/o nutricional. Para el análisis estadístico se utilizó el programa STATA/SE 12.0 y se adoptó el nivel de significación del 5%. Resultados: el riesgo nutricional estuvo presente en el 26,2% de los casos, y de estos el 45,4% realizaron terapia nutricional preoperatoria, con una media de 6,6 ± 2,79 días. El ayuno preoperatorio fue de 4,5 (3,66; 5,50) horas y el ayuno postoperatorio fue de 5,1 (2,5; 20,5) horas. No se encontraron asociaciones entre los parámetros para evaluar la composición corporal y la presencia de complicaciones. Se observó una correlación negativa entre la duración de la estancia y el IMC (p = 0,017), y una correlación positiva entre la pérdida de peso y el tiempo de estancia hospitalaria (p = 0,036). Los pacientes con mayor tiempo de ayuno postoperatorio tuvieron una mayor incidencia de complicaciones (p = 0,021). Conclusión: el mal estado nutricional y la extensión del tiempo de ayuno perioperatorio están asociados a la aparición de complicaciones quirúrgicas y a una mayor duración de la estancia hospitalaria.

  5. [Comparison of glycemic control in diabetic patients with and without metabolic syndrome].

    PubMed

    Cruz del Castillo, A H; Córdova Fernández, J A; Ramos Lagunes, I; Camara, Jorge; Ortiz Solana, X E; Vigil Pérez, C A; García Ramos, G

    2013-01-01

    Objetivo: Comparar el nivel glucémico en pacientes con diabetes tipo 2 (DM2) con y sin síndrome metabólico (SM). Metodología: Estudio transversal analítico. Se incluyeron aleatoriamente pacientes con DM2 corroborado en su expediente clínico. El SM se identificó en pacientes con al menos 3 de 5 criterios del ATP III (AdultTreatment Panel III). Se aplicó un cuestionario estructurado. Se determinó hemoglobina glucosilada (HbA1c), colesterol-HDL, triglicéridos, hipertensión arterial sistémica (HAS), índice de masa corporal (IMC), circunferencia de cintura (CCi) y cadera (CCa). Plan de análisis: prevalencia, prueba t de Student, correlación de Pearson y regresión logística. Resultados: Se incluyeron 283 pacientes. Edad promedio: 59.8±10.6 años. Predominó el sexo femenino (73.6%)Criterios cubiertos para SM: hipocolesterolemia-HDL: 62.9%; hipertrigliceridemia: 56.3%; obesidad abdominal (OA) 90.1%; hipertensión arterial sistémica (HAS): 62.5%. La prevalencia de SM fue 86.6% (IC95% 83% a 89%). No hubo diferencia significativa en el promedio de HbA1c en pacientes con y sin SM, HAS, OA, e hipocolesterolemia-HDL. En cambio, sujetos con hipertrigliceridemia tuvieron un promedio significativamente mayor de HbA1c que aquellos sin hipertrigliceridemia (8.9±2.3 vs 8.5±2.1, respectivamente; p=0.01). HbA1c correlacionó positivamente con trigliceridemia (r=0.24, p=0.001), y negativamente con el peso (r= -0.19, p=0.001), IMC (r= -0.172, p=0.004), CCi (r= -0.12, p=0.004) y CCa (r=-0.14, p=0.02). En el análisis multivariado ajustado, solamente la duración de la diabetes se asoció con el nivel glucémico (OR= 1.014, IC95% 1.010 a 1.016). Conclusiones: No encontramos diferencias significativas en el nivel glucémico en pacientes con y sin SM.

  6. [Implementation of respiratory rehabilitation in the municipalities of Valparaíso, Viña del Mar, Quilpué and Villa Alemana in 2013].

    PubMed

    Manriquez Villarroel, Pablo; Colines Rodríguez, Yasna; Poblete Vega, Felipe; Otárola Bravo, Jaime; Paredes Barrera, Cristhian; Acuña Cabrera, Ana María

    2014-10-03

    Introducción: La rehabilitación respiratoria es un pilar fundamental en el tratamiento del paciente con Enfermedad Pulmonar Obstructiva Crónica. Reduce importantemente los costos para el sistema de salud, el uso de recursos sanitarios, disminuyendo la estadía hospitalaria y las consultas a servicios de urgencia. Objetivo: Describir la condición actual de la rehabilitación respiratoria en los centros de atención primaria ubicados en la región de Valparaíso. Método: Se aplicó una encuesta cerrada a cada profesional a cargo del área respiratoria en los centros de atención primaria de salud. La muestra estuvo conformada por 32 centros de salud correspondientes a las comunas de Valparaíso, Viña del Mar, Quilpué y Villa Alemana. Resultados: 9 centros (28%) del total de la muestra realizan rehabilitación respiratoria y el mismo número tiene un programa de rehabilitación estructurado. En 15 (47%) de los centros existe un Nutricionista dentro del equipo de salud. En el 100% de los centros se evalúa a los pacientes mediante espirometría y escalas de disnea. La mayoría de los centros (89%) realiza entrenamiento de extremidades superiores e inferiores. Dentro de los factores que limitan la realización de la rehabilitación respiratoria, 20 (63%) centros refieren que el horario de atención es uno de los factores más limitantes, mientras que 23 (72%) centros refieren que no cuentan con espacio físico adecuado y 22 (69%) centros relatan no contar con los implementos mínimos necesarios. Discusión: Los datos obtenidos indican que en la mayoría de los centros encuestados no se realiza rehabilitación respiratoria como parte del tratamiento del paciente con Enfermedad Pulmonar Obstructiva Crónica, principalmente por problemas de recursos humanos, materiales e infraestructura.

  7. 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

  8. The impact of a hybrid online and classroom-based course on palliative care competencies of family medicine residents.

    PubMed

    Pereira, J; Palacios, M; Collin, T; Wedel, R; Galloway, L; Murray, A; Violato, C; Lockyer, J

    2008-12-01

    The University of Calgary offers a palliative care course that involves both classroom- and web-based learning for rural-based family medicine residents. This study assessed the impact of the course on palliative care-related competencies for two classes: 2004 and 2005. Instruments were developed to evaluate pre- versus post-course changes in knowledge (15-item quiz), attitudes (12-item survey), self-perceived comfort levels (19-item survey) and skills (3 long Objective Structured Clinical Examination stations (OSCEs), with accompanying standardised score sheets). In all, 16 and 20 residents participated in the 2004 and 2005 classes, respectively. Internal reliability values were acceptable to very good (Knowledge Quiz, Kuder-Richardson 20 = 0.5; Attitude Scale, alpha = 0.68-0.78; OSCE score sheets, alpha = 0.63-0.89; Self-Perceived Comfort Survey, alpha = 0.89-0.92). Inter-rater reliability values of the OSCE score sheets were alpha = 0.87 to 0.92. There was a significant improvement in the pre- versus post-course performances in OSCE 2 for 2004 and 2005 (P = 0.01; P = 0.01; d = 1.42 and 1.94, respectively). Despite statistically insignificant changes in the other OSCEs, acceptable to large effect sizes were noted (d = 0.4-1.34) for OSCE 1 in 2004 and OSCEs 3 in 2004 and 2005. Knowledge improved significantly pre-versus post-course in 2004 and 2005 (t = 4.44 and 8.99; d = 2.29 and 2.24, respectively). Significant improvements and large effect sizes were noted in the comfort scales, but a ceiling effect was noted in the communication subscale. This hybrid course resulted in significant improvements across four domains, knowledge, attitudes, self-perceived comfort scale, and skills, in 2 consecutive classes.

  9. Factors associated with medical student test anxiety in objective structured clinical examinations: a preliminary study

    PubMed Central

    2016-01-01

    Objectives To investigate attributes of medical students associated with their test anxiety on Objective Structured Clinical Examinations (OSCEs). Methods A cross-sectional study using a self-administered questionnaire was conducted of all Year 3 and 4 students at a private medical school in South Korea in 2014. This 53-item questionnaire consisted of factors pertaining to test anxiety on the OSCE identified from a review of relevant literature, which included students’ motivational beliefs and achievement emotions, perceived values of the OSCE, and attitude and orientation towards patients. Participants’ test anxiety levels were measured using the Korean Achievement Emotions Questionnaire. Participants rated their responses using a five-point Likert-type scale. Univariate analysis was performed to examine relationships between the variables. Results A total of 94 students completed the questionnaire (a 93% response rate). No differences in the participants’ test anxiety scores were observed across genders, entry-levels, or years in medical school. Participants’ test anxiety on the OSCE showed moderate association with their class-related achievement emotions (i.e., anxiety and boredom), where r = 0.46 and 0.32, p < 0.01, respectively, and weak negative associations with their patient-centeredness (r = -0.21, p < 0.05) and with their perceived values of the OSCE (r = -0.21, p < 0.05). Conclusions This study found some non-cognitive factors related to medical students’ test anxiety on the OSCE. These findings have implications for developing effective educational interventions for helping students cope with such a stress by enhancing our understanding of the various factors that influence their test anxiety in OSCEs. PMID:28035056

  10. 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.

  11. Middle-aged rats orally supplemented with gel-encapsulated catechin favorably increases blood cytosolic NADPH levels.

    PubMed

    Cueno, Marni E; Tamura, Muneaki; Ochiai, Kuniyasu

    2015-04-15

    Green tea catechins are primarily known to function as free radical scavengers and have several beneficial uses. Orally supplemented catechin (OSC) was previously shown to increase mitochondrial heme and catalase levels in rat heart blood, however, its effect in the cytosol has not been elucidated. Here, we determined the effects of OSC in the rat heart blood cytosol. We used middle-aged (40 week-old) and young (4 week-old) rats throughout the study. We isolated blood cytosol, verified its purity, and determined heme, hydrogen peroxide (H2O2) levels, catalase (CAT) activities, gp91(phox) amounts, NADP and NAD pools, sirtuin 1 (SIRT1) and glutathione reductase (GR) activities, and free fatty acids (FFA). We established that OSC is associated with decreased heme-dependent H2O2 amounts while increasing heme-independent CAT activity. Moreover, we found that OSC-related decrease in NAD(+) amounts among middle-aged rats is associated to increased NADPH levels and SIRT1 activity. In contrast, we associated OSC-related decrease in NAD(+) amounts among young rats to decreased NADPH levels and increased SIRT1 activity. This highlights a major difference between catechin-treated middle-aged and young rats. Furthermore, we observed that cytosolic FFA and GR levels were significantly increased only among OSC-treated middle-aged rats which we hypothesize are related to increased NADPH levels. This insinuates that OSC treatment allows higher catechin amounts to enter the bloodstream of middle-aged rats. We propose that this would favorably increase NADPH amounts and lead to the simultaneous decrease in NADPH-related pro-oxidant activity and increase in NADPH-related biomolecules and anti-oxidant activities.

  12. Characterization of currently marketed heparin products: adverse event relevant bioassays.

    PubMed

    Sommers, Cynthia D; Montpas, Nicolas; Adam, Albert; Keire, David A

    2012-01-01

    The polyanion oversulfated chondroitin sulfate (OSCS) was identified as a contaminant in heparin products and was associated with severe hypotensive responses and other symptoms in patients receiving the drug. The OSCS associated adverse reactions were attributed to activation of the contact system via the plasma mediator, activated factor XII (FXIIa), which triggers kallikrein (KK) activity. Unlike heparin alone, OSCS, is able to activate FXII in plasma and stably bind to FXIIa enhancing plasma KK activity and the induction of vasoactive mediators such as bradykinin (BK), C3a and C5a. Similarly OSCS can interfere with heparin neutralization by the polycationic drug protamine. Here, we assess heparin (heparin sodium, dalteparin, tinzaparin or enoxaparin)-protamine complex formation and plasma based bioassays of KK, BK and C5a in a 96-well plate format. We establish the normal range of variation in the optimized bioassays across multiple lots from 9 manufacturers. In addition, because other oversulfated (OS) glycosaminoglycans (GAGs) besides OSCS could also serve as possible economically motivated adulterants (EMAs) to heparin, we characterize OS-dermatan sulfate (OSDS), OS-heparan sulfate (OSHS) and their native forms in the same assays. For the protamine test, OS-GAGs could be distinguished from heparin. For the KK assay, OSCS and OSDS were most potent followed by OSHS, and all had similar efficacies. Finally, OSDS had a greater efficacy in the C5a and BK assays followed by OSCS then OSHS. These data established the normal range of response of heparin products in these assays and the alteration in the responses in the presence of possible EMAs.

  13. [The importance of recombinant proteins of West Siberian isolates of Borrelia burgdorferi S.L. for serological diagnostic of ixodic tick borreliosis].

    PubMed

    Karavayev, V S; Genina, E S; Ryabchenko, A V; Beklemoschev, A B

    2014-06-01

    The structural proteins OspC, FlaB, FlaA and DbpB of agent of ixodic tick borreliosis are one of main antigens inducing humoral immunity at initial stages of disease. Owing to it, the task was stated to evaluate antigen activity of recombinant proteins OspC (OscP-Bg), fragment of FlaB (f-FlaB) and DbpB of genospecies B. garinii and OspC (OscC-Ba) of genospecies of B. afzelii of West Siberian isolates of Borrelia Burgdorferi S.L. for their possible application as antigens for serological diagnostic of ixodic tick borreliosis The recombinant proteins OscP-Bg, OscC-Ba, f-FlaB, FlaA and DbpB are analyzed using technique of enzymoimmunoassay to detect ability to bound antibodies of serums of patients with ixodic tick borreliosis with localized and disseminated stage of infection. The difference of their sensitivity as antigens during detection of specific antibodies in blood serum of patients with ixodic tick borreliosis was demonstrated In serum of patients with ixodic tick borreliosis with disseminated stage of infection the level of specific IgM and IgG antibodies reacting with OscP-Bg, OscC-Ba, f-FlaB, FlaA and DbpB is within the limits 15.7-52.6% for IgG. The results of enzymoimmunoassay applied to patients with ixodic tick borreliosis for detection of IgM and IgG in serum demonstrated that OscP-Bg and f-FlaB determined the highest antigen activity with antigens. The study results make it possible to consider these proteins as perspective components for development of immune enzyme test system of diagnostic of ixodic tick borreliosis.

  14. Rhinoplasty Education Using a Standardized Patient Encounter

    PubMed Central

    Wright, Eric J.; Khosla, Rohit K.; Howell, Lori

    2016-01-01

    Background Comprehensive aesthetic surgery training continues to be a challenge for residency programs. Our residency program developed a rhinoplasty-based objective structured clinical examination (OSCE) based upon validated methods as part of the residency education curriculum. We report our experience with the rhinoplasty-based OSCE and offer guidance to its incorporation within residency programs. Methods The encounter involved resident evaluation and operative planning for a standardized patient desiring a rhinoplasty procedure. Validated OSCE methods currently used at our medical school were implemented. Residents were evaluated on appropriate history taking, physical examination, and explanation to the patient of treatment options. Examination results were evaluated using analysis of variance (statistical significance P<0.05). Results Twelve residents completed the rhinoplasty OSCE. Medical knowledge assessment showed increasing performance with clinical year, 50% versus 84% for postgraduate year 3 and 6, respectively (P<0.005). Systems-based practice scores showed that all residents incorrectly submitted forms for billing and operative scheduling. All residents confirmed that the OSCE realistically represents an actual patient encounter. All faculty confirmed the utility of evaluating resident performance during the OSCE as a useful assessment tool for determining the Next Accreditation System Milestone level. Conclusions Aesthetic surgery training for residents will require innovative methods for education. Our examination showed a program-educational weakness in billing/coding, an area that will be improved upon by topic-specific lectures. A thoroughly developed OSCE can provide a realistic educational opportunity to improve residents' performance on the nonoperative aspects of rhinoplasty and should be considered as an adjunct to resident education. PMID:27689053

  15. Novel synthetic organosulfur compounds induce apoptosis of human leukemic cells.

    PubMed

    Wong, W W; Macdonald, S; Langler, R F; Penn, L Z

    2000-01-01

    It has been well documented that natural organosulfur compounds (OSCs) derived from plants such as garlic, onions and mahogany trees possess antiproliferative properties; however, the essential chemical features of the active OSC compounds remain unclear. To investigate the association between OSC structure and growth inhibitory activity, we synthesized novel relatives of dysoxysulfone, a natural OSC derived from the Fijian medicinal plant, Dysoxylum richii. In this study, we have examined the antiproliferative effects of these novel OSCs on a model human leukemic cell system and show that the compounds segregate into three groups. Group I, consisting of compounds A, B, G and J, did not affect either cell proliferation or the cell cycle profile of the leukemic cell lines. Group II, consisting of compounds F and H, induced the cells to undergo apoptosis from the G2/M phase of the cell cycle. Group III, consisting of compounds C, D, E and I, decreased cell proliferation and induced apoptosis throughout the cell cycle. The apoptotic agonists of Group II and III shared a common disulfide moiety, essential for leukemic cell cytotoxicity. Interestingly, Group II compounds did not affect cell viability of normal human diploid cells, suggesting the regions flanking the disulfide group contributes to the specificity of cell killing. Thus, we provide evidence that structure-activity analysis of natural products can identify novel compounds for the development of new therapeutics that can trigger apoptosis in a tumor-specific manner.

  16. 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.

  17. Examiners' perceptions of the objective structured clinical examination in colposcopy.

    PubMed

    Qureshi, N S

    2013-02-01

    Certification in Colposcopy by the British Society for Colposcopy and Cervical Pathology (BSCCP) and the Royal College of Obstetricians and Gynaecologists is a formal pre- requisite to the practice of colposcopy within the UK. This certification is awarded after passing an Objective Structured Clinical Examination (OSCE). The aim of the project is to explore examiners' perceptions of the OSCE examination in colposcopy and consider whether it is the right tool to differentiate between safe and unsafe practice in colposcopy. A case study research methodology was employed for the project, and questionnaires were sent to 30 examiners for OSCE in Colposcopy. The project also included conducting semi-structured interviews with two examiners, two trainees and a senior manager of the BSCCP. The questionnaire had a response rate of 28 (94%). The satisfaction rate among the examiners about the standard of questions in OSCE in Colposcopy was 93%, and 89% of the examiners would allow a candidate passing the examination to carry out a clinic in their absence. A total of 26 (94%) examiners thought that the examination was fit for purpose. It was suggested that testing of practical skills should also be made part of the examination. It seems OSCE in Colposcopy is perceived well both by the examiners and the candidates.

  18. Molecular cloning and expression of squalene synthase and 2,3-oxidosqualene cyclase genes in persimmon (Diospyros kaki L.) fruits.

    PubMed

    Zhou, Chunhua; Zhao, Daqiu; Sheng, Yanle; Liang, Guohua; Tao, Jun

    2012-02-01

    Oleanolic acid (OA) and ursolic acid (UA) are the main triterpene acids in persimmon fruit, and squalene synthase and 2,3-oxidosqualene cyclases are important enzymes in pentacyclic triterpene biosynthesis. In order to study their relationship, DkSQS and DkOSC were cloned from persimmon fruits in the present study. The full-length cDNA of DkSQS was 1647 bp, containing an open reading frame (ORF) of 1245 bp that encoded a peptide of 415 amino acids (AA). The 3'-end of DkOSC cDNA fragment contained 522 bp, including a partial ORF of 298 bp, a full poly A tail that encoded 98 AA. Two cultivars of persimmon, i.e. cv. Nishimurawase and cv. Niuxinshi, were used to study the content of OA and UA and the related gene expression. Results showed that OA and UA contents changed in both cultivars during fruit development, the difference in cv. Nishimurawase was greater than that in cv. Niuxinshi. The expression of DkSQS and DkOSC had no obvious correlation with the biosynthesis of OA and UA in the flesh. There may be two main reasons. Firstly, different enzymes involved in the biosynthesis of triterpenes and mutual adjustment were existed in different gene expressions. Secondly, it was not clear that the DkOSC cloned in this research belonged to which subfamily. Therefore, the real relationship between triterpenes and DkSQS and DkOSC in persimmon fruits is still to be revealed.

  19. Polarization-independent efficiency enhancement of organic solar cells by using 3-dimensional plasmonic electrode

    NASA Astrophysics Data System (ADS)

    Li, Xuanhua; Choy, Wallace C. H.; Ren, Xingang; Xin, Jianzhuo; Lin, Peng; Leung, Dennis C. W.

    2013-04-01

    Plasmonic back reflectors have recently become a promising strategy for realizing efficient organic solar cell (OSCs). Since plasmonic effects are strongly sensitive to light polarization, it is highly desirable to simultaneously achieve polarization-independent response and enhanced power conversion efficiency (PCE) by designing the nanostructured geometry of plasmonic reflector electrode. Here, through a strategic analysis of 2-dimensional grating (2D) and 3-dimensional patterns (3D), with similar periodicity as a plasmonic back reflector, we find that the OSCs with 3D pattern achieve the best PCE enhancement by 24.6%, while the OSCs with 2D pattern can offer 17.5% PCE enhancement compared to the optimized control OSCs. Importantly, compared with the 2D pattern, the 3D pattern shows a polarization independent plasmonic response, which will greatly extend its uses in photovoltaic applications. This work shows the significances of carefully selecting and designing geometry of plasmonic nanostructures in achieving high-efficient, polarization-independent plasmonic OSCs.

  20. Embedment of nano-sized Ag layer into Ag-doped In2O3 films for use as highly transparent and conductive anode in organic solar cells

    NASA Astrophysics Data System (ADS)

    Cho, Da-Young; Na, Seok-In; Chung, Kwun-Bum; Kim, Han-Ki

    2015-08-01

    By inserting a nano-sized Ag layer between bottom Ag-doped In2O3 (AIO) and a top AIO layer, we were able to control the sheet resistance and optical transmittance of AIO films for application in organic solar cells (OSCs) as a transparent electrode. To optimize the AIO/Ag/AIO multilayer, we investigated the electrical, optical, structural and morphological properties of the AIO/Ag/AIO multilayer as a function of Ag interlayer thickness with a constant bottom and top AIO thickness of 35 nm. The optimized AIO/Ag/AIO multilayer showed a much lower resistivity of 3.988 × 10-5 Ω cm and a higher optical transmittance of 84.79% than the values (4.625 × 10-4 Ω cm and 78.36%) of the single AIO film, due to the high conductivity of the metallic Ag layer and the antireflection effect of the symmetric AIO/Ag/AIO structure. In addition, we investigated the performances of OSCs with AIO/Ag/AIO electrodes as a function of Ag interlayer thickness to determine the optimal Ag thickness to produce a high power conversion efficiency (PCE) of the OSCs. Based on the PCE of the OSCs, we correlated the performance of the OSCs with the Ag interlayer thickness in the AIO/Ag/AIO multilayer and suggested a possible mechanism to explain the dependency of PCE on Ag thickness in AIO/Ag/AIO multilayer electrodes.

  1. Breaking bad news in amyotrophic lateral sclerosis: the need for medical education.

    PubMed

    Schellenberg, Kerri L; Schofield, Susie J; Fang, Shoufan; Johnston, Wendy S W

    2014-03-01

    The manner in which physicians deliver difficult diagnoses is an area of discontent for patients with amyotrophic lateral sclerosis (ALS). The American Academy of Neurology's Practice Parameter for care of the ALS Patient recommended teaching and evaluating strategies for disclosing the diagnosis (10). Our objective was to examine residents' ability in and perceptions of communicating the diagnosis of ALS. Twenty-two resident physicians were videotaped and rated by two ALS neurologists as they delivered an ALS diagnosis to a standardized patient (SP) during an objective structured clinical examination (OSCE). Residents self-rated immediately after the OSCE, again after viewing their videotape, and completed a survey regarding the OSCE and delivering difficult diagnoses. OSCE performance was suboptimal, particularly for communication skills and empathy. The two examiners' scores correlated except for the empathy subscore. Residents' self-assessments did not align with the examiners' scores either before or after watching their videotape. The survey uncovered residents' apprehension and dissatisfaction with their training in diagnosis delivery. The results highlight a need for resident education in delivering an ALS diagnosis. The lack of correlation between residents' and examiners' scoring requires further study. Evaluation of empathy is particularly challenging. Residents agreed that OSCE participation was worthwhile.

  2. Enhanced transmittance of metallic film with nanoaperture array

    NASA Astrophysics Data System (ADS)

    Xu, Ming; Ou, Xia-Li; Zhang, Xu-Lin; Liu, Yu-Shan; Gao, Qiang

    2016-09-01

    Metallic film as an indium tin oxide alternative, which shows excellent mechanical flexibility and high conductivity, has the ideal physical properties for flexible organic solar cells (OSCs). However, a bottleneck of metallic film was a lack of transmittance that limits the application in OSCs. We have demonstrated a nanoaperture metallic film fabricated by a template striping method, which can overcome the above-mentioned bottleneck. This metallic film has a random nanoaperture array. The size and shape of the nanoaperture were dependent on master templates. This metallic film with nanoaperture array is not only able to show high conductivity but also possesses tunable localized surface plasmon (LSP) resonance as well. The LSP could be coupled with dipole mode in nanostructure, which can account for the transmission enhancement and efficiently increase the light absorption of active layer in the OSCs. Moreover, this metallic film with nanoaperture array will exhibit particular advantage in flexible OSCs because the backing layer itself is a flexible substrate. The nanoaperture metallic film fabricated by this method as an electrode was a good choice for OSCs.

  3. Pharmacy Student Anxiety and Success With Objective Structured Clinical Examinations

    PubMed Central

    2017-01-01

    Objective. To evaluate whether a relationship exists between the degree of student state-anxiety and pass rates on moderate-to-high stakes objective structured clinical examinations (OSCE). Methods. Third-professional year (P3) students were assessed using the Speilberger State-Trait Anxiety Index (STAI) three weeks prior to their first moderate-to-high stakes OSCEs. Students’ OSCE station pass rates, individual station analytical scores, and the overall pass rate for the class were compared with student responses on STAI surveys to measure their association. Results. Seventy-three students (100%) provided consent to participate in the research; 64 (87%) sufficiently completed the STAI survey. Degree of student state-anxiety or train-anxiety was not associated with any of the outcomes assessed in this study. Overall pass rate, individual station pass rates, and station analytical checklist scores were not inversely correlated with state- or trait-anxiety scores. Conclusions. Efforts to assist students in OSCE performance should focus on means other than reducing associated anxiety. Future research in this area should focus on what interventions beyond instruction could be put in place to help students be more successful during OSCEs. PMID:28289297

  4. Pharmacy Student Anxiety and Success With Objective Structured Clinical Examinations.

    PubMed

    Longyhore, Daniel S

    2017-02-25

    Objective. To evaluate whether a relationship exists between the degree of student state-anxiety and pass rates on moderate-to-high stakes objective structured clinical examinations (OSCE). Methods. Third-professional year (P3) students were assessed using the Speilberger State-Trait Anxiety Index (STAI) three weeks prior to their first moderate-to-high stakes OSCEs. Students' OSCE station pass rates, individual station analytical scores, and the overall pass rate for the class were compared with student responses on STAI surveys to measure their association. Results. Seventy-three students (100%) provided consent to participate in the research; 64 (87%) sufficiently completed the STAI survey. Degree of student state-anxiety or train-anxiety was not associated with any of the outcomes assessed in this study. Overall pass rate, individual station pass rates, and station analytical checklist scores were not inversely correlated with state- or trait-anxiety scores. Conclusions. Efforts to assist students in OSCE performance should focus on means other than reducing associated anxiety. Future research in this area should focus on what interventions beyond instruction could be put in place to help students be more successful during OSCEs.

  5. 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

  6. Students' perceptions of practice assessment in the skills laboratory: an evaluation study of OSCAs with immediate feedback.

    PubMed

    Rush, Sue; Ooms, Ann; Marks-Maran, Di; Firth, Terry

    2014-11-01

    Assessment of clinical skills is fundamental to undergraduate nursing programmes. However, enabling assessment to be a good learning experience as well is a challenge to nurse educators. The study presented here presents the change from using an objective structured clinical examination (OSCE) for summative assessment (with feedback given to students after results had gone to the examination board--6 weeks after the OSCE) to one with immediate feedback. Because the previous OSCEs were universally disliked by students, for reasons that included absence of immediate feedback, in making this change the university re-branded the OSCE as an objective structured clinical assessment (OSCA) with immediate feedback provided to students. A survey was undertaken to measure student engagement with the OSCA, its value and impact, and its sustainability from the students' perspectives. There is little in the literature about student engagement with OSCEs and sustainability. Findings show that the OSCA with immediate feedback was perceived positively by students, was valued with regard to a number of factors, had a positively impact on student learning and confidence and was felt to be a form of assessment that this university should continue to use.

  7. Electron Transport Layer-Free Inverted Organic Solar Cells Fabricated with Highly Transparent Low-Resistance Indium Gallium Zinc Oxide/Ag/Indium Gallium Zinc Oxide Multilayer Electrode

    NASA Astrophysics Data System (ADS)

    Kim, Jun Ho; Kwon, Sung-Nam; Na, Seok-In; Kim, Sun-Kyung; Yoo, Young-Zo; Im, Hyeong-Seop; Seong, Tae-Yeon

    2017-04-01

    Inverted organic solar cells (OSCs) have been fabricated with conventional Sn-doped indium oxide (ITO) and amorphous indium gallium zinc oxide (a-IGZO)/Ag/a-IGZO (39 nm/19 nm/39 nm) (a-IAI) electrodes and their electrical characteristics characterized. The ITO and optimized a-IAI electrodes showed high transmittance of 96% and 88% at 500 nm, respectively. The carrier concentration and sheet resistance of the ITO and a-IAI films were 8.46 × 1020 cm-3 and 7.96 × 1021 cm-3 and 14.18 Ω/sq and 4.24 Ω/sq, respectively. Electron transport layer (ETL)-free OSCs with the a-IAI electrode exhibited power conversion efficiency (PCE) of 2.66%, similar to that of ZnO ETL-based OSCs with ITO electrode (3.27%). However, the ETL-free OSCs with the a-IAI electrode showed much higher PCE than the ETL-free OSCs with the ITO electrode (0.84%). Ultraviolet photoelectron spectroscopy results showed that the work function of the a-IAI electrode was 4.15 eV. This improved performance was attributed to the various roles of the a-IAI electrode, e.g., as an effective ETL and a hole blocking layer.

  8. Developing a Framework for Objective Structured Clinical Examinations Using the Nominal Group Technique

    PubMed Central

    Crum, Matthew F.; White, Paul J.; Larson, Ian; Malone, Daniel T.; Manallack, David T.; Nicolazzo, Joseph A.; McDowell, Jennifer; Lim, Angelina S.; Kirkpatrick, Carl M.

    2016-01-01

    Objective. To use the nominal group technique to develop a framework to improve existing and develop new objective structured clinical examinations (OSCEs) within a four-year bachelor of pharmacy course. Design. Using the nominal group technique, a unique method of group interview that combines qualitative and quantitative data collection, focus groups were conducted with faculty members, practicing pharmacists, and undergraduate pharmacy students. Five draft OSCEs frameworks were suggested and participants were asked to generate new framework ideas. Assessment. Two focus groups (n=9 and n=7) generated nine extra frameworks. Two of these frameworks, one from each focus group, ranked highest (mean scores of 4.4 and 4.1 on a 5-point scale) and were similar in nature. The project team used these two frameworks to produce the final framework, which includes an OSCE in every year of the course, earlier implementation of teaching OSCEs, and the use of independent simulated patients who are not examiners. Conclusions. The new OSCE framework provides a consistent structure from course entry to exit and ensures graduates meet internship requirements. PMID:28090107

  9. Highly efficient and bendable organic solar cells using a three-dimensional transparent conducting electrode.

    PubMed

    Wang, Wei; Bae, Tae-Sung; Park, Yeon Hyun; Kim, Dong Ho; Lee, Sunghun; Min, Guanghui; Lee, Gun-Hwan; Song, Myungkwan; Yun, Jungheum

    2014-06-21

    A three-dimensional (3D) transparent conducting electrode, consisting of a quasi-periodic array of discrete indium-tin-oxide (ITO) nanoparticles superimposed on a highly conducting oxide-metal-oxide multilayer using ITO and silver oxide (AgOx) as oxide and metal layers, respectively, is synthesized on a polymer substrate and used as an anode in highly flexible organic solar cells (OSCs). The 3D electrode is fabricated using vacuum sputtering sequences to achieve self-assembly of distinct ITO nanoparticles on a continuous ITO-AgOx-ITO multilayer at room-temperature without applying conventional high-temperature vapour-liquid-solid growth, solution-based nanoparticle coating, or complicated nanopatterning techniques. Since the 3D electrode enhances the hole-extraction rate in OSCs owing to its high surface area and low effective series resistance for hole transport, OSCs based on this 3D electrode exhibit a power conversion efficiency that is 11-22% higher than that achievable in OSCs by means of conventional planar ITO film-type electrodes. A record high efficiency of 6.74% can be achieved in a bendable OSC fabricated on a poly(ethylene terephthalate) substrate.

  10. 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

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

    PubMed

    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.

  12. Agarose-gel electrophoresis for the quality assurance and purity of heparin formulations.

    PubMed

    Volpi, Nicola; Buzzega, Dania

    2012-01-01

    The adulteration of raw heparin (Hep) with a synthetic oversulfated chondroitin sulfate (OSCS) not found in nature produced in 2007-2008 a global crisis giving rise to the development of additional, new and specific methods for its quality assurance and purity. In this study, a simple and sensitive agarose-gel electrophoresis method has been developed for the visualization of OSCS in Hep samples along with other natural glycosaminoglycans possibly present as "process-related impurities", in particular dermatan sulfate (DS) and chondroitin sulfate (CS). Agarose-gel electrophoresis under non-conventional conditions is able to separate OSCS from Hep with its two components, the slow-moving and fast-moving species, DS and CS by performing separation for 15 h (overnight) and under high voltage (100 mA, ∼200 V). Densitometric scanning enabled us to calculate a limit of detection of ∼0.5 μg OSCS with a linear behaviour from 0.1 to 5 μg, comparable to CS/DS. Contaminated samples from Hep manufacturers were analyzed and quantitative data were found comparable to previous studies. Due to its capacity to process many samples in a single run and to the equipment commonly available in laboratories, this analytical method would be suitable for the identification and quantification of contamination by other polysaccharides, in particular OSCS and DS, within Hep preparations and formulations.

  13. Analysis of crude heparin by (1)H NMR, capillary electrophoresis, and strong-anion-exchange-HPLC for contamination by over sulfated chondroitin sulfate.

    PubMed

    Keire, David A; Trehy, Michael L; Reepmeyer, John C; Kolinski, Richard E; Ye, Wei; Dunn, Jamie; Westenberger, Benjamin J; Buhse, Lucinda F

    2010-03-11

    We previously published a strong-anion-exchange-high performance liquid chromatography (SAX-HPLC) method for the detection of the contaminant over sulfated chondroitin sulfate (OSCS) in heparin sodium active pharmaceutical ingredient (API). While APIs have been processed to remove impurities, crude heparins contain insoluble material, chondroitin sulfates, heparan sulfate, and proteins that may interfere with the recovery and measurement of OSCS. We examined 500MHz (1)H NMR, capillary electrophoresis (CE), and SAX-HPLC to quantify OSCS in crude heparin. Using our standard API protocol on OSCS spiked crude heparin samples; we observed a weight percent LOD and LOQ for the NMR approach of 0.1% and 0.3%, respectively, while the SAX-HPLC method gave values of 0.03% and 0.09%, respectively. CE data was not amenable to quantitative measurement of OSCS in crude heparin. We developed a modified HPLC sample preparation protocol using crude dissolved at the 100mg/mL level with a 2.5M NaCl solution. This SAX-HPLC approach gave a weight percent LOD of 0.02% and a LOQ of 0.07% and had better performance characteristics than that of the protocol used for APIs.

  14. Highly sensitive ratiometric detection of heparin and its oversulfated chondroitin sulfate contaminant by fluorescent peptidyl probe.

    PubMed

    Mehta, Pramod Kumar; Lee, Hyeri; Lee, Keun-Hyeung

    2017-05-15

    The selective and sensitive detection of heparin, an anticoagulant in clinics as well as its contaminant oversulfated chondroitin sulfate (OSCS) is of great importance. We first reported a ratiometric sensing method for heparin as well as OSCS contaminants in heparin using a fluorescent peptidyl probe (Pep1, pyrene-GSRKR) and heparin-digestive enzyme. Pep1 exhibited a highly sensitive ratiometric response to nanomolar concentration of heparin in aqueous solution over a wide pH range (2~11) and showed highly selective ratiometric response to heparin among biological competitors such as hyaluronic acid and chondroitin sulfate. Pep1 showed a linear ratiometric response to nanomolar concentrations of heparin in aqueous solutions and in human serum samples. The detection limit for heparin was calculated to be 2.46nM (R(2)=0.99) in aqueous solutions, 2.98nM (R(2)=0.98) in 1% serum samples, and 3.43nM (R(2)=0.99) in 5% serum samples. Pep1 was applied to detect the contaminated OSCS in heparin with heparinase I, II, and III, respectively. The ratiometric sensing method using Pep1 and heparinase II was highly sensitive, fast, and efficient for the detection of OSCS contaminant in heparin. Pep1 with heparinase II could detect as low as 0.0001% (w/w) of OSCS in heparin by a ratiometric response.

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

    DOE PAGES

    Lu, Luyao; Chen, Wei; Xu, Tao; ...

    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

  16. Disodium edetate as a promising interfacial material for inverted organic solar cells and the device performance optimization.

    PubMed

    Li, Xiaodong; Zhang, Wenjun; Wang, Xueyan; Gao, Feng; Fang, Junfeng

    2014-12-10

    Disodium edetate (EDTA-Na), a popular hexadentate ligand in analytical chemistry, was successfully introduced in organic solar cells (OSCs) as cathode interfacial layer. The inverted OSCs with EDTA-Na showed superior performance both in power conversion efficiency and devices stability compared with conventional devices. Interestingly, we found that the performance of devices with EDTA-Na could be optimized through external bias treatment. After optimization, the efficiency of inverted OSCs with device structure of ITO/EDTA-Na/polymer thieno[3,4-b]thiophene/benzodithiophene (PTB7):PC71BM/MoO3/Al was significantly increased to 8.33% from an initial value of 6.75%. This work introduces a new class of interlayer materials, small molecule electrolytes, for organic solar cells.

  17. Effect of the additional anode layers on the absorption enhancement characteristic of plasmonic organic solar cells

    NASA Astrophysics Data System (ADS)

    Yoo, Sanghyuk; Kim, Jungho

    2014-12-01

    We numerically investigate the effect of additional anode layers on the absorption enhancement characteristic of pyramidal-grating plasmonic organic solar cells (OSCs) using the finite element method. The behaviors of the plasmonic absorption enhancement are compared between a “simple” structure consisting of only the active and metal cathode layers and a “practical” structure with the additional anode layers. The plasmonic absorption enhancement is identified by comparing the polarization-dependent absorbance spectra between the planar and plasmonic OSCs. When the active-layer thickness is small, the plasmonic resonance condition changes owing to the addition of the anode layers. When the active-layer thickness is large, the plasmonic resonance condition and corresponding absorption behavior show a slight difference irrespective of the inclusion of the additional anode layers. Therefore, the additional anode layers should be included in the optical analysis and design of plasmonic OSCs when the active-layer thickness is small.

  18. RNAi and overexpression of genes in ovarian somatic cells.

    PubMed

    Saito, Kuniaki

    2014-01-01

    Emerging evidence indicates that PIWI proteins, in collaboration with PIWI-interacting RNAs (piRNAs), play a critical role in retrotransposon silencing in Drosophila gonadal somatic and germ-line cells. The recent establishment of female germ-line stem cells/ovarian somatic sheet and its derivative cell line, ovarian somatic cells (OSCs), allows researchers to study the molecular functions of several protein factors involved in the primary piRNA pathway in Drosophila. Although transgene expression is difficult to achieve in gonad-derived cell lines, transfection of both expression vectors and knockdown reagents is highly effective in OSCs. Here, I focus on techniques that knockdown or overexpress genes of interest in OSCs.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. Functional redundancy of the Notch pathway in ovarian cancer cell lines.

    PubMed

    Silva, Fernanda; Félix, Ana; Serpa, Jacinta

    2016-10-01

    Epithelial ovarian cancer is the most lethal gynecologic malignancy, despite advances in treatment. The most common histological type, high-grade ovarian serous carcinoma (OSC) is usually diagnosed at an advanced stage, and although these types of tumors frequently respond to surgery and platinum-based chemotherapy, they usually recur. Ovarian clear cell carcinoma (OCCC) is an unusual histological type, which is known to be intrinsically chemoresistant and is associated with poor prognosis in advanced stages. In recent years, genetic alterations and epigenetic modulation of signaling pathways have been reported in OSC and OCCC, including the overexpression of Notch pathway elements and histone deacetylases. Histone deacetylase inhibitors (HDACis), including vorinostat (suberoylanilide hydroxamic acid), alter the transcription of genes involved in cell growth, survival and apoptosis, and have become an attractive therapeutic approach. However, no previous work has addressed the effect of HDACis, and in particular vorinostat, on Notch signaling in ovarian cancer. Therefore, the present study aimed to investigate the modulation of the Notch pathway by vorinostat in ovarian cancer. Using immunofluorescence and quantitative polymerase chain reaction, the present results revealed that vorinostat activated the Notch pathway in OCCC and OSC cell lines, through different Notch ligands. In OCCC, the activation of the Notch pathway appeared to occur through Delta-like (Dll) ligands 1, 2 and 3, whereas in OSC Dll1 and Jagged 1 and 2 ligands were involved. The activation of the Notch pathway by vorinostat, in OCCC and OSC cell lines, culminated in the increased expression of the same downstream transcription factors, hairy enhancer of split (Hes) 1 and 5, and Hes-related proteins 1 and 2. In conclusion, vorinostat modulates the expression of several downstream targets of the Notch pathway and independent Notch receptors and ligands that are expressed in OSC and OCCC. This

  4. Cloning and Functional Characterization of Cycloartenol Synthase from the Red Seaweed Laurencia dendroidea

    PubMed Central

    Arendt, Philipp; de Oliveira, Louisi Souza; Thompson, Cristiane; Soares, Angélica Ribeiro; Pereira, Renato Crespo; Goossens, Alain; Thompson, Fabiano L.

    2016-01-01

    The red seaweed Laurencia dendroidea belongs to the Rhodophyta, a phylum of eukaryotic algae that is widely distributed across the oceans and that constitute an important source of bioactive specialized metabolites. Laurencia species have been studied since 1950 and were found to contain a plethora of specialized metabolites, mainly halogenated sesquiterpenes, diterpenes and triterpenes that possess a broad spectrum of pharmacological and ecological activities. The first committed step in the biosynthesis of triterpenes is the cyclization of 2,3-oxidosqualene, an enzymatic reaction carried out by oxidosqualene cyclases (OSCs), giving rise to a broad range of different compounds, such as the sterol precursors cycloartenol and lanosterol, or triterpene precursors such as cucurbitadienol and β-amyrin. Here, we cloned and characterized the first OSC from a red seaweed. The OSC gene was identified through mining of a L. dendroidea transcriptome dataset and subsequently cloned and heterologously expressed in yeast for functional characterization, which indicated that the corresponding enzyme cyclizes 2,3-oxidosqualene to the sterol precursor cycloartenol. Accordingly, the gene was named L. dendroidea cycloartenol synthase (LdCAS). A phylogenetic analysis using OSCs genes from plants, fungi and algae revealed that LdCAS grouped together with OSCs from other red algae, suggesting that cycloartenol could be the common product of the OSC in red seaweeds. Furthermore, profiling of L. dendroidea revealed cholesterol as the major sterol accumulating in this species, implicating red seaweeds contain a ‘hybrid’ sterol synthesis pathway in which the phytosterol precursor cycloartenol is converted into the major animal sterol cholesterol. PMID:27832119

  5. 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.

  6. Improvement in the efficiency of organic solar cells using a low-temperature evaporable optical spacer

    NASA Astrophysics Data System (ADS)

    Song, Hyung-Jun; Kim, Jun Young; Kwon, Yongwon; Ko, Youngjun; Lee, Donggu; Syn, Ho Jung; Song, Jiyun; Kwak, Jeonghun; Lee, Changhee

    2014-08-01

    We demonstrate the enhancement in performance of organic solar cells (OSCs) by employing a low-temperature evaporable optical spacer, consisting of potassium borohydride (KBH4) and bathophenanthroline (Bphen) (0.2:1, volume ratio). Since the KBH4-doped Bphen shows improved electron transporting properties and high transparency in the visible range, it can be used as an efficient optical spacer layer that can maximize the internal electrical field distribution in the active layer. As a result, the power conversion efficiency of the OSCs having the KBH4-doped Bphen with an optimized thickness was improved by 15% in comparison with the device with the non-KBH4-doped Bphen.

  7. 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

  8. 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.

  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. 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.

    PubMed

    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

  11. Effective teaching methods for geriatric competencies.

    PubMed

    Strano-Paul, Lisa

    2011-01-01

    This study assesses how effective classroom sessions are at teaching geriatric competencies to medical students. At Stony Brook Medical School, most geriatric competencies are taught in the Ambulatory Care Clerkship during small-group educational sessions. Clinical exposure to reinforce these specialized skills varies with preceptor assignment. A student's ability to perform geriatric assessments was evaluated by scores on an Objective Structured Clinical Exam (OSCE) with a geriatric patient. Scores from students who received additional clinical practice of these skills were compared with scores from students who did not. No significant difference in OSCE scores were seen between the two groups.

  12. Light Optics for Optical Stochastic Cooling

    SciTech Connect

    Andorf, Matthew; Lebedev, Valeri; Piot, Philippe; Ruan, Jinhao

    2016-06-01

    In Optical Stochastic Cooling (OSC) radiation generated by a particle in a "pickup" undulator is amplified and transported to a downstream "kicker" undulator where it interacts with the same particle which radiated it. Fermilab plans to carry out both passive (no optical amplifier) and active (optical amplifier) tests of OSC at the Integrable Optics Test Accelerator (IOTA) currently in construction*. The performace of the optical system is analyzed with simulations in Synchrotron Radiation Workshop (SRW) accounting for the specific temporal and spectral properties of undulator radiation and being augmented to include dispersion of lens material.

  13. Individual employee's perceptions of " Group-level Safety Climate" (supervisor referenced) versus " Organization-level Safety Climate" (top management referenced): Associations with safety outcomes for lone workers.

    PubMed

    Huang, Yueng-Hsiang; Lee, Jin; McFadden, Anna C; Rineer, Jennifer; Robertson, Michelle M

    2017-01-01

    Research has shown that safety climate is among the strongest predictors of safety behavior and safety outcomes in a variety of settings. Previous studies have established that safety climate is a multi-faceted construct referencing multiple levels of management within a company, most generally: the organization level (employee perceptions of top management's commitment to and prioritization of safety) and group level (employee perceptions of direct supervisor's commitment to and prioritization of safety). Yet, no research to date has examined the potential interaction between employees' organization-level safety climate (OSC) and group-level safety climate (GSC) perceptions. Furthermore, prior research has mainly focused on traditional work environments in which supervisors and workers interact in the same location throughout the day. Little research has been done to examine safety climate with regard to lone workers. The present study aims to address these gaps by examining the relationships between truck drivers' (as an example of lone workers) perceptions of OSC and GSC, both potential linear and non-linear relationships, and how these predict important safety outcomes. Participants were 8095 truck drivers from eight trucking companies in the United States with an average response rate of 44.8%. Results showed that employees' OSC and GSC perceptions are highly correlated (r= 0.78), but notable gaps between the two were observed for some truck drivers. Uniquely, both OSC and GSC scores were found to have curvilinear relationships with safe driving behavior, and both scores were equally predictive of safe driving behavior. Results also showed the two levels of climate significantly interacted with one another to predict safety behavior such that if either the OSC or GSC scores were low, the other's contribution to safety behavior became stronger. These findings suggest that OSC and GSC may function in a compensatory manner and promote safe driving behavior even

  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. 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

  16. 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.

  17. 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…

  18. Immune physiology and oogenesis in fetal and adult humans, ovarian infertility, and totipotency of adult ovarian stem cells.

    PubMed

    Bukovsky, Antonin; Caudle, Michael R; Virant-Klun, Irma; Gupta, Satish K; Dominguez, Roberto; Svetlikova, Marta; Xu, Fei

    2009-03-01

    It is still widely believed that while oocytes in invertebrates and lower vertebrates are periodically renewed throughout life, oocytes in humans and higher vertebrates are formed only during the fetal/perinatal period. However, this dogma is questioned, and clashes with Darwinian evolutionary theory. Studies of oogenesis and follicular renewal from ovarian stem cells (OSCs) in adult human ovaries, and of the role of third-party bone marrow-derived cells (monocyte-derived tissue macrophages and T lymphocytes) could help provide a better understanding of the causes of ovarian infertility, its prevention, and potential treatment. We have reported differentiation of distinct cell types from OSC and the production of new eggs in cultures derived from premenopausal and postmenopausal human ovaries. OSCs are also capable of producing neural/neuronal cells in vitro after sequential stimulation with sex steroid combinations. Hence, OSC represent a unique type of totipotent adult stem cells, which could be utilized for autologous treatment of premature ovarian failure and also for autologous stem cell therapy of neurodegenerative diseases without use of allogeneic embryonic stem cells or somatic cell nuclear transfer. The in vivo application of sex steroid combinations may augment the proliferation of existing neural stem cells and their differentiation into mature neuronal cells (systemic regenerative therapy). Such treatment may also stimulate the transdifferentiation of autologous neural stem cell precursors into neural stem cells useful for topical or systemic regenerative treatment.

  19. 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…

  20. Development and implementation of an objective structured clinical examination to provide formative feedback on communication and interpersonal skills in geriatric training.

    PubMed

    O'Sullivan, Patricia; Chao, Serena; Russell, Matthew; Levine, Sharon; Fabiny, Anne

    2008-09-01

    Teaching and assessment of communication and interpersonal skills, one of the American Council for Graduate Medical Education-designated core competencies, is an important but difficult task in the training of physicians. Assessment of trainees offers an opportunity to provide explicit feedback on their skills and encourages learning. This article describes a pilot study in which clinician-educators affiliated with the geriatrics training programs at Beth Israel Deaconess Medical Center and Boston University Medical Center designed and piloted a novel Objective Structured Clinical Examination (OSCE) to assess the communication and interpersonal skills of medical, dental, and geriatric psychiatry fellows. The OSCE consisted of three stations where geriatricians and standardized patients evaluated candidates using specifically designed checklists and an abbreviated version of the Master Interview Rating Scale. Communication skills were assessed through performance of specific "real life" clinical tasks, such as obtaining a medical history, explaining a diagnosis and prognosis, giving therapeutic instructions, and counseling. Interpersonal skills were assessed through the effect of the communication between doctor and standardized patient on fostering trust, relieving anxiety, and establishing a therapeutic relationship. This pilot study demonstrated that the OSCE format of assessment provides a valid means of evaluating the communication and interpersonal skills of interdisciplinary geriatric trainees and provides a valuable forum for formative assessment and feedback. Given that geriatricians and non geriatricians involved in elder care both need communication and interpersonal skills, this novel OSCE can be used for assessment of these skills in trainees in diverse healthcare subspecialties.

  1. 5 CFR 1830.4 - Requirements for requesting amendment of records.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... request should be sent by regular mail addressed to: Privacy Act Officer, U.S. Office of Special Counsel, 1730 M Street, N.W. (Suite 218), Washington, DC 20036-4505. Such requests may also be faxed to the Privacy Act Officer at the number provided on the FOIA/PA page of OSC's web site (see 1830.1). For...

  2. 5 CFR 1830.4 - Requirements for requesting amendment of records.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... request should be sent by regular mail addressed to: Privacy Act Officer, U.S. Office of Special Counsel, 1730 M Street, N.W. (Suite 218), Washington, DC 20036-4505. Such requests may also be faxed to the Privacy Act Officer at the number provided on the FOIA/PA page of OSC's web site (see 1830.1). For...

  3. 5 CFR 1830.4 - Requirements for requesting amendment of records.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... request should be sent by regular mail addressed to: Privacy Act Officer, U.S. Office of Special Counsel, 1730 M Street, N.W. (Suite 218), Washington, DC 20036-4505. Such requests may also be faxed to the Privacy Act Officer at the number provided on the FOIA/PA page of OSC's web site (see 1830.1). For...

  4. 40 CFR 300.135 - Response operations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... discharge or release poses a substantial threat to the public health or welfare of the United States as... representative for assistance in determining public health threats and call upon the Occupational Safety and... communications networks or procedures agreed to by the RRT and covered in the RCP. (n) OSCs/RPMs should...

  5. 40 CFR 300.212 - Area response drills.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 28 2011-07-01 2011-07-01 false Area response drills. 300.212 Section... PLAN Planning and Preparedness § 300.212 Area response drills. The OSC periodically shall conduct drills of removal capability (including fish and wildlife response capability), without prior notice,...

  6. 40 CFR 300.212 - Area response drills.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 29 2013-07-01 2013-07-01 false Area response drills. 300.212 Section... PLAN Planning and Preparedness § 300.212 Area response drills. The OSC periodically shall conduct drills of removal capability (including fish and wildlife response capability), without prior notice,...

  7. 40 CFR 300.212 - Area response drills.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 28 2014-07-01 2014-07-01 false Area response drills. 300.212 Section... PLAN Planning and Preparedness § 300.212 Area response drills. The OSC periodically shall conduct drills of removal capability (including fish and wildlife response capability), without prior notice,...

  8. 40 CFR 300.212 - Area response drills.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 29 2012-07-01 2012-07-01 false Area response drills. 300.212 Section... PLAN Planning and Preparedness § 300.212 Area response drills. The OSC periodically shall conduct drills of removal capability (including fish and wildlife response capability), without prior notice,...

  9. 40 CFR 300.212 - Area response drills.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 27 2010-07-01 2010-07-01 false Area response drills. 300.212 Section... PLAN Planning and Preparedness § 300.212 Area response drills. The OSC periodically shall conduct drills of removal capability (including fish and wildlife response capability), without prior notice,...

  10. 77 FR 37881 - 36(b)(1) Arms Sales Notification

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-25

    ... frequency expendables. The threats countered by the CMDS include radar-directed anti-aircraft artillery, radar command-guided missiles, radar homing guided missiles, and infrared guided missiles. The system is...- directional protection. The OSC detects the rocket plume of missiles and sends appropriate signals to the...

  11. 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...

  12. Program Manager: Journal of the Defense Systems Management College. Volume 22, Number 2, DSMC 113. Repairing the DoD/Industry Partnership. March - April, 1993.

    DTIC Science & Technology

    1993-04-01

    kiic Can be a delicate c:halletebcue osc tig(Sa ~ osatx. eot ro rsV ~ constituency broad enough1 to Winll~ Ncint ifi groups like NRC or L)SB rou...page of tomorrow’s paper? Program Manager 29 March-April 1993 - Kid /Spoxuse on Shoulder: flowwould The character ethic Coolhng off they uuoall

  13. 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.

  14. 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

  15. Iraq: Politics, Governance, and Human Rights

    DTIC Science & Technology

    2014-09-15

    I ) and a State Department police development program. However, those programs languished as Iraqi leaders sought to end U.S. political and military...Relationship .............................................................................. 35 Office of Security Cooperation-Iraq (OSC- I ...component of the Sunni rebellion that has become a major threat to Iraqi stability in 2014. Its antecedent called itself Al Qaeda in Iraq (AQ- I ), which was

  16. Pupil Imitation of a Rewarding Teacher's Verbal Behavior.

    ERIC Educational Resources Information Center

    Friedman, Philip; Bowers, Norman D.

    Patterns of teacher and student verbal behavior within a framework of reinforcement theory were analyzed through the use of a modified form of the Observation Schedule and Record 4V (OScAR). The study examined the extent to which the rewarding teacher's classroom discourse served as a model for the verbal style of a student among his peers. Data…

  17. 40 CFR 300.305 - Phase II-Preliminary assessment and initiation of action.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... States (including but not limited to fish, shellfish, wildlife, other natural resources, and the public..., shellfish, wildlife, other natural resources, and the public and private beaches and shorelines of the... arranging for the removal of such a discharge. (e) The OSC shall ensure that the natural resource...

  18. 40 CFR 300.305 - Phase II-Preliminary assessment and initiation of action.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... States (including but not limited to fish, shellfish, wildlife, other natural resources, and the public..., shellfish, wildlife, other natural resources, and the public and private beaches and shorelines of the... arranging for the removal of such a discharge. (e) The OSC shall ensure that the natural resource...

  19. 40 CFR 300.305 - Phase II-Preliminary assessment and initiation of action.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... States (including but not limited to fish, shellfish, wildlife, other natural resources, and the public..., shellfish, wildlife, other natural resources, and the public and private beaches and shorelines of the... arranging for the removal of such a discharge. (e) The OSC shall ensure that the natural resource...

  20. 40 CFR 300.135 - Response operations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... discussed in § 300.322; the potential impact on natural resources and property which may be affected... shall ensure that the trustees for natural resources are promptly notified of discharges or releases. (2) The OSC or RPM shall coordinate all response activities with the affected natural resource...

  1. 40 CFR 300.305 - Phase II-Preliminary assessment and initiation of action.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... States (including but not limited to fish, shellfish, wildlife, other natural resources, and the public..., shellfish, wildlife, other natural resources, and the public and private beaches and shorelines of the... arranging for the removal of such a discharge. (e) The OSC shall ensure that the natural resource...

  2. 40 CFR 300.305 - Phase II-Preliminary assessment and initiation of action.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... States (including but not limited to fish, shellfish, wildlife, other natural resources, and the public..., shellfish, wildlife, other natural resources, and the public and private beaches and shorelines of the... arranging for the removal of such a discharge. (e) The OSC shall ensure that the natural resource...

  3. Project 2008: Notes on the Russian Succession

    DTIC Science & Technology

    2007-08-01

    seizure of Yukos and the arrest of its chief executives, Platon Lebedev and Mikhail Khodorkovsky, in 2003-04 represent another example of the resort to...33. Gallina, Op. Cit., 9. 34. OSC Analysis 28 Jun (2007): Russia’s Putin Puts Protégé at Head of Investigating Body , FBIS SOV, June 28, 2007. 35

  4. MoS2 Quantum Dots with a Tunable Work Function for High-Performance Organic Solar Cells.

    PubMed

    Xing, Wang; Chen, Yusheng; Wang, Xinlong; Lv, Lei; Ouyang, Xinhua; Ge, Ziyi; Huang, Hui

    2016-10-12

    An efficient hole extraction layer (HEL) is critical to achieve high-performance organic solar cells (OSCs). In this study, we developed a pinhole-free and efficient HEL based on MoS2 quantum dots (QDs) combined with UV-ozone (UVO) treatment. The optophysical properties and morphology of MoS2 QDs and their photovoltaic performance are investigated. The results showed that MoS2 QDs can form homogeneous films and can be applied as an interfacial layer not only for donors with shallow highest occupied molecular orbital (HOMO) but also for those with deep HOMO energy levels after UVO treatment (O-MoS2 QDs). The solar cells based on O-MoS2 QDs yield a power conversion efficiency (PCE) of 8.66%, which is 71% and 12% higher than those of the OSCs with pristine MoS2 QD and O-MoS2 nanosheets, respectively, and the highest PCEs for OSCs containing MoS2 materials. Furthermore, the stability of solar cells based on MoS2 QDs is greatly improved in comparison with state-of-the-art PEDOT:PSS. These results demonstrate the great potential of O-MoS2 QDs as an efficient HEL for high-performance OSCs.

  5. 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.

  6. Air-stable efficient inverted polymer solar cells using solution-processed nanocrystalline ZnO interfacial layer.

    PubMed

    Tan, Mein Jin; Zhong, Shu; Li, Jun; Chen, Zhikuan; Chen, Wei

    2013-06-12

    In this work, efficient bulk heterojunction (BHJ) organic solar cells (OSC) in inverted configuration have been demonstrated. Power conversion efficiency (PCE) of 3.7% is reported for OSC employing silver top electrodes, molybdenum trioxide (MoO3) as the hole-transport interlayer (HTL), active layer comprising of poly-3-hexylthiophene (P3HT) and [6,6]-phenyl C61 butyric acid methyl ester (PCBM) as well as a nanocrystalline solution-synthesized zinc oxide (ZnO) nanoparticle (NP) film as the electron-transport layer (ETL). By using solution-processable ZnO crystalline NPs as ETL, we can eliminate the typical high temperature processing/annealing step, which is widely adopted in the conventional ZnO ETL fabrication process via the sol-gel method. Such highly crystalline ZnO NP films can enhance charge collection at the electrodes. It is also found that inverted OSCs exhibit greater air stability and lifetime performance compared to the OSC employing the normal structure.

  7. Tin doped indium oxide anodes with artificially controlled nano-scale roughness using segregated Ag nanoparticles for organic solar cells

    PubMed Central

    Kim, Hyo-Joong; Ko, Eun-Hye; Noh, Yong-Jin; Na, Seok-In; Kim, Han-Ki

    2016-01-01

    Nano-scale surface roughness in transparent ITO films was artificially formed by sputtering a mixed Ag and ITO layer and wet etching of segregated Ag nanoparticles from the surface of the ITO film. Effective removal of self-segregated Ag particles from the grain boundaries and surface of the crystalline ITO film led to a change in only the nano-scale surface morphology of ITO film without changes in the sheet resistance and optical transmittance. A nano-scale rough surface of the ITO film led to an increase in contact area between the hole transport layer and the ITO anode, and eventually increased the hole extraction efficiency in the organic solar cells (OSCs). The heterojunction OSCs fabricated on the ITO anode with a nano-scale surface roughness exhibited a higher power conversion efficiency of 3.320%, than that (2.938%) of OSCs made with the reference ITO/glass. The results here introduce a new method to improve the performance of OSCs by simply modifying the surface morphology of the ITO anodes. PMID:27640723

  8. 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…

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

    PubMed

    In, Sungjun; Park, Namkyoo

    2016-02-23

    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.

  10. 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.

  11. Conductometric simultaneous determination of acetic acid, monochloroacetic acid and trichloroacetic acid using orthogonal signal correction-partial least squares.

    PubMed

    Ghorbani, R; Ghasemi, J; Abdollahi, B

    2006-04-17

    A simultaneous conductometric titration method for determination of mixtures of acetic acid, monochloroacetic acid and trichloroacetic acid based on the multivariate calibration partial least squares is proposed. It is possible to obtain an adjustable model to relate squared concentration values of the mixtures used in the calibration range by conductance. The effect of orthogonal signal correction (OSC) as a preprocessing technique used to remove the information unrelated to the target variables is studied. The calibration model was build using conductometric titrations data of 16 mixtures of three acids. The concentration matrix was designed by a orthogonal design. The root mean squares error of prediction (RMSEP) for acetic acid, monochloroacetic acid and trichloroacetic acid with and without OSC were 0.08, 0.30 and 0.08, and 0.15, 0.40 and 0.18, respectively. The results obtained by OSC-PLS are better than the PLS and this indicate the successful application of the OSC filter as a good preprocessing method in multivariate calibration methods. The proposed procedure allows the simultaneous determination of these acids, in the synthetic mixtures.

  12. 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.

  13. 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.

  14. The impact of trained patient educators on musculoskeletal clinical skills attainment in pre-clerkship medical students

    PubMed Central

    2011-01-01

    Background Despite the high burden of musculoskeletal (MSK) diseases, few generalists are comfortable teaching MSK physical examination (PE) skills. Patient Partners® in Arthritis (PP®IA) is a standardized patient educator program that could potentially supplement current MSK PE teaching. This study aims to determine if differences exist in MSK PE skills between non-MSK specialist physician and PP®IA taught students. Methods Pre-clerkship medical students attended 2-hour small group MSK PE teaching by either non-MSK specialist physician tutors or by PP®IA. All students underwent an MSK OSCE and completed retrospective pre-post questionnaires regarding comfort with MSK PE and interest in MSK. Results 83 students completed the OSCE (42 PP®IA, 41 physician taught) and 82 completed the questionnaire (42 PP®IA, 40 physician taught). There were no significant differences between groups in OSCE scores. For all questionnaire items, post-session ratings were significantly higher than pre-session ratings for both groups. In exploratory analysis PP®IA students showed significantly greater improvement in 12 of 22 questions including three of five patient-centred learning questions. Conclusions PP®IA MSK PE teaching is as good as non-MSK specialist physician tutor teaching when measured by a five station OSCE and provide an excellent complementary resource to address current deficits in MSK PE teaching. PMID:21939562

  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. 3 CFR 8608 - Proclamation 8608 of November 30, 2010. Helsinki Human Rights Day, 2010

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... countries of a divided Europe solemnly pledged to work together to realize comprehensive security across the European continent. This occasion also spurred courageous human rights activists in Eastern Europe to form... institutionalized in the Organization for Security and Cooperation in Europe (OSCE), still serve as a beacon to...

  17. 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 ...

  18. A digital peer-to-peer learning platform for clinical skills development

    PubMed Central

    Basnak, Jesse; Ortynski, Jennifer; Chow, Meghan; Nzekwu, Emeka

    2017-01-01

    Background Due to constraints in time and resources, medical curricula may not provide adequate opportunities for pre-clerkship students to practice clinical skills. To address this, medical students at the University of Alberta developed a digital peer-to-peer learning initiative. The initiative assessed if students can learn clinical skills from their peers in co-curricular practice objective structured clinical exams (OSCEs). Methods A total of 144 first-year medical students participated. Students wrote case scenarios that were reviewed by physicians. Students enacted the cases in practice OSCEs, acting as the patient, physician, and evaluator. Verbal and electronic evaluations were completed. A digital platform was used to automate the process. Surveys were disseminated to assess student perceptions of their experience. Results Seventy-five percent of participants said they needed opportunities to practice patient histories and physical exams in addition to those provided in the medical school curriculum. All participants agreed that the co-curricular practice OSCEs met this need. The majority of participants also agreed that the digital platform was efficient and easy to use. Conclusion Students found the practice OSCEs and digital platform effective for learning clinical skills. Thus, peer-to-peer learning and computer automation can be useful adjuncts to traditional medical curricula. PMID:28344717

  19. 5 CFR 1800.2 - Filing disclosures of information.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., 1730 M Street NW., Suite 218, Washington, DC 20036-4505; (ii) By calling OSC, at: (800) 572-2249 (toll... print out and complete on paper, or to complete online). (2) Filers may use another written format to... Counsel, Disclosure Unit, 1730 M Street NW., Suite 218, Washington, DC 20036-4505; (ii) By fax, to:...

  20. Student Connectedness and the Perception of Community of Inquiry Presences in Online Instruction

    ERIC Educational Resources Information Center

    Sharp, Jennie

    2014-01-01

    This study examined student perceptions of effective online instruction, by means of the levels of student connectedness, within the context of the Community of Inquiry model. Both the Online Student Connectedness Survey (OSCS) and the Community of Inquiry (CoI) survey have been previously used to study student connectedness and student perception…

  1. 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.

  2. 5 CFR 1830.2 - Requirements for making Privacy Act requests.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 3 2014-01-01 2014-01-01 false Requirements for making Privacy Act requests. 1830.2 Section 1830.2 Administrative Personnel OFFICE OF SPECIAL COUNSEL PRIVACY § 1830.2 Requirements for making Privacy Act requests. (a) How made and addressed. A request for OSC records under...

  3. 5 CFR 1830.2 - Requirements for making Privacy Act requests.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 3 2013-01-01 2013-01-01 false Requirements for making Privacy Act requests. 1830.2 Section 1830.2 Administrative Personnel OFFICE OF SPECIAL COUNSEL PRIVACY § 1830.2 Requirements for making Privacy Act requests. (a) How made and addressed. A request for OSC records under...

  4. 5 CFR 1830.2 - Requirements for making Privacy Act requests.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Requirements for making Privacy Act requests. 1830.2 Section 1830.2 Administrative Personnel OFFICE OF SPECIAL COUNSEL PRIVACY § 1830.2 Requirements for making Privacy Act requests. (a) How made and addressed. A request for OSC records under...

  5. 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.

  6. Worldwide Emerging Environmental Issues Affecting the U.S. Military. November 2007 Report

    DTIC Science & Technology

    2007-11-01

    Environment and Security On November 30, the Organization for Security and Cooperation in Europe (OSCE) agreed on a Ministerial Declaration on...www.stopclustermunitions.org/news.asp?id=103 7.3 Middle East Biosecurity Assessed Experts from more than 30 countries from the Middle East, Europe ...prices, expansion of biofuels , instability of financial markets, and other economic factors dramatically affect agricultural commodity prices

  7. Students on Academic Probation at Bronx Community College: A Project in Peer-Mediated Self-Management Contracts. Report II.

    ERIC Educational Resources Information Center

    Santa Rita, Emilio

    The study described in this report was launched in Fall 1978 at Bronx Community College (BCC) to determine the efficacy of two procedures for enhancing the academic survival and study skills of students in academic difficulty. Introductory material looks at BCC's Operation Second Chance (OSC), one of these treatment procedures, which employs…

  8. 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…

  9. A Comparison of Two Techniques for Analyzing Classroom Behaviors.

    ERIC Educational Resources Information Center

    Medley, Donald M.; Hill, Russell A.

    This document reports the results of a comparative analysis of the Flanders Interaction Analysis Technique (FIAT) and the Observation Schedule and Record, Form 4, Verbal (OScAR 4V) in terms of the kinds of information about teacher behavior which each observation technique provides. A systematic program of recorded observation (involving 70…

  10. 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…

  11. 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…

  12. 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

    2016-04-06

    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.

  13. Decohesion kinetics in polymer organic solar cells.

    PubMed

    Bruner, Christopher; Novoa, Fernando; Dupont, Stephanie; Dauskardt, Reinhold

    2014-12-10

    We investigate the role of molecular weight (MW) of the photoactive polymer poly(3-hexylthiophene) (P3HT) on the temperature-dependent decohesion kinetics of bulk heterojunction (BHJ) organic solar cells (OSCs). The MW of P3HT has been directly correlated to its carrier field effect mobilities and the ambient temperature also affects OSC in-service performance and P3HT arrangement within the BHJ layer. Under inert conditions, time-dependent decohesion readily occurs within the BHJ layer at loads well below its fracture resistance. We observe that by increasing the MW of P3HT, greater resistance to decohesion is achieved. However, failure consistently occurs within the BHJ layer representing the weakest layer within the device stack. Additionally, it was found that at temperatures below the glass transition temperature (∼41-45 °C), decohesion was characterized by brittle failure via molecular bond rupture. Above the glass transition temperature, decohesion growth occurred by a viscoelastic process in the BHJ layer, leading to a significant degree of viscoelastic deformation. We develop a viscoelastic model based on molecular relaxation to describe the resulting behavior. The study has implications for OSC long-term reliability and device performance, which are important for OSC production and implementation.

  14. Exact Linearization For Control Of Robots

    NASA Technical Reports Server (NTRS)

    Kreutz, Kenneth K.

    1990-01-01

    Equivalence of several theoretical approaches discussed. Report comments on application of geometric control theory (GCT), resolved-acceleration control (RAC), operational-space control (OSC), and nonlinear-decoupling theory (NDT) to remote manipulator consisting of multiple rigid links. Principal concern, search for nonlinear feedback law making end effector behave, for purposes of control, as though its dynamics linear and decoupled.

  15. 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...

  16. 32 CFR 145.6 - Procedures.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 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...

  17. 32 CFR 145.6 - Procedures.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 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...

  18. 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...

  19. 32 CFR 145.6 - Procedures.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 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...

  20. 40 CFR 300.440 - Procedures for planning and implementing off-site response actions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... implementing off-site response actions. 300.440 Section 300.440 Protection of Environment ENVIRONMENTAL... human health and the environment, the On-Scene Coordinator (OSC) may determine that it is necessary to...) Applicable sections of State environmental laws; and (C) In addition, land disposal units at RCRA subtitle...

  1. Organic and perovskite solar cells: Working principles, materials and interfaces.

    PubMed

    Marinova, Nevena; Valero, Silvia; Delgado, Juan Luis

    2017-02-15

    In the last decades organic solar cells (OSCs) have been considered as a promising photovoltaic technology with the potential to provide reasonable power conversion efficiencies combined with low cost and easy processability. Unexpectedly, Perovskite Solar Cells (PSCs) have experienced unprecedented rise in Power Conversion Efficiency (PCE) thus emerging as a highly efficient photovoltaic technology. OSCs and PSCs are two different kind of devices with distinct charge generation mechanism, which however share some similarities in the materials processing, thus standard strategies developed for OSCs are currently being employed in PSCs. In this article, we recapitulate the main processes in these two types of photovoltaic technologies with an emphasis on interfacial processes and interfacial modification, spotlighting the materials and newest approaches in the interfacial engineering. We discuss on the relevance of well-known materials coming from the OSCs field, which are now being tested in the PSCs field, while maintaining a focus on the importance of the material design for highly efficient, stable and accessible solar cells.

  2. 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.

  3. Tin doped indium oxide anodes with artificially controlled nano-scale roughness using segregated Ag nanoparticles for organic solar cells

    NASA Astrophysics Data System (ADS)

    Kim, Hyo-Joong; Ko, Eun-Hye; Noh, Yong-Jin; Na, Seok-In; Kim, Han-Ki

    2016-09-01

    Nano-scale surface roughness in transparent ITO films was artificially formed by sputtering a mixed Ag and ITO layer and wet etching of segregated Ag nanoparticles from the surface of the ITO film. Effective removal of self-segregated Ag particles from the grain boundaries and surface of the crystalline ITO film led to a change in only the nano-scale surface morphology of ITO film without changes in the sheet resistance and optical transmittance. A nano-scale rough surface of the ITO film led to an increase in contact area between the hole transport layer and the ITO anode, and eventually increased the hole extraction efficiency in the organic solar cells (OSCs). The heterojunction OSCs fabricated on the ITO anode with a nano-scale surface roughness exhibited a higher power conversion efficiency of 3.320%, than that (2.938%) of OSCs made with the reference ITO/glass. The results here introduce a new method to improve the performance of OSCs by simply modifying the surface morphology of the ITO anodes.

  4. Tin doped indium oxide anodes with artificially controlled nano-scale roughness using segregated Ag nanoparticles for organic solar cells.

    PubMed

    Kim, Hyo-Joong; Ko, Eun-Hye; Noh, Yong-Jin; Na, Seok-In; Kim, Han-Ki

    2016-09-19

    Nano-scale surface roughness in transparent ITO films was artificially formed by sputtering a mixed Ag and ITO layer and wet etching of segregated Ag nanoparticles from the surface of the ITO film. Effective removal of self-segregated Ag particles from the grain boundaries and surface of the crystalline ITO film led to a change in only the nano-scale surface morphology of ITO film without changes in the sheet resistance and optical transmittance. A nano-scale rough surface of the ITO film led to an increase in contact area between the hole transport layer and the ITO anode, and eventually increased the hole extraction efficiency in the organic solar cells (OSCs). The heterojunction OSCs fabricated on the ITO anode with a nano-scale surface roughness exhibited a higher power conversion efficiency of 3.320%, than that (2.938%) of OSCs made with the reference ITO/glass. The results here introduce a new method to improve the performance of OSCs by simply modifying the surface morphology of the ITO anodes.

  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.

  6. 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.

  7. 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

    2016-10-01

    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.

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

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    .... (2) When using multitrack processing, OSC may provide requesters in its slower track(s) with an opportunity to limit the scope of their requests in order to qualify for faster processing within the specified limits of the faster track(s). (c) Expedited processing. (1) Requests and appeals will be...

  9. 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.

  10. 5 CFR 1800.1 - Filing complaints of prohibited personnel practices or other prohibited activities.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... violation of law; (10) Discrimination based on personal conduct not adverse to job performance; (11...: (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...

  11. Asymmetrical Squaraines Bearing Fluorine-Substituted Indoline Moieties for High-Performance Solution-Processed Small-Molecule Organic Solar Cells.

    PubMed

    Yang, Daobin; Yang, Lin; Huang, Yan; Jiao, Yan; Igarashi, Tsukasa; Chen, Yao; Lu, Zhiyun; Pu, Xuemei; Sasabe, Hisahiro; Kido, Junji

    2015-06-24

    Two novel asymmetrical squaraines based on the indoline unit, ASQ-5-F and ASQ-5-DF, with one and two fluorine substituents, have been developed to investigate the effect of fluorine substituted on small-molecule bulk-heterojunction (BHJ) organic solar cells (OSCs). In comparison with non-fluorine-substituted ASQ-5, both fluorine-substituted ASQ-5-F and ASQ-5-DF possess analogous absorption band gaps but 0.05 and 0.10 eV lowered highest occupied molecular orbital (HOMO) energy levels, respectively. Single-crystal analysis exhibits that ASQ-5-DF shows more desirable intermolecular packing patterns for the hole-carrier collection than ASQ-5 does; hence, higher hole mobility could be acquired. Therefore, solution-processed small-molecule BHJ OSCs fabricated with ASQ-5-F/PC71BM and ASQ-5-DF/PC71BM blends exhibit extremely higher power conversion efficiency (PCE; 5.0% and 6.0%, respectively) than that of ASQ-5/PC71BM (4.5%). The much improved PCE could be attributed to the simultaneously enhanced Voc, Jsc, and FF relative to those of the ASQ-5-based device. To our knowledge, this is the highest PCE (6.0%) among squaraine-based solution-processed BHJ OSCs and the highest PCE in OSCs based on the fluorinated donor segment of small molecules.

  12. Understanding the Impact of Hierarchical Nanostructure in Ternary Organic Solar Cells

    PubMed Central

    Fang, Jin; Wang, Zaiyu; Zhang, Yajie; Deng, Dan; Wang, Zhen; Lu, Kun

    2015-01-01

    Ternary organic solar cells (OSCs), which blend two donors and fullerene derivatives with different absorption ranges, are a promising potential strategy for high‐power conversion efficiencies (PCEs). In this study, inverted ternary OSCs are fabricated by blending a highly crystalline small molecule BDT‐3T‐CNCOO in a low band gap polymer PBDTTT‐C‐T:PC71BM. As the small molecule is introduced, the overall PCEs increase from 7.60% to 8.58%. The morphologies of ternary blends are studied by combining transmission electron microscopy and X‐ray scattering techniques at different length scales. Hierarchical phase separation is revealed in the ternary blend, which is composed of domains with sizes of ≈88, ≈50, and ≈20 nm, respectively. The hierarchical phase separation balances the charge separation and transport in ternary OSCs. As a result, the fill factors of the devices significantly improve from 58.4% to 71.6%. Thus, ternary blends show higher hole mobility and higher fill factor than binary blends, which demonstrates a facile strategy to increase the performance of OSCs. PMID:27722074

  13. Mixing-Induced Anisotropic Correlations in Molecular Crystalline Systems: Rationalizing the Behavior of Organic Semiconductor Blends

    NASA Astrophysics Data System (ADS)

    Broch, Katharina; Aufderheide, Antje; Novak, Jiri; Hinderhofer, Alexander; Gerlach, Alexander; Banerjee, Rupak; Schreiber, Frank

    2013-03-01

    Binary mixtures of organic semiconductors (OSCs) have recently become an important field of research, as they find applications in opto-electronic devices. In these systems, the mixing (intermixing vs. phase separation) and ordering behavior is crucial, since it affects the optical and electronic properties. We present a comprehensive study of binary mixtures of the three prototypical OSCs pentacene (PEN), perfluoropentacene (PFP) and diindenoperlyene (DIP) in all possible combinations. Using X-ray reflectivity and grazing incidence X-ray diffraction we investigate the stuctural properties of the mixed films as well as their impact on the optical spectra obtained by spectroscopic ellipsometry. For PEN:DIP we find an anisotropic ordering behavior, comparable to that observed in some liquid crystals, which is fundamentally new for OSCs. The influence of sterical compatibility and the strength of the intermolecular interactions on the mixing and ordering behavior in the different blends will be discussed by extending a conventional mean-field model. Finally, we discuss general rules for the targeted preparation of blends of OSCs.

  14. 77 FR 24242 - Privacy Act of 1974; System of Records

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-23

    ... Criminal Background Check System (NICS), under the reporting requirements of the Brady Handgun Violence... office) to the OSC; q. Disclose information to the news media and the public when (1) The matter under... requirements of the Brady Handgun Violence Prevention Act, as amended by the NICS Improvement Amendments Act...

  15. 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…

  16. 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…

  17. Semantic transparency in free stems: The effect of Orthography-Semantics Consistency on word recognition.

    PubMed

    Marelli, Marco; Amenta, Simona; Crepaldi, Davide

    2015-01-01

    A largely overlooked side effect in most studies of morphological priming is a consistent main effect of semantic transparency across priming conditions. That is, participants are faster at recognizing stems from transparent sets (e.g., farm) in comparison to stems from opaque sets (e.g., fruit), regardless of the preceding primes. This suggests that semantic transparency may also be consistently associated with some property of the stem word. We propose that this property might be traced back to the consistency, throughout the lexicon, between the orthographic form of a word and its meaning, here named Orthography-Semantics Consistency (OSC), and that an imbalance in OSC scores might explain the "stem transparency" effect. We exploited distributional semantic models to quantitatively characterize OSC, and tested its effect on visual word identification relying on large-scale data taken from the British Lexicon Project (BLP). Results indicated that (a) the "stem transparency" effect is solid and reliable, insofar as it holds in BLP lexical decision times (Experiment 1); (b) an imbalance in terms of OSC can account for it (Experiment 2); and

  18. 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.

  19. 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

  20. Highly efficient and bendable organic solar cells using a three-dimensional transparent conducting electrode

    NASA Astrophysics Data System (ADS)

    Wang, Wei; Bae, Tae-Sung; Park, Yeon Hyun; Kim, Dong Ho; Lee, Sunghun; Min, Guanghui; Lee, Gun-Hwan; Song, Myungkwan; Yun, Jungheum

    2014-05-01

    A three-dimensional (3D) transparent conducting electrode, consisting of a quasi-periodic array of discrete indium-tin-oxide (ITO) nanoparticles superimposed on a highly conducting oxide-metal-oxide multilayer using ITO and silver oxide (AgOx) as oxide and metal layers, respectively, is synthesized on a polymer substrate and used as an anode in highly flexible organic solar cells (OSCs). The 3D electrode is fabricated using vacuum sputtering sequences to achieve self-assembly of distinct ITO nanoparticles on a continuous ITO-AgOx-ITO multilayer at room-temperature without applying conventional high-temperature vapour-liquid-solid growth, solution-based nanoparticle coating, or complicated nanopatterning techniques. Since the 3D electrode enhances the hole-extraction rate in OSCs owing to its high surface area and low effective series resistance for hole transport, OSCs based on this 3D electrode exhibit a power conversion efficiency that is 11-22% higher than that achievable in OSCs by means of conventional planar ITO film-type electrodes. A record high efficiency of 6.74% can be achieved in a bendable OSC fabricated on a poly(ethylene terephthalate) substrate.A three-dimensional (3D) transparent conducting electrode, consisting of a quasi-periodic array of discrete indium-tin-oxide (ITO) nanoparticles superimposed on a highly conducting oxide-metal-oxide multilayer using ITO and silver oxide (AgOx) as oxide and metal layers, respectively, is synthesized on a polymer substrate and used as an anode in highly flexible organic solar cells (OSCs). The 3D electrode is fabricated using vacuum sputtering sequences to achieve self-assembly of distinct ITO nanoparticles on a continuous ITO-AgOx-ITO multilayer at room-temperature without applying conventional high-temperature vapour-liquid-solid growth, solution-based nanoparticle coating, or complicated nanopatterning techniques. Since the 3D electrode enhances the hole-extraction rate in OSCs owing to its high surface area

  1. 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 Central

    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 Rosa26tdTm/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

  2. 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.

  3. Multilevel Safety Climate and Safety Performance in the Construction Industry: Development and Validation of a Top-Down Mechanism

    PubMed Central

    Gao, Ran; Chan, Albert P.C.; Utama, Wahyudi P.; Zahoor, Hafiz

    2016-01-01

    The character of construction projects exposes front-line workers to dangers and accidents. Safety climate has been confirmed to be a predictor of safety performance in the construction industry. This study aims to explore the underlying mechanisms of the relationship between multilevel safety climate and safety performance. An integrated model was developed to study how particular safety climate factors of one level affect those of other levels, and then affect safety performance from the top down. A questionnaire survey was administered on six construction sites in Vietnam. A total of 1030 valid questionnaires were collected from this survey. Approximately half of the data were used to conduct exploratory factor analysis (EFA) and the remaining data were submitted to structural equation modeling (SEM). Top management commitment (TMC) and supervisors’ expectation (SE) were identified as factors to represent organizational safety climate (OSC) and supervisor safety climate (SSC), respectively, and coworkers’ caring and communication (CCC) and coworkers’ role models (CRM) were identified as factors to denote coworker safety climate (CSC). SEM results show that OSC factor is positively related to SSC factor and CSC factors significantly. SSC factor could partially mediate the relationship between OSC factor and CSC factors, as well as the relationship between OSC factor and safety performance. CSC factors partially mediate the relationship between OSC factor and safety performance, and the relationship between SSC factor and safety performance. The findings imply that a positive safety culture should be established both at the organizational level and the group level. Efforts from all top management, supervisors, and coworkers should be provided to improve safety performance in the construction industry. PMID:27834823

  4. Hyaluronan Stabilizes Focal Adhesions, Filopodia, and the Proliferative Phenotype in Esophageal Squamous Carcinoma Cells*

    PubMed Central

    Twarock, Sören; Tammi, Markku I.; Savani, Rashmin C.; Fischer, Jens W.

    2010-01-01

    Hyaluronan (HA) is a polysaccharide component in the parenchyma and stroma of human esophageal squamous cell carcinoma (ESCC). Clinically, esophageal cancer represents a highly aggressive tumor type with poor prognosis resulting in a 5-year survival rate of 5%. The aim of the present study was the detailed analysis of the role of HA synthesis for ESCC phenotype in vitro using the ESCC cell line OSC1. In OSC1 cells, pericellular HA-matrix surrounding extended actin-dependent filopodia was detected. The small molecule inhibitor of HA synthesis, 4-methylumbelliferone (4-MU, 0.3 mm) caused loss of these filopodia and focal adhesions and inhibited proliferation and migration. In search of the underlying mechanism cleavage of focal adhesion kinase (FAK) was detected by immunoblotting. In addition, displacing HA by an HA-binding peptide (Pep-1, 500 μg/ml) and digestion of pericellular HA by hyaluronidase resulted in cleavage of focal adhesions. Furthermore, real-time reverse transcription PCR revealed that HA synthase 3 (HAS3) > HAS2 are the predominant HA-synthases in OSC1. Lentiviral transduction with shHAS3, and to a lesser extent with shHAS2, reduced intact FAK protein and filopodia as well as proliferation and migration. Furthermore, down-regulation by lentiviral shRNA of RHAMM (receptor of HA-mediated motility) but not CD44 induced loss of filopodia and caused FAK cleavage. In contrast, knockdown of both HA receptors inhibited proliferation and migration of OSC1. In conclusion, HA synthesis and, in turn, RHAMM and CD44 signaling promoted an activated phenotype of OSC1. Because RHAMM appears to support both filopodia, FAK, and the proliferative and migratory phenotype, it may be promising to explore RHAMM as a potential therapeutic target in esophageal cancer. PMID:20463012

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. An objective structured clinical exam to measure intrinsic CanMEDS roles

    PubMed Central

    Kassam, Aliya; Cowan, Michèle; Donnon, Tyrone

    2016-01-01

    Background The CanMEDS roles provide a comprehensive framework to organize competency-based curricula; however, there is a challenge in finding feasible, valid, and reliable assessment methods to measure intrinsic roles such as Communicator and Collaborator. The objective structured clinical exam (OSCE) is more commonly used in postgraduate medical education for the assessment of clinical skills beyond medical expertise. Method We developed the CanMEDS In-Training Exam (CITE), a six-station OSCE designed to assess two different CanMEDS roles (one primary and one secondary) and general communication skills at each station. Correlation coefficients were computed for CanMEDS roles within and between stations, and for general communication, global rating, and total scores. One-way analysis of variance (ANOVA) was used to investigate differences between year of residency, sex, and the type of residency program. Results In total, 63 residents participated in the CITE; 40 residents (63%) were from internal medicine programs, whereas the remaining 23 (37%) were pursuing other specialties. There was satisfactory internal consistency for all stations, and the total scores of the stations were strongly correlated with the global scores r=0.86, p<0.05. Noninternal medicine residents scored higher in terms of the Professional competency overall, whereas internal medicine residents scored significantly higher in the Collaborator competency overall. Discussion The OSCE checklists developed for the assessment of intrinsic CanMEDS roles were functional, but the specific items within stations required more uniformity to be used between stations. More generic types of checklists may also improve correlations across stations. Conclusion An OSCE measuring intrinsic competence is feasible; however, further development of our cases and checklists is needed. We provide a model of how to develop an OSCE to measure intrinsic CanMEDS roles that educators may adopt as residency programs move

  10. Does a Rater's Professional Background Influence Communication Skills Assessment?

    PubMed

    Artemiou, Elpida; Hecker, Kent G; Adams, Cindy L; Coe, Jason B

    2015-01-01

    There is increasing pressure in veterinary education to teach and assess communication skills, with the Objective Structured Clinical Examination (OSCE) being the most common assessment method. Previous research reveals that raters are a large source of variance in OSCEs. This study focused on examining the effect of raters' professional background as a source of variance when assessing students' communication skills. Twenty-three raters were categorized according to their professional background: clinical sciences (n=11), basic sciences (n=4), clinical communication (n=5), or hospital administrator/clinical skills technicians (n=3). Raters from each professional background were assigned to the same station and assessed the same students during two four-station OSCEs. Students were in year 2 of their pre-clinical program. Repeated-measures ANOVA results showed that OSCE scores awarded by the rater groups differed significantly: (F(matched_station_1) [2,91]=6.97, p=.002), (F(matched_station_2) [3,90]=13.95, p=.001), (F(matched_station_3) [3,90]=8.76, p=.001), and ((Fmatched_station_4) [2,91]=30.60, p=.001). A significant time effect between the two OSCEs was calculated for matched stations 1, 2, and 4, indicating improved student performances. Raters with a clinical communication skills background assigned scores that were significantly lower compared to the other rater groups. Analysis of written feedback provided by the clinical sciences raters showed that they were influenced by the students' clinical knowledge of the case and that they did not rely solely on the communication checklist items. This study shows that it is important to consider rater background both in recruitment and training programs for communication skills' assessment.

  11. Multilevel Safety Climate and Safety Performance in the Construction Industry: Development and Validation of a Top-Down Mechanism.

    PubMed

    Gao, Ran; Chan, Albert P C; Utama, Wahyudi P; Zahoor, Hafiz

    2016-11-08

    The character of construction projects exposes front-line workers to dangers and accidents. Safety climate has been confirmed to be a predictor of safety performance in the construction industry. This study aims to explore the underlying mechanisms of the relationship between multilevel safety climate and safety performance. An integrated model was developed to study how particular safety climate factors of one level affect those of other levels, and then affect safety performance from the top down. A questionnaire survey was administered on six construction sites in Vietnam. A total of 1030 valid questionnaires were collected from this survey. Approximately half of the data were used to conduct exploratory factor analysis (EFA) and the remaining data were submitted to structural equation modeling (SEM). Top management commitment (TMC) and supervisors' expectation (SE) were identified as factors to represent organizational safety climate (OSC) and supervisor safety climate (SSC), respectively, and coworkers' caring and communication (CCC) and coworkers' role models (CRM) were identified as factors to denote coworker safety climate (CSC). SEM results show that OSC factor is positively related to SSC factor and CSC factors significantly. SSC factor could partially mediate the relationship between OSC factor and CSC factors, as well as the relationship between OSC factor and safety performance. CSC factors partially mediate the relationship between OSC factor and safety performance, and the relationship between SSC factor and safety performance. The findings imply that a positive safety culture should be established both at the organizational level and the group level. Efforts from all top management, supervisors, and coworkers should be provided to improve safety performance in the construction industry.

  12. The Office of Site Closure: Progress in the Face of Challenges

    SciTech Connect

    Fiore, J. J.; Murphie, W. E.; Meador, S. W.

    2002-02-26

    The Office of Site Closure (OSC) was formed in November 1999 when the Department of Energy's (DOE's) Office of Environmental Management (EM) reorganized to focus specifically on site cleanup and closure. OSC's objective is to achieve safe and cost-effective cleanups and closures that are protective of our workers, the public, and the environment, now and in the future. Since its inception, OSC has focused on implementing a culture of safe closure, with emphasis in three primary areas: complete our responsibility for the Closure Sites Rocky Flats, Mound, Fernald, Ashtabula, and Weldon Spring; complete our responsibility for cleanup at sites where the DOE mission has been completed (examples include Battelle King Avenue and Battelle West Jefferson in Columbus, and General Atomics) or where other Departmental organizations have an ongoing mission (examples include the Brookhaven, Livermore, or Los Alamos National Laboratories, and the Nevada Test Site); and create a framework a nd develop specific business closure tools that will help sites close, such as guidance for and decisions on post-contract benefit liabilities, records retention, and Federal employee incentives for site closure. This paper discusses OSC's 2001 progress in achieving site cleanups, moving towards site closure, and developing specific business closure tools to support site closure. It describes the tools used to achieve progress towards cleanup and closure, such as the application of new technologies, changes in contracting approaches, and the development of agreements between sites and with host states. The paper also identifies upcoming challenges and explores options for how Headquarters and the sites can work together to address these challenges. Finally, it articulates OSC's new focus on oversight of Field Offices to ensure they have the systems in place to oversee contractor activities resulting in site cleanups and closures.

  13. High-throughput differentiation of heparin from other glycosaminoglycans by pyrolysis mass spectrometry.

    PubMed

    Nemes, Peter; Hoover, William J; Keire, David A

    2013-08-06

    Sensors with high chemical specificity and enhanced sample throughput are vital to screening food products and medical devices for chemical or biochemical contaminants that may pose a threat to public health. For example, the rapid detection of oversulfated chondroitin sulfate (OSCS) in heparin could prevent reoccurrence of heparin adulteration that caused hundreds of severe adverse events including deaths worldwide in 2007-2008. Here, rapid pyrolysis is integrated with direct analysis in real time (DART) mass spectrometry to rapidly screen major glycosaminoglycans, including heparin, chondroitin sulfate A, dermatan sulfate, and OSCS. The results demonstrate that, compared to traditional liquid chromatography-based analyses, pyrolysis mass spectrometry achieved at least 250-fold higher sample throughput and was compatible with samples volume-limited to about 300 nL. Pyrolysis yielded an abundance of fragment ions (e.g., 150 different m/z species), many of which were specific to the parent compound. Using multivariate and statistical data analysis models, these data enabled facile differentiation of the glycosaminoglycans with high throughput. After method development was completed, authentically contaminated samples obtained during the heparin crisis by the FDA were analyzed in a blinded manner for OSCS contamination. The lower limit of differentiation and detection were 0.1% (w/w) OSCS in heparin and 100 ng/μL (20 ng) OSCS in water, respectively. For quantitative purposes the linear dynamic range spanned approximately 3 orders of magnitude. Moreover, this chemical readout was successfully employed to find clues in the manufacturing history of the heparin samples that can be used for surveillance purposes. The presented technology and data analysis protocols are anticipated to be readily adaptable to other chemical and biochemical agents and volume-limited samples.

  14. Organic Solar Cells Based on WO2.72 Nanowire Anode Buffer Layer with Enhanced Power Conversion Efficiency and Ambient Stability.

    PubMed

    You, Longzhen; Liu, Bin; Liu, Tao; Fan, Bingbing; Cai, Yunhao; Guo, Lin; Sun, Yanming

    2017-04-12

    Tungsten oxide as an alternative to conventional acidic PEDOT:PSS has attracted much attention in organic solar cells (OSCs). However, the vacuum-processed WO3 layer and high-temperature sol-gel hydrolyzed WOX are incompatible with large-scale manufacturing of OSCs. Here, we report for the first time that a specific tungsten oxide WO2.72 (W18O49) nanowire can function well as the anode buffer layer. The nw-WO2.72 film exhibits a high optical transparency. The power conversion efficiency (PCE) of OSCs based on three typical polymer active layers PTB7:PC71BM, PTB7-Th:PC71BM, and PDBT-T1:PC71BM with nw-WO2.72 layer were improved significantly from 7.27 to 8.23%, from 8.44 to 9.30%, and from 8.45 to 9.09%, respectively compared to devices with PEDOT:PSS. Moreover, the photovoltaic performance of OSCs based on small molecule p-DTS(FBTTh2)2:PC71BM active layer was also enhanced with the incorporation of nw-WO2.72. The enhanced performance is mainly attributed to the improved short-circuit current density (Jsc), which benefits from the oxygen vacancies and the surface apophyses for better charge extraction. Furthermore, OSCs based on nw-WO2.72 show obviously improved ambient stability compared to devices with PEDOT:PSS layer. The results suggest that nw-WO2.72 is a promising candidate for the anode buffer layer materials in organic solar cells.

  15. Pharmaceutical care practice in patients with chronic kidney disease.

    PubMed

    Arroyo Monterroza, Dadier Antonio; Castro Bolivar, José Francisco

    2017-03-01

    Introducción: El impacto de la insuficiencia renal crónica en la salud ya dejó de ser solo un problema paciente-médico, no solo por el aumento del número de pacientes diagnosticados, sino por el costo humano y económico que ocasiona en los sistemas de salud. Es por ello que la Atención Farmacéutica debe incluir procedimientos normalizados de trabajo que se encuentren estructurados por criterios consensuados para realizar el Seguimiento Farmacoterapéutico, que permitirá la prevención, identificación y resolución de resultados negativos asociados a la medicación en los pacientes.Objetivos: Conocer los tipos de problemas relacionados con los medicamentos y los resultados negativos asociados a los medicamentos que se pueden detectar, prevenir y resolver en pacientes con insuficiencia renal crónica mediante el seguimiento farmacoterapéutico. Método: Se realizó un estudio de tipo cuasi experimental, con diseño descriptivo y retrospectivo, en 47 pacientes hospitalizados, diagnosticados de Insuficiencia Renal Crónica, en una clínica de alta complejidad, empleando la metodología DADER. Se analizaron sus tratamientos farmacológicos y se verificaron si estos fueron necesarios, efectivos y seguros, teniendo en cuenta variables como los resultados negativos asociados a la medicación, los problemas relacionados con la medicación, las intervenciones farmacéuticas y los estadios de la insuficiencia renal.Resultados: Se detectaron 51 resultados negativos asociados a la medicación durante el estudio, el 13,72% fueron de necesidad, el 45,1% de efectividad y el 41,18% de seguridad. Se realizaron un total de 41 intervenciones farmacéuticas, 35 fueron aceptadas y 6 no fueron aceptadas; de estas 6 intervenciones no aceptadas, 3 problemas de salud no se solucionaron, se realizaron 12 reajustes de dosis, siendo el cefepime el medicamento con mayor número de reajustes. El mayor número de pacientes se encontraban en el estadio III y V

  16. Satisfaction with gastrostomy feeding in caregivers of children with home enteral nutrition; application of the SAGA-8 questionnaire and analysis of involved factors.

    PubMed

    Martínez-Costa, Cecilia; Calderón, Caterina; Gómez-López, Lilianne; Borraz, Soraya; Pedrón-Giner, Consuelo

    2013-01-01

    Objetivos: Valorar el grado de satisfacción de los cuidadores de niños con alimentación mediante gastrostomía aplicando el cuestionario estructurado SAGA-8. Segundo, evaluar si la satisfacción parental guarda relación con diversas variables independientes. Métodos: Se realizó un estudio observacional, transversal en 92 cuidadores de niños con enfermedades crónicas que recibían alimentación mediante gastrostomía. Se analizaron los siguientes datos: satisfacción de los cuidadores con la alimentación por gastrostomía (SAGA-8), edad de implantación de la gastrostomía, parámetros antropométricos, tiempo de soporte nutricional, características demográficas familiares y estado psicológico del cuidador. Resultados: Todos los cuidadores eran madres. La mayoría (82,6%) manifestaron una elevada satisfacción con la alimentación mediante gastrostomía. El 85,9% resaltó la sencillez de la técnica sintiéndose el 85,9% muy satisfecha con el apoyo ofrecido por el centro. Un 73,9% de las madres percibió mejoría nutricional en su hijo, señalando el 89,1% un mayor bienestar familiar. Además, el 75% de las madres comunicaron una disminución en el tiempo de alimentación y el 68,5% una reducción en la morbilidad respiratoria. Finalmente, el 71,7% de las madres reconoció que hubieran aceptado antes el procedimiento. La satisfacción se correlacionó significativamente con la edad de implantación de la gastrostomía y con la duración del soporte nutricional, explicando ambos factores el 19,4% de la varianza de la satisfacción. No se encontró correlación con datos antropométricos, tipo de soporte nutricional, características demográficas familiares ni con el estado psicológico del cuidador. Conclusiones: El cuestionario SAGA-8 es sencillo, específico y fácil de aplicar para evaluar el grado de satisfacción de los padres/cuidadores con la alimentación mediante gastrostomía contribuyendo a su monitorización. La duración del soporte

  17. Flow-Directed Crystallization for Printed Electronics.

    PubMed

    Qu, Ge; Kwok, Justin J; Diao, Ying

    2016-12-20

    The solution printability of organic semiconductors (OSCs) represents a distinct advantage for materials processing, enabling low-cost, high-throughput, and energy-efficient manufacturing with new form factors that are flexible, stretchable, and transparent. While the electronic performance of OSCs is not comparable to that of crystalline silicon, the solution processability of OSCs allows them to complement silicon by tackling challenging aspects for conventional photolithography, such as large-area electronics manufacturing. Despite this, controlling the highly nonequilibrium morphology evolution during OSC printing remains a challenge, hindering the achievement of high electronic device performance and the elucidation of structure-property relationships. Many elegant morphological control methodologies have been developed in recent years including molecular design and novel processing approaches, but few have utilized fluid flow to control morphology in OSC thin films. In this Account, we discuss flow-directed crystallization as an effective strategy for controlling the crystallization kinetics during printing of small molecule and polymer semiconductors. Introducing the concept of flow-directed crystallization to the field of printed electronics is inspired by recent advances in pharmaceutical manufacturing and flow processing of flexible-chain polymers. Although flow-induced crystallization is well studied in these areas, previous findings may not apply directly to the field of printed electronics where the molecular structures (i.e., rigid π-conjugated backbone decorated with flexible side chains) and the intermolecular interactions (i.e., π-π interactions, quadrupole interactions) of OSCs differ substantially from those of pharmaceuticals or flexible-chain polymers. Another critical difference is the important role of solvent evaporation in open systems, which defines the flow characteristics and determines the crystallization kinetics and pathways. In

  18. 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

  19. 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.

  20. 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.

  1. 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.

  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. A Process for Curricular Improvement Based on Evaluation of Student Performance on Milestone Examinations

    PubMed Central

    Hylton, Ann C.; Justice, Michael

    2016-01-01

    Objective. To identify and address areas for curricular improvement by evaluating student achievement of expected learning outcomes and competencies on annual milestone examinations. Design. Students were tested each professional year with a comprehensive milestone examination designed to evaluate student achievement of learning outcomes and professional competencies using a combination of multiple-choice questions, standardized patient assessments (SPAs), and objective structured clinical examination (OSCE) questions. Assessment. Based on student performance on milestone examinations, curricular changes were instituted, including an increased emphasis on graded comprehensive cases, OSCE skills days, and use of patient simulation in lecture and laboratory courses. After making these changes, significant improvements were observed in second and third-year pharmacy students’ grades for the therapeutic case and physician interaction/errors and omissions components of the milestone examinations. Conclusion. Results from milestone examinations can be used to identify specific areas in which curricular improvements are needed to foster student achievement of learning outcomes and professional competencies. PMID:28090108

  4. Triarylamine: Versatile Platform for Organic, Dye-Sensitized, and Perovskite Solar Cells.

    PubMed

    Wang, Jiayu; Liu, Kuan; Ma, Lanchao; Zhan, Xiaowei

    2016-12-14

    Triarylamine (TAA) and related materials have dramatically promoted the development of organic and hybrid photovoltaics during the past decade. The power conversion efficiencies of TAA-based organic solar cells (OSCs), dye-sensitized solar cells (DSSCs), and perovskite solar cells (PSCs) have exceeded 11%, 14%, and 20%, which are among the best results for these three kinds of devices, respectively. In this review, we summarize the recent advances of the high-performance TAA-based materials in OSCs, DSSCs, and PSCs. We focus our discussion on the structure-property relationship of the TAA-based materials in order to shed light on the solutions to the challenges in the field of organic and hybrid photovoltaics. Some design strategies for improving the materials and device performance and possible research directions in the near future are also proposed.

  5. Inhibition of human lanosterol synthase by the constituents of Colocasia esculenta (taro).

    PubMed

    Sakano, Yuichi; Mutsuga, Motoh; Tanaka, Rie; Suganuma, Hiroyuki; Inakuma, Takahiro; Toyoda, Masatake; Goda, Yukihiro; Shibuya, Masaaki; Ebizuka, Yutaka

    2005-02-01

    Ethanol extracts of lyophilized vegetables were tested for inhibition of human lanosterol synthase (hOSC) in order to find the compounds to suppress cholesterol biosynthesis. Of 130 samples tested, twelve samples showed significant inhibition. Among them, Colocasia esculenta (taro) showed the highest inhibition (55% inhibition at 300 microg/ml). Examination of activity variation among eight taro cultivars indicated that "Aichi-wase" and "Yatsugashira" had the most potent activity for hOSC inhibition. In order to identify the active constituent of taro, ethanol extracts of "Aichi-wase" were partitioned with hexane and aqueous methanol, and fractionated by silica gel column chromatography. Inhibitory activity was concentrated in two major active fractions. Further purification of these fractions by preparative HPLC gave three monogalactosyldiacylglycerols and five digalactosyldiacylglycerols as active compounds that showed 28 to 67% inhibitory activities at the concentration 300 microg/ml.

  6. One-step synthesis of carbon nanosheets converted from a polycyclic compound and their direct use as transparent electrodes of ITO-free organic solar cells.

    PubMed

    Son, Su-Young; Noh, Yong-Jin; Bok, Changsuk; Lee, Sungho; Kim, Byoung Gak; Na, Seok-In; Joh, Han-Ik

    2014-01-21

    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.

  7. Creation of a Unified Set of Core-Collapse Supernovae for Training of Photometric Classifiers

    NASA Astrophysics Data System (ADS)

    D'Arcy Kenworthy, William; Scolnic, Daniel; Kessler, Richard

    2017-01-01

    One of the key tasks for future supernova cosmology analyses is to photometrically distinguish type Ia supernovae (SNe) from their core collapse (CC) counterparts. In order to train programs for this purpose, it is necessary to train on a large number of core-collapse SNe. However, there are only a handful used for current programs. We plan to use the large amount of CC lightcurves available on the Open Supernova Catalog (OSC). Since this data is scraped from many different surveys, it is given in a number of photometric systems with different calibration and filters. We therefore created a program to fit smooth lightcurves (as a function of time) to photometric observations of arbitrary SNe. The Supercal method is then used to translate the smoothed lightcurves to a single photometric system. We can thus compile a training set of 782 supernovae, of which 127 are not type Ia. These smoothed lightcurves are also being contributed upstream to the OSC as derived data.

  8. 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.

  9. Hybrid Optical/Digital Processor for Radar Imaging

    DTIC Science & Technology

    2007-11-02

    DDR2 SRAM 2, 4 MB 36 DDR2 SRAM 2, 4 MB DDR2 SRAM 2, 4 MB...36DDR2 SRAM 2, 4 MB DDR2 SRAM 2, 4 MB DDR2 SRAM 2, 4 MB 36 36 36 Prog Osc 3 DDR SDRAM 64 MB 32 88 88 PE 1 VIRTEXTM II XC2V 6000, 8000 I/O #1 DDR2 SRAM 2...4 MB 36 DDR2 SRAM 2, 4 MB DDR2 SRAM 2, 4 MB 36DDR2 SRAM 2, 4 MB DDR2 SRAM 2, 4 MB DDR2 SRAM 2, 4 MB 36 36 36 Prog Osc 3 DDR SDRAM 64 MB 32 168 PE

  10. 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.

  11. 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.

  12. 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.

  13. Bifurcation and nonlinear behavior of compartmentalized granular gases

    NASA Astrophysics Data System (ADS)

    Hou, Meiying; Liu, Rui; Li, Yinchang; Zhang, Yin; Shah, Sajjad Hussain

    2014-12-01

    Different from the molecular gas, clustering is a most commonly observed feature of the granular gas. A review is given of our previous work on the clustering, especially the oscillatory clustering for shaken fluidized granular matter in connected compartments, as examples for pattern formation and bifurcations in far from equilibrium systems. Flux model is presented and discussed for mono-disperse and bi-disperse granular systems. Comparison of the flux model with simulation results is given. They show reasonably well agreements. Besides the homogeneous (HOM), segregation (SEG), and oscillatory (OSC) states, two new stationary states (d-OSC and s-HOM) in the bi-disperse granular system are predicted by our simulation. In our recent work these two new states are observed experimentally, and their flow diagrams are obtained based on the flux model. The transition from degenerate oscillation state to oscillation state demonstrates a homoclinic gluing bifurcation.

  14. 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.

  15. 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

  16. Direct and parametric synchronization of a graphene self-oscillator

    NASA Astrophysics Data System (ADS)

    Houri, S.; Cartamil-Bueno, S. J.; Poot, M.; Steeneken, P. G.; van der Zant, H. S. J.; Venstra, W. J.

    2017-02-01

    We explore the dynamics of a graphene nanomechanical oscillator coupled to a reference oscillator. Circular graphene drums are forced into self-oscillation, at a frequency f osc , by means of photothermal feedback induced by illuminating the drum with a continuous-wave red laser beam. Synchronization to a reference signal, at a frequency f sync , is achieved by shining a power-modulated blue laser onto the structure. We investigate two regimes of synchronization as a function of both detuning and signal strength for direct ( f sync ≈ f o s c ) and parametric locking ( f sync ≈ 2 f osc ) . We detect a regime of phase resonance, where the phase of the oscillator behaves as an underdamped second-order system, with the natural frequency of the phase resonance showing a clear power-law dependence on the locking signal strength. The phase resonance is qualitatively reproduced using a forced van der Pol-Duffing-Mathieu equation.

  17. 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.

  18. Region V regional contingency plan and area contingency plan: Illinois, Indiana, Michigan, Minnesto, Ohio, Wisconsin

    SciTech Connect

    1997-08-01

    This Region 5 Oil and Hazardous Substances Pollution Contingency Plan (RCP) and Area Contingency Plan (ACP) is intended for use by Local, Tribal, State, and Federal emergency response personnel as a tool for procuring resources to respond to an oil or hazardous materials incident. It outlines the response mechanisms that would be activated among the various levels of the response community in the event of an emergency siuation. This RCP/ACP outlines the types of assistance available to Federal OSCs from Regional Response Team (RRT) member agencies during response actions and the cooperative response that should be carried out by OSCs during response actions. The plan also includes resource information from governmental, commercial, and other sources that may be utilized during a response. This plan has been organized to follow the structure of the Incident Command System (ICS), as outlined in the Integrated Contingency Plan guidance developed by the National Response Team (NRT).

  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. Using mixed solvent and changing spin-coating parameters to increase the efficiency and lifetime of organic solar cells.

    PubMed

    Tsai, Yu Sheng; Chu, Wei-Ping; Tang, Rong-Ming; Juang, Fuh-Shyang; Chang, Ming-Hua; Liu, Mark O; Hsieh, Tsung-Eong

    2008-10-01

    The derivative of C60, i.e., PCBM, and P3HT (3-hexylthiophene) were dissolved in chloroform:dichlorobenzene mixed solvent, then spin-coated as the active layer for organic solar cells (OSC). The experimental parameters were studied carefully to obtain the optimum power conversion efficiency (PCE), including the solvent mixing ratio, spin-coating speed, annealing conditions for the active layer, etc. The OSC devices were packaged with glass and a newly developed UV-glue to improve the lifetime and PCE. Dichlorobenzene solvent has great effect upon the PCE. Changing the spin-coating speed and increasing the number of steps increased the PCE apparently to 1.4%.

  1. 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.

  2. Recent Advances in Wide-Bandgap Photovoltaic Polymers.

    PubMed

    Cai, Yunhao; Huo, Lijun; Sun, Yanming

    2017-03-29

    The past decade has witnessed significant advances in the field of organic solar cells (OSCs). Ongoing improvements in the power conversion efficiency of OSCs have been achieved, which were mainly attributed to the design and synthesis of novel conjugated polymers with different architectures and functional moieties. Among various conjugated polymers, the development of wide-bandgap (WBG) polymers has received less attention than that of low-bandgap and medium-bandgap polymers. Here, we briefly summarize recent advances in WBG polymers and their applications in organic photovoltaic (PV) devices, such as tandem, ternary, and non-fullerene solar cells. Addtionally, we also dissuss the application of high open-circuit voltage tandem solar cells in PV-driven electrochemical water dissociation. We mainly focus on the molecular design strategies, the structure-property correlations, and the photovoltaic performance of these WBG polymers. Finally, we extract empirical regularities and provide invigorating perspectives on the future development of WBG photovoltaic materials.

  3. Transparent flexible organic solar cells with 6.87% efficiency manufactured by an all-solution process.

    PubMed

    da Silva, Wilson Jose; Kim, Hyeong Pil; Rashid bin Mohd Yusoff, Abd; Jang, Jin

    2013-10-07

    We demonstrate that polyaniline (PANI) behaves as an anode buffer layer, which makes it an excellent hole transport layer. PANI was coated between the photoactive layer and the top anode in transparent flexible organic solar cells (OSCs). The performances of the devices with different PANI thicknesses were investigated. The results demonstrate that the power conversion efficiency (PCE) increased nearly four-fold with an 18 nm thick PANI layer compared to the reference cell without PANI. The optimum device performance with an 18 nm PANI layer exhibits a Jsc of 11.60 mA cm(-2), a V(oc) of 0.89 V, a FF of 66.87%, and thus a PCE of 6.87% under AM1.5G illumination of 100 mW cm(-2). The conversion efficiency of transparent flexible OSCs changes after 1500 bending cycles.

  4. 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.

  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.

  6. Model-Based Systems Engineering in the Execution of Search and Rescue Operations

    DTIC Science & Technology

    2015-09-01

    At approximately 0730 local time, a sailor from USS Mustin was reported missing at morning muster by a fellow bunkmate. The subsequent man...tasked as the OSC. 2. Civilian Man Overboard Operational Situation It is the middle of another king crab season in the Bering Sea. At 2145 local time, a...marker smoke that was dropped off the aircraft carrier’s 120 radial for 51 nautical miles. At approximately 1430 local time, there was a mid-air

  7. Dermatology - a compulsory part of the UK medical school curriculum?

    PubMed

    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.

  8. The Islamic State Crisis and U.S. Policy

    DTIC Science & Technology

    2015-06-11

    Euphrates rivers in Iraq, seizing population centers including Mosul, one of Iraq’s largest cities . Since then, IS forces have massacred Syrian and...in fall of city of Idlib to Islamic fighters,” April 17, 2015. 8 OSC Report LIN2015050430405051, “Syrian Opposition Sources Cited on Efforts in...River Valley, with operations stretching from Ras al Ayn on the border with Turkey to Hasakah city . These areas are currently held by Kurdish Democratic

  9. Simulating the Effects of an Extended Source on the Shack-Hartmann Wavefront Sensor Through Turbulence

    DTIC Science & Technology

    2011-03-01

    United States Air Force, Department of Defense, or the United States Government. This material is declared a work of the U.S. Government and is not...subject to copyright protection in the United States . AFIT/GE/ENG/11-08 SIMULATING THE EFFECTS OF AN EXTENDED SOURCE ON THE SHACK-HARTMANN WAVEFRONT SENSOR...19 USAF United States Air Force . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 OSC

  10. 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

  11. 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

  12. 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.

  13. Correlating High Power Conversion Efficiency of PTB7:PC71BM Inverted Organic Solar Cells with Nanoscale Structures

    DOE PAGES

    Das, Sanjib; Keum, Jong Kahk; Browning, Jim; ...

    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

  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

    2015-11-03

    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.

  15. Mecânica celeste.

    NASA Astrophysics Data System (ADS)

    de Luca, N.; Ferraz-Mello, S.

    Contents: Os princípios da mec@OSC@@CCF@anica celeste. O problema de 2-corpos. O sistema de equações canônicas. A teoria das perturbações. O movimento de um satélite artifical. A teoria lunar e o movimento de outros satélites naturais. A teoria planetária. Procedimentos numéricos.

  16. Massachusetts needs a PGY-1 option for licensure.

    PubMed

    Donoff, Bruce

    2012-01-01

    The American Dental Association (ADA) House of Delegates voted to eliminate live patient clinical exams in the year 2000. Canadian dental graduates take an objective structured clinical examination (OSCE) for licensure. Several states have changed their dental practice acts to permit licensure by mentored experience of a general residency or specialty Dental students have led the fight, with some results, to eliminate a practice--live patient exams--that perpetuates unprofessional and potentially illegal activity.

  17. 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.

  18. A neural basis for real-world visual search in human occipitotemporal cortex.

    PubMed

    Peelen, Marius V; Kastner, Sabine

    2011-07-19

    Mammals are highly skilled in rapidly detecting objects in cluttered natural environments, a skill necessary for survival. What are the neural mechanisms mediating detection of objects in natural scenes? Here, we use human brain imaging to address the role of top-down preparatory processes in the detection of familiar object categories in real-world environments. Brain activity was measured while participants were preparing to detect highly variable depictions of people or cars in natural scenes that were new to the participants. The preparation to detect objects of the target category, in the absence of visual input, evoked activity patterns in visual cortex that resembled the response to actual exemplars of the target category. Importantly, the selectivity of multivoxel preparatory activity patterns in object-selective cortex (OSC) predicted target detection performance. By contrast, preparatory activity in early visual cortex (V1) was negatively related to search performance. Additional behavioral results suggested that the dissociation between OSC and V1 reflected the use of different search strategies, linking OSC preparatory activity to relatively abstract search preparation and V1 to more specific imagery-like preparation. Finally, whole-brain searchlight analyses revealed that, in addition to OSC, response patterns in medial prefrontal cortex distinguished the target categories based on the search cues alone, suggesting that this region may constitute a top-down source of preparatory activity observed in visual cortex. These results indicate that in naturalistic situations, when the precise visual characteristics of target objects are not known in advance, preparatory activity at higher levels of the visual hierarchy selectively mediates visual search.

  19. Armenia, Azerbaijan, and Georgia: Political Developments and Implications for U.S. Interests

    DTIC Science & Technology

    2011-04-15

    8.37 m.; Georgia: 4.59 m. (CIA, The World Factbook, July 2011 est.). Over 1 million people from the region are migrant workers in Russia and...threat to one or several members, and to provide mutual aid if attacked (current members include Armenia, Belarus , Kazakhstan, Kyrgyzstan, Russia...Azerbaijan) Belarus , Germany, Italy, Portugal, the Netherlands, Sweden, Finland, and Turkey. An OSCE high-level planning group composed of military

  20. A Numerical Solution to the Boltzmann Equation for Use in Calculating Pumping Rates in a CO2 Discharge Laser

    DTIC Science & Technology

    1989-12-01

    Numerical Solution ....... ....................... 113 E.1 Gauss- Jordan .......................................... 113 E.2 L-U Decomposition...2.4 Numerical Solution of the Boltzmann Equation Four numerical were used to solve equation (39). These were: : Gauss- Jordan , L-U Decom- position...both the Gauss- Jordan and L-U decomposition methods. 2.5 Transport Coefficiente In order to provide the required input to the laser design program CO2OSC

  1. Outsourcing Human Security: The Pros and Cons of Private Security Companies in Peacekeeping

    DTIC Science & Technology

    2013-03-01

    ONUSAL United Nations Observer Mission in El Salvador OPM Office of Personnel Management OSCE Organization for Security and Cooperation in...the war would restart; and finally, there were the cases such as El Salvador , Mozambique, and Nicaragua (coded as successes) where peacekeepers were...It is important to note that although the operations in El Salvador and Nicaraqua were coded as successes by Howard, crime, drug, and gang violence

  2. 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.

  3. [Application of wavelet multi-scale orthogonal signal correction in milk components measurement using near-infrared spectroscopy].

    PubMed

    Peng, Dan; Xu, Ke-Xin; Li, Chen-Xi

    2008-04-01

    Spectral interferences can have a significant impact on the spectral variation and as a consequence can adversely affect the results of calibration model in spectra analysis. Wavelet transform (WT) and orthogonal signal correction (OSC) were both the popular preprocessing algorithms. It was known that the former can effectively eliminate the background and noise and the latter can effectively filter out the interference information irrelevant to analyte concentration during the preprocessing of spectra. According to the different characteristics of analyte information and interference information in near-infrared (NIR) spectra, a new hybrid algorithm (WMOSC) that was the combination of discrete wavelet transform (DWT) and OSC was proposed to eliminate the spectral interferences including background, noise and systemic spectral variation irrelevant to the concentration. First, DWT was used to split the spectral signal into different frequency components, which keep the same data points as the original spectra data, to remove noise and background information by threshold method. Then OSC was applied to each frequency components to remove the information uncorrelated to the concentration independently. Finally, the spectra preprocessed by WMOSC were achieved through the summation of all frequency components. WMOSC was successfully applied to preprocess the NIR spectra data of milk. After elimination of the interference in the NIR spectra data by WMOSC, the partial least squares (PLS) regression was used to develop the calibration models for estimating the contents of main constituents in milk.The prediction ability and robustness of models obtained in subsequent PLS calibration using WMOSC were superior to those obtained using either DWT or OSC alone. The root mean square errors of prediction (RMSEP) of the models for fat, protein and lactose were 0.101 6%, 0.087 1% and 0.110 7%, respectively. The experimental results show that WMOSC is an effective method for

  4. HUMAN ENGINEERING FOR AN EFFECTIVE AIR-NAVIGATION AND TRAFFIC-CONTROL SYSTEM, AND APPENDIXES 1 THRU 3

    DTIC Science & Technology

    1951-03-14

    Henneman F. C.Frnick W. E. Kappauf WA R. Garner E. B. Newman F. C . Frick A. C . Williams, Jr.SW. R. Garner j.• JW. Gebhord W. F. Grether A report...Psychology Washington, D. C . UNCLASSIFIED ATI 133 954 (COPIES OSTAIMAULE FROM ASTIA-OSC) OHIO STATE UNIVERSITY RESECNH FOUNDATION, COLmUS HUMAN...Air Navigation Development Board, A-9 Civil Aeronautics Administration Washington 25, D. C . Dear Dr. Ewing: The attached report, entitled Human

  5. 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

  6. Validation of the Algorithm for Base Inspection Costs for the Component Support Cost System (D160B).

    DTIC Science & Technology

    2014-09-26

    DTIC , e 1ELECTE SJUL 1519850 B C-. Submitted to: Prepared by: *HEADQUARTERS LAJ AIR FORCE LOGISTICS COMMAND...Equipment Maintenance Documentation for Aircraft; Air-Launched Missiles; Ground- Launched Missiles; Except ICBMS; Drones ; and Related Training *Equipment, 1...expended in performing inspections and-in allocated portion of base maintenance overhead costs. This volume presents ISIs conclusions and recommendations, and the comments of the Office Of VAM4OSC. sof FILMED 9~ 8-85 * DTIC

  7. Genetics objective structured clinical exams at the Maimonides Infants & Children's Hospital of Brooklyn, New York.

    PubMed

    Altshuler, Lisa; Kachur, Elizabeth; Krinshpun, Shifra; Sullivan, Deborah

    2008-11-01

    In 2003, the Maimonides Infants & Children's Hospital received a Title VII Residency Training in Primary Care grant to integrate genetic-specific competencies into postgraduate pediatrics education. As part of that endeavor, mandatory yearly genetics objective structured clinical exams (OSCEs) were instituted for third-year residents. This article reports on the first three years of experience with this innovative educational tool.After an overview of genetic concepts, dysmorphology, and communication styles, residents complete a five-station OSCE and receive feedback from standardized patients and from the faculty who observe them. After this clinical exercise, the residents participate in a small-group debriefing session to share strategies for effective communication and clinical case management and to discuss the ethical issues that arise with these genetic cases.In three years, 60 residents have completed the genetics OSCE program. Evaluation data demonstrate that the program has been effective in both introducing genetic-specific challenges and assessing residents' clinical skills. It has helped trainees self-identify both strengths and further training needs. Pre- and postsurveys among the trainees show increased comfort levels in performing 5 of 12 genetic-related clinical tasks.We conclude that genetics OSCEs are an enriching educational tool. Merely providing trainees and practicing physicians with the latest scientific information is unlikely to prepare them for counseling patients about complex genetic issues. Developing proficiency requires focused practice and effective feedback.This article is part of a theme issue of Academic Medicine on the Title VII health professions training programs.

  8. 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.

  9. 9.73% Efficiency Nonfullerene All Organic Small Molecule Solar Cells with Absorption-Complementary Donor and Acceptor.

    PubMed

    Bin, Haijun; Yang, Yankang; Zhang, Zhi-Guo; Ye, Long; Ghasemi, Masoud; Chen, Shanshan; Zhang, Yindong; Zhang, Chunfeng; Sun, Chenkai; Xue, Lingwei; Yang, Changduk; Ade, Harald; Li, Yongfang

    2017-03-29

    In the last two years, polymer solar cells (PSCs) developed quickly with n-type organic semiconductor (n-OSs) as acceptor. In contrast, the research progress of nonfullerene organic solar cells (OSCs) with organic small molecule as donor and the n-OS as acceptor lags behind. Here, we synthesized a D-A structured medium bandgap organic small molecule H11 with bithienyl-benzodithiophene (BDTT) as central donor unit and fluorobenzotriazole as acceptor unit, and achieved a power conversion efficiency (PCE) of 9.73% for the all organic small molecules OSCs with H11 as donor and a low bandgap n-OS IDIC as acceptor. A control molecule H12 without thiophene conjugated side chains on the BDT unit was also synthesized for investigating the effect of the thiophene conjugated side chains on the photovoltaic performance of the p-type organic semiconductors (p-OSs). Compared with H12, the 2D-conjugated H11 with thiophene conjugated side chains shows intense absorption, low-lying HOMO energy level, higher hole mobility and ordered bimodal crystallite packing in the blend films. Moreover, a larger interaction parameter (χ) was observed in the H11 blends calculated from Hansen solubility parameters and differential scanning calorimetry measurements. These special features combined with the complementary absorption of H11 donor and IDIC acceptor resulted in the best PCE of 9.73% for nonfullerene all small molecule OSCs up to date. Our results indicate that fluorobenzotriazole based 2D conjugated p-OSs are promising medium bandgap donors in the nonfullerene OSCs.

  10. Development of Spiro[cyclopenta[1,2-b:5,4-b']dithiophene-4,9'-fluorene]-Based A-π-D-π-A Small Molecules with Different Acceptor Units for Efficient Organic Solar Cells.

    PubMed

    Wang, Wengong; Shen, Ping; Dong, Xinning; Weng, Chao; Wang, Guo; Bin, Haijun; Zhang, Jing; Zhang, Zhi-Guo; Li, Yongfang

    2017-02-08

    Three acceptor-π-donor-π-acceptor (A-π-D-π-A) small molecules (STFYT, STFRDN, and STFRCN) with spiro[cyclopenta[1,2-b:5,4-b']dithiophene-4,9'-fluorene] (STF) as the central donor unit, terthiophene as the π-conjugated bridge, indenedione, 3-ethylrhodanine, or 2-(1,1-dicyanomethylene)rhodanine as the acceptor unit are designed, synthesized, and characterized as electron donor materials in solution-processing organic solar cells (OSCs). The effects of the spiro STF-based central core and different acceptors on the molecular configuration, absorption properties, electronic energy levels, carrier transport properties, the morphology of active layers, and photovoltaic properties are investigated in detail. The three molecules exhibit desirable physicochemical features: wide absorption bands (300-850 nm) and high molar absorption coefficients (4.82 × 10(4) to 7.56 × 10(4) M(-1) cm(-1)) and relatively low HOMO levels (-5.15 to -5.38 eV). Density functional theory calculations reveal that the spiro STF central core benefits to reduce the steric hindrance effect between the central donor block and terthiophene bridge and suppress excessive intermolecular aggregations. The optimized OSCs based on these molecules deliver power conversion efficiencies (PCEs) of 6.68%, 3.30%, and 4.33% for STFYT, STFRDN, and STFRCN, respectively. The higher PCE of STFYT-based OSCs should be ascribed to its better absorption ability, higher and balanced hole and electron mobilities, and superior active layer morphology as compared to the other two compounds. So far, this is the first example of developing the A-π-D-π-A type small molecules with a spiro central donor core for high-performance OSC applications. Meanwhile, these results demonstrate that using spiro central block to construct A-π-D-π-A molecule is an alternative and effective strategy for achieving high-performance small molecule donor materials.

  11. Army Task Force on Behavioral Health: Corrective Action Plan

    DTIC Science & Technology

    2013-01-01

    will interface with the VA system and will be fully operational by 2017 . 5. MEDCOM is in the final stages of an OSC Concept Plan to be sent to DCS G-3...system testing at multiple sites, and the agencies must demonstrate significant single-site operations by 2014. Entire system field- ing is set for 2017 ...additional courses of action. The other courses of action included continuing the status quo with maxi - mum utilization of Reservists or partially

  12. 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.

  13. 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.

  14. Worldwide Emerging Environmental Issues Affecting the U.S. Military

    DTIC Science & Technology

    2010-06-30

    Kyrgyzstan, and is ready to help the country with post-conflict rehabilitation. The OSCE is working together with the international community to help... ready for a manned mission after 2021. [Related items: Steps for an International Regime for Space Debris and Space Traffic Control System in May 2009...vegetables and crops production. Similar projects are going on in Kuwait, India, Oman, and the UAE. [May 2010. Military Implications, Sources190] “Arab

  15. Fiscal Year 2013 Comprehensive Oversight Plan for Southwest Asia

    DTIC Science & Technology

    2012-09-26

    START FINAL Strategic Issue COPSWA Ref. No. 458 Supply Support Activities ’ Effectiveness in Sustaining U.S. Forces in Afghanistan Objective...Determine whether selected Supply Support Activities in Afghanistan were effectively and efficiently supporting their customers. Specifically, we...associated agencies to provide specific guidance through planning and funding for the OSC-A and its programs, projects, and activities that support both

  16. Determining the Value of Contractor Performance Assessment Reporting System (CPARS) Narratives for the Acquisition Process

    DTIC Science & Technology

    2014-05-15

    He was commissioned through the Officer Candidate School ( OSC ) program in Pensacola, FL. After OCS, he attended and graduated from the Navy Supply...acquisition team may release a draft RFP to solicit industry feedback on the feasibility of the requirements and to get a feel for industry interest...comment. This ensures the past performance information report card is finalized only after the contractor has the opportunity to provide feedback to the

  17. 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

  18. Analysis of Contracting Processes, Internal Controls, and Procurement Fraud Schemes

    DTIC Science & Technology

    2013-06-01

    The sources of market research data include public information on the industry, feedback from companies, previous experience with similar... feedback to the participants. D. DATA ANALYSIS The methods used to analyze the data included the use of descriptive statistics. The results were...State Internal Control Association (NYSICA). (2006). Internal control survey. 2006 Conference NYS OSC . Retrieved from http://www.nysica.com Office of

  19. Order Out of Chaos: A Case Study of the Application of Auftragstaktik by the 11th Panzer Division during the Chir River Battles 7-19 December 1942

    DTIC Science & Technology

    1989-03-01

    by tanks, the French and British failed to realize their full potential. In his memoirs, 9Dieter Osc, "Dcr ’Auftrag’ Zine deutsche militansche...die Kunst laxer und untersittzen jeden Erfoig..... Translation is the author’s. 10Militirgeschichfliches Forschungsamt. Deutsche Militargeschichte in...Platz, der etwas vom Kampfgeschehen abgesetzt war, hielt Verbindung nach oben und mit den Seiten , dirigierne Verstarkungen usw. nach vome. Ich ffihne

  20. Armed Conflict in Syria: Background and U.S. Response

    DTIC Science & Technology

    2013-09-06

    the SMC is expanding its presence with the assistance of Jordan , Saudi Arabia, and the United States.21 Prospects for a Political Settlement How fast...2012; OSC Report GMP20120607648001, “Al-Jazirah.net Says Jordan Charges 6 With Trying To Enter Syria To Wage Jihad,” Al- Jazirah.net (Doha), June 6...to support the defense of states bordering Syria, such as Turkey and Jordan , with the deployment of Patriot missile batteries to the former and small

  1. 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.

  2. Molecular dynamics and charge transport in organic semiconductors: a classical approach to modeling electron transfer

    DOE PAGES

    Pelzer, Kenley M.; Vázquez-Mayagoitia, Álvaro; Ratcliff, Laura E.; ...

    2017-01-01

    Organic photovoltaics (OPVs) are a promising carbon-neutral energy conversion technology, with recent improvements pushing power conversion efficiencies over 10%. A major factor limiting OPV performance is inefficiency of charge transport in organic semiconducting materials (OSCs). Due to strong coupling with lattice degrees of freedom, the charges form polarons, localized quasi-particles comprised of charges dressed with phonons. These polarons can be conceptualized as pseudo-atoms with a greater effective mass than a bare charge. Here we propose that due to this increased mass, polarons can be modeled with Langevin molecular dynamics (LMD), a classical approach with a computational cost much lower thanmore » most quantum mechanical methods. Here we present LMD simulations of charge transfer between a pair of fullerene molecules, which commonly serve as electron acceptors in OSCs. We find transfer rates consistent with experimental measurements of charge mobility, suggesting that this method may provide quantitative predictions of efficiency when used to simulate materials on the device scale. Our approach also offers information that is not captured in the overall transfer rate or mobility: in the simulation data, we observe exactly when and why intermolecular transfer events occur. In addition, we demonstrate that these simulations can shed light on the properties of polarons in OSCs. In conclusion, much remains to be learned about these quasi-particles, and there are no widely accepted methods for calculating properties such as effective mass and friction. Lastly, our model offers a promising approach to exploring mass and friction as well as providing insight into the details of polaron transport in OSCs.« less

  3. 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

  4. Molecular dynamics and charge transport in organic semiconductors: a classical approach to modeling electron transfer

    SciTech Connect

    Pelzer, Kenley M.; Vázquez-Mayagoitia, Álvaro; Ratcliff, Laura E.; Tretiak, Sergei; Bair, Raymond A.; Gray, Stephen K.; Van Voorhis, Troy; Larsen, Ross E.; Darling, Seth B.

    2017-01-01

    Organic photovoltaics (OPVs) are a promising carbon-neutral energy conversion technology, with recent improvements pushing power conversion efficiencies over 10%. A major factor limiting OPV performance is inefficiency of charge transport in organic semiconducting materials (OSCs). Due to strong coupling with lattice degrees of freedom, the charges form polarons, localized quasi-particles comprised of charges dressed with phonons. These polarons can be conceptualized as pseudo-atoms with a greater effective mass than a bare charge. Here we propose that due to this increased mass, polarons can be modeled with Langevin molecular dynamics (LMD), a classical approach with a computational cost much lower than most quantum mechanical methods. Here we present LMD simulations of charge transfer between a pair of fullerene molecules, which commonly serve as electron acceptors in OSCs. We find transfer rates consistent with experimental measurements of charge mobility, suggesting that this method may provide quantitative predictions of efficiency when used to simulate materials on the device scale. Our approach also offers information that is not captured in the overall transfer rate or mobility: in the simulation data, we observe exactly when and why intermolecular transfer events occur. In addition, we demonstrate that these simulations can shed light on the properties of polarons in OSCs. In conclusion, much remains to be learned about these quasi-particles, and there are no widely accepted methods for calculating properties such as effective mass and friction. Lastly, our model offers a promising approach to exploring mass and friction as well as providing insight into the details of polaron transport in OSCs.

  5. 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

    2016-03-07

    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.

  6. Department of Defense HIV/AIDS Prevention Program: Annual Report 2015

    DTIC Science & Technology

    2016-05-12

    transmitted disease STI – sexually transmitted infection TA – technical assistance TB – tuberculosis UN – United Nations UNAIDS – Joint United...Coordinator OI – opportunistic infection OSC – US Office of Security Cooperation OVC – orphans and vulnerable children PASMO – Pan-American Social...impact of the HIV/AIDS epidemic on military populations and individuals infected with HIV. Along with our many partners, we continue to prevent new

  7. Factors associated with performance in an internal medicine clerkship

    PubMed Central

    McNeal, Tresa; Lezama, Maybelline; Chandler, Martha; Forrester, Lisa; Metting, Austin; Mirkes, Curtis; Van Cleave, Holly; Win, Sonny; Myers, John D.

    2017-01-01

    The purpose of this retrospective study was to examine the relationship between demographic and educational variables and student performance on an internal medicine (IM) clerkship in order to target areas for educational intervention and potential early remediation. This study examined data associated with third-year medical student performance (N = 505) during the IM clerkship at Baylor Scott & White, Temple/Texas A&M Health Science Center College of Medicine from 2005 to 2011. Multiple regression analysis (N = 341) showed that a model containing the following variables was significantly associated with scores on the National Board of Medical Examiners (NBME) subject exam, accounting for 46.5% of the variance: Objective Structured Clinical Exam (OSCE), Medical College Admissions Test (MCAT), US Medical Licensing Exam (USMLE) Step 1, second-year grade point average (GPA), and clinical evaluation. A model containing USMLE Step 1, clinical evaluation, and NBME was significantly associated with OSCE score, accounting for 30% of the variance. Additionally, a model containing age, MCAT score, undergraduate GPA, NBME subject exam score, and OSCE was significantly associated with clinical evaluation score, accounting for 22% of score variance. Age accounted for the most unique variance in clinical evaluation score. Gender and IM interest group were not significantly associated with any outcome variable. In conclusion, in contrast to previous studies in the field, we did not find a significant association between undergraduate GPA and NBME score. Our findings supply further evidence that the OSCE, typically believed to be a clinical performance exam, actually assesses a broader set of domains. Interest group membership did not confer any academic benefit to medical students in IM clerkships in our study. PMID:28127127

  8. Carrier density effect on recombination in PTB7-based solar cell.

    PubMed

    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

  9. Spectral data for F-like ions: Ca, Ti, Cr, Ni

    NASA Astrophysics Data System (ADS)

    Celik, Gultekin; Ates, Sule; Nahar, Sultana

    2015-05-01

    Transition Probabilities, oscillator strengths and lifetimes have been determined for fluorine like Ca, Ti, Cr, and Ni through atomic structure calculations in the relativistic Breit-Pauli approximation. These transition parameters are needed for spectral analysis of iron-peak elements in astrophysical objects. We employed the code SUPERSTRUCTURE. The results are compared with available theoretical and experimental results. Good agreement with results in the literature has been found for most cases. Acknowledgement of Support: NSF, DOE, OSC.

  10. An objective structured clinical examination for the licentiate: report of the pilot project of the Medical Council of Canada.

    PubMed

    Reznick, R; Smee, S; Rothman, A; Chalmers, A; Swanson, D; Dufresne, L; Lacombe, G; Baumber, J; Poldre, P; Levasseur, L

    1992-08-01

    The Medical Council of Canada (MCC) administers a qualifying examination for the issuance of a license to practice medicine. To date, this examination does not test the clinical skills of history taking, physical examination, and communication. The MCC is implementing an objective structured clinical examination (OSCE) to test these skills in October 1992. A pilot examination was developed to test the feasibility, reliability, and validity of running a multisite, two-form, four-hour, 20-station OSCE for national licensure. In February 1991, 240 volunteer first- and second-year residents were tested at four sites. The candidates were randomly assigned to one of two forms of the test and one of two sites for two of the four sites. Generalizability analysis revealed that the variance due to form was 0.0 and that due to site was .16 compared with a total variance of 280.86. The reliabilities (inter-station) were .56 and .60 for the two forms. Station total-test score correlations, used to measure station validity, were significant for 38 of the 40 stations used (range .14-.60). The results of the OSCE correlated moderately with the MCC qualifying examination; these correlations were .32 and .35 for the two test forms. Content validity was assessed by postexamination questionnaires given to the physician examiners using a scale of 0 (low) to 10 (high). The physicians' mean ratings were: importance of the stations, 8.1 (SD, 1.8); success of the examination in testing core skills, 8.1 (SD, 1.6); and degree of challenge, 7.8 (SD, 2.1). The results indicate that a full-scale national administration of an OSCE for licensure is feasible using the model developed. Aspects of validity have been established and strategies to augment reliability have been developed.

  11. 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.

  12. 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.

  13. Solution-Processable Organic Molecule for High-Performance Organic Solar Cells with Low Acceptor Content.

    PubMed

    Wang, Kun; Guo, Bing; Xu, Zhuo; Guo, Xia; Zhang, Maojie; Li, Yongfang

    2015-11-11

    A new planar D2-A-D1-A-D2 structured organic molecule with bithienyl benzodithiophene (BDT) as central donor unit D1 and fluorine-substituted benzothiadiazole (BTF) as acceptor unit and alkyl-dithiophene as end group and donor unit D2, BDT-BTF, was designed and synthesized for the application as donor material in organic solar cells (OSCs). BDT-BTF shows a broad absorption in visible region, suitable highest occupied molecular orbital energy level of -5.20 eV, and high hole mobility of 1.07 × 10(-2) cm(2)/(V s), benefitted from its high coplanarity and strong crystallinity. The OSCs based on BDT-BTF as donor (D) and PC71BM as acceptor (A) at a D/A weight ratio of 3:1 without any extra treatment exhibit high photovoltaic performance with Voc of 0.85 V, Jsc of 10.48 mA/cm(2), FF of 0.66, and PCE of 5.88%. The morphological study by transmission electron microscopy reveals that the blend of BDT-BTF and PC71BM (3:1, w/w) possesses an appropriate interpenetrating D/A network for the exciton separation and charge carrier transport, which agrees well with the good device performance. The optimized D/A weight ratio of 3:1 is the lowest acceptor content in the active layer reported so far for the high-performance OSCs, and the organic molecules with the molecular structure like BDT-BTF could be promising high-performance donor materials in solution-processable OSCs.

  14. Reinventing the reel: an innovative approach to resident skill-building in motivational interviewing for brief intervention.

    PubMed

    Cole, Bonnie; Clark, Denice Crowe; Seale, J Paul; Shellenberger, Sylvia; Lyme, Alan; Johnson, J Aaron; Chhabria, Aruna

    2012-01-01

    To enhance the skills of primary care residents in addressing substance misuse, residency screening, brief intervention, and referral to treatment (SBIRT) programs increasingly offer motivational interviewing (MI) training, but seldom include feedback and coaching. This innovative 2-round "Virginia Reel" approach, supplementing 3 hours of basic MI instruction, was designed to teach and coach residents to use MI while providing ongoing medical care. SBIRT/MI-competent facilitators served as both trainers and actors at 8 carefully sequenced Objective Structured Clinical Examination (OSCE) stations, providing instruction, role-play practice, and feedback on 17 microskills in 2 successive clinical "visits"/rounds addressing alcohol misuse and diabetes management. Evaluation included OSCE checklists, overall competency assessments, and responses to open-ended questions. Three residents showed improvement between rounds. Resident evaluations were strongly positive, identifying practice of MI skills and receipt of coaching and feedback from MI experts as particularly valuable. Further study is needed to confirm effectiveness of the approach and explore the impact of fewer OSCE stations of longer duration.

  15. Uncovering the role of cathode buffer layer in organic solar cells

    PubMed Central

    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

  16. Towards an understanding of light activation processes in titanium oxide based inverted organic solar cells

    NASA Astrophysics Data System (ADS)

    Chambon, S.; Destouesse, E.; Pavageau, B.; Hirsch, L.; Wantz, G.

    2012-11-01

    The light activation phenomenon in inverted P3HT:PCBM bulk heterojunction organic solar cells based on titanium oxide sublayer (TiOx) is characterized by fast acquisition of current-voltage (J-V) curves under light bias as function of time. TiOx layers were thermally treated under inert atmosphere at different temperatures prior active layer deposition and for every device an activation time was extracted. It is shown that the higher the TiOx annealing temperature, the faster the activation. The improvement of the overall device performances is also observed for devices with TiOx layers baked above 100 °C. The evolution of the characteristic of the organic semiconductors (OSC) device, from dielectric to diode, is attributed to the increase of TiOx conductivity by three orders of magnitude upon white light illumination. Additionally, devices based on baked TiOx present higher conductivity than those based on unbaked TiOx which would explain the gain in performances and the short activation time of the OSC. In order to understand the origin of the phenomenon, deactivation experiments were also performed under different conditions on OSC. The deactivation process was shown to be thermally dependent and fully reversible under inert atmosphere, which suggest that deep traps are responsible for the activation phenomenon. An optimal annealing temperature was found at 120 °C and gives a reasonable short activation time of approximately 1 min and photo conversion efficiency up to 4%.

  17. 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.

  18. Identification of marneral synthase, which is critical for growth and development in Arabidopsis.

    PubMed

    Go, Young S; Lee, Saet B; Kim, Hae J; Kim, Jungmook; Park, Hyo-Young; Kim, Jeong-Kook; Shibata, Kyomi; Yokota, Takao; Ohyama, Kiyoshi; Muranaka, Toshiya; Arseniyadis, Siméon; Suh, Mi C

    2012-12-01

    Plants produce structurally diverse triterpenoids, which are important for their life and survival. Most triterpenoids and sterols share a common biosynthetic intermediate, 2,3-oxidosqualene (OS), which is cyclized by 2,3-oxidosqualene cyclase (OSC). To investigate the role of an OSC, marneral synthase 1 (MRN1), in planta, we characterized a Arabidopsis mrn1 knock-out mutant displaying round-shaped leaves, late flowering, and delayed embryogenesis. Reduced growth of mrn1 was caused by inhibition of cell expansion and elongation. Marnerol, a reduced form of marneral, was detected in Arabidopsis overexpressing MRN1, but not in the wild type or mrn1. Alterations in the levels of sterols and triterpenols and defects in membrane integrity and permeability were observed in the mrn1. In addition, GUS expression, under the control of the MRN1 gene promoter, was specifically detected in shoot and root apical meristems, which are responsible for primary growth, and the mRNA expression of Arabidopsis clade II OSCs was preferentially observed in roots and siliques containing developing seeds. The eGFP:MRN1 was localized to the endoplasmic reticulum in tobacco protoplasts. Taken together, this report provides evidence that the unusual triterpenoid pathway via marneral synthase is important for the growth and development of Arabidopsis.

  19. Initial Results of Endoscopic Gastrocutaneous Fistula Closure in Children Using an Over-the-Scope Clip

    PubMed Central

    Wright, Robert; Abrajano, Claire; Koppolu, Raji; Stevens, Megan; Nyznyk, Sarah; Chao, Stephanie; Bruzoni, Matias

    2015-01-01

    Abstract Gastrocutaneous fistula (GCF) occurs commonly in pediatric patients after removal of long-term gastrostomy tubes. Although open repair is generally successful, endoscopic approaches may offer benefits in terms of incisional complications, postoperative pain, and procedure time. In addition, endoscopic approaches may offer particular benefit in patients with varied degrees of skin irritation or erosion surrounding a GCF, making surgical repair difficult, or patients with significant comorbidities, making minimal intervention and anesthesia time preferable. Over-the-scope (OSC) clips are a new technology that enables endoscopic closure of intestinal fistulas up to 2 cm in diameter. Six pediatric patients underwent endoscopic GCF closure using OSC clips under Institutional Review Board approval. The procedure was technically successful in 5 of 6 cases with an average operating time of 29 minutes. The technical failure required an open revision, whereas all other patients reported full healing of the GCF site at 1 month. All successful cases were performed as outpatients without postoperative narcotics. In addition, all patients reported high satisfaction with the procedure and cosmetic results. Endoscopic GCF closure using an OSC clip is technically feasible in the pediatric population. Based on limited cases with a 1-month follow-up, the functional and cosmetic results of technically successful cases are excellent. Endoscopic GCF closure is a potential alternative to standard surgical closure in patients with skin irritation or erosion and/or significant comorbidities. PMID:25531644

  20. 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

    2016-06-15

    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.

  1. Temperature-dependent Schottky barrier in high-performance organic solar cells

    PubMed Central

    Li, Hui; He, Dan; Zhou, Qing; Mao, Peng; Cao, Jiamin; Ding, Liming; Wang, Jizheng

    2017-01-01

    Organic solar cells (OSCs) have attracted great attention in the past 30 years, and the power conversion efficiency (PCE) now reaches around 10%, largely owning to the rapid material developments. Meanwhile with the progress in the device performance, more and more interests are turning to understanding the fundamental physics inside the OSCs. In the conventional bulk-heterojunction architecture, only recently it is realized that the blend/cathode Schottky junction serves as the fundamental diode for the photovoltaic function. However, few researches have focused on such junctions, and their physical properties are far from being well-understood. In this paper based on PThBDTP:PC71BM blend, we fabricated OSCs with PCE exceeding 10%, and investigated temperature-dependent behaviors of the junction diodes by various characterization including current-voltage, capacitance-voltage and impedance measurements between 70 to 290 K. We found the Schottky barrier height exhibits large inhomogeneity, which can be described by two sets of Gaussian distributions. PMID:28071700

  2. An implementation of SISAL for distributed-memory architectures

    SciTech Connect

    Beard, Patrick 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).

  3. Rational Design of Diketopyrrolopyrrole-Based Small Moleculesas Donating Materials for Organic Solar Cells.

    PubMed

    Jin, Ruifa; Wang, Kai

    2015-08-27

    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.

  4. Evaluating the anti-neuroinflammatory capacity of raw and steamed garlic as well as five organosulfur compounds.

    PubMed

    Ho, Su-Chen; Su, Min-Sheng

    2014-10-31

    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.

  5. An Advanced Objective Structured Clinical Examination Using Patient Simulators to Evaluate Pharmacy Students’ Skills in Physical Assessment

    PubMed Central

    Takamura, Norito; Ogata, Kenji; Setoguchi, Nao; Utsumi, Miho; Kourogi, Yasuyuki; Osaki, Takashi; Ozaki, Mineo; Sato, Keizo; Arimori, Kazuhiko

    2014-01-01

    Objective. To implement an advanced objective structured clinical examination (OSCE) in the curriculum and to evaluate Japanese pharmacy students’ skills in physical assessment such as measuring pulse and blood pressure, and assessing heart, lung, and intestinal sounds. Design. An advanced OSCE was implemented in a hospital pharmacy seminar as a compulsory subject. We programmed patient simulators with 21 different patient cases in which normal and abnormal physiological conditions were produced. The virtual patients were then used to evaluate the physical assessment skills of fifth-year pharmacy students. Assessment. Significant differences were observed between the average of all the detailed evaluations and the mean results for the following skills: pulse measurement, blood pressure measurement, deflating the cuff at a rate of 2-3 mmHg/sec, listening to heart sounds, and listening to lung sounds. Conclusion. Administering an advanced OSCE using virtual patients was an effective way of assessing pharmacy students’ skills in a realistic setting. Several areas in which pharmacy students require further training were identified. PMID:25657371

  6. Properties of cerium-zirconium mixed oxides partially substituted by neodymium: Comparison with Zr-Ce-Pr-O ternary oxides

    SciTech Connect

    Mikulova, Jana; Rossignol, Sylvie . E-mail: Sylvie.rossignol@univ-poitiers.fr; Gerard, Francois; Mesnard, Danielle; Kappenstein, Charles; Duprez, Daniel

    2006-08-15

    CeO{sub 2} doped with praseodymium, neodymium and/or zirconium atoms were prepared by coprecipitation and by the sol-gel method. Structural properties were investigated by in situ XRD and Raman spectroscopy while oxygen storage capacity (OSC) was measured by transient CO oxidation. All the compounds, except pure Nd{sub 2}O{sub 3}, have a fluorite-type structure as well as a Raman band at 560 cm{sup -1} characteristic of the oxygen vacancies involving non-stoichiometric oxides. The lattice parameter under hydrogen, being dependent on the temperature, revealed two reduction mechanisms: one at a low temperature at the surface and another at a high temperature in the bulk. Ce-Nd binary oxides show a strong tendency towards crystallite aggregation, which reduces accessibility to gases and OSC properties. Zirconium improves the thermal resistance to sintering of both Ce-Nd and Ce-Pr oxides. The Zr-Ce-Pr-O followed by Zr-Ce-Nd-O compounds displaying high oxygen mobility at a low temperature, appear to be very promising for practical applications such as OSC materials. - Graphical abstract: Variation of oxygen vacancies under hydrogen on ternary oxides.

  7. Potential role of nonstatin cholesterol lowering agents.

    PubMed

    Trapani, Laura; Segatto, Marco; Ascenzi, Paolo; Pallottini, Valentina

    2011-11-01

    Although statins, 3β-hydroxy-3β-methylglutaryl coenzyme A reductase (HMGR) inhibitors, have revolutionized the management of cardiovascular diseases by lowering serum low density lipoproteins, many patients suffer from their side effects. Whether the statin side effects are related to their intrinsic toxicity or to the decrease of HMGR main isoprenoid end products, which are essential compounds for cell viability, is still debated. In addition to HMGR, the key and rate limiting step of cholesterol synthesis, many enzymes are involved in this multi-step pathway whose inhibition could be taken into account for a "nonstatin approach" in the management of hypercholesterolemia. In particular, due to their unique position downstream from HMGR, the inhibition of squalene synthase, farnesyl diphosphate farnesyltransferase (FDFT1), squalene epoxidase (SQLE), and oxidosqualene cyclase:lanosterol synthase (OSC) should decrease plasma levels of cholesterol without affecting ubiquinone, dolichol, and isoprenoid metabolism. Thus, although FDFT1, SQLE and OSC are little studied, they should be considered as perspective targets for the development of novel drugs against hypercholesterolemia. Here, structure-function relationships of FDFT1, SQLE, and OSC are reviewed highlighting the advantages that the downstream inhibition of HMGR could provide when compared to the statin-based therapy.

  8. 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.

  9. Series circuit of organic thin-film solar cells for conversion of water into hydrogen.

    PubMed

    Aoki, Atsushi; Naruse, Mitsuru; Abe, Takayuki

    2013-07-22

    A series circuit of bulk hetero-junction (BHJ) organic thin-film solar cells (OSCs) is investigated for electrolyzing water to gaseous hydrogen and oxygen. The BHJ OSCs applied consist of poly(3-hexylthiophene) as a donor and [6,6]-phenyl C61 butyric acid methyl ester as an acceptor. A series circuit of six such OSC units has an open circuit voltage (V(oc)) of 3.4 V, which is enough to electrolyze water. The short circuit current (J(sc)), fill factor (FF), and energy conversion efficiency (η) are independent of the number of unit cells. A maximum electric power of 8.86 mW cm(-2) is obtained at the voltage of 2.35 V. By combining a water electrolysis cell with the series circuit solar cells, the electrolyzing current and voltage obtained are 1.09 mA and 2.3 V under a simulated solar light irradiation (100 mW cm(-2), AM1.5G), and in one hour 0.65 mL hydrogen is generated.

  10. 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.

  11. 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.

  12. 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.

  13. C-terminal Amidation of an Osteocalcin-derived Peptide Promotes Hydroxyapatite Crystallization*

    PubMed Central

    Hosseini, Samaneh; Naderi-Manesh, Hossein; Mountassif, Driss; Cerruti, Marta; Vali, Hojatollah; Faghihi, Shahab

    2013-01-01

    Genesis of natural biocomposite-based materials, such as bone, cartilage, and teeth, involves interactions between organic and inorganic systems. Natural biopolymers, such as peptide motif sequences, can be used as a template to direct the nucleation and crystallization of hydroxyapatite (HA). In this study, a natural motif sequence consisting of 13 amino acids present in the first helix of osteocalcin was selected based on its calcium binding ability and used as substrate for nucleation of HA crystals. The acidic (acidic osteocalcin-derived peptide (OSC)) and amidic (amidic osteocalcin-derived peptide (OSN)) forms of this sequence were synthesized to investigate the effects of different C termini on the process of biomineralization. Electron microscopy analyses show the formation of plate-like HA crystals with random size and shape in the presence of OSN. In contrast, spherical amorphous calcium phosphate is formed in the presence of OSC. Circular dichroism experiments indicate conformational changes of amidic peptide to an open and regular structure as a consequence of interaction with calcium and phosphate. There is no conformational change detectable in OSC. It is concluded that HA crystal formation, which only occurred in OSN, is attributable to C-terminal amidation of a natural peptide derived from osteocalcin. It is also proposed that natural peptides with the ability to promote biomineralization have the potential to be utilized in hard tissue regeneration. PMID:23362258

  14. Triphenylamine-Based Push–Pull Molecule for Photovoltaic Applications: From Synthesis to Ultrafast Device Photophysics

    PubMed Central

    2017-01-01

    Small push–pull molecules attract much attention as prospective donor materials for organic solar cells (OSCs). By chemical engineering, it is possible to combine a number of attractive properties such as broad absorption, efficient charge separation, and vacuum and solution processabilities in a single molecule. Here we report the synthesis and early time photophysics of such a molecule, TPA-2T-DCV-Me, based on the triphenylamine (TPA) donor core and dicyanovinyl (DCV) acceptor end group connected by a thiophene bridge. Using time-resolved photoinduced absorption and photoluminescence, we demonstrate that in blends with [70]PCBM the molecule works both as an electron donor and hole acceptor, thereby allowing for two independent channels of charge generation. The charge-generation process is followed by the recombination of interfacial charge transfer states that takes place on the subnanosecond time scale as revealed by time-resolved photoluminescence and nongeminate recombination as follows from the OSC performance. Our findings demonstrate the potential of TPA-DCV-based molecules as donor materials for both solution-processed and vacuum-deposited OSCs.

  15. Au@Ag core-shell nanocubes for efficient plasmonic light scattering effect in low bandgap organic solar cells.

    PubMed

    Baek, Se-Woong; Park, Garam; Noh, Jonghyeon; Cho, Changsoon; Lee, Chun-Ho; Seo, Min-Kyo; Song, Hyunjoon; Lee, Jung-Yong

    2014-04-22

    In this report, we propose a metal-metal core-shell nanocube (NC) as an advanced plasmonic material for highly efficient organic solar cells (OSCs). We covered an Au core with a thin Ag shell as a scattering enhancer to build Au@Ag NCs, which showed stronger scattering efficiency than Au nanoparticles (AuNPs) throughout the visible range. Highly efficient plasmonic organic solar cells were fabricated by embedding Au@Ag NCs into an anodic buffer layer, poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), and the power conversion efficiency was enhanced to 6.3% from 5.3% in poly[N-9-hepta-decanyl-2,7-carbazole-alt-5,5-(4,7-di-2-thienyl-2,1,3-benzothiadiazole)] (PCDTBT):[6,6]-phenyl C71-butyric acid methyl ester (PC70BM) based OSCs and 9.2% from 7.9% in polythieno[3,4-b]thiophene/benzodithiophene (PTB7):PC70BM based OSCs. The Au@Ag NC plasmonic PCDTBT:PC70BM-based organic solar cells showed 2.2-fold higher external quantum efficiency enhancement compared to AuNPs devices at a wavelength of 450-700 nm due to the amplified plasmonic scattering effect. Finally, we proved the strongly enhanced plasmonic scattering efficiency of Au@Ag NCs embedded in organic solar cells via theoretical calculations and detailed optical measurements.

  16. High Efficiency Organic Solar Cells Achieved by the Simultaneous Plasmon-Optical and Plasmon-Electrical Effects from Plasmonic Asymmetric Modes of Gold Nanostars.

    PubMed

    Ren, Xingang; Cheng, Jiaqi; Zhang, Shaoqing; Li, Xinchen; Rao, Tingke; Huo, Lijun; Hou, Jianhui; Choy, Wallace C H

    2016-10-01

    The plasmon-optical effects have been utilized to optically enhance active layer absorption in organic solar cells (OSCs). The exploited plasmonic resonances of metal nanomaterials are typically from the fundamental dipole/high-order modes with narrow spectral widths for regional OSC absorption improvement. The conventional broadband absorption enhancement (using plasmonic effects) needs linear-superposition of plasmonic resonances. In this work, through strategic incorporation of gold nanostars (Au NSs) in between hole transport layer (HTL) and active layer, the excited plasmonic asymmetric modes offer a new approach toward broadband enhancement. Remarkably, the improvement is explained by energy transfer of plasmonic asymmetric modes of Au NS. In more detail, after incorporation of Au NSs, the optical power in electron transport layer transfers to active layer for improving OSC absorption, which otherwise will become dissipation or leakage as the role of carrier transport layer is not for photon-absorption induced carrier generation. Moreover, Au NSs simultaneously deliver plasmon-electrical effects which shorten transport path length of the typically low-mobility holes and lengthen that of high-mobility electrons for better balanced carrier collection. Meanwhile, the resistance of HTL is reduced by Au NSs. Consequently, power conversion efficiency of 10.5% has been achieved through cooperatively plasmon-optical and plasmon-electrical effects of Au NSs.

  17. The next (re)generation of ovarian biology and fertility in women: is current science tomorrow's practice?

    PubMed

    Woods, Dori C; Tilly, Jonathan L

    2012-07-01

    Stem cell-based strategies for ovarian regeneration and oocyte production have been proposed as future clinical therapies for treating infertility in women. However, utilization of embryonic stem cells or induced pluripotent stem cells to produce oocytes has had limited success in vitro. A recent report of the isolation and characterization of endogenous oocyte-producing or oogonial stem cells (OSCs) from ovaries of reproductive age women describes the first stable and pure human female germ cell culture model in which a subset of cells appear to initiate and complete meiosis. In addition, purified human OSCs introduced into adult human ovarian cortical tissue generate oocytes that arrest at the diplotene stage of meiosis and successfully recruit granulosa cells to form new primordial follicles. This overview examines the current landscape of in vitro and in vivo gametogenesis from stem cells, with emphasis on generation of human oocytes. Future research objectives for this area of work, as well as potential clinical applications involving the use of human OSCs, are discussed.

  18. 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.

  19. Effect of the microstructural characteristics of a Ga-doped TiO2 hole block layer on an inverted structure organic solar cell

    NASA Astrophysics Data System (ADS)

    Lee, Eun Ju; Ryu, Sang Ouk

    2016-09-01

    Inverted-structure organic solar cells (OSCs) were fabricated using atomic-layer-deposition (ALD) processed Ga-doped TiO2 as hole blocking layer (HBL). Measured photovoltaic efficiencies were greatly related to the crystallinity of the TiO2 films. However, the efficiencies of the OSCs and the crystallinity of the HBL did not show a linear relationship. The HBL was fully crystallized at a deposition temperature of 200 °C or above, and the power conversion efficiency was measured to be 2.7% with for the HBL processed at 200 °C, but the efficiency decreased to 2.4% for the HBL processed at 250 °C. On the other hand, the surface roughness of the crystallized films was found be increased to two fold in the studied temperature range. Once the HBL had been fully crystallized, the major factor that determined the overall performance of OSCs was the surface roughness of the HBL.

  20. Low-Temperature Solution-Processed SnO2 Nanoparticles as a Cathode Buffer Layer for Inverted Organic Solar Cells.

    PubMed

    Tran, Van-Huong; Ambade, Rohan B; Ambade, Swapnil B; Lee, Soo-Hyoung; Lee, In-Hwan

    2017-01-18

    SnO2 recently has attracted particular attention as a powerful buffer layer for organic optoelectronic devices due to its outstanding properties such as high electron mobility, suitable band alignment, and high optical transparency. Here, we report on facile low-temperature solution-processed SnO2 nanoparticles (NPs) in applications for a cathode buffer layer (CBL) of inverted organic solar cells (iOSCs). The conduction band energy of SnO2 NPs estimated by ultraviolet photoelectron spectroscopy was 4.01 eV, a salient feature that is necessary for an appropriate CBL. Using SnO2 NPs as CBL derived from a 0.1 M precursor concentration, P3HT:PC60BM-based iOSCs showed the best power conversion efficiency (PCE) of 2.9%. The iOSC devices using SnO2 NPs as CBL revealed excellent long-term device stabilities, and the PCE was retained at ∼95% of its initial value after 10 weeks in ambient air. These solution-processed SnO2 NPs are considered to be suitable for the low-cost, high throughput roll-to-roll process on a flexible substrate for optoelectronic devices.