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Sample records for objetivo estructurado osce

  1. 40 CFR 300.165 - OSC reports.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 27 2010-07-01 2010-07-01 false OSC reports. 300.165 Section 300.165 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SUPERFUND, EMERGENCY PLANNING, AND... Responsibility and Organization for Response § 300.165 OSC reports. (a) As requested by the NRT or RRT, the...

  2. Electronic acquisition of OSCE performance using tablets

    PubMed Central

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

    2015-01-01

    Background: Objective Structured Clinical Examinations (OSCEs) often involve a considerable amount of resources in terms of materials and organization since the scores are often recorded on paper. Computer-assisted administration is an alternative with which the need for material resources can be reduced. In particular, the use of tablets seems sensible because these are easy to transport and flexible to use. Aim: User acceptance concerning the use of tablets during OSCEs has not yet been extensively investigated. The aim of this study was to evaluate tablet-based OSCEs from the perspective of the user (examiner) and the student examinee. Method: For two OSCEs in Internal Medicine at the University of Heidelberg, user acceptance was analyzed regarding tablet-based administration (satisfaction with functionality) and the subjective amount of effort as perceived by the examiners. Standardized questionnaires and semi-standardized interviews were conducted (complete survey of all participating examiners). In addition, for one OSCE, the subjective evaluation of this mode of assessment was gathered from a random sample of participating students in semi-standardized interviews. Results: Overall, the examiners were very satisfied with using tablets during the assessment. The subjective amount of effort to use the tablet was found on average to be “hardly difficult”. The examiners identified the advantages of this mode of administration as being in particular the ease of use and low rate of error. During the interviews of the examinees, acceptance for the use of tablets during the assessment was also detected. Discussion: Overall, it was found that the use of tablets during OSCEs was well accepted by both examiners and examinees. We expect that this mode of assessment also offers advantages regarding assessment documentation, use of resources, and rate of error in comparison with paper-based assessments; all of these aspects should be followed up on in further studies

  3. 40 CFR 300.165 - OSC reports.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 29 2013-07-01 2013-07-01 false OSC reports. 300.165 Section 300.165 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SUPERFUND, EMERGENCY PLANNING, AND COMMUNITY RIGHT-TO-KNOW PROGRAMS NATIONAL OIL AND HAZARDOUS SUBSTANCES POLLUTION CONTINGENCY...

  4. 40 CFR 300.165 - OSC reports.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 28 2014-07-01 2014-07-01 false OSC reports. 300.165 Section 300.165 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SUPERFUND, EMERGENCY PLANNING, AND COMMUNITY RIGHT-TO-KNOW PROGRAMS NATIONAL OIL AND HAZARDOUS SUBSTANCES POLLUTION CONTINGENCY...

  5. 40 CFR 300.165 - OSC reports.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 28 2011-07-01 2011-07-01 false OSC reports. 300.165 Section 300.165 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SUPERFUND, EMERGENCY PLANNING, AND COMMUNITY RIGHT-TO-KNOW PROGRAMS NATIONAL OIL AND HAZARDOUS SUBSTANCES POLLUTION CONTINGENCY...

  6. 40 CFR 300.165 - OSC reports.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 29 2012-07-01 2012-07-01 false OSC reports. 300.165 Section 300.165 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SUPERFUND, EMERGENCY PLANNING, AND COMMUNITY RIGHT-TO-KNOW PROGRAMS NATIONAL OIL AND HAZARDOUS SUBSTANCES POLLUTION CONTINGENCY...

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

    PubMed Central

    Chima, Margot; Dallaghan, Gary Beck

    2016-01-01

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

  8. The OSCE Has Landed: One Small Step for British Psychiatry?

    ERIC Educational Resources Information Center

    Sauer, Justin; Hodges, Brian; Santhouse, Alastair; Blackwood, Nigel

    2005-01-01

    Objective: In the United Kingdom (UK), an objective structured clinical examination (OSCE) has replaced the individual patient assessment (IPA) for part 1 of the membership examination of the Royal College of Psychiatrists (MRCPsych). The authors' assessment of the OSCE was conducted. Method: Residents completed and evaluated an OSCE designed…

  9. 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

  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. 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…

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

    PubMed

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

    PubMed

    Chahine, Saad; Holmes, Bruce; Kowalewski, Zbigniew

    2016-08-01

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

  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. 77 FR 28638 - OSC Forms And Survey Renewal for FY 2012-Request for Comment

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-15

    ... Counsel (OSC), plans to request approval from the Office of Management and Budget (OMB) for use of four... collection of information is necessary for the proper performance of OSC functions, including whether...

  16. 77 FR 22614 - OSC Forms and Survey Renewal for FY 2012-Request for Comment

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-16

    ... Counsel (OSC), plans to request approval from the Office of Management and Budget (OMB) for use of four... collection of information is necessary for the proper performance of OSC functions, including whether...

  17. Standard Setting for OSCEs: Trial of Borderline Approach

    ERIC Educational Resources Information Center

    Kilminster, Sue; Roberts, Trudie

    2004-01-01

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

  18. Introducing the Objective Structured Clinical Examination (OSCE) in the Undergraduate Psychiatric Curriculum: Evaluation after One Year

    ERIC Educational Resources Information Center

    Zahid, Muhammad Ajmal; Al-Zayed, Adel; Ohaeri, Jude; Varghese, Ramani

    2011-01-01

    Objective: The Objective Structured Clinical Examination (OSCE) was introduced in undergraduate psychiatry clerkship in 2008. The authors studied the effect of OSCE on the students' performance. Methods: The "short case" (SC) and "oral examination" (OE), two of the five components of the previous assessment format, were replaced with the OSCE.…

  19. OSCE and Case Presentations As Active Assessments of Dental Student Performance.

    PubMed

    Park, Sang E; Anderson, Nina K; Karimbux, Nadeem Y

    2016-03-01

    The aim of this study was to evaluate whether the objective structured clinical examination (OSCE) and case presentation (CP) as forms of active assessment were effective measures of overall didactic knowledge and clinical performance in a predoctoral dental curriculum. This evaluation was conducted by statistical analysis of quality points (QP) awarded for didactic and clinical performance, CP grades, and OSCE scores for 185 students at Harvard School of Dental Medicine who graduated during the period 2010-14. As part of the requirements for graduation, each student takes three OSCEs and presents two patient cases. Data for the study were obtained from the Office of the Registrar. The results showed no direct correlation between QP and CP grades and no correlation between CP grades and OSCE scores. However, there was a correlation between OSCE scores and QP. Students with honors-level scores on any of the three OSCEs received significantly more QP than students who did not receive honors. In addition, students with passing scores on OSCEs 2 and 3 received significantly more QP than students with failing or marginal OSCE scores. Innovative formats of active assessment such as OSCEs and CPs can promote a student-centered learning environment. These data indicated that, within this study population, there was a positive association between OSCE scores and clinical and didactic performance, supporting the value of OSCEs as a means of assessment. PMID:26933109

  20. Standard setting for OSCEs: trial of borderline approach.

    PubMed

    Kilminster, Sue; Roberts, Trudie

    2004-01-01

    OSCE examinations were held in May and June 2002 for all third and fourth year and some fifth year medical students at the University of Leeds. There has been an arbitrary pass mark of 65% for these examinations. However, we recognise that it is important to adopt a systematic approach towards standard setting in all examinations so held a trial of the borderline approach to standard setting for third and fifth year examinations. This paper reports our findings. The results for the year 3 OSCE demonstrated that the borderline approach to standard setting is feasible and offers a method to ensure that the pass standard is both justifiable and credible. It is efficient, requiring much less time than other methods and has the advantage of using the judgements of expert clinicians about actual practice. In addition it offers a way of empowering clinicians because it uses their expertise.

  1. Reliability of the OSCE for Physical and Occupational Therapists.

    PubMed

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

    2014-08-01

    [Purpose] To examine agreement rates between faculty members and clinical supervisors as OSCE examiners. [Subjects] The study subjects were involved physical and occupational therapists working in clinical environments for 1 to 5 years after graduating from training schools as OSCE examinees, and a physical or occupational therapy faculty member and a clinical supervisor as examiners. Another clinical supervisor acted as a simulated patient. [Methods] The agreement rate between the examiners for each OSCE item was calculated based on Cohen's kappa coefficient to confirm inter-rater reliability. [Results] The agreement rates for the behavioral aspects of the items were higher in the second than in the first examination. Similar increases were also observed in the agreement rates for the technical aspects until the initiation of each activity; however, the rates decreased during the middle to terminal stages of continuous movements. [Conclusion] The results may reflect the recent implementation of measures for the integration of therapist education in training schools and clinical training facilities. PMID:25202170

  2. The Objective Structured Clinical Examination (OSCE): AMEE Guide No. 81. Part II: organisation & administration.

    PubMed

    Khan, Kamran Z; Gaunt, Kathryn; Ramachandran, Sankaranarayanan; Pushkar, Piyush

    2013-09-01

    The organisation, administration and running of a successful OSCE programme need considerable knowledge, experience and planning. Different teams looking after various aspects of OSCE need to work collaboratively for an effective question bank development, examiner training and standardised patients' training. Quality assurance is an ongoing process taking place throughout the OSCE cycle. In order for the OSCE to generate reliable results it is essential to pay attention to each and every element of quality assurance, as poorly standardised patients, untrained examiners, poor quality questions and inappropriate scoring rubrics each will affect the reliability of the OSCE. The validity will also be influenced if the questions are not realistic and mapped against the learning outcomes of the teaching programme. This part of the Guide addresses all these important issues in order to help the reader setup and quality assure their new or existing OSCE programmes.

  3. 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…

  4. 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…

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

    ERIC Educational Resources Information Center

    Cusimano, Michael D.; And Others

    1994-01-01

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

  6. 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…

  7. Implementing peer learning to prepare students for OSCEs.

    PubMed

    Pegram, Anne; Fordham-Clarke, Carol

    First-year nursing students undertaking a first-year clinical skills module were given an opportunity to take part in a voluntary peer learning scheme, where they would learn from more senior students. It was envisaged this would help the students prepare for the module's summative assessment-an objective structured clinical examination (OSCE), which students can find stressful. The first-year students found peer learning helped them improve clinical skills, reduced anxiety and increased their self-confidence, and they appreciated the non-threatening learning environment and constructive feedback. The more senior students felt it helped prepare them for their mentoring role after registration. Incorporating peer learning more widely into the curriculum would allow it to be evaluated in more depth. PMID:26618676

  8. Implementing peer learning to prepare students for OSCEs.

    PubMed

    Pegram, Anne; Fordham-Clarke, Carol

    First-year nursing students undertaking a first-year clinical skills module were given an opportunity to take part in a voluntary peer learning scheme, where they would learn from more senior students. It was envisaged this would help the students prepare for the module's summative assessment-an objective structured clinical examination (OSCE), which students can find stressful. The first-year students found peer learning helped them improve clinical skills, reduced anxiety and increased their self-confidence, and they appreciated the non-threatening learning environment and constructive feedback. The more senior students felt it helped prepare them for their mentoring role after registration. Incorporating peer learning more widely into the curriculum would allow it to be evaluated in more depth.

  9. 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…

  10. 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

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

    PubMed Central

    Rau, Thea; Fegert, Jörg; Liebhardt, Hubert

    2011-01-01

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

  12. 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 access to special decontamination equipment for chemical releases and advice to the OSC/RPM in...

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

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... treatment technology, biology, chemistry, hydrology, geology, and engineering. (2) The ERT can provide access to special decontamination equipment for chemical releases and advice to the OSC/RPM in...

  14. 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 access to special decontamination equipment for chemical releases and advice to the OSC/RPM in...

  15. 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 access to special decontamination equipment for chemical releases and advice to the OSC/RPM in...

  16. 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 access to special decontamination equipment for chemical releases and advice to the OSC/RPM in...

  17. 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.

  18. 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

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

    PubMed

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

    2002-09-01

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

  20. 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

  1. 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…

  2. Correlation between MMI performance and OSCE performance – a pilot study

    PubMed Central

    Oluwasanjo, Adetokunbo; Wasser, Thomas; Alweis, Richard

    2015-01-01

    Objective The multiple mini-interview (MMI) has been shown to have a positive correlation with early medical school performance, clerkship evaluations, and national licensing examinations. There is limited data on its predictive validity at the postgraduate level. Methods Six hundred and nineteen internship candidates were interviewed using the MMI format by the internal medicine residency program of The Reading Health System, between September 2011 and February 2014. Fifty-two interns were recruited. Each intern participated in an objective structured clinical examination (OSCE) 3–4 months after the start of the program. The OSCE score of each intern was used as the independent variable to test the relationship with both the MMI interpersonal score and the MMI overall score. Results There was a moderate positive correlation between the average MMI interpersonal score and the communication score on the OSCE, r=0.384, n=52, p=0.005, and a negligible relationship between the average MMI overall score and the communication score on the OSCE, r=0.175, n=52, p=0.214. Conclusion The MMI is a useful tool for residency programs to assess interpersonal and communication skills prior to matriculation into residency training. This study provides evidence for its validity in assessing these competencies. PMID:26091663

  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. 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…

  5. 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…

  6. 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…

  7. A Comparison of Standard-Setting Procedures for an OSCE in Undergraduate Medical Education.

    ERIC Educational Resources Information Center

    Kaufman, David M.; Mann, Karen V.; Muijtjens, Arno M. M.; van der Vleuten, Cees P. M.

    2000-01-01

    Compared four standard-setting procedures for an objective structure clinical examination (OSCE) in medical education. Applied Angoff, borderline, relative, and holistic procedures to the data used to establish a cutoff score for a pass/fail decision. The Angoff and borderline procedures gave similar results; however, the relative and holistic…

  8. 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.

  9. Functions of OsDof25 in regulation of OsC4PPDK.

    PubMed

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

    2015-10-01

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

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

    SciTech Connect

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

    1999-01-01

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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2016-06-01

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

  13. Assessing the organizational social context (OSC) of mental health services: implications for research and practice.

    PubMed

    Glisson, Charles; Landsverk, John; Schoenwald, Sonja; Kelleher, Kelly; Hoagwood, Kimberly Eaton; Mayberg, Stephen; Green, Philip

    2008-03-01

    The organizational social context in which mental health services are provided is believed to affect the adoption and implementation of evidence-based practices (EBPs) as well as the quality and outcomes of the services. A fully developed science of implementation effectiveness requires conceptual models that include organizational social context and tools for assessing social context that have been tested in a broad cross-section of mental health systems. This paper describes the role of organizational social context in services and implementation research and evaluates a comprehensive contextual measure, labeled Organizational Social Context (OSC), designed to assess the key latent constructs of culture, climate and work attitudes. The psychometric properties of the OSC measure were assessed in a nationwide study of 1,154 clinicians in 100 mental health clinics with a second-order confirmatory factor analysis of clinician responses, estimates of scale reliabilities, and indices of within-clinic agreement and between-clinic differences among clinicians. Finally, the paper illustrates the use of nationwide norms in describing the OSC profiles of individual mental health clinics and examines the cross-level association of organizational-level culture and climate with clinician-level work attitudes.

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

    Romito, Laura; Schrader, Stuart; Zahl, David

    2014-05-01

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

  16. 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

  17. 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…

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

    PubMed

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

    2015-08-14

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

  19. 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. PMID:26491565

  20. 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…

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

    PubMed Central

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

    2015-01-01

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

  2. Effect of clinically discriminating, evidence-based checklist items on the reliability of scores from an Internal Medicine residency OSCE.

    PubMed

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

    2014-10-01

    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 learners are more likely to use. The purpose of this study was to determine if limiting checklist items to clinically discriminating items and/or adding missing evidence-based items improved score reliability in an Internal Medicine residency OSCE. Six internists reviewed the traditional checklists of four OSCE stations classifying items as clinically discriminating or non-discriminating. Two independent reviewers augmented checklists with missing evidence-based items. We used generalizability theory to calculate overall reliability of faculty observer checklist scores from 45 first and second-year residents and predict how many 10-item stations would be required to reach a Phi coefficient of 0.8. Removing clinically non-discriminating items from the traditional checklist did not affect the number of stations (15) required to reach a Phi of 0.8 with 10 items. Focusing the checklist on only evidence-based clinically discriminating items increased test score reliability, needing 11 stations instead of 15 to reach 0.8; adding missing evidence-based clinically discriminating items to the traditional checklist modestly improved reliability (needing 14 instead of 15 stations). Checklists composed of evidence-based clinically discriminating items improved the reliability of checklist scores and reduced the number of stations needed for acceptable reliability. Educators should give preference to evidence-based items over non-evidence-based items when developing OSCE checklists.

  3. 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.

  4. 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

  5. Dentin Sialophosphoprotein (DSPP) Gene-Silencing Inhibits Key Tumorigenic Activities in Human Oral Cancer Cell Line, OSC2

    PubMed Central

    Joshi, Rajeshree; Tawfik, Amany; Edeh, Nneka; McCloud, Veronica; Looney, Stephen; Lewis, Jill; Hsu, Stephen; Ogbureke, Kalu U. E.

    2010-01-01

    Background We determined recently that dentin sialophosphoprotein (DSPP), a member of the SIBLING (Small integrin-binding ligand N-linked glycoproteins) family of phosphoglycoproteins, is highly upregulated in human oral squamous cell carcinomas (OSCCs) where upregulation is associated with tumor aggressiveness. To investigate the effects of DSPP-silencing on the tumorigenic profiles of the oral cancer cell line, OSC2, short-hairpin RNA (shRNA) interference was employed to silence DSPP in OSC2 cells. Methodology/Principal Findings Multiple regions of DSPP transcript were targeted for shRNA interference using hDSP-shRNA lentiviral particles designed to silence DSPP gene expression. Control shRNA plasmid encoding a scrambled sequence incapable of degrading any known cellular mRNA was used for negative control. Following puromycin selection of stable lines of DSSP-silenced OSC2 cells, phenotypic hallmarks of oral carcinogenesis were assayed by western blot and RT-PCR analyses, MTT (cell-viability), colony-formation, modified Boyden-Chamber (migration and invasion), and flow cytometry (cell-cycle and apoptosis) analyses. DSPP-silenced OSC2 cells showed altered cell morphology, reduced viability, decreased colony-formation ability, decreased migration and invasion, G0/G1 cell-cycle arrest, and increased tumor cell sensitivity to cisplatin-induced apoptosis. Furthermore, MMP-2, MMP-3, MMP-9, VEGF, Ki-67, p53, and EGFR were down-regulated. There was a direct correlation between the degree of DSPP-silencing and MMP suppression, as indicated by least squares regression: MMP-2 {(y = 0.850x, p<0.001) (y = 1.156x, p<0.001)}, MMP-3 {(y = 0.994x, p<0.001) (y = 1.324x, p = 0.004)}, and MMP-9 {(y = 1.248x, p = 0.005, y = 0.809, p = 0.013)}. Conclusions/Significance DSPP-silencing in OSC2 cell decreased salient hallmarks of oral tumorigenesis and provides the first functional evidence of a potential key role for DSPP in oral cancer biology. The

  6. 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

  7. [Quantities analysis of the infrared diffuse reflection spectrum of hydrocarbon source rocks by OSC-iPLS].

    PubMed

    Song, Ning; Xu, Xiao-Xuan; Wang, Bin; Zhang, Cun-Zhou

    2009-02-01

    In many cases, the scattering can be an overpowering contributor to the spectrum, sometimes accounting for most of the variance in the data. Although the degree of scattering is dependent on the wavelength of the light that is used and the particle size and refractive index of the sample, the scattering is not uniform throughout the spectrum. In order to remove the effects of scattering and noise on multivariate calibration of IR spectral signals, orthogonal signal correction (OSC) was used as a method to preprocess the infrared spectra of the hydrocarbon source rocks to be quantitatively determined, thus to establish the calibration model of hydrocarbon source rocks before and after pretreatment by inetval partial least square (iPLS). Pretreatment was smoother and more orderly array. This indicated that the major information in hydrocarbon source rocks spectra could be reserved while part of noise was removed by OSC method. In this study, pretreatment calibration model was obtained, the model's correlation coefficient is 0.994 04 and RMSE is 0.635 2, but with no pretreatment the calibration model's correlation coefficient is 0.770 9 and RMSE is 3.925 7.

  8. Objective structured clinical examinations (OSCEs) as a summative evaluation tool in a ruminant health management rotation for final-year DVM students.

    PubMed

    Bateman, Ken; Menzies, Paula; Sandals, David; Duffield, Todd; LeBlanc, Stephen; Leslie, Ken; Lissemore, Kerry; Swackhammer, Rob

    2008-01-01

    The objective structured clinical examination (OSCE) has been used for 10 years at the Ontario Veterinary College, University of Guelph, to evaluate the clinical competencies in ruminant health management of final-year DVM students. The performance of these students in the summative assessment, which includes the use of OSCEs, was compared to their formative assessment, given at the end of the rotation. Specifically, classification of students' performance as poor (bottom 10% of the grade range versus "serious deficits") or superior ("A grade" versus "exceeds expectations") was compared. Agreement between the two types of assessment is slight, regardless of whether assessing diagnostic process skills or technical skills--and regardless of whether all students were assessed or only those enrolled in food-animal or mixed streams in their final year--which suggests that the two assess different types of skills. OSCEs are a useful and viable tool for objectively assessing clinical skills in ruminant health management.

  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. Combining (1)H NMR spectroscopy and chemometrics to identify heparin samples that may possess dermatan sulfate (DS) impurities or oversulfated chondroitin sulfate (OSCS) contaminants.

    PubMed

    Zang, Qingda; Keire, David A; Wood, Richard D; Buhse, Lucinda F; Moore, Christine M V; Nasr, Moheb; Al-Hakim, Ali; Trehy, Michael L; Welsh, William J

    2011-04-01

    Heparin is a naturally produced, heterogeneous compound consisting of variably sulfated and acetylated repeating disaccharide units. The structural complexity of heparin complicates efforts to assess the purity of the compound, especially when differentiating between similar glycosaminoglycans. Recently, heparin sodium contaminated with oversulfated chondroitin sulfate A (OSCS) has been associated with a rapid and acute onset of an anaphylactic reaction. In addition, naturally occurring dermatan sulfate (DS) was found to be present in these and other heparin samples as an impurity due to incomplete purification. The present study was undertaken to determine whether chemometric analysis of these NMR spectral data would be useful for discrimination between USP-grade samples of heparin sodium API and those deemed unacceptable based on their levels of DS, OSCS, or both. Several multivariate chemometric methods for clustering and classification were evaluated; specifically, principal components analysis (PCA), partial least squares discriminant analysis (PLS-DA), linear discriminant analysis (LDA), and the k-nearest-neighbor (kNN) method. Data dimension reduction and variable selection techniques, implemented to avoid over-fitting the training set data, markedly improved the performance of the classification models. Under optimal conditions, a perfect classification (100% success rate) was attained on external test sets for the Heparin vs OSCS model. The predictive rates for the Heparin vs DS, Heparin vs [DS+OSCS], and Heparin vs DS vs OSCS models were 89%, 93%, and 90%, respectively. In most cases, misclassifications can be ascribed to the similarity in NMR chemical shifts of heparin and DS. Among the chemometric methods evaluated in this study, we found that the LDA models were superior to the PLS-DA and kNN models for classification. Taken together, the present results demonstrate the utility of chemometric methods when applied in combination with (1)H NMR spectral

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

    PubMed Central

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

    2013-01-01

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

  13. 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.

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

    PubMed

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

    2016-08-01

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

  15. Safety in numbers 5: Evaluation of computer-based authentic assessment and high fidelity simulated OSCE environments as a framework for articulating a point of registration medication dosage calculation benchmark.

    PubMed

    Sabin, Mike; Weeks, Keith W; Rowe, David A; Hutton, B Meriel; Coben, Diana; Hall, Carol; Woolley, Norman

    2013-03-01

    This paper reports a key educational initiative undertaken by NHS Education for Scotland (NES), based upon recommendations from a 'Numeracy in Healthcare' consultation. We report here the design of a web-based technical measurement authentic assessment environment evolved from the safeMedicate suite of programs that provided a model for an environment within which a medication dosage calculation problem-solving (MDC-PS) benchmark could be articulated. A sample of 63 third-year pre-registration nursing students was recruited from four participating universities in the UK. A counterbalanced design was employed where the virtual authentic assessment environment was evaluated for internal consistency reliability and criterion-related validity against an objective structured clinical assessment (OSCE) undertaken in high-fidelity simulated clinical environments. Outcome measures indicated an extremely high internal consistency of the web-based environment. It was concluded that the combination of a web-based authentic assessment environment and further assessment of safe technical measurement interpretation and dexterity in a practice/practice simulation setting, populated with a benchmark and a criterion referenced rubric validated by the profession, is an innovative, viable, valid and reliable assessment method for the safe administration of medicines. As a result, the rubric for assessment of the appropriate range of calculation type and complexity informed the NMC's revised Essential Skills Clusters for Medicines Management (NMC, 2010a; NMC, 2010b). This inclusion provides a particularly strong example of both research directly influencing policy and of evidence-based regulation.

  16. 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.

  17. 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

  18. 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

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

    SciTech Connect

    Kristin Persson

    2014-07-09

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

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

    SciTech Connect

    Kristin Persson

    2014-07-09

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

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

    SciTech Connect

    Kristin Persson

    2014-07-09

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

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

    SciTech Connect

    Kristin Persson

    2014-07-09

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

  3. 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. Materials Data on Sb4OsC6(O3F11)2 (SG:14) by Materials Project

    DOE Data Explorer

    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

  5. Graphs as a Visual Aid in English for Special Purposes. Lenguas para objetivos especificos (Languages for Special Purposes), No. 5.

    ERIC Educational Resources Information Center

    Stark, Merritt W.; Stark, Kathleen LaPiana

    Visual aids have been developed to strengthen non-English speaking students' ability to speak and write English effectively in their subject areas. Among these aids, graphs have been valuable for economics students because they readily illustrate the nature of the relationship between two sets of numbers. Frequently, the ability to analyze graphs…

  6. 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),...

  7. 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.

  8. Objective structured clinical exams: a critical review.

    PubMed

    Turner, John L; Dankoski, Mary E

    2008-09-01

    Since their inception in the 1970s, objective structured clinical examinations (OSCEs) have become popular and now are part of the US Medical Licensing Examination for all US medical graduates. Despite general acceptance of this method, there is debate over the value of OSCE testing compared to more traditional methods. A review of reliability and validity research does not clearly show superiority of OSCE testing. To use OSCEs in a valid and reliable way, attention must be paid to test content, test design, and implementation factors, especially when the results will be used for high-stakes decision making. While questions remain around the application of OSCE testing, there are also both known and hidden benefits to students, faculty, and organizations that use OSCEs. This paper reviews the pros and cons of the OSCE method and outlines important issues for medical educators to consider when planning to use OSCEs in their programs. PMID:18988044

  9. Design, synthesis, and biological evaluation of new (2E,6E)-10-(dimethylamino)-3,7-dimethyl-2,6-decadien-1-ol ethers as inhibitors of human and Trypanosoma cruzi oxidosqualene cyclase.

    PubMed

    Galli, Ubaldina; Oliaro-Bosso, Simonetta; Taramino, Silvia; Venegoni, Serena; Pastore, Emanuele; Tron, Gian Cesare; Balliano, Gianni; Viola, Franca; Sorba, Giovanni

    2007-01-01

    New dimethylamino truncated squalene ether derivatives containing a different aromatic moiety (phenyl, naphthyl, and biphenyl) or a simple alkyl (n-hexylic) group were synthesized as inhibitors of the oxidosqualene cyclase (OSC) and of the sterol biosynthetic pathway. The activity against human OSC was compared with the activity against the OSCs of pathogenic organisms such as Pneumocystis carinii and Trypanosoma cruzi. The phenyl derivative was the most potent inhibitor of T. cruzi OSC.

  10. Cloning and functional characterization of three branch point oxidosqualene cyclases from Withania somnifera (L.) dunal.

    PubMed

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

    2014-06-13

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

  11. 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.

  12. Objective structured clinical examination in radiology

    PubMed Central

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

    2010-01-01

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

  13. Objective structured clinical examination in radiology.

    PubMed

    Agarwal, Anurag; Batra, Bipin; Sood, Ak; Ramakantan, Ravi; Bhargava, Satish K; Chidambaranathan, N; Indrajit, Ik

    2010-05-01

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

  14. 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.

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

    PubMed

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

    2014-08-01

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

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

    PubMed Central

    Jindal, Parul; Khurana, Gurjeet

    2016-01-01

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

  17. The experience of an objective, structured clinical examination at Kaohsiung Medical University.

    PubMed

    Lee, Kun-Tai; Liu, Wei-Ting; Yen, Jeng-Hsien; Liu, Ching-Kuan; Liu, Keh-Min; Lai, Chung-Sheng

    2008-12-01

    The objective, structured clinical examination (OSCE) is a method to assess clinical competency based on objective testing, through direct observation in a formal setting. The Kaohsiung Medical University (KMU) has pioneered OSCEs in Taiwan. In KMU, three groups of examinees---medical students in years 3 and 4, medical students in years 5 and 6, and medical students in year 7---were assessed using different OSCEs. Each OSCE was set up using the following five steps: (1) create cases; (2) decide on the items or clinical skills to be evaluated; (3) train standardized patients; (4) run the OSCE and (5) review videos to improve the curriculum. We expect that KMU will become the premier OSCE center in Taiwan.

  18. 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.

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

    PubMed

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

    2015-12-01

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

  20. Enhanced light scattering and trapping effect of Ag nanowire mesh electrode for high efficient flexible organic solar cell.

    PubMed

    Wang, Byung-Yong; Yoo, Tae-Hee; Lim, Ju Won; Sang, Byoung-In; Lim, Dae-Soon; Choi, Won Kook; Hwang, Do Kyung; Oh, Young-Jei

    2015-04-24

    Ag nanowire (NW) mesh is used as transparent conducting electrode for high efficient flexible organic solar cells (OSCs). The Ag NW mesh electrode facilitates light scattering and trapping, allowing enhancement of light absorption in the active layer. OSCs incorporating Ag NW mesh electrode exhibit maximum power conversion efficiency (PCE) of 4.47%, 25%, higher than that of OSCs with a conventional ITO electrode (3.63%).

  1. Evidence that circulatory oscillations accompany ventilatory oscillations during exercise in patients with heart failure.

    PubMed

    Ben-Dov, I; Sietsema, K E; Casaburi, R; Wasserman, K

    1992-04-01

    Periodic breathing (PB) during exercise in patients with congestive heart failure (CHF) is associated with prominent oscillations (OSC) of O2 uptake (VO2). We hypothesized that the VO2 OSC represent OSC in true O2 exchange, resulting from concomitant cardiac output fluctuations and are not merely due to OSC of lung O2 stores. We compared the amplitude of the OSC of VO2, ventilation (VE), and end-expiratory lung volume (EELV) in 17 patients with CHF and PB and in seven healthy control subjects who volitionally simulated PB. Subjects underwent an incremental and/or a constant work-rate exercise test. VE and VO2 were measured breath by breath. EELV change was estimated by summing the difference between inspiratory and expiratory tidal volumes for each breath. The amplitude of the OSC, delta, is expressed as the ratio of the difference between the peak and nadir of the oscillating variable divided by its mean [delta = (peak - nadir)/mean]. In CHF, during incremental testing, the amplitude of the VE OSC was smaller than that of the VO2 OSC (delta VE = 49 +/- 15% [SD], delta VO2 = 63 +/- 25%, p less than 0.01). In contrast, during volitional PB in the control subjects, VE OSC were larger than VO2 OSC (delta VE = 48 +/- 12%, delta VO2 = 25 +/- 11%, p less than 0.01). This suggests that changing VE itself cannot account for the marked VO2 OSC seen in CHF. In the patients, EELV showed no systematic OSC, did not correlate with delta VO2, and was not significantly different from zero.(ABSTRACT TRUNCATED AT 250 WORDS)

  2. 77 FR 35408 - Proposed Collection; Comment Request: Process Evaluation of the Early Independence Award (EIA...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-13

    ... collection projects, the Office of Strategic Coordination (OSC), Division of Program Coordination, Planning, and Strategic Initiatives (DPCPSI), National Institutes of Health (NIH), will publish...

  3. 77 FR 56853 - Submission for OMB Review; Comment Request: Process Evaluation of the Early Independence Award...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-14

    ...)(D) of the Paperwork Reduction Act of 1995, the Office of Strategic Coordination (OSC), Division of Program Coordination, Planning, and Strategic Initiatives (DPCPSI), the National Institutes of Health...

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

    PubMed

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

    2016-05-01

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

  5. 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. PMID:21999901

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

    NASA Astrophysics Data System (ADS)

    Williams, Graeme; Aziz, Hany

    2014-10-01

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

  7. Item Dependency in an Objective Structured Clinical Examination

    ERIC Educational Resources Information Center

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

    2006-01-01

    An Objective Structured Clinical Examination (OSCE) is an assessment approach employed in medical education, in which residents rotate through multiple stations of standardized clinical tasks to evaluate their clinical competence. Because items used to evaluate residents' performance in each OSCE station are linked to the same task and are rated…

  8. 5 CFR 1820.7 - Fees.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... accordingly. OSC may presume that multiple requests of this type made within a 30-day period have been made in... reasonable opportunity to submit further clarification. (2) “Direct costs” means those expenses that OSC... to respond to a FOIA request. Direct costs include, for example, the salary of the...

  9. Assessment of Benefits and Costs of Out of School Care: Insight.

    ERIC Educational Resources Information Center

    Scottish Executive Education Dept., Edinburgh.

    A pivotal part of Scotland's Childcare Strategy is the provision of out-of-school care (OSC). The Scottish Executive Education Department commissioned an assessment of the costs and benefits of OSC in Scotland. Despite methodological issues such as lack of longitudinal studies, the review of existing literature evidenced a range of economic…

  10. 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…

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

    ERIC Educational Resources Information Center

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

    2004-01-01

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

  12. 32 CFR 145.4 - Policy.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... CFR 1250, the Privacy Act, and Civil Service Rule V. (e) Close coordination between DoD and OSC... litigation, release of information shall be accomplished pursuant to MSPB rules of discovery (5 CFR 1201... matters assigned for investigation to the OSC by law, such as the Freedom of Information Act and the...

  13. ROC and Loss Function Analysis in Sequential Testing

    ERIC Educational Resources Information Center

    Muijtjens, Arno M. M.; Van Luijk, Scheltus J.; Van Der Vleuten, Cees P. M.

    2006-01-01

    Sequential testing is applied to reduce costs in SP-based tests (OSCEs). Initially, all candidates take a screening test consisting of a part of the OSCE. Candidates who fail the screen sit the complete test, whereas those who pass the screen are qualified as a pass of the complete test. The procedure may result in a reduction of testing…

  14. 32 CFR 145.6 - Procedures.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

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

  15. 32 CFR 145.6 - Procedures.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

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

  16. 33 CFR 155.T150 - Temporary suspension of requirements to permit support of deepwater horizon spill response.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (OSC), as defined in 40 CFR 300.5, in support of the response to the Deepwater Horizon Spill of..., deployed in coordination with the OSC, as defined in 40 CFR 300.5, in support of the response to the... Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION OIL OR...

  17. 77 FR 24242 - Privacy Act of 1974; System of Records

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-23

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

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

    PubMed Central

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

    2016-01-01

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

  19. 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

  20. 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.

  1. 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.

  2. Simulation as a high stakes assessment tool in emergency medicine.

    PubMed

    O'Leary, Fenton

    2015-04-01

    The Australasian College for Emergency Medicine (ACEM) will introduce high stakes simulation-based summative assessment in the form of Objective Structured Clinical Examinations (OSCEs) into the Fellowship Examination from 2015. Miller's model emphasises that, no matter how realistic the simulation, it is still a simulation and examinees do not necessarily behave as in real life. OSCEs are suitable for assessing the CanMEDS domains of Medical Expert, Communicator, Collaborator and Manager. However, the need to validate the OSCE is emphasised by conflicting evidence on correlation with long-term faculty assessments, between essential actions checklists and global assessment scores and variable interrater reliability within individual OSCE stations and for crisis resource management skills. Although OSCEs can be a valid, reliable and acceptable assessment tool, the onus is on the examining body to ensure construct validity and high interrater reliability. PMID:25690440

  3. [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.

  4. [In Process Citation].

    PubMed

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

    2016-01-01

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

  5. [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.

  6. 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.

  7. 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.

  8. 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

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed Central

    2010-01-01

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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2015-01-01

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

  13. 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.

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

    PubMed

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

    2015-06-22

    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. The triterpene cyclase protein family: a systematic analysis.

    PubMed

    Racolta, Silvia; Juhl, P Benjamin; Sirim, Demet; Pleiss, Jürgen

    2012-08-01

    Triterpene cyclases catalyze a broad range of cyclization reactions to form polycyclic triterpenes. Triterpene cyclases that convert squalene to hopene are named squalene-hopene cyclases (SHC) and triterpene cyclases that convert oxidosqualene are named oxidosqualene cyclases (OSC). Many sequences have been published, but there is only one structure available for each of SHCs and OSCs. Although they catalyze a similar reaction, the sequence similarity between SHCs and OSCs is low. A family classification based on phylogenetic analysis revealed 20 homologous families which are grouped into two superfamilies, SHCs and OSCs. Based on this family assignment, the Triterpene Cyclase Engineering Database (TTCED) was established. It integrates available information on sequence and structure of 639 triterpene cyclases as well as on structurally and functionally relevant amino acids. Family specific multiple sequence alignments were generated to identify the functionally relevant residues. Based on sequence alignments, conserved residues in SHCs and OSCs were analyzed and compared to experimentally confirmed mutational data. Functional schematic models of the central cavities of OSCs and SHCs were derived from structure comparison and sequence conservation analysis. These models demonstrate the high similarity of the substrate binding cavity of SHCs and OSCs and the equivalences of the respective residues. The TTCED is a novel source for comprehensive information on the triterpene cyclase family, including a compilation of previously described mutational data. The schematic models present the conservation analysis in a readily available fashion and facilitate the correlation of residues to a specific function or substrate interaction.

  16. 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

  17. Assessment of first-year veterinary students' clinical skills using objective structured clinical examinations.

    PubMed

    Hecker, Kent; Read, Emma K; Vallevand, Andrea; Krebs, Gord; Donszelmann, Darlene; Muelling, Christoph K W; Freeman, Sarah L

    2010-01-01

    The DVM program at the University of Calgary offers a Clinical Skills course each year for the first three years. The course is designed to teach students the procedural skills required for entry-level general veterinary practice. Objective Structured Clinical Examinations (OSCEs) were used to assess students' performance on these procedural skills. A series of three OSCEs were developed for the first year. Content was determined by an exam blueprint, exam scoring sheets were created, rater training was provided, a mock OSCE was performed with faculty and staff, and the criterion-referencing Ebel method was used to set cut scores for each station using two content experts. Each station and the overall exam were graded as pass or fail. Thirty first-year DVM students were assessed. Content validity was ensured by the exam blueprint and expert review. Reliability (coefficient α) of the stations from the three OSCE exams ranged from 0.0 to 0.71. The three exam reliabilities (Generalizability Theory) were, for OSCE 1, G=0.56; OSCE 2, G=0.37; and OSCE 3, G=0.32. Preliminary analysis has suggested that the OSCEs demonstrate face and content validity, and certain stations demonstrated adequate reliability. Overall exam reliability was low, which reflects issues with first-time exam delivery. Because this year was the first that this course was taught and this exam format was used, work continues in the program on the teaching of the procedural skills and the development and revision of OSCE stations and scoring checklists.

  18. Molecular Beacon-Based Fluorescent Assay for Specific Detection of Oversulfated Chondroitin Sulfate Contaminants in Heparin without Enzyme Treatment.

    PubMed

    Lee, Chih-Yi; Tseng, Wei-Lung

    2015-01-01

    Oversulfated chondroitin sulfate (OSCS) is a harmful contaminant in the pharmaceutical heparin. The development of a rapid, convenient, sensitive, and selective method is required for routine analysis of OSCS in pharmaceutical heparin. Here we report a simple, rapid, sensitive, and enzyme-free method for detecting OSCS in heparin based on the competitive binding between OSCS and the adenosine-repeated molecular beacon (MB) stem to coralyne in the presence of Ca(2+) ions. The MB (A8-MB-A8) contains a 22-mer loop, a stem of a pair of 8-mer adenosine (A) bases, a fluorophore unit at the 5'-end, and a quencher at the 3'-end. The presence of coralyne promotes these A-A mismatches to form a hairpin-shaped MB. However, this kind of MB is incapable of differentiating between heparin and OSCS because they both exhibit strong electrostatic attraction with coralyne. This study found that while Ca(2+) ions can efficiently suppress the negative charges of heparin, they do not neutralize the negative charge of OSCS. Thus, in the presence of Ca(2+) ions, OSCS can remove coralyne from the MB stem, initiating fluorescence of the MB. Under optimal conditions (10 nM A8-MB-A8, 800 nM coralyne, and 0.5 mM Ca(2+) ions), the proposed system can detect 0.01% w/w OSCS in heparin in under 5 min without enzyme treatment. This study also validates the practicality of the proposed system to determine 0.01% w/w OSCS in the pharmaceutical heparin.

  19. Limitations of the of the oscillometric method for blood pressure measurements in dialyzed patients

    PubMed Central

    Czarkowski, Marek; Staszków, Monika; Kostyra, Kacper; Shebani, Zuhier; Różanowski, Krzysztof; Matuszkiewicz-Rowińska, Joanna; Niemczyk, Stanisław

    2011-01-01

    Summary Background Despite more frequent use of the oscillometric method (OSC) for arterial blood pressure (BP) measurement, little is known about OSC’s accuracy when used with hemodialysed patients. This study was undertaken to determine if hemodialysis (HD) and individual features in examined patients can affect the accuracy of OSC for BP measurement. Material/Methods In 54 hemodialysed patients (57±15 years), during 2 sessions (before and after HD), 3 pairs of BP measurements each were performed on arms, alternately employing OSC and auscultatory method, with mercury manometers by 2 observers (REF). Results No difference was found in systolic BP measured before and after HD (SBP before HD: REF −147.3±27.3, OSC −147.5±25.0 mmHg, p>0.05, SBP after HD: REF-141.1±33.9, OSC-141.2±31.5 mmHg, p>0.05, respectively), but diastolic BP (DBP) was significantly higher both before and after HD during REF measurement in comparison with OSC (DBP before HD: REF −79.0±17.0, OSC −76.7±15.0 mmHg, DBP after HD: REF −78.6±18.8, OSC −76.7±16.7 mmHg, p<0.001, respectively). No significant correlation between loss of body weight caused by HD and differences in BP measured by REF and OSC after HD was indicated (Pearson’s correlation coefficients: for SBP −0.041, for DBP 0.030). However, a significant correlation between differences in BP measured by REF and OSC before HD and differences in BP measured by REF and OSC after HD was observed (Spearman’s rank correlation coefficients: for SBP 0.502 and for DBP 0.557, p<0.000001). Conclusions Our study found that individual features, not HD, determine the accuracy of OSC for BP measurement in hemodialysed patients. PMID:21455115

  20. 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.

  1. 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.

  2. 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.

  3. 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.

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

    PubMed

    Cheng, Pei; Zhan, Xiaowei

    2016-05-01

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

  5. 28 CFR 70.2 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... the performance of work under a funding agreement (“subject inventions”), as defined in 37 CFR part... Service (USMS), National Institute of Corrections (NIC), Office of Special Counsel (OSC), and the...

  6. 5 CFR 1800.2 - Filing disclosures of information.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

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

  7. 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

  8. 77 FR 7584 - Draft Guidance for Industry on Heparin for Drug and Medical Device Use; Monitoring Crude Heparin...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-13

    ... (especially ruminant material) contaminants. This draft guidance on crude heparin recommends strategies to... contamination of heparin with the bovine spongiform encephalopathy (BSE) agent derived from ruminant materials... contaminated with OSCS or any non- porcine origin material, especially ruminant material (unless...

  9. 33 CFR 153.305 - Methods and procedures for the removal of discharged oil.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... maximum extent possible; (c) Recover the discharged oil from the water or adjoining shorelines by... the Federal OSC; and (e) Dispose of recovered oil and oil contaminated materials in accordance...

  10. 33 CFR 153.305 - Methods and procedures for the removal of discharged oil.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... maximum extent possible; (c) Recover the discharged oil from the water or adjoining shorelines by... the Federal OSC; and (e) Dispose of recovered oil and oil contaminated materials in accordance...

  11. 33 CFR 153.305 - Methods and procedures for the removal of discharged oil.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... maximum extent possible; (c) Recover the discharged oil from the water or adjoining shorelines by... the Federal OSC; and (e) Dispose of recovered oil and oil contaminated materials in accordance...

  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

    2015-05-01

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

  13. Crystal structure of a squalene cyclase in complex with the potential anticholesteremic drug Ro48-8071.

    PubMed

    Lenhart, Alexander; Weihofen, Wilhelm A; Pleschke, Axel E W; Schulz, Georg E

    2002-05-01

    Squalene-hopene cyclase (SHC) catalyzes the conversion of squalene into pentacyclic compounds. It is the prokaryotic counterpart of the eukaryotic oxidosqualene cyclase (OSC) that catalyzes the steroid scaffold formation. Because of clear sequence homology, SHC can serve as a model for OSC, which is an attractive target for anticholesteremic drugs. We have established the crystal structure of SHC complexed with Ro48-8071, a potent inhibitor of OSC and therefore of cholesterol biosynthesis. Ro48-8071 is bound in the active-center cavity of SHC and extends into the channel that connects the cavity with the membrane. The binding site of Ro48-8071 is largely identical with the expected site of squalene; it differs from a previous model based on photoaffinity labeling. The knowledge of the inhibitor binding mode in SHC is likely to help develop more potent inhibitors for OSC.

  14. 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...

  15. 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...

  16. 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.

  17. 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.

  18. 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

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

    SciTech Connect

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

    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.

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

    PubMed

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

    2016-09-01

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

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

    NASA Astrophysics Data System (ADS)

    Arisawa, Kenta; Harafuji, Kenji

    2015-09-01

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

  2. 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.

  3. 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

    2015-01-01

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

  4. 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.

  5. 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.

  6. Hemodynamic effects of blood loss during a passive response to a stressor in the conscious rabbit.

    PubMed

    Schadt, James C; Hasser, Eileen M

    2004-02-01

    In the conscious rabbit, exposure to an air jet stressor increases arterial pressure, heart rate, and cardiac output. During hemorrhage, air jet exposure extends the blood loss necessary to produce hypotension. It is possible that this enhanced defense of arterial pressure is a general characteristic of stressors. However, some stressors such as oscillation (OSC), although they increase arterial pressure, do not change heart rate or cardiac output. The cardiovascular changes during OSC resemble those seen during freezing behavior. In the present study, our hypothesis was that, unlike air jet, OSC would not affect defense of arterial blood pressure during blood loss. Male New Zealand White rabbits were chronically prepared with arterial and venous catheters and Doppler flow probes. We removed venous blood until mean arterial pressure decreased to 40 mmHg. We repeated the experiment in each rabbit on separate days in the presence and absence (SHAM) of OSC. Compared with SHAM, OSC increased arterial pressure 14 +/- 1 mmHg, central venous pressure 3.3 +/- 0.4 mmHg, and hindquarter blood flow 34 +/- 4% while decreasing mesenteric conductance 32 +/- 3% and not changing heart rate or cardiac output. During normotensive hemorrhage, OSC enhanced hindquarter and renal vasoconstriction. Contrary to our hypothesis, OSC (23.5 +/- 0.6 ml/kg) increased the blood loss necessary to produce hypotension compared with SHAM (16.8 +/- 0.6 ml/kg). In nine rabbits, OSC prevented hypotension even after a blood loss of 27 ml/kg. Thus a stressful stimulus that resulted in cardiovascular changes similar to those seen during freezing behavior enhanced defense of arterial pressure during hemorrhage.

  7. Significantly greater expression of ER, PR, and ECAD in advanced-stage low-grade ovarian serous carcinoma as revealed by immunohistochemical analysis.

    PubMed

    Wong, Kwong-Kwok; Lu, Karen H; Malpica, Anais; Bodurka, Diane C; Shvartsman, Hyun S; Schmandt, Rosemarie E; Thornton, Angela D; Deavers, Michael T; Silva, Elvio G; Gershenson, David M

    2007-10-01

    A 2-tier system that classifies ovarian serous carcinoma (OSC) as low grade or high grade is gaining acceptance. Women with low-grade OSC generally have higher 5-year survival rates than do women with high-grade OSC. We examined the expression of various markers to further understand the molecular differences between low-grade and high-grade OSCs: the potential therapeutic targets or prognostic markers Her-2/neu, estrogen receptor, and progesterone receptor (PR); the metastasis-associated markers cyclin D1 (BCL1), E-cadherin, matrix metalloproteinase (MMP) 2, and MMP-9; and the cell proliferation-associated markers BCL1, Ki-67 antigen (Ki-67), and p53. For this immunohistochemical analysis, we used paraffin-embedded specimens from 47 patients with advanced-stage low-grade OSC and from 49 patients with advanced-stage high-grade OSC. Our results showed that low-grade tumors expressed significantly higher levels of estrogen receptor, PR, and E-cadherin than did high-grade tumors, suggesting the involvement of gonadal steroid hormones, especially in the pathogenesis of low-grade OSC; the PR positivity was also observed in the stromal component of these low-grade tumors. On the other hand, high-grade tumors trended toward increased expression of MMP-9, BCL1, p53, and Ki-67, and robust MMP-9 positivity was observed in the stromal component of these high-grade tumors. These differences may lead to the development of different therapeutic strategies for women with either the low-grade or the high-grade form of OSC.

  8. Lymphocyte transformation as a model system. Final report, January 1, 1980-December 31, 1980

    SciTech Connect

    Yachnin, S.

    1982-01-01

    The following investigations were conducted during the period of this grant: measurement of the insertion of oxygenated sterol compounds (OSC) into human red cells and lymphocyte membranes; the relationship of such insertion to functional and morphological alterations such as echinocyte formation and decreased osmotic fragility in red cells, and inhibition of E-rosette formation and lymphocyte capping in human lymphocytes; a study of the binding of OSC by various lipoprotein fractions of human serum; a study of the effects of human serum lipoprotein on the insertion of OSC into red cell and lymphocyte membranes; a study of the effects of OSC and ML-236B (Compactin) on human lymphocyte proliferation in vitro; a study of the effects of OSC and ML-236B on the synthesis of sterol and nonsterol derived products of mevalonic acid in human lymphocytes; a study of the initiation of cell growth in human lymphocytes by mevalonic acid; and a study of the inhibition of the formation of CFU-C in vitro from human bone marrow mononuclear cells by OSC and ML-236.

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

    NASA Astrophysics Data System (ADS)

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

    2016-07-01

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

  10. Hafnium metallocene compounds used as cathode interfacial layers for enhanced electron transfer in organic solar cells.

    PubMed

    Park, Keunhee; Oh, Seungsik; Jung, Donggeun; Chae, Heeyeop; Kim, Hyoungsub; Boo, Jin-Hyo

    2012-01-09

    We have used hafnium metallocene compounds as cathode interfacial layers for organic solar cells [OSCs]. A metallocene compound consists of a transition metal and two cyclopentadienyl ligands coordinated in a sandwich structure. For the fabrication of the OSCs, poly[3,4-ethylenedioxythiophene]:poly(styrene sulfonate), poly(3-hexylthiophene-2,5-diyl) + 66-phenyl C61 butyric acid methyl ester, bis-(ethylcyclopentadienyl)hafnium(IV) dichloride, and aluminum were deposited as a hole transport layer, an active layer, a cathode interfacial layer, and a cathode, respectively. The hafnium metallocene compound cathode interfacial layer improved the performance of OSCs compared to that of OSCs without the interfacial layer. The current density-voltage characteristics of OSCs with an interfacial layer thickness of 0.7 nm and of those without an interfacial layer showed power conversion efficiency [PCE] values of 2.96% and 2.34%, respectively, under an illumination condition of 100 mW/cm2 (AM 1.5). It is thought that a cathode interfacial layer of an appropriate thickness enhances the electron transfer between the active layer and the cathode, and thus increases the PCE of the OSCs.

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

    PubMed

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

    2016-03-17

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

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

    SciTech Connect

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

    2014-10-15

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

  13. 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.

  14. Sheep stromal-epithelial cell interactions and ovarian tumor progression.

    PubMed

    Wang-Johanning, Feng; Huang, Miao; Liu, Jinsong; Rycaj, Kiera; Plummer, Joshua B; Barnhart, Kirstin F; Satterfield, William C; Johanning, Gary L

    2007-11-15

    Previous studies suggest that underlying ovarian stromal cues may regulate the ovarian surface epithelium. However, little is known about the interaction between ovarian stromal cells (OSC) and ovarian surface epithelial cells (OSE) under normal physiologic and pathologic conditions, largely because of the lack of a suitable model. In the current study, the OSC obtained from a sheep were immortalized with SV-40 T/t antigen (designated IOSC) and telomerase reverse transcriptase (designated IOSCH), followed by transfection with the oncogenic allele of the human H-Ras oncogene (designated IOSChR). IOSC cells transfected with H-Ras before immortalization with telomerase were designated IOSCRH. These sheep OSCs were used in both in vitro and in vivo model systems to evaluate mechanisms by which OSCs influence ovarian tumor progression. Normal sheep OSCs were found to inhibit the growth of SKOV3 and OVCAR3 human ovarian cancer cells, but not normal sheep OSE and human OSE cells (hOSE137 cells). In contrast, IOSChR and IOSCRH cells stimulated the growth of normal sheep and human OSE cells, as well as cancer cells. These findings were confirmed by in vivo studies. Our data provide compelling support for the importance of stromal-epithelial cell interactions during tumor progression, and show for the first time that immortalized and transformed OSCs promote growth of ovarian epithelial tumors.

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

    PubMed

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

    2016-09-01

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

  16. 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.

  17. 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

  18. [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

  19. [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.

  20. 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.

  1. 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

  2. [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.

  3. 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

  4. 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.

  5. [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.

  6. 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.

  7. 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

  8. 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.

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

    PubMed

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

    2015-09-01

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

  10. 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.

  11. Class modeling analysis of heparin 1H NMR spectral data using the soft independent modeling of class analogy and unequal class modeling techniques.

    PubMed

    Zang, Qingda; Keire, David A; Wood, Richard D; Buhse, Lucinda F; Moore, Christine M V; Nasr, Moheb; Al-Hakim, Ali; Trehy, Michael L; Welsh, William J

    2011-02-01

    To differentiate heparin samples with varying amounts of dermatan sulfate (DS) impurities and oversulfated chondroitin sulfate (OSCS) contaminants, proton NMR spectral data for heparin sodium active pharmaceutical ingredient samples from different manufacturers were analyzed using multivariate chemometric techniques. A total of 168 samples were divided into three groups: (a) Heparin, [DS] ≤ 1.0% and [OSCS] = 0%; (b) DS, [DS] > 1.0% and [OSCS] = 0%; (c) OSCS, [OSCS] > 0% with any content of DS. The chemometric models were constructed and validated using two well-established methods: soft independent modeling of class analogy (SIMCA) and unequal class modeling (UNEQ). While SIMCA modeling was conducted using the entire set of variables extracted from the NMR spectral data, UNEQ modeling was combined with variable reduction using stepwise linear discriminant analysis to comply with the requirement that the number of samples per class exceed the number of variables in the model by at least 3-fold. Comparison of the results from these two modeling approaches revealed that UNEQ had greater sensitivity (fewer false positives) while SIMCA had greater specificity (fewer false negatives). For Heparin, DS, and OSCS, respectively, the sensitivity was 78% (56/72), 74% (37/50), and 85% (39/46) from SIMCA modeling and 88% (63/72), 90% (45/50), and 91% (42/46) from UNEQ modeling. Importantly, the specificity of both the SIMCA and UNEQ models was 100% (46/46) for Heparin with respect to OSCS; no OSCS-containing sample was misclassified as Heparin. The specificity of the SIMCA model (45/50, or 90%) was superior to that of the UNEQ model (27/50, or 54%) for Heparin with respect to DS samples. However, the overall prediction ability of the UNEQ model (85%) was notably better than that of the SIMCA model (76%) for the Heparin vs DS vs OSCS classes. The models were challenged with blends of heparin spiked with nonsulfated, partially sulfated, or fully oversulfated chondroitin sulfate

  12. Diminished osmotic fragility of human erythrocytes following the membrane insertion of oxygenated sterol compounds

    SciTech Connect

    Streuli, R.A.; Kanofsky, J.R.; Gunn, R.B.; Yachnin, S.

    1981-08-01

    Oxygenated sterol compounds (OSC), when incubated for 1 hr with human erythrocytes in lipoprotein-depleted medium at concentrations of 0.625-5 x 10/sup -5/M, are inserted into the cell membrane and remain there despite subsequent washing of the cells. The insertion results in expansion of the surface area of the red cell ghost membrane, an increase in critical hemolytic volume, and as a consequence, in dimished osmotic fragility of the erythrocytes. This effect is seen with echinocyte-forming as well as with non-echinocyte-forming OSC. Erythrocytes treated with OSC do not differ from control cells with respect to their mean cell volume (MCV) in isotonic solution, water content, ion fluxes, and filterability through polycarbonate filters. The shift of the osmotic fragility curve toward lower NaCl concentrations is proportional to the amount of OSC inserted into the red cell membrane. 7BETA-Hydroxycholesterol, 22-ketocholesterol, and 20 ..cap alpha..-hydroxycholesterol are the most potent inhibitors of osmotic lysis. The effect of OSC on osmotic fragility is diminished if the erythrocytes are incubated in a lipoprotein-containing medium; free cholesterol, however, does not change this effect. Various progesterones also protect red cells from osmotic lysis if the erythrocytes are directly exposed to the compounds present in the hypotonic NaCl solutions.

  13. 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

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

    NASA Astrophysics Data System (ADS)

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

    2015-07-01

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

  15. 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

  16. Overlapping spreading centres: new accretion geometry on the East Pacific Rise

    NASA Astrophysics Data System (ADS)

    MacDonald, Ken C.

    1983-03-01

    In a detailed Seabeam investigation of the East Pacific Rise (EPR) from 8°N to 18°N, a new kind of volcano-tectonic geometry associated with fast-spreading centres has been discovered (Figs 1, 2). At several locations along the rise axis the neovolcanic zone is discontinuous, and is laterally offset a short distance (1-15 km). In contrast to a classic ridge-transform-ridge plate boundary, however, the offset ridge terminations overlap each other by a distance approximately equal to or greater than the offset. They curve sharply towards each other and often merge into one another along strike. Separating the overlapping spreading centres (OSCs) is a closed contour depression up to several hundred metres deep which is sub-parallel to the trend of the OSCs. The region between the OSCs is a complex zone of both shear and rotational deformation with no obvious transform parallel structures. Based on wax model studies of spreading centres, we suggest here that transform faults fail to develop at fast spreading centres where the lateral offsets are small (<15 km), because the lithosphere is too thin and weak to maintain a classic, rigid plate spreading centre-transform fault pattern. The OSC geometry is unstable and evolves rapidly. One of the two OSCs prevails while the other is abandoned. A significant area of sea floor created at fast spreading rates may bear the imprint of this newly observed process.

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

    NASA Astrophysics Data System (ADS)

    Amrani, Alon

    2014-05-01

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

  18. Coupled thermal, electrical, and fluid flow analyses of AMTEC multitube cell with adiabatic side wall

    NASA Astrophysics Data System (ADS)

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

    1997-01-01

    The paper describes a novel OSC-generated methodology for analyzing the performance of multitube AMTEC (Alkali Metal Thermal-to-Electrical Conversion) cells, which are under development by AMPS (Advanced Modular Power Systems, Inc.) for the Air Force Phillips Laboratory (AFPL) and NASA's Jet Propulsion Laboratory (JPL), for possible application to the Pluto Express and other space missions. The OSC study was supported by the Department of Energy (DOE), and was strongly encouraged by JPL, AFPL, and AMPS. It resulted in an iterative procedure for the coupled solution of the interdependent thermal, electrical, and fluid flow differential and integral equations governing the performance of AMTEC cells and generators. The paper clarifies the OSC procedure by presenting detailed results of its application to an illustrative example of a converter cell with an adiabatic side wall, including the non-linear axial variation of temperature, pressure, open-circuit voltage, interelectrode voltage, current density, axial current, sodium mass flow, and power density. The next paper in these proceedings describes parametric results obtained by applying the same procedure to variations of the baseline adiabatic converter design, culminating in an OSC-recommended revised cell design. A subsequent paper in these proceedings extends the procedure to analyze a variety of OSC-designed radioisotope-heated generators employing non-adiabatic multitube AMTEC cells.

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

    PubMed

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

    2013-10-21

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

  20. Investigation into the optical characteristics of the top-illuminated organic solar cells with graphene electrode

    NASA Astrophysics Data System (ADS)

    Long, Yongbing; Li, Bowen; Li, Yuanxing; Zheng, Wenhao; Wang, Qiwen; Su, Runmei

    2014-06-01

    Optical modeling based on transfer matrix method is employed to investigate optical performance of the top-illuminated organic solar cells (OSCs) with graphene electrode. For the graphene-based OSCs with thin active layer,the upper limit to short-circuit current density (?) is improved when compared with that of the indium tin oxide-based devices. This is attributed to the zero-order optical resonance of the weak microcavity (WMC) constructed within the devices. But for the devices with relatively thicker active layer, ? is reduced by the off-resonance suppression of the WMC structure. By capping a WO3 layer on the graphene electrode to tune the WMC structure, the off-resonance suppression can be eliminated and ? for the graphene-based OSCs is significantly raised due to the combined effects of the first-order and other higher order optical resonance of the WMC. In addition, the capping layer can be used to improve ? for the top-illuminated OSCs with various organic materials as the active layer. Finally, it is demonstrated that ? for the graphene-based OSCs with a WMC structure decreases according to Lambert's cosine law when the incident angle increases.

  1. Apoptotic pathways in ovarian surface epithelium of human embryos during embryogenesis and carcinogenesis: close relationship of developmental plasticity and neoplasm.

    PubMed

    Caric, Ana; Poljicanin, Ana; Tomic, Snjezana; Vilovic, Katarina; Saraga-Babic, Mirna; Vukojevic, Katarina

    2014-03-01

    Cell differentiation and different pathways of cell death were immunohistochemically analyzed in ovaries of six human embryos, 20 serous borderline tumors (SBT) and ovarian serous carcinomas (OSC) using markers for apoptosis (caspase-3, AIF, TUNEL) and stemness (Oct-4). In the 5-8-week ovaries, caspase-3 was absent in the ovarian surface epithelium (ose) and mildly positive in the ovarian stroma (os), AIF was expressed moderately, while Oct-4 expression gradually decreased during that period. Some ovarian cells expressed only caspase-3 or AIF together with TUNEL, while both caspase-3 and AIF were co-expressed in other ovarian cells. Mild expression of Oct-4 and caspase-3 characterized some cells of SBT, while their expression varied from mild to strong in OSC. AIF displayed mild to strong expression in ose of SBT and moderate to strong expression in OSC, while no expression of AIF was observed in os of both tumors. In the ose of both SBT and OSC, caspase-3 and AIF were co-expressed only occasionally, while AIF and Oct-4 were co-expressed strongly. Our study showed the presence of stemness cells and different pathways of cell death (caspase-3 and AIF-mediated) in the ovarian tissue during development and carcinogenesis, indicating the correlation between developmental plasticity in human embryonic ovaries and OSC.

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed

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

    2014-01-01

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

  5. Purification of oogonial stem cells from adult mouse and human ovaries: an assessment of the literature and a view toward the future.

    PubMed

    Woods, Dori C; White, Yvonne A R; Tilly, Jonathan L

    2013-01-01

    Contemporary claims that mitotically active female germ line or oogonial stem cells (OSCs) exist and support oogenesis during postnatal life in mammals have been debated in the field of reproductive biology since March 2004, when a mouse study posed the first serious challenge to the dogma of a fixed pool of oocytes being endowed at birth in more than 50 years. Other studies have since been put forth that further question the validity of this dogma, including the isolation of OSCs from neonatal and adult mouse ovaries by 4 independent groups using multiple strategies. Two of these groups also reported that isolated mouse OSCs, once transplanted back into ovaries of adult female mice, differentiate into fully functional eggs that ovulate, fertilize, and produce healthy embryos and offspring. Arguably, one of the most significant advances in this emerging field was provided by a new research study published this year, which reported the successful isolation and functional characterization of OSCs from ovaries of reproductive age women. Two commentaries on this latest work, one cautiously supportive and one highly skeptical, were published soon afterward. This article evaluates the current literature regarding postnatal oogenesis in mammals and discusses important next steps for future work on OSC biology and function.

  6. Signal transduction pathways leading to cell cycle arrest and apoptosis induction in cancer cells by Allium vegetable-derived organosulfur compounds: a review.

    PubMed

    Herman-Antosiewicz, Anna; Singh, Shivendra V

    2004-11-01

    Epidemiological studies continue to support the premise that dietary intake of Allium vegetables (e.g., garlic, onions and so forth) may lower the risk of various types of cancer. Anticarcinogenic effect of Allium vegetables is attributed to organosulfur compounds (OSCs) that are generated upon processing of these vegetables. Preclinical studies have provided convincing evidence to indicate that Allium vegetable-derived OSCs including diallyl sulfide, diallyl disulfide and diallyl trisulfide are highly effective in affording protection against cancer in laboratory animals induced by a variety of chemical carcinogens. Inhibition of carcinogen activation through modulation of cytochrome P450-dependent monooxygenases and/or acceleration of carcinogen detoxification via induction of phase II enzymes (glutathione transferases, quinone reductase, etc.) are believed to be responsible for protective effects of OSCs against chemically induced cancers. More recent studies have indicated that some naturally occurring OSC analogues can suppress proliferation of cancer cells in culture and inhibit growth of transplanted tumor xenografts in vivo by inducing apoptosis and/or by perturbing cell cycle progression. This review summarizes current knowledge on signal transduction pathways leading to perturbations in cell cycle progression and apoptosis induction by OSCs.

  7. Healthcare utilization and costs associated with tyrosine kinase inhibitor switching in patients with chronic myeloid leukemia.

    PubMed

    Kropf, Patricia; Barnes, Gisoo; Tang, Boxiong; Pathak, Ashutosh; Issa, Jean-Pierre J

    2016-01-01

    Differences in healthcare utilization and costs were examined in chronic myeloid leukemia (CML) patients experiencing first-, second- and third-line tyrosine kinase inhibitor (TKI) therapy. Three CML cohorts were identified from the Truven Health MarketScan® database: No-Switch Cohort (NSc) = did not switch from first-line; One-Switch Cohort (OSc) = switched from first- to second-line only; Two-Switch Cohort (TSc) = switched to second- and then third-line. A total of 3510 patients were identified (mean = 54%; age = 55.8 years). NSc comprised 81% of the sample, OSc comprised 15% and 4% were in the TSc. First-line utilization/costs were significantly higher in the OSc/TSc compared to the NSc. Second-line hospital/outpatient visits and costs were higher in TSc compared to OSc. TSc experienced a significant cost increase from first- to second-line ($4226.46), twice that of OSc ($2488.03). TKI switching is associated with a substantial increase in healthcare utilization and costs, particularly for patients who switch twice.

  8. Pair Box 8 (PAX8) protein expression in high grade, late stage (stages III and IV) ovarian serous carcinoma

    PubMed Central

    Mhawech-Fauceglia, Paulette; Wang, Dan; Samrao, Damanzoopinder; Godoy, Heidi; Ough, Faith; Liu, Song; Pejovic, Tanja; Lele, Shashikant

    2016-01-01

    Objectives Pair-Box 8 (PAX8) is a transcription factor which has been found to be overexpressed in ovarian serous carcinoma (OSC). Silencing PAX8 by using shRNA led to a drop in cell viability in ovarian cancer cell lines, suggesting its use as a targeted therapeutic agent. The prognostic value of PAX8 in OSC is still widely unknown. The aim of this study was to evaluate PAX8 as a prognostic biomarker in patients with advanced stage OSC. Methods PAX8 was evaluated using immunohistochemistry on a tissue microarray of 148 OSC and the expression was correlated to the following clinico-pathologic variables; age of diagnosis, tumor stage, optimal debulking, recurrence free survival (RFS) and overall survival (OS). Results We found that PAX8 was expressed in 61% of cases. There was no association between PAX8 and tumor stage, optimal debulking and disease recurrence. In addition, PAX8 failed to have a predictive value in disease outcome. Conclusion Despite showing that PAX8 protein is not a useful predictive marker in patients with high grade, advanced stage OSC, its overexpression in a large number of these cases makes the inhibition of PAX8 a very attractive targeted therapy. PMID:22705448

  9. 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.

  10. D-A-D structured organic molecules with diketopyrrolopyrrole acceptor unit for solution-processed organic solar cells

    PubMed Central

    Zhang, Jing; He, Chang; Zhang, Zhi-Guo; Deng, Dan; Zhang, Maojie; Li, Yongfang

    2014-01-01

    Four solution-processable D-A-D structured organic molecules with diketopyrrolopyrrole (DPP) as acceptor unit and triphenylamine (TPA) or (4-hexyl)thieno [3,2-b]thiophene (HTT) as donor unit, DPP8-TPA, DPP8-TPA-OR, DPP6-HTT and DPP8-HTT, were designed and synthesized for the application as donor materials in solution-processed organic solar cells (OSCs). The molecules show broad absorption and relatively lower highest occupied molecular orbital energy levels. Photovoltaic properties of the molecules were investigated by fabricating the bulk-heterojunction OSCs with the molecules as donor and PC71BM as acceptor. Power conversion efficiency of the OSC based on DPP8-HTT reached 1.5% under the illumination of AM1.5, 100 mW cm−2. PMID:24615148

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

    NASA Astrophysics Data System (ADS)

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

    2015-07-01

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

  12. 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.

  13. Dynamic infrared scene projectors based upon the DMD

    NASA Astrophysics Data System (ADS)

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

    2009-02-01

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

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

    DOE PAGESBeta

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

    2015-06-04

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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2012-05-01

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

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

    PubMed

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

    2015-12-16

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

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

    PubMed

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

    2016-01-01

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

  19. East Pacific Rise from Siqueiros to Orozco Fracture Zones: Along-strike continuity of axial neovolcanic zone and structure and evolution of overlapping spreading centers

    NASA Astrophysics Data System (ADS)

    MacDonald, Ken; Sempere, Jean-Christophe; Fox, P. J.

    1984-07-01

    We have used the Sea Beam multibeam echo-sounding system to survey the East Pacific Rise (EPR) from 8°20'N to 18°30'N, obtaining complete coverage of the EPR axial neovolcanic zone and all intervening transform faults. Here we focus on the EPR neovolcanic zone and the definition of overlapping spreading centers (OCS's) between the Orozco and Siqueiros transform faults. The neovolcanic zone is narrow (0.5-2.0 km) and continuous along strike and occurs within and near a strike-continuous axial summit graben. The neovolcanic zone and summit graben reside along the crest of a volcanic axial high which is 2-10 km wide and which continues uninterrupted along strike for 40-140 km. Within 20-50 km of an intersection with a transform fault the axial neovolcanic zone narrows and deepens, and within only 3-6 km of the intersection the neovolcanic zone turns sharply into the transform valley. At seven locations between the Siqueiros and Orozco transform faults the axial neovolcanic zone is discontinuous and is laterally offset a short distance (1-15 km). In contrast with a classic ridge/transform/ridge plate boundary, however, offset rise terminations overlap each other by a distance approximately 3 times greater than their offset. They curve toward each other, and often one merges into the other along strike. Separating the OSC's is an elliptical overlap basin up to 600 m deep whose long axis is subparallel to the adjacent spreading centers. The overlap basin is characterized by volcanic constructional edifices. A key difference between these offsets and small transform faults in the Atlantic is that there are no transform fault structures in the overlap basin which link the offset rise axes. A continuous axial depth profile reveals a long-wavelength (20-60 km) undulation of the rise axis which may be associated with variations in the magmatic budget along strike. The lowest points in the axial depth profile occur near transform faults and at OSC's, suggesting that these

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

    PubMed Central

    Silva, Fernanda; Félix, Ana; Serpa, Jacinta

    2016-01-01

    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

  2. Device Stability and Light-Soaking Characteristics of High-Efficiency Benzodithiophene-Thienothiophene Copolymer-Based Inverted Organic Solar Cells with F-TiO(x) Electron-Transport Layer.

    PubMed

    Lim, Fang Jeng; Krishnamoorthy, Ananthanarayanan; Ho, Ghim Wei

    2015-06-10

    Organic solar cells (OSC) based on low-band-gap thienothiophene-benzodithiophene copolymer have achieved relatively high efficiency (7-9%) in recent times. Among this class of material, 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}) (PTB-7) is one of the high-efficiency materials reported for OSC. However, this material seems to be intrinsically unstable compared to the commonly used workhorse polymer, poly(3-hexylthiophene) (P3HT), especially when illuminated in air. Inverted device architecture is usually adopted to improve device stability, but the device stability using PTB-7 is not yet well-understood. In this work, a systematic degradation study on a PTB-7:PC71BM-based inverted OSC employing F-TiO(x) as electron-transport layer (ETL) was conducted for the first time. Air stability, photostability in inert atmosphere, and photostability under ambient conditions of the device were separately carried out to understand better the polymer behavior in inverted OSC. The device's air stability with different polymer absorber layers was studied by exposing the devices in air for up to 1500 h. Because of the long and easily cleavable alkoxy side chains in the polymer backbone, a PTB-7:PC71BM-based inverted OSC device is highly susceptible to oxygen and moisture when compared to a P3HT:PC61BM-based device. In addition, with the presence of F-TiO(x) ETL, a significant reduction in light-soaking time was also observed in PTB-7:PC71BM inverted OSC for the first time. The TiO(x)/organic interface was found to be responsible for the reduction in the light-soaking time.

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

    PubMed

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

    2015-09-01

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

  4. Measuring the effectiveness of small-group and web-based training methods in teaching clinical communication: a case comparison study.

    PubMed

    Artemiou, Elpida; Adams, Cindy L; Vallevand, Andrea; Violato, Claudio; Hecker, Kent G

    2013-01-01

    Current teaching approaches in human and veterinary medicine across North America, Europe, and Australia include lectures, group discussions, feedback, role-play, and web-based training. Increasing class sizes, changing learning preferences, and economic and logistical challenges are influencing the design and delivery of communication skills in veterinary undergraduate education. The study's objectives were to (1) assess the effectiveness of small-group and web-based methods for teaching communication skills and (2) identify which training method is more effective in helping students to develop communication skills. At the Ross University School of Veterinary Medicine (RUSVM), 96 students were randomly assigned to one of three groups (control, web, or small-group training) in a pre-intervention and post-intervention group design. An Objective Structured Clinical Examination (OSCE) was used to measure communication competence within and across the intervention and control groups. Reliability of the OSCEs was determined by generalizability theory to be 0.65 (pre-intervention OSCE) and 0.70 (post-intervention OSCE). Study results showed that (1) small-group training was the most effective teaching approach in enhancing communication skills and resulted in students scoring significantly higher on the post-intervention OSCE compared to the web-based and control groups, (2) web-based training resulted in significant though considerably smaller improvement in skills than small-group training, and (3) the control group demonstrated the lowest mean difference between the pre-intervention/post-intervention OSCE scores, reinforcing the need to teach communication skills. Furthermore, small-group training had a significant effect in improving skills derived from the initial phase of the consultation and skills related to giving information and planning.

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

    PubMed Central

    Silva, Fernanda; Félix, Ana; Serpa, Jacinta

    2016-01-01

    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

  7. Effects of high-frequency chest wall oscillation on pleural pressure and oscillated flow.

    PubMed

    Zucker, Tal; Skjodt, Neil M; Jones, Richard L

    2008-01-01

    The effectiveness of high-frequency chest wall oscillation (HF-CWO) is directly related to the level of oscillated flow (osc) in the airways. We used the Vest system to investigate the effects of HFCWO on chest wall and pleural pressures and we correlated these pressures to the resultant osc. We also compared the latest HFCWO device with it predecessor. Different combinations of vest inflation pressure (background pressure) and oscillation frequency were randomly applied to 10 healthy volunteers. Chest wall pressure was determined using an air-filled bag under the vest and pleural pressure was estimated using an esophageal balloon. Reverse plethysmography was used to measure osc at the mouth and a spirometer was used to measure changes in end-expired lung volume. We found a significant correlation between chest wall and pleural pressure with approximately one-third of the chest wall pressure transmitted into the pleural space. Mean esophageal pressure remained negative at all background pressure/frequency combinations. There was a significant correlation (p<0.0001) between the esophageal pulse pressure and osc, which was highest at 15Hz regardless of the background pressure. The end-expired lung volume correlated with mean chest wall pressure. There was no significant difference between the two Vest systems. Since osc dictates the effectiveness of HFCWO and since osc is dependent on esophageal pulse pressure, which in turn is dependent on chest wall pulse pressure, it follows that the effectiveness of HFCWO is influenced by the ability to generate an effective chest wall pulse pressure.

  8. 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

  9. 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

  10. Immerse precipitation as an efficient protocol to optimize morphology and performance of organic solar cells

    NASA Astrophysics Data System (ADS)

    Zuo, Lijian; Cao, Zhen; Hu, Xiaolian; Gu, Zhuowei; Pan, Hongbin; Chen, Hongzheng

    2012-12-01

    We developed a film-forming processing method for morphology control and organic solar cells (OSCs) optimization. In this protocol, the processing solvent inside a wet active layer is removed by dripping a soaking solvent that is selectively soluble for the processing solvents onto the wet active layer film. By this method, OSCs based on diketopyrrolopyrrole containing copolymers: [6,6]-phenyl-C61-butyric acid methyl ester blend were fabricated. Devices processed by this treatment show a significantly increased efficiency by a factor of 3 compared to devices fabricated by the traditional spin-coating method (from 1.03% to 3.2%), which is mainly attributed to morphology improvements.

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

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-09-01

    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

  13. Measuring a Community-Based Mental Health Organization's Culture and Climate Scores Stability.

    PubMed

    Patterson, David A; Wolf Adelv Unegv Waya, Silver; Maguin, Eugene; Dulmus, Catherine N; Nisbet, Bruce C

    2011-01-01

    This project builds on the work of Glisson et al. (2008) and the knowledge learned from community-based mental health organizations' internal structures (e.g., culture and climate), which possibly impede the implantation and adoption of new technologies. The Organizational Social Context (OSC) Model measurement system is guided by a model of social context that composes both organizational and individual level constructs, including individual and shared perceptions that are believed to mediate the impact of the organization on the individual. Although the OSC has been developed and validated over time, the literature does not provide guidance on test-retest reliability of the scale.

  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. Optimizing Sisal Compiler; Sisal Compiler and Running System

    1992-11-12

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

  16. Efficient organic solar cells with solution-processed carbon nanosheets as transparent electrodes

    NASA Astrophysics Data System (ADS)

    Na, Seok-In; Noh, Yong-Jin; Son, Su-Young; Kim, Tae-Wook; Kim, Seok-Soon; Lee, Sungho; Joh, Han-Ik

    2013-01-01

    We demonstrate that solution-processed carbon nanosheet (CNS) films can efficiently serve as transparent electrodes for organic solar cells (OSCs). The CNS was obtained by spin-coating of polyacrylonitrile (PAN) dissolved in dimethylformamide on quartz substrates, followed by stabilization and carbonization processes to convert polymer into CNS. The thickness of the newly developed CNS films was easily controlled by varying the PAN solution concentration. The polymer-converted CNS films were intensively examined for the feasibility of the use as transparent anodes in solar cells. This approach could be highly desirable for all-solution-processed or printed OSCs.

  17. A novel reductive amination method with isotopic formaldehydes for the preparation of internal standard and standards for determining organosulfur compounds in garlic.

    PubMed

    Tsai, De-Cheng; Liu, Meng-Chieh; Lin, Yi-Reng; Huang, Mei-Fang; Liang, Shih-Shin

    2016-04-15

    Garlic (Allium sativum) is a long-cultivated plant that is widely utilized in cooking and has been employed as a medicine for over 4000 years. In this study, we fabricated standards and internal standards (ISs) for absolute quantification via reductive amination with isotopic formaldehydes. Garlic has four abundant organosulfur compounds (OSCs): S-allylcysteine, S-allylcysteinine sulfoxide, S-methylcysteine, and S-ethylcysteine are abundant in garlic. OSCs with primary amine groups were reacted with isotopic formaldehydes to synthesize ISs and standards. Cooked and uncooked garlic samples were compared, and we utilized tandem mass spectrometry equipped with a selective reaction monitoring technique to absolutely quantify the four organosulfur compounds.

  18. 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

  19. Oscillatory buoyancy-driven flow in horizontal liquid-metal layers

    NASA Astrophysics Data System (ADS)

    Benhadid, Hamda; Roux, Bernard

    1987-02-01

    A two dimensional numerical simulation of the onset of oscillations in horizontal liquid-metal layers (0 is less than Pr is less than 0.1) is described. Layers with upper free surface are treated in order to model horizontal (Bridgman) solidification boat. When this upper surface is assumed conducting, oscillations are found for Pr=0, 0.015, 0.03, and 0.1, when Gr exceeds a critical value, Gr(c,osc). Gr(c,osc) increases with Pr. For Pr=0.03, these oscillations are found to only exist in a limited range of GR (GR(c,osc) is less than or = Gr is less than or = 2 Gr(c,osc)); they are damped when Gr is increased beyond this range. This restabilization phenomenon is not explained. A correlation is found for the theoretical and experimental values of the oscillation frequency in terms of Gr, in the ranges 2 is less than or = Az is less than or = 8 and 0.015 is less than or = Pr is less than or = 0.07. This correlation also includes damped frequencies found in subcritical regimes.

  20. 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

    2016-01-01

    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.

  1. 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.

  2. 32 CFR 145.1 - Purpose.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... THE OFFICE OF SPECIAL COUNSEL OF THE MERIT SYSTEMS PROTECTION BOARD § 145.1 Purpose. This part... Special Counsel (OSC) of the Merit Systems Protection Board (MSPB) in fulfilling the responsibilities of the Special Counsel under Pub. L. 95-454 and 5 CFR 1201 and 1250 to conduct investigations of...

  3. 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…

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

    ERIC Educational Resources Information Center

    Pitt, Rebecca

    2015-01-01

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

  5. 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.

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

    PubMed Central

    Abel, David L; Trevors, Jack T

    2005-01-01

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

  7. 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.

  8. 32 CFR 145.6 - Procedures.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... THE OFFICE OF SPECIAL COUNSEL OF THE MERIT SYSTEMS PROTECTION BOARD § 145.6 Procedures. (a...) Allegations of improper or illegal conduct referred by the OSC to the Secretary of Defense or to a Defense agency (other than the DLA) shall be forwarded to the IG, DoD. (2) Allegations of improper or...

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

    PubMed Central

    2015-01-01

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

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

    PubMed

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

    2007-03-01

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

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

    PubMed

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

    2016-04-01

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

  12. 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.

  13. 5 CFR 1820.7 - Fees.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... resources in this decision making process, however, in deciding to grant waivers or reductions of fees. ...) “Duplication” means the process of making of a copy of a record, or of the information contained in it... clearest proof, but OSC may also look to the past publication record of a requester in making...

  14. 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…

  15. 40 CFR 300.135 - Response operations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 300.135 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SUPERFUND, EMERGENCY PLANNING, AND COMMUNITY RIGHT-TO-KNOW PROGRAMS NATIONAL OIL AND HAZARDOUS SUBSTANCES POLLUTION CONTINGENCY... possible public health emergency exists, the OSC/RPM should notify the Department of Health and...

  16. 40 CFR 300.135 - Response operations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 300.135 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SUPERFUND, EMERGENCY PLANNING, AND COMMUNITY RIGHT-TO-KNOW PROGRAMS NATIONAL OIL AND HAZARDOUS SUBSTANCES POLLUTION CONTINGENCY... possible public health emergency exists, the OSC/RPM should notify the Department of Health and...

  17. 40 CFR 300.135 - Response operations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 300.135 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SUPERFUND, EMERGENCY PLANNING, AND COMMUNITY RIGHT-TO-KNOW PROGRAMS NATIONAL OIL AND HAZARDOUS SUBSTANCES POLLUTION CONTINGENCY... possible public health emergency exists, the OSC/RPM should notify the Department of Health and...

  18. 40 CFR 300.135 - Response operations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 300.135 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SUPERFUND, EMERGENCY PLANNING, AND COMMUNITY RIGHT-TO-KNOW PROGRAMS NATIONAL OIL AND HAZARDOUS SUBSTANCES POLLUTION CONTINGENCY... possible public health emergency exists, the OSC/RPM should notify the Department of Health and...

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

    PubMed

    Abel, David L; Trevors, Jack T

    2005-08-11

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

  20. 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

  1. 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,...

  2. 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,...

  3. 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,...

  4. 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,...

  5. 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,...

  6. 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.

  7. 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.

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

    PubMed

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

    2013-10-23

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

  9. Improving Critical Think Skills Through Online Synchronous Communications: A Study of Learners' Attitudes toward Building Knowledge Networks

    ERIC Educational Resources Information Center

    Kurubacak, Gulsun

    2006-01-01

    The main purpose of this study is to investigate the College learners' attitudes toward Online Synchronous Communications (OSCs) to build knowledge networks. Also, this study focuses on how to improve these learners' critical thinking skills via synchronous communicational activities. Based on the main purpose of this study and the concerns, the…

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

    PubMed

    Jin, Ruifa

    2015-08-01

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

  11. 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...

  12. Development, impact, and measurement of enhanced physical diagnosis skills.

    PubMed

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

    2009-10-01

    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 randomized, blinded, prospective, year-long study involving 3rd year students at the Albert Einstein College of Medicine. Students were randomized to receive intensive instruction in physical examination [study group (n = 46)] or usual instruction [control group (n = 75)] and evaluated by a modified OSCE. The OSCE consisted of 6 real patient stations: Head, ears, eyes, neck, throat; pulmonary; cardiovascular; gastrointestinal; neurology; musculoskeletal; and 2 computer imaging stations: genitourinary and dermatology. A faculty member present at each patient station evaluated student performance. Data were analyzed using t-tests for comparison of the mean scores between the two groups for each station and for average scores across stations. A total of 121 students were tested. The study group performed significantly better than the control group in the gastrointestinal station (p = 0.0004), the combined average score across the six real patient stations (p = 0.0001), and the combined average score across all eight stations (p = 0.0014). Intensive physical diagnosis instruction enhances physical examination skills of 3rd year medical students. The modified OSCE is a useful tool to evaluate these skills.

  13. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2013-07-01

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

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

    ERIC Educational Resources Information Center

    Farrington, Dennis; Abazi, Alajdin

    2009-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2016-06-01

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

  17. 5 CFR 1820.7 - Fees.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... will exercise its discretion to consider the cost-effectiveness of its investment of administrative... reasonable opportunity to submit further clarification. (2) “Direct costs” means those expenses that OSC... to respond to a FOIA request. Direct costs include, for example, the salary of the...

  18. 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…

  19. 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…

  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. 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.

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

    PubMed

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

    2016-08-26

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

  4. 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.

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

    ERIC Educational Resources Information Center

    Lafave, Mark; Katz, Larry; Butterwick, Dale

    2008-01-01

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

  6. 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…

  7. Surface functionalization of polyethylene via covalent immobilization of O-stearoyl-chitosan

    NASA Astrophysics Data System (ADS)

    Xin, Zhirong; Hou, Juan; Ding, Jiaotong; Yang, Zongfeng; Yan, Shunjie; Liu, Chan

    2013-08-01

    When used in blood-contacting field, the hemocompatibility of polyethylene (PE) needs further to be improved. In this article, O-stearoyl-chitosans (OSC) with different esterification degrees were successfully prepared via changing the ratios of chitosan and stearoyl chloride for decreasing the cationic and hydrogen bond strength, thus improving the solubility of chitosan. The PE film was grafted with carboxyl groups of acrylic acid (AA) (PE-g-PAA) by means of O2 plasma pre-treatment and UV-induced graft polymerization, and then PE-g-PAA was used for covalent immobilization of OSC. The above surface modification was confirmed by ATR-FTIR and XPS. Effect of the UV-irradiated graft polymerization parameters, i.e., the discharge power, the plasma pretreatment time, the UV irradiation time and the monomer concentration on the grafting density of AA was investigated. Relative to the value of about 107° for the virgin sample, the water contact angle (WCA) of the PAA-grafted film was about 50°. After the further immobilization of OSC onto the PAA-grafted film, the strength of negative charge of the PAA-grafted surface was decreased by the electropositive OSC, thus presenting a WCA value of about 62° and the excellent performance of anti-platelet adhesion with respect to the virgin and PAA-grafted samples.

  8. 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.

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

    PubMed

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

    2014-09-10

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

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

    PubMed

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

    2016-08-01

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

  11. 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.

  12. 5 CFR 1820.7 - Fees.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... redact it and otherwise prepare it for disclosure. Review time also includes time spent obtaining and... include time spent resolving general legal or policy issues about the application of exemptions. Review... limitations of paragraph (d) of this section. OSC may charge for time spent searching even if it fails...

  13. 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.

  14. 32 CFR 516.71 - Duties.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... improper or illegal conduct. (2) Review for adequacy and legal sufficiency each OSC report of investigation... Service Reform Act of 1978 by obtaining a suitable investigation of allegations of improper or illegal... DOD Inspector General (DODIG) copies of each allegation of improper or illegal conduct referred to...

  15. 32 CFR 516.71 - Duties.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... improper or illegal conduct. (2) Review for adequacy and legal sufficiency each OSC report of investigation... Service Reform Act of 1978 by obtaining a suitable investigation of allegations of improper or illegal... DOD Inspector General (DODIG) copies of each allegation of improper or illegal conduct referred to...

  16. 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

  17. 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.

  18. 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...

  19. 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…

  20. 77 FR 36328 - Agency Information Collection Activities; Request for Comment

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-18

    ... from the Office of Management and Budget (OMB) to use four previously approved information collections... the proper performance of OSC functions, including whether the information will have practical utility... these forms was published in the Federal Register on April 16, 2012 at 77 FR 22614 and on May 15,...

  1. Formative Assessment of Procedural Skills: Students' Responses to the Objective Structured Clinical Examination and the Integrated Performance Procedural Instrument

    ERIC Educational Resources Information Center

    Nestel, Debra; Kneebone, Roger; Nolan, Carmel; Akhtar, Kash; Darzi, Ara

    2011-01-01

    Assessment of clinical skills is a critical element of undergraduate medical education. We compare a traditional approach to procedural skills assessment--the Objective Structured Clinical Examination (OSCE) with the Integrated Performance Procedural Instrument (IPPI). In both approaches, students work through "stations" or "scenarios" undertaking…

  2. 5 CFR 1800.1 - Filing complaints of prohibited personnel practices or other prohibited activities.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... course of any personnel action (unless the Special Counsel determines that the allegation may be resolved...: (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...

  3. 5 CFR 1800.1 - Filing complaints of prohibited personnel practices or other prohibited activities.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... course of any personnel action (unless the Special Counsel determines that the allegation may be resolved...: (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...

  4. 5 CFR 1800.1 - Filing complaints of prohibited personnel practices or other prohibited activities.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... course of any personnel action (unless the Special Counsel determines that the allegation may be resolved...: (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...

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

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... course of any personnel action (unless the Special Counsel determines that the allegation may be resolved...: (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...

  6. 5 CFR 1800.1 - Filing complaints of prohibited personnel practices or other prohibited activities.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... course of any personnel action (unless the Special Counsel determines that the allegation may be resolved...: (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...

  7. 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.

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

    PubMed

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

    2015-01-01

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

  9. 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…

  10. 40 CFR 300.170 - Federal agency participation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... PLANNING, AND COMMUNITY RIGHT-TO-KNOW PROGRAMS NATIONAL OIL AND HAZARDOUS SUBSTANCES POLLUTION CONTINGENCY PLAN Responsibility and Organization for Response § 300.170 Federal agency participation. Federal... be called upon by an OSC/RPM during response planning and implementation to provide assistance...

  11. 76 FR 3099 - Privacy Act of 1974; System of Records

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-19

    ... (February 20, 1996, 61 FR 6427). Dated: January 11, 2011. Morgan F. Park, Alternate OSD Federal Register..., supporting documents, material, and reports relating to the allegation, investigation, or redress of alleged... (DOJ), or the Office of Special Counsel (OSC), to obtain advice regarding statutory and...

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

    PubMed

    Jin, Ruifa

    2015-08-01

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

  14. 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 ...

  15. Control of Subsurface Contaminant Migration by Vertical Engineered Barriers

    EPA Science Inventory

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

  16. 32 CFR 516.71 - Duties.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... LITIGATION Cooperation With the Office of Special Counsel § 516.71 Duties. (a) DA General Counsel. The DA... DOD Inspector General (DODIG) copies of each allegation of improper or illegal conduct referred to DA by OSC. (5) Delegate to The Judge Advocate General the authority to act on behalf of the DA...

  17. 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

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

    ERIC Educational Resources Information Center

    Sarid, Orly; Anson, Ofra; Bentov, Yaakov

    2005-01-01

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

  19. 40 CFR 300.910 - Authorization of use.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... spill control agents listed on the NCP Product Schedule, and the desirability of using appropriate... the oil discharge, provided that the products are listed on the NCP Product Schedule. (c) The OSC..., bioremediation agent, or miscellaneous oil spill control agent, including products not listed on the NCP...

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

    PubMed

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

    2016-04-01

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

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

    PubMed

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

    2016-04-01

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

  2. 32 CFR 145.4 - Policy.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... CFR 1250, the Privacy Act, and Civil Service Rule V. (e) Close coordination between DoD and OSC... litigation, release of information shall be accomplished pursuant to MSPB rules of discovery (5 CFR 1201... 32 National Defense 1 2013-07-01 2013-07-01 false Policy. 145.4 Section 145.4 National...

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

    PubMed

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

    2016-08-01

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

  4. 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...

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

    PubMed

    Bartlett, Maggie; Potts, Jessica; McKinley, Bob

    2016-07-01

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

  6. Large area formation of self-aligned crystalline domains of organic semiconductors on transistor channels using CONNECT (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Park, Steve

    2015-09-01

    The electronic properties of solution-processable small molecule organic semiconductors (OSCs) have rapidly improved in recent years, rendering them highly promising for various low-cost large area electronic applications such as active matrix displays, radio frequency identification tags, and integrated logic circuits. However, practical applications of organic electronics requires patterned and precisely registered OSC film within the transistor channel region with uniform electrical properties over a large area, a task that remains a significant challenge. Here we present a novel technique known as CONNECT (Controlled OSC NucleatioN and Extension for CircuiTs), which utilizes differential surface energy and solution shearing to simultaneously generate self-patterned and self-registered OSC film 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. CONNECT was expanded to use with inkjet printed silver electrodes, showing the versatility of our method to accommodate various solution deposition and fabrication methods.

  7. 43 CFR 11.37 - Must the authorized official confirm exposure before implementing the Assessment Plan?

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... authorized official confirm exposure before implementing the Assessment Plan? (a) Before including any type B... data, such as those collected for response actions by the OSC, or other available studies or surveys of... analyses shall be limited to the number and type required for confirmation of exposure. (3) Where...

  8. 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

    2016-01-01

    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

  9. 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.

  10. Pure spin current transport in Alq3 by spin pumping

    NASA Astrophysics Data System (ADS)

    Jiang, Shengwei; Wang, Peng; Luan, Zhongzhi; Tao, Xinde; Ding, Haifeng; Wu, Di

    2015-03-01

    The use of organic semiconductors (OSCs) in spintronics has aroused considerable interests, owing to their much longer spin-relaxation times of OSCs than those of inorganic counterparts. The most studied example is the organic spin valve (OSV), in which magnetoresistance (MR) effect is frequently reported. However, studies on pure spin current injection and transport in OSCs are scarce. Recently, the pioneering work by Watanabe et al. demonstrated that pure spin current can be pumped into and propagates in semiconducting polymers. In the present work we extend the study to small molecule OSCs, and demonstrate that pure spin current can be injected into Alq3 from the adjacent magnetic insulator Y3Fe5O12 (YIG) by spin pumping. The pure spin current is detected by inverse spin Hall effect (ISHE) in Pd after propagation through Alq3. From the ISHE voltage VISHE as a function of the Alq3 thickness, the spin diffusion length is determined to be ~ 50 nm and does not depend on temperature. This result indicates the MR decrease as increasing temperature in OSVs is not due to the reduced spin diffusion length.

  11. 40 CFR 300.120 - On-scene coordinators and remedial project managers: general responsibilities.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... decision-making processes necessary to ensure compliance with the NCP, including, as appropriate... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SUPERFUND, EMERGENCY PLANNING, AND COMMUNITY RIGHT-TO-KNOW PROGRAMS... release. As part of the planning and preparedness for response, OSCs shall be predesignated by...

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

    PubMed Central

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

    2016-01-01

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

  13. The environmental signals that CAN and CANNOT be inferred from δ18O signals in plant cellulose

    NASA Astrophysics Data System (ADS)

    Kahmen, A.; Sachse, D.; Arndt, S. K.; Tu, K. P.; Vitousek, P.; Dawson, T. E.

    2009-12-01

    Cellulose is one of the most abundant plant compounds on Earth, and contains oxygen that ultimately has its origin from water. The stable oxygen isotope composition, δ18O, of water is strongly associated with environmental conditions. It follows therefore that the δ18O of leaf (δ18OLC) and stem (δ18OSC) cellulose is regarded as a powerful indicator of environmental conditions. Interpretations of what determines the δ18OLC and δ18OSC are, however, complicated by the fact that δ18OLC and δ18OSC are controlled by both air temperature (Tair) that is known to influence the isotopic composition of the plant’s source water and relative humidity (RH) that drives isotope enrichment of H218O in a leaf. Here, we show the results of an investigation where we combined empirical data with model simulations to specifically test 1) the magnitude of the impacts that RH and Tair have on δ18OLC and δ18OSC and 2) determine which environmental signal is ultimately reflected in δ18OLC and δ18OSC. Our analyses revealed that δ18OLC and δ18OSC values are equally sensitive to RH and Tair and that distinguishing which of these factors best explains the underlying variation in δ18OLC and δ18OSC cannot be accomplished in the absence of other biological and environmental data. RH and Tair effects on δ18O values of plant cellulose can, however, be integrated into a single index of aridity - the leaf to air vapor pressure deficit (VPD). We show that there is a near universal relationship between VPD and the δ18O values of plant cellulose that is robust across all the climate zones that we investigated in this study. Despite the fact that several parameters can affect the δ18O values of plant cellulose our analysis shows that δ18O values of plant cellulose is a powerful indicator of aridity and therefore provides a pivotal tool for applications in ecological- climate- or forensic sciences.

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

    PubMed

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

    2016-07-01

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

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

    PubMed

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

    2016-07-01

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

  16. 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

  17. 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

  18. 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

  19. 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

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

    PubMed

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

    2014-06-01

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

  1. 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.

  2. 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.

  3. Small radioisotope thermophotovoltaic (RTPV) generators

    NASA Astrophysics Data System (ADS)

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

    1996-02-01

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

  4. 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

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

    PubMed

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

    2015-12-01

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

  6. Theoretical investigations on enhancing the performance of terminally diketopyrrolopyrrole-based small-molecular donors in organic solar cell applications.

    PubMed

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

    2016-01-01

    Diketopyrrolopyrrole (DPP)-based small molecules with acceptor-core-acceptor (A-core-A) type as donor materials have been used successfully in organic solar cells (OSC). In this work, based on the DPP-core-DPP type molecule SM1 consisting of a DPP unit as acceptor and benzene as the core, we replaced the benzene core with more electron-withdrawing groups in SM1 and further designed four new small-molecular donors (SM2-SM5) in order to improve the electrical properties, optical absorption and performance in OSC applications. The calculated results indicate that the designed small-molecular donors SM2-SM5 exhibit better performances in comparison with SM1, such as lower highest occupied molecular orbital (HOMO), narrower energy gap, larger absorption range, better electronic transfer between donor and acceptor and higher hole mobility. Moreover, the decreased HOMO levels and transition energy of small-molecular donors in OSC applications play an important role in the parameters of open-current voltage, fill factor and short-circuit current. Consequently, adjusting the electron-deficient ability of cores in DPP-core-DPP type small-molecular donors is an efficient approach that can be used to obtain high-efficiency DPP-based small-molecular donors for OSC applications. Graphical Abstract The designed small-molecules with good electronic and photophysical properties will act as a promising donor candidate for organic solar cell applications. Moreover, The decreased HOMO levels and transition energy of small-molecular donors in OSC applications play an important role in the parameters of open-current voltage, fill factor and short-circuit current.

  7. 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

  8. 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.

  9. Calcium channel blockade prevents pressure-dependent inward remodeling in isolated subendocardial resistance vessels.

    PubMed

    Sorop, Oana; Bakker, Erik N T P; Pistea, Adrian; Spaan, Jos A E; VanBavel, Ed

    2006-09-01

    The capacity for myocardial perfusion depends on the structure of the coronary microvascular bed. Coronary microvessels may adapt their structure to various stimuli. We tested whether the local pressure profile affects tone and remodeling of porcine coronary microvessels. Subendocardial vessels (approximately 160 microm, n=53) were cannulated and kept in organoid culture for 3 days under different transvascular pressure profiles: Osc 80: mean 80 mmHg, 60 mmHg peak-peak sine wave pulsation amplitude at 1.5 Hz; St 80: steady 80 mmHg; Osc 40: mean 40 mmHg, 30 mmHg amplitude; St 40: steady 40 mmHg. Under the Osc 80 profile, modest tone developed, reducing the diameter to 81+/-14% (mean+/-SE, n=6) of the maximal, passive diameter. No inward remodeling was found here, as determined from the passive pressure-diameter relation after 3 days of culture. Under all other profiles, much more tone developed (e.g., Osc 40: to 26+/-3%, n=7). In addition, these vessels showed eutrophic (i.e., without a change in wall cross-sectional area) inward remodeling (e.g., Osc 40: passive diameter reduction by 24+/-3%). The calcium blocker amlodipine induced maintained dilation in St 40 vessels and reversed the 22+/-3% (n=6) inward remodeling to 15+/-3% (n=8) outward remodeling toward day 3. Vessels required a functional endothelium to maintain structural integrity in culture. Our data indicate that reduction of either mean pressure or pulse pressure leads to microvascular constriction followed by inward remodeling. These effects could be reversed by amlodipine. Although microvascular pressure profiles distal to stenoses are poorly defined, these data suggest that vasodilator therapy could improve subendocardial microvascular function and structure in coronary artery disease.

  10. From Basalt to Dacite: Examining Magmatic Evolution at the 9° 03'N Overlapping Spreading Center, East Pacific Rise

    NASA Astrophysics Data System (ADS)

    Wanless, D.; Perfit, M.; Ridley, W. I.; Klein, E.; Zaino, A.

    2007-12-01

    Over 280 rock samples were collected in the spring of 2007 from the 9°03' N Overlapping Spreading Center (OSC) using the ROV Jason II. This was done in combination with an extensive DSL 120A side-scan sonar survey, providing one of the most detailed sampling suites from an OSC. The site was also the focus of past geophysical studies that indicated the presence of an extensive magma lens in the region. Lava geochemistry at 9°03' N covers a wide range of compositions (Mg# from 17 to 56), including evolved MORB, FeTi basalts, andesites, and dacites (~67 wt% SiO2). The diversity in composition at the OSC appears to be related to geologic setting of the erupted lavas, shallow magma chamber processes, and variations in magma supply. The 9°03' N OSC can be divided into three main sections: the eastern limb propagating southward, the western receding limb, and an overlap basin separating the two limbs. Lavas erupted within the neovolcanic zone on the eastern limb span the range of compositions erupted at the OSC (7.29 to 0.67 wt% MgO), while those erupted over the northern portion of the overlap basin are more limited in composition (6.47 to 7.23 wt% MgO). Preliminary results suggest that the on-axis major element variations may be due to mixing of evolved MORB and a silica-rich melt beneath eastern limb axis. Magma mixing is also supported by petrographic and macroscopic textural observations. Eruptions on the southern tip of the east limb, which is propagating into cold crust, are more primitive in composition and contain large phenocrysts suggesting that both thermal conditions in the crust and low magma supply may be important factors in the magmatic evolution. The phenocryst abundance and composition of lavas erupted on the dying western limb may also be related to similar factors.

  11. Overlapping Spreading Centers: Implications from Crack Growth Simulation by the Displacement Discontinuity Method

    NASA Astrophysics Data System (ADS)

    Sempere, Jean-Christophe; MacDonald, Ken C.

    1986-02-01

    Overlapping spreading centers (OSC's) are a fundamental aspect of accretionary processes at intermediate and fast-spreading centers and typically occur at deep points along the axial depth profile. They have a characteristic geometry consisting of two en echelon overlapping, curving ridges separated by an elongated depression. The length to width ratio of this overlap basin is typically 3∶1. We have been successful in reproducing the overlapping spreading center geometry by modelling the growth of two initially parallel elastic cracks of given length and offset in a tensile stress field at infinity. A boundary element displacement discontinuity method was used to solve this problem. Our calculated results are compared with seafloor observations in terms of the size and shape of the overlap region. For small OSC's, there is a very good agreement between calculations and observations but, for large ones, the overlap basin tends to be longer than our predicted results indicate. This suggests that the assumptions made in the model (i.e., perfectly elastic, isotropic and homogeneous medium) are perhaps valid for the brittle lid above the magma chamber that underlies OSC's with small offsets (< 2 km) but oversimplified for OSC's with large offsets. Our modelling shows that the initial interaction of closely spaced surface ruptures along spreading centers is to deflect away from one another as they approach. The deflection will be the greatest for small misalignments of the fracture systems, thus even minor misalignments of the spreading centers may result in the development of OSC's. Where the misalignment is less than the width of the cracking front, the fracture systems may meet head-on creating a saddle point along the axial depth profile. Our results support the hypothesis suggested by Macdonald et al. [1984] in which overlapping spreading centers develop where two magmatic pulses migrate toward each other along the strike of the spreading center following fracture

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

    PubMed

    Park, Eun-Sil; Tilly, Jonathan L

    2015-01-01

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

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

    PubMed Central

    2012-01-01

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

  14. Modeling Crustal Thickness Variations Beneath the East Pacific Rise: Mantle Diapirs or Plate Kinematics?

    NASA Astrophysics Data System (ADS)

    George, S. A.; Toomey, D. R.

    2003-12-01

    Geophysical studies along the East Pacific Rise between the Siqueiros and Clipperton fracture zones reveal along- and cross-axis variations in crustal thickness whose origins are poorly understood. By one view, variations in crustal thickness are the result of three-dimensional upwelling of the mantle associated with a melt-rich diapir centered at 9° 50'N. Alternatively, it has been proposed that the migration of the 9° 03'N overlapping spreading center (OSC) alters the thickness of crust by increasing the amount of time that a crustal unit resides near the spreading axis. In this case, crustal thickness variations arise from plate kinematics, and not from three-dimensional variations in mantle upwelling. We report on a modeling study designed to explore how the evolution of OSCs may alter the thickness of newly-formed crust. OSC propagation is modeled using the kinematic algorithm developed by Wilson [1990], modified to track parcels of crust through time. Given an OSC's kinematic history and two-dimensional descriptions of the melt flux out of the mantle (i.e. invariant along the rise), we predict relative variations in crustal thickness. Our modeling assumes that underplating increases the thickness of the crust and/or Moho transition zone as long as a crustal unit resides over the source of mantle-derived melt. Results suggest two general kinematic mechanisms whereby variations in crustal thickness can occur: those due to an offset between the mantle-level magmatic system and the spreading axis, and those due to any relative reduction in the velocity of a crustal unit as it moves off axis. Offset-induced crustal thickness variations are manifest as long-wavelength ( ˜50 km), low-amplitude cross-axis asymmetries. Local slowing of crustal units as they move off axis -- in direct association with the OSC and its overlap basins -- results in relatively short-wavelength ( ˜10 km), high-amplitude variations in crustal thickness. Using a kinematic history

  15. 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

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

    SciTech Connect

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

    2008-01-01

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

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

    NASA Astrophysics Data System (ADS)

    Crane, Kathleen

    1987-05-01

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

  18. Identification of heparin samples that contain impurities or contaminants by chemometric pattern recognition analysis of proton NMR spectral data.

    PubMed

    Zang, Qingda; Keire, David A; Buhse, Lucinda F; Wood, Richard D; Mital, Dinesh P; Haque, Syed; Srinivasan, Shankar; Moore, Christine M V; Nasr, Moheb; Al-Hakim, Ali; Trehy, Michael L; Welsh, William J

    2011-08-01

    Chemometric analysis of a set of one-dimensional (1D) (1)H nuclear magnetic resonance (NMR) spectral data for heparin sodium active pharmaceutical ingredient (API) samples was employed to distinguish USP-grade heparin samples from those containing oversulfated chondroitin sulfate (OSCS) contaminant and/or unacceptable levels of dermatan sulfate (DS) impurity. Three chemometric pattern recognition approaches were implemented: classification and regression tree (CART), artificial neural network (ANN), and support vector machine (SVM). Heparin sodium samples from various manufacturers were analyzed in 2008 and 2009 by 1D (1)H NMR, strong anion-exchange high-performance liquid chromatography, and percent galactosamine in total hexosamine tests. Based on these data, the samples were divided into three groups: Heparin, DS ≤ 1.0% and OSCS = 0%; DS, DS > 1.0% and OSCS = 0%; and OSCS, OSCS > 0% with any content of DS. Three data sets corresponding to different chemical shift regions (1.95-2.20, 3.10-5.70, and 1.95-5.70 ppm) were evaluated. While all three chemometric approaches were able to effectively model the data in the 1.95-2.20 ppm region, SVM was found to substantially outperform CART and ANN for data in the 3.10-5.70 ppm region in terms of classification success rate. A 100% prediction rate was frequently achieved for discrimination between heparin and OSCS samples. The majority of classification errors between heparin and DS involved cases where the DS content was close to the 1.0% DS borderline between the two classes. When these borderline samples were removed, nearly perfect classification results were attained. Satisfactory results were achieved when the resulting models were challenged by test samples containing blends of heparin APIs spiked with non-, partially, or fully oversulfated chondroitin sulfate A, heparan sulfate, or DS at the 1.0%, 5.0%, and 10.0% (w/w) levels. This study demonstrated that the combination of 1D (1)H NMR spectroscopy with

  19. Influence of transition metal electronegativity on the oxygen storage capacity of perovskite oxides.

    PubMed

    Liu, Lu; Taylor, Daniel D; Rodriguez, Efrain E; Zachariah, Michael R

    2016-08-16

    The selection of highly efficient oxygen carriers (OCs) is a key step necessary for the practical development of chemical looping combustion (CLC). In this study, a series of ABO3 perovskites, where A = La, Ba, Sr, Ca and B = Cr, Mn, Fe, Co, Ni, Cu, are synthesized and tested in a fixed bed reactor for reactivity and stability as OCs with CH4 as the fuel. We find that the electronegativity of the transition metal on the B-site (λB), is a convenient descriptor for oxygen storage capacity (OSC) of our perovskite samples. By plotting OSC for total methane oxidation against λB, we observe an inverted volcano plot relationship. These results could provide useful guidelines for perovskite OC design and their other energy related applications. PMID:27478888

  20. 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.

  1. 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.

  2. Identification of Chemically Sulfated/desulfated Glycosaminoglycans in Contaminated Heparins and Development of a Simple Assay for the Detection of Most Contaminants in Heparin

    PubMed Central

    Pan, Jing; Qian, Yi; Zhou, Xiaodong; Pazandak, Andrew; Frazier, Sarah B.; Weiser, Peter; Lu, Hong; Zhang, Lijuan

    2010-01-01

    Contaminated heparin was linked to at least 149 deaths and hundreds of adverse reactions. Published report indicates that heparin contaminants were a natural impurity, dermatan sulfate, and a contaminant, oversulfated chondroitin sulfate (OSCS). OSCS was assumed to derive from animal cartilage. By analyzing 26 contaminated heparin lots from different sources, our data indicate that the heparin contaminants were chemically sulfated or chemically sulfated/desulfated glycosaminoglycans (GAGs) consisting of heparan sulfate, chondroitin sulfate, and dermatan sulfate based on monosaccharide quantification, CE, heparin lyase digestion, and liquid chromatography/mass spectrometry analysis. Since currently recommended heparin quality control assays had failed to detect certain heparin contaminants, a simple method that detects most contaminants in heparin was developed. This assay detects specific heparin structures that most contaminants cannot mimic and can be performed in any laboratory equipped with an UV spectrometer. PMID:20657729

  3. 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.

  4. Advancements in the micromirror array projector technology II

    NASA Astrophysics Data System (ADS)

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

    2005-05-01

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

  5. 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.

  6. Oogonial stem cells as a model to study age-associated infertility in women

    PubMed Central

    Garg, Neha; Sinclair, David A.

    2016-01-01

    Fertility is the first biological process to break down during aging, thereby making it a useful tool to understand fundamental processes of aging. Reproductive aging in females is associated with a loss of ovarian function characterised by a reduction in the number and quality of oocytes. The central dogma, namely that females are born with a fixed pool of oocytes that progressively decline with increasing maternal age, has been challenged by evidence supporting postnatal oogenesis in mammals. Reports demonstrating formation of new oocytes from newly discovered germline stem cells, referred to as oogonial stem cells (OSCs), has opened new avenues for treatment of female infertility. In this review we discuss why the OSCs possibly lose their regenerative potential over time, and focus specifically on the aging process in germline stem cells as a possible mechanism for understanding female age-related infertility and how we can slow or delay ovarian aging. PMID:25897831

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

    PubMed

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

    2015-01-01

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

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Analysis of hybrid donor layer in organic solar cells based on SubPc and rubrene

    NASA Astrophysics Data System (ADS)

    Ming, Deng; Jian, Zhong; Fengyu, Gan; Hongxue, Cheng; Lijuan, Wang

    2014-09-01

    In this paper, photovoltaic characteristics of ITO/PEDOT:PSS/SubPc:Rubrene (mixed ratio R by weight)/C60/Bphen/Ag organic solar cells (OSCs) are analyzed in detail. The intrinsic properties of a SubPc:rubrene doped layer on device performance were discussed based on theoretical analysis of the experimental OSCs. The ratio R was 0, 0.25, 0.5, and 0.75,1, respectively. The results showed that when R was 0.75 performing the best, which owned the highest short circuit current ( J sc ) 6.61 mA/cm2 and highest power conversion efficiency (PCE) 2.44%, the FF was 41% and the open circuit current ( V oc ) was 0.905 V. The suitable HOMO level, absorption capacity, carrier transport ability and exciton diffusion length ( L D ) of organic material are very important for the performance of the device.

  14. Monitoring and assessment of toxic metals in Gulf War oil spill contaminated soil using laser-induced breakdown spectroscopy.

    PubMed

    Hussain, T; Gondal, M A

    2008-01-01

    Laser-induced breakdown spectroscopy (LIBS) was applied for the detection of toxic metals in oil spill contaminated soil (OSCS). The OSCS samples were collected from Khursania Saudi Arabia along the coast of Persian Gulf exposed to oil spills in 1991 Gulf war. Environmentally important elements like Aluminum Magnesium, Calcium, Chromium, Titanium, Strontium, Iron, Barium, Sodium, potassium, Zirconium and Vanadium from the contaminated soil have been detected. Optimal experimental conditions for analysis were investigated. The LIBS system was calibrated using standard samples containing these trace elements. The results obtained using Laser-Induced Breakdown Spectroscopy (LIBS) were compared with the results obtained using Inductively Coupled Plasma Emission Spectroscopy (ICP). The concentrations of some elements (Ba and Cr) were found higher than permissible safe limits. Health risks associated with exposure to such toxic elements are also discussed.

  15. 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.

  16. 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.

  17. Enhanced Organic Solar Cell Stability through the Effective Blocking of Oxygen Diffusion using a Self-Passivating Metal Electrode.

    PubMed

    Lee, Hansol; Jo, Sae Byeok; Lee, Hyo Chan; Kim, Min; Sin, Dong Hun; Ko, Hyomin; Cho, Kilwon

    2016-03-01

    A new and simple strategy for enhancing the stability of organic solar cells (OSCs) was developed by using self-passivating metal top electrodes. Systematic investigations on O2 permeability of Al top electrodes revealed that the main pathways for oxidation-induced degradation could be greatly suppressed by simply controlling the nanoscale morphology of the Al electrode. The population of nanoscale pinholes among Al grains, which critically decided the diffusion of O2 molecules toward the Al-organic interfaces that are vulnerable to oxidation, was successfully regulated by rapidly depositing Al or promoting lateral growth among the Al grains, accompanied by increasing the deposition thickness. Our observations suggested that the stability of OSCs with conventional architectures might be greatly enhanced simply by controlling the fabrication conditions of the Al top electrode, without the aid of additional secondary treatments.

  18. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2013-06-01

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

  20. Favorable electronic structure for organic solar cells induced by strong interaction at interface

    SciTech Connect

    Wang, Shenghao Hao, Xia; Fu, Wei; Akimoto, Katsuhiro; Sakurai, Takeaki; Masuda, Shigeru

    2013-11-14

    To clarify the role of buffer layer in organic solar cells (OSCs), the electronic properties of bathocuproine (BCP)/Mg interface were systematically investigated by using ultraviolet photoemissions spectroscopy, high-resolution X-ray photoemission spectroscopy, angle-resolved X-ray photoemission spectroscopy and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. The results show there are gap states at the interface, which are caused by the interaction between BCP and Mg. The formation of Mg-N bond was found at the interface. The NEXAFS measurements show that BCP molecules for 1-2 monolayers are lying-down on the substrate, whereas orient randomly for thick BCP layer. It was supposed that the gap states and the highly-ordered orientation of thin BCP layer are the reasons for improving the performance of OSC with BCP buffer layer and low work function metal cathode.

  1. Deep-tow studies of the overlapping spreading centers at 9°03&primeN on the East Pacific Rise

    NASA Astrophysics Data System (ADS)

    Sempere, Jean-Christophe; MacDonald, Ken C.

    1986-10-01

    The deeply-towed instrument package of the Scripps Institution of Oceanography was used to study for the first time the fine scale structure of an overlapping spreading center (OSC) system: the 9°03'N OSC on the East Pacific Rise (EPR). The eastern and western limbs of this OSC system which are 8 km apart and overlap by 27 km show marked differences. Away from the tips, the spreading centers are highly tectonized and differ greatly from the ridge tips. The western ridge tip exhibits a few fissures but no sign of recent volcanic activity whereas the eastern ridge tip is highly fissured and has experienced more recent volcanic episodes which are confined to a narrow zone within this highly fissured area. In both cases, the ridge tip fissures are 10°-15° oblique to the strike of the faults that occur on the flanks of the adjacent portion of the opposite spreading axis, indicating a recent change in the direction of deviatoric tension and suggesting that the eastern and western spreading centers have been propagating southward and northward respectively. The eastern ridge tip fissures are transecting the flank of the western spreading axis suggesting that the eastern spreading center is about to become the through-going trace of the East Pacific Rise. In contrast, the western spreading center disappears into abyssal hill terrain that was presumably created at the eastern ridge axis. Some of the very few tectonic features observed in the overlap basin may reflect the existence of a short-lived shear couple due to the interaction of the two overlapping spreading centers. Sediment cover over the whole area and especially in the overlap basin is relatively thick, supporting the idea of a time-averaged deficit in the magmatic budget at this OSC. We suggest that the 9°03'N OSC developed where two magmatic pulses, independent in space and time and propagating along the strike of the East Pacific Rise away from the loci of melt emplacement, failed to meet. Misalignment of

  2. Offshore Space Center (offshore launch site)

    NASA Astrophysics Data System (ADS)

    Harvey, D. G.

    1980-07-01

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

  3. Squalene-Hopene Cyclases▿

    PubMed Central

    Siedenburg, Gabriele; Jendrossek, Dieter

    2011-01-01

    Hopanoids and sterols are members of a large group of cyclic triterpenoic compounds that have important functions in many prokaryotic and eukaryotic organisms. They are biochemically synthesized from linear precursors (squalene, 2,3-oxidosqualene) in only one enzymatic step that is catalyzed by squalene-hopene cyclase (SHC) or oxidosqualene cyclase (OSC). SHCs and OSCs are related in amino acid sequences and probably are derived from a common ancestor. The SHC reaction requires the formation of five ring structures, 13 covalent bonds, and nine stereo centers and therefore is one of the most complex one-step enzymatic reactions. We summarize the knowledge of the properties of triterpene cyclases and details of the reaction mechanism of Alicyclobacillus acidocaldarius SHC. Properties of other SHCs are included. PMID:21531832

  4. Oogonial stem cells as a model to study age-associated infertility in women.

    PubMed

    Garg, Neha; Sinclair, David A

    2015-07-01

    Fertility is the first biological process to break down during aging, thereby making it a useful tool to understand fundamental processes of aging. Reproductive aging in females is associated with a loss of ovarian function characterised by a reduction in the number and quality of oocytes. The central dogma, namely that females are born with a fixed pool of oocytes that progressively decline with increasing maternal age, has been challenged by evidence supporting postnatal oogenesis in mammals. Reports demonstrating formation of new oocytes from newly discovered germline stem cells, referred to as oogonial stem cells (OSCs), has opened new avenues for treatment of female infertility. In this review we discuss why the OSCs possibly lose their regenerative potential over time, and focus specifically on the aging process in germline stem cells as a possible mechanism for understanding female age-related infertility and how we can slow or delay ovarian aging.

  5. OrbView-3 Initial On-Orbit Characterization

    NASA Technical Reports Server (NTRS)

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

    2004-01-01

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

  6. 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).

  7. Offshore space center (offshore launch site)

    SciTech Connect

    Harvey, D.G.

    1980-07-01

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

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

    PubMed Central

    2013-01-01

    An unusual kind of transparent and high-efficiency organic silver conductive ink (OSC ink) was synthesized with silver acetate as silver carrier, ethanolamine as additive, and different kinds of aldehyde-based materials as reduction agents and was characterized by using a thermogravimetric analyzer, X-ray diffraction, a scanning electron microscope, and a four-point probe. The results show that different reduction agents all have an important influence on the conductive properties of the ink through a series of complex chemical reactions, and especially when formic acid or dimethylformamide was used as the reduction agent and sintered at 120°C for 30 s, the resistivity can be lowered to 6 to 9 μΩ·cm. Furthermore, formula mechanism, conductive properties, temperature, and dynamic fatigue properties were investigated systematically, and the feasibility of the OSC ink was also verified through the preparation of an antenna pattern. PMID:23799897

  9. Dentine oxygen isotopes (δ (18)O) as a proxy for odontocete distributions and movements.

    PubMed

    Matthews, Cory J D; Longstaffe, Fred J; Ferguson, Steven H

    2016-07-01

    Spatial variation in marine oxygen isotope ratios (δ (18)O) resulting from differential evaporation rates and precipitation inputs is potentially useful for characterizing marine mammal distributions and tracking movements across δ (18)O gradients. Dentine hydroxyapatite contains carbonate and phosphate that precipitate in oxygen isotopic equilibrium with body water, which in odontocetes closely tracks the isotopic composition of ambient water. To test whether dentine oxygen isotope composition reliably records that of ambient water and can therefore serve as a proxy for odontocete distribution and movement patterns, we measured δ (18)O values of dentine structural carbonate (δ (18) OSC) and phosphate (δ (18) OP) of seven odontocete species (n = 55 individuals) from regional marine water bodies spanning a surface water δ (18)O range of several per mil. Mean dentine δ (18) OSC (range +21.2 to +25.5‰ VSMOW) and δ (18) OP (+16.7 to +20.3‰) values were strongly correlated with marine surface water δ (18)O values, with lower dentine δ (18) OSC and δ (18) OP values in high-latitude regions (Arctic and Eastern North Pacific) and higher values in the Gulf of California, Gulf of Mexico, and Mediterranean Sea. Correlations between dentine δ (18) OSC and δ (18) OP values with marine surface water δ (18)O values indicate that sequential δ (18)O measurements along dentine, which grows incrementally and archives intra- and interannual isotopic composition over the lifetime of the animal, would be useful for characterizing residency within and movements among water bodies with strong δ (18)O gradients, particularly between polar and lower latitudes, or between oceans and marginal basins. PMID:27547302

  10. 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.

  11. 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.

  12. Farnesyloxycoumarins, a new class of squalene-hopene cyclase inhibitors.

    PubMed

    Cravotto, Giancarlo; Balliano, Gianni; Robaldo, Bruna; Oliaro-Bosso, Simonetta; Chimichi, Stefano; Boccalini, Marco

    2004-04-19

    A few naturally occurring prenyl- and prenyloxycoumarins and several new related synthetic derivatives were evaluated as inhibitors of squalene-hopene cyclase (SHC), a useful model enzyme, to predict their interactions with oxidosqualene cyclase (OSC). Umbelliprenin-10',11'-monoepoxide (IC(50) 2.5 microM) and the corresponding 6',7'-10',11' diepoxide (IC(50) 1.5 microM) were the most active enzyme inhibitors.

  13. Solution-Processable Small Molecules for High-Performance Organic Solar Cells with Rigidly Fluorinated 2,2'-Bithiophene Central Cores.

    PubMed

    Wang, Zhenguo; Li, Zuojia; Liu, Jiang; Mei, Jun; Li, Kai; Li, Ying; Peng, Qiang

    2016-05-11

    Small molecules containing an oligothiophene backbone are simple but effective donor materials for organic solar cells (OSCs). In this work, we incorporated rigid 2,2'-bithiophene (BT) or fluorinated 2,2'-bithiophene (FBT) as the central unit and synthesized two novel small molecules (TTH-D3TRh and TTF-D3TRh) with an oligothiophene backbone and 3-ethylrhodanine end groups. Both molecules exhibit good thermal stability as well as strong and broad absorption. The fluorination of the BT central unit made TTF-D3TRh possess a relatively lower-lying HOMO energy level, better molecular stacking, and higher mobility in comparison with those of TTH-D3TRh. Conventional OSCs were fabricated to evaluate the photovoltaic property of these two molecules. Without extra post-treatments, the conventional devices based on TTH-D3TRh and TTF-D3TRh showed high PCEs of 5.00 and 5.80%, respectively. The TTF-D3TRh device exhibited a higher performance, which can be attributed to the improved Voc of 0.92 V, Jsc of 10.04 mA cm(-2), and FF of 62.8%. Using an inverted device structure, the OSCs based on TTH-D3TRh and TTF-D3TRh showed largely elevated PCEs of 5.89 and 7.14%, respectively. The results indicated that the structurally simple TTH-D3TRh and TTF-D3TR molecules are potential donor candidates for achieving highly efficient OSCs. The strategy of fluorination and rigidity designation is an effective approach to develop oligothiophene-based small molecular donors for highly efficient solar cell applications. PMID:27097642

  14. 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

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

    DOE PAGESBeta

    Das, Sanjib; Keum, Jong Kahk; Browning, Jim; Gu, Gong; Yang, Bin; Do, Changwoo; Chen, Wei; Chen, Jihua; Ivanov, Ilia N; Hong, Kunlun; et al

    2015-01-01

    Advances in materials design and device engineering led to inverted organic solar cells (i-OSCs) with superior power conversion efficiencies (PCEs) to their conventional counterparts, in addition to the well-known better ambient stability. Despite the significant progress, however, it has so far been unclear how the morphologies of the photoactive layer and its interface with the cathode modifying layer impact device performance. Here, we report an in-depth morphology study of the i-OSC active and cathode modifying layers, employing a model system with the well-established bulk-heterojunction, PTB7:PC71BM as the active layer and poly-[(9,9-bis(3 -(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)] (PFN) as the cathode surface modifying layer. Wemore » have also identified the role of a processing additive, 1,8-diiodooctane (DIO), used in the spin-casting of the active layer to increase PCE. Using a variety of characterization techniques, we demonstrate that the high PCEs of i-OSCs are due to the smearing (diffusion) of electron-accepting PC71BM into the PFN layer, resulting in improved electron transport. The PC71BM diffusion occurs after spin-casting the active layer onto the PFN layer, when residual solvent molecules act as a plasticizer. The DIO additive, with a higher boiling point than the host solvent, has a longer residence time in the spin-cast active layer, resulting in more PC71BM smearing and therefore more efficient electron transport. This work provides important insight and guidance to further enhancement of i-OSC performance by materials and interface engineering.« less

  16. 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.

  17. The future of airborne sulfur-containing particles in the absence of fossil fuel sulfur dioxide emissions.

    PubMed

    Perraud, Véronique; Horne, Jeremy R; Martinez, Andrew S; Kalinowski, Jaroslaw; Meinardi, Simone; Dawson, Matthew L; Wingen, Lisa M; Dabdub, Donald; Blake, Donald R; Gerber, R Benny; Finlayson-Pitts, Barbara J

    2015-11-01

    Sulfuric acid (H2SO4), formed from oxidation of sulfur dioxide (SO2) emitted during fossil fuel combustion, is a major precursor of new airborne particles, which have well-documented detrimental effects on health, air quality, and climate. Another precursor is methanesulfonic acid (MSA), produced simultaneously with SO2 during the atmospheric oxidation of organosulfur compounds (OSCs), such as dimethyl sulfide. In the present work, a multidisciplinary approach is used to examine how contributions of H2SO4 and MSA to particle formation will change in a large coastal urban area as anthropogenic fossil fuel emissions of SO2 decline. The 3-dimensional University of California Irvine-California Institute of Technology airshed model is used to compare atmospheric concentrations of gas phase MSA, H2SO4, and SO2 under current emissions of fossil fuel-associated SO2 and a best-case futuristic scenario with zero fossil fuel sulfur emissions. Model additions include results from (i) quantum chemical calculations that clarify the previously uncertain gas phase mechanism of formation of MSA and (ii) a combination of published and experimental estimates of OSC emissions, such as those from marine, agricultural, and urban processes, which include pet waste and human breath. Results show that in the zero anthropogenic SO2 emissions case, particle formation potential from H2SO4 will drop by about two orders of magnitude compared with the current situation. However, particles will continue to be generated from the oxidation of natural and anthropogenic sources of OSCs, with contributions from MSA and H2SO4 of a similar order of magnitude. This could be particularly important in agricultural areas where there are significant sources of OSCs.

  18. 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.

  19. Resident Ratings of Communication Skills Using the Kalamazoo Adapted Checklist

    PubMed Central

    Porcerelli, John H.; Brennan, Simone; Carty, Jennifer; Ziadni, Maisa; Markova, Tsveti

    2015-01-01

    Background The Kalamazoo Essential Elements Communication Checklist–Adapted (KEECC-A) is a well-regarded instrument for evaluating communication and interpersonal skills. To date, little research has been conducted that assesses the accuracy of resident self-ratings of their communication skills. Objective To assess whether residents can accurately self-rate communication skills, using the KEECC-A, during an objective structured clinical examination (OSCE). Methods A group of 104 residents from 8 specialties completed a multistation OSCE as part of an institutional communication skills curriculum conducted at a single institution. Standardized patients (SPs) and observers were trained in rating communication skills using the KEECC-A. Standardized patient ratings and resident self-ratings were completed immediately following each OSCE encounter, and trained observers rated archived videotapes of the encounters. Results Resident self-ratings and SP ratings using the KEECC-A were significantly correlated (r104 = 0.238, P = .02), as were resident self-ratings and observer ratings (r104 = 0.284, P = .004). The correlation between the SP ratings and observer (r104 = 0.378, P = .001) ratings were larger in magnitude, but not significantly different (P > .05) from resident/SP or resident/observer correlations. Conclusions The results suggest that residents, with a modicum of training using the KEECC-A, can accurately rate their own communication and interpersonal skills during an OSCE. Using trained observers to rate resident communication skills provides a unique opportunity for evaluating SP and resident self-ratings. Our findings also lend further support for the reliability and validity of the KEECC-A. PMID:26457156

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

    NASA Astrophysics Data System (ADS)

    Moritomo, Yutaka; Yonezawa, Kouhei; Yasuda, Takeshi

    2015-09-01

    Organic solar cells (OSCs) are promising alternatives to the conventional inorganic solar cells due to their low-cost processing and compatibility with flexible substrates. The development of low band-gap polymer, e.g., poly-[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b’]dithiophene-2,6-diyl] [3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3]thiophenediyl

  1. Effect of novel patient interaction on students’ performance of pregnancy options counseling

    PubMed Central

    Shaddeau, Angela; Nimz, Abigail; Sheeder, Jeanelle; Tocce, Kristina

    2015-01-01

    Background Although options counseling is a fundamental skill for medical providers, previous research has identified gaps in medical school reproductive health education. Purpose To determine if a 1-h novel patient interaction (NPI) improves student performance when caring for a standardized patient with an unintended pregnancy. Methods From September 2012 to June 2013 we randomized third-year medical students at the University of Colorado School of Medicine to the standard curriculum plus an NPI, or the standard curriculum only. The NPI consisted of a 1-h small-group session with a patient who discussed her experiences with options counseling and her decision to terminate her pregnancy. Students completed an Objective Structured Clinical Examination (OSCE) at the rotation's end, which included options counseling. The primary outcome was the proportion of participants achieving ‘excellence’ on the OSCE checklist. ‘Excellence’ was defined as a score ≥90%. Examinations were flagged as ‘unsatisfactory encounters’ if core competencies were not addressed. OSCE standardized patients and evaluators were blinded to group assignment. Results In total, 135 students were eligible and randomized: 75 to NPI; 60 to control. During the OSCE, few students achieved ‘excellence’ (24% NPI vs. 28% control, p=0.57). There were no differences between scores for components of options counseling. More students in the control group ‘appeared somewhat uncomfortable’ delivering the pregnancy test results (5% NPI vs. 18% control, p=0.006). More than half (54%) of the intervention group and 67% of controls had ‘unsatisfactory encounters’ (p=0.16), almost exclusively due to omission of adoption. Most students addressed abortion (96% NPI vs. 92% control, p=0.29). Conclusions A 1-h NPI does not improve medical students’ performance of pregnancy options counseling and the option of adoption is routinely omitted. Adoption is clearly an area that needs greater attention

  2. The Role of Self- and Peer Assessment in Dental Students' Reflective Practice Using Standardized Patient Encounters.

    PubMed

    Quick, Karin K

    2016-08-01

    The aim of this study was to gain insight into the nature of the role played by self- and peer assessment in the development of dental students' reflective practice skills and the value gained through structured encounters with standardized patients. Four standardized patient encounters in an objective structured clinical exam (OSCE) format served as a learning experience for students to demonstrate decision making and communication skills in complex scenarios regarding issues of ethics. Self- and peer assessment and peer-to-peer discourse were used to enhance student reflection. A sample of 16 peer pairs was randomly selected from the population of 108 fourth-year students who participated in the 2014 Clinical Dental Ethics OSCE. Data were collected from self- and peer assessment forms. Five overall performance themes (personal affect, verbal communication, professional demeanor, relationship-building, and patient management) and three student learning themes (application and knowledge, ways to change, and impressed with peer/increased confidence in self) were identified. The results showed that peer assessment ratings were consistently higher than those in the self-assessments, but overall the students deemed both their peers' and their own decision making and communication skills to be quite good. These students rated their experience with the OSCE and self- and peer assessments as positive, appreciating the importance of reflection and learning from their peers. These results provide support for the continued formative use of standardized patient OSCEs and self- and peer assessment to help students develop skills in decision making, communication, professionalism, and reflection. PMID:27480703

  3. 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. PMID:23513345

  4. 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

  5. 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.

  6. 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.

  7. Microwave-assisted of dispersive liquid-liquid microextraction and spectrophotometric determination of uranium after optimization based on Box-Behnken design and chemometrics methods.

    PubMed

    Niazi, Ali; Khorshidi, Neda; Ghaemmaghami, Pegah

    2015-01-25

    In this study an analytical procedure based on microwave-assisted dispersive liquid-liquid microextraction (MA-DLLME) and spectrophotometric coupled with chemometrics methods is proposed to determine uranium. In the proposed method, 4-(2-pyridylazo) resorcinol (PAR) is used as a chelating agent, and chloroform and ethanol are selected as extraction and dispersive solvent. The optimization strategy is carried out by using two level full factorial designs. Results of the two level full factorial design (2(4)) based on an analysis of variance demonstrated that the pH, concentration of PAR, amount of dispersive and extraction solvents are statistically significant. Optimal condition for three variables: pH, concentration of PAR, amount of dispersive and extraction solvents are obtained by using Box-Behnken design. Under the optimum conditions, the calibration graphs are linear in the range of 20.0-350.0 ng mL(-1) with detection limit of 6.7 ng mL(-1) (3δB/slope) and the enrichment factor of this method for uranium reached at 135. The relative standard deviation (R.S.D.) is 1.64% (n=7, c=50 ng mL(-1)). The partial least squares (PLS) modeling was used for multivariate calibration of the spectrophotometric data. The orthogonal signal correction (OSC) was used for preprocessing of data matrices and the prediction results of model, with and without using OSC, were statistically compared. MA-DLLME-OSC-PLS method was presented for the first time in this study. The root mean squares error of prediction (RMSEP) for uranium determination using PLS and OSC-PLS models were 4.63 and 0.98, respectively. This procedure allows the determination of uranium synthesis and real samples such as waste water with good reliability of the determination. PMID:25062051

  8. Co-functionalized organic/inorganic hybrid ZnO nanorods as electron transporting layers for inverted organic solar cells.

    PubMed

    Ambade, Swapnil B; Ambade, Rohan B; Eom, Seung Hun; Baek, Myung-Jin; Bagde, Sushil S; Mane, Rajaram S; Lee, Soo-Hyoung

    2016-03-01

    In an unprecedented attempt, we present an interesting approach of coupling solution processed ZnO planar nanorods (NRs) by an organic small molecule (SM) with a strong electron withdrawing cyano moiety and the carboxylic group as binding sites by a facile co-functionalization approach. Direct functionalization by SMs (SM-ZnO NRs) leads to higher aggregation owing to the weaker solubility of SMs in solutions of ZnO NRs dispersed in chlorobenzene (CB). A prior addition of organic 2-(2-methoxyethoxy)acetic acid (MEA) over ZnO NRs not only inhibits aggregation of SMs over ZnO NRs, but also provides enough sites for the SM to strongly couple with the ZnO NRs to yield transparent SM-MEA-ZnO NRs hybrids that exhibited excellent capability as electron transporting layers (ETLs) in inverted organic solar cells (iOSCs) of P3HT:PC60BM bulk-heterojunction (BHJ) photoactive layers. A strongly coupled SM-MEA-ZnO NR hybrid reduces the series resistance by enhancing the interfacial area and tunes the energy level alignment at the interface between the (indium-doped tin oxide, ITO) cathode and BHJ photoactive layers. A significant enhancement in power conversion efficiency (PCE) was achieved for iOSCs comprising ETLs of SM-MEA-ZnO NRs (3.64%) advancing from 0.9% for pristine ZnO NRs, while the iOSCs of aggregated SM-ZnO NRs ETL exhibited a much lower PCE of 2.6%, thus demonstrating the potential of the co-functionalization approach. The superiority of the co-functionalized SM-MEA-ZnO NRs ETL is also evident from the highest PCE of 7.38% obtained for the iOSCs comprising BHJ of PTB7-Th:PC60BM compared with extremely poor 0.05% for non-functionalized ZnO NRs. PMID:26864170

  9. An inverse docking approach for identifying new potential anti-cancer targets.

    PubMed

    Grinter, Sam Z; Liang, Yayun; Huang, Sheng-You; Hyder, Salman M; Zou, Xiaoqin

    2011-04-01

    Inverse docking is a relatively new technique that has been used to identify potential receptor targets of small molecules. Our docking software package MDock is well suited for such an application as it is both computationally efficient, yet simultaneously shows adequate results in binding affinity predictions and enrichment tests. As a validation study, we present the first stage results of an inverse-docking study which seeks to identify potential direct targets of PRIMA-1. PRIMA-1 is well known for its ability to restore mutant p53's tumor suppressor function, leading to apoptosis in several types of cancer cells. For this reason, we believe that potential direct targets of PRIMA-1 identified in silico should be experimentally screened for their ability to inhibit cancer cell growth. The highest-ranked human protein of our PRIMA-1 docking results is oxidosqualene cyclase (OSC), which is part of the cholesterol synthetic pathway. The results of two followup experiments which treat OSC as a possible anti-cancer target are promising. We show that both PRIMA-1 and Ro 48-8071, a known potent OSC inhibitor, significantly reduce the viability of BT-474 and T47-D breast cancer cells relative to normal mammary cells. In addition, like PRIMA-1, we find that Ro 48-8071 results in increased binding of p53 to DNA in BT-474 cells (which express mutant p53). For the first time, Ro 48-8071 is shown as a potent agent in killing human breast cancer cells. The potential of OSC as a new target for developing anticancer therapies is worth further investigation.

  10. 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.

  11. Patterned Growth of Organic Semiconductors: Selective Nucleation of Perylene on Self-Assembled Monolayers.

    PubMed

    Pick, André; Witte, Gregor

    2016-08-16

    Organic semiconductors (OSC) have received a large amount of attention because they afford the fabrication of flexible electronic devices. However, the limited resistance to radiation and etching of such materials does not permit their patterning by photolithography, which has been a driving force for the development of integrated circuits and therefore requires alternative structuring techniques. One approach is based on precoating the substrate with self-assembled monolayers (SAMs) to control the nucleation of subsequently deposited OSC layers, but the underlying mechanism is barely understood. Here, we used alkanethiols with different chemical terminations to prepare SAMs on gold substrates serving as model systems to identify the mechanism of selective nucleation for the case of the OSC perylene. Using atomic force microscopy and fluorescence microscopy, we demonstrate that the chemical functionalization of the SAMs determines the adhesion forces for the OSC that are smallest for CF3-terminated and largest for OH-terminated SAMs, hence yielding distinctly different sticking probabilities upon perylene deposition at room temperature. Microcontact printing and immersion were employed to prepare SAM patterns that enable the selective growth of polycrystalline perylene films. A quite different situation is found upon printing long-chain thiols with low vapor pressure, which leads to the transfer of multilayers and favors the growth of perylene single crystallites. In a more abstract scenario, patterns of silicone oil droplets were printed on a gold substrate, which was previously covered with a repelling fluorinated SAM. Such droplets provide nucleation centers for liquid-mediated growth, often yielding platelet-shaped perylene single crystallites without unwanted perylene nucleation on the remaining surface. PMID:27441921

  12. 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

  13. An immersive “simulation week” enhances clinical performance of incoming surgical interns improved performance persists at 6 months follow-up

    PubMed Central

    Singh, Pritam; Aggarwal, Rajesh; Pucher, Philip H.; Hashimoto, Daniel A.; Beyer-Berjot, Laura; Bharathan, Rasiah; Middleton, Katherine E.; Jones, Joanne; Darzi, Ara

    2015-01-01

    Background The transition from student to intern can be challenging. The “August” or “July effect” describes increased errors and reduced patient safety during this transition. The study objectives were to develop, pilot, and evaluate clinical performance after an immersive simulation course for incoming interns. Methods Graduating students were recruited for a 1-week immersive simulation course. Controls received no simulation training. Primary outcome (at baseline, and 1 and 6 months) was clinical performance on Objective Structured Clinical Examinations (OSCE) of clinical procedures and surgical technical skills. Secondary outcomes were self-reported confidence and clinical procedure logbook data. Results Nineteen students were recruited. Sixteen completed the 6-month follow-up, 10 in the intervention group and 6 in the control group. No differences were demonstrated between interventions and controls at baseline (OSCE [median, 66 vs 78; P = .181], technical skills [48 vs 52.5; P = .381], and confidence [101 vs 96; P = .368]). Interventions outperformed controls at 1 month (OSCE [111 vs 82; P = .001], technical skills [78.5 vs 63; P = .030], and confidence [142 vs 119; P < .001]), and 6 months (OSCE [107 vs 93; P = .007], technical skills [92.5 vs 69; P = .044], and confidence [148 vs 129; P = .022]). No differences were observed in numbers of clinical procedures performed at 1 (P = .958), 4 (P = .093), or 6 months (P = .713). Conclusion The immersive simulation course objectively improved subjects’ clinical skills, technical skills, and confidence. Despite similar clinical experience as controls, the intervention group’s improved performance persisted at 6 months follow-up. This feasible and effective intervention to ease transition from student to intern could reduce errors and enhance patient safety. PMID:25633735

  14. 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

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. Effect of Fluorine Substitution on Photovoltaic Properties of Alkoxyphenyl Substituted Benzo[1,2-b:4,5-b']dithiophene-Based Small Molecules.

    PubMed

    Qiu, Beibei; Yuan, Jun; Xiao, Xuxian; He, Dingjun; Qiu, Lixia; Zou, Yingping; Zhang, Zhi-guo; Li, Yongfang

    2015-11-18

    Two new small molecules, C3T-BDTP and C3T-BDTP-F with alkoxyphenyl-substituted benzo[1,2-b:4,5-b']dithiophene (BDT) and meta-fluorinated-alkoxyphenyl-substituted BDT as the central donor blocks, respectively, have been synthesized and used as donor materials in organic solar cells (OSCs). With the addition of 0.4% v/v 1,8-diiodooctane (DIO), the blend of C3T-BDTP-F/PC71BM showed a higher hole mobility of 8.67 × 10(-4) cm(2) V(-1) s(-1) compared to that of the blend of C3T-BDTP/PC71BM. Two types of interlayers, zirconium acetylacetonate (ZrAcac) and perylene diimide (PDI) derivatives (PDINO and PDIN), were used to further optimize the performance of OSCs. With a device structure of ITO/PEDOT:PSS/donor:PC71BM/PDIN/Al, the OSCs based on C3T-BDTP delivered a satisfying power conversion efficiency (PCE) of 5.27% with an open circuit voltage (V(oc)) of 0.91 V, whereas the devices based on C3T-BDTP-F showed an enhanced PCE of 5.42% with a higher V(oc) of 0.97 V. PMID:26517574

  20. 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

  1. 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.

  2. 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.

  3. High-Performance Electron Acceptor with Thienyl Side Chains for Organic Photovoltaics.

    PubMed

    Lin, Yuze; Zhao, Fuwen; He, Qiao; Huo, Lijun; Wu, Yang; Parker, Timothy C; Ma, Wei; Sun, Yanming; Wang, Chunru; Zhu, Daoben; Heeger, Alan J; Marder, Seth R; Zhan, Xiaowei

    2016-04-13

    We develop an efficient fused-ring electron acceptor (ITIC-Th) based on indacenodithieno[3,2-b]thiophene core and thienyl side-chains for organic solar cells (OSCs). Relative to its counterpart with phenyl side-chains (ITIC), ITIC-Th shows lower energy levels (ITIC-Th: HOMO = -5.66 eV, LUMO = -3.93 eV; ITIC: HOMO = -5.48 eV, LUMO = -3.83 eV) due to the σ-inductive effect of thienyl side-chains, which can match with high-performance narrow-band-gap polymer donors and wide-band-gap polymer donors. ITIC-Th has higher electron mobility (6.1 × 10(-4) cm(2) V(-1) s(-1)) than ITIC (2.6 × 10(-4) cm(2) V(-1) s(-1)) due to enhanced intermolecular interaction induced by sulfur-sulfur interaction. We fabricate OSCs by blending ITIC-Th acceptor with two different low-band-gap and wide-band-gap polymer donors. In one case, a power conversion efficiency of 9.6% was observed, which rivals some of the highest efficiencies for single junction OSCs based on fullerene acceptors.

  4. Test anxiety and academic performance in chiropractic students.

    PubMed

    Zhang, Niu; Henderson, Charles N R

    2014-01-01

    Objective : We assessed the level of students' test anxiety, and the relationship between test anxiety and academic performance. Methods : We recruited 166 third-quarter students. The Test Anxiety Inventory (TAI) was administered to all participants. Total scores from written examinations and objective structured clinical examinations (OSCEs) were used as response variables. Results : Multiple regression analysis shows that there was a modest, but statistically significant negative correlation between TAI scores and written exam scores, but not OSCE scores. Worry and emotionality were the best predictive models for written exam scores. Mean total anxiety and emotionality scores for females were significantly higher than those for males, but not worry scores. Conclusion : Moderate-to-high test anxiety was observed in 85% of the chiropractic students examined. However, total test anxiety, as measured by the TAI score, was a very weak predictive model for written exam performance. Multiple regression analysis demonstrated that replacing total anxiety (TAI) with worry and emotionality (TAI subscales) produces a much more effective predictive model of written exam performance. Sex, age, highest current academic degree, and ethnicity contributed little additional predictive power in either regression model. Moreover, TAI scores were not found to be statistically significant predictors of physical exam skill performance, as measured by OSCEs.

  5. Self-oscillation of standing spin wave in ring resonator with proportional-integral-derivative control

    SciTech Connect

    Peng, B.; Urazuka, Y.; Chen, H.; Oyabu, S.; Otsuki, H.; Tanaka, T. Matsuyama, K.

    2014-05-07

    We report on numerical analysis on self-oscillation of standing spin wave excited in a nanostructured active ring resonator, consists of a ferromagnetic nanowire with perpendicular anisotropy. The confined resonant modes are along the nanowire length. A positive feedback with proportional-integral-derivative gain control was adopted in the active ring. Stable excitation of the 1st order standing spin wave has been demonstrated with micromagnetic simulations, taking into account the thermal effect with a random field model. The stationary standing spin wave with a pre-determined set variable of precession amplitude was attained within 20 ns by optimizing the proportional-integral-derivative gain control parameters. The result indicates that a monochromatic oscillation frequency f{sub osc} is extracted from the initial thermal fluctuation state and selectively amplified with the positive feedback loop. The obtained f{sub osc} value of 5.22 GHz practically agrees with the theoretical prediction from dispersion relation of the magneto static forward volume wave. It was also confirmed that the f{sub osc} change due to the temperature rise can be compensated with an external perpendicular bias field H{sub b}. The observed quick compensation time with an order of nano second suggests the fast operation speed in the practical device application.

  6. Test anxiety and academic performance in chiropractic students*

    PubMed Central

    Zhang, Niu; Henderson, Charles N. R.

    2014-01-01

    Objective We assessed the level of students' test anxiety, and the relationship between test anxiety and academic performance. Methods We recruited 166 third-quarter students. The Test Anxiety Inventory (TAI) was administered to all participants. Total scores from written examinations and objective structured clinical examinations (OSCEs) were used as response variables. Results Multiple regression analysis shows that there was a modest, but statistically significant negative correlation between TAI scores and written exam scores, but not OSCE scores. Worry and emotionality were the best predictive models for written exam scores. Mean total anxiety and emotionality scores for females were significantly higher than those for males, but not worry scores. Conclusion Moderate-to-high test anxiety was observed in 85% of the chiropractic students examined. However, total test anxiety, as measured by the TAI score, was a very weak predictive model for written exam performance. Multiple regression analysis demonstrated that replacing total anxiety (TAI) with worry and emotionality (TAI subscales) produces a much more effective predictive model of written exam performance. Sex, age, highest current academic degree, and ethnicity contributed little additional predictive power in either regression model. Moreover, TAI scores were not found to be statistically significant predictors of physical exam skill performance, as measured by OSCEs. PMID:24350946

  7. Objective structured clinical examination for pharmacy students in Qatar: cultural and contextual barriers to assessment.

    PubMed

    Wilby, K J; Black, E K; Austin, Z; Mukhalalati, B; Aboulsoud, S; Khalifa, S I

    2016-07-10

    This study aimed to evaluate the feasibility and psychometric defensibility of implementing a comprehensive objective structured clinical examination (OSCE) on the complete pharmacy programme for pharmacy students in a Middle Eastern context, and to identify facilitators and barriers to implementation within new settings. Eight cases were developed, validated, and had standards set according to a blueprint, and were assessed with graduating pharmacy students. Assessor reliability was evaluated using inter-class coefficients (ICCs). Concurrent validity was evaluated by comparing OSCE results to professional skills course grades. Field notes were maintained to generate recommendations for implementation in other contexts. The examination pass mark was 424 points out of 700 (60.6%). All 23 participants passed. Mean performance was 74.6%. Low to moderate inter-rater reliability was obtained for analytical and global components (average ICC 0.77 and 0.48, respectively). In conclusion, OSCE was feasible in Qatar but context-related validity and reliability concerns must be addressed prior to future iterations in Qatar and elsewhere.

  8. Noninvasive Recognition and Biomarkers of Early Allergic Asthma in Cats Using Multivariate Statistical Analysis of NMR Spectra of Exhaled Breath Condensate

    PubMed Central

    Fulcher, Yan G.; Fotso, Martial; Chang, Chee-Hoon; Rindt, Hans; Reinero, Carol R.

    2016-01-01

    Asthma is prevalent in children and cats, and needs means of noninvasive diagnosis. We sought to distinguish noninvasively the differences in 53 cats before and soon after induction of allergic asthma, using NMR spectra of exhaled breath condensate (EBC). Statistical pattern recognition was improved considerably by preprocessing the spectra with probabilistic quotient normalization and glog transformation. Classification of the 106 preprocessed spectra by principal component analysis and partial least squares with discriminant analysis (PLS-DA) appears to be impaired by variances unrelated to eosinophilic asthma. By filtering out confounding variances, orthogonal signal correction (OSC) PLS-DA greatly improved the separation of the healthy and early asthmatic states, attaining 94% specificity and 94% sensitivity in predictions. OSC enhancement of multi-level PLS-DA boosted the specificity of the prediction to 100%. OSC-PLS-DA of the normalized spectra suggest the most promising biomarkers of allergic asthma in cats to include increased acetone, metabolite(s) with overlapped NMR peaks near 5.8 ppm, and a hydroxyphenyl-containing metabolite, as well as decreased phthalate. Acetone is elevated in the EBC of 74% of the cats with early asthma. The noninvasive detection of early experimental asthma, biomarkers in EBC, and metabolic perturbation invite further investigation of the diagnostic potential in humans. PMID:27764146

  9. 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.

  10. Morphological study on small molecule acceptor-based organic solar cells with efficiencies beyond 7% (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Ma, Wei; Yan, He

    2015-10-01

    Despite the essential role of fullerenes in achieving best-performance organic solar cells (OSCs), fullerene acceptors have several drawbacks including poor light absorption, high-cost production and purification. For this reason, small molecule acceptor (SMA)-based OSCs have attracted much attention due to the easy tunability of electronic and optical properties of SMA materials. In this study, polymers with temperature dependent aggregation behaviors are combined with various small molecule acceptor materials, which lead to impressive power conversion efficiencies of up to 7.3%. The morphological and aggregation properties of the polymer:small molecule blends are studied in details. It is found that the temperature-dependent aggregation behavior of polymers allows for the processing of the polymer solutions at moderately elevated temperature, and more importantly, controlled aggregation and strong crystallization of the polymer during the film cooling and drying process. This results in a well-controlled and near-ideal polymer:small molecule morphology that is controlled by polymer aggregation during warm casting and thus insensitive to the choice of small molecules. As a result, several cases of highly efficient (PCE between 6-7.3%) SMA OSCs are achieved. The second part of this presentation will describe the morphology of a new small molecule acceptor with a unique 3D structure. The relationship between molecular structure and morphology is revealed.

  11. FACS-sorted putative oogonial stem cells from the ovary are neither DDX4-positive nor germ cells.

    PubMed

    Zarate-Garcia, Larissa; Lane, Simon I R; Merriman, Julie A; Jones, Keith T

    2016-01-01

    Whether the adult mammalian ovary contains oogonial stem cells (OSCs) is controversial. They have been isolated by a live-cell sorting method using the germ cell marker DDX4, which has previously been assumed to be cytoplasmic, not surface-bound. Furthermore their stem cell and germ cell characteristics remain disputed. Here we show that although OSC-like cells can be isolated from the ovary using an antibody to DDX4, there is no good in silico modelling to support the existence of a surface-bound DDX4. Furthermore these cells when isolated were not expressing DDX4, and did not initially possess germline identity. Despite these unremarkable beginnings, they acquired some pre-meiotic markers in culture, including DDX4, but critically never expressed oocyte-specific markers, and furthermore were not immortal but died after a few months. Our results suggest that freshly isolated OSCs are not germ stem cells, and are not being isolated by their DDX4 expression. However it may be that culture induces some pre-meiotic markers. In summary the present study offers weight to the dogma that the adult ovary is populated by a fixed number of oocytes and that adult de novo production is a rare or insignificant event. PMID:27301892

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

    PubMed

    Ho, Su-Chen; Su, Min-Sheng

    2014-01-01

    The anti-neuroinflammatory capacities of raw and steamed garlic extracts as well as five organosulfur compounds (OSCs) were examined in lipopolysaccharide (LPS)-stimulated BV2 microglia. According to those results, steaming pretreatment blocked the formation of alliinase-catalyzed OSCs such as allicin and diallyl trisulfide (DATS) in crushed garlic. Raw garlic, but not steamed garlic, dose-dependently attenuated the production of LPS-induced nitric oxide (NO), interleukin-1β (IL-1β), tumor necrosis factor (TNF)-α, and monocyte chemoattractant protein-1 (MCP-1). DATS and diallyl disulfide at 200 and 400 μM, respectively, displayed significant anti-neuroinflammatory activity. Meanwhile, even at 1 mM, diallyl sulfide, S-allyl cysteine and alliin did not display such activity. Inhibition of nuclear factor-κB activation was the mechanism underlying this protective effect of raw garlic and DATS. Analysis results indicated that the anti-neuroinflammatory capacity of raw garlic is due to the alliin-derived OSCs. Importantly, DATS is a highly promising therapeutic candidate for treating inflammation-related neurodegenerative diseases. PMID:25365295

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

    PubMed

    Qi, Boyuan; Zhang, Zhi-Guo; Wang, Jizheng

    2015-01-01

    Organic solar cells (OSCs) as the third generation photovoltaic devices have drawn intense research, for their ability to be easily deposited by low-cost solution coating technologies. However the cathode in conventional OSCs, Ca, can be only deposited by thermal evaporation and is highly unstable in ambient. Therefore various solution processible cathode buffer layers (CBLs) are synthesized as substitute of Ca and show excellent effect in optimizing performance of OSCs. Yet, there is still no universal consensus on the mechanism that how CBL works, which is evidently a critical scientific issue that should be addressed. In this article detailed studies are targeted on the interfacial physics at the interface between active layer and cathode (with and without treatment of a polar CBL) by using ultraviolet photoelectron spectroscopy, capacitance-voltage measurement, and impedance spectroscopy. The experimental data demonstrate that CBL mainly takes effect in three ways: suppressing surface states at the surface of active layer, protecting the active layer from being damaged by thermally evaporated cathode, and changing the energy level alignment by forming dipole moments with active layer and/or cathode. Our findings here provide a comprehensive picture of interfacial physics in devices with and without CBL. PMID:25588623

  14. Broadband light absorption enhancement in moth's eye nanostructured organic solar cells

    NASA Astrophysics Data System (ADS)

    Lan, Weixia; Cui, Yanxia; Yang, Qingyi; Lo, Ming-Fai; Lee, Chun-Sing; Zhu, Furong

    2015-05-01

    A comprehensive study on inverted organic solar cells (OSCs) with a moth's eye nanostructured (MEN) active layer was carried out. Performance of the MEN-based OSCs and the corresponding control planar cells, fabricated with blend of poly[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-bA] dithiophene-2, 6-diyl][3-fluoro-2-[(2- ethylhexyl) carbonyl]thieno[3,4-b]-thiophenediyl] (PTB7):[6,6]- phenyl-C70- butyric-acid-methyl-ester (PC70BM) was analyzed. The efficiency of the MEN-based OSCs was optimized by adjusting the height of MEN pattern in the active layer. Our experimental and theoretical results reveal that the MEN pattern enhances light absorption in the PTB7:PC70BM active layer, especially over the long wavelength region. This leads to a 7.8% increase in short circuit current density and a 6.1% increase in power conversion efficiency over those of the control planar cell.

  15. 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.

  16. Activation of K+ channel by 1-EBIO rescues the head and neck squamous cell carcinoma cells from Ca2+ ionophore-induced cell death

    PubMed Central

    Yin, Ming Zhe; Park, Seok-Woo; Kang, Tae Wook; Kim, Kyung Soo; Yoo, Hae Young; Lee, Junho; Hah, J. Hun; Sung, Myung Hun

    2016-01-01

    Ion channels in carcinoma and their roles in cell proliferation are drawing attention. Intracellular Ca2+ ([Ca2+]i)-dependent signaling affects the fate of cancer cells. Here we investigate the role of Ca2+-activated K+ channel (SK4) in head and neck squamous cell carcinoma cells (HNSCCs) of different cell lines; SNU-1076, OSC-19 and HN5. Treatment with 1 µM ionomycin induced cell death in all the three cell lines. Whole-cell patch clamp study suggested common expressions of Ca2+-activated Cl- channels (Ano-1) and Ca2+-activated nonselective cation channels (CAN). 1-EBIO, an activator of SK4, induced outward K+ current (ISK4) in SNU-1076 and OSC-19. In HN5, ISK4 was not observed or negligible. The 1-EBIO-induced current was abolished by TRAM-34, a selective SK4 blocker. Interestingly, the ionomycin-induced cell death was effectively prevented by 1-EBIO in SNU-1076 and OSC-19, and the rescue effect was annihilated by combined TRAM-34. Consistent with the lower level of ISK4, the rescue by 1-EBIO was least effective in HN5. The results newly demonstrate the role of SK4 in the fate of HNSCCs under the Ca2+ overloaded condition. Pharmacological modulation of SK4 might provide an intriguing novel tool for the anti-cancer strategy in HNSCC. PMID:26807020

  17. Predicting partition coefficients of Polyfluorinated and organosilicon compounds using polyparameter linear free energy relationships (PP-LFERs).

    PubMed

    Endo, Satoshi; Goss, Kai-Uwe

    2014-01-01

    The environmental behavior, fate, and effects of polyfluorinated compounds (PFCs) and organosilicon compounds (OSCs) have received increasing attention in recent years. In this study, polyparameter linear free energy relationships (PP-LFERs) were evaluated for predicting partition coefficients of neutral PFCs and OSCs, using experimental data for fluorotelomer alcohols (FTOHs) and cyclic volatile methylsiloxanes (cVMS) reported in the literature and measured newly for this work. It was found that the recently proposed PP-LFER model that uses the McGowan characteristic volume (V), the logarithmic hexadecane-air partition coefficient (L), and three polar interaction descriptors can accurately describe partition coefficients of PFCs and OSCs. The prediction errors were <1 log unit when literature descriptors were used, and the errors were reduced to <0.2 log units on average by further optimization of the descriptors. Surprisingly, the conventional forms of PP-LFERs that include the excess molar refraction (E) sometimes led to substantial errors (>1 log unit) even with optimized parameters. The system parameters for octanol-water, air-water, octanol-air, oil-water, liposome-water, and organic carbon-water partition coefficients as well as the solute descriptors for FTOHs and cVMS were recalibrated in this work, which should provide even more reliable predictions of partition coefficients. The results also confirm the consistency of the published experimental partition coefficients for FTOHs and cVMS.

  18. Transparent Conductive ITO/Ag/ITO Electrode Deposited at Room Temperature for Organic Solar Cells

    NASA Astrophysics Data System (ADS)

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

    2016-09-01

    We investigated the optical and electrical properties of room-temperature-deposited indium-tin-oxide (ITO)/Ag (19 nm)/ITO multilayer films as a function of ITO layer thickness. The optical and electrical properties of the ITO/Ag/ITO films were compared with those of high-temperature-deposited ITO-only films for use as an anode in organic solar cells (OSCs). The ITO/Ag/ITO multilayer films had sheet resistances in the range 5.40-5.78 Ω/sq, while the ITO-only film showed 14.18 Ω/sq. The carrier concentration of the ITO/Ag/ITO films gradually decreased from 2.01 × 1022 to 7.20 × 1021 cm-3 as the ITO thickness increased from 17 nm to 83 nm. At 530 nm, the transmittance of the ITO/Ag/ITO (50 nm/19 nm/50 nm) films was ~90%, while that of the ITO-only film gave 96.5%. The multilayer film had a smooth surface with a root mean square (RMS) roughness of 0.49 nm. Poly (3-hexylthiophene) (P3HT):[6,6]-phenyl-C61 butyric acid methylester (PCBM) bulk heterojunction (BHJ)-based OSCs fabricated with the ITO/Ag/ITO (50 nm/19 nm/50 nm) film showed a power conversion efficiency (PCE) (2.84%) comparable to that of OSCs with a conventional ITO-only anode (3.48%).

  19. Transposable element dynamics and PIWI regulation impacts lncRNA and gene expression diversity in Drosophila ovarian cell cultures

    PubMed Central

    Sytnikova, Yuliya A.; Rahman, Reazur; Chirn, Gung-wei; Clark, Josef P.

    2014-01-01

    Piwi proteins and Piwi-interacting RNAs (piRNAs) repress transposable elements (TEs) from mobilizing in gonadal cells. To determine the spectrum of piRNA-regulated targets that may extend beyond TEs, we conducted a genome-wide survey for transcripts associated with PIWI and for transcripts affected by PIWI knockdown in Drosophila ovarian somatic sheet (OSS) cells, a follicle cell line expressing the Piwi pathway. Despite the immense sequence diversity among OSS cell piRNAs, our analysis indicates that TE transcripts are the major transcripts associated with and directly regulated by PIWI. However, several coding genes were indirectly regulated by PIWI via an adjacent de novo TE insertion that generated a nascent TE transcript. Interestingly, we noticed that PIWI-regulated genes in OSS cells greatly differed from genes affected in a related follicle cell culture, ovarian somatic cells (OSCs). Therefore, we characterized the distinct genomic TE insertions across four OSS and OSC lines and discovered dynamic TE landscapes in gonadal cultures that were defined by a subset of active TEs. Particular de novo TEs appeared to stimulate the expression of novel candidate long noncoding RNAs (lncRNAs) in a cell lineage-specific manner, and some of these TE-associated lncRNAs were associated with PIWI and overlapped PIWI-regulated genes. Our analyses of OSCs and OSS cells demonstrate that despite having a Piwi pathway to suppress endogenous mobile elements, gonadal cell TE landscapes can still dramatically change and create transcriptome diversity. PMID:25267525

  20. Rational Design of Diketopyrrolopyrrole-Based Small Molecules as Donating Materials for Organic Solar Cells

    PubMed Central

    Jin, Ruifa; Wang, Kai

    2015-01-01

    A series of diketopyrrolopyrrole-based small molecules have been designed to explore their optical, electronic, and charge transport properties as organic solar cell (OSCs) materials. The calculation results showed that the designed molecules can lower the band gap and extend the absorption spectrum towards longer wavelengths. The designed molecules own the large longest wavelength of absorption spectra, the oscillator strength, and absorption region values. The optical, electronic, and charge transport properties of the designed molecules are affected by the introduction of different π-bridges and end groups. We have also predicted the mobility of the designed molecule with the lowest total energies. Our results reveal that the designed molecules are expected to be promising candidates for OSC materials. Additionally, the designed molecules are expected to be promising candidates for electron and/or hole transport materials. On the basis of our results, we suggest that molecules under investigation are suitable donors for [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) and its derivatives as acceptors of OSCs. PMID:26343640

  1. 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.

  2. Large optics fabrication and testing at the College of Optical Sciences

    NASA Astrophysics Data System (ADS)

    Burge, James H.

    2014-10-01

    The origin of the Optical Sciences Center (OSC) at the University of Arizona was closely tied to the need to expand the national capability for manufacturing large optics. This connection allowed OSC to grow quickly to become a truly unique place where new technologies are born and applied and where students have opportunities to apply academic lessons to real-world projects. In the decades that follow, OSC has grown to become a leader in many other optical disciplines, including photonics, imaging, optical engineering, and optical physics. But the core capability of optical fabrication and testing has remained as a unique University of Arizona asset. The last decade has seen explosive growth in development and implementation of new technologies for manufacturing and measuring large optics at the College of Optical Sciences. The classic polishing techniques have given way to advanced computer controlled machines and highly engineered laps. New measuring methods have enabled accurate metrology of steeply aspheric surfaces, concave and convex, symmetric and freeform. This paper discusses the history of optical fabrication and testing at University of Arizona and reviews some recent major projects and the technical developments that have enabled their success.

  3. Competency-based simulation assessment of resuscitation skills in emergency medicine postgraduate trainees – a Canadian multi-centred study

    PubMed Central

    Dagnone, J. Damon; Hall, Andrew K.; Sebok-Syer, Stefanie; Klinger, Don; Woolfrey, Karen; Davison, Colleen; Ross, John; McNeil, Gordon; Moore, Sean

    2016-01-01

    Background The use of high-fidelity simulation is emerging as a desirable method for competency-based assessment in postgraduate medical education. We aimed to demonstrate the feasibility and validity of a multi-centre simulation-based Objective Structured Clinical Examination (OSCE) of resuscitation competence with Canadian Emergency Medicine (EM) trainees. Method EM postgraduate trainees (n=98) from five Canadian academic centres participated in a high fidelity, 3-station simulation-based OSCE. Expert panels of three emergency physicians evaluated trainee performances at each centre using the Queen’s Simulation Assessment Tool (QSAT). Intraclass correlation coefficients were used to measure the inter-rater reliability, and analysis of variance was used to measure the discriminatory validity of each scenario. A fully crossed generalizability study was also conducted for each examination centre. Results Inter-rater reliability in four of the five centres was strong with a median absolute intraclass correlation coefficient (ICC) across centres and scenarios of 0.89 [0.65–0.97]. Discriminatory validity was also strong (p < 0.001 for scenarios 1 and 3; p < 0.05 for scenario 2). Generalizability studies found significant variations at two of the study centres. Conclusions This study demonstrates the successful pilot administration of a multi-centre, 3-station simulation-based OSCE for the assessment of resuscitation competence in post-graduate Emergency Medicine trainees. PMID:27103954

  4. Relating chemical structure to the mechanical and electrical properties in organic crystalline semiconductors

    NASA Astrophysics Data System (ADS)

    Reyes-Martinez, Marcos; Crosby, Alfred; Briseno, Alejandro

    2015-03-01

    The study of the physical properties of organic single crystals (OSCs) has allowed the advent of a new generation of high-performance organic electronic devices. Despite the profound knowledge of the structural and electrical properties of OSCs, there is little research on their mechanical properties and the effects of strain on their electrical properties. This presentation brings new understanding of the intrinsic mechanical properties of organic semiconductors and the effect of deformation in charge transport phenomena. We utilize rubrene single crystals as model systems. Due to the limited dimensions of crystals and the associated handling difficulty, the wrinkling instability is chosen as a metrology tool for the in-plane elastic constants. To elucidate the effects of mechanical strain on charge transport, we take advantage of wrinkling as a unique way to strain the conducting channel of field-effect transistors in a non-destructive, reversible, and predictable manner and demonstrate the mechanical modulation of field-effect mobility. Our contributions are the first to quantitatively correlate the crystal structure and the mechanical properties of OSCs, as well as the first to study their electro-mechanical behavior. They also represent a significant step forward in structure-function relationships in organic semiconductors and lay the foundation for the effective use of organic semiconductors in mechanically demanding applications such as pressure sensors and electronic skins.

  5. Improving charge transport of P3HT:PCBM organic solar cell using MoO3 nanoparticles as an interfacial buffer layer

    NASA Astrophysics Data System (ADS)

    Kim, Jae-Hyoung; Park, Eung-Kyu; Kim, Ji-Hwan; Cho, Hyeong Jun; Lee, Dong-Hoon; Kim, Yong-Sang

    2016-05-01

    In this work, P3HT:PCBM based organic solar cells (OSCs) were fabricated. We investigated the protection of PEDOT:PSS from active layer using the solution processed molybdenum oxide nanoparticles layer (MoO3 NPs, ≤100 nm). The device structure was ITO/ZnO/P3HT: PCBM/MoO3/PEDOT:PSS/Ag. A thin film MoO3 NPs was spin-coated and it acts as a hole transporting layer between the active layer and PEDOT:PSS. The MoO3 NPs based device showed an improved short circuit current compared without MoO3 NP layer. The pristine OSCs showed short circuit current density ( J sc ) of 11.56 mA/cm2 and PCE of 3.70% under AM 1.5G (100 mW/cm2). MoO3 NPs based device showed an increased PCE of 4.11% with J sc of 12.74 mA/cm2. MoO3 NPs also decreased the charge recombination and resistance of the OSCs. [Figure not available: see fulltext.

  6. 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.

  7. Conjugated Polymer-Small Molecule Alloy Leads to High Efficient Ternary Organic Solar Cells.

    PubMed

    Zhang, Jianqi; Zhang, Yajie; Fang, Jin; Lu, Kun; Wang, Zaiyu; Ma, Wei; Wei, Zhixiang

    2015-07-01

    Ternary organic solar cells are promising candidates for bulk heterojunction solar cells; however, improving the power conversion efficiency (PCE) is quite challenging because the ternary system is complicated on phase separation behavior. In this study, a ternary organic solar cell (OSC) with two donors, including one polymer (PTB7-Th), one small molecule (p-DTS(FBTTH2)2), and one acceptor (PC71BM), is fabricated. We propose the two donors in the ternary blend forms an alloy. A notable averaged PCE of 10.5% for ternary OSC is obtained due to the improvement of the fill factor (FF) and the short-circuit current density (J(sc)), and the open-circuit voltage (V(oc)) does not pin to the smaller V(oc) of the corresponding binary blends. A highly ordered face-on orientation of polymer molecules is obtained due to the formation of an alloy structure, which facilitates the enhancement of charge separation and transport and the reduction of charge recombination. This work indicates that a high crystallinity and the face-on orientation of polymers could be obtained by forming alloy with two miscible donors, thus paving a way to largely enhance the PCE of OSCs by using the ternary blend strategy.

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

    NASA Astrophysics Data System (ADS)

    Qi, Boyuan; Zhang, Zhi-Guo; Wang, Jizheng

    2015-01-01

    Organic solar cells (OSCs) as the third generation photovoltaic devices have drawn intense research, for their ability to be easily deposited by low-cost solution coating technologies. However the cathode in conventional OSCs, Ca, can be only deposited by thermal evaporation and is highly unstable in ambient. Therefore various solution processible cathode buffer layers (CBLs) are synthesized as substitute of Ca and show excellent effect in optimizing performance of OSCs. Yet, there is still no universal consensus on the mechanism that how CBL works, which is evidently a critical scientific issue that should be addressed. In this article detailed studies are targeted on the interfacial physics at the interface between active layer and cathode (with and without treatment of a polar CBL) by using ultraviolet photoelectron spectroscopy, capacitance-voltage measurement, and impedance spectroscopy. The experimental data demonstrate that CBL mainly takes effect in three ways: suppressing surface states at the surface of active layer, protecting the active layer from being damaged by thermally evaporated cathode, and changing the energy level alignment by forming dipole moments with active layer and/or cathode. Our findings here provide a comprehensive picture of interfacial physics in devices with and without CBL.

  9. Use of a radial artery compression device for noninvasive, near-continuous blood pressure monitoring in the ED.

    PubMed

    Thomas, Stephen H; Winsor, Greg R; Pang, Peter S; Driscoll, Karen A; Parry, Blair A

    2004-10-01

    This study's goal was to test a novel device using continuous partial radial artery compression for mean arterial pressure (MAP) measurement. A prospective, nonblind, convenience-sample trial at a level I center (annual ED census 70,000) enrolled 15 adults with indwelling radial arterial catheters and accessible contralateral radial pulse. Subjects had MAPs measured simultaneously by test device (TEST assessments), oscillometric brachial artery cuff (OSC), and arterial line (ART). There was no difference between the three groups' MAP means (P = .98). R(2) values for ART/OSC and ART/TEST were 0.96 and 0.95, respectively (P <.001). TEST and OSC MAP readings were equally likely (P = 0.66) to be within 5 mm Hg of ART in both the overall set of 307 MAPs and in the subset of 120 cases in which ART MAPs were below 80 (P = .47). The TEST device performed at least as well as oscillometric assessment, offering advantages of noninvasive, near-continuous data.

  10. Suppression of 2,3-oxidosqualene cyclase by high fat diet contributes to liver X receptor-alpha-mediated improvement of hepatic lipid profile.

    PubMed

    Dang, Huaixin; Liu, Yan; Pang, Wei; Li, Chenghong; Wang, Nanping; Shyy, John Y-J; Zhu, Yi

    2009-03-01

    The liver X receptors (LXRs) sense oxysterols and regulate genes involved in cholesterol metabolism. Synthetic agonists of LXRs are potent stimulators of fatty acid synthesis, which is mediated largely by sterol regulatory element-binding protein-1c (SREBP-1c). Paradoxically, an improved hepatic lipid profile by LXR was observed in mice fed a Western high fat (HF) diet. To explore the underlying mechanism, we administered mice normal chow or an HF diet and overexpressed LXRalpha in the liver. The HF diet with tail-vein injection of adenovirus of LXRalpha increased the expression of LXR-targeted genes involved in cholesterol reverse transport but not those involved in fatty acid synthesis. A similar effect was also observed with the use of 22R-hydroxycholesterol, an LXR ligand, in cultured hepatocytes. Consequently, SREBP-1c maturation was inhibited by the HF diet, which resulted from the induction of Insig-2a. Importantly, increased cholesterol level suppressed the expression of 2,3-oxidosqualene cyclase (OSC), which led to an increase in endogenous LXR ligand(s). Furthermore, siRNA-mediated knockdown of OSC expression enhanced LXR activity and selectively up-regulated LXR-targeted genes involved in cholesterol reverse transport. Thus, down-regulation of OSC may account for a novel mechanism underlying the LXR-mediated lipid metabolism in the liver of mice fed an HF diet.

  11. Transposable element dynamics and PIWI regulation impacts lncRNA and gene expression diversity in Drosophila ovarian cell cultures.

    PubMed

    Sytnikova, Yuliya A; Rahman, Reazur; Chirn, Gung-Wei; Clark, Josef P; Lau, Nelson C

    2014-12-01

    Piwi proteins and Piwi-interacting RNAs (piRNAs) repress transposable elements (TEs) from mobilizing in gonadal cells. To determine the spectrum of piRNA-regulated targets that may extend beyond TEs, we conducted a genome-wide survey for transcripts associated with PIWI and for transcripts affected by PIWI knockdown in Drosophila ovarian somatic sheet (OSS) cells, a follicle cell line expressing the Piwi pathway. Despite the immense sequence diversity among OSS cell piRNAs, our analysis indicates that TE transcripts are the major transcripts associated with and directly regulated by PIWI. However, several coding genes were indirectly regulated by PIWI via an adjacent de novo TE insertion that generated a nascent TE transcript. Interestingly, we noticed that PIWI-regulated genes in OSS cells greatly differed from genes affected in a related follicle cell culture, ovarian somatic cells (OSCs). Therefore, we characterized the distinct genomic TE insertions across four OSS and OSC lines and discovered dynamic TE landscapes in gonadal cultures that were defined by a subset of active TEs. Particular de novo TEs appeared to stimulate the expression of novel candidate long noncoding RNAs (lncRNAs) in a cell lineage-specific manner, and some of these TE-associated lncRNAs were associated with PIWI and overlapped PIWI-regulated genes. Our analyses of OSCs and OSS cells demonstrate that despite having a Piwi pathway to suppress endogenous mobile elements, gonadal cell TE landscapes can still dramatically change and create transcriptome diversity.

  12. Differential protein mapping of ovarian serous adenocarcinomas: identification of potential markers for distinct tumor stage.

    PubMed

    Wang, Yanfei; Wu, Rong; Cho, Kathleen R; Thomas, Dafydd G; Gossner, Gabrielle; Liu, J Rebecca; Giordano, Thomas J; Shedden, Kerby A; Misek, David E; Lubman, David M

    2009-03-01

    Ovarian serous carcinomas (OSCs) comprise over half of all ovarian carcinomas and account for the majority of ovarian cancer-related deaths. We used a 2-dimensional liquid-based protein mapping strategy to characterize global protein expression patterns in 19 OSC tumor samples from 15 different patients to facilitate molecular classification of tumor stage. Protein expression profiles were produced, using pI-based separation in the first dimension and hydrophobicity-based separation in the second dimension, over a pH range of 4.0-7.0. Hierarchical clustering was applied to protein maps to indicate the tumor interrelationships. The 19 tumor samples could be classified into two different groups, one group associated with low stage (Stage 1) tumors and the other group associated with high stage (Stages 3/4) tumors. Proteins that were differentially expressed in different groups were selected for identification by LTQ-ESI-MS/MS. Fourteen of the selected proteins were overexpressed in the low stage tumors; 46 of the proteins were overexpressed in the high stage tumors. These proteins are known to play an important role in cellular functions such as glycolysis, protein biosynthesis, and cytoskeleton rearrangement and may serve as markers associated with different stages of OSCs. To further confirm the stage-dependent protein identifications, Lamin A/C and Vimentin expression in ovarian serous carcinomas was assessed by immunohistochemistry using ovarian tumor tissue microarrays for 66 samples.

  13. 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.

  14. Clinical simulation training improves the clinical performance of Chinese medical students

    PubMed Central

    Zhang, Ming-ya; Cheng, Xin; Xu, An-ding; Luo, Liang-ping; Yang, Xuesong

    2015-01-01

    Background Modern medical education promotes medical students’ clinical operating capacity rather than the mastery of theoretical knowledge. To accomplish this objective, clinical skill training using various simulations was introduced into medical education to cultivate creativity and develop the practical ability of students. However, quantitative analysis of the efficiency of clinical skill training with simulations is lacking. Methods In the present study, we compared the mean scores of medical students (Jinan University) who graduated in 2013 and 2014 on 16 stations between traditional training (control) and simulative training groups. In addition, in a clinical skill competition, the objective structured clinical examination (OSCE) scores of participating medical students trained using traditional and simulative training were compared. The data were statistically analyzed and qualitatively described. Results The results revealed that simulative training could significantly enhance the graduate score of medical students compared with the control. The OSCE scores of participating medical students in the clinical skill competition, trained using simulations, were dramatically higher than those of students trained through traditional methods, and we also observed that the OSCE marks were significantly increased for the same participant after simulative training for the clinical skill competition. Conclusions Taken together, these data indicate that clinical skill training with a variety of simulations could substantially promote the clinical performance of medical students and optimize the resources used for medical education, although a precise analysis of each specialization is needed in the future. PMID:26478142

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

    PubMed

    Jin, Ruifa; Wang, Kai

    2015-01-01

    A series of diketopyrrolopyrrole-based small molecules have been designed to explore their optical, electronic, and charge transport properties as organic solar cell(OSCs) materials. The calculation results showed that the designed molecules can lower the band gap and extend the absorption spectrum towards longer wavelengths.The designed molecules own the large longest wavelength of absorption spectra,the oscillator strength, and absorption region values. The optical, electronic, and charge transport properties of the designed molecules are affected by the introduction of different π-bridges and end groups. We have also predicted the mobility of the designed molecule with the lowest total energies. Our results reveal that the designed molecules are expected to be promising candidates for OSC materials. Additionally, the designed molecules are expected to be promising candidates for electron and/or hole transport materials. On the basis of our results, we suggest that molecules under investigation are suitable donors for[6,6]-phenyl-C61-butyric acid methyl ester (PCBM) and its derivatives as acceptors of OSCs. PMID:26343640

  16. Plasmonically sensitized metal-oxide electron extraction layers for organic solar cells

    PubMed Central

    Trost, S.; Becker, T.; Zilberberg, K.; Behrendt, A.; Polywka, A.; Heiderhoff, R.; Görrn, P.; Riedl, T.

    2015-01-01

    ZnO and TiOx are commonly used as electron extraction layers (EELs) in organic solar cells (OSCs). A general phenomenon of OSCs incorporating these metal-oxides is the requirement to illuminate the devices with UV light in order to improve device characteristics. This may cause severe problems if UV to VIS down-conversion is applied or if the UV spectral range (λ < 400 nm) is blocked to achieve an improved device lifetime. In this work, silver nanoparticles (AgNP) are used to plasmonically sensitize metal-oxide based EELs in the vicinity (1–20 nm) of the metal-oxide/organic interface. We evidence that plasmonically sensitized metal-oxide layers facilitate electron extraction and afford well-behaved highly efficient OSCs, even without the typical requirement of UV exposure. It is shown that in the plasmonically sensitized metal-oxides the illumination with visible light lowers the WF due to desorption of previously ionosorbed oxygen, in analogy to the process found in neat metal oxides upon UV exposure, only. As underlying mechanism the transfer of hot holes from the metal to the oxide upon illumination with hν < Eg is verified. The general applicability of this concept to most common metal-oxides (e.g. TiOx and ZnO) in combination with different photoactive organic materials is demonstrated. PMID:25592174

  17. An implementation of SISAL for distributed-memory architectures

    SciTech Connect

    Beard, P.C.

    1995-06-01

    This thesis describes a new implementation of the implicitly parallel functional programming language SISAL, for massively parallel processor supercomputers. The Optimizing SISAL Compiler (OSC), developed at Lawrence Livermore National Laboratory, was originally designed for shared-memory multiprocessor machines and has been adapted to distributed-memory architectures. OSC has been relatively portable between shared-memory architectures, because they are architecturally similar, and OSC generates portable C code. However, distributed-memory architectures are not standardized -- each has a different programming model. Distributed-memory SISAL depends on a layer of software that provides a portable, distributed, shared-memory abstraction. This layer is provided by Split-C, a dialect of the C programming language developed at U.C. Berkeley, which has demonstrated good performance on distributed-memory architectures. Split-C provides important capabilities for good performance: support for program-specific distributed data structures, and split-phase memory operations. Distributed data structures help achieve good memory locality, while split-phase memory operations help tolerate the longer communication latencies inherent in distributed-memory architectures. The distributed-memory SISAL compiler and run-time system takes advantage of these capabilities. The results of these efforts is a compiler that runs identically on the Thinking Machines Connection Machine (CM-5), and the Meiko Computing Surface (CS-2).

  18. Does the addition of writing into a pharmacy communication skills course significantly impact student communicative learning outcomes? A pilot study.

    PubMed

    Lonie, John M; Rahim, Hamid

    2010-12-01

    The objective of this study was to determine if the addition of a reflective writing component in a fourth year (P-2) pharmacy communication skills course would significantly affect 2 measures of learning: (1) objective multiple choice examination questions and (2) a patient counseling Objective Structured Clinical Examination (OSCE) score. Using a nonequivalent group quasi-experimental retrospective comparison design, 98 randomly selected final examination scores from students taking a non-writing intensive (NWI) communication skills course were compared with 112 randomly selected final examination scores from students that took a communication skills course in which students engaged in several reflective writing assignments. In addition, 91 randomly selected patient counseling OSCE scores from a NWI course were statistically compared with 112 scores from students that took the writing intensive (WI) course. There were statistically significant improvements in multiple choice examination scores in the group that took the reflective writing communication skills course. There was not a statistically significant difference in patient counseling OSCE scores after students completed the WI course. Studying the effects of using reflective writing assignments in communication skills courses may improve the retention and retrieval of information presented within the course.

  19. 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.

  20. 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.

  1. Nanoscale characterization of the electrical properties of oxide electrodes at the organic semiconductor-oxide electrode interface in organic solar cells

    NASA Astrophysics Data System (ADS)

    MacDonald, Gordon Alex

    This dissertation focuses on characterizing the nanoscale and surface averaged electrical properties of transparent conducting oxide electrodes such as indium tin oxide (ITO) and transparent metal-oxide (MO) electron selective interlayers (ESLs), such as zinc oxide (ZnO), the ability of these materials to rapidly extract photogenerated charges from organic semiconductors (OSCs) used in organic photovoltaic (OPV) cells, and evaluating their impact on the power conversion efficiency (PCE) of OPV devices. In Chapter 1, we will introduce the fundamental principles, benefits, and the key innovations that have advanced this technology. In Chapter 2 of this dissertation, we demonstrate an innovative application of conductive probe atomic force microscopy (CAFM) to map the nanoscale electrical heterogeneity at the interface between ITO, and a well-studied OSC, copper phthalocyanine (CuPc).(MacDonald et al. (2012) ACS Nano, 6, p. 9623) In this work we collected arrays of current-voltage (J-V) curves, using a CAFM probe as the top contact of CuPc/ITO systems, to map the local J-V responses. By comparing J-V responses to known models for charge transport, we were able to determine if the local rate-limiting-step for charge transport is through the OSC (ohmic) or the CuPc/ITO interface (non-ohmic). Chapter 3 focus on the electrical property characterization of RF-magnetron sputtered ZnO (sp-ZnO) ESL films on ITO substrates. We have shown that the energetic alignment of ESLs and the OSC active materials plays a critical role in determining the PCE of OPV devices and UV light soaking sensitivity. We have used a combination of device testing, modeling, and impedance spectroscopy to characterize the effects that energetic alignment has on the charge carrier transport and distribution within the OPV device. In Chapter 4 we demonstrate that the local properties of sp-ZnO films varies as a function of the underlying ITO crystal face. We show that the local ITO crystal face determines

  2. Spectroscopic enhancement from noble mettalic nanoparticles

    NASA Astrophysics Data System (ADS)

    Tsai, Shu-Ju

    2011-12-01

    Resonant coupling of localized surface plasmon resonances (LSPRs) in noble metallic nanostructures to incident radiation and the related subject of localized behavior of electromagnetic waves are currently of great interest due to their potential application to sensors, biochemical assays, optical transmission, and photovoltaic devices. My thesis research is made up of two related parts. In part one I examined enhanced fluorescence in dye molecules in proximity to Ag nanostructures. In part two I studied the effect of Au nanostructure arrays on the performance of poly(3-hexylthiophene-2,5-diyl) : [6,6]-phenyl-C61-butyric acid methyl ester (P3HT:PCBM) bulk heterojunction (BHJ) organic solar cells (OSCs). Nanostructures were fabricated by two different methods: e-beam lithography (top down) and spray pyrolysis (bottom up). Using e-beam lithography, we produced arrays of nanostructures with well defined shapes, sizes, and spacings. By systematically varying these topographical parameters, we measured their effect on nanometer-sized metallic structure-enhanced fluorescence (nMEF) and on absorption and external quantum efficiency (EQE) in OSC devices as a function of optical wavelength. In analyzing experimental results, we carried out numerical simulations of the local electric field under incident light, across plasmonic resonances. The comparison between the calculated local field squared and measured fluorescence/EQE provides physical insight on the configuration-dependence of these two processes. Our results indicate that local field enhancement near nanostructures is dominant in nMEF, and that the local field is strongly affected by the substrate and device architectures. For the OSCs, both measurements and calculations show that absorbance within the active layer is enhanced only in a narrow band of wavelengths (˜640-720 nm) where the active layer is not very absorbing for our prototype nanopillar-patterned devices. The peak enhancement for 180 nm wide Au

  3. [Rapid determination of the multi-marker ingredients in Heterosmilacis Japonicae Rhizoma and Sophorae Flavescentis Radix with near-infrared diffused reflection spectroscopy].

    PubMed

    Zhao, Feng-Chun; Wan, Kai-Yang; Liu, Xiao-Qian; Zhang, Qi-Wei; Gao, Hui-Min; Wang, Zhi-Min

    2014-10-01

    A rapid NIRS method for determination of macrozamin in Heterosmilacis japonicae rhizoma (HJR), and the total content of oxymatrine and matrine (OMT + MT) as well as the total content of oxysophocarpine and sophocarpine (OSC + SC) in sophorae flavescens radix (SFR) was developed to explore the application feasibility of NIRS for the quality assurance system of Chinese patent drugs. The contents of macrozamin in HJR samples, and OMT + MT and OSC + SC in SFR samples were determined by HPLC as reference values. The NIR spectra of the samples were measured in a diffused reflection mode. The different characteristic wavebands and pretreatment methods were optimized. The quantitative calibration models between the NIR spectra and the content reference values of marker components in HJR and SFR samples, were established with partial least square method, and further optimized through the cross validation and external validation. The contents of macrozamin in 88 batches of HJR samples were over the range of 0.36-12.88 mg · g(-1). The total contents of OMT + MT and OSC + SC in 75 batches of SFR samples were over the range of 8.87-66.31 and 2.30-15.11 mg · g(-1), respectively. The performance of the final models for macrozamin, OMT + MT and OSC + SC was evaluated well according to correlation coefficients (r), root mean square error of cross-validation (RMSECV) and root mean square error of prediction (RMSEP). The R2 values of the cross-validation for macrozamin, OMT + MT and OSC + SC were 0.9025, 0.9491 and 0.9137, and those of RMSECV were 0.961, 2.45 and 0.724 mg · g(-1) respectively. The R2 values of external validation for the three models were 0.9817, 0.9826 and 0.9609, and those of RMSEP were 0.693, 2.27 and 0.658 mg · g(-1), respectively. This is the first report on rapid determination of macrozamin in Heterosmilacis japonicae rhizoma, and oxymatrine, matrine, oxysophocarpine and sophocarpine in sophorae flavescens radix by NIRS method. The presented method can

  4. Design, Analyses, and Fabrication Procedure of Amtec Cell, Test Assembly, and Radioisotope Power System for Outer-Planet Missions

    NASA Astrophysics Data System (ADS)

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

    2002-04-01

    This paper describes the results of OSC's department of energy (DOE)-sponsored alkali metal thermal-to-electric conversion (AMTEC) generator studies. The paper was prepared in response to an invitation from the International Astronautic Federation for the presentation of a 1-h keynote lecture on our AMTEC studies at the Space Nuclear Power and Propulsion Systems session of the 48th International Astronautical Congress. The paper covers a broad range of topics, which explains its unusual length. After presenting the background of those studies and the operational principles of the AMTEC converters, it describes a novel methodology for the coupled solution of the interdependent thermal, electrical, and fluid flow differential and integral equations governing their performance, and the application of that procedure to OSC's recommended cell design. As explained in the paper, that design was the result of parametric analyses of 35 cell design variations to determine the individual effects of 27 design parameters and various operating parameters on the cell's power output, efficiency, and critical temperatures. The analysis revealed a method of substantially improving the cell's performance by enhancing the internal reflectivity of the cell wall, and identified a specific cell wall composition and coating to achieve that goal. The paper presents a set of OSC-recommended cell design parameters for the ultimate long-service flight generators, as well as a set of parameters for an interim cell design for planned short-term ground tests. The primary difference between them is that the ultimate design employs refractory metal components to enhance compatibility with high-temperature sodium vapor, while the interim design is based on stainless steel, nickel, and Haynes-25, which are expected to be adequate for initial short-term tests, but not for long-duration missions at high operating temperatures. The paper also presents a detailed fabrication sequence for the recommended

  5. Design and integration of small RTPV generators with new millennium spacecraft for outer solar system

    NASA Astrophysics Data System (ADS)

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

    The National Aeronautics and Space Administration's recently inaugurated New Millennium program, with its emphasis on miniaturized spacecraft, has generated interest in a low-power (10-30 W), low-mass, high-efficiency RTPV (Radioisotope Thermophotovoltaic) power system. This led to a Department of Energy (DOE)-sponsored design study of such a system, which was assigned to OSC (formerly Fairchild) personnel, who have been conducting similar studies of a 75 W RTPV system for the Pluto Express Mission, with very encouraging results. The 75 W design employed two 250 W general purpose heat source (GPHS) modules that DOE had previously developed and safety-qualified for various space missions. These modules were too large for the small RTPVs described in this paper. To minimize the need for new development and safety verification studies, OSC generated derivative designs for 125 W and 62.5 W heat source modules containing identical fuel pellets, clads, impact shell and thermal insulation. OSC also generated a novel heat source support scheme to reduce the heat losses through the structural supports, and a new and much simpler radiator structure, eliminating the need for honeycombs and heat pipes. OSCs previous RTPV study had been based on the use of GaSb PV cells and spectrally selective IR filters that had been partially developed and characterized by Boeing (now EDTEK) personnel. They had supplied us with spectral data on filter reflectivities and cell quantum efficiencies. Two sets of data were furnished: one based on actual measurements made in 1993, and a more optimistic set based on projected performance improvements. Even the measured data set yielded significantly better system performance than present thermoelectric systems, but the projected data yielded much better system performance. Because of these encouraging results, OSC in the fall of 1994 initiated an experimental program at EDTEK to develop improved filters and cells, to demonstrate how much

  6. Electronic properties of disordered organic semiconductors via QM/MM simulations.

    PubMed

    Difley, Seth; Wang, Lee-Ping; Yeganeh, Sina; Yost, Shane R; Van Voorhis, Troy

    2010-07-20

    Organic semiconductors (OSCs) have recently received significant attention for their potential use in photovoltaic, light emitting diode, and field effect transistor devices. Part of the appeal of OSCs is the disordered, amorphous nature of these materials, which makes them more flexible and easier to process than their inorganic counterparts. In addition to their technological applications, OSCs provide an attractive laboratory for examining the chemistry of heterogeneous systems. Because OSCs are both electrically and optically active, researchers have access to a wealth of electrical and spectroscopic probes that are sensitive to a variety of localized electronic states in these materials. In this Account, we review the basic concepts in first-principles modeling of the electronic properties of disordered OSCs. There are three theoretical ingredients in the computational recipe. First, Marcus theory of nonadiabatic electron transfer (ET) provides a direct link between energy and kinetics. Second, constrained density functional theory (CDFT) forms the basis for an ab initio model of the diabatic charge states required in ET. Finally, quantum mechanical/molecular mechanical (QM/MM) techniques allow us to incorporate the influence of the heterogeneous environment on the diabatic states. As an illustration, we apply these ideas to the small molecule OSC tris(8- hydroxyquinolinato)aluminum (Alq(3)). In films, Alq(3) can possess a large degree of short-range order, placing it in the middle of the order-disorder spectrum (in this spectrum, pure crystals represent one extreme and totally amorphous structures the opposite extreme). We show that the QM/MM recipe reproduces the transport gap, charge carrier hopping integrals, optical spectra, and reorganization energies of Alq(3) in quantitative agreement with available experiments. However, one cannot specify any of these quantities accurately with a single number. Instead, one must characterize each property by a

  7. Linking Microearthquakes and Seismic Tomography on the Endeavour Segment of the Juan de Fuca Ridge: Implications for Hydrothermal Circulation

    NASA Astrophysics Data System (ADS)

    Wilcock, W. S.; Weekly, R. T.; Hooft, E. E.; Toomey, D. R.; Kim, E.

    2013-12-01

    We report on a remarkable correlation between the patterns of microearthquakes and three-dimensional upper crustal velocity anomalies on the Endeavour segment of the Juan de Fuca Ridge. Microearthquakes were monitored from 2003-2006 by a small seismic network deployed on the central part of the segment. The velocity model was obtained from a tomography experiment comprising over 5500 shots from a large airgun array that were recorded by ocean bottom seismometers deployed at 64 sites along the Endeavour segment and the adjacent overlapping spreading centers (OSCs). On the segment scale, upper crustal velocities are low in the OSCs indicating that the crust is highly fractured. These low velocities persist off-axis and record the history of ridge propagation. In 2005, two swarm sequences that were interpreted in terms of magmatic intrusions on the limbs of the Endeavour-West Valley OSC were accompanied by extensive seismicity within the overlap basin. Throughout the microearthquake experiment earthquakes were concentrated in a region surrounding the southern tip of the West Valley propagator that coincides closely with the southern limit of the low velocities imaged around the OSC. Beneath the hydrothermal vent fields in the center of the Endeavour segment, the earthquakes were mostly located in a 500-m-thick band immediately above the axial magma chamber. There was a close correlation between the rates of seismicity beneath each vent field and their thermal output. The highest rates of seismicity were observed beneath the High Rise and Main Endeavour fields that each have power outputs of several hundred megawatts. Seismic velocities are generally high beneath the vent fields relative to velocities along the ridge axis immediately to the north and south. However, the High Rise and Main Endeavour fields are underlain by a low velocity region at 2 km depth that coincides with the seismically active region. This is consistent with a region of increased fracturing and

  8. Immunoregulation of follicular renewal, selection, POF, and menopause in vivo, vs. neo-oogenesis in vitro, POF and ovarian infertility treatment, and a clinical trial.

    PubMed

    Bukovsky, Antonin; Caudle, Michael R

    2012-11-23

    The immune system plays an important role in the regulation of tissue homeostasis ("tissue immune physiology"). Function of distinct tissues during adulthood, including the ovary, requires (1) Renewal from stem cells, (2) Preservation of tissue-specific cells in a proper differentiated state, which differs among distinct tissues, and (3) Regulation of tissue quantity. Such morphostasis can be executed by the tissue control system, consisting of immune system-related components, vascular pericytes, and autonomic innervation. Morphostasis is established epigenetically, during morphogenetic (developmental) immune adaptation, i.e., during the critical developmental period. Subsequently, the tissues are maintained in a state of differentiation reached during the adaptation by a "stop effect" of resident and self renewing monocyte-derived cells. The later normal tissue is programmed to emerge (e.g., late emergence of ovarian granulosa cells), the earlier its function ceases. Alteration of certain tissue differentiation during the critical developmental period causes persistent alteration of that tissue function, including premature ovarian failure (POF) and primary amenorrhea. In fetal and adult human ovaries the ovarian surface epithelium cells called ovarian stem cells (OSC) are bipotent stem cells for the formation of ovarian germ and granulosa cells. Recently termed oogonial stem cells are, in reality, not stem but already germ cells which have the ability to divide. Immune system-related cells and molecules accompany asymmetric division of OSC resulting in the emergence of secondary germ cells, symmetric division, and migration of secondary germ cells, formation of new granulosa cells and fetal and adult primordial follicles (follicular renewal), and selection and growth of primary/preantral, and dominant follicles. The number of selected follicles during each ovarian cycle is determined by autonomic innervation. Morphostasis is altered with advancing age, due to

  9. Immunoregulation of follicular renewal, selection, POF, and menopause in vivo, vs. neo-oogenesis in vitro, POF and ovarian infertility treatment, and a clinical trial

    PubMed Central

    2012-01-01

    The immune system plays an important role in the regulation of tissue homeostasis ("tissue immune physiology"). Function of distinct tissues during adulthood, including the ovary, requires (1) Renewal from stem cells, (2) Preservation of tissue-specific cells in a proper differentiated state, which differs among distinct tissues, and (3) Regulation of tissue quantity. Such morphostasis can be executed by the tissue control system, consisting of immune system-related components, vascular pericytes, and autonomic innervation. Morphostasis is established epigenetically, during morphogenetic (developmental) immune adaptation, i.e., during the critical developmental period. Subsequently, the tissues are maintained in a state of differentiation reached during the adaptation by a “stop effect” of resident and self renewing monocyte-derived cells. The later normal tissue is programmed to emerge (e.g., late emergence of ovarian granulosa cells), the earlier its function ceases. Alteration of certain tissue differentiation during the critical developmental period causes persistent alteration of that tissue function, including premature ovarian failure (POF) and primary amenorrhea. In fetal and adult human ovaries the ovarian surface epithelium cells called ovarian stem cells (OSC) are bipotent stem cells for the formation of ovarian germ and granulosa cells. Recently termed oogonial stem cells are, in reality, not stem but already germ cells which have the ability to divide. Immune system-related cells and molecules accompany asymmetric division of OSC resulting in the emergence of secondary germ cells, symmetric division, and migration of secondary germ cells, formation of new granulosa cells and fetal and adult primordial follicles (follicular renewal), and selection and growth of primary/preantral, and dominant follicles. The number of selected follicles during each ovarian cycle is determined by autonomic innervation. Morphostasis is altered with advancing age, due

  10. Estudio espectroscópico de la simbiótica CD-43o14304

    NASA Astrophysics Data System (ADS)

    García, L. G.; Brandi, E.; Ferrer, O. E.; Barbá, R.

    En base a un monitoreo espectroscópico de estrellas simbióticas del hemisferio sur, realizado entre 1990 y 1997, se han reunido espectros en intermedia y alta resolución de la simbiótica CD-43o14304. Se trata de un sistema binario compuesto por una enana blanca y una gigante tipo K5 con un período orbital recientemente determinado, de 1448 días. Por primera vez se analiza el comportamiento espectral del objeto en un amplio rango espectral (3700-10000 Å) y en función de las fases orbitales observadas. Se interpretan las velocidades radiales de las emisiones y absorciones presentes y las variaciones en los perfiles estructurados de las líneas de Balmer y en el resto de las emisiones.

  11. Team-based learning, a learning strategy for clinical reasoning, in students with problem-based learning tutorial experiences.

    PubMed

    Okubo, Yumiko; Ishiguro, Naoko; Suganuma, Taiyo; Nishikawa, Toshio; Takubo, Toshio; Kojimahara, Noriko; Yago, Rie; Nunoda, Shinichi; Sugihara, Shigetaka; Yoshioka, Toshimasa

    2012-01-01

    Acquiring clinical reasoning skills in lectures may be difficult, but it can be learnt through problem-solving in the context of clinical practice. Problem finding and solving are skills required for clinical reasoning; however, students who underwent problem-based learning (PBL) still have difficulty in acquiring clinical reasoning skills. We hypothesized that team-based learning (TBL), a learning strategy that provides the opportunity to solve problems by repeatedly taking tests, can enhance the clinical reasoning ability in medical students with PBL experiences during the pre-clinical years. TBL courses were designed for 4(th) year students in a 6-year program in 2008, 2009, and 2010. TBL individual scores, consisting of a combination of individual and group tests, were compared with scores of several examinations including computer-based testing (CBT), an original examination assessing clinical reasoning ability (problem-solving ability test; P-SAT), term examinations, and Objective Structured Clinical Examination (OSCE). CBT, OSCE and P-SAT scores were compared with those of students who learned clinical reasoning only through PBL tutorials in 2005, 2006, and 2007 (non-TBL students). Individual TBL scores of students did not correlate with scores of any other examination. Assessments on clinical reasoning ability, such as CBT, OSCE, and P-SAT scores, were significantly higher in TBL students compared with non-TBL students. Students found TBL to be effective, particularly in areas of problem solving by both individuals and teams, and feedback from specialists. In conclusion, TBL for clinical reasoning is useful in improving clinical reasoning ability in students with PBL experiences with limited clinical exposure.

  12. Sterol Synthesis in Diverse Bacteria

    PubMed Central

    Wei, Jeremy H.; Yin, Xinchi; Welander, Paula V.

    2016-01-01

    Sterols are essential components of eukaryotic cells whose biosynthesis and function has been studied extensively. Sterols are also recognized as the diagenetic precursors of steranes preserved in sedimentary rocks where they can function as geological proxies for eukaryotic organisms and/or aerobic metabolisms and environments. However, production of these lipids is not restricted to the eukaryotic domain as a few bacterial species also synthesize sterols. Phylogenomic studies have identified genes encoding homologs of sterol biosynthesis proteins in the genomes of several additional species, indicating that sterol production may be more widespread in the bacterial domain than previously thought. Although the occurrence of sterol synthesis genes in a genome indicates the potential for sterol production, it provides neither conclusive evidence of sterol synthesis nor information about the composition and abundance of basic and modified sterols that are actually being produced. Here, we coupled bioinformatics with lipid analyses to investigate the scope of bacterial sterol production. We identified oxidosqualene cyclase (Osc), which catalyzes the initial cyclization of oxidosqualene to the basic sterol structure, in 34 bacterial genomes from five phyla (Bacteroidetes, Cyanobacteria, Planctomycetes, Proteobacteria, and Verrucomicrobia) and in 176 metagenomes. Our data indicate that bacterial sterol synthesis likely occurs in diverse organisms and environments and also provides evidence that there are as yet uncultured groups of bacterial sterol producers. Phylogenetic analysis of bacterial and eukaryotic Osc sequences confirmed a complex evolutionary history of sterol synthesis in this domain. Finally, we characterized the lipids produced by Osc-containing bacteria and found that we could generally predict the ability to synthesize sterols. However, predicting the final modified sterol based on our current knowledge of sterol synthesis was difficult. Some bacteria

  13. Ultrafast laser trimming for reduced device leakage in high performance OTFT semiconductors for flexible displays

    NASA Astrophysics Data System (ADS)

    Karnakis, Dimitris; Cooke, Michael D.; Chan, Y. F.; Ogier, Simon D.

    2013-03-01

    Organic semiconductors (OSC) are solution processable synthetic materials with high carrier mobility that promise to revolutionise flexible electronics manufacturing due to their low cost, lightweight and high volume low temperature printing in reel-to-reel (R2R) [1] for applications such as flexible display backplanes (Fig.1), RFID tags, and logic/memory devices. Despite several recent technological advances, organic thin film transistor (OTFT) printing is still not production-ready due to limitations mainly with printing resolution on dimensionally unstable substrates and device leakage that reduces dramatically electrical performance. OTFTs have the source-drain in ohmic contact with the OSC material to lower contact resistance. If they are unpatterned, a leakage pathway from source to drain develops which results in non-optimum on/off currents and not controllable device uniformity (Fig.2). DPSS lasers offer several key advantages for OTFT patterning including maskless, non-contact, dry patterning, scalable large area operation with precision registration, well-suited to R2R manufacturing at overall μm size resolutions. But the thermal management of laser processing is very important as the devices are very sensitive to heat and thermomechanical damage [2]. This paper discusses 343nm picosecond laser ablation trimming of 50nm thick PTAA, TIPS pentacene and other semiconductor compounds on thin 50nm thick metal gold electrodes in a top gate configuration. It is shown that with careful optimisation, a suitable process window exists resulting in clean laser structuring without damage to the underlying layers while also containing laser debris. Several order of magnitude improvements were recorded in on/off currents up to 106 with OSC mobilities of 1 cm2/Vsec, albeit at slightly higher than optimum threshold voltages which support demanding flexible display backplane applications.

  14. Construct Validity and Generalizability of Simulation-Based Objective Structured Clinical Examination Scenarios

    PubMed Central

    Sidi, Avner; Gravenstein, Nikolaus; Lampotang, Samsun

    2014-01-01

    Background It is not known if construct-related validity (progression of scores with different levels of training) and generalizability of Objective Structured Clinical Examination (OSCE) scenarios previously used with non-US graduating anesthesiology residents translate to a US training program. Objective We assessed for progression of scores with training for a validated high-stakes simulation-based anesthesiology examination. Methods Fifty US anesthesiology residents in postgraduate years (PGYs) 2 to 4 were evaluated in operating room, trauma, and resuscitation scenarios developed for and used in a high-stakes Israeli Anesthesiology Board examination, requiring a score of 70% on the checklist for passing (including all critical items). Results The OSCE error rate was lower for PGY-4 than PGY-2 residents in each field, and for most scenarios within each field. The critical item error rate was significantly lower for PGY-4 than PGY-3 residents in operating room scenarios, and for PGY-4 than PGY-2 residents in resuscitation scenarios. The final pass rate was significantly higher for PGY-3 and PGY-4 than PGY-2 residents in operating room scenarios, and also was significantly higher for PGY-4 than PGY-2 residents overall. PGY-4 residents had a better error rate, total scenarios score, general evaluation score, critical items error rate, and final pass rate than PGY-2 residents. Conclusions The comparable error rates, performance grades, and pass rates for US PGY-4 and non-US (Israeli) graduating (PGY-4 equivalent) residents, and the progression of scores among US residents with training level, demonstrate the construct-related validity and generalizability of these high-stakes OSCE scenarios. PMID:26279774

  15. Oxygen storage properties of La1-xSrxFeO3-δ for chemical-looping reactions–An in-situ neutron and synchrotron X-ray study

    DOE PAGESBeta

    Taylor, Daniel D.; Schreiber, Nathaniel J.; Levitas, Benjamin D.; Xu, Wenqian; Rodriguez, Efrain E.; Whitfield, Pamela S.

    2016-05-16

    Oxygen storage materials (OSMs) provide lattice oxygen for a number of chemical-looping reactions including natural gas combustion and methane reforming. La1–xSrxFeO3-δ has shown promise for use as an OSM in methane reforming reactions due to its high product selectivity, fast oxide diffusion, and cycle stability. Here, we investigate the structural evolution of the series La1–xSrxFeO3-δ for x = 0, 1/3, 1/2, 2/3, and 1, using in situ synchrotron X-ray and neutron diffraction, as it is cycled under the conditions of a chemical-looping reactor (methane and oxygen atmospheres). In the compositions x = 1/3, 1/2, 2/3, and 1, we discover anmore » envelope , or temperature range, of oxygen storage capacity (OSC), where oxygen can easily and reversibly be inserted and removed from the OSM. Our in situ X-ray and neutron diffraction results reveal that while samples with higher Sr contents had a higher OSC, those same samples suffered from slower reaction kinetics and some, such as the x = 1/2 and x = 2/3 compositions, had local variations in Sr content, which led to inhomogeneous regions with varying reaction rates. Therefore, we highlight the importance of in situ diffraction studies, and we propose that these measurements are required for the thorough evaluation of future candidate OSMs. Furthermore, we recommend La2/3Sr1/3FeO3-δ as the optimal OSM in the series because its structure remains homogeneous throughout the reaction, and its OSC envelope is similar to that of the higher doped materials.« less

  16. Sterol Synthesis in Diverse Bacteria.

    PubMed

    Wei, Jeremy H; Yin, Xinchi; Welander, Paula V

    2016-01-01

    Sterols are essential components of eukaryotic cells whose biosynthesis and function has been studied extensively. Sterols are also recognized as the diagenetic precursors of steranes preserved in sedimentary rocks where they can function as geological proxies for eukaryotic organisms and/or aerobic metabolisms and environments. However, production of these lipids is not restricted to the eukaryotic domain as a few bacterial species also synthesize sterols. Phylogenomic studies have identified genes encoding homologs of sterol biosynthesis proteins in the genomes of several additional species, indicating that sterol production may be more widespread in the bacterial domain than previously thought. Although the occurrence of sterol synthesis genes in a genome indicates the potential for sterol production, it provides neither conclusive evidence of sterol synthesis nor information about the composition and abundance of basic and modified sterols that are actually being produced. Here, we coupled bioinformatics with lipid analyses to investigate the scope of bacterial sterol production. We identified oxidosqualene cyclase (Osc), which catalyzes the initial cyclization of oxidosqualene to the basic sterol structure, in 34 bacterial genomes from five phyla (Bacteroidetes, Cyanobacteria, Planctomycetes, Proteobacteria, and Verrucomicrobia) and in 176 metagenomes. Our data indicate that bacterial sterol synthesis likely occurs in diverse organisms and environments and also provides evidence that there are as yet uncultured groups of bacterial sterol producers. Phylogenetic analysis of bacterial and eukaryotic Osc sequences confirmed a complex evolutionary history of sterol synthesis in this domain. Finally, we characterized the lipids produced by Osc-containing bacteria and found that we could generally predict the ability to synthesize sterols. However, predicting the final modified sterol based on our current knowledge of sterol synthesis was difficult. Some bacteria

  17. Direct Uniaxial Alignment of a Donor-Acceptor Semiconducting Polymer Using Single-Step Solution Shearing.

    PubMed

    Shaw, Leo; Hayoz, Pascal; Diao, Ying; Reinspach, Julia Antonia; To, John W F; Toney, Michael F; Weitz, R Thomas; Bao, Zhenan

    2016-04-13

    The alignment of organic semiconductors (OSCs) in the active layers of electronic devices can confer desirable properties, such as enhanced charge transport properties due to better ordering, charge transport anisotropy for reduced device cross-talk, and polarized light emission or absorption. The solution-based deposition of highly aligned small molecule OSCs has been widely demonstrated, but the alignment of polymeric OSCs in thin films deposited directly from solution has typically required surface templating or complex pre- or postdeposition processing. Therefore, single-step solution processing and the charge transport enhancement afforded by alignment continue to be attractive. We report here the use of solution shearing to tune the degree of alignment in poly(diketopyrrolopyrrole-terthiophene) thin films by controlling the coating speed. A maximum dichroic ratio of ∼7 was achieved on unpatterned substrates without any additional pre- or postdeposition processing. The degree of polymer alignment was found to be a competition between the shear alignment of polymer chains in solution and the complex thin film drying process. Contrary to previous reports, no charge transport anisotropy was observed because of the small crystallite size relative to the channel length, a meshlike morphology, and the likelihood of increased grain boundaries in the direction transverse to coating. In fact, the lack of aligned morphological structures, coupled with observed anisotropy in X-ray diffraction data, suggests the alignment of polymer molecules in both the crystalline and the amorphous regions of the films. The shear speed at which maximum dichroism is achieved can be controlled by altering deposition parameters such as temperature and substrate treatment. Modest changes in molecular weight showed negligible effects on alignment, while longer polymer alkyl side chains were found to reduce the degree of alignment. This work demonstrates that solution shearing can be used

  18. Do medical students’ scores using different assessment instruments predict their scores in clinical reasoning using a computer-based simulation?

    PubMed Central

    Fida, Mariam; Kassab, Salah Eldin

    2015-01-01

    Purpose The development of clinical problem-solving skills evolves over time and requires structured training and background knowledge. Computer-based case simulations (CCS) have been used for teaching and assessment of clinical reasoning skills. However, previous studies examining the psychometric properties of CCS as an assessment tool have been controversial. Furthermore, studies reporting the integration of CCS into problem-based medical curricula have been limited. Methods This study examined the psychometric properties of using CCS software (DxR Clinician) for assessment of medical students (n=130) studying in a problem-based, integrated multisystem module (Unit IX) during the academic year 2011–2012. Internal consistency reliability of CCS scores was calculated using Cronbach’s alpha statistics. The relationships between students’ scores in CCS components (clinical reasoning, diagnostic performance, and patient management) and their scores in other examination tools at the end of the unit including multiple-choice questions, short-answer questions, objective structured clinical examination (OSCE), and real patient encounters were analyzed using stepwise hierarchical linear regression. Results Internal consistency reliability of CCS scores was high (α=0.862). Inter-item correlations between students’ scores in different CCS components and their scores in CCS and other test items were statistically significant. Regression analysis indicated that OSCE scores predicted 32.7% and 35.1% of the variance in clinical reasoning and patient management scores, respectively (P<0.01). Multiple-choice question scores, however, predicted only 15.4% of the variance in diagnostic performance scores (P<0.01), while students’ scores in real patient encounters did not predict any of the CCS scores. Conclusion Students’ scores in OSCE are the most important predictors of their scores in clinical reasoning and patient management using CCS. However, real patient

  19. Sterol Synthesis in Diverse Bacteria.

    PubMed

    Wei, Jeremy H; Yin, Xinchi; Welander, Paula V

    2016-01-01

    Sterols are essential components of eukaryotic cells whose biosynthesis and function has been studied extensively. Sterols are also recognized as the diagenetic precursors of steranes preserved in sedimentary rocks where they can function as geological proxies for eukaryotic organisms and/or aerobic metabolisms and environments. However, production of these lipids is not restricted to the eukaryotic domain as a few bacterial species also synthesize sterols. Phylogenomic studies have identified genes encoding homologs of sterol biosynthesis proteins in the genomes of several additional species, indicating that sterol production may be more widespread in the bacterial domain than previously thought. Although the occurrence of sterol synthesis genes in a genome indicates the potential for sterol production, it provides neither conclusive evidence of sterol synthesis nor information about the composition and abundance of basic and modified sterols that are actually being produced. Here, we coupled bioinformatics with lipid analyses to investigate the scope of bacterial sterol production. We identified oxidosqualene cyclase (Osc), which catalyzes the initial cyclization of oxidosqualene to the basic sterol structure, in 34 bacterial genomes from five phyla (Bacteroidetes, Cyanobacteria, Planctomycetes, Proteobacteria, and Verrucomicrobia) and in 176 metagenomes. Our data indicate that bacterial sterol synthesis likely occurs in diverse organisms and environments and also provides evidence that there are as yet uncultured groups of bacterial sterol producers. Phylogenetic analysis of bacterial and eukaryotic Osc sequences confirmed a complex evolutionary history of sterol synthesis in this domain. Finally, we characterized the lipids produced by Osc-containing bacteria and found that we could generally predict the ability to synthesize sterols. However, predicting the final modified sterol based on our current knowledge of sterol synthesis was difficult. Some bacteria

  20. Effect of oxidant exposure on the release of intracellular microcystin, MIB, and geosmin from three cyanobacteria species.

    PubMed

    Wert, Eric C; Korak, Julie A; Trenholm, Rebecca A; Rosario-Ortiz, Fernando L

    2014-04-01

    The release of intracellular microcystin-LR (MC-LR), 2-methylisoborneol (MIB), and geosmin was investigated after the oxidation of three cyanobacteria (Microcystis aeruginosa (MA), Oscillatoria sp. (OSC), and Lyngbya sp. (LYN)). During the oxidation of 200,000 cells/mL of MA, release of intracellular MC-LR exceeded the World Health Organization (WHO) guideline of 1 μg/L during the lowest oxidant exposures (CT) tested: ozone (0 mg-min/L, below the ozone demand), chlorine (<40 mg-min/L), chlorine dioxide (<560 mg-min/L), and chloramine (<640 mg-min/L). As the CT increased, ozone, chlorine, and chlorine dioxide were able to oxidize the released MC-LR. During the oxidation of OSC (2800 cells/mL) and LYN (1600 cells/mL), release of intracellular MIB and geosmin exceeded reported threshold odor values after exposure to chlorine, chlorine dioxide, and chloramine, which have low reactivity with these taste and odor compounds. Ozone oxidation of OSC yielded an increase in MIB concentration at lower exposures (≤2.9 mg-min/L), likely due to insufficient oxidation by hydroxyl radicals. The release of intracellular organic matter (IOM) was also measured to determine the potential of bulk measurements to act as a surrogate for cyanotoxins and metabolite release. In all cases, the dissolved organic carbon (DOC) release was less than 0.25 mgC/L, which lacked the sensitivity to indicate the release of MC-LR, MIB, or geosmin. The fluorescence index proved to be a more sensitive indicator of intracellular organic matter release than DOC for MA. These results illustrate that toxic or odorous compounds may be released from cyanobacteria cells during oxidation processes with minimal changes in the DOC concentration.

  1. Direct Uniaxial Alignment of a Donor-Acceptor Semiconducting Polymer Using Single-Step Solution Shearing.

    PubMed

    Shaw, Leo; Hayoz, Pascal; Diao, Ying; Reinspach, Julia Antonia; To, John W F; Toney, Michael F; Weitz, R Thomas; Bao, Zhenan

    2016-04-13

    The alignment of organic semiconductors (OSCs) in the active layers of electronic devices can confer desirable properties, such as enhanced charge transport properties due to better ordering, charge transport anisotropy for reduced device cross-talk, and polarized light emission or absorption. The solution-based deposition of highly aligned small molecule OSCs has been widely demonstrated, but the alignment of polymeric OSCs in thin films deposited directly from solution has typically required surface templating or complex pre- or postdeposition processing. Therefore, single-step solution processing and the charge transport enhancement afforded by alignment continue to be attractive. We report here the use of solution shearing to tune the degree of alignment in poly(diketopyrrolopyrrole-terthiophene) thin films by controlling the coating speed. A maximum dichroic ratio of ∼7 was achieved on unpatterned substrates without any additional pre- or postdeposition processing. The degree of polymer alignment was found to be a competition between the shear alignment of polymer chains in solution and the complex thin film drying process. Contrary to previous reports, no charge transport anisotropy was observed because of the small crystallite size relative to the channel length, a meshlike morphology, and the likelihood of increased grain boundaries in the direction transverse to coating. In fact, the lack of aligned morphological structures, coupled with observed anisotropy in X-ray diffraction data, suggests the alignment of polymer molecules in both the crystalline and the amorphous regions of the films. The shear speed at which maximum dichroism is achieved can be controlled by altering deposition parameters such as temperature and substrate treatment. Modest changes in molecular weight showed negligible effects on alignment, while longer polymer alkyl side chains were found to reduce the degree of alignment. This work demonstrates that solution shearing can be used

  2. Does Emotional Intelligence at Medical School Admission Predict Future Academic Performance?

    PubMed Central

    Leddy, John J.; Wood, Timothy J.; Puddester, Derek; Moineau, Geneviève

    2014-01-01

    Purpose Medical school admissions committees are increasingly considering noncognitive measures like emotional intelligence (EI) in evaluating potential applicants. This study explored whether scores on an EI abilities test at admissions predicted future academic performance in medical school to determine whether EI could be used in making admissions decisions. Method The authors invited all University of Ottawa medical school applicants offered an interview in 2006 and 2007 to complete the Mayer–Salovey–Caruso EI Test (MSCEIT) at the time of their interview (105 and 101, respectively), then again at matriculation (120 and 106, respectively). To determine predictive validity, they correlated MSCEIT scores to scores on written examinations and objective structured clinical examinations (OSCEs) administered during the four-year program. They also correlated MSCEIT scores to the number of nominations for excellence in clinical performance and failures recorded over the four years. Results The authors found no significant correlations between MSCEIT scores and written examination scores or number of failures. The correlations between MSCEIT scores and total OSCE scores ranged from 0.01 to 0.35; only MSCEIT scores at matriculation and OSCE year 4 scores for the 2007 cohort were significantly correlated. Correlations between MSCEIT scores and clinical nominations were low (range 0.12–0.28); only the correlation between MSCEIT scores at matriculation and number of clinical nominations for the 2007 cohort were statistically significant. Conclusions EI, as measured by an abilities test at admissions, does not appear to reliably predict future academic performance. Future studies should define the role of EI in admissions decisions. PMID:24556771

  3. Cholesterol synthesis inhibitor RO 48-8071 suppresses transcriptional activity of human estrogen and androgen receptor.

    PubMed

    Mafuvadze, Benford; Liang, Yayun; Hyder, Salman M

    2014-10-01

    Breast cancer cells express enzymes that convert cholesterol, the synthetic precursor of steroid hormones, into estrogens and androgens, which then drive breast cancer cell proliferation. In the present study, we sought to determine whether oxidosqualene cyclase (OSC), an enzyme in the cholesterol biosynthetic pathway, may be targeted to suppress progression of breast cancer cells. In previous studies, we showed that the OSC inhibitor RO 48-8071 (RO) may be a ligand which could potentially be used to control the progression of estrogen receptor-α (ERα)-positive breast cancer cells. Herein, we showed, by real-time PCR analysis of mRNA from human breast cancer biopsies, no significant differences in OSC expression at various stages of disease, or between tumor and normal mammary cells. Since the growth of hormone-responsive tumors is ERα-dependent, we conducted experiments to determine whether RO affects ERα. Using mammalian cells engineered to express human ERα or ERβ protein, together with an ER-responsive luciferase promoter, we found that RO dose-dependently inhibited 17β-estradiol (E2)-induced ERα responsive luciferase activity (IC50 value, ~10 µM), under conditions that were non-toxic to the cells. RO was less effective against ERβ-induced luciferase activity. Androgen receptor (AR) mediated transcriptional activity was also reduced by RO. Notably, while ERα activity was reduced by atorvastatin, the HMG-CoA reductase inhibitor did not influence AR activity, showing that RO possesses broader antitumor properties. Treatment of human BT-474 breast cancer cells with RO reduced levels of estrogen-induced PR protein, confirming that RO blocks ERα activity in tumor cells. Our findings demonstrate that an important means by which RO suppresses hormone-dependent growth of breast cancer cells is through its ability to arrest the biological activity of ERα. This warrants further investigation of RO as a potential therapeutic agent for use against hormone

  4. Suppression of intensity transition artifacts in statistical x-ray computer tomography reconstruction through radon inversion initialization.

    PubMed

    Zbijewski, Wojciech; Beekman, Freek J

    2004-01-01

    Statistical reconstruction (SR) methods provide a general and flexible framework for obtaining tomographic images from projections. For several applications SR has been shown to outperform analytical algorithms in terms of resolution-noise trade-off achieved in the reconstructions. A disadvantage of SR is the long computational time required to obtain the reconstructions, in particular when large data sets characteristic for x-ray computer tomography (CT) are involved. As was shown recently, by combining statistical methods with block iterative acceleration schemes [e.g., like in the ordered subsets convex (OSC) algorithm], the reconstruction time for x-ray CT applications can be reduced by about two orders of magnitude. There are, however, some factors lengthening the reconstruction process that hamper both accelerated and standard statistical algorithms to similar degree. In this simulation study based on monoenergetic and scatter-free projection data, we demonstrate that one of these factors is the extremely high number of iterations needed to remove artifacts that can appear around high-contrast structures. We also show (using the OSC method) that these artifacts can be adequately suppressed if statistical reconstruction is initialized with images generated by means of Radon inversion algorithms like filtered back projection (FBP). This allows the reconstruction time to be shortened by even as much as one order of magnitude. Although the initialization of the statistical algorithm with FBP image introduces some additional noise into the first iteration of OSC reconstruction, the resolution-noise trade-off and the contrast-to-noise ratio of final images are not markedly compromised.

  5. Evaluation of cytotoxicity, genotoxicity and teratogenicity of marine sediments from Qingdao coastal areas using in vitro fish cell assay, comet assay and zebrafish embryo test.

    PubMed

    Yang, Fan; Zhang, Qianqian; Guo, Huarong; Zhang, Shicui

    2010-10-01

    Marine sediments are often a final sink for numerous anthropogenic contaminants and may impose serious effects on benthic organisms and ecosystem. An in vitro cell assay using a cell line derived from flounder gill (FG) cells, an in vitro comet assay in FG cells, and an in vitro zebrafish embryo assay were used to evaluate the in vitro cytotoxicity (measured by MTT reduction), genotoxicity and teratogenicity of crude sediment extracts of Li Cang (LC), Zhan Qiao (ZQ) and Olympic Sailing Center (OSC) from Qingdao coastal area. Sediments from the three sites displayed different cytotoxicity, genotoxicity and teratogenicity potencies; however, all three assays yielded similar LOECs (lowest observed effect concentration) for each site, suggesting that the assays were equally sensitive to and suitable for initial screening of the LOECs of marine sediments. The cytotoxicity, genotoxicity and teratogenicity for these three sampling sites were in the same order of LC>ZQ>OSC, indicating different degrees of contamination. Interestingly, trials with the three sediment extracts at the doses inducing a similar cytotoxicity as evaluated with MTT reduction did not produce similar genotoxicity and teratogenicity, with the genotoxic and teratogenic activities of LC and ZQ extracts being markedly higher than those of OSC sediments. These findings indicate that cytotoxicity does not form a fully equivalent toxicity index with that of genotoxicity and teratogenicity. Therefore, in order to assess the true toxic potential of marine sediments, all three assays should be performed. Analysis of 16 EPA (US Environmental Protection Agency) priority PAHs in these three sediment samples showed a clear correlation between PAH concentrations and sediment toxicities, with a higher PAH content corresponding to higher toxicity although PAHs are surely not the only cause.

  6. Diallyl trisulfide-induced apoptosis in human prostate cancer cells involves c-Jun N-terminal kinase and extracellular-signal regulated kinase-mediated phosphorylation of Bcl-2.

    PubMed

    Xiao, Dong; Choi, Sunga; Johnson, Daniel E; Vogel, Victor G; Johnson, Candace S; Trump, Donald L; Lee, Yong J; Singh, Shivendra V

    2004-07-22

    Garlic-derived organosulfides (OSCs) including diallyl trisulfide (DATS) are highly effective in affording protection against chemically induced cancer in animals. Evidence is also mounting to indicate that some naturally occurring OSCs can suppress proliferation of cancer cells by causing apoptosis, but the sequence of events leading to proapoptotic effect of OSCs is poorly defined. Using PC-3 and DU145 human prostate cancer cells as a model, we now demonstrate that DATS is a significantly more potent apoptosis inducer than diallyl sulfide (DAS) or diallyl disulfide (DADS). DATS-induced apoptosis in PC-3 cells was associated with phosphorylation of Bcl-2, reduced Bcl-2 : Bax interaction, and cleavage of procaspase-9 and -3. Bcl-2 overexpressing PC-3 cells were significantly more resistant to apoptosis induction by DATS compared with vector-transfected control cells. DATS treatment resulted in activation of extracellular-signal regulated kinase 1/2 (ERK1/2) and c-jun N-terminal kinase 1 (JNK1) and/or JNK2, but not p38 mitogen-activated protein kinase. Phosphorylation of Bcl-2 in DATS-treated PC-3 cells was fully blocked in the presence of JNK-specific inhibitor SP600125. Moreover, JNK inhibitor afforded significant protection against DATS-induced apoptosis in both cells. DATS-induced Bcl-2 phosphorylation and apoptosis were partially attenuated by pharmacological inhibition of ERK1/2 using PD98059 or U0126. Overexpression of catalase inhibited DATS-mediated activation of JNK1/2, but not ERK1/2, and apoptosis induction in DU145 cells suggesting involvement of hydrogen peroxide as a second messenger in DATS-induced apoptosis. In conclusion, our data point towards important roles for Bcl-2, JNK and ERK in DATS-induced apoptosis in human prostate cancer cells.

  7. An Obvious Improvement in the Performance of Ternary Organic Solar Cells with "Guest" Donor Present at the "Host" Donor/Acceptor Interface.

    PubMed

    Bi, Peng-Qing; Wu, Bo; Zheng, Fei; Xu, Wei-Long; Yang, Xiao-Yu; Feng, Lin; Zhu, Furong; Hao, Xiao-Tao

    2016-09-01

    A small-molecule material, 7,7-(4,4-bis(2-ethylhexyl)-4H-silolo[3,2-b:4,5-b']dithiophene-2,6-diyl)bis(6-fluoro-4-(5'-hexyl-[2,2'-bithiophen]-5-yl)benzo-[c] [1,2,5]thiadiazole) (p-DTS(FBTTH2)2), was used to modify the morphology and electron-transport properties of the polymer blend of poly(3-hexythiophene) (P3HT) and [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) bulk heterojunctions. As a result, a 24% increase in the power-conversion efficiency (PCE) of the p-DTS(FBTTH2)2:P3HT:PC71BM ternary organic solar cells (OSCs) is obtained. The improvement in the performance of OSCs is attributed to the constructive energy cascade path in the ternary system that benefits an efficient Förster resonance energy/charge transfer process between P3HT and p-DTS(FBTTH2)2, thereby improving photocurrent generation. It is shown that p-DTS(FBTTH2)2 molecules engage themselves at the P3HT/PC71BM interface. A combination of absorption enhancement, efficient energy transfer process, and ordered nanomorphology in the ternary system favors exciton dissociation and charge transportation in the polymer bulk heterojunction. The finding of this work reveals that distribution of the appropriate "guest" donor at the "host" donor/acceptor interface is an effective approach for attaining high-performance OSCs. PMID:27525544

  8. Seismic Structure of the Shallow Mantle Beneath the Endeavor Segment of the Juan de Fuca Ridge

    NASA Astrophysics Data System (ADS)

    VanderBeek, B. P.; Toomey, D. R.; Hooft, E. E.; Wilcock, W. S.; Weekly, R. T.; Soule, D. C.

    2013-12-01

    We present tomographic images of the seismic structure of the shallow mantle beneath the intermediate-spreading Endeavor segment of the Juan de Fuca ridge. Our results provide insight into the relationship between magma supply from the mantle and overlying ridge crest processes. We use seismic energy refracted below the Moho (Pn), as recorded by the Endeavor tomography (ETOMO) experiment, to image the anisotropic and isotropic P wave velocity structure. The ETOMO experiment was an active source seismic study conducted in August 2009 as part of the RIDGE2000 science program. The experimental area extends 100 km along- and 60 km across-axis and encompasses active hydrothermal vent fields near the segment center, the eastern end of the Heck seamount chain, and two overlapping spreading centers (OSCs) at either end of the segment. Previous tomographic analyses of seismic arrivals refracted through the crust (Pg), and reflected off the Moho (PmP), constrain a three-dimensional starting model of crustal velocity and thickness. These Pg and PmP arrivals are incorporated in our inversion of Pn travel-time data to further constrain the isotropic and anisotropic mantle velocity structure. Preliminary results reveal three distinct mantle low-velocity zones, inferred as regions of mantle melt delivery to the base of the crust, that are located: (i) off-axis near the segment center, (ii) beneath the Endeavor-West Valley OSC, and (iii) beneath the Cobb OSC near Split Seamount. The mantle anomalies are located at intervals of ~30 to 40 km along-axis and the low velocity anomalies beneath the OSCs are comparable in magnitude to the one located near the segment center. The direction of shallow mantle flow is inferred from azimuthal variations in Pn travel-time residuals relative to a homogeneous isotropic mantle. Continuing analysis will focus on constraining spatial variations in the orientation of azimuthal anisotropy. On the basis of our results, we will discuss the transport of

  9. Problem on the United States Continental Shelf - measuring the environmental {open_quotes}effectiveness{close_quotes} of the Outer Continental Shelf Act (OCSA)

    SciTech Connect

    Dubner, B.H.

    1994-12-31

    This article reviews the interplay of environmental standard with oil and gas leasing on the Outer Continental Shelf (OSC) in order to determine if the marine environment is really protected by the interplay of domestic legislation. The 1982 LOS treaty leaves environmental protection to State (domestic) regulation. There is no customary law regarding this type of domestic shelf regulation. The main problem is measuring the {open_quotes}effectiveness{close_quotes} of our domestic shelf legislation. For example, do we simply review effectiveness in terms of controlling operational damage or in terms of environmental injury caused by catastrophic accidents?

  10. RHIC spin flipper commissioning results

    SciTech Connect

    Bai M.; Roser, T.; Dawson, C.; Kewisch, J.; Makdisi, Y.; Oddo, P.; Pai, C.; Pile, P.

    2012-05-20

    The five AC dipole RHIC spin flipper design in the RHIC Blue ring was first tested during the RHIC 2012 polarized proton operation. The advantage of this design is to eliminate the vertical coherent betatron oscillations outside the spin flipper. The closure of each ac dipole vertical bump was measured with orbital response as well as spin. The effect of the rotating field on the spin motion by the spin flipper was also confirmed by measuring the suppressed resonance at Q{sub s} = 1 - Q{sub osc}.

  11. A "roller-wheel" Pt-containing small molecule that outperforms its polymer analogs in organic solar cells

    DOE PAGESBeta

    He, Wenhan; Wu, Qin; Livshits, Maksim Y.; Dickie, Diane A.; Yang, Jianzhong; Quinnett, Rachel; Rack, Jeffrey R.; Qin, Yang

    2016-05-23

    A novel Pt-bisacetylide small molecule (Pt-SM) featuring “roller-wheel” geometry was synthesized and characterized. When compared with conventional Pt-containing polymers and small molecules having “dumbbell” shaped structures, Pt-SM displays enhanced crystallinity and intermolecular π–π interactions, as well as favorable panchromatic absorption behaviors. Furthermore, organic solar cells (OSCs) employing Pt-SM achieve power conversion efficiencies (PCEs) up to 5.9%, the highest reported so far for Pt-containing polymers and small molecules.

  12. World Climate Research Programme (WCRP) Open Science Conference Final Report

    SciTech Connect

    Amy Honchar

    2012-11-07

    Travel support was provided for a range of invited speakers, students, early-career, and developing-country, and key scientists who required financial assistance to participate, and would otherwise be unable to attend, to contribute to, and benefit from, this important event. This support also allowed participants to present their research findings, provide input to WCRP planning and plans, and encourage collaboration with other research scientists. In particular, the participation and engagement of regional scientists in the OSC helped to ensure communication and advocacy in identifying the climate research needs of the region and their inclusion in the WCRP long-range research priorities.

  13. Performance tuned radioisotope thermophotovoltaic space power system

    NASA Astrophysics Data System (ADS)

    Horne, W. E.; Morgan, M. D.; Saban, S. B.

    1998-01-01

    The trend in space exploration is to use many small, low-cost, special-purpose satellites instead of the large, high-cost, multipurpose satellites used in the past. As a result of this new trend, there is a need for lightweight, efficient, and compact radioisotope fueled electrical power generators. This paper presents an improved design for a radioisotope thermophotovoltaic (RTPV) space power system in the 10 W to 20 W class which promises up to 37.6 watts at 30.1% efficiency and 25 W/kg specific power. The RTPV power system concept has been studied and compared to radioisotope thermoelectric generators (RTG) radioisotope, Stirling generators and alkali metal thermal electric conversion (AMTEC) generators (Schock, 1995). The studies indicate that RTPV has the potential to be the lightest weight, most efficient and most reliable of the three concepts. However, in spite of the efficiency and light weight, the size of the thermal radiator required to eliminate excess heat from the PV cells and the lack of actual system operational performance data are perceived as obstacles to RTPV acceptance for space applications. Between 1994 and 1997 EDTEK optimized the key converter components for an RTPV generator under Department of Energy (DOE) funding administered via subcontracts to Orbital Sciences Corporation (OSC) and EG&G Mound Applied Technologies Laboratory (Horne, 1995). The optimized components included a resonant micromesh infrared bandpass filter, low-bandgap GaSb PV cells and cell arrays. Parametric data from these components were supplied to OSC who developed and analyzed the performance of 100 W, 20 W, and 10 W RTPV generators. These designs are described in references (Schock 1994, 1995 and 1996). Since the performance of each class of supply was roughly equivalent and simply scaled with size, this paper will consider the OSC 20 W design as a baseline. The baseline 20-W RTPV design was developed by Schock, et al of OSC and has been presented elsewhere. The

  14. Age-dependent role of steroids in the regulation of growth of the hen follicular wall

    PubMed Central

    2010-01-01

    Background The ovaries are the primary targets of senescence effects in mammalian and avian species. In the present study, relationships between reproductive aging, sex steroids and the growth pattern of the pre-ovulatory follicle wall were investigated using young hens with long clutch (YLC), old hens with long clutch (OLC), old hens with short clutch (OSC), and old hens with interrupted long clutch (OILC). Methods Experiment 1: Hens were sacrificed 1.5 and 14.5 h after ovulation. Experiment 2: YLC and OILC hens were sacrificed 3.5 h after treatments with LH and/or aminoglutethimide (AG), an inhibitor of steroid synthesis. Volumes of pre-ovulatory follicles (F1-F5) and plasma concentrations of ovarian steroids were determined. Experiment 3: Granulosa and theca cells from F3 follicles of OSC and/or YLC hens were exposed in vitro to estradiol-17beta (E2), testosterone (T) and LH and the proliferative activity of the cells was examined using CellTiter 96 Aqueous One Solution Assay. Results In YLC and OLC groups, the total volume of F1-F5 follicles rose between 1.5 and 14.5 h after ovulation (P < 0.01), negatively correlating with the plasma level of E2 (P < 0.01). There was no growth of pre-ovulatory follicles in the middle of the ovulatory cycle in the OSC group, with a positive correlation being present between E2 and the follicular volume (P < 0.05). In young hens, AG caused a rise in the total follicular volume. This rise was associated with a fall in E2 (r = -0.54, P < 0.05). E2 enhanced proliferation of granulosa cells from YLC and OSC groups. The proliferative activity of granulosa and theca cells of YLC hens depended on the interaction between T and LH (P < 0.01). Conclusions These data indicate for the first time that the growth pattern of pre-ovulatory follicles during the ovulatory cycle changes in the course of reproductive aging. E2 seems to play a dual role in this adjustment; it stimulates the growth of the follicular wall in reproductive aged hens

  15. The Telecommunications and Data Acquisition Report

    NASA Technical Reports Server (NTRS)

    Yuen, Joseph H. (Editor)

    1994-01-01

    This quarterly publication provides archival reports on developments in programs managed by JPL's Telecommunications and Mission Operations Directorate (TMOD), which now includes the former Telecommunications and Data Acquisition (TDA) Office. In space communications, radio navigation, radio science, and ground-based radio and radar astronomy, it reports on activities of the Deep Space Network (DS) in planning, supporting research and technology, implementation, and operations. Also included are standards activity at JPL for space data and information systems and reimbursable DSN work performed for other space agencies through NASA. The preceding work is all performed for NASA's Office of Space Communications (OSC).

  16. DOPS (Direct Observation of Procedural Skills) in undergraduate skills-lab: Does it work? Analysis of skills-performance and curricular side effects

    PubMed Central

    Profanter, Christoph; Perathoner, Alexander

    2015-01-01

    Objective: Sufficient teaching and assessing clinical skills in the undergraduate setting becomes more and more important. In a surgical skills-lab course at the Medical University of Innsbruck fourth year students were teached with DOPS (direct observation of procedural skills). We analyzed whether DOPS worked or not in this setting, which performance levels could be reached compared to tutor teaching (one tutor, 5 students) and which curricular side effects could be observed. Methods: In a prospective randomized trial in summer 2013 (April – June) four competence-level-based skills were teached in small groups during one week: surgical abdominal examination, urethral catheterization (phantom), rectal-digital examination (phantom), handling of central venous catheters. Group A was teached with DOPS, group B with a classical tutor system. Both groups underwent an OSCE (objective structured clinical examination) for assessment. 193 students were included in the study. Altogether 756 OSCE´s were carried out, 209 (27,6%) in the DOPS- and 547 (72,3%) in the tutor-group. Results: Both groups reached high performance levels. In the first month there was a statistically significant difference (p<0,05) in performance of 95% positive OSCE items in the DOPS-group versus 88% in the tutor group. In the following months the performance rates showed no difference anymore and came to 90% in both groups. In practical skills the analysis revealed a high correspondence between positive DOPS (92,4%) and OSCE (90,8%) results. Discussion: As shown by our data DOPS furnish high performance of clinical skills and work well in the undergraduate setting. Due to the high correspondence of DOPS and OSCE results DOPS should be considered as preferred assessment tool in a students skills-lab. The approximation of performance-rates within the months after initial superiority of DOPS could be explained by an interaction between DOPS and tutor system: DOPS elements seem to have improved

  17. Guidance for use of the oil spill liability trust fund

    SciTech Connect

    1997-02-01

    This guidance document has been prepared to assist On-Scene Coordinators (OSCs) and financial management personnel in accessing and using the Oil Spill Liability Trust Fund (OSLTF) in orders to conduct oil pollution removal actions under Section 311(c) of the Clean Water Act (CWA) and Section 1012 of the Oil Pollution Act of 1990 (OPA), and fully accounting for OSLTF funds. This document details the requirments and procedures for use of the OSLTF that are described in the Memorandum of Understanding between the U.S. Environmental Protection Agency and the U.S. Coast Guard for use of the Oil Spill Liability Trust Fund (MOU).

  18. The Telecommunications and Data Acquisition

    NASA Technical Reports Server (NTRS)

    Posner, Edward C. (Editor)

    1992-01-01

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

  19. The Telecommunications and Data Acquisition Report

    NASA Technical Reports Server (NTRS)

    Yuen, Joseph H. (Editor)

    1995-01-01

    This quarterly publication provides archival reports on developments in programs managed by JPL's Telecommunications and Mission Operations Directorate (TMOD), which now includes the former Telecommunications and Data Acquisition (TDA) Office. In space communications, radio navigation, radio science, and ground-based radio and radar astronomy, it reports on activities of the Deep Space Network (DSN) in planning, supporting research and technology, implementation, and operations. Also included are standards activity at JPL for space data and information systems and reimbursable DSN work performed for other space agencies through NASA. The preceding work is all performed for NASA's Office of Space Communications (OSC).

  20. Three-Year Change in the Wellbeing of Orphaned and Separated Children in Institutional and Family-Based Care Settings in Five Low- and Middle-Income Countries

    PubMed Central

    Whetten, Kathryn; Ostermann, Jan; Pence, Brian W.; Whetten, Rachel A.; Messer, Lynne C.; Ariely, Sumedha; O'Donnell, Karen; Wasonga, Augustine I.; Vann, Vanroth; Itemba, Dafrosa; Eticha, Misganaw; Madan, Ira; Thielman, Nathan M.

    2014-01-01

    Background With more than 2 million children living in group homes, or “institutions”, worldwide, the extent to which institution-based caregiving negatively affects development and wellbeing is a central question for international policymakers. Methods A two-stage random sampling methodology identified community representative samples of 1,357 institution-dwelling orphaned and separated children (OSC) and 1,480 family-dwelling OSC aged 6–12 from 5 low and middle income countries. Data were collected from children and their primary caregivers. Survey-analytic techniques and linear mixed effects models describe child wellbeing collected at baseline and at 36 months, including physical and emotional health, growth, cognitive development and memory, and the variation in outcomes between children, care settings, and study sites. Findings At 36-month follow-up, institution-dwelling OSC had statistically significantly higher height-for-age Z-scores and better caregiver-reported physical health; family-dwelling OSC had fewer caregiver-reported emotional difficulties. There were no statistically significant differences between the two groups on other measures. At both baseline and follow-up, the magnitude of the differences between the institution- and family-dwelling groups was small. Relatively little variation in outcomes was attributable to differences between sites (11–27% of total variation) or care settings within sites (8–14%), with most variation attributable to differences between children within settings (60–75%). The percent of variation in outcomes attributable to the care setting type, institution- versus family-based care, ranged from 0–4% at baseline, 0–3% at 36-month follow-up, and 0–4% for changes between baseline and 36 months. Interpretation These findings contradict the hypothesis that group home placement universally adversely affects child wellbeing. Without substantial improvements in and support for family settings, the removal of