Sample records for parent-based intervention pbi

  1. Newborn Parent Based Intervention to Increase Child Safety Seat Use

    Directory of Open Access Journals (Sweden)

    Xiangxiang Liu


    Full Text Available This paper intends to assess the effect of a maternity department intervention on improvement of knowledge and use of child safety seats (CSS among newborn parents. An intervention study included three groups (one education plus free CSS intervention group, one education only group, and one control group. The participants were parents of newborns in the maternity department of two hospitals. Both of the intervention groups received a folded pamphlet of child passenger safety, a height chart and standardized safety education during their hospital stay after giving birth. The education plus free CSS intervention group received an additional free CSS and professional installation training at hospital discharge. The control group received a pamphlet with educational information about nutrition and food safety. Three months after enrollment, a telephone follow-up was conducted among participants in the three groups. Data on child passenger safety knowledge, risky driving behaviors, and use of CSS were evaluated before and after the intervention. A total of 132 newborn parents were enrolled in the study; of those, 52 (39.4% were assigned into the education plus free CSS intervention group, 44 (33.3% were in the education intervention only group, and 36 (27.3% were in the control group. No significant differences existed in demographics among the three groups. There was a significant difference in newborn parents’ child passenger safety knowledge and behaviors in the three groups before and after the intervention. In addition, the CSS use increased significantly in the education plus free CSS group after the intervention compared to parents in the education only or control groups. Education on safety, combined with a free CSS and professional installation training, were effective at increasing newborn parents’ knowledge and use of CSS. Future studies with larger sample sizes and longer follow-up are needed to determine a long-term effect of the

  2. Newborn Parent Based Intervention to Increase Child Safety Seat Use (United States)

    Liu, Xiangxiang; Yang, Jingzhen; Cheng, Fuyuan; Li, Liping


    This paper intends to assess the effect of a maternity department intervention on improvement of knowledge and use of child safety seats (CSS) among newborn parents. An intervention study included three groups (one education plus free CSS intervention group, one education only group, and one control group). The participants were parents of newborns in the maternity department of two hospitals. Both of the intervention groups received a folded pamphlet of child passenger safety, a height chart and standardized safety education during their hospital stay after giving birth. The education plus free CSS intervention group received an additional free CSS and professional installation training at hospital discharge. The control group received a pamphlet with educational information about nutrition and food safety. Three months after enrollment, a telephone follow-up was conducted among participants in the three groups. Data on child passenger safety knowledge, risky driving behaviors, and use of CSS were evaluated before and after the intervention. A total of 132 newborn parents were enrolled in the study; of those, 52 (39.4%) were assigned into the education plus free CSS intervention group, 44 (33.3%) were in the education intervention only group, and 36 (27.3%) were in the control group. No significant differences existed in demographics among the three groups. There was a significant difference in newborn parents’ child passenger safety knowledge and behaviors in the three groups before and after the intervention. In addition, the CSS use increased significantly in the education plus free CSS group after the intervention compared to parents in the education only or control groups. Education on safety, combined with a free CSS and professional installation training, were effective at increasing newborn parents’ knowledge and use of CSS. Future studies with larger sample sizes and longer follow-up are needed to determine a long-term effect of the intervention. PMID

  3. Evaluating complex health financing interventions: using mixed methods to inform further implementation of a novel PBI intervention in rural Malawi. (United States)

    McMahon, Shannon A; Brenner, Stephan; Lohmann, Julia; Makwero, Christopher; Torbica, Aleksandra; Mathanga, Don P; Muula, Adamson S; De Allegri, Manuela


    Gaps remain in understanding how performance-based incentive (PBI) programs affect quality of care and service quantity, whether programs are cost effective and how programs could be tailored to meet client and provider needs while remaining operationally viable. In 2014, Malawi's Ministry of Health launched the Service Delivery Integration-PBI (SSDI-PBI) program. The program is unique in that no portion of performance bonuses are paid to individual health workers, and it shifts responsibility for infrastructure and equipment procurement from facility staff to implementing partners. This protocol outlines an approach that analyzes processes and outcomes, considers expected and unexpected consequences of the program and frames the program's outputs relative to its costs. Findings from this evaluation will inform the intended future scale-up of PBI in Malawi. This study employs a prospective controlled before-and-after triangulation design to assess effects of the PBI program by analyzing quantitative and qualitative data from intervention and control facilities. Guided by a theoretical framework, the evaluation consists of four main components: service provision, health worker motivation, implementation processes and costing. Quality and access outcomes are assessed along four dimensions: (1) structural elements (related to equipment, drugs, staff); (2) process elements (providers' compliance with standards); (3) outputs (service utilization); (4) experiential elements (experiences of service delivery). The costing component includes costs related to start-up, ongoing management, and the cost of incentives themselves. The cost analysis considers costs incurred within the Ministry of Health, funders, and the implementing agency. The evaluation relies on primary data (including interviews and surveys) and secondary data (including costing and health management information system data). Through the lens of a PBI program, we illustrate how complex interventions can be

  4. Parent-based interventions for preventing or reducing adolescent substance use: A systematic literature review

    NARCIS (Netherlands)

    Kuntsche, S.; Kuntsche, E.N.


    Despite the increasing relevance of peers, parents remain important socializing agents for their adolescent children and are therefore promising agents for inclusion in prevention or intervention programs. This systematic review provides an overview of the effectiveness of parent-based programs in

  5. Parent-based adolescent sexual health interventions and effect on communication outcomes: a systematic review and meta-analyses. (United States)

    Santa Maria, Diane; Markham, Christine; Bluethmann, Shirley; Mullen, Patricia Dolan


    Parent-based adolescent sexual health interventions aim to reduce sexual risk behaviors by bolstering parental protective behaviors. Few studies of theory use, methods, applications, delivery and outcomes of parent-based interventions have been conducted. A systematic search of databases for the period 1998-2013 identified 28 published trials of U.S. parent-based interventions to examine theory use, setting, reach, delivery mode, dose and effects on parent-child communication. Established coding schemes were used to assess use of theory and describe methods employed to achieve behavioral change; intervention effects were explored in meta-analyses. Most interventions were conducted with minority parents in group sessions or via self-paced activities; interventions averaged seven hours, and most used theory extensively. Meta-analyses found improvements in sexual health communication: Analysis of 11 controlled trials indicated a medium effect on increasing communication (Cohen's d, 0.5), and analysis of nine trials found a large effect on increasing parental comfort with communication (0.7); effects were positive regardless of delivery mode or intervention dose. Intervention participants were 68% more likely than controls to report increased communication and 75% more likely to report increased comfort. These findings point to gaps in the range of programs examined in published trials-for example, interventions for parents of sexual minority youth, programs for custodial grandparents and faith-based services. Yet they provide support for the effectiveness of parent-based interventions in improving communication. Innovative delivery approaches could extend programs' reach, and further research on sexual health outcomes would facilitate the meta-analysis of intervention effectiveness in improving adolescent sexual health behaviors. Copyright © 2015 by the Guttmacher Institute.

  6. Parent-based interventions for preventing or reducing adolescent substance use - A systematic literature review. (United States)

    Kuntsche, Sandra; Kuntsche, Emmanuel


    Despite the increasing relevance of peers, parents remain important socializing agents for their adolescent children and are therefore promising agents for inclusion in prevention or intervention programs. This systematic review provides an overview of the effectiveness of parent-based programs in preventing, curbing or reducing substance use (i.e. alcohol, tobacco and cannabis) among 10 to 18-year-olds. The databases PubMed, PsychInfo, Eric and Google Scholar were used to identify randomized trials published within the past 12years evaluating effects on adolescent substance use. Of the 653 identified in the first screening, 39 publications dealing with 13 programs were included. Results reveal desirable effects of parenting measures such as rule-setting, monitoring and parent-child communication. There was also some evidence in terms of preventing, curbing or reducing adolescent substance use. However, this appears to depend particularly on the age group of the adolescents in question, the kind of parents included and the intensity of the program. To conclude, the results of this systematic review underline the importance of including parents in programs aiming to impede initiation of substance use or curb or reduce already existing substance use in adolescence. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. [Behavioral intervention for preschool children with autism – outcome of parent-based Intervention]. (United States)

    Molnár, Claire; Eldevik, Sigmund


    Early intensive behavioral intervention (EIBI) has proved to be an effective intervention for children with autism spectrum disorder (ASD). In this exploratory study, we evaluated the effects of a community-based service model with parents as active therapists. 13 children with ASD between 2 and 5 years of age at intake participated in the study. A waiting-list control design was employed. The children received 1 year of home-based EIBI for approximately 20 hours a week, their parents functioning as primary therapists. The waiting-list control group consisted of seven children who were tested 6 months before the intervention commenced. The intervention was based on the University of California at Los Angeles Young Autism Project model (UCLA YAP; Lovaas, 1981, 1987, 2003). The Psychoeducational Profile (3rd ed., PEP-3), the Parenting Stress Index (PSI), and the Childhood Autism Rating Scale (2nd ed., CARS 2) were used to measure outcome. In addition, a mental developmental index (MDI) was calculated on the basis of the Cognitive Verbal/Preverbal subscale of the PEP-3. After 1 year of EIBI, we found a significant increase in the PEP-3 scores and MDI scores as well as a significant reduction in the CARS 2 scores. No significant changes were seen when participants were on the waiting list. The stress level of the parents did not change significantly and in fact showed overall a slight decrease. This model of providing EIBI appears to hold some promise. Comprehensive parental involvement did not affect their stress level. The study need to be replicated with a larger sample and an improved design.

  8. A randomized, controlled trial to test the efficacy of an online, parent-based intervention for reducing the risks associated with college-student alcohol use (United States)

    Donovan, Elizabeth; Wood, Mollie; Frayjo, Kezia; Black, Ryan A.; Surette, Daniel A.


    Alcohol consumption among college students remains a major public health concern. Universal, Web-based interventions to reduce risks associated with student alcohol consumption have been found to be effective in changing their alcohol-related behavior. Recent studies also indicate that parent-based interventions, delivered in booklet form, are effective. A parent-based intervention that is also Web-based may be well suited to a dispersed parent population; however, no such tool is currently available. The purpose of this study was to test the efficacy of an online parent-based intervention designed to (1) increase communication between parents and students about alcohol and (2) reduce risks associated with alcohol use to students. A total of 558 participants, comprising 279 parent-teen dyads, were enrolled in the study. The findings suggested that parents who participated in the online intervention were more likely to discuss protective behavioral strategies, particularly those related to manner of drinking and stopping/limiting drinking, with their teens, as compared with parents in an e-newsletter control group. Moreover, students whose parents received the intervention were more likely to use a range of protective behavioral strategies, particularly those related to manner of drinking and stopping/limiting drinking, as compared with students whose parents did not receive the intervention. A universal, online, parent-based intervention to reduce risks associated with student alcohol consumption may be an efficient and effective component of a college’s overall prevention strategy. PMID:21963316

  9. Evaluation of Timing and Dosage of a Parent-Based Intervention to Minimize College Students’ Alcohol Consumption (United States)

    Turrisi, Rob; Mallett, Kimberly A.; Cleveland, Michael J.; Varvil-Weld, Lindsey; Abar, Caitlin; Scaglione, Nichole; Hultgren, Brittney


    Objective: The study evaluated the timing and dosage of a parent-based intervention to minimize alcohol consumption for students with varying drinking histories. Method: First-year students (N = 1,900) completed Web assessments during the summer before college (baseline) and two follow-ups (fall of first and second years). Students were randomized to one of four conditions (pre-college matriculation [PCM], pre-college matriculation plus boosters [PCM+B], after college matriculation [ACM], and control conditions). Seven indicators of drinking (drink in past month, been drunk in past month, weekday [Sunday to Wednesday] drinking, Thursday drinking, weekend [Friday, Saturday] drinking, heavy episodic drinking in past 2 weeks, and peak blood alcohol concentration students. PMID:23200148

  10. Evaluation of timing and dosage of a parent-based intervention to minimize college students' alcohol consumption. (United States)

    Turrisi, Rob; Mallett, Kimberly A; Cleveland, Michael J; Varvil-Weld, Lindsey; Abar, Caitlin; Scaglione, Nichole; Hultgren, Brittney


    The study evaluated the timing and dosage of a parent-based intervention to minimize alcohol consumption for students with varying drinking histories. First-year students (N = 1,900) completed Web assessments during the summer before college (baseline) and two follow-ups (fall of first and second years). Students were randomized to one of four conditions (pre-college matriculation [PCM], pre-college matriculation plus boosters [PCM+B], after college matriculation [ACM], and control conditions). Seven indicators of drinking (drink in past month, been drunk in past month, weekday [Sunday to Wednesday] drinking, Thursday drinking, weekend [Friday, Saturday] drinking, heavy episodic drinking in past 2 weeks, and peak blood alcohol concentration students.

  11. Steering teens safe: a randomized trial of a parent-based intervention to improve safe teen driving. (United States)

    Peek-Asa, Corinne; Cavanaugh, Joseph E; Yang, Jingzhen; Chande, Vidya; Young, Tracy; Ramirez, Marizen


    Crashes are the leading cause of death for teens, and parent-based interventions are a promising approach. We assess the effectiveness of Steering Teens Safe, a parent-focused program to increase safe teen driving. Steering Teens Safe aimed to improve parental communication with teens about safe driving using motivational interviewing techniques in conjunction with 19 safe driving lessons. A randomized controlled trial involved 145 parent-teen dyads (70 intervention and 75 control). Intervention parents received a 45-minute session to learn the program with four follow-up phone sessions, a DVD, and a workbook. Control parents received a standard brochure about safe driving. Scores were developed to measure teen-reported quantity and quality of parental communication about safe driving. The main outcome measure was a previously validated Risky Driving Score reported by teens. Because the Score was highly skewed, a generalized linear model based on a gamma distribution was used for analysis. Intervention teens ranked their parent's success in talking about driving safety higher than control teens (p = 0.035) and reported that their parents talked about more topics (non-significant difference). The Risky Driving Score was 21% lower in intervention compared to control teens (85% CI = 0.60, 1.00). Interaction between communication quantity and the intervention was examined. Intervention teens who reported more successful communication had a 42% lower Risky Driving Score (95% CI = 0.37, 0.94) than control parents with less successful communication. This program had a positive although not strong effect, and it may hold the most promise in partnership with other programs, such as Driver's Education or Graduated Driver's License policies. NCT01014923. Registered Nov. 16, 2009.

  12. Implementation Evaluation of "Steering Teens Safe": Engaging Parents to Deliver a New Parent-Based Teen Driving Intervention to Their Teens (United States)

    Ramirez, Marizen; Yang, Jingzhen; Young, Tracy; Roth, Lisa; Garinger, Anne; Snetselaar, Linda; Peek-Asa, Corinne


    Parents play a fundamental role in teaching their children safe driving skills to reduce risk of motor vehicle crashes, the leading cause of death for teens. "Steering Teens Safe" is a new parent-based intervention that equips parents with communication skills to talk about, demonstrate, and practice safe driving behaviors and skills…

  13. Ultrathin metallized PBI paper (United States)

    Chenevey, E. C.


    A study to determine the feasibility of preparing ultrathin papers with a target weight of 3.5 g/m squared from polybenzimidazole (PBI) fibrids was undertaken. Small hand sheets of target weight were fabricated. They were light brown, low density materials with sufficient strength to be readily handleable. Characterization of these sheets included strength, fold endurance, thermal gravimetric analysis in air and nitrogen and photomicrographs. Two different batches of PBI fibrids were studied and differences in fabrication performance were noted. In neither case could target weight papers be prepared using conventional paper making techniques.

  14. A parent-based intervention to promote healthy eating and active behaviours in pre-school children: evaluation of the MEND 2-4 randomized controlled trial. (United States)

    Skouteris, H; Hill, B; McCabe, M; Swinburn, B; Busija, L


    There is a paucity of studies evaluating targeted obesity prevention interventions in pre-school children. We conducted a randomized controlled trial to evaluate the efficacy of a parent-based obesity prevention intervention for pre-schoolers - MEND (Mind, Exercise, Nutrition … Do It!) 2-4 on child diet, eating habits, physical activity/sedentary behaviours, and body mass index (BMI). Parent-child dyads attended 10 weekly 90-min workshops relating to nutrition, physical activity and behaviours, including guided active play and healthy snack time. Assessments were conducted at baseline, immediately post-intervention, and 6 and 12 months post-intervention; child intake of vegetables, fruit, beverages, processed snack foods, fussiness, satiety responsiveness, physical activity, sedentary behaviour and neophobia were assessed via parent proxy report. Parent and child height and weight were measured. Two hundred one parent-child dyads were randomized to intervention (n = 104) and control (n = 97). Baseline mean child age was 2.7 (standard deviation [SD] 0.6) years, and child BMI-for-age z-score (World Health Organization) was 0.66 (SD 0.88). We found significant positive group effects for vegetable (P = 0.01) and snack food (P = 0.03) intake, and satiety responsiveness (P = 0.047) immediately post-intervention. At 12 months follow-up, intervention children exhibited less neophobia (P = 0.03) than controls. Future research should focus on additional strategies to support parents to continue positive behaviour change. ACTRN12610000200088. © 2015 World Obesity.

  15. Implementation evaluation of steering teens safe: engaging parents to deliver a new parent-based teen driving intervention to their teens. (United States)

    Ramirez, Marizen; Yang, Jingzhen; Young, Tracy; Roth, Lisa; Garinger, Anne; Snetselaar, Linda; Peek-Asa, Corinne


    Parents play a fundamental role in teaching their children safe driving skills to reduce risk of motor vehicle crashes, the leading cause of death for teens. Steering Teens Safe is a new parent-based intervention that equips parents with communication skills to talk about, demonstrate, and practice safe driving behaviors and skills with their teens. This implementation evaluation focuses on a sample of 83 parents who delivered Steering Teens Safe to their teens. One-, 2- and 3-month follow-up assessments were conducted with intervention parents to evaluate the self-reported quantity and quality of talking about, demonstrating, and practicing safe driving goals with teens; perceived success and benefit of the program; and barriers to implementation. Over 3 months of follow-up, parents discussed driving goals with their teens for a median of 101.5 minutes. The most frequently addressed topics were general safety principles, including distracted driving, driving in bad weather, wearing a seat belt, and being a safe passenger. Parents spent a median of 30 minutes practicing safe driving skills such as changing lanes. Sixty-seven percent of parents talked to their children about rural road safety, but just 36% demonstrated and half practiced these skills with their teens. Barriers to implementation include time and opportunity barriers and resistant attitudes of their teens. However, barriers neither affected frequency of engagement nor parents' perceived benefit and comfort in delivering the program. Parents with time/opportunity barriers also had higher practice and demonstration times than parents without these barriers. Findings indicate high acceptability among parent implementers and promise for real-world delivery. Future studies are needed to assess intervention impact.

  16. Ultrafine PBI fibers and yarns (United States)

    Leal, J. R.; Tan, M.


    Gentle precisely controlled process is used to draw polybenzimidazole (PBI) fibers to denier as low as 0.17 per fiber. Yarns of lightweight fibers could be useful in applications where lightweight textiles must withstand high temperatures, corrosion, or radiation.

  17. Ultralow denier polybenzimidazole (PBI) yarns (United States)

    Tan, M.; Leal, J. R.


    A study to determine the feasibility of preparing ultralow denier polybenzimidazole (PBI) yarns was undertaken. Conditions that presently yield multifilament yarns with bundle deniers ranging from 75 to 15,000 were used as a baseline. From this starting point, process parameters were identified that give five filament yarns with yarn densiers as low as 0.80. Physical properties from such ultralow denier yarns were at levels that would permit subsequent fabrication into fabrics.

  18. Thermoactivation processes in PbI2:Zr and PbI2 crystals

    International Nuclear Information System (INIS)

    Panasyuk, M.R.; Kapustyanik, V.B.; Tsibul's'kij, V.S.; Dubov, Yu.G.; Pasternak, R.M.


    The X-ray luminescence, thermal emission and thermally stimulated depolarisation spectra as well as the influence of IR-illumination on the thermal emission and thermally stimulated depolarisation spectra of the PbI 2 :Zr and PbI 2 crystals have been studied. There were found the hole traps in the PbI 2 :Zr crystals that are absent in PbI 2 . For the observed traps the activation energy has been calculated. The mechanisms describing the traps' nature and that of thermally stimulated depolarisation currents have been proposed

  19. meta-PBI/methylated PBI-OO blend membranes for acid doped HT PEMFC

    DEFF Research Database (Denmark)

    Cho, Hyeongrae; Hur, Eun; Henkensmeier, Dirk


    Methylation of polybenzimidazole leads to positively charged polymer backbones, and moveable anions. Ion exchange of methylated PBI-OO in phosphoric acid (PA) shows that the resulting polymers dissolve. meta-PBI, however, absorbs about 400wt% PA while remaining a self supported membrane. We inves...

  20. Training Bilingual Educators at a PBI (United States)

    Montes, Amanda Lira Gordenstein; Valenciano, Cynthia Kay; Fernandez, Miguel


    While Bilingual Education has traditionally been associated with linguistic diversity, the rise of the number of African-American teacher candidates in a Bilingual Education program at a mid-west Predominantly Black Institution (PBI) is causing the authors to reevaluate the input of this program's curriculum and the output of the candidates'…

  1. Flame retardant treatments of PBI fabric. (United States)

    Temin, S. C.


    Fabrics knitted or woven from polybenzimidazole (PBI) fibers were treated to reduce flammability in oxygen atmospheres, particularly that of 5 psia oxygen. Bromination to approximately 15% weight gain of such fabrics led to markedly lower burning rates; samples brominated to over 80% weight gain were self-extinguishing in 5 psia oxygen. The loss in tensile strength of fabrics due to bromination was negligible although shrinkage was observed. Free fibers showed negligible losses on bromination. Treatment of PBI fabric with organophosphorus compounds also achieved self-extinguishing character in 5 psia oxygen but the enhanced flameproofing was largely lost on leaching. Reaction with POCl3 in pyridine led to a permanent reduction in flammability.

  2. Mathematical model of a PEMFC using a PBI membrane

    International Nuclear Information System (INIS)

    Cheddie, Denver; Munroe, Norman


    Proton exchange membrane fuel cells (PEMFC) operating with Nafion[reg] membranes have encountered numerous problems associated with water management and CO poisoning because of their low temperature of operation. Alternative high temperature membranes have been investigated, one such membrane being polybenzimidazole (PBI). This paper presents a one dimensional mathematical model, which predicts the polarization performance of a PEMFC using a PBI membrane. Peak power densities in the same order as Nafion[reg] are predicted. Results indicate that the greatest scope for improving PBI PEMFC performance is increasing the membrane conductivity and improving the catalyst performance as it interfaces with the PBI membrane

  3. Proton Conductivity and Operational Features Of PBI-Based Membranes

    DEFF Research Database (Denmark)

    Qingfeng, Li; Jensen, Jens Oluf; Precht Noyé, Pernille


    As an approach to high temperature operation of PEMFCs, acid-doped PBI membranes are under active development. The membrane exhibits high proton conductivity under low water contents at temperatures up to 200°C. Mechanisms of proton conduction for the membranes have been proposed. Based on the me...... on the membranes fuel cell tests have been demonstrated. Operating features of the PBI cell include no humidification, high CO tolerance, better heat utilization and possible integration with fuel processing units. Issues for further development are also discussed....

  4. Fabrication and characterization of solid PbI2 nanocrystals

    International Nuclear Information System (INIS)

    Kasi, Gopi K; Dollahon, Norman R; Ahmadi, Temer S


    Lead iodide nanoparticles are synthesized in reverse micelle solution of AOT/H 2 O/n-heptane. Optical absorption spectra and TEM analysis indicated the formation of crystalline particles with an average radius of 1.5 nm, which is less than the Bohr radius of the exciton (1.9 nm) in bulk PbI 2 . Using theoretical models and optical spectra of quantum confined PbI 2 nanoparticles, a radius of 1.5 nm and a thickness of 1.7 nm was calculated, which are in full agreement with the TEM results. Particles were isolated from the dispersed medium and were analysed by powder XRD and Raman spectroscopy, indicating the formation of a predominantly 2H-PbI 2 polytype. This work presents the first case of fully isolated, fully characterized solid nanoparticles of PbI 2 . It also presents XRD and Raman spectrum for the first time for PbI 2 nanoparticles of intermediate quantum confinement

  5. Fabrication of radiation detector using PbI2 crystals

    International Nuclear Information System (INIS)

    Shoji, T.; Ohba, K.; Suehiro, T.; Hiratate, Y.


    Radiation detectors have been fabricated from lead iodide (PbI 2 ) crystals grown by two methods: zone melting and Bridgman methods. In response characteristics of the detector fabricated from crystals grown by the zone melting method, a photopeak for γ-rays from an 241 Am source (59.5 KeV) has been clearly observed with applied detector bias of 500 V at room temperature. The hole drift mobility is estimated to be about 5.5 cm 2 /Vs from measurement of pulse rise time for 5.48 MeV α-rays from 241 Am. By comparing the detector bias versus saturated peak position of the PbI 2 detector with that of CdTe detector, the average energy for producing electron-hole pairs is estimated to be about 8.4 eV for the PbI 2 crystal. A radiation detector fabricated from PbI 2 crystals grown by the Bridgman method, however, exhibited no response for γ-rays

  6. Investigation on thermal evaporated CH3NH3PbI3 thin films

    Directory of Open Access Journals (Sweden)

    Youzhen Li


    Full Text Available CH3NH3I, PbI2 and CH3NH3PbI3 films were fabricated by evaporation and characterized with X-ray Photoelectron Spectroscopy (XPS and X-ray diffraction (XRD. The XPS results indicate that the PbI2 and CH3NH3PbI3 films are more uniform and stable than the CH3NH3I film. The atomic ratio of the CH3NH3I, PbI2 and CH3NH3PbI3 films are C:N:I=1.00:1.01:0.70, Pb:I= 1.00:1.91 and C: N: Pb: I = 1.29:1.07:1.00:2.94, respectively. The atomic ratio of CH3NH3PbI3 is very close to that of the ideal perovskite. Small angle x-ray diffraction results demonstrate that the as evaporated CH3NH3PbI3 film is crystalline. The valence band maximum (VBM and work function (WF of the CH3NH3PbI3 film are about 0.85eV and 4.86eV, respectively.

  7. Luminescence and photosensitivity of PbI2 crystals

    International Nuclear Information System (INIS)

    Novosad, S.S.; Novosad, I.S.; Matviishin, I.M.


    One studied effect of temperature treatment and storage conditions on spectra features of PbI 2 crystals grown by the Bridgman-Stockbarger method from salt additionally purified by directed crystallization. Spectra of X-ray luminescence, photoluminescence and thermostimulated luminescence were investigated within 85-295 K temperature range under stationary X-ray excitation and emission of N 2 -laser. One studied photoelectret properties of those crystals under 85 K. Luminescence of PbI 2 crystals with maximum within 595 nm region observed following their thermal annealing under 475-495 K temperature and typical for near-the-surface section of specimens may be caused by oxygen-containing centres [ru

  8. [Partial breast irradiation (PBI): the therapy of the future?]. (United States)

    Koning, Caro C E; Bijker, Nina; van Tienhoven, Geertjan


    Breast-conserving therapy with radiation therapy of 50 Gy over 5 weeks to the entire breast plus a tumour bed boost is the standard treatment for patients with early stage breast cancer. Several attempts have been made to lower the treatment burden, such as omitting either all radiotherapy or the tumour bed boost, without success. Phase III trials are now being carried out to evaluate the treatment of the primary tumour area only (PBI). Various methods for selection of patient groups and of delivering the radiation dose have been employed. Vaidya et al. report the same favourable local recurrence rates following PBI with single dose intraoperative radiotherapy as with whole-breast irradiation. As the follow-up period so far has been short, long-time results should be awaited.

  9. A comprehensive review of PBI-based high temperature PEM fuel cells

    DEFF Research Database (Denmark)

    Simon Araya, Samuel; Zhou, Fan; Liso, Vincenzo


    of their design and characterization techniques at single cell, stack and system levels is given. The state-of-the-art concepts of different degradation mechanisms and methods of their mitigation are also discussed. Moreover, accelerated stress testing (AST) procedures for HT-PEMFCs available in literature...... fuel cell faults for targeted interventions based on the observed conditions to prevent sudden failures and to prolong the fuel cell's lifetime. However, the technology is still under development and robust on-line diagnostics tools are hardly available. Currently, mitigation is mainly done based......The current status on the understanding of the various operational aspects of high temperature proton exchange membrane fuel cells (HT-PEMFC) has been summarized. The paper focuses on phosphoric acid-doped polybenzimidazole (PBI)-based HT-PEMFCs and an overview of the common practices...

  10. Phosphoric acid doped AB-PBI membranes and its applications in high temperature PEMFC

    DEFF Research Database (Denmark)

    He, Ronghuan; Qingfeng, Li; Bjerrum, Niels


    Poly(2,5-benzimidazole) (ab-PBI) was prepared from 3,4-diaminobenzoic acid via a polymerisation reaction. The obtained polymer exhibits excellent thermal stability in a temperature range ….. The membrane of ab-PBI when doped with phosphoric acid at room temperaturepresents high proton conductivity...

  11. Systems of Rb2I2-CdI2-PbI2 and Cs2I2-CdI2-PbI2

    International Nuclear Information System (INIS)

    Volchanskaya, V.V.; Il'yasov, I.I.


    The Rb 2 I 2 -CdI 2 -PbI 2 and Cs 2 I 2 -CdI 2 -PbI 2 triple systems have been studied, using the visual-polythermal method. The liquidus of the systems researched consists of the components and compounds crystallization fields: 2RbIxCdI 2 , 2RbIxRbI 2 , RbIxPbI 2 and 2CsIxCdI 2 , 4CsIxPbI 2 , CsIxPbI 2 , respectively. The crystallization fields converge in four non-variant points at 360, 280, 205 and 192 deg C in the Rb 2 I 2 -CdI 2 -PbI 2 system and at 375, 368, 208 and 190 deg C in the CsI 2 -CdI 2 -PbI 2 system

  12. Parametric investigation to enhance the performance of a PBI-based high-temperature PEMFC

    International Nuclear Information System (INIS)

    Ferng, Y.M.; Su, A.; Hou, J.


    Highlights: • A in-house PBI PEMFC is prepared by the Fuel Cell Center of Yuan Ze University. • Parametric effects to enhance the PBI based PEMFC performance are investigated. • Experiments and simulations are performed to study these parametric effects. • Cell performance is enhanced with the lower PBI loading and higher temperature. • Thinner CL thickness and higher acid doping benefit to the cell performance also. - Abstract: With the advantages of simpler heat and water management, lower CO poisoning, and higher reaction kinetics, the high-temperature polybenzimidazole (PBI)-based proton exchange membrane fuel cell (PEMFC) can be considered as one of the commercialized energy generators in the near future. This paper experimentally and analytically investigates different design and operating parameters to enhance the performance of a PBI-based PEMFC, an in-house cell prepared in the Fuel Cell Center of Yuan Ze University. These parameters studied include PBI loading, operating temperature, gas flowrate, electrode thickness and porosity, and acid doping level. Experiments are performed to study the effects of PBI loading, operating temperature, and gas flowrate on the cell performance. Validated against the measured data of polarization and power curves, a simplified two-dimensional model for this PBI-based PEMFC is also developed to help the experiments to investigate other parameters. Based on the experimental data and the model predictions, the cell performance can be enhanced as the PBI loading is reduced, the operating temperature is elevated. Thinner electrode thickness, smaller porosity, and higher acid doping level are also predicted to benefit to the performance of the PBI-based PEMFC

  13. Controlling Photoconductivity in PBI Films by Supramolecular Assembly. (United States)

    Draper, Emily R; Archibald, Lewis J; Nolan, Michael C; Schweins, Ralf; Zwijnenburg, Martijn A; Sproules, Stephen; Adams, Dave J


    Perylene bisimides (PBIs) self-assemble in solution. The solubility of the PBIs is commonly changed through the choice of substituents at the imide positions. It is generally assumed this substitution does not affect the electronic properties of the PBI, and that the properties of the self-assembled aggregate are essentially that of the isolated molecule. However, substituents do affect the self-assembly, resulting in potentially different packing in the formed aggregates. Here, we show that the photoconductivity of films formed from a library of substituted PBIs varies strongly with the substituent and demonstrate that this is due to the different ways in which they pack. Our results open the possibility for tuning the optoelectronic properties of self-assembled PBIs by controlling the aggregate structure through careful choice of substituent, as demonstrated by us here optimising the photoconductivity of PBI films in this way. © 2018 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  14. Mechanical Stability of H3PO4-Doped PBI/Hydrophilic-Pretreated PTFE Membranes for High Temperature PEMFCs

    International Nuclear Information System (INIS)

    Park, Jaehyung; Wang, Liang; Advani, Suresh G.; Prasad, Ajay K.


    Graphical abstract: - Highlights: • PBI/PTFE membrane was prepared by porous PTFE with hydrophilic surface pretreatment. • The durability of the prepared PBI/PTFE membrane was compared with pure PBI, PBI with untreated PTFE, and PBI-Nafion with untreated PTFE membranes. • Accelerated durability tests and SEM showed improved durability based the PBI/PTFE membrane with pretreated PTFE. - Abstract: A novel polybenzimidazole (PBI)/poly(tetrafluoroethylene) (PTFE) composite membrane doped with phosphoric acid was fabricated for high temperature operation in a polymer electrolyte membrane (PEM) fuel cell. A hydrophilic surface pretreatment was applied to the porous PTFE matrix film to improve its interfacial adhesion to the PBI polymer, thereby avoiding the introduction of Nafion ionomer which is traditionally used as a coupling agent. The pretreated PTFE film was embedded within the composite membrane during solution-casting using 5wt% PBI/DMAc solution. The mechanical stability and durability of three types of MEAs assembled with PBI only, PBI with pretreated PTFE, and PBI-Nafion with untreated PTFE membranes were evaluated under an accelerated degradation testing protocol employing extreme temperature cycling. Degradation was characterized by recording polarization curves, hydrogen crossover, and proton resistance. Cross-sections of the membranes were examined before and after thermal cycling by scanning electron microscope. Energy-dispersive X-ray spectroscopy verified that the PBI is dispersed homogeneously in the porous PTFE matrix. Results show that the PBI composite membrane with pretreated PTFE has a lower degradation rate than the Nafion/PBI membrane with untreated PTFE. Thus, the hydrophilic pretreatment employed here greatly improved the mechanical stability of the composite membrane, which resulted in improved durability under an extreme thermal cycling regime

  15. Enhancement of Th1 type cytokine production and primary T cell activation by PBI-1393. (United States)

    Allam, Mustapha; Julien, Nathalie; Zacharie, Boulos; Penney, Christopher; Gagnon, Lyne


    In previous reports, we have shown that PBI-1393 (formerly BCH-1393), N,N-Dimethylaminopurine pentoxycarbonyl D-arginine, stimulates cytotoxic T-lymphocyte (CTL) responses both in vitro and in vivo in normal immune status and immunosuppressed mice. Additionally, PBI-1393 was tested for anticancer activity in syngeneic mouse experimental tumor models and it displayed significant inhibition of tumor outgrowths when given in combination with sub-therapeutic doses of cytotoxic drugs (cyclophosphamide, 5-fluorouracil, doxorubicin and cis-platinum). However, the mechanism of action of PBI-1393 was still unknown. Here, we report that PBI-1393 enhances IL-2 and IFN-gamma production in human activated T cells by 51% and 46% respectively. PBI-1393 increases also IL-2 and IFN-gamma mRNA expression as shown by RT-PCR. The physiological relevance of IL-2 and IFN-gamma gene modulation by PBI-1393 is illustrated by the advantageous increase of T cell proliferation (39+/-0.3% above control) and human CTL response against prostate (PC-3) cancer cells (42+/-0.03%). The enhancement of human T cell proliferation and CTL activation by PBI-1393 demonstrates that this compound potentiates the immune response and in this regard, it could be used as an alternative approach to IL-2 and/or IFN-gamma therapy against cancer.

  16. Thermal curing of PBI membranes for high temperature PEM fuel cells

    DEFF Research Database (Denmark)

    Aili, David; Cleemann, Lars N.; Li, Qingfeng


    (MEAs) is currently hampering the commercial viability of the technology. In the present study, thermoset PBI membranes were prepared by curing the membranes under inert atmosphere at temperatures of up to 350 °C prior to the acid doping. The systematic membrane characterizations with respect...... to solubility, phosphoric acid doping, radical-oxidative resistance and mechanical strength indicated that the PBI membranes were irreversibly cured by the thermal treatment. After curing, the PBI membranes demonstrated features that are fundamental characteristics of a thermoset resin including complete...

  17. CH3NH3PbI3 based solar cell: Modified by antisolvent treatment (United States)

    Nandi, Pronoy; Giri, Chandan; Bansode, Umesh; Topwal, D.


    Solar cells based on new class of organic inorganic hybrid perovskite CH3NH3PbI3 were prepared by Ethyl acetate (EA); antisolvent treatment for the first time. This treatment results in new morphology for CH3NH3PbI3 thin film. FESEM image shows microrod type structures of CH3NH3PbI3 after EA antisolvent treatment. Energy band diagram was constructed using photoluminescence and photoemission studies. A better power conversion efficiency was achieved in EA treated film compare to without EA treated film.

  18. Partially fluorinated aarylene polyethers and their ternary blends with PBI and H3PO4

    DEFF Research Database (Denmark)

    Li, Qingfeng; Jensen, Jens Oluf; Pan, Chao


    Ternary blend membranes based on sulphonated partially fluorinated arylene polyether, polybenzimidazole (PBI) and phosphoric acid were prepared and characterised as electrolyte for high temperature proton exchange membrane fuel cells. Partially fluorinated arylene polyether was first prepared from...

  19. Roll-to-roll coated PBI membranes for high temperature PEM fuel cells

    DEFF Research Database (Denmark)

    Steenberg, Thomas; Hjuler, Hans Aage; Terkelsen, Carina


    We employed roll-to-roll coating in the preparation of 40 μm thick poly[2,2′(m-phenylene)-5,5′bibenzimidazole] (PBI) films for fuel cells using both knife-coating (KC) and slot-die (SD) coating. The films were coated directly from a 9% (w/w) solution of PBI in dimethylacetamide onto a sacrificial...

  20. Emotional reasoning and parent-based reasoning in normal children.


    Morren, M.; Muris, P.; Kindt, M.


    A previous study by Muris, Merckelbach, and Van Spauwen demonstrated that children display emotional reasoning irrepective of their anxiety levels. That is when estimating whether a situation is dangerous, childen not only rely on objective danger information but also on their own anciety-response. The present study further examined emotional reasoning in childeren aged 7-13 years (N=508). In addition, it was investigated whether children also show parent-based reasoning, which can be defined...

  1. Optical monitoring of CH3NH3PbI3 thin films upon atmospheric exposure

    International Nuclear Information System (INIS)

    Ghimire, Kiran; Zhao, Dewei; Cimaroli, Alex; Ke, Weijun; Yan, Yanfa; Podraza, Nikolas J


    CH 3 NH 3 PbI 3 perovskite films of interest for photovoltaic (PV) devices have been prepared by (i) vapor deposition and (ii) solution processing. Complex dielectric function ( ε   =   ε 1   +  i ε 2 ) spectra and structural parameters of the films have been extracted using near infrared to ultraviolet spectroscopic ellipsometry. In situ real time spectroscopic ellipsometry (RTSE) over a 48 h period has been performed on vapor deposited CH 3 NH 3 PbI 3 after the deposition in normal atmospheric laboratory ambient conditions. Analysis of RTSE data for vapor deposited CH 3 NH 3 PbI 3 film prepared under un-optimized conditions identifies phase segregated PbI 2 and CH 3 NH 3 I at the substrate/film interface and unreacted PbI 2 and CH 3 NH 3 I on the film surface. This analysis also provides the time dependence of the effective thicknesses of perovskite film, unreacted components, and phase segregated layers to track CH 3 NH 3 PbI 3 decomposition. (paper)

  2. CH3 NH3 PbI3 and HC(NH2 )2 PbI3 Powders Synthesized from Low-Grade PbI2 : Single Precursor for High-Efficiency Perovskite Solar Cells. (United States)

    Zhang, Yong; Kim, Seul-Gi; Lee, Do-Kyoung; Park, Nam-Gyu


    High-efficiency perovskite solar cells are generally fabricated by using highly pure (>99.99 %) PbI 2 mixed with an organic iodide in polar aprotic solvents. However, the use of such an expensive chemical may impede progress toward large-scale industrial applications. Here, we report on the synthesis of perovskite powders by using inexpensive low-grade (99 %) PbI 2 and on the photovoltaic performance of perovskite solar cells prepared from a powder-based single precursor. Pure APbI 3 [A=methylammonium (MA) or formamidinium (FA)] perovskite powders were synthesized by treating low-grade PbI 2 with MAI or FAI in acetonitrile at ambient temperature. The structural phase purity was confirmed by X-ray diffraction. The solar cell with a MAPbI 3 film prepared from the synthesized perovskite powder demonstrated a power conversion efficiency (PCE) of 17.14 %, which is higher than the PCE of MAPbI 3 films prepared by using both MAI and PbI 2 as precursors (PCE=13.09 % for 99 % pure PbI 2 and PCE=16.39 % for 99.9985 % pure PbI 2 ). The synthesized powder showed better absorption and photoluminescence, which were responsible for the better photovoltaic performance. For the FAPbI 3 powder, a solution with a yellow non-perovskite δ-FAPbI 3 powder synthesized at room temperature was found to lead to a black perovskite film, whereas a solution with the black perovskite α-FAPbI 3 powder synthesized at 150 °C was not transformed into a black perovskite film. The α↔δ transition between the powder and film was assumed to correlate with the difference in the iodoplumbates in the powder-dissolved solution. An average PCE of 17.21 % along with a smaller hysteresis [ΔPCE=PCE reverse -PCE forward )=1.53 %] was demonstrated from the perovskite solar cell prepared by using δ-FAPbI 3 powder; this PCE is higher than the average PCE of 17.05 % with a larger hysteresis (ΔPCE=2.71 %) for a device based on a conventional precursor solution dissolving MAI with high

  3. Prediction on electronic structure of CH3NH3PbI3/Fe3O4 interfaces (United States)

    Hou, Xueyao; Wang, Xiaocha; Mi, Wenbo; Du, Zunfeng


    The interfacial electronic structures of CH3NH3PbI3(MAPbI3)/Fe3O4 heterostructures are predicted by density functional theory. Four models (MAI/FeBO, PbI2/FeBO, MAI/FeA and PbI2/FeA) are included. Especially, a half-metal to semiconductor transition of Fe3O4 appears in PbI2/FeA model. A series of electric field is added to PbI2/FeA model, and a direct-indirect bandgap transition of Fe3O4 appears at a 500-kV/cm field. The electric field can control the bandgap of Fe3O4 in PbI2/FeA model by modulating the hybridization. The prediction of spin-related bandgap characteristic in MAPbI3/Fe3O4 is meaningful for further study.

  4. Thin-Film Transformation of NH4 PbI3 to CH3 NH3 PbI3 Perovskite: A Methylamine-Induced Conversion-Healing Process. (United States)

    Zong, Yingxia; Zhou, Yuanyuan; Ju, Minggang; Garces, Hector F; Krause, Amanda R; Ji, Fuxiang; Cui, Guanglei; Zeng, Xiao Cheng; Padture, Nitin P; Pang, Shuping


    Methylamine-induced thin-film transformation at room-temperature is discovered, where a porous, rough, polycrystalline NH 4 PbI 3 non-perovskite thin film converts stepwise into a dense, ultrasmooth, textured CH 3 NH 3 PbI 3 perovskite thin film. Owing to the beneficial phase/structural development of the thin film, its photovoltaic properties undergo dramatic enhancement during this NH 4 PbI 3 -to-CH 3 NH 3 PbI 3 transformation process. The chemical origins of this transformation are studied at various length scales. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Fabrication of CH3NH3PbI3/PVP Composite Fibers via Electrospinning and Deposition (United States)

    Chao, Li-Min; Tai, Ting-Yu; Chen, Yueh-Ying; Lin, Pei-Ying; Fu, Yaw-Shyan


    In our study, one-dimensional PbI2/polyvinylpyrrolidone (PVP) composition fibers have been prepared by using PbI2 and PVP as precursors dissolved in N,N-dimethylformamide via a electrospinning process. Dipping the fibers into CH3NH3I solution changed its color, indicating the formation of CH3NH3PbI3, to obtain CH3NH3PbI3/PVP composite fibers. The structure, morphology and composition of the all as-prepared fibers were characterized by using X-ray diffraction and scanning electron microscopy. PMID:28793517

  6. Fabrication of CH3NH3PbI3/PVP Composite Fibers via Electrospinning and Deposition

    Directory of Open Access Journals (Sweden)

    Li-Min Chao


    Full Text Available In our study, one-dimensional PbI2/polyvinylpyrrolidone (PVP composition fibers have been prepared by using PbI2 and PVP as precursors dissolved in N,N-dimethylformamide via a electrospinning process. Dipping the fibers into CH3NH3I solution changed its color, indicating the formation of CH3NH3PbI3, to obtain CH3NH3PbI3/PVP composite fibers. The structure, morphology and composition of the all as-prepared fibers were characterized by using X-ray diffraction and scanning electron microscopy.

  7. PBI creams: a spontaneously mutated mouse strain showing wild animal-type reactivity. (United States)

    Hendrie, C A; Van Driel, K S; Talling, J C; Inglis, I R


    PBI creams are mice derived from warfarin-resistant wild stock that has been maintained under laboratory conditions since the 1970s. This study compares their behaviour to that of laboratory mice and wild house and wood mice. Animals were tested in a black/white box and a 2.64x1.4 m runway. In the black/white box, the behaviour of PBI creams was not significantly different from that of house mice and differed most from that of laboratory mice. Notably, the PBI creams showed the greatest activity and escape-orientated behaviours. When animals were approached by the experimenter in the open runway test, the PBI creams had higher flight speeds than both house and wood mice, whilst laboratory mice failed to respond. In the closed runway test where the animals could not escape, the PBI creams, house mice and wood mice all turned and attempted to run past the approaching experimenter, whilst the laboratory mice again failed to react. At the end of this test session, the time taken to catch each animal was recorded. It took less than 5 s to catch laboratory mice but significantly longer to catch the wild strains and the PBI creams (90-100 s for the latter). In these tests, the PBI creams showed wild animal-type reactivity, and as this behaviour has been retained in the laboratory colony for over 30 years, these animals may be useful in the study of the physiological and genetic basis of fear/anxiety in mice.

  8. The energy level alignment at the CH_3NH_3PbI_3/pentacene interface

    International Nuclear Information System (INIS)

    Ji, Gengwu; Zhao, Bin; Song, Fei; Zheng, Guanhaojie; Zhang, Xiaonan; Shen, Kongchao; Yang, Yingguo; Chen, Shi; Gao, Xingyu


    Highlights: • The Energy Level Alignment at the CH_3NH_3PbI_3/Pentacene Interface was resolved experimentally. • The downward band bending and the dipole found at the pentacene side would favorably drive holes away from the interface into pentacene. • A ∼0.7 eV offset between pentacene HOMO and CH_3NH_3PbI_3 VBM would be in favor of hole transfer whereas a ∼1.35 eV offset between pentacene LUMO and CH_3NH_3PbI_3 CBM should efficiently block the unwanted electron transfer from perovskite to pentacene. • Pentacene could be a viable hole transfer material candidate on perovskite to be explored in perovskite devices. - Abstract: Pentacene thin film on CH_3NH_3PbI_3 was studied by in-situ X-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy to determine their interfacial energy level alignment. A 0.2 eV downward band bending together with a 0.1 eV interfacial dipole was found at the pentacene side, whereas there was no band bending found at the CH_3NH_3PbI_3 side. The offset between CH_3NH_3PbI_3 Valance Band Maximum (VBM) and pentacene Highest Occupied Molecular Orbital (HOMO) and that between CH_3NH_3PbI_3 Conduction Band Minimum (CBM) and pentacene Lowest Unoccupied Molecular Orbital (LUMO) was determined to be 0.7 and 1.35 eV, respectively. The band alignment at this interface is favor of efficient hole transfer, which suggests pentacene as a viable HTL candidate to be explored in perovskite solar cells.

  9. Photoelectric characteristics of CH3NH3PbI3/p-Si heterojunction (United States)

    Yamei, Wu; Ruixia, Yang; Hanmin, Tian; Shuai, Chen


    Organic-inorganic hybrid perovskite CH3NH3PbI3 film is prepared on p-type silicon substrate using the one-step solution method to form a CH3NH3PbI3/p-Si heterojunction. The film morphology and structure are characterized by atomic force microscopy (AFM) and scanning electron microscopy (SEM). The photoelectric properties of the CH3NH3PbI3/p-Si heterojunction are studied by testing the current-voltage (I-V) with and without illumination and capacitance-voltage (C-V) characteristics. It turns out from the I-V curve without illumination that the CH3NH3PbI3/p-Si heterojunction has a rectifier feature with the rectification ratio over 70 at the bias of ±5 V. Also, there appears a photoelectric conversion phenomenon on this heterojunction with a short circuit current (Isc) of 0.16 μA and an open circuit voltage (Voc) of about 10 mV The high frequency C-V characteristic of the Ag/CH3NH3PbI3/p-Si heterojunction turns out to be similar to that of the metal-insulator-semiconductor (MIS) structure, and a parallel translation of the C-V curve along the forward voltage axis is found. This parallel translation means the existence of defects at the CH3NH3PbI3/p-Si interface and positive fixed charges in the CH3NH3PbI3 layer. The defects at the interface of the CH3NH3PbI3/p-Si heterojunction result in the dramatic decline of the Voc. Besides, the C-V test of CH3NH3PbI3 film shows a non-linear dielectric property and the dielectric value is about 4.64 as calculated. Project supported by the Hebei Province Natural Science Foundation of China (No. F2014202184) and the Tianjin Natural Science Foundation of China (No. 15JCZDJC37800).

  10. Novel composite Zr/PBI-O-PhT membranes for HT-PEFC applications. (United States)

    Kondratenko, Mikhail S; Ponomarev, Igor I; Gallyamov, Marat O; Razorenov, Dmitry Yu; Volkova, Yulia A; Kharitonova, Elena P; Khokhlov, Alexei R


    Novel composite membranes for high temperature polymer-electrolyte fuel cells (HT-PEFC) based on a poly[oxy-3,3-bis(4'-benzimidazol-2″-ylphenyl)phtalide-5″(6″)-diyl] (PBI-O-PhT) polymer with small amounts of added Zr were prepared. It was shown in a model reaction between zirconium acetylacetonate (Zr(acac)4) and benzimidazole (BI) that Zr-atoms are capable to form chemical bonds with BI. Thus, Zr may be used as a crosslinking agent for PBI membranes. The obtained Zr/PBI-O-PhT composite membranes were examined by means of SAXS, thermomechanical analysis (TMA), and were tested in operating fuel cells by means of stationary voltammetry and impedance spectroscopy. The new membranes showed excellent stability in a 2000-hour fuel cell (FC) durability test. The modification of the PBI-O-PhT films with Zr facilitated an increase of the phosphoric acid (PA) uptake by the membranes, which resulted in an up to 2.5 times increased proton conductivity. The existence of an optimal amount of Zr content in the modified PBI-O-PhT film was shown. Larger amounts of Zr lead to a lower PA doping level and a reduced conductivity due to an excessively high degree of crosslinking.

  11. Exceptional durability enhancement of PA/PBI based polymer electrolyte membrane fuel cells for high temperature operation at 200°C

    DEFF Research Database (Denmark)

    Aili, David; Zhang, Jin; Jakobsen, Mark Tonny Dalsgaard


    The incorporation of phosphotungstic acid functionalized mesoporous silica in phosphoric acid doped polybenzimidazole (PA/PBI) substantially enhances the durability of PA/PBI based polymer electrolyte membrane fuel cells for high temperature operation at 200°C.......The incorporation of phosphotungstic acid functionalized mesoporous silica in phosphoric acid doped polybenzimidazole (PA/PBI) substantially enhances the durability of PA/PBI based polymer electrolyte membrane fuel cells for high temperature operation at 200°C....

  12. Structural study on cubic-tetragonal transition of CH3NH3PbI3

    International Nuclear Information System (INIS)

    Kawamura, Yukihiko; Mashiyama, Hiroyuki; Hasebe, Katsuhiko


    The cubic-tetragonal phase transition of CH 3 NH 3 PbI 3 was investigated by single crystal X-ray diffractometry. The crystal structure was refined at five temperatures in the tetragonal phase. The PbI 6 octahedron rotates around the c-axis alternatively to construct the SrTiO 3 -type tetragonal structure. A methylammonium ion is partially ordered; 24 disordered states in the cubic phase are reduced to 8. With decreasing temperature, the rotation angle of the octahedron increases monotonically, which indicates it is an order parameter of the cubic-tetragonal transition. (author)

  13. Recent advances in radiotherapy: Partial Breast Irradiation (PBI) in breast cancer patients after breast conserving surgery

    International Nuclear Information System (INIS)

    Niwinska, A.


    The interest in accelerated partial breast irradiation (PBI) after conservative surgery has increased over the past decade as a result of many factors, including clinical and pathological data questioning the efficacy of whole breast irradiation in highly selected patients, as well as factors related to patient's convenience. High dose rate and low dose rate brachytherapy, brachytherapy MammoSite, Electron Intraoperative Therapy - ELIOT and Targeted Intraoperative Radiotherapy - TARGIT are the subject of investigation. The tolerability and efficacy of the treatment are of special interest. In this review article, methods of accelerated PBI, eligibility criteria, techniques of radiotherapy, early results and side effects are reviewed. (author)

  14. Crystal growth and properties of PbI2 doped with Fe and Ni

    International Nuclear Information System (INIS)

    Rybak, O.V.; Lun', Yu.O.; Bordun, I.M.; Omelyan, M.F.


    A procedure is described for doping PbI 2 monocrystals with Fe and Ni during vapor-phase growth in a closed system in the presence of excess iodine. The rate of mass transfer in the system and the doping level of the crystals are shown to be governed by the dopant content in the source material and the source temperature. The effect of Fe and Ni doping on the low-temperature (5 K) exciton photoluminescence spectrum of PbI 2 is discussed [ru

  15. Using Low Temperature Photoluminescence Spectroscopy to Investigate CH3NH3PbI3 Hybrid Perovskite Degradation

    Directory of Open Access Journals (Sweden)

    Khaoula Jemli


    Full Text Available Investigating the stability and evaluating the quality of the CH3NH3PbI3 perovskite structures is quite critical both to the design and fabrication of high-performance perovskite devices and to fundamental studies of the photophysics of the excitons. In particular, it is known that, under ambient conditions, CH3NH3PbI3 degrades producing some PbI2. We show here that low temperature Photoluminescence (PL spectroscopy is a powerful tool to detect PbI2 traces in hybrid perovskite layers and single crystals. Because PL spectroscopy is a signal detection method on a black background, small PbI2 traces can be detected, when other methods currently used at room temperature fail. Our study highlights the extremely high stability of the single crystals compared to the thin layers and defects and grain boundaries are thought to play an important role in the degradation mechanism.

  16. Improved perovskite morphology and crystallinity using porous PbI2 layers for efficient planar heterojunction solar cells (United States)

    Jia, Xianyu; Hu, Ziyang; Xu, Jie; Huang, Like; Zhang, Jing; Zhang, Jianjun; Zhu, Yuejin


    We demonstrate the flexible and facile use of porous PbI2 layers to fabricate high quality perovskite films with a dense surface and without residual PbI2. PbI2 precursor solutions by adding polystyrene pore-forming agents are first spin-coated to fabricate the wet film. A porous PbI2 layer is formed by washing off polystyrene using organic solvents. The porous PbI2 layer not only serves as a channel for transporting the CH3NH3I solution but also offers extremely enlarged contact areas, facilitating interfacial reaction with CH3NH3I. Shiny smooth perovskite films with excellent electronic quality and solar cells with an efficiency up to 17% are obtained.

  17. Effect of PbI2 deposition rate on two-step PVD/CVD all-vacuum prepared perovskite

    International Nuclear Information System (INIS)

    Ioakeimidis, Apostolos; Christodoulou, Christos; Lux-Steiner, Martha; Fostiropoulos, Konstantinos


    In this work we fabricate all-vacuum processed methyl ammonium lead halide perovskite by a sequence of physical vapour deposition of PbI 2 and chemical vapour deposition (CVD) of CH 3 NH 3 I under a static atmosphere. We demonstrate that for higher deposition rate the (001) planes of PbI 2 film show a higher degree of alignment parallel to the sample's surface. From X-ray diffraction data of the resulted perovskite film we derive that the intercalation rate of CH 3 NH 3 I is fostered for PbI 2 films with higher degree of (001) planes alignment. The stoichiometry of the produced perovskite film is also studied by Hard X-ray photoelectron spectroscopy measurements. Complete all-vacuum perovskite solar cells were fabricated on glass/ITO substrates coated by an ultra-thin (5 nm) Zn-phthalocyanine film as hole selective layer. A dependence of residual PbI 2 on the solar cells performance is displayed, while photovoltaic devices with efficiency up to η=11.6% were achieved. - Graphical abstract: A two-step PVD/CVD processed perovskite film with the CVD intercalation rate of CH 3 NCH 3 molecules been fostered by increasing the PVD rate of PbI 2 and prolonging the CVD time. - Highlights: • A simple PVD/CVD process for perovskite film production. • Increased PVD rate yields better alignment of the PbI 2 (001) crystallite planes. • CH 3 NH 3 I intercalation process fostered by increased PbI 2 PVD rate. • Stoichiometric CH 3 NH 3 PbI 3 suitable as absorber in photovoltaic applications • Reduced PbI 2 residue at the bottom of CH 3 NH 3 PbI 3 improves device performance.

  18. Automated Transportation Management System (ATMS) V2.0 logistics module PBI acceptance criteria

    International Nuclear Information System (INIS)

    Weidert, R.S.


    This document defines the acceptance criteria for the Automated Transportation Management System V2.0 Logistics Module Performance Based Incentive (PBI). This acceptance criteria will be the primary basis for the generation of acceptance test procedures. The purpose of this document is to define the minimum criteria that must be fulfilled to guarantee acceptance of the Logistics Module

  19. Electronic and optical properties of bilayer PbI2: a first-principles study (United States)

    Shen, Chenhai; Wang, Guangtao


    By employing first-principles methods, we investigate the effects of stacking patterns and interlayer coupling on the electronic structures and optical properties of bilayer (BL) PbI2. For optical properties, excitonic effects are considered. The results show that crystal-type BL PbI2 stacking pattern is the most stable bilayer structures with the equilibrium interlayer distance of 3.27 Å and a direct band structure. Moreover, for all considered patterns, the interlayer coupling can induce the band structures to transform from indirect to direct and also the band gap values to vary from 2.56 eV to 2.62 eV. In addition, our calculations show that the exciton binding energy of the most stable pattern is 0.81 eV, and excitonic effects have obvious influences on optical responses of BL PbI2. These results may be useful to future experimental studies on optoelectronic properties of two-dimensional BL PbI2 nanosheets.

  20. Preparation of porous carbon nanofibers derived from PBI/PLLA for supercapacitor electrodes. (United States)

    Jung, Kyung-Hye; Ferraris, John P


    Porous carbon nanofibers were prepared by electrospinning blend solutions of polybenzimidazole/poly-L-lactic acid (PBI/PLLA) and carbonization. During thermal treatment, PLLA was decomposed, resulting in the creation of pores in the carbon nanofibers. From SEM images, it is shown that carbon nanofibers had diameters in the range of 100-200 nm. The conversion of PBI to carbon was confirmed by Raman spectroscopy, and the surface area and pore volume of carbon nanofibers were determined using nitrogen adsorption/desorption analyses. To investigate electrochemical performances, coin-type cells were assembled using free-standing carbon nanofiber electrodes and ionic liquid electrolyte. cyclic voltammetry studies show that the PBI/PLLA-derived porous carbon nanofiber electrodes have higher capacitance due to lower electrochemical impedance compared to carbon nanofiber electrode from PBI only. These porous carbon nanofibers were activated using ammonia for further porosity improvement and annealed to remove the surface functional groups to better match the polarity of electrode and electrolyte. Ragone plots, correlating energy density with power density calculated from galvanostatic charge-discharge curves, reveal that activation/annealing further improves energy and power densities.

  1. Convergent validity of the dimensions underlying the parental bonding instrument (PBI) and the EMBU

    NARCIS (Netherlands)

    Arrindell, W.A.; Gerlsma, C.; Vandereycken, W.; Hageman, W.J J M; Daeseleire, T

    It has been suggested that the major dimensions of perceived parental rearing behaviour that underlie the EMBU (Emotional Warmth, Rejection and Protection) and the PBI (Care and Protection) may be considered parallel tests of the same constructs. Empirical findings however to back up this allegation

  2. Probing interfacial electronic properties of graphene/CH3NH3PbI3 heterojunctions: A theoretical study (United States)

    Hu, Jisong; Ji, Gepeng; Ma, Xinguo; He, Hua; Huang, Chuyun


    Interfacial interactions and electronic properties of graphene/CH3NH3PbI3 heterojunctions were investigated by first-principles calculations incorporating semiempirical dispersion-correction scheme to describe van der Waals interactions. Two lattice match configurations between graphene and CH3NH3PbI3(0 0 1) slab were constructed in parallel contact and both of them were verified to form remarkable van der Waals heterojunctions with similar work functions. Our calculated energy band structures show that the Dirac-cone of graphene and the direct band gap of CH3NH3PbI3 are still preserved in the heterojunctions, thus graphene can be a promising candidate either as a capping or supporting layer for encapsulating CH3NH3PbI3 layer. It is identified that the Schottky barrier of graphene/CH3NH3PbI3 heterojunctions can be controlled by the interlayer distance and affected by the stacking pattern of graphene and CH3NH3PbI3. The 3D charge density differences present the build-in internal electric field from graphene to CH3NH3PbI3 after interface equilibrium and thus, a low n-type Schottky barrier is needed for high efficient charge transferring in the interface. The possible mechanism of the band edge modulations in the heterojunctions and corresponding photoinduced charge transfer processes are also described.

  3. Patient benefit index (PBI) in the treatment of psoriasis--results of the National Care Study "PsoHealth". (United States)

    Radtke, Marc Alexander; Schäfer, Ines; Blome, Christine; Augustin, Matthias


    Psoriasis vulgaris is a common disease that follows a chronic course. So far, few studies have addressed outcome methods which evaluate the benefits of drugs and medical devices by measuring patient preferences. Assessment of patients' outcomes using the "Patient benefit index" (PBI), a validated goal attainment scaling tool, in the treatment of psoriasis. Data were obtained within an epidemiological study in 2,009 patients with psoriasis vulgaris and/or psoriatic arthritis. Cross-sectional study in 133 nationwide German dermatological practices and hospital departments. The following were recorded a) in the doctors' questionnaire--previous treatments and diseases, clinical characteristics and psoriasis area and severity index (PASI), b) in the patients' questionnaire--quality of life (LQ), patient-relevant therapeutic benefits and satisfaction with care. On average, patients achieved a total PBI of 2.5±1.1. 86.7% of patients showed a more than minimum benefit (PBI>1). Patients treated with biologicals had a higher benefit (mean PBI 3.0) than patients in other groups (e.g. PBI 2.6 in systemics). PBI values indicate that systemic agents and biologics are of high therapeutic benefit to the vast majority of patients. The development of the PBI has enabled a decisive step to be taken in the area of scientifically-based outcome assessments.

  4. CH3NH3PbI3 grain growth and interfacial properties in meso-structured perovskite solar cells fabricated by two-step deposition (United States)

    Yao, Zhibo; Wang, Wenli; Shen, Heping; Zhang, Ye; Luo, Qiang; Yin, Xuewen; Dai, Xuezeng; Li, Jianbao; Lin, Hong


    Although the two-step deposition (TSD) method is widely adopted for the high performance perovskite solar cells (PSCs), the CH3NH3PbI3 perovskite crystal growth mechanism during the TSD process and the photo-generated charge recombination dynamics in the mesoporous-TiO2 (mp-TiO2)/CH3NH3PbI3/hole transporting material (HTM) system remains unexploited. Herein, we modified the concentration of PbI2 (C(PbI2)) solution to control the perovskite crystal properties, and observed an abnormal CH3NH3PbI3 grain growth phenomenon atop mesoporous TiO2 film. To illustrate this abnormal grain growth mechanism, we propose that a grain ripening process is taking place during the transformation from PbI2 to CH3NH3PbI3, and discuss the PbI2 nuclei morphology, perovskite grain growing stage, as well as Pb:I atomic ratio difference among CH3NH3PbI3 grains with different morphology. These C(PbI2)-dependent perovskite morphologies resulted in varied charge carrier transfer properties throughout the mp-TiO2/CH3NH3PbI3/HTM hybrid, as illustrated by photoluminescence measurement. Furthermore, the effect of CH3NH3PbI3 morphology on light absorption and interfacial properties is investigated and correlated with the photovoltaic performance of PSCs.

  5. Mesoscopic CH 3 NH 3 PbI 3 /TiO 2 Heterojunction Solar Cells

    KAUST Repository

    Etgar, Lioz


    We report for the first time on a hole conductor-free mesoscopic methylammonium lead iodide (CH 3NH 3PbI 3) perovskite/TiO 2 heterojunction solar cell, produced by deposition of perovskite nanoparticles from a solution of CH 3NH 3I and PbI 2 in γ-butyrolactone on a 400 nm thick film of TiO 2 (anatase) nanosheets exposing (001) facets. A gold film was evaporated on top of the CH 3NH 3PbI 3 as a back contact. Importantly, the CH 3NH 3PbI 3 nanoparticles assume here simultaneously the roles of both light harvester and hole conductor, rendering superfluous the use of an additional hole transporting material. The simple mesoscopic CH 3NH 3PbI 3/TiO 2 heterojunction solar cell shows impressive photovoltaic performance, with short-circuit photocurrent J sc= 16.1 mA/cm 2, open-circuit photovoltage V oc = 0.631 V, and a fill factor FF = 0.57, corresponding to a light to electric power conversion efficiency (PCE) of 5.5% under standard AM 1.5 solar light of 1000 W/m 2 intensity. At a lower light intensity of 100W/m 2, a PCE of 7.3% was measured. The advent of such simple solution-processed mesoscopic heterojunction solar cells paves the way to realize low-cost, high-efficiency solar cells. © 2012 American Chemical Society.

  6. Degradation mechanism of CH3NH3PbI3 perovskite materials upon exposure to humid air

    International Nuclear Information System (INIS)

    Shirayama, Masaki; Kato, Masato; Fujiseki, Takemasa; Hara, Shota; Kadowaki, Hideyuki; Murata, Daisuke; Fujiwara, Hiroyuki; Miyadera, Tetsuhiko; Sugita, Takeshi; Chikamatsu, Masayuki


    Low stability of organic-inorganic perovskite (CH 3 NH 3 PbI 3 ) solar cells in humid air environments is a serious drawback which could limit practical application of this material severely. In this study, from real-time spectroscopic ellipsometry characterization, the degradation mechanism of ultra-smooth CH 3 NH 3 PbI 3 layers prepared by a laser evaporation technique is studied. We present evidence that the CH 3 NH 3 PbI 3 degradation in humid air proceeds by two competing reactions of (i) the PbI 2 formation by the desorption of CH 3 NH 3 I species and (ii) the generation of a CH 3 NH 3 PbI 3 hydrate phase by H 2 O incorporation. In particular, rapid phase change occurs in the near-surface region and the CH 3 NH 3 PbI 3 layer thickness reduces rapidly in the initial 1 h air exposure even at a low relative humidity of 40%. After the prolonged air exposure, the CH 3 NH 3 PbI 3 layer is converted completely to hexagonal platelet PbI 2 /hydrate crystals that have a distinct atomic-scale multilayer structure with a period of 0.65 ± 0.05 nm. We find that conventional x-ray diffraction and optical characterization in the visible region, used commonly in earlier works, are quite insensitive to the surface phase change. Based on results obtained in this work, we discuss the degradation mechanism of CH 3 NH 3 PbI 3 in humid air.

  7. A mindfulness training program based on brief practices (M-PBI) to reduce stress in the workplace: a randomised controlled pilot study. (United States)

    Arredondo, M; Sabaté, M; Valveny, N; Langa, M; Dosantos, R; Moreno, J; Botella, L


    Work stress is a major contributor to absenteeism and reduced work productivity. A randomised and controlled study in employee-volunteers (with Perceived Stress Scale [PSS-14]>22) was performed to assess a mindfulness program based on brief integrated mindfulness practices (M-PBI) with the aim of reducing stress in the workplace. The PSS-14 of the employees before and after 8-weeks M-PBI program, as well as after a 20-week follow-up, was assessed (primary endpoint). The employees also carried the following questionnaires (secondary endpoints): Five Facet Mindfulness Questionnaire (FFMQ), Self-Compassion Scale (SCS), Experiences Questionnaire-Decentering (EQ-D), and Maslach Burnout Inventory-General Survey (MBI-GS). Heart Rate Variability (HRV) was measured during each session in a subgroup of employees (n = 10) of the interventional group randomly selected. A total of 40 employees (77.5% female median [SD] age of 36.6 [5.6] years) took part in this study: 21 and 19 in the intervention and control group, respectively. No differences in baseline characteristics were encountered between the groups. Results show a significant decrease in stress and increase in mindfulness over time in the intervention group (PSS-14 and FFMQ; p < 0.05 both). Additionally, an improvement in decentering (EQ-D), self-compassion (SCS) and burnout (MBI-GS) were also observed compared to the control group (p < 0.05 in all). HRV measurement also showed an improvement. In conclusion, a brief practices, 8-weeks M-BIP program is an effective tool to quickly reduce stress and improve well-being in a workplace.

  8. Study of the influence of the amount of PBI-H{sub 3}PO{sub 4} in the catalytic layer of a high temperature PEMFC

    Energy Technology Data Exchange (ETDEWEB)

    Lobato, Justo; Canizares, Pablo; Rodrigo, Manuel A.; Linares, Jose J.; Pinar, F. Javier [Chemical Engineering Department, Enrique Costa Building, University of Castilla-La Mancha, Av. Camilo Jose Cela, n 12, 13071, Ciudad Real (Spain)


    The influence of the amount of polybenzimidazole (PBI)-H{sub 3}PO{sub 4} (normalized with respect to the PBI loading, which expressed as C/PBI weight ratio) content in both the anode and cathode has been studied for a PBI-based high temperature proton exchange membrane (PEM) fuel cell. The electrodes prepared with different amounts of PBI have been characterized physically, by measuring the pore size distribution, and visualizing the surface microstructure. Afterwards, the electrochemical behaviour of the electrodes has been evaluated. The catalytic electrochemical activity has been measured by voltamperometry for each electrode prepared with a different PBI content, and the cell performance results have been studied, supported by the impedance spectra, in order to determine the influence of the PBI loading in each electrode. The best results have been achieved with a C/PBI weight ratio of 20, for both the anode and the cathode. A lower C/PBI weight ratio (larger amount of PBI in the catalytic layer) reduced the electrocatalytic activity, and impaired the mass transport processes, due to the large amount of polymer covering the catalyst particle, lowering the cell performance. A higher C/PBI weight ratio (lower amount of PBI in the catalytic layer) reduced the electrocatalytic activity, and slightly increased the ohmic resistance. The low amount of the polymeric ionic carrier PBI-H{sub 3}PO{sub 4} limited the proton mobility, despite of the presence of large amounts of ''free'' H{sub 3}PO{sub 4} in the catalytic layer. (author)

  9. Role of hydrogen-bonding and its interplay with octahedral tilting in CH3NH3PbI3


    Lee, Paul David; Bristowe, Nicholas C; Bristowe, Paul D; Cheetham, Anthony Kevin


    First principles calculations on the hybrid perovskite CH3NH3PbI3 predict strong hydrogen-bonding which influences the structure and dynamics of the methylammonium cation and reveal its interaction with the tilting of the PbI6 octahedra. The calculated atomic coordinates are in excellent agreement with neutron diffraction results. [Image - see article] Funding from the Winton Programme for the Physics of Sustainability at the University of Cambridge is gratefully acknowledged. NCB acknowle...

  10. On the growth of CH3NH3PbI3-xClx single crystal and characterization (United States)

    Su, J.; Wang, W. F.; Lei, Y.; Zhang, L.; Xu, L. H.; Wang, D.; Lu, D.; Bai, Y.


    In this paper, CH3NH3PbI3-xClx crystal was grown by solution cooling method with CH3NH3I and PbCl2 as raw materials. Lead compounds and CH3NH3PbI3-xClx crystal with size about 6 mm × 4 mm × 2 mm were obtained. The chemical reactions with different CH3NH3I/PbCl2 ratios were analyzed. XPS shows the content of chlorine in CH3NH3PbI3-xClx is about 0.91%. PXRD, FT-IR, Raman and absorbance spectra were used to study the structure and optical properties of CH3NH3PbI3-xClx by comparing with CH3NH3PbI3 crystal. The CH3NH3PbI3-xClx crystal grown is of tetragonal structure with the lattice constants a = b = 8.8165 Å, c = 12.7920 Å and the bandgap value of 1.57 eV.

  11. PBI/Nafion/SiO2 hybrid membrane for high-temperature low-humidity fuel cell applications

    International Nuclear Information System (INIS)

    Wang, Liang; Advani, Suresh G.; Prasad, Ajay K.


    A novel composite membrane for fuel cell applications was prepared by incorporating SiO 2 in PBI/Nafion resin by the sol–gel method. Polybenzimidazole (PBI) was blended with Nafion to improve the membrane stability. The presence of PBI also improves the dimensional stability of the composite membrane over a wide range of hydration conditions. Being highly hygroscopic, SiO 2 enhances water absorption and retention in the membrane which improves fuel cell performance under low relative humidity conditions. Scanning electron microscopy showed that the PBI and Nafion polymers can be blended uniformly. Energy dispersive X-ray spectroscopy confirmed the presence of SiO 2 in the composite membrane. Thermal gravimetric analysis confirmed the improved thermal stability of the SiO 2 /PBI/Nafion membrane. Tensile strength, water uptake and swelling of the composite membrane were also measured at 60 °C and compared with Nafion. The fuel cell performance of the novel SiO 2 /PBI/Nafion composite membrane at 120 °C and 35% relative humidity significantly improved over a pure Nafion membrane of the same thickness

  12. Trace impurities analysis determined by neutron activation in the PbI 2 crystal semiconductor (United States)

    Hamada, M. M.; Oliveira, I. B.; Armelin, M. J.; Mesquita, C. H.


    In this work, a methodology for impurity analysis of PbI 2 was studied to investigate the effectiveness of the purification. Commercial salts were purified by the multi passes zone refining and grown by the Bridgman method. To evaluate the purification efficiency, samples from the bottom, middle and upper sections of the ZR ingot were analyzed after 200, 300 and 500 purification passes, by measurements of the impurity concentrations, using the neutron activation analysis (NAA) technique. There was a significant reduction of the impurities according to the purification numbers. The reduction efficiency was different for each element, namely: Au>Mn>Co˜Ag>K˜Br. The impurity concentration of the crystals grown after 200, 300 and 500 passes and the PbI 2 starting material were analyzed by NAA and plasma optical emission spectroscopy.

  13. Growth of semiconductor alloy InGaPBi on InP by molecular beam epitaxy

    International Nuclear Information System (INIS)

    Wang, K; Wang, P; Pan, W W; Wu, X Y; Yue, L; Gong, Q; Wang, S M


    We report the first successful growth of InGaPBi single crystals on InP substrate with Bi concentration far beyond the doping level by gas source molecular beam epitaxy. The InGaPBi thin films reveal excellent surface and structural qualities, making it a promising new III–V compound family member for heterostructures. The strain can be tuned between tensile and compressive by adjusting Ga and Bi compositions. The maximum achieved Bi concentration is 2.2 ± 0.4% confirmed by Rutherford backscattering spectroscopy. Room temperature photoluminescence shows strong and broad light emission at energy levels much smaller than the InP bandgap. (paper)

  14. Comparative study of PBI Cross Linked Utilizing Agents of Varying Steric Configurations

    DEFF Research Database (Denmark)

    Kirkebcek, Andreas; Aili, David; Li, Qingfeng


    ionic or covalent cross linking. When considering such, little attention is devoted to explore the effect of the sterical configuration of the cross linking agent. In this contribution three different cross linking agents are utilized to evaluate how these affects final membrane properties.......The high thermal and chemical stability of poly[2,2'-(m-phenylene)-5,5' bibenzimidazole] (PBI) accounts for its wise spread use in high temperature polymer electrolyte membrane fuel cells (HT- PEMFC). By doping the membrane with phosphoric acid (PA) ionic conductivity is obtained. Thus conductivity...... is dependent on the amount of PA present within the membrane. However mechanical properties are reduced are significantly reduced due to the plasticizing effect shown by PA [1]. This effect is due to PBI chain displacement. This effect can be lessened by use of cross linking [2-4]. This can be obtained using...

  15. Ultrafine polybenzimidazole (PBI) fibers. [separators for alkaline batteries and dfuel cells (United States)

    Chenevey, E. C.


    Mats were made from ultrafine polybenzimidazole (PBI) fibers to provide an alternate to the use of asbestos as separators in fuel cells and alkaline batteries. To minimize distortion during mat drying, a process to provide a dry fibrid was developed. Two fibrid types were developed: one coarse, making mats for battery separators; the other fine, making low permeability matrices for fuel cells. Eventually, it was demonstrated that suitable mat fabrication techniques yielded fuel cell separators from the coarser alkaline battery fibrids. The stability of PBI mats to 45% KOH at 123 C can be increased by heat treatment at high temperatures. Weight loss data to 1000 hours exposure show the alkali resistance of the mats to be superior to that of asbestos.

  16. Photovoltaic performance and the energy landscape of CH3NH3PbI3. (United States)

    Zhou, Yecheng; Huang, Fuzhi; Cheng, Yi-Bing; Gray-Weale, Angus


    Photovoltaic cells with absorbing layers of certain perovskites have power conversion efficiencies up to 20%. Among these materials, CH3NH3PbI3 is widely used. Here we use density-functional theory to calculate the energies and rotational energy barriers of a methylammonium ion in the α or β phase of CH3NH3PbI3 with differently oriented neighbouring methylammonium ions. Our results suggest the methylammonium ions in CH3NH3PbI3 prefer to rotate collectively, and to be parallel to their neighbours. Changes in polarization on rotation of methylammonium ions are two to three times larger than those on relaxation of the lead ion from the centre of its coordination shell. The preferences for parallel configuration and concerted rotation, with the polarisation changes, are consistent with ferroelectricity in the material, and indicate that this polarisation is governed by methylammonium orientational correlations. We show that the field due to this polarisation is strong enough to screen the field hindering charge transport, and find this screening field in agreement with experiment. We examine two possible mechanisms for the effect of methylammonium ion rotation on photovoltaic performance. One is that rearrangement of methylammoniums promotes the creation and transport of charge carriers. Some effective masses change greatly, but changes in band structure with methylammonium rotation are not large enough to explain current-voltage hysteresis behaviour. The second possible mechanism is that polarization screens the hindering electric field, which arises from charge accumulation in the transport layers. Polarization changes on methylammonium rotation favour this second mechanism, suggesting that collective reorientation of methylammonium ions in the bulk crystal are in significant part responsible for the hysteresis and power conversion characteristics of CH3NH3PbI3 photovoltaic cells.

  17. Crystal Structure Formation of CH3NH3PbI3-xClx Perovskite

    Directory of Open Access Journals (Sweden)

    Shiqiang Luo


    Full Text Available Inorganic-organic hydride perovskites bring the hope for fabricating low-cost and large-scale solar cells. At the beginning of the research, two open questions were raised: the hysteresis effect and the role of chloride. The presence of chloride significantly improves the crystallization and charge transfer property of the perovskite. However, though the long held debate over of the existence of chloride in the perovskite seems to have now come to a conclusion, no prior work has been carried out focusing on the role of chloride on the electronic performance and the crystallization of the perovskite. Furthermore, current reports on the crystal structure of the perovskite are rather confusing. This article analyzes the role of chloride in CH3NH3PbI3-xClx on the crystal orientation and provides a new explanation about the (110-oriented growth of CH3NH3PbI3 and CH3NH3PbI3-xClx.

  18. Control of PbI2 nucleation and crystallization: towards efficient perovskite solar cells based on vapor-assisted solution process (United States)

    Yang, Chongqiu; Peng, Yanke; Simon, Terrence; Cui, Tianhong


    Perovskite solar cells (PSC) have outstanding potential to be low-cost, high-efficiency photovoltaic devices. The PSC can be fabricated by numerous techniques; however, the power conversion efficiency (PCE) for the two-step-processed PSC falls behind that of the one-step method. In this work, we investigate the effects of relative humidity (RH) and dry air flow on the lead iodide (PbI2) solution deposition process. We conclude that the quality of the PbI2 film is critical to the development of the perovskite film and the performance of the PSC device. Low RH and dry air flow used during the PbI2 spin coating procedure can increase supersaturation concentration to form denser PbI2 nuclei and a more suitable PbI2 film. Moreover, airflow-assisted PbI2 drying and thermal annealing steps can smooth transformation from the nucleation stage to the crystallization stage.

  19. The effects of synthesis parameters on the formation of PbI2 particles under DTAB-assisted hydrothermal process

    International Nuclear Information System (INIS)

    Zhu Gangqiang; Hojamberdiev, Mirabbos; Liu Peng; Peng Jianhong; Zhou Jianping; Bian Xiaobin; Huang Xijin


    Highlights: ► Submicron- and micron-sized PbI 2 particles were hydrothermally synthesized. ► Structural transformation form belt-like to rod- and microtube-like was observed. ► Phase-pure PbI 2 particles could be hydrothermally obtained at pH 2 particles. ► The optical band gap energy of PbI 2 was slightly affected by morphology. - Abstract: Submicron- and micron-sized lead iodide (PbI 2 ) particles with well-controlled morphologies were successfully fabricated via a low-temperature hydrothermal process assisted by dodecyltrimethylammonium bromide (DTAB) as cationic surfactant. The as-synthesized powders were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and UV–vis spectroscopy. The effects of synthesis parameters (temperature, time, pH, and surfactant amount) were systematically investigated. The obtained results showed that the submicron structure was belt-like at 100–120 °C, transformed to rod-like by increasing temperature to 140 °C and it became a microtube-like at 160–200 °C. By changing the pH of the synthesizing solution, it was found that a pure PbI 2 phase could be obtained below 7. With the addition of increasing amount of surfactant, microparticles were converted to microrods → submicron belts → microtubes. The time-dependent experimental results revealed that the dissolution–recrystallization and dissolution–recrystallization–self-oriented-attachment were considered to be the possible mechanisms for the formation of the belt- and tube-like PbI 2 submicron- and micron-sized particles, respectively. The optical properties of the PbI 2 particles synthesized at 100–200 °C for 8 h under hydrothermal conditions were also studied.

  20. Fabrication and Scale-up of Polybenzimidazole (PBI) Membrane Based System for Precombustion-Based Capture of Carbon Dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Krishnan, Gopala; Jayaweera, Indira; Sanjrujo, Angel; O' Brien, Kevin; Callahan, Richard; Berchtold, Kathryn; Roberts, Daryl-Lynn; Johnson, Will


    The primary objectives of this project are to (1) demonstrate the performance and fabrication of a technically and economically viable pre-combustion-based CO{sub 2} capture system based on the high temperature stability and permeance of PBI membranes, (2) optimize a plan for integration of PBI capture system into an IGCC plant and (3) develop a commercialization plan that addresses technical issues and business issues to outline a clear path for technology transfer of the PBI membrane technology. This report describes research conducted from April 1, 2007 to March 30, 2012 and focused on achieving the above objectives. PBI-based hollow fibers have been fabricated at kilometer lengths and bundled as modules at a bench-scale level for the separation of CO{sub 2} from H{sub 2} at high temperatures and pressures. Long term stability of these fibers has been demonstrated with a relatively high H{sub 2}/CO{sub 2} selectivity (35 to 50) and H{sub 2} permeance (80 GPU) at temperatures exceeding 225°C. Membrane performance simulations and systems analysis of an IGCC system incorporating a PBI hollow fiber membrane modules have demonstrated that the cost of electricity for CO{sub 2} capture (<10%) using such a high temperature separator. When the cost of transporting, storing, and monitoring the CO{sub 2} is accounted for, the increase in the COE is only 14.4%.

  1. Adverse Effects of Excess Residual PbI2 on Photovoltaic Performance, Charge Separation, and Trap-State Properties in Mesoporous Structured Perovskite Solar Cells. (United States)

    Wang, Hao-Yi; Hao, Ming-Yang; Han, Jun; Yu, Man; Qin, Yujun; Zhang, Pu; Guo, Zhi-Xin; Ai, Xi-Cheng; Zhang, Jian-Ping


    Organic-inorganic halide perovskite solar cells have rapidly come to prominence in the photovoltaic field. In this context, CH 3 NH 3 PbI 3 , as the most widely adopted active layer, has been attracting great attention. Generally, in a CH 3 NH 3 PbI 3 layer, unreacted PbI 2 inevitably coexists with the perovskite crystals, especially following a two-step fabrication process. There appears to be a consensus that an appropriate amount of unreacted PbI 2 is beneficial to the overall photovoltaic performance of a device, the only disadvantageous aspect of excess residual PbI 2 being viewed as its insulating nature. However, the further development of such perovskite-based devices requires a deeper understanding of the role of residual PbI 2 . In this work, PbI 2 -enriched and PbI 2 -controlled perovskite films, as two extreme cases, have been prepared by modulating the crystallinity of a pre-deposited PbI 2 film. The effects of excess residual PbI 2 have been elucidated on the basis of spectroscopic and optoelectronic studies. The initial charge separation, the trap-state density, and the trap-state distribution have all been found to be adversely affected in PbI 2 -enriched devices, to the detriment of photovoltaic performance. This leads to a biphasic recombination process and accelerates the charge carrier recombination dynamics. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Effects of current stressing on the p-Bi2Te3/Sn interfacial reactions

    International Nuclear Information System (INIS)

    Chan, Hsing-Ting; Lin, Chih-Fan; Yen, Yee-Wen; Chen, Chih-Ming


    The Sn/p-Bi 2 Te 3 /Sn sandwich-type sample was current stressed with a density of 150 A/cm 2 to investigate the effects of current stressing on the p-Bi 2 Te 3 /Sn interfacial reactions. Asymmetrical heating phenomenon was observed at the anodic Sn/p-Bi 2 Te 3 (50 °C) and cathodic p-Bi 2 Te 3 /Sn (120 °C) interfaces due to the Peltier effect. Besides the Peltier effect, the electromigration effect also influenced the growth of the SnTe phase and therefore polarity growth behavior was observed at the two interfaces. The growth of the SnTe phase at the cathodic p-Bi 2 Te 3 /Sn interface was accelerated because Peltier and electromigration effects drove more Sn atoms (dominant diffusion species) for the phase growth. By measuring the electromigration-induced atomic flux of Sn, the product of diffusivity and effective charge number (D × z*) was calculated to be 6.3 × 10 −9 cm 2 s −1 at 120 °C. - Highlights: • Sn/p-Bi 2 Te 3 /Sn sandwich-type sample is current stressed with a density of 150 A/cm 2 . • Passage of an electric current induces Peltier and electromigration effects. • Peltier effect causes asymmetrical heating at the anode and cathode interfaces. • Both effects accelerate the SnTe growth at the cathode interface. • Sn is the dominant diffusion species identified by a marker experiment.

  3. Organoelemental intercalation compounds in the system PbI2-ethan olamine

    International Nuclear Information System (INIS)

    Gurina, G.I.; Evtushenko, V.D.; Muraeva, O.A.; Ignatyuk, V.P.; Koshkin, V.M.


    Two intercalation phases with different stoichiometry in system PbI 2 -ethanolamine are identified, using the methods of IR spectroscopy, spectroscopy of diffusion reflection, X-ray phase and thermogravimetric analyses. Formation kinetics of intercalation compounds in the system, having two phases, differing in the content of intercalant in the matrix layers, is studied. In conformity with thermodynamic theory of intercalation, it is shown experimentally, that the value of a charge, transferred from intercalant molecules to the matrix layer, decreases with the increase in intercalant content in interlayer spaces

  4. Shape-Evolution Control of hybrid perovskite CH3NH3PbI3 crystals via solvothermal synthesis (United States)

    Zhang, Baohua; Guo, Fuqiang; Yang, Lianhong; Jia, Xiuling; Liu, Bin; Xie, Zili; Chen, Dunjun; Lu, Hai; Zhang, Rong; Zheng, Youdou


    We systematically synthesized CH3NH3PbI3 crystals using solvothermal process, and the reaction conditions such as concentration of the precursor, temperature, time, and lead source have been comprehensively investigated to obtain shape-controlled CH3NH3PbI3 crystals. The results showed that the CH3NH3PbI3 crystals exhibit tetragonal phase and the crystals change from nanoparticles to hopper-faced cuboids. Photoluminescence spectra of the crystals obtained with different lead sources show a blue shift due to the presence of defects in the crystals, and the peak intensity is very sensitive to the lead sources. Moreover, impurities (undesirable byproducts and excess components like HI or CH3NH2) presented during crystal growth can result in hopper growth.

  5. Investigation and thermodynamic calculation of phase diagram of CdI2-PbI2-NaI system

    International Nuclear Information System (INIS)

    Storonkin, A.V.; Vasil'kova, I.V.; Korobkov, S.V.


    Using the thermographic and X-ray phase analyses binary CdI 2 -PbI 2 , PI 2 -NaI, CdI 2 -NaI systems and a triple CdI 2 -PbI 2 -NaI system are investigated and their melting diagrams are plotted. A method of thermodynamic calculation has been proposed and tested of the shape of the eutectic lines for the system CdI 2 -PbI 2 -NaI, taking into account the non-ideality of the liquid phase. The method uses data obtained for the binary systems. The liquidus surface of the triple system has been constructed on the basis of the calculation. The results of the calculation of the triple eutectics are in good agreement with the experimental data

  6. Hybrid perovskite solar cells: In situ investigation of solution-processed PbI2 reveals metastable precursors and a pathway to producing porous thin films

    KAUST Repository

    Barrit, Dounya


    The successful and widely used two-step process of producing the hybrid organic-inorganic perovskite CH3NH3PbI3, consists of converting a solution deposited PbI2 film by reacting it with CH3NH3I. Here, we investigate the solidification of PbI2 films from a DMF solution by performing in situ grazing incidence wide angle X-ray scattering (GIWAXS) measurements. The measurements reveal an elaborate sol–gel process involving three PbI2⋅DMF solvate complexes—including disordered and ordered ones—prior to PbI2 formation. The ordered solvates appear to be metastable as they transform into the PbI2 phase in air within minutes without annealing. Morphological analysis of air-dried and annealed films reveals that the air-dried PbI2 is substantially more porous when the coating process produces one of the intermediate solvates, making this more suitable for subsequent conversion into the perovskite phase. The observation of metastable solvates on the pathway to PbI2 formation open up new opportunities for influencing the two-step conversion of metal halides into efficient light harvesting or emitting perovskite semiconductors.

  7. Can Parental Bonding Be Assessed in Children? Factor Structure and Factorial Invariance of the Parental Bonding Instrument (PBI) between Adults and Children (United States)

    Tsaousis, Ioannis; Mascha, Katerina; Giovazolias, Theodoros


    This study examined the factorial structure of the Parental Bonding Instrument (PBI) in the Greek population. Using confirmatory factor analysis different proposed models of the basic dimensions of PBI were evaluated. The results indicated that Kendler's three-factor (i.e. care, protectiveness and authoritarianism) solution was found to be more…


    Directory of Open Access Journals (Sweden)

    Septiana Ika Purwandari


    Full Text Available Tujuan penelitian ini untuk mengetahui sikap pekerja informal non PBI terhadap program JKN di Kabupaten Brebes.Jenis Penelitian ini deskriptif dengan pendekatan kuantitatif. Populasi semua pekerja informal non PBI yang belum terdaftar JKN di Kabupaten Brebes. Sampel berjumalah 347 responden menggunakan teknik accidental sampling. Instrumen yang digunakan dalam penelitian ini adalah kuesioner.Dari 347 responden didapatkan hasil dengan 56,5% pekerja informal non PBI di Kabupaten Brebes mendukung terhadap program JKNdan 43,5% tidak mendukung, 83,3%mendukung menjadi peserta PBI, 25,4% mendukung dengan adanya denda, rata rata 86,76% mendukung semua pelayanan dalam JKN, rata rata 78,4% mendukung terhadap pengelolaan dana oleh BPJS kesehatan, dan 92,5% mendukung fasilitasnya.Saran bagi BPJS kesehatan untuk menginformasikan secara jelas dan lengkap tentang jaminan kesehatan nasional, bagi kelurahan untuk memilih warganya dengan adil dan bijaksana dan bagi peneliti selanjutnya untuk lebih mengembangkan penelitian mengenai BPJS kesehatan dan JKN. The purpose of this research was to know the attitude of informal workers non PBI(not supporting fund receiver that has not been registered in national health insurance at the district of Brebes. This research was descriptive quantitative. The population in this research were all informal workers non PBI(not supporting fund receiver that has not been registered national health insurance at the district of Brebes. Thesample were 347 respondents which obtained by accidental sampling technique. An instrument used in this research was the questionnaire.Based on the research of 347 respondents were obtained the result with 56,5% of informalworkersnon PBI(not supporting fund receiver at the district of Brebes was support the national health care program and 43,5% were not support, 83,3% support to become participants PBI (supporting fund receiver, 25,4% support with the fines, average 86,76% supported of all regarding

  9. Time-resolved photoemission spectroscopy of electronic cooling and localization in CH3NH3PbI3 crystals (United States)

    Chen, Zhesheng; Lee, Min-i.; Zhang, Zailan; Diab, Hiba; Garrot, Damien; Lédée, Ferdinand; Fertey, Pierre; Papalazarou, Evangelos; Marsi, Marino; Ponseca, Carlito; Deleporte, Emmanuelle; Tejeda, Antonio; Perfetti, Luca


    We measure the surface of CH3NH3PbI3 single crystals by making use of two-photon photoemission spectroscopy. Our method monitors the electronic distribution of photoexcited electrons, explicitly discriminating the initial thermalization from slower dynamical processes. The reported results disclose the fast-dissipation channels of hot carriers (0.25 ps), set an upper bound to the surface-induced recombination velocity (PbI3 samples is consistent with the progressive reduction of photoconversion efficiency in operating devices. Minimizing the density of shallow traps and solving the aging problem may boost the macroscopic efficiency of solar cells to the theoretical limit.

  10. Transparent and flexible photodetectors based on CH3NH3PbI3 perovskite nanoparticles (United States)

    Jeon, Young Pyo; Woo, Sung Jun; Kim, Tae Whan


    Transparent and flexible photodetectors (PDs) based on CH3NH3PbI3 perovskite nanoparticles (NPs) were fabricated by using co-evaporation of methyl ammonium iodide and lead iodide. X-ray diffraction patterns and high-resolution transmission electron microscopy images demonstrated the formation of perovskite NPs. The optical transmittance of the perovskite NPs/glass was above 80% over the entire range of visible wavelengths, indicative of high transparency. The PDs based on CH3NH3PbI3 perovskite NPs were sensitive to a broad range of visible light from 450 to 650 nm. The currents in the PDs under exposure to red, green, and blue light-emitting diodes were enhanced to 5, 10, and 20 times that of the PD in the dark, respectively. The rise and the decay times of the PDs were 50 and 120 μs. The current in the perovskite NP PD on a polyethylene terephthalate substrate was enhanced by approximately 69% when the NP PD was exposed to a blue LED emitting at a wavelength of 459 nm. Despite multiple bending, the transparent and flexible PDs based on methyl ammonium iodide and lead iodide NPs showed reproducibility and high stability in performance.

  11. Enhanced forward osmosis from chemically modified polybenzimidazole (PBI) nanofiltration hollow fiber membranes with a thin wall

    KAUST Repository

    Wang, Kai Yu; Yang, Qian; Chung, Tai-Shung; Rajagopalan, Raj


    To develop high-flux and high-rejection forward osmosis (FO) membranes for water reuses and seawater desalination, we have fabricated polybenzimidazole (PBI) nanofiltration (NF) hollow fiber membranes with a thin wall and a desired pore size via non-solvent induced phase inversion and chemically cross-linking modification. The cross-linking by p-xylylene dichloride can finely tune the mean pore size and enhance the salt selectivity. High water permeation flux and improved salt selectivity for water reuses were achieved by using the 2-h modified PBI NF membrane which has a narrow pore size distribution. Cross-linking at a longer time produces even a lower salt permeation flux potentially suitable for desalination but at the expense of permeation flux due to tightened pore sizes. It is found that draw solution concentration and membrane orientations are main factors determining the water permeation flux. In addition, effects of membrane morphology and operation conditions on water and salt transport through membrane have been investigated. © 2008 Elsevier Ltd. All rights reserved.

  12. Room temperature solution processed low dimensional CH3NH3PbI3 NIR detector (United States)

    Besra, N.; Paul, T.; Sarkar, P. K.; Thakur, S.; Sarkar, S.; Das, A.; Chanda, K.; Sardar, K.; Chattopadhyay, K. K.


    Metal halide perovskites have recently drawn immense research interests among the worldwide scientific community due to their excellent light harvesting capabilities and above all, cost effectiveness. These new class of materials have already been used as efficient optoelectronic devices e.g. solar cells, photo detectors, etc. Here in this work, room temperature NIR (near infra red) response of organic-inorganic lead halide perovskite CH3NH3PbI3 (Methylammonium lead tri iodide) nanorods has been studied. A very simple solution process technique has been adopted to synthesize CH3NH3PbI3 nanostructures at room temperature. The NIR exposure upon the sample resulted in a considerable hike in its dark current with very good responsivity (0.37 mA/W). Along with that, a good on-off ratio (41.8) was also obtained when the sample was treated under a pulsed NIR exposure with operating voltage of 2 V. The specific detectivity of the device came in the order of 1010 Jone.

  13. Electrochemical promotion of catalytic reactions with Pt/C (or Pt/Ru/C)//PBI catalysts

    DEFF Research Database (Denmark)

    Petrushina, Irina; Bjerrum, Niels; Bandur, Viktor


    The paper is an overview of the results of the investigation on electrochemical promotion of three catalytic reactions: methane oxidation with oxygen, NO reduction with hydrogen at 135 degrees C and Fischer-Tropsch synthesis (FTS) at 170 degrees C in the [CH4/O-2(or NO/H-2 or CO/H-2)/Ar//Pt(or Pt....../Ru)//PBI(H3PO4)/H-2, Ar] fuel cell. It has been shown that the partial methane oxidation to C2H2 and the C-2 selectivity were electrochemically promoted by the negative catalyst polarization. This was also the case in NO reduction with hydrogen for low NO and H-2 partial pressures. In both cases the catalytic...... reactions have been promoted by the electrochemically produced hydrogen. It has been found that the NO reduction with hydrogen on the Pt/PBI strongly depends on NO and hydrogen partial pressures in the working gas mixture. At higher NO and H-2 partial pressures the catalysis is promoted...

  14. Definitive hematopoietic stem/progenitor cells manifest distinct differentiation output in the zebrafish VDA and PBI. (United States)

    Jin, Hao; Sood, Raman; Xu, Jin; Zhen, Fenghua; English, Milton A; Liu, P Paul; Wen, Zilong


    One unique feature of vertebrate definitive hematopoiesis is the ontogenic switching of hematopoietic stem cells from one anatomical compartment or niche to another. In mice, hematopoietic stem cells are believed to originate in the aorta-gonad-mesonephros (AGM), subsequently migrate to the fetal liver (FL) and finally colonize the bone marrow (BM). Yet, the differentiation potential of hematopoietic stem cells within early niches such as the AGM and FL remains incompletely defined. Here, we present in vivo analysis to delineate the differentiation potential of definitive hematopoietic stem/progenitor cells (HSPCs) in the zebrafish AGM and FL analogies, namely the ventral wall of dorsal aorta (VDA) and the posterior blood island (PBI), respectively. Cell fate mapping and analysis of zebrafish runx1(w84x) and vlad tepes (vlt(m651)) mutants revealed that HSPCs in the PBI gave rise to both erythroid and myeloid lineages. However, we surprisingly found that HSPCs in the VDA were not quiescent but were uniquely adapted to generate myeloid but not erythroid lineage cells. We further showed that such distinct differentiation output of HSPCs was, at least in part, ascribed to the different micro-environments present in these two niches. Our results highlight the importance of niche in shaping the differentiation output of developing HSPCs.

  15. Enhanced forward osmosis from chemically modified polybenzimidazole (PBI) nanofiltration hollow fiber membranes with a thin wall

    KAUST Repository

    Wang, Kai Yu


    To develop high-flux and high-rejection forward osmosis (FO) membranes for water reuses and seawater desalination, we have fabricated polybenzimidazole (PBI) nanofiltration (NF) hollow fiber membranes with a thin wall and a desired pore size via non-solvent induced phase inversion and chemically cross-linking modification. The cross-linking by p-xylylene dichloride can finely tune the mean pore size and enhance the salt selectivity. High water permeation flux and improved salt selectivity for water reuses were achieved by using the 2-h modified PBI NF membrane which has a narrow pore size distribution. Cross-linking at a longer time produces even a lower salt permeation flux potentially suitable for desalination but at the expense of permeation flux due to tightened pore sizes. It is found that draw solution concentration and membrane orientations are main factors determining the water permeation flux. In addition, effects of membrane morphology and operation conditions on water and salt transport through membrane have been investigated. © 2008 Elsevier Ltd. All rights reserved.

  16. Growing large columnar grains of CH3NH3PbI3 using the solid-state reaction method enhanced by less-crystallized nanoporous PbI2 films (United States)

    Zheng, Huifeng; Wang, Weiqi; Liu, Yangqiao; Sun, Jing


    Compact, pinhole-free and PbI2-free perovskite films, are desirable for high-performance perovskite solar cells (PSCs), especially if large columnar grains are obtained in which the adverse effects of grain boundaries will be minimized. However, the conventional solid-state reaction methods, originated from the two-step method, failed to grow columnar grains of CH3NH3PbI3 in a facile way. Here, we demonstrate a strategy for growing large columnar grains of CH3NH3PbI3, by less-crystallized nanoporous PbI2 (ln-PbI2) film enhanced solid-state reaction method. We demonstrated columnar grains were obtainable only when ln-PbI2 films were applied. Therefore, the replacement of compact PbI2 by ln-PbI2 in the solid-sate reaction, leads to higher power conversion efficiency, better reproducibility, better stability and less hysteresis. Furthermore, by systematically investigating the effects of annealing temperature and duration, we found that an annealing temperature ≥120 °C was also critical for growing columnar grains. With the optimal process, a champion efficiency of 16.4% was obtained and the average efficiency reached 14.2%. Finally, the mechanism of growing columnar grains was investigated, in which a VPb″ -assisted hooping model was proposed. This work reveals the origins of grain growth in the solid-state reaction method, which will contribute to preparing high quality perovskite films with much larger columnar grains.

  17. Effect of the Ultrasonic Substrate Vibration on Nucleation and Crystallization of PbI2 Crystals and Thin Films

    Directory of Open Access Journals (Sweden)

    Fatemeh Zabihi


    Full Text Available Preparation of defect-free and well-controlled solution-processed crystalline thin films is highly desirable for emerging technologies, such as perovskite solar cells. In this work, using PbI2 as a model solution with a vast variety of applications, we demonstrate that the excitation of a liquid thin film by imposed ultrasonic vibration on the film substrate significantly affects the nucleation and crystallization kinetics of PbI2 and the morphology of the resulting solid thin film. It is found that by applying ultrasonic vibration to PbI2 solution spun onto an ITO substrate with a moderate power and excitation duration (5 W and 1 min for the 40 kHz transducer used in this study, the nucleation rate increases and the crystals transform from 2D or planar to epitaxial 3D columnar structures, resulting in the suppression of crystallization dewetting. The effects of various induced physical phenomena as a result of the excitation by ultrasonic vibration are discussed, including microstreaming and micromixing, increased heat transfer and local temperature, a change in the thermodynamic state of the solution, and a decrease in the supersaturation point. It is shown that the ultrasonic-assisted solution deposition of the PbI2 thin films is controllable and reproducible, a process which is low-cost and in line with the large-scale fabrication of such solution-processed thin films.

  18. Third-order nonlinear optical properties of GeSe2-Ga2Se3-PbI2 glasses

    International Nuclear Information System (INIS)

    Tang Gao; Liu Cunming; Luo Lan; Chen Wei


    The third-order nonlinear optical (NLO) properties of new selenium-based GeSe 2 -Ga 2 Se 3 -PbI 2 glasses have been measured using the optical Kerr effect (OKE) technique, with picosecond and femtosecond laser pulses. The 0.70GeSe 2 -0.15Ga 2 Se 3 -0.15PbI 2 glass has the largest third-order optical nonlinear susceptibility in GeSe 2 -Ga 2 Se 3 -PbI 2 glass system with χ (3) of 5.28x10 12 esu. In addition, the response time of glasses is sub-picosecond, which is predominantly associated with electron cloud. Local structure of the glasses has been identified by using Raman studies, while the origins of the observed nonlinear optical response are discussed. The [Ge(Ga)Se 4 ] tetrahedral and lone-pair electrons from highly polarizable Pb atom in glasses play an important role in enhanced NLO response. These results as well as their good chemical stability indicate that GeSe 2 -Ga 2 Se 3 -PbI 2 glasses are promising materials for photonic applications of third-order nonlinear optical signal processing.

  19. Synergic solventing-out crystallization with subsequent time-delay thermal annealing of PbI2 precursor in mesostructured perovskite solar cells (United States)

    Jia, Fujin; Guo, Yanqun; Che, Lijia; Liu, Zhiyong; Zeng, Zhigang; Cai, Chuanbing


    Although the two-step sequential deposition method provides an efficient route to fabricate high performance perovskite solar cells (PSSCs) with increasing reproducibility, the inefficient and incomplete conversion of PbI2 to perovskite is still quite a challenge. Following pioneering works, we found that the conversion process from PbI2 to perovskite mainly involves diffusion, infiltration, contact and reaction. In order to facilitate the conversion from PbI2 to perovskite, we demonstrate an effective method to regulate supersaturation level (the driving force to crystallization) of PbI2 by solventing-out crystallization combining with subsequent time-delay thermal annealing of PbI2 wet film. Enough voids and spaces in resulting porous PbI2 layer will be in favor of efficient diffusion, infiltration of CH3NH3I solution, and further enhance the contact and reaction between PbI2 and CH3NH3I in the whole film, leading to rapid, efficient and complete perovskite conversion with a conversion level of about 99.9%. Enhancement of light harvesting ranging from visible to near-IR region was achieved for the resultant high-quality perovskite. Upon this combined method, the fabricated mesostructured solar cells show tremendous power conversion efficiency (PCE) improvement from 3.2% to about 12.3% with less hysteresis owing to the simultaneous enhancement of short-circuit photocurrent density (J sc), open-circuit voltage (V oc) and fill factor (FF).

  20. Evolution of Chemical Composition, Morphology, and Photovoltaic Efficiency of CH 3 NH 3 PbI 3 Perovskite under Ambient Conditions

    KAUST Repository

    Huang, Weixin; Manser, Joseph S.; Kamat, Prashant V.; Ptasinska, Sylwia


    © 2015 American Chemical Society. The surface composition and morphology of CH3NH3PbI3 perovskite films stored for several days under ambient conditions were investigated by X-ray photoelectron spectroscopy, scanning electron microscopy, and X-ray diffraction techniques. Chemical analysis revealed the loss of CH3NH3 + and I- species from CH3NH3PbI3 and its subsequent decomposition into lead carbonate, lead hydroxide, and lead oxide. After long-term storage under ambient conditions, morphological analysis revealed the transformation of randomly distributed defects and cracks, initially present in the densely packed crystalline structure, into relatively small grains. In contrast to PbI2 powder, CH3NH3PbI3 exhibited a different degradation trend under ambient conditions. Therefore, we propose a plausible CH3NH3PbI3 decomposition pathway that explains the changes in the chemical composition of CH3NH3PbI3 under ambient conditions. In addition, films stored under such conditions were incorporated into photovoltaic cells, and their performances were examined. The chemical changes in the decomposed films were found to cause a significant decrease in the photovoltaic efficiency of CH3NH3PbI3.

  1. Evolution of Chemical Composition, Morphology, and Photovoltaic Efficiency of CH 3 NH 3 PbI 3 Perovskite under Ambient Conditions

    KAUST Repository

    Huang, Weixin


    © 2015 American Chemical Society. The surface composition and morphology of CH3NH3PbI3 perovskite films stored for several days under ambient conditions were investigated by X-ray photoelectron spectroscopy, scanning electron microscopy, and X-ray diffraction techniques. Chemical analysis revealed the loss of CH3NH3 + and I- species from CH3NH3PbI3 and its subsequent decomposition into lead carbonate, lead hydroxide, and lead oxide. After long-term storage under ambient conditions, morphological analysis revealed the transformation of randomly distributed defects and cracks, initially present in the densely packed crystalline structure, into relatively small grains. In contrast to PbI2 powder, CH3NH3PbI3 exhibited a different degradation trend under ambient conditions. Therefore, we propose a plausible CH3NH3PbI3 decomposition pathway that explains the changes in the chemical composition of CH3NH3PbI3 under ambient conditions. In addition, films stored under such conditions were incorporated into photovoltaic cells, and their performances were examined. The chemical changes in the decomposed films were found to cause a significant decrease in the photovoltaic efficiency of CH3NH3PbI3.

  2. Remnant PbI2, an unforeseen necessity in high-efficiency hybrid perovskite-based solar cells?

    Directory of Open Access Journals (Sweden)

    Duyen H. Cao


    Full Text Available Perovskite-containing solar cells were fabricated in a two-step procedure in which PbI2 is deposited via spin-coating and subsequently converted to the CH3NH3PbI3 perovskite by dipping in a solution of CH3NH3I. By varying the dipping time from 5 s to 2 h, we observe that the device performance shows an unexpectedly remarkable trend. At dipping times below 15 min the current density and voltage of the device are enhanced from 10.1 mA/cm2 and 933 mV (5 s to 15.1 mA/cm2 and 1036 mV (15 min. However, upon further conversion, the current density decreases to 9.7 mA/cm2 and 846 mV after 2 h. Based on X-ray diffraction data, we determined that remnant PbI2 is always present in these devices. Work function and dark current measurements showed that the remnant PbI2 has a beneficial effect and acts as a blocking layer between the TiO2 semiconductor and the perovskite itself reducing the probability of back electron transfer (charge recombination. Furthermore, we find that increased dipping time leads to an increase in the size of perovskite crystals at the perovskite-hole-transporting material interface. Overall, approximately 15 min dipping time (∼2% unconverted PbI2 is necessary for achieving optimal device efficiency.

  3. Performance Degradation Tests of Phosphoric Acid Doped PBI Membrane Based High Temperature PEM Fuel Cells

    DEFF Research Database (Denmark)

    Zhou, Fan; Araya, Samuel Simon; Grigoras, Ionela


    Degradation tests of two phosphoric acid (PA) doped PBI membrane based HT-PEM fuel cells were reported in this paper to investigate the effects of start/stop and the presence of methanol in the fuel to the performance degradation. Continuous tests with H2 and simulated reformate which was composed...... of H2, water steam and methanol as the fuel were performed on both single cells. 12-h-startup/12-h-shutdown dynamic tests were performed on the first single cell with pure dry H2 as the fuel and on the second single cell with simulated reformate as the fuel. Along with the tests electrochemical...... techniques such as polarization curves and electrochemical impedance spectroscopy (EIS) were employed to study the degradation mechanisms of the fuel cells. Both single cells showed an increase in the performance in the H2 continuous tests, because of a decrease in the ORR kinetic resistance probably due...

  4. Mechanical response of CH3NH3PbI3 nanowires (United States)

    Ćirić, L.; Ashby, K.; Abadie, T.; Spina, M.; Duchamp, M.; Náfrádi, B.; Kollár, M.; Forró, L.; Horváth, E.


    We report a systematic study of the mechanical response of methylammonium lead triiodide CH3NH3PbI3 nanowires by employing bending measurements using atomic force microscope on suspended wires over photo-lithographically patterned channels. Force-deflection curves measured at room temperature give a Young's modulus between 2 and 14 GPa. This broad range of values is attributed to the variations in the microcrystalline texture of halide perovskite nanowires. The mechanical response of a highly crystalline nanowire is linear with force and has a brittle character. The braking modulus of 48 ± 20 MPa corresponds to 100 μm of radius of curvature of the nanowires, rendering them much better structures for flexible devices than spin coated films. The measured moduli decrease rapidly if the NW is exposed to water vapor.

  5. Effects of GeI2 or ZnI2 addition to perovskite CH3NH3PbI3 photovoltaic devices (United States)

    Tanaka, Hiroki; Ohishi, Yuya; Oku, Takeo


    CH3NH3PbI3 added with GeI2 or ZnI2 perovskite photovoltaic devices were fabricated characterized. The surface coverages of the perovskite layers were improved by the addition of GeI2 or ZnI2. Formation of PbI2 observed for the pristine CH3NH3PbI3 was suppressed by the GeI2 or ZnI2 addition, which resulted in the improvement of the conversion efficiencies of the perovskite photovoltaic devices.

  6. Emotional Reasoning and Parent-Based Reasoning in Non-Clinical Children, and Their Prospective Relationships with Anxiety Symptoms (United States)

    Morren, Mattijn; Muris, Peter; Kindt, Merel; Schouten, Erik; van den Hout, Marcel


    Emotional and parent-based reasoning refer to the tendency to rely on personal or parental anxiety response information rather than on objective danger information when estimating the dangerousness of a situation. This study investigated the prospective relationships of emotional and parent-based reasoning with anxiety symptoms in a sample of…

  7. Emotional reasoning and parent-based reasoning in non-clinical children and their prospective relationships with anxiety symptoms

    NARCIS (Netherlands)

    Morren, M.; Muris, P.; Kindt, M.; Schouten, E.; van den Hout, M.


    Emotional and parent-based reasoning refer to the tendency to rely on personal or parental anxiety response information rather than on objective danger information when estimating the dangerousness of a situation. This study investigated the prospective relationships of emotional and parent-based

  8. Symmetric and asymmetric zeolitic imidazolate frameworks (ZIFs)/polybenzimidazole (PBI) nanocomposite membranes for hydrogen purification at high temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Tingxu; Shi, Gui Min; Chung, Tai-Shung [Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore (Singapore)


    High-performance zeolitic imidazolate frameworks (ZIFs)/polybenzimidazole (PBI) nanocomposites are molecularly designed for hydrogen separation at high temperatures, and demonstrate it in a useful configuration as dual-layer hollow fibers for the first time. By incorporating as-synthesized nanoporous ZIF-8 nanoparticles into the high thermal stability but extremely low permeability polybenzimidazole (PBI), the resultant mixed matrix membranes show an impressive enhancement in H{sub 2} permeability as high as a hundred times without any significant deduction in H{sub 2}/CO{sub 2} selectivity. The 30/70 ZIF-8/PBI dense membrane has a H{sub 2} permeability of 105.4 Barrer and a H{sub 2}/CO{sub 2} selectivity of 12.3. This performance is far superior to ZIF-7/PBI membranes and is the best ever reported data for H{sub 2}-selective polymeric materials in the literature. Meanwhile, defect-free ZIF-8-PBI/Matrimid dual-layer hollow fibers are successfully fabricated, without post-annealing and coating, by optimizing ZIF-8 nanoparticle loadings, spinning conditions, and solvent-exchange procedures. Two types of hollow fibers targeted at either high H{sub 2}/CO{sub 2} selectivity or high H{sub 2} permeance are developed: i) PZM10-I B fibers with a medium H{sub 2} permeance of 64.5 GPU (2.16 x 10{sup -8} mol m{sup -2} s{sup -1} Pa{sup -1}) at 180 C and a high H{sub 2}/CO{sub 2} selectivity of 12.3, and, ii) PZM33-I B fibers with a high H{sub 2} permeance of 202 GPU (6.77 x 10{sup -8} mol m{sup -2} s{sup -1} Pa{sup -1}) at 180 C and a medium H{sub 2}/CO{sub 2} selectivity of 7.7. This work not only molecularly designs novel nanocomposite materials for harsh industrial applications, such as syngas and hydrogen production, but also, for the first time, synergistically combines the strengths of both ZIF-8 and PBI for energy-related applications. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  9. Stable and metastable phases in reciprocal systems PbSe + Ag2I2 Ag2Se + PbI2 and PbSe + CdI2 = CdSe + PbI2

    International Nuclear Information System (INIS)

    Odin, I.N.; Grin'ko, V.V.; Kozlovskij, V.F.; Safronov, E.V.


    Mutual system PbSe + Ag 2 I 2 = Ag 2 Se + PbI 2 is investigated. It is shown that diagonal Ag 2 Se-PbI 2 is stable. Liquidus surface and isothermal section at 633 K of phase diagram of PbSe-Ag 2 Se-PbI 2 system are built. Transformations directing to crystallization metastable ternary compound forming in PbSe-PbI 2 system and metastable polytype modifications of lead iodide in PbSe-Ag 2 Se-PbI 2 system at 620-685 K are studied. By hardening from molten state (1150-1220 K) new interstitial metastable phases crystallizing in CdCl 2 structural type are obtained in PbSe-Ag 2 Se-PbI 2 and PbSe + CdI 2 = CdSe + PbI 2 systems [ru

  10. Preparation of planar CH3NH3PbI3 thin films with controlled size using 1-ethyl-2-pyrrolidone as solvent

    International Nuclear Information System (INIS)

    Hao, Qiuyan; Chu, Yixia; Zheng, Xuerong; Liu, Zhenya; Liang, Liming; Qi, Jiakun; Zhang, Xin; Liu, Gang; Liu, Hui; Chen, Hongjian; Liu, Caichi


    Recently, planar perovskite solar cells based on CH 3 NH 3 PbI 3 have attracted many researcher's interest due to their unique advantages such as simple cell architecture, easy fabrication and potential multijunction construction comparing to the initial mesoporous structure. However, the preparation of planar perovskite films with high quality is still in challenge. In this paper, we developed a vapor-assisted solution process using a novel and green solvent of 1-Ethyl-2-pyrrolidone (NEP) instead of the traditional N, N-dimethylformamide (DMF) to construct a high-quality perovskite CH 3 NH 3 PbI 3 thin film with pure phase, high compactness, small surface roughness and controlled size. The phase evolution and growth mechanism of the perovskite films are also discussed. Utilizing the NEP of low volatility and moderate boiling point as solvent, we dried the PbI 2 -NEP precursor films at different temperature under vacuum and then obtained PbI 2 thin films with different crystalline degree from amorphous to highly crystalline. The perovskite films with crystal size ranged from hundreds of nanometers to several micrometers can be prepared by reacting the PbI 2 films of different crystalline degree with CH 3 NH 3 I vapor. Moreover, planar-structured solar cells combining the perovskite film with TiO 2 and spiro-OMeTAD as the electron and holes transporting layer achieves a power conversion efficiency of 10.2%. - Highlights: • A novel and green solvent of 1-Ethyl-2-pyrrolidone (NEP) was used to construct high-quality perovskite CH 3 NH 3 PbI 3 thin film. • The CH 3 NH 3 PbI 3 grain with different sizes ranged from hundreds of nanometers to several micrometers can be obtained. • Planar-structured perovskite CH 3 NH 3 PbI 3 solar cells using NEP as solvent achieves a power conversion efficiency of 10.2%.

  11. Chemopreventive effects of PBI-Se, a selenium-containing analog of PBIT, on AOM-induced aberrant crypt foci in F344 rats. (United States)

    Janakiram, Naveena B; Mohammed, Altaf; Ravillah, Durgadevi; Choi, Chang In; Zhang, Yuting; Desai, Dhimant; Amin, Shantu; Rao, Chinthalapally V


    Inducible nitric oxide synthase (iNOS) is a potential target for the treatment of inflammation and cancer. Previously, we showed that the selective iNOS inhibitor S,S'-1,4-phenylenebis(1,2-ethanediyl)bis-isothiourea (PBIT) caused significant inhibition of colon carcinogenesis induced by azoxymethane (AOM), although it did not completely abrogate NO production due to the exogenous bioavailability of NO and NO generation by eNOS in tumor tissues. To create an iNOS-targeting molecule that may have additional benefits, a novel isosteric analog of PBIT, PBI-Se, was developed, in which sulfur was replaced with selenium. Chemopreventive efficacy of PBI-Se was evaluated in an AOM-induced rat colon carcinogenesis model using aberrant crypt foci (ACF) as the endpoint. At 7 weeks of age, rats (12/group) were fed the control diet (AIN 76A) and then colonic ACF were induced with two AOM treatments. Three days later, rats were fed diets containing PBI-Se (0-20 ppm) for 8 weeks, and then ACF were evaluated histopathologically. Dietary administration of 10 or 20 ppm of PBI-Se significantly suppressed AOM-induced total colonic ACF formation (32 or 41%, pPBI-Se was dose-dependent and was half the dose of PBIT for inhibiting total ACF in rats. Both PBIT and PBI-Se induced dose-dependent apoptosis in CaCo2 cells and caused a significant decrease in the cell cycle proteins cyclin D1 (70%, pPBI-Se (2 and 4  µM) significantly decreased the LPS-induced cytokine interleukin-6 level. Incorporation of selenium into the structure of PBIT provided the agent with additional novel cytotoxic and immunologic properties. Results from the in vitro and in vivo bioassays suggest that PBI-Se could be developed further for the prevention and treatment of colon cancer.

  12. PBI-05204, a supercritical CO₂ extract of Nerium oleander, inhibits growth of human pancreatic cancer via targeting the PI3K/mTOR pathway. (United States)

    Pan, Yong; Rhea, Patrea; Tan, Lin; Cartwright, Carrie; Lee, Ho-Jeong; Ravoori, Murali K; Addington, Crandell; Gagea, Mihai; Kundra, Vikas; Kim, Sun-Jin; Newman, Robert A; Yang, Peiying


    Introduction Oleandrin, a cardiac glycoside, exerts strong anti-proliferative activity against various human malignancies in in vitro cells. Here, we report the antitumor efficacy of PBI-05204, a supercritical C0₂ extract of Nerium oleander containing oleandrin, in a human pancreatic cancer Panc-1 orthotopic model. Results While all the control mice exhibited tumors by the end of treatment, only 2 of 8 mice (25%) treated for 6 weeks with PBI-05204 (40 mg/kg) showed dissectible tumor at the end of the treatment period. The average tumor weight (222.9 ± 116.9 mg) in mice treated with PBI-05204 (20 mg/kg) was significantly reduced from that in controls (920.0 ± 430.0 mg) (p PBI-05204 (40 mg/kg) treated group showed that the pancreatic tissues of 5/6 mice were normal while the remaining mouse had a tumor the largest diameter of which was less than 2.3 mm. In contrast, while gemcitabine alone did not significantly reduce tumor growth, PBI-05204 markedly enhanced the antitumor efficacy of gemcitabine in this particular model. Ki-67 staining was reduced in pancreatic tumors from mice treated with PBI-05204 (20 mg/kg) compared to that of control, suggesting that PBI-05204 inhibited the proliferation of the Panc-1 tumor cells. PBI-05204 suppressed expression of pAkt, pS6, and p4EPB1 in a concentration-dependent manner in both Panc-1 tumor tissues and human pancreatic cancer cell lines, implying that this novel botanical drug exerts its potent antitumor activity, at least in part, through down-regulation of PI3k/Akt and mTOR pathways.

  13. Rietveld refinement of the crystal structure of perovskite solar cells using CH3NH3PbI3 and other compounds (United States)

    Ando, Yuji; Ohishi, Yuya; Suzuki, Kohei; Suzuki, Atsushi; Oku, Takeo


    The crystal structures of perovskite thin films including CH3NH3PbI3, CH3NH3Pb1-xSbxI3, and CH3NH3PbI3-yCly in the solar cell configuration were studied by using Rietveld refinement. For the CH3NH3PbI3 and CH3NH3Pb1-xSbxI3 samples, satisfactory agreement with the measured profiles was obtained with a weighted profile R-factor (Rwp) of as low as 3%. It was shown that the site occupancy of methylammonium (MA) was decreased in the antimonized cell due to the compensation effect of an increased positive charge brought about by replacing Pb2+ with Sb3+. Photovoltaic measurements showed that the power conversion efficiency was enhanced by adding a small amount of Sb to the CH3NH3PbI3 cell, but it was monotonically decreased as the mole fraction of Sb exceeded 0.03. This variation of the conversion efficiency was considered as a result of suppressed crystallization of PbI2 and carrier recombination via MA vacancies in the antimonized cells. In the case of CH3NH3PbI2.88Cl0.12 sample, the agreement with the measured profile with an Rwp of as high as 7% suggested the co-existence of cubic and tetragonal phases in the chlorinated cell.

  14. Stable and metastable equilibria in PbSe + SnI2=SnSe + PbI2

    International Nuclear Information System (INIS)

    Odin, I.N.; Grin'ko, V.V.; Kozlovskij, V.F.; Demidova, E.D.


    T-x-y phase diagrams of the PbSe + SnI 2 =SnSe + PbI 2 mutual system (stable states) are plotted for the first time. It is shown that melt, solid solutions on the base of components of the mutual system and phase on the base of Sn 2 SeI 4 take part in phase equilibria. Transformations in the PbSe + SnI 2 =SnSe + PbI 2 mutual system leading to crystallization of metastable polytype modifications of lead iodides and metastable ternary compound forming in PbSe-PbI 2 system are investigated for the first time [ru

  15. Laser-induced surface recrystallization of polycrystalline PbI2 thick films for X-ray detector application (United States)

    Sun, Hui; Zhao, Beijun; Zhu, Xinghua; Zhu, Shifu; Yang, Dingyu; Wangyang, Peihua; Gao, Xiuyin


    In this work, laser-induced surface recrystallization process was developed to improve the surface properties and device performance of the polycrystalline PbI2 thick films prepared by using close space vapor deposition method. A continuous polycrystalline PbI2 recrystallized layer with a better mechanical strength and reflectivity improved from 2% to 4%-6% was obtained by this recrystallization process for the films with mechanical pretreatment. Other polytypes is absent in the recrystallized layer with the 2H-polytype remaining before and after treatment and obtaining improved electrical and X-ray photoelectric response performance. The pretreatment such as mechanical cutting/polishing and hydrogenation is necessary to lower the non-wetting crystallization behavior during the recrystallization process due to the rough surface state and oxygen contamination.

  16. Effects of CuBr addition to CH3NH3PbI3(Cl) perovskite photovoltaic devices (United States)

    Oku, Takeo; Ohishi, Yuya; Tanaka, Hiroki


    Effects of CuBr addition to perovskite CH3NH3PbI3(Cl) precursor solutions on photovoltaic properties were investigated. The CH3NH3Pb(Cu)I3(Cl,Br)-based photovoltaic devices were fabricated by a spin-coating technique, and the microstructures of the devices were investigated by X-ray diffraction, optical microscopy and scanning electron microscopy. Current density-voltage characteristics were improved by a small amount of CuBr addition, which resulted in improvement of the conversion efficiencies of the devices. The structure analysis showed decrease of unit cell volume and increase of Cu/Br composition by the CuBr addition, which would indicate the Cu/Br substitution at the Pb/I sites in the perovskite crystal, respectively.

  17. New Polymer Electrolyte Membranes Based on Acid Doped PBI For Fuel Cells Operating above 100°C

    DEFF Research Database (Denmark)

    Li, Qingfeng


    The technical achievement and challenges for the PEMFC technology based on perfluorosulfonic acid (PFSA) polymer membranes (e.g. Nafion®) are briefly discussed. The newest development for alternative polymer electrolytes for operation above 100°C. As one of the successful approaches to high...... operational temperatures, the development and evaluation of acid doped PBI membranes are reviewed, covering polymer synthesis, membrane casting, acid doping, physiochemical characterization and fuel cell tests....

  18. Role of organic cations on hybrid halide perovskite CH3NH3PbI3 surfaces (United States)

    Teng, Qiang; Shi, Ting-Ting; Tian, Ren-Yu; Yang, Xiao-Bao; Zhao, Yu-Jun


    Organic-inorganic hybrid halide perovskite CH3NH3PbI3 (MAPbI3) has received rapid progress in power conversion efficiency as promising photovoltaic materials, yet the surface structures and the role of MA cations are not well understood. In this work, we investigated the structural stability and electronic properties of (001) surface of cubic, (001) and (110) surfaces of tetragonal and orthorhombic phases of MAPbI3 with considering the orientation of MA cations, by density functional theory calculations. We demonstrate that the orientation of MA cations has profound consequences on the structural stability and the electronic properties of the surfaces, in contrast to the bulk phases. Compared with the MA-I terminated surfaces, the Pb-I2 terminated ones generally have smaller band gaps and the advantage to enable the photo-excited holes to transfer to the hole-transport materials in both tetragonal and orthorhombic phases. Overall, we suggest that the films with Pb-I2 terminated surfaces would prevail in high performance solar energy absorbers.

  19. Novel composite membranes based on PBI and dicationic ionic liquids for high temperature polymer electrolyte membrane fuel cells

    International Nuclear Information System (INIS)

    Hooshyari, Khadijeh; Javanbakht, Mehran; Adibi, Mina


    Two types of innovative composite membranes based on polybenzimidazole (PBI) containing dicationic ionic liquid 1,3-di(3-methylimidazolium) propane bis (trifluoromethylsulfonyl) imide (PDC 3 ) and monocationic ionic liquid 1-hexyl-3-methylimidazolium bis (trifluoromethanesulfonyl) imide (PMC 6 ) are prepared as electrolyte for high temperature fuel cells applications under anhydrous conditions. The analyses of results display promising characteristics such as high proton conductivity and thermal stability. Moreover the fuel cell performance of PA doped PDC 3 composite membranes is enhanced in comparison with PA doped PMC 6 and PA doped PBI membranes at high temperatures. Dicationic ionic liquid with high number of charge carriers provides well-developed ionic channels which form facile pathways and considerably develop the anhydrous proton conductivity. The highest proton conductivity of 81 mS/cm is achieved for PA doped PDC 3 composite membranes with PBI/IL mole ratio: 4 at 180 °C. A power density of 0.44 W/cm 2 is obtained at 0.5 V and 180 °C for PA doped PDC 3 composite membranes, which proves that these developed composite membranes can be considered as most promising candidates for high temperature fuel cell applications with enhanced proton conductivity.

  20. Electroluminescence of organic light-emitting diodes consisting of an undoped (pbi)2Ir(acac) phosphorescent layer (United States)

    Lei, Xia; Yu, Junsheng; Zhao, Juan; Jiang, Yadong


    The electroluminescence (EL) characteristics of phosphorescent organic light-emitting diodes (OLEDs) with an undoped bis(1,2-dipheny1-1H-benzoimidazole) iridium (acetylacetonate) [(pbi)2Ir(acac)] emissive layer (EML) of various film thicknesses were studied. The results showed that the intensity of green light emission decreased rapidly with the increasing thickness of (pbi)2Ir(acac), which was relevant to the triplet excimer emission. It suggested that the concentration quenching of monomer emission in the undoped (pbi)2Ir(acac) film was mainly due to the formation of triplet excimer and partly due to the triplet-triplet annihilation (TTA) and triplet-polaron annihilation (TPA). A green OLED with a maximum luminance of 26,531 cd/m2, a current efficiency of 36.2 cd/A, and a power efficiency of 32.4 lm/W was obtained, when the triplet excimer emission was eliminated. Moreover, the white OLED with low efficiency roll-off was realized due to the broadened recombination zone and reduced quenching effects in the EML when no electron blocking layer was employed.

  1. Double functions of porous TiO2 electrodes on CH3NH3PbI3 perovskite solar cells: Enhancement of perovskite crystal transformation and prohibition of short circuiting

    Directory of Open Access Journals (Sweden)

    Govindhasamy Murugadoss


    Full Text Available In order to analyze the crystal transformation from hexagonal PbI2 to CH3NH3PbI3 by the sequential (two-step deposition process, perovskite CH3NH3PbI3 layers were deposited on flat and/or porous TiO2 layers. Although the narrower pores using small nanoparticles prohibited the effective transformation, the porous-TiO2 matrix was able to help the crystal transformation of PbI2 to CH3NH3PbI3 by sequential two-step deposition. The resulting PbI2 crystals in porous TiO2 electrodes did not deteriorate the photovoltaic effects. Moreover, it is confirmed that the porous TiO2 electrode had served the function of prohibiting short circuits between working and counter electrodes in perovskite solar cells.

  2. Preclinical Biodistribution and Safety Evaluation of a pbi-shRNA STMN1 Lipoplex after Subcutaneous Delivery. (United States)

    Wang, Zhaohui; Jay, Christopher M; Evans, Courtney; Kumar, Padmasini; Phalon, Connor; Rao, Donald D; Senzer, Neil; Nemunaitis, John


    Stathmin-1 (STMN1) is a microtubule-destabilizing protein which is overexpressed in cancer. Its overexpression is associated with poor prognosis and also serves as a predictive marker to taxane therapy. We have developed a proprietary bi-functional shRNA (bi-shRNA) platform to execute RNA interference (RNAi)-mediated gene silencing and a liposome-carrier complex to systemically deliver the pbi-shRNA plasmids. In vitro and in vivo testing demonstrated efficacy and specificity of pbi-shRNA plasmid in targeting STMN1 (Phadke, A. P., Jay, C. M., Wang, Z., Chen, S., Liu, S., Haddock, C., Kumar, P., Pappen, B. O., Rao, D. D., Templeton, N. S., et al. (2011). In vivo safety and antitumor efficacy of bifunctional small hairpin RNAs specific for the human Stathmin 1 oncoprotein. DNA Cell Biol. 30, 715-726.). Biodistribution and toxicology studies in bio-relevant Sprague Dawley rats with pbi-shRNA STMN1 lipoplex revealed that the plasmid DNA was delivered to a broad distribution of organs after a single subcutaneous injection. Specifically, plasmid was detected within the first week using QPCR (threshold 50 copies plasmid/1 µg genomic DNA) at the injection site, lung, spleen, blood, skin, ovary (limited), lymph nodes, and liver. It was not detected in the heart, testis or bone marrow. No plasmid was detected from any organ 30 days after injection. Treatment was well tolerated. Minimal inflammation/erythema was observed at the injection site. Circulating cytokine response was also examined by ELISA. The IL-6 levels were induced within 6 h then declined to the vehicle control level 72 h after the injection. TNFα induction was transiently observed 4 days after the DNA lipoplex treatment. In summary, the pbi-shRNA STMN1 lipoplex was well tolerated and displayed broad distribution after a single subcutaneous injection. The pre-clinical data has been filed to FDA and the pbi-shRNA STMN1 lipoplex is being investigated in a phase I clinical study. © The Author 2016. Published

  3. Transport Properties Of PbI2 Doped Silver Oxysalt Based Amorphous Solid Electrolytes (United States)

    Shrisanjaykumar Jayswal, Manishkumar

    with that a detailed review on fast ion conducting glasses is included. At the end of the chapter, the aim of the present work has been given. Chapter 2: A discussion about various theoretical models to explain fast ion conduction mechanism in superionic conductors in general and superionic conducting glasses in particular is given. In addition to that, impedance spectroscopy and its various formalisms are discussed. Chapter 3: This chapter describes the method of preparation of the glass samples and various characterizations and techniques to study their various properties. Chapter 4: Physical properties of the prepared glass samples are studied and discussed in this chapter. The glass samples are found to be fully amorphous as exhibited by x-ray diffraction studies. The density of the prepared samples is increasing consistently with increasing PbI 2 content in the glass. For glass series (a), the molar volume also increases with PbI2 content. However, for glass series (b) and (c), molar volume is reducing with increasing PbI2 content, showing that glass is getting compacted with increasing PbI2 content. Chapter 5: Transport properties of the prepared glass samples have been investigated using impedance spectroscopy and its various formalisms. The chapter discusses DC conductivity, AC conductivity, dielectric permittivity and modulus analysis of the obtained impedance spectra. The sigma' spectra were scaled using Summerfield scaling law using sigmaDCT as the scaling factor for frequency axis and a well defined Time-Temperature Superposition (TTS) is observed as a function of temperature. The dielectric spectra show the presence of a dielectric relaxation in all glass samples. The dielectric permittivity, epsilon', spectra were scaled using the scaling law given by Sidebottom. The modulus spectra exhibit non-Debye relaxation of Ag+ ions and could be explained using KWW (Kohlrausch-Williams-Watts) decay function. Scaling analysis of the modulus spectra as a function of

  4. Novel EDTA-ligands containing an integral perylene bisimide (PBI) core as an optical reporter unit. (United States)

    Marcia, Mario; Singh, Prabhpreet; Hauke, Frank; Maggini, Michele; Hirsch, Andreas


    The synthesis, characterization and metal complexation of a new class of perylene bisimides (PBIs) as an integral part of ethylenediaminetetraacetic acid (EDTA) are reported. The simplest representative, namely derivative 1a, was synthesized both by a convergent as well as a direct approach while the elongated derivatives, 1b and 1c, were obtained only via a convergent synthetic pathway. All these new prototypes of water-soluble perylenes are bolaamphiphiles and were fully characterized by (1)H- and (13)C-NMR spectroscopy, matrix assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry and IR spectroscopy. In order to acquaint ourselves with the behaviour in solution of our PBIs bearing dendritic wedges, the simplest derivative, 1a, was chosen and tested by means of UV/Vis and fluorescence spectroscopy as well as by zeta-potential measurements. A photoexcitation induced intramolecular photo-electron transfer (PET) can be observed in these molecules. Therefore their potential applications as sensors can be imagined. Model compound 1a efficiently coordinates trivalent metal cations both in water and dimethyl sulfoxide (DMSO). Significantly, the effects of the complexation strongly depend on the aggregation state of the PBI molecules in solution. As a matter of fact, in water, the presence of M(3+) ions triggers the formation of light emitting supramolecular aggregates (excimers). On the other hand, in DMSO-rich solutions metal complexation leads to the suppression of the PET and leads to a strong fluorescence enhancement.

  5. Break-in and Performance Issues on a single cell PBI-based PEM Fuel Cell

    DEFF Research Database (Denmark)

    Kær, Søren Knudsen; Jespersen, Jesper Lebæk

    of the fuel cell, even though break-in of a fuel cell implemented in a commercial application would most likely not be feasible. In the present work a commercially available PBI-based high temperature MEA is subject to a break-in procedure, as specified by the manufacturer. The cell was operated at 160 °C...... during the break-in procedure at a current density of 0.2 A/cm2. The performance of the cell was measured over the 100 hour break-in period and a polarization curve was recorded after completion of break-in. The performance change was minimal during the break-in cycle. However, in the first hour of op......-eration a significant performance decrease of 30 mV was observed. Hereafter a performance in-crease started and the overall performance change during the break-in procedure was a voltage in-crease of 35 mV corresponding to a rate of 240 μV/hr. The performance increase was however fast-est in the first 50 hours...

  6. The efficiency limit of CH3NH3PbI3 perovskite solar cells

    International Nuclear Information System (INIS)

    Sha, Wei E. I.; Ren, Xingang; Chen, Luzhou; Choy, Wallace C. H.


    With the consideration of photon recycling effect, the efficiency limit of methylammonium lead iodide (CH 3 NH 3 PbI 3 ) perovskite solar cells is predicted by a detailed balance model. To obtain convincing predictions, both AM 1.5 spectrum of Sun and experimentally measured complex refractive index of perovskite material are employed in the detailed balance model. The roles of light trapping and angular restriction in improving the maximal output power of thin-film perovskite solar cells are also clarified. The efficiency limit of perovskite cells (without the angular restriction) is about 31%, which approaches to Shockley-Queisser limit (33%) achievable by gallium arsenide (GaAs) cells. Moreover, the Shockley-Queisser limit could be reached with a 200 nm-thick perovskite solar cell, through integrating a wavelength-dependent angular-restriction design with a textured light-trapping structure. Additionally, the influence of the trap-assisted nonradiative recombination on the device efficiency is investigated. The work is fundamentally important to high-performance perovskite photovoltaics

  7. A numerical study on the effects of temperature and mass transfer in high temperature PEM fuel cells with ab-PBI membrane

    International Nuclear Information System (INIS)

    Sun, Hong; Xie, Chen; Chen, Hao; Almheiri, Saif


    Highlights: • A two-dimensional model is developed to study the HT-PEMFC with ab-PBI membrane. • The temperature distribution in the ab-PBI membrane is uneven. • With the increase of temperature, the resistance in ab-PBI membrane decreases. • Porosity has the most significant effect on the performance of HT-PEMFC. - Abstract: A two-dimensional, single-phase model is developed to study high temperature proton exchange membrane (HT-PEM) fuel cell with poly(2,5-benzimidazole) (ab-PBI) membrane. In this model, simulation region not only includes the cathode and anode, but also includes ab-PBI membrane; the continuity boundary condition at the interface between the catalyst layer (CL) and the gas diffusion layer (GDL) at each side of the cell is omitted by including the catalyst layers in the respective unified domains for the cathode and the anode. The flows, species, energy, current density are all coupled in the model. Experiments have been conducted to validate the proposed numerical simulations, and it is found that there is a good agreement between the modeling results and those obtained experimentally. By this simulation, not only the oxygen and water fraction distribution in the cathode, but also the temperature distribution and resistance distribution in the ab-PBI membrane are obtained, and the effects of the cell temperature, the porosity in the diffusion layer and its thickness on the current density are analyzed. The innovative researching results are that the temperature distribution is uneven in the ab-PBI membrane and its resistance is greatly affected by the operating temperature. Other results show that the increase of the cell temperature and the porosity in the diffusion layer, and the decrease of the diffusion layer thickness all improve the performance of HT-PEM fuel cells by promoting its internal mass transfer.

  8. Investigation of Structural and Electronic Properties of CH3NH3PbI3 Stabilized by Varying Concentrations of Poly(Methyl Methacrylate (PMMA

    Directory of Open Access Journals (Sweden)

    Celline Awino


    Full Text Available Studies have shown that perovskites have a high potential of outdoing silicon based solar cells in terms of solar energy conversion, but their rate of degradation is also high. This study reports on improvement on the stability of CH3NH3PbI3 by passivating it with polymethylmethacrylate (PMMA. Structural and electronic properties of CH3NH3PbI3 stabilized by polymethylmethacrylate (PMMA were investigated by varying concentrations of PMMA in the polymer solutions. Stability tests were performed over a period of time using modulated surface photovoltage (SPV spectroscopy, X-ray diffraction (XRD, and photoluminescence (PL measurements. The XRD patterns confirm the tetragonal structure of the deposited CH3NH3PbI3 for every concentration of PMMA. Furthermore, CH3NH3PbI3 coated with 40 mg/mL of PMMA did not show any impurity phase even after storage in air for 43 days. The Tauc gap (ETauc determined on the basis of the in-phase SPV spectra was found in the range from 1.585 to 1.62 eV for the samples stored during initial days, but shifted towards lower energies as the storage time increased. This can be proposed to be due to different chemical reactions between CH3NH3PbI3/PMMA interfaces and air. PL intensity increased with increasing concentration of PMMA except for the perovskite coated with 40 mg/mL of PMMA. PL quenching in the perovskite coated with 40 mg/mL of PMMA can be interpreted as fast electron transfer towards the substrate in the sample. This study shows that, with an optimum concentration of PMMA coating on CH3NH3PbI3, the lifetime and hence stability on electrical and structural behavior of CH3NH3PbI3 is improved.

  9. Observation of the long-lived triplet excited state of perylenebisimide (PBI) in C^N cyclometalated Ir(III) complexes and application in photocatalytic oxidation. (United States)

    Sun, Jifu; Zhong, Fangfang; Zhao, Jianzhang


    Perylenebisimide (PBI) was used to prepare C^N cyclometalated Ir(III) complexes that show strong absorption of visible light and it is the first time the long-lived triplet excited state of PBI chromophore was observed in a transition metal complex (τT = 22.3 μs). Previously, the lifetime of the triplet state of PBI in transition metal complexes was usually shorter than 1.0 μs. Long-lived triplet excited states are useful for applications in photocatalysis or other photophysical processes concerning triplet-triplet-energy-transfer. PBI and amino-PBI were used for preparation of cyclometalated Ir(III) complexes (Ir-2 and Ir-3), in which the PBI chromophore was connected to the coordination center via C≡C π-conjugation bond. The new complexes show strong absorption in visible region (ε = 34,200 M(-1) cm(-1) at 541 nm for Ir-2, and ε = 19,000 at 669 nm for Ir-3), compared to the model complex Ir(ppy)(bpy)[PF6] Ir-1 (ε PBI-localized long-lived (3)IL states were populated for Ir-2 and Ir-3 upon photoexcitation. The complexes were used as triplet photosensitizers for (1)O2-mediated photooxidation of 1,5-dihydronaphthalene to produce juglone, an important intermediate for preparation of anti-cancer compounds. (1)O2 quantum yields (Φ(Δ)) up to 91% were observed for the new Ir(III) complexes and the overall photosensitizing ability is much higher than the conventional Ir(III) complex Ir-1, which shows the typical weak visible light absorption in visible region. Our results are useful for preparation of transition metal complexes that show strong absorption of visible light and long-lived triplet excited state and for the application of these complexes in photocatalysis.

  10. Improvement of photovoltaic performance of the inverted planar perovskite solar cells by using CH3NH3PbI3-xBrx films with solvent annealing (United States)

    Wang, Shan; Zhang, Weijia; Ma, Denghao; Jiang, Zhaoyi; Fan, Zhiqiang; Ma, Qiang; Xi, Yilian


    In this paper, the CH3NH3PbI3-xBrx films with various Br-doping contents were successfully prepared by solution processed deposition and followed by annealing process. This method simultaneously modified the morphology and composition of the CH3NH3PbI3 film. The effects of annealing treatment of CH3NH3PbI3-xBrx films under N2 and DMSO conditions on the microstructure of films and photoelectric properties of the solar cells were systematically investigated. The relationship of the component ratio of RBr/I= CH3NH3PbI3-xBrx/CH3NH3PbI3 in the resulting perovskite versus CH3NH3Br concentration also was explored. The results revealed that the CH3NH3PbI3-xBrx films annealed under DMSO exhibited increased grain sizes, enhanced crystallinity, enlarged bandgap and reduced defect density compared with that of the N2 annealing. It also was found that the RBr/I linearly increased in the resulting perovskite with the increased of CH3NH3Br concentration in the methylammonium halide mixture solutions. Furthermore, the photovoltaic performances of devices fabricated using DMSO precursor solvent were worse than that of DMF under N2 annealing atmosphere. When CH3NH3Br concentration was 7.5 mg ml-1, the planar perovskite solar cell based on CH3NH3PbI3-xBrx annealed under DMSO showed the best efficiency of 13.7%.

  11. Low-temperature (75 °C) solid-state reaction enhanced by less-crystallized nanoporous PbI2 films for efficient CH3NH3PbI3 perovskite solar cells

    International Nuclear Information System (INIS)

    Zheng, Huifeng; Liu, Yangqiao; Sun, Jing


    Highlights: • Efficient perovskite solar cells were prepared with solid-state reaction at 75 °C. • Ln-PbI 2 is superior to c-PbI 2 when applied in low-temperature solid-state reaction. • A higher champion PCE was obtained at 75 °C (13.8%) than that of 140 °C (11.8%). • Non-radiative defects increase significantly when annealed at high temperature. - Abstract: Organohalide perovskite films are usually prepared with the solid-state reaction at a high temperature ≥100 °C, which causes the increase of non-radiative defects and decomposition of perovskite films. Here, we demonstrate it’s feasible to prepare high-quality perovskite films with the solid-state reaction method even at a temperature of 75 °C, when enhanced by less-crystallized nanoporous PbI 2 (ln-PbI 2 ) films. The replacement of compact PbI 2 (c-PbI 2 ) by ln-PbI 2 , results in a significant improvement of crystallinity of perovskite films, besides the elimination of remnant PbI 2 . As a result, ln-PbI 2 based perovskite solar cells display much higher power conversion efficiency (PCE) and better stability. Moreover, annealing duration was found to be critical for high PCE and was optimized as 60 min. Finally, with the optimal process, the champion device displayed a PCE of 13.8% and the average PCE reached 10.1% with a satisfactory deviation. Furthermore, we found annealing at high temperature (140 °C) led to a lower PCE compared with that annealed at 75 °C, because non-radiative defects increased significantly during high-temperature annealing. This work may open up a promising avenue for preparing high-quality perovskite films with the low-temperature solid-state reaction method, which is desirable for real application.

  12. Hexamethylenetetramine-mediated growth of grain-boundary-passivation CH3NH3PbI3 for highly reproducible and stable perovskite solar cells (United States)

    Zheng, Yan-Zhen; Li, Xi-Tao; Zhao, Er-Fei; Lv, Xin-Ding; Meng, Fan-Li; Peng, Chao; Lai, Xue-Sen; Huang, Meilan; Cao, Guozhong; Tao, Xia; Chen, Jian-Feng


    Simultaneously achieving the long-term device stability and reproducibility has proven challenging in perovskite solar cells because solution-processing produced perovskite film with grain boundary is sensitive to moisture. Herein, we develop a hexamethylenetetramine (HMTA)-mediated one-step solution-processing deposition strategy that leads to the formation of high-purity and grain-boundary-passivation CH3NH3PbI3 film and thereby advances cell optoelectronic performance. Through morphological and structural characterizations and theoretical calculations, we demonstrate that HMTA fully occupies the moisture-exposed surface to build a bridge across grain boundary and coordinates with Pb ions to inhibit the formation of detrimental PbI2. Such HMTA-mediated grown CH3NH3PbI3 films achieves a decent augmentation of power conversion efficiency (PCE) from 12.70% to 17.87%. A full coverage of PbI2-free CH3NH3PbI3 surface on ZnO also boosts the device's stability and reproducibility.

  13. Dual activities of the anti-cancer drug candidate PBI-05204 provide neuroprotection in brain slice models for neurodegenerative diseases and stroke. (United States)

    Van Kanegan, Michael J; Dunn, Denise E; Kaltenbach, Linda S; Shah, Bijal; He, Dong Ning; McCoy, Daniel D; Yang, Peiying; Peng, Jiangnan; Shen, Li; Du, Lin; Cichewicz, Robert H; Newman, Robert A; Lo, Donald C


    We previously reported neuroprotective activity of the botanical anti-cancer drug candidate PBI-05204, a supercritical CO2 extract of Nerium oleander, in brain slice and in vivo models of ischemic stroke. We showed that one component of this neuroprotective activity is mediated through its principal cardiac glycoside constituent, oleandrin, via induction of the potent neurotrophic factor brain-derived neurotrophic factor (BDNF). However, we also noted that the concentration-relation for PBI-05204 in the brain slice oxygen-glucose deprivation (OGD) model is considerably broader than that for oleandrin as a single agent. We thus surmised that PBI-05204 contains an additional neuroprotective component(s), distinct from oleandrin. We report here that neuroprotective activity is also provided by the triterpenoid constituents of PBI-05204, notably oleanolic acid. We demonstrate that a sub-fraction of PBI-05204 (Fraction 0-4) containing oleanolic and other triterpenoids, but without cardiac glycosides, induces the expression of cellular antioxidant gene transcription programs regulated through antioxidant transcriptional response elements (AREs). Finally, we show that Fraction 0-4 provides broad neuroprotection in organotypic brain slice models for neurodegeneration driven by amyloid precursor protein (APP) and tau implicated in Alzheimer's disease and frontotemporal dementias, respectively, in addition to ischemic injury modeled by OGD.

  14. The Effect of Solvents on the Performance of CH3NH3PbI3 Perovskite Solar Cells

    Directory of Open Access Journals (Sweden)

    Pao-Hsun Huang


    Full Text Available The properties of perovskite solar cells (PSCs fabricated using various solvents was studied. The devices had an indium tin oxide (ITO/poly(3,4-ethylenedioxythiophene: poly(styrenesulfonate (PEDOT:PSS/CH3NH3PbI3 (fabricated by using various solvents/fullerene (C60/bathocuproine (BCP/silver (Ag structure. The solvents used were dimethylformamide (DMF, γ-butyrolactone (GBL, dimethyl sulfoxide (DMSO, a mixture of DMSO and DMF (1:1 v/v, and a mixture of DMSO and GBL (DMSO: GBL, 1:1 v/v, respectively. The power conversion efficiency (PCE of the device fabricated using DMF is zero, which is attributed to the poor coverage of CH3NH3PbI3 film on the substrate. In addition, the PCE of the device made using GBL is only 1.74% due to the low solubility of PbI2 and CH3NH3I. In contrast, the PCE of the device fabricated using the solvents containing DMSO showed better performance. This is ascribed to the high solubilization properties and strong coordination of DMSO. As a result, a PCE of 9.77% was obtained using a mixed DMSO:GBL solvent due to the smooth surface, uniform film coverage on the substrate and the high crystallization of the perovskite structure. Finally, a mixed DMSO: DMF:GBL (5:2:3 v/v/v solvent that combined the advantages of each solvent was used to fabricate a device, leading to a further improvement of the PCE of the resulting PSC to 10.84%.

  15. Interfacial electronic structures revealed at the rubrene/CH3NH3PbI3 interface. (United States)

    Ji, Gengwu; Zheng, Guanhaojie; Zhao, Bin; Song, Fei; Zhang, Xiaonan; Shen, Kongchao; Yang, Yingguo; Xiong, Yimin; Gao, Xingyu; Cao, Liang; Qi, Dong-Chen


    The electronic structures of rubrene films deposited on CH 3 NH 3 PbI 3 perovskite have been investigated using in situ ultraviolet photoelectron spectroscopy (UPS) and X-ray photoelectron spectroscopy (XPS). It was found that rubrene molecules interacted weakly with the perovskite substrate. Due to charge redistribution at their interface, a downward 'band bending'-like energy shift of ∼0.3 eV and an upward band bending of ∼0.1 eV were identified at the upper rubrene side and the CH 3 NH 3 PbI 3 substrate side, respectively. After the energy level alignment was established at the rubrene/CH 3 NH 3 PbI 3 interface, its highest occupied molecular orbital (HOMO)-valence band maximum (VBM) offset was found to be as low as ∼0.1 eV favoring the hole extraction with its lowest unoccupied molecular orbital (LUMO)-conduction band minimum (CBM) offset as large as ∼1.4 eV effectively blocking the undesired electron transfer from perovskite to rubrene. As a demonstration, simple inverted planar solar cell devices incorporating rubrene and rubrene/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) hole transport layers (HTLs) were fabricated in this work and yielded a champion power conversion efficiency of 8.76% and 13.52%, respectively. Thus, the present work suggests that a rubrene thin film could serve as a promising hole transport layer for efficient perovskite-based solar cells.

  16. Photovoltaic properties of Cu-doped CH3NH3PbI3 with perovskite structure (United States)

    Shirahata, Yasuhiro; Oku, Takeo


    Photovoltaic properties of copper (Cu)-doped perovskite (CH3NH3PbCuxI3+x) photovoltaic devices with different Cu content were investigated. The CH3NH3PbCuxI3+x films were polycrystalline with a tetragonal system, and their lattice constants and crystallite size varied with Cu doping. Compared to conversion efficiencies of non-doped CH3NH3PbI3 photovoltaic device, those of CH3NH3PbCuxI3+x photovoltaic devises increased. The improvement of photovoltaic properties was attributed to partial substitution of Cu at the Pb sites.

  17. Investigating the effects of methanol-water vapor mixture on a PBI-based high temperature PEM fuel cell

    DEFF Research Database (Denmark)

    Araya, Samuel Simon; Andreasen, Søren Juhl; Nielsen, Heidi Venstrup


    This paper investigates the effects of methanol and water vapor on the performance of a high temperature proton exchange membrane fuel cell (HT-PEMFC). A H3PO4-doped polybenzimidazole (PBI) membrane electrode assembly (MEA), Celtec P2100 of 45 cm2 of active surface area from BASF was employed....... A long-term durability test of around 1250 h was performed, in which the concentrations of methanol-water vapor mixture in the anode feed gas were varied. The fuel cell showed a continuous performance decay in the presence of vapor mixtures of methanol and water of 5% and 8% by volume in anode feed...

  18. Relationship between microstructure and optical properties of a novel perovskite C12PbI4 embedded in matrix of porous alumina (United States)

    Zaghdoudi, W.; Bardaoui, A.; Khalifa, N.; Chtourou, R.


    In this study, organic-inorganic hybrid perovskite multiple quantum wells (PbI QWs) embedded in porous anodic alumina (PAA) thin films on glass and aluminum substrates are investigated in detail. The pore height and diameter of the nanoscale structure of porous anodic alumina (PAA) film produced by the anodization technique are controllable. The synthesized films are characterized morphologically using the atomic force microscopy (AFM). Scanning electron microscopy (SEM) study showed granular surface. The structural and optical properties were investigated by X-ray diffraction (XRD), photoluminescence (PL) and UV-Vis-NIR spectrophotometer. The effect of the two different substrates on the impregnation of the PbI QW in the PAA is presented. Both PL and AFM studies show a better penetration of the PbI QW in the case of the Al substrate providing a wider pore diameter. Remarkable enhancement of quantum confinement is demonstrated.

  19. Effects of CsBr addition on the performance of CH3NH3PbI3-xClx-based solar cells (United States)

    Ueoka, Naoki; Oku, Takeo; Ohishi, Yuya; Tanaka, Hiroki; Suzuki, Atsushi; Sakamoto, Hiroki; Yamada, Masahiro; Minami, Satoshi; Tsukada, Shinichiro


    Perovskite-type photovoltaic devices were prepared by a spin-coating method using a precursor solution of CH3NH3I and lead(II) chloride in N,N-dimethylformamide. Effects of cesium bromide (CsBr) addition on the photovoltaic properties and microstructures of the perovskite phase were investigated. The fill factor was increased by adding the CsBr to the CH3NH3PbI3-xClx precursor solution, which resulted in increase of the conversion efficiency. The crystallinity of the CH3NH3PbI3-xClx perovskite phase was also improved by adding the CsBr to the H3NH3PbI3-xClx precursor solution.

  20. Room temperature atomic layer deposited Al2O3 on CH3NH3PbI3 characterized by synchrotron-based X-ray photoelectron spectroscopy (United States)

    Kot, Małgorzata; Das, Chittaranjan; Henkel, Karsten; Wojciechowski, Konrad; Snaith, Henry J.; Schmeisser, Dieter


    An ultrathin Al2O3 film deposited on methylammonium lead triiodide (CH3NH3PbI3) perovskite has the capability to suppress the carrier recombination process and improve the perovskite solar cells efficiency and stability. However, annealing at temperatures higher than 85 °C degrades the CH3NH3PbI3 perovskite film. The X-ray photoelectron spectroscopy study performed in this work indicates that it is possible to grow Al2O3 by atomic layer deposition on the perovskite at room temperature, however, besides pure Al2O3 some OH groups are found and the creation of lead and iodine oxides at the Al2O3/CH3NH3PbI3 interface takes place.

  1. Multiple-Stage Structure Transformation of Organic-Inorganic Hybrid Perovskite CH3NH3PbI3 (United States)

    Chen, Qiong; Liu, Henan; Kim, Hui-Seon; Liu, Yucheng; Yang, Mengjin; Yue, Naili; Ren, Gang; Zhu, Kai; Liu, Shengzhong; Park, Nam-Gyu; Zhang, Yong


    By performing spatially resolved Raman and photoluminescence spectroscopy with varying excitation wavelength, density, and data acquisition parameters, we achieve a unified understanding towards the spectroscopy signatures of the organic-inorganic hybrid perovskite, transforming from the pristine state (CH3NH3PbI3 ) to the fully degraded state (i.e., PbI2 ) for samples with varying crystalline domain size from mesoscopic scale (approximately 100 nm) to macroscopic size (centimeters), synthesized by three different techniques. We show that the hybrid perovskite exhibits multiple stages of structure transformation occurring either spontaneously or under light illumination, with exceptionally high sensitivity to the illumination conditions (e.g., power, illumination time, and interruption pattern). We highlight four transformation stages (stages I-IV, with stage I being the pristine state) along either the spontaneous or photoinduced degradation path exhibiting distinctly different Raman spectroscopy features at each stage, and point out that previously reported Raman spectra in the literature reflect highly degraded structures of either stage III or stage IV. Additional characteristic optical features of partially degraded materials under the joint action of spontaneous and photodegradation are also given. This study offers reliable benchmark results for understanding the intrinsic material properties and structure transformation of this unique category of hybrid materials, and the findings are pertinently important to a wide range of potential applications where the hybrid material is expected to function in greatly different environment and light-matter interaction conditions.

  2. Formation Dynamics of CH3NH3PbI3 Perovskite Following Two-Step Layer Deposition. (United States)

    Patel, Jay B; Milot, Rebecca L; Wright, Adam D; Herz, Laura M; Johnston, Michael B


    Hybrid metal-halide perovskites have emerged as a leading class of semiconductors for optoelectronic devices because of their desirable material properties and versatile fabrication methods. However, little is known about the chemical transformations that occur in the initial stages of perovskite crystal formation. Here we follow the real-time formation dynamics of MAPbI3 from a bilayer of lead iodide (PbI2) and methylammonium iodide (MAI) deposited through a two-step thermal evaporation process. By lowering the substrate temperature during deposition, we are able to initially inhibit intermixing of the two layers. We subsequently use infrared and visible light transmission, X-ray diffraction, and photoluminescence lifetime measurements to reveal the room-temperature transformations that occur in vacuum and ambient air, as MAI diffuses into the PbI2 lattice to form MAPbI3. In vacuum, the transformation to MAPbI3 is incomplete as unreacted MAI is retained in the film. However, exposure to moist air allows for conversion of the unreacted MAI to MAPbI3, demonstrating that moisture is essential in making MAI more mobile and thus aiding perovskite crystallization. These dynamic processes are reflected in the observed charge-carrier lifetimes, which strongly fluctuate during periods of large ion migration but steadily increase with improving crystallinity.

  3. Chlorine Incorporation in the CH3NH3PbI3 Perovskite: Small Concentration, Big Effect. (United States)

    Quarti, Claudio; Mosconi, Edoardo; Umari, Paolo; De Angelis, Filippo


    The role of chlorine doping in CH 3 NH 3 PbI 3 represents an important open issue in the use of hybrid perovskites for photovoltaic applications. In particular, even if a positive role of chlorine doping on perovskite film formation and on material morphology has been demonstrated, an inherent positive effect on the electronic and photovoltaic properties cannot be excluded. Here we carried out periodic density functional theory and Car-Parrinello molecular dynamics simulations, going down to ∼1% doping, to investigate the effect of chlorine on CH 3 NH 3 PbI 3 . We found that such a small doping has important effects on the dynamics of the crystalline structure, both with respect to the inorganic framework and with respect to the cation libration motion. Together, we observe a dynamic spatial localization of the valence and conduction states in separated spatial material regions, which takes place in the 10 -1 ps time scale and which could be the key to ease of exciton dissociation and, likely, to small charge recombination in hybrid perovskites. Moreover, such localization is enhanced by chlorine doping, demonstrating an inherent positive role of chlorine doping on the electronic properties of this class of materials.

  4. Sequence and annotation of the 314-kb MT325 and the 321-kb FR483 viruses that infect Chlorella Pbi. (United States)

    Fitzgerald, Lisa A; Graves, Michael V; Li, Xiao; Feldblyum, Tamara; Hartigan, James; Van Etten, James L


    Viruses MT325 and FR483, members of the family Phycodnaviridae, genus Chlorovirus, infect the fresh water, unicellular, eukaryotic, chlorella-like green alga, Chlorella Pbi. The 314,335-bp genome of MT325 and the 321,240-bp genome of FR483 are the first viruses that infect Chlorella Pbi to have their genomes sequenced and annotated. Furthermore, these genomes are the two smallest chlorella virus genomes sequenced to date, MT325 has 331 putative protein-encoding and 10 tRNA-encoding genes and FR483 has 335 putative protein-encoding and 9 tRNA-encoding genes. The protein-encoding genes are almost evenly distributed on both strands, and intergenic space is minimal. Approximately 40% of the viral gene products resemble entries in public databases, including some that are the first of their kind to be detected in a virus. For example, these unique gene products include an aquaglyceroporin in MT325, a potassium ion transporter protein and an alkyl sulfatase in FR483, and a dTDP-glucose pyrophosphorylase in both viruses. Comparison of MT325 and FR483 protein-encoding genes with the prototype chlorella virus PBCV-1 indicates that approximately 82% of the genes are present in all three viruses.

  5. Evolution of Photoluminescence, Raman, and Structure of CH3NH3PbI3 Perovskite Microwires Under Humidity Exposure (United States)

    Segovia, Rubén; Qu, Geyang; Peng, Miao; Sun, Xiudong; Shi, Hongyan; Gao, Bo


    Self-assembled organic-inorganic CH3NH3PbI3 perovskite microwires (MWs) upon humidity exposure along several weeks were investigated by photoluminescence (PL) spectroscopy, Raman spectroscopy, and X-ray diffraction (XRD). We show that, in addition to the common perovskite decomposition into PbI2 and the formation of a hydrated phase, humidity induced a gradual PL redshift at the initial weeks that is stabilized for longer exposure ( 21 nm over the degradation process) and an intensity enhancement. Original perovskite Raman band and XRD reflections slightly shifted upon humidity, indicating defects formation and structure distortion of the MWs crystal lattice. By correlating the PL, Raman, and XRD results, it is believed that the redshift of the MWs PL emission was originated from the structural disorder caused by the incorporation of H2O molecules in the crystal lattice and radiative recombination through moisture-induced subgap trap states. Our study provides insights into the optical and structural response of organic-inorganic perovskite materials upon humidity exposure.

  6. The pure rotational spectra of the open-shell diatomic molecules PbI and SnI

    Energy Technology Data Exchange (ETDEWEB)

    Evans, Corey J., E-mail:, E-mail:; Needham, Lisa-Maria E. [Department of Chemistry, University of Leicester, Leicester LE1 7RH (United Kingdom); Walker, Nicholas R., E-mail:, E-mail:; Köckert, Hansjochen; Zaleski, Daniel P.; Stephens, Susanna L. [School of Chemistry, Newcastle University, Newcastle upon Tyne NE1 7RU (United Kingdom)


    Pure rotational spectra of the ground electronic states of lead monoiodide and tin monoiodide have been measured using a chirped pulsed Fourier transform microwave spectrometer over the 7-18.5 GHz region for the first time. Each of PbI and SnI has a X {sup 2}Π{sub 1/2} ground electronic state and may have a hyperfine structure that aids the determination of the electron electric dipole moment. For each species, pure rotational transitions of a number of different isotopologues and their excited vibrational states have been assigned and fitted. A multi-isotopologue Dunham-type analysis was carried out on both species producing values for Y{sub 01}, Y{sub 02}, Y{sub 11}, and Y{sub 21}, along with Λ-doubling constants, magnetic hyperfine constants and nuclear quadrupole coupling constants. The Born-Oppenheimer breakdown parameters for Pb have been evaluated and the parameter rationalized in terms of finite nuclear field effects. Analysis of the bond lengths and hyperfine interaction indicates that the bonding in both PbI and SnI is ionic in nature. Equilibrium bond lengths have been evaluated for both species.

  7. The pure rotational spectra of the open-shell diatomic molecules PbI and SnI. (United States)

    Evans, Corey J; Needham, Lisa-Maria E; Walker, Nicholas R; Köckert, Hansjochen; Zaleski, Daniel P; Stephens, Susanna L


    Pure rotational spectra of the ground electronic states of lead monoiodide and tin monoiodide have been measured using a chirped pulsed Fourier transform microwave spectrometer over the 7-18.5 GHz region for the first time. Each of PbI and SnI has a X (2)Π1/2 ground electronic state and may have a hyperfine structure that aids the determination of the electron electric dipole moment. For each species, pure rotational transitions of a number of different isotopologues and their excited vibrational states have been assigned and fitted. A multi-isotopologue Dunham-type analysis was carried out on both species producing values for Y01, Y02, Y11, and Y21, along with Λ-doubling constants, magnetic hyperfine constants and nuclear quadrupole coupling constants. The Born-Oppenheimer breakdown parameters for Pb have been evaluated and the parameter rationalized in terms of finite nuclear field effects. Analysis of the bond lengths and hyperfine interaction indicates that the bonding in both PbI and SnI is ionic in nature. Equilibrium bond lengths have been evaluated for both species.

  8. Preclinical Justification of pbi-shRNA EWS/FLI1 Lipoplex (LPX) Treatment for Ewing's Sarcoma. (United States)

    Rao, Donald D; Jay, Christopher; Wang, Zhaohui; Luo, Xiuquan; Kumar, Padmasini; Eysenbach, Hilary; Ghisoli, Maurizio; Senzer, Neil; Nemunaitis, John


    The EWS/FLI1 fusion gene is well characterized as a driver of Ewing's sarcoma. Bi-shRNA EWS/FLI1 is a functional plasmid DNA construct that transcribes both siRNA and miRNA-like effectors each of which targets the identical type 1 translocation junction region of the EWS/FLI1 transcribed mRNA sequence. Previous preclinical and clinical studies confirm the safety of this RNA interference platform technology and consistently demonstrate designated mRNA and protein target knockdown at greater than 90% efficiency. We initiated development of pbi-shRNA EWS/FLI1 lipoplex (LPX) for the treatment of type 1 Ewing's sarcoma. Clinical-grade plasmid was manufactured and both sequence and activity verified. Target protein and RNA knockdown of 85-92% was demonstrated in vitro in type 1 human Ewing's sarcoma tumor cell lines with the optimal bi-shRNA EWS/FLI1 plasmid. This functional plasmid was placed in a clinically tested, liposomal (LP) delivery vehicle followed by in vivo verification of activity. Type 1 Ewing's sarcoma xenograft modeling confirmed dose related safety and tumor response to pbi-shRNA EWS/FLI1 LPX. Toxicology studies in mini-pigs with doses comparable to the demonstrated in vivo efficacy dose resulted in transient fever, occasional limited hypertension at low- and high-dose assessment and transient liver enzyme elevation at high dose. These results provide the justification to initiate clinical testing.

  9. Incorporating C60 as Nucleation Sites Optimizing PbI2 Films To Achieve Perovskite Solar Cells Showing Excellent Efficiency and Stability via Vapor-Assisted Deposition Method. (United States)

    Chen, Hai-Bin; Ding, Xi-Hong; Pan, Xu; Hayat, Tasawar; Alsaedi, Ahmed; Ding, Yong; Dai, Song-Yuan


    To achieve high-quality perovskite solar cells (PSCs), the morphology and carrier transportation of perovskite films need to be optimized. Herein, C 60 is employed as nucleation sites in PbI 2 precursor solution to optimize the morphology of perovskite films via vapor-assisted deposition process. Accompanying the homogeneous nucleation of PbI 2 , the incorporation of C 60 as heterogeneous nucleation sites can lower the nucleation free energy of PbI 2 , which facilitates the diffusion and reaction between PbI 2 and organic source. Meanwhile, C 60 could enhance carrier transportation and reduce charge recombination in the perovskite layer due to its high electron mobility and conductivity. In addition, the grain sizes of perovskite get larger with C 60 optimizing, which can reduce the grain boundaries and voids in perovskite and prevent the corrosion because of moisture. As a result, we obtain PSCs with a power conversion efficiency (PCE) of 18.33% and excellent stability. The PCEs of unsealed devices drop less than 10% in a dehumidification cabinet after 100 days and remain at 75% of the initial PCE during exposure to ambient air (humidity > 60% RH, temperature > 30 °C) for 30 days.

  10. Hybrid perovskite solar cells: In situ investigation of solution-processed PbI2 reveals metastable precursors and a pathway to producing porous thin films

    KAUST Repository

    Barrit, Dounya; Sheikh, Arif D.; Munir, Rahim; Barbe, Jeremy; Li, Ruipeng; Smilgies, Detlef-M.; Amassian, Aram


    from a DMF solution by performing in situ grazing incidence wide angle X-ray scattering (GIWAXS) measurements. The measurements reveal an elaborate sol–gel process involving three PbI2⋅DMF solvate complexes—including disordered and ordered ones

  11. Interfacial Charge-Carrier Trapping in CH3NH3PbI3-Based Heterolayered Structures Revealed by Time-Resolved Photoluminescence Spectroscopy. (United States)

    Yamada, Yasuhiro; Yamada, Takumi; Shimazaki, Ai; Wakamiya, Atsushi; Kanemitsu, Yoshihiko


    The fast-decaying component of photoluminescence (PL) under very weak pulse photoexcitation is dominated by the rapid relaxation of the photoexcited carriers into a small number of carrier-trapping defect states. Here, we report the subnanosecond decay of the PL under excitation weaker than 1 nJ/cm(2) both in CH3NH3PbI3-based heterostructures and bare thin films. The trap-site density at the interface was evaluated on the basis of the fluence-dependent PL decay profiles. It was found that high-density defects determining the PL decay dynamics are formed near the interface between CH3NH3PbI3 and the hole-transporting Spiro-OMeTAD but not at the CH3NH3PbI3/TiO2 interface and the interior regions of CH3NH3PbI3 films. This finding can aid the fabrication of high-quality heterointerfaces, which are required improving the photoconversion efficiency of perovskite-based solar cells.

  12. Larger spontaneous polarization ferroelectric inorganic-organic hybrids: [PbI3](infinity) chains directed organic cations aggregation to Kagomé-shaped tubular architecture. (United States)

    Zhao, Hai-Rong; Li, Dong-Ping; Ren, Xiao-Ming; Song, You; Jin, Wan-Qin


    Four isostructural inorganic-organic hybrid ferroelectric compounds, assembled from achiral 3-R-benzylidene-1-aminopyridiniums (R = NO(2), Br, Cl, or F for 1-4, respectively) and [PbI(3)](-) anions with the chiral Kagomé-shaped tubular aggregating architecture, show larger spontaneous polarizations.

  13. Effects of hot airflow during spin-coating process on CH3NH3PbI3-xClx perovskite solar cells (United States)

    Tanaka, Hiroki; Ohishi, Yuya; Oku, Takeo


    CH3NH3PbI3-xClx photovoltaic devices were fabricated, and the effects of hot airflow during spin-coating were investigated. Cubic perovskite crystals that is a high temperature phase were obtained by the hot airflow method. The conversion efficiencies of the devices prepared by the hot airflow were remained even after 56 days.

  14. The post-growth treatment of PbI2 thick films as an attempt to suppress the films surface effect

    International Nuclear Information System (INIS)

    Dmitriev, Yuri; Bennett, Paul R.; Cirignano, Leonard J.; Klugerman, Mikhail; Shah, Kanai S.


    PbI 2 thick films were coated with different materials (Parylene C, HumiSeal and PbBr 2 ) in order to improve the films' surface properties. It was shown that Parylene C and HumiSeal coating decreased the dark current of PbI 2 films and changed the shape of the I-V and I-t curves. X-ray-irradiated films demonstrated a significant increase in signal-to-noise ratio due to a decrease in the dark current, a slightly increased rise time, and a decreased decay time compared to non-coated PbI 2 films. In addition, Pd atoms from the electrical contact easily penetrated the Parylene C protective layer over a period of 1-2 h. The Pd diffusion coefficient and Parylene C dark resistivity estimated from these experiments were D Pd =(3.6±2.1)x10 -13 cm 2 /s and ρ ParyleneC =(130±70) T Ω cm, respectively. Only the PbBr 2 coating led to decreased rise and decay times compared to non-coated PbI 2 films

  15. Improvement of CH3NH3PbI3 thin film using the additive 1,8-diiodooctane for planar heterojunction perovskite cells (United States)

    Abdulrahman, Solh; Wang, Chunhua; Cao, Chenghao; Zhang, Chujun; Yang, Junliang; Jiang, Li


    The thin-film quality is critical for obtaining high-performance perovskite solar cells (PSCs). The additive 1,8-diiodooctane (DIO) was used to control the morphology and structure of CH3NH3PbI3 perovskite thin films, and planar heterojunction (PHJ) PSCs with an architecture of ITO/PEDOT: PSS/CH3NH3PbI3/PCBM/Al was fabricated. It was found that the DIO played an important role on CH3NH3PbI3 thin-film quality and the performance of PHJ-PSCs. With the optimal volume ratio of 2%, the compact and uniform high-quality CH3NH3PbI3 thin films with enhanced crystallinity and less roughness were achieved, resulting in the great improvement of power conversion efficiency (PCE) from about 4.5% to over 9.0%. The research results indicate that the additive DIO is a simple and effective method to produce high-quality perovskite thin film and accordingly develop high-performance PHJ-PSCs.

  16. T-x-y diagrams for reciprocal systems PbX + CdI2 = CdX + PbI2 (X=S, Se, Te)

    International Nuclear Information System (INIS)

    Odin, I.N.


    The present research is undertaken in search of the new complex phases with interesting physical properties. The synthesized samples was analyzed by differential thermal, X-ray diffraction and microstructural methods. The diagonal cross-section CdTe - PbI 2 of the mutual PbTe + CdI 2 = CdTe + PbI 2 system is stable. The T-x phase diagram of the CdTe - PbI 2 system possess eutectic type, the coordinates of eutectic point is 657 ± 2 K, 15 ± 1 mol. % of CdTe. The lead iodide based solid solutions with the mixed structure and the CdTe based solid solutions take place in the equilibria. Solid CdTe dissolves 0.2 mol. % PbI 2 . The fields of the primary crystallization of the CdTe, Pb 1-x Cd x I 2 , PbTe based solid solutions are on the liquidus surface [ru

  17. Impact of CH3NH3PbI3-PCBM bulk heterojunction active layer on the photovoltaic performance of perovskite solar cells (United States)

    Chaudhary, Dhirendra K.; Kumar, Pankaj; Kumar, Lokendra


    We report here the impact of CH3NH3PbI3-PCBM bulk heterojunction (BHJ) active layer on the photovoltaic performance of perovskite solar cells. The solar cells were prepared in normal architecture on FTO coated glass substrates with compact TiO2 (c-TiO2) layer on FTO as electron transport layer (ETL) and poly(3-hexylthiophene) (P3HT) as hole transport layer (HTL). For comparison, a few solar cells were also prepared in planar heterojunction structure using CH3NH3PbI3 only as the active layer. The bulk heterojunction CH3NH3PbI3-PCBM active layer exhibited very large crystalline grains of 2-3 μm compared to ∼150 nm only in CH3NH3PbI3 active layer. Larger grains in bulk-heterojunction solar cells resulted in enhanced power conversion efficiency (PCE) through enhancement in all the photovoltaic parameters compared to planar heterojunction solar cells. The bulk-heterojunction solar cells exhibited ∼9.25% PCE with short circuit current density (Jsc) of ∼18.649 mA/cm2, open circuit voltage (Voc) of 0.894 V and Fill Factor (FF) of 0.554. There was ∼36.9% enhancement in the PCE of bulk-heterojunction solar cells compared to that of planar heterojunction solar cells. The larger grains are formed as a result of incorporation on PCBM in the active layer.

  18. Species Boundaries and Interrelationships of Solanum Sect. Petota (Wild and Cultivated Potatoes) are Drastically Altered as a Result of PBI-Funded Research (United States)

    In 1990, the latest comprehensive taxonomic monograph of Solanum section Petota Dumort recognized 232 species partitioned into 21 series. PBI-sponsored research has drastically altered knowledge of their species boundaries and interrelationships. The series contains diploids (2n = 2x = 24), tetraplo...

  19. Facile hydrothermal synthesis and characterization of cesium-doped PbI2 nanostructures for optoelectronic, radiation detection and photocatalytic applications (United States)

    Shkir, Mohd; AlFaify, S.; Yahia, I. S.; Hamdy, Mohamed S.; Ganesh, V.; Algarni, H.


    Low-temperature hydrothermal-assisted synthesis of pure and cesium (Cs) (1, 3, 5, 7 and 10 wt%) doped lead iodide (PbI2) nanorods and nanosheets have been achieved successfully for the first time. The structural and vibrational studies confirm the formation of a 2H-polytypic PbI2 predominantly. Scanning electron microscope analysis confirms the formation of well-aligned nanorods of average size 100 nm at low concentration and nanosheets of average thicknesses in the range of 20-40 nm at higher concentrations of Cs doping. The presence of Cs doping was confirmed by energy dispersive X-ray study. Ultra-violet-visible absorbance spectra were recorded, and energy gap was calculated in the range of 3.33 to 3.45 eV for pure and Cs-doped PbI2 nanostructures which is higher than the bulk value (i.e., 2.27 eV) due to quantum confinement effect. Dielectric constant, loss, and AC conductivity studies have been done. Enhancement in Gamma linear absorption coefficient due to Cs doping confirms the suitability of prepared nanostructures for radiation detection applications. Furthermore, the photocatalytic performance of the synthesized nanostructures was evaluated in the decolorization of methyl green (MG) and methyl orange (MO) under the illumination of visible light (λ > 420 nm). The observed photocatalytic activity for 5 and 7 wt% Cs-doped PbI2 was observed to be more than pure PbI2 and also > 10 times higher than the commercially available photocatalysts. The results suggest that the prepared nanostructures are highly applicable in optoelectronic, radiation detection and many other applications. [Figure not available: see fulltext.

  20. Effect of Different CH3NH3PbI3 Morphologies on Photovoltaic Properties of Perovskite Solar Cells (United States)

    Chen, Lung-Chien; Lee, Kuan-Lin; Wu, Wen-Ti; Hsu, Chien-Feng; Tseng, Zong-Liang; Sun, Xiao Hong; Kao, Yu-Ting


    In this study, the perovskite layers were prepared by two-step wet process with different CH3NH3I (MAI) concentrations. The cell structure was glass/FTO/TiO2-mesoporous/CH3NH3PbI3 (MAPbI3)/spiro-OMeTAD/Ag. The MAPbI3 perovskite films were prepared using high and low MAI concentrations in a two-step process. The perovskite films were optimized at different spin coating speed and different annealing temperatures to enhance the power conversion efficiency (PCE) of perovskite solar cells. The PCE of the resulting device based on the different perovskite morphologies was discussed. The PCE of the best cell was up to 17.42%, open circuit voltage of 0.97 V, short current density of 24.06 mA/cm2, and fill factor of 0.747.

  1. CH(3)NH(3)PbI(3) perovskite / silicon tandem solar cells: characterization based optical simulations. (United States)

    Filipič, Miha; Löper, Philipp; Niesen, Bjoern; De Wolf, Stefaan; Krč, Janez; Ballif, Christophe; Topič, Marko


    In this study we analyze and discuss the optical properties of various tandem architectures: mechanically stacked (four-terminal) and monolithically integrated (two-terminal) tandem devices, consisting of a methyl ammonium lead triiodide (CH(3)NH(3)PbI(3)) perovskite top solar cell and a crystalline silicon bottom solar cell. We provide layer thickness optimization guidelines and give estimates of the maximum tandem efficiencies based on state-of-the-art sub cells. We use experimental complex refractive index spectra for all involved materials as input data for an in-house developed optical simulator CROWM. Our characterization based simulations forecast that with optimized layer thicknesses the four-terminal configuration enables efficiencies over 30%, well above the current single-junction crystalline silicon cell record of 25.6%. Efficiencies over 30% can also be achieved with a two-terminal monolithic integration of the sub-cells, combined with proper selection of layer thicknesses.

  2. Optical characterization of voltage-accelerated degradation in CH3NH3PbI3 perovskite solar cells. (United States)

    Handa, Taketo; Tex, David M; Shimazaki, Ai; Aharen, Tomoko; Wakamiya, Atsushi; Kanemitsu, Yoshihiko


    We investigate the performance degradation mechanism of CH3NH3PbI3 perovskite solar cells under bias voltage in air and nitrogen atmospheres using photoluminescence and electroluminescence techniques. When applying forward bias, the power conversion efficiency of the solar cells decreased significantly in air, but showed no degradation in nitrogen atmosphere. Time-resolved photoluminescence measurements on these devices revealed that the application of forward bias in air accelerates the generation of non-radiative recombination centers in the perovskite layer buried in the device. We found a negative correlation between the electroluminescence intensity and the injected current intensity in air. The irreversible change of the perovskite grain surface in air initiates the degradation of the perovskite solar cells.

  3. Creation and annealing of metastable defect states in CH3NH3PbI3 at low temperatures (United States)

    Lang, F.; Shargaieva, O.; Brus, V. V.; Rappich, J.; Nickel, N. H.


    Methylammonium lead iodide (CH3NH3PbI3), an organic-inorganic perovskite widely used for optoelectronic applications, is known to dissociate under illumination with light at photon energies around 2.7 eV and higher. Here, we show that photo-induced dissociation is not limited to ambient temperatures but can be observed even at 5 K. The photo-induced dissociation of N-H bonds results in the formation of metastable states. Photoluminescence (PL) measurements reveal the formation of defect states that are located 100 meV within the bandgap. This is accompanied by a quenching of the band-to-band PL by one order of magnitude. Defect generation is reversible and annealing at 30 K recovers the band-to-band PL, while the light-induced defect states disappear concurrently.

  4. High performance photodetector based on 2D CH3NH3PbI3 perovskite nanosheets

    International Nuclear Information System (INIS)

    Li, Pengfei; Shivananju, B N; Li, Shaojuan; Bao, Qiaoliang; Zhang, Yupeng


    In this work, a high performance vertical-type photodetector based on two-dimensional (2D) CH 3 NH 3 PbI 3 perovskite nanosheets was fabricated. The low trap density of the perovskite nanosheets and their short carrier diffusion distance result in a significant performance enhancement of the perovskite-based photodetector. The photoresponsivity of this vertical-type photodetector is as high as 36 mA W −1 at visible wavelength, which is much better than traditional perovskite photodetectors (0.34 mA W −1 ). Compared with traditional planar-type perovskite-based photodetectors, this vertical-type photodetector also shows the advantages of low-voltage operation and large responsivity. These results may pave the way for exploiting high performance perovskite-based photodetectors with an ingenious device design. (paper)

  5. Morphology-photovoltaic property correlation in perovskite solar cells: One-step versus two-step deposition of CH3NH3PbI3

    Directory of Open Access Journals (Sweden)

    Jeong-Hyeok Im


    Full Text Available Perovskite CH3NH3PbI3 light absorber is deposited on the mesoporous TiO2 layer via one-step and two-step coating methods and their photovoltaic performances are compared. One-step coating using a solution containing CH3NH3I and PbI2 shows average power conversion efficiency (PCE of 7.5%, while higher average PCE of 13.9% is obtained from two-step coating method, mainly due to higher voltage and fill factor. The coverage, pore-filling, and morphology of the deposited perovskite are found to be critical in photovoltaic performance of the mesoporous TiO2 based perovskite solar cells.

  6. Increasing the electrical anisotropy of solution-grown PbI2 thin films by addition of CdI2

    International Nuclear Information System (INIS)

    Ponpon, J.P.; Amann, M.


    In the present study up to 20% CdI 2 has been added to a lead iodide-water solution, which is used to grow PbI 2 polycrystalline thin films. As a result, a significant increase in the anisotropy of the lead iodide film's electrical properties has been observed: the resistivity in the direction parallel to the c-axis reached 10 15 Ω cm but did not change significantly in the orthogonal direction. This behavior can be explained by the modification of the transport properties related to the crystallographic structure of the films along the c-axis. As suggested by thermally stimulated current measurements, only a small number of the Cd atoms incorporated into the PbI 2 lattice could behave as dopants.

  7. Relativistic GW calculations on CH3NH3PbI3 and CH3NH3SnI3 perovskites for solar cell applications. (United States)

    Umari, Paolo; Mosconi, Edoardo; De Angelis, Filippo


    Hybrid AMX3 perovskites (A = Cs, CH3NH3; M = Sn, Pb; X = halide) have revolutionized the scenario of emerging photovoltaic technologies, with very recent results demonstrating 15% efficient solar cells. The CH3NH3PbI3/MAPb(I(1-x)Cl(x))3 perovskites have dominated the field, while the similar CH3NH3SnI3 has not been exploited for photovoltaic applications. Replacement of Pb by Sn would facilitate the large uptake of perovskite-based photovoltaics. Despite the extremely fast progress, the materials electronic properties which are key to the photovoltaic performance are relatively little understood. Density Functional Theory electronic structure methods have so far delivered an unbalanced description of Pb- and Sn-based perovskites. Here we develop an effective GW method incorporating spin-orbit coupling which allows us to accurately model the electronic, optical and transport properties of CH3NH3SnI3 and CH3NH3PbI3, opening the way to new materials design. The different CH3NH3SnI3 and CH3NH3PbI3 electronic properties are discussed in light of their exploitation for solar cells, and found to be dominantly due to relativistic effects. These effects stabilize the CH3NH3PbI3 material towards oxidation, by inducing a deeper valence band edge. Relativistic effects, however, also increase the material band-gap compared to CH3NH3SnI3, due to the valence band energy downshift (~0.7 eV) being only partly compensated by the conduction band downshift (~0.2 eV).

  8. Quantum well effect in bulk PbI(2) crystals revealed by the anisotropy of photoluminescence and Raman spectra. (United States)

    Baltog, I; Baibarac, M; Lefrant, S


    On subjecting a bulk 2H-PbI(2) crystal to vacuum annealing at 500 K followed by a sudden cooling at liquid nitrogen temperature stacking faults are generated that separate distinct layers of nanometric thickness in which different numbers of I-Pb-I atomic layers are bundled together. Such structures, containing two, three, four, five etc I-Pb-I atomic layers, behave as quantum wells of different widths. The signature of such a transformation is given by a shift towards higher energies of the fundamental absorption edge, which is experimentally revealed by specific anisotropies in the photoluminescence and Raman spectra. The quantum confining effect is made visible by specific variations of a wide extra-excitonic band (G) at 2.06 eV that originates in the radiative recombination of carriers (electrons and holes), trapped on the surface defects. The excitation spectrum of the G band, with p polarized exciting light, reveals a fine structure comprised of narrow bands at 2.75, 2.64, 2.59 and 2.56 eV, which are associated with the PbI(2) quantum wells formed from two, three, four and five I-Pb-I atomic layers of 0.7 nm thickness. Regardless of the polarization state of the laser exciting light of 514.5 nm (2.41 eV), which is close to the band gap energy of PbI(2) (2.52 eV), the Raman scattering on bulk as-grown PbI(2) crystals has the character of a resonant process. For p polarized exciting light, the Raman scattering process on vacuum annealed PbI(2) becomes non-resonant. This originates from the quantum well structures generated inside the crystal, whose band gap energies are higher than the energy of the exciting light.

  9. Donor-acceptor random copolyesters containing perylenebisimide (PBI) and oligo(p-phenylene vinylene) (OPV) by melt condensation polymerization: energy transfer studies. (United States)

    Nisha, S Kumari; Asha, S K


    Novel copolyesters consisting of oligo(p-phenylene vinylene) (OPV) as donor (D) and perylenebisimide (PBI) as acceptor (A) were synthesized by melt polycondensation. Photoinduced energy transfer and photoinduced charge separation in these polyesters were studied in solution as well as in the solid state. Selective excitation of OPV moiety resulted in the energy transfer with >90% efficiency from OPV to PBI chromophore in the solution state. The direct excitation of PBI in the D-A copolyester resulted in reduced fluorescence emission of acceptor, indicating electron transfer between the D and A moieties. The effect of distance between donor and acceptor on the energy transfer efficiency from donor to acceptor was studied. Compared to a physical mixture of D and A polyesters alone, the energy transfer was 4 times more efficient in the D-A copolyester, highlighting the influence of covalently linking D and A in a single polymer chain. A strong fluorescence quenching (∼ 100%) of both chromophores in solid state indicated an efficient photoinduced charge transfer after photoexcitation of either D or A. Thus, OPV-PBI main chain copolyester is an excellent system for the study of energy- and electron-transfer processes in organic semiconductor. Reactive blend of D/A copolyester was also prepared by the transesterification reaction between D and A alone copolyesters. The energy transfer efficiency from D to A moiety upon selective excitation of D chromophore in the D/A copolyester blend was ∼4 times higher compared to a physical mixture of D and A alone copolyesters, which gave direct proof for the transesterification reaction in polyester/polyester reactive blending.

  10. Efficiency enhancement of perovskite solar cells using structural and morphological improvement of CH3NH3PbI3 absorber layers (United States)

    Alidaei, Maryam; Izadifard, Morteza; Ghazi, Mohammad E.; Ahmadi, Vahid


    Perovskite solar cells have been heavily investigated due to their unique properties such as high power conversion efficiency (PCE), low-cost fabrication by solution processes, high diffusion length, large absorption coefficient, and direct and tunable band gap. PCE of perovskite devices is strongly dependent on the absorber layer properties such as morphology, crystallinity, and compactness, which are required to be optimized. In this work, the CH3NH3PbI3 (170-480 nm) absorber layers with various methylammonium iodine (MAI) concentrations (7, 10, 20 and 40 mg ml-1) and perovskite solar cells with the fluorine-doped tin oxide (400 nm)/C-TiO2 (30 nm)/Meso-TiO2 (400 nm)/CH3NH3PbI3 (170-480 nm)/P3HT (30 nm)/Au (100 nm) structure were fabricated. A two-step solution process was used for deposition of the CH3NH3PbI3 absorber layers. The morphology, crystal structure, and optical properties of the perovskite layer grown on glass and also the photovoltaic properties of the fabricated solar cells were studied. The results obtained showed that by controlling the deposition conditions, due to the reduction in charge recombination, PCE enhancement of the perovskite solar cell (up to 11.6%) was accessible.

  11. Homogeneous Emission Line Broadening in the Organo Lead Halide Perovskite CH3NH3PbI3-xClx. (United States)

    Wehrenfennig, Christian; Liu, Mingzhen; Snaith, Henry J; Johnston, Michael B; Herz, Laura M


    The organic-inorganic hybrid perovskites methylammonium lead iodide (CH3NH3PbI3) and the partially chlorine-substituted mixed halide CH3NH3PbI3-xClx emit strong and broad photoluminescence (PL) around their band gap energy of ∼1.6 eV. However, the nature of the radiative decay channels behind the observed emission and, in particular, the spectral broadening mechanisms are still unclear. Here we investigate these processes for high-quality vapor-deposited films of CH3NH3PbI3-xClx using time- and excitation-energy dependent photoluminescence spectroscopy. We show that the PL spectrum is homogenously broadened with a line width of 103 meV most likely as a consequence of phonon coupling effects. Further analysis reveals that defects or trap states play a minor role in radiative decay channels. In terms of possible lasing applications, the emission spectrum of the perovskite is sufficiently broad to have potential for amplification of light pulses below 100 fs pulse duration.

  12. Structural phase transition causing anomalous photoluminescence behavior in perovskite (C6H11NH3)2[PbI4 (United States)

    Yangui, A.; Pillet, S.; Mlayah, A.; Lusson, A.; Bouchez, G.; Triki, S.; Abid, Y.; Boukheddaden, K.


    Optical and structural properties of the organic-inorganic hybrid perovskite-type (C6H11NH3)2[PbI4] (abbreviated as C6PbI4) were investigated using optical absorption, photoluminescence (PL), and x-ray diffraction measurements. Room temperature, optical absorption measurements, performed on spin-coated films of C6PbI4, revealed two absorption bands at 2.44 and 3.21 eV. Upon 325 nm (3.815 eV) laser irradiation, strong green PL emission peaks were observed at 2.41 eV (P1) and 2.24 eV (P2) and assigned to free and localized excitons, respectively. The exciton binding energy was estimated at 356 meV. At low temperature, two additional emission bands were detected at 2.366 eV (P3) and a large band (LB) at 1.97 eV. The former appeared only below 40 K and the latter emerged below 130 K. The thermal dependence of the PL spectra revealed an abnormal behavior accompanied by singularities in the peak positions and intensities at 40 and 130 K. X-ray diffraction studies performed on powder and single crystals as a function of temperature evidenced significant changes of the interlayer spacing at 50 K and ˜138 K. Around 138 K, a commensurate to incommensurate structural phase transition occurred on cooling. It involves a symmetry breaking leading to a distortion of the PbI6 octahedron. The resulting incommensurate spatial modulation of the Pb-I distances (and Pb-I-Pb angles) causes a spatial modulation of the band gap, which is at the origin of the emergence of the LB below ˜130 K and the anomalous behavior of the position of P1 below 130 K. The change of the interlayer spacing in the 40-50 K range may in turn be related to the significant decrease of the intensity of P2 and the maximum emission of the LB. These results underline the intricate character of the structural and the PL properties of the hybrid perovskites; understanding such properties should benefit to the design of optoelectronic devices with targeted properties.

  13. Fouling behaviors of polybenzimidazole (PBI)-polyhedral oligomeric silsesquioxane (POSS)/polyacrylonitrile (PAN) hollow fiber membranes for engineering osmosis processes

    KAUST Repository

    Chen, Sicong; Fu, Xiuzhu; Chung, Neal Tai-Shung


    This paper investigated the individual effects of reverse salt flux and permeate flux on fouling behaviors of as-spun and annealed polybenzimidazole (PBI)-polyhedral oligomeric silsesquioxane (POSS)/polyacrylonitrile (PAN) hollow fiber membranes under forward osmosis (FO) and pressure retarded osmosis (PRO) processes. Two types of membrane fouling had been studied; namely, inorganic fouling (CaSO4·2H2O gypsum scaling) during FO operations and organic fouling (sodium alginate fouling) during PRO operations. It is found that gypsum scaling on the membrane surface may be inhibited and even eliminated with an increase in reverse MgCl2 flux due to competitive formations of MgSO4° and CaSO4·2H2O. In contrast, the increase of reverse NaCl flux exhibits a slight enhancement on alginate fouling in both FO and PRO processes. Comparing to the reverse salt flux, the permeate flux always plays a dominant role in fouling. Therefore, lesser fouling has been observed on the membrane surface under the pressurized PRO process than FO process because the reduced initial flux mitigates the fouling phenomena more significantly than the enhancement caused by an increase in reverse NaCl flux. © 2013 Elsevier B.V.

  14. Piezoelectric scattering limited mobility of hybrid organic-inorganic perovskites CH3NH3PbI3 (United States)

    Lu, Ying-Bo; Kong, Xianghua; Chen, Xiaobin; Cooke, David G.; Guo, Hong


    Carrier mobility is one of the most important parameters for semiconducting materials and their use in optoelectronic devices. Here we report a systematic first principles analysis of the acoustic phonon scattering mechanism that limits the mobility of CH3NH3PbI3 (MAPbI3) perovskites. Due to the unique hybrid organic-inorganic structure, the mechanical, electronic and transport properties are dominated by the same factor, i.e. the weak interatomic bond and the easy rotation of methylammonium (MA) molecules under strain. Both factors make MAPbI3 soft. Rotation of MA molecule induces a transverse shift between Pb and I atoms, resulting in a very low deformation potential and a strong piezoelectricity in MAPbI3. Hence the carrier mobility of pristine MAPbI3 is limited by the piezoelectric scattering, which is consistent to the form of its temperature dependence. Our calculations suggest that in the pristine limit, a high mobility of about several thousand cm2 V−1 S−1 is expected for MAPbI3. PMID:28150743

  15. First-principles study on the initial decomposition process of CH3NH3PbI3 (United States)

    Xue, Yuanbin; Shan, Yueyue; Xu, Hu


    Hybrid perovskites are promising materials for high-performance photovoltaics. Unfortunately, hybrid perovskites readily decompose in particular under humid conditions, and the mechanisms of this phenomenon have not yet been fully understood. In this work, we systematically studied the possible mechanisms and the structural properties during the initial decomposition process of MAPbI3 (MA = CH3NH3+) using first-principles calculations. The theoretical results show that it is energetically favorable for PbI2 to nucleate and crystalize from the MAPbI3 matrix ahead of other decomposition products. Additionally, the structural instability is an intrinsic property of MAPbI3, regardless of whether the system is exposed to humidity. We find that H2O could facilitate the desorption of gaseous components, acting as a catalyst to transfer the H+ ion. These results provide insight into the cause of the instability of MAPbI3 and may improve our understanding of the properties of hybrid perovskites.

  16. Performance Improvement of CH3NH3PbI3 Perovskite Solar Cell by CH3SH Doping

    Directory of Open Access Journals (Sweden)

    Hong Li


    Full Text Available Organometal halide perovskites have recently emerged as an appealing candidate in photovoltaic devices due to their excellent properties. Therefore, intense efforts have been devoted to find the ideal organics for perovskite solar cells. In response, we investigate the doping effect of CH3SH organic on the structure and related performance of a CH3NH3PbI3 perovskite solar cell, via in situ synchrotron- based grazing incidence X-ray diffraction (GIXRD, together with scanning electron microscopy (SEM. In situ GIXRD investigations clearly illustrated the transformation and modification of the perovskite structure induced by the organic dopant, which subsequently led to the enhance‐ ment of the power conversion efficiency of fabricated solar cells. Notably, nanoporous morphology and nanocrystal‐ line structures were discovered in the perovskite film by SEM; they were also confirmed by the increase in broad‐ ening peaks/features in the GIXRD measurements. Overall, our study may ultimately result in an attractive strategy for the fabrication of high performance perovskite solar cells.

  17. Influence of the Grain Size on the Properties of CH3NH3PbI3 Thin Films. (United States)

    Shargaieva, Oleksandra; Lang, Felix; Rappich, Jörg; Dittrich, Thomas; Klaus, Manuela; Meixner, Matthias; Genzel, Christoph; Nickel, Norbert H


    Hybrid perovskites have already shown a huge success as an absorber in solar cells, resulting in the skyrocketing rise in the power conversion efficiency to more than η = 22%. Recently, it has been established that the crystal quality is one of the most important parameters to obtain devices with high efficiencies. However, the influence of the crystal quality on the material properties is not fully understood. Here, the influence of the morphology on electronic properties of CH 3 NH 3 PbI 3 thin films is investigated. Postannealing was used to vary the average grain size continuously from ≈150 to ≈1000 nm. Secondary grain growth is thermally activated with an activation energy of E a = 0.16 eV. The increase in the grain size leads to an enhancement of the photoluminescence, indicating an improvement in the material quality. According to surface photovoltage measurements, the charge-carrier transport length exhibits a linear increase with increasing grain size. The charge-carrier diffusion length is limited by grain boundaries. Moreover, an improved morphology leads to a drastic increase in power conversion efficiency of the devices.

  18. Temperature-Dependent Electric Field Poling Effects in CH3NH3PbI3 Optoelectronic Devices. (United States)

    Zhang, Chuang; Sun, Dali; Liu, Xiaojie; Sheng, Chuan-Xiang; Vardeny, Zeev Valy


    Organo-lead halide perovskites show excellent optoelectronic properties; however, the unexpected inconsistency in forward-backward I-V characteristics remains a problem for fabricating solar panels. Here we have investigated the reasons behind this "hysteresis" by following the changes in photocurrent and photoluminescence under electric field poling in transverse CH 3 NH 3 PbI 3 -based devices from 300 to 10 K. We found that the hysteresis disappears at cryogenic temperatures, indicating the "freeze-out" of the ionic diffusion contribution. When the same device is cooled under continuous poling, the built-in electric field from ion accumulation brings significant photovoltaic effect even at 10 K. From the change of photoluminescence upon polling, we found a second dipole-related mechanism which enhances radiative recombination upon the alignment of the organic cations. The ionic origin of hysteresis was also verified by applying a magnetic field to affect the ion diffusion. These findings reveal the coexistence of ionic and dipole-related mechanisms for the hysteresis in hybrid perovskites.

  19. Electrical Stress Influences the Efficiency of CH3 NH3 PbI3 Perovskite Light Emitting Devices. (United States)

    Zhao, Lianfeng; Gao, Jia; Lin, YunHui L; Yeh, Yao-Wen; Lee, Kyung Min; Yao, Nan; Loo, Yueh-Lin; Rand, Barry P


    Organic-inorganic hybrid perovskite materials are emerging as semiconductors with potential application in optoelectronic devices. In particular, perovskites are very promising for light-emitting devices (LEDs) due to their high color purity, low nonradiative recombination rates, and tunable bandgap. Here, using pure CH 3 NH 3 PbI 3 perovskite LEDs with an external quantum efficiency (EQE) of 5.9% as a platform, it is shown that electrical stress can influence device performance significantly, increasing the EQE from an initial 5.9% to as high as 7.4%. Consistent with the enhanced device performance, both the steady-state photoluminescence (PL) intensity and the time-resolved PL decay lifetime increase after electrical stress, indicating a reduction in nonradiative recombination in the perovskite film. By investigating the temperature-dependent characteristics of the perovskite LEDs and the cross-sectional elemental depth profile, it is proposed that trap reduction and resulting device-performance enhancement is due to local ionic motion of excess ions, likely excess mobile iodide, in the perovskite film that fills vacancies and reduces interstitial defects. On the other hand, it is found that overstressed LEDs show irreversibly degraded device performance, possibly because ions initially on the perovskite lattice are displaced during extended electrical stress and create defects such as vacancies. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Fouling behaviors of polybenzimidazole (PBI)-polyhedral oligomeric silsesquioxane (POSS)/polyacrylonitrile (PAN) hollow fiber membranes for engineering osmosis processes

    KAUST Repository

    Chen, Sicong


    This paper investigated the individual effects of reverse salt flux and permeate flux on fouling behaviors of as-spun and annealed polybenzimidazole (PBI)-polyhedral oligomeric silsesquioxane (POSS)/polyacrylonitrile (PAN) hollow fiber membranes under forward osmosis (FO) and pressure retarded osmosis (PRO) processes. Two types of membrane fouling had been studied; namely, inorganic fouling (CaSO4·2H2O gypsum scaling) during FO operations and organic fouling (sodium alginate fouling) during PRO operations. It is found that gypsum scaling on the membrane surface may be inhibited and even eliminated with an increase in reverse MgCl2 flux due to competitive formations of MgSO4° and CaSO4·2H2O. In contrast, the increase of reverse NaCl flux exhibits a slight enhancement on alginate fouling in both FO and PRO processes. Comparing to the reverse salt flux, the permeate flux always plays a dominant role in fouling. Therefore, lesser fouling has been observed on the membrane surface under the pressurized PRO process than FO process because the reduced initial flux mitigates the fouling phenomena more significantly than the enhancement caused by an increase in reverse NaCl flux. © 2013 Elsevier B.V.

  1. CH 3 NH 3 PbI 3 /GeSe bilayer heterojunction solar cell with high performance (United States)

    Hou, Guo-Jiao; Wang, Dong-Lin; Ali, Roshan; Zhou, Yu-Rong; Zhu, Zhen-Gang; Su, Gang


    Perovskite (CH3NH3PbI3) solar cells have made significant advances recently. In this paper, we propose a bilayer heterojunction solar cell comprised of a perovskite layer combining with a IV-VI group semiconductor layer, which can give a conversion efficiency even higher than the conventional perovskite solar cell. Such a scheme uses a property that the semiconductor layer with a direct band gap can be better in absorption of long wavelength light and is complementary to the perovskite layer. We studied the semiconducting layers such as GeSe, SnSe, GeS, and SnS, respectively, and found that GeSe is the best, where the optical absorption efficiency in the perovskite/GeSe solar cell is dramatically increased. It turns out that the short circuit current density is enhanced 100% and the power conversion efficiency is promoted 42.7% (to a high value of 23.77%) larger than that in a solar cell with only single perovskite layer. The power conversion efficiency can be further promoted so long as the fill factor and open-circuit voltage are improved. This strategy opens a new way on developing the solar cells with high performance and practical applications.

  2. Assessment of intravenous pbi-shRNA PDX1 nanoparticle (OFHIRNA-PDX1) in yucatan swine. (United States)

    Jay, C M; Ruoff, C; Kumar, P; Maass, H; Spanhel, B; Miller, M; Arrington, A; Montalvo, N; Gresham, V; Rao, D D; Evans, C; Wang, Z; Brunicardi, F C; Liu, S-H; Zhou, G; Senzer, N; Nemunaitis, J; King, L; Weeks, B; Clubb, F J; Fossum, T W; Maples, P B


    PDX1 (pancreatic and duodenal homeobox 1) is overexpressed in pancreatic cancer, and its reduction results in tumor regression. Bi-functional pbi-shRNA PDX1 nanoparticle (OFHIRNA-PDX1) utilizes the endogenous micro-RNA biogenesis pathway to effect cleavage- and non-cleavage-dependent degradation of PDX1 mRNA. We have shown that OFHIRNA-PDX1 reduces pancreatic tumor volume in xenograft models. Thus, we are now exploring biorelevant large animal safety of OFHIRNA-PDX1. Mini pigs were chosen as the biorelevant species based on the similarity of human and pig PDX1 target sequence. In the initial study, animals developed fever, lethargy, hyporexia and cutaneous hyperemia following administration of OFHIRNA-PDX1. Twenty-one days later, the same animals demonstrated less toxicity with a second OFHIRNA-PDX1 infusion in conjunction with a prophylactic regimen involving dexamethasone, diphenhydramine, Indocin and ranitidine. In a new group of animals, PDX1 protein (31 kDa) expression in the pancreas was significantly repressed at 48 and 72 h (85%, P=0.018 and 88%, P=0.013; respectively) following a single infusion of OFHIRNA-PDX1 but recovered to normal state within 7 days. In conclusion, a single intravenous infusion of OFHIRNA-PDX1 in conjunction with premedication in pigs was well tolerated and demonstrated significant PDX1 knockdown.

  3. Polarization tunable photogenerated carrier transfer of CH3NH3PbI3/polyvinylidene fluoride heterostructure (United States)

    Yang, Kang; Deng, Zun-Yi; Feng, Hong-Jian


    The integration of ferroelectrics and organic-inorganic halide perovskites could be a promising way to facilitate the separation of electron-hole pairs and charge extraction for the application of solar cells. To explore the effect of the external ferroelectric layer on the CH3NH3PbI3 (MAPbI3) side, we perform first-principles calculations to study the charge transfer properties of the MAPbI3/polyvinylidene fluoride (PVDF) heterostructure. Our calculations demonstrate that the ferroelectric polarization pointing to the PVDF side can clearly facilitate the separation of photo-induced carriers and enhance charge extraction from MAPbI3, while opposite polarization direction hinders the charge extraction and collection. Notably, the carrier behavior at the interface is strongly tuned by the electric field associated with the ferroelectric polarization. In addition, excited state simulation confirms the tunable charge transfer of the MAPbI3/PVDF heterojunction. Therefore, the polarization-driven charge transfer mechanism provides a route for fabricating the ferroelectrics-based high-efficiency photovoltaics and switchable diode devices.

  4. Shallow trapping vs. deep polarons in a hybrid lead halide perovskite, CH3NH3PbI3. (United States)

    Kang, Byungkyun; Biswas, Koushik


    There has been considerable speculation over the nature of charge carriers in organic-inorganic hybrid perovskites, i.e., whether they are free and band-like, or they are prone to self-trapping via short range deformation potentials. Unusually long minority-carrier diffusion lengths and moderate-to-low mobilities, together with relatively few deep defects add to their intrigue. Here we implement density functional methods to investigate the room-temperature, tetragonal phase of CH 3 NH 3 PbI 3 . We compare charge localization behavior at shallow levels and associated lattice relaxation versus those at deep polaronic states. The shallow level originates from screened Coulomb interaction between the perturbed host and an excited electron or hole. The host lattice has a tendency towards forming these shallow traps where the electron or hole is localized not too far from the band edge. In contrast, there is a considerable potential barrier that must be overcome in order to initiate polaronic hole trapping. The formation of a hole polaron (I 2 - center) involves strong lattice relaxation, including large off-center displacement of the organic cation, CH 3 NH 3 + . This type of deep polaron is energetically unfavorable, and active shallow traps are expected to shape the carrier dynamics in this material.


    Directory of Open Access Journals (Sweden)

    Suzete Silveira Fichtner


    Full Text Available

    Foram analisados 71 hemossoros de bovinos mestiços holandês-zebu, procedentes de cinco municípios da micro-região Mato-Grosso de Goiás. Os autores observaram que os valores obtidos para o gado mestiço holandês-zebu não diferem dos parâmetros fisiológicos estabelecidos pelos investigadores consultados, que trabalharam com gado de origem européia. As diferenças ocorridas poderão ser atribuídas a condições diversas, como por exemplo, as em que se desenvolveram o presente trabalho. Concluímos que, nas condições em que se realizou o presente trabalho, com animais em regime de campo, o gado mestiço holandês-zebu apresenta a importante característica de não aumentar a atividade de sua tireóide, em comparação com o gado de origem européia, apesar de habitar uma região onde as necessidades de dissipação do calor e de circulação sangüínea são mais intensas.

    It was analyzed 71 blood serum of crossbreed zebu from 5 counties of e specific region in the State of Goiás, Brazil. PBI serum levels were (in mg/100 ml of serum: calves 3.6 +/- 0.88; bullock 3.4 +/- 1.04 and cows 3.3 +/- 1.35.

  6. Translating tools for better parent-based assessment: An exploratory study (United States)


    Background Current speech language assessment and intervention measures are not always culturally valid, as they are not standardised specifically for the various cultural groups within the South African population; and thus need to be adapted. Objectives The objective of this study was to examine the appropriateness and utility of translations of the Ages & Stages Questionnaire (ASQ) instrument (60 month age group) from English to the Hindi language and culture, which is represented in South Africa. Methods Biographical questionnaires, ASQ and evaluation thereof were translated in Hindi and completed by parents of 15 typically developing South African preschool children of Indian origin, at the 60 month age level (including children between 57 and 66 months). Results Participants reported that the questions were well phrased, and that illustrations and tips helped them to complete the questionnaires quickly and accurately. They preferred to be questioned in Hindi, which helped them understand the questions and made it easier to provide the necessary information to answer the questions. Conclusions In conclusion, it is evident that this translation of the ASQ (60 month age group) from English to Hindi served as an appropriate tool for use with the middle socioeconomic class Hindi (Indian) language and culture. The results of this study would assist to determine the functionality of culturally and linguistically valid assessment tools for different populations, and would contribute to the development of Early Childhood Intervention as a whole in South Africa. It would also contribute to the development of multilingual informal school-readiness screening questionnaires appropriate for the South African context. This is particularly relevant, as school-readiness assessments take place at 60 months to ensure that the child is ready to learn by school age (6–7 years). PMID:26304214

  7. Comparison of orthogonal kilovolt X-ray images and cone-beam CT matching results in setup error assessment and correction for EB-PBI during free breathing

    International Nuclear Information System (INIS)

    Wang Wei; Li Jianbin; Hu Hongguang; Ma Zhifang; Xu Min; Fan Tingyong; Shao Qian; Ding Yun


    Objective: To compare the differences in setup error (SE) assessment and correction between the orthogonal kilovolt X-ray images and CBCT in EB-PBI patients during free breathing. Methods: Nineteen patients after breast conserving surgery EB-PBI were recruited. Interfraction SE was acquired using orthogonal kilovolt X-ray setup images and CBCT, after on-line setup correction,calculate the residual error and compare the SE, residual error and setup margin (SM) quantified for orthogonal kilovolt X-ray images and CBCT. Wilcoxon sign-rank test was used to evaluate the differences. Results: The CBCT based SE (systematic error, ∑) was smaller than the orthogonal kilovolt X-ray images based ∑ in AP direction (-1.2 mm vs 2.00 mm; P=0.005), and there was no statistically significant differences for three dimensional directions in random error (σ) (P=0.948, 0.376, 0.314). After on-line setup correction,CBCT decreases setup residual error than the orthogonal kilovolt X-ray images in AP direction (Σ: -0.20 mm vs 0.50 mm, P=0.008; σ: 0.45 mm vs 1.34 mm, P=0.002). And also the CBCT based SM was smaller than orthogonal kilovolt X-ray images based SM in AP direction (Σ: -1.39 mm vs 5.57 mm, P=0.003; σ: 0.00 mm vs 3.2 mm, P=0.003). Conclusions: Compared with kilovolt X-ray images, CBCT underestimate the setup error in the AP direction, but decreases setup residual error significantly.An image-guided radiotherapy and setup error assessment using kilovolt X-ray images for EB-PBI plans was feasible. (authors)

  8. Viscosity, surface tension, density and contact angle of selected PbI2, PbCl2 and methylammonium lead halide perovskite solutions used in perovskite solar cells

    Directory of Open Access Journals (Sweden)

    Mohammad-Reza Ahmadian-Yazdi


    Full Text Available Perovskite solar cells (PSCs are currently under vigorous research and development, owing to their compelling power conversion efficiencies. PSCs are solution-processed and, therefore, are fabricated using casting and printing methods, such as spin, spray and blade coating. The coating characteristics significantly depend on the physical and rheological properties of the solutions. Thus, due to the scarcity of such properties, in this work, we report the surface tension, viscosity, density, and contact angle of selected methylammonium lead halide perovskite solutions, in order to gain insight into the behavior of the perovskite solutions and the range of such physical properties. The contact angles were measured on PEDOT:PSS and compact TiO2 (c-TiO2 substrates, commonly used as the underneath layers of the perovskite film. In total, 12 solutions of CH3NH3PbI3 and CH3NH3PbI3-xClx dissolved in common solvents, as well as solutions of PbI2, PbCl2, and CH3NH3I were tested. Among the results, it is shown that the tested perovskite solutions are Newtonian, the apparent contact angles on the mesoporous TiO2 (m-TiO2 are close to zero, on the PEDOT:PSS are around 10°, and on the c-TiO2 are around 30°. Also, contact angle hysteresis is observed in the case of the c-TiO2 substrates. Representative impact dynamics and spreading of perovskite solution droplets are also studied, to demonstrate the importance of the solution properties and process parameters on the coating process.

  9. Viscosity, surface tension, density and contact angle of selected PbI2, PbCl2 and methylammonium lead halide perovskite solutions used in perovskite solar cells (United States)

    Ahmadian-Yazdi, Mohammad-Reza; Rahimzadeh, Amin; Chouqi, Zineb; Miao, Yihe; Eslamian, Morteza


    Perovskite solar cells (PSCs) are currently under vigorous research and development, owing to their compelling power conversion efficiencies. PSCs are solution-processed and, therefore, are fabricated using casting and printing methods, such as spin, spray and blade coating. The coating characteristics significantly depend on the physical and rheological properties of the solutions. Thus, due to the scarcity of such properties, in this work, we report the surface tension, viscosity, density, and contact angle of selected methylammonium lead halide perovskite solutions, in order to gain insight into the behavior of the perovskite solutions and the range of such physical properties. The contact angles were measured on PEDOT:PSS and compact TiO2 (c-TiO2) substrates, commonly used as the underneath layers of the perovskite film. In total, 12 solutions of CH3NH3PbI3 and CH3NH3PbI3-xClx dissolved in common solvents, as well as solutions of PbI2, PbCl2, and CH3NH3I were tested. Among the results, it is shown that the tested perovskite solutions are Newtonian, the apparent contact angles on the mesoporous TiO2 (m-TiO2) are close to zero, on the PEDOT:PSS are around 10°, and on the c-TiO2 are around 30°. Also, contact angle hysteresis is observed in the case of the c-TiO2 substrates. Representative impact dynamics and spreading of perovskite solution droplets are also studied, to demonstrate the importance of the solution properties and process parameters on the coating process.

  10. Enhanced Crystalline Phase Purity of CH3NH3PbI3-xClx Film for High-Efficiency Hysteresis-Free Perovskite Solar Cells. (United States)

    Yang, Yingguo; Feng, Shanglei; Xu, Weidong; Li, Meng; Li, Li; Zhang, Xingmin; Ji, Gengwu; Zhang, Xiaonan; Wang, Zhaokui; Xiong, Yimin; Cao, Liang; Sun, Baoquan; Gao, Xingyu


    Despite rapid successful developments toward promising perovskite solar cells (PSCs) efficiency, they often suffer significant hysteresis effects. Using synchrotron-based grazing incidence X-ray diffraction (GIXRD) with different probing depths by varying the incident angle, we found that the perovskite films consist of dual phases with a parent phase dominant in the interior and a child phase with a smaller (110) interplanar space (d (110) ) after rapid thermal annealing (RTA), which is a widely used post treatment to improve the crystallization of solution-processed perovskite films for high-performance planar PSCs. In particular, the child phase composition gradually increases with decreasing depth till it becomes the majority on the surface, which might be one of the key factors related to hysteresis in fabricated PSCs. We further improve the crystalline phase purity of the solution-processed CH 3 NH 3 PbI 3-x Cl x perovskite film (referred as g-perovskite) by using a facile gradient thermal annealing (GTA), which shows a uniformly distributed phase structure in pinhole-free morphology with less undercoordinated Pb and I ions determined by synchrotron-based GIXRD, grazing incidence small-angle X-ray scattering, scanning electron microscopy, and X-ray photoelectron spectroscopy. Regardless of device structures (conventional and inverted types), the planar heterojunction PSCs employing CH 3 NH 3 PbI 3-x Cl x g-perovskite films exhibit negligible hysteresis with a champion power conversion efficiency of 17.04% for TiO 2 -based conventional planar PSCs and 14.83% for poly(3,4-ethylenedioxythiophene:poly(styrenesulfonate) (PEDOT:PSS)-based inverted planar PSCs. Our results indicate that the crystalline phase purity in CH 3 NH 3 PbI 3-x Cl x perovskite film, especially in the surface region, plays a crucial role in determining the hysteresis effect and device performance.

  11. Nickel oxide electrode interlayer in CH3 NH3 PbI3 perovskite/PCBM planar-heterojunction hybrid solar cells. (United States)

    Jeng, Jun-Yuan; Chen, Kuo-Cheng; Chiang, Tsung-Yu; Lin, Pei-Ying; Tsai, Tzung-Da; Chang, Yun-Chorng; Guo, Tzung-Fang; Chen, Peter; Wen, Ten-Chin; Hsu, Yao-Jane


    This study successfully demonstrates the application of inorganic p-type nickel oxide (NiOx ) as electrode interlayer for the fabrication of NiOx /CH3 NH3 PbI3 perovskite/PCBM PHJ hybrid solar cells with a respectable solar-to-electrical PCE of 7.8%. The better energy level alignment and improved wetting of the NiOx electrode interlayer significantly enhance the overall photovoltaic performance. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Analysis of HgI2 and PbI2 crystals and detectors by particle-induced x-ray emission (PIXE) and ion backscattering spectroscopy (IBS)

    International Nuclear Information System (INIS)

    Bench, G.S.; Heikkinen, D.W.; Antolak, A.J.; Morse, D.H.; Pontau, A.E.; James, R.B.; David, D.C.; Burger, A.; Van Den Berg, L.


    The Ion Micro-Analysis Group (IMAG) in Livermore conducts quantitative trace elemental analysis with PIXE and depth profiling with IBS using an MeV ion microbeam. The system has the capability to produce two-dimensional trace element and IBS images. PIXE analyses have been conducted on HgI 2 and PbI 2 crystals and detector materials in order to identify and quantify near surface trace contaminants. IBS measurements have been conducted to investigate elemental depth distributions in various materials. The results of measurements on several different samples are reported and a discussion of factors affecting quantitative in vacuo microanalysis of these materials is presented

  13. Perspective: Understanding of ripening growth model for minimum residual PbI2 and its limitation in the planar perovskite solar cells

    Directory of Open Access Journals (Sweden)

    Se-Yun Kim


    Full Text Available The power conversion efficiency of lead halide perovskite solar cells recently surpassed 22.1%. In this study, we suggest the perovskite absorber growth mechanism of the two-step process could be explained by an Ostwald ripening growth model for planar-structure perovskite solar cells. We attempt to find out the source of two main problems such as unreacted PbI2 and non-uniformed morphology by the proposed ripening growth mechanism and experimental results. This growth mechanism opens the way toward understanding a key aspect of the photovoltaic operation of high-efficiency, two-step perovskite solar cells.

  14. Structural phase transition causing anomalous photoluminescence behavior in perovskite (C6H11NH3)2[PbI4

    International Nuclear Information System (INIS)

    Yangui, A.; Pillet, S.; Mlayah, A.; Lusson, A.; Bouchez, G.; Boukheddaden, K.; Triki, S.; Abid, Y.


    Optical and structural properties of the organic-inorganic hybrid perovskite-type (C 6 H 11 NH 3 ) 2 [PbI 4 ] (abbreviated as C 6 PbI 4 ) were investigated using optical absorption, photoluminescence (PL), and x-ray diffraction measurements. Room temperature, optical absorption measurements, performed on spin-coated films of C 6 PbI 4 , revealed two absorption bands at 2.44 and 3.21 eV. Upon 325 nm (3.815 eV) laser irradiation, strong green PL emission peaks were observed at 2.41 eV (P1) and 2.24 eV (P2) and assigned to free and localized excitons, respectively. The exciton binding energy was estimated at 356 meV. At low temperature, two additional emission bands were detected at 2.366 eV (P3) and a large band (LB) at 1.97 eV. The former appeared only below 40 K and the latter emerged below 130 K. The thermal dependence of the PL spectra revealed an abnormal behavior accompanied by singularities in the peak positions and intensities at 40 and 130 K. X-ray diffraction studies performed on powder and single crystals as a function of temperature evidenced significant changes of the interlayer spacing at 50 K and ∼138 K. Around 138 K, a commensurate to incommensurate structural phase transition occurred on cooling. It involves a symmetry breaking leading to a distortion of the PbI 6 octahedron. The resulting incommensurate spatial modulation of the Pb–I distances (and Pb–I–Pb angles) causes a spatial modulation of the band gap, which is at the origin of the emergence of the LB below ∼130 K and the anomalous behavior of the position of P1 below 130 K. The change of the interlayer spacing in the 40-50 K range may in turn be related to the significant decrease of the intensity of P2 and the maximum emission of the LB. These results underline the intricate character of the structural and the PL properties of the hybrid perovskites; understanding such properties should benefit to the design of optoelectronic devices with targeted properties

  15. Optical spectroscopy of two-dimensional layered (C(6)H(5)C(2)H(4)-NH(3))(2)-PbI(4) perovskite. (United States)

    Gauthron, K; Lauret, J-S; Doyennette, L; Lanty, G; Al Choueiry, A; Zhang, S J; Brehier, A; Largeau, L; Mauguin, O; Bloch, J; Deleporte, E


    We report on optical spectroscopy (photoluminescence and photoluminescence excitation) on two-dimensional self-organized layers of (C(6)H(5)C(2)H(4)-NH(3))(2)-PbI(4) perovskite. Temperature and excitation power dependance of the optical spectra gives a new insight into the excitonic and the phononic properties of this hybrid organic/inorganic semiconductor. In particular, exciton-phonon interaction is found to be more than one order of magnitude higher than in GaAs QWs. As a result, photoluminescence emission lines have to be interpreted in the framework of a polaron model.

  16. Phase diagrams of high-order critical phenomene and high-temperature equilibria in the H2O-HgI2-PbI2 system

    International Nuclear Information System (INIS)

    Valyashko, V.M.; Urusova, M.A.


    The paper studies the principal schemes of complete state diagram of volatile component-two non-volatile components three-component system with tricritical point and sequence of phase transformations at variation of temperature, pressure and composition of mixture. H 2 O-HgI 2 -PbI 2 system, solid phase dissolving process, stratification of solutions and critical phenomena under 200-400 deg C are studied experimentally. General nature of the system phase diagram and parameters of three-phase equilibrium critical point (tricritical point), that is, gas-liquid 1 -liquid 2 are determined. 17 refs., 8 figs., 3 tabs

  17. Translating tools for better parent-based assessment: An exploratory study

    Directory of Open Access Journals (Sweden)

    Shabnam Abdoola


    Objectives: The objective of this study was to examine the appropriateness and utility of translations of the Ages & Stages Questionnaire (ASQ instrument (60 month age group from English to the Hindi language and culture, which is represented in South Africa. Methods: Biographical questionnaires, ASQ and evaluation thereof were translated in Hindi and completed by parents of 15 typically developing South African preschool children of Indian origin, at the 60 month age level (including children between 57 and 66 months. Results: Participants reported that the questions were well phrased, and that illustrations and tips helped them to complete the questionnaires quickly and accurately. They preferred to be questioned in Hindi, which helped them understand the questions and made it easier to provide the necessary information to answer the questions. Conclusions: In conclusion, it is evident that this translation of the ASQ (60 month age group from English to Hindi served as an appropriate tool for use with the middle socioeconomic class Hindi (Indian language and culture. The results of this study would assist to determine the functionality of culturally and linguistically valid assessment tools for different populations, and would contribute to the development of Early Childhood Intervention as a whole in South Africa. It would also contribute to the development of multilingual informal school-readiness screening questionnaires appropriate for the South African context. This is particularly relevant, as school-readiness assessments take place at 60 months to ensure that the child is ready to learn by school age (6–7 years. [PDF to follow

  18. Influence of PbCl2 content in PbI2 solution of DMF on the absorption, crystal phase, morphology of lead halide thin films and photovoltaic performance in planar perovskite solar cells

    International Nuclear Information System (INIS)

    Wang, Mao; Shi, Chengwu; Zhang, Jincheng; Wu, Ni; Ying, Chao


    In this paper, the influence of PbCl 2 content in PbI 2 solution of DMF on the absorption, crystal phase and morphology of lead halide thin films was systematically investigated and the photovoltaic performance of the corresponding planar perovskite solar cells was evaluated. The result revealed that the various thickness lead halide thin film with the small sheet-like, porous morphology and low crystallinity can be produced by adding PbCl 2 powder into PbI 2 solution of DMF as a precursor solution. The planar perovskite solar cell based on the 300-nm-thick CH 3 NH 3 PbI 3−x Cl x thin film by the precursor solution with the mixture of 0.80 M PbI 2 and 0.20 M PbCl 2 exhibited the optimum photoelectric conversion efficiency of 10.12% along with an open-circuit voltage of 0.93 V, a short-circuit photocurrent density of 15.70 mA cm −2 and a fill factor of 0.69. - Graphical abstract: The figure showed the surface and cross-sectional SEM images of lead halide thin films using the precursor solutions: (a) 0.80 M PbI 2 , (b) 0.80 M PbI 2 +0.20 M PbCl 2 , (c) 0.80 M PbI 2 +0.40 M PbCl 2 , and (d) 0.80 M PbI 2 +0.60 M PbCl 2 . With the increase of the PbCl 2 content in precursor solution, the size of the lead halide nanosheet decreased and the corresponding thin films gradually turned to be porous with low crystallinity. - Highlights: • Influence of PbCl 2 content on absorption, crystal phase and morphology of thin film. • Influence of perovskite film thickness on photovoltaic performance of solar cell. • Lead halide thin film with small sheet-like, porous morphology and low crystallinity. • Planar solar cell with 300 nm-thick perovskite thin film achieved PCE of 10.12%.

  19. Fabrication and Characterization of CH3NH3PbI3−x−yBrxCly Perovskite Solar Cells

    Directory of Open Access Journals (Sweden)

    Atsushi Suzuki


    Full Text Available Fabrication and characterization of CH3NH3PbI3−x−yBrxCly perovskite solar cells using mesoporous TiO2 as electron transporting layer and 2,2′,7,7′-tetrakis-(N,N-di-4-methoxyphenylamino-9,9′-spirobifluorene as a hole-transporting layer (HTL were performed. The purpose of the present study is to investigate role of halogen doping using iodine (I, bromine (Br and chlorine (Cl compounds as dopant on the photovoltaic performance and microstructures of CH3NH3PbI3−x−yBrxCly perovskite solar cells. The X-ray diffraction identified a slight decrease of crystal spacing in the perovskite crystal structure doped with a small amount of I, Br, and Cl in the perovskite compounds. Scanning electron microscopy (SEM and energy dispersive X-ray spectroscopy (EDX showed the perovskite crystal behavior depended on molar ratio of halogen of Pb, I, Br and Cl. Incorporation of the halogen doping into the perovskite crystal structure improved photo generation, carrier diffusion without carrier recombination in the perovskite layer and optimization of electronic structure related with the photovoltaic parameters of open-circuit voltage, short-circuit current density and conversion efficiency. The energy diagram and photovoltaic mechanisms of the perovskite solar cells were discussed in the context of the experimental results.

  20. Nanoscale charge localization induced by random orientations of organic molecules in hybrid perovskite CH3NH3PbI3 (United States)

    Ma, Jie; Wang, Lin-Wang


    Perovskite-based solar cells have achieved high solar-energy conversion efficiencies and attracted wide attentions nowadays. Despite the rapid progress in solar-cell devices, many fundamental issues of the hybrid perovskites have not been fully understood. Experimentally, it is well known that in CH3NH3PbI3, the organic molecules CH3NH3 are randomly orientated at the room temperature, but the impact of the random molecular orientation has not been investigated. Using linear-scaling ab-initiomethods, we have calculated the electronic structures of the tetragonal phase of CH3NH3PbI3 with randomly orientated organic molecules in large supercells up to ~20,000 atoms. Due to the dipole moment of the organic molecule, the random orientation creates a novel system with long-range potential fluctuations unlike alloys or other conventional disordered systems. We find that the charge densities of the conduction-band minimum and the valence-band maximum are localized separately in nanoscales due to the potential fluctuations. The charge localization causes electron-hole separation and reduces carrier recombination rates, which may contribute to the long carrier lifetime observed in experiments. We have also proposed a model to explain the charge localization.

  1. Electronic structure calculations and optical properties of a new organic-inorganic luminescent perovskite: (C9H19NH3)2PbI2Br2

    International Nuclear Information System (INIS)

    Abid, H.; Samet, A.; Dammak, T.; Mlayah, A.; Hlil, E.K.; Abid, Y.


    (C 9 H 19 NH 3 ) 2 PbI 2 Br 2 compound is a new crystal belonging to the large hybrid organic-inorganic perovskites compounds family. Optical properties are investigated by optical absorption UV-visible and photoluminescence (PL) techniques. Bands to band absorption peak at 2.44 eV as well as an extremely strong yellow-green photoluminescence emission at 2.17 eV is observed at room temperature. First principle calculations based on the DFT and FLAPW methods combined with LDA approximation are performed as well. Density of state close to the gap is presented and discussed in terms of optical absorption and photoluminescence experimental results. The perfect agreement between experimental data and electronic structure calculations is highlighted. - Highlights: → (C 9 H 19 NH 3 ) 2 PbI 2 Br 2 compound is a new crystal with strong yellow-green PL emission at 2.17 eV. → Calculations based on DFT and FLAPW method combined with LDA approximation are performed. → Gap, optical transitions and exciton presence were predicted from density of states. → Agreement between experimental data and electronic structure calculations.

  2. Carrier injection and recombination processes in perovskite CH3NH3PbI3 solar cells studied by electroluminescence spectroscopy (United States)

    Handa, Taketo; Okano, Makoto; Tex, David M.; Shimazaki, Ai; Aharen, Tomoko; Wakamiya, Atsushi; Kanemitsu, Yoshihiko


    Organic-inorganic hybrid perovskite materials, CH3NH3PbX3 (X = I and Br), are considered as promising candidates for emerging thin-film photovoltaics. For practical implementation, the degradation mechanism and the carrier dynamics during operation have to be clarified. We investigated the degradation mechanism and the carrier injection and recombination processes in perovskite CH3NH3PbI3 solar cells using photoluminescence (PL) and electroluminescence (EL) imaging spectroscopies. By applying forward bias-voltage, an inhomogeneous distribution of the EL intensity was clearly observed from the CH3NH3PbI3 solar cells. By comparing the PL- and EL-images, we revealed that the spatial inhomogeneity of the EL intensity is a result of the inhomogeneous luminescence efficiency in the perovskite layer. An application of bias-voltage for several tens of minutes in air caused a decrease in the EL intensity and the conversion efficiency of the perovskite solar cells. The degradation mechanism of perovskite solar cells under bias-voltage in air is discussed.

  3. Antiferroelectric Nature of CH3NH3PbI3-xClx Perovskite and Its Implication for Charge Separation in Perovskite Solar Cells (United States)

    Sewvandi, Galhenage A.; Kodera, Kei; Ma, Hao; Nakanishi, Shunsuke; Feng, Qi


    Perovskite solar cells (PSCs) have been attracted scientific interest due to high performance. Some researchers have suggested anomalous behavior of PSCs to the polarizations due to the ion migration or ferroelectric behavior. Experimental results and theoretical calculations have suggested the possibility of ferroelectricity in organic-inorganic perovskite. However, still no studies have been concretely discarded the ferroelectric nature of perovskite absorbers in PSCs. Hysteresis of P-E (polarization-electric field) loops is an important evidence to confirm the ferroelectricity. In this study, P-E loop measurements, in-depth structural study, analyses of dielectric behavior and the phase transitions of CH3NH3PbI3-xClx perovskite were carried out and investigated. The results suggest that CH3NH3PbI3-xClx perovskite is in an antiferroelectric phase at room temperature. The antiferroelectric phase can be switched to ferroelectric phase by the poling treatment and exhibits ferroelectric-like hysteresis P-E loops and dielectric behavior around room temperature; namely, the perovskite can generate a ferroelectric polarization under PSCs operating conditions. Furthermore, we also discuss the implications of ferroelectric polarization on PSCs charge separation.

  4. Efficient and stable CH3NH3PbI3-x(SCN)x planar perovskite solar cells fabricated in ambient air with low-temperature process (United States)

    Zhang, Zongbao; Zhou, Yang; Cai, Yangyang; Liu, Hui; Qin, Qiqi; Lu, Xubing; Gao, Xingsen; Shui, Lingling; Wu, Sujuan; Liu, Jun-Ming


    Planar perovskite solar cells (PSCs) based on CH3NH3PbI3-x(SCN)x (SCN: thiocyanate) active layer and low-temperature processed TiO2 films are fabricated by a sequential two-step method in ambient air. Here, alkali thiocyanates (NaSCN, KSCN) are added into Pb(SCN)2 precursor to improve the microstructure of CH3NH3PbI3-x(SCN)x perovskite layers and performance of the as-prepared PSCs. At the optimum concentrations of alkali thiocyanates as additives, the as-prepared NaSCN-modified and KSCN-modified PSCs demonstrate the efficiencies of 16.59% and 15.63% respectively, being much higher than 12.73% of the reference PSCs without additives. This improvement is primarily ascribed to the enhanced electron transport, reduced recombination rates and much improved microstructures with large grain size and low defect density at grain boundaries. Importantly, it is revealed that the modified PSCs at the optimized concentrations of alkali thiocyanates additives exhibit remarkably improved stability than the reference PSCs against humid circumstance, and a continuous exposure to humid air without encapsulation over 45 days only records about 5% degradation of the efficiency. These findings provide a facile approach to fabricate efficient and stable PSCs by low processing temperature in ambient air, both of which are highly preferred for future practical applications of PSCs.

  5. Role of bromine doping on the photovoltaic properties and microstructures of CH3NH3PbI3 perovskite solar cells

    International Nuclear Information System (INIS)

    Suzuki, Atsushi; Okada, Hiroshi; Oku, Takeo


    Organic-inorganic hybrid heterojunction solar cells containing CH 3 NH 3 PbI 3 perovskite compound were fabricated using mesoporous TiO 2 as the electronic transporting layer and spirobifluorence as the hole-transporting layer. The purpose of the present study is to investigate role of bromine (Br) doping on the photovoltaic properties and microstructure of CH 3 NH 3 PbI 3 perovskite solar cells. Photovoltaic, optical properties and microstructures of perovskite-based solar cells were investigated. The X-ray diffraction identified crystal structure of the perovskite layer doped with Br in the solar cell. Scanning electron microscopy observation showed a different behavior of surface morphology and the perovskite crystal structure on the TiO 2 mesoporous structure depending on extent amount of hydrogen doping of Br. The role of bromide halogen doping on the perovskite crystal structure and photovoltaic properties was due to improvement of carrier mobility, optimization of electron structure, band gap related with the photovoltaic parameters of V oc , J sc and η. Energy diagram and photovoltaic mechanism of the perovskite solar cells varied with halogen doping was discussed by experimental results

  6. High-Performance CH3NH3PbI3-Inverted Planar Perovskite Solar Cells with Fill Factor Over 83% via Excess Organic/Inorganic Halide. (United States)

    Jahandar, Muhammad; Khan, Nasir; Lee, Hang Ken; Lee, Sang Kyu; Shin, Won Suk; Lee, Jong-Cheol; Song, Chang Eun; Moon, Sang-Jin


    The reduction of charge carrier recombination and intrinsic defect density in organic-inorganic halide perovskite absorber materials is a prerequisite to achieving high-performance perovskite solar cells with good efficiency and stability. Here, we fabricated inverted planar perovskite solar cells by incorporation of a small amount of excess organic/inorganic halide (methylammonium iodide (CH 3 NH 3 I; MAI), formamidinium iodide (CH(NH 2 ) 2 I; FAI), and cesium iodide (CsI)) in CH 3 NH 3 PbI 3 perovskite film. Larger crystalline grains and enhanced crystallinity in CH 3 NH 3 PbI 3 perovskite films with excess organic/inorganic halide reduce the charge carrier recombination and defect density, leading to enhanced device efficiency (MAI+: 14.49 ± 0.30%, FAI+: 16.22 ± 0.38% and CsI+: 17.52 ± 0.56%) compared to the efficiency of a control MAPbI 3 device (MAI: 12.63 ± 0.64%) and device stability. Especially, the incorporation of a small amount of excess CsI in MAPbI 3 perovskite film leads to a highly reproducible fill factor of over 83%, increased open-circuit voltage (from 0.946 to 1.042 V), and short-circuit current density (from 18.43 to 20.89 mA/cm 2 ).

  7. Research Paper: Effect of Navayesh Parent-Based Comprehensive Rehabilitation Program on the Development of Early Language and Communication Skills in Deaf Children Aged 0-2 Years

    Directory of Open Access Journals (Sweden)

    Saeid Hassanzadeh


    Conclusion The results are indicative of the effect of the Navayesh parent-based comprehensive rehabilitation program on the development of early language and communication skills of deaf children. Therefore, it is recommended that this program should be used at rehabilitation centers for deaf children, aiming at training parents as the primary therapists of deaf children.

  8. A Review of Parent-Based Barriers to Parent-Adolescent Communication about Sex and Sexuality: Implications for Sex and Family Educators (United States)

    Malacane, Mona; Beckmeyer, Jonathon J.


    Although adolescents' sexual health is generally better when parents and adolescents communicate about sex and sexuality, researchers have found parents can be reluctant to engage adolescents in conversations about those topics. To better understand why, we reviewed prior literature and identified four types of parent-based barriers to…

  9. DFT analysis and FDTD simulation of CH3NH3PbI3-x Cl x mixed halide perovskite solar cells: role of halide mixing and light trapping technique (United States)

    Saffari, Mohaddeseh; Mohebpour, Mohammad Ali; Rahimpour Soleimani, H.; Bagheri Tagani, Meysam


    Since perovskite solar cells have attracted a great deal of attention over the past few years, the enhancement of their optical absorption and current density are among the basic upcoming challenges. For this reason, first, we have studied the structural and optical properties of organic-inorganic hybrid halide perovskite CH3NH3PbI3 and the compounds doped by chlorine halogen CH3NH3PbI3-x Cl x in the cubic phase by using a density functional theory (DFT). Then, we model a single-junction perovskite solar cell based on a full solution to Maxwell’s equations, using a finite difference time domain (FDTD) technique, which helps us to investigate the light absorption efficiency and optical current density of the cell with CH3NH3PbI3-x Cl x (x  =  0, 1, 2, 3) as the active layer. The results suggest that increasing the amount of chlorine in CH3NH3PbI3-x Cl x compound leads to an increase in the bandgap energy, as well as a decrease in the lattice constants and optical properties, like the refractive index and extinction coefficient of the structure. Also, the results obtained by the simulation express that by taking advantage of the light trapping techniques of SiO2, a remarkable increase of light absorption will be achieved to the magnitude of 83.13%, which is noticeable.


    Directory of Open Access Journals (Sweden)

    Mardiana Nurdin


    Full Text Available Abstrak: Penelitian ini bertujuan untuk mengeksplorasi kapasitas pengajaran yang profe­sional mahasiswa PPL PBI UIN Alauddin Makassar yang melibatkan 4 guru pamong dan 30 mahasiswa PPL. Data dikumpulkan melalui survei online, lembar pengamatan dan dokumentasi yang dianalisis dengan menggunakan metode campuran qualitatif dan kuantitatif. Penelitian ini menyimpulkan bahwa: 1 mahasiswa PPL berpendapat bahwa seorang guru bahasa Inggris seharusnya mampu melakukan tanggung jawabnya sebagai seorang guru yang memiliki kompetensi paedagogik, profesional, sosial, dan kepribadian, 2 mahasiswa PPL cenderung menerima pebelajar mandiri, kerja berpasangan dan kerja kelompok, mengadaptasi pengajaran untuk memenuhi kebutuhan siswa sebelum praktik pembelajaran, tetapi cenderung menguranginya selama proses pembelajaran; mahasiswa PPL juga cenderung menerima pengajaran grammar secara eksplisit, koreksi kesalahan, dan pengucapan seperti penutur asli, pengetahuan teknikal, dan keterampilan interpersonal sebelum praktik mengajar dan meningkatkan proporsinya selama proses mengajar, 3 Guru pamong berpendapat bahwa maha­siswa PPL PBI UIN alauddin harus meningkatkan kemampuan bahasa Inggris, penggunaan metode pengajaran yang inovatif, penilaian autentik, dan penggu­naan media yang bervariasi. Abstract: This research aims to explore the professional teaching capacity of undergraduate English education students of UIN Alauddin Makassar. It involves 4 supervising-teachers and 30 student-teachers. The data were collected through online survey questionnaires, feedback observation sheets and documentation; analyzed quanti­tatively and qualitatively. The research finds that: 1 the student-teachers perceive an EFL teacher should be able to do their responsibilities which involves peda­gogic, professional, social, and personal competences; 2 the student-teachers have a tendency to accept learner autonomy, pair/group work, adapting teaching to cater for learner needs before

  11. Small angle, quasielastic and inelastic neutron scattering from 0.85AgPO3-0.15PbI2 glass

    International Nuclear Information System (INIS)

    Malugani, J.P.; Tachez, M.; Mercier, R.


    A small angle neutron scattering (SANS) experiment and a quasielastic neutron scattering (QENS) experiment were performed on the fast ionic conductor 0.85AgPO 3 -0.15PbI 2 , which is a vitreous electrolyte. The SANS data show that the scattering obeys Guinier's law for Q -2 A; dispersed heterogeneities are present in the glass with a mean radius of gyration of 20 A. The QENS spectra show a quasielastic broadening of the elastic peak and a long tail up to 40 meV which is due to an inelastic distribution. The results seem to confirm the hypothesis on the structure of this glass: small 'clusters' of AgI with tetrahedral coordination are dispersed in the AgPO 3 host glass. In order to build these clusters, an exchange between Ag + and Pb 2+ is proposed. 18 refs.; 6 figs.; 2 tabs

  12. Antisolvent-assisted powder engineering for controlled growth of hybrid CH3NH3PbI3 perovskite thin films

    Directory of Open Access Journals (Sweden)

    Yong Chan Choi


    Full Text Available We develop antisolvent-assisted powder engineering for the controlled growth of hybrid inorganic-organic CH3NH3PbI3 (MAPbI3 perovskite thin films. The powders, which are used as the precursors for solution processing, are synthesized by pouring a MAPbI3 precursor solution into various antisolvents, such as dichloromethane, chloroform, diethyl ether, and toluene. Two types of powders having different colors are obtained, depending on the antisolvent used. The choice of the antisolvent used for synthesizing the powders strongly influences not only the phases of the powders but also the morphology and structure of the thin films subsequently fabricated by solution processing. This, in turn, affects the photovoltaic performance.

  13. Trapping charges at grain boundaries and degradation of CH3NH3Pb(I1-x Br x )3 perovskite solar cells (United States)

    Phuong Nguyen, Bich; Kim, Gee Yeong; Jo, William; Kim, Byeong Jo; Jung, Hyun Suk


    The electrical properties of CH3NH3Pb(I1-x Br x )3 (x = 0.13) perovskite materials were investigated under ambient conditions. The local work function and the local current were measured using Kelvin probe force microscopy and conductive atomic force microscopy, respectively. The degradation of the perovskite layers depends on their grain size. As the material degrades, an additional peak in the surface potential appears simultaneously with a sudden increase and subsequent relaxation of the local current. The potential bending at the grain boundaries and the intragrains is the most likely reason for the change of the local current surface of the perovskite layers. The improved understanding of the degradation mechanism garnered from this study helps pave the way toward an improved photo-conversion efficiency in perovskite solar cells.

  14. Graphene assisted effective hole-extraction on In2O3:H/CH3NH3PbI3 interface: Studied by modulated surface spectroscopy (United States)

    Vinoth Kumar, Sri Hari Bharath; Muydinov, Ruslan; Kol'tsova, Tat‘yana; Erfurt, Darja; Steigert, Alexander; Tolochko, Oleg; Szyszka, Bernd


    Charge separation in CH3NH3PbI3 (MAPbI3) films deposited on a hydrogen doped indium oxide (In2O3:H) photoelectrode was investigated by modulated surface photovoltage (SPV) spectroscopy in a fixed capacitor arrangement. It was found that In2O3:H reproducibly extracts photogenerated-holes from MAPbI3 films. The oxygen-plasma treatment of the In2O3:H surface is suggested to be a reason for this phenomenon. Introducing graphene interlayer increased charge separation nearly 6 times as compared to that on the In2O3:H/MAPbI3 interface. Furthermore, it is confirmed by SPV spectroscopy that the defects of the MAPbI3 interface are passivated by graphene.

  15. In-situ X-ray diffraction reveals the degradation of crystalline CH3NH3PbI3 by water-molecule collisions at room temperature (United States)

    Hada, Masaki; Hasegawa, Yoichi; Nagaoka, Ryota; Miyake, Tomoya; Abdullaev, Ulugbek; Ota, Hiromi; Nishikawa, Takeshi; Yamashita, Yoshifumi; Hayashi, Yasuhiko


    We have developed a vacuum-compatible chamber for in-situ X-ray diffraction (XRD) studies and have used it to characterize the changing crystal structure of an inorganic-organic hybrid perovskite material, CH3NH3PbI3 (MAPbI3), during interactions with water vapor at room temperature. In the XRD spectra, we have observed the degradation of MAPbI3 and the creation of MAPbI3 hydrates, which follow simple rate equations. The time constant for the degradation of MAPbI3 during accelerated aging suggests that multiple collisions of water molecules with the MAPbI3 crystal trigger the degradation of the crystal.

  16. Temperature dependence of the effective mass of the hybrid organic-inorganic perovskites CH3NH3PbI3 (United States)

    Lu, Ying-Bo; Yang, Haozhi; Cong, Wei-Yan; Zhang, Peng; Guo, Hong


    The material of methylammonium lead iodide, CH3NH3PbI3 (MAPbI3), has shown significant promise in solar cell applications. A way to infer the microscopic scattering mechanism(s) in MAPbI3 is through the measured temperature dependence of carrier mobility. To this end, how does the carrier effective mass depend on temperature, m* = m*(T), is a useful information since the mobility is a function of m*. By atomistic first principles, we report the calculated m*(T) due to the thermal expansion of MAPbI3 materials, in the experimentally relevant range of 130 K to room temperature. The calculated results suggest m* = m*(T) to be linear in T. The increase of m* versus temperature is predominantly due to the expansion of the longitudinal atomic spacing that weakens the s/p hybridization between the I/Pb atoms.

  17. Metastable phases freezing from melts of reciprocal systems PbX + CdI2=CdX + PbI2 (X=S, Se, Te)

    International Nuclear Information System (INIS)

    Odin, I.N.; Chukichev, M.V.


    The transformations in the mutual PbX + CdI 2 =CdX + PbI 2 (X=S, Se, Te) systems leading to the crystallization of metastable polytypical modifications of lead iodide in metastable ternary compounds are studied for the first time. Microstructural and X-ray diffraction analyses were conducted. Their phase diagrams were constructed. The luminescence properties of the stable and metastable modifications of the lead iodide and the metastable compound Pb 4 SeI 6 were investigated. The lines 504 and 512 nm are noted in the 2H-PbI 2 cathodoluminescence spectra. The close lines - 508 and 516 nm provide for the 6R-PbI 2 modification. The metastable compound Pb 4 SeI 6 is characterized by the 769 and 868 nm lines [ru

  18. Influence of hydration water on CH3NH3PbI3 perovskite films prepared through one-step procedure. (United States)

    Wang, Ziyi; Yuan, Sijian; Li, Dahai; Jin, Feng; Zhang, Rongjun; Zhan, Yiqiang; Lu, Ming; Wang, Songyou; Zheng, Yuxiang; Guo, Junpeng; Fan, Zhiyong; Chen, Liangyao


    Organic-inorganic perovskites were fabricated through a one-step procedure with different levels of hydration water in precursor solutions. The optical properties of CH3NH3PbI3 films were investigated through spectroscopic ellipsometry and photoluminescence measurements. With the measured optical constants, the efficiency limit of perovskite solar cells is predicted with a detailed balance model. By comparing the optical measurement to that of planar heterojunction solar cells, we conclude that the radiative efficiency and porosity of the perovskite film significantly influence the performance of perovskite solar cells. An optimized hydration-water concentration is obtained for the 3CH3NH3I:1PbAc2•xH2O precursor solution. The results can provide guidance for further optimization of the device performance of perovskite solar cells by utilizing hydration water.

  19. Electron energy transfer effect in Au NS/CH3NH3PbI3-xClx heterostructures via localized surface plasmon resonance coupling. (United States)

    Cai, Chunfeng; Zhai, Jizhi; Bi, Gang; Wu, Huizhen


    Localized surface plasmon resonance coupling effects (LSPR) have attracted much attention due to their interesting properties. This Letter demonstrates significant photoluminescence (PL) enhancement in the Au NS/CH3NH3PbI3-xClx heterostructures via the LSPR coupling. The observed PL emission enhancement is mainly attributed to the hot electron energy transfer effect related to the LSPR coupling. For the energy transfer effect, photo-generated electrons will be directly extracted into Au SPs, rather than relaxed into exciton states. This energy transfer process is much faster than the diffusion and relaxation time of free electrons, and may provide new ideas on the design of high-efficiency solar cells and ultrafast response photodetectors.

  20. Formation of stable and metastable phases in reciprocal systems PbSe + MI2 = MSe + PbI2 (M = Hg, Mn, Sn)

    International Nuclear Information System (INIS)

    Odin, I.N.; Grin'ko, V.V.; Kozlovskij, V.F.; Safronov, E.V.; Gapanovich, M.V.


    Using data of differential thermal, X-ray phase and microstructural analyses, phase diagrams of reciprocal systems PbSe + MI 2 = MSe + PbI 2 (M=Hg (1), Mn (2), Sn (3)) were constructed. It was ascertained that the HgSe-PbI 2 diagonal in system 1 is stable. Transformations leading to crystallization of metastable ternary compound formed in the system PbSe-PbI 2 and metastable polytypes of lead iodide in systems 1 and 2 in the range of temperatures from 620 to 685 K were studied. New intermediate metastable phases in systems 1, 2 and 3 were prepared by melt quenching. Crystal lattice parameters of the phases crystallizing in the CdCl 2 structural type were defined [ru

  1. One-Step Cationic Grafting of 4-Hydroxy-TEMPO and its Application in a Hybrid Redox Flow Battery with a Crosslinked PBI Membrane. (United States)

    Chang, Zhenjun; Henkensmeier, Dirk; Chen, Ruiyong


    By using a one-step epoxide ring-opening reaction between 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl (4-hydroxy-TEMPO) and glycidyltrimethylammonium cation (GTMA + ), we synthesized a cation-grafted TEMPO (g + -TEMPO) and studied its electrochemical performance against a Zn 2+ /Zn anode in a hybrid redox flow battery. To conduct Cl - counter anions, a crosslinked methylated polybenzimidazole (PBI) membrane was prepared and placed between the catholyte and anolyte. Compared to 4-hydroxy-TEMPO, the positively charged g + - TEMPO exhibits enhanced reaction kinetics. Moreover, flow battery tests with g + -TEMPO show improved Coulombic, voltage, and energy efficiencies and cycling stability over 140 cycles. Crossover of active species through the membrane was not detected. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Mindfulness Interventions. (United States)

    Creswell, J David


    Mindfulness interventions aim to foster greater attention to and awareness of present moment experience. There has been a dramatic increase in randomized controlled trials (RCTs) of mindfulness interventions over the past two decades. This article evaluates the growing evidence of mindfulness intervention RCTs by reviewing and discussing (a) the effects of mindfulness interventions on health, cognitive, affective, and interpersonal outcomes; (b) evidence-based applications of mindfulness interventions to new settings and populations (e.g., the workplace, military, schools); (c) psychological and neurobiological mechanisms of mindfulness interventions; (d) mindfulness intervention dosing considerations; and (e) potential risks of mindfulness interventions. Methodologically rigorous RCTs have demonstrated that mindfulness interventions improve outcomes in multiple domains (e.g., chronic pain, depression relapse, addiction). Discussion focuses on opportunities and challenges for mindfulness intervention research and on community applications.

  3. Families Matter! Presexual Risk Prevention Intervention (United States)

    Lasswell, Sarah M.; Riley, Drewallyn B.; Poulsen, Melissa N.


    Parent-based HIV prevention programming may play an important role in reaching youths early to help establish lifelong patterns of safe and healthy sexual behaviors. Families Matter! is a 5-session, evidence-based behavioral intervention designed for primary caregivers of children aged 9 to 12 years to promote positive parenting and effective parent–child communication about sexuality and sexual risk reduction. The program’s 5-step capacity-building model was implemented with local government, community, and faith-based partners in 8 sub-Saharan African countries with good intervention fidelity and high levels of participant retention. Families Matter! may be useful in other resource-constrained settings. PMID:24028229

  4. First-in-human study of pbi-05204, an oleander-derived inhibitor of akt, fgf-2, nf-κΒ and p70s6k, in patients with advanced solid tumors. (United States)

    Hong, D S; Henary, H; Falchook, G S; Naing, A; Fu, S; Moulder, S; Wheler, J J; Tsimberidou, A; Durand, J B; Khan, R; Yang, P; Johansen, M; Newman, R A; Kurzrock, R


    PBI-05204, a Nerium oleander extract (NOE) containing the cardiac glycoside oleandrin, inhibits the α-3 subunit of Na-K ATPase, as well as FGF-2 export, Akt and p70S6K, hence attenuating mTOR activity. This first-in-human study determined the safety, pharmacokinetics (PK) and pharmacodynamics (PD) of PBI-05204 in patients with advanced cancer. Methods Forty-six patients received PBI-05204 by mouth for 21 of 28 days (3 + 3 trial design). Dose was escalated 100% using an accelerated titration design until grade 2 toxicity was observed. Plasma PK and mTOR effector (p70S6K and pS6) protein expressions were evaluated. Results Dose-limiting toxicities (grade 3 proteinuria, fatigue) were observed at dose level 8 (0.3383 mg/kg/day). Common possible drug-related adverse were fatigue (26 patients, 56.5%), nausea (19 patients, 41.3%) and diarrhea (15 patients, 32.6 %). Electrocardiogram monitoring revealed grade 1 atrioventricular block (N = 10 patients) and grade 2 supraventricular tachycardia (N = 1). The MTD was DL7 (0.2255 mg/kg) where no toxicity of grade ≥ 3 was observed in seven patients treated. Seven patients (15%) had stable disease > 4 months. Mean peak oleandrin concentrations up to 2 ng/mL were achieved, with area under the curves 6.6 to 25.5 μg/L*hr and a half-life range of 5-13 h. There was an average 10% and 35% reduction in the phosphorylation of Akt and pS6 in PBMC samples in 36 and 32 patients, respectively, tested between predose and 21 days of treatment. Conclusions PBI-05204 was well tolerated in heavily pretreated patients with advanced solid tumors. The recommended Phase II dose is 0.2255 mg/kg/day.

  5. CH3NH3PbI3 and CsPbI3 Supramolecular Clusters in 1D: Do They Evolve with the Same Principle of Cooperative Binding? (United States)

    Varadwaj, Arpita; Varadwaj, Pradeep R.; Yamashita, Koichi

    Development of novel semiconductor-based photo-catalytic and -voltaic systems is a major area of research in nanoscience and technologies, and engineering. The process can be either direct or indirect in converting the light energy into electricity. Some of the photovoltaics include the organic, dye-sensitized, and halide perovskite solar cells, among others. Methylammonium lead iodide (CH3NH3PbI3) inorganic-organic hybrid perovskite is one among the many highly valued semiconductors reported till date, comparable with the inorganic cesium lead iodide (CsPbI3) perovskite. These are competitive candidates in the solar energy race. Nevertheless, this study was concentrated on the fundamental understanding of the rational designs of the CH3NH3PbI3 and CsPbI3 supramolecular materials using first-principles calculations, emerged though the self-assembly of the respective building blocks. It therefore addresses the question whether the (CH3NH3PbI3)n and (CsPbI3)n (n =1-10) supramolecular clusters are the consequences of additivity, or non-additive cooperative binding? For addressing this question, the supramolecular properties such as the polarizability, the intermolecular charge transfer, and the binding energy, etc., all w.r.t the cluster size n, are exploited. CREST-JST, 7 Gobancho, Chiyoda-ku, Tokyo, Japan 102-0076.

  6. Evidence and detailed study of a second-order phase transition in the (C6H11NH3)2[PbI4] organic-inorganic hybrid material

    International Nuclear Information System (INIS)

    Yangui, A.; Pillet, S.; Garrot, D.; Boukheddaden, K.; Triki, S.; Abid, Y.


    The thermal properties of the organic-inorganic hybrid material (C 6 H 11 NH 3 ) 2 [PbI 4 ] are investigated using diffuse reflectivity, spectroscopic ellipsometry, differential scanning calorimetry, Raman spectroscopy, and X-ray diffraction. The diffuse reflectivity, performed in heating mode, clearly evidences the presence of a singularity at 336 K. This is confirmed by the temperature dependence of the spectroscopic ellipsometry spectra, which points out a second-order phase transition at 336 K with a critical exponent ∼0.5. Differential scanning calorimetry measurements on a polycrystalline powder of (C 6 H 11 NH 3 ) 2 [PbI 4 ] show a reversible phase transition detected at T C  = 336 K without hysteresis. Raman spectroscopy data suggest that this transition arises from a change in the interactions between inorganic sheets (([PbI 4 ] 2− ) ∞ ) and organic protonated molecules ([C 6 H 11 NH 3 ] + ). The structural analysis from power X-ray diffraction reveals an incomplete order-disorder transition of the cyclohexylammonium cation, causing a subtle contraction of the inter-plane distance. The transition results from repulsive close contacts between the organic molecules in the interlayer spacing

  7. Unraveling current hysteresis effects in regular-type C60-CH3NH3PbI3 heterojunction solar cells. (United States)

    Chen, Lung-Chien; Lin, Yu-Shiang; Tang, Po-Wen; Tai, Chao-Yi; Tseng, Zong-Liang; Lin, Ja-Hon; Chen, Sheng-Hui; Kuo, Hao-Chung


    Comprehensive studies were carried out to understand the origin of the current hysteresis effects in highly efficient C 60 -CH 3 NH 3 PbI 3 (MAPbI 3 ) heterojunction solar cells, using atomic-force microscopy, transmittance spectra, photoluminescence spectra, X-ray diffraction patterns and a femtosecond time-resolved pump-probe technique. The power conversion efficiency (PCE) of C 60 -MAPbI 3 solar cells can be increased to 18.23% by eliminating the point (lattice) defects in the MAPbI 3 thin film which is fabricated by using the one-step spin-coating method with toluene washing treatment. The experimental results show that the point defects and surface defects of the MAPbI 3 thin films can be minimized by varying the dropping time of the washing solvent. The point defects (surface defects) can be reduced with an (a) increase (decrease) in the dropping time, resulting in an optimized dropping time for obtaining the defect-minimized MAPbI 3 thin film deposited on top of the C 60 thin film. Consequently, the formation of the defect-minimized MAPbI 3 thin film allows for high-efficiency MAPbI 3 solar cells.

  8. Nanostructured TiO2/CH3NH3PbI3 heterojunction solar cells employing spiro-OMeTAD/Co-complex as hole-transporting material

    KAUST Repository

    Noh, Jun Hong


    For using 2,2′,7,7′-tetrakis(N,N′-di-p- methoxyphenylamine)-9,9′-spirobifluorene (spiro-OMeTAD) as a hole conductor in solar cells, it is necessary to improve its charge-transport properties through electrochemical doping. With the aim of fabricating efficient mesoscopic TiO2/CH3NH3PbI3 heterojunction solar cells, we used tris[2-(1H-pyrazol-1-yl)-4-tert- butylpyridine)cobalt(iii) tris(bis(trifluoromethylsulfonyl) imide)] (FK209) as a p-dopant for spiro-OMeTAD. The mixture of spiro-OMeTAD, FK209, lithium bis(trifluoromethylsulfonyl)imide (Li-TFSI), and 4-tert-butylpyridine (TBP) exhibited significantly higher performance than mixtures of pristine spiro-OMeTAD, spiro-OMeTAD, and FK209, and spiro-OMeTAD, Li-TFSI, and TBP. Such a synergistic effect between the Co-complex and Li-TFSI in conjunction with spiro-OMeTAD effectively improved the power conversion efficiency (PCE) of the fabricated solar cells. As a result, we achieved PCE of 10.4%, measured under standard solar conditions (AM 1.5G, 100 mW cm-2). © 2013 The Royal Society of Chemistry.

  9. Experimental Characterization of the Poisoning Effects of Methanol-Based Reformate Impurities on a PBI-Based High Temperature PEM Fuel Cell

    Directory of Open Access Journals (Sweden)

    Samuel Simon Araya


    Full Text Available In this work the effects of reformate gas impurities on a H3PO4-doped polybenzimidazole (PBI membrane-based high temperature proton exchange membrane fuel cell (HT-PEMFC are studied. A unit cell assembly with a BASF Celtec®-P2100 high temperature membrane electrode assembly (MEA of 45 cm2 active surface area is investigated by means of impedance spectroscopy. The concentrations in the anode feed gas of all impurities, unconverted methanol-water vapor mixture, CO and CO2 were varied along with current density according to a multilevel factorial design of experiments. Results show that all the impurities degrade the performance, with CO being the most degrading agent and CO2 the least. The factorial analysis shows that there is interdependence among the effects of the different factors considered. This interdependence suggests, for example, that tolerances to concentrations of CO above 2% may be compromised by the presence in the anode feed of CO2. Methanol has a poisoning effect on the fuel cell at all the tested feed ratios, and the performance drop is found to be proportional to the amount of methanol in feed gas. The effects are more pronounced when other impurities are also present in the feed gas, especially at higher methanol concentrations.

  10. High throughput two-step ultrasonic spray deposited CH3NH3PbI3 thin film layer for solar cell application (United States)

    Lan, Ding-Hung; Hong, Shao-Huan; Chou, Li-Hui; Wang, Xiao-Feng; Liu, Cheng-Liang


    Organometal halide perovskite materials have demonstrated tremendous advances in the photovoltaic field recently because of their advantageous features of simple fabrication and high power conversion efficiency. To meet the high demand for high throughput and cost-effective, we present a wet process method that enables the probing of the parameters for perovskite layer deposition through two-step sequential ultrasonic spray-coating. This paper describes a detailed investigation on the effects of modification of spray precursor solution (PbI2 and CH3NH3I precursor concentration and solvents used) and post-annealing condition (temperature and time), which can be performed to create optimal film quality as well as improve device efficiency. Through the systematic optimization, the inverted planar perovskite solar cells show the reproducible photovoltaic properties with best power conversion efficiency (PCE) of 10.40% and average PCE of 9.70 ± 0.40%. A continuous spray-coating technique for rapid fabrication of total 16 pieces of perovskite films was demonstrated for providing a viable alternative for the high throughput production of the perovskite solar cells.

  11. Effect of Thermal and Structural Disorder on the Electronic Structure of Hybrid Perovskite Semiconductor CH3NH3PbI3. (United States)

    Singh, Shivam; Li, Cheng; Panzer, Fabian; Narasimhan, K L; Graeser, Anna; Gujar, Tanaji P; Köhler, Anna; Thelakkat, Mukundan; Huettner, Sven; Kabra, Dinesh


    In this Letter, we investigate the temperature dependence of the optical properties of methylammonium lead iodide (MAPbI3 = CH3NH3PbI3) from room temperature to 6 K. In both the tetragonal (T > 163 K) and the orthorhombic (T photoluminescence (PL) measurements) decreases with decrease in temperature, in contrast to what is normally seen for many inorganic semiconductors, such as Si, GaAs, GaN, etc. We show that in the perovskites reported here, the temperature coefficient of thermal expansion is large and accounts for the positive temperature coefficient of the band gap. A detailed analysis of the exciton line width allows us to distinguish between static and dynamic disorder. The low-energy tail of the exciton absorption is reminiscent of Urbach absorption. The Urbach energy is a measure of the disorder, which is modeled using thermal and static disorder for both the phases separately. The static disorder component, manifested in the exciton line width at low temperature, is small. Above 60 K, thermal disorder increases the line width. Both these features are a measure of the high crystal quality and low disorder of the perovskite films even though they are produced from solution.

  12. Structural, optical and morphological studies of Cd2+ doping in CH3NH3PbI3 perovskite semiconductor at Pb2+ site for photovoltaic applications (United States)

    Parrey, Khursheed; Warish, Mohd.; Devi, Nisha; Niazi, A.; Aziz, A.; Ansari, S. G.


    Doping of semiconductors in a controlled mannner have paramount technological importance as far as the optical and electronic properties of the devices are concerned. Hybrid organic-inorganic perovskites (HOPs) as intrinsic semiconductors have sensational properties required for both the solar photovoltaics and perovskite light emitting diodes. However, undoped and complexity in the dpoing process of HOPs have limited their exploitation in the field of elcronics. In this papper we present the synthesis of HOP semiconductor (CH3NH3PbI3) doped in Pb2+ position by Cd2+. We studied the effect of the incorporation of Cd2+ into the crystalline structure and analysed the changes in the properties like crystal structure, optical absorption and the surface morphology. The structure of HOPs confirmed by X-ray diffraction analysis is tetragonal perovskite type. It can be found that the crystallinity of the samples was enhanced with the doping concentration as the intensity of diffraction peaks were observed to increase with doping. The absorption spectra as obtained from UV-Visible spectrophotometry and Tauc plot analysis indicated that the band gap observed (1.73 eV) is direct type and gets reduced to 1.67 eV with the doping concentration. The red shift may be due to the increase in the size of nanocrystalline material with doping.

  13. A Feasible and Effective Post-Treatment Method for High-Quality CH3NH3PbI3 Films and High-Efficiency Perovskite Solar Cells

    Directory of Open Access Journals (Sweden)

    Yaxiao Jiang


    Full Text Available The morphology control of CH3NH3PbI3 (MAPbI3 thin-film is crucial for the high-efficiency perovskite solar cells, especially for their planar structure devices. Here, a feasible and effective post-treatment method is presented to improve the quality of MAPbI3 films by using methylamine (CH3NH2 vapor. This post-treatment process is studied thoroughly, and the perovskite films with smooth surface, high preferential growth orientation and large crystals are obtained after 10 s treatment in MA atmosphere. It enhances the light absorption, and increases the recombination lifetime. Ultimately, the power conversion efficiency (PCE of 15.3% for the FTO/TiO2/MAPbI3/spiro-OMeTAD/Ag planar architecture solar cells is achieved in combination with this post-treatment method. It represents a 40% improvement in PCE compared to the best control cell. Moreover, the whole post-treatment process is simple and cheap, which only requires some CH3NH2 solution in absolute ethanol. It is beneficial to control the reaction rate by changing the volume of the solution. Therefore, we are convinced that the post-treatment method is a valid and essential approach for the fabrication of high-efficiency perovskite solar cells.

  14. Dependence of Acetate-Based Antisolvents for High Humidity Fabrication of CH3NH3PbI3 Perovskite Devices in Ambient Atmosphere. (United States)

    Yang, Fu; Kapil, Gaurav; Zhang, Putao; Hu, Zhaosheng; Kamarudin, Muhammad Akmal; Ma, Tingli; Hayase, Shuzi


    High-efficiency perovskite solar cells (PSCs) need to be fabricated in the nitrogen-filled glovebox by the atmosphere-controlled crystallization process. However, the use of the glovebox process is of great concern for mass level production of PSCs. In this work, notable efficient CH 3 NH 3 PbI 3 solar cells can be obtained in high humidity ambient atmosphere (60-70% relative humidity) by using acetate as the antisolvent, in which dependence of methyl, ethyl, propyl, and butyl acetate on the crystal growth mechanism is discussed. It is explored that acetate screens the sensitive perovskite intermediate phases from water molecules during perovskite film formation and annealing. It is revealed that relatively high vapor pressure and high water solubility of methyl acetate (MA) leads to the formation of highly dense and pinhole free perovskite films guiding to the best power conversion efficiency (PCE) of 16.3% with a reduced hysteresis. The devices prepared using MA showed remarkable shelf life stability of more than 80% for 360 h in ambient air condition, when compared to the devices fabricated using other antisolvents with low vapor pressure and low water solubility. Moreover, the PCE was still kept at 15.6% even though 2 vol % deionized water was added in the MA for preparing the perovskite layer.

  15. Efficient CH3NH3PbI3 perovskite/fullerene planar heterojunction hybrid solar cells with oxidized Ni/Au/Cu transparent electrode (United States)

    Lai, Wei-Chih; Lin, Kun-Wei; Guo, Tzung-Fang; Chen, Peter; Liao, Yuan-Yu


    We demonstrated the performance of inverted CH3NH3PbI3 perovskite-based solar cells (SCs) with a thermally oxidized nickel/gold/copper (Ni/Au/Cu) trilayer transparent electrode. Oxidized Ni/Au/Cu is a high transparent layer and has less resistance than the oxidized Ni/Au layer. Like the oxidized Ni/Au layer, oxidized Ni and Cu in oxidized Ni/Au/Cu could perform as a hole transport layer of the perovskite-based SCs. It leads to improved perovskite SC performance on an open circuit voltage of 1.01 V, a short circuit current density of 14.36 mA/cm2, a fill factor of 76.7%, and a power conversion efficiency (η%) of 11.1%. The η% of perovskite SCs with oxidized Ni (10 nm)/Au (6 nm)/Cu (1 nm) improved by approximately 10% compared with that of perovskite SCs with oxidized Ni/Au.

  16. Stability and carrier mobility of organic-inorganic hybrid perovskite CH3NH3PbI3 in two-dimensional limit (United States)

    Huang, Kui; Lai, Kang; Yan, Chang-Lin; Zhang, Wei-Bing


    Recently, atomically thin organic-inorganic hybrid perovskites have been synthesized experimentally, which opens up new opportunities for exploring their novel properties in the 2D limit. Based on the comparative density functional theory calculation with and without spin-orbit coupling effects, the stability, electronic structure, and carrier mobility of the two-dimensional organic-inorganic hybrid perovskites MAPbI3 (MA = CH3NH3) have been investigated systemically. Two single-unit-cell-thick 2D MAPbI3 terminated by PbI2 and CH3NH3I are constructed, and their thermodynamic stabilities are also evaluated using the first-principles constrained thermodynamics method. Our results indicate that both 2D MAPbI3 with different terminations can be stable under certain conditions and have a suitable direct bandgap. Moreover, they are also found to have termination-dependent band edge and carrier mobility. The acoustic-phonon-limited carrier mobilities estimated using the deformation theory and effective mass approximation are on the order of thousands of square centimeters per volt per second and also highly anisotropic. These results indicate that 2D MAPbI3 are competitive candidates for low-dimensional photovoltaic applications.

  17. Optical absorption enhancement in NH2CH=NH2PbI3 lead halide perovskite solar cells with nanotextures (United States)

    Xie, Ziang; Sun, Shuren; Xie, Xixi; Hou, Ruixiang; Xu, Wanjin; Li, Yanping; Qin, G. G.


    This article reports, for the first time to our knowledge, that the power conversion efficiencies (PCEs) of planar NH2CH=NH2PbI3 (FAPbI3) lead halide perovskite solar cells (SCs) can be largely improved by fabricating nanotextures on the SC surface. Four kinds of nanotextures are investigated and compared with each other: column hollow (CLH) nanoarrays, cone hollow (CNH) nanoarrays, square prism hollow (SPH) nanoarrays, and pyramid hollow (PYH) nanoarrays. Compared with the PCEs of the planar SCs with the same layer depth d, it is found that when d is in the range of 125-500 nm and when the array period, as well as the filling fraction of the nanotexture, are optimized, the ultimate efficiency increased 29%-50% for the CLH and SPH textured FAPbI3 SCs relative to the planar ones, and 20%-41% for the CNH and PYH textured FAPbI3 SCs relative to the planar ones. When d < 250 nm, the optimized ultimate efficiencies of the CLH and SPH textured FAPbI3 SCs with optimized nanotextures are higher than those of the CNH and PYH ones, and vice versa. The reasons why fabricating nanotextures on SC surfaces can largely improve the PCE of the FAPbI3 SCs are discussed.

  18. Electron Transfer from Triplet State of TIPS-Pentacene Generated by Singlet Fission Processes to CH3NH3PbI3 Perovskite. (United States)

    Lee, Sangsu; Hwang, Daesub; Jung, Seok Il; Kim, Dongho


    To reveal the applicability of singlet fission processes in perovskite solar cell, we investigated electron transfer from TIPS-pentacene to CH 3 NH 3 PbI 3 (MAPbI 3 ) perovskite in film phase. Through the observation of the shorter fluorescence lifetime in TIPS-pentacene/MAPbI 3 perovskite bilayer film (5 ns) compared with pristine MAPbI 3 perovskite film (20 ns), we verified electron-transfer processes between TIPS-pentacene and MAPbI 3 perovskite. Furthermore, the observation of singlet fission processes, a faster decay rate, TIPS-pentacene cations, and the analysis of kinetic profiles of the intensity ratio between 500 and 525 nm in the TA spectra of the TIPS-pentacene/MAPbI 3 perovskite bilayer film indicate that electron transfer occurs from triplet state of TIPS-pentacene generated by singlet fission processes to MAPbI 3 perovskite conduction band. We believe that our results can provide useful information on the design of solar cells sensitized by singlet fission processes and pave the way for new types of perovskite solar cells.

  19. Ba2+ Doped CH3NH3PbI3 to Tune the Energy State and Improve the Performance of Perovskite Solar Cells

    International Nuclear Information System (INIS)

    Zhang, Hanbing; Shang, Ming-hui; Zheng, Xiaoying; Zeng, Zhaobing; Chen, Renjie; Zhang, Ying; Zhang, Jing; Zhu, Yuejin


    Highlights: •Ba doping enlarges the energy band gap of MAPb 1-x Ba x I 3 . •Voc and Jsc are enhanced in perovskite solar cells. •DFT calculation proves the experiment results. -- Abstract: Elements substitution and doping in perovskite CH 3 NH 3 PbI 3 exhibit versatile tunability of energy band structure and opto-electric properties. Ba 2+ is chosen to substitute Pb 2+ for its similar valence state and ionic radius with Pb 2+ . Ba 2+ doping in perovskite (mol% <5) slightly enlarges the optic energy gap by conduction band minimum(CBM) upshifting to vacuum energy level, which is due to the smaller electronegativity of Ba than Pb. The enlarged band gap is also verified by density function theory calculations. In n-i-p structure perovskite solar cells (PSCs), because of the higher CBM of doped perovskite, the Fermi energy difference between n and p side is enlarged and the electron injection from the perovskite to TiO 2 is improved. Thus, both the photovoltage and photocurrent are improved by small amount Ba 2+ doping, resulting optimized 17.4% efficiency under AM1.5. This work reveals the relationship between the doping element property and the energy band structure of the perovskite, and highlights the doping method to improve the performance of PSCs.

  20. Interventional ultrasound

    International Nuclear Information System (INIS)

    VanSonnenberg, E.


    This book contains 12 chapters and several case studies. Some of the chapter titles are: The Interplay of Ultrasound and Computed Tomography in the Planning and Execution of Interventional Procedures: Ulltrasound Guided Biopsy; Interventioal Genitourinary Sonography; Diagnosis and Treatment of Pericardial Effusion Using Ultrasonic Guidance; and New Ultrasound-Guided Interventional Procedures--Cholecystostomy, Pancreatography, Gastrostomy

  1. Systematic characterization of HT PEMFCs containing PBI/H{sub 3}PO{sub 4} systems. Thermodynamic analysis and experimental investigations

    Energy Technology Data Exchange (ETDEWEB)

    Bandlamudi, George Chakravarthy


    High temperature PEMFCs (HT PEMFCs), operating at 120 C - 200 C are rather new and offer tremendous advantages. For instance fuel cells operating at > 100 C reduce issues related to water management substantially. Circulating excess heat energy from such fuel cells into other system processes where heat is needed would be much more practical (due to higher {delta}T) compared to the standard LT PEMFCs where the produced heat has less than 90 C (lower {delta}T). Higher tolerance to fuel impurities such as CO, by these HT PEMFCs has made them very practical for many applications. Although PBI/H{sub 3}PO{sub 4} based membranes have been explored for use in PEMFCs from the early 1990s, only recently PEMEAS (currently BASF) has marketed them as commercially available MEAs. Besides, some companies such as Sartorius (currently Elcomax) and Fuma Tech of Germany, Danish Power Systems of Denmark are offering HT-MEAs on a commercial basis. Although some issues remain, such as development of durable and low cost catalyst and catalyst support materials, acid management, the rapid development of membranes and MEAs has been motivated by a huge demand from many a market. Recently, DLR in Germany has tested its pilot airplane (Antares) fully operated with a HT PEMFC stack (with on-board H{sub 2} bottle). ClearEdge Power in Portland, USA has been developing systems based on HT PEMFC technology to be deployed in the US as well as in South Korean households. Many more companies are increasingly interested in this technology due to the many fold advantages it has to offer. This work is aimed at elucidating this HT PEMFC technology, in terms of giving an in-depth view of what it means to operate a HT PEMFC. (orig.)

  2. Interventional neuroradiology

    International Nuclear Information System (INIS)

    Mehta, B.A.; Quint, D.J.; Sanders, W.P.; Patel, S.C.; Boulos, R.S.; Burke, T.H.


    This presentation reviews the authors' angiographic approach to interventional cases and demonstrates examples of procedures we have performed including preoperative embolizations (dural, arteriovenous malformations, meningioma, juvenile angiofibroma, gliosarcoma, glomus tympanicum, hemangiopericytoma, and spinal hemangioma), therapeutic interventions (balloon occlusion of cavernous-carotid and vertebral fistulas, intracranial and extracranial aneurysms, and angioplasty of vertebral, external carotid, and subclavian arteries), and pain management (alcohol injection of spine metastases). Potential and actual complications are reviewed

  3. Pediatric interventional radiology: vascular interventions

    International Nuclear Information System (INIS)

    Kandasamy, Devasenathipathy; Gamanagatti, Shivanand; Gupta, Arun Kumar


    Pediatric interventional radiology (PIR) comprises a range of minimally invasive diagnostic and therapeutic procedures that are performed using image guidance. PIR has emerged as an essential adjunct to various surgical and medical conditions. Over the years, technology has undergone dramatic and continuous evolution, making this speciality grow. In this review, the authors will discuss various vascular interventional procedures undertaken in pediatric patients. It is challenging for the interventional radiologist to accomplish a successful interventional procedure. There are many vascular interventional radiology procedures which are being performed and have changed the way the diseases are managed. Some of the procedures are life saving and have become the treatment of choice in those patients. The future is indeed bright for the practice and practitioners of pediatric vascular and non-vascular interventions. As more and more of the procedures that are currently being performed in adults get gradually adapted for use in the pediatric population, it may be possible to perform safe and successful interventions in many of the pediatric vascular lesions that are otherwise being referred for surgery. (author)

  4. Effect of Annealing Process on CH3NH3PbI3-XClX Film Morphology of Planar Heterojunction Perovskite Solar Cells with Optimal Compact TiO2 Layer

    Directory of Open Access Journals (Sweden)

    Dan Chen


    Full Text Available The morphology of compact TiO2 film used as an electron-selective layer and perovskite film used as a light absorption layer in planar perovskite solar cells has a significant influence on the photovoltaic performance of the devices. In this paper, the spin coating speed of the compact TiO2 is investigated in order to get a high-quality film and the compact TiO2 film exhibits pinhole- and crack-free films treated by 2000 rpm for 60 s. Furthermore, the effect of annealing process, including annealing temperature and annealing program, on CH3NH3PbI3-XClX film morphology is studied. At the optimal annealing temperature of 100°C, the CH3NH3PbI3-XClX morphology fabricated by multistep slow annealing method has smaller grain boundaries and holes than that prepared by one-step direct annealing method, which results in the reduction of grain boundary recombination and the increase of Voc. With all optimal procedures, a planar fluorine-doped tin oxide (FTO substrate/compact TiO2/CH3NH3PbI3-XClX/Spiro-MeOTAD/Au cell is prepared for an active area of 0.1 cm2. It has achieved a power conversion efficiency (PCE of 14.64%, which is 80.3% higher than the reference cell (8.12% PCE without optimal perovskite layer. We anticipate that the annealing process with optimal compact TiO2 layer would possibly become a promising method for future industrialization of planar perovskite solar cells.

  5. Interfacial Interactions in Monolayer and Few-Layer SnS/CH3 NH3 PbI3 Perovskite van der Waals Heterostructures and Their Effects on Electronic and Optical Properties. (United States)

    Li, Jian-Cai; Wei, Zeng-Xi; Huang, Wei-Qing; Ma, Li-Li; Hu, Wangyu; Peng, Ping; Huang, Gui-Fang


    A high light-absorption coefficient and long-range hot-carrier transport of hybrid organic-inorganic perovskites give huge potential to their composites in solar energy conversion and environmental protection. Understanding interfacial interactions and their effects are paramount for designing perovskite-based heterostructures with desirable properties. Herein, we systematically investigated the interfacial interactions in monolayer and few-layer SnS/CH 3 NH 3 PbI 3 heterostructures and their effects on the electronic and optical properties of these structures by density functional theory. It was found that the interfacial interactions in SnS/CH 3 NH 3 PbI 3 heterostructures were van der Waals (vdW) interactions, and they were found to be insensitive to the layer number of 2D SnS sheets. Interestingly, although their band gap decreased upon increasing the layer number of SnS, the near-gap electronic states and optical absorption spectra of these heterostructures were found to be strikingly similar. This feature was determined to be critical for the design of 2D layered SnS-based heterostructures. Strong absorption in the ultraviolet and visible-light regions, type II staggered band alignment at the interface, and few-layer SnS as an active co-catalyst make 2D SnS/CH 3 NH 3 PbI 3 heterostructures promising candidates for photocatalysis, photodetectors, and solar energy harvesting and conversion. These results provide first insight into the nature of interfacial interactions and are useful for designing hybrid organic-inorganic perovskite-based devices with novel properties. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Empiricist Interventions

    DEFF Research Database (Denmark)

    Munk, Anders Kristian; Abrahamsson, Sebastian


    Recent papers by prominent scholars in science and technology studies (notably JohnLaw and Bruno Latour) have crystallized a fundamental disagreement about the scope and purpose of intervention in actor-network theory or what we here choose to bracket as empirical philosophy. While the precept of...... contending agendas as distinct options which map on to the positions of our two main interlocutors. In doing so, it becomes possible to compare their respective tactical implications as we work through two examples of what might constitute an empiricist intervention.......Recent papers by prominent scholars in science and technology studies (notably JohnLaw and Bruno Latour) have crystallized a fundamental disagreement about the scope and purpose of intervention in actor-network theory or what we here choose to bracket as empirical philosophy. While the precept...... by notions of due process and parliamentary procedure? In this paper we think about this disagreement as a question of research strategy (a normative discord about the desirable outcome of an intervention) in order to assess its implications for research tactics (a descriptive accord about the practical...

  7. Advances in family-based interventions in the neonatal ICU. (United States)

    Welch, Martha G; Myers, Michael M


    Despite advances in medical care, preterm infants remain at risk for many adverse outcomes. This article reviews findings from several recent neonatal ICU (NICU) interventions and a trial of a novel nurture-based approach, Family Nurture Intervention (FNI). Recent trials reviewed here find positive effects of a variety of family-related interventions focused on parental guidance. These interventions target prescribed physical activities with infants, parents' stress, and the parents' ability to recognize their positive and negative behaviors with their infants. Beneficial effects include reductions in parenting stress, maternal anxiety, and depression. A different approach, FNI, is aimed at establishing mother-infant emotional connection. As in other trials, FNI also decreased maternal symptoms of anxiety and depression, and increased maternal sensitivity. Additionally, FNI led to positive short and long-term effects on infant neurobehavioral outcomes at term and 18 months. A number of recent parent-based NICU interventions have been effective at reducing preterm parent stress. Another, FNI, has positive effects on both maternal and infant outcomes and promises to be cost-effective. Future decreases in long-term morbidity in preterm infants will increasingly rely on nonmedical interventions. Therefore, the rigorous development and testing of such interventions should be a high priority in perinatology research.

  8. PBI treated polypropylene battery separator (United States)

    Veryzwyvelt, S. A.


    A generalized procedure for fabricating the separator is described. Some of the desired properties considered in fabricating the separator material for nickel-cadmium cells were good mechanical strength, good chemical stability, good wettability to the electrolyte, high electrolyte retention, and gas passage.

  9. Interventional MRI

    Energy Technology Data Exchange (ETDEWEB)

    Harada, Junta; Dohi, Michiko; Yoshihiro, Akiko; Mogami, Takuji; Kuwada, Tomoko; Nakata, Norio [Jikei Univ., Chiba (Japan). Kashiwa Hospital


    Open type MR system and fast sequence is now available and MRI becomes a new modality for interventional Radiology, including biopsy, drainage operation, and monitoring for minimally invasive therapy. Experimental studies of temperature monitoring were performed under hot and cold status. Signal changes of porcine disc and meat under microwave and laser ablation were observed as low signal area by signal intensity method. Using proton chemical shift method, signal change by laser ablation was displaced color imaging and correlated with thermometric temperature measurement. The very T2 relaxation time of ice affords excellent contrast between ice and surrounding gelatin tissue allowing acute depiction of the extent of the iceball under MRI. (author)

  10. Using Intervention Mapping to develop the Parents as Agents of Change (PAC©) intervention for managing pediatric obesity. (United States)

    Ball, Geoff D C; Mushquash, Aislin R; Keaschuk, Rachel A; Ambler, Kathryn A; Newton, Amanda S


    Pediatric obesity has become increasingly prevalent over recent decades. In view of the psychosocial and physical health risks, and the high likelihood that children with obesity will grow to become adults with obesity, there is a clear need to develop evidence-based interventions that can be delivered in the health care system to optimize the health and well-being of children with obesity and their families. The aim of this paper is to describe the development, implementation, and planned evaluation of a parent-based weight management intervention designed for parents of 8-12 year olds with obesity. The principles of Intervention Mapping (IM) were used to develop an intervention called Parents as Agents of Change (PAC © ). From 2006 to 2009, an environmental scan plus qualitative (individual interviews with parents and children), quantitative (medical record reviews), and literature review data were collected to gain broad insight into family factors related to pediatric obesity and its management. Theoretical frameworks and empirical evidence guided curriculum development, which was founded primarily on the tenets of family systems theory and cognitive behavioral theory. PAC was developed as a manualized, 16-session, group-based, health care professional-led intervention for parents to address individual, family, and environmental factors related to the management of pediatric obesity. The intervention was refined based on feedback from local and international experts, and has been implemented successfully in a multi-disciplinary weight management centre in a children's hospital. IM provided a practical framework to guide the systematic development of a pediatric weight management intervention for parents of children with obesity. This logical, step-by-step process blends theory and practice and is broadly applicable in the context of obesity management intervention development and evaluation. Following intervention development, the PAC intervention was

  11. Oxygen influencing the photocarriers lifetime of CH3NH3PbI3-xClx film grown by two-step interdiffusion method and its photovoltaic performance (United States)

    Yuan, Shuai; Qiu, Zhiwen; Zhang, Hailiang; Gong, Haibo; Hao, Yufeng; Cao, Bingqiang


    During the growth of CH3NH3PbI3-xClx (MAPbI3-xClx) perovskite films by the two-step inter-diffusion method, the presence of a trace amount of oxygen gas is critical to their physical properties and photovoltaic performance. As the oxygen concentration increases, poor film morphologies and incomplete surface coverage are observed. Moreover, by XRD, Raman scattering, and photoluminescence measurements, we find that MAPbI3-xClx grains become more distorted and the electron-hole recombination rate dramatically increases. Higher oxygen concentration triggers a sharp decrease in the current density and the fill factor of corresponding solar cells, which degrades device performance, on average, from 14.3% to 4.4%. This work proves the importance of controlling the oxygen atmosphere in the fabrication of high-performance perovskite solar cells.

  12. Near-band-edge optical responses of solution-processed organic-inorganic hybrid perovskite CH3NH3PbI3 on mesoporous TiO2 electrodes (United States)

    Yamada, Yasuhiro; Nakamura, Toru; Endo, Masaru; Wakamiya, Atsushi; Kanemitsu, Yoshihiko


    We studied the near-band-edge optical responses of solution-processed CH3NH3PbI3 on mesoporous TiO2 electrodes, which is utilized in mesoscopic heterojunction solar cells. Photoluminescence (PL) and PL excitation spectra peaks appear at 1.60 and 1.64 eV, respectively. The transient absorption spectrum shows a negative peak at 1.61 eV owing to photobleaching at the band-gap energy, indicating a direct band-gap semiconductor. On the basis of the temperature-dependent PL and diffuse reflectance spectra, we clarified that the absorption tail at room temperature is explained in terms of an Urbach tail and consistently determined the band-gap energy to be ˜1.61 eV at room temperature.

  13. Bloating in (Pb0.95Sn0.05Te)0.92(PbS)0.08-0.055%PbI2 Thermoelectric Specimens as a Result of Processing Conditions (United States)

    Ni, Jennifer E.; Case, Eldon D.; Stewart, Ryan; Wu, Chun-I.; Hogan, Timothy P.; Kanatzidis, Mercouri G.


    Lead chalcogenides such as (Pb0.95Sn0.05Te)0.92(PbS)0.08-0.055%PbI2 have received attention due to their encouraging thermoelectric properties. For the hot pressing (HP) and pulsed electric current sintering (PECS) techniques used in this study, decomposition reactions can generate porosity (bloating). Porosity in turn can degrade electrical, thermal, and mechanical properties. In this study, microstructural observations (scanning electron microscopy) and room-temperature elasticity measurements (resonant ultrasound spectroscopy) were used to characterize bloating generated during post-densification anneals. Although every HP specimen bloated during post-densification annealing, no bloating was observed for the PECS specimens processed from dry milled only powders. The lack of bloating for the annealed PECS specimens may be related to the electrical discharge intrinsic in the PECS process, which reportedly cleans the powder particle surfaces during densification.

  14. Oxygen influencing the photocarriers lifetime of CH3NH3PbI3−xClx film grown by two-step interdiffusion method and its photovoltaic performance

    International Nuclear Information System (INIS)

    Yuan, Shuai; Qiu, Zhiwen; Zhang, Hailiang; Gong, Haibo; Cao, Bingqiang; Hao, Yufeng


    During the growth of CH 3 NH 3 PbI 3−x Cl x (MAPbI 3−x Cl x ) perovskite films by the two-step inter-diffusion method, the presence of a trace amount of oxygen gas is critical to their physical properties and photovoltaic performance. As the oxygen concentration increases, poor film morphologies and incomplete surface coverage are observed. Moreover, by XRD, Raman scattering, and photoluminescence measurements, we find that MAPbI 3−x Cl x grains become more distorted and the electron-hole recombination rate dramatically increases. Higher oxygen concentration triggers a sharp decrease in the current density and the fill factor of corresponding solar cells, which degrades device performance, on average, from 14.3% to 4.4%. This work proves the importance of controlling the oxygen atmosphere in the fabrication of high-performance perovskite solar cells

  15. Aortoiliac interventions

    International Nuclear Information System (INIS)

    Chatziioannou, A.


    Full text: Atheromatosis is a systemic disease that involves various vascular beds. The most known risk factors are smoking, diabetes mellitus, dyslipedemia, hypertension, advanced age, black gender and male sex. Occlusive aortoiliac disease is due to atheromatosis in the vast majority of cases and is a common distribution of that pathology. Historically aortoiliac occlusions were treated with surgery. Nowadays, the endovascular minimally invasive techniques have revolutionized the treatment of such lesions. The success rate is extremely high with a technical success of 96%. Long term (5 years) patency of the diseased vessel can be as high as 71%. These results combined to the advent of new materials and techniques have set the new standards for treating aortoiliac occlusive disease. The first TASC recommendations (TASC I) were recently revised (TASC II) and the new guidelines (TASC III) will be shortly published. On the other hand endovascular techniques are not always successful. Technical failure (inability to cross the lesion) is estimated to be approximately 5% in single short iliac occlusions and can rise up to 15- 20% in complex long or multiple occlusive lesions. Possible, although not very frequent, complications are dissection, rupture and distal embolization. In the case of total occlusions we can use different materials and techniques. For example in an acute or subacute total occlusion chemical (urokinase or rtPA), mechanical or aspiration thrombolysis can be implemented. These minimally invasive techniques are of the outmost importance if we consider that the majority of the patients are old with a high rate of cardiac and other co-morbidities and therefore cannot go into surgery. That is the reason why the risk of morbidity and mortality following open surgical intervention remains high (5 - 20%). In chronic lesions we can use rentry catheters, glidewires, laser or thrombolysis/thrombectomy (if the clot is not very 'old'). Nevertheless, it should

  16. Perylene bisimide hydrogels and lyotropic liquid crystals with temperature-responsive color change† †Electronic supplementary information (ESI) available: Detailed procedures and results for all reported experiments, along with synthetic details for PBI 1. See DOI: 10.1039/c6sc02249a Click here for additional data file. (United States)

    Görl, Daniel; Soberats, Bartolome; Herbst, Stefanie; Stepanenko, Vladimir


    The self-assembly of perylene bisimide (PBI) dyes bearing oligo ethylene glycol (OEG) units in water affords responsive functional nanostructures characterized by their lower critical solution temperature (LCST). Tuning of the LCST is realized by a supramolecular approach that relies on two structurally closely related PBI–OEG molecules. The two PBIs socially co-assemble in water and the resulting nanostructures exhibit a single LCST in between the transition temperatures of the aggregates formed by single components. This permits to precisely tune the transition from a hydrogel to a lyotropic liquid crystal state at temperatures between 26 and 51 °C by adjusting the molar fraction of the two PBIs. Owing to concomitant changes in PBI–PBI interactions this phase transition affords a pronounced color change with “fluorescence-on” response that can be utilized as a smart temperature sensory system. PMID:28451124

  17. Development and pilot evaluation of an Internet-facilitated cognitive-behavioral intervention for maternal depression. (United States)

    Sheeber, Lisa B; Seeley, John R; Feil, Edward G; Davis, Betsy; Sorensen, Erik; Kosty, Derek B; Lewinsohn, Peter M


    Develop and pilot an Internet-facilitated cognitive-behavioral treatment intervention for depression, tailored to economically disadvantaged mothers of young children. Mothers (N = 70) of children enrolled in Head Start, who reported elevated levels of depressive symptoms, were randomized to either the 8-session, Internet-facilitated intervention (Mom-Net) or delayed intervention/facilitated treatment-as-usual (DI/TAU). Outcomes were measured using the Beck Depression Inventory (BDI-II; Beck, Steer, & Brown, 1996); the Patient Health Questionnaire 9 (PHQ-9; Spitzer et al., 1999), Behavioral Observations of Parent-Child Interactions using the Living in Family Environments coding system (LIFE; Hops, Davis, & Longoria, 1995); the Dyadic Parent-Child Interaction Coding Systems (DPICS; Eyberg, Nelson, Duke, & Boggs, 2005); the Parent Behavior Inventory (PBI; Lovejoy, Weis, O'Hare, & Rubin, 1999); and the Parenting Sense of Competence scale (PSOC; Gibaud-Wallston & Wandersman, 1978). Mom-Net demonstrated high levels of feasibility as indicated by low attrition and high program usage and satisfaction ratings. Participants in the Mom-Net condition demonstrated significantly greater reduction in depression, the primary outcome, at the level of both symptoms and estimates of criteria-based diagnoses over the course of the intervention. They also demonstrated significantly greater improvement on a questionnaire measure of parent satisfaction and efficacy as well as on both questionnaire and observational indices of harsh parenting behavior. Initial results suggest that the Mom-Net intervention is feasible and efficacious as a remotely delivered intervention for economically disadvantaged mothers. (PsycINFO Database Record (c) 2012 APA, all rights reserved).


    Directory of Open Access Journals (Sweden)

    Tri Muah


    Full Text Available Penelitian tindakan kelas ini bertujuan untuk meningkatkan keaktifan dan hasil belajar matematika siswa pada materi peluang dengan penerapan model pembelajaran PBI bagi kelas 9B Semester Gasal SMP Negeri 2 Tuntang Kabupaten Semarang. Hasil penelitian kondisi awal menggunakan wawancara, observasi dan analisis butir soal, siswa kelas 9B ini memiliki keaktifan belajar yang kurang, kemudian berdampak pada hasil belajar siswa rendah juga. Berdasarkan kondisi awal tersebut, perlu dilakukan penelitian tindakan kelas untuk meningkatkan keaktifan belajar dan hasil belajar matematika siswa. Penelitian ini merupakan Penelitian Tindakan Kelas (PTK dengan mengetahui model prosedur penelitian yang dikembangkan oleh Kemmis dan Mc Taggart berupa model penelitian yang spiral yang pada umumnya direncanakan terdiri dari dua siklus. Setiap siklus terdiri dari empat tahap yaitu: 1 tahap pelaksanaan tindakan (planning, 2 tahap pelaksanaan tindakan (acting, 3 tahap pengamatan (observing, dan 4 tahap refleksi (reflecting. Subjek penelitian ini adalah siswa kelas 9B SMP Negeri 2 Tuntang yang terdiri dari 32 orang siswa. Data diperoleh melalui tes kognitif dan lembar observasi siswa. Dari hasil penelitian ini dapat disimpulkan bahwa model pembelajaran PBI dapat meningkatkan keaktifan belajar dan hasil belajar matematika siswa. Hal ini ditunjukan dengan hasil wawancara dan observasi yang dilakukan sebelum penelitian ini dilakukan dimana keaktifan belajar siswa secara individu 14% dan keaktifan belajar siswa secara kelompok 50% dan hasil belajar matematika siswa pada materi sebelumnya juga menunjukkan hasil belajar yang rendah dimana dari 32 siswa 6.25% siswa mendapatkan nilai tuntas dengan rata-rata 34,3. Setelah dilakukan tindakan pada siklus I, terjadi peningkatan terhadap keaktifan belajar dan hasil belajar matematika. Lembar observasi pada siklus I menunjukkan keaktifan siswa secara individu meningkat menjadi 27.4% dan keaktifan belajar siswa secara kelompok 65% dan

  19. Inorganic alkali lead iodide semiconducting APbI3 (A = Li, Na, K, Cs and NH4PbI3 films prepared from solution: Structure, morphology, and electronic structure

    Directory of Open Access Journals (Sweden)

    Eric Mankel


    Full Text Available APbI3 alkali lead iodides were prepared from aqueous (A= Na, Cs, ammonium NH4+, and methyl­ammonium CH3NH3+ and acetone (A= Li, K solutions by a self-organization low temperature process. Diffraction analysis revealed that the methylammonium-containing system (MAPbI3 crystallizes into a tetragonal perovskite structure, whereas the alkali and NH4+ systems adopt orthorhombic structures. Morphological inspection confirmed the influence of the cation on the growth mechanism: for A = Cs and NH4+, needle-like crystallites with lengths up to 3–4 mm; for A = K, thin stripes with lengths up to 5–6 mm; and for A = MA+, dodecahedral crystallites were observed. For A = Li and Na, the APbI3 systems typically resulted in polycrystalline aggregates. Optical absorption measurements demonstrated large energy band gaps for the alkali and ammonium systems with values between 2.19 and 2.40 eV. For electronic and chemical characterization by photoelectron spectroscopy, the as-prepared powders were dissolved in di-methylformamide and re-crystallized as thin films on F:SnO2 substrates by spin-coating. The binding energy differences between Pb4f and I3d core levels are highly similar in the investigated systems and close to the value measured for PbI2, indicating similar relative partial charges and formal oxidation states. The binding energies of the alkali ions are in accordance with oxidation state +1. The X-ray excited valence band spectra of the investigated APbI3 systems exhibited similar line shapes in the region between the valence band maximum and 4.5 eV higher binding energy due to common PbI6 octahedra which dominate the electronic structure. While the ionization energy values are quite similar (6.15 ± 0.25 eV, the Fermi-level positions of the unintentionally doped materials vary for different cations and different batches of the same material, which indicates that the position of the Fermi level can be influenced by changing the process parameters.

  20. Memories of early attachment: the use of PBI as a predictor of outcome in Pesso-Boyden System Psychomotor (PBSP) group therapy, Cognitive-Behavioural Group Therapy (CBGT), Individual Cognitive-Behavioural Therapy (CBT) and Individual Treatment As Usual (TAU) with adult out-patients. (United States)

    Ryum, Truls; Vogel, Patrick A; Hagen, Roger; Stiles, Tore C


    To examine the predictive validity of the Parental Bonding Instrument (PBI) for outcome in individual and group psychotherapy. Data from four different clinical trials were combined, yielding a total of 105 patients. After controlling for gender, age and initial symptomatic distress, the predictive validity of the PBI subscales was investigated using the symptom checklist-90-revised (SCL-90-R) and inventory of interpersonal problems-64 (IIP-64) at termination as dependent measures in each treatment condition using separate hierarchical multiple regression analyses. Using the SCL-90-R at termination as dependent measure, reports of higher paternal and maternal care were related to a worse outcome in the Pesso-Boyden System Psychomotor condition, whereas reports of higher paternal care were related to a better outcome in the Cognitive-Behavioural Therapy condition. Also, higher maternal protection was related to a better outcome in the Cognitive-Behavioral Group condition. Using the IIP-64 at termination as dependent measure, reports of higher paternal protection were related to a better outcome in the Treatment As Usual condition. The study shows that the PBI may function as a clinical predictor for treatment response, although the results were somewhat contrary to previous reportings. Future studies should contrast and investigate possible differences between individual and group treatments further, as well as more clearly defined diagnostic groups. Clinical implications are presented. Copyright (c) 2008 John Wiley & Sons, Ltd.

  1. Scintillation properties of (C sub 6 H sub 1 sub 3 NH sub 3) sub 2 PbI sub 4 Exciton luminescence of an organic/inorganic multiple quantum well structure compound induced by 2.0 MeV protons

    CERN Document Server

    Shibuya, K; Takeoka, Y; Asai, K


    We report a new type of scintillator especially suitable for pulse-radiation detection. Thin films of organic/inorganic perovskite compound (n-C sub 6 H sub 1 sub 3 NH sub 3) sub 2 PbI sub 4 , which is characterized by a multiple quantum well structure, were bombarded by 2.0 MeV protons, and their radiation-induced emission spectra were obtained. A single and sharp emission peak due to an exciton was observed at the wavelength of 524 nm. This emission was clearly detected even at room temperature, and its quantum efficiency was very high. The line shape of this emission did not change, retaining its sharpness, and no other emissions appeared throughout the irradiation. The optical response of (n-C sub 6 H sub 1 sub 3 NH sub 3) sub 2 PbI sub 4 is very fast. (n-C sub 6 H sub 1 sub 3 NH sub 3) sub 2 PbI sub 4 is a promising scintillator material, meeting requirements not satisfied by conventional scintillators.

  2. [Agrobacterium-mediated sunflower transformation (Helianthus annuus L.) in vitro and in Planta using strain of LBA4404 harboring binary vector pBi2E with dsRNA-suppressor proline dehydrogenase gene]. (United States)

    Tishchenko, E N; Komisarenko, A G; Mikhal'skaia, S I; Sergeeva, L E; Adamenko, N I; Morgun, B V; Kochetov, A V


    To estimate the efficiency of proline dehydrogenase gene suppression towards increasing of sunflower (Helianthus annuus L.) tolerance level to water deficit and salinity, we employed strain LBA4404 harboring pBi2E with double-stranded RNA-suppressor, which were prepared on basis arabidopsis ProDH1 gene. The techniques of Agrobacterium-mediated transformation in vitro and in planta during fertilization sunflower have been proposed. There was shown the genotype-depended integration of T-DNA in sunflower genome. PCR-analysis showed that ProDH1 presents in genome of inbred lines transformed in planta, as well as in T1- and T2-generations. In trans-genic regenerants the essential accumulation of free L-proline during early stages of in vitro cultivation under normal conditions was shown. There was established the essential accumulation of free proline in transgenic regenerants during cultivation under lethal stress pressure (0.4 M mannitol and 2.0% sea water salts) and its decline upon the recovery period. These data are declared about effectiveness of suppression of sunflower ProDH and gene participation in processes connected with osmotolerance.

  3. Sequential Introduction of Cations Deriving Large-Grain Csx FA1-x PbI3 Thin Film for Planar Hybrid Solar Cells: Insight into Phase-Segregation and Thermal-Healing Behavior. (United States)

    Huang, Jiahao; Xu, Pan; Liu, Jian; You, Xiao-Zeng


    Composition engineering of perovskite materials has been demonstrated to be important for high-performance solar cells. Recently, the energy favorable hybridization of formamidinium (FA) and cesium (Cs) in three dimension lead halide perovskites has been attracting increasing attention due to its potential benefit on durability. Herein, we reported a simple and effective method to produce phase-pure CsxFA1-xPbI3 thin film via sequential introduction of cations, in which the FA cation was introduced by interdiffusion annealing in the presence of N-methylimidazole (NMI). NMI was employed as an additive to slow down the crystallization and thus drive the formation of CsxFA1-xPbI3 with micrometer grain size, which probably facilitate the charge dissociation and transportation in photovoltaic devices. More importantly, composition dependent phase-segregation has been revealed and investigated for the first time during the phase-pure mixed-cation perovskites CsxFA1-xPbI3. The present findings demonstrated that suppressing phase-segregation of mixed-cation perovskites by meticulous composition engineering is significant for further development of efficient photovoltaics. It also suggested that phase-pure Cs0.15FA0.85PbI3 may be a promising candidate with superior phase-durability, which performed an efficiency over 16% in planar perovskite solar cells. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Hybrid perovskite resulting from the solid-state reaction between the organic cations and perovskite layers of alpha1-(Br-(CH(2))(2)-NH(3))(2)PbI(4). (United States)

    Sourisseau, Sebastien; Louvain, Nicolas; Bi, Wenhua; Mercier, Nicolas; Rondeau, David; Buzaré, Jean-Yves; Legein, Christophe


    The alpha1-(Br-(CH(2))(2)-NH(3))(2)PbI(4) hybrid perovskite undergoes a solid-state transformation, that is, the reaction between the organic cations and the perovskite layers to give the new hybrid perovskite (Br-(CH(2))(2)-NH(3))(2-x)(I-(CH(2))(2)-NH(3))(x)PbBr(x)I(4-x), based on mixed halide inorganic layers. This transformation has been followed by a conventional powder X-ray diffraction system equipped with a super speed detector, and both solid-state (13)C NMR and ESI/MS measurements have been adopted in the estimation of the rate of halide substitution. The first reaction step leads to the special composition of x approximately 1 (A phase), while the complete substitution is not achieved even at elevated temperature (x(max) approximately 1.85 (B phase)). This unprecedented solid-state reaction between organic and inorganic components of a hybrid perovskite can be considered as a completely new strategy to achieve interesting hybrid perovskites.

  5. Fast self-diffusion of ions in CH 3 NH 3 PbI 3 : the interstiticaly mechanism versus vacancy-assisted mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Ji-Hui; Yin, Wan-Jian; Park, Ji-Sang; Wei, Su-Huai


    The stability of organic-inorganic halide perovskites is a major challenge for their applications and has been extensively studied. Among the possible underlying reasons, ion self-diffusion has been inferred to play important roles. While theoretical studies congruously support that iodine is more mobile, experimental studies only observe the direct diffusion of the MA ion and possible diffusion of iodine. The discrepancy may result from the incomplete understanding of ion diffusion mechanisms. With the help of first-principles calculations, we studied ion diffusion in CH3NH3PbI3 (MAPbI3) through not only the vacancy-assisted mechanisms presumed in previous theoretical studies, but also the neglected interstiticaly mechanisms. We found that compared to the diffusion through the vacancy-assisted mechanism, MA ion diffusion through the interstiticaly mechanism has a much smaller barrier which could explain experimental observations. For iodine diffusion, both mechanisms can yield relatively small barriers. Depending on the growth conditions, defect densities of vacancies and interstitials can vary and so do the diffusion species as well as diffusion mechanisms. Our work thus supports that both MA and iodine ion diffusion could contribute to the performance instability of MAPbI3. While being congruous with experimental results, our work fills the research gap by providing a full understanding of ion diffusion in halide perovskites.

  6. Optical characterization and bandgap engineering of flat and wrinkle-textured FA0.83Cs0.17Pb(I1-xBrx)3 perovskite thin films (United States)

    Tejada, A.; Braunger, S.; Korte, L.; Albrecht, S.; Rech, B.; Guerra, J. A.


    The complex refractive indices of formamidinium cesium lead mixed-halide [FA0.83Cs0.17Pb(I1- xBrx)3] perovskite thin films of compositions ranging from x = 0 to 0.4, with both flat and wrinkle-textured surface topographies, are reported. The films are characterized using a combination of variable angle spectroscopic ellipsometry and spectral transmittance in the wavelength range of 190 nm to 850 nm. Optical constants, film thicknesses and roughness layers are obtained point-by-point by minimizing a global error function, without using optical dispersion models, and including topographical information supplied by a laser confocal microscope. To evaluate the bandgap engineering potential of the material, the optical bandgaps and Urbach energies are then accurately determined by applying a band fluctuation model for direct semiconductors, which considers both the Urbach tail and the fundamental band-to-band absorption region in a single equation. With this information, the composition yielding the optimum bandgap of 1.75 eV for a Si-perovskite tandem solar cell is determined.

  7. Drinking norms, readiness to change, and gender as moderators of a combined alcohol intervention for first-year college students. (United States)

    Grossbard, Joel R; Mastroleo, Nadine R; Geisner, Irene Markman; Atkins, David; Ray, Anne E; Kilmer, Jason R; Mallett, Kimberly; Larimer, Mary E; Turrisi, Rob


    Alcohol interventions targeting college students and their parents have been shown to be efficacious. Little research has examined moderators of intervention efficacy to help tailor interventions for subgroups of students. This study is a secondary data analysis of readiness to change, drinking norms, and gender as moderators of an efficacious peer- and parent-based intervention (Turrisi et al., 2009). Students (n=680) were randomized to the combined peer and parent intervention (n=342) or assessment-only control (n=338). The combined intervention reduced peak blood alcohol content (BAC) compared to control. Gender and norms did not moderate the relationship between the intervention and drinking. Significant interactions were found between gender, precontemplation, and intervention. Students in the combined condition with higher precontemplation had lower weekly drinking compared to those with lower precontemplation. This pattern was also found among men for peak BAC and alcohol-related consequences but not among women, indicating a three-way interaction. Interventions may need to consider readiness to change and gender to optimize effectiveness. Published by Elsevier Ltd.

  8. Paediatric Interventional Uroradiology

    International Nuclear Information System (INIS)

    Barnacle, Alex M.; Wilkinson, A. Graham; Roebuck, Derek J.


    Paediatric interventional uroradiology lies at the intersection of the disciplines of paediatric interventional radiology and paediatric endourology. Interdisciplinary collaboration has led to the development of new techniques and refinement of procedures adopted from adult practice. This article reviews the major procedures used in paediatric interventional uroradiology, with emphasis on nephrostomy, percutaneous nephrolithotomy, balloon-burst pyeloplasty, and antegrade ureteric stenting.

  9. Etude de l'effet du vieillissement sur les proprietes d'un tissu en melange KevlarRTM-PBI utilise dans le revetement exterieur des habits de protection contre le feu (United States)

    Arrieta, Carlos

    The aim of this work is to study and model the effect of three aging factors, temperature, humidity and light radiation, on the properties of a fabric made of a blend of KevlarRTM and PBI fibers frequently used to manufacture fire-protective garments. Accelarated-aging treatments carried out at carefully chosen conditions for the three factors resulted in a sizeable loss of mechanical performance. The breaking force of both the fabric and the yarns extracted from it decreases to less than 50% after one month of continuous exposure. X-ray diffraction (XRD) tests performed on thermally-aged samples indicated an increase of the crystallinity of the fabric, whereas the disappearance of Raman spectral lines suggested instead a reduction of the crystallinity following thermal aging. To explain these seemingly contradictory results, a hypothesis was introduced, stating that two different processes occurred simultaneously during thermal aging. The first one, an increase of size of the crystallites in the direction of the fibers' axis, accounted for the increase in crystallinity observed in XRD tests. The second one, an increase in the gap separating lamellar crystallites that causes a non-measurable reduction of the crystallinity of the sample, was highlighted by the Raman analyses. The results of the dielectric spectroscopy analyses carried out on thermally-aged samples confirmed the XRD results showing a significant change in the Kevlar's morphology during thermal aging. Despite the important decrease of the breaking force that ensued thermal aging, no evidence of a chemical structure modification of KevlarRTM was found. On the other hand, differential thermal analyses conducted on thermally aged fabric samples indicated a reduction of the glass transition temperature of the other component of the blend, namely the PBI, a fact that suggests a decrease of molecular weight after thermal aging. Infrared spectroscopy analyses performed on samples exposed to high humidity

  10. O3 fast and simple treatment-enhanced p-doped in Spiro-MeOTAD for CH3NH3I vapor-assisted processed CH3NH3PbI3 perovskite solar cells

    Institute of Scientific and Technical Information of China (English)

    En-Dong Jia; Xi Lou; Chun-Lan Zhou; Wei-Chang Hao; Wen-Jing Wang


    We demonstrate a simple and fast post-deposition treatment with high process compatibility on the hole transport material (HTM) Spiro-MeOTAD in vapor-assisted solution processed methylammonium lead triiodide (CH3NH3PbI3)-based solar cells.The prepared Co-doped p-type Spiro-MeOTAD films are treated by O3 at room temperature for 5 min,10 min,and 20 min,respectively,prior to the deposition of the metal electrodes.Compared with the traditional oxidation of Spiro-MeOTAD films overnight in dry air,our fast O3 treatment of HTM at room temperature only needs just 10 min,and a relative 40.3% increment in the power conversion efficiency is observed with respect to the result of without-treated perovskite solar cells.This improvement of efficiency is mainly attributed to the obvious increase of the fill factor and short-circuit current density,despite a slight decrease in the open-circuit voltage.Ultraviolet photoelectron spectroscopy (UPS) and Hall effect measurement method are employed in our study to determine the changes of properties after O3 treatment in HTM.It is found that after the HTM is exposed to O3,its p-type doping level is enhanced.The enhancement of conductivity and Hall mobility of the film,resulting from the improvement in p-doping level of HTM,leads to better performances of perovskite solar cells.Best power conversion efficiencies (PCEs) of 13.05% and 16.39% are achieved with most properly optimized HTM via CH3NH3I vapor-assisted method and traditional single-step method respectively.

  11. Interventional Radiology in Paediatrics. (United States)

    Chippington, Samantha J; Goodwin, Susie J


    As in adult practice, there is a growing role for paediatric interventional radiology expertise in the management of paediatric pathologies. This review is targeted for clinicians who may refer their patients to paediatric interventional radiology services, or who are responsible for patients who are undergoing paediatric interventional radiology procedures. The article includes a brief overview of the indications for intervention, techniques involved and the commonest complications. Although some of the procedures described are most commonly performed in a tertiary paediatric centre, many are performed in most Children's hospitals.

  12. Interventional neuroradiology techniques in interventional radiology

    CERN Document Server

    Murphy, Kieran; Robertson, Fergus; Watkinson, Anthony


    This book provides accessible technique-specific information on interventional radiology procedures, in a format suitable for reference in the IR treatment room or as a carry-around guide. Offers step-by-step points, key point summaries and illustrations.

  13. cardiovascular disease intervention programme

    African Journals Online (AJOL)

    ... trial was conducted as part of a coronary risk factor intervention study in three rural ... habits, which was defined as the residual change in the intervention areas after ... finally to change behaviour in such a way that modified lifestyles would ...

  14. Practical interventional radiology

    International Nuclear Information System (INIS)

    Lammer, J.; Schreyer, H.


    The book is intended as a practical guide and manual for interventional radiology applications. Main emphasis is placed on the performance of the various techniques, with explanations of the various steps to be taken, illustrated by drawings or pictures. Indications, contra-indications and clinical achievements are given in brief. There is one chapter each for the following techniques: angioplasty - intra-arterial fibrinolysis - vascular stents - neuroembolisation - embolisation of other vessels - biliary interventions - abscess drainage - nephrostomy and ureteral manipulations -percutaneous fine-needle biopsy - vena cava filters - interventional radiology in infants. (orig.)

  15. Guidelines for radiological interventions

    International Nuclear Information System (INIS)

    Kauffmann, G.W.


    The German Radiological Society, in cooperation with other German professional bodies, set up draft Guidelines for Radiological Interventions and submitted them to the professional community for discussion. The Guidelines are meant to assess the potential of radiological interventions as treatment alternatives to surgery or aggressive therapy such as chemotherapy. In fact, technical practicability on its own is insufficient to warrant intervention. The Guidelines are systematically compiled notions and recommendations whose aim it is to provide support to physicians and patients in choosing suitable medical care provisions (prevention, diagnosis, therapy, aftertreatment) in specific circumstances. A complete Czech translation of the Guidelines is given. (P.A.)

  16. Pursuing prosody interventions. (United States)

    Hargrove, Patricia M


    This paper provides an overview of evidence-based prosodic intervention strategies to facilitate clinicians' inclusion of prosody in their therapeutic planning and to encourage researchers' interest in prosody as an area of specialization. Four current evidence-based prosodic interventions are reviewed and answers to some important clinical questions are proposed. Additionally, the future direction of prosodic intervention research is discussed in recommendations about issues that are of concern to clinicians. The paper ends with a call for participation in an online collaboration at the Clinical Prosody blog at

  17. Guideline for Early Interventions

    National Research Council Canada - National Science Library

    Vries, de, Maaike


    .... During the last years, the demand for early interventions has been increasing. International literature has shown that the psychosocial effects of disaster and military deployment may last for years...

  18. Society of Interventional Radiology (United States)

    ... Picture yourself in L.A. Register now SIR Essentials Purchase/register Search SIR's entire catalog for educational ... Quality Improvement Clinical practice MACRA Matters Health Policy, Economics, Coding Toolkits Society of Interventional Radiology 3975 Fair ...

  19. Family intervention for schizophrenia. (United States)

    Pharoah, F M; Mari, J J; Streiner, D


    It has been showed that people with schizophrenia from families that express high levels of criticism, hostility, or over involvement, have more frequent relapses than people with similar problems from families that tend to be less expressive of their emotions. Psychosocial interventions designed to reduce these levels of expressed emotions within families now exist for mental health workers. These interventions are proposed as adjuncts rather than alternatives to drug treatments, and their main purpose is to decrease the stress within the family and also the rate of relapse. To estimate the effects of family psychosocial interventions in community settings for the care of those with schizophrenia or schizophrenia-like conditions compared to standard care. Electronic searches of the Cochrane Library (Issue 2, 1998), the Cochrane Schizophrenia Group's Register (June 1998), EMBASE (1981-1995) and MEDLINE (1966-1995) were undertaken and supplemented with reference searching of the identified literature. Randomised or quasi-randomised studies were selected if they focused on families of people with schizophrenia or schizoaffective disorder and compared community-orientated family-based psychosocial intervention of more than five sessions to standard care. Data were reliably extracted, and, where appropriate and possible, summated. Peto odds ratios (OR), their 95% confidence intervals (CI) and number needed to treat (NNT) were estimated. The reviewers assume that people who died or dropped out had no improvement and tested the sensitivity of the final results to this assumption. Family intervention may decrease the frequency of relapse (one year OR 0.57 CI 0.4-0.8, NNT 6.5 CI 4-14). The trend over time of this main finding is towards the null and some small but negative studies may not have been identified by the search. Family intervention may decrease hospitalisation and encourage compliance with medication but data are few and equivocal. Family intervention does not

  20. Frailty Intervention Trial (FIT

    Directory of Open Access Journals (Sweden)

    Lockwood Keri


    Full Text Available Abstract Background Frailty is a term commonly used to describe the condition of an older person who has chronic health problems, has lost functional abilities and is likely to deteriorate further. However, despite its common use, only a small number of studies have attempted to define the syndrome of frailty and measure its prevalence. The criteria Fried and colleagues used to define the frailty syndrome will be used in this study (i.e. weight loss, fatigue, decreased grip strength, slow gait speed, and low physical activity. Previous studies have shown that clinical outcomes for frail older people can be improved using multi-factorial interventions such as comprehensive geriatric assessment, and single interventions such as exercise programs or nutritional supplementation, but no interventions have been developed to specifically reverse the syndrome of frailty. We have developed a multidisciplinary intervention that specifically targets frailty as defined by Fried et al. We aim to establish the effects of this intervention on frailty, mobility, hospitalisation and institutionalisation in frail older people. Methods and Design A single centre randomised controlled trial comparing a multidisciplinary intervention with usual care. The intervention will target identified characteristics of frailty, functional limitations, nutritional status, falls risk, psychological issues and management of chronic health conditions. Two hundred and thirty people aged 70 and over who meet the Fried definition of frailty will be recruited from clients of the aged care service of a metropolitan hospital. Participants will be followed for a 12-month period. Discussion This research is an important step in the examination of specifically targeted frailty interventions. This project will assess whether an intervention specifically targeting frailty can be implemented, and whether it is effective when compared to usual care. If successful, the study will establish a

  1. Refusal to medical interventions. (United States)

    Palacios, G; Herreros, B; Pacho, E


    Refusal to medical interventions is the not acceptance, voluntary and free, of an indicated medical intervention. What the physician should do in case of refusal? It is understandable that the rejection of a validated medical intervention is difficult to accept by the responsible physician when raises the conflict protection of life versus freedom of choice. Therefore it is important to follow some steps to incorporate the most relevant aspects of the conflict. These steps include: 1) Give complete information to patients, informing on possible alternatives, 2) determine whether the patient can decide (age, competency and level of capacity), 3) to ascertain whether the decision is free, 4) analyze the decision with the patient, 5) to persuade, 6) if the patient kept in the rejection decision, consider conscientious objection, 7) take the decision based on the named criteria, 8) finally, if the rejection is accepted, offer available alternatives. Copyright © 2013 Elsevier España, S.L.U. All rights reserved.

  2. Early Intervention in Psychosis (United States)

    McGorry, Patrick D.


    Abstract Early intervention for potentially serious disorder is a fundamental feature of healthcare across the spectrum of physical illness. It has been a major factor in the reductions in morbidity and mortality that have been achieved in some of the non-communicable diseases, notably cancer and cardiovascular disease. Over the past two decades, an international collaborative effort has been mounted to build the evidence and the capacity for early intervention in the psychotic disorders, notably schizophrenia, where for so long deep pessimism had reigned. The origins and rapid development of early intervention in psychosis are described from a personal and Australian perspective. This uniquely evidence-informed, evidence-building and cost-effective reform provides a blueprint and launch pad to radically change the wider landscape of mental health care and dissolve many of the barriers that have constrained progress for so long. PMID:25919380

  3. Paediatric interventional radiology

    International Nuclear Information System (INIS)

    McLaren, Clare


    Paediatric interventional radiology (PIR) is a rapidly-growing subspecialty, which offers a wide range of procedures applicable to almost all areas of hospital paediatrics. There are many important differences between paediatric and adult practice in interventional radiology, including disease processes and treatment goals, anatomical considerations, periprocedural patient management, radiation exposure optimisation and legal aspects. The use of retrievable or absorbable interventional devices such as stents will probably become more widespread in PIR practice. Recent advances in the technology of imaging equipment have been accompanied by an increase in the complexity of the work done by the radiographer. These developments present challenges and opportunities related to training and maintenance of skills, staffing arrangements, and the potential for advanced practice. It is likely that specialisation in PIR will become a more common role for radiographers in the future

  4. Interventional uroradiology since ESWL

    International Nuclear Information System (INIS)

    Tegtmeyer, C.J.


    The extracorporeal shock wave lithotriptor is an excellent example of modern technology that is successfully applied to solve a medical problem. ESWL is rapidly becoming the standard method for treating patients with persistent urinary tract stones. The extracorporeal shock wave lithotriptor represents an enormous advance in the treatment of renal calculi, however, the machine is not infallible. Presently, a slightly more than 5% of the patients require additional interventional radiographic procedures to facilitate passage of their stones. The authors' data indicates that large stones (≥ 2.5 cm) are more likely to need interventional procedures. As more large stones are treated by ESWL, the need for interventional radiographic procedures will increase. This necessity has led to the development of new techniques, such as the lithocenosis catheter and waterpik procedure, to relieve the obstructed urinary tract by removal of the stone fragments

  5. Interventions in everyday lives

    DEFF Research Database (Denmark)

    Dreier, Ole


    The purpose of psychotherapy is to help clients address and overcome problems troubling them in their everyday lives. Therapy can therefore only work if clients include it in their ongoing lives to deal with their problems. Detailed, systematic research is needed on how clients do so...... clients change their everyday lives to overcome their troubles. They also highlight what it involves for clients to accomplish this. It is concluded that we need more research on how to understand intervention; on the interaction between interventions and clients’ conduct of their everyday life...

  6. Who needs intervention?

    DEFF Research Database (Denmark)

    Jørgensen, Line Dahl


    Who needs intervention? A phonological screening tool for children with cleft palate Children with cleft palate +/- cleft lip (CP) are at risk of speech and language delay. It is important to identify children with difficulties as early as possible in order to offer appropriate intervention. Conv....... Lieberman, M., & Lohmander, A. (2014). Observation is a valid way of assessing common variables in typical babbling and identifies infants who need further support. Acta Paediatrica, 103(12), 1251–1257. doi:10.1111/apa.12776...

  7. Angiography and interventional radiology

    International Nuclear Information System (INIS)

    Bundy, A.L.


    The decrease in angiographic procedures as a result of less invasive imaging modalities has been counterbalanced by the rise in interventional radiological techniques. Because the interventional radiologist behaves somewhat like a surgeon, his legal responsibilities also approach those of his surgical colleagues. The basic concerns of negligent malpractice are amplified by the issues of informed consent and vicarious liability. Also, damages resulting from these procedures are costly because of the severity of the injuries. The angiographer must become versed in medicolegal issues of this rapidly evolving specialty

  8. Interventional magnetic resonance imaging

    International Nuclear Information System (INIS)

    Debatin, J.F.; Adam, G.


    With the advent of open configuration MR imaging systems, the vision of MRI-based guidance, control, and monitoring of minimally invasive interventions has evolved from a hypothetical concept to a practical possibility. This book provides a comprehensive overview of the very exciting emerging field of interventional MRI. The international authorship provides firsthand experience of all relevant topics. This book will familiarize the reader with the basic principles underlying currently available hardware and software configurations. In addition, technical aspects of thermosensitive imaging, techniques for instrument visualization, and safety aspects are covered. Finally, the book emphasizes both existing and future clinical applications. (orig.)

  9. Anesthesia for interventional radiology

    International Nuclear Information System (INIS)

    van Sonnenberg, E.; Casola, G.; Varney, R.R.; D'Agostino, H.B.; Zornow, M.; Mazzie, W.


    We recognized that the complexity and surgical nature of many interventional radiology procedures dictate essential radiologic involvement into traditional anesthesiologic areas. They reviewed our experience with a variety of interventional procedures to document complications and problems related to anesthetic use (or misuse) and compile recommendations for rational monitoring and control for these procedures. In particular, the authors have studied complications of drug therapies and the treatment of these complications; use of complex anesthesia procedures (e.g., epidural anesthesia, succinylcholine blockage); reasons for choice of drugs (e.g., fentanyl vs meperidine vs morphine); and medico-legal aspects of radiologist performing traditional anesthesiology-type procedures

  10. The Weekend Intervention Program. (United States)

    Siegal, Harvey A.

    The Weekend Intervention Program (WIP) at the Wright State University School of Medicine is described in this report. Designed to address severe health and social problems while supporting the university's academic mission, the program began with the goal of addressing the health and social problems of alcohol abusers. WIP is a 72-hour intensive…

  11. Sedoanalgesia in interventional radiology

    International Nuclear Information System (INIS)

    Linsenmaier, U.; Pfeifer, K.J.; Reiser, M.


    Purpose: Development of a save and effective protocol for analgosedation of patients undergoing painful interventional procedures. Material and Methods: In a prospective trial a consecutive series of 72 adult patients underwent analgosedation during painful interventions. A radiologist performed the analgosedation, the patients received a combination of a shortly effective piperidine derivative (Alfentanil [Rapifen trademark ]; 7.5-15 μg/kg body weight) and Benzodiazepine (midazolam [Dormicum trademark ]; 20 μg/kg body weight). After pre-procedure oxygenation patients were continuously monitored. Pain and discomfort were scored using an established visual-analog pain score (0-10). A control group (n=24) had received midazolam, pentazocine or fentanyl according to the study protocol. Results: All procedures could be carried out by an interventional radiologist and a nurse and/or technologist only. In 69/72 cases adequate analgosedation could be achieved. Injection of alfentanil was titrated, with a rapid onset and short acting effect of the analgesia. Patients reported an average pain score of 2.6 vs. 4.5 in the control group. Over 55% experienced no or mild pain (score 0-3), in the control group only 8% reached this level. Conclusion: A combination of shortly effective alfentanil and midazolam allows interventional radiologists to perform major procedures alone under effective analgosedation. This medication scheme is superior to the medication upon demand. (orig.) [de

  12. Work–Life Interventions

    Directory of Open Access Journals (Sweden)

    He Lu Calvin Ong


    Full Text Available Despite disparities in the conceptualization of work–life balance (WLB and work–life harmony (WLH in the literature, there remains no evidence till date to validate these differences. Furthermore, there are currently no insights that shed light on the relationship between work–life initiatives and key business strategies of contemporary organizations. Hence, the current study investigated the differences between the constructs of WLB and WLH using a cognitive dissonance approach and assessed the impact of work–life interventions, based on these approaches, on individual creativity at work. Hundred participants, age ranging from 18 to 32 years (M = 23.94, SD = 3.87, with at least 6 months of working experience were recruited. Using an online questionnaire, participants were randomly assigned into WLB (n = 55 or WLH (n = 45 conditions. Participants were tasked to complete pre- and post-intervention measures of individual creativity, as well as a manipulation check using a cognitive dissonance scale. Results showed that participants in the WLB condition elicit higher levels of cognitive dissonance compared with participants in the WLH condition. This indicates an implicit difference in the constructs of WLB and harmony. Second, findings also suggest that work–life interventions adopting a WLH approach will have a more positive impact on individuals’ creativity at work compared with interventions targeted at achieving balance. Research, practical, and cultural implications of the findings are discussed in the article.

  13. Early Intervention in Budapest. (United States)

    Gallai, Maria; Katona, Ferenc; Balogh, Erzsebet; Schultheisz, Judit; Deveny, Anna; Borbely, Sjoukje


    This article presents five models of early intervention used in Budapest. Diagnostic and treatment methods used by the Pediatric Institute and the Conductive Education System are described, along with the Deveny Special Manual Technique and Gymnastic Method, the Gezenguz method and techniques used in the Early Developmental Center. (CR)

  14. Intervention as Workplace Learning (United States)

    Elkjaer, Bente; Nickelsen, Niels Christian Mossfeldt


    Purpose: The purpose of this paper is to illustrate how workplace interventions may benefit from a simultaneous focus on individuals' learning and knowledge and on the situatedness of workplaces in the wider world of changing professional knowledge regimes. This is illustrated by the demand for evidence-based practice in health care.…

  15. Diagnostic and interventional radiology

    Energy Technology Data Exchange (ETDEWEB)

    Vogl, Thomas J. [Klinikum der Johann Wolfgang Goethe-Universitaet, Frankfurt am Main (Germany). Inst. fuer Diagnostische und Interventionelle Radiologie; Reith, Wolfgang [Universitaetsklinikum des Saarlandes, Homburg/Saar (Germany). Klinik fuer Diagnostische und Interventionelle Neuroradiologie; Rummeny, Ernst J. (ed.) [Technische Univ. Muenchen Klinikum rechts der Isar, Muenchen (Germany). Inst. fuer Radiologie


    This exceptional book covers all aspects of diagnostic and interventional radiology within one volume, at a level appropriate for the specialist. From the basics through diagnosis to intervention: the reader will find a complete overview of all areas of radiology. The clear, uniform structure, with chapters organized according to organ system, facilitates the rapid retrieval of information. Features include: Presentation of the normal radiological anatomy Classification of the different imaging procedures according to their diagnostic relevance Imaging diagnosis with many reference images Precise description of the interventional options The inclusion of many instructive aids will be of particular value to novices in decision making: Important take home messages and summaries of key radiological findings smooth the path through the jungle of facts Numerous tables on differential diagnosis and typical findings in the most common diseases offer a rapid overview and orientation Diagnostic flow charts outline the sequence of diagnostic evaluation All standard procedures within the field of interventional radiology are presented in a clinically relevant and readily understandable way, with an abundance of illustrations. This is a textbook, atlas, and reference in one: with more than 2500 images for comparison with the reader's own findings. This comprehensive and totally up-to-date book provides a superb overview of everything that the radiology specialist of today needs to know.

  16. Cardiovascular and interventional radiology

    International Nuclear Information System (INIS)

    White, R.I. Jr.


    A symposium of eight short but complete papers giving an overview of interventional radiology is presented. Organized by Dr. William Casarella, this symposium is certainly the most current review of the subject available. This year's cardiovascular section is again heavily weighted toward interventional radiology. Abrams and Doubilet's article on the underutilization of angioplasty is important because it describes the cost effectiveness of this method. Most health planners, right or wrong, have complained about overutilization of diagnostic radiology procedures. In general, the opposite is true for interventional procedures - they are underutilized. If the authors draw the attention of their hospital administrators to these approaches and also produce the data on long-term follow-up for our medical colleagues, interventional radiology may realize its full potential. Articles on cardiac magnetic resonance imaging are beginning to appear and this technique seems to have great potential. An important article, which is the first prospective study comparing lung scintigraphy and pulmonary angiography in the diagnosis of pulmonary embolism, supports the increased use of pulmonary angiography. Finally, an article on complications of percutaneous biliary drainage provokes some discussion of its value for routine preoperative use

  17. Interventions for vaginismus. (United States)

    Melnik, Tamara; Hawton, Keith; McGuire, Hugh


    Vaginismus is an involuntary contraction of the vaginal muscles which makes sexual intercourse difficult or impossible. It is one of the more common female psychosexual problems. Various therapeutic strategies for vaginismus, such as sex therapy and desensitisation, have been proposed, and uncontrolled case series appear promising. To assess the effects of different interventions for vaginismus. We searched the Cochrane Depression, Anxiety and Neurosis Group's Specialised Register (CCDANCTR-Studies and CCDANCTR-References) to August 2012. This register contains relevant randomised controlled trials from: The Cochrane Library (all years), EMBASE (1974 to date), MEDLINE (1950 to date) and PsycINFO (1967 to date). We searched reference lists and conference abstracts. We contacted experts in the field regarding unpublished material. Controlled trials comparing treatments for vaginismus with another treatment, a placebo treatment, treatment as usual or waiting list control. The review authors extracted data which we verified with the trial investigator where possible. Five studies were included, of which four with a total of 282 participants provided data. No meta-analysis was possible due to heterogeneity of comparisons within included studies as well as inadequate reporting of data. All studies were considered to be at either moderate or high risk of bias. The results of this systematic review indicate that there is no clinical or statistical difference between systematic desensitisation and any of the control interventions (either waiting list control, systematic desensitisation combined with group therapy or in vitro (with women under instruction by the therapist) desensitisation) for the treatment of vaginismus. The drop-out rates were higher in the waiting list groups. A clinically relevant effect of systematic desensitisation when compared with any of the control interventions cannot be ruled out. None of the included trials compared other behaviour therapies (e

  18. Effects of psycho-behavioral interventions on immune functioning in cancer patients: a systematic review. (United States)

    Tong, Guixian; Geng, Qingqing; Cheng, Jing; Chai, Jing; Xia, Yi; Feng, Rui; Zhang, Lu; Wang, Debin


    This study aimed at summarizing evidence about effects of psycho-behavioral interventions (PBIs) on immune responses among cancer patients and analyzing quality of published studies so as to inform future researches. Literature retrieval utilized both highly inclusive algorithms searching randomized controlled studies published in English and Chinese and manual searching of eligible studies from references of relevant review papers. Two researchers examined the articles selected separately and extracted the information using a pre-designed form for soliciting data about the trials (e.g., sample size, disease status, intervention, immune responses) and quality ratings of the studies. Both narrative descriptions and meta-analysis (via Review manager 5) were used synthesizing the effects of PBIs on immune responses among cancer patients and state of art of the researches in this area. Seventy-six RCTs met inclusion criteria. PBIs implemented were divided into three major categories including psychological state adjustment, physical activity and dietary modification. Immune indicators measured included CD4+ cells, CD8+ cells, CD4/CDC8+ ratio, CD3+ cells, NK cell activity, etc. Effects of PBIs on immune responses documented in individual papers were mixed and pooled analysis of CD4+ cells, CD4+/CD8+ ratio, CD3+ cells, NKCA, IgG, IgM and IL-2 showed modest effects. However, there were huge discrepancies in intervention effects between studies published in English and Chinese and the results should be interpreted with caution. Besides, most studies suffer from some quality flaws concerning blinding, randomization procedures, compliance, attrition and intention-to-treat analyses, etc. Although there are considerable evidences of PBI effects on some immune indicators, the effect sizes are modest and it is still premature to conclude whether PBIs have effects on immune functions among cancer patients. There is a clear need for much more rigorous efforts in this area

  19. Early intervention in psychosis

    DEFF Research Database (Denmark)

    Csillag, Claudio; Nordentoft, Merete; Mizuno, Masafumi


    AIM: Early intervention in psychosis (EIP) is a well-established approach with the intention of early detection and treatment of psychotic disorders. Its clinical and economic benefits are well documented. This paper presents basic aspects of EIP services, discusses challenges to their implementa......AIM: Early intervention in psychosis (EIP) is a well-established approach with the intention of early detection and treatment of psychotic disorders. Its clinical and economic benefits are well documented. This paper presents basic aspects of EIP services, discusses challenges...... benefits alone is not enough to promote implementation, as economic arguments and political and social pressure have shown to be important elements in efforts to achieve implementation. CONCLUSIONS: Users' narratives, close collaboration with community organizations and support from policy-makers and known...

  20. Interventional therapy of hyperthyroidism

    International Nuclear Information System (INIS)

    Liang Jun; Yang Shibin; Yue Yu; Chen Tingcong


    Objective: To evaluate clinical application of arterial embolotherapy on hyperthyroidism. Methods: 11 patients with hyperthyroidism were performed with thyroid superior and inferior arterial super-selective arteriography and interventional embolization by polyvinyl alcohol (PVA), gelfoam particles and wool coil. Results: The procedures were succeeded in 11 patients. After the embolotherapy, the thyroid function gradually returned to normal level in 10 patients. The symptom was not controlled satisfactorily in 1 patient, who underwent the right thyroid inferior arteries super selective arteriography and interventional embolization, and then the thyroid function gradually returned to normal level. No serious complications occurred in all patients. Conclusions: Arterial embolotherapy is a safe, simple, symptomless, reliable and very effective for treatment of hyperthyroidism

  1. Effectiveness of medical interventions. (United States)

    Stegenga, Jacob


    To be effective, a medical intervention must improve one's health by targeting a disease. The concept of disease, though, is controversial. Among the leading accounts of disease-naturalism, normativism, hybridism, and eliminativism-I defend a version of hybridism. A hybrid account of disease holds that for a state to be a disease that state must both (i) have a constitutive causal basis and (ii) cause harm. The dual requirement of hybridism entails that a medical intervention, to be deemed effective, must target either the constitutive causal basis of a disease or the harms caused by the disease (or ideally both). This provides a theoretical underpinning to the two principle aims of medical treatment: care and cure. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Time-dependent interventions


    Weil, Max Harry; Tang, Wanchun


    The contribution by Pepe and colleagues provides additional evidence that initial defibrillation is not necessarily the optimal intervention for victims of cardiac arrest and especially when cardiac arrest has been untreated for more than 3 min. Precordial compression therefore remains the mainstay of basic life support cardiopulmonary resuscitation after sudden death. It is increasingly apparent that neither epinephrine whether in conventional or high doses nor vasopressin improve ultimate s...

  3. Interventional vascular radiology

    International Nuclear Information System (INIS)

    Yune, H.Y.


    The papers published during this past year in the area of interventional vascular radiology presented some useful modifications and further experiences both in the area of thromboembolic therapy and in dilation and thrombolysis, but no new techniques. As an introductory subject, an excellent monograph reviewing the current spectrum of pharmacoangiography was presented in Radiographics. Although the presented material is primarily in diagnostic application of various pharmacologic agents used today to facilitate demonstration of certain diagnostic criteria of various disease processes, both vasodilatory and vasoconstrictive reaction to these agents are widely used in various therapeutic vascular procedures. This monograph should be reviewed by every angiographer whether or not he or she performs interventional procedures, and it would be very convenient to have this table available in the angiography suite. In a related subject, Bookstein and co-workers have written an excellent review concerning pharmacologic manipulations of various blood coagulative parameters during angiography. Understanding the proper method of manipulation of the bloodclotting factors during angiography, and especially during interventional angiography, is extremely important. Particularly, the method of manipulating the coagulation with the use of heparin and protamine and modification of the platelet activity by using aspirin and dipyridamole are succinctly reviewed. The systemic and selective thrombolytic activities of streptokianse are also discussed

  4. Phytotherapy management: a new intervention for nursing intervention classification. (United States)

    Paloma, Echevarria; Ovidio, Céspedes; Jessica, Rojas; Francisca, Sánchez Ayllón; Isabel, Morales; Maravillas, Gimenez


    We present a new nurse intervention: "Phytotherapy Management," which has been accepted by the editorial board of the Nursing Interventions Classification for inclusion in the 7th edition of the Nursing Intervention Classification. This could have implications for nursing practice and research. Content analysis, extensive search in the literature.

  5. Biobehavioral Intervention for Cancer Stress: Conceptualization, Components, and Intervention Strategies (United States)

    Andersen, Barbara L.; Golden-Kreutz, Deanna M.; Emery, Charles F.; Thiel, Debora L.


    Trials testing the efficacy of psychological interventions for cancer patients had their beginnings in the 1970s. Since then, hundreds of trials have found interventions to be generally efficacious. In this article, we describe an intervention grounded in a conceptual model that includes psychological, behavioral, and biological components. It is…

  6. Attention for pediatric interventional radiology

    International Nuclear Information System (INIS)

    Zhu Ming; Cheng Yongde


    Radiological interventions possess wide utilization in the diagnosis and treatment for pediatric patients. Pediatric interventional radiology is an important branch of interventional radiology and also an important branch of pediatric radiology. Pediatric interventional radiology has grown substantially over the last 30 years, radiologists closely cooperation with surgeons and other physicians providing a new horizon in the management of pediatric diseases in western countries. It includes pediatric cardiac interventional radiology, pediatric neuro-interventional radiology, pediatric vascular interventional radiology, pediatric nonvascular interventional radiology, pediatric tumor interventional radiology and others. In the United States, every children hospital which owns two hundred beds has to have special trained interventional radiologists in radiologic department installing with advanced digital subtraction angiographic equipment. Interventional therapeutic procedures and diagnostic angiography have been proceeding more and more for the congenital and acquired diseases of children. The promising results give use uprising and interventional therapy as an alternative or a replacement or supplement to surgical operation. Pediatric interventional radiology is rather underdeveloped in China with a few special pediatric interventional radiologist, lack of digital subtraction angiography equipment. Pediatric radiologists have no enough field for interventional procedures such as pediatric neuro-interventional radiology and pediatric vascular interventional radiology. In the contrary adult interventional radiologists do have better interventional jobs in China and Pediatric cardiologists also share the same trend. They perform angiocardiography for congenital heart diseases and treat congenital heart disease with interventional procedures including balloon dilation of valves and vessels, coil embolization of collaterals, patent ducts and other arterial fistulae

  7. Interventions for preoperative smoking cessation

    DEFF Research Database (Denmark)

    Møller, A; Villebro, N


    Smokers have a substantially increased risk of intra- and postoperative complications. Preoperative smoking intervention may be effective in decreasing this incidence. The preoperative period may be a well chosen time to offer smoking cessation interventions due to increased patient motivation....

  8. Interventional radiology and undesirable effects

    International Nuclear Information System (INIS)

    Benderitter, M.


    As some procedures of interventional radiology are complex and long, doses received by patients can be high and cause undesired effects, notably on the skin or in underlying tissues (particularly in the brain as far as interventional neuroradiology is concerned and in lungs in the case of interventional cardiology). The author briefly discusses some deterministic effects in interventional radiology (influence of dose level, delay of appearance of effects, number of accidents). He briefly comments the diagnosis and treatment of severe radiological burns

  9. The Danish Alzheimer intervention study

    DEFF Research Database (Denmark)

    Waldemar, G; Waldorff, F B; Buss, D V


    Background: There is a lack of appropriately designed trials investigating the efficacy of psychosocial interventions for patients with mild dementia and their family caregivers. This paper reports the rationale and design of the Danish Alzheimer Disease Intervention Study and baseline characteri......Background: There is a lack of appropriately designed trials investigating the efficacy of psychosocial interventions for patients with mild dementia and their family caregivers. This paper reports the rationale and design of the Danish Alzheimer Disease Intervention Study and baseline...

  10. Psychosocial Intervention Model

    DEFF Research Database (Denmark)

    Singla, Rashmi


    The article is based on a research project drawing upon survey data (N=628) and qualitative interviews (N=60) of youth and their parents belonging to the five largest ethnic minority groups in Denmark i.e. Turkey, former Yugoslavia, Pakistan, Lebanon and Somalia, along with the experiences of psy.......K. as well as Nordic countries. Finally a model for psychosocial intervention is presented which directs attention to the issues of ageism, sexism as well as racism at personal, interpersonal and structural levels....

  11. Recommendations for intervention

    International Nuclear Information System (INIS)

    Touzet, R.; Descalzo, A.; Peralta, O.


    The objective of this work is set a 'radiological protection criteria' for patients and staff involved for the purpose of the doses involved are as low as reasonably achievable considering the limitations that each technique and its objectives. Establish criteria for injury prevention in the patient's skin for long exposures and intense when complications arise in the process. Set levels for some well Dimensional procedures. Establish procedures for patient dosimetry control and operator personnel. These criteria will be established by the interventional radiology team with participation of specialists in radiation protection, medical physics, dosimetry and X rays equipment specialists

  12. Shopper marketing nutrition interventions. (United States)

    Payne, Collin R; Niculescu, Mihai; Just, David R; Kelly, Michael P


    Grocery stores represent a context in which a majority of people's food purchases occur. Considering the nutrition quality of the population's food intake has dramatically decreased, understanding how to improve food choice in the grocery store is paramount to healthier living. In this work, we detail the type of financial resources from which shoppers could draw (i.e., personal income and benefits from government food assistance programs to low income populations) and explain how these financial resources are allocated in the grocery store (i.e., planned, unplanned, error). Subsequently, we identify a conceptual framework for shopper marketing nutrition interventions that targets unplanned fruit and vegetable purchases (i.e., slack, or willingness to spend minus list items). Targeting slack for fresh fruit and vegetable purchases allows retailers to benefit economically (i.e., fruit and vegetables are higher margin) and allows shoppers to improve their nutrition without increasing their budgets (i.e., budget neutrality). We also provide preliminary evidence of what in-store marketing of fresh fruits and vegetables could entail by modifying grocery carts and grocery floors to provide information of what is common, normal, or appropriate fruit and vegetable purchases. In each example, fresh fruit and vegetable purchases increased and evidence suggested shopper budget neutrality. To provide context for these results, we detail measurement tools that can be used to measure shopper behaviors, purchases, and consumption patterns. Finally, we address theoretical, practical, and policy implications of shopper marketing nutrition interventions. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Psychotherapeutic intervention by telephone

    Directory of Open Access Journals (Sweden)

    Erika Mozer


    Full Text Available Erika Mozer1,2, Bethany Franklin1,3, Jon Rose11Department of Veterans Affairs, Palo Alto Health Care System, Palo Alto, CA, USA; 2PGSP Stanford PsyD Consortium Palo Alto, CA, USA; 3Pacific Graduate School of Psychology Palo Alto, California, USAAbstract: Psychotherapy conducted over the telephone has received increasing amounts of empirical attention given practical advantages that side-step treatment barriers encountered in traditional office-based care. The utility and efficacy of telephone therapy appears generalizable across diverse clinical populations seeking care in community-based hospital settings. Treatment barriers common to older adults suggest that telephone therapy may be an efficient and effective mental health resource for this population. This paper describes empirical studies of telehealth interventions and case examples with psychotherapy conducted via telephone on the Spinal Cord Injury Unit of the Palo Alto Veterans’ Administration. Telephone therapy as appears to be a viable intervention with the aging population.Keywords: telehealth, rural mental health, psychotherapy, healthcare delivery, telecare

  14. [Lifestyle interventions at work?]. (United States)

    Hulshof, Carel T J


    So far many worksite lifestyle or health promotion programmes have shown only moderate evidence of effectiveness and cost-effectiveness. However, participation in work is in itself an important determinant of health. For this reason ensuring of fitting work and sustained workability should be an aspect of health policy. Workers' health is not only determined by their working environment but also by health practices and lifestyle factors. Under certain preconditions (e.g. on a voluntary basis, confidentiality, integration with health protection) lifestyle interventions during work time can contribute to a healthier working population. As such programmes may result in financial and social benefits for employers, they should be partly responsible for paying the costs. From a societal perspective, governmental commitment to a preventive policy and the involvement of health and income insurance companies are also required.

  15. Angiography - interventional diagnostic applications

    International Nuclear Information System (INIS)

    Schild, H.


    The angiography system is very different from the other systems used in diagnostic radiology. The invasivity of angiography requires special, high standards in theoretical and practical training and experience both of beginners and experienced personnel. This textbook fully meets the demand for in-depth and exhaustive information, as it presents: - The fundamentals and techniques of angiography, the vascular anatomy, and many hints and tips of great help in practice. - A comprehensive survey of diagnostic problems and examination approaches, including neuro-angiography, with 221 reproductions of original angiographs, and additional schematic representations. - A special chapter devoted to indication and relevant techniques for the major vascular interventional examinations. - A great number of tables explain at a glance standard examination techniques, indications and diagnostic criteria. (orig./CB) [de

  16. Long-term effectiveness of a parenting intervention for children at risk of developing conduct disorder. (United States)

    Bywater, Tracey; Hutchings, Judy; Daley, David; Whitaker, Chris; Yeo, Seow Tien; Jones, Karen; Eames, Catrin; Edwards, Rhiannon Tudor


    The typical pattern for intervention outcome studies for conduct problems has been for effect sizes to dissipate over time with decreasing effects across subsequent follow-ups. To establish whether the short-term positive effects of a parenting programme are sustained longer term. To observe trends, and costs, in health and social service use after intervention. Parents with children aged 36-59 months at risk of developing conduct disorder (n = 104) received intervention between baseline and first follow-up (6 months after baseline n = 86) in 11 Sure Start areas in North Wales. Follow-ups two (n = 82) and three (n = 79) occurred 12 and 18 months after baseline. Child problem behaviour and parenting skills were assessed via parent self-report and direct observation in the home. The significant parent-reported improvements in primary measures of child behaviour, parent behaviour, parental stress and depression gained at follow-up one were maintained to follow-up three, as were improved observed child and parent behaviours. Overall, 63% of children made a minimum significant change (0.3 standard deviations) on the Eyberg Child Behavior Inventory problem scale between baseline and follow-up (using intention-to-treat data), 54% made a large change (0.8 standard deviations) and 39% made a very large change (1.5 standard deviations). Child contact with health and social services had reduced at follow-up three. Early parent-based intervention reduced child antisocial behaviour and benefits were maintained, with reduced reliance on health and social service provision, over time.

  17. Designing equitable workplace dietary interventions: perceptions of intervention deliverers. (United States)

    Smith, Sarah A; Visram, Shelina; O'Malley, Claire; Summerbell, Carolyn; Araujo-Soares, Vera; Hillier-Brown, Frances; Lake, Amelia A


    Workplaces are a good setting for interventions that aim to support workers in achieving a healthier diet and body weight. However, little is known about the factors that impact on the feasibility and implementation of these interventions, and how these might vary by type of workplace and type of worker. The aim of this study was to explore the views of those involved in commissioning and delivering the Better Health at Work Award, an established and evidence-based workplace health improvement programme. One-to-one semi-structured interviews were conducted with 11 individuals in North East England who had some level of responsibility for delivering workplace dietary interventions. Interviews were transcribed verbatim and analysed using thematic framework analysis. A number of factors were felt to promote the feasibility and implementation of interventions. These included interventions that were cost-neutral (to employee and employer), unstructured, involved colleagues for support, took place at lunchtimes, and were well-advertised and communicated via a variety of media. Offering incentives, not necessarily monetary, was perceived to increase recruitment rates. Factors that militate against feasibility and implementation of interventions included worksites that were large in size and remote, working patterns including shifts and working outside of normal working hours that were not conducive to workers being able to access intervention sessions, workplaces without appropriate provision for healthy food on site, and a lack of support from management. Intervention deliverers perceived that workplace dietary interventions should be equally and easily accessible (in terms of cost and timing of sessions) for all staff, regardless of their job role. Additional effort should be taken to ensure those staff working outside normal working hours, and those working off-site, can easily engage with any intervention, to avoid the risk of intervention-generated inequalities (IGIs).

  18. Percutaneous intervention in obstructive

    International Nuclear Information System (INIS)

    Souftas, V.


    Percutaneous intervention procedures in obstructive uropathy include percutaneous nephrostomy tube placements, nephroureteral stents, percutaneous nephrostomy combined with ureteral embolization, percutaneous management of stone disease, suprapubic tube placements into the bladder, and perinephric/retroperitoneal urinomas/abscesses drainages. Percutaneous nephrostomy is performed to relieve urinary obstruction or divert the urinary stream away from the ureter or bladder. Patients are given preprocedure antibiotics. Percutaneous nephrostomies can be emergent cases because of risk of pyuria and sepsis from a stagnant urine collection. The procedure is performed using both ultrasound and fluoroscopy (or fluoroscopy alone using anatomic landmarks, or an internal radiopaque calculus, or delayed phase excretion of the contrast into the renal collecting system) under local anesthesia or conscious sedation. Ureteral stents are placed to bypass an obstructing stone or to stent across of an area of stricture or ureteral laceration. Stents may be placed by the urologist via a transurethral approach or by the interventional radiologist via a percutaneous approach. The decision as to method of stent placement is based upon the location and accessibility of the ureteral pathology. Ureteral embolization is performed in patients with unresectable tumors of the pelvis with long-standing nephrostomy tubes and distal urine leaks refractory to other treatments. Coils, gelfoam and liquid embolic materials can be used. Ureteral embolization for ureteral fistulas and incontinence is technically successful in 100% of the patients. Complications include bleeding, infection, ureteral or renal injury, and deployment (or movement) of the coils within the renal pelvis. Percutaneous management of stone disease, including renal, ureteral, and bladder stones requires close cooperation between the urologist and interventional radiologist, because of availability of sonographic lithotripsy

  19. Ethics of the humanitarian intervention

    Directory of Open Access Journals (Sweden)

    Savić Mile


    Full Text Available The main subject of this paper are the ethical aspects of humanitarian military intervention. Author shows the weaknesses and difficulties of consequentialistic and deontological justification of humanitarian intervention. He points to the impossibility of a coherent moral theory of humanitarian intervention and argues that the humanitarian interventions of the nineties of the 20th century do not compliance just war. In his opinion, they represent an attempt of the quasi moral masking the real politics which lead the most powerful states in order to protect their national interests. .

  20. Interventional chest procedures in pregnancy.

    LENUS (Irish Health Repository)

    Morgan, Ross K


    Interventional pulmonology encompasses diagnostic and therapeutic bronchoscopic procedures, and pleural interventions. In the last 10 years older techniques have been refined and exciting new technologies have extended the reach and application of the instruments used. The main areas within pulmonary medicine for which these interventions have a role are malignant and nonmalignant airway disease, pleural effusion, pneumothorax, and artificial airways. There are no data from well-designed prospective trials to guide recommendations for interventional pulmonary procedures in pregnancy. The recommendations provided in this article are based on critical review of reported case series, opinion from recognized experts, and personal observations.

  1. Interventional chest procedures in pregnancy.

    LENUS (Irish Health Repository)

    Morgan, Ross K


    Interventional pulmonology encompasses diagnostic and therapeutic bronchoscopic procedures, and pleural interventions. In the last 10 years older techniques have been refined and exciting new technologies have extended the reach and application of the instruments used. The main areas within pulmonary medicine for which these interventions have a role are malignant and nonmalignant airway disease, pleural effusion, pneumothorax, and artificial airways. There are no data from well-designed prospective trials to guide recommendations for interventional pulmonary procedures in pregnancy. The recommendations provided in this article are based on critical review of reported case series, opinion from recognized experts, and personal observations.

  2. Intervention procedures for radionuclides

    International Nuclear Information System (INIS)

    Adelstein, S.J.


    As in the case of smoking and lung cancer, for large radionuclide releases, an ounce of prevention is worth a pound of cure. On the other hand, we feel compelled to do something sensible after an accident even if the principal benefit of intervention may be to comfort the population at risk. Of course, for populations near the site of an accident, evacuation should be considered, but it is unreasonable to apply this measure to distant populations, e.g., large segments of the European community could not be moved about as we observe the shifting of a radioactive cloud in response to changing winds. If the radionuclides are delivered as particulates, bringing people indoors and employing primitive air filters can temporarily reduce exposures, but these stratagems are not very effective against gaseous or volatile elements. What, then, can be done for populations downwind of a radioactive release whose air, water, and/or food supply are, or are about to become contaminated? 5 refs

  3. Wellness interventions for anesthesiologists. (United States)

    Saadat, Haleh; Kain, Zeev N


    The review examines the different preventive measures that have been found to be useful to abolish or decrease the negative effects of burnout and increase resilience in anesthesiologists. Studies in anesthesiology cite autonomy, control of the work environment, professional relationships, leadership, and organizational justice as the most important factors in job satisfaction. Factors such as difficulty in balancing personal and professional life, poor attention to wellness, work alcoholism, and genetic factors increase an individual's susceptibility to burnout. Exposure to chronic or repeated stress instigates a spectrum of autonomic, endocrine, immunologic, and behavioral responses that activate the sympathetic-adrenal-medullary and hypothalamic-pituitary-adrenal axis. Investigating the difference in psychobiologic reactivity, as well as defining the psychological symptoms that are characteristic to individuals vulnerable to stress-induced illness, would enable scientists to better look into the modalities to eradicate the negative effects. Recent studies have shown that a combination of individual and structural changes in institutions can increase resilience in physicians. Burnout is a pathological syndrome that is triggered by constant levels of high stress. A combination of individual efforts as well as structural interventions can help to increase wellbeing in physicians.

  4. Implications for Therapeutic Intervention

    Directory of Open Access Journals (Sweden)

    A. L. Hof


    Full Text Available Patients with an upper motor neurone syndrome (CP suffer from many disabling primary symptoms: spasms, weakness, and loss of dexterity. These primary ‘neurogenic’ symptoms often lead to secondary disabilities, muscle contractures, and tertiary effects, bone deformations. A common symptom of CP is hypertonia, with. the consequence that the involved muscles remain in an excessively shortened length for most of the time. As a normal reaction of the muscle tissue, the number of sarcomeres is reduced and the muscle fibers shorten permanently: a contracture develops. A possible second type of contracture is that normal muscle lengthening along with bone growth is affected. Current treatments for the secondary effects include (1 reduction of muscle force, (2lengthening of the muscle fibers by serial plaster casts, and (3surgical lengthening of tendons or aponeurosis. The choice of treatment depends on the cause of the functional deficit. Bone tissue also adapts itself to abnormal forces, especially in the growth period. The hypertonias or contractures of CP so may give rise to bone malformations that interfere with function (e.g. femur endorotation or may reduce the action of muscles by changing the lever arm (e.g. ankle varus. Although prevention should always be preferred, a timely surgical intervention cannot always be avoided. The differences in treatment for the various groups require and justify an extensive laboratory investigation, including EMG recordings in gait, measurement of passive elastic properties, and long-term observation of the hypertonia.

  5. Interventions for actinic keratoses. (United States)

    Gupta, Aditya K; Paquet, Maryse; Villanueva, Elmer; Brintnell, William


    Actinic keratoses are a skin disease caused by long-term sun exposure, and their lesions have the potential to develop into squamous cell carcinoma. Treatments for actinic keratoses are sought for cosmetic reasons, for the relief of associated symptoms, or for the prevention of skin cancer development. Detectable lesions are often associated with alteration of the surrounding skin (field) where subclinical lesions might be present. The interventions available for the treatment of actinic keratoses include individual lesion-based (e.g. cryotherapy) or field-directed (e.g. topical) treatments. These might vary in terms of efficacy, safety, and cosmetic outcomes. To assess the effects of topical, oral, mechanical, and chemical interventions for actinic keratosis. We searched the following databases up to March 2011: the Cochrane Skin Group Specialised Register, CENTRAL in The Cochrane Library, MEDLINE (from 2005), EMBASE (from 2010), and LILACS (from 1982). We also searched trials registers, conference proceedings, and grey literature sources. Randomised controlled trials (RCTs) comparing the treatment of actinic keratoses with either placebo, vehicle, or another active therapy. At least two authors independently abstracted data, which included adverse events, and assessed the quality of evidence. We performed meta-analysis to calculate a weighted treatment effect across trials, and we expressed the results as risk ratios (RR) and 95% confidence intervals (CI) for dichotomous outcomes (e.g. participant complete clearance rates), and mean difference (MD) and 95% CI for continuous outcomes (e.g. mean reduction in lesion counts). We included 83 RCTs in this review, with a total of 10,036 participants. The RCTs covered 18 topical treatments, 1 oral treatment, 2 mechanical interventions, and 3 chemical interventions, including photodynamic therapy (PDT). Most of the studies lacked descriptions of some methodological details, such as the generation of the randomisation

  6. Job Demands-Resources Interventions

    NARCIS (Netherlands)

    J. Van Wingerden (Jessica)


    markdownabstractThe main aim of this dissertation was to examine whether positive organizational interventions based on JD-R theory can enhance employees’ work engagement and performance. This thesis presented five empirical intervention studies from different perspectives; (a) a personal resources

  7. AAC Modeling Intervention Research Review (United States)

    Sennott, Samuel C.; Light, Janice C.; McNaughton, David


    A systematic review of research on the effects of interventions that include communication partner modeling of aided augmentative and alternative communication (AAC) on the language acquisition of individuals with complex communication needs was conducted. Included studies incorporated AAC modeling as a primary component of the intervention,…

  8. Culinary Quality and foodbased interventions

    DEFF Research Database (Denmark)

    Røjel, Terkel

    -score, following a “Familystyle meal program”. Despite these results the overall effects on the nutritional status of the participants was not consistent. Discussion: A majority of the identified studies consisted of multicomponent and cross-disciplinary meal-time interventions. Thus few interventions solely...

  9. Interventional studies in nuclear medicine

    International Nuclear Information System (INIS)

    Saha, G.B.; Swanson, D.P.; Hladik, W.B. III


    Pharmacological interventions in nuclear medicine studies have been in practice for a long time. The triiodothyronine (T/sub 3/) suppression, Thyroid-stimulating hormone (TSH) stimulation, and perchlorate discharge tests are common examples of well-established diagnostic interventional studies. In recent years, pharmacologic and physiologic interventions in other nuclear medicine procedures have drawn considerable attention. The primary purpose of these interventions is to augment, complement or, more often, differentiate the information obtained from conventional nuclear medicine diagnostic studies. Pharmacologic interventions involve the administration of a specific drug before, during, or after the administration of radiopharmaceutical for a given study. The change in information due to intervention of the drug offers clues to differentiating various disease conditions. These changes can be brought about by physiologic interventions also, e.g., exercise in radionuclide ventriculography. In the latter interventions, the physiologic function of an organ is enhanced or decreased by physical maneuvers, and the changes observed can be used to differentiate various disease conditions

  10. Obesogenic environment – intervention opportunities

    Directory of Open Access Journals (Sweden)

    Mauro Fisberg


    Conclusion: Intervention opportunities are related to modifications in political, environmental, and individual settings. School and physical activities in the educational environment are intertwined with nutrition intervention in continuous education. A critical review of some different scenarios in Latin American countries is presented.

  11. Intervention principles: Theory and practice

    International Nuclear Information System (INIS)

    Jensen, P.H.; Crick, M.J.


    After the Chernobyl accident, it became clear that some clarification of the basic principles for intervention was necessary as well as more internationally recognised numerical guidance on intervention levels. There was in the former USSR and in Europe much confusion over, and lack of recognition of, the very different origins and purposes of dose limits for controlling deliberate increases in radiation exposure for practices and dose levels at which intervention is prompted to decrease existing radiation exposure. In the latest recommendations from ICRP in its Publication 60, a clear distinction is made between the radiation protection systems for a practice and for intervention. According to ICRP, the protective measures forming a program of intervention, which always have some disadvantages, should each be justified on their own merit in the sense that they should do more good than harm, and their form, scale, and duration should be optimised so as to do the most good. Intervention levels for protective actions can be established for many possible accident scenarios. For planning and preparedness purposes, a generic optimisation based on generic accident scenario calculations, should result in optimised generic intervention levels for each protective measure. The factors entering such an optimisation will on the benefit side include avertable doses and avertable risks as well as reassurance. On the harm side the factors include monetary costs, collective and individual risk for the action itself, social disruption and anxiety. More precise optimisation analyses based on real site and accident specific data can be carried out and result in specific intervention levels. It is desirable that values for easily measurable quantities such as dose rate and surface contamination density be developed as surrogates for intervention levels of avertable dose. However, it is important that these quantities should be used carefully and applied taking account of local

  12. The economics of interventional radiology

    International Nuclear Information System (INIS)

    Price, G.W.


    At a time when policy makers and regulators are scheming to reduce the costs and utilization of medical services, interventional radiology is poised for growth. Part of this potential for growth is based on wider acceptance of the procedures performed by interventional radiologists. A second factor in the growth potential is the relative value in cost of these procedures compared with alternative therapies. The author presents a discussion of the differences in the relative value of these procedures when performed by physicians of different specialties. This paper reviews the status of the economic climate in the health care delivery system and the role and potential growth of interventional radiology. This includes a review of current data on the utilization of interventional radiology procedures in the Medicare program. This overview includes a discussion of the initiatives of the federal government which directly impact interventional radiology

  13. Communication with parents concerning withholding or withdrawing of life-sustaining interventions in neonatology. (United States)

    Janvier, Annie; Barrington, Keith; Farlow, Barbara


    The nature and content of the conversations between the healthcare team and the parents concerning withholding or withdrawing of life-sustaining interventions for neonates vary greatly. These depend upon the status of the infant; for some neonates, death may be imminent, while other infants may be relatively stable, yet with a potential risk for surviving with severe disability. Healthcare providers also need to communicate with prospective parents before the birth of premature infants or neonates with uncertain outcomes. Many authors recommend that parents of fragile neonates receive detailed information about the potential outcomes of their children and the choices they have provided in an unbiased and empathetic manner. However, the exact manner this is to be achieved in clinical practice remains unclear. Parents and healthcare providers may have different values regarding the provision of life-sustaining interventions. However, parents base their decisions on many factors, not just probabilities. The role of emotions, regret, hope, quality of life, resilience, and relationships is rarely discussed. End-of-life discussions with parents should be individualized and personalized. This article suggests ways to personalize these conversations. The mnemonic "SOBPIE" may help providers have fruitful discussions: (1) What is the Situation? Is the baby imminently dying? Should withholding or withdrawing life-sustaining interventions be considered? (2) Opinions and options: personal biases of healthcare professionals and alternatives for patients. (3) Basic human interactions. (4) Parents: their story, their concerns, their needs, and their goals. (5) Information: meeting parental informational needs and providing balanced information. (6) Emotions: relational aspects of decision making which include the following: emotions, social supports, coping with uncertainty, adaptation, and resilience. In this paper, we consider some aspects of this complex process. Copyright

  14. Dietary intervention in acne (United States)

    Melnik, Bodo


    The purpose of this paper is to highlight the endocrine signaling of Western diet, a fundamental environmental factor involved in the pathogenesis of epidemic acne. Western nutrition is characterized by high calorie uptake, high glycemic load, high fat and meat intake, as well as increased consumption of insulin- and IGF-1-level elevating dairy proteins. Metabolic signals of Western diet are sensed by the nutrient-sensitive kinase, mammalian target of rapamycin complex 1 (mTORC1), which integrates signals of cellular energy, growth factors (insulin, IGF-1) and protein-derived signals, predominantly leucine, provided in high amounts by milk proteins and meat. mTORC1 activates SREBP, the master transcription factor of lipogenesis. Leucine stimulates mTORC1-SREBP signaling and leucine is directly converted by sebocytes into fatty acids and sterols for sebaceous lipid synthesis. Over-activated mTORC1 increases androgen hormone secretion and most likely amplifies androgen-driven mTORC1 signaling of sebaceous follicles. Testosterone directly activates mTORC1. Future research should investigate the effects of isotretinoin on sebocyte mTORC1 activity. It is conceivable that isotretinoin may downregulate mTORC1 in sebocytes by upregulation of nuclear levels of FoxO1. The role of Western diet in acne can only be fully appreciated when all stimulatory inputs for maximal mTORC1 activation, i.e., glucose, insulin, IGF-1 and leucine, are adequately considered. Epidemic acne has to be recognized as an mTORC1-driven disease of civilization like obesity, type 2 diabetes, cancer and neurodegenerative diseases. These new insights into Western diet-mediated mTORC1-hyperactivity provide a rational basis for dietary intervention in acne by attenuating mTORC1 signaling by reducing (1) total energy intake, (2) hyperglycemic carbohydrates, (3) insulinotropic dairy proteins and (4) leucine-rich meat and dairy proteins. The necessary dietary changes are opposed to the evolution of

  15. Patient doses in interventional cardiology

    International Nuclear Information System (INIS)

    Carrera, F.; Ojeda, C.; Ruiz-Cruces, R.; Francisco Diaz, J.; Sanchez, A.; Tort, I.


    Cardiovascular diseases are the first cause of death in Spain. The most usual procedures in interventional cardiology are coronariography and PTCA. The first is a diagnostic technique, and the second one is interventional. Our goal has been to study procedures made during the first six months in the Interventional Cardiology Unit of the Juan Ramon Jimenez Hospital (Huelva-Spain), taking into account radiation protection issues. We have studied 178 patients; 145 of them underwent coronariography, and 33 of the patients had PTCA too. Every case was analyzed taking into account technical and dosimetric parameters. We show parameters values gathered: Diagnostic techniques (valvular and non-valvular patients), and interventional techniques (coronariography and PTCA in different or in the same intervention). Higher doses were obtained with valvular patients, although the number of frames was similar. Attending to therapeutic procedures, the highest values were gotten with the 'double' interventions. Interventional procedures exceed in 60% doses gotten in diagnostic studies: this is because of the number of series and number of frames per series. Similar values obtained by other authors have been gotten. (author)

  16. International Humanitarian intervention in Kosovo

    Directory of Open Access Journals (Sweden)

    Valmir Hylenaj


    Full Text Available Humanitarian intervention in Kosovo did not happen by any geopolitical interest, but simply by an entirely humanitarian character which is closely connected with democratic principles, human rights, and the lack of moral order. Except for damages, massacres and destruction by fire of very sophisticated military artillery, Serbian army and police have forced with violence more than thousands of Kosovo Albanians to leave their home (Pllana, 2010, 241. With humanitarian intervention, NATO had shown it was ready to defend universal human values as the fundamental principle of humanity (free life. Main purpose of this article is an analysis of the international human intervention in Kosovo

  17. Interventions for emergency contraception. (United States)

    Shen, Jie; Che, Yan; Showell, Emily; Chen, Ke; Cheng, Linan


    Emergency contraception (EC) is using a drug or copper intrauterine device (Cu-IUD) to prevent pregnancy shortly after unprotected intercourse. Several interventions are available for EC. Information on the comparative effectiveness, safety and convenience of these methods is crucial for reproductive healthcare providers and the women they serve. This is an update of a review previously published in 2009 and 2012. To determine which EC method following unprotected intercourse is the most effective, safe and convenient to prevent pregnancy. In February 2017 we searched CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL, Popline and PubMed, The Chinese biomedical databases and UNDP/UNFPA/WHO/World Bank Special Programme on Human Reproduction (HRP) emergency contraception database. We also searched ICTRP and as well as contacting content experts and pharmaceutical companies, and searching reference lists of appropriate papers. Randomised controlled trials including women attending services for EC following a single act of unprotected intercourse were eligible. We used standard methodological procedures recommended by Cochrane. The primary review outcome was observed number of pregnancies. Side effects and changes of menses were secondary outcomes. We included 115 trials with 60,479 women in this review. The quality of the evidence for the primary outcome ranged from moderate to high, and for other outcomes ranged from very low to high. The main limitations were risk of bias (associated with poor reporting of methods), imprecision and inconsistency. Comparative effectiveness of different emergency contraceptive pills (ECP)Levonorgestrel was associated with fewer pregnancies than Yuzpe (estradiol-levonorgestrel combination) (RR 0.57, 95% CI 0.39 to 0.84, 6 RCTs, n = 4750, I 2 = 23%, high-quality evidence). This suggests that if the chance of pregnancy using Yuzpe is assumed to be 29 women per 1000, the chance of pregnancy using levonorgestrel would be between

  18. Personal Change and Intervention Style (United States)

    Andrews, John D. W.


    Presents a theory of personal change and analyzes growth-producing interventions using examples from the film, "Three Approaches to Psychotherapy". Compares the styles of Carl Rogers, Frttz Perls, and Albert Ellis to illustrate the theory. (Editor/RK)

  19. Alternative food safety intervention technologies (United States)

    Alternative nonthermal and thermal food safety interventions are gaining acceptance by the food processing industry and consumers. These technologies include high pressure processing, ultraviolet and pulsed light, ionizing radiation, pulsed and radiofrequency electric fields, cold atmospheric plasm...


    Directory of Open Access Journals (Sweden)

    Gonzalo Hervás


    Full Text Available Positive interventions have been developed extensively in recent years and they have been tested and applied in very diverse settings. Despite the fact that most of the findings regarding their efficacy can be considered from positive to very positive, the possibility that, in some cases, positive interventions may have unexpected or even iatrogenic effects cannot be discarded. In this article, research from several sources is reviewed in order to inform decisions about what interventions might be inadequate for cases with specific characteristics or vulnerability traits. Finally, the importance of using positive interventions with caution and rigor even when working with individuals who do not have overt problems or psychological disorders is discussed.


    African Journals Online (AJOL)


    Jul 29, 2010 ... work approach to therapy) in an attempt to develop a model for complicated grief intervention ..... way feels right for them, thus making them equal partners with .... This question points out the benefits of success and affords the.

  2. Interventions for preoperative smoking cessation

    DEFF Research Database (Denmark)

    Thomsen, Thordis; Villebro, Nete; Møller, Ann Merete


    BACKGROUND: Smokers have a substantially increased risk of postoperative complications. Preoperative smoking intervention may be effective in decreasing this incidence, and surgery may constitute a unique opportunity for smoking cessation interventions. OBJECTIVES: The objectives of this review...... are to assess the effect of preoperative smoking intervention on smoking cessation at the time of surgery and 12 months postoperatively, and on the incidence of postoperative complications. SEARCH METHODS: We searched the Cochrane Tobacco Addiction Group Specialized Register in January 2014. SELECTION CRITERIA......: Randomized controlled trials that recruited people who smoked prior to surgery, offered a smoking cessation intervention, and measured preoperative and long-term abstinence from smoking or the incidence of postoperative complications or both outcomes. DATA COLLECTION AND ANALYSIS: The review authors...

  3. Therapeutic interventions in cerebral palsy. (United States)

    Patel, Dilip R


    Various therapeutic interventions have been used in the management of children with cerebral palsy. Traditional physiotherapy and occupational therapy are widely used interventions and have been shown to be of benefit in the treatment of cerebral palsy. Evidence in support of the effectiveness of the neurodevelopmental treatment is equivocal at best. There is evidence to support the use and effectiveness of neuromuscular electrical stimulation in children with cerebral palsy. The effectiveness of many other interventions used in the treatment of cerebral palsy has not been clearly established based on well-controlled trials. These include: sensory integration, body-weight support treadmill training, conductive education, constraint-induced therapy, hyperbaric oxygen therapy, and the Vojta method. This article provides an overview of salient aspects of popular interventions used in the management of children with cerebral palsy.

  4. Interventional Management for Pelvic Pain. (United States)

    Nagpal, Ameet S; Moody, Erika L


    Interventional procedures can be applied for diagnostic evaluation and treatment of the patient with pelvic pain, often once more conservative measures have failed to provide relief. This article reviews interventional management strategies for pelvic pain. We review superior and inferior hypogastric plexus blocks, ganglion impar blocks, transversus abdominis plane blocks, ilioinguinal, iliohypogastric and genitofemoral blocks, pudendal nerve blocks, and selective nerve root blocks. Additionally, we discuss trigger point injections, sacroiliac joint injections, and neuromodulation approaches. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Interventions for paracetamol (acetaminophen) overdoses

    DEFF Research Database (Denmark)

    Brok, J; Buckley, N; Gluud, C


    Self-poisoning with paracetamol (acetaminophen) is a common cause of hepatotoxicity in the Western World. Interventions for paracetamol poisoning encompass inhibition of absorption, removal from the vascular system, antidotes, and liver transplantation.......Self-poisoning with paracetamol (acetaminophen) is a common cause of hepatotoxicity in the Western World. Interventions for paracetamol poisoning encompass inhibition of absorption, removal from the vascular system, antidotes, and liver transplantation....

  6. The Ethics of Workplace Interventions

    DEFF Research Database (Denmark)

    Hasle, Peter; Limborg, Hans Jørgen


    A discussion of the ethical dilemmas confronting occupational health and safety professionals when they are involved in workplace interventions. Case stories from the Danish occupational health service are used as the emperical point of departure for paper.......A discussion of the ethical dilemmas confronting occupational health and safety professionals when they are involved in workplace interventions. Case stories from the Danish occupational health service are used as the emperical point of departure for paper....

  7. Robotics in percutaneous cardiovascular interventions. (United States)

    Pourdjabbar, Ali; Ang, Lawrence; Behnamfar, Omid; Patel, Mitul P; Reeves, Ryan R; Campbell, Paul T; Madder, Ryan D; Mahmud, Ehtisham


    The fundamental technique of performing percutaneous cardiovascular (CV) interventions has remained unchanged and requires operators to wear heavy lead aprons to minimize exposure to ionizing radiation. Robotic technology is now being utilized in interventional cardiology partially as a direct result of the increasing appreciation of the long-term occupational hazards of the field. This review was undertaken to report the clinical outcomes of percutaneous robotic coronary and peripheral vascular interventions. Areas covered: A systematic literature review of percutaneous robotic CV interventions was undertaken. The safety and feasibility of percutaneous robotically-assisted CV interventions has been validated in simple to complex coronary disease, and iliofemoral disease. Studies have shown that robotically-assisted PCI significantly reduces operator exposure to harmful ionizing radiation without compromising procedural success or clinical efficacy. In addition to the operator benefits, robotically-assisted intervention has the potential for patient advantages by allowing more accurate lesion length measurement, precise stent placement and lower patient radiation exposure. However, further investigation is required to fully elucidate these potential benefits. Expert commentary: Incremental improvement in robotic technology and telecommunications would enable treatment of an even broader patient population, and potentially provide remote robotic PCI.

  8. Endovascular interventions for multiple trauma

    International Nuclear Information System (INIS)

    Kinstner, C.; Funovics, M.


    In recent years interventional radiology has significantly changed the management of injured patients with multiple trauma. Currently nearly all vessels can be reached within a reasonably short time with the help of specially preshaped catheters and guide wires to achieve bleeding control of arterial und venous bleeding. Whereas bleeding control formerly required extensive open surgery, current interventional methods allow temporary vessel occlusion (occlusion balloons), permanent embolization and stenting. In injured patients with multiple trauma preinterventional procedural planning is performed with the help of multidetector computed tomography whenever possible. Interventional radiology not only allows minimization of therapeutic trauma but also a considerably shorter treatment time. Interventional bleeding control has developed into a standard method in the management of vascular trauma of the chest and abdomen as well as in vascular injuries of the upper and lower extremities when open surgical access is associated with increased risk. Additionally, pelvic trauma, vascular trauma of the superior thoracic aperture and parenchymal arterial lacerations of organs that can be at least partially preserved are primarily managed by interventional methods. In an interdisciplinary setting interventional radiology provides a safe and efficient means of rapid bleeding control in nearly all vascular territories in addition to open surgical access. (orig.) [de

  9. Bringing parenting interventions back to the future: How randomized microtrials may benefit parenting intervention efficacy

    NARCIS (Netherlands)

    Leijten, P.; Dishion, T.J.; Thomaes, S.; Raaijmakers, M.A.J.; Orobio de Castro, B.; Matthys, W.


    A novel approach is needed to promote the efficacy of parenting interventions designed to improve children's mental health. The proposed approach bridges developmental and intervention science to test which intervention elements contribute to parenting intervention program efficacy. The approach

  10. Psychological interventions for cystic fibrosis. (United States)

    Glasscoe, C A; Quittner, A L


    As survival estimates for cystic fibrosis (CF) steadily increase long-term management has become an important focus for intervention. Psychological interventions are largely concerned with emotional and social adjustments, adherence to treatment and quality of life, however no systematic review of such interventions has been undertaken for this disease. To describe the extent and quality of effectiveness studies utilising psychological interventions for CF and whether these interventions provide significant psychosocial and physical benefits in addition to standard care. Relevant trials were identified from searches of Ovid MEDLINE, the Cochrane trial registers for CF and Depression, Anxiety and Neurosis Groups and PsychINFO; unpublished trials were located through professional networks and Listserves. Most recent search: April 2003. This review included RCTs and quasi-randomised trials. Study participants were children and adults diagnosed with CF, and their immediate family members. Psychological interventions were from a broad range of modalities and outcomes were primarily psychosocial, although physical outcomes and cost effectiveness were also considered. Two reviewers independently selected relevant trials and assessed their methodological quality. For binary and continuous outcomes a pooled estimate of treatment effect was calculated for each outcome. This review is based on the findings of eight studies, representing data from a total of 358 participants. Studies fell into four conceptually similar groups: (1) gene pre-test education counselling for relatives of those with CF (one study); (2) biofeedback, massage and music therapy to assist physiotherapy (three studies); (3) behavioural intervention to improve dietary intake in children up to 12 years (three studies); and (4) self-administration of treatments to improve quality of life in adults (one study). Interventions were largely educational or behavioural, targeted at specific treatment concerns

  11. Occupational exposure in interventional radiology

    International Nuclear Information System (INIS)

    Oh, H.J.; Lee, K.Y.; Cha, S.H.; Kang, Y.K.; Kim, H.J.; Oh, H.J.


    This study was conducted to survey of radiation safety control and to measure occupational radiation exposure dose of staff in interventional radiology in Korea. Interventioanl radiology requires the operator and assisting personnel to remain close to the patient, and thus close to primary beams of radiation. Therefore exposure doses of these personnel are significant from a radiological protection point of view. We surveyed the status of radiation safety on interventional radiology of 72 hospitals. The result were that 119 radiation equipments are using in interventional radiology and 744 staffs are composed of 307 radiologists, 116 residents of radiology, 5 general physicians, 171 radiologic technologists and 145 nurses. 81.4% and 20.2 % of operating physicians are using neck collar protector and goggle respectively. The average radiation dose was measured 0.46±0.15 mSv/10 hours fluoroscopy inside examination room in radiation protection facilities. Occupational radiation exposure data on the staff were assessed in interventional radiology procedures from 8 interventional radiology equipments of 6 university hospitals. The dose measurements were made by placing a thermoluminesent dosimeter(TLD) on various body surface of operation and assistant staff during actual interventional radiology. The measured points were the corner of the eyes, neck(on the thyroid) , wrists, chest(outside and inside of the protector), and back. Average radiation equivalent dose of the corner of left eye and left wrist of operating physicians were 1.19 mSv(0.11∼4.13 mSv)/100 minutes fluoroscopy and 4.32 mSv(0.16∼11.0 mSv)/100 minutes fluoroscopy respectively. Average exposure dose may vary depending on the type of procedure, personal skills and the quality of equipment. These results will be contributed to prepare the guide line in interventional radiology in Korea

  12. Community interventions for cardiovascular disease. (United States)

    Parker, Donna R; Assaf, Annlouise R


    Review of the community-based CVD intervention programs suggests that a number of components have been successful using varying methods and materials for CVD risk reduction. It should be noted, however, that in multi-intervention programs it is often difficult to determine which components of the intervention were responsible for the overall success of the study. The community-based approach to CVD prevention is generalizable, cost-effective (because of the use of mass communication methods), and has the potential for modifying the environment and influencing health policies. Based on the experiences and successes of a number of community projects, recommendations have been proposed for developing future programs. Although they are not totally comprehensive, it has been suggested that a community-based intervention program should consider the following recommendations: 1) An understanding of the community: the needs and priorities of the community should be assessed, and close collaboration with individuals from the community, including community leaders, opinion leaders, community health care providers, and community organizations from various sectors of the community, should be consulted. Efforts should be focused on underserved and vulnerable populations. 2) Inclusion of community activities: these activities should be integrated within the context of the community environment, including primary health care services, voluntary organizations, grocery stores, restaurants, work sites, schools, and local media. 3) Inclusion mass media messages: the mass media can provide information and reinforcement of the behavior change. 4) Develop cost-effective interventions to assure that the community is exposed to an effective dose of the intervention. 5) Work with community organizations to help change social and physical environments to make them more conducive to health and healthy life-styles changes. 6) Develop a reliable monitoring and evaluation system: monitor the

  13. Phase Engineering of Perovskite Materials for High-Efficiency Solar Cells: Rapid Conversion of CH3NH3PbI3 to Phase-Pure CH3NH3PbCl3 via Hydrochloric Acid Vapor Annealing Post-Treatment. (United States)

    Zhou, Weiran; Zhou, Pengcheng; Lei, Xunyong; Fang, Zhimin; Zhang, Mengmeng; Liu, Qing; Chen, Tao; Zeng, Hualing; Ding, Liming; Zhu, Jun; Dai, Songyuan; Yang, Shangfeng


    Organometal halide CH 3 NH 3 PbI 3 (MAPbI 3 ) has been commonly used as the light absorber layer of perovskite solar cells (PSCs), and, especially, another halide element chlorine (Cl) has been often incorporated to assist the crystallization of perovskite film. However, in most cases, a predominant MAPbI 3 phase with trace of Cl - is obtained ultimately and the role of Cl involvement remains unclear. Herein, we develop a low-cost and facile method, named hydrochloric acid vapor annealing (HAVA) post-treatment, and realize a rapid conversion of MAPbI 3 to phase-pure MAPbCl 3 , demonstrating a new concept of phase engineering of perovskite materials toward efficiency enhancement of PSCs for the first time. The average grain size of perovskite film after HAVA post-treatment increases remarkably through an Ostwald ripening process, leading to a denser and smoother perovskite film with reduced trap states and enhanced crystallinity. More importantly, the generation of MAPbCl 3 secondary phase via phase engineering is beneficial for improving the carrier mobility with a more balanced carrier transport rate and enlarging the band gap of perovskite film along with optimized energy level alignment. As a result, under the optimized HAVA post-treatment time (2 min), we achieved a significant enhancement of the power conversion efficiency (PCE) of the MAPbI 3 -based planar heterojunction-PSC device from 14.02 to 17.40% (the highest PCE reaches 18.45%) with greatly suppressed hysteresis of the current-voltage response.

  14. Endovascular interventional magnetic resonance imaging

    International Nuclear Information System (INIS)

    Bartels, L W; Bakker, C J G


    Minimally invasive interventional radiological procedures, such as balloon angioplasty, stent placement or coiling of aneurysms, play an increasingly important role in the treatment of patients suffering from vascular disease. The non-destructive nature of magnetic resonance imaging (MRI), its ability to combine the acquisition of high quality anatomical images and functional information, such as blood flow velocities, perfusion and diffusion, together with its inherent three dimensionality and tomographic imaging capacities, have been advocated as advantages of using the MRI technique for guidance of endovascular radiological interventions. Within this light, endovascular interventional MRI has emerged as an interesting and promising new branch of interventional radiology. In this review article, the authors will give an overview of the most important issues related to this field. In this context, we will focus on the prerequisites for endovascular interventional MRI to come to maturity. In particular, the various approaches for device tracking that were proposed will be discussed and categorized. Furthermore, dedicated MRI systems, safety and compatibility issues and promising applications that could become clinical practice in the future will be discussed. (topical review)

  15. Diagnostic interventions in nuclear medicine

    International Nuclear Information System (INIS)

    Thrall, J.H.; Swanson, D.P.


    Diagnostic interventions in nuclear medicine may be defined as the coadministration of a nonradioactive drug or application of a physical stimulus or physiologic maneuver to enhance the diagnostic utility of a nuclear medicine test. The rationale for each interventional maneuver follows from the physiology or metabolism of the particular organ or organ system under evaluation. Diagnostic inference is drawn from the pattern of change in the biodistribution of the tracer in response to the intervention-induced change in metabolism or function. In current practice, the most commonly performed interventional maneuvers are aimed at studies of the heart, genitourinary system, hepatobiliary system, and gastrointestinal tract. The single most commonly performed interventional study in the United States is the stress Thallium-201 myocardial perfusion scan aimed at the diagnosis of coronary artery disease. The stress portion of the study is accomplished with dynamic leg exercise on a treadmill and is aimed at increasing myocardial oxygen demands. Areas of myocardium distal to hemodynamically significant lesions in the coronary arteries become ischemic at peak stress due to the inability of the stenotic vessel to respond to the oxygen demand/blood flow needs of the myocardium. Ischemic areas are readily recognized as photopenic defects on scans obtained immediately after exercise, with normalization upon delayed imaging. Diuresis renography is aimed at the differential diagnosis of hydroureteronephrosis. By challenging the urinary tract collecting structures with an augmented urine flow, dilated, unobstructed systems can be differentiated from systems with significant mechanical obstruction. 137 references

  16. Computational radiology for orthopaedic interventions

    CERN Document Server

    Li, Shuo


    This book provides a cohesive overview of the current technological advances in computational radiology, and their applications in orthopaedic interventions. Contributed by the leading researchers in the field, this volume covers not only basic computational radiology techniques such as statistical shape modeling, CT/MRI segmentation, augmented reality and micro-CT image processing, but also the applications of these techniques to various orthopaedic interventional tasks. Details about following important state-of-the-art development are featured: 3D preoperative planning and patient-specific instrumentation for surgical treatment of long-bone deformities, computer assisted diagnosis and planning of periacetabular osteotomy and femoroacetabular impingement, 2D-3D reconstruction-based planning of total hip arthroplasty, image fusion for  computer-assisted bone tumor surgery, intra-operative three-dimensional imaging in fracture treatment, augmented reality based orthopaedic interventions and education, medica...

  17. Interventions for preoperative smoking cessation

    DEFF Research Database (Denmark)

    Thomsen, Thordis; Villebro, N.; Møller, Ann Merete


    Background Smokers have a substantially increased risk of postoperative complications. Preoperative smoking intervention may be effective in decreasing this incidence, and surgery may constitute a unique opportunity for smoking cessation interventions. Objectives The objective of this review...... was to assess the effect of preoperative smoking intervention on smoking cessation at the time of surgery and 12 months postoperatively and on the incidence of postoperative complications. Search strategy The specialized register of the Cochrane Tobacco Addiction Group was searched using the free text...... and keywords (surgery) or (operation) or (anaesthesia) or (anesthesia). MEDLINE, EMBASE and CINAHL were also searched, combining tobacco- and surgery-related terms. Most recent search April 2010. Selection criteria Randomized controlled trials that recruited people who smoked prior to surgery, offered...

  18. Equipment standards for interventional cardiology

    International Nuclear Information System (INIS)

    Dowling, A.; Gallagher, A.; Walsh, C.; Malone, J.


    Interventional radiology has seen rapid growth in cardiology and represents an alternative to hazardous surgery. Recently there has been a substantial growth in the number of procedures being performed and interventional cardiology (IC) procedures are the most common interventional procedures in Europe. Advances in imaging technology have facilitated the development of increasingly complex radiological IC equipment. Currently, the technology is developing at a rate ahead of supporting research, equipment standards and a regulatory framework. International standards play a key role in the design, manufacture and performance of radiological IC equipment. A survey of 12 IC systems (15 imaging chains) was conducted in Irish hospitals. The aim of the study was to assess the imbalance between rapidly advancing technology and existing standards and to propose recommendations for new IC equipment standards. The results demonstrate the need for definitive equipment requirements and standardisation in the design, manufacture, acceptance and maintenance of IC equipment. (authors)

  19. Psychosocial Interventions in Depressive Disorders

    Directory of Open Access Journals (Sweden)

    Ceyda Basogul


    Full Text Available In the last ten years, improvements in effective psychosocial interventions in the prevention and treatment of depression are remarkable. The World Health Organization stated that major depression affects children, adults and the elderly and is the leading cause of approximately 12% of all disabilities around the World. Medical expenses, loss of workforce, suicide risk, the risk of relapse or recurrence are taken into account, depression is an issue that needs to be handled with utmost care for health care workers especially psychiatric nurses. The purpose of this literature review is to examine psychosocial interventions and effectiveness of these interventions for depressive disorders shows a gradual increase in prevalence in worlwide. [Psikiyatride Guncel Yaklasimlar - Current Approaches in Psychiatry 2015; 7(1: 1-15

  20. [Radiation protection in interventional radiology]. (United States)

    Adamus, R; Loose, R; Wucherer, M; Uder, M; Galster, M


    The application of ionizing radiation in medicine seems to be a safe procedure for patients as well as for occupational exposition to personnel. The developments in interventional radiology with fluoroscopy and dose-intensive interventions require intensified radiation protection. It is recommended that all available tools should be used for this purpose. Besides the options for instruments, x‑ray protection at the intervention table must be intensively practiced with lead aprons and mounted lead glass. A special focus on eye protection to prevent cataracts is also recommended. The development of cataracts might no longer be deterministic, as confirmed by new data; therefore, the International Commission on Radiological Protection (ICRP) has lowered the threshold dose value for eyes from 150 mSv/year to 20 mSv/year. Measurements show that the new values can be achieved by applying all X‑ray protection measures plus lead-containing eyeglasses.

  1. Impact evaluation of infrastructure interventions

    DEFF Research Database (Denmark)

    Hansen, Henrik; Andersen, Ole Winckler; White, Howard


    in this volume. Understanding impact means understanding the context in which an intervention takes place and the channels through which the impact on outcomes is expected to occur. Such analysis typically requires mixing both quantitative and qualitative approaches. The analysis will also anticipate......The focus on results in development agencies has led to increased focus on impact evaluation to demonstrate the effectiveness of development programmes. A range of methods are available for counterfactual analysis of infrastructure interventions, as illustrated by the variety of papers...

  2. Improving evaluation of obstetric interventions

    NARCIS (Netherlands)

    van 't Hooft, J.


    In most pregnancies the synergy between mother and her unborn child is adequately balanced, resulting in the birth of the baby at the end of an uncomplicated pregnancy. Unfortunately, not all pregnancies and deliveries remain in such optimal balance. Many new and existing interventions can be

  3. Early Childhood Intervention in China (United States)

    Zheng, Yuzhu; Maude, Susan P.; Brotherson, Mary Jane


    With rapid economic development and increasing awareness of the importance of early childhood intervention (ECI), China is re-examining its social and educational practices for young children with disabilities. This re-examination may have a significant impact on young children with disabilities in China. It may also set an example for other…

  4. Imaging in percutaneous musculoskeletal interventions

    International Nuclear Information System (INIS)

    Gangi, Afshin; Guth, Stephane; Guermazi, Ali


    This is one of the first books to deal specifically with imaging in percutaneous musculoskeletal interventions. The use of different imaging modalities during these procedures is well described. In the first chapter, the basic procedures and different guidance techniques are presented and discussed. The ensuing chapters describe in exhaustive detail the abilities and uses of imaging in guiding procedures ranging from biopsy and joint injection to management of pain and tumors. These procedures are extensively documented in adults as well as in the pediatric population. The third part of the book describes the different indications for vascular interventions in musculoskeletal lesions. The final chapter focuses on ultrasound-guided interventions, as they are more common and tend to be fashionable. The book is well illustrated with carefully chosen and technically excellent images. Each of the 18 chapters is written by an expert of international repute, making this book the most current and complete treatment of the subject available. It should be of great interest to interventional radiologists and also musculoskeletal and general radiologists. (orig.)

  5. Neighborhood Interventions to Reduce Violence (United States)

    Michelle C. Kondo; Elena Andreyeva; Eugenia C. South; John M. MacDonald; Charles C. Branas


    Violence is a widespread problem that affects the physical, mental, and social health of individuals and communities. Violence comes with an immense economic cost to its victims and society at large. Although violence interventions have traditionally targeted individuals, changes to the built environment in places where violence occurs show promise as practical,...

  6. Exercise as a Counseling Intervention. (United States)

    Okonski, Verna O.


    The focus of wellness counseling is to guide individuals to live a healthy life in which body, mind, and spirit are integrated in order to experience fulfillment and happiness. The purpose of this article is to provide counselors steps to follow when using exercise as a counseling intervention and to provide techniques that will encourage exercise…

  7. Music interventions for dental anxiety. (United States)

    Bradt, J; Teague, A


    Anxiety is a significant issue in the dental care of adults and children. Dental anxiety often leads to avoidance of dental care which may result in significant deterioration of oral and dental health. Non-pharmacological anxiety management interventions such as music listening are increasingly used in dental care. Although efficacy for music's anxiolytic effects has been established for pre-operative anxiety, findings regarding the use of music listening for dental anxiety are inconclusive, especially for children. The use of music for passive distraction may not be adequate for children and highly anxious adults. Instead, interventions offered by a trained music therapist may be needed to optimize music's anxiolytic impact. Music therapy interventions are individualized to the patient's presenting needs and geared at enhancing patients' active engagement in the management of their anxiety. Interventions may include (i) active refocusing of attention, (ii) music-guided deep breathing, (iii) music-assisted relaxation, and (iv) music-guided imagery. In addition, music therapists can teach patients music-based anxiety management skills prior to dental treatments, offer them the opportunity to express emotions related to the upcoming procedure, and help them gain a sense of control and safety. Clinical guidelines for the use of music listening by dental practitioners are offered. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. Diagnoses and interventions in podiatry.

    NARCIS (Netherlands)

    Zuijderduin, W.M.; Dekker, J.


    In the present study a quantitative description is given of diagnoses and interventions in podiatry. Data are used from a survey on podiatry practice in The Netherlands. Data have been recorded by 36 podiatrists on 897 patients. Information was gathered on patient characteristics, the medical



    Schaeken Willemaers, Gaëtane


    This article wishes to contribute to the debate on how to best regulate the European retail financial market. This article is a reflection on the recent emphasis put by the European regulator on product intervention to address the various risks facing the retail investor.

  10. Brain aging and therapeutic interventions

    DEFF Research Database (Denmark)

    This book brings together most up-to-date information on different aspects of brain aging and on the strategies for intervention and therapy of age-related brain disorders. It includes 18 chapters by leading researchers, and each chapter is a comprehensive and critical review of the topic...

  11. Towards Behaviorally Informed Public Interventions

    Directory of Open Access Journals (Sweden)

    Karol Olejniczak


    Full Text Available Purpose: This article informs readers about the theoretical and practical origins of the behaviorally informed interventions (BIPI, analyzes examples of the BIPI from different policy sectors and strategies they offer for policy and regulatory design, and discusses applications and implications of BIPI for public interventions Methodology: This paper is based on a review of literature, as well as an inspection of administrative practices in OECD countries. It encompasses a systematic analysis of scientific papers fromthe SCOPUS database and a query carried out at the library of George Washington University. Findings: The traditional approach to public policy research is based on rational choice theory. It offers limited support, because by assuming perfect rationality of policy decisions, it overlooks existence of systematic errors and biases of human decision-making. The authors argue that behaviorally informed public interventions (BIPI might contribute to improving the effectiveness of a number of public measures – regulation, projects, programs, and even entire policies. Practical implications: The behavioral approach allows decision-makers to better understand the decisions and behaviors of citizens, as well as to design more effective interventions with minimum effort by adapting the existing solutions to real decision mechanisms of citizens. Originality: By combining the concepts of traditional approach with the growing behavioral approach, the authors aim to propose a new theoretical framework (BIPI to be used as a tool for policy design, delivery and evaluation.

  12. Humanitarian Crises, Intervention and Security

    NARCIS (Netherlands)

    Heyse, Liesbet; Zwitter, Andrej; Wittek, Rafael; Herman, Joost


    This book presents a new framework of analysis to assess natural and man-made disasters and humanitarian crises, and the feasibility of interventions in these complex emergencies. The past half-century has witnessed a dramatic increase in such crises – such as in Haiti, Iraq and Sudan – and this

  13. [Quality assurance in interventional cardiology]. (United States)

    Gülker, H


    Quality assurance in clinical studies aiming at approval of pharmaceutical products is submitted to strict rules, controls and auditing regulations. Comparative instruments to ensure quality in diagnostic and therapeutic procedures are not available in interventional cardiology, likewise in other fields of cardiovascular medicine. Quality assurance simply consists of "quality registers" with basic data not externally controlled. Based on the experiences of clinical studies and their long history of standardization it is assumed that these data may be severely flawed thus being inappropriate to set standards for diagnostic and therapeutic strategies. The precondition for quality assurance are quality data. In invasive coronary angiography and intervention medical indications, the decision making process interventional versus surgical revascularization, technical performance and after - care are essential aspects affecting quality of diagnostics and therapy. Quality data are externally controlled data. To collect quality data an appropriate infrastructure is a necessary precondition which is not existent. For an appropriate infrastructure investments have to be done both to build up as well as to sustain the necessary preconditions. As long as there are no infrastructure and no investments there will be no "quality data". There exist simply registers of data which are not proved to be a basis for significant assurance and enhancement in quality in interventional coronary cardiology. Georg Thieme Verlag KG Stuttgart, New York.

  14. Reducing stillbirths: interventions during labour (United States)

    Darmstadt, Gary L; Yakoob, Mohammad Yawar; Haws, Rachel A; Menezes, Esme V; Soomro, Tanya; Bhutta, Zulfiqar A


    Background Approximately one million stillbirths occur annually during labour; most of these stillbirths occur in low and middle-income countries and are associated with absent, inadequate, or delayed obstetric care. The low proportion of intrapartum stillbirths in high-income countries suggests that intrapartum stillbirths are largely preventable with quality intrapartum care, including prompt recognition and management of intrapartum complications. The evidence for impact of intrapartum interventions on stillbirth and perinatal mortality outcomes has not yet been systematically examined. Methods We undertook a systematic review of the published literature, searching PubMed and the Cochrane Library, of trials and reviews (N = 230) that reported stillbirth or perinatal mortality outcomes for eight interventions delivered during labour. Where eligible randomised controlled trials had been published after the most recent Cochrane review on any given intervention, we incorporated these new trial findings into a new meta-analysis with the Cochrane included studies. Results We found a paucity of studies reporting statistically significant evidence of impact on perinatal mortality, especially on stillbirths. Available evidence suggests that operative delivery, especially Caesarean section, contributes to decreased stillbirth rates. Induction of labour rather than expectant management in post-term pregnancies showed strong evidence of impact, though there was not enough evidence to suggest superior safety for the fetus of any given drug or drugs for induction of labour. Planned Caesarean section for term breech presentation has been shown in a large randomised trial to reduce stillbirths, but the feasibility and consequences of implementing this intervention routinely in low-/middle-income countries add caveats to recommending its use. Magnesium sulphate for pre-eclampsia and eclampsia is effective in preventing eclamptic seizures, but studies have not demonstrated impact

  15. Supporting Families through Early Intervention

    Directory of Open Access Journals (Sweden)

    Roy McConkey


    Full Text Available Internationally early intervention programmes for infants and preschoolers with disabilities have proved to be remarkably successful. In many countries, they began with teachers for visually impaired or hearing impaired children visiting the family home to teach parents how they could overcome the child's impairments. The logic of early intervention was inequitable. For example, the sooner children with visual impairments learnt to be independently mobile, then the greater their potential to learn and to kad an ordinary life. In time, this philosophy was extended to children with neurological and developmental delays, such as mental retardation, although success could be variable. In part, many different factors contributed to this variability: the form the interventions took, the extent of family involvement in the intervention and the lack of sensitivity of the measures used to assess a child's progress, to name but three. Perhaps the most extensive and intensive Early intervention schemes have been in the United States with their Head Start programmes. They were aimed at promoting the educational potential of preschoolers from deprived socio - economic backgrounds. Although the first phase of programmes had varying success, those in the second phase yielded impressive results which were mainly attributed to a greater focus on parental participation and links forged with the school system. Recently in developing countries, priority has been given to establishing early intervention as a means of creating new styles of family-based and community-based service in these countries in contrast to the hospital or institutional-services that were a legacy from a previous generation. Although formal evaluations are largely lacking, informal reports have been broadly enthusiastic. In sum, early intervention is no longer a new approach to developmental disabilities. It is an approach of proven effectiveness with children who have different impairments

  16. Early Intervention in Bipolar Disorder. (United States)

    Vieta, Eduard; Salagre, Estela; Grande, Iria; Carvalho, André F; Fernandes, Brisa S; Berk, Michael; Birmaher, Boris; Tohen, Mauricio; Suppes, Trisha


    Bipolar disorder is a recurrent disorder that affects more than 1% of the world population and usually has its onset during youth. Its chronic course is associated with high rates of morbidity and mortality, making bipolar disorder one of the main causes of disability among young and working-age people. The implementation of early intervention strategies may help to change the outcome of the illness and avert potentially irreversible harm to patients with bipolar disorder, as early phases may be more responsive to treatment and may need less aggressive therapies. Early intervention in bipolar disorder is gaining momentum. Current evidence emerging from longitudinal studies indicates that parental early-onset bipolar disorder is the most consistent risk factor for bipolar disorder. Longitudinal studies also indicate that a full-blown manic episode is often preceded by a variety of prodromal symptoms, particularly subsyndromal manic symptoms, therefore supporting the existence of an at-risk state in bipolar disorder that could be targeted through early intervention. There are also identifiable risk factors that influence the course of bipolar disorder, some of them potentially modifiable. Valid biomarkers or diagnosis tools to help clinicians identify individuals at high risk of conversion to bipolar disorder are still lacking, although there are some promising early results. Pending more solid evidence on the best treatment strategy in early phases of bipolar disorder, physicians should carefully weigh the risks and benefits of each intervention. Further studies will provide the evidence needed to finish shaping the concept of early intervention. AJP AT 175 Remembering Our Past As We Envision Our Future April 1925: Interpretations of Manic-Depressive Phases Earl Bond and G.E. Partridge reviewed a number of patients with manic-depressive illness in search of a unifying endo-psychic conflict. They concluded that understanding either phase of illness was "elusive" and

  17. Interventions for paracetamol (acetaminophen) overdose. (United States)

    Chiew, Angela L; Gluud, Christian; Brok, Jesper; Buckley, Nick A


    Paracetamol (acetaminophen) is the most widely used non-prescription analgesic in the world. Paracetamol is commonly taken in overdose either deliberately or unintentionally. In high-income countries, paracetamol toxicity is a common cause of acute liver injury. There are various interventions to treat paracetamol poisoning, depending on the clinical status of the person. These interventions include inhibiting the absorption of paracetamol from the gastrointestinal tract (decontamination), removal of paracetamol from the vascular system, and antidotes to prevent the formation of, or to detoxify, metabolites. To assess the benefits and harms of interventions for paracetamol overdosage irrespective of the cause of the overdose. We searched The Cochrane Hepato-Biliary Group Controlled Trials Register (January 2017), CENTRAL (2016, Issue 11), MEDLINE (1946 to January 2017), Embase (1974 to January 2017), and Science Citation Index Expanded (1900 to January 2017). We also searched the World Health Organization International Clinical Trials Registry Platform and database (US National Institute of Health) for any ongoing or completed trials (January 2017). We examined the reference lists of relevant papers identified by the search and other published reviews. Randomised clinical trials assessing benefits and harms of interventions in people who have ingested a paracetamol overdose. The interventions could have been gastric lavage, ipecacuanha, or activated charcoal, or various extracorporeal treatments, or antidotes. The interventions could have been compared with placebo, no intervention, or to each other in differing regimens. Two review authors independently extracted data from the included trials. We used fixed-effect and random-effects Peto odds ratios (OR) with 95% confidence intervals (CI) for analysis of the review outcomes. We used the Cochrane 'Risk of bias' tool to assess the risks of bias (i.e. systematic errors leading to overestimation of

  18. Radiological protection in interventional radiology

    International Nuclear Information System (INIS)

    Padovani, R.


    Interventional radiology (IR) reduces the need for many traditional interventions, particularly surgery, so reducing the discomfort and risk for patients compared with traditional systems. IR procedures are frequently performed by non-radiologist physicians, often without the proper radiological equipment and sufficient knowledge of radiation protection. Levels of doses to patients and staff in IR vary enormously. A poor correlation exists between patient and staff dose, and large variations of dose are reported for the same procedure. The occurrence of deterministic effects in patients is another peculiar aspect of IR owing to the potentially high skin doses of some procedures. The paper reviews the use of IR and the radiological protection of patients and staff, and examines the need for new standards for IR equipment and the training of personnel. (author)

  19. Interventions for paracetamol (acetaminophen) overdose

    DEFF Research Database (Denmark)

    Chiew, Angela L; Gluud, Christian; Brok, Jesper


    BACKGROUND: Paracetamol (acetaminophen) is the most widely used non-prescription analgesic in the world. Paracetamol is commonly taken in overdose either deliberately or unintentionally. In high-income countries, paracetamol toxicity is a common cause of acute liver injury. There are various...... of paracetamol. Acetylcysteine should be given to people at risk of toxicity including people presenting with liver failure. Further randomised clinical trials with low risk of bias and adequate number of participants are required to determine which regimen results in the fewest adverse effects with the best...... was abandoned due to low numbers recruited), assessing several different interventions in 700 participants. The variety of interventions studied included decontamination, extracorporeal measures, and antidotes to detoxify paracetamol's toxic metabolite; which included methionine, cysteamine, dimercaprol...

  20. Interventions for preoperative smoking cessation

    DEFF Research Database (Denmark)

    Thomsen, Thordis; Villebro, Nete; Møller, Ann Merete


    a smoking cessation intervention, and measured preoperative and long-term abstinence from smoking and/or the incidence of postoperative complications. Data collection and analysis The authors independently assessed studies to determine eligibility. Results were discussed between the authors. Main results...... Eight trials enrolling a total of 1156 people met the inclusion criteria. One of these did not report cessation as an outcome. Two trials initiated multisession face to face counselling at least 6 weeks before surgery whilst six used a brief intervention. Nicotine replacement therapy (NRT) was offered......; pooled RR 10.76 (95% confidence interval (CI) 4.55 to 25.46, two trials) and RR 1.41 (95% CI 1.22 to 1.63, five trials) respectively. Four trials evaluating the effect on long-term smoking cessation found a significant effect; pooled RR 1.61 (95% CI 1.12 to 2.33). However, when pooling intensive...

  1. Psychosocial interventions for premature ejaculation

    Directory of Open Access Journals (Sweden)

    Tamara Melnik

    Full Text Available BACKGROUND: Premature ejaculation (PE is a very common sexual dysfunction among patients, and with varying prevalence estimates ranging from 3% to 20%. Although psychological issues are present in most patients with premature PE, as a cause or as a consequence, research on the effects of psychological approaches for PE has in general not been controlled or randomised and is lacking in long-term follow up. OBJECTIVE: To assess the efficacy of psychosocial interventions for PE. CRITERIA FOR CONSIDERING STUDIES FOR THIS REVIEW: Trials were searched in computerized general and specialized databases, such as: MEDLINE by PubMed (1966 to 2010; PsycINFO (1974 to 2010; EMBASE (1980 to 2010; LILACS (1982 to 2010; the Cochrane Central Register of Controlled Trials (Cochrane Library, 2010; and by checking bibliographies, and contacting manufacturers and researchers. SELECTION CRITERIA: Randomised or quasi-randomised controlled trials evaluating psychosocial interventions compared with different psychosocial interventions, pharmacological interventions, waiting list, or no treatment for PE. DATA COLLECTION AND ANALYSIS: Information on patients, interventions, and outcomes was extracted by at least two independent reviewers using a standard form. The primary outcome measure for comparing the effects of psychosocial interventions to waiting list and standard medications was improvement in IELT (i.e., time from vaginal penetration to ejaculation. The secondary outcome was change in validated PE questionnaires. MAIN RESULTS: In one study behavioral therapy (BT was significantly better than waiting list for duration of intercourse (MD (mean difference 407.90 seconds, 95% CI 302.42 to 513.38, and couples' sexual satisfaction (MD -26.10, CI -50.48 to -1.72. BT was also significantly better for a new functional-sexological treatment (FS (MD 412.00 seconds, 95% CI 305.88 to 518.12, change over time in subjective perception of duration of intercourse (Women: MD 2

  2. Risk reduction: perioperative smoking intervention

    DEFF Research Database (Denmark)

    Møller, Ann; Tønnesen, Hanne


    Smoking is a well-known risk factor for perioperative complications. Smokers experience an increased incidence of respiratory complications during anaesthesia and an increased risk of postoperative cardiopulmonary complications, infections and impaired wound healing. Smokers have a greater risk...... of postoperative intensive care admission. Even passive smoking is associated with increased risk at operation. Preoperative smoking intervention 6-8 weeks before surgery can reduce the complications risk significantly. Four weeks of abstinence from smoking seems to improve wound healing. An intensive, individual...... approach to smoking intervention results in a significantly better postoperative outcome. Future research should focus upon the effect of a shorter period of preoperative smoking cessation. All smokers admitted for surgery should be informed of the increased risk, recommended preoperative smoking cessation...

  3. Coastal Hazards Impacts And Interventions

    Directory of Open Access Journals (Sweden)

    Rosanna D. Gonzales


    Full Text Available Communitys participation in the activities like the preparation and creation of historical timeline. resource and hazard mapping as well as vulnerability assessment matrix VAM are effective tools in determining hazards impacts and interventions of a certain locality. The most common hazards are typhoons saltwater intrusion floods and drought. Data were collected through focus group discussions FGDs from respondents along coastal areas. Findings revealed that natural calamities had great impact to livelihood properties and health. The damaged business operations fishing and agricultural livelihood led to loss of income likewise the sources of water were also contaminated. Planned interventions include launching of periodic education and awareness program creation of evacuation centers and relocation sites rescue centers installation of deep well water pumps and irrigation systems solid waste management drainage and sea walls construction canal rehabilitationdredging tree planting and alternative livelihood programs.

  4. Microdialysis technique and interventional radiology

    International Nuclear Information System (INIS)

    An Xiao; Xiao Xiangsheng


    Basic research in interventional radiology, including transcatheter artery perfusion especially, is progressing slowly due to lack of proper method. Microdialysis technique, a kind of accurate sampling technique in vivo, may help to solve the problem. Just as its name implies, microdialysis means tiny dialysis with advantages of authenticity, exactness and less error. Furthermore it has been applied widely and should be received with great attention and popularity. (authors)

  5. Intervention model in organizational climate


    Cárdenas Niño, Lucila; Universidad Pedagógica y Tecnológica de Colombia, Facultad de Ciencias de la Salud, Escuela de Psicología, Hospital Antiguo, Carrera 10 No 16ª05; Arciniegas Rodríguez, Yuly Cristina; Universidad Pedagógica y Tecnológica de Colombia, Facultad de Ciencias de la Salud, Escuela de Psicología, Hospital Antiguo, Carrera 10 No 16ª05; Barrera Cárdenas, Mónica; Universidad Pedagógica y Tecnológica de Colombia, Facultad de Ciencias de la Salud, Escuela de Psicología, Hospital Antiguo, Carrera 10 No 16ª05


    The aim of this study was to assess whether the intervention model in organizational climate PMCO, was effective in the Hospital of Yopal, Colombia. The following five phases, proposed by the model, were implemented: 1) problem analysis, 2) awareness, 3) strategies design and planning, at the individual, intergroup, and organizational levels, 4) implementation of the strategy, and 5) process evaluation. A design composed of two groups, experimental and control, was chosen, analyzing whether t...

  6. Internet Interventions for Hearing Loss. (United States)

    Thorén, Elisabet Sundewall; Öberg, Marie; Andersson, Gerhard; Lunner, Thomas


    The purpose of the two studies presented in this research forum article was to develop audiological rehabilitation programs for experienced hearing aid users and evaluate them in online versions. In this research forum article, the differences between the two studies are discussed. Two randomized controlled trials (RCTs) were performed evaluating the efficacy of online rehabilitation, including professional guidance by an audiologist. In each RCT, the effects of the online programs were compared with the effects measured in a control group. The results from the first RCT showed a significant increase in activity and participation for both groups with participants in the intervention group improving more than those in the control group. At the 6-month follow-up, after the study, the significant increase was maintained; however, amounts of increase in the two groups were no longer significantly different. The results from the second RCT showed significant increase in activity and participation for the intervention group, although the control group did not improve. The results from the RCTs provide evidence that the Internet can be used to deliver rehabilitation to hearing-aid users and that their problems are reduced by the intervention; however, the content of the online rehabilitation program requires further investigation.

  7. Interventions in Infrainguinal Bypass Grafts

    International Nuclear Information System (INIS)

    Mueller-Huelsbeck, S.; Order, B.-M.; Jahnke, T.


    The interventional radiologist plays an important role in the detection and prevention of infrainguinal bypass failure. Early detection and evaluation of flow-limiting lesions effectively preserve graft (venous bypass and polyester or expanded polytetrafluoroethylene bypass) patency by identifying stenoses before occlusion occurs. Delay in treatment of the at-risk graft may result in graft failure and a reduced chance of successful revascularization. For this reason, surveillance protocols form an important part of follow-up after infrainguinal bypass surgery. As well as having an understanding of the application of imaging techniques including ultrasound, MR angiography, CT angiography and digital subtraction angiography, the interventional radiologist should have detailed knowledge of the minimally invasive therapeutic options. Percutaneous transluminal angioplasty (PTA), or alternatively cutting balloon angioplasty, is the interventional treatment of choice in prevention of graft failure and occlusion. Further alternatives include metallic stent placement, fibrinolysis, and mechanical thrombectomy. Primary assisted patency rates following PTA can be up to 65% at 5 years. When the endovascular approach is unsuccessful, these therapeutic options are complemented by surgical procedures including vein patch revision, jump grafting, or placement of a new graft

  8. Interventions for heartburn in pregnancy. (United States)

    Phupong, Vorapong; Hanprasertpong, Tharangrut


    Heartburn is one of the most common gastrointestinal symptoms in pregnant women. It can occur in all trimesters of pregnancy. The symptoms of heartburn in pregnancy may be frequent, severe and distressing, but serious complications are rare. Many interventions have been used for the treatment of heartburn in pregnancy. These interventions include advice on diet, lifestyle modification and medications. However, there has been no evidence-based recommendation for the treatment of heartburn in pregnancy. To assess the effects of interventions for relieving heartburn in pregnancy. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 June 2015), (2 March 2015), Asian & Oceanic Congress of Obstetrics & Gynaecology (AOCOG) conference proceedings (20-23 October 2013, Centara Grand & Bangkok Convention Centre, Bangkok, Thailand), and reference lists of retrieved studies. Randomised controlled trials (RCTs) and quasi-RCTS of interventions for heartburn in pregnancy compared with another intervention, or placebo, or no intervention. Cluster-RCTs would have been eligible for inclusion but none were identified. We excluded studies available as abstracts only and those using a cross-over design.Interventions could include advice on diet, lifestyle modification and medications (such as antacids, sucralfate, histamine 2-receptor antagonists, promotility drugs and proton pump inhibitors (PPIs)). Two review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy. We included nine RCTs involving 725 women. However, five trials did not contribute data. Four trials involving 358 women contributed data. Trials were generally at mixed risk of bias.We only identified data for three comparisons: pharmaceutical treatment versus placebo or no treatment; acupuncture versus no treatment and pharmacological intervention versus advice on dietary and lifestyle changes. Pharmaceutical treatment

  9. Image guided percutaneous splenic interventions

    International Nuclear Information System (INIS)

    Kang, Mandeep; Kalra, Naveen; Gulati, Madhu; Lal, Anupam; Kochhar, Rohit; Rajwanshi, Arvind


    Aim: The objective of this study is to evaluate the efficacy and safety of image-guided percutaneous splenic interventions as diagnostic or therapeutic procedures. Materials and methods: We performed a retrospective review of our interventional records from July 2001 to June 2006. Ninety-five image-guided percutaneous splenic interventions were performed after informed consent in 89 patients: 64 men and 25 women who ranged in age from 5 months to 71 years (mean, 38.4 years) under ultrasound (n = 93) or CT (n = 2) guidance. The procedures performed were fine needle aspiration biopsy of focal splenic lesions (n = 78) and aspiration (n = 10) or percutaneous catheter drainage of a splenic abscess (n = 7). Results: Splenic fine needle aspiration biopsy was successful in 62 (83.78%) of 74 patients with benign lesions diagnosed in 43 (58.1%) and malignancy in 19 (25.67%) patients. The most common pathologies included tuberculosis (26 patients, 35.13%) and lymphoma (14 patients, 18.91%). Therapeutic aspiration or pigtail catheter drainage was successful in all (100%) patients. There were no major complications. Conclusions: Image-guided splenic fine needle aspiration biopsy is a safe and accurate technique that can provide a definitive diagnosis in most patients with focal lesions in the spleen. This study also suggests that image-guided percutaneous aspiration or catheter drainage of splenic abscesses is a safe and effective alternative to surgery

  10. International harmonization of intervention levels

    International Nuclear Information System (INIS)

    Jensen, P.H.


    A summary is given on international guidance on intervention levels in circumstances in which remedial actions might be considered in nuclear accident situations. The nature and limitations of international work and their effect on the resulting guidance are discussed. The basic international principles recommended can be expressed in the following compressed form: (1) serious deterministic effects should be avoided by intervention, (2) each protective measure should be justified, i.e. do more good than harm, (3) the level at which the protective measures are to be introduced should be optimized, i.e. do most good, and (4) each protective measure should be optimized separately and independent of all other countermeasures. It is of great importance that decision makers inform the public of all aspects of their decisions in order to make the decisions transparent, especially when the interventions chosen are mainly for political or social reason rather than health protection grounds. Otherwise the public may be misled and the radiological protection community will be mistrusted. 17 refs., 6 tabs

  11. Adaptive intervention design in mobile health: Intervention design and development in the Cell Phone Intervention for You trial. (United States)

    Lin, Pao-Hwa; Intille, Stephen; Bennett, Gary; Bosworth, Hayden B; Corsino, Leonor; Voils, Corrine; Grambow, Steven; Lazenka, Tony; Batch, Bryan C; Tyson, Crystal; Svetkey, Laura P


    The obesity epidemic has spread to young adults, and obesity is a significant risk factor for cardiovascular disease. The prominence and increasing functionality of mobile phones may provide an opportunity to deliver longitudinal and scalable weight management interventions in young adults. The aim of this article is to describe the design and development of the intervention tested in the Cell Phone Intervention for You study and to highlight the importance of adaptive intervention design that made it possible. The Cell Phone Intervention for You study was a National Heart, Lung, and Blood Institute-sponsored, controlled, 24-month randomized clinical trial comparing two active interventions to a usual-care control group. Participants were 365 overweight or obese (body mass index≥25 kg/m2) young adults. Both active interventions were designed based on social cognitive theory and incorporated techniques for behavioral self-management and motivational enhancement. Initial intervention development occurred during a 1-year formative phase utilizing focus groups and iterative, participatory design. During the intervention testing, adaptive intervention design, where an intervention is updated or extended throughout a trial while assuring the delivery of exactly the same intervention to each cohort, was employed. The adaptive intervention design strategy distributed technical work and allowed introduction of novel components in phases intended to help promote and sustain participant engagement. Adaptive intervention design was made possible by exploiting the mobile phone's remote data capabilities so that adoption of particular application components could be continuously monitored and components subsequently added or updated remotely. The cell phone intervention was delivered almost entirely via cell phone and was always-present, proactive, and interactive-providing passive and active reminders, frequent opportunities for knowledge dissemination, and multiple tools

  12. Specificity of the Best Possible Self intervention for increasing optimism: Comparison with a gratitude intervention


    Peters, Madelon L; Meevissen, Yvo M. C; Hanssen, Marjolein M


    The present study compared the effects of a one week best possible self intervention and a one week gratitude intervention on life satisfaction and optimism. We hypothesized that both interventions would lead to similar increases in life satisfaction, but that only the best possible self intervention would increase optimism. The results partly confirmed the hypotheses: only the best possible self intervention led to increased optimism immediately after the intervention period, which further i...

  13. White Paper: Curriculum in Interventional Radiology. (United States)

    Mahnken, Andreas H; Bücker, Arno; Hohl, Christian; Berlis, Ansgar


    Purpose  Scope and clinical importance of interventional radiology markedly evolved over the last decades. Consequently it was acknowledged as independent subspecialty by the "European Union of Medical Specialists" (UEMS). Based on radiological imaging techniques Interventional Radiology is an integral part of Radiology. Materials und Methods  In 2009 the German Society for Interventional Radiology and minimally-invasive therapy (DeGIR) developed a structured training in Interventional Radiology. In cooperation with the German Society of Neuroradiology (DGNR) this training was extended to also cover Interventional Neuroradiology in 2012. Tailored for this training in Interventional Radiology a structured curriculum was developed, covering the scope of this modular training. Results  The curriculum is based on the DeGIR/DGNR modular training concept in Interventional Radiology. There is also an European Curriculum and Syllabus for Interventional Radiology developed by the "Cardiovascular and Interventional Radiological Society of Europe" (CIRSE). The presented curriculum in Interventional Radiology is designed to provide a uniform base for the training in Interventional Radiology in Germany, based on the competencies obtained during residency. Conclusion  This curriculum can be used as a basis for training in Interventional Radiology by all training sites. Key Points: · Interventional Radiology is an integral part of clinical radiology. · The German Society for Interventional Radiology and minimally-invasive therapy (DeGIR) developed a curriculum in Interventional Radiology. · This curriculum is an integrative basis for the training in interventional. Citation Format · Mahnken AH, Bücker A, Hohl C et al. White Paper: Curriculum in Interventional Radiology. Fortschr Röntgenstr 2017; 189: 309 - 311. © Georg Thieme Verlag KG Stuttgart · New York.

  14. Extremity doses to interventional radiologists

    International Nuclear Information System (INIS)

    Wihtby, M.; Martin, C. J.


    Radiologists performing interventional procedures are often required to stand close to the patient's side when carrying out manipulations under fluoroscopic control. This can result in their extremities receiving a high radiation dose, due to scattered radiation. These doses are sometimes high enough to warrant that the radiologist in question be designated a classified radiation worker. Classification in the UK is a result of any worker receiving or likely to receive in the course of their duties in excess of 3/10ths of any annual dose limit (500mSv to extremities, skin). The doses to the legs of radiologists have received less attention than those to the hands, however the doses may be high, due to the proximity of the legs and feet to scattered radiation. The legs can be exposed to a relatively high level of scattered radiation as the radiation in produced from scatter of the un attenuated beam from the bottom of the patient couch. The routine monitoring of extremity doses in interventional radiology is difficult due to several factors. Firstly a wide range of interventional procedures in undertaken in every radiology department, and these procedures require many different techniques, equipment and skills. This means that the position the radiologist adopts in relation to scattering medium and therefore their exposure, depends heavily on the type of procedure. As the hands which manipulate the catheters within the patient are often located close to the patients side and to the area under irradiation, the distribution of dose across the hands can be variable, with very high localised doses, making routine monitoring difficult. The purpose of this study was to determine the magnitude and distribution of dose to the hands and legs of interventional radiologists carrying out a wide range of both diagnostic and therapeutic interventional procedures. To ascertain the most effective method of monitoring the highest dose in accordance with the Basic safety standards

  15. Intervention: Help a Loved One Overcome Addiction (United States)

    Intervention: Help a loved one overcome addiction An intervention can motivate someone to seek help for alcohol or drug misuse, compulsive eating, or ... successful. By Mayo Clinic Staff It's challenging to help a loved one struggling with any type of ...

  16. Latin American foreign exchange intervention - Updated


    Da Silva, Sergio; Nunes, Mauricio


    We examine Latin American foreign exchange intervention in a framework where the exchange rate regime is endogenous and there exists an inefficient, equilibrium foreign exchange intervention bias. The model suggests that greater central bank independence is associated with lesser intervention in the foreign exchange market, and also with leaning-against-the-wind intervention. Both results are confirmed by data from 13 Latin American countries.

  17. Exercise interventions for smoking cessation. (United States)

    Ussher, Michael H; Taylor, Adrian H; Faulkner, Guy E J


    Taking regular exercise may help people give up smoking by moderating nicotine withdrawal and cravings, and by helping to manage weight gain. To determine whether exercise-based interventions alone, or combined with a smoking cessation programme, are more effective than a smoking cessation intervention alone. We searched the Cochrane Tobacco Addiction Group Specialized Register in April 2014, and searched MEDLINE, EMBASE, PsycINFO, and CINAHL Plus in May 2014. We included randomized trials which compared an exercise programme alone, or an exercise programme as an adjunct to a cessation programme, with a cessation programme (which we considered the control in this review). Studies were required to recruit smokers or recent quitters and have a follow-up of six months or more. Studies that did not meet the full inclusion criteria because they only assessed the acute effects of exercise on smoking behaviour, or because the outcome was smoking reduction, are summarised but not formally included. We extracted data on study characteristics and smoking outcomes. Because of differences between studies in the characteristics of the interventions used we summarized the results narratively, making no attempt at meta-analysis. We assessed risk of selection and attrition bias using standard methodological procedures expected by The Cochrane Collaboration. We identified 20 trials with a total of 5,870 participants. The largest study was an internet trial with 2,318 participants, and eight trials had fewer than 30 people in each treatment arm. Studies varied in the timing and intensity of the smoking cessation and exercise programmes offered. Only one included study was judged to be at low risk of bias across all domains assessed. Four studies showed significantly higher abstinence rates in a physically active group versus a control group at end of treatment. One of these studies also showed a significant benefit for exercise versus control on abstinence at the three-month follow

  18. Bivalirudin in percutaneous coronary intervention

    Directory of Open Access Journals (Sweden)

    Sam J Lehman


    Full Text Available Sam J Lehman, Derek P ChewDepartment of Medicine, Flinders University, South Australia, AustraliaAbstract: Bivalirudin is a member of the direct thrombin inhibitor group of anticoagulants. It has been evaluated as an alternative to unfractionated and low-molecular-weight heparins in the settings of percutaneous coronary intervention (PCI and acute coronary syndrome (ACS. Results of clinical trials to date suggest bivalirudin is a viable alternative to the use of a heparin combined with a glycoprotein (GP IIb/IIIa inhibitor in these settings. Thrombin has a central role in coagulation and platelet activation in ACS and during PCI. Its direct inhibition is an attractive target for therapy in these settings. Bivalirudin is a 20 amino acid polypeptide hirudin analog. It displays bivalent and reversible binding to the thrombin molecule, inhibiting its action. Direct inhibition of thrombin with bivalirudin has theoretical pharmacokinetic and pharmacodynamic advantages over the indirect anticoagulants. A reduction in rates of bleeding without loss of anti-thrombotic efficacy has been a consistent finding across multiple clinical trials. There may be economic benefits to the use of bivalirudin if it permits a lower rate of use of the GP IIb/IIIa inhibitors. This article reviews the pharmacology of bivalirudin and clinical trial evidence to date. There are now data from multiple clinical trials and meta-analyses in the setting of ACS and PCI. Early results from the acute catheterization and urgent intervention strategy (ACUITY trial are discussed. Keywords: bivalirudin, direct thrombin inhibitor, acute coronary syndrome, percutaneous coronary intervention

  19. Nondirective counseling interventions with schizophrenics. (United States)

    Gerwood, J B


    Counseling interventions with paranoid schizophrenics can be daunting. While chemical, directive, and behavioral controls often are considered important, nondirective counseling techniques used by the therapeutic staff may help schizophrenic patients explore their thoughts and feelings. Several nondirective concepts pioneered by Carl Rogers are examined. These methods, which represent basic concepts of the person-centered approach, are empathy, unconditional positive regard, and congruence. A brief illustration of an interaction with a patient diagnosed as paranoid schizophrenic is presented to suggest the effectiveness of Rogerian counseling.

  20. Early intervention for childhood overweight

    DEFF Research Database (Denmark)

    Larsen, Lone Marie; Hertel, Niels Thomas; Mølgaard, Christian


    , identified by International Obesity Task Force criteria, aged 5-9 years. INTERVENTION: Model 1 with health consultations in general practice during a two-year period or Model 2, an educational programme for the children and their families in addition to the health consultations. MAIN OUTCOME MEASURES: Change...... in body mass index (BMI) z-score in order to compare the results, independent of gender- and age-related changes over time. RESULTS: A total of 80 children were recruited with 35 and 45 children allocated to Model 1 and Model 2, respectively. No significant differences were found in the change in BMI z...

  1. Bias in clinical intervention research

    DEFF Research Database (Denmark)

    Gluud, Lise Lotte


    Research on bias in clinical trials may help identify some of the reasons why investigators sometimes reach the wrong conclusions about intervention effects. Several quality components for the assessment of bias control have been suggested, but although they seem intrinsically valid, empirical...... evidence is needed to evaluate their effects on the extent and direction of bias. This narrative review summarizes the findings of methodological studies on the influence of bias in clinical trials. A number of methodological studies suggest that lack of adequate randomization in published trial reports...

  2. Response to intervention in math

    CERN Document Server

    Riccomini, Paul J


    Boost academic achievement for all students in your mathematics classroom! This timely resource leads the way in applying RTI to mathematics instruction. The authors describe how the three tiers can be implemented in specific math areas and illustrate RTI procedures through case studies. Aligned with the NMAP final report and IES practice guide, this book includes: Intervention strategies for number sense, fractions, problem solving, and more Procedures for teaching math using systematic and explicit instruction for assessment, instructional planning, and evaluation Essential components to con

  3. Interventional therapy for neuropathic pain

    Directory of Open Access Journals (Sweden)

    YANG Yang


    Full Text Available Neuropathic pain (NP is a common clinical refractory pain for which there are limited methods to treat. In this article, based on typical diseases, such as postherpetic neuralgia (PHN, trigeminal neuralgia, complex regional pain syndrome (CRPS, lower back pain with radiculopathy and failed back surgery syndrome (FBSS, phantom pain, the general treatment principle and method for NP are expatiated. Interventional methods for NP, including intraspinal block, radiofrequeney rhizotomy of trigeminal neuralgia, selective nerve root block, spinal cord stimulation (SCS and motor cortex stimulation (MCS are introduced, especially their indications, complications and matters needing attention.

  4. Gratitude as a psychotherapeutic intervention. (United States)

    Emmons, Robert A; Stern, Robin


    Gratitude practice can be a catalyzing and relational healing force, often untapped in clinical practice. In this article, we provide an overview of current thinking about gratitude's defining and beneficial properties, followed by a brief review of the research on mental health outcomes that result from gratitude practice. Following an analysis of our case study of the use of gratitude as a psychotherapeutic intervention, we present various self-strategies and techniques for consciously choosing and cultivating gratitude. We conclude by describing ways in which gratitude might be capitalized upon for beneficial outcomes in therapeutic settings. © 2013 Wiley Periodicals, Inc.

  5. Nonpathologizing trauma interventions in abnormal psychology courses. (United States)

    Hoover, Stephanie M; Luchner, Andrew F; Pickett, Rachel F


    Because abnormal psychology courses presuppose a focus on pathological human functioning, nonpathologizing interventions within these classes are particularly powerful and can reach survivors, bystanders, and perpetrators. Interventions are needed to improve the social response to trauma on college campuses. By applying psychodynamic and feminist multicultural theory, instructors can deliver nonpathologizing interventions about trauma and trauma response within these classes. We recommend class-based interventions with the following aims: (a) intentionally using nonpathologizing language, (b) normalizing trauma responses, (c) subjectively defining trauma, (d) challenging secondary victimization, and (e) questioning the delineation of abnormal and normal. The recommendations promote implications for instructor self-reflection, therapy interventions, and future research.

  6. Guide for intervention levels in radiological accidents

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jong Tai; Khang, Byung Oui; Lee, Goan Yup; Han, Gee Yang [Korea Atomic Energy Resesrch Institute, Taejon (Korea, Republic of)


    Based on IAEA SS109 and ICRP63, intervention levels and action levels are derived using cost-benefit approach method. Intervention levels are optimized so that the net benefit from protective measures will be maximized. Evacuation, sheltering, relocation, permanent resettlement, administration of stable iodine and food restriction are included in protective measures. Intervention levels are calculated using site specific parameters in Korea. As a results of calculation, general intervention levels are similar to IAEA recommendation and action levels for food restriction are a little higher than IAEA recommendation and Japan guide. Guide on intervention levels in Korea is also suggested based on the calculated results.

  7. Durability Issues and Status of PBI-Based Fuel Cells

    DEFF Research Database (Denmark)

    Jakobsen, Mark Tonny Dalsgaard; Jensen, Jens Oluf; Cleemann, Lars Nilausen


    This chapter briefly reviews durability and stability issues with key materials and components for HT-PEMFCs, including the polymer membrane, the doping acid, the electrocatalyst, the catalyst support and bipolar plates. Degradation mechanisms and their dependence on fuel cell operating condition...

  8. Transtheoretical Model-based Nursing Intervention on Lifestyle Change: A Review Focused on Intervention Delivery Methods

    Directory of Open Access Journals (Sweden)

    Joo Yun Lee, RN


    Conclusions: ICT is not yet actively used in the TTM-based nursing interventions. Stage-matched interventions and TTM concepts were shown to be in partial use also in the TTM-based interventions. Therefore, it is necessary to develop a variety of ways to use ICT in tailored nursing interventions and to use TTM frameworks and concepts.

  9. Handwriting development, competency, and intervention. (United States)

    Feder, Katya P; Majnemer, Annette


    Failure to attain handwriting competency during the school-age years often has far-reaching negative effects on both academic success and self-esteem. This complex occupational task has many underlying component skills that may interfere with handwriting performance. Fine motor control, bilateral and visual-motor integration, motor planning, in-hand manipulation, proprioception, visual perception, sustained attention, and sensory awareness of the fingers are some of the component skills identified. Poor handwriting may be related to intrinsic factors, which refer to the child's actual handwriting capabilities, or extrinsic factors which are related to environmental or biomechanical components, or both. It is important that handwriting performance be evaluated using a valid, reliable, standardized tool combined with informal classroom observation and teacher consultation. Studies of handwriting remediation suggest that intervention is effective. There is evidence to indicate that handwriting difficulties do not resolve without intervention and affect between 10 and 30% of school-aged children. Despite the widespread use of computers, legible handwriting remains an important life skill that deserves greater attention from educators and health practitioners.

  10. [Community intervention during economic disasters]. (United States)

    de León, O A


    A political conflict forced banks to close down in Panama during March 1988. Thus, thousand of families were unable to meet their most basic needs during that lapse of time. This paper describes a community intervention program that was set up in the midst of such an economic disaster. That program emphasized mental health consultation techniques to help devising an effective organizational action as well as developing standards to determine needs, and a clear-cut two-way communication with the affected families. The incidence of emotional disorder was assessed with the Self Report Questionnaire, and crisis intervention was offered to any people who should apply for it. Cognitive responses, coping behaviors, and social supports were also assessed. Results showed that those individuals excluded from a full participation in their culture were much more likely to develop emotional disorders. Finding that affected people showed a scarce self-help behavior was interpreted as a feature of the transcultural transaction between affected people, and professionals.

  11. Patient dosimetry in interventional radiology

    International Nuclear Information System (INIS)

    Silva, Mauro Wilson O. da; Canevaro, Lucia V.; Rodrigues, Barbara Beatriz D.


    Mapping skin doses in interventional radiology is useful to determine the probability of a possible injury, to detect areas of overlapping field and to obtain a permanent register of the most exposed skin areas. A method for the evaluation of patient doses in interventional radiology procedures is the slow film, Kodak EDR2 (Extended Dose Range). Kodak EDR 2 film was calibrated in the range of 50 kVp to 120 kVp beam qualities. Its dose-response curve was plotted up to the saturation point of 1000 mGy. Dose responses are a function of facility dependent factors including processing conditions the density sampling, and exposure monitoring equipment. The distribution and the form of all the irradiation fields have been registered in the Kodak EDR 2 films. The Dosimetric analysis was performed in a sample of 37 patients submitted the procedures coronariography and angioplasty. The film has a threshold of saturation around 1 Gy, the applied methodology is efficient to quantify the doses and to identify the distribution of the fields. (author)

  12. Adolescent childbearing: consequences and interventions. (United States)

    Ruedinger, Emily; Cox, Joanne E


    Adolescent childbearing in the United States continues to occur at high rates compared with other industrialized nations, despite a recent decline. Adolescent mothers and their offspring are at risk for negative outcomes. Recent literature exploring the consequences of teenage childbearing and interventions to ameliorate these consequences are presented. Negative consequences of adolescent childbearing can impact mothers and their offspring throughout the lifespan. These consequences are likely attributable to social and environmental factors rather than solely to maternal age. Increasing educational attainment, preventing repeat pregnancy and improving mother-child interactions can improve outcomes for mothers and their children. Home, community, school and clinic-based programs are all viable models of service delivery to this population. Connecting teen mothers with comprehensive services to meet their social, economic, health and educational needs can potentially improve long-term outcomes for both mothers and their offspring. Programs that deliver care to this population in culturally sensitive, developmentally appropriate ways have demonstrated success. Future investigation of parenting interventions with larger sample sizes and that assess multiple outcomes will allow comparison among programs. Explorations of the role of the father and coparenting are also directions for future research.

  13. Interventional radiology in pediatric oncology

    International Nuclear Information System (INIS)

    Hoffer, Fredric A.


    There are many radiological interventions necessary for pediatric oncology patients, some of which may be covered in other articles in this publication. I will discuss a number of interventions including percutaneous biopsy for solid tumor and hematological malignancy diagnosis or recurrence, for the diagnosis of graft versus host disease after stem cell or bone marrow transplantation, and for the diagnosis of complications of immunosuppression such as invasive pulmonary aspergillosis. In the past, tumor localization techniques have been necessary to biopsy or resect small lesions. However improved guidance techniques have allowed for more precise biopsy and the use of thermal ablation instead of excision for local tumor control. A percutaneously placed radio frequency, microwave, laser or cryogen probe can ablate the primary and metastatic tumors of the liver, lung, bone, kidney and other structures in children. This is an alternative treatment for the local control of tumors that may not be amenable to surgery, chemotherapy or radiotherapy. I will also describe how chemoembolization can be used to treat primary or metastatic tumors of the liver that have failed other therapies. This treatment delivers chemotherapy in the hepatic artery infused with emboli to increase the dwell time and concentration of the agents

  14. Web-based interventions in nursing. (United States)

    Im, Eun-Ok; Chang, Sun Ju


    With recent advances in computer and Internet technologies and high funding priority on technological aspects of nursing research, researchers at the field level began to develop, use, and test various types of Web-based interventions. Despite high potential impacts of Web-based interventions, little is still known about Web-based interventions in nursing. In this article, to identify strengths and weaknesses of Web-based nursing interventions, a literature review was conducted using multiple databases with combined keywords of "online," "Internet" or "Web," "intervention," and "nursing." A total of 95 articles were retrieved through the databases and sorted by research topics. These articles were then analyzed to identify strengths and weaknesses of Web-based interventions in nursing. A strength of the Web-based interventions was their coverage of various content areas. In addition, many of them were theory-driven. They had advantages in their flexibility and comfort. They could provide consistency in interventions and require less cost in the intervention implementation. However, Web-based intervention studies had selected participants. They lacked controllability and had high dropouts. They required technical expertise and high development costs. Based on these findings, directions for future Web-based intervention research were provided.

  15. Deepening the reform of interventional radiology education and speeding up the development of interventional radiology

    International Nuclear Information System (INIS)

    Lu Chuan; Liu Linxiang; Cheng Yongde


    For recent years, although interventional radiology in China has achieved rapid development, it is still facing some rigorous challenges, such as the lack of personnel in interventional field and the flowing-away of certain patients who are definitely suitable for interventional therapy. This paper aims to discuss the reform of interventional radiology education for the undergraduates, postgraduates and clinical practitioners in the medical colleges in order to seek effective solutions to these issues the interventional radiology has confronted with. (authors)

  16. The Use of Intervention Mapping to Develop a Tailored Web-Based Intervention, Condom-HIM


    Miranda, Joyal; C?t?, Jos?


    Background Many HIV (human immunodeficiency virus) prevention interventions are currently being implemented and evaluated, with little information published on their development. A framework highlighting the method of development of an intervention can be used by others wanting to replicate interventions or develop similar interventions to suit other contexts and settings. It provides researchers with a comprehensive development process of the intervention. Objective The objective of this pap...

  17. Interventions for suspected placenta praevia. (United States)

    Neilson, J P


    Because placenta praevia is implanted unusually low in the uterus, it may cause major, and/or repeated, antepartum haemorrhage. The traditional policy of care of women with symptomatic placenta praevia includes prolonged stay in hospital and delivery by caesarean section. To assess the impact of any clinical intervention applied specifically because of a perceived likelihood that a pregnant woman might have placenta praevia. A comprehensive electronic search was performed to identify relevant literature. Searched databases included the Trials Register maintained by the Cochrane Pregnancy and Childbirth Group (August 2002), and the Cochrane Controlled Trials Register (The Cochrane Library, Issue 2, 2002). Any controlled clinical trial that has assessed the impact of an intervention in women diagnosed as having, or being likely to have, placenta praevia. Data were extracted, unblinded, by the author without consideration of results. Three trials were included, involving a total of 114 women. Both tested interventions (home versus hospitalisation and cervical cerclage versus no cerclage) were associated with reduced lengths of stay in hospital antenatally: weighted mean difference (WMD) respectively -18.50 days (95% confidence interval (CI) -26.83 to -10.17), -4.80 days (95% CI -6.37 to -3.23). Otherwise, there was little evidence of any clear advantage or disadvantage to a policy of home versus hospital care. The one woman who had a haemorrhage severe enough to require immediate transfusion and delivery was in the home care group. Cervical cerclage may reduce the risk of delivery before 34 weeks: relative risk (RR) 0.45 (95% CI 0.23 to 0.87), or the birth of a baby weighing less than two kilograms RR 0.34 (0.14 to 0.83) or having a low five minute Apgar score RR 0.19 (0.04 to 1.00). In general, these possible benefits were more evident in the trial of lower methodological quality. There are insufficient data from trials to recommend any change in clinical practice

  18. Properties, degradation and high temperature fuel cell test of different types of PBI and PBI blend membranes

    DEFF Research Database (Denmark)

    Li, Qingfeng; Rudbeck, Hans Christian; Chromik, Andreas


    Polybenzimidazoles (PBIs) with synthetically modified structures and their blends with a partially fluorinated sulfonated aromatic polyether have been prepared and characterized for high temperature proton exchange membrane fuel cells. Significant improvement in the polymer chemical stability...

  19. Vocational rehabilitation: a multidisciplinary intervention. (United States)

    Gobelet, C; Luthi, F; Al-Khodairy, A T; Chamberlain, M A


    Vocational rehabilitation is by definition a multidisciplinary intervention in a process linked to the facilitation of return to work or to the prevention of loss of the work. Clinical staff in contact with a person who has lost his job (general practitioner, specialized physician) must promote vocational rehabilitation. Medical rehabilitation for those with disabilities, whether new or old, has to be followed without delay by vocational rehabilitation. It is even better if these two intertwined processes are overlapping. They involve many professionals including physiotherapists, occupational therapists, psychologists, vocational trainers, job counsellors, teachers, case-managers, job placement agencies. Vocational rehabilitation has a financial cost, borne by many state organizations (security, social system, social affairs) as well as by employers and private insurances, which are in case of accident, concerned by this process. However, the evidence suggests that this is recouped 2- to 10-fold as suggested by the British Society of Rehabilitation Medicine.

  20. Prioritising interventions against medication errors

    DEFF Research Database (Denmark)

    Lisby, Marianne; Pape-Larsen, Louise; Sørensen, Ann Lykkegaard

    errors are therefore needed. Development of definition: A definition of medication errors including an index of error types for each stage in the medication process was developed from existing terminology and through a modified Delphi-process in 2008. The Delphi panel consisted of 25 interdisciplinary......Abstract Authors: Lisby M, Larsen LP, Soerensen AL, Nielsen LP, Mainz J Title: Prioritising interventions against medication errors – the importance of a definition Objective: To develop and test a restricted definition of medication errors across health care settings in Denmark Methods: Medication...... errors constitute a major quality and safety problem in modern healthcare. However, far from all are clinically important. The prevalence of medication errors ranges from 2-75% indicating a global problem in defining and measuring these [1]. New cut-of levels focusing the clinical impact of medication...

  1. Left main percutaneous coronary intervention. (United States)

    Teirstein, Paul S; Price, Matthew J


    The introduction of drug-eluting stents and advances in catheter techniques have led to increasing acceptance of percutaneous coronary intervention (PCI) as a viable alternative to coronary artery bypass graft (CABG) for unprotected left main disease. Current guidelines state that it is reasonable to consider unprotected left main PCI in patients with low to intermediate anatomic complexity who are at increased surgical risk. Data from randomized trials involving patients who are candidates for either treatment strategy provide novel insight into the relative safety and efficacy of PCI for this lesion subset. Herein, we review the current data comparing PCI with CABG for left main disease, summarize recent guideline recommendations, and provide an update on technical considerations that may optimize clinical outcomes in left main PCI. Copyright © 2012 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  2. Interventional radiology in pain treatment

    International Nuclear Information System (INIS)

    Kastler, B.


    Disease whether it is acute, chronic, or at end stage, is all too regularly accompanied by pain. Pain is often difficult to control, in malignant disease in particular, even by using appropriate medications. Anesthesiologists and pain therapists have developed new invasive therapies including nerve block, sympatholysis, and neurolysis useful for both diagnosis and pain management. To insure the efficiency and safety of these procedures, and furthermore for elaborate techniques such as vertebroplasty, cementoplasty, and radio frequency bone ablation, imaging guidance becomes mandatory. This state-of-the-art book describes the techniques elaborated by interventional radiologists in the treatment and palliation of a variety of benign and malignant painful conditions. Each chapter written by an expert in the field concentrates on a particular aspect of pain management, with emphasis on practical issues. This book will serve as an invaluable source of information for the radiologist willing to learn about new pain therapy techniques aimed at optimizing or replacing more invasive traditional methods. (orig.)

  3. Early intervention services in psychosis

    DEFF Research Database (Denmark)

    Csillag, Claudio; Nordentoft, Merete; Mizuno, Masafumi


    AIM: Early intervention (EI) in psychosis is a comprehensive and evidence-based approach aimed at detection and treatment of psychotic symptoms in their early stages. This paper presents core features and noteworthy aspects of the evidence basis and limitations of EI, the importance of programme ....... Wider dissemination of EI services will probably benefit from better integration of potential funders, promotion of joint targets and shared financial or budgetary incentives....... overcome these difficulties. CONCLUSIONS: Funding for mental health in general and for EI services appears low relative to need. One key argument for better funding for EI can be found in its favourable cost-effectiveness, but not all stakeholders beyond mental health administrators are aware of this...

  4. Interventional embolization for refractory hyperthyroidism

    International Nuclear Information System (INIS)

    Jiang Guomin; Zhang Yunping; Chen Yaxian; Zhao Jinwei; Yang Weihuai; Chen Jinluo


    Objective: To evaluate the clinical effects of the thyroid artery embolization for refractory hyperthyroidism. Methods: Super selective catheterization and interventional embolization of thyroid superior and inferior arteries were performed with PVA microspheres and Gelfoam particles. Changes of function and size of thyroid were investigated after embolization. Results: The procedures were succeeded in all 21 patients. Followed up by 3-12 months, serum level of thyroid hormones dropped significantly (median FT 3 from 17.1 pmol/L to 7.44 pmol/L, median FT 4 from 51.1 pmol/L to 23.3 pmol/L, P< 0.01). The size of thyroid glands decreased remarkably. Symptoms of hyperthyroidism were controlled in 4 patients and were effectively controlled through low dose antithyroid medication in 17 patients. No serious complications occurred. Conclusions: Thyroid artery embolization is a new safe and effective method for refractory hyperthyroidism

  5. Cognitive Benefits of Exercise Intervention. (United States)

    Archer, T; Ricci, S; Massoni, F; Ricci, L; Rapp-Ricciardi, M


    Exercise, as a potent epigenetic regulator, implies the potential to counteract pathophysiological processes and alterations in most cardiovascular/respiratory cells and tissues not withstanding a paucity of understanding the underlying molecular mechanisms and doseresponse relationships. In the present account, the assets accruing from physical exercise and its influence upon executive functioning are examined. Under conditions of neuropsychiatric and neurologic ill-health, age-related deterioration of functional and biomarker indicators during healthy and disordered trajectories, neuroimmune and affective unbalance, and epigenetic pressures, exercise offers a large harvest of augmentations in health and well-being. Both animal models and human studies support the premise of manifest gains from regular exercise within several domains, besides cognitive function and mood, notably as the agency of a noninvasive, readily available therapeutic intervention.

  6. The interventional radiology business plan. (United States)

    Beheshti, Michael V; Meek, Mary E; Kaufman, John A


    Strategic planning and business planning are processes commonly employed by organizations that exist in competitive environments. Although it is difficult to prove a causal relationship between formal strategic/business planning and positive organizational performance, there is broad agreement that formal strategic and business plans are components of successful organizations. The various elements of strategic plans and business plans are not common in the vernacular of practicing physicians. As health care becomes more competitive, familiarity with these tools may grow in importance. Herein we provide an overview of formal strategic and business planning, and offer a roadmap for an interventional radiology-specific plan that may be useful for organizations confronting competitive and financial threats. Copyright © 2012 SIR. Published by Elsevier Inc. All rights reserved.

  7. Obesogenic environment – intervention opportunities

    Directory of Open Access Journals (Sweden)

    Mauro Fisberg


    Full Text Available Objectives: To evaluate environmental obesogenic-related factors, such as physical activity in neighborhoods and schools, nutritional behavior, and intervention programs. Sources: Critical analysis of literature with personal point of view from infant obesity experts and political advisors for public intervention. Data synthesis: Although obesity is a public health problem affecting several age groups, it is among children and adolescents that it plays a more important role, due to treatment complexity, high likelihood of persistence into adulthood, and association with other non-transmissible diseases while still in early age. Environment is a main component of the genesis and outcomes in the near future or long term. Modification of intake with high-density food, meal skipping, and high intake of saturated fat, sugar, and salt, associated to high levels of sedentarism are main causes of obesity. Conclusion: Intervention opportunities are related to modifications in political, environmental, and individual settings. School and physical activities in the educational environment are intertwined with nutrition intervention in continuous education. A critical review of some different scenarios in Latin American countries is presented. Resumo: Objetivos: Avaliar os fatores relacionados ao ambiente obesogênico, como atividade física nos bairros e nas escolas, comportamento nutricional e programas de intervenção. Fontes: Análise crítica da literatura com ponto de vista de especialistas em obesidade infantil e conselheiros políticos de intervenções públicas. Resumo dos dados: Embora a obesidade seja um problema de saúde pública que afeta diversas faixas etárias, é entre crianças e adolescentes que ela desempenha um papel mais importante devido à complexidade do tratamento, à alta probabilidade de persistência na vida adulta e à associação com outras doenças não transmissíveis com início precoce. O ambiente é um componente

  8. Women in interventional cardiology: The French experience. (United States)

    Vautrin, E; Marlière, S; Bellemain-Appaix, A; Gilard, M; Manzo-Silberman, S


    Exploring the discrepancy in sex-ratio among interventional cardiologists by analysing the population of the female interventionalist. Despite an increase number of women who graduate from medical school in France during the last generation today, women represent only 24% of all cardiologists and 3% are interventional cardiologists. To face this international gender-based issue of interventional cardiology, committees were established in US (WIN) and recently within the EAPCI: the Women EAPCI chaired by Drs Mehilli and Mauri. In France, the Intervention'Elles committee emerged in order to participate in this concern. As a first initiative, the Intervention'Elles group launched an e-survey to obtain information on the population of French female interventional cardiologists, focused on demography, work patterns, maternity and radiation exposure. Mean age is 40 years old (±7,4), 68% are working in large volume center, 28% have also structural interventional activity. Only 40% have left arm coverage. Despite 80% of French female interventional cardiologists wear personal dosimeters only 45% of them have a dosimetry feedback. Interestingly, even if 54% of women have children (mean: 1.9±1) 28% of them report that childbearing had interfered with their career plan. This questionnaire identifies for the first time the women population in interventional cardiology in France and highlights some of the issues encountered in more detail. This first descriptive step would help to develop strategies for attaining gender equality in interventional cardiology. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  9. Suicide intervention training evaluation: a preliminary report. (United States)

    Tierney, R J


    To date, very little work has been done on evaluating training in suicide intervention. This study developed and piloted a comprehensive method for evaluating suicide intervention training by applying three studies of immediate training effects on (a) suicide intervention abilities, (b) attitudes to suicide and suicide intervention, and (c) knowledge about suicide. The focus of the evaluation was a broadly used 2-day suicide intervention training program. Changes in suicide intervention abilities were measured by the Suicide Intervention Response Inventory (SIRI) and by performance in simulated suicide intervention situations, scored with the Suicide Intervention Protocol (SIP). Subjects consisted of 19 workshop participants in a pre-post condition and 17 participants in a post-test only condition. Results indicated significant increases in skills in suicide intervention situations. No significant effects were noted on the SIRI. Results from the attitudes and knowledge studies were very preliminary. They are reported here so that others may become aware of the methodology being used and the status of evaluation of the target program. Implications for further research are discussed.

  10. The Use of Intervention Mapping to Develop a Tailored Web-Based Intervention, Condom-HIM. (United States)

    Miranda, Joyal; Côté, José


    Many HIV (human immunodeficiency virus) prevention interventions are currently being implemented and evaluated, with little information published on their development. A framework highlighting the method of development of an intervention can be used by others wanting to replicate interventions or develop similar interventions to suit other contexts and settings. It provides researchers with a comprehensive development process of the intervention. The objective of this paper was to describe how a systematic approach, intervention mapping, was used to develop a tailored Web-based intervention to increase condom use among HIV-positive men who have sex with men. The intervention was developed in consultation with a multidisciplinary team composed of academic researchers, community members, Web designers, and the target population. Intervention mapping involved a systematic process of 6 steps: (1) needs assessment; (2) identification of proximal intervention objectives; (3) selection of theory-based intervention methods and practical strategies; (4) development of intervention components and materials; (5) adoption, implementation, and maintenance; and (6) evaluation planning. The application of intervention mapping resulted in the development of a tailored Web-based intervention for HIV-positive men who have sex with men, called Condom-HIM. Using intervention mapping as a systematic process to develop interventions is a feasible approach that specifically integrates the use of theory and empirical findings. Outlining the process used to develop a particular intervention provides clarification on the conceptual use of experimental interventions in addition to potentially identifying reasons for intervention failures. ©Joyal Miranda, José Côté. Originally published in JMIR Public Health and Surveillance (, 19.04.2017.

  11. Adaptive Intervention Design in Mobile Health: Intervention Design and Development in the Cell Phone Intervention for You (CITY) Trial (United States)

    Lin, Pao-Hwa; Intille, Stephen; Bennett, Gary; Bosworth, Hayden B; Corsino, Leonor; Voils, Corrine; Grambow, Steven; Lazenka, Tony; Batch, Bryan C; Tyson, Crystal; Svetkey, Laura P


    Background/Aims The obesity epidemic has spread to young adults, and obesity is a significant risk factor for cardiovascular disease. The prominence and increasing functionality of mobile phones may provide an opportunity to deliver longitudinal and scalable weight management interventions in young adults. The aim of this manuscript is to describe the design and development of the intervention tested in the Cell Phone Intervention for You (CITY) study and to highlight the importance of adaptive intervention design (AID) that made it possible. The CITY study was an NHLBI-sponsored, controlled 24-month randomized clinical trial (RCT) comparing two active interventions to a usual-care control group. Participants were 365 overweight or obese (BMI ≥ 25 kg/m2) young adults. Methods Both active interventions were designed based on social cognitive theory and incorporated techniques for behavioral self-management and motivational enhancement. Initial intervention development occurred during a 1-year formative phase utilizing focus groups and iterative, participatory design. During the intervention testing, AID, where an intervention is updated or extended throughout a trial while assuring the delivery of exactly the same intervention to each cohort, was employed. The AID strategy distributed technical work and allowed introduction of novel components in phases intended to help promote and sustain participant engagement. AID was made possible by exploiting the mobile phone's remote data capabilities so that adoption of particular application components could be continuously monitored and components subsequently added or updated remotely. Results The cellphone intervention was delivered almost entirely via cell phone and was always-present, proactive, and interactive – providing passive and active reminders, frequent opportunities for knowledge dissemination, and multiple tools for self-tracking and receiving tailored feedback. The intervention changed over two years to

  12. Emotional Reasoning and Parent-Based Reasoning in Normal Children (United States)

    Morren, Mattijn; Muris, Peter; Kindt, Merel


    A previous study by Muris, Merckelbach, and Van Spauwen [1] demonstrated that children display emotional reasoning irrespective of their anxiety levels. That is, when estimating whether a situation is dangerous, children not only rely on objective danger information but also on their "own" anxiety-response. The present study further examined…

  13. Emotional reasoning and parent-based reasoning in normal children.

    NARCIS (Netherlands)

    Morren, M.; Muris, P.; Kindt, M.


    A previous study by Muris, Merckelbach, and Van Spauwen demonstrated that children display emotional reasoning irrepective of their anxiety levels. That is when estimating whether a situation is dangerous, childen not only rely on objective danger information but also on their own anciety-response.

  14. Emotional reasoning and parent-based reasoning in normal children

    NARCIS (Netherlands)

    Morren, M.; Muris, P.; Kindt, M.


    A previous study by Muris, Merckelbach, and Van Spauwen demonstrated that children display emotional reasoning irrespective of their anxiety levels. That is, when estimating whether a situation is dangerous, children not only rely on objective danger information but also on their own

  15. The IDEFICS Community-Oriented Intervention Programme

    DEFF Research Database (Denmark)

    De Henauw, Stefaan; Verbestel, Vera; Mårild, Staffan


    to develop new pathways for sustainable health-promoting communities. Against this background, the IDEFICS (Identification and prevention of dietary- and lifestyle-induced health effects in children and infants) study developed and implemented innovative community-oriented intervention programmes for obesity....... The sphere of action encompassed both children and their (grand) parents, schools, local public authorities and influential stakeholders in the community. All materials for the interventions were centrally developed and culturally adapted. Results: So far, the following has been achieved: focus group...... research, literature review and expert consultations were done in an early phase as a basis for the development of the intervention modules. The intervention mapping protocol was followed as guide for structuring the intervention research. The overall intervention programme's duration was 2 years...

  16. School-based interventions to address bullying

    Directory of Open Access Journals (Sweden)

    Peter K. Smith


    Full Text Available Following some background studies on the nature of school bullying, its prevalence, and the negative consequences it can have, this article reviews the history of anti-bullying interventions over the last 30 years. It considers several major programmes in detail, such as the Olweus Bullying Prevention Program, KiVa, Steps to Respect, and Friendly Schools. The nature and evaluation of the interventions is discussed, followed by a review of meta-analyses of the programmes effectiveness. Issues considered are the effect at different ages; components of interventions; work with peers; disciplinary methods, non-punitive and restorative approaches; challenges regarding cyberbullying; the role of parents; the role of teachers and teacher training; set menu versus à la carte approaches; sustainability of interventions and societal context. Conclusions show that interventions have had some success, with traditional bullying. However, further progress is needed in strengthening theoretical underpinnings to interventions, and in tackling cyberbullying.

  17. Tracing Early Interventions on Childhood Overweight

    DEFF Research Database (Denmark)

    Ditlevsen, Kia

    This thesis presents results from a qualitative research project on early interventions to counter childhood obesity in Denmark. Overall, it was found that these interventions in families with preschool children were rarely performed. One barrier to the interventions is the structural setting...... in families with a non-western ethnic minority background and with low socioeconomic status. In families who participated in interventions, other social problems and a sense of insecurity caused by precarious living conditions of different kinds influenced the parents’ readiness to restrict children in order...... in the Danish health care system, which was found to be insufficient to initiate and facilitate early interventions. In addition, cultural stereotypes were found to affect the health care practitioners who are performing early interventions, and this can create reluctance to address overweight problems...

  18. [Clinical use of interventional MR imaging]. (United States)

    Kahn, Thomas; Schulz, Thomas; Moche, Michael; Prothmann, Sascha; Schneider, Jens-Peter


    The integration of diagnostic and therapeutic procedures by MRI is based on the combination of excellent morphologic and functional imaging. The spectrum of MR-guided interventions includes biopsies, thermal ablation procedures, vascular applications, and intraoperative MRI. In all these applications, different scientific groups have obtained convincing results in basic developments as well as in clinical use. Interventional MRI (iMRI) is expected to attain an important role in interventional radiology, minimal invasive therapy, and monitoring of surgical procedures.

  19. Interventional techniques in medicine and radioprotection

    International Nuclear Information System (INIS)

    Le Guen, B.; Bar, O.; Benderitter, M.; Bourguignon, M.; Chevillard, S.; Gauron, Ch.; Lallemand, J.; Lombard, J.; Maccia, C.; Sapoval, M.; Bernier, M.O.; Pirard, Ph.; Jacob, S.; Donadille, L.; Aubert, B.; Clairand, I.; Mozziconacci, J.G.; Brot, A.M.; Jarrige, V.; Huet, Ch.; Marchal, C.; Martin, M.; Bar, O.; Degrange, J.P.; Livarek, B.; Menechal, Ph.; Sapoval, M.; Pellerin, O.


    This document gathers the slides of the available presentations given during this conference day. Nineteen presentations are assembled in the document and deal with: 1 - Interventional radiology: why is it developing? (M. Sapoval); 2 - exposure particularities in interventional radiology (O. Bar); 3 - doses received by organs in interventional cardiology (C. Maccia); 4 - Patients exposure: description of cumulated exposure of patients treated in interventional cardiology (M.O. Bernier); 5 - 2004 inquiry to dermatologists about post-interventional radiology radio-dermatitis (P. Pirard); 6 - exposure and risks to operators (S. Jacob); 7 - dosimetric evaluation techniques and results about interventional imaging operators' extremities (L. Donadille and F. Merat); 8 - bibliographic study of doses received by operators with non-protected organs (B. Aubert); 9 - ORAMED European project: optimization of operational dosimeter uses in interventional radiology (I. Clairand); 10 - reference levels and dosimetric evaluation of patients (C. Maccia); 11 - optimization in coronary angioplasty (J.G. Mozziconacci, A.M. Brot and V. Jarrige); 12 - dosimetry in medical over-exposure situation (C. Huet); 13 - significant radioprotection events in interventional radiology declared to the Nuclear Safety Authority (ASN) - status and experience feedback (C. Marchal); 14 - interventional radiology and unwanted effects (M. Benderitter); 15 - global analyses and new exposure indicators in human epidermis cells (M. Martin); 16 - radioprotection regulations and training (O. Bar); 17 - zoning and workplace analysis in interventional cardiology (J.P. Degrange); 18 - guide of good clinical practices: example of interventional cardiology (B. Livarek); 19 - how to encourage the radioprotection optimization in interventional radiology: the ASN's point of view (P. Menechal). (J.S.)

  20. A Positive Psychology Intervention With Emerging Adults


    Sophie Leontopoulou


    This study assessed the impact of a positive psychology intervention in a sample of 40 young men (35%) and women (65%) aged 18-30 years. Participants were 1st and 4th year undergraduate University students, postgraduate students and working youths. The study examined the effects of a battery of interventions commonly used in positive psychology interventions, including a video and three exercises (i.e. expressing gratitude, best possible selves, goal setting) on character strengths, hope, gra...

  1. Nursing burnout interventions: what is being done? (United States)

    Henry, Barbara J


    Many studies have documented high prevalence of burnout and compassion fatigue in oncology nurses. Burnout has detrimental effects on nurses, patients, and healthcare organizations. However, burnout interventions have been shown to improve the physical and mental health of nurses, patient satisfaction, and the organizational bottom line by reducing associated costs of burnout. Although treatment centers may prevent and correct burnout in oncology nurses by providing various interventions, few articles focus on those interventions. This article compiles and describes interventions that will serve as a reference to nurses and healthcare organization leaders interested in implementing similar programs.

  2. Randomized, interventional, prospective, comparative study to ...

    African Journals Online (AJOL)

    Randomized, interventional, prospective, comparative study to evaluate the antihypertensive efficacy and tolerability of ramipril versus telmisartan in stage 1 hypertensive patients with diabetes mellitus.

  3. Documenting pharmacist interventions on an intranet. (United States)

    Simonian, Armen I


    The process of developing and implementing an intranet Web site for clinical intervention documentation is described. An inpatient pharmacy department initiated an organizationwide effort to improve documentation of interventions by pharmacists at its seven hospitals to achieve real-time capture of meaningful benchmarking data. Standardization of intervention types would allow the health system to contrast and compare medication use, process improvement, and patient care initiatives among its hospitals. After completing a needs assessment and reviewing current methodologies, a computerized tracking tool was developed in-house and integrated with the organization's intranet. Representatives from all hospitals agreed on content and functionality requirements for the Web site. The site was completed and activated in February 2002. Before this Web site was established, the most documented intervention types were Renal Adjustment and Clarify Dose, with a daily average of four and three, respectively. After site activation, daily averages for Renal Adjustment remained unchanged, but Clarify Dose is now documented nine times per day. Drug Information and i.v.-to-p.o. intervention types, which previously averaged less than one intervention per day, are now documented an average of four times daily. Approximately 91% of staff pharmacists are using this site. Future plans for this site include enhanced accessibility to the site with wireless personal digital assistants. The design and implementation of an intranet Web site to document pharmacists' interventions doubled the rate of intervention documentation and standardized the intervention types among hospitals in the health system.

  4. Neuropsychological intervention in the acute phase

    DEFF Research Database (Denmark)

    Norup, Anne; Siert, Lars; Mortensen, Erik Lykke


    This pilot study investigated the effects of acute neuropsychological intervention for relatives of patients with severe brain injury. Participants were enrolled in an intervention group comprising 39 relatives, and a control group comprising 47 relatives. The intervention consisted of supportive.......0100.30), but also significantly lower Role Emotional scores (= 2.12 = 0.043, = 0.40). In the sub-acute setting, an analysis of covariance model showed a borderline significant difference between the intervention and the control group on the anxiety scale (= 0.066 = 0.59). Any effects of the acute neuropsychological...

  5. More are awaiting for craniofacial intervention

    International Nuclear Information System (INIS)

    Fan Xindong


    The scale of craniofacial intervention lies between the fields of neuro-intervention and peripheral interventional for the main purpose to investigate, diagnose and treat the disease entities originating from or supplied by the external carotid arterial system. Patients are usually refered to the oral and maxillofacial surgery, plastic surgery and otolaryngeal surgery. Craniofacial intervention includes mainly the diagnosis and treatment with adjuvant embolization of high-flow vascular diseases, intra-arterial chemotherapy of malignant tumors, embolization of epistaxis, etc. At present, there is no consensus with regard to the diagnosis and treatment of some craniofacial diseases, therefore further investigation and discussion are needed. (authors)

  6. Interventional and intravascular MR angiography

    International Nuclear Information System (INIS)

    Ladd, M.E.; Debatin, J.F.


    Magnetic resonance imaging (MRI) has a number of characteristics which make it attractive for guidance of intravascular therapeutic procedures, including high soft tissue contrast, imaging in any arbitrary oblique plane, lack of ionizing radiation, and the ability to provide functional information, such as flow velocity and volume per unit time. For MR guidance of vascular interventions to be safe, catheters and guidewires must be visualized relative to the vascular system and surrounding tissues. A number of approaches for making instruments visible in an MR environment are presented, including both passive and active techniques. Passive techniques depend on contrast agents or susceptibility artifacts, whereas active techniques, including MR tracking, MR profiling, and active field inhomogeneity, use some form of electrical coil built into the instrument. The potential for obtaining high-resolution images of the vessel wall using coils built into a catheter is also discussed. These images provide the capability to distinguish and identify various plaque components. The additional capabilities of MRI could potentially open up new applications beyond those currently performed under X-ray fluoroscopic guidance. (orig.) [de

  7. Radiation doses in interventional neuroradiology

    International Nuclear Information System (INIS)

    Theodorakou, C.; Butler, P.; Horrocks, J.A.


    Patient radiation doses during interventional radiology (IR) procedures may reach the thresholds for radiation-induced skin and eye lens injuries. This study investigates the radiation doses received by patients undergoing cerebral embolization. Measurements were conducted using thermoluminescent dosimeters. Radiotherapy verification films were used in order to visualise the radiation field. For each procedure the fluoroscopic and digital dose-area product, the fluoroscopic time, the total number of acquired images and entrance-skin dose calculated by the angiographic unit were recorded. In this paper, the skin, eye and thyroid glands doses on a sample of patients are presented. From a preliminary study of 13 patients having undergone cerebral embolization, it was deduced that six of them have received a dose above 1 Gy. Detailed dose data from patients undergoing IR procedures will be collected in the future with the aim of developing a model to allow estimation of the dose prior to the procedure as well as to look at techniques of dose reduction. (author)

  8. Coaching: an effective leadership intervention. (United States)

    Karsten, Margo A


    Organizations are transitioning from a management industrial era to a humanistic era. This transition will require a different set of leadership competencies. Competencies that reflect relationships, connections with employees, and having the skill to unleash the human capability at all levels of an organization are essential. Similar to when a sports team needs a different play book to be successful, leaders need a new play book. Coaches within the sports team are the ones who assist players in learning how to adapt to a different set of rules. They teach the players how to show up differently and how to implement different plays, with the overall goal of being a successful team. New competencies are being required to reflect a humanistic approach to leadership. It is critical that organizations offer coaching as an intervention to all levels of leadership. This actual case study demonstrates that coaching not only assisted leaders in learning a new way of leading but also improved overall organizational effectiveness. The results that have been accomplished through the use of implementing a 360-degree feedback system, with coaching, reaped overall organization improvement. Copyright 2010 Elsevier Inc. All rights reserved.

  9. Treatment of Neck Pain: Noninvasive Interventions (United States)

    Carragee, Eugene J.; van der Velde, Gabrielle; Carroll, Linda J.; Nordin, Margareta; Guzman, Jaime; Peloso, Paul M.; Holm, Lena W.; Côté, Pierre; Hogg-Johnson, Sheilah; Cassidy, J. David; Haldeman, Scott


    Study Design. Best evidence synthesis. Objective. To identify, critically appraise, and synthesize literature from 1980 through 2006 on noninvasive interventions for neck pain and its associated disorders. Summary of Background Data. No comprehensive systematic literature reviews have been published on interventions for neck pain and its associated disorders in the past decade. Methods. We systematically searched Medline and screened for relevance literature published from 1980 through 2006 on the use, effectiveness, and safety of noninvasive interventions for neck pain and associated disorders. Consensus decisions were made about the scientific merit of each article; those judged to have adequate internal validity were included in our best evidence synthesis. Results. Of the 359 invasive and noninvasive intervention articles deemed relevant, 170 (47%) were accepted as scientifically admissible, and 139 of these related to noninvasive interventions (including health care utilization, costs, and safety). For whiplash-associated disorders, there is evidence that educational videos, mobilization, and exercises appear more beneficial than usual care or physical modalities. For other neck pain, the evidence suggests that manual and supervised exercise interventions, low-level laser therapy, and perhaps acupuncture are more effective than no treatment, sham, or alternative interventions; however, none of the active treatments was clearly superior to any other in either the short-or long-term. For both whiplash-associated disorders and other neck pain without radicular symptoms, interventions that focused on regaining function as soon as possible are relatively more effective than interventions that do not have such a focus. Conclusion. Our best evidence synthesis suggests that therapies involving manual therapy and exercise are more effective than alternative strategies for patients with neck pain; this was also true of therapies which include educational interventions

  10. Radiofrequency (thermal) ablation versus no intervention or other interventions for hepatocellular carcinoma

    DEFF Research Database (Denmark)

    Weis, Sebastian; Franke, Annegret; Mössner, Joachim


    Hepatocellular carcinoma is the fifth most common cancer worldwide. Percutaneous interventional therapies, such as radiofrequency (thermal) ablation (RFA), have been developed for early hepatocellular carcinoma. RFA competes with other interventional techniques such as percutaneous ethanol...

  11. The development of an adolescent smoking cessation intervention--an Intervention Mapping approach to planning. (United States)

    Dalum, Peter; Schaalma, Herman; Kok, Gerjo


    The objective of this project was to develop a theory- and evidence-based adolescent smoking cessation intervention using both new and existing materials. We used the Intervention Mapping framework for planning health promotion programmes. Based on a needs assessment, we identified important and changeable determinants of cessation behaviour, specified change objectives for the intervention programme, selected theoretical change methods for accomplishing intervention objectives and finally operationalized change methods into practical intervention strategies. We found that guided practice, modelling, self-monitoring, coping planning, consciousness raising, dramatic relief and decisional balance were suitable methods for adolescent smoking cessation. We selected behavioural journalism, guided practice and Motivational Interviewing as strategies in our intervention. Intervention Mapping helped us to develop as systematic adolescent smoking cessation intervention with a clear link between behavioural goals, theoretical methods, practical strategies and materials and with a strong focus on implementation and recruitment. This paper does not present evaluation data.

  12. Hungry for an intervention? : Adolescents' ratings of acceptability of eating-related intervention strategies

    NARCIS (Netherlands)

    Stok, F Marijn; de Ridder, Denise T D; de Vet, Emely; Nureeva, Liliya; Luszczynska, Aleksandra; Wardle, Jane; Gaspar, Tania; de Wit, John B F


    BACKGROUND: Effective interventions promoting healthier eating behavior among adolescents are urgently needed. One factor that has been shown to impact effectiveness is whether the target population accepts the intervention. While previous research has assessed adults' acceptance of eating-related

  13. Hungry for an intervention? Adolescents' ratings of acceptability of eating-related intervention strategies

    NARCIS (Netherlands)

    Stok, F.M.; Ridder, de D.T.D.; Vet, de Emely; Nureeva, Liliya; Luszczynska, Aleksandra; Wardle, Jane; Gaspar, Tania; Wit, de J.B.F.


    Background: Effective interventions promoting healthier eating behavior among adolescents are urgently needed. One factor that has been shown to impact effectiveness is whether the target population accepts the intervention. While previous research has assessed adults' acceptance of

  14. Pharmacological Interventions for Students with ADD. (United States)

    Austin, Vance L.


    A review of the research on pharmacological interventions for students with attention deficit disorder finds that psychostimulants such as methylphenidate (Ritalin) are effective in improving focus and impulse control, but should be used in conjunction with psychosocial and behavioral interventions. Comprehensive medical screenings and guidelines…

  15. Rethinking Intervention: Changing the Cultures of Schooling (United States)

    Daniels, Harry


    In this paper I will discuss intervention in the culture of schools as part of a range of responses to the concerns expressed, the difficulties caused by and the dissatisfaction and unhappiness experienced by pupils with social, emotional and behavioural difficulties. I will discuss such intervention at the levels of staff relations and…

  16. Enhancing reporting of behavior change intervention evaluations

    NARCIS (Netherlands)

    Abraham, C.; Johnson, B.T.; de Bruin, M.; Luszczynska, A.


    Many behavior change interventions for the prevention and treatment of HIV have been evaluated, but suboptimal reporting of evaluations hinders the accumulation of evidence and the replication of interventions. In this article, we address 4 practices contributing to this problem. First, detailed

  17. Biodiversity and Tourism : Impacts and Interventions

    NARCIS (Netherlands)

    Duim, van der V.R.; Caalders, J.D.A.D.


    This paper sets a framework for intervention in the relationship between biodiversity and tourism against the background of the Convention on Biological Diversity. It is argued that intervention cannot and should not only be based on considerations of measurable impacts of tourism on biodiversity

  18. Responsiveness to intervention in children with dyslexia

    NARCIS (Netherlands)

    Tilanus, E.A.T.; Segers, P.C.J.; Verhoeven, L.T.W.


    We examined the responsiveness to a 12-week phonics intervention in 54 s-grade Dutch children with dyslexia, and compared their reading and spelling gains to a control group of 61 typical readers. The intervention aimed to train grapheme–phoneme correspondences (GPCs), and word reading and spelling

  19. News in early intervention in autism. (United States)

    Geoffray, Marie-Maude; Thevenet, Marion; Georgieff, Nicolas


    Autism Spectrum Disorder (ASD) is a complex neurodevelopmental trouble which prevents the child from socio-communicative interaction, and learning from his environment. Non-medical early intervention attempts to improve prognosis. We will review the main current hypothesis, intervention models and scientific supports about early intervention. We conducted a search of the literature published on Medline between 2010 and 2015 related to intervention models provided to children with ASD aged less than 3 years. Data were extracted from systematic reviews and recent randomized controlled trials with moderate to high GRADE quality of evidence. Early intervention refers to brain plasticity theory. With the epidemiological studies of infant "at risk" there is an attempt to intervene earlier before full syndrome is present. Interventions tend to follow more on a developmental hierarchy of socio-communicative skills and to focus on the dyadic relation between the child and the caregivers to improve the core autistic symptoms. Over the last 6 years, there's been news and fine-tuned ways about early intervention, and more and more systematic evaluation. However, there are only few interventions which were evaluated in trial with a strong GRADE recommendation and all of them have methodological concerns. It is important to be cautious in recommendations for mental health politic, even if it is important to improve access to services for all children and their families, hence finance and design rigorous project in research.

  20. Public Health Interventions for School Nursing Practice (United States)

    Schaffer, Marjorie A.; Anderson, Linda J. W.; Rising, Shannon


    School nurses (SNs) use public health nursing knowledge and skills to provide nursing services to school populations. The Public Health Intervention Wheel is a practice framework that can be used to explain and guide public health nursing interventions. SNs who were also members of the National Association of School Nurses completed an electronic…

  1. Early identification and intervention in cerebral palsy

    DEFF Research Database (Denmark)

    Herskind, Anna; Greisen, Gorm; Nielsen, Jens Bo


    Infants with possible cerebral palsy (CP) are commonly assumed to benefit from early diagnosis and early intervention, but substantial evidence for this is lacking. There is no consensus in the literature on a definition of 'early', but this review focuses on interventions initiated within...

  2. Attribution Theory and Crisis Intervention Therapy. (United States)

    Skilbeck, William M.

    It was proposed that existing therapeutic procedures may influence attributions about emotional states. Therefore an attributional analysis of crisis intervention, a model of community-based, short-term consultation, was presented. This analysis suggested that crisis intervention provides attributionally-relevant information about both the source…

  3. The future of transcatheter mitral valve interventions

    DEFF Research Database (Denmark)

    Maisano, Francesco; Alfieri, Ottavio; Banai, Shmuel


    of transcatheter mitral valve interventions will be. The purpose of the present report is to review the current state-of-the-art of mitral valve intervention, and to identify the potential future scenarios, which might benefit most from the transcatheter repair and replacement devices under development....

  4. Personality Plasticity, Healthy Aging, and Interventions (United States)

    Mroczek, Daniel K.


    This commentary on the special section on conscientiousness and healthy aging focuses on several topics brought up in this collection of articles. One is the promise of personality interventions. Despite skepticism on the part of some, such interventions may ultimately prove successful. This is in part because of similarities between personality…

  5. 19 CFR 210.19 - Intervention. (United States)


    ... 19 Customs Duties 3 2010-04-01 2010-04-01 false Intervention. 210.19 Section 210.19 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE ADJUDICATION AND ENFORCEMENT Motions § 210.19 Intervention. Any person desiring to intervene in an...

  6. Pharmacological interventions for improved colonic anastomotic healing

    DEFF Research Database (Denmark)

    Oines, Mari Nanna; Krarup, Peter-Martin; Jorgensen, Lars Nannestad


    with the primary purpose of promoting healing of anastomoses made in the colon or rectum under uncomplicated conditions. We excluded studies on adverse events from interventions, nutritional interventions or in situ physical supporting biomaterials. The primary outcome was biomechanical strength or AL. We...

  7. ADHD in the Classroom: Effective Intervention Strategies (United States)

    DuPaul, George J.; Weyandt, Lisa L.; Janusis, Grace M.


    School-related difficulties are commonly associated with attention deficit hyperactivity disorder (ADHD). This article describes effective school-based intervention strategies including behavioral interventions, modifications to academic instruction, and home-school communication programs. One overlooked aspect of treatment of children with ADHD…

  8. Ergonomics intervention in manual handling of oxygen

    Directory of Open Access Journals (Sweden)

    M Motamedzadeh


    Conclusion: With the implementation of ergonomic intervention is casting unit, the risk of exposure to musculoskeletal disorders caused by manual handling of oxygen cylinders was eliminated and safety of employees against the risk of explosion of the cylinders in comparison with before the intervention was improved.

  9. Adapting Behavioral Interventions for Social Media Delivery (United States)

    Waring, Molly E; May, Christine N; Ding, Eric Y; Kunz, Werner H; Hayes, Rashelle; Oleski, Jessica L


    Patients are increasingly using online social networks (ie, social media) to connect with other patients and health care professionals—a trend called peer-to-peer health care. Because online social networks provide a means for health care professionals to communicate with patients, and for patients to communicate with each other, an opportunity exists to use social media as a modality to deliver behavioral interventions. Social media-delivered behavioral interventions have the potential to reduce the expense of behavioral interventions by eliminating visits, as well as increase our access to patients by becoming embedded in their social media feeds. Trials of online social network-delivered behavioral interventions have shown promise, but much is unknown about intervention development and methodology. In this paper, we discuss the process by which investigators can translate behavioral interventions for social media delivery. We present a model that describes the steps and decision points in this process, including the necessary training and reporting requirements. We also discuss issues pertinent to social media-delivered interventions, including cost, scalability, and privacy. Finally, we identify areas of research that are needed to optimize this emerging behavioral intervention modality. PMID:26825969

  10. The EHDI and Early Intervention Connection (United States)

    Nelson, Lauri; Bradham, Tamala S.; Houston, K. Todd


    State coordinators of early hearing detection and intervention (EHDI) programs completed a strengths, weaknesses, opportunities, and threats, or SWOT, analysis that examined 12 areas within state EHDI programs. For the early intervention focus question, 48 coordinators listed 273 items, and themes were identified within each SWOT category. A…

  11. Language learning interventions | Kilfoil | Journal for Language ...

    African Journals Online (AJOL)

    The results for that intervention show that the hypothesis was correct and students need more time and structure if they are to improve their language competence sufficiently. Keywords: language learning interventions, English for specific purposes, language competence, fossilization. Journal for Language Teaching Vol.

  12. Public health interventions: evaluating the economic evaluations

    Directory of Open Access Journals (Sweden)

    Martin Forster


    Full Text Available Recent years have witnessed much progress in the incorporation of economic considerations into the evaluation of public health interventions. In England, the Centre for Public Health Excellence within the National Institute for Health and Care Excellence works to develop guidance for preventing illness and assessing which public health interventions are most effective and provide best value for money...

  13. Radiation exposure in CT-guided interventions

    Energy Technology Data Exchange (ETDEWEB)

    Kloeckner, Roman, E-mail: [Department of Diagnostic and Interventional Radiology, Johannes Gutenberg-University, Langenbeckstraße 1, 55131 Mainz (Germany); Santos, Daniel Pinto dos; Schneider, Jens [Department of Diagnostic and Interventional Radiology, Johannes Gutenberg-University, Langenbeckstraße 1, 55131 Mainz (Germany); Kara, Levent [Department of Radiology, Inselspital Bern, Freiburgstraße 18, 3010 Bern (Switzerland); Dueber, Christoph; Pitton, Michael B. [Department of Diagnostic and Interventional Radiology, Johannes Gutenberg-University, Langenbeckstraße 1, 55131 Mainz (Germany)


    Purpose: To investigate radiation exposure in computed tomography (CT)-guided interventions, to establish reference levels for exposure, and to discuss strategies for dose reduction. Materials and methods: We analyzed 1576 consecutive CT-guided procedures in 1284 patients performed over 4.5 years, including drainage placements; biopsies of different organs; radiofrequency and microwave ablations (RFA/MWA) of liver, bone, and lung tumors; pain blockages, and vertebroplasties. Data were analyzed with respect to scanner settings, overall radiation doses, and individual doses of planning CT series, CT intervention, and control CT series. Results: Eighy-five percent of the total radiation dose was applied during the pre- and post-interventional CT series, leaving only 15% applied by the CT-guided intervention itself. Single slice acquisition was associated with lower doses than continuous CT-fluoroscopy (37 mGy cm vs. 153 mGy cm, p < 0.001). The third quartile of radiation doses varied considerably for different interventions. The highest doses were observed in complex interventions like RFA/MWA of the liver, followed by vertebroplasty and RFA/MWA of the lung. Conclusions: This paper suggests preliminary reference levels for various intervention types and discusses strategies for dose reduction. A multicenter registry of radiation exposure including a broader spectrum of scanners and intervention types is needed to develop definitive reference levels.

  14. Attention Deficit Hyperactivity Disorder Intervention: Strategies ...

    African Journals Online (AJOL)

    The need for teachers' intervention strategies has been extensively discussed in this paper with a view of developing an intervention programme in other to promote care and support for the pupils who manifest symptoms of ADHD. It is recommended among other things that teachers' knowledge should be enhanced to ...

  15. Estimating the Costs of Preventive Interventions (United States)

    Foster, E. Michael; Porter, Michele M.; Ayers, Tim S.; Kaplan, Debra L.; Sandler, Irwin


    The goal of this article is to improve the practice and reporting of cost estimates of prevention programs. It reviews the steps in estimating the costs of an intervention and the principles that should guide estimation. The authors then review prior efforts to estimate intervention costs using a sample of well-known but diverse studies. Finally,…

  16. Adapting Behavioral Interventions for Social Media Delivery. (United States)

    Pagoto, Sherry; Waring, Molly E; May, Christine N; Ding, Eric Y; Kunz, Werner H; Hayes, Rashelle; Oleski, Jessica L


    Patients are increasingly using online social networks (ie, social media) to connect with other patients and health care professionals--a trend called peer-to-peer health care. Because online social networks provide a means for health care professionals to communicate with patients, and for patients to communicate with each other, an opportunity exists to use social media as a modality to deliver behavioral interventions. Social media-delivered behavioral interventions have the potential to reduce the expense of behavioral interventions by eliminating visits, as well as increase our access to patients by becoming embedded in their social media feeds. Trials of online social network-delivered behavioral interventions have shown promise, but much is unknown about intervention development and methodology. In this paper, we discuss the process by which investigators can translate behavioral interventions for social media delivery. We present a model that describes the steps and decision points in this process, including the necessary training and reporting requirements. We also discuss issues pertinent to social media-delivered interventions, including cost, scalability, and privacy. Finally, we identify areas of research that are needed to optimize this emerging behavioral intervention modality.

  17. Internet interventions for depressive disorders: an overview

    NARCIS (Netherlands)

    Cuijpers, P.; Riper, H.


    Research on psychotherapeutic internet interventions started in the late 1990s and since then a considerable number of trials have shown that these interventions are effective in the treatment of depression. There is also no reason to assume that they are less effective than face-to-face treatments.

  18. Beauty and Hope: A Moral Beauty Intervention (United States)

    Diessner, Rhett; Rust, Teri; Solom, Rebecca C.; Frost, Nellie; Parsons, Lucas


    Pedagogical intervention regarding engagement with natural, artistic and moral beauty can lead to an increase in trait hope. In a quasi-experimental design with college students the intervention group showed significantly higher gain scores on trait hope than did the comparison group; the effect size was moderate. The experimental group also…

  19. The Dutch Intervention and Implementation Law. A personal intervention

    International Nuclear Information System (INIS)

    Aarts, V.P.


    The Electricity Act 1998 and the Gas Act have been changed drastically through the so-called I+I Act (Intervention and Implementation Act) of 1 July 2004. One of the changes is related to the way in which rules are set in connection with regulated third party access to the electricity and gas networks. Under the Electricity Act 1998 these rules ('codes') have traditionally been set by DTE, the energy market regulator, with the involvement of the joint network operators and market representative organisations. Pursuant to the I+I Act the DTe will have to set similar rules for regulated access to the gas networks. In addition, the I+I Act requires that the Minister of Economic affairs adopts regulations in ministerial decrees. The DTe rules must comply with these decrees. This effectively adds a regulatory layer to the existing regulatory framework for electricity and gas network rTPA. The decrees are subject to prior Parliamentary approval. After a brief overview of legal history, this contribution criticizes the introduction of an extra regulatory layer. The I+I Act has failed to specify the subjects which the ministerial decrees should address and to what extent they should contain specific norms. This results in a situation where it is effectively up to the minister to decide where and to what extent the DTe and energy market players will be made subject to superior norms. While hardly creating additional value, the new regulatory set-up threatens to cause legal uncertainty and procedural ambiguities and it provides an added platform for lobby groups to canvass their wish lists. Concluding remarks set out that the I+I Act has equipped the minister and the DTe with new powers and enhanced the ministers' accountability to Parliament, but that it has failed to mark out the norms which the legislator deems essential to the welt-functioning of the energy markets. A comprehensive approach to the respective roles of legislator, policy maker and regulator in setting

  20. An Assessment of Intervention Fidelity in Published Social Work Intervention Research Studies (United States)

    Corley, Nicole A.; Kim, Irang


    Objectives: Intervention fidelity is a critical strategy to help advance the usefulness and integrity of social work research. This study assessed the extent to which a selected sample of published social work intervention researchers reported its intervention protocols. Methods: Six core social work journals were reviewed in this analysis. The…

  1. Science, Social Work, and Intervention Research: The Case of "Critical Time Intervention" (United States)

    Jenson, Jeffrey M.


    Intervention research is an important, yet often neglected, focus of social work scholars and investigators. The purpose of this article is to review significant milestones and recent advances in intervention research. Methodological and analytical developments in intervention research are discussed in the context of science and social work.…

  2. Music-based interventions in neurological rehabilitation. (United States)

    Sihvonen, Aleksi J; Särkämö, Teppo; Leo, Vera; Tervaniemi, Mari; Altenmüller, Eckart; Soinila, Seppo


    During the past ten years, an increasing number of controlled studies have assessed the potential rehabilitative effects of music-based interventions, such as music listening, singing, or playing an instrument, in several neurological diseases. Although the number of studies and extent of available evidence is greatest in stroke and dementia, there is also evidence for the effects of music-based interventions on supporting cognition, motor function, or emotional wellbeing in people with Parkinson's disease, epilepsy, or multiple sclerosis. Music-based interventions can affect divergent functions such as motor performance, speech, or cognition in these patient groups. However, the psychological effects and neurobiological mechanisms underlying the effects of music interventions are likely to share common neural systems for reward, arousal, affect regulation, learning, and activity-driven plasticity. Although further controlled studies are needed to establish the efficacy of music in neurological recovery, music-based interventions are emerging as promising rehabilitation strategies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Neuropsychological intervention in the acute phase

    DEFF Research Database (Denmark)

    Norup, Anne; Siert, Lars; Mortensen, Erik Lykke


    This pilot study investigated the effects of acute neuropsychological intervention for relatives of patients with severe brain injury. Participants were enrolled in an intervention group comprising 39 relatives, and a control group comprising 47 relatives. The intervention consisted of supportive......-acute rehabilitation. Outcome measures included selected scales from the Symptom Checklist Revised 90 (SCL-90-R), the Short Form 36 (SF-36), and a visual analogue quality of life scale. The intervention group showed a significant decrease in anxiety scores from the acute to the sub-acute setting (= 2.70 = 0.......0100.30), but also significantly lower Role Emotional scores (= 2.12 = 0.043, = 0.40). In the sub-acute setting, an analysis of covariance model showed a borderline significant difference between the intervention and the control group on the anxiety scale (= 0.066 = 0.59). Any effects of the acute neuropsychological...

  4. What Does Competence Entail in Interventional Radiology?

    International Nuclear Information System (INIS)

    Ahmed, Kamran; Keeling, Aoife N.; Khan, Reenam S.; Ashrafian, Hutan; Arora, Sonal; Nagpal, Kamal; Burrill, Joshua; Darzi, Ara; Athanasiou, Thanos; Hamady, Mohamad


    Interventional radiology is a relatively new speciality and may be referred to as 'image-guided surgery without a scalpel.' Training and accreditation bodies regard interventional radiology training as being 'different' from general radiology because of the additional need for dexterity and clinical acumen. Due to the multidimensional role of an interventional radiologist, a practitioner in this discipline must have a number of the competencies of anesthetists, surgeons, and radiologists. The attributes required of an interventional radiologist are akin to those required of a surgeon. This paper gives an overview of the skills required to be a competent interventional radiologist along with a succinct introduction to methods of assessment of technical and non-technical skills.

  5. Parents' Evaluation of the IDEFICS Intervention

    DEFF Research Database (Denmark)

    Nicholls, Stuart G.; Pohlabeln, Hermann; De Bourdeaudhuij, Ilse


    Introduction: From April 2008 to August 2010 the Identification and prevention of Dietary- and lifestyle-induced health EFfects In Children and infantS (IDEFICS) intervention aimed to encourage healthier diets, higher physical activity levels and lower stress levels among European children and th...... the results represent a broad endorsement of the IDEFICS intervention, they also suggest the importance of vigilance concerning the psychological effects of obesity interventions on overweight and obese children....... positive difference, but also more likely to report that the intervention had had negative effects. Parents of overweight and obese children were more likely to report negative effects - above all, that 'the intervention had made their child feel as if he/she was "fat" or "overweight." Conclusion: While...

  6. An Educational–Vocational Intervention

    Directory of Open Access Journals (Sweden)

    Kalervo Friberg


    Full Text Available Changes in student-affective entry characteristics were examined in an educational−vocational intervention at Finnish comprehensive school. The conceptual framework constructed from attitudes as learned dispositions (Fishbein & Ajzen, 1975 and self-determination (Deci & Ryan, 1985 was tested in a longitudinal study. A person-based survey questionnaire was designed, piloted, and validated. Spearman−Brown reliability was calculated. In the first observation, 669 (Time One Cohort, and in the second, 649 (Time Two Cohort subjects (girls and boys of mean ages of 14.5 and 16.0 years took the Web-based survey. The tested hypotheses were (a variables of self-determination, self-regulation, and intrinsic and extrinsic motivation would emerge as attitudinal domains in work−life orientation; (b the experiences during the implementation of a work−life orientation program would decrease the effects of seventh-grade student background factors at the end of the program in the ninth grade, and (c work−life orientation would be effective and have efficacy in changing student attitudes in relation to further education and occupations. Three factors emerged in the Maximum Likelihood Factor Analysis. The factors Independence, Self-Direction, and Flexibility were used as the dependents in repeated measures in a general linear model. The factor means were subjected to a paired samples t test. There was development toward stronger Independence and Flexibility in the case of both genders. The boys had gained the girls’ seventh-grade lead at the end of the program. Self-Direction did not show any changes. Empirical findings tentatively supported the program’s efficacy in changing entry characteristics.

  7. ALARA and planning of interventions

    Energy Technology Data Exchange (ETDEWEB)

    Rocaboy, A. [Electricite de France, Avoine (France)


    The implementation of ALARA programs implies integration of radiation protection criterion at all stages of outage management. Within the framework of its ALARA policy, Electricide de France (EDF) has given an incentive to all of its nuclear power plants to develop {open_quotes}good practices{close_quotes} in this domain, and to exchange their experience by the way of a national feed back file. Among the developments in the field of outage organization, some plants have focused on the planning stage of activities because of its influence on the radiological conditions of interventions and on the good succession of tasks within the radiological controlled areas. This paper presents the experience of Chinon nuclear power plant. At Chinon, we are pursuing this goal through careful outage planning. We want the ALARA program during outages to be part of the overall maintenance task planning. This planning includes the provision of the availability of every safety-related component, and of the variations of water levels in hthereactor and steam generators to take advantage of the shield created by the water. We have developed a computerized data base with the exact position of all the components in the reactor building in order to avoid unnecessary interactions between different tasks performed in the same room. A common language between Operation and Maintenance had been established over the past years, using {open_quotes}Milestones and Corridors{close_quotes}. A real time dose rate counting system enables the Radiation Protection (RP) Department to do an accurate and efficient follow up during the outage for all the {open_quotes}ALARA{close_quotes} maintenance tasks.

  8. Pharmacological interventions for acute pancreatitis. (United States)

    Moggia, Elisabetta; Koti, Rahul; Belgaumkar, Ajay P; Fazio, Federico; Pereira, Stephen P; Davidson, Brian R; Gurusamy, Kurinchi Selvan


    In people with acute pancreatitis, it is unclear what the role should be for medical treatment as an addition to supportive care such as fluid and electrolyte balance and organ support in people with organ failure. To assess the effects of different pharmacological interventions in people with acute pancreatitis. We searched the Cochrane Central Register of Controlled Trials (CENTRAL, 2016, Issue 9), MEDLINE, Embase, Science Citation Index Expanded, and trial registers to October 2016 to identify randomised controlled trials (RCTs). We also searched the references of included trials to identify further trials. We considered only RCTs performed in people with acute pancreatitis, irrespective of aetiology, severity, presence of infection, language, blinding, or publication status for inclusion in the review. Two review authors independently identified trials and extracted data. We did not perform a network meta-analysis as planned because of the lack of information on potential effect modifiers and differences of type of participants included in the different comparisons, when information was available. We calculated the odds ratio (OR) with 95% confidence intervals (CIs) for the binary outcomes and rate ratios with 95% CIs for count outcomes using a fixed-effect model and random-effects model. We included 84 RCTs with 8234 participants in this review. Six trials (N = 658) did not report any of the outcomes of interest for this review. The remaining 78 trials excluded 210 participants after randomisation. Thus, a total of 7366 participants in 78 trials contributed to one or more outcomes for this review. The treatments assessed in these 78 trials included antibiotics, antioxidants, aprotinin, atropine, calcitonin, cimetidine, EDTA (ethylenediaminetetraacetic acid), gabexate, glucagon, iniprol, lexipafant, NSAIDs (non-steroidal anti-inflammatory drugs), octreotide, oxyphenonium, probiotics, activated protein C, somatostatin, somatostatin plus omeprazole, somatostatin

  9. Proposals for regulating future humanitarian interventions

    Directory of Open Access Journals (Sweden)

    Raičević Nebojša


    Full Text Available Although the legality of approved humanitarian intervention is undisputable in the positive international law, this legal institute should be further regulated in order to remove certain legal ambiguity and difficulties in its application. The future regulation of humanitarian intervention may be carried out in one of the three ways: by adopting a special international treaty, by entering amendments in the UN Charter, or by embarking on the factual revision of the UN Charter. Due to the limiting effects of Article 103 of the UN Charter as well as the problematic status of UN member states which would not ratify the international agreements on humanitarian intervention, the regulation of future humanitarian intervention seems to be the least likely option. Formal revision of the UN Charter is not a viable option either because, thus far, the major world powers have been against introducing any substantial changes to this treaty. For this reason, the factual revision of the UN Charter is currently the most appropriate way of regulating future humanitarian interventions. When it comes to substantive rules governing humanitarian intervention, it is necessary to focus on the problem of humanitarian intervention decision-making as well as on the conditions and criteria for the approval and carrying out a humanitarian intervention. The UN Security Council must retain the right to decide on approving such an intervention but it is also necessary to establish an independent expert body whose task would be to determine the presence of serious and mass violations of human rights in a specific country and notify the Security Council about such occurrences. The specification of conditions and criteria for undertaking a humanitarian intervention should strengthen its legitimacy and prevent unreasonable disruption of states' territorial integrity and political independence.

  10. Social media interventions to prevent HIV: A review of interventions and methodological considerations. (United States)

    Tso, Lai Sze; Tang, Weiming; Li, Haochu; Yan, H Yanna; Tucker, Joseph D


    Persistent new HIV infections and risky behaviors underscore the need for enhanced HIV prevention. Social media interventions may promote safe sexual behaviors, increase HIV testing uptake, and promote safe injection behaviors. This review discusses how social media interventions tap into the wisdom of crowds through crowdsourcing, build peer-mentored communities, and deliver interventions through social networks. Social media HIV prevention interventions are constrained by ethical issues, low social media usage among some key populations, and implementation issues. Comprehensive measurement of social media interventions to prevent HIV is necessary, but requires further development of metrics.

  11. Intervention quality is not routinely assessed in Cochrane systematic reviews of radiation therapy interventions. (United States)

    Abdul Rahim, Mohamad R; James, Melissa L; Hickey, Brigid E


    The aim of this study was to maximise the benefits from clinical trials involving technological interventions such as radiation therapy. High compliance to the quality assurance protocols is crucial. We assessed whether the quality of radiation therapy intervention was evaluated in Cochrane systematic reviews. We searched 416 published Cochrane systematic reviews and identified 67 Cochrane systematic reviews that investigated radiation therapy or radiotherapy as an intervention. For each systematic review, either quality assurance or quality control for the intervention was identified by a description of such processes in the published systematic reviews. Of the 67 Cochrane systematic reviews studied, only two mentioned quality assurance or quality control. Our findings revealed that 65 of 67 (97%) Cochrane systematic reviews of radiation therapy interventions failed to consider the quality of the intervention. We suggest that advice about the evaluation of intervention quality be added to author support materials. © 2017 The Royal Australian and New Zealand College of Radiologists.

  12. The current practices of intervention with batterers

    Directory of Open Access Journals (Sweden)

    Olga Cunha


    Full Text Available Background Since the 70s there was a proliferation of intervention programs for batterers; however the results remain controversial. Objectives This study aims to analyse the literature published between the years of 2000 and 2013 about the effectiveness of the intervention with batterers. Methods A review of papers about intervention with batterers published during this period (2000-2013 was conducted. Social sciences databases were checked. Papers about programs for a specific public or programs with a broad intervention focus, and with female and homosexual offenders were excluded. Results Thirty-six studies that described 37 intervention programs fulfilled the inclusion criteria. In general, the analysed programs adopted a group format (70.3% and a cognitive-behavioural (56.8% or psychoeducational (18.9% intervention model (32.4% assumed to adopt a Duluth model. Concerning the effectiveness, results showed success rates of 39.4%-97%, dropout rates of 10%-58% and recidivism rates of 0%-65.9%. Discussion The effectiveness of intervention with batterers remains controversial, which seems to be due to the different methodologies used in the studies. Despite the inconsistencies, programs for perpetrators are an important way to reduce intimate partner violence recidivism.

  13. Interventional Cardiology for Congenital Heart Disease. (United States)

    Kenny, Damien


    Congenital heart interventions are now replacing surgical palliation and correction in an evolving number of congenital heart defects. Right ventricular outflow tract and ductus arteriosus stenting have demonstrated favorable outcomes compared to surgical systemic to pulmonary artery shunting, and it is likely surgical pulmonary valve replacement will become an uncommon procedure within the next decade, mirroring current practices in the treatment of atrial septal defects. Challenges remain, including the lack of device design focused on smaller infants and the inevitable consequences of somatic growth. Increasing parental and physician expectancy has inevitably lead to higher risk interventions on smaller infants and appreciation of the consequences of these interventions on departmental outcome data needs to be considered. Registry data evaluating congenital heart interventions remain less robust than surgical registries, leading to a lack of insight into the longer-term consequences of our interventions. Increasing collaboration with surgical colleagues has not been met with necessary development of dedicated equipment for hybrid interventions aimed at minimizing the longer-term consequences of scar to the heart. Therefore, great challenges remain to ensure children and adults with congenital heart disease continue to benefit from an exponential growth in minimally invasive interventions and technology. This can only be achieved through a concerted collaborative approach from physicians, industry, academia and regulatory bodies supporting great innovators to continue the philosophy of thinking beyond the limits that has been the foundation of our specialty for the past 50 years. Copyright © 2018. The Korean Society of Cardiology.

  14. Intervention program efficacy for spelling difficulties. (United States)

    Sampaio, Maria Nobre; Capellini, Simone Aparecida


    To develop an intervention procedure for spelling difficulties and to verify the effectiveness of the intervention program in students with lower spelling performance. We developed an intervention program for spelling difficulties, according to the semiology of the errors. The program consisted of three modules totaling 16 sessions. The study included 40 students of the third to fifth grade of public elementary education of the city of Marilia (SP), of both genders, in aged of eight to 12 years old, being distributed in the following groups: GI (20 students with lower spelling performance) and GII (20 students with higher spelling performance). In situation of pre and post-testing, all groups were submitted to the Pro-Orthography. The results statistically analyzed showed that, in general, all groups had average of right that has higher in post-testing, reducing the types of errors second semiologycal classification, mainly related to natural spelling errors. However, the results also showed that the groups submitted to the intervention program showed better performance on spelling tests in relation to not submitted. The intervention program developed was effective once the groups submitted showed better performance on spelling tests in relation to not submitted. Therefore, the intervention program can help professionals in the Health and Education to minimize the problems related to spelling, giving students an intervention that is effective for the development of the spelling knowledge.

  15. Effectiveness of Evidence-Based Asthma Interventions. (United States)

    Kennedy, Suzanne; Bailey, Ryan; Jaffee, Katy; Markus, Anne; Gerstein, Maya; Stevens, David M; Lesch, Julie Kennedy; Malveaux, Floyd J; Mitchell, Herman


    Researchers often struggle with the gap between efficacy and effectiveness in clinical research. To bridge this gap, the Community Healthcare for Asthma Management and Prevention of Symptoms (CHAMPS) study adapted an efficacious, randomized controlled trial that resulted in evidence-based asthma interventions in community health centers. Children (aged 5-12 years; N = 590) with moderate to severe asthma were enrolled from 3 intervention and 3 geographically/capacity-matched control sites in high-risk, low-income communities located in Arizona, Michigan, and Puerto Rico. The asthma intervention was tailored to the participant's allergen sensitivity and exposure, and it comprised 4 visits over the course of 1 year. Study visits were documented and monitored prospectively via electronic data capture. Asthma symptoms and health care utilization were evaluated at baseline, and at 6 and 12 months. A total of 314 intervention children and 276 control children were enrolled in the study. Allergen sensitivity testing (96%) and home environmental assessments (89%) were performed on the majority of intervention children. Overall study activity completion (eg, intervention visits, clinical assessments) was 70%. Overall and individual site participant symptom days in the previous 4 weeks were significantly reduced compared with control findings (control, change of -2.28; intervention, change of -3.27; difference, -0.99; P asthma in these high-need populations. Copyright © 2017 by the American Academy of Pediatrics.

  16. Family Intervention in First-Episode Psychosis

    Directory of Open Access Journals (Sweden)

    Anvar Sadath


    Full Text Available Family interventions have produced benefits on clinical and family outcomes in long standing psychosis. However, little is known about the efficacy of such interventions in the early stages of psychosis. This article reviews published research over the last two decades on family intervention in first-episode psychosis. Electronic databases, such as PubMed, PsycINFO, and ScienceDirect, have been systematically searched. In addition, an exhaustive Internet search was also carried out using Google and Google Scholar to identify the potential studies that evaluated family interventions in first-episode psychosis. We have identified seven reports of five randomized controlled trials (RCTs and five non-randomized and uncontrolled studies of family intervention. Our review on 12 reports of family intervention studies has shown mixed effects on outcomes in first-episode psychosis. Most of the reports showed no added benefits or very short-term benefits on primary clinical or family outcome variables. There is a dearth of family intervention studies in first-episode psychosis. More RCTs are needed to reach reliable conclusions.

  17. Developing an intervention to overcome procrastination. (United States)

    Otermin-Cristeta, Solange; Hautzinger, Martin


    The main goal of this study was the development of a reliable intervention to overcome general procrastination orientated to college students, designed to be used in practical clinical work. The workshops involved six meetings based on behavioral and cognitive techniques, paradox intervention, and psychoeducation. 175 students participated voluntarily. Their procrastination levels were measured in a pretest, post-test, and a 3-month follow-up. After the first interview, the participants were randomly divided into three groups (Intervention A, Intervention B, and a control group with no intervention). There was a significant improvement after the intervention. After 3 months, the average score was still significantly lower than in the pretest, whereas the score of the control group remained unchanged. The participants in Workshop A scored significantly lower in the post-test than the ones in Workshop B. After 3 months, the participants in Workshop B scored significantly lower in the follow up. So both interventions resulted to be effective in reducing procrastination sustainably.

  18. E-health interventions for suicide prevention. (United States)

    Christensen, Helen; Batterham, Philip J; O'Dea, Bridianne


    Many people at risk of suicide do not seek help before an attempt, and do not remain connected to health services following an attempt. E-health interventions are now being considered as a means to identify at-risk individuals, offer self-help through web interventions or to deliver proactive interventions in response to individuals' posts on social media. In this article, we examine research studies which focus on these three aspects of suicide and the internet: the use of online screening for suicide, the effectiveness of e-health interventions aimed to manage suicidal thoughts, and newer studies which aim to proactively intervene when individuals at risk of suicide are identified by their social media postings. We conclude that online screening may have a role, although there is a need for additional robust controlled research to establish whether suicide screening can effectively reduce suicide-related outcomes, and in what settings online screening might be most effective. The effectiveness of Internet interventions may be increased if these interventions are designed to specifically target suicidal thoughts, rather than associated conditions such as depression. The evidence for the use of intervention practices using social media is possible, although validity, feasibility and implementation remains highly uncertain.

  19. Quasi experimental designs in pharmacist intervention research. (United States)

    Krass, Ines


    Background In the field of pharmacist intervention research it is often difficult to conform to the rigorous requirements of the "true experimental" models, especially the requirement of randomization. When randomization is not feasible, a practice based researcher can choose from a range of "quasi-experimental designs" i.e., non-randomised and at time non controlled. Objective The aim of this article was to provide an overview of quasi-experimental designs, discuss their strengths and weaknesses and to investigate their application in pharmacist intervention research over the previous decade. Results In the literature quasi experimental studies may be classified into five broad categories: quasi-experimental design without control groups; quasi-experimental design that use control groups with no pre-test; quasi-experimental design that use control groups and pre-tests; interrupted time series and stepped wedge designs. Quasi-experimental study design has consistently featured in the evolution of pharmacist intervention research. The most commonly applied of all quasi experimental designs in the practice based research literature are the one group pre-post-test design and the non-equivalent control group design i.e., (untreated control group with dependent pre-tests and post-tests) and have been used to test the impact of pharmacist interventions in general medications management as well as in specific disease states. Conclusion Quasi experimental studies have a role to play as proof of concept, in the pilot phases of interventions when testing different intervention components, especially in complex interventions. They serve to develop an understanding of possible intervention effects: while in isolation they yield weak evidence of clinical efficacy, taken collectively, they help build a body of evidence in support of the value of pharmacist interventions across different practice settings and countries. However, when a traditional RCT is not feasible for

  20. Early psychosocial intervention in Alzheimer's disease

    DEFF Research Database (Denmark)

    Søgaard, Rikke; Sørensen, Jan; Waldorff, Frans B


    in five Danish districts. PARTICIPANTS: 330 community-dwelling patients and their primary caregivers. INTERVENTION: Psychosocial counselling and support lasting 8-12 months after diagnosis and follow-up at 3, 6, 12 and 36 months in the intervention group or follow-up only in the control group. MAIN...... and the caregiver before aggregation for the main analysis. RESULTS: None of the observed cost and QALY measures were significantly different between the intervention and control groups, although a tendency was noted for psychosocial care leading to cost increases with informal care that was not outweighed...