Encapsulation and Outdoor Testing of Perovskite Solar Cells: Comparing Industrially Relevant Process with a Simplified Lab Procedure.

Perovskite solar cells (PSCs) have shown great potential for next-generation photovoltaics. One of the main barriers to their commercial use is their poor long-term stability under ambient conditions and, in particular, their sensitivity to moisture and oxygen. Therefore, several encapsulation strategies are being developed in an attempt to improve the stability of PSCs in a humid environment. The lack of common testing procedures makes the comparison of encapsulation strategies challenging. In this paper, we optimized and investigated two common encapsulation strategies: lamination-based glass-glass encapsulation for outdoor operation and commercial use (COM) and a simple glue-based encapsulation mostly utilized for laboratory research purposes (LAB). We compare both approaches and evaluate their effectiveness to impede humidity ingress under three different testing conditions: on-shelf storage at 21 °C and 30% relative humidity (RH) (ISOS-D1), damp heat exposure at 85 °C and 85% RH (ISOS-D3), and outdoor operational stability continuously monitoring device performance for 10 months under maximum power point tracking on a roof-top test site in Berlin, Germany (ISOS-O3). LAB encapsulation of perovskite devices consists of glue and a cover glass and can be performed at ambient temperature, in an inert environment without the need for complex equipment. This glue-based encapsulation procedure allowed PSCs to retain more than 93% of their conversion efficiency after 1566 h of storage in ambient atmosphere and, therefore, is sufficient and suitable as an interim encapsulation for cell transport or short-term experiments outside an inert atmosphere. However, this simple encapsulation does not pass the IEC 61215 damp heat test and hence results in a high probability of fast degradation of the cells under outdoor conditions. The COM encapsulation procedure requires the use of a vacuum laminator and the cells to be able to withstand a short period of air exposure and at least 20 min at elevated temperatures (in our case, 150 °C). This encapsulation method enabled the cells to pass the IEC 61215 damp heat test and even to retain over 95% of their initial efficiency after 1566 h in a damp heat chamber. Above all, passing the damp heat test for COM-encapsulated devices translates to devices fully retaining their initial efficiency for the full duration of the outdoor test (>10 months). To the best of the authors' knowledge, this is one of the longest outdoor stability demonstrations for PSCs published to date. We stress that both encapsulation approaches described in this work are useful for the scientific community as they fulfill different purposes: the COM for the realization of prototypes for long-term real-condition validation and, ultimately, commercialization of perovskite solar cells and the LAB procedure to enable testing and carrying out experiments on perovskite solar cells under noninert conditions.

Efficiency of new custom-made pulse oximeter sensor holder in assessment of actual pulp status.

AIM: This study aims to assess the diagnostic accuracy of new custom-made pulse oximeter sensor holder in assessment of actual pulp status with three pulp sensibility tests. MATERIALS AND METHODS: Seventy-nine single canal teeth requiring endodontic therapy was included in the study. The tooth that was requiring root canal treatment was tested with heat test, cold test, electric pulp test, and pulse oximeter. Between each test, a time period of 2 min was allowed. The response from three pulp sensibility tests and the reading from pulse oximeter were recorded. Following which root canal treatment was performed. The result obtained from four pulp tests were correlated with the clinical finding after access cavity preparation. The data obtained was statistically assessed. Receiver operator characteristic (ROC) curve analysis was performed to assess the efficacy of the pulp tests. In the above statistical tools, the probability value. 05 is considered as significant level. RESULTS: The overall diagnostic accuracy was found to be significantly higher with pulse oximeter when compared with other three pulp sensibility tests. The ROC curve demonstrates the results obtained from pulse oximeter was found to be more reliable than other pulp tests. CONCLUSION: Within the limitation of the study, diagnostic accuracy of pulse oximeter with custom made sensor holder was reliable and accurate in assessment of actual pulp status.

Diagnostic accuracy of dental pulse oximeter with customized sensor holder, thermal test and electric pulp test for the evaluation of pulp vitality: an in vivo study / Precisão diagnóstica do oxímetro de pulso odontológico com suporte de sensor personalizado, teste térmico e teste elétrico da polpa para avaliação da vitalidade pulpar: um estudo in vivo

Background: the efficiency of the diagnostic aids plays an important role in the treatment plan. This study aims to assess the diagnostic accuracy of dental pulse oximeter with a customized sensor holder, thermal test and electric pulp tester in assessing the actual pulp status and to evaluate the oxygen saturation level in control healthy teeth, non-vital and teeth with irreversible pulpitis. Material and methods: thirty-seven single canal teeth requiring endodontic therapy were included in the study. The selected teeth were tested with dental pulse oximeter, electric pulp test, cold spray, and heated gutta percha stick. Between each test a time lag of 2 minutes was allowed for the central sensitization to occur. Three blinded operators were involved in the study. The actual status of the pulp was evaluated after the initiation of endodontic treatment, by direct visual examination of the accessed cavity. The data was statistically analysed using (ANOVA) Analysis of Variance and Post-hoc Tukey test. Results: sensitivity of pulse oximeter, heat test, cold and electric pulp test, was 100, 25, 50, and 12, respectively. The specificity of these tests was 100, 72 81, and 77, respectively. The ANOVA showed that there was statistical difference between all the groups (p=0.0005). Post-Hoc Tukey revealed that there was statistical difference among all the groups, nonvital group (p=0.0005), control group (p=0.01) and for irreversible pulpitis (p=0.01). The overall diagnostic accuracy of pulse oximeter was 100% followed by cold test 66%, heat test to be 49% and electric pulp test to be 45%. Conclusion: the custom-made holder used in the present study aided in providing accurate response for pulp vitality testing. In this study the diagnostic accuracy was high with dental pulse oximeter followed by cold, heat and the least was electric pulp tester in different pulpal conditions. (AU)

Fundamentação: a eficiência dos meios de diagnóstico desempenha um papel importante no plano de tratamento. Este estudo tem como objetivo avaliar a precisão diagnóstica do oxímetro de pulso odontológico com um suporte de sensor personalizado, teste térmico e testador de polpa elétrico na avaliação da condição pulpar e na avaliação do nível de saturação de oxigênio em dentes controle saudáveis, não vitais e dentes com pulpite irreversível. Material e métodos: trinta e sete dentes de canal único que necessitavam de terapia endodôntica foram incluídos no estudo. Os dentes selecionados foram testados com oxímetro de pulso, teste pulpar elétrico, spray frio e bastão de guta-percha aquecido. Entre cada teste, foi permitido um intervalo de tempo de 2 minutos para a sensibilização central ocorrer. Três operadores cegos foram envolvidos no estudo. A condição real da polpa foi avaliada após o início do tratamento endodôntico, por meio de exame visual direto da cavidade de acesso. Os dados foram analisados estatisticamente pelo teste de Análise de Variância (ANOVA) e pelo teste Post-hoc de Tukey. Resultados: a sensibilidade do oxímetro de pulso, teste de calor, de frio e teste pulpar elétrico foi de 100, 25, 50 e 12, respectivamente. A especificidade desses testes foi de 100, 72 81 e 77, respectivamente. O teste de ANOVA mostrou que houve diferença estatística entre todos os grupos (p = 0,0005). O teste Post-Hoc de Tukey revelou que houve diferença estatística entre todos os grupos, grupo não-vital (p = 0,0005), grupo controle (p = 0,01) e pulpite irreversível (p = 0,01). A precisão diagnóstica geral do oxímetro de pulso foi de 100%, seguida pelo teste a frio de 66%, o teste de calor a 49% e o teste pulpar elétrico a 45%. Conclusão: o suporte personalizado utilizado no presente estudo ajudou a fornecer uma resposta precisa para o teste de vitalidade pulpar. Neste estudo, a precisão diagnóstica foi alta com o oxímetro de pulso dental, seguido do teste com frio e calor, sendo o teste elétrico o menos eficaz nas diferentes condições pulpares testadas.(AU)

Diagnostic Accuracy of 5 Dental Pulp Tests: A Systematic Review and Meta-analysis.

INTRODUCTION: The aim of this systematic review was to investigate and compare the diagnostic accuracy including sensitivity, specificity, adjusted accuracy, adjusted positive predictive value (PPV), and adjusted negative predictive value (NPV) of cold pulp testing (CPT), heat pulp testing (HPT), electric pulp testing (EPT), laser Doppler flowmetry (LDF), and pulse oximetry (PO). METHODS: Three electronic databases were searched from January 1964 to December 2016. True-positive, false-positive, true-negative, and false-negative values were extracted from data in each study. Sensitivity, specificity, adjusted accuracy, adjusted PPV, and adjusted NPV were calculated from those values, if not presented. A random effects model was used to calculate pooled estimates of sensitivity, specificity, adjusted accuracy, adjusted PPV, and adjusted NPV. RESULTS: A total of 125 articles were identified, and 28 studies were included for the final review. The pooled estimates of sensitivity for CPT, EPT, HPT, LDF, and PO were 0.87, 0.72, 0.78, 0.98, and 0.97, respectively. Those of specificity were 0.84, 0.93, 0.67, 0.95, and 0.95, respectively. Those of adjusted accuracy were 0.84, 0.82, 0.72, 0.97, and 0.97, respectively. For adjusted PPV, they were 0.81, 0.89, 0.62, 0.94, and 0.94, respectively, and for adjusted NPV, they were 0.87, 0.80, 0.79, 1.00, and 0.99, respectively. CONCLUSIONS: LDF and PO were the most accurate diagnostic methods, and HPT was the least accurate diagnostic method. EPT showed high accuracy when testing vital teeth (specificity = 0.93) but low accuracy when assessing nonvital teeth (sensitivity = 0.72). CPT had moderate accuracy when evaluating vital (specificity = 0.84) and nonvital (sensitivity = 0.87) teeth.

Assessment of heat provocation tests on the human gingiva: the effect of periodontal disease and smoking.

UNLABELLED: Periodontal inflammation is associated with morphological changes in the blood vessels which may influence the regulation of gingival blood flow (GBF). Our aim was to adapt the heat provocation test to the human gingiva to assess vascular reactivity in periodontal inflammation. METHOD: GBF was recorded by Laser Doppler Flowmetry before and after heat provocation in healthy volunteers (n = 50). Heat was generated either by warm saline or a halogen lamp. The latter method was also utilized for a heat test in non-smoking and smoking patients with periodontal inflammation. The circulatory parameters were correlated to the inflammatory marker, i.e. gingival crevicular fluid (GCF) production measured by Periotron. RESULTS: Local application of heat caused a rapid, significant and transient increase in GBF regardless of the method used. The increase in the speed and not in the concentration of moving blood cells was responsible for increased GBF. Higher GCF values were correlated with increased peak flow, flux pulse amplitude and faster restoration of GBF after the test in non-smokers, but not in smokers. CONCLUSIONS: The heat test could be a valuable tool to check the vascular reactivity of gingival vessels. Moderate periodontal inflammation may facilitate gingival vascular responsiveness which can be suppressed by smoking.