Search results for "OLED"

Efficacy and safety of direct transnasal cholangioscopy with standard ultraslim endoscopes: results of a large cohort study.

2013

Background Direct cholangioscopy (DC) with ultraslim endoscopes and free-hand cannulation of the common bile duct (CBD) is a promising technique for evaluating and treating cholangiopathy. However, its safety and success rates are as yet unclear. Objective To evaluate the overall success rates and adverse events with the procedure. Design Single-center, prospective cohort study; 12 patients retrospectively enrolled. Setting Academic tertiary referral center. Patients A total of 100 DC procedures in 84 patients with biliary disease were evaluated prospectively. Interventions DC performed with the patient under conscious sedation. Main Outcome Measurements Overall success rates and adverse ev…

Prevalence and risk factors of bisphosphonate-associated osteonecrosis of the jaw in prostate cancer patients with advanced disease treated with zole…

2008

Abstract Background In addition to other treatments, patients with prostate cancer (pCA) and bone metastasis receive bisphosphonates. Since 2003, a previously unknown side-effect of bisphosphonates—bisphosphonate-associated osteonecrosis of the jaws (BP-ONJ)—has been described, and frequency has since increased. An exact incidence is still unknown. Objectives The aim of this study was to assess the incidence and additional factors in the development of BP-ONJ. Design, setting, and participants From July 2006 to October 2007, patients with advanced pCA and osseous metastasis receiving bisphosphonate therapy in the Department of Urology or Haematology and Oncology at the Johannes-Gutenberg-Un…

Associations Between Physical Activity and Perceived School Performance of Young Adolescents in Health Behavior in School-Aged Children Countries

2020

Background: Regular physical activity and doing well in school are important for growing adolescents. In this study, the associations between physical activity and perceived school performance (PSP) are examined together. Methods: Young adolescents from 42 countries (n = 193,949) in Europe and Canada were examined for associations between self-reported moderate to vigorous physical activity (MVPA) and PSP. Multinominal analyses were conducted with 0 to 2 days of MVPA and below average PSP as reference categories. Adjusted odds ratios and 95% confidence intervals were reported for pooled data and individual countries after controlling for family affluence scale. Results: Girls had better PSP…

Starpdisciplinārie pētījumi medicīnas koledžās : tēžu krājums

2021

Latvijas Universitātes 79. starptautiskās zinātniskās konferences “Starpdisciplinārie pētījumi medicīnas koledžās” tēzes raksturo medicīnas koledžās veikto pētījumu daudzpusību, pētniecības kvalitāti un arī lietišķumu, kas šogad izceļas ar raksturvārdiem “drošība” un “atbildība”. Konferencē prezentēto un diskutēto jautājumu loks ievērojami pārsniedz veselības aprūpē apskatīto jautājumu loku un veicinās studentus, pētniekus un sociālos partnerus aktīvāk sadarboties ne tikai studiju kvalitātes uzlabošanā, bet arī pētniecībā.

Hysteresis in the temperature dependence of the IR bending vibration of deeply cooled confined water.

2019

Using Fourier Transform Infrared (FTIR) spectroscopy, we investigate the temperature dependence of the bending vibrations of water confined in the pores of a silica hydrogel in the temperature interval of 270-180 K. We also investigate the presence of thermal hysteresis by cooling and reheating temperature scans. The results clearly show the presence, at about 230 K, of a crossover in the temperature dependence of the IR spectra; moreover, the presence of hysteresis is clearly demonstrated. By comparing FTIR data with neutron diffraction data and previous calorimetric data on the same samples, we conclude that the crossover and the hysteretical behavior do not involve a water glass transiti…

Diarylethenes in Optically Switchable Organic Light-Emitting Diodes: Direct Investigation of the Reversible Charge Carrier Trapping Process

2021

Advanced optical materials 10, (2021). doi:10.1002/adom.202101116

Structure and dynamics of water confined in silica hydrogels: X-ray scattering and dielectric spectroscopy studies.

2003

We have used a sol-gel technique to obtain optically transparent hydrogels in which water is confined within a 3D silica matrix. In this work we report X-ray scattering and dielectric spectroscopy measurements on samples having different aging times and compare them with previously obtained results with near-infrared (NIR) absorption spectroscopy. X-ray scattering at room temperature enables to characterize the structure and size of the matrix pores and the non-uniform distribution of water inside the hydrogel. Broad band dielectric spectroscopy in the temperature range 130-280 K enables to study water dynamics. In aged hydrogels two relaxations are clearly evident and show characteristic t…

Ambipolar Phosphine Derivatives to Attain True Blue OLEDs with 6.5% EQE

2016

A family of new branched phosphine derivatives {Ph2N-(C6H4)n-}3P → E (E = O 1-3, n = 1-3; E = S 4-6, n = 1-3; E = Se 7-9, n = 1-3; E = AuC6F5 4-6, n = 1-3), which are the donor-acceptor type molecules, exhibit efficient deep blue room temperature fluorescence (λem = 403-483 nm in CH2Cl2 solution, λem = 400-469 nm in the solid state). Fine tuning the emission characteristics can be achieved varying the length of aromatic oligophenylene bridge -(C6H4)n-. The pyramidal geometry of central R3P → E fragment on the one hand disrupts π-conjugation between the branches to preserve blue luminescence and high triplet energy, while on the other hand provides amorphous materials to prevent excimer form…

Hybrid organic-inorganic light emitting diodes: effect of the metal oxide

2010

Hybrid organic-inorganic light emitting diodes (HyLEDs), employing metal oxides as the electron injecting contacts, are interesting as an alternative to OLEDs. Until recently, the metal oxide of choice was either titanium dioxide or zinc oxide. In this work two wide bandgap metal oxides, HfO2 and MgO, are employed as electron injecting layer in HyLEDs. It is demonstrated that both the current density and the luminance values obtained are directly related to the barriers for electron injection (from the ITO to the metal oxide) and for hole transfer to the same metal oxide, outlining a new design rule for the optimization of HyLEDs. Record device efficacies (3.3 cd/A, >10000 cd/m2) using the …

2016

Two light-emitting polyphenylene dendrimers with both hole and electron transporting moieties were synthesized and characterized. Both molecules exhibited pure blue emission solely from the pyrene core and efficient surface-to-core energy transfers when characterized in a nonpolar environment. In particular, the carbazole- and oxadiazole-functionalized dendrimer (D1) manifested a pure blue emission from the pyrene core without showing intramolecular charge transfer (ICT) in environments with increasing polarity. On the other hand, the triphenylamine- and oxadiazole-functionalized one (D2) displayed notable ICT with dual emission from both the core and an ICT state in highly polar solvents. …