Polymeric tandem organic light-emitting diodes using a self-organized interfacial layer

The authors have demonstrated efficient polymeric tandem organic light-emitting diodes (OLEDs) with a self-organized interfacial layer, which was formed by differences in chemical surface energy. Hydrophilic poly(styrene sulfonate)-doped poly(3,4-ethylene dioxythiophene) (PEDOT:PSS) was spin coated onto the hydrophobic poly(9,9-dyoctilfluorene) (PFO) surface and a PEDOT:PSS bubble or dome was built as an interfacial layer. The barrier heights of PEDOT:PSS and PFO in the two-unit tandem OLED induced a charge accumulation at the interface in the heterojunction and thereby created exciton recombination at a much higher level than in the one-unit reference. This effect was confirmed in both the hole only and the electron only devices. (c) 2008 American Institute of Physicsopen8

Heterogeneity of Invasive Ductal Carcinoma: Proposal for a Hypothetical Classification

To investigate what heterogeneity exists in breast cancer, 228 consecutive patients with operable invasive duetal carcinoma (IDC), not otherwise specified, were categorized on the basis of the horizontal progression model of carcinogenesis. Using the reversed Black's nuclear grade (RBNG) in the IDC component and the association of ductal carcinoma in situ (DCIS), the patients were classified into pure IDC (IDC de novo or ab initio) as Group I, non-high grade (RBNG 1 and 2) IDC with DCIS as Group II, and high grade (RBNG 3) IDC with DCIS as Group III. The Groups classified in the present study appeared as a prognostic factor independent of known prognostic and predictive factors in multivariate test. Group I had the worst prognosis among the three groups and was the most non-responsive to tamoxifen. After performing stratifying analyses by group, it was found that metastasis-free survival was statistically associated with the status of hormone receptors estrogen receptor and progesterone receptor and tamoxifen therapy only in Group II. In addition, the status of c-erbB-2 expression had prognostic significance only within the Group III. Our results may be used to frame an alternative hypothetical model for breast cancer evolution and will lead us to reconsider the tailoring of the comprehensive therapeutic modality used at the present time

Comparison of reducing sugar content, sensory traits, and fatty acids and volatile compound profiles of the among Korean cattle, Holsteins, and Angus steers

Objective This study was performed to compare fat content, reducing sugar contents, sensory traits, and fatty acid (FA) and volatile compound profiles in longissimus thoracis (LT) among Korean cattle (KC), Holstein (HO), and Angus (AN) steers. Methods Twelve LT samples (about 500 g each) of KC with an average age of 31±0.42 months, an average carcass weight of 431±12.5 kg, and a quality grade (QG) of 1+ were obtained from the joint livestock products market. Twelve LT samples of HO cattle with an average age of 24±0.54 months, an average carcass weight of 402±7.81 kg, and a QG of 2 were also obtained from the same market. Twelve LT samples of AN steers with an average age of about 20 months and a QG of choice were purchased from a beef delivery company. After slaughter, samples were kept at 4°C for 42 days and prepared for immediate analysis or stored at appropriate conditions. The chemical composition, color, pH, shear force, collagen content, reducing sugars, sensory evaluation, FA composition, and volatile compound content for each LT sample were analyzed. Results The LT of KC had the highest (p<0.05) fat content, the highest reducing sugar content, and the highest scores in the sensory evaluation (flavor, tenderness, juiciness, and overall acceptance). All the sensory traits were positively correlated (p<0.001) with intramuscular fat and reducing sugar content. Several FAs and volatile compound profiles varied among the breeds. KC LT had the highest (p<0.05) concentrations of acetaldehyde, 3-methyl butanal, and 3-hydroxy-2-butanone, and these volatile compounds were positively correlated (p<0.05) with all the sensory traits. Conclusion Variations in fat content and reducing sugar contents and FA and volatile compound profiles may contribute to differences in the sensory quality of LT among breeds

Sustainable highly charged C-60-functionalized polyimide in a non-contact mode triboelectric nanogenerator

In this paper, we report on a new dielectric, a C-60-containing block polyimide (PI-b-C-60). This was realized by introducing C-60 as pendent groups into a polymer backbone. When this dielectric was used in a non-contact mode triboelectric nanogenerator (TENG), it achieved high output power and reliable operation. Compared with perfluoroalkoxy alkane film-based TENGs, the TENG based on PI-b-C-60 generated 4.3 times higher output power and a superior charge density of over 300 mu C m(-2) with a 3 times slower charge decay rate. These results are most likely due to the excellent charge-retention characteristics induced by the most negative electrostatic potential of C-60 within the backbone, and these characteristics were confirmed by surface potential measurements. Furthermore, in the course of our work, two non-contact mode applications, a keyless electronic door lock system and a speed sensor with a tone wheel for a car, were developed. Without an ion injection process being needed, very sensitive and reliable operations of the speed sensor were successfully demonstrated, even under very humid conditions (similar to 99% RH)

Metastable hexagonal close-packed palladium hydride in liquid cell TEM

Metastable phases-kinetically favoured structures-are ubiquitous in nature1,2. Rather than forming thermodynamically stable ground-state structures, crystals grown from high-energy precursors often initially adopt metastable structures depending on the initial conditions, such as temperature, pressure or crystal size1,3,4. As the crystals grow further, they typically undergo a series of transformations from metastable phases to lower-energy and ultimately energetically stable phases1,3,4. Metastable phases sometimes exhibit superior physicochemical properties and, hence, the discovery and synthesis of new metastable phases are promising avenues for innovations in materials science1,5. However, the search for metastable materials has mainly been heuristic, performed on the basis of experiences, intuition or even speculative predictions, namely &apos;rules of thumb&apos;. This limitation necessitates the advent of a new paradigm to discover new metastable phases based on rational design. Such a design rule is embodied in the discovery of a metastable hexagonal close-packed (hcp) palladium hydride (PdHx) synthesized in a liquid cell transmission electron microscope. The metastable hcp structure is stabilized through a unique interplay between the precursor concentrations in the solution: a sufficient supply of hydrogen (H) favours the hcp structure on the subnanometre scale, and an insufficient supply of Pd inhibits further growth and subsequent transition towards the thermodynamically stable face-centred cubic structure. These findings provide thermodynamic insights into metastability engineering strategies that can be deployed to discover new metastable phases. © 2022. The Author(s), under exclusive licence to Springer Nature Limited.11Nsciescopu