In-Depth Consideration of Vertically 3D Microstructured Bulk Heterojunction Layers via Solvent Vapor Annealing in DR3TSBDT:PC₇₁BM Solar Cells

The physical nature of solvent vapor annealing (SVA) treatment is quite straightforward, and its application is ideal in small molecule-based bulk heterojunction solar cells. It has been suggested to rapidly achieve high-performance small-molecule photovoltaics by alternating the blends to ideally connect the crystallite morphology. However, most previous reports on SVA have shown only influences of the degree of donor/acceptor phase separation within part of active textures. Here, we investigated solution-processed small-molecule solar cells consisting of the previously developed DR3TSBDT and [6,6]-phenyl-C₇₁-butyric acid methyl ester (PC₇₁BM) after SVA in terms of the vertical gradient crystalline phase in three-dimensional (3D) active layers. These systematic studies of the vertically phase-separated morphology for 3D heterojunction structures clarified in more detail varied active blend morphology underlying SVA and showed a clear structure–property relationship in related device performance. This provided not only a clear understanding of the precise effect of SVA treatments on varied 3D morphological structures but also a path toward the rational optimization of device performance

Schematic Studies on the Structural Properties and Device Physics of All Small Molecule Ternary Photovoltaic Cells

Although the field of ternary organic solar cells has seen much progress in terms of device performance in the past few years, limited understanding has restricted further development. For example, studies of the crystalline packing structure of ternary blends have rarely been reported in the solar cell field. Consequently, we chose two ternary blends of small molecules, two fullerene derivatives (small-molecule:PC₇₁BM:PC₆₁BM or small-molecule:PC₇₁BM:ICBA), to investigate crystallization behavior and interactions among the three components. The crystalline structure of the ternary active blends was characterized using various techniques such as 2D-GIWAXS and AFM, and the relationship of the observed morphologies to device performance is discussed. Furthermore, the device physics associated with the charge generation, transport, and recombination dynamics of these ternary blend systems were investigated

Structure–Property Correlation: A Comparison of Charge Carrier Kinetics and Recombination Dynamics in All-Polymer Solar Cells

We report a comparison of charge carrier kinetics and recombination dynamics correlated with the device performances of <b>PBDTTT-C</b> and <b>PBDTTT-CT</b> in nonfullerene <b>P­(NDI2OD-T2)</b> solar cells. The nanoscale morphological characteristics are found to be remarkably different for these two polymers in all-polymer bulk heterojunction (BHJ) blends. Important insights into the carrier dynamics and crystalline packing features of these different donor materials are provided in detail. The higher device performance of the <b>PBDTTT-CT:P­(NDI2OD-T2)</b> device [2.78% compared to 1.56% for the <b>PBDTTT-C:P­(NDI2OD-T2)</b> cell] is shown to result from efficient charge generation and faster carrier separation, reducing nongeminate recombination during charge collection, which is attributed to the perfect intermixing between the donor and acceptor polymer networks

Tumor-specific mutation detection rates in groups classified according to the presence of distant metastasis at the time of blood sampling.

<p>Tumor-specific mutation detection rates in groups classified according to the presence of distant metastasis at the time of blood sampling.</p

Comparison of survival rates of patients in the metastasis group with or without detectable plasma tumor-specific <i>KRAS</i> mutations.

<p>Overall survival rates are poorer for patients with detectable plasma <i>KRAS</i> mutations than patients without detectable plasma <i>KRAS</i> mutations.</p

Box and whisker plots of concentrations of circulating DNA.

<p>The concentration of DNA was significantly higher in patient groups (metastasis and non-metastasis groups) than in healthy volunteers (<i>P</i><0.001). There was no significant difference between patient groups. (Horizontal line in the middle of each box, median; boxes, 25 percentile ~ 75 percentile; whiskers, 1.5 x interquartile range from each boundary of the boxes; circles, outlier values with corresponding case number; <i>P</i>-value by Mann-Whitney U test, two-tailed).</p

Comparison of clinicopathological features between patient subgroups with or without detectable plasma tumor-specific <i>KRAS</i> mutations within the metastasis group (n = 106).

<p>Comparison of clinicopathological features between patient subgroups with or without detectable plasma tumor-specific <i>KRAS</i> mutations within the metastasis group (n = 106).</p

Isolation of Coralmycins A and B, Potent Anti-Gram Negative Compounds from the Myxobacteria <i>Corallococcus coralloides</i> M23

Two new potent anti-Gram negative compounds, coralmycins A (<b>1</b>) and B (<b>2</b>), were isolated from cultures of the myxobacteria <i>Corallococcus coralloides</i> M23, together with another derivative (<b>3</b>) that was identified as the very recently reported cystobactamid 919-2. Their structures including the relative stereochemistry were elucidated by interpretation of spectroscopic, optical rotation, and CD data. The relative stereochemistry of <b>3</b> was revised to “<i>S*R*</i>” by NMR analysis. The antibacterial activity of <b>1</b> was most potent against Gram-negative pathogens, including <i>Escherichia coli</i>, <i>Pseudomonas aeruginosa</i>, <i>Acinetobacter baumanii</i>, and <i>Klebsiella pneumoniae</i>, with MICs of 0.1–4 μg/mL; these MICs were 4–10 and 40–100 times stronger than the antibacterial activities of <b>3</b> and <b>2</b>, respectively. Thus, these data indicated that the β-methoxyasparagine unit and the hydroxy group of the benzoic acid unit were critical for antibacterial activity

Efficient Encapsulation and Sustained Release of Basic Fibroblast Growth Factor in Nanofilm: Extension of the Feeding Cycle of Human Induced Pluripotent Stem Cell Culture

Basic fibroblast growth factor (bFGF) has an established pivotal function in biomedical engineering, especially for the human pluripotent stem cells (iPSCs). However, the limitation of bFGF is the ease of denaturation under normal physiological conditions, inducing loss of its activity. In this study, we designed multi-trilayered nanofilm composed of a repeating polycation/polyanion/bFGF structure, which has high loading efficiency and short buildup time. We also investigated that the loading and release of bFGF from the nanofilm with two parameters (counter-polyanion and film architectures). Then, we prepared the optimized nanofilm which maintains a sustained bFGF level in physiological condition to apply the nanofilm to human iPSCs culture. The amount of bFGF release from 12 trilayer nanofilm was 36.4 ng/cm², and activity of bFGF encapsulated into the nanofilm was maintained (60%) until 72 h during incubation at 37 °C. As a result, the iPSCs grown in the presence of the nanofilm with tridaily replacement of growth medium maintained undifferentiated morphology and expression levels of pluripotency marker proteins

Dithienobenzodithiophene-Based Small Molecule Organic Solar Cells with over 7% Efficiency via Additive- and Thermal-Annealing-Free Processing

Here we introduce a novel small molecule based on dithienobenzodithiophene and rhodanine, <b>DTBDT-Rho</b>, developed to study the effect of the rhodanine substitutuent on small molecule bulk heterojunction (BHJ) solar cells. <b>DTBDT-Rho</b> possesses distinct crystalline characteristics, sufficient solubility in chlorinated solvents, and broad absorption properties. Therefore, solution-processed BHJ photovoltaic cells made with <b>DTBDT-Rho</b>:PC₇₁BM blends showed an extremely high power conversion efficiency (PCE; 7.10%); notably, this PCE value was obtained without the use of additives or thermal treatments. To our knowledge, the PCE over 7% is a significantly powerful value among rhodanine-based small molecule BHJ solar cells without additives or thermal treatments