Palladium-Catalyzed Direct Arylation of Imidazolone <i>N</i>-Oxides with Aryl Bromides and Its Application in the Synthesis of GSK2137305

The palladium-catalyzed direct arylation of imidazolone <i>N</i>-oxides with aryl bromides to afford the corresponding 4-aryl imidazolone <i>N</i>-oxides is described. This method has been successfully used for the synthesis of GSK2137305

Interplay between Longitudinal and Transverse Contrasts in Fe₃O₄ Nanoplates with (111) Exposed Surfaces

Iron oxide has been developed as either <i>T</i>₁ or <i>T</i>₂ magnetic resonance imaging (MRI) contrast agents by controlling the size and composition; however, the underlying mechanism of <i>T</i>₁ and <i>T</i>₂ contrasts in one iron oxide entity is still not well understood. Herein, we report that freestanding superparamagnetic magnetite nanoplates with (111) exposed facets have significant but interactional <i>T</i>₁ and <i>T</i>₂ contrast effects. We demonstrate that the main contribution of the <i>T</i>₁ contrast of magnetic nanoplates is the chemical exchange on the iron-rich Fe₃O₄(111) surfaces, whereas the <i>T</i>₂ relaxation is dominated by the intrinsic superparamagnetism of the nanoplates with an enhanced perturbation effect. We are able to regulate the balance of <i>T</i>₁ and <i>T</i>₂ contrasts by controlling structure and surface features, including morphology, exposed facets, and surface coating. This study provides an insightful understanding on the <i>T</i>₁ and <i>T</i>₂ contrast mechanisms, which is urgently needed to allow more sophisticated design of high-performance MRI contrast agents

Investigation of Pathogenesis of H1N1 Influenza Virus and Swine <i>Streptococcus suis</i> Serotype 2 Co-Infection in Pigs by Microarray Analysis

<div><p>Swine influenza virus and <i>Streptococcus suis</i> are two important contributors to the porcine respiratory disease complex, and both have significant economic impacts. Clinically, influenza virus and <i>Streptococcus suis</i> co-infections in pigs are very common, which often contribute to severe pneumonia and can increase the mortality. However, the co-infection pathogenesis in pigs is unclear. In the present study, co-infection experiments were performed using swine H1N1 influenza virus and <i>Streptococcus suis</i> serotype 2 (SS2). The H1N1-SS2 co-infected pigs exhibited more severe clinical symptoms, serious pathological changes, and robust apoptosis of lungs at 6 days post-infection compared with separate H1N1 and SS2 infections. A comprehensive gene expression profiling using a microarray approach was performed to investigate the global host responses of swine lungs against the swine H1N1 infection, SS2 infection, co-infection, and phosphate-buffered saline control. Results showed 457, 411, and 844 differentially expressed genes in the H1N1, SS2, and H1N1-SS2 groups, respectively, compared with the control. Noticeably, genes associated with the immune, inflammatory, and apoptosis responses were highly overexpressed in the co-infected group. Pathway analysis indicated that the cytokine–cytokine receptor interactions, MAPK, toll-like receptor, complement and coagulation cascades, antigen processing and presentation, and apoptosis pathway were significantly regulated in the co-infected group. However, the genes related to these were less regulated in the separate H1N1 and SS2 infection groups. This observation suggested that a certain level of synergy was induced by H1N1 and SS2 co-infection with significantly stronger inflammatory and apoptosis responses, which may lead to more serious respiratory disease syndrome and pulmonary pathological lesion.</p></div

Characterization of the differential expression of genes.

<p>(A) Categories of genes based on biological process GO term in each group. Only the top20 terms based on the gene numbers are showed. (B) Clustered pathways of the DE genes by KEGG analysis. Only the pathways containing more genes are presented. Many categories shared the same genes.</p

Virus isolation of nasal swabs and lungs in each group.

<p>Swabs were collected from the right nostrils of pigs from each group every other day. The obtained nasal swabs were inserted into vials containing 1.5 mL of sterile PBS. Supernatants were collected and viruses were qualified as LgEID₅₀. At the day 6 of the experiment, all pigs were humanely euthanized and lungs were collected and homogenized in sterile PBS and then centrifuged to collect the supernatant. Virus titer was quantified as LgEID₅₀. Data were showed as mean ± SEM by Student’s t-test. <i>P</i>-value less than 0.05 was noted with a single-asterisk and p-value less than 0.01 was noted with a double-asterik.</p

Expression of genes related to inflammation and apoptosis by qRT-PCR.

<p>RNA was extracted from lungs of each infection group, and was reversely transcribed. mRNA levels were measured by real-time PCR. (A) Changes of genes related to proinflammatory response. (B) Changes of genes related to apoptosis. Data were showed as mean ± SEM and were representatives of two independent experiments. Significant levels were analyzed by T-test.</p

Apoptosis induced by H1N1 virus, SS2, H1N1-SS2 and PBS control.

<p>Histological sections of lungs from each group were evaluated for apoptosis by TUNEL test. (A) The infected groups showed varying degrees of apoptosis. Brown ovals (red arrows) indicate apoptotic nucleus. Blue ovals (blue arrows) indicate normal nucleus. (B) Statistical analysis of apoptosis rate in each infection group. Data was showed as mean ± SEM. T-test was used to analyze the significance.</p

Histopathologic changes in lungs of infected pigs.

<p>Pigs were PBS-control infected or infected with H1N1, SS2 and H1N1-SS2 as described in methods. On day 6 of the experiment, lungs were removed and underwent Hematoxylin and eosin stain. (A) The microscopic lesions of lung tissues from each group showed different extent of acute pneumonia with pathological changes: alveolar wall thickening, bleeding (red arrow), debris in the lumen (green arrow), erythrocyte effusion (blue arrow), and the accumulation of inflammatory cells. (B) Histological score of sections of lungs in pigs from each group were showed as mean ± SEM by two-tailed Student’s t-test. <i>P</i>-value less than 0.05 was considered to represent a statistically significant difference.</p

Highly Efficient, Solution-Processed Organic Light-Emitting Diodes Based on Thermally Activated Delayed-Fluorescence Emitter with a Mixed Polymer Interlayer

The efficiency of solution-processed organic light-emitting diodes based on pure organic thermally activated delayed-fluorescence (TADF) emitters is limited by the hole-injection/severe exciton quenching of poly­(styrenesulfonate)-doped poly­(3,4-ethylenedioxythiophene) (PEDOT:PSS) and the exction quenching of TADF emitters due to the self-aggregation. In order to effectively enhance the hole-injection from PEDOT:PSS and to alleviate the exciton quenching of the PEDOT:PSS, the mixed interlayer of poly­(9-vinylcarbazole) (PVK) and poly­[(9,9-dioctylfluorenyl-2,7-diyl)-<i>co</i>-(4,4′-(<i>N</i>-(4-s-butylphenyl)­diphenylamine)) (TFB) was inserted between emitting layer (EML) and the PEDOT:PSS layer. Additionally, the cohost of 3′,5′-di­(carbazol-9-yl)-[1,1′-biphenyl]-3,5-dicarbonitrile (DCzDCN) and bis­(3,5-di­(9<i>H</i>-carbazol-9-yl)­phenyl)­diphenylsilane (SimCP2) was used to suppress the self-aggregation of the TADF emitter of 2-(9-phenyl-9<i>H</i>-carbazol-3-yl)-10,10-dioxide-9 thioxanthone (TXO-PhCz) and tune the charge carrier transport. By optimizing the mix ratio, highly efficient, solution-processed, green-emitting TADF-OLEDs with the hole-transport layer (HTL) of TFB:PVK (1:1) and the EML host of DCzDCN:SimCP2 (1:2) can be turned on at 4 V and can show a maximum current efficiency (CE) of 55.6 cd/A, a maximum power efficiency (PE) of 47.2 lm/W, and an external quantum efficiency (EQE) of 18.86%. The devices are among the most efficient OLEDs fabricated by solution-processed methods. These results indicate that the employment of a mixed HTL and EML cohost is a promising way toward the high-efficiency solution-processed OLEDs

The Role of Balancing Carrier Transport in Realizing an Efficient Orange-Red Thermally Activated Delayed-Fluorescence Organic Light-Emitting Diode

Simultaneously realizing improved carrier mobility and good photoluminescence (PL) efficiency in red thermally activated delayed-fluorescence (TADF) emitters remains challenging but important. Herein, two isomeric orange-red TADF emitters, oPDM and pPDM, with the same basic donor–acceptor backbone but a pyrimidine (Pm) attachment at different positions are designed and synthesized. The two emitters show similarly good PL properties, including narrow singlet–triplet energy offsets (0.11 and 0.15 eV) and high photoluminescence quantum yields (ca. 100 and 88%) in doped films. An orange-red organic light-emitting diode (OLED) employing oPDM as an emitter achieves an almost twice as high maximum external quantum efficiency (28.2%) compared with that of a pPDM-based OLED. More balanced carrier-transporting properties are responsible for their contrasting device performances, and the position effect of the Pm substituent leads to significantly distinct molecular packing behaviors in the aggregate states and different carrier mobilities