A convenient and efficient method for the synthesis of various arylketones by nickel-catalyzed addition of arylboronic acids to nitriles is described. A catalytic cycle involving Ni(II) species as ...the catalytic intermediates is proposed to account for the present catalytic reaction.
Full text
Available for:
IJS, KILJ, NUK, PNG, UL, UM
Transforming triplet excitons into singlet excitons is a topic of great interest to material scientists in order to surpass the exciton utilization efficiency (EUE) limit of 25% in ...electro-fluorescent devices. Towards this goal, the donor-acceptor strategy of molecular design has been proven to be an effective approach to obtain high electroluminescence (EL) efficiency. In this context, herein, we report two benzothiadiazole (BTD)-based donor-acceptor π-conjugated fluorescent molecules,
1
and
2
, which exhibited an external quantum efficiency (EQE) as high as 7.0% and 8.1%, respectively, in solution-processed doped green OLED devices. The observed high photoluminescence (PL) quantum yield of 81% for
1
and 85% for
2
corroborate the high EUE values of 43% and 48%, respectively, exceeding the traditional limit (25%), hence suggest the utilization of triplet excitons. The reported emitters combine two parameters,
i.e.
high PL efficiency and high EUE, which are of key importance to harvest maximum EL in OLED devices. Based on the photophysical (solvatochromic experiment) and quantum chemical calculations, the impacts of the D-π-A-π-D molecular design on the regulation of the locally excited and charge transfer components were revealed, which explained the observed high EQE (>5%) and EUE (>25%) values for the BTD-based emitters. The development of emitters with a hybrid local and charge transfer state in combination with the 'hot exciton' mechanism is an important strategy to produce highly efficient fluorescent-emitter materials. Besides the impressive EL properties of the emitters, the studied compound
1
as a chemosensor showed the selective sensing of metal cation (Fe
2+
) and anion (I
−
) together with the staining agent of
Hibiscus rosa-sinensis
pollen grains.
Benzothiadiazole-based donor-acceptor emitters with hybrid local and charge transfer state exhibit high external quantum efficiency in solution-processed green OLEDs.
Purpose This paper aims to examine how situational factors with social support affecting purchase intention in social commerce (SC). In Taiwan’s SC, the relationship between trust belief and purchase ...intention has always been a key issue.Design/methodology/approach This study presents a research model that comprises five hypothesis with five constructs, including situational factors, social support, senses, trust belief and purchase intention. The model is tested on data collected from 532 valid samples in Taiwan, using structural equation modeling. The results show that, in order of importance, control senses and raise mediation trust belief reach the better purchase intention.Findings The findings of the study provide practical insights in understanding how seller should notice consumer’s trust belief, in order to enhance purchase intention for the SC as a whole.Originality/value Much existing consumer behavior research is focused on decision making rather than the trust belief themselves. Accordingly, analyzing how senses influence trust belief and purchase intention is an important issue in SC.
Background: The third-generation epidermal growth factor receptor (EGFR) inhibitor, Osimertinib, is used to treat non-small cell lung cancer (NSCLC) patients with tyrosine kinase inhibitor (TKI) ...resistance caused by acquired EGFR T790M mutation. However, patients eventually develop resistance against Osimertinib with mechanisms not yet fully clarified. Activated alternative survival pathways within the tumor cells and cancer-associated fibroblasts (CAFs) have been proposed to contribute to Osimertinib resistance. MET and MEK inhibitors may overcome EGFR-independent resistance. Another acquired resistance mechanism of EGFR-TKI is the up-regulation of the RAS/RAF/MEK/ERK signaling pathway, which is the key to cell survival and proliferation; this may occur downstream of various other signaling pathways. In this report, we reveal the possible regulatory mechanism and inhibitory effect of the MEK inhibitor trametinib applied to MEK/ERK/miR-21 axis and PDCD4 in Osimertinib resistance. We found a possible regulatory role of PDCD4 in ERK signaling. PDCD4 is a new type of tumor suppressor that has multiple functions of inhibiting cell growth, tumor invasion, metastasis, and inducing apoptosis. Previous bioinformatics analysis has confirmed that PDCD4 contains the binding site of miR-21 and acts as a tumor suppressor in the regulation of various processes associated with the development of cancer, including cell proliferation, invasion, metastasis, and neoplastic transformation. Based on the above analysis, we hypothesized that the tumor suppressor PDCD4 is one of the effective inhibitory targets of miR-21-5p. Methods: The expression between EGFR and ERK2 in lung adenocarcinoma was evaluated from the TCGA database. Osimertinib-sensitive and resistant NSCLC cells obtained from patients were used to co-culture with human lung fibroblasts (HLFs) to generate CAF cells (termed CAF_R1 and CAF_S1), and the functional roles of these CAF cells plus the regulatory mechanisms were further explored. Then, MEK inhibitor Trametinib with or without Osimertinib was applied in xenograft model derived from patients to validate the effects on growth inhibition of Osimertinib-resistant NSCLC tumors. Result: ERK2 expression correlated with EGFR expression and higher ERK2 level was associated with worse prognosis of patients and Osimertinib resistance. CAFs derived from Osimertinib-resistant cells secreted more IL-6, IL-8, and hepatocyte growth factor (HGF), expressed stronger CAF markers including α-smooth muscle actin (α-SMA), fibroblast activation protein (FAP) plus platelet-derived growth factor receptor (PDGFR), and enhanced stemness and Osimertinib resistance in NSCLC cells. Meanwhile, increased MEK/ERK/miR-21 expressions were found in both CAFs and NSCLC cells. MEK inhibitor Trametinib significantly abrogated the abovementioned effects by modulating β-catenin, STAT3, and ERK. The xenograft model showed combining Osimertinib and Trametinib resulted in the most prominent growth inhibition of Osimertinib-resistant NSCLC tumors. Conclusions: Our results suggested that MEK/ERK/miR-21 signaling is critical in Osimertinib resistance and CAF transformation of NSCLC cells, and MEK inhibitor Trametinib significantly suppressed Osimertinib-resistant NSCLC tumor growth by abolishing both processes.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Exploring the effects of sowing date and ecological points on the yield of semi-winter wheat is of great significance. This study aims to reveal the effects of sowing date and ecological points on ...the climate resources associated with wheat yield in the Rice–Wheat Rotation System. With six sowing dates, the experiments were carried out in Donghai and Jianhu counties, Jiangsu Province, China using two semi-winter wheat varieties as the objects of this study. The basic seedlings of the first sowing date (S1) were planted at 300×104 plants ha−1, which was increased by 10% for each of the delayed sowing dates (S2–S6). The results showed that the delay of sowing date decreased the number of days, the effective accumulated temperature and the cumulative solar radiation in the whole growth period. The yields of S1 were higher than those of S2 to S6 by 0.22–0.31, 0.5–0.78, 0.86–0.98, 1.14–1.38, and 1.36–1.59 t ha–1, respectively. For a given sowing date, the growth days increased as the ecological point was moved north, while both mean daily temperature and effective accumulative temperature decreased, but the cumulative radiation increased. As a result, the yields at Donghai County were 0.01–0.39 t ha–1 lower than those of Jianhu County for the six sowing dates. The effective accumulative temperature and cumulative radiation both had significant positive correlations with yield. The average temperature was significantly negatively correlated with the yield. The decrease in grain yield was mainly due to the declines in grains per spike and 1 000-grain weight caused by the increase in the daily temperature and the decrease in the effective accumulative temperature.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Abstract
All Free-form architecture has novel and unique shapes, complex and diverse changes, and has become the trend of modern architectural development with its rich shape changes and soft lines. ...The traditional grid layout method is not applicable to the grid division of free-form surfaces, and how to divide a smooth and beautiful grid is a hot research problem for large-span spatial structures. In response to the above problems, after investigating the current scientific research results at home and abroad, our team proposes a meshing method using the 3D software Rhino platform to solve the problems of uneven meshing of free-form surfaces and low intelligence, and to divide a smooth and beautiful mesh.
We report a novel DNA-programmed plasmonic enzyme-linked immunosorbent assay (ELISA) for the ultrasensitive detection of protein biomarkers with the naked eye. The DNA-programmed plasmonic assay was ...based on two enzyme-free and isothermal nucleic acid amplification methods: hybridization chain reaction (HCR) and catalyzed hairpin assembly (CHA). In this study, a biotin-labeled DNA probe was utilized insteand of an enzyme-label probe in well-developed ELISA method. The biotin-labeled DNA probe was able to trigger the HCR and CHA processes, and the products could hybridize with DNA-modified gold nanoparticles (AuNPs) to induce the aggregation of the AuNPs and a color change in the solution. The developed method was able to detect as low as 1 pg mL
−1
PSA target with the naked eye. Clinical serum samples demonstrated satisfactory results, indicating that the method is useful for early diagnostics and monitoring curative effects after a medical treatment. The developed method presents a simple and portable platform for ultrasensitive protein detection and has potential for point-of-care (POC) diagnostics in less developed areas.
We report a novel DNA-programmed plasmonic enzyme-linked immunosorbent assay (ELISA) for the ultrasensitive detection of protein biomarkers with the naked eye.
Although gastroprotective drugs have been used for peptic ulcer disease prevention and treatment, side effects have been observed. Finding a safe and effective treatment strategy is important.
Edible ...Trichodesma khasianum (T. khasianum) Clarke leaves are considered to protect against peptic ulcers. However, scientific evidence of this effect of T. khasianum Clarke leaves remains limited.
In this study, we aimed to evaluate the effect of T. khasianum Clarke leaves on ethanol-induced gastric injury and gut microbiota using RAW 264.7 cells, RGM-1 cells, and BALB/c mice, respectively.
The rosmarinic acid was identified as the major component of T. khasianum Clarke leaves extracted by 80% ethanol (80EETC). The results showed that 80EETC suppressed inflammatory mediator protein levels in LPS-induced RAW 264.7 cells. Additionally, heat shock protein expression, antiapoptotic ability, and wound healing migration capability were increased by 80EETC pretreatment in RGM-1 cells with the ethanol-induced injury. Remarkably, pretreatment with 80EETC (150 mg/kg b.w.) promoted gastric mucosal healing by decreasing oxidative stress, inflammatory response, proapoptotic protein expression, and gastric mucosa damage in ethanol-induced gastric injury in mice. Crucially, no liver or kidney toxicities were observed by 80EETC oral gavage. Moreover, 80EETC increased gut microbiota diversity and short-chain fatty acid production.
Our results illustrated the remarkable gastroprotective effect by 80EETC treatment in vitro and in vivo. These findings are the first to demonstrate the powerful protective effect of T. khasianum Clarke leaves against gastric mucosal injury development.
The schematic illustrates the gastroprotection properties of Trichodesma khasianum Clarke leaves and its major compound against ethanol-induced gastric mucosal injury in vitro and in vivo. Display omitted
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
This study seeks to explore how business leaders should respond to COVID-19. In advancing theoretical development of strategic crisis communication, we incorporated theoretical frameworks of ...organizational resilience, social support, and values-centered communication to make sense of CEO's COVID-19 responses. Using structural topic modeling, this study analyzed 192 CEO open letters from 152 multinational corporations that are listed on the 2020 Fortune Magazine's World's Most Admired Companies. Fourteen valid topics and four general themes were identified and discussed. Results suggested that in those letters, CEOs demonstrated organizational resilience by giving sense to current crisis situations and expressing their self-efficacy and response efficacy in handling challenges, which supported the conceptualization and operationalization of organizational resilience in this new crisis context. Additionally, both emotional and instrumental support provisions were found in CEOs' letters. A values-centered and care ethics communication approach was widely taken in CEOs' messages, highlighting the importance of social solidarity in facing a public health crisis. This study also explored how topic prevalence varied by business sectors and CEOs' genders and associated with companies' financial performance. These summarized communication strategies and narrative topics shed light on crisis communication practice and theory, especially in the context of a global public health crisis.
Full text
Available for:
BFBNIB, NUK, PILJ, SAZU, UL, UM, UPUK
This paper devises a general modeling and analyzing framework for a heterogeneous wireless network (HetNet) in which several wireless subnetworks coexist and use multiple radio access technologies ...(multi-RATs). The coexisting coverage and network capacity in such a multi-RAT HetNet are hardly investigated in prior works. To characterize the coexisting interactions in a multi-RAT HetNet, in this paper, we consider a HetNet consisting of <inline-formula> <tex-math notation="LaTeX">K </tex-math></inline-formula> tiers of access points (APs) and two different RATs, RAT-<inline-formula> <tex-math notation="LaTeX"> \mathsf {L} </tex-math></inline-formula> and RAT-<inline-formula> <tex-math notation="LaTeX"> \mathsf {U} </tex-math></inline-formula>, are adopted in the HetNet. RAT-<inline-formula> <tex-math notation="LaTeX"> \mathsf {L} </tex-math></inline-formula> is adopted by the APs in the first <inline-formula> <tex-math notation="LaTeX">K-1 </tex-math></inline-formula> tiers and APs in the <inline-formula> <tex-math notation="LaTeX">K </tex-math></inline-formula>th tier only use RAT-<inline-formula> <tex-math notation="LaTeX"> \mathsf {U} </tex-math></inline-formula>. Both noncrossing-RAT and crossing-RAT user association scenarios are considered. In each scenario, the void probability and the channel access probability of the APs in each tier are first found and then the tight lower bounds and their lowest limits on the proposed coexisting coverage and network capacity are derived. We show that multi-RAT networks in general can achieve higher link coverage and capacity by using opportunistic carrier sense multiple access with collision avoidance that avoids/alleviates severe interfering between all coexisting APs. Also, crossing-RAT user association is shown to achieve much higher coexisting coverage and network capacity than noncrossing-RAT user association. Finally, numerical simulations for the LTE-U and WiFi networks coexisting in the HetNet validate our findings.
PDF
