Tuning the Energy Levels of Aza-Heterocycle-Based Polymers for Long-Term <i>n</i>-Channel Bottom-Gate/Top-Contact Polymer Transistors

Ma, Suxiang,Zhang, Guobing,Wang, Feifei,Dai, Yanrong,Lu, Hongbo,Qiu, Longzhen,Ding, Yunsheng,Cho, Kilwon American Chemical Society 2018 Macromolecules Vol.51 No.15

<P>Conjugated polymer-based organic thin film transistors (OTFTs) have received tremendous attention due to their potential applications. In addition to their high performances, air stability is also essential for application and another main property that OTFTs have. In this paper, three aza-heterocycle (BABDF)-based polymers were designed and synthesized using strong donor thiophene-vinylene-thiophene (TVT), weak donor thiophene-cyanovinylene-thiophene (TCNT), and weak acceptor dithiazole (TZ) as co-units. The lowest unoccupied molecular orbital (LUMO)/highest occupied molecular orbital (HOMO) energy levels were effectively lowered by introducing TCNT and TZ units, especially for PBABDF-TZ, for which the too much deep LUMO/HOMO energy levels of −4.28/-6.06 eV were obtained. These levels are low enough for air-stable electron transport and large enough for the hole injection barriers in OTFTs. Consequently, the unencapsulated bottom-gate/top-contact (BG/TC) devices exhibited unipolar electron transport under air conditions. Furthermore, these devices had high air stability and maintained unipolar electron transport with a mobility of up to 0.01 cm<SUP>2</SUP> V<SUP>-1</SUP> s<SUP>-1</SUP> during the one-year characterization period. Very low LUMO and HOMO levels were necessary for electron transport and the hole barriers, respectively, and both were important for long-term, air-stable <I>n</I>-channel polymer transistors.</P> [FIG OMISSION]</BR>

LncRNA CRNDE Promotes the Progression of B-cell Precursor Acute Lymphoblastic Leukemia by Targeting the miR-345-5p/CREB Axis

Weimin Wang,Feifei Wu,Ping Ma,Silin Gan,Xue Li,Li Chen,Ling Sun,Hui Sun,Zhongxing Jiang,Feng Guo 한국분자세포생물학회 2020 Molecules and cells Vol.43 No.8

The imbalance between the proliferation and apoptosis of B-cell precursors is an important contributor to the pathogenesis of B-cell precursor acute lymphoblastic leukemia (BCP-ALL), while its specific regulatory mechanism remains perplexing. This study aimed to expound the underlying mechanism of the proliferation and apoptosis of BCP-ALL cells from the perspective of non-coding RNA. In this study, long non-coding RNA colorectal neoplasia differentially expressed (LncRNA CRNDE) was upregulated in the bone marrow of BCP-ALL patients and BCP-ALL cell lines (NALM-6 and RS4;11). Functionally, LncRNA CRNDE knockdown restrained cell proliferation and boosted cell apoptosis in NALM-6 and RS4;11 cells. The subsequent investigation confirmed that LncRNA CRNDE bound to miR-345-5p and negatively regulated miR-345-5p expression. The overexpression of miR-345-5p suppressed cell proliferation and boosted cell apoptosis in NALM-6 and RS4;11 cells. Further experiments revealed that miR-345-5p downregulated cyclic AMP response element-binding protein (CREB) expression by targeting its mRNA directly. CREB overexpression reversed the effect of miR-345-5p mimic on cell proliferation and apoptosis in NALM-6 and RS4;11 cells. Finally, in vivo experiments showed that LncRNA CRNDE knockdown prolonged the survival of mice xenotransplanted with NALM-6 cells. In conclusion, LncRNA CRNDE upregulated CREB expression by suppressing miR-345-5p, thus promoting cell proliferation and reducing cell apoptosis in BCP-ALL.

Intracerebral Hemorrhage Progression Score: A Novel Risk Score to Predict Neurological Deterioration after Intracerebral Hemorrhage

Ruijun Ji,Linlin Wang,Feifei Ma,Wenjuan Wang,Yanfang Liu,Runhua Zhang,Dandan Wang,Jiaokun Jia,Hao Feng,Gaifen Liu,Yi Ju,Jingjing Lu,Xingquan Zhao 대한뇌졸중학회 2022 Journal of stroke Vol.24 No.2

.

Influence of Alkalization Treatment on the Color Quality and the Total Phenolic and Anthocyanin Contents in Cocoa Powder

Yue Li,Song Zhu,Yun Feng,Feifei Xu,Jianguo Ma,Fang Zhong 한국식품과학회 2014 Food Science and Biotechnology Vol.23 No.1

The effects of alkalization treatments on color,colorimetric fractions, total polyphenol content, andanthocyanin content of cocoa powder were investigated. Adarker color and a lower total polyphenol content wereobtained for cocoa powder alkalized using a K2CO3solution than with an NaOH solution. A high temperatureand basic pH conditions favored formation of darkcomponents during alkalization due to sugar degradation,Maillard reactions, and anthocyanin polymerizing. Theanthocyanin content decreased with an increasing alkaliconcentration, suggesting that more anthocyanins weretransformed into brown polymers in darker cocoa powder. Cocoa powder with a heavy degree of alkalization had thelowest ratio of monomer anthocyanins to yellow/brownpolymer content. OD460/OD525 values for alkalized sampleswere higher than for non-alkalized samples. Cocoa powderpresented a better color quality after alkalization treatment.

Study of the Non-Linearity on TiO2(0 0 1) Surface with Oxygen Defects: A First-Principles Study

Yuehua Dai,Xu Zhang,Chengzhi Ma,Zhiyong Pan,Feifei Wang,Wenjuan Lu,Jin Yang,Fei Yang 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2017 NANO Vol.12 No.8

First-principles plane-wave pseudopotential calculations were performed to study the energetics and electronic structures of oxygen defects on rutile TiO2(0 0 1). The influence of the material thickness on non-linearity (NL) was studied. With the increase in the thickness, the NL became stronger. Calculating the site-projected density of states by applying an external electric field showed that the NL of the bulk is due to the exchange of electrons between O 2p orbitals and Ti 3d orbitals. Finally, the influence of oxygen defects—oxygen vacancies (Vo), oxygen interstitials (Oi), and oxygen vacancies/oxygen interstitial (Vo + Oi) pairs (Frenkel pair defects)—on the NL of TiO2 was studied. These results demonstrate that the band gap (Eg) of TiO2 became gradually narrower as the electric field increased. The Stark effect and defects can lead to the splitting of degenerate energy levels. Stronger electric fields increase the band splitting and reduce Eg. With the increase in the Vo concentration, the decrease in the splitting amplitude and width of the energy level lead to weakening of the transfer of electrons between O and Ti atoms and optimizing the NL of TiO2. Therefore, the incorporation of Vo plays a significant role in improving the NL of TiO2.

Development of a Malignancy Potential Binary Prediction Model Based on Deep Learning for the Mitotic Count of Local Primary Gastrointestinal Stromal Tumors

Yang Jiejin,Chen Zeyang,Liu Weipeng,Wang Xiangpeng,Ma Shuai,Jin Feifei,Wang Xiaoying 대한영상의학회 2021 Korean Journal of Radiology Vol.22 No.3

Objective: The mitotic count of gastrointestinal stromal tumors (GIST) is closely associated with the risk of planting and metastasis. The purpose of this study was to develop a predictive model for the mitotic index of local primary GIST, based on deep learning algorithm. Materials and Methods: Abdominal contrast-enhanced CT images of 148 pathologically confirmed GIST cases were retrospectively collected for the development of a deep learning classification algorithm. The areas of GIST masses on the CT images were retrospectively labelled by an experienced radiologist. The postoperative pathological mitotic count was considered as the gold standard (high mitotic count, > 5/50 high-power fields [HPFs]; low mitotic count, ≤ 5/50 HPFs). A binary classification model was trained on the basis of the VGG16 convolutional neural network, using the CT images with the training set (n = 108), validation set (n = 20), and the test set (n = 20). The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated at both, the image level and the patient level. The receiver operating characteristic curves were generated on the basis of the model prediction results and the area under curves (AUCs) were calculated. The risk categories of the tumors were predicted according to the Armed Forces Institute of Pathology criteria. Results: At the image level, the classification prediction results of the mitotic counts in the test cohort were as follows: sensitivity 85.7% (95% confidence interval [CI]: 0.834–0.877), specificity 67.5% (95% CI: 0.636–0.712), PPV 82.1% (95% CI: 0.797–0.843), NPV 73.0% (95% CI: 0.691–0.766), and AUC 0.771 (95% CI: 0.750–0.791). At the patient level, the classification prediction results in the test cohort were as follows: sensitivity 90.0% (95% CI: 0.541–0.995), specificity 70.0% (95% CI: 0.354–0.919), PPV 75.0% (95% CI: 0.428–0.933), NPV 87.5% (95% CI: 0.467–0.993), and AUC 0.800 (95% CI: 0.563–0.943). Conclusion: We developed and preliminarily verified the GIST mitotic count binary prediction model, based on the VGG convolutional neural network. The model displayed a good predictive performance.