The kinetics of chirality assignment in catalytic single-walled carbon nanotube growth and the routes towards selective growth

Xu, Ziwei,Qiu, Lu,Ding, Feng Royal Society of Chemistry 2018 Chemical Science Vol.9 No.11

<▼1><P>The routes towards carbon nanotube's chirality control during growth was revealed by kinetic modelling.</P></▼1><▼2><P>Depending on its specific structure, or so-called chirality, a single-walled carbon nanotube (SWCNT) can be either a conductor or a semiconductor. This feature ensures great potential for building ∼1 nm sized electronics if chirality-selected SWCNTs could be achieved. However, due to the limited understanding of the growth mechanism of SWCNTs, reliable methods for chirality-selected SWCNTs are still pending. Here we present a theoretical model on the chirality assignment and control of SWCNTs during the catalytic growth. This study reveals that the chirality of a SWCNT is determined by the kinetic incorporation of pentagons, especially the last (6<SUP>th</SUP>) one, during the nucleation stage. Our analysis showed that the chirality of a SWCNT is randomly assigned on a liquid or liquid-like catalyst surface, and two routes of synthesizing chirality-selected SWCNTs, which are verified by recent experimental achievements, are demonstrated. They are (i) by using high melting point crystalline catalysts, such as Ta, W, Re, Os, or their alloys, and (ii) by frequently changing the chirality of SWCNTs during their growth. This study paves the way for achieving chirality-selective SWCNT growth for high performance SWCNT based electronics.</P></▼2>

Elastography for the differential diagnosis of malignant versus benign testicular lesions: a meta-analysis

Ziwei Lin,Rui Lin,Huaiyu Wu,Linghu Wu,Jieying Zeng,Jinfeng Xu,Fajin Dong 대한초음파의학회 2021 ULTRASONOGRAPHY Vol.40 No.4

Purpose: The aim of this study was to evaluate the value of elastography in the differential diagnosis of benign versus malignant testicular lesions.Methods: The PubMed, Cochrane Library, and Embase databases were searched for relevant studies. The diagnostic accuracy of elastography was evaluated using pooled sensitivity, specificity, likelihood ratio, post-test probability, diagnostic odds ratio, and by summarizing the area under the hierarchical summary receiver operating characteristic (HSROC) curve.Results: Seven studies with 568 lesions were included. The pooled sensitivity and specificity were 87% (95% confidence interval [CI], 81% to 92%) and 81% (95% CI, 65% to 90%), respectively. The pooled estimates of the positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio were 4.48 (95% CI, 2.37 to 8.47), 0.16 (95% CI, 0.10 to 0.25), and 28.11 (95% CI, 11.39 to 69.36), respectively. The area under the HSROC curve was 90% (95% CI, 88% to 93%).Conclusion: Elastography is useful for assessing the stiffness of testicular lesions and for differentiating benign from malignant lesions. Elastography can be an effective supplement to conventional ultrasonography.

Effect of phosphorus deficiency on erythrocytic morphology and function in cows

Ziwei Zhang,Mingyu Bi,Jie Yang,Haidong Yao,Zhonghua Liu,Shiwen Xu 대한수의학회 2017 Journal of Veterinary Science Vol.18 No.3

The aim of this study was to evaluate the influence of phosphorus (P) deficiency on the morphological and functional characteristics of erythrocytes in cows. Forty Holstein-Friesian dairy cows in mid-lactation were randomly divided into two groups of 20 each and were fed either a low-P diet (0.03% P/kg dry matter [DM]) or a control diet (0.36% P/kg DM). Red blood cell (RBC) indices results showed RBC and mean corpuscular hemoglobin decreased while mean corpuscular volume increased significantly (p < 0.05) in P-deficient cows. Erythrocyte morphology showed erythrocyte destruction in P-deficient cows. Erythrocytes’ functional characteristics results showed total bilirubin and indirect bilirubin concentrations and aspartate transaminase and alanine transaminase activity levels in the serum of P-deficient cows were significantly higher than those in control diet-fed cows. Activities of superoxide dismutase and glutathione peroxidase in erythrocytes were lower, while the malondialdehyde content was greater, in P-deficient cows than in control diet-fed cows. Na+/K+-ATPase and Mg2+-ATPase activities were lower in P-deficient cows than in control diet-fed cows; however, Ca2+-ATPase activity was not significantly different. The phospholipid composition of the erythrocyte membrane changed and membrane fluidity rigidified in P-deficient cows. The results indicate that P deficiency might impair erythrocyte integrity and functional characteristics in cows.

Effect of Gas Sensing Properties by Sn-Rh Codoped ZnO Nanosheets

Ziwei Chen,Zhidong Lin,Mengying Xu,Yuyuan Hong,Na Li,Ping Fu,Ze Chen 대한금속·재료학회 2016 ELECTRONIC MATERIALS LETTERS Vol.12 No.3

The hierarchically porous Sn-Rh codoped ZnO, Sn-doped ZnO and pureZnO nanosheets have been successfully synthesized through a simplehydrothermal reaction process without any surfactant or template at 180°C. The morphology and composition were carefully characterized by X-raydiffraction, energy dispersive X-ray spectrometer, field emission scanningelectronic microscopy and BET. The gas-sensing testing results indicatedthat the Sn-Rh codoped ZnO nanosheets, with the specific surface area was26.9 m2/g, exhibited enhanced gas-sensing performance compared withthat of pure ZnO and Sn-doped ZnO. The high sensitivity of the sensorbased on Sn-Rh codoped ZnO was 149.38 to 100 ppm ethanol and thedetection limit was less than 5 ppm (5.8). The response and recovery timeswere measured to be ~3 s and ~10 s when exposed to 100 ppm ethanol atthe test temperature of 300°C. The good sensing performance of the Sn-Rhcodoped ZnO sensor indicated that hierarchically porous Sn-Rh codopedZnO could be a promising candidate for highly sensitive gas sensors.

Is there chiral correlation between graphitic layers in double-wall carbon nanotubes?

He, Maoshuai,Xu, Ziwei,Shang, Danhong,Zhang, Xiuyun,Zhang, Hao,Li, Dong,Jiang, Hua,Kauppinen, Esko,Ding, Feng Elsevier 2019 Carbon Vol.144 No.-

<P><B>Abstract</B></P> <P>Because of the unique concentric structure, double-wall carbon nanotubes (DWNTs) possess fascinating properties which depend on the respective chirality of both the outer and the inner tubes. In this work, we study the chiral correlations of DWNTs synthesized by chemical vapor deposition on Fe nanoparticles. Contrary to some recent report, the distribution of chiral angle difference between inner and outer tubes in our work agrees with that calculated for all possible configurations. Remarkably, DWNTs with commensurate structures, <I>i.e</I>. outer and inner tubes have same chiral angles, are observed. The mechanism for the formation of DWNTs with approximately commensurate structures is discussed on the basis of layer by layer model. Furthermore, the interactional energies between the inner and outer walls are calculated to address the stability of different DWNT configurations. This work helps understand the growth mechanism of DWNTs and comprehend their structure stabilities with different configurations.</P> <P><B>Graphical abstract</B></P> <P>Double-wall carbon nanotubes (DWNTs) synthesized by chemical vapor deposition show randomly distributed chiral angle differences between inner and outer tubes. The mechanism for the formation of DWNTs with approximately commensurate structures is discussed based on layer by layer model. The interactional energies between the inner and outer walls are calculated to address the stability of different DWNT configurations.</P> <P>[DISPLAY OMISSION]</P>

Risk of Death in Colorectal Cancer Patients with Multi-morbidities of Metabolic Syndrome: A Retrospective Multicohort Analysis

Qingting Feng,Lingkai Xu,Lin Li,Junlan Qiu,Ziwei Huang,Yiqing Jiang,Tao Wen,Shun Lu,Fang Meng,Xiaochen Shu 대한암학회 2021 Cancer Research and Treatment Vol.53 No.3

Purpose The prevalence of multi-morbidities with colorectal cancer (CRC) is known to be increasing. Particularly prognosis of CRC patients co-diagnosed with metabolic syndrome (MetSyn) was largely unknown. We aimed to examine the death risk of CRC patients according to the multiple MetSyn morbidities.Materials and Methods We identified CRC patients with MetSyn from the electronic medical records (EMR) systems in five independent hospitals during 2006-2011. Information on deaths was jointly retrieved from EMR, cause of death registry and chronic disease surveillance as well as study-specific questionnaire. Cox proportional hazards regression was used to calculate the overall and CRC-specific hazards ratios (HR) comparing MetSyn CRC cohort with reference CRC cohort.Results A total of 682 CRC patients in MetSyn CRC cohort were identified from 24 months before CRC diagnosis to 1 month after. During a median follow-up of 92 months, we totally observed 584 deaths from CRC, 245 being in MetSyn cohort and 339 in reference cohort. Overall, MetSyn CRC cohort had an elevated risk of CRC-specific mortality (HR, 1.49; 95% confidence interval [CI], 1.07 to 1.90) and overall mortality (HR, 1.43; 95% CI, 1.09 to 1.84) compared to reference cohort after multiple adjustment. Stratified analyses showed higher mortality risk among women (HR, 1.87; 95% CI, 1.04 to 2.27) and specific components of MetSyn. Notably, the number of MetSyn components was observed to be significantly related to CRC prognosis.Conclusion Our findings supported that multi-morbidities of MetSyn associated with elevated death risk after CRC. MetSyn should be considered as an integrated medical condition more than its components in CRC prognostic management.

Upregulation of adiponectin by Ginsenoside Rb1 contributes to amelioration of hepatic steatosis induced by high fat diet

Yaru Li,Shuchen Zhang,Ziwei Zhu,Ruonan Zhou,Pingyuan Xu,Lingyan Zhou,Yue Kan,Jiao Li,Juan Zhao,Penghua Fang,Xizhong Yu,Wenbin Shang 고려인삼학회 2022 Journal of Ginseng Research Vol.46 No.4

Background: Ginsenoside Rb1 (GRb1) is capable of regulating lipid and glucose metabolism through itsaction on adipocytes. However, the beneficial role of GRb1-induced up-regulation of adiponectin in liversteatosis remains unelucidated. Thus, we tested whether GRb1 ameliorates liver steatosis and insulinresistance by promoting the expression of adiponectin. Methods: 3T3-L1 adipocytes and hepatocytes were used to investigate GRb1's action on adiponectinexpression and triglyceride (TG) accumulation. Wild type (WT) mice and adiponectin knockout (KO)mice fed high fat diet were treated with GRb1 for 2 weeks. Hepatic fat accumulation and function as wellas insulin sensitivity was measured. The activation of AMPK was also detected in the liver andhepatocytes. Results: GRb1 reversed the reduction of adiponectin secretion in adipocytes. The conditioned medium(CM) from adipocytes treated with GRb1 reduced TG accumulation in hepatocytes, which was partlyattenuated by the adiponectin antibody. In the KO mice, the GRb1-induced significant decrease of TGcontent, ALT and AST was blocked by the deletion of adiponectin. The elevations of GRb1-induced insulinsensitivity indicated by OGTT, ITT and HOMA-IR were also weakened in the KO mice. The CM treatmentsignificantly enhanced the phosphorylation of AMPK in hepatocytes, but not GRb1 treatment. Likewise,the phosphorylation of AMPK in liver of the WT mice was increased by GRb1, but not in the KO mice. Conclusions: The up-regulation of adiponectin by GRb1 contributes to the amelioration of liver steatosisand insulin resistance, which further elucidates a new mechanism underlying the beneficial effects ofGRb1 on obesity

MLL4 Regulates the Progression of Non-Small-Cell Lung Cancer by Regulating the PI3K/AKT/SOX2 Axis

Yang Yang,Rongfang Qiu,Qiaoyou Weng,Ziwei Xu,Jingjing Song,Siyu Zhao,Miaomiao Meng,Dengke Zhang,Chunli Kong,Hailin Wang,Min Xu,Zhongwei Zhao,Jiansong Ji 대한암학회 2023 Cancer Research and Treatment Vol.55 No.3

Purpose Mixed-lineage leukemia protein 4 (MLL4/KMT2D) is a histone methyltransferase, and its mutation has been reported to be associated with a poor prognosis in many cancers, including lung cancer. We investigated the function of MLL4 in lung carcinogenesis. Materials and Methods RNA sequencing (RNA-seq) in A549 cells transfected with control siRNA or MLL4 siRNA was performed. Also, we used EdU incorporation assay, colony formation assays, growth curve analysis, transwell invasion assays, immunohistochemical staining, and in vivo bioluminescence assay to investigate the function of MLL4 in lung carcinogenesis. Results We found that MLL4 expression was downregulated in non–small cell lung cancer (NSCLC) tissues compared to adjacent normal tissues and tended to decrease with disease stage progression. We analyzed the transcriptomes in control and MLL4- deficient cells using high-throughput RNA deep sequencing (RNA-seq) and identified a cohort of target genes, such as SOX2, ATF1, FOXP4, PIK3IP1, SIRT4, TENT5B, and LFNG, some of which are related to proliferation and metastasis. Our results showed that low expression of MLL4 promotes NSCLC cell proliferation and metastasis and is required for the maintenance of NSCLC stem cell properties. Conclusion Our findings identify an important role of MLL4 in lung carcinogenesis through transcriptional regulation of PIK3IP1, affecting the PI3K/AKT/SOX2 axis, and suggest that MLL4 could be a potential prognostic indicator and target for NSCLC therapy.