Creat membership Creat membership
Sign in

Forgot password?

  • Forgot password?
    Sign Up
  • Confirm
    Sign In
home > search

Now showing items 1 - 16 of 19

  • Zheng Qiao (1104–1162), the ‘Jiaochou lüe’ (Treatise on Collation), and the Retrieval of Lost Books

    Barenghi Maddalena  

    Download Collect
  • Nuclear Shadowing Effect on the K Factor in Au-Au Collisions

    Hou Zhao Yu   Zheng Qiao   Zhang Ben Ai  

    We investigate the nuclear shadowing effect on the K factor in theDrell-Yan process by introducing a shadowing factorinto the corresponding quantum chromodynamical αs ordercorrections. K factors for Au-Au collisions are calculated at thecentre-of-mass system energies (s)1/2 = 60, 130 and 200 GeVwhile the nuclear shadowing factor is taken into account. The numericalresults indicate that the nuclear shadowing factor obviously raisesthe K value in the small x region, and for the same nucleon the Kvalue becomes smaller as the energy increases. The nuclear shadowingeffect could be one reason for creating the non-constancy ofthe K factor.
    Download Collect
  • Profitability news or valuation news? A diagnostic analysis on the different news components in conditional conservatism

    Shengmin Hung   Zheng Qiao  

    The sign of stock return has been widely used to proxy for news in the conditional conservatism model. Under discount cash flow model, firm value changes are caused by either cash flow news or discount rate news. Simply using the sign of stock returns to define good (bad) news can be problematic. Following the classic return decomposition method, this paper decomposes return news into cash flow news and discount rate news. We find that cash flow news component demonstrates consistent results with previous findings. However, with respect to discount rate news, positive return news turns out to be recognized more quickly in earnings. The conventional timeliness asymmetry even disappears in the highest quintile of discount rate news shock magnitude. In additional tests, we also document weakened timeliness asymmetry conditional on a battery of proxy variables for discount rate news. Our findings suggest that we should use stock return sign with caution in conditional conservatism tests, especially when discount rate news shock is large.
    Download Collect
  • Neutralization of TNFα in tumor with a novel nanobody potentiates paclitaxel-therapy and inhibits metastasis in breast cancer

    Xuemei Ji   Zhengxin Peng   Xiaorui Li   Zhonghui Yan   Yue Yang   Zheng Qiao   Yu Liu  

    Abstract Metastatic disease is the major cause of death from cancer, and immunotherapy and chemotherapy have had limited success in reversing its progression. Researchers have suggested that inflammatory factors in the tumor environment can promote cancer invasion and metastasis, stimulating cancer progression. Thus, novel strategies that target cytokines and modulate the tumor microenvironment may emerge as important approaches for treating metastatic breast cancer. Specific neutralization of pathogenic TNF signaling using a TNFα antibody has gained increasing attention. Considering this, a selective human TNFα neutralized antibody was generated based on nanobody technology. A TNFα-specific nanobody was produced in Pichia pastoris with a molecular mass of 15 kDa and affinity constant of 2.05 nM. In the proliferation experiment, the TNFα nanobody could inhibit the proliferation of the breast cancer cell line MCF-7 induced by hTNFα in a dose-dependent manner. In the microinvasion model, the TNFα nanobody could inhibit the migration of the breast cancer cell lines MCF-7, MDA-MB-231 and the invasiveness of MDA-MB-231 induced by hTNFα in a dose-dependent manner. Drug administration of the combination of paclitaxel with the TNFα nanobody in vivo significantly enhanced the efficacy against 4T-1 breast tumor proliferation and lung metastasis; meanwhile, E-cadherin tumor epithelial marker expression was upregulated, supporting the anti-tumor therapeutic relevance of paclitaxel and the TNFα nanobody on EMT. This study highlights the importance of neutralizing low TNFα levels in the tumor microenvironment to sensitize the chemotherapeutic response, which has attractive potential for clinical applications. Highlights • Novel TNFα nanobody was generated with high affinity and low molecular weight. • TNFα nanobody inhibited increased migration and invasiveness of MCF-7 and MDA-MB-231. • Combining Taxol with TNFα nanobody enhanced anti-tumor efficacy. • TNFα nanobody inhibited mice 4T-1 tumor EMT. • TNFα nanobody penetrated into and neutralized TNFα interior tumor.
    Download Collect
  • Biomimetic interfacial assembly of CaCO3 microspheres using egg-white foam and their interaction with Sr2+

    Zheng Qiao   Xun Liu   Xiaohui Duan   Yong Zhou   Chonghua Pei   Yongjun Ma  

    Abstract Since egg-white protein is an excellent amphoteric surfactant and an outstanding regulator of CaCO 3 mineralization, we prepared an egg-white foam as the organic matrix and template to regulate mineralization of CaCO 3 and assemble primary mineralization particles. Samples were characterized by scanning electron microscopy, powder X-ray diffraction, Fourier transform infrared spectroscopy and high-resolution transmission electron microscopy, showing that the particles are homogeneous (2 µm) vaterite spherules of CaCO 3 . The results of the interaction between the particles and Sr 2+ show that Sr 2+ can induce transformation of the particles from vaterite to calcite and that it is simultaneously adsorbed by the particles, reaching 89.9% adsorption after 36 h.
    Download Collect
  • Octadecyl functionalized core–shell magnetic silica nanoparticle as a powerful nanocomposite sorbent to extract urinary volatile organic metabolites

    Zheng Qiao   Rosa Perestrelo   Emilia M. Reyes-Gallardo   R. Lucena   S. Cárdenas   João Rodrigues   José S. Câmara  

    Highlights • Evaluation of functionalized magnetic nanoparticles Fe 3 O 4 @SiO 2 -C18 as a nanosorbent. • Reported for the first time as innovative strategy to isolate urinary EVOMs. • Attractive, promising and reliable alternative to commonly used methods. • Good results for selectivity, linearity, precision, accuracy and matrix effect. • Rapid screening for quantification of urinary EVOMs. Abstract In this present study, magnetic Fe 3 O 4 @SiO 2 nanoparticles (MNPs) functionalized with octadecyl groups (Fe 3 O 4 @SiO 2 -C 18 NPs) were synthesized, characterized and employed, for the first time, as powerful nanosorbent to extract endogenous volatile organic metabolites (EVOMs) namely, hexanal, heptanal, decanal, benzaldehyde, 4-heptanone, 5-methyl-2-furfural and phenol, described as potential biomarkers of cancer, from human urine. By using co-precipitation, surface modification methods, the carbon-ferromagnetic nanocomposite was synthesized and characterized by infrared spectrum (IR) and transmission electron microscopy (TEM). By coupling with gas chromatography–mass spectrometry (GC–qMS), a reliable, sensitive and cost-effective method was validated. To test the extraction efficiency of the carbon-ferromagnetic nanocomposite toward urinary EVOMs experimental variables affecting the extraction performance, including nanosorbent amount, adsorption time, elution time, and nature of elution solvent, were investigated in detail. The extraction process was performed by dispersing Fe 3 O 4 @SiO 2 -C18 NPs into working solution containing targeted VOMs, and into urine samples, and then eluted with an adequate organic solvent. The eluate was collected, concentrated and analyzed by GC–qMS. Under the optimized conditions, the LODs and LOQs achieved were in the range of 9.7–57.3 and 32.4–190.9 ng/mL, respectively. Calibration curves were linear ( r 2 ≥ 0. 988) over the concentration ranges from 0.25 to 250 ng/mL. In addition, a satisfying reproducibility was achieved by evaluating the intra- and inter-day precisions with relative standard deviations (RSDs) less than 3 and 11%, respectively. The method also afforded satisfactory results in terms of the matrix effect (72.8–96.1%) and recoveries (accuracy) higher than 75.1% for most of the studied EVOMs. The Fe 3 O 4 @SiO 2 -C 18 NPs-based sorbent extraction combined with GC–qMS revealed that the new nanosorbent had a strong ability to retain the target metabolites providing a new, reliable and high throughput strategy for isolation of targeted EVOMs in human urine, suggesting their potential to be applied in other EVOMs.
    Download Collect
  • Azoxymethane-induced beta-catenin-accumulated crypts in colonic mucosa of rodents as an intermediate biomarker for colon carcinogenesis.

    Yoshinobu Hirose   Toshiya Kuno   Yasuhiro Yamada   Keiko Sakata   Masaki Katayama   Koujiro Yoshida   Zheng Qiao   Kazuya Hata   Naoki Yoshimi   Hideki Mori  

    It is now well established that bile acids act as colon tumor promoters. However, a previous study provided conflicting data showing that dietary exposure of cholic acid (CHA), a primary bile acid, inhibits the carcinogen-induced formation of aberrant crypt foci (ACF), possible preneoplastic lesions, in colonic mucosa of rodents. Recently we found beta-catenin-accumulated crypts (BCAC) in colonic mucosa of rats initiated with azoxymethane (AOM) and provided evidence that BCAC might be preneoplastic lesions independent from ACF. In the present study, we investigated the modifying effects of dietary CHA on the formation of BCAC as well as ACF in male F344 rats after exposure to AOM to determine if the differences in the effect of CHA on these lesions could account for this discrepancy. The results indicate that administration of CHA (0.5%) in the diet during the post-initiation phase significantly reduced the total number, multiplicity and size of ACF (P < 0.00001) in AOM-exposed colonic mucosa as reported previously. The number of ACF even with >4 aberrant crypts/focus was also decreased significantly (P < 0.0002), suggesting that the large ACF are little resistant to continuous feeding of 0.5% CHA diet. Interestingly, the dietary CHA significantly enhanced both the multiplicity (P < 0.002) and size (P < 0.00001), but not the incidence, of AOM-induced BCAC when compared with the control diet group. Importantly, the number of large BCAC with >6 crypts/lesion was increased significantly by the dietary CHA (P < 0.003). Our results support the concept that BCAC are precursors of colon tumors and indicate the usefulness of BCAC as intermediate biomarkers for colon carcinogenesis, although the methodology for their detection requires further improvement.
    Download Collect
  • Zheng Qiao (1104–1162), the ‘Jiaochou lüe’ (Treatise on Collation), and the Retrieval of Lost Books

    Barenghi, Maddalena  

    Download Collect
  • Comparative Analysis of Three Types of Peaches:Identification of the Key Individual Characteristic Flavor Compounds by Integrating Consumers' Acceptability with Flavor Quality

    Zheng Qiao   Lu Juanfang   Quan Junping  

    In order to recognize the key flavor compounds influencing the consumers' choice for honey peach, nectarine, and flat peach and provide important information for orientation breeding, sugars, organic acids, and aroma volatiles in 3 types of peaches were examined by high performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS) and their key individual characteristic flavor compounds were identified by multivariate analysis integrated with consumers' evaluation. No significant differences in sugar and organic acid were observed between 3 types of peaches. In hierarchical clustering analysis (HCA) and principal component analysis (PCA) models, 3 types of peaches could not be differentiated by sugars or organic acids, but could be identified completely by aroma volatiles or by flavor compounds. A partial least squares regression (PLSR) model revealed that the key individual characteristic volatiles in nectarine, honey peach, and flat peach are C9 compounds and terpenic compounds, norisoprenoids and C6 compounds, and benzaldehyde, gamma-decalactone, and 3-dodecalactone, respectively. These results suggest that sugars and organic acids form the background flavor of peach fruit and lactones shape the typical peach aroma. However, the individual aroma volatiles play the decisive role in unique flavor determination of different types of peaches.
    Download Collect
  • Pregnancy Interruption with RU 486 in Combination with dl-15-methyl-prostaglandin-F2@a-methyl ester: The Chinese Experienceby Gao Ji; Qiao Gen-Mei; Wu Yu-Ming; Wu Muzh-En; Zheng Shu-Rong; Han Zhi-Bai; Fan Huimin; Yao Guang-Zhen; Meng Ung; Catherine Dubois; Andre Ulmann; Etienne-Emile Baulieu

    Download Collect
  • Pressure transient analysis of a finite-conductivity multiple fractured horizontal well in linear composite gas reservoirs

    Ren Jun-jie   Gao Yang-yang   Zheng Qiao   Guo Ping   Wang De-long  

    Faulted gas reservoirs are very common in reality, where some linear leaky faults divide the gas reservoir into several reservoir regions with distinct physical properties. This kind of gas reservoirs is also known as linear composite (LC) gas reservoirs. Although some analytical/semi-analytical models have been proposed to investigate pressure behaviors of producing wells in LC reservoirs based on the linear composite ideas, almost all of them focus on vertical wells and studies on multiple fractured horizontal wells are rare. After the pressure wave arrives at the leaky fault, pressure behaviors of multiple fractured horizontal wells will be affected by the leaky faults. Understanding the effect of leaky faults on pressure behaviors of multiple fractured horizontal wells is critical to the development design. Therefore, a semi-analytical model of finite-conductivity multiple fractured horizontal (FCMFH) wells in LC gas reservoirs is established based on Laplace-space superposition principle and fracture discrete method. The proposed model is validated against commercial numerical simulator. Type curves are obtained to study pressure characteristics and identify flow regimes. The effects of some parameters on type curves are discussed. The proposed model will have a profound effect on developing analytical/semi-analytical models for other complex well types in LC gas reservoirs.
    Download Collect
  • An interval gas flow analysis in natural gas and electricity coupled networks considering the uncertainty of wind power

    Zheng Qiao   Qinglai Guo   Hongbin Sun   Zhaoguang Pan   Yuquan Liu   Wen Xiong  

    Highlights • A comprehensive model of natural gas and electricity coupled networks is built. • Two methods on the uncertainty analysis using interval algorithm is proposed. • The interval solutions can provide great insights into the coupled systems. • An accessible capacity model of wind power under gas network constraints is built. Abstract The wide application of renewable energy sources in power systems has a significant influence on both electrical and tightly coupled systems. The aim of this paper is to build a comprehensive system model of a natural gas and electricity coupled network. The concept of distributed stack nodes was introduced to overcome the shortcoming of adjusting active power by a single gas-fired unit to achieve power balance. On this basis, the impact of the active power output uncertainty of wind farms was studied, and the interval flow of the natural gas system was analyzed by two proposed methods. The results were compared with Monte Carlo stochastic simulation. Case studies demonstrated the effectiveness of the proposed method and led to the conclusion that the uncertainty of wind power has a significant impact on the steady-state operation of natural gas systems. Interval solutions could provide great insights into the operating and planning of coupled systems with wind power uncertainty.
    Download Collect
  • Low-temperature hydrothermal synthesis of Zn2SiO4 nanostructures and the novel photocatalytic application in wastewater treatment

    Zheng Qiao   Tingjiang Yan   Xiaofang Zhang   Caixia Zhu   Wenjuan Li   Baibiao Huang  

    Abstract Zn 2 SiO 4 nanocrystallines were synthesized by a low-temperature hydrothermal method, in which the composition and morphology were tailored by changing the hydrothermal temperature and pH value. Zn 2 SiO 4 was applied as novel photocatalyst to degrade various organic pollutants and it exhibited excellent photocatalytic activity and stability as compared to traditional ZnO. The better photocatalytic performance of Zn 2 SiO 4 than ZnO can be attributed to the more generated charge carries, the stronger oxidation ability of h + and the higher concentration of active O 2 − radicals. Graphical abstract Image 2 Highlights • Zn 2 SiO 4 nanocrystallines were synthesized by a low-temperature hydrothermal method. • Hydrothermal temperature and pH value influenced the composition and morphologies. • Zn 2 SiO 4 exhibits much higher photocatalytic activity and stability than ZnO. • Zn 2 SiO 4 had high concentration of O 2 – and strong oxidation capacity (h + ). • Zn 2 SiO 4 had more generated charge carries and efficient charge transfer.
    Download Collect
  • Pregnancy Interruption with RU 486 in Combination with dl-15-methyl-prostaglandin-F2@a-methyl ester: The Chinese Experienceby Gao Ji; Qiao Gen-Mei; Wu Yu-Ming; Wu Muzh-En; Zheng Shu-Rong; Han Zhi-Bai; Fan Huimin; Yao Guang-Zhen; Meng Ung; Catherine Dubois; Andre Ulmann; Etienne-Emile Baulieu

    Download Collect
  • Unified Power Flow Analysis in Natural Gas and Electricity Coupled Networks Considering the Uncertainty of Wind Power

    Zheng Qiao   Shangyuan Huang   Rui Li   Qinglai Guo   Hongbin Sun   Zhaoguang Pan  

    Abstract The widely application of renewable energy in power system makes a big influence on the system security and stability. The main work of this paper was building a comprehensive system model of a natural gas and electricity coupled network and analyzing the steady-state power flow of the coupled network. On this basis, this paper further studied the impact of uncertainty of wind power, and analyzed the interval range of the variables of natural gas system using interval algorithm. The analysis and case studies led to the conclusion that the uncertainty of wind power has a significant impact on the security of natural gas system.
    Download Collect
  • Plasma metabolic profiling analysis of toxicity induced by brodifacoum using metabonomics coupled with multivariate data analysis

    Hui Yan   Zheng Qiao   Baohua Shen   Ping Xiang   Min Shen  

    Highlights ⿢ Metabonomic investigations were performed in plasma of rats administrated with brodifacoum. ⿢ GC⿿MS and LC⿿MS/MS were both applied to screen potential biomarkers. ⿢ Brodifacoum induces alteration in lipid metabolism and amino acid metabolism. Abstract Brodifacoum is one of the most widely used rodenticides for rodent control and eradication; however, human and animal poisoning due to primary and secondary exposure has been reported since its development. Although numerous studies have described brodifacoum induced toxicity, the precise mechanism still needs to be explored. Gas chromatography mass spectrometry (GC⿿MS) coupled with an ultra performance liquid chromatography tandem mass spectrometry (UPLC⿿MS/MS) was applied to characterize the metabolic profile of brodifacoum induced toxicity and discover potential biomarkers in rat plasma. The toxicity of brodifacoum was dose-dependent, and the high-dose group obviously manifested toxicity with subcutaneous hemorrhage. The blood brodifacoum concentration showed a positive relation to the ingestion dose in toxicological analysis. Significant changes of twenty-four metabolites were identified and considered as potential toxicity biomarkers, primarily involving glucose metabolism, lipid metabolism and amino acid metabolism associated with anticoagulant activity, nephrotoxicity and hepatic damage. MS-based metabonomics analysis in plasma samples is helpful to search for potential poisoning biomarkers and to understand the underlying mechanisms of brodifacoum induced toxicity.
    Download Collect
1 2


If you have any feedback, Please follow the official account to submit feedback.

Turn on your phone and scan

Submit Feedback