The Size Dependence of Dissolution Thermodynamics of Nanoparticles

Zhi-Qiang Wang,Yongqiang Xue,Zixiang Cui,Huijuan Duan,Xiao-Yan Xia 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2016 NANO Vol.11 No.9

Dissolution of nanoparticles is involved in the preparation, research and application of nanomaterials, but there is a surprising difference in dissolution thermodynamics between nanoparticles and the corresponding bulk materials. In the paper, the relations of dissolution thermodynamic properties, equilibrium constant of nanoparticles, respectively, and particle size were derived by introducing interface variables and the surface chemical potential. Experimentally, the solubility of nano-barium sulfate with different average particle sizes at different temperatures were determined by the method of electrical conductivity, obtaining the influencing regularities of particle size on the dissolution thermodynamic properties and the equilibrium constant. The regularities are in accordance with the theory. The results show that there are remarkable effects of particle size of nanoparticles on the dissolution thermodynamic properties and the equilibrium constant; with the decreasing of the size of nanoparticles, the dissolution equilibrium constant increases, while the standard dissolution Gibbs free energy, the standard dissolution enthalpy and the standard dissolution entropy decrease; and the logarithm of the dissolution equilibrium constant, the standard dissolution Gibbs free energy, the standard dissolution enthalpy and the standard dissolution entropy are linearly associated with the reciprocal of particle size, respectively. This new theory provides a quantitative description of nanoparticles dissolution behavior, and has important scientific significance for understanding and predicting of thermodynamic regularity of dissolution concerned in the preparation, researches and applications of nanomaterials.

Clinical Application of Transcatheter Arterial Chemoembolization Combined with Synchronous C-arm Cone-Beam CT Guided Radiofrequency Ablation in treatment of Large Hepatocellular Carcinoma

Wang, Zhi-Jun,Wang, Mao-Qiang,Duan, Feng,Song, Peng,Liu, Feng-Yong,Wang, Yan,Yan, Jie-Yu,Li, Kai,Yuan, Kai Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.3

Objective: This work aimed to evaluate the safety and clinical efficacy of transcatheter arterial chemoembolization (TACE) combined with c-arm cone-beam CT guided synchronous radiofrequency ablation (RFA) in treatment of large hepatocellular carcinoma (HCC). Methods: 21 patients with large HCC were studied from January 2010 to March 2012. TACE combined with synchronous C-arm cone-beam CT guided RFA were performed on a total of 25 lesions. Conventional imaging examination (CEUS, enhanced CT or MRI) and AFP detection were regularly conducted to evaluate the technical success rate of combined treatment, complications, treatment response, time without disease recurrence and survival rate. Results: The technical success rate of combined treatment was 100%, without any significant complication. After 1 month, there were 19 cases with complete response and 2 cases with partial response, with an complete response rate of 90.4% (19/21) and a clinical effective rate of 100% (21/21). The complete response rates of single nodular lesions (100%, 17/17) was significantly higher than that of multiple nodular lesions (50%, 2/4) (P<0. 05). During 2 to 28 months of follow-up, in 19 cases with complete response, the average time without disease recurrence was $10.8{\pm}6$ months. The total survival rates of 6, 12 and 18 months in 21 patients were 100%, respectively. Conclusion: TACE combined with synchronous C-arm CT guided RFA is safe and effective for treatment of large HCC. The treatment efficacy for single nodular lesion is better than that for multiple nodular lesions.

Chemoenzymatic Synthesis of Phytosterol and Policosanol Derivatives and Evaluation of Their Anti-Inflammatory Activities

Zhi Qiang Wang,Seung Hwan Hwang,Bo Huang,Soon Sung Lim 한국식품영양과학회 2013 한국식품영양과학회 학술대회발표집 Vol.2013 No.11

Fault Analysis and Tolerant Control for High Speed PEMS Maglev Train End Joint Structure with Disturbance Rejection

Zhi-Qiang Wang,Zhi-Qiang Long,Xiao-Long Li 대한전기학회 2019 Journal of Electrical Engineering & Technology Vol.14 No.3

It is observed in test operation that for permanent magnet electro-magnetic suspension (PEMS) type high speed maglev train, when a single levitation unit in an end joint structure fails to work, the performance of the entire joint structure deteriorates rapidly, whereas in electro-magnetic suspension (EMS) type maglev system, there is no such phenomenon under the same failure. To solve this problem and to enhance system performance under faulty condition, fi rstly a comparative modeling of EMS and PEMS maglev end joint structure system was made to analyze the underlying reasons. Then a dynamic compensation method and a disturbance rejection method based on disturbance estimation and feedback linearization were proposed respectively. The performances of the proposed measures are verifi ed and compared in simulations.

Preliminary Proteomic Analysis of Indomethacin's Effect on Tumor Transplanted with Colorectal Cancer Cell in Nude Mice

Wang, Yu-Jie,Zhang, Gui-Ying,Xiao, Zhi-Qiang,Wang, Hong-Mei,Chen, Zhu-Chu Korean Society for Biochemistry and Molecular Biol 2006 Journal of biochemistry and molecular biology Vol.39 No.2

Nonsteroidal anti-inflammatory drugs such as indomethacin (IN) can exert anti-colorectal cancer (CRC) activity through cyclooxygenase independent mechanism, but the exactly biological mechanism is not completely known. Here we use proteomic tools to investigate the molecular mechanism of this action. First, nude mice bearing tumors derived from subcutaneous injection with human CRC cell line HCT116 were randomly allocated to groups treated with or without indomethacin. Later, tumor lumps were incised and then total proteins extracted. After separated with two-dimensional electrophoresis, thirty-one differently expressed spots were found between IN-treated and non-IN-treated groups, of which 25 spots decreased and 6 spots increased in abundance in IN-treated group. Through matrix-assisted laser desorption ionization time of flight mass spectrometry and then NCBInr and SWISS-PROT databases searching, 12 protein spots were finally identified including galectin-1, annexin A1, annexin IV, trancription factor BTF3A, calreticulin. Most of the identified proteins are correlated with tumor's biological prosperities of proliferation, invasion, apoptosis and immunity, or take part in cell's signal transduction. From above we thought that indomethacin can exert its effect on colorectal cancer through regulating several proteins' expression directly or indirectly. Further study of these proteins may be helpful in founding new targets of drugs for cancer chemotherapy.

Analysis of Corrosion-induced Expansive Stress and Internal Cracking of Concrete under Considering Cover Thickness

Wang Ben,Wang Hong,Zhang Zhi-qiang 보안공학연구지원센터 2016 International Journal of Smart Home Vol.10 No.10

After considering the actual dimension of reinforced concrete structure, the thickness and geometrical boundary condition of concrete cover, the model of corrosion-induced expansion can be simplified as a plane model of semi-infinite body. Through theoretical analysis, formulas are got to calculate corrosion-induced expansive stress of concrete cover. The results shows that: the corrosion-induced crack originated on the interface between concrete and the corrosion layer, if initial cracking is not in vertical direction to the surface of concrete cover, cracks along the rebar induced by the uplift and horizontal tension stress on the surface of the concrete cover may occur from its outer to inner, it also presents that the anti-rust ability of reinforced concrete structures could be improved by increasing the thickness of concrete cover, raising the grade of concrete, and increasing the diameter of rebar. Compared with the existing literatures, the precision of the theoretical solutions is verified.

Dynamic behavior analysis of push-the-bit rotary steerable bottom hole assembly

Zhi-chuan Guan,Heng Wang,Yu-cai Shi,Wei-qing Chen,Guo-shan Zhao,Jian-yun Wang,Guang-qiang Cao 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.4

Rotary steerable drilling technology is currently an advanced technology in the field of drilling engineering. A good understanding of dynamic behavior of rotary steerable system will benefit the drilling progress. Aimed at push-the-bit type of rotary steerable tool, finite element method was employed to model the rotary steerable bottom hole assembly (RSBHA) and establish the motion equation. Contact interaction between drill string and wellbore wall was analyzed and taken as the constraint condition in solving RSBHA motion equation. Force applied by steering pads was as the external force acting at the pads node. Then RSBHA motion state and bit lateral force were obtained by using Newmark method to solve the motion equation. A case was given and effects of influencing factors were analyzed. The results show that stick-slip phenomenon occurs under 60 r/min rotary speed condition and disappears when rotary speed rises to 90 r/min. Fully developed backward whirl comes into being at the near-bit stabilizer when rotary speed increases to 120 r/min. High weight on bit intensifies bit torsional vibration while larger pads’ steering force decreases the bit torsional vibration. Upper stabilizer plays a part in weakening RSBHA backward whirl under high rotary speed condition but reduces the inclination force. Time average of bit lateral force is mainly determined by pads’ steering force. Based on the results, corresponding suggestions were proposed to make the RSBHA be better used in the field applications.

Diversity of Endophytic Fungi from Different Verticillium-Wilt-Resistant Gossypium hirsutum and Evaluation of Antifungal Activity Against Verticillium dahliae In Vitro

( Zhi Fang Li ),( Ling Fei Wang ),( Zi Li Feng ),( Li Hong Zhao ),( Yong Qiang Shi ),( He Qin Zhu ) 한국미생물 · 생명공학회 2014 Journal of microbiology and biotechnology Vol.24 No.9

Cotton plants were sampled and ranked according to their resistance to Verticillium wilt. In total, 642 endophytic fungi isolates representing 27 genera were recovered from Gossypium hirsutum root, stem, and leaf tissues, but were not uniformly distributed. More endophytic fungi appeared in the leaf (391) compared with the root (140) and stem (111) sections. However, no significant difference in the abundance of isolated endophytes was found among resistant cotton varieties. Alternaria exhibited the highest colonization frequency (7.9%), followed by Acremonium (6.6%) and Penicillium (4.8%). Unlike tolerant varieties, resistant and susceptible ones had similar endophytic fungal population compositions. In three Verticillium-wilt-resistant cotton varieties, fungal endophytes from the genus Alternaria were most frequently isolated, followed by Gibberella and Penicillium. The maximum concentration of dominant endophytic fungi was observed in leaf tissues (0.1797). The evenness of stem tissue endophytic communities (0.702) was comparatively more uniform than the other two tissues. Eighty endophytic fungi selected from 27 genera were evaluated for their inhibition activity against highly virulent Verticillium dahliae isolate Vd080 in vitro. Thirty-nine isolates exhibited fungistasis against the pathogen at varying degrees. Seven species, having high growth inhibition rates (≥75%), exhibited strong antifungal activity against V. dahliae. The antifungal activity of both volatile and nonvolatile metabolites was also investigated. The nonvolatile substances produced by CEF-818 (Penicillium simplicissimum), CEF-325 (Fusarium solani), CEF-714 (Leptosphaeria sp.), and CEF-642 (Talaromyces flavus) completely inhibited V. dahliae growth. These findings deepen our understanding of cotton-endophyte interactions and provide a platform for screening G. hirsutum endophytes with biocontrol potential.

The effects of LNG-tank sloshing on the global motions of FLNG system

Zhi-Qiang Hu,Shu-Ya Wang,Gang Chen,Shu-Hong Chai,Yu-Ting Jin 대한조선학회 2017 International Journal of Naval Architecture and Oc Vol.9 No.1

This paper addresses a study of inner-tank sloshing effect on motion responses of a Floating Liquefied Natural Gas (FLNG) system, through experimental analysis and numerical modeling. To investigate hydrodynamic characteristics of FLNG under the conditions of with and without LNG-tank sloshing, a series of numerical simulations were carried out using potential flow solver SESAM. To validate the numerical simulations, model tests on the FLNG system was conducted in both liquid and solid ballast conditions with 75% tank filling level in height. Good correlations were observed between the measured and predicted results, proving the feasibility of the numerical modeling technique. On the verified numerical model, Response Amplitude Operators (RAOs) of the FLNG with 25% and 50% tank filling levels were calculated in six degrees of freedom. The influence of tank sloshing with varying tank filling levels on the RAOs has been presented and analyzed. The results showed that LNG-tank sloshing has a noticeable impact on the roll motion response of the FLNG and a moderate tank filling level is less helpful in reducing the roll motion response.

Nausea and Vomiting after Transcatheter Arterial Chemoembolization for Hepatocellular Carcinoma: Incidence and Risk Factor Analysis

Wang, Shi-Ying,Zhu, Wen-Hao,Vargulick, Sonya,Lin, Sam Bill,Meng, Zhi-Qiang Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.10

Background: Nausea and vomiting after transcatheter arterial chemoembolization (TACE) for hepatocellular carcinoma (HCC) are common in clinical practice, but few studies have reported the incidence and risk factors of such events. Objective: The purpose of this study was to analyze the incidence and risk factors of nausea and vomiting after TACE for HCC. Methods: This study was a single-center retrospective analysis of a prospectively maintained database. Between May 2010 and October 2012, 150 patients with HCC were analyzed for incidence and preprocedural risk factors. Results: The incidence of postembolization nausea and vomiting was 38.8% and 20.9%, respectively, in patients with HCC. Patients who developed nausea had lower levels (<100 IU/L) of serum alkaline phosphatase (ALP) compared to those without nausea ($123.04{\pm}69.38$ vs. $167.41{\pm}138.95$, respectively, p=0.044). Female gender correlated to a higher incidence of nausea as well (p=0.024). Patients who developed vomiting, compared to those who did not, also had lower levels (<100 IU/L) of serum ALP ($112.52{\pm}62.63$ vs. $160.10{\pm}127.80$, respectively, p=0.010), and serum alanine transferase (ALT) ($35.61{\pm}22.87$ vs. $4.97{\pm}29.62$, respectively, p=0.045). There were no statistical significances in the incidences of nausea and vomiting between male patients over 50 years old and female patients who have entered menopause (p=0.051 and p=0.409, respectively). Multivariate analysis by logistic regression analysis demonstrated that female gender and ALP>100 IU/L were the most independent predictive factors of postembolization nausea (odds ratio (OR): 3.271, 95% CI: 1.176-9.103, p=0.023 and OR: 0.447, 95% CI: 0.216-0.927, p=0.030, respectively). ALP>100 IU/L was also the most independent predictive risk factor of postembolization vomiting (OR: 0.389, 95% CI: 0.159-0.952, p=0.039). Conclusions: Postembolizaiton nausea and vomiting are common in patients with HCC. Recognition of the risk factors presented above before TACE is important for early detection and proper management of postembolization nausea and vomiting. Nevertheless, future studies are required.