Pronuclear Formation and DNA Synthesis in Pig Oocytes following Intracytoplasmic Injection of Pig or Mouse Spermatozoon

Xiang Sun Cui,Bong-Ki Kim,Sun Hong Jun,Dong Il Jin,Chang Sik Park,Nam-Hyung Kim 한국동물번식학회 2002 Reproductive & Developmental Biology(Supplement) Vol.26 No.1s

Fuzzy-Logic-Based <tex> $V/f$</tex> Control of an Induction Motor for a DC Grid Power-Leveling System Using Flywheel Energy Storage Equipment

Xiang-Dong Sun,Kang-Hoon Koh,Byung-Gyu Yu,Matsui, M. IEEE 2009 IEEE transactions on industrial electronics Vol.56 No.8

<P>Since natural distribution power generation systems such as wind energy contain electric power fluctuation, flywheel energy storage (FWES) equipment for power compensation is used. Fuzzy-logic-based <I>V</I>/<I>f</I> control of the induction motor is proposed for the speed sensorless power-leveling system in this paper. Only two sensors, including one DC voltage sensor and one DC current sensor, are utilized. The flywheel is composed of two modes, namely, the speed picking-up control mode and the power control mode. According to the DC-link average current of an inverter, the rotating speed of the flywheel in the speed picking-up control mode is detected by regulating the output frequency and the output voltage based on fuzzy logic control. The power control mode consists of the outer voltage loop and the inner current loop. Although the outer loop is also realized by fuzzy logic control, the inner loop is the key object in this paper, i.e., the proportional and integral gains of a proportional-integral regulator are optimized by means of fuzzy logic reasoning for the purpose of the reliability and rapid response of leveling power. The experiments are carried out with the FWES equipment of 40-kJ energy, and the results verify that the proposed method is reliable, and better dynamic and static performance is demonstrated.</P>

A Novel Single-Voltage-Sensor-Based Maximum Power Point Tracking Method

Xiang-Dong Sun,Mikihiko Matsui,Kouji Yanagimura 전력전자학회 2007 ICPE(ISPE)논문집 Vol.- No.-

A novel maximum power point tracking method for photovoltaic systems based on a single voltage sensor is proposed in this paper. By means of the simulation studies with PSIM software, it has been found that there are similar relationship curves between the expression (C-d)ㆍ(-ΔVPV)and the actual power PPV of a photovoltaic array regardless of the chopper stage topology connected to the array. Therefore the maximum power point tracking based on PPV is replaced with the expression (C-d)ㆍ(-ΔVPV). For the purpose of diminishing the power fluctuation in the steady state, the averaged voltages of a photovoltaic array and the average duty ratios are used for the calculation. Experimental results obtained on a 50W prototype of a lead acid battery charger show high performance such as the less power fluctuation and the less ambient, i.e. irradiation and temperature, influence.

A Novel Islanding Detection Method Based on Minute Asymmetrical Current Injection for Three-Phase Grid-Connected PV Inverters

Xiang-Dong Sun,Mikihiko Matsui,Byung-Gyu Yu 전력전자학회 2007 ICPE(ISPE)논문집 Vol.- No.-

An active anti-islanding method based on the current control for a three-phase grid-connected PV inverter is proposed in this paper. The current of phase a is synchronous with the corresponding voltage at the common coupling point in its positive half cycle, and a zero-current zone is inserted into the end of the cycle in a negative half cycle. As for phase c, the zero-current zone is inserted in the positive half cycle of the current, and the current of phase c in a negative half cycle is synchronous with the corresponding voltage. Therefore the currents of phase a and c in one cycle become asymmetrical slightly. Before the islanding takes place, because of the operation of utility voltage the positive and negative half cycles of three-phase voltages are symmetrical. While the islanding occurs, the time differences between the positive and negative half cycles of the voltages of phase a and c will generate and the islanding is detected in accordance with the repetitive cycles fulfilling the conditions of the time differences. On the basis of the above analysis for three-phase four-wire power systems, three-phase three-wire systems are designed. The experiment on a 0.3㎾ PV inverter system connected to 200V/50㎐ utility are carried out, and it is verified that the method can detect the islanding for the parallel RLC loads even if the voltage frequency is within the non-detection zone. It is seen from the analysis of the detecting principle that there is no influence on the proposed method even if a large load connected in parallel frequently starts up or stops.

Pronuclear Formation and DNA Synthesis in Pig Oocytes following Intracytoplasmic Injection of Pig or Mouse Spermatozoon

Xiang Sun Cui,Bong-Ki Kim,Sun Hong Jun,Dong Il Jin,Chang Sik Park,Nam-Hyung Kim 한국동물생명공학회(구 한국동물번식학회) 2002 Reproductive & developmental biology Vol.26 No.1

TNM Stages and Prognostic Features of Colorectal and Mucinous Adenocarcinoma Patients: a Meta Analysis

Chen, Jing-Xiang,Tang, Xu-Dong,Xiang, De-Bing,Dong, Xiao-Ling,Peng, Fang-Yi,Sun, Gui-Yin Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.7

Aim: The significance of the mucinous adenocarcinoma in TNM staging and prognosis for colorectal tumor patients is still controversial. The aim was to provide a meta-analysis for TNM staging and prognostic features of colorectal tumors. Methods: 30 individual case-control studies were finally included into this meta-analysis, involving a total of 444,489 cancer cases and 45,050 mucinous adenocarcinomas, of relations with TNM staging and prognostic features. Results: Compared to non-mucinous adenocarcinoma patients, the TNM IV stage accounted for a larger percentage of mucinous adenocarcinomas (OR=1.48, 95%CI 1.28-1.71, POR<0.001) and the prognosis was significantly poor (HR=1.06, 95%CI 1.04-1.08, P<0.001). After heterogeneity testing, the results was similar to the holistic approach outcome (HR=1.48, 95%CI 1.35-1.62, P<0.001). Conclusion: Compared to patients with non-mucinous adenocarcinomas, mucinous adenocarcinoma patients with later TNM staging make up a big percentage, and mucinous adenocarcinoma is an independent risk factor for poor prognosis.

Aging effects on chemical transformation and metal(loid) removal by entrapped nanoscale zero-valent iron for hydraulic fracturing wastewater treatment

Sun, Yuqing,Lei, Cheng,Khan, Eakalak,Chen, Season S.,Tsang, Daniel C.W.,Ok, Yong Sik,Lin, Daohui,Feng, Yujie,Li, Xiang-dong Elsevier 2018 Science of the Total Environment Vol.615 No.-

<P><B>Abstract</B></P> <P>In this study, alginate and polyvinyl alcohol (PVA)-alginate entrapped nanoscale zero-valent iron (nZVI) was tested for structural evolution, chemical transformation, and metals/metalloids removal (Cu(II), Cr(VI), Zn(II), and As(V)) after 1–2month passivation in model saline wastewaters from hydraulic fracturing. X-ray diffraction analysis confirmed successful prevention of Fe<SUP>0</SUP> corrosion by polymeric entrapment. Increasing ionic strength (<I>I</I>) from 0 to 4.10M (deionized water to Day-90 fracturing wastewater (FWW)) with prolonged aging time induced chemical instability of alginate due to dissociation of carboxyl groups and competition for hydrogen bonding with nZVI, which caused high Na (7.17%) and total organic carbon (24.6%) dissolution from PVA-alginate entrapped nZVI after 2-month immersion in Day-90 FWW. Compared to freshly-made beads, 2-month aging of PVA-alginate entrapped nZVI in Day-90 FWW promoted Cu(II) and Cr(VI) uptake in terms of the highest removal efficiency (84.2% and 70.8%), pseudo-second-order surface area-normalized rate coefficient <I>k</I> <SUB> <I>sa</I> </SUB> (2.09×10<SUP>−1</SUP> Lm<SUP>−2</SUP> h<SUP>−1</SUP> and 1.84×10<SUP>−1</SUP> Lm<SUP>−2</SUP> h<SUP>−1</SUP>), and Fe dissolution after 8-h reaction (13.9% and 8.45%). However, the same conditions inhibited Zn(II) and As(V) sequestration in terms of the lowest removal efficiency (31.2% and 39.8%) by PVA-alginate nZVI and <I>k</I> <SUB> <I>sa</I> </SUB> (4.74×10<SUP>−2</SUP> Lm<SUP>−2</SUP> h<SUP>−1</SUP> and 6.15×10<SUP>−2</SUP> Lm<SUP>−2</SUP> h<SUP>−1</SUP>) by alginate nZVI. The X-ray spectroscopic analysis and chemical speciation modelling demonstrated that the difference in metals/metalloids removal by entrapped nZVI after aging was attributed to distinctive removal mechanisms: (i) enhanced Cu(II) and Cr(VI) removal by nZVI reduction with accelerated electron transfer after pronounced dissolution of non-conductive polymeric immobilization matrix; (ii) suppressed Zn(II) and As(V) removal by nZVI adsorption due to restrained mass transfer after blockage of surface-active micropores. Entrapped nZVI was chemically fragile and should be properly stored and regularly replaced for good performance.</P> <P><B>Highlights</B></P> <P> <UL> <LI> nZVI entrapment successfully prevented Fe<SUP>0</SUP> corrosion in fracturing wastewaters. </LI> <LI> Entrapped nZVI was chemically fragile due to dissolution of Na and TOC. </LI> <LI> nZVI passivation promoted Cu(II) and Cr(VI) but inhibited Zn(II) and As(V) removal. </LI> <LI> Effects of nZVI aging on removal efficiency depended on interaction mechanisms. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

CT Quantitative Analysis and Its Relationship with Clinical Features for Assessing the Severity of Patients with COVID-19

Sun Dong,Li Xiang,Guo Dajing,Wu Lan,Chen Ting,Fang Zheng,Chen Linli,Zeng Wenbing,Yang Ran 대한영상의학회 2020 Korean Journal of Radiology Vol.21 No.7

Objective: To investigate the value of initial CT quantitative analysis of ground-glass opacity (GGO), consolidation, and total lesion volume and its relationship with clinical features for assessing the severity of coronavirus disease 2019 (COVID-19). Materials and Methods: A total of 84 patients with COVID-19 were retrospectively reviewed from January 23, 2020 to February 19, 2020. Patients were divided into two groups: severe group (n = 23) and non-severe group (n = 61). Clinical symptoms, laboratory data, and CT findings on admission were analyzed. CT quantitative parameters, including GGO, consolidation, total lesion score, percentage GGO, and percentage consolidation (both relative to total lesion volume) were calculated. Relationships between the CT findings and laboratory data were estimated. Finally, a discrimination model was established to assess the severity of COVID-19. Results: Patients in the severe group had higher baseline neutrophil percentage, increased high-sensitivity C-reactive protein (hs-CRP) and procalcitonin levels, and lower baseline lymphocyte count and lymphocyte percentage (p < 0.001). The severe group also had higher GGO score (p < 0.001), consolidation score (p < 0.001), total lesion score (p < 0.001), and percentage consolidation (p = 0.002), but had a lower percentage GGO (p = 0.008). These CT quantitative parameters were significantly correlated with laboratory inflammatory marker levels, including neutrophil percentage, lymphocyte count, lymphocyte percentage, hs-CRP level, and procalcitonin level (p < 0.05). The total lesion score demonstrated the best performance when the data cut-off was 8.2%. Furthermore, the area under the curve, sensitivity, and specificity were 93.8% (confidence interval [CI]: 86.8–100%), 91.3% (CI: 69.6–100%), and 91.8% (CI: 23.0–98.4%), respectively. Conclusion: CT quantitative parameters showed strong correlations with laboratory inflammatory markers, suggesting that CT quantitative analysis might be an effective and important method for assessing the severity of COVID-19, and may provide additional guidance for planning clinical treatment strategies.

Zero-valent iron for the abatement of arsenate and selenate from flowback water of hydraulic fracturing

Sun, Yuqing,Chen, Season S.,Tsang, Daniel C.W.,Graham, Nigel J.D.,Ok, Yong Sik,Feng, Yujie,Li, Xiang-Dong Elsevier 2017 CHEMOSPHERE - Vol.167 No.-

<P><B>Abstract</B></P> <P>Zero-valent iron (ZVI) was tested for the removal of 150 μg L<SUP>−1</SUP> As(V) and 350 μg L<SUP>−1</SUP> Se(VI) in high-salinity (ionic strength 0.35–4.10 M) flowback water of hydraulic fracturing. Over 90% As(V) and Se(VI) was removed by 2.5 g L<SUP>−1</SUP> ZVI in Day-14 flowback water up to 96-h reaction, with the remaining concentration below the maximum contaminant level for As(V) and criterion continuous concentration for Se(VI) recommended by US EPA. The kinetics of As(V) and Se(VI) removal followed a pseudo-second-order rate expression with the observed rates of 4.51 × 10<SUP>−2</SUP>–4.91 × 10<SUP>−1</SUP> and 3.48 × 10<SUP>−2</SUP>–6.58 × 10<SUP>−1</SUP> h<SUP>−1</SUP> (with 0.5–10 g L<SUP>−1</SUP> ZVI), respectively. The results showed that Se(VI) removal significantly decreased with increasing ionic strength, while As(V) removal showed little variation. Common competing anions (nitrate, bicarbonate, silicate, and phosphate), present in shallow groundwater and stormwater, caused marginal Se(VI) desorption (2.42 ± 0.13%) and undetectable As(V) desorption from ZVI. The competition between As(V) and Se(VI) for ZVI removal depended on the initial molar ratio and surface sites, which occurred when the Se(VI) concentration was higher than the As(V) concentration in this study. The characterization of As(V)- and Se(VI)-loaded ZVI by X-ray diffraction and Raman analysis revealed that ZVI gradually converted to magnetite/maghemite corrosion products with lepidocrocite in flowback water over 30 days. Similar corrosion compositions were confirmed in aerobic and anaerobic conditions regardless of the molar ratio of As(V) to Se(VI). The high reactivity and stability of ZVI showed its suitability for <I>in-situ</I> prevention of As(V) and Se(VI) migration due to accidental leakage, spillage, or overflow of flowback water.</P> <P><B>Highlights</B></P> <P> <UL> <LI> As(V) and Se(VI) in high-salinity flowback water was effectively removed by ZVI. </LI> <LI> As(V) removal was less susceptible to ionic strength variations than Se(V). </LI> <LI> Competing anions in groundwater and stormwater caused insignificant desorption. </LI> <LI> As(V) and Se(VI) competition depended on their molar ratio and ZVI surface sites. </LI> <LI> Surface characteristics of ZVI were unaffected by molar ratio and dissolved oxygen. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Nanoscale zero-valent iron for metal/metalloid removal from model hydraulic fracturing wastewater

Sun, Yuqing,Lei, Cheng,Khan, Eakalak,Chen, Season S.,Tsang, Daniel C.W.,Ok, Yong Sik,Lin, Daohui,Feng, Yujie,Li, Xiang-dong Elsevier 2017 CHEMOSPHERE - Vol.176 No.-

<P><B>Abstract</B></P> <P>Nanoscale zero-valent iron (nZVI) was tested for the removal of Cu(II), Zn(II), Cr(VI), and As(V) in model saline wastewaters from hydraulic fracturing. Increasing ionic strength (<I>I</I>) from 0.35 to 4.10 M (Day-1 to Day-90 wastewaters) increased Cu(II) removal (25.4–80.0%), inhibited Zn(II) removal (58.7–42.9%), slightly increased and then reduced Cr(VI) removal (65.7–44.1%), and almost unaffected As(V) removal (66.7–75.1%) by 8-h reaction with nZVI at 1–2 g L<SUP>−1</SUP>. The removal kinetics conformed to pseudo-second-order model, and increasing <I>I</I> decreased the surface area-normalized rate coefficient (<I>k</I> <SUB> <I>sa</I> </SUB>) of Cu(II) and Cr(VI), probably because agglomeration of nZVI in saline wastewaters restricted diffusion of metal(loid)s to active surface sites. Increasing <I>I</I> induced severe Fe dissolution from 0.37 to 0.77% in DIW to 4.87–13.0% in Day-90 wastewater; and Fe dissolution showed a significant positive correlation with Cu(II) removal. With surface stabilization by alginate and polyvinyl alcohol, the performance of entrapped nZVI in Day-90 wastewater was improved for Zn(II) and Cr(VI), and Fe dissolution was restrained (3.20–7.36%). The X-ray spectroscopic analysis and chemical speciation modelling demonstrated that the difference in removal trends from Day-1 to Day-90 wastewaters was attributed to: (i) distinctive removal mechanisms of Cu(II) and Cr(VI) (adsorption, (co-)precipitation, and reduction), compared to Zn(II) (adsorption) and As(V) (bidentate inner-sphere complexation); and (ii) changes in solution speciation (e.g., from Zn<SUP>2+</SUP> to ZnCl<SUB>3</SUB> <SUP>−</SUP> and ZnCl<SUB>4</SUB> <SUP>2−</SUP>; from CrO<SUB>4</SUB> <SUP>2−</SUP> to CaCrO<SUB>4</SUB> complex). Bare nZVI was susceptible to variations in wastewater chemistry while entrapped nZVI was more stable and environmentally benign, which could be used to remove metals/metalloids before subsequent treatment for reuse/disposal.</P> <P><B>Highlights</B></P> <P> <UL> <LI> nZVI could remove Cu(II), Zn(II), Cr(VI), and As(V) from fracturing wastewaters. </LI> <LI> High salinity enhanced Fe dissolution and reduced removal rates except Cu(II). </LI> <LI> nZVI entrapment mitigated Fe dissolution and improved metal(loid) removal. </LI> <LI> Removal efficiency varied with interaction mechanisms and solution speciation. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>