Rational quartic Said-Ball Conics

Qian-Qian Hu,Guo-Jin Wang (사)한국CDE학회 2007 한국CAD/CAM학회 국제학술발표 논문집 Vol.2007 No.8

Nano-Rheology of Single Unentangled Polymeric Lubricant Films

Guo, Qian,Chung, Pil Seung,Jhon, Myung S.,Choi, Hyoung Jin WILEY-VCH Verlag 2008 Macromolecular theory and simulations Vol.17 No.9

<P>Rheology and tribology become more and more critical issues in order to satisfy the harsh requirements for ultra-small head/media spacing HDDs. In this communication, MD simulations with a bead/spring model were employed to examine the nano-rheological response of nonfunctional and functional PFPEs by analyzing the shear viscosity of nanoscale PFPE films and the relaxation processes as a function of wall interaction/separation and endgroup functionality. Our simulation results indicate that thin PFPE films show more solid-like behavior, especially under high shear rate. The film deformation and shear viscosity change by tuning the film thickness and the endgroup functionality was discussed in conjunction with the relaxation processes.</P><P> <img src='wiley_img/10221344-2008-17-9-MATS200800048-gra001.gif' alt='wiley_img/10221344-2008-17-9-MATS200800048-gra001'> </P>

Highly Efficient Shoot Regeneration from Cotyledonary Nodes of Vegetable Soybean

Qian-Qian Liu,Gang Chen,Jun-Yi Gai,Yue-Lin Zhu,Li-Fei Yang,Guo-Ping Wei,Cong Wang 한국원예학회 2010 원예과학기술지 Vol.28 No.2

풋콩(Glycine max (L.) Merrill) 6개 품종의 자엽절 절편체로부터 thidiazuron(TDZ)과 NAA 농도를 달리한 배지에서 신초의 효율적인 재분화를 조사한 후, 가장 효과가 좋은 생장조절물질 조합으로 배지 종류, 접종방법 및 품종별 신초 재분화율을 조사하였다. 또한 절편체를 배지에 수직 또는 수평으로 치상하는 방법과 B5, 1/2 B5, MS, 1/2 MS, MSB(MS salts + B5 organics) 등의 5가지 기본 배지에 관하여 시험하였다. B5 배지에 1㎎?L<SUP>-1</SUP> TDZ, 0.05㎎?L<SUP>-1</SUP> NAA, 5㎎?L<SUP>-1</SUP> AgNO₃를 첨가한 처리에서 6개 품종의 신초 재분화율이 55.3-88.9%로 높았다. ‘L?ling No. 1’의 경우 수직으로 치상하는 것이 수평으로 치상하는 것보다 신초 재분화율이 37.5% 더 높았다. 따라서 풋콩은 TDZ를 처리한 B5 배지에 자엽절을 수직으로 치상할 때 신초 재분화율이 높았다. To establish a highly efficient system for shoot regeneration in vegetable soybean (Glycine max (L.) Merrill), explants were obtained from six genotypes and adventitious shoots were regenerated from cotyledonary nodes cultured on medium supplemented with different concentrations of N-phenyl-N′-1, 2, 3-thiadiazol-5-ylurea (thidiazuron TDZ) and 1-naphthylacetic acid (NAA). The most effective combination of plant growth regulators was selected first and then the effects of medium types, inoculation methods and genotypic differences on shoot regeneration were studied. The explants were inserted either vertically or horizontally into the medium and five basal media, including B5, ½ B5, MS, ½ MS, and MSB (MS salts and B5 organics), were tested. The shoot regeneration frequency of the six genotypes ranged from 53.5% to 88.9% and three of them reached 88.9%, 87.5% and 83.3%, respectively, on B5 medium supplemented with 1 ㎎?L<SUP>-1</SUP> TDZ, 0.05 ㎎?L<SUP>-1</SUP> NAA, and 5 ㎎?L<SUP>-1</SUP> AgNO₃. The shoot regeneration frequency of explants cultured on B5 medium was significantly higher than that of the other four basal media. The vertically inserted explants were found to yield a higher shoot regeneration frequency than that of horizontally inserted ones; the maximum difference of regenerating percentages between the two methods was 37.5%. In summary, TDZ was an efficient plant growth regulator for shoot induction. B5 medium and vertically inserted explants promoted shoot regeneration. We believe this highly efficient shoot regeneration system will provide foundation for the further transgenic studies in vegetable soybean.

Protective effects of blueberry drink on cognitive impairment induced by chronic mild stress in adult rats

Qian Guo,Young-Nam Kim,Bog-Hieu Lee 대한지역사회영양학회 2017 Nutrition Research and Practice Vol.11 No.1

BACKGROUND/OBJECTIVES: Stress-induced cognitive impairment is related to the suppression of hippocampal neurogenesis that results from an increase of oxidative stress. Therefore, the aim of this study was to investigate the effects of administration of a blueberry drink, having a high antioxidant power, on the cognitive performance of adult rats exposed to chronic mild stress. MATERIALS/METHODS: Twelve-week-old male Sprague-Dawley rats (n = 48) were randomly divided into four groups: control (CO), stress (ST), control + 5% blueberry drink (CO + B), and stress + 5% blueberry drink (ST + B). After eight weeks, the cognitive performance was assessed using a multiple T-maze water test. Levels of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and ascorbic acid were measured in the brain, and catecholamine concentrations were measured in plasma. RESULTS: The brain weights of the rats from the ST and ST + B groups were significantly lower than those of the rats from the CO and CO + B groups. The cognitive performance of the ST group was impaired when compared to that of the CO group. This impairment was significantly improved by the blueberry drink supplementation (P < 0.05). The brain SOD and CAT concentrations were not influenced by the stress or by the blueberry drink. However, the brain levels of GPx and ascorbic acid were significantly lower in the ST group than those in the CO group and were increased by the blueberry drink supplementation. The plasma catecholamine concentrations were affected by chronic mild stress and by the blueberry drink. The plasma norepinephrine and dopamine concentrations were decreased by the chronic stress and improved by the blueberry drink supplementation. The plasma epinephrine level was only influenced by the stress. CONCLUSION: These findings suggest that the blueberry drink may protect against the cognitive impairment induced by chronic mild stress.

Preparation and Characterization of Acid and Pepsin-soluble Collagens from Scales of Croceine and Redlip Croakers

Qian-Qian Wu,Tao Li,Bin Wang,Guo-Fang Ding 한국식품과학회 2015 Food Science and Biotechnology Vol.24 No.6

Acid-soluble (ASC) and pepsin-soluble collagen (PSC) from scales of croceine croaker (ASCPC and PSC-PC) and redlip croaker (ASC-PP and PSC-PP) were prepared with yields of 0.37±0.08% (ASCPC), 1.09±0.23% (PSC-PC), 0.42±0.09% (ASC-PP), and 1.14±0.30% (PSC-PP) (dry scale basis). Gly (347.1- 359.8 residues/1,000 residues) was the major amino acid. Contents of imino acid were between 189.4 and 192.9 residues/1,000 residues in all 4 collagens. ASC-PC and ASC-PP were type I collagens. Differences in subunit components between ASC and PSC were observed. Denaturation temperature values of ASC-PC, ASC-PP, PSC-PC, and PSC-PP were 30.7, 30.1, 27.5, and 26.6℃, respectively. All 4 collagens were soluble at pH 1-4. Values declined when NaCl concentrations exceeded 2%. Freeze-dried collagens showed loose, fibrous, and porous structures. The 4 scale collagens can be alternatives to collagen from terrestrial animals for applications in functional food, cosmetic, and biomedical industries.

Ginsenoside-Rh2 Inhibits Proliferation and Induces Apoptosis of Human Gastric Cancer SGC-7901 Side Population Cells

Qian, Jun,Li, Jing,Jia, Jian-Guang,Jin, Xin,Yu, Da-Jun,Guo, Chen-Xu,Xie, Bo,Qian, Li-Yu Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.4

Objectives: To observed the effects of ginsenoside -Rh2 (GS-Rh2) on proliferation and apoptosis of side population (SP) human gastric cancer SGC-7901 cells. Materials and Methods: SGC-7901 SP and Non-SP cells were sorted by flow cytometry and assessed using the cck-8 method. Expression of apoptosis-related proteins Bax and Bcl-2 of SP before and after the intervention was determined by Western-blotting. Results: It was found that the proliferation of SP was significantly faster than that of NSP (P<0.05). In addition, GS-Rh2 inhibited proliferation of gastric cancer SP cells, induced cell cycle arrest and cell apoptosis, and changed the expression of BAX/Bcl-2 proteins in a time-dependent and concentration-dependent manner (P<0.05). Conclusions: With increase of GS-Rh2 dose, GS-Rh2 gradually inhibit the proliferation of SGC-7901 SP cells, which have high proliferation rate, through G1/G0 phase arrest, followed by apoptosis which involves the up-regulation of Bax and the down-regulation of Bcl-2.

Distributed Secondary Voltage Control of Islanded Microgrids with Event-Triggered Scheme

Guo, Qian,Cai, Hui,Wang, Ying,Chen, Weimin The Korean Institute of Power Electronics 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.6

In this study, the distributed secondary voltage control of islanded microgrids with multi-agent consensus algorithm is investigated. As an alternative to a time-triggered approach, an event-triggered scheme is proposed to reduce the communication load among inverter-based distributed generators (DGs). The proposed aperiodic control scheme reduced unnecessary utilization of limited network bandwidth without degrading control performance. By properly establishing a distributed triggering condition in DG local controller, each inverter is only required to send voltage information when its own event occurs. The compensation of voltage amplitude deviation can be realized, and redundant data exchange related to fixed high sampling rate can be avoided. Therefore, an efficient use of communication infrastructure can be realized, particularly when the system is operating in steady state. The effectiveness of the proposed scheme is verified by simulations on a microgrid test system.

Rs7574865 polymorphism of STAT4 and risk of anti-tuberculosis drug-induced hepatotoxicity in Chinese Han

Guo Chen,Wei Mao,Shou‑Quan Wu,Yu Wang,Gui‑Yi Ji,Miao‑Miao Zhang,Qian‑Qian Liu,Jian‑Qing He 한국유전학회 2017 Genes & Genomics Vol.39 No.11

Anti-tuberculosis drug-induced hepatotoxicity (ATDH) is the most frequent, and potentially fatal adverse effect in the treatment of tuberculosis (TB). The rs7574865 polymorphism in the signal transducer and activator of transcription 4 gene (STAT4) was reported to be associated with drug-induced liver injury. However, there was no study aimed to this association in Chinese patients. The aim of this study was to investigate the influence of STAT4 polymorphisms on the susceptibility to ATDH in a Chinese Han population. A total of 280 TB patients with the prescription of anti-TB therapy, of Chinese Han origin, were enrolled. They were followed up for 3 months and demographic, clinical, laboratory and therapeutic data at each visit were collected. Two single nucleotide polymorphisms (SNPs) (rs7574865 and rs7582694) of STAT4 were genotyped with the MassARRAY platform. The associations between SNPs and ATDH risk were analyzed by logistic regression adjusting for confounding factors. A total of 24 patients were diagnosed with ATDH and considered as the case group, and 33 patients were lost to follow-up; the remaining 223 subjects without ATDH were considered as the control group. There was strong linkage disequilibrium (LD) between rs7574865 and rs7582694 ( r2 = 0.928 and D′ = 1). No significant association was found between SNPs or haplotypes of STAT4 and ATDH after correction for confounding factors. This prospective study is the first to investigate the association of genetic polymorphisms of STAT4 and ATDH in Chinese individuals. There was no significant association between the rs7574865 of STAT4 and ATDH in a Chinese Han population.

Predictors and Dynamic Nomogram to Determine the Individual Risk of Malignant Brain Edema After Endovascular Thrombectomy in Acute Ischemic Stroke

Qian-mei Jiang,Shuai Yu,Xiaofeng Dong,Huai-shun Wang,Jie Hou,Zhi-chao Huang,Zhi-liang Guo,Shou-jiang You,Guo-dong Xiao 대한신경과학회 2022 Journal of Clinical Neurology Vol.18 No.3

Background and Purpose This study aimed to construct an optimal dynamic nomogram for predicting malignant brain edema (MBE) in acute ischemic stroke (AIS) patients after endovascular thrombectomy (ET). Methods We enrolled AIS patients after ET from May 2017 to April 2021. MBE was defined as a midline shift of >5 mm at the septum pellucidum or pineal gland based on follow-up computed tomography within 5 days after ET. Multivariate logistic regression and LASSO (least absolute shrinkage and selection operator) regression were used to construct the nomogram. The area under the receiver operating characteristic curve (AUC) and decisioncurve analysis were used to compare our nomogram with two previous risk models for predicting brain edema after ET. Results MBE developed in 72 (21.9%) of the 329 eligible patients. Our dynamic web-based nomogram (https://successful.shinyapps.io/DynNomapp/) consisted of five parameters: basal cistern effacement, postoperative National Institutes of Health Stroke Scale (NIHSS) score, brain atrophy, hypoattenuation area, and stroke etiology. The nomogram showed good discrimination ability, with a C-index (Harrell’s concordance index) of 0.925 (95% confidence interval=0.890–0.961), and good calibration (Hosmer-Lemeshow test, p=0.386). All variables had variance inflation factors of <1.5 and tolerances of >0.7, suggesting no significant collinearity among them. The AUC of our nomogram (0.925) was superior to those of Xiang-liang Chen and colleagues (0.843) and Ming-yang Du and colleagues (0.728). Conclusions Our web-based dynamic nomogram reliably predicted the risk of MBE in AIS patients after ET, and hence is worthy of further evaluation.

The effects of a summer reading program for migrant children in migrant schools: First-year results from a randomized experiment

Qian Guo,Young-Suk Grace Kim,Yan Liu,Yan Peng,WENKAI SUN,Yijie Wang,Li Yang 서울대학교 교육연구소 2021 Asia Pacific Education Review Vol.22 No.1

Thanks to urbanization, some developing countries have a large migrant population. Academic performance of migrant children is usually far from satisfactory, much to the concern of educators and legislators. Meanwhile, research has attested to the importance of reading skill development by the end of third grade for later academic achievement. Against this background, we evaluated the effects of providing self-selected, developmentally appropriate books on the reading performance and summer reading amount of students in migrant schools in China, employing a randomized controlled trial. The intervention program improved rising second-graders’ word reading scores and summer reading amount. It proved particularly beneficial to low-performing children and children from disadvantaged families. The findings have implications for improving the academic achievement of migrant children in migrant schools in China and similar developing countries, especially where parental support may not be expected for the academic development of children.