Analyzing Errors Made by Eighth-Grade Students in Solving Geometrical Problems

( Huang Xing Feng ),( Cheng Long Hai ) 한국수학교육학회 2011 수학교육연구 Vol.15 No.4

In mathematical problem solving, students may make various errors. In order to draw useful lessons from the errors, and then correct them, we surveyed 24 eighth-grade students` performances in geometrical problem solving according to Casey`s hierarchy of errors. It was found that: 1. Students`` effect can lead to errors at the stage of "comprehension", "strategy selection", and "skills manipulation"; and 2. Students`` geometric schemas also influenced their strategy selection".

Associations of Plasma Glucagon Levels with Estimated Glomerular Filtration Rate, Albuminuria and Diabetic Kidney Disease in Patients with Type 2 Diabetes Mellitus

Hua-Xing Huang,Liang-Lan Shen,Hai-Yan Huang,Li-Hua Zhao,Feng Xu,Dong-Mei Zhang,Xiu-Lin Zhang,Tong Chen,Xue-Qin Wang,Yan Xie,Jian-Bin Su 대한당뇨병학회 2021 Diabetes and Metabolism Journal Vol.45 No.6

Background: Type 2 diabetes mellitus (T2DM) is characterized by elevated fasting glucagon and impaired suppression of postprandial glucagon secretion, which may participate in diabetic complications. Therefore, we investigated the associations of plasma glucagon with estimated glomerular filtration rate (eGFR), albuminuria and diabetic kidney disease (DKD) in T2DM patients.Methods: Fasting glucagon and postchallenge glucagon (assessed by area under the glucagon curve [AUCgla]) levels were determined during oral glucose tolerance tests. Patients with an eGFR <60 mL/min/1.73 m2 and/or a urinary albumin-to-creatinine ratio (UACR) ≥30 mg/g who presented with diabetic retinopathy were identified as having DKD.Results: Of the 2,436 recruited patients, fasting glucagon was correlated with eGFR and UACR (r=–0.112 and r=0.157, respectively; P<0.001), and AUCgla was also correlated with eGFR and UACR (r=–0.267 and r=0.234, respectively; P<0.001). Moreover, 31.7% (n=771) presented with DKD; the prevalence of DKD was 27.3%, 27.6%, 32.5%, and 39.2% in the first (Q1), second (Q2), third (Q3), and fourth quartile (Q4) of fasting glucagon, respectively; and the corresponding prevalence for AUCgla was 25.9%, 22.7%, 33.7%, and 44.4%, respectively. Furthermore, after adjusting for other clinical covariates, the adjusted odds ratios (ORs; 95% confidence intervals) for DKD in Q2, Q3, and Q4 versus Q1 of fasting glucagon were 0.946 (0.697 to 1.284), 1.209 (0.895 to 1.634), and 1.521 (1.129 to 2.049), respectively; the corresponding ORs of AUCgla were 0.825 (0.611 to 1.114), 1.323 (0.989 to 1.769), and 2.066 (1.546 to 2.760), respectively. Additionally, when we restricted our analysis in patients with glycosylated hemoglobin <7.0% (n=471), we found fasting glucagon and AUCgla were still independently associated with DKD.Conclusion: Both increased fasting and postchallenge glucagon levels were independently associated with DKD in T2DM patients.

<i>In Situ</i> Atomic-Scale Observation of Surface-Tension-Induced Structural Transformation of Ag-NiP_<i>x</i> Core-Shell Nanocrystals

Huang, Xing,Liu, Zhongqiang,Millet, Marie-Mathilde,Dong, Jichen,Plodine, Milivoj,Ding, Feng,Schlö,gl, Robert,Willinger, Marc-Georg American Chemical Society 2018 ACS NANO Vol.12 No.7

<P>The properties of nanocrystals are highly dependent on their morphology, composition, and structure. Tailored synthesis over these parameters is successfully applied for the production of nanocrystals with desired properties for specific applications. However, in order to obtain full control over the properties, the behavior of nanocrystals under external stimuli and application conditions needs to be understood. Herein, using Ag-NiP<SUB><I>x</I></SUB> nanocrystals as a model system, we investigate the structural evolution upon thermal treatment by <I>in situ</I> aberration-corrected scanning transmission electron microscopy. A combination of real-time imaging with elemental analysis enables the observation of the transformation from a Ag-NiP<SUB><I>x</I></SUB> core-shell configuration to a Janus structure at the atomic scale. The transformation occurs through dewetting and crystallization of the NiP<SUB><I>x</I></SUB> shell and is accompanied by surface segregation of Ag. Further temperature increase leads to a complete sublimation of Ag and formation of individual Ni<SUB>12</SUB>P<SUB>5</SUB> nanocrystals. The transformation is rationalized by theoretical modeling based on density functional theory calculations. Our model suggests that the transformation is driven by changes of the surface energy of NiP<SUB><I>x</I></SUB> and the interfacial energy between NiP<SUB><I>x</I></SUB> and Ag. The direct observation of atomistic dynamics during thermal-treatment-induced structural modification will help to understand more complex transformations that are induced by aging over time or the interaction with a reactive gas phase in applications such as catalysis.</P> [FIG OMISSION]</BR>

Chemical, optical, and electrical characterization of Ga2O3 thin films grown by plasma-enhanced atomic layer deposition

Xing Li,Hong-Liang Lu,Hong-Ping Ma,Jian-Guo Yang,Jin-Xin Chen,Wei Huang,Qixin Guo,Jijun Feng,David Wei Zhang 한국물리학회 2019 Current Applied Physics Vol.19 No.2

Thin Ga2O3 films were grown on Si (100) using trimethylgallium (TMG) and oxygen as the precursors through plasma-enhanced atomic layer deposition. The depositions were made over a temperature range of 80–250 °C with a growth per cycle of around 0.07 nm/cycle. Surface self-saturating growth was obtained with TMG pulse time ≥20 ms at a temperature of 150 °C. The root mean square surface roughness of the obtained Ga2O3 films increased from 0.1 nm to 0.3 nm with increasing the growth temperature. Moreover, the x-ray photoelectron spectroscopy analysis indicated that the obtained film was Ga-rich with the chemical oxidation states Ga3+ and Ga1+, and no carbon contamination was detected in the films after Ar+ sputtering. The electron density of films measured by x-ray reflectivity varied with the growth temperature, increasing from 4.72 to 5.80 g/cm3 . The transmittance of Ga2O3 film deposited on a quartz substrate was obtained through ultraviolet visible (UV–Vis) spectroscopy. An obvious absorption in the deep UV region was demonstrated with a wide band gap of 4.6–4.8 eV. The spectroscopic ellipsometry analysis indicated that the average refractive index of the Ga2O3 film was 1.91 at 632.8 nm and increased with the growth temperature due to the dense structure of the films. Finally, the I-V and C-V characteristics proved that the Ga2O3 films prepared in this work had a low leakage current of 7.2 × 10−11 A/cm2 at 1.0 MV/cm and a high permittivity of 11.9, suitable to be gate dielectric.

Activating Transcription Factor 1 is a Prognostic Marker of Colorectal Cancer

Huang, Guo-Liang,Guo, Hong-Qiang,Yang, Feng,Liu, Ou-Fei,Li, Bin-Bin,Liu, Xing-Yan,Lu, Yan,He, Zhi-Wei Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.3

Objective: Identifying cancer-related genes or proteins is critical in preventing and controlling colorectal cancer (CRC). This study was to investigate the clinicopathological and prognostic value of activating transcription factor 1 (ATF1) in CRC. Methods: Protein expression of ATF1 was detected using immunohistochemistry in 66 CRC tissues. Clinicopathological association of ATF1 in CRC was analyzed with chi-square test or Fisher's exact test. The prognostic value of ATF1 in CRC is estimated using the Kaplan-Meier analysis and Cox regression models. Results: The ATF1 protein expression was significantly lower in tumor tissues than corresponding normal tissues (51.5% and 71.1%, respectively, P = 0.038). No correlation was found between ATF1 expression and the investigated clinicopathological parameters, including gender, age, depth of invasion, lymph node status, metastasis, pathological stage, vascular tumoral emboli, peritumoral deposits, chemotherapy and original tumor site (all with P > 0.05). Patients with higher ATF1 expression levels have a significantly higher survival rate than that with lower expression (P = 0.026 for overall survival, P = 0.008 for progress free survival). Multivariate Cox regression model revealed that ATF1 expression and depth of invasion were the predictors of the overall survival (P = 0.008 and P = 0.028) and progress free survival (P = 0.002 and P = 0.005) in CRC. Conclusions: Higher ATF1 expression is a predictor of a favorable outcome for the overall survival and progress free survival in CRC.

Preparation of Chitooligosaccharides from Chitosan using Crude Enzyme of Bacillus cereus D-11

( Xing Ai Gao ),( Yong Feng Zhang ),( Ro Dong Park ),( Xiao Huang ),( Xin Ying Zhao ),( Jiao Xie ),( Rong De Jin ) 한국응용생명화학회 2012 Journal of Applied Biological Chemistry (J. Appl. Vol.55 No.1

In order to enzymatically produce chitooligosaccharide using the crude enzyme preparation from Bacillus cereus D-11, we first studied the optimal reaction conditions. It was found that the optimal temperature for hydrolysis of chitosan was 55oC. The ratio of enzyme/substrate should not be lower than 0.13 U/mg in the reaction mixture. The enzyme activity was stable below 50oC. The products of enzymatic reaction were analyzed by both thin layer chromatography and high performance liquid chromatography. Under the appropriate condition, chitosan was hydrolyzed using the enzyme preparation. The resulting chitooligosaccharides were purified and separated by Dowex (H+) ion exchange chromatography. From 4 g soluble chitosan, 0.95 g (GlcN)2, 1.43 g (GlcN)3, and 1.18 g (GlcN)4 were recovered.

Effect of Combined Manual Acupuncture and Massage on Body Weight and Body Mass Index Reduction in Obese and Overweight Women: A Randomized, Short-term Clinical Trial

Huiyong Huang,Jun-Feng He,Xing Zhang,Ya-Ting Qu,Xia Liu,Jia Du,Shengtong Guo 사단법인약침학회 2015 Journal of Acupuncture & Meridian Studies Vol.8 No.2

Obesity is one of the leading health risk factors worldwide and is associated with several other risk factors and health problems. Acupuncture is utilized to treat a variety of health problems, one of which is obesity. Fifty-six obese women with body mass index (BMI) ≥25 kg/m2 were recruited for this trial and were randomly divided into two groups, one with combined manual acupuncture and massage therapy (MAMT), and the other with only manual acupuncture therapy (MAT). In addition, 40 overweight women with BMI 23–25 kg/m2 were randomly divided into two groups, one with MAMT and the other with MAT. Therapy was carried out once per day for 21 days, and the body weights and the BMIs were recorded every day. The results showed that both MAMT and MAT could reduce body weight and BMI significantly, compared with the pretreatment values, for all the participants (p < 0.001); however, the differences in body weight and BMI reductions between pre- and posttreatment for the MAMT and the MAT groups were not statistically significant. The optimal periods for reductions in both body weight and in BMI were the first 4 days. Accounting for the economic strategy (time and money) in alternative therapy, MAT alone may present a reasonable option in the treatment of overweight and obesity in adults.

Characterization and Electrical Conductivity of Carbon-Coated Metallic (Ni, Cu, Sn) Nanocapsules

Wang, Dong Xing,Shah, Asif,Zhou, Lei,Zhang, Xue Feng,Liu, Chun Jing,Huang, Hao,Dong, Xing Long Korean Society of Microscopy 2015 Applied microscopy Vol.45 No.4

Carbon-coated Ni, Cu and Sn nanocapsules were investigated by means of X-ray diffraction (XRD), transmission electron microscopy (TEM) and a four-point probe device. All of these nanocapsules were prepared by an arc-discharge method, in which the bulk metals were evaporated under methane ($CH_4$) atmosphere. Three pure metals (Ni, Cu, Sn) were typically diverse in formation of the carbon encapsulated nanoparticles and their different mechanisms were investigated. It was indicated that a thick carbon layers formed on the surface of Ni(C) nanocapsules, whereas a thin shell of carbon with 1~2 layers covered on Cu(C) nanocapsules, and the Sn(C) nanocapsules was, in fact, a longger multi-walled carbon nanotubes partially-filled with metal Sn. As one typical magnetic/dielectric nanocomposite particles, Ni(C) nanocapsules and its counterpart of oxide-coated Ni(O) nanocapsules were compared in the electrically conductive behaviors for further applications as the electromagnetic materials.

The Lymphotoxin-α 252 A>G Polymorphism and Breast Cancer: A Meta-analysis

Zhou, Ping,Huang, Wei,Chu, Xing,Du, Liang-Feng,Li, Jian-Ping,Zhang, Chun Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.5

Objective: The aim of this meta-analysis is to evaluate associations between LTA-252 A>G and breast cancer (BC). Methods: Electronic searches of several databases were conducted for all online publications. A total of 7 studies involving 4,625 BC patients and 4,373 controls were identified. Results: This meta-analysis showed no significant association between the LTA-252 A>G polymorphism and BC in overall or Caucasian populations. However, a positive association was found limited to Asian populations. Conclusion: Although there was no significant association found between the LTA-252 A>G polymorphism and BC overall, a positive association was found in Asian populations.

Fabrication of PVDF-blended ultrafiltration membranes incorporated by chiral mesoporous silica for enantioseparation

Ting Wang,Xiao-xing Huang,Li-guang Wu,Chun-juan Li,Dong-feng Zhu 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.109 No.-

Novel poly(vinylidene fluoride) (PVDF) ultrafiltration membranes blending with chiral mesoporous SiO2materials were constructed to improve the anti-fouling and separation performance of PVDF-blendedmembranes. The formation of asymmetric mesoporous structure of chiral mesoporous SiO2 caused theirlarge hydrophilic surface and significant chiral features, which enhanced the hydrophilicity and polarityof the resulting PVDF membranes blended with chiral mesoporous SiO2. So, the PVDF-blended membranescontaining chiral mesoporous SiO2 had a high permeation performance and anti-fouling property. After blending with chiral mesoporous SiO2, the maximum flux of membranes exceeded 500 Lm2h1and was 6.5-fold higher than that of neat PVDF. Due to the stereo-specific interaction between enantiomersand chiral recognition sites introduced by chiral mesoporous SiO2 in the membranes, allPVDF-blended membranes had evident enantioseparation performance for DL-racemic tryptophan. TheC-SiO2-20/PVDF-blended membranes had the highest enantioseparation performance under the sameaddition content and the maximum enantiomeric excess (e.e.%) was more than 20 %. Given the strongstereo-specific interaction and hydrogen bonding between d-tryptophan and b-cyclodextrin (b-CD), theaddition of more b-CD would introduce more chiral recognition sites into the membranes, therebyenhancing the enantioseparation performance of the membranes for d-tryptophan. The maximum e.e. % of C-SiO2-20/b-CD/PVDF-blended membranes for the tryptophan enantiomer reached 55%.