Triangular angles parameterization for the correlation matrix of bivariate longitudinal data

Lu Fei,Xue Liugen,Wang Zhaoliang 한국통계학회 2020 Journal of the Korean Statistical Society Vol.49 No.2

Multivariate longitudinal data is often encountered in the jobs of statisticians and practitioners. It is challenging to model the covariance matrix due to the complex structure of correlations among multiple responses. For this modeling task, several effective Cholesky decomposition based methods have been studied. However, direct interpretation of the covariation structure among multiple responses is still less well investigated to the best of our knowledge. In this paper, we propose a joint meanvariance correlationmodelingmethod based on the triangular angles parameterization (TAP) for the correlation matrix of bivariate longitudinal data. The proposed unconstrained parameterization is able to automatically eliminate the positive definiteness constraint of the correlation matrix and leads to the aforementioned direct interpretation. Furthermore, the variance matrix is diagonal rather than block-diagonal, so the positive-definiteness constraint of this matrix can be easily satisfied. The entries of the proposed decomposition are modeled by regression models, and the maximum likelihood estimators of regression parameters are obtained. The resulting estimators are shown to be consistent and asymptotically normal. Simulations and a study of poplar growth illustrate that the proposed method performs well.

Genetic variations in the bitter taste receptor gene TAS2R38 are related to cigarette smoking behavior in Han Chinese smokers

Qi Fei-Yan,Zhu Zhou-Hai,Li Meng,Guan Ying,Peng Qi-Yuan,Lu She-Ming,Liu Zhi-Hua,Wang Ming-Feng,Miao Ming-Ming,Chen Zhang-Yu,Li Xue-Mei,Bai Jie,Yao Jian-Hua 한국유전학회 2022 Genes & Genomics Vol.44 No.11

Background: Smoking behavior is influenced by multiple genes, including the bitter taste gene TAS2R38. It has been reported that the correlation between TAS2R38 and smoking behavior has ethnicity-based differences. However, the TAS2R38 status in Chinese smokers is still unclear. Objective: This study aims to investigate the possible relationship between genetic variations in TAS2R38 (A49P, V262A and I296V) and smoking behaviors in the Han Chinese population. Methods: The haplotype analyses were performed and smoking behavior questionnaire was completed by 1271 individuals. Genetic association analyses for smoking behavior were analyzed using chi-square test. Further, for investigating the molecular mechanism of TAS2R38 variants effect on smoking behavior, we conducted TAS2R38-PAV and TAS2R38-AVI expression plasmids and tested the cellular calcium assay by cigarette smoke compounds stimulus in HEK293. Results: Significant associations of genetic variants within TAS2R38 were identified with smoking behavior. We found a higher PAV/PAV frequency than AVI/AVI in moderate and high nicotine dependence (FTND ≥ 4; X2 = 4.611, 1 df, p = 0.032) and strong cigarette smoke flavor intensity preference (X2 = 4.5383, 1 df, p = 0.033) in participants. Furthermore, in the in vitro cellular calcium assay, total particle matter (TPM), N-formylnornicotine and cotinine, existing in cigarette smoke, activated TAS2R38-PAV but not TAS2R38-AVI-transfected cells. Conclusion: Our data highlights that genetic variations in TAS2R38 are related to smoking behavior, especially nicotine dependence and cigarette smoke flavor intensity preference. Our findings may encourage further consideration of the taste process to identify individuals susceptible to nicotine dependence, particularly Han Chinese smokers.

Effect of Growth on Fatty Acid Composition of Total Intramuscular Lipid and Phospholipids in Ira Rabbits

Shan Xue,Zhi-Fei He,Jingzhi Lu,Xiaoqi Tao,Li Zheng,Yuejie Xie,Xia Xiao,Rong Peng,Hong-Jun Li 한국축산식품학회 2015 한국축산식품학회지 Vol.35 No.1

The changes in fatty acid composition of total intramuscular lipid and phospholipids were investigated in the longissimusdorsi, left-hind leg muscle, and abdominal muscle of male Ira rabbits. Changes were monitored at 35, 45, 60, 75, and 90 d. Analysis using gas chromatography identified 21 types of fatty acids. Results showed that the intramuscular lipid increasedand the intramuscular phospholipids (total intramuscular lipid %) decreased in all muscles with increasing age (p<0.05). Anabundant amount of unsaturated fatty acids, especially polyunsaturated fatty acids, was distributed in male Ira rabbits atdifferent ages and muscles. Palmitic acid (C16:0), stearic acid (C18:0), oleic acid (C18:1), linoleic acid (C18:2), and arachi-donic acid (C20:4) were the major fatty acids, which account to the dynamic changes of the n-6/n-3 value in Ira rabbit meat.

Robust estimation with a modified Huber’s loss for partial functional linear models based on splines

Cai Xiong,Xue Liugen,Lu Fei 한국통계학회 2020 Journal of the Korean Statistical Society Vol.49 No.4

In this article, we consider a new robust estimation procedure for the partial functional linear model (PFLM) with the slope function approximated by spline basis functions. This robust estimation procedure applies a modifed Huber’s function with tail function replaced by the exponential squared loss (ESL) to achieve robustness against outliers. A data-driven procedure is presented for selecting the tuning parameters of the new estimation method, which enables us to reach better robustness and efciency than other methods in the presence of outliers or non-normal errors. We construct robust estimators of both parametric coefcients and function coefcient in the PFLM. Moreover, some asymptotic properties of the resulting estimators are established. The fnite sample performance of our proposed method is studied through simulations and illustrated with a data example.

Prognostic Role of Hypoxic Inducible Factor Expression in Non-small Cell Lung Cancer: A Meta-analysis

Li, Cong,Lu, Hua-Jun,Na, Fei-Fei,Deng, Lei,Xue, Jian-Xin,Wang, Jing-Wen,Wang, Yu-Qing,Li, Qiao-Ling,Lu, You Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.6

Introduction: Reported prognostic roles of hypoxic inducible factor (HIF) expression in non-small cell lung cancer (NSCLC) have varied. This meta-analysis aimed to examine the relationship between HIF expression and clinical outcome in NSCLC patients. Methods: PubMed were used to identify relevant literature with the last report up to December $20^{th}$, 2012. After careful review, survival data were collected from eligible studies. We completed the meta-analysis using Stata statistical software (Version 11) and combined hazard ratio (HR) for overall survival (OS). Subgroup specificity, heterogeneity and publication bias were also assessed. All of the results were verified by two persons to ensure accuracy. Results: Eight studies were finally stepped into this meta-analysis in which seven had available data for HIF-$1{\alpha}$ and three for HIF-$2{\alpha}$. Combined HRs suggested that higher expression of $HIF1{\alpha}$ had a negative impact on NSCLC patient survival (HR=1.50; 95%CI=1.07-2.10; p=0.019). The expression of HIF-$2{\alpha}$ was also relative to a poorer survival (HR=2.02; 95%CI=1.47-2.77; p=0.000). No bias existed in either of the two groups. Conclusion: This study suggests that elevations of HIF-$1{\alpha}$ and HIF-$2{\alpha}$ expression are both associated with poor outcome for patients with NSCLC. The data support further and high quality investigation of HIF expression for predicting poor outcome in patients with NSCLC.

Breast Cancer Association Studies in a Han Chinese Population using 10 European-ancestry-associated Breast Cancer Susceptibility SNPs

Guan, Yan-Ping,Yang, Xue-Xi,Yao, Guang-Yu,Qiu, Fei,Chen, Jun,Chen, Lu-Jia,Ye, Chang-Sheng,Li, Ming Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.1

Background: Genome-wide association studies (GWAS) have identified various genetic susceptibility loci for breast cancer based mainly on European-ancestry populations. Differing linkage disequilibrium patterns exist between European and Asian populations. Methods: Ten SNPs (rs2075555 in COL1A1, rs12652447 in FBXL17, rs10941679 in 5p12/MRPS30, rs11878583 in ZNF577, rs7166081 in SMAD3, rs16917302 in ZNF365, rs311499 in 20q13.3, rs1045485 in CASP8, rs12964873 in CDH1 and rs8170 in 19p13.1) were here genotyped in 1009 Chinese females (487 patients with breast cancer and 522 control subjects) using the Sequenom MassARRAY iPLEX platform. Association analysis based on unconditional logistic regression was carried out to determine the odds ratio (OR) and 95% confidence interval (95% CI) for each SNP. Stratification analyses were carried out based on the estrogen receptor (ER) and progesterone receptor (PR) status. Results: Among the 10 SNPs, rs10941679 showed significant association with breast cancer when differences between the case and control groups in this Han Chinese population were compared (30.09% GG, 45.4% GA and 23.7% AA; P = 0.012). Four SNPs (rs311499, rs1045485, rs12964873 and rs8170) showed no polymorphisms in our study. The remaining five SNPs showed no association with breast cancer in the present population. Immunohistochemical tests showed that rs2075555 was associated with ER status; the AA genotype showed greater association with ER negative than ER positive (OR = 0.54, 95% CI, 0.29-0.99; P = 0.046). AA of rs7166081 was also associated with ER status, but showed a greater association with ER positive than negative (OR = 1.59, 95% CI = 1.04-2.44; P = 0.031). However, no significant associations were found among the SNPs and PR status. Conclusion: In this study using a Han Chinese population, rs10941679 was the only SNP associated with breast cancer risk, indicating a difference between European and Chinese populations in susceptibility loci. Therefore, confirmation studies are necessary before utilization of these loci in Chinese.

A Novel Kinetic Analysis of Crystallization of Polypropylene (PP) in Dynamically-vulcanized PP/Ethylene-propylene-diene Rubber (EPDM) Blends Using an In-situ Measurement Technique

Lei Hu,Bin Yang,Yan-Li Deng,Fei-Xue Lu,Ru Xia,Zheng-Zhi Zheng,Ji-Bin Miao,Jia-Sheng Qian,Chuan-Ru Zhang,Peng Chen,Yu-Chuan Zhang 한국고분자학회 2017 폴리머 Vol.41 No.4

The effects of cooling medium temperatures and plastic/rubber ratios on solidification and crystallization kinetics of dynamically-vulcanized polypropylene/ethylene-propylene-diene rubber (PP/EPDM) blends were investigated with the aid of an in-situ measurement technique. The cooling medium temperature heavily influenced the solidification kinetics primarily due to a combination of latent heat liberated from the molten polymer and the heat transferred away via the metallic wall during the cooling period. Interestingly, the parameter C in three-parameter model was not only affected by the material properties, but also by the cooling condition, different from the previous literature. The crystallization kinetics analysis indicated that the effect of EPDM in the blends consisted of both nucleation-promoting effect (low EPDM loading) and steric effect (higher EPDM loading). The present kinetic analysis may be helpful to further studies on improving the product performances for industrial applications.

Pyrotinib Combined with Vinorelbine in Patients with Previously Treated HER2-Positive Metastatic Breast Cancer: A Multicenter, Single-arm, Prospective Study

Kuikui Jiang,Ruoxi Hong,Wen Xia,Qianyi Lu,Liang Li,Jianhao Huang,Yanxia Shi,Zhongyu Yuan,Qiufan Zheng,Xin An,Cong Xue,Jiajia Huang,Xiwen Bi,Meiting Chen,Jingmin Zhang,Fei Xu,Shusen Wang 대한암학회 2024 Cancer Research and Treatment Vol.56 No.2

Purpose This study aims to evaluate the efficacy and safety of a new combination treatment of vinorelbine and pyrotinib in human epidermal growth factor receptor 2 (HER2)–positive metastatic breast cancer (MBC) and provide higher level evidence for clinical practice. Materials and Methods This was a prospective, single-arm, phase 2 trial conducted at three institutions in China. Patients with HER2-positive MBC, who had previously been treated with trastuzumab plus a taxane or trastuzumab plus pertuzumab combined with a chemotherapeutic agent, were enrolled between March 2020 and December 2021. All patients received pyrotinib 400 mg orally once daily plus vinorelbine 25 mg/m2 intravenously or 60-80 mg/m2 orally on day 1 and day 8 of 21-day cycle. The primary endpoint was progression-free survival (PFS), and the secondary endpoints included the objective response rate (ORR), disease control rate (DCR), overall survival, and safety. Results A total of 39 patients were enrolled. All patients had been pretreated with trastuzumab and 23.1% (n=9) of them had accepted trastuzumab plus pertuzumab. The median follow-up time was 16.3 months (95% confidence interval [CI], 5.3 to 27.2), and the median PFS was 6.4 months (95% CI, 4.0 to 8.8). The ORR was 43.6% (95% CI, 27.8% to 60.4%) and the DCR was 84.6% (95% CI, 69.5% to 94.1%). The median PFS of patients with versus without prior pertuzumab treatment was 4.6 and 8.3 months (p=0.017). The most common grade 3/4 adverse events were diarrhea (28.2%), neutrophil count decreased (15.4%), white blood cell count decreased (7.7%), vomiting (5.1%), and anemia (2.6%). Conclusion Pyrotinib plus vinorelbine showed promising efficacy and tolerable toxicity as second-line treatment in patients with HER2-positive MBC.

Lack of Influence of an XRCC3 Gene Polymorphism on Oral Cancer Susceptibility: Meta-analysis

Zhang, En-Jiao,Cui, Zhi-Gang,Xu, Zhong-Fei,Duan, Wei-Yi,Huang, Shao-Hui,Tan, Xue-Xin,Yin, Zhi-Hua,Sun, Chang-Fu,Lu, Li Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.23

Background: To systematically summarize the association between the X-ray repair cross complementing 3 (XRCC3) gene polymorphism and oral cancer susceptibility by meta-analysis. Materials and Methods: Databases including PubMed, EMbase, CNKI, VIP and WanFang Data were searched to identify case-control studies concerning the association between an XRCC3 gene polymorphism and the risk of oral cancer from the inception to June 2014. Two reviewers independently screened the literature according to the criteria, extracted the data and assessed the quality. Then meta-analysis was performed using Stata 11.0 software. Results: Seven published case-control studies including 775 patients with oral cancer and 1922 controls were selected. Associations between the rs861539 polymorphism and overall oral cancer risk were not statistically significant in all kinds of comparison models (CT vs CC: OR=0.94, 95%CI=0.74-1.18; TT vs CC: OR=0.94, 95%CI=0.64-1.38; dominant model: OR=0.95, 95%CI=0.76-1.18; recessive model: OR=0.94, 95%CI=0.69-1.29; allele T vs C: OR=0.97, 95%CI=0.84-1.11). In the stratified analysis by ethnicity, no significant associations were found among Asians and Caucasians. On stratification by tumor type, no significant associations were found for cancer and oral premalignant lesions. Conclusions: The XRCC3 gene polymorphism was not found to be associated with the risk of oral cancer. Considering the limited quality of the included case-control studies, more high quality studies with large sample size are needed to verify the above conclusion.

Application of the French Codes to the Pressurized Thermal Shocks Assessment

Mingya Chen,Guian Qian,Jinhua Shi,Rongshan Wang,Weiwei Yu,Feng Lu,Guodong Zhang,Fei Xue,Zhilin Chen 한국원자력학회 2016 Nuclear Engineering and Technology Vol.48 No.6

The integrity of a reactor pressure vessel (RPV) related to pressurized thermal shocks (PTSs)has been extensively studied. This paper introduces an integrity assessment of an RPVsubjected to a PTS transient based on the French codes. In the USA, the “screening criterion”for maximum allowable embrittlement of RPV material is developed based on theprobabilistic fracture mechanics. However, in the French RCC-M and RSE-M codes, whichare developed based on the deterministic fracture mechanics, there is no “screening criterion”. In this paper, the methodology in the RCC-M and RSE-M codes, which are used forPTS analysis, are firstly discussed. The bases of the French codes are compared with ASMEand FAVOR codes. A case study is also presented. The results show that the method in theRCC-M code that accounts for the influence of cladding on the stress intensity factor (SIF)may be nonconservative. The SIF almost doubles if the weld residual stress is considered. The approaches included in the codes differ in many aspects, which may result in significantdifferences in the assessment results. Therefore, homogenization of the codes inthe long time operation of nuclear power plants is needed.