Browsing by Author "Zhang, Min"

Now showing 1 - 10 of 16
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    Absorptive capacity and mass customization capability
    (Emerald, 2015) Zhang, Min; Zhao, Xiande; Lyles, Marjorie A.; Guo, Hangfei; School of Business
    Purpose – The purpose of this paper is to investigate the effects of a manufacturer’s absorptive capacity (AC) on its mass customization capability (MCC). Design/methodology/approach – The authors conceptualize AC within the supply chain context as four processes: knowledge acquisition from customers, knowledge acquisition from suppliers, knowledge assimilation, and knowledge application. The authors then propose and empirically test a model on the relationships among AC processes and MCC using structural equation modeling and data collected from 276 manufacturing firms in China. Findings – The results show that AC significantly improves MCC. In particular, knowledge sourced from customers and suppliers enhances MCC in three ways: directly, indirectly through knowledge application, and indirectly through knowledge assimilation and application. The study also finds that knowledge acquisition significantly enhances knowledge assimilation and knowledge application, and that knowledge assimilation leads to knowledge application. Originality/value – This study provides empirical evidence of the effects of AC processes on MCC. It also indicates the relationships among AC processes. Moreover, it reveals the mechanisms through which knowledge sourced from customers and suppliers contributes to MCC development, and demonstrates the importance of internal knowledge management practices in exploiting knowledge from supply chain partners. Furthermore, it provides guidelines for executives to decide how to manage supply chain knowledge and devote their efforts and resources in absorbing new knowledge for MCC development.
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    Altered metabolite levels and correlations in patients with colorectal cancer and polyps detected using seemingly unrelated regression analysis
    (Springer Nature, 2017-11) Chen, Chen; Gowda, G. A. Nagana; Zhu, Jiangjiang; Deng, Lingli; Gu, Haiwei; Chiorean, E. Gabriela; Zaid, Mohammad Abu; Harrison, Marietta; Zhang, Dabao; Zhang, Min; Raftery, Daniel; Graduate Medical Education, IU School of Medicine
    Introduction: Metabolomics technologies enable the identification of putative biomarkers for numerous diseases; however, the influence of confounding factors on metabolite levels poses a major challenge in moving forward with such metabolites for pre-clinical or clinical applications. Objectives: To address this challenge, we analyzed metabolomics data from a colorectal cancer (CRC) study, and used seemingly unrelated regression (SUR) to account for the effects of confounding factors including gender, BMI, age, alcohol use, and smoking. Methods: A SUR model based on 113 serum metabolites quantified using targeted mass spectrometry, identified 20 metabolites that differentiated CRC patients (n = 36), patients with polyp (n = 39), and healthy subjects (n = 83). Models built using different groups of biologically related metabolites achieved improved differentiation and were significant for 26 out of 29 groups. Furthermore, the networks of correlated metabolites constructed for all groups of metabolites using the ParCorA algorithm, before or after application of the SUR model, showed significant alterations for CRC and polyp patients relative to healthy controls. Results: The results showed that demographic covariates, such as gender, BMI, BMI2, and smoking status, exhibit significant confounding effects on metabolite levels, which can be modeled effectively. Conclusion: These results not only provide new insights into addressing the major issue of confounding effects in metabolomics analysis, but also shed light on issues related to establishing reliable biomarkers and the biological connections between them in a complex disease.
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    Clinical Predictors of Functional Cure in Children 1–6 Years-old with Chronic Hepatitis B
    (Xia & He, 2022) Pan, Jing; Wang, Haiyan; Yao, Tiantian; Liao, Xuejiao; Cheng, Hao; Liangpunsakul, Suthat; Wang, Yan; Zhang, Min; Zhang, Zheng; Medicine, School of Medicine
    Background and aims: Hepatitis B surface antigen (HBsAg) clearance is significantly more common in children with chronic hepatitis B (CHB) than in adults; however, the possible influencing factors related to HBsAg loss have yet to be found. This study aimed to explore the efficacy of long-term interferon (IFN)α therapy in treating children with CHB and analyzed the factors influencing functional cure after treatment. Methods: A total of 236 children aged 1-6 years and diagnosed with CHB via liver biopsy were included in the study, all receiving IFNα treatment (IFNα-2b monotherapy, IFNα-2b followed by lamivudine [LAM] or IFNα-2b combined with LAM) and followed up for 144 weeks. A comprehensive analysis was conducted on clinical data, including biochemical items, serum markers of hepatitis B virus (HBV) and immunological indexes, and logistic regression analysis was used to screen the influencing factors related to HBsAg loss. Results: The cumulative loss rates of HBsAg were 79.5%, 62.1% and 42.1% at 144 weeks after the start of treatment in the 1-3 years-old group, 3-5 years-old group and 5-7 years-old group, respectively (p<0.05). IFNα-2b combined with LAM treatment displayed the highest HBsAg loss rates compared with monotherapy and sequential treatment (p=0.011). Younger baseline age and lower HBsAg levels were independent factors for the prediction of HBsAg loss (p<0.05). The baseline PreS1 and hepatitis B core antibody levels in the HBsAg loss group were lower than those in the HBsAg non-loss group. In addition, the PreS1 level was positively corelated with the level of HBsAg, HBV DNA and liver inflammation. Conclusions: Long-term treatment with IFNα was effective in achieving HBsAg loss in CHB children aged 1-6 years-old. Age less than 3 years-old and lower HBsAg levels are independent predictors of functional cure in children with CHB.
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    Effects of absorptive capacity, trust and information systems on product innovation
    (Emerald, 2018) Zhang, Min; Zhao, Xiande; Lyles, Marjorie A.; Kelley School of Business - Indianapolis
    Purpose The purpose of this paper is to empirically investigate the mechanisms through which absorptive capacity (AC), trust and information systems jointly influence product innovation. Design/methodology/approach This study proposes a research model to examine the mediating role of AC on the impacts of trust and information systems on product innovation and the moderating roles of trust and information systems on the relationship between AC and product innovation. The hypotheses are empirically tested using regression and bootstrapping methods and data collected from 276 manufacturing firms in China. Findings This study finds that trust and information systems positively affect product innovation and the effects are fully mediated by AC. AC also significantly enhances product innovation, and the effect is amplified by trust as well as information systems. In addition, the results show that trust and information systems improve AC both individually and interactively. Originality/value The findings extend existing knowledge on the antecedents of AC and the contingent conditions under which a manufacturer’s AC is more effective than that of its rivals. The results also clarify the mechanisms through which trust and information systems improve product innovation. This study provides insights into the complex relationships among a manufacturer’s sociotechnical systems, knowledge management processes and new product development, and reveals how to design organisational systems to fully capitalise the value of AC on product innovation.
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    Fatty acid desaturase 1 gene polymorphisms control human hepatic lipid composition
    (Wiley, 2015-01) Wang, Libo; Athinarayanan, Shaminie; Jiang, Guanglong; Chalasani, Naga; Zhang, Min; Liu, Wanqing; Department of Medical and Molecular Genetics, IU School of Medicine
    Fatty acid desaturase (FADS) genes and their variants have been associated with multiple metabolic phenotypes, including liver enzymes and hepatic fat accumulation, but the detailed mechanism remains unclear. We aimed to delineate the role of FADSs in modulating lipid composition in human liver. We performed a targeted lipidomic analysis of a variety of phospholipids, sphingolipids, and ceramides among 154 human liver tissue samples. The associations between previously genome-wide association studies (GWASs)-identified six FADS single-nucleotide polymorphisms (SNPs), and these lipid levels as well as total hepatic fat content (HFC) were tested. The potential function of these SNPs in regulating transcription of three FADS genes (FADS1, FADS2, and FADS3) in the locus was also investigated. We found that though these SNPs were in high linkage disequilibrium (r(2) > 0.8), the rare alleles of these SNPs were consistently and significantly associated with the accumulation of multiple long-chain fatty acids (LCFAs), with C47H85O13P (C36:4), a phosphatidylinositol (PI), and C43H80O8PN (C38:3), a phosphatidylethanolamine (PE), reached the Bonferroni corrected significance (P < 3 × 10(-4)). Meanwhile, these SNPs were significantly associated with increased ratios between the more saturated and relatively less saturated forms of LCFAs, especially between PEs, PIs, and phosphatidylcholines (PCs; P ≤ 3.5 × 10(-6)). These alleles were also associated with increased total HFC (P < 0.05). Further analyses revealed that these alleles were associated with decreased hepatic expression of FADS1 (P = 0.0018 for rs174556), but not FADS2 or FADS3 (P > 0.05). CONCLUSION: Our findings revealed critical insight into the mechanism underlying FADS1 and its polymorphisms in modulating hepatic lipid deposition by altering gene transcription and controlling lipid composition in human livers.
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    Gene-by-Diet Interactions Affect Serum 1,25-Dihydroxyvitamin D Levels in Male BXD Recombinant Inbred Mice
    (Oxford University Press, 2016-02) Fleet, James C.; Replogle, Rebecca A.; Reyes-Fernandez, Perla; Wang, Libo; Zhang, Min; Clinkenbeard, Erica L.; White, Kenneth E.; Department of Medical & Molecular Genetics, IU School of Medicine
    1,25-Dihydroxyvitamin D (1,25[OH]2D) regulates calcium (Ca), phosphate, and bone metabolism. Serum 1,25(OH)2D levels are reduced by low vitamin D status and high fibroblast growth factor 23 (FGF23) levels and increased by low Ca intake and high PTH levels. Natural genetic variation controls serum 25-hydroxyvitamin D (25[OH]D) levels, but it is unclear how it controls serum 1,25(OH)2D or the response of serum 1,25(OH)2D levels to dietary Ca restriction (RCR). Male mice from 11 inbred lines and from 51 BXD recombinant inbred lines were fed diets with either 0.5% (basal) or 0.25% Ca from 4 to 12 weeks of age (n = 8 per line per diet). Significant variation among the lines was found in basal serum 1,25(OH)2D and in the RCR as well as basal serum 25(OH)D and FGF23 levels. 1,25(OH)2D was not correlated to 25(OH)D but was negatively correlated to FGF23 (r = -0.5). Narrow sense heritability of 1,25(OH)2D was 0.67 on the 0.5% Ca diet, 0.66 on the 0.25% Ca diet, and 0.59 for the RCR, indicating a strong genetic control of serum 1,25(OH)2D. Genetic mapping revealed many loci controlling 1,25(OH)2D (seven loci) and the RCR (three loci) as well as 25(OH)D (four loci) and FGF23 (two loci); a locus on chromosome 18 controlled both 1,25(OH)2D and FGF23. Candidate genes underlying loci include the following: Ets1 (1,25[OH]2D), Elac1 (FGF23 and 1,25[OH]2D), Tbc1d15 (RCR), Plekha8 and Lyplal1 (25[OH]D), and Trim35 (FGF23). This report is the first to reveal that serum 1,25(OH)2D levels are controlled by multiple genetic factors and that some of these genetic loci interact with the dietary environment.
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    Inhibiting the Plasmodium eIF2α Kinase PK4 Prevents Artemisinin-Induced Latency
    (Elsevier, 2017-12) Zhang, Min; Gallego-Delgado, Julio; Fernandez-Arias, Cristina; Waters, Norman C.; Rodriguez, Ana; Tsu, Moriya; Wek, Ronald C.; Nussenzweig, Victor; Sullivan, William J., Jr.; Pharmacology and Toxicology, School of Medicine
    Artemisinin and its derivatives (ARTs) are frontline antimalarial drugs. However, ART monotherapy is associated with a high frequency of recrudescent infection, resulting in treatment failure. A subset of parasites is thought to undergo ART-induced latency, but the mechanisms remain unknown. Here, we report that ART treatment results in phosphorylation of the parasite eukaryotic initiation factor-2α (eIF2α), leading to repression of general translation and latency induction. Enhanced phosphorylated eIF2α correlates with high rates of recrudescence following ART, and inhibiting eIF2α dephosphorylation renders parasites less sensitive to ART treatment. ART-induced eIF2α phosphorylation is mediated by the Plasmodium eIF2α kinase, PK4. Overexpression of a PK4 dominant-negative or pharmacological inhibition of PK4 blocks parasites from entering latency and abolishes recrudescence after ART treatment of infected mice. These results show that translational control underlies ART-induced latency and that interference with this stress response may resolve the clinical problem of recrudescent infection.
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    Monoclonal Antibodies against Plasmodium falciparum Circumsporozoite Protein
    (MDPI, 2017-08-23) Zhang, Min; Mandraju, Rajakumar; Rai, Urvashi; Shiratsuchi, Takayuki; Tsuji, Moriya; Pharmacology and Toxicology, School of Medicine
    Malaria is a mosquito-borne infectious disease caused by the parasite Plasmodium spp. Malaria continues to have a devastating impact on human health. Sporozoites are the infective forms of the parasite inside mosquito salivary glands. Circumsporozoite protein (CSP) is a major and immunodominant protective antigen on the surface of Plasmodium sporozoites. Here, we report a generation of specific monoclonal antibodies that recognize the central repeat and C-terminal regions of P. falciparum CSP. The monoclonal antibodies 3C1, 3C2, and 3D3-specific for the central repeat region-have higher titers and protective efficacies against challenge with sporozoites compared with 2A10, a gold standard monoclonal antibody that was generated in early 1980s.
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    Optimal transport- and kernel-based early detection of mild cognitive impairment patients based on magnetic resonance and positron emission tomography images
    (BMC, 2022) Liu, Ziyu; Johnson, Travis S.; Shao, Wei; Zhang, Min; Zhang, Jie; Huang, Kun; Biostatistics and Health Data Science, School of Medicine
    Background: To help clinicians provide timely treatment and delay disease progression, it is crucial to identify dementia patients during the mild cognitive impairment (MCI) stage and stratify these MCI patients into early and late MCI stages before they progress to Alzheimer's disease (AD). In the process of diagnosing MCI and AD in living patients, brain scans are collected using neuroimaging technologies such as computed tomography (CT), magnetic resonance imaging (MRI), or positron emission tomography (PET). These brain scans measure the volume and molecular activity within the brain resulting in a very promising avenue to diagnose patients early in a minimally invasive manner. Methods: We have developed an optimal transport based transfer learning model to discriminate between early and late MCI. Combing this transfer learning model with bootstrap aggregation strategy, we overcome the overfitting problem and improve model stability and prediction accuracy. Results: With the transfer learning methods that we have developed, we outperform the current state of the art MCI stage classification frameworks and show that it is crucial to leverage Alzheimer's disease and normal control subjects to accurately predict early and late stage cognitive impairment. Conclusions: Our method is the current state of the art based on benchmark comparisons. This method is a necessary technological stepping stone to widespread clinical usage of MRI-based early detection of AD.
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    PK4, a eukaryotic initiation factor 2α(eIF2α) kinase, is essential for the development of the erythrocytic cycle of Plasmodium
    (National Academy of Sciences, 2012) Zhang, Min; Mishra, Satish; Sakthivel, Ramanavelan; Rojas, Margarito; Ranjan, Ravikant; Sullivan, William J., Jr.; Fontoura, Beatriz M. A.; Ménard, Robert; Dever, Thomas E.; Nussenzweig, Victor; Pharmacology and Toxicology, School of Medicine
    In response to environmental stresses, the mammalian serine threonine kinases PERK, GCN2, HRI, and PKR phosphorylate the regulatory serine 51 of the eukaryotic translation initiation factor 2α (eIF2α) to inhibit global protein synthesis. Plasmodium, the protozoan that causes malaria, expresses three eIF2α kinases: IK1, IK2, and PK4. Like GCN2, IK1 regulates stress response to amino acid starvation. IK2 inhibits development of malaria sporozoites present in the mosquito salivary glands. Here we show that the phosphorylation by PK4 of the regulatory serine 59 of Plasmodium eIF2α is essential for the completion of the parasite's erythrocytic cycle that causes disease in humans. PK4 activity leads to the arrest of global protein synthesis in schizonts, where ontogeny of daughter merozoites takes place, and in gametocytes that infect Anopheles mosquitoes. The implication of these findings is that drugs that reduce PK4 activity should alleviate disease and inhibit malaria transmission.