Authors: Seshadri, Sridhar | Wu, Qi
Article Type: Research Article
Abstract: We report on a unified method to carry out sensitivity analysis under uncertainty for a wide range of problems in production planning, inventory management and portfolio planning, when the decision maker exhibits decreasing absolute risk aversion.
Keywords: Comparative statics, decisions under risk, production planning, inventory management, portfolio optimization
DOI: 10.3233/RDA-140101
Citation: Risk and Decision Analysis, vol. 5, no. 1, pp. 63-73, 2014
Authors: Wu, Qi | Sak, Halis | Seshadri, Sridhar | Haksoz, Cagri
Article Type: Research Article
Abstract: We consider a two-period sourcing and production problem. First, a firm (OEM) sources from multiple suppliers who have limited capacity and correlated disruption risk. After the supply is realized, the firm also has access to the spot market for the extra material needed for its production. The firm must decide (1) which suppliers to source from, (2) how much to source from them, and (3) how much to produce and how much to source from the spot market. We formulate this as a stochastic optimization problem to study the tradeoff the firm faces between costs and default risk. In order to incorporate the …correlation of the supplier’s default risk, we use the t -copula dependence structure. A contract default is a rare event. Thus, in a Monte Carlo simulation, there is considerable variance around the optimal sourcing quantity. This variance leads to complexity in computing the optimal decision. We find that a diligent combination of importance sampling and conditional Monte Carlo schemes effectively reduces the variance in simulation estimates for the first-order conditions in the stochastic optimization problem. This paper shows that, for a supply chain with correlated default risks, the optimal sourcing problem can be solved by using importance sampling and a conditional Monte Carlo simulation. Show more
Keywords: Supply chain disruption, risk management, importance sampling, conditional Monte Carlo
DOI: 10.3233/RDA-180049
Citation: Risk and Decision Analysis, vol. 7, no. 3-4, pp. 77-89, 2018
Authors: Sun, Si | Wu, Qi | Song, Junlong | Sun, Shengrong
Article Type: Research Article
Abstract: Besides the crucial role of hyperinsulinemia in the development of breast cancer with Type 2 diabetes mellitus (T2DM), it has been shown that hyperglycemia could contribute to promote cancer progression. A remarkable association within hyperglycemia, PKCδ and Ubiquitin-proteasome system (UPS) has been reported, suggesting that PKCδ may mediate high glucose-induced UPS activation in breast cancer cells. Although the independent effects of PKCδ or UPS on breast cancer and T2DM are increasingly supported by experimental evidence, the complex interactional link between PKCδ and UPS is still unclear. Hence, we focus on the relationship between PKCδ and UPS in breast cancer with …T2DM. We hypothesize that PKCδ may have the function to regulate the activity of UPS. Further, we speculate that PKCδ combine with proteasome α 2 promoter, that indicate PKCδ regulate the function of UPS by change the composition of proteasome. Therefore, we surmise that PKCδ mediated high glucose-induced UPS activation in breast cancer cells, and specific PKCδ inhibitor rottlerin significantly suppressed elevated glucose induced the activity of UPS. We hope that our paper will stimulate further studies the relationship between PKCδ and UPS, and a new targeted therapy and early medical intervention for PKCδ could be a useful option for breast cancer cases complicated with T2DM or hyperglycemia. Show more
Keywords: Protein kinase C δ, Ubiquitin-proteasome system, breast cancer
DOI: 10.3233/CBM-170451
Citation: Cancer Biomarkers, vol. 21, no. 1, pp. 1-9, 2018
Authors: Samake, Moussa | Wu, Qi-Tang | Mo, Ce-hui | Morel, Jean-Louis
Article Type: Research Article
Abstract: The production of sewage sludge in China has been increasing sharply in order to treat 40% of the municipal sewage in 2005 as planned by central government. The main sludge disposal method is landfill owing to heavy metal contamination, but it presents an attractive potential for agricultural land application. Experiments were carried out to study the simultaneous metal removal and sludge stabilization by plants. The sludge samples were collected from Datansha Wastewater Treatment Plant of Guangzhou, it contained excessive Cu and Zn compared with the Chinese National Standard for Agricultural Use of Sewage Sludge. Plants growing on sludge beds were …investigated to follow their growth and metal uptake. 30 sludge plants were identified during 1 year's observation. A Zn high-accumulating and high growth rate plant (Alocasia macrorrhiza) was selected and grown on sludge beds in plots. The water, organic matter, heavy metals and nutrients contents, the E. coli number and the cress seed germination index were monitored for the sludge samples collected monthly. The plant growth parameters and its heavy metals contents were also determined. The sewage sludge treated by plants could be stabilized at about 5 months, the E. coli number was significantly decreased and the cress seed germination index attained 100%. Crop on sludge could ameliorate the sludge drying. The experiments are continuing to find out the appropriate plant combination for simultaneous sludge stabilization and metal removal for an acceptable period. Comparisons between the proposed processes and other methods for treating produced sludge such as composting, chemical and bacterial leaching were discussed. Show more
Keywords: sewage sludge, hyper-accumulator, heavy metal removal, stabilization
Citation: Journal of Environmental Sciences, vol. 15, no. 5, pp. 622-627, 2003
Authors: Huang, Guo-feng | Wu, Qi-tang | Li, Fang-bai | Wong, J.W.C.
Article Type: Research Article
Abstract: Composting is now suggested as one of the environmentallyand friendly alternative method for disposal of solid organic wastes, as it leads to minimization, stabilization, and utilization of organic waste. Transformations of nitrogen were investigated inco-composting of pig manure with different amendments, such as sawdust and leaves. Samples were analyzed for pH, total-N, soluble NH4-N, soluble NO3-N and soluble organic-N. The total-N increased after 63 days of composting, as well as the soluble NO3-N and soluble organic-N. Soluble NH4-N increased significantly and showed peak values at day 7, thereafter decreased sharply and gradually to lower levels. Seed germination index (GI) showed …that co-composting of pig manure with sawdust reached maturity after 49 days of composting, while co-composting of pig manure with sawdust and leaves required shorter time for 35 days. Soluble NH4-N was significantly negatively (P<0.05), while soluble NO3-N and soluble organic-N were significantly positively (P<0.05), correlated with seed germination index (GI). Addition of leaves in co-composting of pig manure with sawdust had no significant impacts on nitrogen transformations, but it was beneficial for maturity of pig manure compost. Show more
Keywords: pig manure, maturity, transformation, nitrogen, composting
Citation: Journal of Environmental Sciences, vol. 13, no. 4, pp. 401-405, 2001
Authors: Qu, Siwei | Ma, Ning | Wang, Weixin | Chen, Sen | Wu, Qi | Li, Yangqun | Yang, Zhe
Article Type: Research Article
Abstract: BACKGROUND: Human adipose-derived stem cells have been identified as a promising candidate for cell-assisted therapy to improve graft survival. OBJECTIVE: To objective of the study was to add human adipose-derived stem cells into filling materials. METHODS: The filling materials were prepared and divided into 6 groups: fat particles with phosphate buffer saline or human adipose-derived stem cells; acellular dermal matrix particles with phosphate buffer saline or human adipose-derived stem cells; mixture of fat particles and acellular dermal matrix particles with phosphate buffer saline or human adipose-derived stem cells. The survival rate, vascular density and histological at 2, 6 and 12 …weeks were investigated. RESULTS: Human adipose-derived stem cells significantly improved survival rate in each group at 6 and 12 weeks, and it significantly increased the vascular density in the fat particles and porcine acellular dermal matrix combined group and porcine acellular dermal matrix group at three time points, but human adipose-derived stem cells did not have a significant effect in the fat particles group. CONCLUSION: Human adipose-derived stem cells as assisted cells added into filling material can improve survival rate and vascular density in rats. Show more
Keywords: Human adipose-derived stem cells, porcine acellular dermal matrix, filling material
DOI: 10.3233/BME-222503
Citation: Bio-Medical Materials and Engineering, vol. 34, no. 4, pp. 345-355, 2023
Authors: Li, Shuyan | Sun, Yan | Qi, Xiaodan | Shi, Yan | Gao, Han | Wu, Qi | Liu, Xiucai | Yu, Haitao | Zhang, Chunjing
Article Type: Research Article
Abstract: In recent years, diabetes and its associated complications have become a major public health concern. The cardiovascular risk increases significantly in diabetes patients. It is a complex disease characterized by multiple metabolic derangements and is known to impair cardiac function by disrupting the balance between pro-oxidants and antioxidants at the cellular level. The subsequent generation of reactive oxygen species (ROS) and accompanying oxidative stress are hallmarks of the molecular mechanisms responsible for cardiovascular disease. Protein thiols act as redox-sensitive switches and are believed to be a key element in maintaining the cellular redox balance. The redox state of protein thiols …is regulated by oxidative stress and redox signaling and is important to cellular functions. The potential of the thiol–disulfide oxidoreductase enzymes (thioredoxin and glutaredoxin systems) in defense against oxidative stress has been noted previously. Increasing evidence demonstrates that glutaredoxin 1 (Grx1), a cytosolic enzyme responsible for the catalysis of protein deglutathionylation, plays distinct roles in inflammation and apoptosis by inducing changes in the cellular redox system. This study investigates whether and how Grx1 protects coronary artery vascular endothelial cells against high glucose (HG) induced damage. Results indicate that the activation of eNOS/NO system is regulated by Grx 1 and coupled with inhibition of JNK and NF-κB signaling pathway which could alleviate the oxidative stress and apoptosis damage in coronary arteries endothelial cells induced by HG. Show more
Keywords: Grx 1, diabetes cardiovascular complications, redox homeostasis, eNOS/NO system, redox signaling pathway
DOI: 10.3233/BME-141221
Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3897-3903, 2014
Authors: Zhao, Li | Wang, Hao | Li, Shan-Shan | Xin, Feng | Wu, Qi | Li, Zheng-Ye | Ma, Xian-Jun
Article Type: Research Article
Abstract: OBJECTIVE: This study aimed to retrospectively analyze the blood protective effect of autologous platelet separation in operations for acute aortic dissection. METHODS: A total of 130 patients with acute aortic dissection were enrolled into the present study. The average age of these patients was 52.962±10.5061 years old. These patients underwent the modified aortic arch replacement with the elephant trunk technique or endovascular aortic exclusion with covered stent. Among these patients, 68 patients who underwent autologous platelet separation were assigned to the platelet separation group, while the remaining patients were assigned to the control group. All operations were performed under deep …hypothermic circulatory arrest. After anesthesia, 1–2 therapeutic doses of autologous platelets were isolated from patients in the platelet separation group, and these platelets were quickly infused back to these patients after heparin was neutralized by protamine at the end of the cardiopulmonary bypass. The preoperative and postoperative indexes in these two groups were compared. RESULTS: There were no statistically significant differences in age, gender, smoking history, drinking history and hypertension history between these two groups. Compared with controls, the transfusion volume of allogeneic platelets in the perioperative period significantly decreased in the platelet separation group (1.919±1.6226 vs. 0.794±1.1789, P < #x003C;< #x200A;0.05), and the use rate of allogeneic platelets also significantly decreased (74.19% vs. 45.59%, P < #x003C;< #x200A;0.05). CONCLUSION: The intraoperative auto transfusion of platelets significantly reduced the volume of allogeneic platelet transfusion after the operation for aortic dissection, which has a significant blood protective effect. Show more
Keywords: Aortic dissection, autologous plateletpheresis, cardiopulmonary bypass, blood conservation, allogeneic platelet transfusions
DOI: 10.3233/CH-200871
Citation: Clinical Hemorheology and Microcirculation, vol. 76, no. 3, pp. 361-366, 2020
PCSK9 Promotes oxLDL-Induced PC12 Cell Apoptosis Through the Bcl-2/Bax-Caspase 9/3 Signaling Pathway
Authors: Liu, Lu-Shan | Bai, Xue-Qin | Gao, Ya | Wu, Qi | Ren, Zhong | Li, Qing | Pan, Li-Hong | He, Ni-Ya | Peng, Juan | Tang, Zhi-Han
Article Type: Research Article
Abstract: Background: Hyperlipidemia is a risk factor for neurodegenerative diseases. Proprotein convertase subtilisin / Kexin type 9 (PCSK9) degrades hepatic low-density lipoprotein receptor (LDLR) to regulate lipid metabolism. It is unclear if PCSK9 plays a role in neurodegenerative diseases. Objective: This study was designed to determine whether PCSK9 is crucial between hyperlipidemia and Alzheimer’s disease. The interrelationship between PCSK9 and neuronal apoptosis was explored in PC12 cells in response to treatment with oxidized low-density lipoprotein (oxLDL). Methods: Cultured PC12 cells were serum-starved and incubated with different concentrations of oxLDL for 24 h. Intracytoplasmic lipid droplets were observed by oil red O staining. …Morphological assessment of apoptotic cells was performed using Hoechst 33258 staining and flow cytometry analysis. The expression of mRNA and protein was detected by reverse-transcription polymerase chain reaction (RT-PCR) and western blot analyses, respectively. Transfection of small interfering RNA (siRNA) into PC12 cells was conducted using HiperFect Transfection Reagent. Concentrations of Aβ40 and Aβ42 were detected by enzyme-linked immunosorbent assay (ELISA) kit. Results: Intracellular lipid content, the number of apoptotic cells, and PCSK9 expression were increased in PC12 cells after oxLDL treatment. Transfection with PCSK9 siRNA reduced the oxLDL-induced apoptosis of PC12 cells. We further confirmed the involvement of Bcl-2/Bax-Caspase (9, 3) signaling pathway in the regulation of PC12 cells apoptosis.β-Secretase 1, another target gene of PCSK9, was downregulated in PC12 cells in response to oxLDL treatment. Aβ40 and Aβ42 contents were also decreased. Conclusion: PCSK9 promotes oxLDL-induced PC12 cell apoptosis through the Bcl-2/Bax-Caspase 9/3 signaling pathway. Show more
Keywords: Amyloid β peptide, apoptosis, β-site AβPP cleaving enzyme 1, caspases, oxidized low-density lipoprotein, PC12 cell, proprotein convertase subtilisin/kexin type 9, signal pathway
DOI: 10.3233/JAD-161136
Citation: Journal of Alzheimer's Disease, vol. 57, no. 3, pp. 723-734, 2017
Authors: Wang, Lijun | Wu, Qi | Zhu, Shan | Li, Zhiyu | Yuan, Jingping | Liu, Lin | Yu, Dehua | Xu, Zhiliang | Li, Juanjuan | Sun, Shengrong | Wang, Changhua
Article Type: Research Article
Abstract: DNER, Delta/Notch-like epidermal growth factor (EGF)-related receptor, is a neuron-specific transmembrane protein carrying extracellular EGF-like repeats. The prognostic value of DNER in prostate cancer has not been evaluated. Here we showed that the up-regulation of DNER protein was observed in prostate cancer detected by immunohistochemistry (IHC) and quantum dot-based immunofluorescent imaging and quantitative analytical system (QD-IIQAS). However, a higher accuracy of measurements of DNER expression in prostate cancer was found by QD-IIQAS than by IHC (AUC = 0.817 and 0.617, respectively). DNER was significantly higher in patients undergoing bone metastasis (P = 0.045, RR = 3.624). In addition, DNER overexpression …was associated with poor overall survival (OS) (P = 0.028, adjusted HR = 8.564) and recurrence-free survival (RFS) (P = 0.042, adjusted HR = 3.474) in patients suffering prostate cancer. Thus, QD-IIQAS is an easy and accurate method for assessing DNER and the DNER expression was an independent prognostic factor in prostate cancer. Show more
Keywords: Quantum dot-based immunofluorescent imaging, DNER, prognostic value, prostate cancer
DOI: 10.3233/CBM-171107
Citation: Cancer Biomarkers, vol. 22, no. 4, pp. 683-691, 2018