229 research outputs found
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Oncogenic R132 IDH1 Mutations Limit NADPH for De Novo Lipogenesis through (D)2-Hydroxyglutarate Production in Fibrosarcoma Sells.
Neomorphic mutations in NADP-dependent isocitrate dehydrogenases (IDH1 and IDH2) contribute to tumorigenesis in several cancers. Although significant research has focused on the hypermethylation phenotypes associated with (D)2-hydroxyglutarate (D2HG) accumulation, the metabolic consequences of these mutations may also provide therapeutic opportunities. Here we apply flux-based approaches to genetically engineered cell lines with an endogenous IDH1 mutation to examine the metabolic impacts of increased D2HG production and altered IDH flux as a function of IDH1 mutation or expression. D2HG synthesis in IDH1-mutant cells consumes NADPH at rates similar to de novo lipogenesis. IDH1-mutant cells exhibit increased dependence on exogenous lipid sources for in vitro growth, as removal of medium lipids slows growth more dramatically in IDH1-mutant cells compared with those expressing wild-type or enzymatically inactive alleles. NADPH regeneration may be limiting for lipogenesis and potentially redox homeostasis in IDH1-mutant cells, highlighting critical links between cellular biosynthesis and redox metabolism
Türk Dili ve Edebiyatı Sahasında Yapılmış Doktora ve Yüksek Lisans Tezleri (1987-1999) -II- (Eski ve Yeni Türk Dili)
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Elements of paradoxes in supply chain management literature: A systematic literature review
This study reports the results of a systematic literature review investigating paradoxes in supply chain management. This issue is important because supply chain practitioners frequently face paradoxes in industry with little direction provided in supply chain literature. Investigating the years 1997 through 2019, we identified 64 articles as the basis of our research containing a total of 68 unique paradoxes. In identifying the paradox elements (PEs), we adopted paradox theory (PT) as the base theoretical approach, which was utilized in only 7 of the articles. We employed contingency theory, institutional complexity theory, and complexity theory to support our findings. For each paradox, we also extracted and summarized managerial insights for practitioners. This study addresses the emergent needs of investigating paradoxes in the supply chain management domain to extend the use of PT and complementary theories that can aid practitioners in how to efficiently manage the paradoxes they encounter in industry
Effect of sonication on the reactivity of silica fume in portland cement mortars
Permission is granted by ICE Publishing to print one copy for personal use. Any other use of these PDF files is subject to reprint fees.Currently, the use of silica fume for the production of mortars and high-performance concrete is of great importance
to the construction materials sector. Different applications of silica fume have generated extensive studies about its
high reactivity as a pozzolanic material, in addition to its effect on the properties of some materials within which it is
incorporated. In this study a sonication process was applied by means of which the deagglomeration of the larger
particles of densi¿ed silica fume (CSF) was achieved. The result is a CSF treated with the ultrasound probe, which is
obtained for different tests where the parameters of sonication such as sonication power level and sonication time
are varied. This treatment makes it possible to increase the quantity of submicrometric particles in the sample. The
effect of sonication process on CSF produces a greater quantity of very ¿ne particles, which improve the pozzolanic
reactivity of silica fume and increase the ¿xation of hydrated lime. This behaviour also produces higher mechanical
strength in mortars manufactured with sonicated silica fume (SSF). The mechanical strengths of SSF mortars were
greater than those for control and CSF mortar. Different percentages of cement were substituted (between 0 and
15% by weight), and in all cases the SSF mortars showed important differences from the CSF mortar. It was observed
that for the longest sonication times and highest sonication power levels, mechanical strengths were increased.The authors are grateful to the Spanish company Ferroatlantica S.L. for their financial support; to the Spanish Agency of International Cooperation and Development (AECID) for the doctorate grant to D.M.-V.; to the Spanish government for their support to the project BIA 2007-63252; and to FEDER for its financial support to our research projects.Martínez Velandia, DA.; Paya Bernabeu, JJ.; Monzó Balbuena, JM.; Borrachero Rosado, MV. (2011). Effect of sonication on the reactivity of silica fume in portland cement mortars. Advances in Cement Research. (1):23-31. https://doi.org/10.1680/adcr.8.00027S2331
Analysis of coronary angiography related psychophysiological responses
<p>Abstract</p> <p>Background</p> <p>Coronary angiography is an important tool in diagnosis of cardiovascular diseases. However, it is the administration is relatively stressful and emotionally traumatic for the subjects. The aim of this study is to evaluate psychophysiological responses induced by the coronary angiography instead of subjective methods such as a questionnaire. We have also evaluated the influence of the tranquilizer on the psychophysiological responses.</p> <p>Methods</p> <p>Electrocardiography (ECG), Blood Volume Pulse (BVP), and Galvanic Skin Response (GSR) of 34 patients who underwent coronary angiography operation were recorded. Recordings were done at three phases: "1 hour before," "during," and "1 hour after" the coronary angiography test. Total of 5 features obtained from the physiological signals were compared across these three phases. Sixteen of the patients were administered 5 mg of a tranquilizer (Diazepam) before the operation and remaining 18 were not.</p> <p>Results</p> <p>Our results indicate that there is a strong correlation between features (LF/HF, Bk, DN1/DN2, skin conductance level and seg_mean) in terms of reflecting psychophysiological responses. However only DN1/DN2 feature has statistically significant differences between angiography phases (for diazepam: p = 0.0201, for non_diazepam p = 0.0224). We also note that there are statistically significant differences between the diazepam and non-diazepam groups for seg_mean features in "before", "during" and "after" phases (p = 0.0156, 0.0282, and 0.0443, respectively).</p> <p>Conclusions</p> <p>The most intense sympathetic activity is observed in the "during" angiography phase for both of the groups. The obtained features can be used in some clinical studies where generation of the customized/individual diagnoses styles and quantitative evaluation of psychophysiological responses is necessary.</p
Is the US 3PL industry overcoming paradoxes amid the pandemic?
Purpose: Third-party logistics (3PL) companies have experienced an explosion of volume during coronavirus disease 2019 (COVID-19). Special tiers have been introduced to provide differentiated levels of service to the customers. However, such changes in an organization reveal and intensify tensions known as paradoxes. The purpose of this research is to identify what paradoxes emerged or have become more salient specifically due to COVID-19 in 3PLs\u27 ground operations and how they are dealt with by ground operation managers.
Design/methodology/approach: This is a qualitative study conducted in two phases. Phase one utilizes a questionnaire approach to identify the paradoxes within the 3PLs operating in the USA. Phase two, conducted six months after phase one, follows an in-depth one-on-one interview approach. NVivo 12 is employed to analyze the interview data.
Findings: The results show that new paradoxes did in fact emerge due to the COVID-19 and are mostly related to the performing paradox category. Findings from in-depth interviews show that the 3PL managers focus on keeping safety as priority to manage COVID-19 related paradoxes, along with modifying operational plans, improving communication, investing in training, optimizing hub network, introducing modified/new methods and adapting modified human resource policies.
Originality/value: This paper is among the first known to identify paradoxes within the 3PL operations during the COVID-19 and provides insights into how these paradoxes are dealt with at mid-management level. Findings of this study provide foundations for the development of a theoretical framework on handling paradoxes within 3PLs
A novel network data envelopment analysis model for performance measurement of Turkish electric distribution companies
Electric distribution companies have a significant role for both households and industries. Benchmarking of the electric distribution companies in the energy sector has become a subject that is studied widely nowadays due to the effect of privatization policies for developing countries. Since there are multiple production stages regarding the generation and supply procedures of electric power, Network DEA technique is used. Directional Distance Function is also integrated into Network DEA technique. Electric distribution companies are organizations that are aiming at maximizing profit while minimizing the expenses. The main problem is how the profit idea can be integrated into the evaluation process. The aim of the proposed model is to evaluate profit efficiency of electric distribution companies while taking into account expansion cost for additional energy supply. This two stage approach is applied to Turkish electric distribution companies. Results are presented based on radial and profit efficiency measures. The proposed model is demonstrates realistic results by considering the expenses and incomes of distribution companies
Interactions in sustainable supply chain management: a framework review
Purpose – This study evaluates the research conducted among the interim, dyadic interactions that bridge the stand-alone measures of economic, environmental, and social performance and the level of sustainability, as suggested in the Carter & Rogers (2008) framework.
Design/methodology/approach – This paper conducts a systematic literature review based on the Tranfield et al. (2003) method of the articles published in 13 major journals in the area of supply chain management between the years of 2010 and 2016. Results were analyzed using an expert panel.
Findings – The area of research between environmental and social performance is sparse and relegated to empirical investigation. As an important area of interaction, this area needs more research to answer the how and why questions. The economic activity seems to be the persistent theme among the interactions.
Research implications – The literature on the “ES” interactions is lacking in both theoretical and analytical content. Studies explaining the motivations, optimal levels, and context that drive these interactions are needed. The extant research portrays economic performance as if it cannot be sacrificed for social welfare. This approach is not in line with the progressive view of SSCM but instead the binary view with an economic emphasis.
Practical implications – To improve sustainability, organizations need the triple bottom line (TBL) framework that defines sustainability in isolation. However, they also need to understand how and why these interactions take place that drive sustainability in organizations.
Originality/value – This is the first study to examine the literature specifically dedicated to the essential, interim, dyadic interactions that bridge the gap between stand-alone performance and the TBL that creates true sustainability. It also shows how the literature views the existence of sustainability is progressive, but many describe sustainability as binary. It is possible that economic sustainability is binary, and progressive characterizations of SSCM could be the reason behind the results favoring economic performance over environmental and social
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