1,767 results on '"Chivu A"'
Search Results
2. Gastrointestinal stromal tumors: a focus on the impact of interstitial cells of Cajal in disease development
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Petru Radu, Mihai Zurzu, Anca Tigora, Vlad Paic, Mircea Bratucu, Dragos Garofil, Valeriu Surlin, Stefan Patrascu, Virgiliu Prunoiu, Ionut Simion Coman, Valentin Georgescu, Razvan Daniel Chivu, Florian Popa, Victor Strambu, and Raluca Gabriela Ioan
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gist ,cajal cells ,cd117 ,cd34 ,dog-1 ,icc ,immunohistochemistry ,Medicine (General) ,R5-920 - Abstract
Introduction. Interstitial Cells of Cajal (ICCs) play a critical role in the regulation of gastrointestinal motility and have been implicated in various functional gastrointestinal disorders. Recent research indicates a possible association between ICCs and the tumor risk of Gastrointestinal Stromal Tumors (GISTs). This research aims to examine the clinical, histopathological, and biomolecular characteristics of ICCs and their relevance in assessing GIST risk. Materials and Methods. This study examined fourteen GIST patients who underwent surgical intervention at the Surgery Department of Carol Davila Nephrology Hospital in Bucharest. Parameters including age, gender, tumor location/ dimensions were scrutinized. Immunohistochemistry employing markers CD117, DOG-1, and CD34 was employed to ascertain the presence of ICCs and GISTs. Results. The GIST risk stratification revealed distribution with 35.71% very low-risk, 21.42% low-risk, 14.28% intermediate-risk, and 28.57% high-risk categories. Predominantly, 57.14% of cases fell within the very low-risk and low-risk categories. Positive immunoreactivity for CD117 and DOG-1 was noted in 92.86% of patients, while CD34 exhibited positivity in 85.71% of cases. Gastric GISTs manifested heightened marker expression. Notably, immunohistochemistry unveiled robust positivity for CD117, DOG-1, and CD34, illustrating a positive correlation between elevated ICC levels and high-risk GISTs. Conclusions. The findings propose an association between ICC levels and high-risk GISTs, accentuating the diagnostic utility of CD117, DOG-1, and CD34 markers in GIST assessment.
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- 2024
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3. Determinants of Organisations’ Decisions Regarding Investments in Human Resource Development
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Bîrcă, Alic, Chivu, Luminița, Sandu, Christiana Brigitte, Chivu, Luminita, editor, Ioan-Franc, Valeriu, editor, Georgescu, George, editor, De Los Ríos Carmenado, Ignacio, editor, and Andrei, Jean Vasile, editor
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- 2024
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4. Conclusions and Follow-Ups
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Chivu, Luminița, Georgescu, George, Andrei, Jean Vasile, Chivu, Luminita, editor, Ioan-Franc, Valeriu, editor, Georgescu, George, editor, De Los Ríos Carmenado, Ignacio, editor, and Andrei, Jean Vasile, editor
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- 2024
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5. EEG Microstates in Mood and Anxiety Disorders: A Meta-analysis
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Chivu, Alina, Pascal, Simona A., Damborská, Alena, and Tomescu, Miralena I.
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- 2024
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6. INTEGRATING ARTIFICIAL INTELLIGENCE INTO THE PHOTOGRAPHIC DESIGN PROCESS
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Ioana Catalina ENACHE, Narcisa VALTER, Florin-Felix RADUICA, and Oana CHIVU
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AI ,editing image ,photography ,artistic effects ,Architectural engineering. Structural engineering of buildings ,TH845-895 ,Engineering design ,TA174 - Abstract
This paper explores the impact of using Artificial Intelligence (AI) in the photographic design process. In the context of rapidly evolving technology, AI applications have become increasingly prominent in various fields, including the photographic industry. This study examines how advanced machine learning and image processing algorithms can improve and simplify creative processes in photography. The main issues addressed include the use of AI in automatic image selection and editing, automatic identification of relevant subjects and generation of artistic effects. These technologies bring not only efficiency but also an increase in the quality of the final results. The paper also highlights the ethical issues associated with the use of AI in photographic design and the importance of human control in these automated processes. The study draws on current research in AI and photography, examining practical applications of existing technologies and exploring future prospects. The results indicate that the intelligent integration of AI into the photographic design process can bring significant benefits, but it is essential to consider ethical issues and maintain a balance between human creativity and automation.
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- 2024
7. Unveiling the Power of Social Media: Innovative Strategies and SOCMINT Insights in Modern Marketing
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Raluca-Giorgiana Chivu (Popa) and Ionut-Claudiu Popa
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social media marketing ,consumer behaviour ,social media intelligence ,Business ,HF5001-6182 ,Economics as a science ,HB71-74 - Abstract
In the era of rapid technological advancements, traditional marketing strategies no longer wield the same effectiveness. The focal point has shifted to social media, a pivotal virtual realm where platforms not only serve as social networks but also as digital advertising spaces utilizing innovative and captivating marketing techniques. Marketers recognize the indispensability of these digital forums, leveraging them to reach a vast audience while optimizing budgetary resources. In addition to conventional marketing, the less highlighted realm of social media intelligence (SOCMINT) plays a crucial role. SOCMINT involves harnessing data collected from social media platforms to gain deeper insights into consumer behavior. This article delves into research conducted among social media users, unveiling the voluntarily shared data and information. It also measures users' awareness of how other entities utilize their publicly displayed information. In this dynamic landscape, the fusion of strategic digital marketing and SOCMINT emerges as a powerful tandem for navigating the evolving realm of consumer engagement.
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- 2024
8. Soluble PD-L1 as a diagnostic and prognostic biomarker in resectable gastric cancer patients
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Chivu-Economescu, Mihaela, Herlea, Vlad, Dima, Simona, Sorop, Andrei, Pechianu, Catalin, Procop, Alexandru, Kitahara, Shuji, Necula, Laura, Matei, Lilia, Dragu, Denisa, Neagu, Ana-Iulia, Bleotu, Coralia, Diaconu, Carmen C., Popescu, Irinel, and Duda, Dan G.
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- 2023
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9. Energy transition or energy diversification? Assessing the complexity of energy ecosystem towards transiting a climate neutral society
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Andrei, Jean-Vasile, Zaharia, Alina, Graci, Giuseppe, and Chivu, Luminița
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- 2023
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10. Synthetic Composite Indicators for Monitoring Changes in Countries’ Development Rankings – A Bibliometric Analysis
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Chivu, Luminița, Georgescu, George, Zaharia, Alina, Chivu, Luminita, editor, De Los Ríos Carmenado, Ignacio, editor, and Andrei, Jean Vasile, editor
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- 2023
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11. On the parametric description of log-growth rates of Romanian city sizes
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Băncescu, Irina, Chivu, Luminiţa, Massing, Till, Preda, Vasile, Puente-Ajovín, Miguel, and Ramos, Arturo
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- 2024
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12. Prediction of histone post-translational modification patterns based on nascent transcription data.
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Wang, Zhong, Chivu, Alexandra G, Choate, Lauren A, Rice, Edward J, Miller, Donald C, Chu, Tinyi, Chou, Shao-Pei, Kingsley, Nicole B, Petersen, Jessica L, Finno, Carrie J, Bellone, Rebecca R, Antczak, Douglas F, Lis, John T, and Danko, Charles G
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Chromatin ,Nucleosomes ,Histones ,Protein Processing ,Post-Translational ,Histone Code ,Human Genome ,Genetics ,1.1 Normal biological development and functioning ,Underpinning research ,Generic health relevance ,Biological Sciences ,Medical and Health Sciences ,Developmental Biology - Abstract
The role of histone modifications in transcription remains incompletely understood. Here, we examine the relationship between histone modifications and transcription using experimental perturbations combined with sensitive machine-learning tools. Transcription predicted the variation in active histone marks and complex chromatin states, like bivalent promoters, down to single-nucleosome resolution and at an accuracy that rivaled the correspondence between independent ChIP-seq experiments. Blocking transcription rapidly removed two punctate marks, H3K4me3 and H3K27ac, from chromatin indicating that transcription is required for active histone modifications. Transcription was also required for maintenance of H3K27me3, consistent with a role for RNA in recruiting PRC2. A subset of DNase-I-hypersensitive sites were refractory to prediction, precluding models where transcription initiates pervasively at any open chromatin. Our results, in combination with past literature, support a model in which active histone modifications serve a supportive, rather than an essential regulatory, role in transcription.
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- 2022
13. Premises of Improving the Quality of the Didactic Process in Pre-university Education in the Context of Education 4.0
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Chivu, Diana-Elena, primary
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- 2023
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14. 3D printing of five tensile samples in lateral position C from ABS+ material
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A.M Rugescu, C. Babiș, S A Fica, A Dimitescu, Ooana Roxana Chivu, and I C Enache
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tensile samples ,slicing settings ,abs+ material ,lateral printing position ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
This work presents the manufacturing by 3D printing in lateral position C, of five samples made of ABS+ material. 3D printing has more and more applications in all industrial fields and is a modern additive manufacturing process. Among the many advantages of using this process are the use of a digital model in the design phase, a very high material efficiency in the execution phase as well as a significant reduction in the costs related to the tools and equipment required. This work is part of a larger study in which tensile specimens are fabricated using three printing positions and three types of filaments. The manufactured samples are intended to be later used for tensile tests.
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- 2023
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15. FEM for the tensile specimens printed in horizontal position A and made of ABS+ material
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C Babiş, S A Fica, A Dimitrescu, A M Rugescu, O R Chivu, and I C Enache
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sample test ,3d printing ,material ,printing position ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
3D printing is finding more and more applications in the industrial field and represents a modern additive manufacturing process based on a digital model. There are a number of advantages of additive manufacturing through 3D printing compared to classic manufacturing processes such as: material economy, design optimization, the possibility of rapid prototyping, shortening the design and manufacturing cycle, eliminating errors and many others. Because 3D printed elements are more and more often found in various applications, an investigation is required by material categories and printing positions of the mechanical properties and how the respective landmarks behave in terms of displacements and internal stresses. The investigation of the mechanical characteristics, displacements and internal stresses can be done through laboratory tests on samples classically subjected to traction, bending, torsion. In order to reduce the number of mechanical tests, in order to investigate displacements and internal stresses, we must use finite element analysis methods. In the present work, the finite element analysis of some tensile specimens, 3D printed from ABS+ material, in the horizontal position A, will be presented..
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- 2023
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16. 3D printing by Fused Deposition Modeling - FDM technology - with PETG type filament in horizontal position A
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A Dimitescu, C Babiş, S A Fica, A M Rugescu, I C Enache, and O R Chivu
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3d printing ,petg material ,horizontal printing position ,fdm ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
In this work, it is proposed to realize by 3D printing, which is an additive manufacturing process using Fused Deposition Modeling - FDM - some samples using PETG type filament. The position in which printing is performed is variant A corresponding to the horizontal position. 3D printing has more and more applications in all industrial fields and is a modern additive manufacturing process. Among the many advantages of using this process are the use of a digital model in the design phase, a very high material efficiency in the execution phase as well as a significant reduction in the costs related to the tools and equipment required. Another advantage that must be taken into account very seriously, in this case of industrial speed, is the time elapsed from the idea to the realization of the prototype. Using 3D printing, it is possible to optimize the design from the design phase, making the finished product with minimal losses. In this context it is important to make a study on the positions of printing the landmarks, in the case of this work of the specimens, to determine the mechanical properties as well as the displacements and internal stresses that occur due to several types of stresses.
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- 2023
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17. An analysis of the environmentally friendly furniture used in airports
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Ioana Catalina Enache, Oana Roxana Chivu, Catana Roxana-Teodora, and Raduica Florin Felix
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sustainability ,airport furniture ,modular furniture ,design ,life cycle assessment ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
This article delves into the realm of eco-design furniture as a pioneering solution for enhancing the sustainability of airport environments, both indoors and outdoors. The primary objective of adopting eco-design principles within airport spaces is to mitigate the adverse environmental effects associated with traditional furniture choices. By prioritizing the utilization of functional, sustainable, and aesthetically pleasing products, this research seeks to contribute to the creation of airport environments that align with contemporary ecological concerns. The study emphasizes a holistic approach that encompasses various facets of eco-design, including manufacturing technologies, material composition, and energy efficiency. Special attention is given to the exclusion of toxic substances from the furniture's composition, ensuring that the end product not only enhances the overall aesthetic appeal of the airport but also remains environmentally friendly throughout its life cycle. Moreover, the research evaluates and proposes strategies to minimize energy consumption during the production phase, thereby further reducing the ecological footprint associated with the furniture
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- 2023
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18. Study on the situation of accidents at work in Romania compared to other EU member countries
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Alexandru-Ionuț Mihail, Oana Roxana Chivu, Enache Ioana - Cătălina, Borda Claudia, Larisa Butu, Giulia-Madalina Bobocea, Demetrius DUBIC (PETRESCU), Alin Ion Țăpirdea, and Dan Nitoi
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work environment ,accidents at work ,exposure ,fatality ,incidence rate ,records of accidents at work. ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
Occupational accidents are a significant occupational health and safety problem in Romania and worldwide. This research examines recent developments and trends in occupational accidents in Romania, assessing the incidence rate of fatal accidents at work in relation to other EU countries. The aim of this research is to identify the main sectors that rank high in employee exposure and to highlight the need for urgent action to reduce incidents and improve workplace safety. It also provides a better understanding of the phenomenon of accidents at work in the Romanian context, including the advocacy of a safer working environment for all employees in the country.
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- 2023
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19. FEM for tensile specimens printed in vertical position B and made of ABS+ material
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C Babiş, S A Fica, A Dimitescu, A M Rugescu, O R Chivu, and I C Enache
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sample test ,3d printing ,material ,vertical printing position ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
3D printing is finding more and more applications in the industrial field and an investigation is required by material categories and by printing positions of the mechanical properties and how the respective landmarks behave in terms of displacements and internal stresses. In order to reduce the number of mechanical tests, in order to investigate displacements and internal stresses, we can use finite element analysis methods. In the present paper, the analysis with finite elements of some tensile specimens, printed 3D from ABS+ material, in the vertical position B will be presented.
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- 2023
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20. Studies on geotextiles and their use in municipal waste disposal construction
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Bogdan Ivan, Oana Roxana Chivu, Marilena Gheorghe, Cătălina Enache, Dan Nitoi, Alin Țăpîrdea, Demetrius Dubic (Petrescu), and Ioana Cătălina Enache
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ecology ,geotextiles ,landfill ,reduce pollution. ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
Landfill is one of the world's most prevalent and commonly utilized waste disposal systems. The effectiveness of landfilling is dependent on a technological, economic, and regulatory framework that appears to be insufficient in many nations. There are several areas of geotextile application in landfill covers, each with its own set of needs and concerns for optimal material selection and assessment. This article presents an examination of several landfill covering possibilities
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- 2023
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21. Considerations on improving or integrating new technologies in HSE activities
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Alexandru-Ionuț Mihail, Oana Roxana Chivu, Enache Ioana - Cătălina, Borda Claudia, Marinela Marinescu, Demetrius Dubic (Petrescu), Alin Ion Țăpirdea, and Dan Nitoi
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health and safety at work ,technology ,activities ,hazards ,iot ,electronic archiving. ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
Technology is constantly expanding. Workplaces have undergone drastic changes due to processes of automation, robotisation, working remotely and so on, which has caused some workplace hazards to disappear and be replaced by other hazards. This is also felt in the conduct of occupational health and safety activities, which need to keep up with all these technological changes. Automation of processes, digitisation of information - IoT is at the heart of what is happening in most areas of business. The field of HSE can be streamlined by adopting such best practices as electronic archiving of documents
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- 2023
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22. 3D printing of five tensile samples in horizontal position A from PLA+ material
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I C Enache, S A Fica, O R Chivu, C. Babiș, A.M Rugescu, and A Dimitrescu
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tensile samples ,slicing settings ,pla+ material ,horizontal printing position ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
A contemporary additive manufacturing technology based on a digital model, 3D printing is finding more and more uses in the industrial sector. This procedure, often referred to as fused deposition modelling, has been standardized as fused filament fabrication (FFF). Comparing additive manufacturing using 3D printing to conventional manufacturing methods has a lot of benefits. Compared to conventional production methods, additive manufacturing with 3D printing enables material savings. The mechanical strength of various materials used in additive manufacturing is presented in many studies. The purpose of this work is to outline the procedures required for 3D printing specimens that can be used to assess the mechanical characteristics of the substance polylactic acid (PLA+)
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- 2023
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23. 3D printing of five tensile samples in lateral position C from PETG material
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A.M Rugescu, C. Babiș, S A Fica, A Dimitescu, O R Chivu, and I C Enache
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tensile samples ,slicing settings ,petg material ,lateral printing position ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
This work presents the manufacturing by 3D printing in lateral position C, of five samples made of PETG material. Polyethylene terephthalate glycol, commonly known as PETG or PET-G, is a thermoplastic polyester that provides significant chemical resistance, durability, and excellent formability for manufacturing. PETG can be easily vacuumed and pressure-formed as well as heat-bent thanks to its low forming temperatures. This makes it exceptionally popular for consumer and commercial applications that involve 3D printing, or other heat-forming manufacturing techniques. Additionally, PETG is well-suited for fabrication techniques like die cutting, routing, and bending.. 3D printing has more and more applications in all industrial fields and is a modern additive manufacturing process. Among the many advantages of using this process are the use of a digital model in the design phase, a very high material efficiency in the execution phase as well as a significant reduction in the costs related to the tools and equipment required. This work is part of a larger study in which tensile specimens are fabricated using three printing positions and three types of filaments. The manufactured samples are intended to be later used for tensile tests.
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- 2023
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24. RNA polymerase II dynamics shape enhancer–promoter interactions
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Barshad, Gilad, Lewis, James J., Chivu, Alexandra G., Abuhashem, Abderhman, Krietenstein, Nils, Rice, Edward J., Ma, Yitian, Wang, Zhong, Rando, Oliver J., Hadjantonakis, Anna-Katerina, and Danko, Charles G.
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- 2023
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25. Correction: EEG Microstates in Mood and Anxiety Disorders: A Meta-analysis
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Chivu, Alina, Pascal, Simona A., Damborská, Alena, and Tomescu, Miralena I.
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- 2024
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26. Patterns and Emerging Trends in Acute Poisoning with Substances of Abuse Used for Recreational Purposes in Adolescents: A Six-Year Multicentre Study
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Teodora-Adela Turcu, Andreea Lescaie, Andreea Rodica Grama, Andreea-Cătălina Strătulă, Andreea-Iasmina Vincene, Laura-Maria Grigoraș, Cristina Jităreanu, Alina Maria Babeu, Mihai Gafencu, Maria-Dorina Crăciun, Carmen-Daniela Chivu, Daniela Luiza Baconi, Cristina Maria Mihai, Coriolan Emil Ulmeanu, and Gabriela Viorela Nițescu
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substance abuse ,poisoning ,adolescents ,cannabis ,new psychoactive substances ,public health ,Science - Abstract
This six-year multicentre study investigated acute intentional poisoning with substances of abuse in adolescents to identify changes and patterns in substance use. Data from 562 adolescents were collected from three paediatric poison centres in Romania between January 2017 and December 2022. This study analysed the epidemiological and sociodemographic characteristics of the adolescents, including age, gender, place of residence, history of substance abuse, psychiatric history, and history of institutionalised care. The findings revealed that cannabis and new psychoactive substances (NPSs) are the most commonly implicated substances, each with distinct profiles among adolescents. Cannabis was involved in 46.1% of cases, with a significant association with urban residency. NPSs were identified as the second most prevalent substance, accounting for 39.3% of cases. These were more prevalent in rural areas and among patients with psychiatric disorders. Cannabis and NPSs were also the most commonly implicated substances in acute intentional poisoning cases with substances of abuse. These substances have distinct profiles among adolescents, including age, gender, residency area, history of substance abuse, psychiatric history, and institutional care. These findings underscore the necessity of targeted public health interventions and integrated care approaches to address substance use and related mental health issues in adolescents.
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- 2024
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27. Viruses in Wastewater—A Concern for Public Health and the Environment
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Coralia Bleotu, Lilia Matei, Laura Denisa Dragu, Laura Georgiana Necula, Ioana Madalina Pitica, Mihaela Chivu-Economescu, and Carmen Cristina Diaconu
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viruses ,wastewater ,wastewater treatment ,environmental surveillance ,Biology (General) ,QH301-705.5 - Abstract
Wastewater monitoring provides essential information about water quality and the degree of contamination. Monitoring these waters helps identify and manage risks to public health, prevent the spread of disease, and protect the environment. Standardizing the appropriate and most accurate methods for the isolation and identification of viruses in wastewater is necessary. This review aims to present the major classes of viruses in wastewater, as well as the methods of concentration, isolation, and identification of viruses in wastewater to assess public health risks and implement corrective measures to prevent and control viral infections. Last but not least, we propose to evaluate the current strategies in wastewater treatment as well as new alternative methods of water disinfection.
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- 2024
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28. The Impact of ZnO Nanofillers on the Mechanical and Anti-Corrosion Performances of Epoxy Composites
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Raluca Şomoghi, Augustin Semenescu, Vili Pasăre, Oana Roxana Chivu, Dan Florin Nițoi, Dragoş Florin Marcu, and Bogdan Florea
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ZnO ,epoxy resin ,mechanical property ,anti-corrosion ,Organic chemistry ,QD241-441 - Abstract
Epoxy resins were reinforced with different ZnO nanofillers (commercial ZnO nanoparticles (ZnO NPs), recycled ZnO and functionalized ZnO NPs) in order to obtain ZnO–epoxy composites with suitable mechanical properties, high adhesion strength, and good resistance to corrosion. The final properties of ZnO–epoxy composites depend on several factors, such as the type and contents of nanofillers, the epoxy resin type, curing agent, and preparation methods. This paper aims to review the preparation methods, mechanical and anti-corrosion performance, and applications of ZnO–epoxy composites. The epoxy–ZnO composites are demonstrated to be valuable materials for a wide range of applications, including the development of anti-corrosion and UV-protective coatings, for adhesives and the chemical industry, or for use in building materials or electronics.
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- 2024
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29. Assessment of Engine Performance and Emissions with Eucalyptus Oil and Diesel Blends
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Robert Mădălin Chivu, Jorge Martins, Florin Popescu, Margarida Gonçalves, Krisztina Uzuneanu, Michael Frătița, and Francisco P. Brito
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biofuel ,eucalyptus oil ,sustainable diesel fuel alternatives ,engine performance and emissions ,Technology - Abstract
This research evaluates the feasibility of using eucalyptus oil blended with conventional diesel fuel in diesel engines. Eucalyptus globulus is one of the main tree species cultivated for paper pulp in western European countries such as Portugal, and eucalyptus oil is one of the byproducts that so far has not been sufficiently evaluated as a biofuel. This study assesses the impact of using this additive on engine performance parameters and emissions as a means to contribute to reducing fossil fuel consumption and pollutant and greenhouse gas (GHG) emissions. The analysis revealed that the addition of eucalyptus oil had a positive effect on torque, a critical performance parameter, with biofuel blends showing consistent torque increases at lower engine speeds. However, torque tended to decrease towards the higher range of engine speed for eucalyptus oil–diesel blends. Several blends showed lower brake specific fuel consumption compared to regular diesel at high engine loads and low engine speeds. Brake thermal efficiency did not vary substantially at lower engine speeds and loads but decreased at higher speeds and loads. Pollutant emissions, particularly unburned hydrocarbons and nitrogen oxides, were influenced by fuel composition, with biofuel blends showing both increases and decreases compared to diesel. It is noteworthy that eucalyptus oil blends exhibited up to a 60% reduction in smoke opacity under specific operating conditions at low speed and high load for 10% incorporation (10EU90D), suggesting that in addition to the already positive effects of cutting down fossil CO2 emissions in proportion to the substitution of fossil diesel with nearly carbon-neutral eucalyptus oil, more environmental benefits may be expected from the incorporation of this product. Although the present economic viability of using eucalyptus oil as a biofuel is still not guaranteed, the present study seems to reinforce its technical viability. Future prospects for the improvement of oil yield through biotechnology, the economic interest of this product for several countries, and the updating and upscaling industrial processes may allow the viability of this biofuel to remain a possibility in the future
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- 2024
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30. Hybrid Immunity and the Incidence of SARS-CoV-2 Reinfections during the Omicron Era in Frontline Healthcare Workers
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Carmen-Daniela Chivu, Maria-Dorina Crăciun, Daniela Pițigoi, Victoria Aramă, Monica Luminița Luminos, Gheorghiță Jugulete, Viorela Gabriela Nițescu, Andreea Lescaie, Cătălin Gabriel Apostolescu, and Adrian Streinu Cercel
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SARS-CoV-2 ,reinfection ,healthcare workers ,vaccines protection ,variant of concern ,Medicine - Abstract
During the coronavirus disease (COVID-19) pandemic healthcare workers (HCWs) acquired immunity by vaccination or exposure to multiple variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Our study is a comparative analysis between subgroups of HCWs constructed based on the number of SARS-CoV-2 infections, vaccination, and the dominant variant of SARS-CoV-2 in the population. We collected and analyzed data using the χ2 test and density incidence of reinfections in Microsoft Excel for Mac, Version 16.84, and MedCalc®, 22.026. Of the 829 HCWs, 70.1% (581) had only one SARS-CoV-2 infection and 29.9% (248) had two infections. Of the subjects with two infections, 77.4% (192) worked in high-risk departments and 93.2% (231) of the second infections were registered during Omicron dominance. The density incidence of reinfections was higher in HCWs vaccinated with the primary schedule than those vaccinated with the first booster, and the incidence ratio was 2.8 (95% CI: 1.2; 6.7). The probability of reinfection was five times lower (95% CI: 2.9; 9.2) in HCWs vaccinated with the primary schedule if the first infection was acquired during Omicron dominance. The subjects vaccinated with the first booster had a density incidence of reinfection three times lower (95% CI: 1.9; 5.8) if the first infection was during Omicron. The incidence ratio in subgroups constructed based on characteristics such as gender, age group, job category, and department also registered significant differences in density incidence. The history of SARS-CoV-2 infection by variant is important when interpreting and understanding public health data and the results of studies related to vaccine efficacy for hybrid immunity subgroup populations.
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- 2024
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31. Neurological Manifestations of Acute SARS-CoV-2 Infection in Pediatric Patients: A 3-Year Study on Differences between Pandemic Waves
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Iolanda Cristina Vivisenco, Andreea Lescaie, Ana Dragomirescu, Ioana Cătălina Ioniță, Irina Florescu, Bogdan Ciocea, Andreea Rodica Grama, Maria-Dorina Crăciun, Carmen-Daniela Chivu, Coriolan Emil Ulmeanu, and Viorela Gabriela Nițescu
- Subjects
COVID-19 ,SARS-CoV-2 ,pandemic waves ,children ,neurologic manifestations ,Omicron ,Microbiology ,QR1-502 - Abstract
This study analyzed the neurological manifestation profiles of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection across pandemic waves in pediatric patients. The study collected data on patients aged between 0 and 18 years, diagnosed with acute SARS-CoV-2 infection, admitted to a pediatric tertiary hospital between 1 March 2020 and 28 February 2023. This study included 1677 patients. Neurological manifestations were noted in 10% (n = 168) of patients with a median age of 3.2 years (interquartile range: 1–11.92). Neurological manifestations were significantly associated with the pandemic waves (p = 0.006) and age groups (p < 0.001). Seizures were noted in 4.2% of cases and reached an increasing frequency over time (p = 0.001), but were not associated with age groups. Febrile seizures accounted for the majority of seizures. Headache was reported in 2.6% of cases and had similar frequencies across the pandemic waves and age groups. Muscular involvement was noted in 2% of cases, reached a decreasing frequency over time (p < 0.001), and showed different frequencies among the age groups. Neurological manifestations of acute SARS-CoV-2 infection exhibit distinct patterns, depending on the pandemic wave and patient age group. The Wuhan and Omicron waves involved the nervous system more often than the other waves.
- Published
- 2024
- Full Text
- View/download PDF
32. Emissions of noxes in the case of welding in shielding gases: a systematic literature review
- Author
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Alina Trifu, Oana Chivu, Daniel Onuț Badea, Claudia Borda, Dan Nitoi, Cornelia Luchian, and Ioana Cătălina Enache
- Subjects
welding ,noxes ,prevention ,control ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
The paper presents the results of a systematic review regarding emissions of noxes in the case of welding in shielding gases. For this paper it was used The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) published in 2009. A total of 65 academic papers retrieved from the ScienceDirect Freedom Collection, Elsevier database, Web of Science - Core Collection, Clarivate Analytics, Scopus, SpringerLink Journals databases were identified and analysed. The main objectives of this review were to answer the following questions: (1) What are the major health issues related emissions of noxes in the case of welding in shielding gases? (2) What are the measures of control for the fumes and gases? The search was conducted in January 2023. The results were organized into two major sections. The first include information on major health issues associated with welding noxes. The second contains studies thought to be relevant on measures of prevention and control.
- Published
- 2023
- Full Text
- View/download PDF
33. Considerations on Prevention and Protections Measures Against Occupational Risks
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Eduard Smidu, Oana Roxana Chivu, Doru Costin Darabont, Marilena Gheorghe, Dan Nițoi, Constantin Radu, Silviu Dumitrescu, and Ioana Cătălina Enache
- Subjects
occupational safety and health ,prevention and protection measures ,identification of professional risks ,assessment of risks ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
A general trend, manifested at the European and international level, is to promote the use of scientific methods in preventive activity, both in terms of the design of work security measures, and the motivation of employers for the application of these measures. The argument to which any entrepreneur reacts positively is profit. As a result, prevention specialists have tried to demonstrate that efforts to reduce the number of occupational accidents and illnesses ultimately bring financial benefits to the company. The paper presents the classification, prioritization and distribution of prevention and protection measures on the 4 components of the work system: the worker, the workload, the means of production, the work environment. Also, a case study on taking measures for a job is presented.
- Published
- 2023
- Full Text
- View/download PDF
34. FEM modeling of a tooth behavior depending on mineralization state
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Marta Maria-Monica, Dan Nitoi, Raluca Ioana Teleanu, Daniel Mihai Teleanu, Oana Roxana Chivu, and Stefan Milicescu
- Subjects
mineralization ,tooth ,fem ,displacement ,stress ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
The problem of mineralization of bone structures has been a subject of research and discussion for a long time due to the influence it has on the functioning of the entire human system. In practice, to improve the concentration of minerals in the bones, there are currently multiple dietary supplements that act on them. However, less research has been done on the chemical composition of teeth and how these mineral concentrations influence their behavior. The present research refers to the way in which a tooth behaves under the action of forces acting on its enamel surface. For this, the finite element method was used, which lends itself very well in this situation where, based on the specialized literature, mechanical properties and forces acting on a tooth were used as input data. Its mechanical properties, such as the modulus of elasticity, have different values for the situation of a normal tooth or a demineralized one. The article thus presents the state of tension and deformation that appears in a tooth in the two situations presented, resulting in interesting conclusions in this sense useful to a practitioner in the field of dentistry
- Published
- 2023
- Full Text
- View/download PDF
35. Instructional Design Strategies for Teaching the Mental Status Examination and Psychiatric Interview: a Scoping Review
- Author
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Lenouvel, Eric, Chivu, Camelia, Mattson, Janet, Young, John Q., Klöppel, Stefan, and Pinilla, Severin
- Published
- 2022
- Full Text
- View/download PDF
36. Influenza Vaccination of Romanian Medical Students during COVID-19 Times: From Knowledge to Behavior
- Author
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Bianca Georgiana Enciu, Andreea Marilena Păuna, Carmen Daniela Chivu, Oana Săndulescu, Anna Crispo, Liliana Veronica Diaconescu, Anca Cristina Drăgănescu, Maria-Dorina Crăciun, Daniela Pițigoi, and Victoria Aramă
- Subjects
influenza vaccination ,vaccine ,medical students ,vaccine hesitancy ,Medicine - Abstract
In Romania, influenza vaccination uptake among healthcare workers decreased over time despite access to the vaccine being constantly improved. The aim of this paper is to provide a comparative analysis of the knowledge and attitudes of Dental Medicine and Medicine students towards recommended vaccinations for healthcare workers, focusing on influenza vaccination. A cross-sectional study was conducted during the entire 2021–2022 academic year. Data were collected using 2 electronic questionnaires which were applied to the students from the Faculty of Medicine (n = 883) and, respectively, the Faculty of Dental Medicine of the Carol Davila University of Medicine and Pharmacy, Bucharest, Romania. The questionnaires were offered to 1187 students and completed by 911 students (response rate = 77%). Out of these, 85% (n = 778) identified the influenza vaccine as recommended; 35% (n = 321) reported getting an annual influenza vaccination; and 37% (333) reported getting an influenza vaccination in the previous season. Overall, 45% (n = 222) of the respondents who completed the questionnaires from October 2021 to February 2022 reported that they intend to get vaccinated against influenza in the 2021–2022 season and approximately 8% (n = 39) reported that they had already been vaccinated. The multivariable analysis showed that the habit of getting annually vaccinated against influenza as well as the knowledge that influenza vaccine is recommended for all healthcare workers were associated with a higher probability of intending to get vaccinated. The current study emphasizes the need to raise awareness among medical students regarding influenza vaccination and to involve medical education institutions, public health authorities, and healthcare facilities in promoting this vaccination among students since the influenza vaccine uptake rate among medical students included in this study was suboptimal.
- Published
- 2024
- Full Text
- View/download PDF
37. Energy Analysis of Waste Heat Recovery Using Supercritical CO2 Brayton Cycle for Series Hybrid Electric Vehicles
- Author
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Gabriel Mocanu, Cristian Iosifescu, Ion V. Ion, Florin Popescu, Michael Frătița, and Robert Mădălin Chivu
- Subjects
internal combustion engine ,waste heat ,supercritical CO2 recompression Brayton cycle ,heat recovery ,Technology - Abstract
Waste heat recovery from exhaust gas is one of the most convenient methods to save energy in internal combustion engine-driven vehicles. This paper aims to investigate a reduction in waste heat from the exhaust gas of an internal combustion engine of a serial Diesel–electric hybrid bus by recovering part of the heat and converting it into useful power with the help of a split-flow supercritical CO2 (sCO2) recompression Brayton cycle. It can recover 17.01 kW of the total 33.47 kW of waste heat contained in exhaust gas from a 151 kW internal combustion engine. The thermal efficiency of the cycle is 38.51%, and the net power of the cycle is 6.55 kW. The variation in the sCO2 temperature at the shutdown of the internal combustion engine is analyzed, and a slow drop followed by a sudden and then a slow drop is observed. After 80 s from stopping the engine, the temperature drops by (23–33)% depending on the tube thickness of the recovery heat exchanger. The performances (net power, thermal efficiency, and waste heat recovery efficiency) of the split-flow sCO2 recompression Brayton cycle are clearly superior to those of the steam Rankine cycle and the organic Rankine cycle (ORC) with cyclopentane as a working fluid.
- Published
- 2024
- Full Text
- View/download PDF
38. Botulism Cases in Romania—An Overview of 14-Year National Surveillance Data
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Andreea Marilena Păuna, Maria-Dorina Crăciun, Anca Sîrbu, Rodica Popescu, Bianca Georgiana Enciu, Carmen-Daniela Chivu, Mădălina Simoiu, and Daniela Piţigoi
- Subjects
botulism cases ,surveillance ,Romania ,Biology (General) ,QH301-705.5 - Abstract
Botulism is a priority disease worldwide because it has a very severe course of evolution that can lead to death. This paper aims to describe the main epidemiological characteristics of botulism cases confirmed in Romania over 14 years (2007–2020). We performed a retrospective study using the publicly available national surveillance data and reported to the National Institute of Public Health. A total of 325 cases of foodborne botulism were reported in Romania, with no infant or wound botulism. Most of the cases (125, 38.5%) were reported among young adults (25–44 years old), over half (205, 63%) of them living in rural areas. The incriminated food item was identified in 161 cases; in most cases (145, 90%) the food item was prepared in the household. The main food category was represented by meat and meat-based products (94, 68.6%). In almost all cases the identified type was BoNT/B (230/231, 99.5%). Fifteen deaths were recorded, and the case fatality rate was 4.6%. Botulism cases were reported annually in Romania. Surveillance data are essential for implementing control measures and adapting educational campaigns according to existing needs.
- Published
- 2024
- Full Text
- View/download PDF
39. Pathogenesis, Prophylaxis, and Treatment of Candida auris
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Madalina Preda, Razvan Daniel Chivu, Lia Mara Ditu, Oana Popescu, and Loredana Sabina Cornelia Manolescu
- Subjects
Candida auris ,fungal pathogen ,emerging threat ,diagnosis ,antifungal resistance ,Biology (General) ,QH301-705.5 - Abstract
Candida auris poses a serious threat to infection control and patient care since it can produce invasive infections that have a high fatality rate, has been linked to outbreaks in hospital environments, and is typically resistant to several antifungal medications. Since its first description in 2009, six clades have been described. The emerging fungal pathogen possesses adhesins that allow it to adhere to host tissues and medical devices, can form biofilms, produces various hydrolytic enzymes, employs several strategies to evade host immune responses, and exhibits high genetic diversity, which may contribute to its ability to adapt to different environmental conditions and evade host defenses. C. auris is very resistant to various disinfectants and may be difficult to detect.
- Published
- 2024
- Full Text
- View/download PDF
40. Leukemic conversion involving RAS mutations of type 1 CALR-mutated primary myelofibrosis in a patient treated for HCV cirrhosis: a case report
- Author
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Petruta Gurban, Cristina Mambet, Anca Botezatu, Laura G. Necula, Ana I. Neagu, Lilia Matei, Ioana M. Pitica, Saviana Nedeianu, Mihaela Chivu-Economescu, Coralia Bleotu, Marius Ataman, Gabriela Mocanu, Carmen Saguna, Anca G. Pavel, Danae Stambouli, Elise Sepulchre, Gabriela Anton, Carmen C. Diaconu, and Stefan N. Constantinescu
- Subjects
primary myelofibrosis (PMF) ,hepatitis C virus (HCV) cirrhosis ,type 1 calreticulin (CALR) ,targeted next-generation sequencing (NGS) ,NRAS ,acquired uniparental disomy (aUPD) ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Somatic frameshift mutations in exon 9 of calreticulin (CALR) gene are recognized as disease drivers in primary myelofibrosis (PMF), one of the three classical Philadelphia-negative myeloproliferative neoplasms (MPNs). Type 1/type 1-like CALR mutations particularly confer a favorable prognostic and survival advantage in PMF patients. We report an unusual case of PMF incidentally diagnosed in a 68-year-old woman known with hepatitis C virus (HCV) cirrhosis who developed a progressive painful splenomegaly, without anomalies in blood cell counts. While harboring a type 1 CALR mutation, the patient underwent a leukemic transformation in less than 1 year from diagnosis, with a lethal outcome. Analysis of paired DNA samples from chronic and leukemic phases by a targeted next-generation sequencing (NGS) panel and single-nucleotide polymorphism (SNP) microarray revealed that the leukemic clone developed from the CALR-mutated clone through the acquisition of genetic events in the RAS signaling pathway: an increased variant allele frequency of the germline NRAS Y64D mutation present in the chronic phase (via an acquired uniparental disomy of chromosome 1) and gaining NRAS G12D in the blast phase. SNP microarray analysis showed five clinically significant copy number losses at regions 7q22.1, 8q11.1-q11.21, 10p12.1-p11.22, 11p14.1-p11.2, and Xp11.4, revealing a complex karyotype already in the chronic phase. We discuss how additional mutations, detected by NGS, as well as HCV infection and antiviral therapy, might have negatively impacted this type 1 CALR-mutated PMF. We suggest that larger studies are required to determine if more careful monitoring would be needed in MPN patients also carrying HCV and receiving anti-HCV treatment.
- Published
- 2023
- Full Text
- View/download PDF
41. Randomized, controlled clinical trial of the DIALIVE liver dialysis device versus standard of care in patients with acute-on- chronic liver failure
- Author
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Agarwal, Banwari, Cañizares, Rafael Bañares, Saliba, Faouzi, Ballester, Maria Pilar, Tomescu, Dana Rodica, Martin, Daniel, Stadlbauer, Vanessa, Wright, Gavin, Sheikh, Mohammed, Morgan, Carrie, Alzola, Carlos, Lavin, Phillip, Green, Daniel, Kumar, Rahul, Sacleux, Sophie Caroline, Schilcher, Gernot, Koball, Sebastian, Tudor, Andrada, Minten, Jaak, Domenech, Gema, Aragones, Juan Jose, Oettl, Karl, Paar, Margret, Waterstradt, Katja, Bode-Boger, Stefanie M., Ibáñez-Samaniego, Luis, Gander, Amir, Ramos, Carolina, Chivu, Alexandru, Stange, Jan, Lamprecht, Georg, Sanchez, Moises, Mookerjee, Rajeshwar P., Davenport, Andrew, Davies, Nathan, Pavesi, Marco, Andreola, Fausto, Albillos, Agustin, Cordingley, Jeremy, Schmidt, Hartmut, Carbonell-Asins, Juan Antonio, Arroyo, Vicente, Fernandez, Javier, Mitzner, Steffen, and Jalan, Rajiv
- Published
- 2023
- Full Text
- View/download PDF
42. Molecular Aspects of Hypoxic Stress Effects in Chronic Ethanol Exposure of Neuronal Cells
- Author
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Simona Isabelle Stoica, Gelu Onose, Ioana Madalina Pitica, Ana Iulia Neagu, Gabriela Ion, Lilia Matei, Laura Denisa Dragu, Lacramioara-Elena Radu, Mihaela Chivu-Economescu, Laura Georgiana Necula, Aurelian Anghelescu, Carmen Cristina Diaconu, Constantin Munteanu, and Coralia Bleotu
- Subjects
hypoxic stress effect ,chronic ethanol exposure ,neuronal cells ,neurorehabilitation ,Biology (General) ,QH301-705.5 - Abstract
Experimental models of a clinical, pathophysiological context are used to understand molecular mechanisms and develop novel therapies. Previous studies revealed better outcomes for spinal cord injury chronic ethanol-consuming patients. This study evaluated cellular and molecular changes in a model mimicking spinal cord injury (hypoxic stress induced by treatment with deferoxamine or cobalt chloride) in chronic ethanol-consuming patients (ethanol-exposed neural cultures (SK-N-SH)) in order to explain the clinical paradigm of better outcomes for spinal cord injury chronic ethanol-consuming patients. The results show that long-term ethanol exposure has a cytotoxic effect, inducing apoptosis. At 24 h after the induction of hypoxic stress (by deferoxamine or cobalt chloride treatments), reduced ROS in long-term ethanol-exposed SK-N-SH cells was observed, which might be due to an adaptation to stressful conditions. In addition, the HIF-1α protein level was increased after hypoxic treatment of long-term ethanol-exposed cells, inducing fluctuations in its target metabolic enzymes proportionally with treatment intensity. The wound healing assay demonstrated that the cells recovered after stress conditions, showing that the ethanol-exposed cells that passed the acute step had the same proliferation profile as the cells unexposed to ethanol. Deferoxamine-treated cells displayed higher proliferative activity than the control cells in the proliferation–migration assay, emphasizing the neuroprotective effect. Cells have overcome the critical point of the alcohol-induced traumatic impact and adapted to ethanol (a chronic phenomenon), sustaining the regeneration process. However, further experiments are needed to ensure recovery efficiency is more effective in chronic ethanol exposure.
- Published
- 2023
- Full Text
- View/download PDF
43. THE ROLE OF IRRATIONAL BELIEFS AND PERCEIVED STRESS IN THE DEVELOPMENT OF DYSFUNCTIONAL ATTITUDES AMONG STUDENTS
- Author
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Simona A. PASCAL and Alina C. CHIVU
- Subjects
dysfunctional attitudes ,irrational beliefs ,mediation model ,perceived stress ,Education ,Theory and practice of education ,LB5-3640 - Abstract
The literature raises concerns in terms of the psychological functioning of the students. Their well-being can be impaired by some problems they may face, like academic, personal, financial, or social ones. Cognitive theories support the fact that at the origin of the psycho-emotional consequences lies a dysfunctional thinking pattern. It can determine how people perceive events or their attitudes regarding the situations they experience. All these aspects play an important role in mental health. Thus, the first objective of the present study was to identify possible associations between dysfunctional attitudes, irrational beliefs, and perceived stress among students. The second objective was to test whether the relationship between irrational beliefs and dysfunctional attitudes is explained by perceived stress, through a mediation model. In this research, 148 students filled in three psychological scales that measure the following constructs: dysfunctional attitudes, irrational beliefs, and perceived stress. In general, the results emphasized negative and weak associations between attitudes and cognitions (r = -.265, p = .001) and perceived stress and attitudes (r = -.167, p = .043), but a positive relationship between cognition and perceived stress (r = .312, p < .001). Also, the mediation analysis showed that there are misgivings that perceived stress does explain the relationship between irrational cognitions and dysfunctional attitudes. These preliminary findings could be an initial step in the educational environment to improve the beliefs and attitudes assessment among students by targeting them as important elements.
- Published
- 2022
- Full Text
- View/download PDF
44. Food security in a food self-sufficient economy: A review of China's ongoing transition to a zero hunger state
- Author
-
Vasilii Erokhin, Gao Tianming, Luminita Chivu, and Jean Vasile Andrei
- Subjects
access to food ,agriculture ,availability of food ,hunger ,poverty ,sustainable development ,trade ,Agriculture - Abstract
In a contemporary globalised world, assuring food security in the conditions of developing a food self-sufficient economic structure represents not only a challenge in terms of the changing agricultural paradigm, but also an important instrument in assuring, in a long-term manner, societal resilience. However, while achieving self-sufficiency in food, China still faces challenges in terms of establishing sustainable food security and transitioning to a zero hunger state. Rapid economic growth and urbanisation have resulted in shifting food consumption patterns from crops towards more nutritious meat and dairy products and higher-qualitative imported foods. In this study, the current state of food security and production and trade in food and agricultural products in China during 2000-2020 have been analysed and an overview of the strategic directions of the domestic sustainable development, food security, and zero hunger policies are highlighted. The main aim of the study is dedicated to identifying the critical shortcomings and gaps in combating hunger and food insecurity in China and proposing policy recommendations regarding improving the stability of the food supply in the country and deigning new possible strategies to achieve it. The results highlight the major trends and shifts of the food security paradigm in the process of developing a food self-sufficient economy.
- Published
- 2022
- Full Text
- View/download PDF
45. Titanium joining - a brief review of the processes used on this material
- Author
-
Corina David, Oana-Roxana Chivu, Anamaria Feier, and Silvia Hernea
- Subjects
welding ,production ,titanium ,construction of custom car parts ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
. In a few decades, titanium has gone from being used almost exclusively in top-secret aerospace projects to being used in the construction of custom car parts. Thanks to its incredibly high strength-to-weight ratio and excellent corrosion resistance, titanium will be used even more extensively in the future. There are various ways of joining titanium, one of the most used being welding. Titanium generally has good weldability, but welding it poses problems in terms of the danger of atmospheric contamination of the joint, as titanium, along with zirconium, beryllium, hafnium, and several other metals, has a high affinity for atmospheric gases. In this paper, the characteristics of titanium and its alloys will be presented, as well as the main processes for joining them by welding and a brief review of some examples.
- Published
- 2022
- Full Text
- View/download PDF
46. Study of the technology of vbration jointing of thermoplastic materials used in the automotive sector
- Author
-
Felicia Enache, Oana Roxana Chivu, Anamaria Feier, and Silvia Hernea
- Subjects
welding ,plastics ,abs ,pmma ,automotive ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
Plastics have a wide use in almost all economic areas, their appearance and use has emerged as a necessity to reduce the consumption of natural products and thus decrease the impact on the environment. In the automotive field, a wide range of plastic products are used due to the additional advantage of weight saving and the production rate of large parts, but which in the assembly process requires joint operations with each other respectively with other objects. An important factor in the studied theme was the challenge of combining 2 different PPMA and ABS materials, taking into account the advantages of each one, namely the PMMA polymer plastic material ensuring the transparency property and the ABS polymer plastic material ensuring the strength and stability of the jointed part. The study presents a part used in the automotive industry for which the process of combining the component materials was detailed
- Published
- 2022
- Full Text
- View/download PDF
47. Creating Value with Big Data in Marketing
- Author
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Moşescu, Ionuţ Adrian, Chivu, Raluca-Giorgiana, Popa, Ionuţ Claudiu, Botezatu, Florina, and Busu, Mihail, editor
- Published
- 2022
- Full Text
- View/download PDF
48. Human Resources Management - A Process Adapted to 2022
- Author
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Ionuț-Claudiu Popa, Raluca-Giorgiana (Popa) Chivu, and Florina (Mihai) Floroiu
- Subjects
hrm ,change ,strategies ,adaptation ,novelty ,Business ,HF5001-6182 ,Economics as a science ,HB71-74 - Abstract
Human Resource Management (HRM) is a collective term for all formal systems created to help manage employees and other stakeholders within an entity. Human resource management has three main functions: recruiting and compensating employees and assigning work. In the corporate world, the role of HRM is unlikely to change significantly. In this article, we have conducted quantitative research in the form of a questionnaire, and the objectives include: analyzing the opinions of specialists working in the HRM segment, highlighting the best tools that contribute to improving current HR processes and highlighting how which specialists in this field can implement in the recent activity the latest generation tools. Because of the results obtained, it can be highlighted that in Romania, the processes in the HRM area are in a comprehensive development process, that in our country, it is necessary to use policies that have proven to be successful and used. Furthermore, in public and private entities in other states, internet of things technology can be one of the tools that can be used successfully to achieve the new goals of human resource management.
- Published
- 2022
49. Analysis of the Trust Offered to Companies Based on the Number of Followers on Instagram
- Author
-
Raluca-Giorgiana (Popa) Chivu, Ionuț-Claudiu Popa, and Bianca Cristiana Voicu
- Subjects
marketing ,consumer behaviour ,instagram ,the social networking platform ,Business ,HF5001-6182 ,Economics as a science ,HB71-74 - Abstract
The presence of companies on social networks has become, in recent years, a must for attracting and retaining customers. Instagram is one of the most popular social networks, used for promotion and communication campaigns directly from the company and through "influencers". Influencers are those people who are considered role models/landmarks/people of interest by the public, promoting their values and ideas (including companies, products used, customs, etc.). In the online sphere, the more followers you have, the more credibility and importance of opium grows, which is valid for influencers and companies. In this article, we have conducted a marketing experiment to highlight how much the trust offered to companies is based on the number of followers on Instagram.
- Published
- 2022
50. Cellular gene delivery via polymeric biguanides
- Author
-
Chivu, Alexandru, Song, W., Davidson, B., and Good, L.
- Subjects
572.8 - Abstract
Controlled and efficient cell and tissue delivery of exogenous nucleic acids for the purposes of gene delivery remains an enormous technical challenge. Multiple cellular and pre-cellular barriers must be overcome for this to take effect and research into identification of potential candidates is ongoing. This project has explored the ability of widely used antiseptic poly(hexamethylene biguanide) (PHMB) to transport DNA into model mammalian cell lines HepG2, HEK293T and HeLa in vitro, under serum conditions. PHMB was shown to bind, neutralise and condense DNA at ratios above 3 (w/w), similar to the well established polymer polyethyleneimine (PEI), and form submicron particles with positive zeta potentials (> +26 mV). Particle internalisation was successful in all three cell lines in higher extent than for the PEI control. Despite this, gene expression following pEGFP-N1 and pLuciferase transfection was only significant in HEK293T, and only if the polyplex was assembled under basic conditions (pH 12). Two oligomeric biguanides - P(HMB-EEG) and P(HMB-EDSB) - were also synthesised, with the aim to improve the transfection of PHMB. Even though they also formed submicron, positively charged (+25 mV) polyplex particles above ratios 3 (w/w), their uptake properties were not as good as for PHMB. However, higher molecular weight analogues remain to be synthesised for proper comparison and assess the contribution of the biguanide moiety. The branched widely used polymers PAMAM and bPEI were also functionalised with terminal biguanide moieties. They also interacted with and neutralised DNA at ratios above 9 and 1 (w/w) respectively. PAMAM-biguanide hydroiodide presented solubility issues and due to time constraints it was not pursued, and its efficiency assessment is pending ion exchange. bPEI-biguanide promoted higher fluorescent oligodeoxynucleotide uptake compared to its nonfunctionalised (amine-terminated) counterpart, but it did not induce GFP or luciferase expression in any of the three cell lines. The current study showed that the presence of the biguanide functional group in a vector promotes uptakes of molecular cargoes it interacts with electrostatically and condenses into submicron particles.
- Published
- 2019
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