21 research outputs found

    Three-dimensional CFD-DEM simulation of raceway transport phenomena in a blast furnace

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    Improving energy efficiency in a blast furnace (BF) has a significant effect on energy consumption and pollutant emission in a steel plant. In the BF, the blast injection creates a cavity, the so-called raceway, near the inlet. On the periphery of the raceway, a ring-type zone is formed which is associated with the highest coke combustion rate and temperatures in the raceway. Therefore, predicting the raceway size or in other words, the periphery of the ring-type zone with accuracy is important for estimating the BF’s energy and coke consumption. In the present study, Computational Fluid Dynamics (CFD) is coupled to Discrete Element Method (DEM) to develop a three-dimensional (3D) model featuring a gas–solid reacting flow, to study the transport phenomena inside the raceway. The model is compared to a previously developed two-dimensional (2D) model and it is shown that the assumptions associated with a 2D model, result in an overestimation of the size of the raceway. The 3D model is then used to investigate the coke particles’ combustion and heat generation and distribution in the raceway. It is shown that a higher blast flow rate is associated with a higher reaction rate and a larger raceway. A 10% increase in the inlet velocity (from 200 m/s to 220 m/s) caused the raceway volume to grow by almost 40%. The DEM model considers a radial discretization over the particle, therefore the heat and mass distributions over the particle are analyzed as well

    A Deep Insight Into CAR-T Cell Therapy in Non-Hodgkin Lymphoma: Application, Opportunities, and Future Directions

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    Non-Hodgkin’s lymphoma (NHL) is a cancer that starts in the lymphatic system. In NHL, the important part of the immune system, a type of white blood cells called lymphocytes become cancerous. NHL subtypes include marginal zone lymphoma, small lymphocytic lymphoma, follicular lymphoma (FL), and lymphoplasmacytic lymphoma. The disease can emerge in either aggressive or indolent form. 5-year survival duration after diagnosis is poor among patients with aggressive/relapsing form of NHL. Therefore, it is necessary to understand the molecular mechanisms of pathogenesis involved in NHL establishment and progression. In the next step, we can develop innovative therapies for NHL based on our knowledge in signaling pathways, surface antigens, and tumor milieu of NHL. In the recent few decades, several treatment solutions of NHL mainly based on targeted/directed therapies have been evaluated. These approaches include B-cell receptor (BCR) signaling inhibitors, immunomodulatory agents, monoclonal antibodies (mAbs), epigenetic modulators, Bcl-2 inhibitors, checkpoint inhibitors, and T-cell therapy. In recent years, methods based on T cell immunotherapy have been considered as a novel promising anti-cancer strategy in the treatment of various types of cancers, and particularly in blood cancers. These methods could significantly increase the capacity of the immune system to induce durable anti-cancer responses in patients with chemotherapy-resistant lymphoma. One of the promising therapy methods involved in the triumph of immunotherapy is the chimeric antigen receptor (CAR) T cells with dramatically improved killing activity against tumor cells. The CAR-T cell-based anti-cancer therapy targeting a pan–B-cell marker, CD19 is recently approved by the US Food and Drug Administration (FDA) for the treatment of chemotherapy-resistant B-cell NHL. In this review, we will discuss the structure, molecular mechanisms, results of clinical trials, and the toxicity of CAR-T cell-based therapies. Also, we will criticize the clinical aspects, the treatment considerations, and the challenges and possible drawbacks of the application of CAR-T cells in the treatment of NHL

    Emerging Themes and Future Directions of Multi-Sector Nexus Research and Implementation

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    Water, energy, and food are all essential components of human societies. Collectively, their respective resource systems are interconnected in what is called the “nexus”. There is growing consensus that a holistic understanding of the interdependencies and trade-offs between these sectors and other related systems is critical to solving many of the global challenges they present. While nexus research has grown exponentially since 2011, there is no unified, overarching approach, and the implementation of concepts remains hampered by the lack of clear case studies. Here, we present the results of a collaborative thought exercise involving 75 scientists and summarize them into 10 key recommendations covering: the most critical nexus issues of today, emerging themes, and where future efforts should be directed. We conclude that a nexus community of practice to promote open communication among researchers, to maintain and share standardized datasets, and to develop applied case studies will facilitate transparent comparisons of models and encourage the adoption of nexus approaches in practice

    Global overview of the management of acute cholecystitis during the COVID-19 pandemic (CHOLECOVID study)

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    Background: This study provides a global overview of the management of patients with acute cholecystitis during the initial phase of the COVID-19 pandemic. Methods: CHOLECOVID is an international, multicentre, observational comparative study of patients admitted to hospital with acute cholecystitis during the COVID-19 pandemic. Data on management were collected for a 2-month study interval coincident with the WHO declaration of the SARS-CoV-2 pandemic and compared with an equivalent pre-pandemic time interval. Mediation analysis examined the influence of SARS-COV-2 infection on 30-day mortality. Results: This study collected data on 9783 patients with acute cholecystitis admitted to 247 hospitals across the world. The pandemic was associated with reduced availability of surgical workforce and operating facilities globally, a significant shift to worse severity of disease, and increased use of conservative management. There was a reduction (both absolute and proportionate) in the number of patients undergoing cholecystectomy from 3095 patients (56.2 per cent) pre-pandemic to 1998 patients (46.2 per cent) during the pandemic but there was no difference in 30-day all-cause mortality after cholecystectomy comparing the pre-pandemic interval with the pandemic (13 patients (0.4 per cent) pre-pandemic to 13 patients (0.6 per cent) pandemic; P = 0.355). In mediation analysis, an admission with acute cholecystitis during the pandemic was associated with a non-significant increased risk of death (OR 1.29, 95 per cent c.i. 0.93 to 1.79, P = 0.121). Conclusion: CHOLECOVID provides a unique overview of the treatment of patients with cholecystitis across the globe during the first months of the SARS-CoV-2 pandemic. The study highlights the need for system resilience in retention of elective surgical activity. Cholecystectomy was associated with a low risk of mortality and deferral of treatment results in an increase in avoidable morbidity that represents the non-COVID cost of this pandemic

    Emerging Themes and Future Directions of Multi-Sector Nexus Research and Implementation

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    Water, energy, and food are all essential components of human societies. Collectively, their respective resource systems are interconnected in what is called the “nexus”. There is growing consensus that a holistic understanding of the interdependencies and trade-offs between these sectors and other related systems is critical to solving many of the global challenges they present. While nexus research has grown exponentially since 2011, there is no unified, overarching approach, and the implementation of concepts remains hampered by the lack of clear case studies. Here, we present the results of a collaborative thought exercise involving 75 scientists and summarize them into 10 key recommendations covering: the most critical nexus issues of today, emerging themes, and where future efforts should be directed. We conclude that a nexus community of practice to promote open communication among researchers, to maintain and share standardized datasets, and to develop applied case studies will facilitate transparent comparisons of models and encourage the adoption of nexus approaches in practice

    Users’ Expectation from the User Interface Screen of an Academic Digital Library

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    The present paper investigates the E-learner’s expectations concerning the features incorporated within the user interface screen of an academic digital library. A researcher-made questionnaire was used for the survey. The sample was taken from the E-learners using this technology in Iranian universities. 200 questionnaires were distributed. The data analysis showed a general consensus about the priority of comprehensibility of the terms used in the User Interface Screen (uis) as well as the display features and clarity of the navigational functions as the usability criteria for UIS. ANOVA analysis indicated that, with the exception of navigation and guidance functions, there was no significance with respect to three categories of students. In other words, all students had similar expectations and their ICT skill is not a factor influencing the prioritization of these criteria. The results further indicated that except for the browsing page, there is no significant difference between novice, intermediate and advanced students with respect to search screen features

    Investigating the Link between self-citation and authors’ co-incidence with journal impact factors in Iran: Case study of Economic Journals indexed in Islamic Science Citation Database

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      The present paper examines the links between self-citation and authors’ co-incidence with impact factors of economic journals indexed in ISC. It is essentially a scientometric research employing citation analysis and literature survey. Data was collected by querying ISC and leafing through the journals studied. Self-citation, authors’ co-incidence and impact factor of the journal studied formed the variables. Correlation analysis indicated that there is a significance between authors’ self-citations and co-incidence with impact factor of the journals studied. Significance was also found between authors’ co-incidence and self-citation of the journals studied

    Effects of Mechanical Stirring and Ultrasound Treatment on the Separation of Graphite Electrode Materials from Copper Foils of Spent LIBs: A Comparative Study

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    In this paper, mechanical stirring and ultrasonic treatment are used to separate graphite electrode materials from copper foils in recycling spent lithium-ion batteries (LIBs). Firstly, the effects of ultrasonic power (60–180 W), ultrasonic time (1–8 min), stirring speed (420–2000 rpm), and stirring time (1–8 min) on the abscission rate of active material on copper foil were studied. It was found that the peeling-off ratio of electrode material under ultrasonic treatment was 91.34% compared with stirring treatment (84.22%). The removal of electrode material from copper foil during stirring was mainly through mechanical scrubbing. As a comparison, the generation of the microjets induced by ultrasound, the local high-temperature and high-pressure environment, and the free radicals during ultrasonic treatment are the key factors to further improve electrode material removal efficiency. An integrated ultrasound-mechanical stirrer technique can achieve a high-efficient separation performance (approximately 100% peeling-off ratio) of anode electrode materials from copper foils. The effects of mechanical stirring speed, temperature, and treatment time on the peeling-off ratios of the ultrasound-mechanical stirrer-assisted system were investigated. Finally, the results of XRF (X-ray fluorescence spectrometer), XRD (X-ray diffraction), and SEM-EDS (scanning electron microscopy coupled with energy dispersive X-ray spectroscopy) showed that the as-separated graphite electrode material had high purity and contained almost no copper foil impurities. Numerical simulation analyses briefly showed that the difference between pressure and ultrasonic temperature changes in the boundary between different anode layers (graphite on copper foil in aqueous solution) was the main effective factor in the considerable separation of graphite from copper anode foil under ultrasonic-assisted delamination

    Aryl Quinazolinone Derivatives as Novel Therapeutic Agents against Brain-Eating Amoebae

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    Naegleria fowleri and Balamuthia mandrillaris are protist pathogens that infect the central nervous system, causing primary amoebic meningoencephalitis and granulomatous amoebic encephalitis with mortality rates of over 95%. Quinazolinones and their derivatives possess a wide spectrum of biological properties, but their antiamoebic effects against brain-eating amoebae have never been tested before. In this study, we synthesized a variety of 34 novel arylquinazolinones derivatives (Q1–Q34) by altering both quinazolinone core and aryl substituents. To study the antiamoebic activity of these synthetic arylquinazolinones, amoebicidal and amoebistatic assays were performed against N. fowleri and B. mandrillaris. Moreover, amoebae-mediated host cells cytotopathogenicity and cytotoxicity assays were performed against human keratinocytes cells in vitro. The results revealed that selected arylquinazolinones derivatives decreased the viability of B. mandrillaris and N. fowleri significantly (P < 0.05) and reduced cytopathogenicity of both parasites. Furthermore, these compounds were also found to be least cytotoxic against HaCat cells. Considering that nanoparticle-based materials possess potent in vitro activity against brain-eating amoebae, we conjugated quinazolinones derivatives with silver nanoparticles and showed that activities of the drugs were enhanced successfully after conjugation. The current study suggests that quinazolinones alone as well as conjugated with silver nanoparticles may serve as potent therapeutics against brain-eating amoebae
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