59 research outputs found

    A Model for Complex Heat and Mass Transport Involving Porous Media with Related Applications

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    Heat and mass transfer involving porous media is prevalent in, for example, air-conditioning, drying, food storage, and chemical processing. Such applications require non-equilibrium heat and mass (or moisture) transfer modeling inside porous media in conjugate fluid/porous/solid framework. Moreover, modeling of turbulence and turbulent heat and mass transfer becomes essential for many applications. A comprehensive literature review shows a scarcity of models having such capabilities. In this respect, the objectives of the present thesis are to: i) develop a formulation that simulates non-equilibrium heat and mass transfer in conjugate fluid/porous/solid framework, ii) demonstrate the capabilities of the developed formulation by simulating complex related problems, and iii) extend the developed model to such class of problems that involve turbulence and turbulent heat and mass transfer. To develop the required formulation, we first specify transport equations for each region. In the fluid region, mass, momentum, energy, and water vapour transport equations are solved to model flow and energy of moist air-vapour mixture. The volume-averaged version of these equations form the model for the fluid-constituent of porous media, while the transport equations of energy and water mass fraction are solved inside the solid-constituent of porous media and solid region. Mathematical conditions are developed at all the interfaces to ensure smooth transport of relevant quantities across the interfaces. The developed formulation is demonstrated and validated by simulating the problems of evaporative cooling and convective drying of wet porous materials. In this respect, each simulated case demonstrates critical aspects of the developed formulation. Moreover, the simulated cases are found to be in excellent agreement with experimental data. The developed formulation is extended to turbulent flow regimes often encountered in heat and mass transfer problems related to food stacks. In this respect, the closure is obtained for the macroscopic turbulence and turbulent non-equilibrium heat and mass transfer model inside porous media composed of randomly packed spheres. The closure is obtained by simulating the problem at the pore-level scale of a bed of randomly-packed spheres. Lastly, the closure results are presented in the form of power law-based correlations to be utilized in the macroscopic model

    The randomized clinical trial trustworthiness crisis

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    Background The rising number of retracted randomised clinical trials (RCTs) is a concern over their trustworthiness. In today’s digital landscape electronic observational data is easily accessible for research purposes. This emerging perspective, in tandem with the growing scrutiny of RCT credibility, may steer some researchers towards favouring non-randomized studies. It is crucial to emphasize the ongoing need for robust RCTs, shedding light on the areas within trial design that require enhancements and addressing existing gaps in trial execution. Main body Evidence-based medicine pivots on the nexus between empirical medical research and the theoretical and applied facets of clinical care. Healthcare systems regularly amass patient data, creating a vast reservoir of information. This facilitates large-scale observational studies, which may appear as potential substitutes for RCTs. These large-scale studies inherently possess biases that place them a notch below randomized evidence. Honest errors, data manipulation, lapses in professionalism, and methodological shortcomings tarnish the integrity of RCTs, compromising trust in trials. Research institutions, funding agencies, journal editors and other stakeholders have the responsibility to establish robust frameworks to prevent both deliberate and inadvertent mishandling of RCT design, conduct and analysis. Systematic reviews that collate robust RCTs are invaluable. They amalgamate superior evidence instrumental in improving patient outcomes via informed health policy decisions. For systematic reviews to continue to retain trust, validated integrity assessment tools must be developed and routinely applied. This way it will be possible to prevent false or untrustworthy research from becoming part of the recommendations based on the evidence. Conclusion High-quality RCTs and their systematic reviews play a crucial role in acquiring valid and reliable evidence that is instrumental in improving patient outcomes. They provide vital information on healthcare effectiveness, and their trustworthiness is key to evidence-based medicine.Beatriz Galindo (senior modality) programme of the Spanish Ministry of Educatio

    Fine-grained sentiment analysis for measuring customer satisfaction using an extended set of fuzzy linguistic hedges

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    © 2020 The Authors. Published by Atlantis Press SARL. In recent years, the boom in social media sites such as Facebook and Twitter has brought people together for the sharing of opinions, sentiments, emotions, and experiences about products, events, politics, and other topics. In particular, sentiment-based applications are growing in popularity among individuals and businesses for the making of purchase decisions. Fuzzy-based sentiment analysis aims at classifying customer sentiment at a fine-grained level. This study deals with the development of a fuzzy-based sentiment analysis by extending fuzzy hedges and rule-sets for a more efficient classification of customer sentiment and satisfaction. Prior studies have used a limited number of linguistic hedges and polarity classes in their rule-sets, resulting in the degraded efficiency of their fuzzy-based sentiment analysis systems. The proposed analysis of the current study classifies customer reviews using fuzzy linguistic hedges and an extended rule-set with seven sentiment analysis classes, namely extremely positive, very positive, positive, neutral, negative, very negative, and extremely negative. Then, a fuzzy logic system is applied to measure customer satisfaction at a fine-grained level. The experimental results demonstrate that the proposed analysis has an improved performance over the baseline works

    Antistaphylococcal and biofilm inhibitory activities of acetyl-11-keto-β-boswellic acid from Boswellia serrata

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    <p>Abstract</p> <p>Background</p> <p>Boswellic acids are pentacyclic triterpenes, which are produced in plants belonging to the genus <it>Boswellia</it>. Boswellic acids appear in the resin exudates of the plant and it makes up 25-35% of the resin. β-boswellic acid, 11-keto-β-boswellic acid and acetyl-11-keto-β-boswellic acid have been implicated in apoptosis of cancer cells, particularly that of brain tumors and cells affected by leukemia or colon cancer. These molecules are also associated with potent antimicrobial activities. The present study describes the antimicrobial activities of boswellic acid molecules against 112 pathogenic bacterial isolates including ATCC strains. Acetyl-11-keto-β-boswellic acid (AKBA), which exhibited the most potent antibacterial activity, was further evaluated in time kill studies, postantibiotic effect (PAE) and biofilm susceptibility assay. The mechanism of action of AKBA was investigated by propidium iodide uptake, leakage of 260 and 280 nm absorbing material assays.</p> <p>Results</p> <p>AKBA was found to be the most active compound showing an MIC range of 2-8 μg/ml against the entire gram positive bacterial pathogens tested. It exhibited concentration dependent killing of <it>Staphylococcus aureus </it>ATCC 29213 up to 8 × MIC and also demonstrated postantibiotic effect (PAE) of 4.8 h at 2 × MIC. Furthermore, AKBA inhibited the formation of biofilms generated by <it>S. aureus </it>and <it>Staphylococcus epidermidis </it>and also reduced the preformed biofilms by these bacteria. Increased uptake of propidium iodide and leakage of 260 and 280 nm absorbing material by AKBA treated cells of <it>S aureus </it>indicating that the antibacterial mode of action of AKBA probably occurred via disruption of microbial membrane structure.</p> <p>Conclusions</p> <p>This study supported the potential use of AKBA in treating <it>S. aureus </it>infections. AKBA can be further exploited to evolve potential lead compounds in the discovery of new anti-Gram-positive and anti-biofilm agents.</p

    Drug overdose: a wake up call! Experience at a tertiary care centre in Karachi, Pakistan

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    OBJECTIVE: To study the characteristics of patients admitted with drug overdose caused either by accidental overdose of the prescribed medications or as an act of deliberate self harm (DSH) at a tertiary care hospital in Karachi, Pakistan.METHODS: A retrospective case series review was conducted at the Aga Khan University Hospital from January 2002 to October 2006. Three hundred and twenty four adult patients admitted with drug overdose were included in the study.RESULTS: Our sample group revealed mean age of 36.2 +/- 17.0 years, more females (59%), housewives (34%), and students (20%). Fifty six percent of patients committing DSH were married (p = 0.001), 81% needed in-patient psychiatric services (p = 0.016) of whom a significantly high number (38%) refused it. Domestic and social issues were rated highest among DSH group (p = 0.003), depression among females was common (p = 0.028) and Benzodiazepines (41%) was the most frequently used drug (p = 0.021). Sub-group analysis of accidental overdoses revealed mean age of 45.6 +/- 19.6 years, single (75.4%) and males (54.1%). Drugs used were mainly Benzodiazepines (18%) followed by Opioids (11%), Antiepileptics (10%) and Warfarin (10%).CONCLUSION: Our study showed that depressed housewives are at greater risk for DSH. Domestic and social issues were rated highest and Benzodiazepines were the most commonly used agents. Most of our patients refused inpatient psychiatric treatment leading us to believe that general awareness of psychiatric illnesses is imperative in our community. High number of accidental overdoses is alarming in older, single males convincing us to believe that existing pharmacy system needs further evaluation and modification

    PD-1 and PD-L1: architects of immune symphony and immunotherapy breakthroughs in cancer treatment

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    PD-1 (Programmed Cell Death Protein-1) and PD-L1 (Programmed Cell Death Ligand-1) play a crucial role in regulating the immune system and preventing autoimmunity. Cancer cells can manipulate this system, allowing them to escape immune detection and promote tumor growth. Therapies targeting the PD-1/PD-L1 pathway have transformed cancer treatment and have demonstrated significant effectiveness against various cancer types. This study delves into the structure and signaling dynamics of PD-1 and its ligands PD-L1/PD-L2, the diverse PD-1/PD-L1 inhibitors and their efficacy, and the resistance observed in some patients. Furthermore, this study explored the challenges associated with the PD-1/PD-L1 inhibitor treatment approach. Recent advancements in the combination of immunotherapy with chemotherapy, radiation, and surgical procedures to enhance patient outcomes have also been highlighted. Overall, this study offers an in-depth overview of the significance of PD-1/PD-L1 in cancer immunotherapy and its future implications in oncology

    A qualitative study exploring perceptions and attitudes of community pharmacists about extended pharmacy services in Lahore, Pakistan

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    Background In recent decades, community pharmacies reported a change of business model, whereby a shift from traditional services to the provision of extended roles was observed. However, such delivery of extended pharmacy services (EPS) is reported from the developed world, and there is scarcity of information from the developing nations. Within this context, the present study was aimed to explore knowledge, perception and attitude of community pharmacists (CPs) about EPS and their readiness and acceptance for practice change in the city of Lahore, Pakistan. Methods A qualitative approach was used to gain an in-depth knowledge of the issues. By using a semi-structured interview guide, 12 CPs practicing in the city of Lahore, Pakistan were conveniently selected. All interviews were audio-taped, transcribed verbatim, and were then analyzed for thematic contents by the standard content analysis framework. Results Thematic content analysis yielded five major themes. (1) Familiarity with EPS, (2) current practice of EPS, (3) training needed to provide EPS, (4) acceptance of EPS and (5) barriers toward EPS. Majority of the CPs were unaware of EPS and only a handful had the concept of extended services. Although majority of our study respondents were unaware of pharmaceutical care, they were ready to accept practice change if provided with the required skills and training. Lack of personal knowledge, poor public awareness, inadequate physician-pharmacist collaboration and deprived salary structures were reported as barriers towards the provision of EPS at the practice settings. Conclusion Although the study reported poor awareness towards EPS, the findings indicated a number of key themes that can be used in establishing the concept of EPS in Pakistan. Over all, CPs reported a positive attitude toward practice change provided to the support and facilitation of health and community based agencies in Pakistan
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