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A novel time-current-temperature difference (T-I-T) defrosting control method for air source heat pump based on outdoor fan operation characteristics in space heating
No full textIn space heating, air source heat pumps (ASHPs) always encounter mal-defrosting incidents, resulting in significant energy waste. To improve the defrosting accuracy of ASHP, this paper proposes a novel Time-Current-Temperature difference (T-I-T) defrosting control method based on the characteristic parameter of outdoor fan operation (current). Through theoretical analysis and experimental tests, the influence of frosting on the characteristic parameters of outdoor fan operation was revealed. Then, based on the optimal defrosting control point theory, a method for selecting the defrosting current threshold close to the actual ASHP was proposed. Ultimately, a novel Time-Current-Temperature Difference (T-I-T) defrosting control method was developed, using the current increment to control the defrosting operation. The results showed that, the defrosting current thresholds decreased as the severity of frosting decreases, from 1.52 to 0.78 A. The T-I-T defrosting control method enables the ASHP unit to operate stably and efficiently in space heating. The defrosting frequency decreased from 0.93 to 0.56 times per hour, a reduction of 39.80 %; the average duration of the frosting/defrosting cycle increases from 64.30 to 106.90 min (an increase of 66.25 %), and the average COP of the ASHP unit increases by 10.60 % compared to the T-T defrosting control method.This work was financially supported by the National Natural Science Foundation of China (No. 52378086)
Bridging the gap: investigating discrepancies between subjective and objective sleep assessment in university students
No full textIntroduction
Sleep quality among university students is crucial for academic success and overall well-being. This study investigated the discrepancies between subjective and objective sleep assessment in university students and explored associated factors.
Method
A total of 19 male university students (mean age: 25 ± 3 years; mean weight: 79.36 ± 15.18 kg; mean height: 1.77 ± 0.09 m; mean body mass index: 25.09 ± 3.99) participated, providing subjective self-reports and objective measurements of sleep quality. Actigraphy was utilized to objectively assess sleep patterns. Statistical analysis included descriptive statistics, Pearson correlation analysis, and a linear mixed-effects model to examine associations between subjective and objective sleep measures and academic performance.
Results
Significant associations between subjective and objective sleep measures were found, with higher academic performance linked to better sleep efficiency. However, subjective sleep quality metrics did not significantly predict sleep efficiency. Objective measures, such as total sleep time and wake after sleep onset, were significant predictors of sleep efficiency.
Discussion
These findings underscore the importance of subjective and objective sleep assessments in understanding sleep quality among university students.This work was supported by Qatar University under Collaborative Grant QUCG-CED-21-22-1 & QUCG-CED-24_25-495. The authors would like to thank all the participants for taking part in this study. The authors gratefully acknowledge the assistance of ChatGPT 4, an artificial intelligence language model developed by OpenAI, for its invaluable support in correcting flaws and refining sentences throughout the writing process of this manuscript. After using this tool, the authors reviewed and edited the content as needed, and take full responsibility for the content of the publication.Scopu
A BRET-based Mpro biosensor containing a nanobody and tandem cleavage sites shows an increased cleavage rate
Get PDFHere, we report the engineering of a Bioluminescence Resonance Energy Transfer (BRET)-based SARS-CoV-2 main protease (Mpro) biosensor containing the Mpro N-terminal autocleavage sequence in tandem and a nanobody that shows an enhanced rate of Mpro-mediated proteolytic cleavage. Specifically, we designed Mpro biosensors containing 2×, 4× and 8× repeats of Mpro N-terminal autocleavage sequences and a combination of Mpro cleavage sequences containing a total of 12 cleavage sites sandwiched between mNeonGreen (mNG) and NanoLuc (NLuc). Gaussian accelerated molecular dynamics (GaMD) simulations of the predicted alpha-helical synthetic Mpro cleavage sequences revealed a dynamic nature of the cleavage sequences, which is critical for their efficient cleavage, and a relatively short end-to-end distances, which is required for high BRET. Live cell assays revealed a cleavage sequence length-dependent resonance energy transfer, except for the 12× -syn cleavage site, and an increased rate of cleavage and a decreased pharmacological inhibitor efficacy for the Mpro biosensor containing 2× cleavage sequences. Further, mutational analysis revealed a requirement for both cleavage sites to be intact for increased cleavage rate. Importantly, the inclusion of an Mpro-binding, but non-inhibiting, NB2E3 nanobody at the N-terminal further increased the cleavage rate of the 2× cleavage sequence-containing Mpro biosensor. We envisage that the NB2E3 nanobody-2× Mpro biosensor engineered here will be useful in drug discovery and functional characterization of Mpro mutants in newly emerging SARS-CoV-2 variants as well as in detecting SARS-CoV-2 infection in a point-of-care testing (POCT) format.This work is supported by the Undergraduate Research Experience Program (UREP) grant (# 28–264–3–092) awarded by the Qatar National Research Foundation (QNRF), Qatar Foundation and an internal funding from the College of Health & Life Sciences (CHLS), Hamad Bin Khalifa University (HBKU), a member of the Qatar Foundation. Some of the computational research work reported in the manuscript were performed using high-performance computer resources and services provided by the Research Computing group in Texas A&M University at Qatar. Research Computing is funded by the Qatar Foundation for Education, Science and Community Development (http://www.qf.org.qa). A.M.G. was supported by a postdoctoral fellowship from CHLS/HBKU. A.S., A.F., and S.M.N.U. were supported by scholarships from CHLS/HBKU
Landmarks of Terminological and Conceptual Renewal in Yūsuf al-Qaraḍāwī (Renewal, Jurisprudence, and the Umma)
Get PDFأهداف البحث: اشترع العلامة القرضاوي معالم وصوًى لتجديد المفاهيم والمصطلحات في عالم الوعي ومساحة السعي؛ تأصيلًا للتصورات وتنزيلًا للتصرفات، محتكمًا إلى منهجية علمية تستقرئ سياقات اللغة وتطورها التاريخي، وتستوعب نصوص الوحيين، واستعمالات التراث، وتستصحب مقاصد الشارع، وغايات الواضع، وتستجيب لإشكالات الواقع، وتستشرف تحديات المستقبل.
فهدفت هذه الدراسة إلى بيان منهج القرضاوي في تجديد ثلاثة مفاهيم ومصطلحات، وهي: (التجديد، الأمة، الفقه)، ولتسليط الضوء على معانيها وآفاق تجديدها بنهج وسطي واستيعاب شمولي ونظر إبداعي؛ لينسج الباحثون والعلماء على ذات المنوال ويضيفون في هذه المسارات، استنادا إلى هذا المنهج الرحيب.
منهج الدراسة: اعتمدت الدراسة على المنهج الاستقرائي لتراث القرضاوي وكتبه ومحاضراته، والمنهج التحليلي لها.
النتائج: أبرز البحث منهج التجديد عند القرضاوي في المفاهيم، وبين محدداته ومعالمه، كما كشفت الدراسة شدة اهتمام الشيخ بحقل المفاهيم والمصطلحات تأصيلًا وتنزيلًا، ونقدًا وتجديدًا.
أصالة البحث: تحفل المكتبة الإسلامية بكتابات القرضاوي كما أن الكتابات والدراسات المتعلقة بفقهه ومشروعه الفكري تكاد تفوت الحصر، غير أن هذه الدراسة تركز على موضوع المفاهيم والمصطلحات، وتتخصص في مفاهيم نموذجية اشتغل عليها القرضاوي في مختلف مصنفاته، وتحليل منهج التجديد فيها.Objectives: Al-Qaraḍāwī established principles and guidelines for modernizing concepts and terminology, with the goal of fostering their sound understanding and effective application. His approach follows a systematic method that considers the context and historical development of language. He incorporates insights from the Qur’an and the Sunna, references traditional usage, and keeps the goals of the Sharia and the intentions of the lawgiver in mind. His methodology is responsive to current issues and looks ahead to future challenges. This study seeks to explore al-Qaraḍāwī’s approach to renewing three key concepts: ‘renewal’, ‘umma’ (the Islamic community), and ‘jurisprudence’. It aims to clarify their meanings and the potential for their renewal through a balanced approach that values both depth and creativity. The study intends to offer a model that researchers and scholars can use to further develop and expand these areas within an inclusive framework.Methodology: This study relies on an inductive approach to explore al-Qaraḍāwī’s legacy, including his books and lectures, as well as an analytical approach to examining these sources.Results: The article highlights al-Qaraḍāwī’s approach to renewal in conceptual terms, outlining its guidelines and characteristics. It also reveals his deep focus on terminology, emphasising foundational understanding, practical application, as well as critique and renewal.Originality: Although there is a wealth of Islamic scholarship on al-Qaraḍāwī’s jurisprudential and intellectual work, this study focuses on his approach to concepts and terminology. It examines crucial ideas he developed in his writings and how he approached updating them
DEEP LEARNING IN ENDOMETRIAL CANCER: PREDICTING MALIGNANCY FROM HISTOPATHOLOGICAL IMAGES OF QATARI PATIENTS.
No full textEndometrial cancer is the second most common gynecological malignancy, and an accurate diagnosis is essential for determining appropriate treatment and improving patient outcomes. Traditional diagnostic methods rely on histopathological examination, which can be subjective and prone to variability. Deep learning techniques have emerged as powerful tools to automate and enhance diagnostic workflows in pathology. This study assesses the performance of a deep learning model in predicting malignancy in endometrial cancer using digitized hematoxylin and eosin (H&E) stained histopathological slides from Qatari patients. A retrospective analysis was conducted on 1,312 slides from 70 patients, which were scanned using a slide scanner to obtain high-quality digitized images. Through a collaborative effort with expert pathologists, we classified 880 images as benign or malignant, which were then divided into training (60%, 527 images), validation (20%, 176 images), and test (20%, 177 images) sets. Our study employed the deep learning model-MobileNetV2, a convolutional neural network (CNN)-to classify the tissue samples. The model's training accuracy improved from 75% at epoch 0 to 95% by epoch 50. On the test set, the model achieved an overall accuracy of 90.96%, with a precision of 90.22%, a recall of 92.22%, and an F1-score of 91.21%. The confusion matrix revealed that 83 out of 90 malignant cases and 78 out of 87 benign cases were correctly classified, with 9 false positives and 7 false negatives. These detailed quantitative results underscore the effectiveness of our deep learning approach in accurately distinguishing between benign and malignant endometrial tissues, highlighting its potential for integration into clinical practice to enhance diagnostic precision and support clinical decision-making. Moreover, this method can assist in prioritizing cases for review, ensuring that high-risk samples receive immediate attention, which is critical for timely patient management. Importantly, by using locally sourced data from Qatari patients, our findings lay the foundation for developing a region-specific deep learning model that captures the unique histopathological nuances present in this population. Such a model could further optimize diagnostic accuracy and ultimately contribute to improved patient outcomes in Qatar, providing a valuable tool for personalized and efficient cancer care in the future
Assessing the Relationship Between the Type of Internet Use and Internet Addiction in Early and Middle Adolescents: Cross-Sectional Study From Qatar
Get PDFBackground: With the increasing prevalence of digital technology, adolescent internet addiction (IA) has become a global concern. Excessive internet use, especially among adolescents, has been linked to various negative outcomes such as poor academic performance, social isolation, and mental health issues. Conducted among adolescents of Arab origin, our study addressed the limitations of the literature, which predominantly focuses on Western, educated, industrialized, rich, and democratic populations. Objective: This study aimed to differentiate between essential and nonessential internet use and how they relate to IA in early and middle adolescents, as well as the relationship between subjective happiness with the amount of time spent on nonessential internet use and IA. Methods: A cross-sectional survey was conducted among 377 students from 16 schools in Qatar. The survey measured essential and nonessential internet use, subjective happiness with nonessential use, and IA symptoms using the Internet Addiction Diagnostic Questionnaire, as well as participant demographics. To explore age-specific associations, participants were categorized into early (age 11-13 years) and middle (age 14-17 years) adolescents. Factorial analysis, multiple regression, and logistic regression were used for statistical analysis. Results: Nonessential internet use significantly predicted IA in both early (P<.001) and middle (P<.001) adolescents, with early adolescents showing a stronger association. Subjective happiness with nonessential internet use negatively predicted IA only in middle adolescents (P<.001) as greater dissatisfaction led to a higher IA risk. Essential internet use did not predict IA in either group. Conclusions: Differentiating between essential and nonessential internet use is crucial in understanding IA. This study highlights the importance of developmental differences in shaping IA symptoms. The findings suggest that interventions aimed at addressing IA should be age specific and focus on addressing nonessential use specifically rather than considering internet use and screen time in general as a single entity. Cultural and regional factors also play a role in shaping internet use patterns and IA in the Middle East, necessitating context-specific, culturally sensitive approaches to IA prevention
Evaluating the effectiveness and risks of bread fortification programs in the middle eastern region: a comprehensive review
Get PDFFortification of staple foods such as bread has been implemented as a public health strategy to address nutrient deficiencies. Currently, 11 out of 22 Middle Eastern countries have mandatory wheat flour fortification, primarily with iron and folic acid, while others have voluntary initiatives. Despite progress in bread fortification efforts across the Middle East the long-term effectiveness and safety of these programs remain unclear. We assess the historical context, existing policies, and standards of fortification, focusing on public health outcomes, implementation challenges, and potential risks. A comprehensive search in PubMed, MEDLINE, Cochrane, and ProQuest databases, and relevant studies from the inception of the fortification efforts till 2024 were selected. Our search included Bread or flour fortification and their effectiveness and potential risks specific to Middle Eastern Regions. Findings from the literature indicate that fortification was effective in combating micronutrient deficiencies without causing the harmful effects of overload. However, ongoing research is needed to monitor potential risks, such as micronutrient overload. Most studies are concentrated in Egypt and Iran, with limited data from Saudi Arabia, Turkey, and Jordan, and a notable absence of research from other Middle Eastern countries. This highlights the need for further studies across a wider range of countries to provide a more comprehensive understanding of the regional impact and effectiveness of fortification policies. Addressing the challenges of inadequate coverage, compliance issues, and infrastructure limitations could provide a more comprehensive understanding of the region's fortification policies and their effectiveness.Scopu
Reply to Editorial Comment on “Hypospadias Reconstruction Training: Development of an Ex-Vivo Model for Objective Evaluation of Surgical Skills”
No full textW e sincerely appreciate the thoughtful feedback provided. The objective nature of the
comments aligns closely with the goals of our
work. As noted, this study1 was primarily aimed at
evaluating technical skills in a hypospadias reconstruction model using EMG monitoring technology coupled
with machine learning, which we believe presents a
significant step forward in the objective assessment of
surgical competence.
Our primary aim was to assess skill acquisition across a
wide range of experience levels, rather than focusing on a
single group. This allowed us to explore how EMG data
could capture measurable differences in skill gained from
the course across different ranges of expertise. However,
we acknowledge that the study was not specifically designed to delineate distinct trainee levels—novice, intermediate, or expert—which would further enhance the
construct validity of the technology.
We fully agree with your insightful observation that a
future study focusing specifically on differences between
trainees at various stages of training would add substantial value. Such research would enhance the use of
EMG data in objectively assessing skill progression and
readiness for independent practice. We are actively
considering a follow-up study designed to address this
aspect
Failure Mode Effects Analysis and Design of Experiments to Sensitive and Sustainable Microwave-Aided Spectrofluorophotometric Estimation of Teneligliptin and Method's Chlor-Tox Scale and Blue Applicability Grade Index Assessment
No full textTeneligliptin hydrobromide hydrate is efficiently controls blood sugar levels while minimizing the risk of hypoglycemia. Determination of teneligliptin in commercial formulations and biological-fluids has been documented in literature using a plethora of chromatographic, spectrophotometric, and hyphenated methods and they required toxic organic solvents. But, there was no published spectrofluorophotometric technique for teneligliptin estimation. Hence, microwave-aided spectrofluorophotometric method was developed to estimate teneligliptin with using green solvents and 7-chloro-4-nitrobenzoxadiazole as a fluorescent probe. An integrated approach of white analytical chemistry and analytical quality by design was used to estimate teneligliptin in a robust, accurate, and precise manner. The failure mode effect analysis was used to identify the critical analytical method parameters and response variables. The design of experiments was used to carry forward the important analytical method parameters and response variables for response surface modeling. The proposed spectrofluorophotometric method was applied to evaluate commercially available formulations and investigate the pharmacokinetics of teneligliptin–loaded nano-carriers that was developed in-house. The fluorescent product that was derivatized using microwaves was separated and studied using mass spectrometry. After greenness and whiteness profile assessment, researchers discovered that the suggested approach to teneligliptin estimate was eco-friendly, precise, robust, rapid, economical, and easy to apply
Joint analysis of diet quality, inflammatory potential of diet and ultra-processed food exposure in relation to chronic respiratory diseases and lung cancer mortality
No full textObjectiveExamined the combined effects of ultra-processed food (UPF), Dietary Inflammatory Index (DII), Healthy Eating Index-2015 (HEI-2015), and Dietary Antioxidant Index (DAI) on mortality from chronic respiratory diseases (CRDs), chronic obstructive pulmonary disease (COPD), and lung cancer. MethodsA prospective analysis included 96,607 participants (53 % women). Diet intake was measured using food frequency questionnaire. Associations of dietary exposures with CRD, COPD, and lung cancer mortality were examined using Cox regression. ResultsDuring 1,459,299 person-years of follow-up, there were 30,623 all-cause deaths, including 5218 from CRDs, 1613 from COPD, and 2127 from lung cancer. A 10 % increase in UPF intake (% grams/day) showed a non-linear association with higher CRD and COPD mortality but not lung cancer. Stronger curvature was observed between DII and mortality from all three conditions. However, HEI-2015 was inversely associated with CRD, COPD, and lung cancer mortality, while DAI showed an inverse relationship with CRD and COPD mortality but not lung cancer. Adjusting for DII attenuated UPF-related mortality risks by 39 % (CRD), 11 % (COPD), and 18 % (lung cancer), while HEI-2015 adjustment showed less attenuation. Additionally, the DII-mortality associations were less attenuated after adjusting for UPF intake but were offset after adjusting for HEI-2015. However, the HEI-2015-mortality associations remained unaffected when adjusted for UPF, DII, or DAI. ConclusionsThe findings highlight that the UPF-mortality relationship is potentially explained by DII and, to a lesser extent, by HEI-2015. Adhering to HEI-2015 guidelines can counterbalance the effects of DII on respiratory health but may not offset the effects associated with UPF.YAM is supported by a National Health and Medical Research Council Emerging Leadership Fellowship (2009776)