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Onion pollenkitt: Function, DNase activity, fatty acid composition, and SEM imaging
Pollenkitt, a sticky substance produced by the tapetal cells of pollen grains, plays a crucial role in pollen functionality, yet it remains an understudied component in plant biology. In this study, we investigated the role of pollenkitt in onion (Allium cepa) pollen, focusing on its effects on pollen germination, DNase activity, fatty acid composition, and ultrastructure. Our findings reveal that pollenkitt is essential for successful onion pollen germination and tube growth on the stigma, as its removal significantly inhibited these processes. Additionally, we demonstrated that onion pollenkitt exhibits DNase activity, degrading plasmid DNA in a concentration-dependent manner, with EDTA effectively inhibiting the degradation. Gas chromatography identified 20 fatty acids in pollenkitt, with a predominance of unsaturated fatty acids. Using scanning electron microscopy (SEM), we showed structural differences between pollen grains with and without pollenkitt, and we observed the process of pollenkitt removal from the surface of pollen grains by water washing. These results offer valuable insights for future research aimed at optimizing pollen-mediated gene-editing systems and highlight the importance of considering pollenkitt in such applications.
Unveiling the origins of elastic anisotropy and thermodynamic stability in Mg Zn alloy strengthening phases via first principles
Abstract This study systematically investigates the elastic anisotropy and thermodynamic properties of $$\:{{\upbeta\:}}_{1}^{{\prime\:}}$$ phase in Mg-Zn alloys through first-principles calculations combined with Debye-Grüneisen theory. Three critical intermetallic phases - monoclinic Mg4Zn7, cubic MgZn2 (C-MgZn2), and hexagonal MgZn2 (H-MgZn2) phases were comparatively analyzed. Electronic structure analysis reveals that C-MgZn2 and H-MgZn2 exhibit stronger chemical bonding stability compared to Mg4Zn7. Phonon dispersion characteristics demonstrate distinct vibrational patterns: C-MgZn2 and Mg4Zn7 display enhanced phonon modes at both low and high frequency ranges, while H-MgZn2 shows predominant medium-frequency vibrational modes. Elastic anisotropy evaluation identifies Mg4Zn7 as moderately anisotropic, H-MgZn2 as significantly anisotropic, and C-MgZn2 as nearly isotropic. Thermodynamic analysis predicts superior thermal stability for C-MgZn2, evidenced by its highest Debye temperature (θd = 366 K), maximum sound velocity (vm=3.468 m/s), and minimal Grüneisen parameter (γ = 0.641), correlating with its exceptional thermal conductivity. In contrast, Mg4Zn7 exhibits the highest thermal expansion coefficient among the investigated phases. These findings establish fundamental structure-property relationships that advance the understanding of $$\:{{\upbeta\:}}_{1}^{{\prime\:}}$$ phase stabilization mechanisms, providing critical guidance for designing high-performance Mg-Zn alloys through phase engineering strategies.
Qualitative phytochemical profiling, and in vitro antimicrobial and antioxidant activity of Psidium guajava (Guava)
Psidium guajava is a well-known tropic tree, widely cultivated for its fruits, and traditionally, it has long been used for medicinal purposes. For instance, its fruit peels are also being used to alleviate stomach cramps in Namibia and its leaves-derived aqueous extract are used to treat Candidiasis (yeast infection) caused by Candida albicans in some parts of the world. Therefore, this study identified the phytochemical compounds in Psidium guajava leaf and fruit peels extracts, determined its antioxidant and antimicrobial activities. Psidium guajava leaves and fruit peels extracts were obtained using five solvents (Acetone, methanol, aqueous acetone, aqueous methanol and water) via maceration and boiling extraction methods. The extracts were then subjected to phytochemical screening, Gas chromatography-Mass spectrometry, Fourier Transform Infrared Spectroscopy, antioxidant, and antimicrobial analyses (against pathogenic bacteria: Escherichia coli, Salmonella spp., Staphylococcus aureus and fungus; Candida albicans). The qualitative phytochemical screening revealed the presence of alkaloids, flavonoids, phenols, tannins, steroids, saponins and terpenoids, and some of their associated functional groups were revealed by Fourier transform infrared spectroscopy analysis. Gas chromatography-Mass spectrometry analysis identified various compounds with antimicrobial and antioxidant properties. The different crude extracts exhibited varying inhibitory effects against the selected pathogens, with the leave extracts exhibiting the highest antimicrobial activity whereas, the peel extract exhibited the highest antioxidant activity. This study thus highlights Psidium guajava’s intriguing therapeutic contribution towards the survival of humankind and it can be strategized for future use to treat pathogenic bacterial diseases.
Evaluation of climate indices related to water resources in Iran over the past 3 decades
Assessment of antigen immunogenicity formulated in minigenes transfected into antigen-presenting cells
Tumor cells exhibit deficient antigen presentation to T cells, significantly contributing to immune evasion and tumor genesis. Peptide pulsed Antigen-presenting cells (APCs) are commonly used in cancer immunotherapy to circumvent the defects of tumor cells in processing and presenting antigens to T lymphocytes. However, peptides do not always represent epitopes naturally processed by tumor cells, which might reduce the identification of actual immunogenic antigens. Minigenes encoding concatenated immunogenic tumor epitope sequences offer a promising alternative to select tumor antigens naturally processed and presented to T cells. Hence, using APCs transfected with minigenes might contribute to immunotherapy’s effectiveness, avoiding non-naturally processed epitopes as vaccine candidates. This study evaluates APCs transfected with a minigene construct encoding HLA-A0201-restricted immunogenic antigens to stimulate antigen-specific CD8+ T lymphocytes in vitro. Artificial APCs (aAPCs) were also designed by co-transfecting the HEK293 cell line with plasmids encoding co-stimulatory molecules (CD80, CD83, CD137L) to assess CD8+ T cell activation efficiency, intracellular cytokine production, cytotoxic activity, activation and exhaustion marker expression. In this study, we successfully implemented a transfection methodology of HEK293 cells with a minigene encoding viral and tumor HLA-A * 0201 epitopes. These cells, used as aAPCs, allow studying the expansion and the phenotype of antigen-specific CD8+ T cells. However, our results indicate that epitope presentation alone is sufficient to activate CD8+ T cells, suggesting that the presence of co-stimulatory molecules may not be necessary for effective T cell activation. Considering that the use of HEK293 cells as aAPCs has yet to be explored and due to their high transfection efficiency with minigenes, the methodology implemented in this work enables their use to identify naturally processed immunogenic neoantigens. We believe our findings can contribute to selecting and designing personalized vaccines based on tumor neoantigens that are useful for cancer immunotherapy.
Exploring peculiarities and performance predictors of character strengths in individual and team sports
Abstract Research has indicated that character strengths are relevant to well-being and performance across various life domains; however, they have rarely been considered in the context of sports. The present study examined the potential of character strengths, meaning positive and personally fulfilling traits, in predicting (a) participation in individual/team sports and (b) competition levels among athletes in both individual and team sports. A sample of 683 adults (50.7% women; mean age = 27.9 years), including individual (n = 284) and team sports (n = 399) athletes engaged in different sports and competition levels, completed self-reports assessing their sporting backgrounds. Additionally, the VIA-120 (Values in Action Inventory of Strengths) was employed to measure the 24 character strengths in the VIA classification. The results reveal that (a) a set of character strengths significantly contributes to predicting individual/team sport participation and (b) adding character strengths to the prediction of performance levels leads to a small, albeit non-significant, increase in explained variances. These findings help guide future research on the mechanisms linking character strengths and sports participation and inform the design of personality development and other interventions in sports. While valuable insights are provided, character strengths research in sports should be expanded to include well-being-related outcomes and different methodologies.
The use of brain-machine interface, motor imagery, and action observation in the rehabilitation of individuals with Parkinson’s disease: A protocol study for a randomized clinical trial
Background Parkinson’s disease (PD) is a neurodegenerative condition that impacts motor planning and control of the upper limbs (UL) and leads to cognitive impairments. Rehabilitation approaches, including motor imagery (MI) and action observation (AO), along with the use of brain-machine interfaces (BMI), are essential in the PD population to enhance neuroplasticity and mitigate symptoms. Objective To provide a description of a rehabilitation protocol for evaluating the effects of isolated and combined applications of MI and action observation (AO), along with BMI, on upper limb (UL) motor changes and cognitive function in PD. Methods This study provides a detailed protocol for a single-blinded, randomized clinical trial. After selection, participants will be randomly assigned to one of five experimental groups. Each participant will be assessed at three points: pre-intervention, post-intervention, and at a follow-up four weeks after the intervention ends. The intervention consists of 10 sessions, each lasting approximately 60 minutes. Expected results The primary outcome expected is an improvement in the Test d’Évaluation des Membres Supérieurs de Personnes Âgées score, accompanied by a reduction in task execution time. Secondary outcomes include motor symptoms in the upper limbs, assessed via the Unified Parkinson’s Disease Rating Scale - Part III and the 9-Hole Peg Test; cognitive function, assessed with the PD Cognitive Rating Scale; and occupational performance, assessed with the Canadian Occupational Performance Measure. Discussion This study protocol is notable for its intensive daily sessions. Both MI and AO are low-cost, enabling personalized interventions that physiotherapists and occupational therapists can readily replicate in practice. While BMI use does require professionals to acquire an exoskeleton, the protocol ensures the distinctiveness of the interventions and, to our knowledge, is the first to involve individuals with PD. Trial registration ClinicalTrials.gov NCT05696925.
Comparison of the proteomic landscape in experimental ischemia reperfusion with versus without ischemic preconditioning
Abstract Myocardial ischemic preconditioning (IPC) enhances myocardial resilience to ischemic injury. Myocardial stunning is a transient, reversible dysfunction, while necrosis involves irreversible cell death. The relationship between IPC, stunning, and necrosis is not well understood, requiring further molecular investigation. This study aimed to investigate the proteomic changes associated with IPC, focusing on its relationship with myocardial stunning and necrosis. A novel 13.5-minute ischemia-reperfusion (I/R) rat model was specifically chosen to induce myocardial stunning, providing a unique approach to assess IPC effects in this context. Rats underwent either IPC with two 5-minute ischemia/reperfusion cycles followed by a 13.5-minute ischemic period or the procedure without IPC (no ischemic preconditioning, NIPC). Myocardial samples were collected at early (T1) and 4-hour post-reperfusion (T2) time points for proteomic analysis. Protein levels were quantified by differential labeling using TMTpro reagents, and subsequent liquid chromatography–mass spectrometry. IPC induced upregulation of proteins involved in endocytosis and Fc gamma R-mediated phagocytosis pathways at T1, while downregulating proteins related to tissue remodeling, immune response, and coagulation at T2. Conversely, NIPC exhibited upregulation of proteins associated with tissue damage and inflammation. IPC rats demonstrated enhanced leukocyte migration, complement activation, and immune response between T1 and T2. Consistent proteomic changes were observed between T1 and T2 in IPC vs. NIPC groups, and common alterations between IPC T2 vs. T1 and NIPC T2 vs. T1 comparisons underline shared pathways in cardiac complement and coagulation cascades. Our study reveals distinct proteomic changes induced by IPC in the context of myocardial stunning and necrosis. IPC activates early protective pathways, attenuates tissue damage and inflammation, and preserves myocardial function. These findings underscore IPC’s reparative potential and identify myocardial stunning as an important, transient adaptation, which may have implications for supportive clinical management in I/R.
Ensemble deep learning for Alzheimer’s disease diagnosis using MRI: Integrating features from VGG16, MobileNet, and InceptionResNetV2 models
Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by the accumulation of amyloid plaques and neurofibrillary tangles in the brain, leading to distinctive patterns of neuronal dysfunction and the cognitive decline emblematic of dementia. Currently, over 5 million individuals aged 65 and above are living with AD in the United States, a number projected to rise by 2050. Traditional diagnostic methods are fraught with challenges, including low accuracy and a significant propensity for misdiagnosis. In response to these diagnostic challenges, our study develops and evaluates an innovative deep learning (DL) ensemble model that integrates features from three pre-trained models—VGG16, MobileNet, and InceptionResNetV2—for the precise identification of AD markers from MRI scans. This approach aims to overcome the limitations of individual models in handling varying image shapes and textures, thereby improving diagnostic accuracy. The ultimate goal is to support primary radiologists by streamlining the diagnostic process, facilitating early detection, and enabling timely treatment of AD. Upon rigorous evaluation, our ensemble model demonstrated superior performance over contemporary classifiers, achieving a notable accuracy of 97.93%, along with a specificity of 98.04%, sensitivity of 95.89%, precision of 95.94%, and an F1-score of 87.50%. These results not only underscore the efficacy of the ensemble approach but also highlight the potential for DL to revolutionize AD diagnosis, offering a promising pathway to more accurate, early detection and intervention.
Global trends and age-period-cohort effects of chronic respiratory disease mortality attributed to industrial gaseous pollutants from 1990 to 2021
Classroom network structure learning engagement and parallel temporal attention LSTM based knowledge tracing
In order to accurately assess the students’ learning process and the cognitive state of knowledge points in smart classroom. A classroom network structure learning engagement and parallel temporal attention LSTM based knowledge tracing model (CL-PTKT) is proposed in this paper. First, a classroom network is constructed based on the information of student ID, seating relationship, and head-up/head-down state obtained from the smart classroom video. Second, a learning engagement model is established by utilizing the head-up/head-down state of students and the structural characteristics of the classroom network. Finally, in this paper innovatively proposes a parallel temporal attention LSTM feature tracking algorithm based on the learning engagement model and the knowledge-exercise data. It can fully considers the potential associated attributes of the knowledge-knowledge, knowledge-exercise and knowledge-learning engagement. And accurately characterizes the knowledge state during the knowledge point’s lecture time. To provide effective support for teachers to make seat adjustments and accurate interventions for in the teaching process. This paper conducts extensive experiments under four real datasets. The algorithm in this paper shows optimal performance in all four evaluation metrics compared to the state-of-the-art knowledge tracing models.
Enhanced superconducting properties of Bi$$_2$$Sr$$_2$$CaCu$$_2$$O$$_{8+x}$$ films with sub-50-nm thickness
Abstract Few-unit cell thick Bi $$_2$$ Sr $$_2$$ CaCu $$_2$$ O $$_{8+x}$$ (Bi-2212) layers have recently attracted much interest due to their extreme anisotropy and two-dimensional superconductivity, although they are typically susceptible to ambient conditions. In this study, we report on thin films approximately 13 unit cells thick that are stable in air, exhibit high anisotropy, and demonstrate extraordinarily high critical currents. By examining the superconducting transition under magnetic fields applied in both out-of-plane and in-plane orientations, we estimate key parameters such as pinning potentials, coherence lengths, London penetration depth, anisotropy factor, and the Ginzburg–Landau parameter. The volume pinning force is better described by a model incorporating an exponential decay term attributed to pronounced thermally-assisted flux flow. The Hall effect in the Bi-2212 films exhibits an extensive anomaly with a double sign change that may challenge existing theoretical explanations for this poorly understood phenomenon in copper-oxide superconductors.
Retraction: Ensemble learning for multi-class COVID-19 detection from big data
Current status and prospects of computer vision-based attitude and deformation measurement applications in wind tunnels
Abstract Computer vision-based model attitude and deformation measurement is essential in wind tunnel testing, offering benefits such as non-contact operation, automation, visualization, flexible configuration, and high near-field accuracy. However, the specific conditions of wind tunnel environments impose certain limitations on the practical applications of visual measurement techniques. In response to the intelligent demands of wind tunnel tests, this paper summarizes applications for model attitude and deformation measurement in wind tunnels. Over time, visual measurement techniques in wind tunnels have advanced from simple non-contact methods to real-time attitude and deformation assessments. Current trends highlight a shift towards multi-dimensional data fusion and deep learning techniques, which harness the complementary strengths of various technologies. This integration enables the simultaneous measurement of diverse data, significantly improving the efficiency of wind tunnel tests and achieving higher measurement accuracy.
ATF6β is not essential for the development of physiological cardiac hypertrophy
Physiological cardiac hypertrophy is a compensatory remodeling of the heart in response to stimuli such as exercise training or pregnancy that is reversible and well-tolerated. We previously described how the activating transcription factor 6 (ATF6) proteins, ATF6α and ATF6β, were required for pathological hypertrophy in response to hemodynamic stress. Here, we examine the functional roles of both ATF6 proteins in the context of exercise-induced physiological hypertrophy. After 20 days of swim training, we found differential roles: whole body gene-deleted mice lacking ATF6α had an attenuated hypertrophic response compared to wild-type mice but those lacking ATF6β did not. Additionally, mice lacking ATF6α displayed ventricular dilation and reduced fractional shortening after swimming. While we observed no differences in the expression of downstream UPR signaling between the exercise groups, mice lacking ATF6α showed enhanced phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2). Thus, in response to swim training, loss of ATF6β did not hinder the development of physiological hypertrophy, but loss of ATF6α resulted in significantly reduced cardiac fractional shortening.
Characterization of contrast-mediated collinear interactions in the human visual system
Abstract Collinear modulation represents a fundamental building block of our perceptual world, and its study has enhanced our understanding of contrast sensitivity, spatial integration, and neural plasticity in the visual system. In this phenomenon, the visibility of a target is influenced by collinear elements. Four key factors modulate this effect: the distance between target and flankers, the contrast of the flankers, retinal eccentricity, and spatial frequency. Each of these elements affects collinear modulation, increasing or reducing the target’s visibility. Short target-to-flankers separations decrease contrast sensitivity, while larger separations increase it. However, this pattern holds for high contrast flankers, whereas low contrast flankers increase contrast sensitivity at short separations, while the effect is weaker or absent at large separations. Moreover, eccentricity appears to increase the spatial extent of inhibition. Across three experiments, we systematically varied these key factors. In Experiments 1 and 2, we manipulated spatial frequency, flankers’ separation, and flankers’ contrast in foveal vision. In Experiment 3, we varied flankers’ separation and flankers’ contrast in peripheral vision. The results reveal a complex pattern that may help reconcile previously conflicting findings in both healthy participants and clinical populations, offering an updated framework for the study of neural plasticity in the visual system.
Improving HIV outcomes in Miami’s Black populations with clinic-based community health workers protocol: The integrated navigation and support for treatment adherence, counseling, and research (INSTACARE) randomized controlled trial
Miami-Dade is an HIV epicenter where Black populations experience excess AIDS-related deaths due to poor medication adherence, which prevents achieving an undetectable HIV viral load (VL). A promising approach to improving HIV outcomes in Black populations has been the use of community health workers (CHWs). Evidence shows CHWs trained in motivational interviewing (MI) may further improve outcomes, however little data exists about Black CHWs trained in MI who support Black patients with HIV. While CHWs traditionally help address social determinants of health in nonclinical locations, there is less information on CHWs who provide support in clinical settings, which may result in even greater improvements in HIV outcomes. To examine effects of CHWs trained in MI who provide HIV care in both clinic and community settings, a randomized controlled trial (RCT) is being conducted in Miami-Dade’s largest public hospital. The Integrated Navigation and Support for Treatment, Adherence, Counseling, and Research intervention is a RCT of 300 Black adults with an unmanaged HIV VL ( > 200 copies/mL). CHWs trained in MI are embedded into HIV clinical care teams and participate in hospital rounds with clinicians treating inpatients. Participants randomized into the CHW intervention arm receive 12 months of CHW-led health education and assistance with health care navigation and social services. The primary outcome is change in HIV viral load suppression at 12 months. Secondary outcomes include changes in medication adherence and social determinants of health. Study enrollment began in 2023 and will be completed by 2027. The first results are expected to be submitted for publication in 2025. INSTACARE is one of the first RCTs to examine effects of clinic-based support provided by CHWs trained in MI on Black populations with an unmanaged VL and will provide evidence on the impact of such strategies on medication adherence and social determinants of health. Trial registration ClinicalTrials.gov NCT04663152 .
Handling method for GPS outages based on PSO-LSTM and fading adaptive Kalman filtering
Abstract To mitigate the degradation in GPS/INS integrated navigation performance during GPS signal outages, a PSO-optimized LSTM method is proposed to predict the pseudo position. The PSO algorithm is utilized to optimize two hyperparameters, neuron count and learning rate, which are essential to improve the training efficiency and prediction accuracy in the LSTM model. Considering that the predicted pseudo-position may contain outliers or accumulated errors, a robust algorithm is employed to mitigate its impact on correcting INS errors. Therefore, a Fading Adaptive Kalman Filter is introduced, which incorporates a dynamic fading factor to adaptively adjust the observation noise covariance matrix. This mitigates the impact of observation anomalies, further refining the filtering process. Experimental results demonstrate that the proposed PSO-LSTM method effectively reduces positional errors associated with inertial navigation during GPS outages and enhances the reliability of positioning. Compared to the conventional Extended Kalman Filter (EKF), the Fading adaptive EKF further improves three-dimensional positioning accuracy by up to 23.6%, 18.3%, and 22.7%, respectively.
Patients’ experiences of a Virtual Fracture Assessment Clinic Pathway: A qualitative study
Background and objectives Existing literature has demonstrated the efficacy of a virtual fracture assessment clinic pathway, however there is limited research exploring patients’ experiences of a complete pathway, from initial presentation at the Emergency Department or Injury Unit to discharge. The aim of this study was to explore the experiences of patients who have recently sustained a stable peripheral limb fracture, having received care across a complete virtual fracture assessment clinic pathway, in order to improve patient care. Methods One-to-one semi-structured interviews were completed via recorded phone and video calls, with a purposive sample of 12 participants. Interviews were completed until data saturation was achieved. Interviews were transcribed verbatim and data was analysed using thematic analysis. Results Six overarching themes were identified; ‘trust’ (in the pathway and management plan), ‘conflicting advice’ (on diagnosis and management plan), ‘information’ (need for more basic information), ‘severity of injury’ (participants’ perceptions of the severity of their injuries), ‘reassurance’ (through follow-up x-rays and physiotherapy consultations) and ‘efficiency’. Conclusions This is the first qualitative study exploring patients’ experiences of a complete virtual fracture assessment clinic pathway. Patients’ experiences may be improved through patient education on the pathway process and providing standardised injury-specific patient information documentation. Regular communication between different healthcare professionals involved in the pathway may reduce conflicting advice. Developing an opt-in physiotherapy service and providing patients with a standardised text message informing patients when their virtual consultation will occur may also improve patients’ experience of the pathway. Establishing a referral pathway with a fracture liaison service is also recommended to further enhance a virtual fracture assessment clinic pathway. Future research is needed to investigate how therapeutic relationships can be developed when care is delivered virtually and to explore the experiences of patient cohorts who were not included in this study.