Rapid and unbiased enrichment of extracellular vesicles via a meticulously engineered peptide

Extracellular vesicles (EVs) have garnered significant attention in biomedical applications. However, the rapid, efficient, and unbiased separation of EVs from complex biological fluids remains a challenge due to their heterogeneity and low abundance in biofluids. Herein, we report a novel approach to reconfigure and modify an artificial insertion peptide for the unbiased and rapid isolation of EVs in 20 min with ∼80% recovery in neutral conditions. Moreover, the approach demonstrates exceptional anti-interference capability and achieves a high purity of EVs comparable to standard ultracentrifugation and other methods. Importantly, the isolated EVs could be directly applied for downstream protein and nucleic acid analyses, including proteomics analysis, exome sequencing analysis, as well as the detection of both epidermal growth factor receptor (EGFR) and V-Ki-ras2 Kirsten Rat Sarcoma Viral Oncogene Homologue (KRAS) gene mutation in clinical plasma samples. Our approach offers great possibilities for utilizing EVs in liquid biopsy, as well as in various other biomedical applications

Does online case-based learning foster clinical reasoning skills? A mixed-methods study

Background: Blended learning, integrating face-to-face and virtual methods, has become essential in clinical education, enhancing student satisfaction, engagement and knowledge outcomes. Particularly, online case-based learning emerges as a promising pedagogy to foster clinical reasoning skills. Despite the well-documented clinical reasoning cultivation through face-to-face case-based learning, the ability of online case-based learning to cultivate clinical reasoning remains unexplored. This study investigates the role of online case-based learning in fostering clinical reasoning skills among clinical-year medical students. Methods: A mixed-methods sequential explanatory research study was adopted. In the first phase, quantitative data were gathered through a 16-item Likert scale questionnaire adapted from validated clinical reasoning questionnaires. In the second phase, focus group discussions were conducted to expand on the understanding of quantitative results. Results: In total, 160 students completed the questionnaire (45% response rate), and 26 participated in focus group discussions. Participants agreed that online case-based learning fostered clinical reasoning skills (mean = 2.94) through different formats, such as clinical role play, simulated ward rounds and virtual consultation. Compared to face-to-face clinical teaching, the focus group revealed that participants were allowed to practise giving explanations to patients, engage in more in-depth discussions, and receive more comprehensive feedback on their clinical reasoning skills during online case-based learning. The barriers to online clinical reasoning skills development were poorer communication skills development and reduced student engagement. The lack of patient complexities of cases and the inability to perform physical examinations hindered students’ clinical reasoning ability. Suggestions to improve clinical reasoning cultivation include utilising actual patient cases, increasing case complexity and session interactivity. Conclusion: This study highlights how online case-based learning can support the development of clinical reasoning skills in medical students, encouraging future educators to adopt a blended learning approach. Future research should focus on objective assessments, long-term impacts and innovative methods to improve clinical reasoning skill development continuously

HGDetector: A hybrid Android malware detection method using network traffic and Function call graph

The malicious infestations of Android malware caused huge economic losses to users over the past few years. Machine learning-based malware detection enhances the accuracy and partially mitigates these security threats. However, when the static or dynamic features cannot effectively represent software behavior, the accuracy of the model will be reduced. For this issue, a multi-features hybrid malware detection and category classification method HGDetector is proposed, this approach provides a more comprehensive representation of software behavior. HGDetector first extracts the software static function call graph and constructs the network behavior function call graph, then applies the dynamic network traffic features of the software to build the node interaction graph and edge-node graph; Subsequently, these features were fused and converted into a vector representation employing graph embedding method; Finally, combined with the proposed HGDetector, different classifiers were used to test the accuracy of malware detection and category classification. The experimental results demonstrate that the fusion of hybrid features can enhance malware detection accuracy by approximately 4 % when network traffic features effectively capture APP's behavior. Conversely, in cases where network traffic features alone are insufficient to represent software's network behavior, the application of hybrid features can improve malware detection accuracy by 21 %-26 %

Virtual Reality Portable Perimetry and Home Monitoring of Glaucoma: Retention and Compliance over a 2-year Period

Purpose: To evaluate long-term retention, compliance, and performance of glaucoma patients using a virtual reality portable perimeter to monitor visual fields (VFs) at home. Design: Prospective, longitudinal, cohort study. Subjects: Twenty-five glaucoma patients with stable and reliable VFs (average age 67.4 years) were recruited at Toronto Western Hospital, Ontario, Canada. Methods: Participants were instructed to perform bilateral home VF tests fortnightly for 2 years using the Toronto Portable Perimeter (TPP). Based on empirical home monitoring data, simulation analyses were conducted to evaluate the progression detection performance of high-frequency TPP testing. Main Outcome Measures: Retention rates were calculated as the percentage of participants who performed ≥1 home VF test. Compliance rates measured the percentage of participants adhering to the recommended test frequency of every 2-month period. Visual field indices, test reliability, intertest variability, and the precision of estimating progression rate with TPP were compared to those with the Humphrey Field Analyzer (HFA). After 6 months, participants completed a questionnaire to evaluate their experiences and preferences. The years required to detect progression were also compared between HFA and TPP tests. Results: Eighteen of the 25 participants (72%) completed ≥1 unsupervised VF test at home, with an average test frequency of 1.6 tests/month. Compliance decreased as the monitoring duration progressed, dropping from 83% (initial 2 months) to 11% (final 2 months). Unfamiliarity with technology and time constraints were identified as the main barriers to regular testing. Visual field indices of TPP home tests were strongly correlated with clinical results (r > 0.900). Home testing significantly reduced intertest variability (P < 0.001) and improved the precision of progression rate estimates (P < 0.010). Participants overwhelmingly preferred home testing over clinic VF follow-ups (P < 0.001). Simulations showed that TPP tests can significantly shorten the time to detect progression for different progression rates compared with clinical VF follow-up, even with compromised compliance. Conclusions: Despite the small sample size, our study demonstrated that glaucoma patients could reliably perform VF tests at home over a 2-year period. However, issues with retention rate and compliance with long-term VF monitoring were observed in some participants. Nevertheless, high-quality VF data from home tests can provide supplementary information to improve the timely detection of VF progression. Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article

Effect of ethanol concentration on the catalytic performance of WO3/MCF-Si and WO3/SBA-15 catalysts toward ethanol dehydration to ethylene

In this study, the WO3/MCF-Si and WO3/SBA-15 catalysts were developed for the ethanol dehydration reaction under different ethanol concentrations including 99, 70, and 50 % v/v in water. It aims to evaluate the effect of water presence in the reaction medium on the catalytic performance and properties of the catalyst which can be applied to developing industrial process. Both catalysts were tested under the vapor phase ethanol dehydration at temperature of 400 °C for 10 h via time on stream. WO3/MCF-Si exhibited superior catalytic activity and greater resistance to both coke formation and water in the feedstock compared to WO3/SBA-15. It was found that variations in ethanol concentrations had negligible influence on the textural properties of the developed catalysts. Nevertheless, a discernible effect on the acidity of the catalyst was observed. Additionally, the use of lower ethanol concentrations (with higher water content) as a feed enhanced the selectivity of ethylene and inhibited the formation of Bronsted acid sites leading to a decrease of coke formation. On the contrary, it also had an adverse effect by attenuating the ethanol conversion. WO3/MCF-Si with using 70 % v/v ethanol as feed demonstrated highest steady-state activity showing the maximal yield of ethylene between 95 and 96.6 %

Effect of heat input on microstructural evolution and impact toughness in dissimilar weld metals between medium Mn and V-microalloyed steel

High-quality weld metals are a prerequisite for ensuring the integrity of dissimilar steel welded joints. This research investigates the influence of heat input on the inclusion characteristics, variant selection, crystallographic texture, and resultant impact toughness of dissimilar weld metals used in joining heavy-plate medium Mn steel (MMS) and V-microalloyed steel (VMS). Results revealed that inclusion density decreased but its size increased as heat input increased from 10 to 15 and 20 kJ/cm, which alters in the nucleation mechanism of acicular ferrite (AF) from intragranular nucleation to sympathetic nucleation. The percentage of AF initially rose from 81.3 % to 83.2 %, and then declined to 79.1 %. Variant selection also transitioned from random to specific due to the variation in transition temperature and nucleation mechanism. Meanwhile, the fraction of unfavourable crystallographic texture increased from 1.5 % to 22.9 % and 26.1 %. Impact toughness was higher (128 J) at 10 kJ/cm compared to 15 kJ/cm (108 J) and 20 kJ/cm (110 J) owing to its smaller inclusion size and a lower percentage of unfavourable crystallographic texture. These findings offered theoretical guidance for selecting welding parameters in industrial applications for dissimilar welded joints of MMS and VMS

Experimental and numerical study of soot formation in hydrocarbon sprays under high-pressure fuel pyrolysis conditions

This study combined high-speed optical diagnostics and numerical simulation to investigate soot formation in n-dodecane sprays under conditions characterized by fuel pyrolysis and low oxygen concentrations. Numerical models were employed to predict the evolution of polycyclic aromatic hydrocarbons (PAHs), while the experiments focused on soot formation. A 186-µm single-hole orifice nominal diameter injector was employed to inject well-controlled fuel sprays into a constant-volume chamber operating at 76 bar. We use a short injection duration of approximately 100 µs to maximize the residence time of the fuel, with variations in the ambient gas temperature within the range of 1,400 to 1,700 K, and the oxygen concentration was ranged from 0 to 5 %. Additionally, we conducted closed-homogeneous-reactor and two-stage Lagrangian simulations with various kinetic mechanisms to predict PAH formation and compared the results with experimental data. The experimental results revealed that variations in the ambient temperature and oxygen percentage significantly influenced the pyrolysis and oxidation processes. Soot onset occurred at 1,450 K for oxygen levels of 0, 1, and 3 %, whereas at 5 % oxygen, soot formed at temperatures below 1,400 K. Interestingly, higher oxygen concentrations increased the rates of soot formation at all temperatures tested. By contrast, elevated temperatures reduce the total soot mass owing to enhanced oxidation. The present study also evaluates the influence of fuel composition on soot formation and observes that a higher aromatics content in the fuel leads to a lower soot onset temperature and increased soot mass. Notably, similar trends for both ethanol and n-dodecane fuels are identified in this study. Furthermore, the numerical calculations revealed distinct trends in PAH formation. Although the different mechanisms reasonably captured the trends in benzene formation, they differed in their predictions of the formation rate of pyrene, resulting in potential differences in soot processes. This disparity highlights the need for a comprehensive review and potential modification of the current soot modeling approach

Luminescence of copper-doped α-quartz crystal after oxygen treatment

Treatment of copper-doped natural α-quartz in oxygen atmosphere at 1200 °C leads to changes in luminescence properties. The luminescence center of AlO4−-Cu+ is modified. The intensity is low in the annealed sample and increases after X-ray irradiation at 293 K. Annealing of the irradiated sample leads to a strong peak of thermally stimulated luminescence (TSL) at ∼500 K. Its spectral composition is mainly due to the AlO4−-Cu+ center. Irradiation of the sample treated with oxygen at 77 K gives a new TSL peak at ∼180 K and a peak at 244 K existing in the untreated sample. Both peaks were attributed to Cuo centers released from different sites and recombined with a hole in AlO4 having additional oxygen. The introduction of copper ions into quartz removes alkali metal ions and eliminates the corresponding luminescence, but after treatment in oxygen, luminescence with similar parameters is restored at low temperatures. In this case, only the glow of the AlO4−-Cu+ center is observed in the recombination luminescence (TSL and afterglow). Therefore, modification of the AlO4−-Cu + center with oxygen imparts to this center properties similar to the complex center AlO4− (K, Na or Li ion) with monovalent aluminum ions, although the alkali ions are replaced by copper ions. The oxygen-treated sample exhibits an increased efficiency of energy transfer by excitons to the luminescence center, measured as excitation spectra in the region of fundamental absorption of silicon dioxide. The X-ray excitation of the self-trapped exciton luminescence does not depend on oxygen treatment. Also, the spectra of intrinsic optical reflection and Raman scattering do not change compared to the untreated sample. The obtained result is interpreted as a modification of the defect by high-temperature treatment in oxygen

Mechanical and tribological characterization of polyamide 66/graphite nanocomposites

Polymer nanocomposites can be employed in diverse engineering applications where wear is a critical concern. Understanding the mechanical and wear properties as applied to polymer nanocomposites is crucial for comprehending the behaviour of workpieces. In this study, three types of nanographites were incorporated at a concentration of 2.5 wt% into a polyamide 6.6 matrix. The graphites differ owing its production process. Tests of wear, impact, and elastic deformation resistance, hardness, and morphology were conducted to evaluate the performance of the PA66/graphite nanocomposites. All nanocomposites exhibit a homogeneous morphology with good dispersion, distribution, and orientation of the nanographites in the matrix, suggesting the effectiveness of the processing methods employed. The incorporation of 2.5 wt% of nanographites A, B, and C improved the wear resistance of PA66 by 52%, 74%, and 44%, respectively. The PA66/graphite nanocomposites exhibited an increase in Shore D hardness up to 2.8%, and in elastic modulus between 8.3% and 13.0%. The impact resistance of the nanocomposites decreased by 15.4%–21.3%. The results revealed that the production process of the nanographites impacted the performance of the produced nanocomposites

Interface dipole evolution from the hybrid coupling between nitrogen-doped carbon quantum dots and polyethylenimine featuring the electron transport thin layer at Al/Si interfaces

The assessment of electron transport layer (ETL) for rear-contact engineering of silicon (Si) based optoelectronics has been considered as one of the critical challenges that leverage the performance improvement and device reliability. In this work, the hybrid design of ETL, obtained from the solution-processed nitrogen-doped carbon quantum dots (NCQDs) incorporated with organic polyethylenimine (PEI) demonstrates the feasible contact characteristics for the modification of Si/Al contacts, which greatly facilitates the transport and collection of photoexcited electrons in the Si-based optoelectronics. The aspects of microstructures, functional groups, chemical features, interfacial characteristics and band structures of NCQD/PEI are explicated, visualizing that the evolution of interface dipoles mediated by the overall outcome of physisorption and chemisorption effects, modifies the surface potential difference and results in the explicit reduction of the Al work function from 4.3 eV for pristine Al to 3.23 eV based on the optimized constitutional design (0.10 % NCQD in PEI). These findings are practically employed on the Si-based hybrid solar cells at Si/Al interfaces, fulfilling the conversion-efficiency improvement by 30.9 % compared with reference cells without ETL employment, which are experimentally interpreted by the efficient electron transport across the Si/Al heterojunction and charge collection