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Formation of wind-fed black hole high-mass X-ray binaries: The role of Roche-lobe-overflow post black hole formation
Get PDFThe three dynamically confirmed wind-fed black hole high-mass X-ray binaries (BH-HMXBs) are suggested to all contain a highly spinning black hole (BH). However, based on the theories of efficient angular momentum transport inside the stars, we expect that the first-born BHs in binary systems should have low spins, which is consistent with gravitational-wave observations. As a result, the origin of the high BH spins measured in wind-fed BH-HMXBs remains a mystery. In this paper, we conduct a binary population synthesis study on wind-fed BH-HMXBs at solar metallicity with the use of the newly developed code POSYDON, considering three scenarios for BH accretion: Eddington-limited, moderately super-Eddington, and fully conservative accretion. Taking into account the conditions for accretion-disk formation, we find that regardless of the accretion model, these systems are more likely to have already experienced a phase of Roche-lobe overflow after the BH formation. To account for the extreme BH spins, highly conservative accretion onto BHs is required, when assuming the accreted material carries the specific angular momentum at the innermost stable orbit. Besides, in our simulations we found that the systems with donor stars within the mass range of 10 − 20 M⊙ are prevalent, posing a challenge in explaining simultaneously all observed properties of the BH-HMXB in our Galaxy, Cygnus X-1, and potentially hinting that the accretion efficiency onto non-degenerate stars, before the formation of the BH, is also more conservative than assumed in our simulations.published_or_final_versio
Patients’ understanding and perception of erectile dysfunction: Hong Kong versus Europe
Get PDFPurposeTo estimate the prevalence of Erectile dysfunction (ED) in a Hong Kong (HK) population, evaluate the understanding and perception of ED and compare results with the European Association of Urology (EAU) and The Urology Foundation Trust (TRTed-TUF) data.MethodsA survey-based study was conducted between Dec 2023 and Mar 2024. The EAU and TRTed-TUF surveys were used as a template to design the current survey to ensure consistent reporting. Questions on the understanding of ED, healthcare seeking behaviour and awareness of treatment options were included. The survey was distributed via an online link to students and staff from The Hong Kong University (HKU) and to patients attending outpatient clinics at HKU Queen Mary Hospital.Results616 responses were received from men aged 18–81 years. The prevalence of ED in our population was 51.8%. 53.2% (EAU 33.6%) were incorrect about what ED is, 54.0% (EAU 56.5%) knew that ED could be treated and 26.4% (TRTed-TUF 22%) were aware that ED could be a sign of heart disease. 73.6% (EAU, 26.3%) do not talk with anyone about ED. 88.3% (TRTed-TUF 77%) would be more likely to seek help if they knew ED was a sign of heart disease. Up to 32.6% (EAU 17.2%) have heard of alternative therapies to oral phosphodiesterase-5 inhibitors.ConclusionsED awareness is low, and it is important to raise awareness possibly through charity campaigns, social media and education in primary care in order to detect underlying cardiovascular disease and reduce the impact of ED on psychosocial health.published_or_final_versio
Photothermal Cavitation-Driven Micromotor to Penetrate Cell Membrane
Get PDFPhotothermally driven micro/nanomotors efficiently convert light into mechanical motion, making them highly attractive for biomedical applications due to their exceptional biocompatibility and safety. However, one mystery of the photothermally driven micro/nanomotor is the wide range of reported light intensities applied, ranging from 1 W cm-2 to over 105 W cm-2. To address this mystery, we systematically investigated the propulsion of a carbon microbottle-based micromotor under three illumination conditions: continuous laser, pulsed laser, and scanning laser, where a new cavitation-driven mechanism is identified. Using a high-speed camera, we find that the instantaneous deposition of laser energy on the micromotors can lead to transient and localized evaporation of the solvent, creating cavitation bubbles to drive micromotors with ultrafast speed, where instantaneous velocity over 1 m s-1 is observed. Through precise modulation of the scanning orientation and intensity of the laser, directional propulsion and targeted explosions of the microbottles are achieved, where the instant force is strong enough to penetrate live cell membranes. Finally, the cavitation-driven micromotors are exploited as gene transfection tools, where targeted cytoplasmic transfection is demonstrated.published_or_final_versio
DiffGraph: Heterogeneous Graph Diffusion Model
No full textRecent advances in Graph Neural Networks (GNNs) have revolutionized graph-structured data modeling, yet traditional GNNs struggle with complex heterogeneous structures prevalent in real-world scenarios. Despite progress in handling heterogeneous interactions, two fundamental challenges persist: noisy data significantly compromising embedding quality and learning performance, and existing methods' inability to capture intricate semantic transitions among heterogeneous relations, which impacts downstream predictions. To address these fundamental issues, we present the Heterogeneous Graph Diffusion Model (DiffGraph), a pioneering framework that introduces an innovative cross-view denoising strategy. This advanced approach transforms auxiliary heterogeneous data into target semantic spaces, enabling precise distillation of task-relevant information. At its core, DiffGraph features a sophisticated latent heterogeneous graph diffusion mechanism, implementing a novel forward and backward diffusion process for superior noise management. This methodology achieves simultaneous heterogeneous graph denoising and cross-type transition, while significantly simplifying graph generation through its latent-space diffusion capabilities. Through rigorous experimental validation on both public and industrial datasets, we demonstrate that DiffGraph consistently surpasses existing methods in link prediction and node classification tasks, establishing new benchmarks for robustness and efficiency in heterogeneous graph processing. The model implementation is publicly available at: https://github.com/HKUDS/DiffGraph.link_to_subscribed_fulltex
MixRec: Heterogeneous Graph Collaborative Filtering
No full textFor modern recommender systems, the use of low-dimensional latent representations to embed users and items based on their observed interactions has become commonplace. However, many existing recommendation models are primarily designed for coarse-grained and homogeneous interactions, which limits their effectiveness in two critical dimensions. Firstly, these models fail to leverage the relational dependencies that exist across different types of user behaviors, such as page views, collects, comments, and purchases. Secondly, they struggle to capture the fine-grained latent factors that drive user interaction patterns. To address these limitations, we present a heterogeneous graph collaborative filtering model MixRec that excels at disentangling users' multi-behavior interaction patterns and uncovering the latent intent factors behind each behavior. Our model achieves this by incorporating intent disentanglement and multi-behavior modeling, facilitated by a parameterized heterogeneous hypergraph architecture. Furthermore, we introduce a novel contrastive learning paradigm that adaptively explores the advantages of self-supervised data augmentation, thereby enhancing the model's resilience against data sparsity and expressiveness with relation heterogeneity. To validate the efficacy of MixRec, we conducted extensive experiments on three public datasets. The results clearly demonstrate its superior performance, significantly outperforming various state-of-the-art baselines. Our model is open-sourced and available at: https://github.com/HKUDS/MixRec.link_to_subscribed_fulltex
Upper arm arteriovenous graft or transposed brachiobasilic fistula—competitive or complementary?
No full textPredicting 10-year risk of chronic kidney disease in lithium-treated patients with bipolar disorder: A risk model development and internal cross-validation study
No full textLithium is a first-line maintenance treatment for bipolar-disorder (BD) but has increased risk for chronic-kidney-disease (CKD). There is a paucity of research on risk-model development predicting CKD during/following lithium treatment, and none was conducted in Asian regions. This study aimed to derive and validate 10-year risk prediction model for CKD-stage 3 in first-diagnosed BD patients receiving ≥ 1 prescription of lithium during 2002–2018 in Hong-Kong, using electronic-medical-record database of public-healthcare services. Literature-informed predictor selection included demographics, physical comorbidities, mean lithium serum-levels and non-lithium psychotropic use. The risk-equation was developed using Least-Absolute-Shrinkage-and-Selection-Operator (LASSO) Cox-proportional hazards regression model with 4-fold internal cross-validation over 1,000 iterations. We identified 2,258 lithium-treated BD patients, with CKD incidence of 12.6 per 1000 person-years (95 %CI=11.1–14.4) over a median follow-up of 7.7 years (interquartile range=3.7–12.3). Our results showed that older age at BD-diagnosis, male sex, physical comorbidities, higher mean lithium serum-level, fewer antipsychotic and mood-stabilizing anticonvulsant use, and greater antidepressant exposure were independent risk factors predicting CKD, with an event-per-variable ratio of 25.2. The 10-year risk prediction model had satisfactory area-under-the-curve (AUC) (0.74 [95 %CI=0.66–0.83]), with good calibration (calibration slope=0.88 [95 %CI=0.61–1.15]; observed/expected risk ratio=1.14 [95 %CI=0.86–1.42]), and discrimination performances (Harrell's C-index=0.75 [95 %CI=0.68–0.82]; Royston and Sauerbrei's D statistic=1.45 [95 %CI=0.99–1.92]). In conclusion, this CKD risk-model for lithium-treated BD patients demonstrated satisfactory prediction performance in a predominantly-Chinese population. Further research including external validation is needed to verify model performance to facilitate implementation of this CKD risk prediction tool for individualized clinical decision-making and outcomes in real-world practice
Exploring the potential relationships between idiopathic scoliosis and various multifactorial diseases: a systematic scoping review
No full textBackgroundAlthough the etiology of adolescent idiopathic scoliosis (AIS) remains largely elusive, it is widely recognized as a multifactorial condition shaped by both genetic predispositions and environmental influences. This review seeks to explore the intricate relationships between idiopathic scoliosis and its associated comorbidities, with the goal of advancing our understanding of this multifaceted disorder.MethodsPrimary studies involving human subjects diagnosed with idiopathic scoliosis and presenting comorbid conditions were included. Six online databases (AMED, CENTRAL, CINAHL, EMBASE, MEDLINE, and WOS) were systematically searched. Two reviewers independently screened citations and extracted data. Studies were categorized based on commonly examined diagnoses, and outcome measures were descriptively reported.ResultsOur search yielded 1185 citations, with 9 studies meeting the eligibility after screening. These studies examined comorbidities involving conditions like malocclusion, central precocious puberty (CPP), gingival diseases, malignant hematopoietic neoplasms (MHN), temporomandibular joint disorders (TMD), and functional gastrointestinal disorders (FGD). Significant associations were found between AIS and these multifactorial disorders, including dental anomalies (i.e., asymmetrical canine, midline deviations, crossbites, overbite, multiple malocclusion, gingivitis, distocclusion, asymmetric molar occlusion, maxillary overjet, crowding, and reverse chewing cycles), digestive issues (i.e., FGD), endocrine disruptions (i.e., CPP), musculoskeletal imbalances (i.e., reduced masseter muscle volume, higher Fonseca Anamnestic Index score, and greater Helkimo Clinical Dysfunction Index score), and oncological conditions (i.e., MHN).ConclusionWe have presented the multifactorial and potential systemic nature of AIS by revealing its associations with comorbid conditions. These relationships may indicate shared genetic, hormonal, neuromuscular, and immunological pathways.</p
A Cross-Sectional Survey Exploring the Willingness of Hong Kong People to Use Teleconsultation in Primary Care During the COVID-19 Pandemic
No full textObjectives: To investigate the willingness of the general Hong Kong population to use teleconsultation in primary care and the factors affecting their decisions and to ascertain the medical problems for which people will consider using teleconsultation in primary care. The study was a cross-sectional territory-wide random population survey on adults recruited through a computer-assisted telephone interview system. Outcome Measures: Outcomes were the proportion of the general Hong Kong population indicating their willingness to use teleconsultation in primary care; the drivers and barriers affecting their willingness; and the medical problems in primary care for which people would consider using teleconsultation. Results: After applying population weighting, 51.6% of the study respondents were found to be willing to use teleconsultation in primary care. The main drivers were possessing the perception that teleconsultation would serve the majority of their health problems (odds ratio [OR] = 3.693, p < 0.001), provision of government subsidy (OR = 3.567, p < 0.001), and ownership of a computer/tablet (OR = 2.116, p < 0.001). A major barrier for people’s reluctance to use teleconsultation in primary care was having an education level of primary or below (OR = 0.388, p = 0.002). The majority of people had reasonable expectations on which medical conditions teleconsultation could be helpful but misunderstandings did exist. Conclusion: Our survey estimated that more than half of the general Hong Kong population was willing to use teleconsultation in primary care. Health care service providers and the government should address the drivers and barriers and clarify any misconceptions if teleconsultation is to be further developed in the Hong Kong primary care system
A Flat-bottomed Buried Crater and Paleo-layered Structures Revealed at the Von Kármán Crater Using Lunar Penetrating Radar
No full textImpact cratering is the most common geological process occurring on terrestrial planets. The morphologies of impact craters reflect not only the impact conditions but the target properties as well. They have been widely used as subsurface probes into regolith thickness and mechanical properties. A population of paleo-buried impact craters has been discovered by recent geophysical investigations of the Moon; however, their morphologies have never been constrained. The lunar penetrating radar onboard the Chang’e-4 rover has offered an unprecedented opportunity to study the morphology of those paleo-buried craters and reveal obscured depositing history. In this study, we have identified a flat-bottomed paleocrater (450 m in diameter; 11.5 m in depth) on an extraterrestrial world and reconstructed its morphology. This discovery reinforces how impacts would modify layered structures, providing additional evidence regarding subsurface interfaces between the paleoregolith layers and the final-stage lava layers, shedding light on similar processes on all planets