GraphMaker: Can Diffusion Models Generate Large Attributed Graphs?

Large-scale graphs with node attributes are fundamental in real-world scenarios, such as social and financial networks. The generation of synthetic graphs that emulate real-world ones is pivotal in graph machine learning, aiding network evolution understanding and data utility preservation when original data cannot be shared. Traditional models for graph generation suffer from limited model capacity. Recent developments in diffusion models have shown promise in merely graph structure generation or the generation of small molecular graphs with attributes. However, their applicability to large attributed graphs remains unaddressed due to challenges in capturing intricate patterns and scalability. This paper introduces GraphMaker, a novel diffusion model tailored for generating large attributed graphs. We study the diffusion models that either couple or decouple graph structure and node attribute generation to address their complex correlation. We also employ node-level conditioning and adopt a minibatch strategy for scalability. We further propose a new evaluation pipeline using models trained on generated synthetic graphs and tested on original graphs to evaluate the quality of synthetic data. Empirical evaluations on real-world datasets showcase GraphMaker's superiority in generating realistic and diverse large-attributed graphs beneficial for downstream tasks.Comment: Code available at https://github.com/Graph-COM/GraphMake

Experiment and Numerical Simulation of Damage Progression in Transparent Sandwich Structure under Impact Load

Crack initiation and propagation is a long-standing difficulty in solid mechanics, especially for elastic brittle materials. A new type of transparent sandwich structure, with a magnesium–aluminum spinel ceramic glass as the outer structure, was proposed in this paper. Its dynamic response was studied by high-speed impact experiments and numerical simulations of peridynamics under impact loads, simultaneously. In the experiments, a light gas cannon was used to load the projectile to 180 m/s, and the front impacted the transparent sandwich structure. In the numerical simulations, the discontinuous Galerkin peridynamics method was adopted to investigate the dynamic response of the transparent sandwich structure. We found that both the impact experiments and the numerical simulations could reproduce the crack propagation process of the transparent sandwich structure. The radial cracks and circumferential cracks of the ceramic glass layer and the inorganic glass layer were easy to capture. Compared with the experiments, the numerical simulations could easily observe the damage failure of every layer and the splashing of specific fragments of the transparent sandwich structure. The ceramic glass layer and the inorganic glass layer absorbed the most energy in the impact process, which is an important manifestation of the impact resistance of the transparent sandwich structure

Anal Human Papillomavirus Genotyping among HIV-Positive Men Who Have Sex with Men in Xi'an, China.

Anal human papillomavirus (HPV) infection and its related diseases are relatively common in men who have sex with men (MSM), especially in those HIV positive. In China, molecular epidemiology of anal HPV infection among HIV-positive MSM has been sparsely studied.A cross-sectional study was conducted among HIV-positive MSM in Xi'an, China between April and July 2014. Anal swabs were collected for HPV genotyping.A total of 195 HIV-positive MSM were included in this study. HPV genotyping showed that 99.0% (191/193) of participants were positive for at least one of the targeted 37 HPV genotypes. 183 (94.8%) of them were infected with multiple high-risk types and 154 (79.8%) of them with low-risk HPV types. HPV 18 was the most frequently identified high-risk type, followed by HPV 16 and HPV 51. As for low-risk types, HPV11, HPV 6 and HPV 81 were most commonly observe. High-risk HPV infection was found to be associated with the status of antiretroviral therapy (ART), the distribution of low-risk types was observed to be varied by CD4+ T cell level.Almost all HIV-positive MSM were anal HPV infected in our study. It is highly recommended to consider regular active screening and preventive intervention of HPV infection among this high risk population

Association of human papillomavirus infection and abnormal anal cytology among HIV-infected MSM in Beijing, China.

BACKGROUND: In the recent years, dramatic increases in HIV transmission among men who have sex with men (MSM) have been observed in China. Human papillomavirus (HPV) infection related anal cancer is more common among HIV-infected MSM as compared to the general population. However, HPV infection and anal cytology has been rarely studied in HIV-infected MSM in China. METHODS: HIV-infected MSM in Beijing, China were invited to participate in this study between January and April 2011. Anal swabs were collected for examining cytology and HPV genotypes. RESULTS: Ninety-five eligible participants with complete questionnaire and laboratory data were included in the analyses. Thirty six of them (37.9%) showed abnormal anal cytology as follows: atypical squamous cells of undetermined significance (ASC-US) in 19 (20.0%), atypical squamous cells but cannot exclude HSIL (ASC-H) in 1 (1.1%), low-grade squamous intraepithelial lesion (LSIL) in 15 (15.8%), and high-grade squamous intraepithelial lesion (HSIL) in 1 (1.1%). HPV6 (20.0%), HPV16 (10.9%), HPV56 (10.9%), HPV52 (9.1%) and HPV39 (9.1%) were observed most frequently among those with normal anal cytology, while different distribution was found in the ones with abnormal anal cytology as HPV6 (19.4%), HPV16 (19.4%), HPV45 (16.7%), HPV52 (16.7%) and HPV18 (11.1%). In addition, HPV16, HPV45, HPV52 and HPV18 were the most frequent high-risk types in patients with abnormal anal cytology. HPV multiplicity was found to be significantly related to the prevalence of abnormal anal cytology (p for trend = 0.04). CONCLUSIONS: High prevalence of HPV infection and abnormal anal cytology was observed among HIV-infected MSM in China. Infection of multiple HPV types or high-risk types was found to be associated with an increased risk of abnormal anal cytology

The Association of Sport Performance with <em>ACE</em> and <em>ACTN3</em> Genetic Polymorphisms: A Systematic Review and Meta-Analysis

<div><h3>Background</h3><p>Genetic polymorphism is suggested to be associated with human physical performance. The angiotensin I-converting enzyme insertion/deletion (<em>ACE</em> I/D) polymorphism and the α-actinin-3 gene (<em>ACTN3</em>) R577X polymorphism have been most widely studied for such association analysis. However, the findings are frequently heterogeneous. We aim to summarize the associations of <em>ACE</em> I/D and <em>ACTN3</em> R577X with sport performance by means of meta-analysis.</p> <h3>Methods</h3><p>We systematically reviewed and quantitatively summarized published studies, until October 31, 2012, on relationship between <em>ACE/ACTN3</em> genetic polymorphisms and sports performance, respectively.</p> <h3>Results</h3><p>A total of 366 articles on <em>ACE</em> and 88 articles on <em>ACTN3</em> were achieved by literature search. A significant association was found for ACE II genotype compared to D allele carriage (DD+ID) with increased possibility of physical performance (OR, 1.23; 95% CI, 1.05–1.45). With respect to sport discipline, the II genotype was found to be associated with performance in endurance athletes (OR, 1.35; 95% CI, 1.17–1.55). On the other hand, no significant association was observed for <em>ACTN3</em> RR genotype as compared to X allele carriage (XX+RX) (OR, 1.03; 95% CI, 0.92–1.15). However, when restricted the analyses to power events, a significant association was observed (OR, 1.21; 95% CI, 1.03–1.42).</p> <h3>Conclusion</h3><p>Our results provide more solid evidence for the associations between <em>ACE</em> II genotype and endurance events and between <em>ACTN3</em> R allele and power events. The findings suggest that the genetic profiles might influence human physical performance.</p> </div

Seroprevalence of <i>Entamoeba histolytica</i> Infection among Chinese Men Who Have Sex with Men

<div><p>Background</p><p>Men who have sex with men (MSM) were found to be one of the high-risk populations for <i>Entamoeba histolytica</i> (<i>E. histolytica</i>) infection. Accompanied by the prevalence of human immunodeficiency virus (HIV) among MSM, invasive amebiasis caused by <i>E. histolytica</i> has been paid attention to as an opportunistic parasitic infection. However, the status of <i>E. histolytica</i> infection among MSM has been barely studied in mainland China.</p><p>Methods</p><p>Seroprevalance of <i>E. histolytica</i> was determined using an enzyme-linked immunosorbent assay based on a cross-sectional study conducted in Beijing and Tianjin, China. Factors potentially associated with <i>E. histolytica</i> infection were identified by logistic regression analysis.</p><p>Results</p><p>A total of 602 MSM were included in the study and the laboratory data on serostatus of <i>E. histolytica</i> were available for 599 of them (99.5%). 246 (41.1%) and 51 (8.5%) of the study participants were <i>E. histolytica</i> seropositive and HIV seropositive, respectively. Univariate analyses suggested preferred anal sex behaviors were associated with <i>E. histolytica</i> seropositivity. In multivariate logistic regression analysis, “only has receptive anal sex” (OR: 2.03; 95% CI: 1.22 3.37), “majority receptive anal sex” (OR: 1.83; 95% CI: 1.13, 2.95), and “sadomasochistic behavior (SM)” (OR: 2.30; 95% CI: 1.04, 5.13) were found to be significantly associated with <i>E. histolytica</i> infection.</p><p>Conclusions</p><p>High seroprevalence of <i>E. histolytica</i> infection was observed among MSM from Beijing and Tianjin, China. Receptive anal sex behavior and SM were identified as potential predictors. Therefore, <i>E. histolytica</i> and HIV co-infection needs to be concerned among MSM due to their sharing the common risk behaviors.</p></div

Flow Diagram of study design.

<p>Flow Diagram of study design.</p