41 research outputs found

    Geometric instability of graph neural networks on large graphs

    Full text link
    We analyse the geometric instability of embeddings produced by graph neural networks (GNNs). Existing methods are only applicable for small graphs and lack context in the graph domain. We propose a simple, efficient and graph-native Graph Gram Index (GGI) to measure such instability which is invariant to permutation, orthogonal transformation, translation and order of evaluation. This allows us to study the varying instability behaviour of GNN embeddings on large graphs for both node classification and link prediction

    Effects of toe-out and toe-in gaits on lower-extremity kinematics, dynamics, and electromyography

    Get PDF
    Toe-in and toe-out gait modifications have received increasing attention as an effective, conservative treatment for individuals without severe osteoarthritis because of its potential for improving knee adduction moment (KAM) and knee flexion moment (KFM). Although toe-in and toe-out gaits have positive effects on tibiofemoral (TF) joint pain in the short term, negative impacts on other joints of the lower extremity may arise. The main purpose of this study was to quantitatively compare the effects of foot progression angle (FPA) gait modification with normal walking speeds in healthy individuals on lower-extremity joint, ground reaction force (GRF), muscle electromyography, joint moment, and TF contact force. Experimental measurements using the Vicon system and multi-body dynamics musculoskeletal modelling using OpenSim were conducted in this study. Gait analysis of 12 subjects (n = 12) was conducted with natural gait, toe-in gait, and toe-out gait. One-way repeated measures of ANOVA (p < 0.05) with Tukey’s test was used for statistical analysis. Results showed that the toe-in and toe-out gait modifications decreased the max angle of knee flexion by 8.8 and 12.18 degrees respectively (p < 0.05) and the max angle of hip adduction by 1.28 and 0.99 degrees respectively (p < 0.05) compared to the natural gait. Changes of TF contact forces caused by FPA gait modifications were not statistically significant; however, the effect on KAM and KFM were significant (p < 0.05). KAM or combination of KAM and KFM can be used as surrogate measures for TF medial contact force. Toe-in and toe-out gait modifications could relieve knee joint pain probably due to redistribution of TF contact forces on medial and lateral condylar through changing lateral contact centers and shifting bilateral contact locations

    Strain Enhanced Visible–Ultraviolet Absorption of Blue Phosphorene/MoX2 (X = S,Se) Heterolayers

    Full text link
    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149231/1/pssr201800659.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149231/2/pssr201800659_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149231/3/pssr201800659-sup-0001-SuppFig-S1.pd

    Highly Efficient Polarized GeS/MoSe2 van der Waals Heterostructure for Water Splitting from Ultraviolet to Near‐Infrared Light

    Full text link
    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/152744/1/pssr201900582.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/152744/2/pssr201900582_am.pd

    Simulating storm surge and compound flooding events with a creek-to-ocean model: Importance of baroclinic effects

    Get PDF
    We present a creek-to-ocean 3D baroclinic model based on unstructured grids that aims to unite traditional hydrologic and ocean models in a single modeling platform, by taking full advantage of the polymorphism (i.e. a single model grid can seamlessly morph between full 3D, 2DV, 2DH and quasi-1D configurations). Using Hurricane Irene (2011)\u27s impact on the Delaware Bay as an example, a seamless 2D-3D model grid is implemented to include the entire US East Coast and Gulf of Mexico with a highly resolved Delaware Bay (down to 20-m resolution). The model is forced by flows from a hydrological model (National Water Model ) at the landward boundary. We demonstrate the model\u27s accuracy, stability and robustness with the simulation of the storm surge and subsequent river flooding events and compound surges. Through a series of sensitivity tests, we illustrate the importance of including in the simulation the baroclinic effects, as provided by the large-scale Gulf Stream, in order to correctly capture the adjustment process following the main surge and the subsequent compound flooding events. The baroclinicity can explain up to 14% of the elevation error during the adjustment phase after the storm

    Seasonal variations in carbon, nitrogen and phosphorus concentrations and C:N:P stoichiometry in different organs of a Larix principis-rupprechtii Mayr. plantation in the Qinling Mountains, China

    Get PDF
    Understanding how concentrations of elements and their stoichiometry change with plant growth and age is critical for predicting plant community responses to environmental change. Weusedlong-term field experiments to explore how the leaf, stem and root carbon (C), nitrogen (N) and phosphorous (P) concentrations and their stoichiometry changed with growth and stand age in a L.principis-rupprechtii Mayr. plantation from 2012–2015 in the Qinling Mountains, China. Our results showed that the C, N and P concentrations and stoichiometric ratios in different tissues of larch stands were affected by stand age, organ type andsampling month and displayed multiple correlations with increased stand age in different growing seasons. Generally, leaf C and N concentrations were greatest in the fast-growing season, but leaf P concentrations were greatest in the early growing season. However, no clear seasonal tendencies in the stem and root C, N and P concentrations were observed with growth. In contrast to N and P, few differences were found in organ-specific C concentrations. Leaf N:P was greatest in the fast-growing season, while C:N and C:P were greatest in the late-growing season. No clear variations were observed in stem and root C:N, C:P andN:Pthroughout the entire growing season, but leaf N:P was less than 14, suggesting that the growth of larch stands was limited by N in our study region. Compared to global plant element concentrations and stoichiometry, the leaves of larch stands had higher C, P, C:NandC:PbutlowerNandN:P,andtherootshadgreater PandC:NbutlowerN,C:Pand N:P. Our study provides baseline information for describing the changes in nutritional elements with plant growth, which will facilitates plantation forest management and restoration, and makes avaluable contribution to the global data pool on leaf nutrition and stoichiometry

    GaN LEDs with in situ synthesized transparent graphene heat-spreading electrodes fabricated by PECVD and penetration etching

    Get PDF
    Currently, applying graphene on GaN based electronic devices requires the troublesome, manual, lengthy, and irreproducible graphene transfer procedures, making it infeasible for real applications. Here, a semiconductor industry compatible technique for the in situ growth of patterned graphene directly onto GaN LED epiwafers for transparent heat-spreading electrode application is introduced. Pre-patterned sacrificial Co acts as both an etching mask for the GaN mesa and a catalyst for graphene growth. The Co helps in catalyzing the hydrocarbon decomposition and the subsequent graphitization, and is removed by wet etching afterwards. The use of plasma enhancement in the graphene chemical vapor deposition reduces the growth temperature to as low as 600 °C and improves the graphene quality, where highly crystalline graphene can be obtained in just 2 min of deposition. This method reduces the exposure of the GaN epilayers to high temperature to its limit, avoiding the well-known GaN decomposition and In segregation problems. Importantly, it can directly pattern the graphene without using additional lithographic steps and in doing so avoids any unintentional deleterious doping and damage of graphene from contact with the photoresist. The approach simplifies the fabrication and enables mass production by eliminating the bottlenecks of graphene transfer and patterning procedures. By comparing the GaN LEDs with and without graphene, we find that graphene greatly improves the device optical, electrical and thermal performances, due to the high optical transparency (91.74%) and high heat spreading capability of the graphene electrode. Unlike transferred graphene, this method is intrinsically scalable, reproducible, and compatible with the planar process, and is beneficial to the industrialization of GaN-graphene optoelectronic devices, where the integrated graphene serves as a superior sustainable and functional substitute to other transparent conducting materials such as ITO.<br/

    Biomarkers and risk factors for the early prediction of immune-related adverse events: a review

    No full text
    In recent years, immunotherapy has been widely used to treat patients with malignant tumors. While immune checkpoint inhibitors (ICIs) significantly improve the prognosis of cancer patients, the incidence of immune-related adverse events (irAEs) is increasing. Not only can irAEs accumulate in multiple organ systems throughout the body, but rare adverse reactions may also occur continuously. In severe cases, irAEs can be life-threatening or even lead to death. Therefore, the early identification, diagnosis and treatment of irAEs are very important. Early identification of patients with high-risk irAEs as well as the reduction or avoidance of severe irAEs have important clinical significance. This article will review the research progress of early predictive biomarkers and risk factors for the occurrence of irAEs and propose potential future directions for follow-up research and clinical applications

    PD-1 inhibitor treatment in a penile cancer patient with MMR/MSI status heterogeneity: A case report

    No full text
    Penile cancer is a rare malignant disease. Paclitaxel combined with platinum is often used as a first-line chemotherapeutic regimen for late-stage penile cancer, and there is no standard second-line treatment. Clinical trials of immunotherapy for penile cancer are ongoing. There are no reports on PD1 inhibitor treatment in metastatic penile carcinoma patients with MMR/MSI status heterogeneity. A 68-year-old patient was hospitalized with bilateral inguinal lymph node metastasis and local penile recurrence after penile cancer surgery. The lesion of the right inguinal lymph node showed a mismatch-repair-deficient (dMMR)/microsatellite instability-low (MSI-L) status. After 3 cycles of sintilimab (a PD1 inhibitor) combined with paclitaxel and cisplatin, the partial response of the tumor was evaluated. Subsequently, sintilimab monotherapy was used as maintenance treatment for 2 months. However, The lesion of local penile recurrence showed mismatch repair proficient (pMMR)/microsatellite stability (MSS) status by secondary biopsy when progressed rapidly. Interestingly, after continued treatment with sintilimab combined with gemcitabine, the patient achieved a partial response again. We should be aware of the importance of secondary biopsy for different lesions to confirm the heterogeneity of MMR/MSI status. For penile cancer patients with MMR/MSI status heterogeneity, PD1 inhibitors combined with chemotherapy are safe and effective. Due to oligometastatic lesion progression caused only by the heterogeneity of MMR/MSI status, PD1 inhibitor cross-line therapy can also be considered an appropriate treatment
    corecore