StratMed: Relevance Stratification for Low-resource Medication Recommendation

With the growing imbalance between limited medical resources and escalating demands, AI-based clinical tasks have become paramount. Medication recommendation, as a sub-domain, aims to amalgamate longitudinal patient history with medical knowledge, assisting physicians in prescribing safer and more accurate medication combinations. Existing methods overlook the inherent long-tail distribution in medical data, lacking balanced representation between head and tail data, which leads to sub-optimal model performance. To address this challenge, we introduce StratMed, a model that incorporates an innovative relevance stratification mechanism. It harmonizes discrepancies in data long-tail distribution and strikes a balance between the safety and accuracy of medication combinations. Specifically, we first construct a pre-training method using deep learning networks to obtain entity representation. After that, we design a pyramid-like data stratification method to obtain more generalized entity relationships by reinforcing the features of unpopular entities. Based on this relationship, we designed two graph structures to express medication precision and safety at the same level to obtain visit representations. Finally, the patient's historical clinical information is fitted to generate medication combinations for the current health condition. Experiments on the MIMIC-III dataset demonstrate that our method has outperformed current state-of-the-art methods in four evaluation metrics (including safety and accuracy)

HfB2-SiC-MoSi2 oxidation resistance coating fabricated through in-situ synthesis for SiC coated C/C composites

A brand new HfB2-SiC-MoSi2 coating was fabricated to protect carbon/carbon (C/C) composites with inner SiC coating from oxidation, which was prepared by in-situ synthesis. In this paper, the C/C substrate with the protection of the HfB2-SiC-MoSi2/SiC coating could resist oxidation in 1773 K air for 408 h. The double coating also presented expected oxidation protection performance at dynamic oxidation environment. In the test process, the surface coating was oxidized to form a self-sealing silicate glass layer containing HfO2 and HfSiO4, which could hinder crack propagation in coating

DESIGN AND ANALYSIS OF AN INNER BURR REMOVAL DEVICE IN LONGITUDINALLY WELDED PIPE

The application field of longitudinally welded pipe is expanding day by day, and its quality requirements are increasing.The inner burr removal device, as a key equipment to improve the quality of the inner surface of the longitudinally welded pipe, has gradually attracted the attention of manufacturers.Taking the high frequency longitudinally welded pipe with constant bottom surface as the research object, an inner burr removal device was proposed based on the cantilever arbor to improve the burr scraping quality of the welded pipe.According to the working principle and functional requirements of the inner burr removal device, the structure of the inner burr removal device was designed and the three-dimensional model was established; According to the actual production conditions, using the ANSYS software, the finite element model of the inner burr removal device under different extreme working conditions was established and simulation analysis was performed to ensure the rationality of the structural design.The inner burr removal device, which integrates lifting, rotating, knife lifting and other auxiliary movements, also has the function of online breaking the inner burr, avoiding falling off inner burrs to block the welded pipe, enriching the functions of the inner burr removal device and laying a foundation for product development

A novel decoupled parallel mechanism with two translational and one rotational degree of freedom and its performance indices analysis

Less degrees of freedom parallel mechanism is widely used in many fields with its unique advantages. A decoupled parallel mechanism with 2 degree-of-freedom translation and 1 degree-of-freedom rotation is presented, and its performance evaluation indices analysis is performed. By the constraint screw method, the motion feature of the mechanism and its number of degree of freedom are analyzed. The constrained equations of the mechanism are established according to the constrained conditions of the pole length. The analytical expression of the forward and inverse position for the mechanism is deduced, and the expression of the Jacobian matrix is derived, which validated the decoupling feature of the mechanism. The singularity of the mechanism is also carried out. The performance evaluation indices for the decoupled parallel mechanism are discussed and the corresponding performance indices analysis of the proposed decoupled parallel mechanism is executed. The novel decoupled parallel mechanism presented herein enriches the parallel mechanism structure, and the definition and analysis of the performance evaluation indices should be meaningful for the further design and optimization of the decoupled parallel mechanism

Synthesis, characterization, and ceramization of a SiC–ZrC–C preceramic polymer precursor

A silicon- and zirconium-containing polymer precursor (PSZC) for SiC–ZrC–C ceramic was successfully synthesized by chemical reaction of phenol, paraformaldehyde, tetraethoxysilane, acetylacetone, and ZrOCl2·8H2O. The chemical structure, pyrolysis behaviors, and pyrolysis products of PSZC were characterized by the combination of FT-IR, 1H-NMR, TG-DTG, XRD, Raman, SEM, and EDS. It indicates that the obtained PSZC might be Zr–O–Zr and Si–O–Si chain polymer connected by Si–O–Zr bond with hydroxymethyl phenol and acetylacetone as ligands. And the most probable reaction mechanism to form PSZC was proposed. Decomposition of PSZC is completed at 800 °C, and it gives amorphous carbon, SiO2, and ZrO2 with a yield of 70 %. During heat treatment, SiC forms at about 1500 °C, followed by the appearance of ZrC. Defects of the carbon are cumulated to the highest at 1500 °C. Further heating at 1800 °C induces highly crystallized ZrC, SiC ceramic, and structure-ordered carbon with a structure of ZrC and SiC particles uniformly distributed in the carbon matrix

SINGULARITY CONFIGURATION AND MECHANICS UNLOADING ANALYSIS FOR 3-SPS/S SPHERICAL PARALLEL MECHANISM OF HIP JOINT

Combined with the actual structure and function characteristics of the human hip joint,3-SPS/S（ S for spherical pair,P for prismatic pair） spherical parallel mechanism is chosen as the prototype for the hip joint. After the inverse kinetic solution was solved,the singularity trajectory equations were established and the singular tracks were plotted. The static equilibrium equations of each component of the mechanism were established using the vector method. The curves of the exerted force on branches with the variety of poses were plotted by numerical examples,and then the mechanics unloading effect of the middle limb was analyzed. Through simulation analysis of the mechanism with ADAMS software,the force-time curves of the hinges fixed to the mechanism ’s branches corresponding to prescribed trajectory were obtained,which verified mechanics unloading function of mechanism. The research contents should possess certain theoretical guiding significance for the development and control of the hip joint of the humanoid robot

Layer zero-line modes in antiferromagnetic topological insulators

Recently, the magnetic domain walls have been experimentally observed in antiferromagnetic topological insulators MnBi$_2$Te$_4$, where we find that the topological zero-line modes (ZLMs) appear along the domain walls. Here, we theoretically demonstrate that these ZLMs are layer-dependent in MnBi$_2$Te$_4$ multilayers. For domain walls with out-of-plane ferromagnetism, we find that ZLMs are equally distributed in the odd-number layers. When domain walls possess in-plane magnetization, the ZLMs can also exist in even-number layers due to in-plane mirror-symmetry breaking. Moreover, the conductive channels are mainly distributed in the outermost layers with increasing layer thickness. Our findings lay out a strategy in manipulating ZLMs and also can be utilized to distinguish the corresponding magnetic structures.Published versionThis work was financially supported by the National Natural Science Foundation of China (Grants No. 11974327 and No. 12004369), Fundamental Research Funds for the Central Universities (WK3510000010 and WK2030020032), Anhui Initiative in Quantum Information Technologies (AHY170000)

Significance of CAVI, hs-CRP and Homocysteine in subclinical arteriosclerosis among a healthy population in China

Purpose: The purpose of this study is to evaluate the ability of cardio-ankle vascular index (CAVI), high-sensitivity C-reactive protein (hs-CRP) levels and homocysteine (Hcy) levels to screen for subclinical arteriosclerosis (subAs) in an apparently healthy population, with the view to obtaining an optimal diagnostic marker or profile for subAs. Methods: Subjects (152) undergoing routine health examinations were recruited and divided into two groups: carotid arteriosclerosis (CA) and non-carotid arteriosclerosis (NCA), according to carotid intima-media thickness (CMIT). CAVI was calculated based on blood pressure and pulse wave velocity. Serum hs-CRP and Hcy levels were also measured. A Receiver Operating Characteristic (ROC) curve was plotted to evaluate the efficacy of each in carotid arteriosclerosis screening. Ten parameter combinations, designated W1 to W10, were compared in terms of sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). Results: The levels of all three parameters were significantly higher in the CA group, compared with the NCA group. ROC curves showed that the area under the curve (AUC) for CAVI was 0.708 (95%CI: 0.615-0.800), which is significantly larger than that of either hs-CRP (0.622) or Hcy (0.630), respectively (P < 0.001). Maximum sensitivity (100%) and NPV (100%) were attained with W10, while maximum specificity (86.2%) and PPV (46.7%) were obtained with W7. With W9, the maximum Youden index (0.416) was obtained, with a sensitivity of 77.8% and specificity of 63.8%. Conclusions: CAVI is more effective than hs-CRP or Hcy for subAs screening. The optimal profile was obtained with a combination of CAVI and other parameters