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Objective To investigate the optimal clinical therapy effects and prognostic factors of cerebral arteriovenous malformation (CAVM) in children following different treatment methods. Methods The clinical data of 47 children (< 18 years old) with CAVM who were admitted to Tianjin Huanhu Hospital from October 2011 to September 2022 were collected, and the multimodality treatment and prognostic factors of different grades were analyzed. Spetzler - Martin grading system and vascular nest dispersion classification were used to evaluate the risk and angiogenesis of CAVM, different treatment modalities such as microsurgery, gamma knife radiosurgery, and multi-mode therapy were used to evaluate the total resection rate, prognosis, and imaging follow-up results. Results 1) Treatment plan: among the total 47 children in this group, 35 (74.47%) received simple microsurgery, of which 10 (28.57%) suffered surgery within one week of hemorrhage, and 25 (71.43%) suffered surgery over one week; 6 (12.77%) received conservative treatment; 3 (6.38%) received gamma knife radiosurgery; 3 (6.38%) received multimodal therapy (microsurgery + interventional embolism/gamma knife radiosurgery). 2) Spetzler - Martin grading and prognosis: among the 38 patients (80.85%) of Spetzler - Martin grade Ⅰ - Ⅲ , 29 (76.32%) underwent microsurgery, one (2.63%) received multimodal therapy, and 2 (5.26%) received gamma knife radiosurgery. The total surgical resection rate was 9/9 in grade Ⅰ, 13/14 in grade Ⅱ and 6/9 in grade Ⅲ. Eight patients (21.05%) had a poor prognosis during 5 years followed-up period. There was one (2.63%) recurrence on imaging follow-up. Among 9 patients whose Spetzler-Martin grade were between Ⅳ and Ⅴ , 6 patients underwent microsurgery, 2 patients received multimodal therapy, and one received gamma knife radiosurgery. Total surgical resection rate was 4/8 in grade Ⅳ and 1/1 in grade Ⅴ, and prognosis was poor in 5 cases. 3) Diffusion classification and prognosis of malformed vascular mass: the total resection rate of dense type was 17/17, and that of diffuse type was 66.67% (16/24). The incidence of poor prognosis was 3/ 18 for dense type and 34.48% (10/29) for diffuse type. Conclusions Microsurgery resection is a relatively safe and effective method for the treatment of CAVM in children. The operation was recommended to be performed at least one week after acute hemorrhage if possible. A preoperative evaluation of surgical risks and the density of abnormal vascular clusters can assist in selecting the best treatment plan, thus could increase the total resection rate of lesions and improve the prognosis.

In the fixed prosthesis process dental prosthesis treatment, the dentist needs to conceive the morphology of the tooth preparation and make numerous micro-adjustments by manual operation. This study aims to establish a digital design system for accurate designing of veneer preparation and study the trajectory planning of the robot-assisted preparation. According to the standard operation requirements, the projection line segmentation method based on point drawing is proposed for interactive selection to ensure the margin smoothness of the preparation area. The preparation depth is parameterized, and the foldback point correction method based on secondary segmentation is used for repairing the offset preparation area to ensure surface smoothness. The fenestration preparation model was obtained in the digital interactive design software. The model is divided into two feature areas which are interpolated by the B-spline curve and NURBS surface, respectively. The isoparametric curve method is used to plan the preparation trajectory. The experimental and theoretical values of the target feature points from the X, Y and Z coordinate directions were also calculated and analyzed. The experiment is carried out by the physical prototype of the tooth preparation robot. The maximum error of the feature points on the preparation are 0.180 mm, 0.104 mm and 0.142 mm in X, Y and Z directions, respectively. The confidence interval of the system error is stable within 0.30 mm. The error of the feature points verifies the feasibility of the digital interactive design system and the correctness of the trajectory planning of tooth veneer preparation. The system could have the potential to assist dentists in the precise design of the veneer preparation, improve the processing efficiency and ensure the effect of tooth veneer prosthesis.

Novel surface molecularly imprinted polymers (MIPs) combined to restricted access materials (RAMs) were prepared by reversible addition-fragmentation chain transfer (RAFT) polymerization for selective and efficient determination of 17[beta]-estradiol (E2) in milk powder. TiO.sub.2 nanoparticles were coated by a MIP layer via RAFT polymerization and formed a core-shell structure. 3-Glycidoxypropyltrimethoxysilane was grafted on the surface of MIP and hydrolyzed to form hydroxyl group to block unspecific adsorption of macromolecules. RAM-MIPs were characterized by infrared, thermal analyzer, surface area and porosimeter analyzer, and others. RAM-MIP exhibited efficient adsorption performance for E2. E2 in milk powder was dissolved in water, cleaned up by RAM-MIP solid phase extraction cartridge, silanized by N-methyl-N-(trimethylsilyl)trifluoroacetamide, dithioerythritol, and trimethyliodosilane, and determined by gas chromatography-mass spectrometry. The limit of quantification for E2 in milk powder samples was 0.001 mg/kg. The recoveries and relative standard deviations of E2 spiked at 0.001-0.01 mg/kg were 82.0-107.5% and 2.9-5.8%, respectively. Thus, RAM-MIP can be successfully applied to the determination of E2 in milk powder samples., Author(s): Hai Gen Zuo [sup.1] , Xiao Yu Liu [sup.1] , Yong Qin Du [sup.1] , Shi Yu Xiong [sup.1] , Ren Qing Hao [sup.1] , Zhi Fang Huang [sup.1] [...]

The mechanism of hydrolysis and extension diffusion of heavy metal pollution elements infiltrated into rock is analyzed by the theory of ion hydrolysis displacement. The hydrolysis properties of typical elements such as cadmium, zinc, lead, and copper are verified by convective dispersion model, and the diffusion law and fission characteristics of heavy metal with different hydrolysis constant are discussed. A three-dimensional constitutive relation model of rock extension diffusion surface is established by combining viscoelastic monomer model with a damage monomer model. Considering the influence of diffusion coefficient, hydrolysis constant, deformation factor, and other parameters, the rationality of the test results and model fitting results of heavy metal invading rock are verified. The results show that the replacement rate of colloidal mineral elements in rock varies with different hydrolysis constant, when the hydrolysis constant is large, the extension diffusion rate in rock is large; otherwise, the extension diffusion rate is small. Constitutive relation curves of polluted rock with different lithologies are in good agreement with the fitting results of the combination model under the influence of the same test conditions and the same parameters.