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Multi-axis additive manufacturing enables high flexibility of material deposition along dynamically varied directions. The Cartesian motion platforms of these machines include three parallel axes and two rotational axes. Singularity on rotational axes is a critical issue to be tackled in motion planning for ensuring high quality of manufacturing results. The highly nonlinear mapping in the singular region can convert a smooth toolpath with uniformly sampled waypoints defined in the model coordinate system into a highly discontinuous motion in the machine coordinate system, which leads to over-extrusion/under-extrusion of materials in filament-based additive manufacturing. The problem is challenging as both the maximal and the minimal speeds at the tip of a printer head must be controlled in motion. Moreover, collision may occur when sampling-based collision avoidance is employed. In this letter, we present a motion planning method to support the manufacturing realization of designed toolpaths for multi-axis additive manufacturing. Problems of singularity and collision are considered in an integrated manner to improve the motion therefore the quality of fabrication.

3例精氨酸联合可乐定复合激发试验患儿于药物激发第2天出现肉眼血尿，激发后6 d内快速消退，尿红细胞形态学分析提示肾小球性来源。该血尿是良性、一过性的，预后良好；临床医师在矮身材儿童诊治中应严格把握激发试验适应证。.

To identify the valuable predictors of grade≥2 radiation pneumonitis (RP) in patient treated with radiotherapy after pneumonectomy for non-small cell lung cancer (NSCLC); and to construct a nomogram predicting the incidence of grade≥2 RP in such patients.We reviewed 82 patients with NSCLC received radiotherapy after pneumonectomy from 2008 to 2018. The endpoint was grade≥2 RP. Univariate and multivariate regression analysis were conducted to evaluate significant factors of grade≥2 RP. Receiver operating characteristic (ROC) curve was used to establish optimal cutoff values and the nomogram was built to make the predictive model visualized. Descriptive analysis was performed on 5 patients with grade 3 RP.A total of 22(26.8%) patients developed grade 2 RP and 5(6.1%) patients were grade 3 RP. V5, V10, V20, V30, MLD, PTV, and PTV/TLV were associated with the occurrence of grade≥2 RP in univariate analysis, while none of the clinical factors was significant; V5(OR,1.213;95%CI,1.099-1.339; P0.001) and V20(OR,1.435;95%CI,1.166-1.765; P=0.001) were the independent significant predictors by multivariate analysis and were included in the nomogram. The ROC analysis for the cutoff values for predicting grade≥2 RP were V523% (AUC=0.819, sensitivity:0.701, specificity:0.832) and V208% (AUC=0.812, sensitivity:0.683, specificity:0.811). Additionally, grade≥3 RP did not occur when V530%, V2013% and MLD751.2cGy, respectively.Our study showed that V5 and V20 were independent predictors for grade≥2 RP in NSCLC patients receiving radiotherapy after pneumonectomy. Grade 3 RP did not occur whenV530%, V2013% and MLD751.2cGy, respectively. In addition, patient underwent right pneumonectomy may have a lower tolerance to radiation compared to left pneumonectomy.

Synthetic hydroxyapatite (HA) and its related materials have made great progress in basic research and clinical application in spinal repair and reconstruction. However, the effect of HA and its composites used in spinal fusion still remained controversial. This meta-analysis aimed at evaluating the efficacy and safety of HA compared with autologous bone.A systematic search in PubMed, MEDLINE, China National Knowledge Internet, EMBASE, and the Cochrane Library was conducted for relevant studies from inception until May 2021. Studies investigating the application of HA and its related composites in spinal fusion were selected for analysis.The operation time of patients treated with artificial bone containing HA was less than that of patients with autologous bone (p = 0.02). The amount of operative blood loss in patients in the HA group was less than that in the autograft group (p = 0.007). Patients treated with autologous bone got a more significant advantage in fusion rate at 6 months (p = 0.009). Nevertheless, there was no significant difference in the fusion rate between patients in the two groups at 12 months or no less than 24 months postoperatively (p = 0.24; p = 0.87). Compared to the autograft group, the HA group significantly decreased postoperative adverse events (p = 0.03). Furthermore, there was no significant difference in the Oswestry Disability Index (p = 1.00) nor the Visual Analogue Scale score (p = 0.94) between the two groups.This meta-analysis suggests that the clinical application of HA and its related composite materials in spinal reconstruction is comparable to that of autologous bone, with satisfactory efficacy and safety.