When machining narrow grooves, corners, and other complex cavities with trochoidal milling, the irrationally large trochoidal step usually leads to chatter, while the conservative trochoidal step constrains the machining efficiency. In this paper, a stability prediction model of trochoidal milling is established to solve these problems. An approach considering trochoidal steps and spindle speeds is presented to predict stability boundary of trochoidal milling. With considering the varying cutter-workpiece engagements, the stability of trochoidal milling process is predicted by obtaining the stability lobes of different cutter location (CL) points along the trochoidal milling tool paths. Based on the proposed stability model, a trochoidal step optimization strategy is developed to improve the machining efficiency of trochoidal milling under other parameters in a given situation. Cutting experiments are performed on the machining center GMC 1600H/2 to show the effectiveness of the proposed trochoidal milling stability model. Finally, simulations are adopted to illustrate the optimization strategy.

A 3-year-old male child, who presented with fever for 4 days, was admitted to our hospital. The blood count analysis showed elevated white blood cells (151 x10 9 /L), decreased hemoglobin (Hb, 55 g/L), and neutrophil and lymphocyte percentages of 7.5% and 91.3%, respectively. The peripheral blood and bone marrow smear showed that the blast percentages were 79% and 73.5%, respectively. Flow cytometry of the bone marrow identified a 79.5% abnormal cell population of nuclear cells, which was positive for HLA-DR (91.94%), CD13 (76.22%), CD33 (94.25%), CD34 (30.43%), CD38 (79.99%), CD117 (96.76%), CD123 (98.93%), and MPO (47.52%). Acute myeloid leukemia (AML) prognostic gene sequencing detected a mutation in IDH1(NM_001282386 c. 395G>A (p. R132H)), and whole-exome sequencing and RNA sequencing of hematological malignancies were also performed. The patient was diagnosed with AML (M2) and hyperleukocytosis, and was tentatively classified as at intermediate risk.

Hypothyroidism as a long-term complication in cancer survivors has been an issue, but few studies have focused on changes in thyroid hormone levels during chemotherapy for leukaemia. This retrospective study was conducted to assess the characteristics of children with acute lymphoblastic leukaemia (ALL) and hypothyroidism during induction chemotherapy and to investigate the prognostic value of hypothyroidism in ALL. Patients with a detailed thyroid hormone profile at ALL diagnosis were enrolled. Hypothyroidism was defined as low serum levels of free tetraiodothyronine (FT4) and/or free triiodothyronine (FT3). The Kaplan-Meier method was used to create survival curves, and multivariate Cox regression analysis was used to screen prognostic factors associated with progression-free survival (PFS) and overall survival (OS). There were 276 children eligible for the study, and 184 patients (66.67%) were diagnosed with hypothyroidism, including 90 cases (48.91%) with functional central hypothyroidism and 82 cases (44.57%) with low T3 syndrome. Hypothyroidism was correlated with the dosages of L-Asparaginase (L-Asp) (P = .004) and glucocorticoids (P = .010), central nervous system (CNS) status (P = .012), number of severe infections (grade 3, 4 or 5) (P = .026) and serum albumin level (P = .032).Hypothyroidism was an independent prognostic factor for PFS in ALL children (P = .024, 95% CI: 1.1-4.1). We conclude that hypothyroidism is commonly present in ALL children during induction remission, which is related to chemotherapy drugs and severe infections. Hypothyroidism was a predictor of poor prognosis in childhood ALL.