A LIE GROUP APPROACH TO THE MODULAR MODELING OF KINEMATICALLY NON-REDUNDANT PARALLEL MECHANISMS
PROCEEDINGS OF THE ASME INTERNATIONAL DESIGN ENGINEERING TECHNICAL CONFERENCES AND COMPUTERS AND INFORMATION IN ENGINEERING CONFERENCE, 2019, VOL 6
Authors: Mueller, Andreas
Abstract
Parallel kinematics manupulators (PKM) are established robotic systems. Yet there is no established modeling approach that takes into account the special kinematics of the (usually structurally identical) limbs. In this paper a modeling approach is proposed that accounts for the special kinematics and topology of PKM. It makes use of modern Lie group formulations for rigid body systems that admits efficient description independent of modeling conventions. A task space formulation is presented that can be directly used for model-based control purposes.
Glycolysis gene expression analysis and selective metabolic advantage in the clinical progression of colorectal cancer
PHARMACOGENOMICS JOURNAL
Authors: Graziano, F.; Ruzzo, A.; Giacomini, E.; Ricciardi, T.; Aprile, G.; Loupakis, F.; Lorenzini, P.; Ongaro, E.; Zoratto, F.; Catalano, V.; Sart, D.; Rulli, E.; Cremolini, C.; De Nictolis, M.; De Maglio, G.; Falcone, A.; Fiorentinil, G.; Magnani, M.
Abstract
Production of lactate even in the presence of sufficient levels of oxygen (aerobic glycolysis) seems the prevalent energy metabolism pathway in cancer cells. The analysis of altered expression of effectors causing redirection of glucose metabolism would help to characterize this phenomenon with possible therapeutic implications. We analyzed mRNA expression of the key enzymes involved in aerobic glycolysis in normal mucosa (NM), primary tumor (PT) and liver metastasis (LM) of colorectal cancer (CRC) patients (pts) who underwent primary tumor surgery and liver metastasectomy. Tissues of 48 CRC pts were analyzed by RT-qPCR for mRNA expression of the following genes: hexokinase-1 (HK-1) and 2 (HK-2), embryonic pyruvate kinase (PKM-2), lactate dehydrogenase-A (LDH-A), glucose transporter-1 (GLUT-1), voltage-dependent anion-selective channel protein-1 (VDAC-1). Differences in the expression of the candidate genes between tissues and associations with clinical/pathologic features were studied. GLUT-1, LDH-A, HK-1, PKM-2 and VDAC-1 mRNA expression levels were significantly higher in PT/LM tissues compared with NM. There was a trend for higher expression of these genes in LM compared with PT tissues, but differences were statistically significant for LDH-A expression only. RAS mutation-positive disease was associated with high GLUT-1 mRNA expression levels only. Right-sided colon tumors showed significantly higher GLUT-1, PKM-2 and LDH-A mRNA expression levels. High glycolytic profile was significantly associated with poor prognosis in 20 metastatic, RAS-mutated pts treated with first-line chemotherapy plus Bevacizumab. Altered expression of effectors associated with upregulated glucose uptake and aerobic glycolysis occurs in CRC tissues. Additional analyses are warranted for addressing the role of these changes in anti-angiogenic resistance and for developing novel therapeutics.