Rigid Body Dynamics using Equimomental Systems of Point-Masses

The inertia matrix of any rigid body is the same as the inertia matrix of some system of four point-masses. In this work the possible disposition of these point-masses is investigated. It is found that every system of possible point-masses with the same inertia matrix can be parameterised by the elements of the orthogonal group in four dimensions modulo permutation of the points. It is shown that given a fixed inertia matrix, it is possible to find a system of point-masses with the same inertia matrix but where one of the points is located at some arbitrary point. It is also possible to place two point-masses on an arbitrary line or three of the points on an arbitrary plane. The possibility of placing some of the point- masses at infinity is also investigated. Applications of these ideas to rigid-body dynamics is considered. The equation of motion for a rigid body is derived in terms of a system of four point-masses. These turn out to be very simple when written in a 6-vector notation

Preparation and Properties of PTFE-PMMA Core-Shell Nanoparticles and Nanocomposites

he preparation of polytetrafluoroethylene-poly(methyl methacrylate) (PTFE-PMMA) core-shell particles was described, featuring controlled size and narrow size distribution over a wide compositional range, through a seeded emulsion polymerization starting from a PTFE seed of 26 nanometers. Over the entire MMA/PTFE range, the particle size increases as the MMA/PTFE ratio increases. A very precise control over the particle size can be exerted by properly adjusting the ratio between the monomer and the PTFE seed. Particles in the 80240 nm range can be prepared with uniformity indexes suited to build 2D and 3D colloidal crystals. These core-shell particles were employed to prepare nanocomposites with different compositions, through an annealing procedure at a temperature higher than the glass transition temperature of the shell forming polymer. A perfect dispersion of the PTFE particles within the PMMA matrix was obtained and optically transparent nanocomposites were prepared containing a very high PTFE amount

Effect of Thiamine Pyrophosphate (Bicarbossilasi®) Administration on the Exercising Horse Metabolism

Thiamine pyrophosphate (TPP) is the phosphorylated and active form of thiamine (Vitamin B1). We hypothesized that the administration of thiamine in its immediately available active form could provide the metabolic pathways for a supplement able to promote the metabolism of ketoacids and to reduce lactate accumulation in exercising horses. Ten horses were conditioned for 20 days to daily standardized exercise. All horses underwent a first “stress test” (ST) consisting in 1,200 meters at maximum speed on track, and were checked before and after for clinical and clinical pathology parameters. After the ST, the same animals were administered TPP (Bicarbossilasi®, ©Teknofarmas.p.a., Torino, Italy), 1 mg/Kg b.w., I.V., twice daily for seven days. At the end of treatment, a second stress test (STTPP) was performed. Post-exercise serum lactate concentration resulted in significantly lower levels (p< 0.05) after treatment with TPP (ST vs STTPP). These data suggest that supplementation with thiamine in its active form improves glucose metabolism and prevents lactate accumulation in muscle, enhancing aerobic capacity and metabolic pathways of glucose utilization during exercise

Three-Dimensional Automated, Machine-Learning-Based Left Heart Chamber Metrics: Associations with Prevalent Vascular Risk Factors and Cardiovascular Diseases

Background. Three-dimensional transthoracic echocardiography (3DE) powered by artificial intelligence provides accurate left chamber quantification in good accordance with cardiac magnetic resonance and has the potential to revolutionize our clinical practice. Aims. To evaluate the association and the independent value of dynamic heart model (DHM)-derived left atrial (LA) and left ventricular (LV) metrics with prevalent vascular risk factors (VRFs) and cardiovascular diseases (CVDs) in a large, unselected population. Materials and Methods. We estimated the association of DHM metrics with VRFs (hypertension, diabetes) and CVDs (atrial fibrillation, stroke, ischemic heart disease, cardiomyopathies, &gt;moderate valvular heart disease/prosthesis), stratified by prevalent disease status: participants without VRFs or CVDs (healthy), with at least one VRFs but without CVDs, and with at least one CVDs. Results. We retrospectively included 1069 subjects (median age 62 [IQR 49–74]; 50.6% women). When comparing VRFs with the healthy, significant difference in maximum and minimum indexed atrial volume (LAVi max and LAVi min), left atrial ejection fraction (LAEF), left ventricular mass/left ventricular end-diastolic volume ratio, and left ventricular global function index (LVGFI) were recorded (p &lt; 0.05). In the adjusted logistic regression, LAVi min, LAEF, LV ejection fraction, and LVGFI showed the most robust association (OR 3.03 [95% CI 2.48–3.70], 0.45 [95% CI 0.39–0.51], 0.28 [95% CI 0.22–0.35], and 0.22 [95% CI 0.16–0.28], respectively, with CVDs. Conclusions. The present data suggested that novel 3DE left heart chamber metrics by DHM such as LAEF, LAVi min, and LVGFI can refine our echocardiographic disease discrimination capacity

Quantification of Myocardial Contraction Fraction with Three-Dimensional Automated, Machine-Learning-Based Left-Heart-Chamber Metrics: Diagnostic Utility in Hypertrophic Phenotypes and Normal Ejection Fraction

Aims: The differentiation of left ventricular (LV) hypertrophic phenotypes is challenging in patients with normal ejection fraction (EF). The myocardial contraction fraction (MCF) is a simple dimensionless index useful for specifically identifying cardiac amyloidosis (CA) and hypertrophic cardiomyopathy (HCM) when calculated by cardiac magnetic resonance. The purpose of this study was to evaluate the value of MCF measured by three-dimensional automated, machine-learning-based LV chamber metrics (dynamic heart model [DHM]) for the discrimination of different forms of hypertrophic phenotypes. Methods and Results: We analyzed the DHM LV metrics of patients with CA (n = 10), hypertrophic cardiomyopathy (HCM, n = 36), isolated hypertension (IH, n = 87), and 54 healthy controls. MCF was calculated by dividing LV stroke volume by LV myocardial volume. Compared with controls (median 61.95%, interquartile range 55.43–67.79%), mean values for MCF were significantly reduced in HCM—48.55% (43.46–54.86% p &lt; 0.001)—and CA—40.92% (36.68–46.84% p &lt; 0.002)—but not in IH—59.35% (53.22–64.93% p &lt; 0.7). MCF showed a weak correlation with EF in the overall cohort (R2 = 0.136) and the four study subgroups (healthy adults, R2 = 0.039 IH, R2 = 0.089; HCM, R2 = 0.225; CA, R2 = 0.102). ROC analyses showed that MCF could differentiate between healthy adults and HCM (sensitivity 75.9%, specificity 77.8%, AUC 0.814) and between healthy adults and CA (sensitivity 87.0%, specificity 100%, AUC 0.959). The best cut-off values were 55.3% and 52.8%. Conclusions: The easily derived quantification of MCF by DHM can refine our echocardiographic discrimination capacity in patients with hypertrophic phenotype and normal EF. It should be added to the diagnostic workup of these patients

Cirurgia de catarata em cães: observações trans e pós-operatórias em 10 casos

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Antioxidant capacity, phenolic and vitamin C contents of quinoa (Chenopodium quinoa Willd.) as affected by sprouting and storage conditions

Antioxidant capacity (AC) of quinoa (Chenopodium quinoa Willd. cv. Real) seeds and sprouts obtained after 4 days of seed germination at 20°C and 70% humidity was evaluated using trolox equivalent antioxidant capacity (TEAC) and oxygen radical absorbance capacity (ORAC) assays, able to highlight reducing activity and peroxyl radical scavenging capacity, respectively; phenolic content (PC) was also measured. Both TEAC and ORAC assays revealed a significantly higher (about 2- and 2.8-fold, respectively) AC of 4-day-old sprouts compared to seeds; consistently, also PC values of sprouts resulted about 2.6 times higher than seeds. In order to investigate the influence of storage on AC and PC, as well as on vitamin C content (VCC), 4-day-old sprouts were subjected for 7 days at 5°C to three different conditions of controlled atmosphere storage (CAS) compared with air. Interestingly, whatever the CAS conditions, storage of quinoa sprouts up to 7 days induced an increase of AC evaluated in terms of reducing activity by TEAC assay. Consistently, an increase of PC and VCC was measured during storage, positively correlated to TEAC values. Moreover, a decrease of peroxyl radical scavenging activity, measured by ORAC, was observed after 7 days of storage, in accordance with a shift of AC towards the reducing activity component. Overall, these findings indicate that sprouting approach using quinoa may provide highly antioxidant-enriched seedlings that may improve nutritional quality of diet or of functional foods. Interestingly, antioxidant properties of quinoa sprouts may be deeply influenced by storage, able to increase reducing activity by increasing phenols and vitamin C

Osimertinib versus platinum-pemetrexed for patients with EGFR T790M advanced NSCLC and progression on a prior EGFR-tyrosine kinase inhibitor: AURA3 overall survival analysis.

In AURA3 (NCT02151981), osimertinib, a third-generation epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI), significantly prolonged progression-free survival and improved response in patients with EGFR T790M advanced non-small-cell lung cancer (NSCLC) and progression on prior EGFR-TKI treatment. We report the final AURA3 overall survival (OS) analysis.Adult patients were randomized 2 : 1 to osimertinib (80 mg orally, once daily) or pemetrexed plus carboplatin/cisplatin (platinum-pemetrexed) intravenously, every 3 weeks (≤6 cycles). Patients could crossover to osimertinib on progression confirmed by blinded independent central review. OS and safety were secondary end points.A total of 279 patients were randomly assigned to receive osimertinib and 140 to platinum-pemetrexed (136 received treatment). At data cut-off (DCO; 15 March 2019), 188 patients (67%) receiving osimertinib versus 93 (66%) receiving platinum-pemetrexed had died. The hazard ratio (HR) for OS was 0.87 [95% confidence interval (CI) 0.67-1.12; P = 0.277]; the median OS was 26.8 months (95% CI 23.5-31.5) versus 22.5 months (95% CI 20.2-28.8) for osimertinib and platinum-pemetrexed, respectively. The estimated 24- and 36-month survival was 55% versus 43% and 37% versus 30%, respectively. After crossover adjustment, there was an HR of 0.54 (95% CI 0.18-1.6). Time to first subsequent therapy or death showed a clinically meaningful advantage toward osimertinib (HR 0.21, 95% CI 0.16-0.28; P0.001). At DCO, 99/136 (73%) patients in the platinum-pemetrexed arm had crossed over to osimertinib, 66/99 (67%) of whom had died. The most common adverse events possibly related to study treatment were diarrhea (32%; grade ≥3, 1%) and rash (grouped term; 32%; grade ≥3,1%) in the osimertinib arm, versus nausea (47%; grade ≥3, 3%) in the platinum-pemetrexed arm.In patients with T790M advanced NSCLC, no statistically significant benefit in OS was observed for osimertinib versus platinum-pemetrexed, which possibly reflects the high crossover rate of patients from platinum-pemetrexed to osimertinib.ClinicalTrials.gov NCT02151981; https://clinicaltrials.gov/ct2/show/NCT02151981