Using a smartphone acceleration sensor to study uniform and uniformly accelerated circular motions

The acceleration sensor of a smartphone is used for the study of the uniform and uniformly accelerated circular motions in two experiments. Data collected from both experiments are used for obtaining the angular velocity and the angular acceleration, respectively. Results obtained with the acceleration sensor are shown to be in good agreement with alternative methods, like using video recordings of both experiments and a physical model of the second experiment.Castro-Palacio, JC.; Velazquez, L.; Gómez-Tejedor, JA.; Manjón Herrera, FJ.; Monsoriu Serra, JA. (2014). Using a smartphone acceleration sensor to study uniform and uniformly accelerated circular motions. Revista Brasileira de Ensino de Fisica. 36(2):2315-2315. doi:10.1590/S1806-11172014000200015S2315231536

Experimental verification of the motion of a loaded hoop

We report the results of an experiment on the rolling motion of a loaded hoop. The data are obtained using a high-speed video camera, and the motion is analyzed on a frame-by-frame basis. Our analysis demonstrates that the experimental results are in reasonably close agreement with previously reported theoretical results. © 2012 American Association of Physics Teachers

Premasticating food for weaning african infants: A possible vehicle for transmission of HIV

BACKGROUND: Although premastication of food for weaning infants might have nutritional benefit, it is also associated with transmission of pathogens. We investigated premastication practices in Cape Town, South Africa, in lower socioeconomic status caregivers of infants below 2 years of age. METHODS: A previously reported questionnaire was adapted for South African conditions. A convenience sample of infant caregivers was captured at public maternal/pediatric and HIV outpatient clinics and home visits. RESULTS: We interviewed 154 caregivers, 92% of whom were the biological mothers (median age: 29). Of these, 70% were black, and 29% were colored. There were 106 (69%) caregivers who practiced premastication. The median age of infants who received premasticated food was 6 (interquartile range: 4-6) months. Forty-six (43%) infants were teething, and 44 (42%) had oral mucosal lesions while receiving premasticated food. Fifty-five (52%) caregivers reported an oral condition, mostly bleeding gums, mouth sores, and thrush, and 41 (39%) caregivers reported blood in the food. Premasticating caregivers had a significantly lower educational level than those caregivers who did not engage in this practice. Premastication practices were cultural (40%), habit (20%), and on mother's advice (75%). Reasons for premastication were to pretaste (68%), encourage eating (61%), estimate food temperature (85%), and homogenize food (60%). CONCLUSIONS: Counselors and caregivers should be aware of the adverse effects of premastication. Education should include advice to avoid premastication and to seek health advice for oral conditions in the caregiver and child. More studies are needed to better define the extent and risks of premastication, including its possible role in increasing HIV-1 transmission. Copyright © 2011 by the American Academy of Pediatrics.Articl

Inertial microfluidic purification of CAR-T-Cell products

Published online: December 8, 2021Chimeric antigen receptor T (CAR-T) cell therapy is rapidly becoming a frontline cancer therapy. However, the manufacturing process is time-, labor- and cost-intensive, and it suffers from significant bottlenecks. Many CAR-T products fail to reach the viability release criteria set by regulators for commercial cell therapy products. This results in non-recoupable costs for the manufacturer and is detrimental to patients who may not receive their scheduled treatment or receive out-of-specification suboptimal formula-tion. It is demonstrated here that inertial microfluidics can, within minutes, efficiently deplete nonviable cells from low-viability CAR-T cell products. The percentage of viable cells increases from 40% (SD ± 0.12) to 71% (SD ± 0.09) for untransduced T cells and from 51% (SD ± 0.12) to 71% (SD ± 0.09) for CAR-T cells, which meets the clinical trials’ release parameters. In addition, the processing of CAR-T cells formulated in CryStor yields a 91% reduction in the amount of the cryoprotectant dimethyl sulfoxide. Inertial microfluidic processing has no detrimental effects on the proliferation and cytotoxicity of CAR-T cells. Interestingly, ≈50% of T-regulatory and T-suppressor cells are depleted, suggesting the potential for inertial microfluidic processing to tune the phenotypical composition of T-cell products.Mona T. Elsemary, Michelle F. Maritz, Louise E. Smith, Majid Warkiani, Veronika Bandara, Silvana Napoli, Simon C. Barry, Justin T. Coombs, and Benjamin Thie

The ASOS Surgical Risk Calculator: development and validation of a tool for identifying African surgical patients at risk of severe postoperative complications

Background: The African Surgical Outcomes Study (ASOS) showed that surgical patients in Africa have a mortality twice the global average. Existing risk assessment tools are not valid for use in this population because the pattern of risk for poor outcomes differs from high-income countries. The objective of this study was to derive and validate a simple, preoperative risk stratification tool to identify African surgical patients at risk for in-hospital postoperative mortality and severe complications. Methods: ASOS was a 7-day prospective cohort study of adult patients undergoing surgery in Africa. The ASOS Surgical Risk Calculator was constructed with a multivariable logistic regression model for the outcome of in-hospital mortality and severe postoperative complications. The following preoperative risk factors were entered into the model; age, sex, smoking status, ASA physical status, preoperative chronic comorbid conditions, indication for surgery, urgency, severity, and type of surgery. Results: The model was derived from 8799 patients from 168 African hospitals. The composite outcome of severe postoperative complications and death occurred in 423/8799 (4.8%) patients. The ASOS Surgical Risk Calculator includes the following risk factors: age, ASA physical status, indication for surgery, urgency, severity, and type of surgery. The model showed good discrimination with an area under the receiver operating characteristic curve of 0.805 and good calibration with c-statistic corrected for optimism of 0.784. Conclusions: This simple preoperative risk calculator could be used to identify high-risk surgical patients in African hospitals and facilitate increased postoperative surveillance. © 2018 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.Medical Research Council of South Africa gran