Dragonfly‐inspired wing design enabled by machine learning and Maxwell's reciprocal diagrams

Number theory, Algebra and Geometr

Compaction simulation of nano-crystalline metals with molecular dynamics analysis

The molecular-dynamics analysis is presented for 3D compaction simulation of nano-crystalline metals under uniaxial compaction process. The nano-crystalline metals consist of nickel and aluminum nano-particles, which are mixed with specified proportions. The EAM pair-potential is employed to model the formation of nano-particles at different temperatures, number of nano-particles, and mixing ratio of Ni and Al nano-particles to form the component into the shape of a die. The die-walls are modeled using the Lennard-Jones inter-atomic potential between the atoms of nano-particles and die-walls. The forming process is model in uniaxial compression, which is simulated until the full-dense condition is attained at constant temperature. Numerical simulations are performed by presenting the densification of nano-particles at different deformations and distribution of dislocations. Finally, the evolutions of relative density with the pressure as well as the stress-strain curves are depicted during the compaction process

Compaction simulation of nano-crystalline metals with molecular dynamics analysis

The molecular-dynamics analysis is presented for 3D compaction simulation of nano-crystalline metals under uniaxial compaction process. The nano-crystalline metals consist of nickel and aluminum nano-particles, which are mixed with specified proportions. The EAM pair-potential is employed to model the formation of nano-particles at different temperatures, number of nano-particles, and mixing ratio of Ni and Al nano-particles to form the component into the shape of a die. The die-walls are modeled using the Lennard-Jones inter-atomic potential between the atoms of nano-particles and die-walls. The forming process is model in uniaxial compression, which is simulated until the full-dense condition is attained at constant temperature. Numerical simulations are performed by presenting the densification of nano-particles at different deformations and distribution of dislocations. Finally, the evolutions of relative density with the pressure as well as the stress-strain curves are depicted during the compaction process

An autonomous oscillator times and executes centriole biogenesis

The accurate timing and execution of organelle biogenesis is crucial for cell physiology. Centriole biogenesis is regulated by Polo-like kinase 4 (Plk4) and initiates in S-phase when a daughter centriole grows from the side of a preexisting mother. Here we show that Plk4 forms an adaptive oscillator at the base of the growing centriole to initiate and time centriole biogenesis, ensuring that centrioles grow at the right time and to the right size. The Plk4 oscillator is normally entrained to the cell-cycle oscillator, but can run autonomously of it – explaining how centrioles can duplicate independently of cell cycle progression under certain conditions. Mathematical modelling indicates that this autonomously oscillating system is generated by a time-delayed negative-feedback loop in which Plk4 inactivates its centriolar receptor through multiple rounds of phosphorylation. We postulate that such organelle-specific autonomous oscillators could regulate the timing and execution of organelle biogenesis more generally

An autonomous oscillator times and executes centriole biogenesis

The accurate timing and execution of organelle biogenesis is crucial for cell physiology. Centriole biogenesis is regulated by Polo-like kinase 4 (Plk4) and initiates in S-phase when a daughter centriole grows from the side of a preexisting mother. Here we show that Plk4 forms an adaptive oscillator at the base of the growing centriole to initiate and time centriole biogenesis, ensuring that centrioles grow at the right time and to the right size. The Plk4 oscillator is normally entrained to the cell-cycle oscillator, but can run autonomously of it – explaining how centrioles can duplicate independently of cell cycle progression under certain conditions. Mathematical modelling indicates that this autonomously oscillating system is generated by a time-delayed negative-feedback loop in which Plk4 inactivates its centriolar receptor through multiple rounds of phosphorylation. We postulate that such organelle-specific autonomous oscillators could regulate the timing and execution of organelle biogenesis more generally

The Impact of COVID-19 Pandemic Lockdown on Emergency Department Visits in a Tertiary Hospital

Bisheng Shen,1 Baoxin Chen,2 Kuangyi Li,1 Weiyin Cheng,3 Mohammad Mofatteh,4 Robert W Regenhardt,5 Jack Wellington,6 Zhangrong Liang,1 Qi Tang,1 Jingli Chen,1 Yimin Chen7 1Department of Emergency Medicine, Foshan Hospital of Traditional Chinese Medicine, Foshan City, Guangdong Province, People’s Republic of China; 2Faculty of Humanities and Social Sciences, Macao Polytechnic University, Macao, People’s Republic of China; 3Department of Clinical Nutrition, Foshan Hospital of Traditional Chinese Medicine, Foshan City, People’s Republic of China; 4School of Medicine, Dentistry and Biomedical Sciences, Queen’s University Belfast, Belfast, UK; 5Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA; 6School of Medicine, Cardiff University, Cardiff, Wales, UK; 7Department of Neurology and Advanced National Stroke Center, Foshan Sanshui District People’s Hospital, Foshan, People’s Republic of ChinaCorrespondence: Baoxin Chen, Faculty of Humanities and Social Sciences, Macao Polytechnic University, Macao, People’s Republic of China, Email [email protected] Kuangyi Li, Department of Emergency Medicine, Foshan Hospital of Traditional Chinese Medicine, Foshan City, Guangdong Province, People’s Republic of China, Email [email protected]: This study aimed to highlight the impact of the COVID-19 pandemic lockdown on emergency department (ED) visits of non-COVID-19 patients in a tertiary hospital and evaluate protocol development during this period.Patients and Methods: Clinical data of patients who visited the ED of Foshan Hospital of Traditional Chinese Medicine during the first-level response in Foshan, Guangdong province in 2020 (from January 23 to February 24) and the same period in 2019 and 2021 were collected. A retrospective cross-sectional analysis was performed to understand the characteristics of critically ill patients and compare the proportion of hospitalizations, deaths, and emergency ambulance calls (EACs).Results: The number of patients presenting to the ED was significantly decreased, with a 37.75% reduction in 2020 (6196) compared to the same period in 2019 (9954). A rise in patient ED presentations was observed in the same period in 2021 (10,503). This decline was mostly in the 15– 45 age group. In 2019, 2020, and 2021, critically ill patients treated by the ED totaled 568 (5.706%), 339 (5.495%), and 590 (5.617%), respectively. Compared to the same period in 2019 and 2021, the proportion of critically ill patients with respiratory system involvement, severe trauma, and poisoning decreased most significantly in 2020 (P< 0.05). In contrast, the rates of EACs, hospitalizations, and deaths increased significantly (P< 0.05).Conclusion: The number of ED visits to hospitals was decreased during the 2020 lockdown, while the rates of EACs, hospitalizations, and deaths increased significantly though there were no documented COVID-19 cases. Optimizing emergency medical resources and ensuring the safety of healthcare providers and patients were essential to provide efficient emergency diagnosis and treatment during the lockdown.Keywords: COVID-19 pandemic, emergency medicine, coping strategies, emergency visit, non-COVID-19 patient

An autonomous oscillation times and executes centriole biogenesis

The accurate timing and execution of organelle biogenesis is crucial for cell physiology. Centriole biogenesis is regulated by Polo-like kinase 4 (Plk4) and initiates in S-phase when a daughter centriole grows from the side of a pre-existing mother. Here, we show that a Plk4 oscillation at the base of the growing centriole initiates and times centriole biogenesis to ensure that centrioles grow at the right time and to the right size. The Plk4 oscillation is normally entrained to the cell-cycle oscillator but can run autonomously of it—potentially explaining why centrioles can duplicate independently of cell-cycle progression. Mathematical modeling indicates that the Plk4 oscillation can be generated by a time-delayed negative feedback loop in which Plk4 inactivates the interaction with its centriolar receptor through multiple rounds of phosphorylation. We hypothesize that similar organelle-specific oscillations could regulate the timing and execution of organelle biogenesis more generally