Cyclin B1/CDK1-regulated mitochondrial bioenergetics in cell cycle progression and tumor resistance.

A mammalian cell houses two genomes located separately in the nucleus and mitochondria. During evolution, communications and adaptations between these two genomes occur extensively to achieve and sustain homeostasis for cellular functions and regeneration. Mitochondria provide the major cellular energy and contribute to gene regulation in the nucleus, whereas more than 98% of mitochondrial proteins are encoded by the nuclear genome. Such two-way signaling traffic presents an orchestrated dynamic between energy metabolism and consumption in cells. Recent reports have elucidated the way how mitochondrial bioenergetics synchronizes with the energy consumption for cell cycle progression mediated by cyclin B1/CDK1 as the communicator. This review is to recapitulate cyclin B1/CDK1 mediated mitochondrial activities in cell cycle progression and stress response as well as its potential link to reprogram energy metabolism in tumor adaptive resistance. Cyclin B1/CDK1-mediated mitochondrial bioenergetics is applied as an example to show how mitochondria could timely sense the cellular fuel demand and then coordinate ATP output. Such nucleus-mitochondria oscillation may play key roles in the flexible bioenergetics required for tumor cell survival and compromising the efficacy of anti-cancer therapy. Further deciphering the cyclin B1/CDK1-controlled mitochondrial metabolism may invent effect targets to treat resistant cancers

Cerebral aneurysm treatment: modern neurovascular techniques.

Endovascular treatment of cerebral aneurysm continues to evolve with the development of new technologies. This review provides an overview of the recent major innovations in the neurointerventional space in recent years

Sequential Appointment Scheduling Considering Walk-In Patients

This paper develops a sequential appointment algorithm considering walk-in patients. In practice, the scheduler assigns an appointment time for each call-in patient before the call ends, and the appointment time cannot be changed once it is set. Each patient has a certain probability of being a no-show patient on the day of appointment. The objective is to determine the optimal booking number of patients and the optimal scheduling time for each patient to maximize the revenue of all the arriving patients minus the expenses of waiting time and overtime. Based on the assumption that the service time is exponentially distributed, this paper proves that the objective function is convex. A sufficient condition under which the profit function is unimodal is provided. The numerical results indicate that the proposed algorithm outperforms all the commonly used heuristics, lowering the instances of no-shows, and walk-in patients can improve the service efficiency and bring more profits to the clinic. It is also noted that the potential appointment is an effective alternative to mitigate no-show phenomenon

On shotnoise and Brownian motion limits to the accuracy of particle positioning with optical tweezers

This paper examines the fundamental resolution limit of particle positioning with optical tweezers due to the combined effects of Brownian motion and optical shotnoise. It is found that Brownian motion dominates at low signal frequencies, whilst shotnoise dominates at high frequencies, with the exact crossover frequency varying by many orders of magnitude depending on experimental parameters such as particle size and trapping beam power. These results are significant both for analysis of the bandwidth limits of particle monitoring with optical tweezers and for enhancements of optical tweezer systems based on non-classical states of light

Power loss investigation of series-connected current source inverters

Current-source inverters (CSIs) are a type of direct current (DC) to alternating current (AC) converters that generate a defined AC output current waveform from a DC current supply. As the counterpart of voltage source inverters (VSIs), they feature a simple converter structure, low switching dv/dt on the ac-side, and reliable short-circuit protection. These advantages have made CSIs widely used in high power medium voltage drives. Besides, they have also been studied in other applications, such as wind energy conversion systems, superconducting magnetic energy storage (SMES) systems, and microgrid systems. Different topologies of CSIs and modulation schemes have been evolved to tailor various application requirements. For those applications with a higher power rating, two or more CSIs can be connected in series to form series-connected CSIs (SC-CSIs) to increase the power handling capability. To the best of the author’s knowledge, three topologies of SC-CSIs have been developed so far. The first topology referred to as topology A is constructed by connecting several identical CSIs in series. These CSIs are identical in terms of topology, modulation, and control. A multi-winding transformer is employed at the output to provide a clear current path for each CSI and step up the voltage if necessary. In the second topology designated as topology B, the multi-winding transformer is replaced by a phase-shifting transformer, and a phase-shifting modulation scheme is implemented. This topology features an increased DC current utilization, decreased switching losses, and reduced passive components. The third topology denominated as topology C adopts a different arrangement of switches leading to a reduced number of switching devices. A multi-winding transformer is used at the output in this topology. Power losses are an important attribute of SC-CSIs since they have a significant impact on the efficiency of the system. Besides, it is necessary to find out the power loss distribution of inverters to design an appropriate cooling system. However, the power losses and the power loss distribution of these three topologies have not been figured out. [...