Cycling Rate-Induced Spatially-Resolved Heterogeneities in Commercial Cylindrical Li-Ion Batteries.

Synchrotron high-energy X-ray diffraction computed tomography has been employed to investigate, for the first time, commercial cylindrical Li-ion batteries electrochemically cycled over the two cycling rates of C/2 and C/20. This technique yields maps of the crystalline components and chemical species as a cross-section of the cell with high spatiotemporal resolution (550 × 550 images with 20 × 20 × 3 µm voxel size in ca. 1 h).

Ab initio structure solution of proteins at atomic resolution using charge-flipping techniques and cloud computing.

Large protein structures at atomic resolution can be solved in minutes using charge-flipping techniques operating on hundreds of virtual machines (computers) on the Amazon Web Services cloud-computing platform driven by the computer programs TOPAS or TOPAS-Academic at a small financial cost. The speed of operation has allowed charge-flipping techniques to be investigated and modified, leading to two strategies that can solve a large range of difficult protein structures at atomic resolution. Techniques include the use of space-group symmetry restraints on the electron density as well as increasing the intensity of a randomly chosen high-intensity electron-density peak.

Physical activity is associated with grit and resilience in college students: Is intensity the key to success?

To determine the independent associations among physical activity, sitting, grit, and resilience in college students. Undergraduate students (n = 244) from a regional university participated in the study in January 2018. An online survey regarding physical activity, grit, and resilience was distributed via email.

In vitro effect of photodynamic therapy on aggregatibacter actinomycetemcomitans and Streptococcus sanguinis.

New periodontal disease treatments are needed to prevent infection progression. Photodynamic therapy (PDT) is one of the greatest pledges for this purpose. It involves the use of light of specific wavelength to activate a nontoxic photosensitizing agent in the presence of oxygen for eradication of target cells, and can be used for photokilling of microorganisms.

EMG-torque relationship and reliability of the medial and lateral hamstring muscles.

Purpose: The objectives of the present investigation were to examine the EMG-joint torque relation and day-to-day reliability of the medial (MH) and lateral hamstring (LH) muscles during isometric contractions.

Methods: Twenty young adults performed five maximal voluntary isometric hamstring contractions (MVC) followed by contractions at 10%-90% MVC, in a random order. Full-wave-rectified and -integrated EMG during the middle 3 s of each contraction was expressed as a percent of the EMG during the three highest averaged MVC.

Contraction mode shift in quadriceps femoris muscle activation during dynamic knee extensor exercise with increasing loads.

The objective of the present study was to examine the superficial quadriceps femoris (QF) muscle electromyogram (EMG) during dynamic sub-maximal knee extension exercise between young adult men and women. Thirty subjects completed, in a random order, 2 sub-maximal repetitions of single-leg knee extensions at 20-90% of their one-repetition maximum (1RM). Vastus medialis (VM), vastus lateralis (VL) and rectus femoris (RF) muscle integrated EMG (IEMG) during each sub-maximal lift was normalized to the respective 1RM for concentric, isometric and eccentric modes.

Quadriceps femoris electromyogram during concentric, isometric and eccentric phases of fatiguing dynamic knee extensions.

The objective of this study was to examine the superficial quadriceps femoris (QF) muscle electromyogram (EMG) during fatiguing knee extensions. Thirty young adults were evaluated for their one-repetition maximum (1RM) during a seated, right-leg, inertial knee extension. All subjects then completed a single set of repeated knee extensions at 50% 1RM, to failure.

Mo2P4O15--the most complex oxide structure solved by single crystal methods?

We report the crystal structure and phase transitions of Mo2P4O15 which, despite a simple chemical formula, has 441 crystallographically unique atoms in its asymmetric unit and thus has the most complex structure of any extended oxide reported to date.

Angle- and gender-specific quadriceps femoris muscle recruitment and knee extensor torque.

The objectives were to examine knee angle-, and gender-specific knee extensor torque output and quadriceps femoris (QF) muscle recruitment during maximal effort, voluntary contractions. Fourteen young adult men and 15 young adult women performed three isometric maximal voluntary contractions (MVC), in a random order, with the knee at 0 degrees (terminal extension), 10 degrees, 30 degrees, 50 degrees, 70 degrees, and 90 degrees flexion. Knee extensor peak torque (PT), and average torque (AT) were expressed in absolute (N m), relative (N m kg(-1)) and allometric-modeled (N m kg(-n)) units.

Gender differences in perceived exertion during fatiguing knee extensions.

Purpose: To examine gender differences in knee extensor strength, fatigue, and perceived exertion during a single set of continuous dynamic knee extensor contractions.

Methods: Fifteen men and 15 women were evaluated for their one-repetition maximum (1RM) during a single-leg, inertial knee extension with their right leg. All subjects then completed a single set of repeated knee extensions with a load equivalent to 50% of their 1RM to failure.

Knee flexor torque and perceived exertion: a gender and reliability analysis.

Purpose: The objectives of the present study were to examine gender differences and between-day variability of isometric hamstring muscle peak torque and perceived exertion.

Methods: Subjects included 20 healthy, college-aged male (N = 10) and female (N = 10) volunteers. Each subject completed five maximal voluntary isometric hamstring muscle contractions (MVC), in a prone position, with their knee at 30 degrees flexion.

Knee extensor torque, work, and EMG during subjectively graded dynamic contractions.

We examined knee extensor peak torque, work, and electromyogram (EMG) during dynamic contractions to perceived exertion levels in men and women. Thirty subjects performed three maximal effort isokinetic knee extensions (60 deg x s(-1)), followed by three contractions to each of nine separate levels of perceived exertion. Surface EMG of the vastus medialis (VM), vastus lateralis (VL), and rectus femoris (RF), and knee extensor peak torque and work were normalized to a percent of each respective value obtained during the maximal effort contractions.

Perceived exertion and maximal quadriceps femoris muscle strength during dynamic knee extension exercise in young adult males and females.

The objectives of the present study were to: (1) examine perceived exertion across different target voluntary-contraction intensities; (2) compare perceived exertion ratings with actual target intensities, and (3) compare perceived exertion ratings between males and females. Subjects for this study included 30 healthy, college-aged male (n=15) and female (n=15) volunteers. All subjects were free of orthopedic, cardiopulmonary, systemic and neurological disease.

The effects of voluntary contraction effort on quadriceps femoris electromyogram median frequency in humans: a muscle and sex comparison.

The purpose of this study was to examine the effect of voluntary contraction efforts on the median frequency (f(med)) of the electromyogram (EMG) recorded from the quadriceps femoris muscle in healthy men and women. A group of 30 healthy volunteers (15 men, 15 women) were assessed for EMG activity of the vastus medialis (VM), vastus lateralis (VL), and rectus femoris (RF) muscles during isometric contractions with the knee at 60 degrees flexion. Subjects performed a series of 5 s maximal voluntary isometric contractions that anchored the perceptual range with a "10" on a 10-point scale.