3D printing of hollow geometries using blocking liquid substitution stereolithography.

Micrometer scale arbitrary hollow geometries within a solid are needed for a variety of applications including microfluidics, thermal management and metamaterials. A major challenge to 3D printing hollow geometries using stereolithography is the ability to retain empty spaces in between the solidified regions. In order to prevent unwanted polymerization of the trapped resin in the hollow spaces-known as print-through-significant constraints are generally imposed on the primary process parameters such as resin formulation, exposure conditions and layer thickness.

A Cross-Training Program Does Not Alter Self-Reported Physical Activity Levels in Elementary School Children.

The purpose of the study was to examine the effects of a school-based cross-training program on body mass index (BMI), attitudes toward physical activity (ATPA), and physical activity (PA) levels of children in the 4 and 5 grades. Children ( = 118) were divided into control ( = 60) and experimental ( = 58) groups based on class availability. While the control group continued academic classes as usual, the experimental group participated in cross-training involving resistance training (RT), calisthenics, and stretching twice a week for 10 weeks.

Caffeine supplementation and reactive agility in elite youth soccer players.

This study examined the effects of caffeine supplementation (6 mg·kg-1) on performance of a reactive agility test (RAT) in 17 elite, male, youth (M = 14 y) soccer players. Using a double-blind, repeated-measures design, players completed 4 days of testing on the RAT after a standardized warm-up. On day 1, anthropometric measurements were taken and players were accommodated to the RAT.

The Relationship between Cortisol and Bone Mineral Density in Competitive Male Cyclists.

Objective. The purpose of this study was to determine whether race day cortisol was related to bone mineral density (BMD) in competitive male cyclists. A secondary purpose was to determine additional factors associated with BMD in competitive male cyclists.

Occlusion training increases muscular strength in division IA football players.

The purpose of this study was to investigate the effectiveness of 4 weeks of low-intensity resistance training with blood-flow occlusion on upper and lower body muscular hypertrophy and muscular strength in National Collegiate Athletic Association Division IA football players. There were 32 subjects (average age 19.2 ± 1.

The Impact of a Pilot Community Intervention on Health-Related Fitness Measures in Overweight Children.

The purpose of this study was to pilot a 5-week community-based intervention on improving measures of health-related fitness in overweight children. Data were obtained from 8 overweight and obese 8- to 14-year-old children. Measurements included muscular fitness (curl-ups and modified pull-ups), aerobic capacity (20 meter progressive aerobic cardiovascular endurance run [PACER] test), body composition (triceps and calf skinfolds), body mass index (BMI), and flexibility (back saver sit-and-reach).

Efficient near-infrared polymer and organic light-emitting diodes based on electrophosphorescence from (tetraphenyltetranaphtho[2,3]porphyrin)platinum(II).

The new metalloporphyrin Pt(tptnp), where tptnp = tetraphenyltetranaphtho[2,3]porphyrin, has been prepared and subjected to photophysical and electrooptical device studies. In degassed toluene solution at room temperature Pt(tptnp) features efficient phosphorescence emission with lambda(max) 883 nm with a quantum efficiency of 0.22.

Physical fitness and academic achievement in elementary school children.

Background: The benefits of physical fitness are widely acknowledged and extend across many domains of wellness. The association between fitness and academic achievement, however, remains to be clarified, especially in young children. Therefore, the purpose of this study was to examine the relationship between fitness and academic achievement in elementary school children.

The effect of static stretching on phases of sprint performance in elite soccer players.

The purpose of this study was to determine which phase of a 30-m sprint (acceleration and/or maximal velocity) was affected by preperformance static stretching. Data were collected from 20 elite female soccer players. On two nonconsecutive days, participants were randomly assigned to either the stretch or no-stretch condition.

Oxygen consumption, heart rate, rating of perceived exertion, and systolic blood pressure with water treadmill walking.

The purpose of this study was to examine the cardiovascular responses to water treadmill walking at 2.0 mph (3.2 km/hr), 2.

Photophysics of diplatinum polyynediyl oligomers: chain length dependence of the triplet state in sp carbon chains.

The series of polyynes with the structure trans, trans-[Ar-Pt(P 2)-(C[triple bond]C) n -Pt(P 2)-Ar], where P = tri( p-tolyl)phosphine, Ar = p-tolyl, and n = 3, 4, 5, 6 (6, 8, 10, 12 sp carbon atoms), has been subjected to a comprehensive photophysical investigation. At low temperature ( T < 140 K) in a 2-methyltetrahydrofuran (MTHF) glass, the complexes exhibit moderately efficient phosphorescence appearing as a series of narrow (fwhm < 200 cm (-1)) vibronic bands separated by ca. 2100 cm (-1).

Platinum acetylide two-photon chromophores.

To explore the photophysics of platinum acetylide chromophores with strong two-photon absorption cross-sections, we have investigated the synthesis and spectroscopic characterization of a series of platinum acetylide complexes that feature highly pi-conjugated ligands substituted with pi-donor or -acceptor moieties. The molecules (numbered 1-4) considered in the present work are analogs of bis(phenylethynyl)bis(tributylphosphine)platinum(II) complexes. Molecule 1 carries two alkynyl-benzothiazolylfluorene ligands, and molecule 2 has two alkynyl-diphenylaminofluorene ligands bound to the central platinum atom.

An iridium(III) complex that exhibits dual mechanism nonlinear absorption.

The photophysical properties of the complex (L)Ir(ppy)(2)(+), where ppy = 2-phenylpyridine and L = 4,4'-(2,2'-bipyridine-5,5'-diylbis(ethyne-2,1-diyl))bis(N,N-dihexylaniline), have been investigated under one- and two-photon excitation conditions. In THF solution, the complex exhibits broad ground-state absorption with lambda(max) approximately 500 nm and weak photoluminescence with lambda(max) approximately 730 nm. Excitation of (L)Ir(ppy)(2)(+) at 355 nm produces a long-lived excited state (tau approximately 1 mus) that features a strong excited-state absorption in the near-infrared (lambda(max) approximately 875 nm, Deltaepsilon approximately 6.

A platinum acetylide polymer with sterically demanding substituents: effect of aggregation on the triplet excited state.

The effect of interchain interaction on the triplet excited state is explored in two Pt-acetylide polymers of the type [-trans-Pt(PBu(3))(2)-C triple bond C-Ar-C triple bond C-](n), where Ar is either 1,4-phenylene or is based on the pentiptycene unit (polymers 2 and 3, respectively). To explore the effect of interchain interaction in Pt-acetylide materials, the optical properties of parent polymer 2 are compared with those of polymer 3 in which interchain interaction is precluded by the sterically bulky pentiptycene moiety. Insight into the effect of the pentiptycene unit on packing in the solid state comes from the X-ray structure of monomer 1b, Ph-C triple bond C-[trans-Pt(PBu(3))(2)]-C triple bond C-Ar-C triple bond C-[trans-Pt(PBu(3))(2)]-C triple bond C-Ph.