22 research outputs found
Improvement of Propylene Epoxidation Caused by Silver Plasmon Excitation by UV-LED Irradiation on a Sodium-Modified Silver Catalyst Supported on Strontium Carbonate
The effect that UV-LED irradiation exerted on a sodium-modified silver catalyst supported on strontium carbonate (Ag-Na/SrCO3) was examined during an epoxidation of propylene to propylene oxide. Based on our previous study, we used Ag(56)-Na(1)/SrCO3 in this study. The numbers in parentheses refer to the weight percentage of silver and sodium. Although this catalyst system did not contain typical photocatalysts such as titanium oxide or tungsten oxide, UV-LED irradiation of Ag(56)-Na(1)/SrCO3 resulted in an evident improvement in the selectivity and yield of propylene oxide. Such an advantageous effect of UV-LED irradiation could not be discussed based on the bandgap used in photocatalysts and, therefore, we proposed a mechanism based on the plasmon excitation of silver, which could be accomplished using the irradiation wavelength of UV-LED to produce electrons. Since the lifespan of these electrons is expected to be short, it is difficult to place them into direct contact with the gas phase of oxygen. Once the generated electrons move to SrCO3, however, the lifespan is improved, which could allow suitable contact with oxygen in the gas phase to form active oxygen. If the oxygen is active for epoxidation as hydrogen peroxide, this could explain the improvement in activity from UV-LED irradiation
Wind- and Operation-Induced Vibration Measurements of the Main Reflector of the Nobeyama 45 m Radio Telescope
As deformations of the main reflector of a radio telescope directly affect
the observations, the evaluation of the deformation is extremely important.
Dynamic characteristics of the main reflector of the Nobeyama 45 m radio
telescope, Japan, are measured under two conditions: The first is when the
pointing observation is in operation, and the second is when the reflector is
stationary and is subjected to wind loads when the observation is out of
operation. Dynamic characteristics of the main reflector are measured using
piezoelectric accelerometers. When the telescope is in operation, a vibration
mode with one nodal line horizontally or vertically on the reflector is
induced, depending on whether the reflector is moving in the azimuthal or
elevational planes, whereas under windy conditions, vibration modes that have
two to four nodal lines are simultaneously induced. The predominant mode is
dependent on the direction of wind loads.Comment: Accepted for publication in Journal of Vibration Engineering &
Technologie
Time Course Analysis of Skeletal Muscle Pathology of GDE5 Transgenic Mouse
<div><p>Glycerophosphodiesterase 5 (GDE5) selectively hydrolyses glycerophosphocholine to choline and is highly expressed in type II fiber-rich skeletal muscles. We have previously generated that a truncated mutant of GDE5 (GDE5dC471) that lacks phosphodiesterase activity and shown that transgenic mice overexpressing GDE5dC471 in skeletal muscles show less skeletal muscle mass than control mice. However, the molecular mechanism and pathophysiological features underlying decreased skeletal muscle mass in GDE5dC471 mice remain unclear. In this study, we characterized the skeletal muscle disorder throughout development and investigated the primary cause of muscle atrophy. While type I fiber-rich soleus muscle mass was not altered in GDE5dC471 mice, type II fiber-rich muscle mass was reduced in 8-week-old GDE5dC471 mice. Type II fiber-rich muscle mass continued to decrease irreversibly in 1-year-old transgenic mice with an increase in apoptotic cell. Adipose tissue weight and blood triglyceride levels in 8-week-old and 1-year-old transgenic mice were higher than those in control mice. This study also demonstrated compensatory mRNA expression of neuromuscular junction (NMJ) components, including nicotinic acetylcholine receptors (α1, γ, and ε subunits) and acetylcholinesterase in type II fiber-rich quadriceps muscles in GDE5dC471 mice. However, we did not observe morphological changes in NMJs associated with skeletal muscle atrophy in GDE5dC471 mice. We also found that HSP70 protein levels are significantly increased in the skeletal muscles of 2-week-old GDE5dC471 mice and in mouse myoblastic C2C12 cells overexpressing GDE5dC471. These findings suggest that GDE5dC471 mouse is a novel model of early-onset irreversible type II fiber-rich myopathy associated with cellular stress.</p></div
HSP70 protein expression in GDE5dC471 mice.
<p>Total protein from gastrocnemius muscle of 2-week-old and 4-week-old GDE5dC471 mice (Tg) and age-matched control mice (Wild) was subjected to SDS-PAGE followed by Western blotting using anti-GDE5 and anti-HSP70 antibodies. The filter was stained with Coomassie Brilliant Blue (CBB) as a control of protein loading.</p
Two transcriptomes of quadriceps muscle in 2-week-old and 12-week-old of GDE5dC471 mice.
<p>The venn diagram shows genes that are altered in the quadriceps muscle of 2-week-old and 12-week-old GDE5dC471 mice. <i>A</i>, Of a total 96 genes up-regulated in quadriceps muscle of 2-week-old GDE5dC471 mice (<i>p</i><0.05), the expression of 18 genes were also increased in that of 12-week-old. On the contrary (<i>B</i>), the expression of 35 genes were also down-regulated in quadriceps muscle of 12-week-old GDE5dC471 mice.</p
Time course alterations of body weight and skeletal muscle weight in GDE5dC471 mice and age-matched control mice.
<p>Time course alterations of body weight and skeletal muscle weight in GDE5dC471 mice and age-matched control mice.</p
GDE5dC471 overexpression in skeletal muscle increases neuromuscular junctions-related mRNA expression.
<p><i>A</i>, Total RNA from gastrocnemius muscle of GDE5dC471 mice (Tg) and age-matched control mice (Wild) (4-week-old, n = 4; 8-week-old, n = 3; and 1-year-old, n = 5) was subjected to quantitative PCR to examine mRNA expression level of genes related to neuromuscular junctions. Data represent mean ± SE. *<i>p</i><0.05, **<i>p</i><0.01. <i>B</i>, Representative photographs of fluorescent α-bungarotoxin staining in transverse sections of gastrocnemius muscle, Left; 1-year-old of GDE5dC471 mice (Tg), and right; age-matched control mice (Wild). No morphological alteration of nicotinic acetylcholine receptor (nAchR) was observed between GDE5dC471 and control mice.</p
Obesity-related parameters in 8-week-old and 1-year-old of GDE5dC471 mice, and age-matched control mice.
<p>Obesity-related parameters in 8-week-old and 1-year-old of GDE5dC471 mice, and age-matched control mice.</p