Tsumura (Japan)

Our previous study found that one maximal voluntary eccentric contraction (MVC-ECC) performed daily for 5 days a week for 4 weeks increased MVC-ECC, isometric (MVC-ISO), and concentric contraction (MVC-CON) torque of the elbow flexors more than 10%. The present study investigated the effects of six maximal voluntary eccentric contractions on the MVC torques and biceps brachii and brachialis muscle thickness (MT). Thirty-six healthy young adults were placed to one of the three groups (N=12 per group); the 6 × 1 group that performed one set of six contractions once a week, the 6 × 5 group that performed one set of six contractions a day for 5 days a week, and the 30 × 1 group that performed five sets of six contractions a day in a week. The training duration was 4 weeks for all groups, and changes in MVC-ECC, MVC-CON and MVC-ISO torque, and MT before and after the 4-week training were compared among the groups. The 6 × 1 group did not show significant changes in muscle strength and MT. Significant (p < 0.05) increases in MVC-ECC (13.5 ± 11.5%), MVC-ISO (9.3 ± 5.5%), MVC-CON torque (11.1 ± 7.4%) were evident for the 6 × 5 group only, and increases in MT were found for the 6 × 5 (10.4 ± 4.4%) and 30 × 1 (8.0 ± 5.8%) groups without a significant difference. These results suggest that performing a small number of eccentric contractions 5 days a week is more effective for increasing muscle strength than performing a larger volume of eccentric contractions once a week. However, it appears that training volume is a factor for muscle hypertrophy in a short-term training.

Goshajinkigan (GJG) is a traditional Japanese Kampo medicine used clinically to treat muscle pain in Japan. However, its underlying mechanism remains unclear. Since voltage-gated sodium channel (Nav) 1.4 is involved in skeletal muscle contraction, we investigated the possibility that GJG may affect Nav1.4 currents. By using an electrophysiological technique on skeletal muscle cell line C2C12, we found that GJG suppresses Nav1.4 currents in C2C12 cells. It is suggested that GJG may improve skeletal muscle stiffness or cramps by inhibiting abnormal Nav1.4 excitation. GJG may act as a Nav1.4 blocker and may be useful to treat muscle stiffness and clamps as well as easing the pain.

The Japanese guidelines for acute otitis media in children recommend classifying acute otitis media by age, manifestations and local findings, and also recommend myringotomy for moderate-grade cases with severe local findings, severe-grade cases, and treatment-resistant cases. The heptavalent pneumococcal conjugate vaccine was released in Japan in February 2010. In Hiroshima City, public funding allowing free inoculation with this vaccine was initiated from January 2011, and the number of vaccinated individuals has since increased dramatically. This study investigated changes in the number of myringotomies performed to treat acute otitis media during the 5-year period from January 2008 to December 2012 at two hospitals and five clinics in the Asa Area of Hiroshima City, Japan. A total of 3,165 myringotomies for acute otitis media were performed. The rate of procedures per child-year performed in <5-year-old children decreased by 29.1% in 2011 and by 25.2% in 2012 compared to the mean rate performed in the 3 years prior to the introduction of public funding. A total of 895 myringotomies were performed for 1-year-old infants. The rate of myringotomies per child-year performed for acute otitis media in 1-year-old infants decreased significantly in the 2 years after the introduction of public funding for heptavalent pneumococcal conjugate vaccine compared to all years before introduction (p<0.000001). Our results suggest a benefit of heptavalent pneumococcal conjugate vaccine for acute otitis media in reducing the financial burden of myringotomy. In addition, this vaccine may help prevent acute otitis media with severe middle ear inflammation in 1-year-old infants.

Laterally aligned carbon nanotube (CNT) arrays “blossomed” homogeneously in honeycomb holes of a metal grid substrate were explored as rational architecture for field emission. A low turn-on field (TOF) of 1.09 V/μm for 10 μA/cm2 emission was achieved, which approaches or exceeds the lowest reported TOF values for field emitter arrays. We interpret that these lateral CNT arrays act as source of CNT “loop” arrays enabling a structure suited toward low TOF field emission.

Field emission microscopy (FEM) study of carbon nanotube (CNT) with various tip radii was performed to reveal the origin of different types of FEM patterns (“pentagon” and “dim” patterns) so far reported. Dynamic behaviour and degradation mechanism of field-emitting CNTs were also studied by in-situ transmission electron microscopy (TEM).

A high-resolution carbon nanotube (CNT) -field emission display (FED) was investigated for graphic-displays. The sub-pixel size was 0.2mm × 0.6mm. The panel structure was developed based on the unique stack-structure for character-display of 1.0mm-dot-pitch [1]. The configuration of the display was a metal-backed color-phosphor screen, tall-spacer of 0.5–1.0mm height for individual phosphor line, a metal gate-substrate and CVD-grown-CNT on a metal-electrode. In order to realize 2.0–3.0mm tall spacer, we introduced the new rib structure using a metal sheet. And the CNT emitter was grown on a metal electrode by newly developed technology. The diameter of deposited CNT was reduced down to 6–10nm. And also, a laser irradiation was effective to improve emission characteristics. The experimental panel was performed high luminance and high resolution display. The screen size was 36mm × 36mm.

To clarify the mechanism responsible for neurological impairment associated with chronic subdural hematoma (CSDH), we performed quantitative measurements of cerebral blood flow (CBF) with xenon-enhanced computed tomographic scans in eight patients with unilateral CSDH. Vascular reserve capacity was also evaluated with acetazolamide challenge. CBF was depressed in all regions examined except the corona radiata. There was no statistical difference in hemispheric and regional CBF between the lesion and non-lesion sides. A significant increase in CBF values ranging from 32% to 69% was observed after acetazolamide administration in the whole brain. Postoperatively CBF remained depressed in all regions we analyzed except for the frontal and temporal lobes, despite the fact that all patients had improved clinical symptoms. Amplitude of N20 and central conduction time (N13-20) in SSEP showed no significant change in CSDH patients compared to normal control. So we conclude that preoperative neurological signs in CSDH are related to a reduction of CBF in the whole brain. However, other mechanisms must be involved to explain preoperative focal signs and good postoperative recovery.