Chemical and isotopic (D, 18O) compositions of 40 shallow groundwater, 14 observation well water and 2 river water samples in the Sho river fan, Toyama, northern part of central Japan, were analyzed to examine their water quality, origins and water flow in order to obtain baseline geochemical data for application of groundwater to geothermal heat pump (Geo-HP). Water temperatures of the groundwaters in the observation wells are almost constant at 15°C from surface to ca. 60 m in depth and increase up to 25°C at depth of 200 m with the thermal gradient of 6°C/100 m. This geothermal gradient is twice as high as that of the other areas in Japan, suggesting existence of high temperature geothermal sources beneath this region and a high potential for heat usage in winter. The isotopic results show that the groundwaters are a mixture of two big river waters (Sho and Oyabe rivers) and precipitation in the Sho river fan and that the contribution of infiltration from the Sho river has increased in recent 10 years. The Sho river has lower δ18O values than the Oyabe river. The groundwaters shallower than 80 m depth are of a Ca–HCO3 type. Deep groundwaters from observation wells were characterized by high in pH and HCO3 compared to the shallow groundwaters due to ion exchange with rocks containing clay minerals. The deep groundwaters are almost saturated or oversaturated with respect to calcite and dolomite, becoming confined due to the presence of an impermeable layer. In this paper, formation of calcite and iron hydroxide scale inside pipes of the Geo-HP was discussed from the chemical compositions of groundwater to examine whether the water is applicable to geothermal heat pump or not.
The vertical snow samples collected from 6 locations (Iou-zen: 800m A.M.S.L; the nearest site from the Sea of Japan, Kongoudou-zan: 1300m, Nishi-Hodaka-Dake: 2200m; the Northern Japan Alps, Hachimori-yama: 2100m, Kiriga-mine: 2000m, Yatsuga-take: 2200m; the most inlying site) in the central mountainous area, Japan, during early spring season 2004, were analyzed for size-separated concentrations of water-insoluble particles in snow layers to investigation of long-range transportation of chemical substances from the Asian continent to high mountainous areas in Japan. Most of particles are less than 30 Pm in diameter, the greater part of particles observed at the 6 locations were considered to be transported from the Asian continent sources as Asian dust (KOSA). The variation patterns of the vertical profiles of particle concentrations in snow layers were corresponding among each location. The concentrations of particles with less than 30 Pm was gradually increased with increasing distance from the Sea of Japan to the Japan Alps, although, sharply-decreased at 3 sites located the monsoon-leeward of the Japan Alps, suggesting that the particles transported with monsoon were gradually removed from air and deposited in snow cover when the air parcel pass through the Japan Alps.
Rupture of the flexor pollicis longus tendon is a major complication after volar locking plate fixation of distal radius fracture. This study used ultrasonography to assess the flexor pollicis longus tendon and intermediate tissue. The study assessed 27 patients (28 wrists) who underwent removal of the volar locking plate. Before plate removal, radiography and ultrasonography were performed to assess the relation between the flexor pollicis longus tendon and the volar locking plate. Intraoperatively, the authors evaluated the intermediate tissues between the flexor pollicis longus tendon and the distal volar margin of the plate. Preoperative and intraoperative findings were compared. Intraoperative findings were strongly related to the distance between the flexor pollicis longus tendon and the volar locking plate on ultrasonography. The sensitivity of ultrasonography in detecting thin, membrane-like intermediate tissue through which the plate was visible was 95%, and the specificity was 89% if the distance between the flexor pollicis longus tendon and the plate was less than 0.7 mm. Compression of the flexor pollicis longus tendon was seen in 11 cases (39.3%), and this finding suggested the presence of thin, membrane-like intermediate tissue. The study results showed that ultrasonography could be used to identify the type of intermediate tissue between the flexor pollicis longus tendon and the volar locking plate. [Orthopedics. 2017; 40(1):e104-e108.].
Although osteochondral autograft transplantation (OAT) provides satisfactory outcomes for osteochondral defects, for large defects OAT is often inadequate because of graft availability. Osteochondral allograft transplantation is an alternative treatment for large defects, but this approach is limited by graft storage constraints and carries disease transmission risks. Platelet-rich fibrin (PRF) is a second-generation platelet concentrate, and its positive effect on articular cartilage has been reported. However, the effect of PRF with OAT of osteochondral defects is unknown.To compare the effects of OAT with platelet-rich plasma (PRP) and PRF on osteochondral defects in a rabbit model.Controlled laboratory study.Forty-two juvenile rabbits were divided into control, PRP, and PRF groups. In the control and PRP groups, a cylindrical osteochondral defect (5 mm in diameter and 2 mm in depth) was created on the patellar groove, and an osteochondral graft (3.5 mm in diameter and 5 mm in length) harvested from the contralateral side was inserted into the distal portion of the defect. After wound closure, either normal saline or PRP was injected in the knee. In the PRF group, a PRF clot was placed in the defect before grafting. The surgical site was macroscopically and histologically assessed after 3 and 12 weeks.At 3 weeks, the PRF group (n = 8) was macroscopically healed compared with the other 2 groups (control, n = 7; PRP, n = 6) ( P < .005). Histologically, osteochondral graft cartilage of the PRF group had normal cellularity and higher amounts of safranin O staining relative to the other 2 groups ( P < .005). At 12 weeks, all 3 groups (n = 8 per group) were macroscopically healed with normal or nearly normal cartilage, and osteochondral graft cartilage was histologically hyaline cartilage. In contrast, the PRF group healed with hyaline-like cartilage at nongrafted defects, whereas the other 2 groups healed with fibrocartilage ( P < .001).OAT with PRF maintained hyaline cartilage, and the nongrafted defect healed with hyaline-like cartilage.PRF has the potential to improve clinical outcomes of OAT used to treat osteochondral lesions.
Hydrogen usually occurs in sheared silicate rocks and its concentration much fluctuates, spatially and temporally. The concentration of H2 from activee faults associated with historical earthquakes usually amounts to as high as several percent in maximum. On the other hand, the H2 concentration from Quaternary faults not associated with historical earthquakes is at most 100ppm. Gases from both types of active faults are impoverished in O2. A series of laboratory experiments showed that (1) hydrogen is produced from a mixture of fresh rock poweder and water and (2) the production rate fluctuates according to rock type, reaction temperature and atmosphere above the mixture. The mixture made of pegmatite powder gave H2 as high as several percent. Oxygen decreased when the reaction proceeded. The experiments suggests that the fresh mineral surface formed by tectonic stresses reacts with groundwater to produce H2. Since the mineral surface loses its activity with time, discrimination between recently moved faults and other Quaternary faults can be made by the H2 concentration. Hydrogen isotope thermomenter, as well as field evidence, suggests a deepseated origin of H2 in an active fault. Successive measurements showed that much H2 simultaneously issued at several monitoring stations on historical active faults and that H2 appeared in bubble gases from mineral springs during about one month prior to earthquakes. The evidence suggests that H2 measurement at monitoring stations gives information at depth on mechanisms that operate perior to earthquakes.
Little is known about the optimal timing of early return to sports after which the osteochondritis dissecans (OCD) lesion can completely heal. The aims of this study were to investigate the clinical outcomes of nonoperative treatment and elucidate the relationship between the radiographic findings and the timing for the return to sports.We performed a retrospective review of 32 patients who presented with stable OCD of the capitellum and were treated nonoperatively for a minimum of 3 months. The mean follow-up period was 22.1 months. OCD lesions were assessed qualitatively and quantitatively on anteroposterior radiographs of the elbow at 45° of flexion every 3 months. The width of the OCD lesion (OCDw) and lateral width of the normal capitellum were measured and were associated with return to sports activities.In 21 patients (66%), the progression of ossification was seen at a mean period of 4.1 months. Eighteen (56%) had partial union at a mean period of 4.3 months. Twenty-nine cases (91%) returned to sports activities after a mean of 4.6 months. Nine cases (28%) achieved complete union after a mean period of 15.0 months. Fifteen (47%) required surgery after a mean period of 11.8 months. The mean OCDw (%) was 10.2 ± 3.9 mm (56%) at the initial presentation and 8.0 ± 6.0 mm (41%) at the final follow-up examination, and the decrease in OCDw was 2.2 ± 3.1 mm (15%). The mean decrease in OCDw in patients with progression of ossification during the first 3 months was significantly larger than in patients without progression of ossification (4.9 ± 4.7 mm and -0.7 ± 4.5 mm, respectively; P = .002). In patients who had both an OCDw value of <8.0 mm and a lateral width value of >2.0 mm at the time of the return to sports, the rate of successful nonoperative treatment (86%) and complete union (71%) was significantly higher in comparison with other patients (P = .03 and P = .02).OCD lesions showed difficult healing in the middle one-third of the capitellum. The progression of ossification during the first 3 months was a significant predictor of successful nonoperative treatment and complete union. Surgery should be considered for lesions without the progression of ossification during the first 3 months. We propose both an OCD lesion width of <8.0 mm and a lateral normal width of >2.0 mm as radiographic landmarks of the timing of the return to sports.
