Structure determination of the rutile-TiO2(110)-(1 × 2) surface using total-reflection high-energy positron diffraction (TRHEPD).

The exact structure of the rutile-TiO2(110)-(1 × 2) surface, which had been under debate over the past 30 years, was investigated using the newly developed technique of total-reflection high-energy positron diffraction (TRHEPD), which is a positron counterpart of reflection high-energy electron diffraction (RHEED). The rocking-curves for the 00-spot obtained from the experimental diffraction patterns were compared to the curves for various models calculated with a full-dynamical theory. It was found that the rocking-curves matched those for a surface consisting of a Ti2O3 configuration, originally suggested by Onishi and Iwasawa [H. Onishi and Y. Iwasawa, Surf. Sci., 1994, 313, L783], but with a further modification of atomic positions close to the ones proposed by Wang et al. [Q. Wang, A. R. Oganov, Q. Zhu and X. F. Zhou, Phys. Rev. Lett., 2014, 113, 266101]. This result demonstrates that TRHEPD can distinguish between the existence and absence of the oxygen atoms on the topmost surface, and between the Ti atoms residing in positions at the interstitial-vertical sites and those at interstitial-horizontal sites.

Charge-to-Spin Conversion and Spin Diffusion in Bi/Ag Bilayers Observed by Spin-Polarized Positron Beam.

Charge-to-spin conversion induced by the Rashba-Edelstein effect was directly observed for the first time in samples with no magnetic layer. A spin-polarized positron beam was used to probe the spin polarization of the outermost surface electrons of Bi/Ag/Al2O3 and Ag/Bi/Al2O3 when charge currents were only associated with the Ag layers. An opposite surface spin polarization was found between Bi/Ag/Al2O3 and Ag/Bi/Al2O3 samples with the application of a charge current in the same direction. The surface spin polarizations of both systems decreased exponentially with the outermost layer thickness, suggesting the occurrence of spin diffusion from the Bi/Ag interface to the outermost surfaces. This work provides a new technique to measure spin diffusion length.

Current-induced spin polarization on metal surfaces probed by spin-polarized positron beam.

Current-induced spin polarization (CISP) on the outermost surfaces of Au, Cu, Pt, Pd, Ta, and W nanoscaled films were studied using a spin-polarized positron beam. The Au and Cu surfaces showed no significant CISP. In contrast, the Pt, Pd, Ta, and W films exhibited large CISP (3~15% per input charge current of 10(5) A/cm(2)) and the CISP of Ta and W were opposite to those of Pt and Pd. The sign of the CISP obeys the same rule in spin Hall effect suggesting that the spin-orbit coupling is mainly responsible for the CISP. The magnitude of the CISP is explained by the Rashba-Edelstein mechanism rather than the diffusive spin Hall effect. This settles a controversy, that which of these two mechanisms dominates the large CISP on metal surfaces.

Dietary gamma-aminobutyric acid affects the brain protein synthesis rate in young rats.

The purpose of this study was to determine whether the gamma-aminobutyric acid (GABA) affects the rate of brain protein synthesis in male rats. Two experiments were done on five or three groups of young rats (5 wk) given the diets containing 20% casein administrated 0 mg, 25 mg, 50 mg, 100 mg or 200 mg/100 g body weight GABA dissolved in saline by oral gavage for 1 day (d) (Experiment 1), and given the diets contained 0%, 0.25% or 0.5% GABA added to the 20% casein diet (Experiment 2) for 10 d. The plasma concentration of growth hormone (GH) was the highest in rats administrated 50 mg and 100 mg/100 g body weight GABA. The concentration of serum GABA increased significantly with the supplementation groups. The fractional (Ks) rates of protein synthesis in brain regions, liver and gastrocnemius muscle increased significantly with the 20% casein + 0.25% GABA diet and still more 20% casein + 0.5% GABA compared with the 20% casein diet. In brain regions, liver and gastrocnemius muscle, the RNA activity [g protein synthesized/(g RNA . d)] significantly correlated with the fractional rate of protein synthesis. The RNA concentration (mg RNA/g protein) was not related to the fractional rate of protein synthesis in any organ. Our results suggest that the treatment of GABA to young male rats are likely to increase the concentrations of plasma GH and the rate of protein synthesis in the brain, and that RNA activity is at least partly related to the fractional rate of brain protein synthesis.

Effect of adding dietary L-lysine, L-threonine and L-methionine to a low gluten diet on urea synthesis in rats.

We have shown that urinary urea excretion increased in rats fed a low quality protein. The purpose of present study was to determine whether an addition of dietary limiting amino acids affected urea synthesis in rats fed a low gluten diet. Experiments were done on three groups of rats given diets containing 10% gluten, 10% gluten +0.5% L-lysine or 10% gluten+0.5% L-lysine, 0.2% L-threonine and 0.2% L-methionine for 10 d. The urinary excretion of urea, and the liver concentrations of serine and ornithine decreased with the addition of dietary L-lysine, L-threonine and L-methionine. The fractional and absolute rates of protein synthesis in tissues increased with the treatment of limiting amino acids. The activities of hepatic urea-cycle enzymes was not related to the urea excretion. These results suggest that the addition of limiting amino acids for the low gluten diet controls the protein synthesis in tissues and hepatic ornithine and decline urea synthesis.

Phase transition from asymmetric to symmetric dimer structure on the Si(001) surface at high temperature.

The dimer configurations on the Si(001) surface at high temperatures have been investigated using the rocking curve of reflection high-energy electron diffraction. The Si(001) surface shows a displacive phase transition around 900 K, where a well-known asymmetric (tilted) dimer structure on the Si(001) at room temperature transforms to a symmetric dimer structure around 900 K. The metallic feature of the Si(001) surface above 900 K can be explained by the phase transition.

[Minimally invasive direct coronary artery bypass in a patient with idiopathic thrombocytopenic purpura; report of a reoperative case].

A 77-year-old man who had undergone coronary artery bypass grafting (CABG) to segment 3, 7 and 12-14 with saphenous vein grafts (SVG) 15 years before, and ligation of coronary arteriovenous (AV) fistula 8 years before was admitted to our hospital, and diagnosed as acute heart failure and idiopathic thrombocytopenic purpura. Coronary angiography showed multiple stenosis of three vessels, and the grafts to segment 3 and 7 were occluded. The area of left anterior descending (LAD) had no viability, but the inferior wall had viability on dobutamine load echocardiography. The platelet count was about 5.0 x 10(4)/mm3. Minimally invasive direct coronary artery bypass (MIDCAB) for right coronary artery (RCA) using right internal thoracic artery (RITA) was performed through right parasternotomy. Operative and postoperative bleeding was slight, and postoperative course was uneventful. Reoperative MIDCAB can be safely performed in a patient with idiopathic thrombocytopenic purpura, and should be considered a viable alternative for highrisk patients.

[Effects of signals on memory and comprehension of history text: insertion of signals that relate the main text with corresponding information in the margins].

History texts for elementary school children have unique discourse structures that involve variety of information and style. This study investigated the effects of signals that relate the main text with corresponding information in the margins on memory and comprehension of the text. One hundred thirty-five undergraduate students were assigned to read the text being divided into two groups: texts with signals, and texts without signals. The text with signals contained four signals, for example, "look at the picture above". After reading the text, subjects recalled the text content (written information only) and took a comprehension test. The result of recall task suggested that students who read the text with signals remembered more information in the margins than those who read the text without signals. In the comprehension test, those in the former group indicated integrated comprehension of the two parts of the text.

Effects of topical latanoprost on optic nerve head circulation in rabbits, monkeys, and humans.

PURPOSE: To evaluate the effect of topically administrated latanoprost on optic nerve head (ONH) circulation in Dutch rabbits, cynomolgus monkeys, and normal humans. METHODS: The ONH tissue blood velocity (NB(ONH)) was determined using the laser speckle method. Latanoprost (0.005%, 30 microl) was instilled into one eye, and vehicle into the other eye as a control. In rabbits, NB(ONH) was measured for 90 minutes after a single instillation and before and after a 7-day once-daily instillation regimen. In monkeys, NB(ONH) was measured before and after 1, 4, and 7 days of a once-daily instillation regimen. The effect of intravenous indomethacin on the latanoprost-induced NB(ONH) change was also studied in rabbits and monkeys. In humans, the time-course changes in NB(ONH) were measured for 4.5 hours before and after a 7-day once-daily instillation regimen. Intraocular pressure (IOP) and systemic parameters were simultaneously studied in each experiment. All measurements were performed by investigators masked to the experimental condition. RESULTS: Latanoprost significantly increased NB(ONH) 10% to 19% in treated eyes after a single instillation (P = 0.035) or 7-day instillation regimen (P = 0.035) in rabbits, after a 4-day (P = 0.035) or 7-day (P = 0.035) instillation regimen in monkeys, and after a 7-day (P = 0.013) instillation regimen in humans, whereas there were no significant changes in the vehicle-treated eyes in any of the experiments (P > 0.5). Pretreatment with indomethacin (5 mg/kg) abolished the NB(ONH) increase but not the IOP reduction in latanoprost-treated eyes in rabbits and monkeys. IOP remained unchanged in both eyes in rabbits (P > 0.4), whereas it significantly decreased only in latanoprost-treated eyes in monkeys (P < 0.05) and humans (P < 0.05). CONCLUSIONS: Topical latanoprost significantly increased ONH blood velocity only in treated eyes in rabbits, monkeys, and humans. This effect was independent of the IOP-reducing effect of latanoprost and probably was associated with local penetration of the drug and the production of endogenous prostaglandins.

New phase and surface melting of Si(111) at high temperature above the (7x7)-(1x1) phase transition

The surface structure of Si(111) at high temperatures (950-1380 degrees C) has been studied with reflection high-energy electron diffraction. We have found three different surface structures: (1) A relaxed bulklike structure with adatoms of 0.25 monolayer (ML) is formed (950-1210 degrees C); (2) there is a new phase where the adatom coverage decreases to 0.20 ML (1250-1270 degrees C); (3) the surface melting occurs over 1290 degrees C. The crystalline structure below the melting layer can be explained by the vacancy model missing all adatoms and 0.45 ML of atoms in the first-double layer.

Effects of semotiadil, a novel calcium antagonist, on the retina and optic nerve head circulation.

The effects of semotiadil, a novel benzothiazine calcium antagonist, on the retinal and optic nerve head (ONH) tissue circulation were evaluated using the noninvasive laser speckle method. In urethane-anesthetized Dutch or albino rabbits, before and up to 90 min following intravenous injection of 400 microg/kg semotiadil fumarate (semotiadil group) or vehicle (control group), normalized blur value, a quantitative index of tissue blood velocity, in the retina (NB(retina)) or ONH (NB(onh)), was serially obtained with monitoring intraocular pressure (IOP) and systemic parameters: arterial pressure, pulse rate, arterial blood gas, and body temperature. There were no significant differences in IOP and the systemic parameters except arterial pressure between semotiadil and control groups during the experiments. Arterial pressure showed an acute and transient drop during the first 5 min after semotiadil administration. The time courses of the normalized blur value were significantly different between semotiadil and control groups in the retina (P = 0.0001, repeated measures two-way ANOVA), but not in the ONH (P = 0.6724). Changes in NB(retina) from the baseline in the semotiadil group was significantly greater than those in the control group 50 min or later after the administration (P < 0.0500, Mann-Whitney test). NB(onh) showed no significant differences between the two groups except during the first few min when arterial pressure acutely decreased in the semotiadil group. In conclusion, intravenously injected semotiadil increased the tissue blood velocity in the retina, but not in the ONH. This vascular selectivity in the ocular neural tissues differs from those of other calcium antagonists, such as nicardipine.

Clinical experience of a vacuum-assisted nonroller extra-corporeal circulation system.

We designed a nonroller extra-corporeal circulation system (NRECC) to minimize space requirements and to improve the safety and ease of cardiopulmonary bypass. The NRECC includes a circuit, a centrifugal pump, and a vacuum regulator. The vacuum regulator has five channels, each of which can control negative pressure independently. Negative pressure is applied to suctions, a vent, and a venous reservoir. Auto Vent-SV and one-way valves were placed between the suctions/vent and the reservoir. The total space required for the NRECC with a heat exchanger was 0.49 m2, which is much smaller than that of our current roller pump system. The maximum volume through the suction/vent was 2.5 L/min at -100 mmHg measured in a simulated system. We used the NRECC for six CABG cases and compared results with those of five CABG cases managed by traditional roller pump extra-corporeal circulation (RECC). The two systems were compared in terms of set-up time and stability/accuracy of the suction/vent. The set-up time of the NRECC (5.3 +/- 1.9 min) was significantly shorter than that of RECC (29 +/- 3.4 min) (p < .01). Stable and accurate blood flow were achieved with the NRECC operating between -15 mmHg and -25 mmHg. In conclusion, NRECC can run a bypass easily and safely and has the benefit of reducing space requirements and shortening set-up time.

Effect of naloxone on the bladder activity of rabbits with acute spinal injury.

BACKGROUND: Naloxone enhances bladder activity in patients with chronic spinal cord injury. However, there are few reports on naloxone for bladder morbidity in acute spinal cord injury. METHODS: We performed a prospective, controlled study of the effects of naloxone on bladder function in rabbits with and without surgical transection of the spinal cord at the 10th thoracic vertebra. Acute and chronic stages of injury were defined according to bladder function. Naloxone was given intravenously at both stages, and intrathecally at the acute stage. Bladder activity was monitored by cystometry. Blood concentrations of methionine-enkephalin were measured by radioimmunoassay. RESULTS: Spinal cord injuries were acute 1 or 2 days after surgery, and chronic after 1 or 2 weeks. Bladder capacity significantly decreased after 0.01 mg of intravenous naloxone in uninjured control rabbits, and after 0.03 mg of intravenous naloxone in rabbits with chronic-phase injuries. During the acute-injury phase, 0.3 mg of intravenous naloxone, or 0.02 mg of intrathecal naloxone, was necessary to evoke the micturition reflex. No significant changes in blood enkephalin levels were seen before or after spinal cord injury. CONCLUSION: In rabbits with acute spinal cord injury, intrathecal naloxone evoked the micturition reflex at a much lower dose than did intravenous naloxone. Intrathecal naloxone promises to become a new therapy for the acute stage of spinal cord injury for active recovery of bladder function, and could replace current therapy.

Combined therapies for composite graft infection after Bentall's procedure.

We present a patient who suffered from composite graft infection and mediastinitis. After replacement of the infected composite graft, in addition to administration of antibiotics, continuous irrigation of the mediastinum with solutions containing povidone-iodine and cefazolin sodium and transposition of the greater omentum were performed. His postoperative course was uneventful. Combined therapies including mediastinal irrigation and omental transposition should be considered after an operation for composite graft infection complicated with mediastinitis.

Echocardiographic diagnosis of subepicardial aneurysm ruptured into the right ventricle after inferior myocardial infarction.

A subepicardial aneurysm is a rare complication of myocardial infarction that sometimes causes a left to right shunt at the ventricular level. We report on echocardiographic observations in two recent cases of inferior myocardial infarction complicated by rupture of a subepicardial aneurysm into the right ventricle (RV). Two-dimensional and color flow Doppler images in several planes offered diagnostic characteristics of the lesion, including discontinuity of the myocardium at the neck of the aneurysm, a narrow neck relative to the diameter of the aneurysm, and a back and forth flow at the neck of the aneurysm. These techniques also provided new findings, such as a two-chambered structure of the aneurysm and a circular flow pattern within the inner aneurysmal cavity. In addition, color flow Doppler imaging showed multiple shunt flows from the aneurysm to the RV. Echocardiographically diagnosed abnormalities were verified by and successfully treated with surgery in both cases. In conclusion, echocardiography with color flow Doppler imaging may have the potential to diagnose the anatomic and hemodynamic condition of a subepicardial aneurysm.

[A case of a successfully treated subclavian aneurysm complicated by a brachiocephalic aneurysm, and the left vertebral artery occlusion].

The patient was a 67-year-old male. Preoperative DSA study revealed a right subclavian aneurysm, a brachiocephalic aneurysm, stenosis of the left common carotid artery and the left subclavian artery, and occlusion of the left vertebral artery. An intraoperative occlusion test of the right vertebral artery showed a decline of the brainstem auditory evoked responses (BAER) seven minutes after the start of the procedure. Cardiopulmonary bypass was established by femoral arterial and bicaval cannulation. Under selective cerebral perfusion by cannulation of both common caroid arteries, a partial aortic arch replacement was performed using a graft patch with 3 branches. These three branches were connected to the right subclavian artery and to both common carotid arteries, respectively. Under deep hypothermia the right vertebral artery was reconstructed with the saphenous vein graft. Proximal anastomosis between the saphenous vein graft and the right caroid graft was done perfusion from a branch of the saphenous vein graft in order to shorten ischemic time of basilar arterial region. The patient was weaned from bypass without problems. After weaning the BAER test was again performed and found to be normal. The postoperative course was uneventful. Postoperative DSA examination showed good blood flow in all the reconstructed vessels. This study suggests that deep hypothermia and shortening of ischemic time of the basilar arterial region are effective in preventing ischemic injury of the brain stem and the cerebellum.

[Injury to ascending aorta by cross-clamp--histologic evaluation].

To evaluate the injury to ascending aorta by cross-clamp, the trauma to the vessel wall was examined microscopically and the occlusive intensity of the vascular clamp was measured. Six patients were underwent total replacement of the ascending aorta and the aortic arch for aortic dissection. The ascending aorta and the aortic arch were resected during operation, the clamped regions of the ascending aorta were cut into the four pieces (the distal site, two part of the medial site, the proximal site applied by the vascular clamp) after operation. The four pieces of the ascending aorta were examined microscopically. The occlusive intensity of the vascular clamp were measured at the distal site, the medial site, and the proximal site by the load-measuring scale. The trauma to the vessel wall were classified to three degrees (grade 1 to grade 3). Grade 1 showed the minimal changes--narrowing of interstices between collagen fibers and muscle fibers in the media. Grade 2 showed the moderate changes--decrease of collagen fibers, atrophy and disruption of smooth muscle and elastic fiber in the media. Grade 3 showed the severe changes--disruption of the intima and defluvium of endothelial cells. The occlusive intensity of the vascular clamp were 1.0 kg at the distal site, 1.9 kg at the medial site and 3.6 kg at the proximal site, respectively. In the microscopic examinations, grade 1 changes were most frequent at the distal site, grade 1 and grade 2 changes were observed equally at the medial site, grade 3 change was observed only at the proximal site. The degree of the trauma to the vessel wall becomes severer in proportion to increase of the occlusive intensity of the vascular clamp.