Propagation dynamics of spin excitations along skyrmion strings.

Magnetic skyrmions, topological solitons characterized by a two-dimensional swirling spin texture, have recently attracted attention as stable particle-like objects. In a three-dimensional system, a skyrmion can extend in the third dimension forming a robust and flexible string structure, whose unique topology and symmetry are anticipated to host nontrivial functional responses. Here we experimentally demonstrate the coherent propagation of spin excitations along skyrmion strings for the chiral-lattice magnet Cu2OSeO3. We find that this propagation is directionally non-reciprocal and the degree of non-reciprocity, as well as group velocity and decay length, are strongly dependent on the character of the excitation modes. These spin excitations can propagate over a distance exceeding 50 µm, demonstrating the excellent long-range ordered nature of the skyrmion-string structure. Our combined experimental and theoretical analyses offer a comprehensive account of the propagation dynamics of skyrmion-string excitations and suggest the possibility of unidirectional information transfer along such topologically protected strings.

Realization of Spin-dependent Functionality by Covering a Metal Surface with a Single Layer of Molecules.

An interface of molecule and metal has attracted much attention in the research field of nanoelectronics because of their high degree of design freedom. Here, we demonstrate an efficient spin-to-charge current conversion at the metal surface covered by a single layer of molecules. Spin currents are injected into an interface between metal (Cu) and lead(II) phthalocyanine by means of the spin pumping method. An observed voltage signal is caused by the inverse Edelstein effect, i.e., spin-to-charge current conversion at the interface. The conversion coefficient, inverse Edelstein length, is estimated to be 0.40 ± 0.06 nm, comparable with the largest Rashba spin splitting of interfaces with heavy metals. Interestingly, the Edelstein length strongly depends on the thickness of the molecule and takes a maximum value when a single layer of molecules is formed on the Cu surface. Comparative analysis between scanning probe microscopy and first-principles calculations reveal that the formation of interface state with Rashba spin splitting causes the inverse Edelstein effect, whose magnitude is sensitive to the adsorption configuration of the molecules.

Current-Nonlinear Hall Effect and Spin-Orbit Torque Magnetization Switching in a Magnetic Topological Insulator.

The current-nonlinear Hall effect or second harmonic Hall voltage is widely used as one of the methods for estimating charge-spin conversion efficiency, which is attributed to the magnetization oscillation by spin-orbit torque (SOT). Here, we argue the second harmonic Hall voltage under a large in-plane magnetic field with an in-plane magnetization configuration in magnetic-nonmagnetic topological insulator (TI) heterostructures, Cr_{x}(Bi_{1-y}Sb_{y})_{2-x}Te_{3}/(Bi_{1-y}Sb_{y})_{2}Te_{3}, where it is clearly shown that the large second harmonic voltage is governed not by SOT but mainly by asymmetric magnon scattering without macroscopic magnetization oscillation. Thus, this method does not allow an accurate estimation of charge-spin conversion efficiency in TI. Instead, the SOT contribution is exemplified by current pulse induced nonvolatile magnetization switching, which is realized with a current density of 2.5×10^{10} A m^{-2}, showing its potential as a spintronic material.

Observation of the intrinsic pinning of a magnetic domain wall in a ferromagnetic nanowire.

The spin transfer torque is essential for electrical magnetization switching. When a magnetic domain wall is driven by an electric current through an adiabatic spin torque, the theory predicts a threshold current even for a perfect wire without any extrinsic pinning. The experimental confirmation of this 'intrinsic pinning', however, has long been missing. Here, we give evidence that this intrinsic pinning determines the threshold, and thus that the adiabatic spin torque dominates the domain wall motion in a perpendicularly magnetized Co/Ni nanowire. The intrinsic nature manifests itself both in the field-independent threshold current and in the presence of its minimum on tuning the wire width. The demonstrated domain wall motion purely due to the adiabatic spin torque will serve to achieve robust operation and low energy consumption in spintronic devices.

Novel antioxidants isolated from plants of the genera Ferula, Inula, Prangos and Rheum collected in Uzbekistan.

We examined the effects of 48 compounds isolated from Ferula pallida, F. penninervis, Inula macrophylla, Prangos pabularia, P. tschimganica and Rheum maximowiczii collected in Uzbekistan on ADP/Fe2+-induced lipid peroxidation of egg yolk phosphatidylcholine liposomes. Of those compounds, 23 inhibited ADP/Fe2+-induced lipid peroxidation and nine showed especially strong inhibition of lipid peroxidation. Most compounds that inhibited peroxidation scavenged the 1,1'-diphenyl-2-picrylhydrazyl (DPPH) radical, indicating that the inhibition was due to radical scavenging. However, some compounds did not scavenge DPPH but inhibited lipid peroxidation significantly, suggesting that their inhibitory effect was not due to radical scavenging but to some other mechanism, such as prevention of Fe2+ function. Thus, we found various new antioxidants, some of which had a unique mechanism of action, in Ferula, Inula, Prangos and Rheum plants collected in Uzbekistan as seeds used in medicine.

Germinoma with a granulomatous reaction. Problems of differential diagnosis.

The patient was a 6 year-old girl with a progressive loss of visual acuity. Magnetic resonance imaging showed a suprasellar mass lesion with enhanced gadolinium which was resected. Histopathological study showed a remarkable granulomatous reaction, but a diagnosis was difficult. However, immunohistochemical study showed a few cells that were positive for placental alkaline phosphatase and it was diagnosed as germinoma. Intracranial germinoma with a remarkable granulomatous reaction is rare. However, when germinoma is suspected clinically, an immunohistochemical study is able to identify germinoma even if granulomatous disease is diagnosed histopathologically.

Increase in neurotrophin-3 expression followed by Purkinje cell degeneration in the adult rat cerebellum after spinal cord transection.

Changes in brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) contents following thoracic spinal cord transection were investigated in the cerebral cortex, hippocampus, and cerebellum of rats. The NT-3 content became significantly elevated at 3 days after transection only in the cerebellum and gradually declined to the control level by 6 days after the injury, remaining unchanged in the cerebral cortex and hippocampus. No significant change in the BDNF content was observed in any of the regions tested. Immunohistochemical analysis showed that the labeling indicating NT-3-like immunoreactivity was intensified in both cerebellar granule and Purkinje cells 3 days after the injury. The number of Purkinje cells with aggregation of chromatin around the nuclear membrane and swelling of the cytoplasm and/or organelles gradually increased with time starting 4 days after the injury, demonstrating morphological changes indicative of necrosis. However, no abnormal morphology was found in cerebellar granule cells at any time examined. We suggest that it is reasonable that increased NT-3 stimulated the death of Purkinje cells, because 1) the degeneration was necrosis, which is known to be accelerated by neurotrophins under certain pathological conditions, and 2) the increase in NT-3 occurred prior to Purkinje cell degeneration. Therefore, our present results may imply that spinal cord injury-induced NT-3 accelerates injury rather than alleviates degeneration of Purkinje cells.

Oxidation and epimerization of epigallocatechin in banana fruits.

To examine the metabolism of proanthocyanidins in banana fruit, (-)-epigallocatechin was treated with the homogenate of the fruit flesh to yield (-)-gallocatechin and an oxidation product, 1-(3,4,5-trihydroxyphenyl)-3-(2,4,6-trihydroxyphenyl)-2-hydroxy-1-propan one. The latter product is a stable form of a key intermediate in the oxidative metabolism of flavan-3-ols, and is also related to the biogenesis of A-type proanthocyanidins. In addition, treatment of the reaction mixture with o-phenylenediamine afforded monomeric and dimeric phenazine derivatives generated by condensation with the o-quinone form of the oxidation product.

[Propofol-air-oxygen anesthesia reduces the incidence of sore throat after laryngeal mask anesthesia].

We investigated the effects of the presence or absence of N2O in propofol anesthesia using a laryngeal mask on the incidence of postoperative sore throat. In the N2O-combined anesthesia group (n = 25), score 0 (no sore throat) was observed in 11 patients; score 1 (slight pain and discomfort that improved on the next day of operation) in 9; and score 2 (persistent pain on the next day) in 5. In the non-N2O-combined anesthesia group (n = 25), score 0 was observed in 21 patients, score 1 in 3; and score 2 in 1, showing a significantly lower incidence of sore throat and milder sore throat than in the N2O-combined anesthesia group. These results suggest that propofol anesthesia using a laryngeal mask not combined with N2O reduces the incidence of postoperative sore throat.

Purification and characterization of triacylglycerol lipase from Aspergillus oryzae.

Triacylglycerol lipase (L3) was purified from Aspergillus oryzae RIB128 by ammonium sulfate fractionation, acetone precipitation, anion-exchange chromatography, and gel filtration. The purified enzyme was formed from a glycoprotein and a monomeric protein with molecular masses of 25 and 29 kDa, by SDS-PAGE and gel filtration, respectively. The optimum pH at 40 degrees C was 5.5 and the optimum temperature at pH 5.5 was 40 degrees C. The enzyme was stable between a pH range of 4.0-7.5 at 30 degrees C for 24 h, and at up to 30 degrees C at pH 5.5 for 1 h. Heavy metal ions, detergents, DFP, and DEP strongly inhibited the enzyme activity. The lipase hydrolyzed not only triacylglycerols but also monoacylglycerols and diacylglycerols. The enzyme had higher specificity toward triacylglycerols of middle-chain saturated fatty acids than short-chain or long-chain fatty acids. The enzyme had 1,3-positional specificity. The N-terminal amino acid sequence of the enzyme was not significantly similar to that of other lipases with published sequences.

[A case of mobile left atrial thrombus without mitral valve disease].

A 70-year-old woman who had a left atrial thrombus without mitral valve disease was reported. On admission her electrocardiogram showed atrial fibrillation, but there was no cardiac murmur. Transthoracic echocardiogram revealed a dilated left atrium and an intact mitral valve, but did not detect any thrombus. Transesophageal echocardiogram, however, demonstrated the thrombus attaching to the left atrial appendage. Removal of the thrombus and maze procedure were performed at the same time. Although a pacemaker (DDDR mode) was required postoperatively, she spends uneventful daily life at two years after the surgery.

The effects of 20 days bed rest on serum lipids and lipoprotein concentrations in healthy young subjects.

The effects of 20 days bed rest (BR) on serum lipids and lipoprotein concentrations were investigated in 23 healthy young subjects (13 males and 10 females, aged 19 to 25 yr.). After 20 days BR, VO2max was reduced in both genders, but body composition did not change. The ratio of glucose area to insulin area during an oral glucose tolerance test decreased gradually throughout BR, which suggested a decrease in insulin sensitivity. Estimated changes in plasma volume from the beginning of BR were largest at day 3 of BR (-9.1% in females and -3.4% in males) and seemed to return the initial level at the end of BR in both genders. The increase in serum triglycerides and the decrease in high density lipoprotein (HDL) cholesterol, and apolipoprotein AI were observed in both genders during BR. In a smaller study of 4 males and 5 females, 20 days BR was associated with a decrease in HDL, cholesterol, a decrease in apolipoprotein AI and apolipoprotein AII, decrease in a plasma postheparin lipoprotein lipase activity and an increase in very low density lipoprotein triglyceride. Overall, the data suggested that the decrease in lipoprotein lipase activity and insulin sensitivity may contribute to the impairment in HDL metabolism.

[Clinical study of ten cases with acute abdomen after eating raw firefly squid (Watasenia scintillans, Hotaruika), which are probably due to type X larvae of the suborder spirurina].

We studied ten cases with abdominal pain after eating raw firefly squid, Watasenia scintillans, Hotaruika. Characteristic clinical features were abdominal pain, nausea, vomiting, diarrhea, creeping eruption and ileus with ascites. In ten patients, there were all cases with abdominal pain, nine with nausea and vomiting, four with diarrhea, one with creeping eruption, six with ileus. Laboratory examination revealed eosinophilia on peripheral blood in ten cases and high serum IgE value in nine cases. The infection rate of type X lavae of the suborder spirurina in Watasenia scintillans is almost 3%, so we measured the antibody to type X larvae of the suborder spirurina in nine patients by indirect fluorescent antibody method and the antibody titer was positive in seven cases. Most patients recovered in several days from first visit. But one patient was diagnosed peritonitis and operated with partial ileectomy. Pathological finding of resected specimen showed an erosion in the mucosal layer and an inflammation with marked eosinophilia in the submucosal layer. These results suggest that abdominal complaints after eating Watasenia scintillans are due to type X larvae of the suborder spirurina.

[Treatment of solid tumor by a small amount of direct current].

Solid tumor treatment was given in our animal laboratory to determine the mechanism of tumor disappearance by direct electric current, and clinical trials were done on 9 far advanced recurrent rectal cancers. Solid tumors of Yoshida sarcoma in Donryu rat were treated by 1 mA of constant direct current for 1 hour a day, for 4 days. The tumors disappeared in 13/16 within 21 days. Positive results of DNA Nick-end labeling and ladder patterns in the gel electrophoresis of DNA were observed in the regressing tumor specimen. It is considered that apoptosis is the one of the mechanisms of a disappearing tumor. As for the clinical trial concern, in 9 cases of rectal cancer, one CR and 5 PR were seen.

[The high-dose gamma-globulin therapy for inflammatory demyelinating peripheral neuropathy: evaluations of clinical effects and serum IgG subclasses].

PURPOSE OF THE STUDY: To clarify the clinical effects and the influence of high-dose therapy of gamma-globulin for inflammatory demyelinating peripheral neuropathy, we have investigated changes of serum IgG subclass distribution of the patients with these diseases by this therapy. SUBJECTS AND METHODS: gamma-Globulin (20g/day) was intravenously administrated for 5 days in 4 cases of CIDP, 2 cases of Fisher syndrome and 1 case of Guillain-Barré syndrome. The IgG subclass was measured by sandwich ELISA method four times, namely before the treatment, immediately after, and 2 and 4 weeks after the treatment. RESULTS: Marked symptomatical improvement was observed in all cases. Serum levels of all IgG subclasses were highest just after the therapy, and all subclasses recovered to the pretherapeutic levels in 4 weeks. Attitude of changes in all IgG subclasses of all cases was fairly similar each other. CONCLUSION: These results suggest that high-dose therapy of gamma-globulin is an effective therapy for inflammatory demyelinating peripheral neuropathy with little influences on IgG production and metabolism of IgG.

Establishment and characterization of human gastric and colonic xenograft lines resistant to CPT-11 (a new derivative of camptothecin).

CPT-11-resistant human gastric and colonic xenograft lines were established by direct intratumoral injection of CPT-11 into subcutaneous SC-1-NU and CC-2-NU tumors in nude mice once a week for 10 months. The resistance of these xenograft lines to CPT-11 was confirmed by growth inhibition rate, to be 36.3% and 45.4%, respectively, compared to each parent cell line. DNA topoisomerase I activity of the nuclear extracts of SC-1-NU/CPT-11 and CC-2-NU/CPT-11, as assayed by relaxation of supercoiled DNA Col-E1, was significantly less than those of the parent lines. The cellular levels of topoisomerase I in those resistant lines measured by Western blot analysis were 0.57- and 0.79-fold lower than those of the parental lines, respectively. However, the activity of DNA topoisomerase II of those resistant cell lines assayed by decatenation of kinetoplast DNA was higher than that of the parental lines and the cellular levels of topoisomerase II in the resistant lines measured by Western blot analysis were 10.8- and 8.1-fold higher than those of the parent lines. Intracellular accumulation of CPT-11 in CPT-11-resistant tumors was not changed as compared to that of the parental lines, but hydrolysis of CPT-11 to more active SN-38 was reduced in the resistant tumors.

Sevoflurane anesthesia following administration of atropine-guaifenesin-thiopental in spontaneous-breathing adult cattle.

The effect of sevoflurane-oxygen anesthesia at surgical depth on clinically important features was evaluated in spontaneously breathing cattle given atropine-guaifenesin-thiopental. The mean end-tidal sevoflurane concentrations ranged from 1.4 to 2.0% for 75 min maintenance. Recovery from anesthesia was extremely rapid and smooth. Heart rate increased and arterial pressure was higher during anesthesia, but respiratory rate did not change significantly. Arrhythmia was not observed. Minute ventilation was low due to decreased tidal volume during anesthesia, and changes in blood gases and pH showed mild respiratory acidosis. There were no marked changes in hematologic or serum biochemical values for 7 days postanesthesia. These findings suggest that sevoflurane is an effective inhalant anesthetic showing rapid recovery from anesthesia.

Bilateral ptosis with ophthalmoplegia in a 72-year-old woman with diabetes.

Ophthalmoplegia is common cranial neuropathy of Diabetes. In case of 3rd nerve involvement, usually unilateral extra ocular muscles are affected. However, ptosis is very rare in patients with diabetic neuropathy. In this report, we describe bilateral ptosis with ophthalmoplegia in diabetes. In ophthalmoplegia associated with diabetes, ischemic nerve infarction was reported. We treated this patient with Lipo prostaglandin (PG) E1. Since then, increased platelet aggregation activity was found in this patient. After two months, the symptoms of this patient were improved.