Majorana quantization and half-integer thermal quantum Hall effect in a Kitaev spin liquid.

The quantum Hall effect in two-dimensional electron gases involves the flow of topologically protected dissipationless charge currents along the edges of a sample. Integer or fractional electrical conductance is associated with edge currents of electrons or quasiparticles with fractional charges, respectively. It has been predicted that quantum Hall phenomena can also be created by edge currents with a fundamentally different origin: the fractionalization of quantum spins. However, such quantization has not yet been observed. Here we report the observation of this type of quantization of the Hall effect in an insulating two-dimensional quantum magnet1, α-RuCl3, with a dominant Kitaev interaction (a bond-dependent Ising-type interaction) on a two-dimensional honeycomb lattice2-7. We find that the application of a magnetic field parallel to the sample destroys long-range magnetic order, leading to a field-induced quantum-spin-liquid ground state with substantial entanglement of local spins8-12. In the low-temperature regime of this state, the two-dimensional thermal Hall conductance reaches a quantum plateau as a function of the applied magnetic field and has a quantization value that is exactly half of the two-dimensional thermal Hall conductance of the integer quantum Hall effect. This half-integer quantization of the thermal Hall conductance in a bulk material is a signature of topologically protected chiral edge currents of charge-neutral Majorana fermions (particles that are their own antiparticles), which have half the degrees of freedom of conventional fermions13-16. These results demonstrate the fractionalization of spins into itinerant Majorana fermions and Z2 fluxes, which is predicted to occur in Kitaev quantum spin liquids1,3. Above a critical magnetic field, the quantization disappears and the thermal Hall conductance goes to zero rapidly, indicating a topological quantum phase transition between the states with and without chiral Majorana edge modes. Emergent Majorana fermions in a quantum magnet are expected to have a great impact on strongly correlated quantum matter, opening up the possibility of topological quantum computing at relatively high temperatures.

Unusual Thermal Hall Effect in a Kitaev Spin Liquid Candidate α-RuCl_{3}.

The Kitaev quantum spin liquid displays the fractionalization of quantum spins into Majorana fermions. The emergent Majorana edge current is predicted to manifest itself in the form of a finite thermal Hall effect, a feature commonly discussed in topological superconductors. Here we report on thermal Hall conductivity κ_{xy} measurements in α-RuCl_{3}, a candidate Kitaev magnet with the two-dimensional honeycomb lattice. In a spin-liquid (Kitaev paramagnetic) state below the temperature characterized by the Kitaev interaction J_{K}/k_{B}∼80 K, positive κ_{xy} develops gradually upon cooling, demonstrating the presence of highly unusual itinerant excitations. Although the zero-temperature property is masked by the magnetic ordering at T_{N}=7 K, the sign, magnitude, and T dependence of κ_{xy}/T at intermediate temperatures follows the predicted trend of the itinerant Majorana excitations.

Incorporation of apical lymph node status into the seventh edition of the TNM classification improves prediction of prognosis in stage III colonic cancer.

BACKGROUND: The node classification outlined in the seventh edition of the TNM classification is based solely on the number of metastasized lymph nodes. This study examined the prognostic value of apical lymph node (ALN) metastasis and the additional value of incorporating ALN status into a risk model based on the seventh edition. METHODS: This was a cohort study of patients with stage III colonic cancer who underwent tumour resection with dissection of regional (including apical) lymph nodes at 71 hospitals across Japan between 2000 and 2002. The main exposure was pathologically confirmed ALN metastasis, and the primary endpoint was cancer-specific death. RESULTS: ALN metastasis was present in 113 (8·3 per cent) of 1355 patients. During 5356 patient-years of follow-up (median 5·0 years), 221 instances (16·3 per cent) of cancer-specific death were observed. After adjustment for tumour and node classification (as described in the seventh edition of the TNM classification) and other prognostic factors, ALN metastasis was found to be independently associated with cancer-specific death (hazard ratio 2·29, 95 per cent confidence interval (c.i.) 1·49 to 3·52). Incorporation of ALN metastasis into the prognostic model based on the seventh edition of the TNM classification significantly improved discriminative performance for cancer-specific death (difference in concordance index 0·0146, 95 per cent c.i. 0·0030 to 0·0262) and risk reclassification for cancer-specific death at 5 years (category-free net reclassification improvement 19·4 (95 per cent c.i. 5·0 to 33·4) per cent). CONCLUSION: Assessment of ALN metastasis provided independent prognostic information beyond that achievable with the seventh edition of the TNM classification in patients with stage III colonic cancer.

Kosterlitz-Thouless-type transition in a charge ordered state of the layered organic conductor α-(BEDT-TTF)2I3.

The current-voltage characteristics in the charge order state of the two-dimensional organic conductor α-(BEDT-TTF)(2)I(3) exhibit power law behavior at low temperatures. The power law is understood in terms of the electric-field-dependent potential between electrons and holes, which are thermally excited from the charge order state. The power law exponent steeply changes from 1 to 3 in the range from 30 to 45 K with decreasing temperature, thereby suggesting the occurrence of a Kosterlitz-Thouless-type transition; many (few) unbound electron-hole pairs are thermally excited above (below) the transition. The effects of the finite size and interlayer coupling on the power law behavior are discussed.

Clinical characteristics classified by the serum KL-6 level in patients with organizing pneumonia.

BACKGROUND: The serum Krebs von der Lungen-6 (KL-6) level is a useful marker correlated with the severity of various interstitial lung diseases. There have been few reports about the clinical characteristics of organizing pneumonia (OP) associated with the serum KL-6 levels. OBJECTIVE: This study was performed to determine whether the serum KL-6 levels can help determine the optimal treatment for OP. DESIGNS: Patients diagnosed with OP by clinical, radiological and histopathological findings were retrospectively reviewed. The OP patients were classified into two groups based on their serum KL-6 levels: normal KL-6 and high KL-6 groups. The two groups were compared with regard to their clinical and radiological data and therapeutic response one month after the start of treatment. RESULTS: The clinical records of twenty-two patients diagnosed with OP were reviewed. The serum KL-6 level was elevated in 11 of the 22 patients. There were no obvious differences in the clinical data between the two groups, although patients in the normal KL-6 group tended to have a fever. There were no significant differences in the chest X-ray (CXR) score or computed tomography (CT) score between the two groups. The CXR scores were correlated with the serum KL-6 levels. At 1 month after the diagnosis, 11 patients who needed treatment with prednisolone were included in the high KL-6 group. CONCLUSIONS: Patients with normal KL-6 levels showed lower CXR and CT scores. The serum KL-6 level on admission is a useful marker to judge the need for corticosteroid treatment in OP patients.

Hopelessness and Depression Predict Sarcopenia in Advanced CKD and Dialysis: A Multicenter Cohort Study.

BACKGROUND/OBJECTIVES: Depression and hopelessness are frequently experienced in chronic kidney disease (CKD) and are generally associated with lessened physical activity. The aim of this study was to quantify the associations between sarcopenia as determined by SARC-F with both depression and hopelessness. DESIGN AND SETTING: This multicenter cohort study involving cross-sectional and longitudinal analyses was conducted in a university hospital and four general hospitals, each with a nephrology center, in Japan. PARTICIPANTS: Participants consisted of 314 CKD patients (mean age 67.6), some of whom were receiving dialysis (228, 73%). MEASUREMENTS: The main exposures were depression, measured using the Center for Epidemiologic Studies Depression (CES-D) questionnaire, and hopelessness, measured using a recently developed 18-item health-related hope scale (HR-Hope). The outcomes were sarcopenia at baseline and one year after, measured using the SARC-F questionnaire. Logistic regression models were applied. RESULTS: The cross-sectional and longitudinal analyses included 314 and 180 patients, respectively. Eighty-nine (28.3%) patients experienced sarcopenia at baseline, and 44 (24.4%) had sarcopenia at the one-year follow-up. More hopelessness (per 10-point lower, adjusted odds ratio [AOR]: 1.33, 95% confidence interval [95% CI] 1.12-1.58), depression (AOR: 1.87, 95% CI 1.003-3.49), age (per 10-year higher, AOR: 1.70, 95% CI 1.29-2.25), being female (AOR: 2.67, 95% CI 1.43-4.98), and undergoing hemodialysis (AOR, 2.92; 95% CI, 1.41-6.05) were associated with a higher likelihood of having baseline sarcopenia. More hopelessness (per 10-point lower, AOR: 1.69, 95% CI 1.14-2.51) and depression (AOR: 4.64, 95% CI: 1.33-16.2) were associated with a higher likelihood of having sarcopenia after one year. CONCLUSIONS: Among patients with different stages of CKD, both hopelessness and depression predicted sarcopenia. Provision of antidepressant therapies or goal-oriented educational programs to alleviate depression or hopelessness can be useful options to prevent sarcopenia.

Half-integer quantized anomalous thermal Hall effect in the Kitaev material candidate α-RuCl3.

Half-integer thermal quantum Hall conductance has recently been reported for the two-dimensional honeycomb material α-RuCl3 We found that the half-integer thermal Hall plateau appears even for a magnetic field with no out-of-plane components. The measured field-angular variation of the quantized thermal Hall conductance has the same sign structure as the topological Chern number of the pure Kitaev spin liquid. This observation suggests that the non-Abelian topological order associated with fractionalization of the local magnetic moments persists even in the presence of non-Kitaev interactions in α-RuCl3.

Quasi-two-dimensional Fermi surfaces and coherent interlayer transport in KFe2As2.

We report the results of the angular-dependent magnetoresistance oscillations (AMROs), which can determine the shape of bulk Fermi surfaces (FSs) in quasi-two-dimensional (Q2D) systems, in a highly hole-doped Fe-based superconductor KFe2As2 with Tc ≈ 3.7 K. From the AMROs, we determined the two Q2D FSs with rounded-square cross sections, correspond to 12% and 17% of the first Brillouin zone. The rounded-squared shape of the FS cross section is also confirmed by the analyses of the interlayer transport under in-plane fields. From the obtained FS shape, we infer the character of the 3d orbitals that contribute to the FSs.

Effects of xenon on ischemic spinal cord injury in rabbits: a comparison with propofol.

BACKGROUND: Xenon has been shown to reduce cellular injury after cerebral ischemia. However, the neuroprotective effects of xenon on ischemic spinal cord are unknown. The authors compared the effects of xenon and propofol on spinal cord injury following spinal cord ischemia in rabbits. METHODS: Thirty-two male New Zealand white rabbits were randomly assigned to one of three groups. In the xenon and propofol group, 70% of xenon and 0.8 mg/kg/min of propofol were administered 30 min before an aortic occlusion and maintained until the end of the procedure. The aortic occlusion was performed for 15 min. In the sham group, the aorta was not occluded. After an assessment of the hind limb motor function using the Tarlov score (0=paraplegia, 4=normal) at 48 h after reperfusion, gray and white matter injuries were evaluated based on the number of normal neurons in the anterior spinal cord and the percentage areas of vacuolation in the white matter, respectively. RESULTS: In the xenon and propofol groups, the Tarlov score and the number of normal neurons were significantly lower than those in the sham group, whereas the percentage areas of vacuolation were similar among the three groups. There were no significant differences in Tarlov scores and the number of normal neurons between the xenon and the propofol groups. CONCLUSION: The results indicated that 70% of xenon has no additional neuroprotective effects on ischemic spinal cord injury in rabbits compared with propofol.

SARC-F Validation and SARC-F+EBM Derivation in Musculoskeletal Disease: The SPSS-OK Study.

OBJECTIVES: To validate the SARC-F questionnaire for sarcopenia screening in musculoskeletal disease setting, and to assess improvements in diagnostic accuracy by adding "EBM" (elderly and body mass index information) to the SARC-F. DESIGN: Diagnostic accuracy study. SETTING AND PARTICIPANTS: The center involved in this study was located in an urban area of Kobe City, Japan. People with musculoskeletal disease in the knee, hip, or spine who were scheduled for surgical treatment were included. MEASUREMENTS: Sarcopenia was evaluated using the Asian Working Group for Sarcopenia (AWGS) and the European Working Group on Sarcopenia in Older People (EWGSOP2), which included bioimpedance, handgrip strength, and gait speed. Patients answered the SARC-F questionnaire and their body mass index was measured. SARC-F and "EBM" information were combined into an original score. The sensitivities, specificities, and areas under the receiver operating characteristic curve (AUC) were estimated and compared to identify sarcopenia. RESULTS: A total of 959 patients were included. Sarcopenia by AWGS criteria was identified in 36 (3.8%) patients. SARC-F had a sensitivity of 41.7% and specificity of 68.5%. SARC-F+EBM had a sensitivity of 77.8% and specificity of 69.6%, with substantial improvement in sensitivity (P<0.001). The AUCs for SARC-F and SARC-F+EBM were 0.557 (95% confidence interval [CI] 0.452-0.662) and 0.824 (95% CI 0.762-0.886), respectively (P<0.001). Similar results were obtained when EWGSOP2 criteria were used as the reference standard. CONCLUSION: The SARC-F alone is not adequate for finding cases in musculoskeletal disease settings. SARC-F+EBM significantly improved the sensitivity and overall diagnostic accuracy of the SARC-F for screening sarcopenia. SARC-F+EBM is potentially useful for screening sarcopenia in different ethnic and disease settings.

TRITIUM, HYDROGEN AND OXYGEN ISOTOPE COMPOSITIONS IN MONTHLY PRECIPITATION SAMPLES COLLECTED AT TOKI, JAPAN.

Monthly precipitation samples have been collected at Toki, Japan, from November 2013 to March 2017. In this report, selected data were analysed to identify the regional hydrogen and oxygen isotope compositions. Tritium (3H) concentration in the precipitation ranged from 0.10 to 0.61 Bq L-1 and higher 3H concentrations were observed in spring rather than in other seasons. This range was similar to values reported in Chiba City, Japan. 3H concentration and the ratio d-excess, and δD values were roughly clustered according to each separate season. These regional hydrogen and oxygen isotope compositions will be used for environmental assessments of effects of the deuterium plasma experiments of the large fusion test device.

A phase I/II trial of intrabone marrow cord blood transplantation and comparison of the hematological recovery with the Japanese nationwide database.

Intrabone marrow cord blood transplantation (IB-CBT) was proposed as a promising treatment modality to improve hematological recovery. However, clinical advantages of IB-CBT over conventional IV CBT have been unclear. We conducted a prospective single-center trial of IB-CBT to evaluate its safety and superiority in terms of hematological recovery. Fifteen adults with hematological malignancies were enrolled. A thawed and unwashed single cord blood unit was injected into the bilateral superior-posterior iliac crests under local anesthesia. Engraftments of neutrophils and platelets were achieved in 13 cases, with medians of 17 and 45 days, respectively. For the control, we extracted data from the Japanese nationwide database and compared the hematological recovery of contemporaneously transplanted 1135 CBT cases. Multivariate analysis revealed that IB-CBT enhanced platelet recovery (hazard ratio, 2.13; P=0.007), but neutrophil recovery did not differ significantly (hazard ratio, 1.70; P=0.19). Better donor chimerism was seen in the bone marrow of the ilium than of the sternum on day 14, suggesting that the local hematopoiesis at the injected site was established earlier than that at the remote bone marrow site. Collectively, IB-CBT was well tolerated and may enhance local engraftment, which promotes prompter platelet recovery than does IV-CBT.

Impact of length of cryopreservation and origin of cord blood units on hematologic recovery following cord blood transplantation.

As the history of the cord blood banking system has lengthened, the number of cord blood units (CBUs) cryopreserved for years has increased. The global expansion of cord blood banking resulted in active international exchange of CBUs. To determine whether long-term cryopreservation and international shipment of CBUs affect the quality of the units and outcome after transplantation, we retrospectively analyzed the quality of 95 CBUs and the hematologic recovery of 127 patients with hematological malignancy following single-unit cord blood transplantation. Of the 127 CBUs used to transplant, 42 units were cryopreserved for long periods (5-11.8 years), and 44 units were shipped from distant countries. We found that length of cryopreservation and origin of CBUs did not affect the ratio of viable total-nucleated cells after thawing. Also, neutrophil engraftment was not affected by long-term cryopreservation (> 5 years) or origin (from distant countries), (hazard ratio, 0.91 and 1.2; P=0.65 and 0.41; respectively). The number of CD34(+) cells before freezing (> 1.4 cells/kg recipient) was the only factor that enhanced neutrophil engraftment (hazard ratio, 1.8; P<0.01). This suggests that length of cryopreservation and origin need not be prioritized over the CD34(+) cell dose when selecting CBUs.

Killing of Histoplasma capsulatum by gamma-interferon-activated human monocyte-derived macrophages: evidence for a superoxide anion-dependent mechanism.

The interaction of human macrophages with the yeast form of the thermally dimorphic fungal pathogen, Histoplasma capsulatum, was studied. Macrophages derived from monocytes by culture in vitro for 3 days ingested H. capsulatum, but were neither fungicidal or fungistatic. In contrast, when monocytes were exposed to human recombinant gamma-interferon (gamma-IFN) during their differentiation into macrophages, those macrophages were able to reduce the number of ingested or adherent cfu of H. capsulatum by 44-75% in 2 h. Activation of macrophages for fungicidal activity by gamma-IFN was dose dependent and 500-1000 units ml were optimal. Antibody to gamma-IFN abrogated the gamma-IFN activation process. Killing of H. capsulatum by activated macrophages in 2-h assays could be inhibited by superoxide dismutase but not by sodium azide.

Multiple organ damage caused by a new toxin azaspiracid, isolated from mussels produced in Ireland.

A new type of food poisoning resulting from ingestion of mussels produced in Ireland occurred in the Netherlands in 1995 and then reoccurred in Ireland in 1997. As the causative agent, azaspiracid, was isolated in pure form and revealed to have a structure entirely unlike other known algal toxins, in vivo studies with mice were carried out to elucidate the pathological injuries caused by the toxin. By per os administration, the toxin caused necrosis in the lamina propria of the small intestine and in lymphoid tissues such as thymus, spleen and the Peyer's patches. Both T and B lymphocytes were injured. Additionally a fatty change was observed in the liver. These injuries distinctly differed from those caused by the representative diarrhetic shellfish toxin, okadaic acid.

Computing the relative gas-phase populations of C60 and C70: beyond the traditional delta H(fo),298 scale.

Computations and experiments have shown that the relative heat of formation (i.e., the heat of formation per carbon atom) of C70 is lower than of C60. Moreover, various computations suggest that this is actually a general trend among fullerene cages. The relationship is particularly important for gas-phase fullerenes. Experiments have shown that C60 is typically more populated than C70 when produced in high-temperature gas-phase synthesis. It is not immediately obvious how to reconcile those two terms, or whether the relative heats of formation and the relative populations are in conflict or in agreement. This article deals with this problem, treating it as a general task of relative stabilities of gas-phase clusters of different dimensions (i.e., nonisomeric clusters) under different types of thermodynamic equilibria. The results are then applied to C60 and C70 and point out that the conventional standard pressure of 1 atm is considerably different from actual fullerene-synthesis conditions. Apparently, we should expect considerably lower cluster pressures in carbon-arc synthesis. At 1 atm, C70 is more populated than C60, but at the conditions of a saturated carbon vapor the stability order is reversed in favor of C60 so that an agreement with experiment is obtained already within the thermodynamic treatment. The pressure effects are modeled using the MNDO, AM1, PM3, and SAM1 quantum-chemical semi-empirical methods as well as the available experimental data. The computations consistently show that, if the pressure effects are considered, C60 becomes more populated than C70. Relationships of the thermodynamic treatment to more sophisticated but impractical kinetic analysis are also discussed.

Alterations in the growth and cycling status of granulocyte-monocyte colony-forming units (CFU-GM) in rats injected single doses of aflatoxin B1.

To determine the toxic effect of aflatoxin B1 (AFB1) on granulopoiesis in vitro, cultures of myeloid progenitor cells for granulocytes and macrophages CFU-GM in semisolid agar medium were used to evaluate colony formation and tritiated thymidine suicide technique for analysis of cycling status of CFU-GM. Male Fischer rats, 5 to 6 weeks old, were given a single i.p. injection of 1 mg/kg or 0.1 mg/kg of AFB1 which were approximately 1/5 or 1/50, respectively, of LD50 dose of AFB1. The administration of either dose of AFB1 caused a significant reduction of the number of CFU-GM derived colonies on the first and the second day after injection. This reduction was followed by a strong enhancement in CFU-GM colony formation on the third day, and by restoration to the normal level on the fourth day. The increase in percentage of CFU-GM in S-phase preceded one day the peak in CFU-GM colony formation. The two different doses of AFB1 exerted similar effects on the growth and cycling status of CFU-GM. Our data outline an early suppressive effect exerted by AFB1 to the rat granulopoiesis in vivo.

Gastric function after pylorus-preserving duodenectomy in dogs.

BACKGROUND/AIMS: The purpose of this study was to delineate the alterations in gastric physiology after pylorus-preserving duodenectomy (PPD). METHODOLOGY: The duodenum was transected 2 cm distal to the pyloric ring in five dogs. A patch graft around the papilla of Vater was preserved. Reconstruction was completed using an end-to-end duodenojejunostomy, anastomosis of the patch graft to the jejunum, and cholecystojejunostomy, in that order. Gastric acid analysis, serum gastrin and secretin concentrations, and gastric emptying were investigated before and one and three months after surgery. RESULTS: The postoperative mean basal and maximal acid outputs were not significantly increased. Fasting serum gastrin concentrations remained unchanged. The fasting serum secretin concentrations one month after surgery increased significantly as compared to the controls. There were no significant differences in meal-stimulated gastrin or secretin responses or gastric emptying after surgery. CONCLUSIONS: The acid output and gut hormone release after PPD were maintained at preoperative levels. Preservation of the duodenal bulb is postulated to be responsible for the maintenance of near-normal gastric physiology.

Effects of exercise on nasal resistance and nasal blood flow.

Nasal resistance and nasal blood flow were measured consecutively before exercise, immediately after exercise, 5, 10, 15, 20, 25, and 30 minutes after exercise in 11 normal subjects and 18 patients with perennial allergic rhinitis. Nasal resistance was measured by Nihon-Koden Rhinorheograph MRP 2100, and nasal blood flow was measured by Periflux PF2, a laser doppler flowmeter. 77% of unilateral nasal cavities in normal subjects and 75% of unilateral cavities in patients with allergic rhinitis showed a decrease of both nasal resistance and nasal blood flow immediately after exercise. However, rates of changes in nasal resistance and in nasal blood flow were not correlated with each other. In the latter period after exercise, there was a discrepancy between nasal resistance and nasal blood flow. A laser doppler flowmeter is considered to measure blood flow in the superficial part of the nasal mucosa. Based upon our results, an intensive stimulus such as exercise seems to induce vasoconstriction in the superficial part as well as in the deeper part of the nasal mucosa. However, it is also suggested that the vessels in the various parts of the nasal mucosa don't always respond in the same way.