Enhancement of the spin polarization of an Fe3O4(100) surface by nitric oxide adsorption.

The geometric, electronic and magnetic properties of a nitric oxide (NO) adsorbed Fe3O4(100) surface have been investigated using density functional theory (DFT) calculations. NO molecules preferentially bond with surface Fe(B) atoms via their N atoms. The generalized gradient approximation (GGA) is not recommended to be used in such a strongly correlated system since it provides not only an overestimation of the adsorption energy and an underestimation of the Fe(B)-N bond length, but also magnetic quenching of the adsorbate and the bonded Fe(B) atoms. In contrast, a tilted geometry and magnetization of the adsorbate and the bonded Fe(B) atom are obtained after including the strong on-site Coulomb interactions through a Hubbard term (GGA+U). The spin-down 2π* states of the NO molecule are filled and broadened due to the adsorbate-substrate interaction and the molecule-molecule interaction. The surface spin polarization close to the Fermi level is expected to be greatly enhanced by the NO adsorption which has significance for interface design in spintronic devices.

Reversible switching of the spin state in a manganese phthalocyanine molecule by atomic nitrogen.

Reversible control of the spin state of an organic molecule is significant for the development of molecular spintronic devices. Here, density functional theory calculations have been performed to study the adsorption of atomic nitrogen on a single manganese phthalocyanine (MnPc) molecule, three-layered MnPc, and MnPc on an Fe(100) surface. For all three cases, the N atom strongly adsorbs on top of the Mn atom and induces a significant variation of the geometric, electronic and magnetic properties. After N adsorption, an energy gap appears and the electronic states become unpolarized. Different functionals including three hybrid functionals are used in these calculations, and all yield a switchable spin state.

Factors that predict in-hospital mortality in eosinophilic granulomatosis with polyangiitis.

BACKGROUND: Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare systemic small-vessel vasculitis associated with asthma, eosinophilia, and necrotizing vasculitis. EGPA is potentially life-threatening and often involves peripheral neuropathies, peptic ulcers, cerebral vessel disease, and cardiovascular disease. However, there is limited understanding of the prognostics factors for patients with EGPA. We investigated the clinical features and factors affecting patients' in-hospital mortality, using a national inpatient database in Japan. METHODS: We retrospectively collected data of EGPA patients who required hospitalization between July 2010 and March 2013, using the Diagnosis Procedure Combination database. We evaluated EGPA patients' characteristics and performed multivariate logistic regression analyses to assess the factors associated with in-hospital mortality. RESULTS: A total of 2195 EGPA patients were identified. The mean age was 61.9 years, 42.1% (924/2195) were male, and 41.6% (914/2195) had emergent admission. In-hospital deaths occurred in 97/2195 patients (4.4%). Higher in-hospital mortality was associated with age older than 65 years, disturbance of consciousness on admission, unscheduled admission, respiratory disease, cardio-cerebrovascular disease, renal disease, sepsis, and malignant disease on admission. Lower mortality was associated with female gender and peripheral neuropathies. CONCLUSIONS: Our study revealed the clinical features of EGPA patients who required hospitalization and the factors associated with their mortality. These results may be useful for physicians when assessing disease severity or treatments for hospitalized EGPA patients.

Complex relationship of body mass index with mortality in patients with critical limb ischemia undergoing endovascular treatment.

OBJECTIVE: To investigate the relationship between body mass index (BMI) and long-term outcomes of patients with CLI after endovascular treatment (EVT). DESIGN: Retrospective multicenter study. SUBJECTS: 1088 consecutive patients (1306 limbs, mean age 72 ± 10 years) with CLI who underwent EVT for isolated infrapopliteal artery lesions were evaluated. These subjects were identified in the J-BEAT III registry. METHODS: The patients were divided into groups based on BMI <18.5 kg/m2 (underweight, n = 188; 219 limbs), 18.5 to 24.9 kg/m2 (normal weight, n = 718; 868 limbs), and >25.0 kg/m2 (overweight/obese, n = 182; 219 limbs). The endpoints were overall survival and freedom from major adverse limb events (MALE). RESULTS: The median follow up period was 1.5 years (range: 1 month-8.7 years). The 3 year overall survival rates were 33.3%, 61.2%, and 69.8% in underweight, normal, and overweight/obese patients, respectively. The survival rate was significantly lower in underweight patients and significantly higher in overweight/obese patients compared with patients of normal weight (both p < .0001). The 3 year rates of freedom from MALE did not differ significantly among the three groups (36.4%, 45.4%, and 52.3%, respectively, p = .32). Age, BMI <18.5 kg/m2, heart failure, aortic valve stenosis, renal failure, triglyceride levels, serum albumin <3.0 g/dL, anticoagulant treatment, non-ambulatory status, and Rutherford 6 classification all were significantly associated with overall survival. CONCLUSIONS: BMI has a complex correlation with mortality in patients with CLI after EVT for isolated infrapopliteal artery lesions. Underweight patients with CLI have an extremely poor prognosis. Such patients have many other factors associated with mortality, but low BMI was identified as an independent predictor of a poor prognosis in patients with CLI. Similarly, normal weight patients had a small but significant increase in mortality compared with overweight/obese patients.

Predictors of delayed wound healing after endovascular therapy of isolated infrapopliteal lesions underlying critical limb ischemia in patients with high prevalence of diabetes mellitus and hemodialysis.

OBJECTIVES: Acceptable limb salvage rates underlie the widespread use of endovascular therapy (EVT) for patients with critical limb ischemia (CLI) secondary to isolated infrapopliteal lesions; however, post-EVT delayed wound healing remains a challenge. Predictors of delayed wound healing and their use in risk stratification of EVT in patients with CLI due to isolated infrapopliteal lesions are explored. METHODS: This was a retrospective multicenter study. 871 consecutive critically ischemic limbs were studied. There was tissue loss in 734 patients (age: 71 ± 10 years old; 71% male) who had undergone EVT between April 2004 and December 2012. The wound healing rate after EVT was estimated by the Kaplan-Meier method. The association between baseline characteristics and delayed wound healing was assessed by the Cox proportional hazard model. RESULTS: Diabetes mellitus and regular dialysis were present in 75% (553/734) and 64% (476/734) of patients, respectively; 67% of limbs (585/871) had Rutherford class 5 CLI; 8% (67/871) of wounds were located in the heel only; 25% (219/871) of limbs had Rutherford 6 (involving not only the heel); and 42% (354/871) of wounds were complicated by infection. The rate of freedom from major amputation at 1 year reached 88%, whereas the wound healing rate was 67%. Median time to wound healing was 146 days. By multivariate analysis, non-ambulatory status (hazard ratio [HR], 1.58; 95% confidence interval [CI] 1.31-1.91) serum albumin <3 g/dL (HR 1.42; 95% CI 1.08-1.86), Rutherford 6 (not only heel) (HR 1.68; 95% CI 1.33-2.14), wound infection (HR 1.24; 95% CI 1.03-1.50), EVT not based on angiosome concept (HR 1.28; 95% CI 1.06-1.55), and below the ankle (BTA) 0 vessel runoff after EVT (HR 1.45; 95% CI 1.14-1.86) were independent predictors of delayed wound healing. CONCLUSIONS: Non-ambulatory status, low albumin level, Rutherford 6 (not only heel), wound infection, indirect intervention, and poor BTA runoff were independent predictors for delayed wound healing after EVT in patients with CLI secondary to infrapopliteal lesions, and their use in risk stratification allows estimation of the wound healing rate.

Half-metallicity induced by boron adsorption on an Fe3O4(100) surface.

The spin polarization of magnetite Fe3O4 is significantly reduced at its surfaces, which is unfavorable for the development of spintronic devices based on this material. In order to enhance the surface spin polarization, the Fe3O4(100) surface is modified here through the adsorption of boron (B) atoms and investigated using density functional theory (DFT) calculations. We find for the bulk-terminated and cation-redistributed surfaces that a band gap is opened in the spin-up electronic states due to the formation of a strong bond between the B atom and a surface oxygen atom, i.e., B adsorption induces half-metallicity at the Fe3O4(100) surface. Besides the surface Fe and O atoms, the adsorbed B atoms have a considerable density of -100% spin-polarized electronic states at the Fermi level, which might provide a means of improving the efficiency of spin injection into spintronic devices.

Perioperative complications after aorto-iliac stenting: associated factors and impact on follow-up cardiovascular prognosis.

OBJECTIVES: To investigate factors associated with 30-day perioperative complications (POC) after aorto-iliac (AI) stenting, and to compare follow-up cardiovascular prognosis between patients with and without POC. MATERIALS AND METHODS: This was a retrospective multicenter study. We used a multicenter database of 2012 consecutive patients who successfully underwent AI stenting for peripheral arterial disease in 18 centers in Japan from January 2005 to December 2009 to analyze independent predictors of POC and impact of POC on prognosis by logistic regression and a Cox proportional hazard regression model, respectively. RESULTS: Mean age was 71 ± 9 years (median: 72 years; range: 37-98 years), and 1,636 patients (81%) were men. POC occurred in 126 patients (6.3%). In multivariate logistic regression analysis, old age (≥80 years), critical limb ischemia (CLI), and Trans Atlantic Inter-Societal Consensus (TASC) II class C/D were independently associated with POC with adjusted odds ratios and 95% confidence intervals (CI) of 1.9 (1.3-2.9), 2.3 (1.5-3.4), and 2.4 (1.6-3.4), respectively. Out of 2012 patients, 1995 were followed up for more than 30 days (mean: 2.6 ± 1.5 years; range: 2-2,393 days). In a Cox hazard regression model adjusted for baseline clinical characteristics, POC was positively and independently associated with follow-up major adverse cardiac events (adjusted hazard ratio [HR]: 1.9; 95% CI: 1.3-2.8; p = .002), but not with major adverse limb events and target lesion revascularization (adjusted HR: 1.4; 95% CI: 0.7-2.7; p = .25; and adjusted HR: 1.2; 95% CI 0.6-2.6; p = .568), respectively. CONCLUSIONS: Age >80 years, CLI, and TASC C/D lesion were positively associated with POC after AI stenting. Occurrence of POC appears to adversely affect follow-up cardiovascular, but not limb and vessel prognosis.

Significant variation of surface spin polarization through group IV atom (C, Si, Ge, Sn) adsorption on Fe3O4(100).

The adsorption of group IV atoms (C, Si, Ge, Sn) on the magnetite Fe3O4(100) surface is investigated by density functional theory calculations. All these atoms prefer to bond to the surface oxygen atom which has no tetrahedral Fe(A) neighbor. The spin-up surface states of clean Fe3O4(100) are completely removed and half-metallicity is recovered by C adsorption. The spin-up band gap of the C-adsorbed Fe3O4(100) surface is wider than that of the H-adsorbed one and closer to the value of bulk Fe3O4. For the adsorption of other group IV atoms, the adsorbate-substrate interaction decreases and the adsorbate-adsorbate interaction increases with the increase of atomic number Z. As a consequence, the spin polarization varies from -99.4% (C adsorption) to +44.2% (Sn adsorption) for the electronic states of the adsorbed atom integrated from -0.5 eV to the Fermi level. The ability to tune the surface spin polarization by the choice of adsorbate is of significance for magnetite-based spintronic devices.

Magnetic moment enhancement and spin polarization switch of the manganese phthalocyanine molecule on an IrMn(100) surface.

The geometric, electronic, and magnetic structures of a manganese phthalocyanine (MnPc) molecule on an antiferromagnetic IrMn(100) surface are studied by density functional theory calculations. Two kinds of orientation of the adsorbed MnPc molecule are predicted to coexist due to molecular self-assembly on the surface-a top-site geometry with the Mn-N bonds aligned along the ⟨100⟩ direction, and a hollow-site orientation in which the Mn-N bonds are parallel to the ⟨110⟩ direction. The MnPc molecule is antiferromagnetically coupled to the substrate at the top site with a slight reduction in the magnetic moment of the Mn atom of the MnPc molecule (Mnmol). In contrast, the magnetic moment of the Mnmol is enhanced to 4.28 µB at the hollow site, a value larger than that in the free MnPc molecule (3.51 µB). Molecular distortion induced by adsorption is revealed to be responsible for the enhancement of the magnetic moment. Furthermore, the spin polarization of the Mnmol atom at around the Fermi level is found to change from negative to positive through an elongation of the Mn-N bonds of the MnPc. We propose that a reversible switch of the low/high magnetic moment and negative/positive spin polarization might be realized through some mechanical engineering methods.

Retinoic acids up-regulate functional eosinophil-driving receptor CCR3.

Eotaxins and their receptor CCR3 have a definitive role for tissue accumulation of eosinophils both under homeostatic and pathologic conditions. However, physiological stimuli that can up-regulate CCR3 in blood-derived human eosinophils have not been recognized. As a prior gene microarray study revealed up-regulation of CCR3 in eosinophils stimulated with retinoic acids (RAs), the expression of functional CCR3 was examined. We found that 9-cis RA and all-trans RA (ATRA) significantly induced surface CCR3 expression regardless of the presence of IL-3 or IL-5. Pharmacological manipulations with receptor-specific agonists and antagonists indicated that retinoic acid receptor-α activation is critical for CCR3 up-regulation. RA-induced CCR3 was associated with its functional capacity, in terms of the calcium mobilization and chemotactic response to eotaxin-1 (CCL11). Our study suggests an important role of vitamin A derivatives in the tissue accumulation of eosinophils.

Worse limb prognosis for indirect versus direct endovascular revascularization only in patients with critical limb ischemia complicated with wound infection and diabetes mellitus.

OBJECTIVES: To investigate factors in patients with critical limb ischemia (CLI) and isolated infrapopliteal lesions that adversely affect outcomes of endovascular therapy (EVT) with or without angiosome-oriented revascularization. METHODS: This was a retrospective multicenter study. We used a database of 718 consecutive CLI patients (70 ± 11 years, 75% diabetics, 68% on hemodialysis, 24% Rutherford class 6) with ischemic tissue loss due to isolated infrapopliteal lesions undergoing primary EVT. Primary outcome was MALE (major adverse limb event). Association between indirect EVT (recanalization of a non-angiosome-based artery) and outcome was assessed by Cox proportional hazard regression model. RESULTS: C-reactive protein (CRP) level was >3 mg/dL in 32% of cases. Indirect EVT (in 307 CLI patients, 43%), was associated with MALE (p = .04, hazard ratio [95% confidence interval] 1.25 [1.01, 1.55]), and interacted with CRP >3 mg/dL (p < .004) but not with other baseline characteristics. Indirect EVT with CRP >3 mg/dL had higher MALE risk (HR 2.08), and interacted with diabetes mellitus (DM) presence. Indirect EVT with CRP >3 mg/dL and DM had higher MALE risk (HR 2.17). CONCLUSION: Limb prognosis was equivalent for direct and indirect endovascular revascularization except in the presence of both diabetes and wound infection, when indirect revascularization has a poorer outcome.

Anatomical predictors of major adverse limb events after infrapopliteal angioplasty for patients with critical limb ischaemia due to pure isolated infrapopliteal lesions.

OBJECTIVE: To identify anatomical factors associated with major adverse limb events (MALE) after angioplasty as the basis for a novel morphology-driven classification of infrapopliteal lesions. DESIGN: Retrospective-multicenter study. MATERIALS AND METHODS: Between March 2004 and October 2010, 1057 limbs from 884 patients with CLI due to isolated infrapopliteal lesions were studied. Freedom-from MALE, defined as major amputation or any reintervention, was assessed out to 2 years by the Kaplan-Meier methods. Anatomical predictors and risk stratification for MALE were analyzed by multivariate analysis. RESULTS: Freedom-from MALE was 47 ± 1% at 2 years. Lesion calcification, target vessel diameter<3.0 mm, lesion length>300 mm and no below-the-ankle (BA) run-off were positively associated with MALE by multivariate-analysis. The total number of risk factors was used to calculate the risk score for each limbs for subsequent categorization into 3 groups with 0 or 1 (low-risk), 2 (moderate-risk) and 3 or 4 (high-risk) factors. Freedom-from MALE at 2 year-rates was 59% in low-risk, 46% in moderate-risk, and 29% in high-risk, respectively. CONCLUSION: Target vessel diameter <3.0 mm, lesion calcification, lesion length > 300 mm and no-BA run-off were associated with MALE after infrapopliteal angioplasty. Risk stratification based on these predictors allows estimation of future incidence of MALE in CLI with isolated infrapopliteal lesions.

Glycaemic management in a child with ornithine transcarbamylase deficiency undergoing cardiac surgery with hypothermic cardiopulmonary bypass.

There is a lack of evidence regarding the optimal intra-operative glycaemic level of patients with ornithine transcarbamylase deficiency to prevent cerebral oedema due to protein catabolism and hyperammonemia. We describe a case of a two-year-old girl with ornithine transcarbamylase deficiency who underwent cardiac surgery requiring cardiopulmonary bypass. A high-dose dextrose infusion to prevent protein catabolism was given throughout surgery, which caused uncontrollable hyperglycaemia unresponsive to high-dose insulin administration. Factors contributing to the hyperglycaemia may have included surgical stress, steroid administration and hypothermia. During invasive surgery, anaesthetists should carefully adjust the rates of dextrose and insulin infusions, guided by close monitoring of blood ammonia, glucose and lactate.

Intracellular bacteria recognition contributes to maximal interleukin (IL)-12 production by IL-10-deficient macrophages.

Interleukin (IL)-12 is a key factor that induces T helper cell type 1-mediated immunity and inflammatory diseases. In some colitis models, such as IL-10 knock-out (KO) mice, IL-12 triggers intestinal inflammation. An abundant amount of IL-12 is produced by intestinal macrophages in response to stimulation by commensal bacteria in IL-10 KO mice. Intact bacteria are more potent inducers of macrophage IL-12 production than cell surface components in this model. This suggested that cell surface receptor signalling and intracellular pathogen recognition mechanisms are important for the induction of IL-12. We addressed the importance of intracellular recognition mechanisms and demonstrated that signal transducers and activator of transcription 1 (STAT1) signalling activated bacterial phagocytosis and was involved in the induction of abnormal IL-12 production. In IL-10 KO mouse bone marrow-derived (BM) macrophages, Escherichia coli stimulation induced increased IL-12p70 production compared to lipopolysaccharide combined with interferon (IFN)-γ treatment. Significant repression of IL-12 production was achieved by inhibition of phagocytosis with cytochalasin D, and inhibition of de novo protein synthesis with cycloheximide. Induction of IFN regulatory factors-1 and -8, downstream molecules of STAT1 and the key transcription factors for IK-12 transcription, following E. coli stimulation, were mediated by phagocytosis. Interestingly, STAT1 was activated after stimulation with E. coli in IL-10 KO BM macrophages, although IFN-γ could not be detected. These data suggest that molecules other than IFN-γ are involved in hyper-production mechanisms of IL-12 induced by E. coli stimulation. In conclusion, enteric bacteria stimulate excessive IL-12p70 production in IL-10 KO BM macrophages via phagocytosis-dependent signalling.

Spin-dependent low-energy 4He+ ion scattering from nonmagnetic surfaces.

We investigated electron-spin-polarized (4)He(+) ion scattering on various nonmagnetic surfaces at kinetic energies below 2 keV. It was observed that the scattered He(+) ion yield depends on the He(+) ion spin. We interpret this spin-dependent scattering in terms of the spin-orbit coupling that acts transiently on the He(+)1s electron spin in the He(+)-target binary collision. This interpretation qualitatively explains the relationship between the spin-dependent scattering and the scattering geometry, incident velocity, and magnetic field arrangement. This is the first study to report spin-orbit coupling caused by projectile electron spin in ion scattering.

Silicon micro/nanofabrication using metastable helium atom beam lithography.

We utilize metastable helium (He*) atom beam lithography to pattern silicon substrates by using self-assembled monolayer (SAM) of octadecyltrichlorosilane (OTS) grown directly on silicon surface as resist. An improved wet-chemical etching method was used to transfer the resist pattern into silicon substrate. Negative and positive pattern formations with well-defined edges were observed for silicon(100) substrate with SAM after exposure to the He* atom beam followed by the etching. Results indicate a clear transition from positive to negative patterns relies on the He* dosage. The pattern sizes on silicon were successfully decreased to the order of 100 nm, even less than 50 nm.

Induction of antibodies to nuclear antigens in rabbits by immunization with hydralazine-human serum albumin conjugates.

The antihypertensive drug hydralazine can induce in man a syndrome similar to spontaneous systemic lupus erythematosus (SLE). The pathogenesis of this drug-induced syndrome is not understood. In this investigation, five groups of rabbits were studied: group I, 10 rabbits hyperimmunized with hydralazine conjugated to human serum albumin (HSA) in complete Freund's adjuvant (CFA); group II, four rabbits with HSA in CFA; group III, four rabbits with CFA alone; group IV, five rabbits with hydralazine conjugated to rabbit serum albumin (RSA); and group V, four rabbits with a major metabolite of hydralazine conjugated to HSA. The rabbits immunized with hydralazine-HSA developed rising titers of antibodies to hydralazine and progressively increasing amounts of antibodies to both single-stranded and native DNA. The antibodies to DNA were cross-reactive with hydralazine as determined by inhibition of DNA binding and DNA hemagglutination tests. Similar results were obtained in rabbits immunized with the metabolite-HSA compound except the major hapten antibody response was to the metabolite. The DNA antibodies in this group were also capable of being absorbed by metabolite-HSA as well as hydralazine-HSA, indicative of the cross-reactivity between hydralazine and its metabolite. Immunization with hydralazine-RSA caused rabbits to produce antibodies to hydralazine but not to DNA, indicating the requirement for an immune response to the carrier protein in order for antibodies reactive with DNA to be produced. Thus, hyperimmunization of rabbits with hydralazine-protein conjugates may provide a useful animal model of SLE. The data suggests that an immune response to hydralazine may be important in human hydralazine-induced SLE.

Genetic evidence for the Lewis enzyme, which synthesizes type-1 Lewis antigens in colon tissue, and intracellular localization of the enzyme.

To determine whether the Lewis enzyme responsible for the Lewis blood type antigens on erythrocytes synthesizes the Lewis antigens on normal cells and cancer cells in colon tissue, we performed genotyping of the Lewis gene by the PCR-RFLP method and by immunohistochemical staining of Lewis antigens and the Lewis enzyme with specific monoclonal antibodies (mAbs) in colon tissues obtained from 100 colon cancer patients. Five of the 100 patients were identified as homozygotes for the mutant Lewis gene, i.e., the le/le genotype that cannot encode functional Lewis enzyme. The cells in both the normal and cancerous regions of colon tissue from these five le/le patients were completely devoid of staining with mAbs against Lewis antigens with the type 1 chain, i.e., Lewis a, Lewis b, and sialyl Lewis a. In contrast, the cells in cancerous regions of the colon tissue of the 95 patients with the Le/Le or Le/le genotype positively stained with all three mAbs, anti-Lewis a, anti-Lewis b, and anti-sialyl Lewis a. The cells in the cancerous regions of the colon tissue of the five le/le patients stained with DU-PAN-2 mAb, whose recognizing epitope is known to be sialyl Lewis c, a precursor structure of sialyl Lewis a. By immunohistochemical staining with FTA 1-16 mAb, which is directed at the human Lewis enzyme, we were able to demonstrate for the first time that the enzyme is localized in the Golgi area of the colon epithelial cells of patients with the Le/Le or Le/le genotype. No staining was observed in the Golgi area of the cells of the patients with the le/le genotype. From these results, we conclude that individuals with the Le/Le or Le/le genotype possess a functional Lewis enzyme synthesizing fucosylated type-1 Lewis antigens in the Golgi apparatus of the colon epithelial cells, but that individuals with the le/le genotype are devoid of the Lewis enzyme in the Golgi apparatus, resulting in an inability to synthesize Lewis antigens with the type-1 chain, and that it is inappropriate to use CA19-9, whose antigenic epitope is defined as sialyl Lewis a, as a tumor marker in patients with the le/le genotype.