Operando resonant soft X-ray emission spectroscopy of the LiMn2O4 cathode using an aqueous electrolyte solution.

The Mn 3d electronic-structure change of the LiMn2O4 cathode during Li-ion extraction/insertion in an aqueous electrolyte solution was studied by operando resonant soft X-ray emission spectroscopy (RXES). The Mn L3 RXES spectra for the charged state revealed the Mn4+ state with strong charge-transfer from the O 2p to Mn 3d orbitals dominates, while for the open-circuit-voltage and discharged states it is ascribed to the mixture of sites with Mn3+ and Mn4+ states. The degree of charge transfer is significantly different between the Mn3+ and Mn4+ states, indicating that the redox reaction takes place on the strongly-hybridized Mn 3d-O 2p orbital rather than the localized Mn 3d orbital.

Prevalence of peri-implant disease and risk indicators in a Japanese population with at least 3 years in function-A multicentre retrospective study.

OBJECTIVES: The aim of this study was to evaluate the prevalence of peri-implant disease and analyze risk indicators in Japanese subjects with ≥3 years of implant function. MATERIAL AND METHODS: Five hundred and forty-three subjects treated with 1,613 implants were evaluated. Information was collected about the patients' physical and dental history, as well as implant details. Peri-implant evaluation included probing depth, bleeding on probing (BoP), suppuration (Sup), and keratinized tissue width. Bone loss was calculated from intra-oral radiographs taken after 1 year and more than 3 years of function. Implants were classified into three groups: healthy, peri-implant mucositis (BoP without bone loss), and peri-implantitis (BoP and/or Sup with bone loss >1 mm). These data were analyzed by multivariable multinomial logistic regression. RESULTS: The prevalence of peri-implant mucositis and peri-implantitis at the subject level was 23.9% and 15.8%, respectively. An association was found between peri-implant mucositis and plaque control record (PCR) >20% and keratinized tissue width <2 mm. Peri-implantitis was associated with PCR >20%, smoking, insertion in the maxilla, and keratinized tissue width <2 mm. CONCLUSIONS: Within the limitations of this study, the prevalence of peri-implant diseases was elucidated in a Japanese population. Peri-implant mucositis was associated with poor oral hygiene and less keratinized tissue. Poor oral hygiene, smoking, insertion in the maxilla, and less keratinized tissue were risk indicators for peri-implantitis.

Large Charge-Transfer Energy in LiFePO4 Revealed by Full-Multiplet Calculation for the Fe L3 -edge Soft X-ray Emission Spectra.

We analyzed the Fe 3d electronic structure in LiFePO4 /FePO4 (LFP/FP) nanowire with a high cyclability by using soft X-ray emission spectroscopy (XES) combined with configuration-interaction full-multiplet (CIFM) calculation. The ex situ Fe L2,3 -edge resonant XES (RXES) spectra for LFP and FP are ascribed to oxidation states of Fe2+ and Fe3+ , respectively. CIFM calculations for Fe2+ and Fe3+ states reproduced the Fe L3 RXES spectra for LFP and FP, respectively. In the calculations for both states, the charge-transfer energy was considerably larger than those for typical iron oxides, indicating very little electron transfer from the O 2p to Fe 3d orbitals and a weak hybridization on the Fe-O bond during the charge-discharge reactions.

Investigation of the relationship between the cycle performance and the electronic structure in LiAlxMn2-xO4 (x = 0 and 0.2) using soft X-ray spectroscopy.

Al doping into LiMn2O4 is one of the well-known methods to improve the cycle performance of the LiMn2O4 cathode. We carried out soft X-ray emission spectroscopy (XES) for LiMn2O4 and LiAl0.2Mn1.8O4 to elucidate the relationship between the Mn 3d electronic structures and cycle performances. After the first cycle, the XES spectra of LiAl0.2Mn1.8O4 are almost unchanged compared to the initial state. In contrast, charge-transfer excitation for the XES of LiMn2O4 is significantly reduced, indicating that the Mn 3d-O 2p hybridization in LiMn2O4 should be easily weakened by charge-discharge. In LiAl0.2Mn1.8O4, the Mn-O bond becomes more stable due to the decrease of Mn3+ ions with Jahn-Teller distortion by Al3+ doping, resulting in the improved cycle performance.

Mid-ventricular Obstructive Cardiomyopathy after Takotsubo Cardiomyopathy.

A 93-year-old woman was transferred to our hospital for lightheadedness. She had had Takotsubo cardiomyopathy for seven years. Transthoracic apical four-chamber echocardiography showed a large apical aneurysm. Pulsed-wave Doppler echocardiography at the left ventricular (LV) basal obstruction showed flow directed from the apex to the base during systole and isovolumic relaxation time. The patient was therefore diagnosed with mid-ventricular obstructive cardiomyopathy with a large apical aneurysm and paradoxical flow. The present case suggests that Takotsubo cardiomyopathy may become mid-ventricular obstructive hypertrophic cardiomyopathy without change in its structure.

[Two cases of fulminant type 1 diabetes mellitus].

We report 2 elderly patients with fulminant type 1 diabetes mellitus. Case 1: A 61-year-old-man was admitted because of hyperglycemia (blood glucose level, 1,071 mg/dl) and metabolic acidosis. His hemoglobin A1c level was almost normal (5.8%), glutamic acid decarboxylase (GAD) antibody was not detected, and a low level of C-peptide (CPR) was excreted in his urine. We diagnosed his condition as diabetic ketoacidosis, and administered intensive insulin therapy. Case 2: A 77-year-old-man was admitted because of hyperglycemia (blood glucose level, 925 mg/dl). His hemoglobin A1c level was slightly high (5.9%), GAD antibody was not detected, and low levels of CPR were excreted in his urine. He showed no signs of metabolic acidosis, but showed metabolic ketosis. The findings of these cases were consistent with those of fulminant type 1 diabetes mellitus. Thus, it is necessary to consider the possibility of this disease in elderly people.

A case of hepatitis C-associated osteosclerosis: accelerated bone turnover controlled by pulse steroid therapy.

Hepatitis C-associated osteosclerosis (HCAO), a very rare disorder in which an extremely rapid bone turnover occurs and results in osteosclerosis, was acknowledged in 1990s as a new clinical entity with the unique bone disorder and definite link to chronic type C hepatitis, although the pathogenesis still remains unknown. Affected patients suffer from excruciating deep bone pains. We report the 19th case of HCAO with diagnosis confirmed by bone biopsy, and treated initially with a bisphosphonate, next with corticosteroids and finally with direct acting antivirals (DAA: sofosbuvir and ribavirin) for HCV infection. Risedronate, 17.5 mg/day for 38 days, did not improve the patient's symptoms or extremely elevated levels of bone markers, which indicated hyper-bone-formation and coexisting hyper-bone-resorption in the patient. Next, intravenous methylprednisolone pulse therapy followed by high-dose oral administration of prednisolone evidently improved them. DAA therapy initiated after steroid therapy successfully achieved sustained virological response, but no additional therapeutic effect on them was observed. Our results strongly suggested that the underlying immunological alteration is the crucial key to clarify the pathogenesis of HCAO. Bone mineral density of lumbar vertebrae of the patient was increased by 14% in four-month period of observation. Clarification of the mechanisms that develop osteosclerosis in HCAO might lead to a new therapeutic perspective for osteoporosis. LEARNING POINTS: HCAO is an extremely rare bone disorder, which occurs exclusively in patients affected with HCV, of which only 18 cases have been reported since 1992 and pathogenesis still remains unclear.Pathophysiology of HCAO is highly accelerated rates of both bone formation and bone resorption, with higher rate of formation than that of resorption, which occur in general skeletal leading to the diffuse osteosclerosis with severe bone pains.Steroid therapy including intravenous pulse administration in our patient evidently ameliorated his bone pains and reduced elevated values of bone markers. This was the first successful treatment for HCAO among cases reported so far and seemed to propose a key to solve the question for its pathogenesis.The speed of increase in the bone mineral content of the patient was very high, suggesting that clarification of the mechanism(s) might lead to the development of a novel therapy for osteoporosis.

Gel-derived cation-π stacking films of carbon nanotube-graphene complexes as oxygen cathodes.

A key challenge in processing carbon nanotubes and their composites for large-scale applications is aggregation. Cation-π stacking interactions have been discovered to disperse heavily entangled single-walled carbon nanotube (SWNT) bundles in ionic liquids (ILs). In this work, we found that a dispersible, silky single-layer graphene (SLG) can be readily gathered together to form a crosslinked gel after entrapping sufficient IL molecular via the likely noncovalent interaction. By incorporating the dispersed SWNTs into the gathered SLG gel synchronously, we prepared solid, finely crosslinked SWNTs-SLG films, assisted by an avenue of 2-step extraction to remove the IL completely. The gel-derived SWNTs-SLG complex film was applied as a support material of oxygen cathodes for Li-O2 batteries. It exhibited a remarkable improved cycleability in comparison to made of SWNTs and SLG alone due to the finely crosslinked feature. Decorated SWNTs and SLG can also form gel-derived complexes via the same process to construct support-catalyst complexes. A SWNTs-SLG film loaded with Ru nanoparticles exhibited not only catalytic effects, but also the ability to suppress the side reactions, and hence stabilized the whole Li-O2 battery. Our research introduces a gel-derived, high-dispersed processing of carbon nanotube-graphene complexes and demonstrates their favorable applications on Li-O2 batteries.

Synthesis of triaxial LiFePO4 nanowire with a VGCF core column and a carbon shell through the electrospinning method.

A triaxial LiFePO4 nanowire with a multi wall carbon nanotube (VGCF:Vapor-grown carbon fiber) core column and an outer shell of amorphous carbon was successfully synthesized through the electrospinning method. The carbon nanotube core oriented in the direction of the wire played an important role in the conduction of electrons during the charge-discharge process, whereas the outer amorphous carbon shell suppressed the oxidation of Fe2+. An electrode with uniformly dispersed carbon and active materials was easily fabricated via a single process by heating after the electrospinning method is applied. Mossbauer spectroscopy for the nanowire showed a broadening of the line width, indicating a disordered coordination environment of the Fe ion near the surface. The electrospinning method was proven to be suitable for the fabrication of a triaxial nanostructure.

Synthesis of single crystalline spinel LiMn2O4 nanowires for a lithium ion battery with high power density.

How to improve the specific power density of the rechargeable lithium ion battery has recently become one of the most attractive topics of both scientific and industrial interests. The spinel LiMn2O4 is the most promising candidate as a cathode material because of its low cost and nontoxicity compared with commercial LiCoO2. Moreover, nanostructured electrodes have been widely investigated to satisfy such industrial needs. However, the high-temperature sintering process, which is necessary for high-performance cathode materials based on high-quality crystals, leads the large grain size and aggregation of the nanoparticles which gives poor lithium ion battery performance. So there is still a challenge to synthesize a high-quality single-crystal nanostructured electrode. Among all of the nanostructures, a single crystalline nanowire is the most attractive morphology because the nonwoven fabric morphology constructed by the single crystalline nanowire suppresses the aggregation and grain growth at high temperature, and the potential barrier among the nanosize grains can be ignored. However, the reported single crystalline nanowire is almost the metal oxide with an anisotropic crystal structure because the cubic crystal structure such as LiMn2O4 cannot easily grow in the one-dimentional direction. Here we synthesized high-quality single crystalline cubic spinel LiMn2O4 nanowires based on a novel reaction method using Na0.44MnO2 nanowires as a self-template. These single crystalline spinel LiMn2O4 nanowires show high thermal stability because the nanowire structure is maintained after heating to 800 degrees C for 12 h and excellent performance at high rate charge-discharge, such as 20 A/g, with both a relative flat charge-discharge plateau and excellent cycle stability.

Synthesis of a perpendicular TiO2 nanosheet film with the superhydrophilic property without UV irradiation.

A method was developed for preparing perpendicular TiO2 nanosheet films from titanate nanosheet films produced on a titanium metal sheet by hydrothermal treatment with aqueous urea. The method is based on the consideration of some important points relating to the thermodynamics of nucleation and crystal growth. The resulting anatase TiO2 nanosheet films showed a specific superhydrophilicity without the need for any prior UV irradiation.

Systematic characterization of spectral surface plasmon resonance sensors with absorbance measurement.

Spectral surface plasmon resonance (SPR) sensors with absorbance measurement were prepared. Resonant wavelengths (lambda) versus effective refractive indexes of the SPR mode were measured with different media in contact with the gold layer. An investigation into the refractive-index sensitivity of the sensor at a fixed angle reveals a linear dependence of lambda(R) on the refractive index of the solution (n(c)), with Dlambda /Dn(c) = 3553.6 nm in a small range of 1.333< or = n(c) < or =1.347. It was observed that the effective refractive index slowly decreases with increasing n(c), attributable to wavelength-induced modulation of optical dielectric constant for the gold layer. Adsorption of bromothymol blue (BTB) on the gold layer leads to a redshift of Dlambda(R) = 3.7 nm, larger than Dlambda(R) = 2.5 nm induced by myoglobin (Mb) adsorption. On the basis of Fresnel equations, calculations with d approximately 1 nm and n=1.69 for BTB and d approximately 3 nm and n = 1.40 for Mb also demonstrate that the SPR band shift induced by full-monolayer adsorption of BTB is larger than that for full-monolayer Mb adsorption. The combination of both measured and calculated results suggests that the contribution of the adlayer index of refraction to the sensitivity of the sensor is greater than that of the adlayer thickness.

[Electrocardiographic discrimination of infarct-related artery between left circumflex and right coronary artery: comparison of ST elevation between leads II and III].

OBJECTIVES: Admission electrocardiography was evaluated to discriminate left circumflex artery (LCX) versus right coronary artery (RCA) as the cause of acute myocardial infarction. METHODS: Electrocardiographic findings were assessed in patients with RCA (n = 60) and LCX (n = 60) occlusion. RESULTS: ST segment elevation in the inferior leads or right precordial leads was more common in the RCA group. ST segment depression or negative T wave was more common in leads I, aVL in the RCA group. ST segment elevation was more common in leads V5, V6 in the LCX group. ST segment was elevated in inferior leads in 55 patients in the RCA group and 27 patients in the LCX group. Mean ST level was higher in lead III than in lead II in the RCA group, but not in the LCX group. The ST level was higher in lead III than in lead II in 78% of the RCA group, but only 44% of the LCX group (p < 0.01). CONCLUSIONS: Comparison of ST levels between leads II and III, and a three-dimensional analysis in 12-lead electrocardiography is useful for discriminating the left circumflex artery from the right coronary artery as the cause of acute myocardial infarction.