Dissociation dynamics of ethylene molecules on a Ni cluster using ab initio molecular dynamics simulations

The atomistic mechanism of dissociative adsorption of ethylene molecules on a Ni cluster is investigated by ab initio molecular-dynamics simulations. The activation free energy to dehydrogenate an ethylene molecule on the Ni cluster and the corresponding reaction rate is estimated. A remarkable finding is that the adsorption energy of ethylene molecules on the Ni cluster is considerably larger than the activation free energy, which explains why the actual reaction rate is faster than the value estimated based on only the activation free energy. It is also found from the dynamic simulations that hydrogen molecules and an ethane molecule are formed from the dissociated hydrogen atoms, whereas some exist as single atoms on the surface or in the interior of the Ni cluster. On the other hand, the dissociation of the C-C bonds of ethylene molecules is not observed. On the basis of these simulation results, the nature of the initial stage of carbon nanotube growth is discussed.

A histological study on microthrombi in autopsy cases of DIC

Microthrombi in 43 untreated and 26 treated cases of DIC were studied histologically and immunohistochemically. In the untreated cases, four types of microthrombi (intraluminal microthrombi with or without fibroblastic and/or smooth muscle cell reaction) were identified. Microthrombi in the former three types showed various degrees of thrombolysis. Failure of thrombolysis seemed to lead the organization of microthrombi. These morphological findings were considered to indicate the course of DIC and the degree of disappearance of the microthrombi in DIC. Microthrombi in the hepatic sinusoids and glomerular capillaries were studied with special reference to the removal processes of the microthrombi. Pathogenesis of renal cortical necrosis in DIC was also discussed. The number of microthrombi was markedly decreased by heparin and gabexate mesilate treatment. The incidences of microthrombi in the liver, kidney, lung, and heart were compared in the two treated groups.

Impact of glucose fluctuation and monocyte subsets on coronary plaque rupture

BACKGROUND AND AIMS

It remains unclear whether glycemic fluctuation can affect plaque rupture in acute myocardial infarction (AMI). Here we investigate the impact of glucose fluctuation on plaque rupture, as observed by optical coherence tomography (OCT), and monocyte subsets in patients with AMI.

METHODS AND RESULTS

We studied 37 consecutive patients with AMI. All patients underwent OCT examination, which revealed 24 patients with plaque rupture and 13 patients without plaque rupture at the culprit site. Peripheral blood sampling was performed on admission. Three monocyte subsets (CD14(+)CD16(-), CD14(bright)CD16(+), and CD14(dim)CD16(+)) were assessed by flow cytometry. Glycemic variability, expressed as the mean amplitude of glycemic excursion (MAGE), was determined by a continuous glucose monitoring system 7 days after the onset of AMI. MAGE was significantly higher in the rupture patients than in the non-rupture patients (P=0.036). Levels of CD14(bright)CD16(+) monocytes from the rupture patients were significantly higher than those from the non-rupture patients (P=0.042). Of interest, levels of CD14(bright)CD16(+) monocytes correlated positively and significantly with MAGE (r=0.39, P=0.02).

CONCLUSION

Dynamic glucose fluctuation may be associated with coronary plaque rupture, possibly through the preferential increase in CD14(bright)CD16(+) monocyte levels.

Electrical control of the ferromagnetic phase transition in cobalt at room temperature

Electrical control of magnetic properties is crucial for device applications in the field of spintronics. Although the magnetic coercivity or anisotropy has been successfully controlled electrically in metals as well as in semiconductors, the electrical control of Curie temperature has been realized only in semiconductors at low temperature. Here, we demonstrate the room-temperature electrical control of the ferromagnetic phase transition in cobalt, one of the most representative transition-metal ferromagnets. Solid-state field effect devices consisting of a ultrathin cobalt film covered by a dielectric layer and a gate electrode were fabricated. We prove that the Curie temperature of cobalt can be changed by up to 12 K by applying a gate electric field of about ±2 MV cm(-1). The two-dimensionality of the cobalt film may be relevant to our observations. The demonstrated electric field effect in the ferromagnetic metal at room temperature is a significant step towards realizing future low-power magnetic applications.

CeF3 and PrF3 as UV-visible Faraday rotators

CeF3 and PrF3 single crystals are investigated as Faraday rotators for the UV-visible region. Their properties are compared with those of the industrial standard reference terbium-gallium-garnet (TGG) single crystal. In contrast to TGG, CeF3 exhibits a higher transparency in the whole near UV-visible-IR, and a remarkable higher figure of merit which rapidly increases towards the cutoff. In the case of PrF3, the transparency extends to even shorter wavelengths, and analogously to CeF3 its figure of merit increases notably in the UV. These results indicate the potential of CeF3 and PrF3 as optical isolators in the UV-visible, where at present there are no alternative candidates.

Early stress exposure impairs synaptic potentiation in the rat medial prefrontal cortex underlying contextual fear extinction

Traumatic events during early life may affect the neural systems associated with memory function, including extinction, and lead to altered sensitivity to stress later in life. We recently reported that changes in prefrontal synaptic efficacy in response to extinction trials did not occur in adult rats exposed to early postnatal stress (i.e. footshock [FS] stress during postnatal day 21-25 [3W-FS group]). However, identifying neurocircuitry and neural mechanisms responsible for extinction retrieval after extinction training have not been precisely determined. The present study explored whether synaptic transmission in the hippocampal-medial prefrontal cortex (mPFC) neural pathway is altered by extinction retrieval on the day after extinction trials using electrophysiological approaches combined with behavioral analysis. We also elucidated the effects of early postnatal stress on the synaptic response in this neural circuit underlying extinction retrieval. Evoked potential in the mPFC was enhanced following extinction retrieval, accompanied by reduced freezing behavior. This synaptic facilitation (i.e. a long-term potentiation [LTP]-like response) did not occur; rather synaptic inhibition was observed in the 3W-FS group, accompanied by sustained freezing. The behavioral deficit and synaptic inhibition observed in the 3W-FS group were time-dependently ameliorated by the partial N-methyl-D-aspartate (NMDA) receptor agonist D-cycloserine (15 mg/kg, i.p.). These findings suggest that the LTP-like response in the hippocampal-mPFC pathway is associated with extinction retrieval of context-dependent fear memory. Early postnatal stress appears to induce neurodevelopmental dysfunction of this neural circuit and lead to impaired fear extinction later in life. The present data indicate that psychotherapy accompanied by pharmacological interventions that accelerate and strengthen extinction, such as d-cycloserine treatment, may have therapeutic potential for the treatment of anxiety disorders, including posttraumatic stress disorder.

Dendritic cell-based vaccination in combination with gemcitabine/S-1 in patients with advanced pancreatic cancer

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Background: Pancreatic cancer has a poor prognosis. Tumor-specific cytotoxic T lymphocytes (CTLs) can be activated in vivo by dendritic cell (DC)-based vaccination. However, clinical responses to the immunotherapy with DC vaccination have only been observed in a minority of patients with solid cancer. Combination with other treatment modalities such as chemotherapy may overcome immunoresistance of cancer cells. It has been shown previously that gemcitabine as well as S-1 sensitises human pancreatic carcinoma cells against CTL-mediated lysis. In the current study, the clinical efficacy of the DC vaccine pulsed with the peptide derived from pancreatic cancer-associated antigen in combination with gemcitabine/S-1 has been evaluated in the patients with advanced, inoperable pancreatic cancer. Methods: Thirteen patients with advanced, inoperable pancreatic cancer refractory to standard treatment were entered the study. DCs that were generated from CD14+ monocytes from leukapheresis by 6-day cultivation with granulocyte macrophage-colony stimulating factor (GM-CSF) and interleukin (IL)-4 were matured by OK-432, a streptococcal agent, and were pulsed with the pancreatic cancer-associated antigen. These DCs (1 x 107) were intradermally administered 5 times at 14-day intervals concomitantly combined with gemcitabine and/or S-1. Results: Of the 13 patients, complete response (CR) was observed in 2 (15.4%), partial response (PR) in 7 (54.8%), stable disease (SD) in 2 (15.4%), progressive disease (PD) in 2 (15.4%). Response rate was 69.2%. Survival rate, quality of life, and performance status were markedly increased. Severe side effects of more than grade 3 that were assessed in accordance with NCI-Common Toxicity Criteria v.2.0, were not observed. Conclusions: It was strongly suggested that the DC vaccination pulsed with cancer associated-peptid in combination with gemcitabine and/or S-1 was safety and effective in the patients with the inoperable pancreatic cancer refractory to standard treatment.

No significant financial relationships to disclose.

Development of a process for the recovery of phosphorus resource from digested sludge by crystallization technology

Removal and recovery of phosphorus from sewage in form of MAP (magnesium ammonium phosphate) have attracted attention from the viewpoint of eutrophication prevention and phosphorus resource recovery as well as scaling prevention inside digestion tanks. In this work, phosphorus recovery demonstration tests were conducted in a 50 m3/d facility having a complete mixing type reactor and a liquid cyclone. Digested sludge, having 690 mg/L T-P and 268 mg/L PO4-P, was used as test material. The T-P and PO4-P of treated sludge were 464 mg/L and 20 mg/L achieving a T-P recovery efficiency of 33% and a PO4-P crystallization ratio of 93%. The reacted phosphorus did not become fine crystals and the recovered MAP particles were found to be valuable as a fertilizer. A case study in applying this phosphorus recovery process for treatment of sludge from an anaerobic-aerobic process of a 21,000 m3/d sewage system, showed that 30% of phosphorus concentration can be reduced in the final effluent, recovering 315 kg/d as MAP.

Amplification of plant genomic DNA by Phi29 DNA polymerase for use in physical mapping of the hypermethylated genomic region

Plant genomes contain a heavily methylated region in which cytosines are methylated in both the symmetrical and asymmetrical sequences. The physical mapping of such a hypermethylated region is difficult because many restriction enzymes are sensitive to methylated cytosine residues in their recognition sites. The Phi29 DNA polymerase provides an efficient and representative amplification of the genomic DNA that is methylation-free. Using this amplified genomic DNA, we were able to show that a heavily methylated genomic DNA region becomes amenable to physical mapping with any restriction enzymes. This protocol will be especially useful for analysis of the heavily methylated region of plant genomes.