On the Spectral Analysis of Quantum Electrodynamics with Spatial Cutoffs. I

In this paper, we consider the spectrum of a model in quantum electrodynamics with a spatial cutoff. It is proven that (1) the Hamiltonian is self-adjoint; (2) under the infrared regularity condition, the Hamiltonian has a unique ground state for sufficiently small values of coupling constants. The spectral scattering theory is studied as well and it is shown that asymptotic fields exist and the spectral gap is closed

Kaonic nuclei studied based on a new framework of Antisymmetric Molecular Dynamics

We have developed a new framework of Antisymmetrized Molecular Dynamics (AMD), to adequately treat the I=0 \={K}N interaction, which is essential to study kaonic nuclei. The improved points are 1) pK$^-$/n\={K}$^0$ mixing and 2) total spin and isospin projections. These improvements enable us to investigate various kaonic nuclei (ppnK$^-$, pppK$^-$, pppnK$^-$, $^6$BeK$^-$ and $^9$BK$^-$) systematically. We have found that they are deeply bound and extremely dense with a variety of shapes.Comment: 10 pages, 5 figure

Effects of the Charge Density of the Anions of Ionic Liquids on the Electrode Kinetics of Ruthenium 2,2'-Bipyridine Complexes

The electrode reaction of ruthenium 2,2'-bipyridine complexes has been investigated in 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIBF 4 ) ionic liquid. The diffusion of the ruthenium complexes in EMIBF 4 was slower than that we have reported in EMITFSA (TFSA -= bis(trifluoromethylsulfonyl)amide), of which the viscosity (36 mPa s) is close to that of EMIBF 4 (37 mPa s). The rate constant of the ruthenium redox couple in EMIBF 4 was also smaller than that in EMITFSA. It was suggested that the difference in these kinetic parameters in EMIBF 4 and EMITFSA is ascribed to the coulombic interaction between the positively charged species and the anions of ionic liquids. Introduction Electrode reactions of iron and ruthenium 2,2'-bipyridine (bpy) complexes have been investigated in some amide-type ionic liquids (1,2). The diffusion coefficients of [Fe(bpy) 2+ was found to depend on the charge density of the anion of ionic liquids (2). Thus, the coulombic interaction is considered one of the major factor in the diffusion of the charged species in addition to the viscosity (4). On the other hand, the rate constant of [Ru(bpy) Experimental EMIBF 4 was purchased from Kanto Chemical and used as supplied. The water content of EMIBF 4 was confirmed to be below 10 ppm by Karl Fischer titration (Metrohm, 831 KF). EMITFSA was prepared by interacting EMICl (Kanto Chemical) with LiTFSA (Kanto Chemical), followed by extraction into dichloromethane, separated by evaporation, and finally dried under vacuum (2). [Ru(bpy) 3 ](BF 4 ) 2 was prepared by the reaction between [Ru(bpy) 3 ]Cl 2 ·6H 2 O (Aldrich, 99.5%) and NaBF 4 (Wako Pure Chemical Industries, 98%) in deionized water and dried under vacuum at 120 °C. Platinum was used as a working and counter electrode. Silver wire immersed in 0.1 M AgCF 3 SO 3 (Aldrich, 99%) / EMITFSA was used as a reference electrode. The potential of this reference electrode was 0.46 V vs. Fc/Fc + in EMIBF 4 . The viscosity of ionic liquid was measured by a vibronic viscometer (Yamaichi Electric, VM-1G-L). All the electrochemical measurements were conducted with the aid of potentio/galvanostats, HABF-501 (Hokuto denko) and PARSTAT 2263 or 2273 using an air-tight electrochemical cell assembled in a glove box filled with dry argon (Miwa MFG, DBO-1KP-K01 and DBO-1K-SH). 3+ , which formed during the preceding anodic potential sweep. The anodic peak potential shifted slightly to the more positive side with an increase in the scan rate, probably reflecting the ohmic drop due to low conductivity of the ionic liquid. There was a linear dependence of the anodic peak current density on the square root of scan rate, as shown in Results and Discussion where K p is a precursor equilibrium constant, ν n is the nuclear frequency factor, κ el is the electronic transmission coefficient, and ∆ ‡ G is the activation Gibbs energy. ∆ ‡ G can be given by the following relation. where λ is the reorganization energy, E is the electrode potential, and E° is the standard electrode potential. Thus, ∆ ‡ G is equal to λ/4 at E = E°. λ is divided into two components. One is the inner reorganization energy, which corresponds to the energy required for changing the chemical bonds in a complex. The other is the outer reorganization energy, which is related to the interaction between the complex and the species surrounding the complex. Since ν n is known to approximately inversely proportional to the viscosity, there must be the contribution of the activation energy for the viscosity in the apparent activation energy for the rate constant. We have reported the activation energy for the rate constant of [Fe(bpy) Conclusions Coulombic interaction between a redox couple and an ionic liquid has been found to affect not only the diffusion of species but also the rate constant of redox reaction. Although the viscosity of EMIBF 4 is very close to that of EMITFSA, the diffusion of ruthenium-bipyridine complexes in EMIBF 4 was slower than that in EMITFSA, indicating the coulombic retarding force for the positively charged species in EMIBF 4 is stronger than that in EMITFSA. The rate constant for [Ru(bpy

Structural elaboration of the surprising ortho-zincation of benzyl methyl ether

Breaking with convention, the reaction of the sodium zincate, [(TMEDA)Na(μ-TMP)(μ-tBu)Zn(tBu)] with benzyl methyl ether (PhCH2OMe) produces exclusively an ortho-zincated intermediate [(TMEDA)Na(μ-TMP)(μ-C6H4CH2OMe)Zn(tBu)] instead of the expected 'thermodynamic' α-metallated product

Scaling Limits for the System of Semi-Relativistic Particles Coupled to a Scalar Bose Field

In this paper the Hamiltonian for the system of semi-relativistic particles interacting with a scalar bose field is investigated. A scaled total Hamiltonian of the system is defined and its scaling limit is considered. Then the semi-relativistic Schrodinger operator with an effective potential is derived

Genetic diversity and population structure of Plasmodium falciparum in the Philippines

<p>Abstract</p> <p>Background</p> <p>In the Philippines, malaria morbidity and mortality have decreased since the 1990s by effective malaria control. Several epidemiological surveys have been performed in the country, but the characteristics of the <it>Plasmodium falciparum </it>populations are not yet fully understood. In this study, the genetic structure of <it>P. falciparum </it>populations in the Philippines was examined.</p> <p>Methods</p> <p>Population genetic analyses based on polymorphisms of 10 microsatellite loci of the parasite were conducted on 92 isolates from three provinces (Kalinga, Palawan, and Davao del Norte) with different malaria endemicity.</p> <p>Results</p> <p>The levels of genetic diversity and the effective population sizes of <it>P. falciparum </it>in the Philippines were similar to those reported in the mainland of Southeast Asia or South America. In the low malaria transmission area (Kalinga), there was a low level of genetic diversity and a strong linkage disequilibrium (LD) when the single-clone haplotype (SCH) was used in the multilocus LD analysis, while in the high malaria transmission areas (Palawan and Davao del Norte), there was a high level of genetic diversity and a weak LD when SCH was used in the multilocus LD analysis. On the other hand, when the unique haplotypes were used in the multilocus LD analysis, no significant LD was observed in the Kalinga and the Palawan populations. The Kalinga and the Palawan populations were, therefore, estimated to have an epidemic population structure. The three populations were moderately differentiated from each other.</p> <p>Conclusion</p> <p>In each area, the level of genetic diversity correlates with the local malaria endemicity. These findings confirm that population genetic analyses using microsatellite loci are a useful tool for evaluating malaria endemicity.</p

Morphological evidence for an invasion-independent metastasis pathway exists in multiple human cancers

BACKGROUND: We have previously described an alternative invasion-independent pathway of cancer metastasis in a murine mammary tumor model. This pathway is initiated by intravasation of tumor nests enveloped by endothelial cells of sinusoidal vasculature within the tumor. In this study, we examined whether evidence for the invasion-independent pathway of metastasis is present in human cancers. METHODS: Archival specimens of 10 common types of human cancers were examined for the presence of sinusoidal vasculature enveloping tumor nests and subsequently generated endothelial-covered tumor emboli in efferent veins. RESULTS: A percentage of tumor emboli in all cancers was found to be enveloped by endothelial cells, but these structures were particularly prevalent in renal cell carcinomas, hepatocellular carcinomas and follicular thyroid carcinomas. A common feature of the vasculature in these tumors was the presence of dilated sinusoid-like structures surrounding tumor nests. A high mean vascular area within tumors, an indication of sinusoidal vascular development, was significantly related to the presence of endothelial-covered tumor emboli. CONCLUSIONS: These results suggest that an invasion-independent metastatic pathway is possible in a wide variety of human cancers. Further investigation of this phenomenon may present new therapeutic strategies for the amelioration of cancer metastasis

Practical application of cure mixture model for long-term censored survivor data from a withdrawal clinical trial of patients with major depressive disorder

<p>Abstract</p> <p>Background</p> <p>Survival analysis methods such as the Kaplan-Meier method, log-rank test, and Cox proportional hazards regression (Cox regression) are commonly used to analyze data from randomized withdrawal studies in patients with major depressive disorder. However, unfortunately, such common methods may be inappropriate when a long-term censored relapse-free time appears in data as the methods assume that if complete follow-up were possible for all individuals, each would eventually experience the event of interest.</p> <p>Methods</p> <p>In this paper, to analyse data including such a long-term censored relapse-free time, we discuss a semi-parametric cure regression (Cox cure regression), which combines a logistic formulation for the probability of occurrence of an event with a Cox proportional hazards specification for the time of occurrence of the event. In specifying the treatment's effect on disease-free survival, we consider the fraction of long-term survivors and the risks associated with a relapse of the disease. In addition, we develop a tree-based method for the time to event data to identify groups of patients with differing prognoses (cure survival CART). Although analysis methods typically adapt the log-rank statistic for recursive partitioning procedures, the method applied here used a likelihood ratio (LR) test statistic from a fitting of cure survival regression assuming exponential and Weibull distributions for the latency time of relapse.</p> <p>Results</p> <p>The method is illustrated using data from a sertraline randomized withdrawal study in patients with major depressive disorder.</p> <p>Conclusions</p> <p>We concluded that Cox cure regression reveals facts on who may be cured, and how the treatment and other factors effect on the cured incidence and on the relapse time of uncured patients, and that cure survival CART output provides easily understandable and interpretable information, useful both in identifying groups of patients with differing prognoses and in utilizing Cox cure regression models leading to meaningful interpretations.</p

Assessment of risk factors related to healthcare-associated methicillin-resistant Staphylococcus aureus infection at patient admission to an intensive care unit in Japan

<p>Abstract</p> <p>Background</p> <p>Healthcare-associated methicillin-resistant <it>Staphylococcus aureus </it>(HA-MRSA) infection in intensive care unit (ICU) patients prolongs ICU stay and causes high mortality. Predicting HA-MRSA infection on admission can strengthen precautions against MRSA transmission. This study aimed to clarify the risk factors for HA-MRSA infection in an ICU from data obtained within 24 hours of patient ICU admission.</p> <p>Methods</p> <p>We prospectively studied HA-MRSA infection in 474 consecutive patients admitted for more than 2 days to our medical, surgical, and trauma ICU in a tertiary referral hospital in Japan. Data obtained from patients within 24 hours of ICU admission on 11 prognostic variables possibly related to outcome were evaluated to predict infection risk in the early phase of ICU stay. Stepwise multivariate logistic regression analysis was used to identify independent risk factors for HA-MRSA infection.</p> <p>Results</p> <p>Thirty patients (6.3%) had MRSA infection, and 444 patients (93.7%) were infection-free. Intubation, existence of open wound, treatment with antibiotics, and steroid administration, all occurring within 24 hours of ICU admission, were detected as independent prognostic indicators. Patients with intubation or open wound comprised 96.7% of MRSA-infected patients but only 57.4% of all patients admitted.</p> <p>Conclusions</p> <p>Four prognostic variables were found to be risk factors for HA-MRSA infection in ICU: intubation, open wound, treatment with antibiotics, and steroid administration, all occurring within 24 hours of ICU admission. Preemptive infection control in patients with these risk factors might effectively decrease HA-MRSA infection.</p

In Vivo Tracking of Transplanted Mononuclear Cells Using Manganese-Enhanced Magnetic Resonance Imaging (MEMRI)

BACKGROUND: Transplantation of mononuclear cells (MNCs) has previously been tested as a method to induce therapeutic angiogenesis to treat limb ischemia in clinical trials. Non-invasive high resolution imaging is required to track the cells and evaluate clinical relevance after cell transplantation. The hypothesis that MRI can provide in vivo detection and long-term observation of MNCs labeled with manganese contrast-agent was investigated in ischemic rat legs. METHODS AND FINDINGS: The Mn-labeled MNCs were evaluated using 7-tesla high-field magnetic resonance imaging (MRI). Intramuscular transplanted Mn-labeled MNCs were visualized with MRI for at least 7 and up to 21 days after transplantation in the ischemic leg. The distribution of Mn-labeled MNCs was similar to that of ¹¹¹In-labeled MNCs measured with single-photon emission computed tomography (SPECT) and DiI-dyed MNCs with fluorescence microscopy. In addition, at 1-2 days after transplantation the volume of the site injected with intact Mn-labeled MNCs was significantly larger than that injected with dead MNCs, although the dead Mn-labeled MNCs were also found for approximately 2 weeks in the ischemic legs. The area covered by CD31-positive cells (as a marker of capillary endothelial cells) in the intact Mn-MNCs implanted site at 43 days was significantly larger than that at a site implanted with dead Mn-MNCs. CONCLUSIONS: The present Mn-enhanced MRI method enabled visualization of the transplanted area with a 150-175 µm in-plane spatial resolution and allowed the migration of labeled-MNCs to be observed for long periods in the same subject. After further optimization, MRI-based Mn-enhanced cell-tracking could be a useful technique for evaluation of cell therapy both in research and clinical applications