1,323 research outputs found

    Dynamical mean-field theory of Hubbard-Holstein model at half-filling: Zero temperature metal-insulator and insulator-insulator transitions

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    We study the Hubbard-Holstein model, which includes both the electron-electron and electron-phonon interactions characterized by UU and gg, respectively, employing the dynamical mean-field theory combined with Wilson's numerical renormalization group technique. A zero temperature phase diagram of metal-insulator and insulator-insulator transitions at half-filling is mapped out which exhibits the interplay between UU and gg. As UU (gg) is increased, a metal to Mott-Hubbard insulator (bipolaron insulator) transition occurs, and the two insulating states are distinct and can not be adiabatically connected. The nature of and transitions between the three states are discussed.Comment: 5 pages, 4 figures. Submitted to Physical Review Letter

    A randomized prospective trial of the postoperative quality of life between laparoscopic uterine artery ligation and laparoscopy-assisted vaginal hysterectomy for the treatment of symptomatic uterine fibroids: clinical trial design

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    <p>Abstract</p> <p>Background</p> <p>Laparoscopy-assisted vaginal hysterectomy is one of the definite methods for the treatment of symptomatic uterine fibroids with lesser intraoperative bleeding and shorter hospitalization compared with abdominal hysterectomy. However, laparoscopy-assisted vaginal hysterectomy cannot preserve uterus and can show postoperative complications by the change of pelvic structure. Thus, laparoscopic uterine artery ligation has been introduced for relieving the symptoms caused by uterine fibroids in place of hysterectomy. The current study was designed to compare postoperative quality of life between laparoscopic uterine artery ligation and laparoscopy-assisted vaginal hysterectomy, and to evaluate the efficacy of laparoscopic uterine artery ligation which can treat symptomatic uterine fibroids with the preservation of uterus.</p> <p>Methods and design</p> <p>Patients enrolled the current study are randomized to laparoscopic uterine artery ligation or laparoscopy-assisted vaginal hysterectomy. The primary outcome is to compare postoperative quality of life between laparoscopic uterine artery ligation and laparoscopy-assisted vaginal hysterectomy using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire for Cancer patients version 3.0. Secondary outcomes are to evaluate the volume reduction of uterus, uterine fibroids and ovaries by the 2 treatments, to compare the improvement of subjective symptoms using 11-point symptom score and postoperative clinical outcomes between laparoscopic uterine artery ligation and laparoscopy-assisted vaginal hysterectomy, and to investigate the improvement of postoperative vaginal bleeding by laparoscopic uterine artery ligation.</p> <p>Discussion</p> <p>Among treatment methods for symptomatic uterine fibroids with the preservation of uterus, laparoscopic uterine artery ligation is expected to have the efficacy like uterine artery embolization, which appeared to be safe for routine use with symptomatic relief. The current study fully recruited in June 2008 and the results will be available in June 2009. If there is no difference of postoperative QOL between laparoscopic uterine artery ligation and laparoscopy-assisted vaginal hysterectomy for the treatment of symptomatic uterine fibroids, the comparison of quality of life between laparoscopic uterine artery ligation and uterine artery embolization will be also needed as a surgical treatment for preserving uterus.</p> <p>Trial registration</p> <p>Current Controlled Trials ISRCTN76790866</p

    Monoclinic and Correlated Metal Phase in VO_2 as Evidence of the Mott Transition: Coherent Phonon Analysis

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    In femtosecond pump-probe measurements, the appearance of coherent phonon oscillations at 4.5 THz and 6.0 THz indicating the rutile metal phase of VO_2 does not occur simultaneously with the first-order metal-insulator transition (MIT) near 68^oC. The monoclinic and correlated metal(MCM) phase between the MIT and the structural phase transition (SPT) is generated by a photo-assisted hole excitation which is evidence of the Mott transition. The SPT between the MCM phase and the rutile metal phase occurs due to subsequent Joule heating. The MCM phase can be regarded as an intermediate non-equilibrium state.Comment: 4 pages, 2 figure

    EFFECTS OF WALKING SPEED AND AGE ON THE DIRECTIONAL STRIDE REGULARJRY AND GAIT VARIABILITY IN TREADMILL WALKING

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    The purpose of this study was to assess the directional stride regularity (SR) and gait variability (GV) of data from shoe-type inertial measurement unit (IMU) sensors during levelled treadmill walking. The DynaStabtm (IMU based gait analysis system) including Smart Balance' (shoe-type data logger) was used to collect normal gait data from forty-four subjects in their 20s (n=20), 40s (n=13), and 60s (n=ll). Four different walking speeds (3, 4, 5, and 6 km/h, respectively) on a treadmill were applied for one-minute of continuous levelled walking. Only lateral kinematics (mediolateral acceleration and yawing and rolling angular velocities) revealed significant interactions from walking speed and age, demonstrating lower stride regularity and higher gait variability than the anteroposterior and vertical kinematics

    Biosynthesis of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (P(HB-co-HHx)) from butyrate using engineered Ralstonia eutropha

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    Polyhydroxyalkanoates (PHAs), a promising family of bio-based polymers, are considered to be alternatives to traditional petroleum-based plastics. Copolymers like poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (P(HB-co-HHx)) have been shown to exhibit favorable physical and mechanical properties, due to decreased crystallinity resulting from the presence of medium-chain-length 3-hydroxyhexanoate (3HHx) monomers. In this study, we produced P(HB-co-HHx) using engineered Ralstonia eutropha strains containing deletions of the acetoacetyl-CoA reductase (phaB) genes and replacing the native PHA synthase with phaC2 from Rhodococcus aetherivorans I24 and by using butyrate, a short-chain organic acid, as the carbon source. Although the wild-type R. eutropha did not produce P(HB-co-HHx) when grown on mixed acids or on butyrate as the sole carbon source, we are able to produce polymer containing up to 40 wt% 3HHx monomer with the aforementioned engineered R. eutropha strains using various concentrations of just butyrate as the sole carbon source. This is the first report for the production of P(HB-co-HHx) copolymer in R. eutropha using butyrate.Korea Polar Research Institute. Polar Academic Program (PAP, PD13010)Korea (South). Rural Development Administration (Project No. 010205022014

    Effects of a Tumor Necrosis Factor-α Antagonist on Experimentally Induced Rhinosinusitis

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    This prospective, randomized, and controlled study examined the effects of tumor necrosis factor soluble receptor type I (sTNFRI, a TNF-α antagonist) on experimentally induced rhinosinusitis in rats. The experimental groups received an instillation of lipopolysaccharide (LPS) plus an intramuscular injection of amoxicillin/clavulanate (antibiotic group), an instillation of sTNFRI (sTNFRI group), an instillation of sTNFRI and an injection of amoxicillin/clavulanate (sTNFRI/antibiotic group), or no additional treatment (LPS group). Histopathological changes were determined using hematoxylin-eosin and periodic acid-Schiff (PAS) staining. Leakage of exudate was determined using fluorescence microscopy. Vascular permeability was measured using the Evans blue dye technique. Expression of MUC5AC was measured using reverse transcriptase PCR. The sTNFRI, antibiotic, and sTNFRI/antibiotic groups had significantly less capillary permeability, mucosal edema, PAS staining, and expression of MUC5AC than the LPS group. There were no differences in capillary permeability, mucosal edema, PAS staining, and MUC5AC expression between the sTNFRI and sTNFRI/antibiotic groups. The antibiotic group had PAS staining similar to that of the sTNFRI and sTNFRI/antibiotic groups but had a greater increase in capillary permeability, mucosal edema, and MUC5AC expression. This study shows that sTNFRI reduces inflammatory activity and mucus hypersecretion in LPS-induced rhinosinusitis in rats

    Domestication of Oryza species eco-evolutionarily shapes bacterial and fungal communities in rice seed

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    Abstract Background Plant-associated microbiomes, which are shaped by host and environmental factors, support their hosts by providing nutrients and attenuating abiotic and biotic stresses. Although host genetic factors involved in plant growth and immunity are known to shape compositions of microbial communities, the effects of host evolution on microbial communities are not well understood. Results We show evidence that both host speciation and domestication shape seed bacterial and fungal community structures. Genome types of rice contributed to compositional variations of both communities, showing a significant phylosymbiosis with microbial composition. Following the domestication, abundance inequality of bacterial and fungal communities also commonly increased. However, composition of bacterial community was relatively conserved, whereas fungal membership was dramatically changed. These domestication effects were further corroborated when analyzed by a random forest model. With these changes, hub taxa of inter-kingdom networks were also shifted from fungi to bacteria by domestication. Furthermore, maternal inheritance of microbiota was revealed as a major path of microbial transmission across generations. Conclusions Our findings show that evolutionary processes stochastically affect overall composition of microbial communities, whereas dramatic changes in environments during domestication contribute to assembly of microbiotas in deterministic ways in rice seed. This study further provides new insights on host evolution and microbiome, the starting point of the holobiome of plants, microbial communities, and surrounding environments. Video Abtract

    Reconstituting ring-rafts in bud-mimicking topography of model membranes.

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    During vesicular trafficking and release of enveloped viruses, the budding and fission processes dynamically remodel the donor cell membrane in a protein- or a lipid-mediated manner. In all cases, in addition to the generation or relief of the curvature stress, the buds recruit specific lipids and proteins from the donor membrane through restricted diffusion for the development of a ring-type raft domain of closed topology. Here, by reconstituting the bud topography in a model membrane, we demonstrate the preferential localization of cholesterol- and sphingomyelin-enriched microdomains in the collar band of the bud-neck interfaced with the donor membrane. The geometrical approach to the recapitulation of the dynamic membrane reorganization, resulting from the local radii of curvatures from nanometre-to-micrometre scales, offers important clues for understanding the active roles of the bud topography in the sorting and migration machinery of key signalling proteins involved in membrane budding

    CVD-grown monolayer MoS2 in bioabsorbable electronics and biosensors

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    Transient electronics entails the capability of electronic components to dissolve or reabsorb in a controlled manner when used in biomedical implants. Here, the authors perform a systematic study of the processes of hydrolysis, bioabsorption, cytotoxicity and immunological biocompatibility of monolayer MoS2
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