1,117 research outputs found

    Identification of predictive variables for the recurrence of oral mucocele

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    Oral mucocele is the most common minor salivary gland lesion with good prognosis after surgical removal. However, its recurrence is not rare, sometimes bothersome. This study aimed to identify the possible predictive variables affecting the recurrence rate of oral mucocele. The histoclinical data of 164 patients diagnosed with oral mucocele were retrospectively obtained by reviewing dental records. The predictive variables for its recurrence were identified by analyzing its recurrence rate according to clinical variables. The recurrence rate showed the significant differences according to location and age. Oral mucocele recurred with significantly higher frequency on the ventral mucosa of tongue (50.0%) than on the labial/buccal mucosa (8.8%). Its recurrence was significantly more common in the younger patients (aged 30 years, 4.4%). However, there was no significant difference in recurrence rates between surgical procedures using scalpels and those using lasers. Patients with oral mucocele should be more carefully informed of its possible recurrence, especially when it is found on the ventral surface of the tongue or in a younger population

    Optical spectroscopic investigation on the coupling of electronic and magnetic structure in multiferroic hexagonal RMnO3 (R = Gd, Tb, Dy, and Ho) thin films

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    We investigated the effects of temperature and magnetic field on the electronic structure of hexagonal RMnO3 (R = Gd, Tb, Dy, and Ho) thin films using optical spectroscopy. As the magnetic ordering of the system was disturbed, a systematic change in the electronic structure was commonly identified in this series. The optical absorption peak near 1.7 eV showed an unexpectedly large shift of more than 150 meV from 300 K to 15 K, accompanied by an anomaly of the shift at the Neel temperature. The magnetic field dependent measurement clearly revealed a sizable shift of the corresponding peak when a high magnetic field was applied. Our findings indicated strong coupling between the magnetic ordering and the electronic structure in the multiferroic hexagonal RMnO3 compounds.Comment: 16 pages including 4 figure

    Arterial Injury Associated with Tension-Free Vaginal Tapes-SECUR Procedure Successfully Treated by Radiological Embolization

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    Various postoperative complications have been reported after the use of tension-free vaginal tapes (TVT). The transobturator approach was introduced to minimize the potential complications. The next generation of recently introduced TVT-SECUR is intended to minimize the incidence of complications. Herein we report a case of internal pudendal artery injury sustained during this procedure that was successfully treated by radiological embolization. Angiography with vessel embolization, when available, should be considered when the arterial injury is suspected

    Effect of interlayer interactions on exciton luminescence in atomic-layered MoS2 crystals

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    The atomic-layered semiconducting materials of transition metal dichalcogenides are considered effective light sources with both potential applications in thin and flexible optoelectronics and novel functionalities. In spite of the great interest in optoelectronic properties of two-dimensional transition metal dichalcogenides, the excitonic properties still need to be addressed, specifically in terms of the interlayer interactions. Here, we report the distinct behavior of the A and B excitons in the presence of interlayer interactions of layered MoS 2 crystals. Micro-photoluminescence spectroscopic studies reveal that on the interlayer interactions in double layer MoS 2 crystals, the emission quantum yield of the A exciton is drastically changed, whereas that of the B exciton remains nearly constant for both single and double layer MoS 2 crystals. First-principles density functional theory calculations confirm that a significant charge redistribution occurs in the double layer MoS 2 due to the interlayer interactions producing a local electric field at the interfacial region. Analogous to the quantum-confined Stark effect, we suggest that the distinct behavior of the A and B excitons can be explained by a simplified band-bending model.1

    The Speed and Impact of a New Technology Diffusion in Organ Transplantation: A Case Study Approach

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    A miracle in medical procedure, organ transplantation, has taken place in recent decades due to the diffusion of a new technology. The new technology refers to a family of the so‐called immunosuppressive drugs. As a result, survival rates of major organ transplants have risen to a record‐level of 80 to 90%. This paper has four objectives. First, the speed of new technology diffusion is measured from the historical penetration ratio for the major immunosuppressive drugs. It took, on average, 6 to 8 years for new drugs to gain the 50% penetration ratio. Second, historical improvement patterns of survival rates for major organ transplants are analyzed by the use of both classical and kinked experience curves. The results indicate that kinked experience equations generated much steeper slopes. Third, the relationship between the increased penetration ratios of new drugs to the improved survival rates of organ transplants is analyzed. Overall, rapid diffusion of new drugs appears to have caused faster improvement of the survival rates. Finally, we forecast the future improvement of survival rates through 2030 by the use of kinked experience equations. Our forecast shows that nearly every type of transplant will reach 90% or higher survival rates by 2020

    Extracellular matrix cues regulate the differentiation of pluripotent stem cell-derived endothelial cells

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    The generation of endothelial cells (ECs) from human pluripotent stem cells (PSCs) has been a promising approach for treating cardiovascular diseases for several years. Human PSCs, particularly induced pluripotent stem cells (iPSCs), are an attractive source of ECs for cell therapy. Although there is a diversity of methods for endothelial cell differentiation using biochemical factors, such as small molecules and cytokines, the efficiency of EC production varies depending on the type and dose of biochemical factors. Moreover, the protocols in which most EC differentiation studies have been performed were in very unphysiological conditions that do not reflect the microenvironment of native tissue. The microenvironment surrounding stem cells exerts variable biochemical and biomechanical stimuli that can affect stem cell differentiation and behavior. The stiffness and components of the extracellular microenvironment are critical inducers of stem cell behavior and fate specification by sensing the extracellular matrix (ECM) cues, adjusting the cytoskeleton tension, and delivering external signals to the nucleus. Differentiation of stem cells into ECs using a cocktail of biochemical factors has been performed for decades. However, the effects of mechanical stimuli on endothelial cell differentiation remain poorly understood. This review provides an overview of the methods used to differentiate ECs from stem cells by chemical and mechanical stimuli. We also propose the possibility of a novel EC differentiation strategy using a synthetic and natural extracellular matrix

    Short-Term Effects of Ginkgo biloba Extract on Peripapillary Retinal Blood Flow in Normal Tension Glaucoma

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    PURPOSE: Based on the vascular theory of glaucoma pathogenesis, we wanted to evaluate the effect of Ginkgo biloba extract (GBE) on peripapillary blood flow in patients with normal tension glaucoma (NTG). METHODS: Thirty patients with NTG were randomly placed in the GBE-treated or control groups. The GBE-treated group received 80 mg GBE orally, twice a day for four weeks, and the control group received a placebo twice a day for four weeks. Complete ocular examinations including visual field, Heidelberg retina flowmeter, and systemic examinations were performed on the first study day and on the day treatment was completed. RESULTS: After GBE treatment, the mean blood flow, volume, and velocity increased at almost all points, and there was a statistically significant increase in blood flow at almost all points, in comparison to the placebo. Blood volume significantly increased only in the superior nasal and superior temporal neuroretinal rim areas. GBE also significantly increased blood velocity in areas of the inferior temporal neuroretinal rim and superior temporal peripapillary area. CONCLUSIONS: GBE administration appears to have desirable effect on ocular blood flow in NTG patients.ope

    Electronic structures of hexagonal RMnO3 (R = Gd, Tb, Dy, and Ho) thin films

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    We investigated the electronic structure of multiferroic hexagonal RMnO3 (R = Gd, Tb, Dy, and Ho) thin films using both optical spectroscopy and first-principles calculations. Using artificially stabilized hexagonal RMnO3, we extended the optical spectroscopic studies on the hexagonal multiferroic manganite system. We observed two optical transitions located near 1.7 eV and 2.3 eV, in addition to the predominant absorption above 5 eV. With the help of first-principles calculations, we attribute the low-lying optical absorption peaks to inter-site transitions from the oxygen states hybridized strongly with different Mn orbital symmetries to the Mn 3d3z2-r2 state. As the ionic radius of the rare earth ion increased, the lowest peak showed a systematic increase in its peak position. We explained this systematic change in terms of a flattening of the MnO5 triangular bipyramid
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