2,015 research outputs found

    Glorified optics and wave propagation in nonplanar structure

    Get PDF
    Waves propagating in varying nonplanar structure can produce many interesting phenomena, such as focusing, caustics, and triplications. A high-frequency technique based on the first-motion approximation, referred to as glorified optics, has been developed to generate synthetic seismograms for these types of problems. The technique, in its simplest form, uses the spreading rate of a beam with transmission and reflection coefficients along each possible ray path. The time behavior of each arrival is either that of the original pulse or its Hilbert transform depending on the position of caustics. The geophysically interesting structure of a soft basin over a half-space is investigated in detail by this method. Synthetic seismograms appropriate for various locations are compared with the results of finite difference and finite element methods. The technique appears rich in insight and should prove very useful in modeling problems

    Near- and far-field expansions for stationary solutions of Poisson--Nernst--Planck equations

    Full text link
    This work is concerned with the stationary Poisson--Nernst--Planck equation with a large parameter which describes a huge number of ions occupying an electrolytic region. Firstly, we focus on the model with a single specie of positive charges in one-dimensional bounded domains due to the assumption that these ions are transported in the same direction along a tubular-like mircodomain. We show that the solution asymptotically blows up in a thin region attached to the boundary, and establish the refined "near-field" and "far-field" expansions for the solutions with respect to the parameter. Moreover, we obtain the boundary concentration phenomenon of the net charge density, which mathematically confirms the physical description that the non-neutral phenomenon occurs near the charged surface. In addition, we revisit a nonlocal Poisson--Boltzmann model for monovalent binary ions and establish a novel comparison for these two models

    Peritoneal metastatic adenocarcinoma possibly due to a gastric duplication cyst: a case report and literature review

    Get PDF
    BACKGROUND: Gastric duplication cysts are rare congenital abnormalities, and malignant transformation of these duplications is also thought to be rare. CASE PRESENTATION: During a routine health checkup, a 28-year-old man underwent abdominal sonography followed by computed tomography (CT) with contrast agent, which revealed a cystic lesion with no enhancement. Laparoscopic surgery showed a 10 × 10 cm cyst adhering to the gastric corpus. However, attempts to remove the lesion en bloc were unsuccessful, and the ruptured cyst had contaminated the peritoneal cavity. Gastric duplication was diagnosed from microscopic examination of the cyst. Seven months later, the patient suffered a progressive increase in ascites, and repeated cytological analysis showed small nests of adenocarcinoma cells, with primary lesion unknown. Diagnostic laparoscopy showed multiple white nodules scattered over the surface of the liver, greater omentum, and peritoneum. Biopsy of the omental nodules confirmed adenocarcinoma, while carcinomatosis was diagnosed in the peritoneum. CONCLUSIONS: Clinical presentation and chronological developments indicated that the malignancy probably originated from the gastric duplication cyst. This case highlights the importance of accurate preoperative diagnosis and optimal surgical management for gastric duplication as well as considering the potential existence of malignant transformation during surgical evaluation of adult patients with gastric duplication cysts

    5-ALA mediated photodynamic therapy induces autophagic cell death via AMP-activated protein kinase

    Get PDF
    Photodynamic therapy (PDT) has been developed as an anticancer treatment, which is based on the tumor-specific accumulation of a photosensitizer that induces cell death after irradiation of light with a specific wavelength. Depending on the subcellular localization of the photosensitizer, PDT could trigger various signal transduction cascades and induce cell death such as apoptosis, autophagy, and necrosis. In this study, we report that both AMP-activated protein kinase (AMPK) and mitogen-activated protein kinase (MAPK) signaling cascades are activated following 5-aminolevulinic acid (ALA)-mediated PDT in both PC12 and CL1-0 cells. Although the activities of caspase-9 and -3 are elevated, the caspase inhibitor zVAD-fmk did not protect cells against ALA-PDT-induced cell death. Instead, autophagic cell death was found in PC12 and CL1-0 cells treated with ALA-PDT. Most importantly, we report here for the first time that it is the activation of AMPK, but not MAPKs that plays a crucial role in mediating autophagic cell death induced by ALA-PDT. This novel observation indicates that the AMPK pathway play an important role in ALA-PDT-induced autophagy

    Myopia among children and adolescents: an epidemiological study in Fuzhou City

    Get PDF
    ObjectiveTo provide a reference for the prevention and control of myopia by analyzing and discussing the findings of an epidemiological survey of the prevalence of myopia among children and adolescents in Fuzhou City from 2019 to 2021.MethodsParticipants for this cross-sectional study were drawn from Gulou District and Minqing County in Fuzhou City using cluster random sampling to account for differences in population density, economic development, and other environmental variables.ResultsMyopia was more prevalent in 2020 than in 2019, but by 2021 it had dropped to about the same level as in 2019. Myopia was more prevalent among girls than boys during the course of the study period, with a three-year prevalence of 44.72% for boys and 52.16% for girls. Mild myopia accounted for 24.14% of all cases, followed by moderate myopia at 19.62%, and severe myopia at 4.58%. Students in urban regions had a prevalence of myopia equivalent to that of students in the suburbs, and this prevalence rose with age.ConclusionMyopia was quite prevalent among children and adolescents in Fuzhou City, and was shown to be steadily rising as students progressed through the school system. This suggests that all levels of government, educational institutions, medical facilities, and concerned parents in Fujian Province should focus on the issue of myopia and collaborate to reduce the risk factors for the development of myopia in school-aged participants

    The nucleolar protein NIFK promotes cancer progression via CK1α/β-catenin in metastasis and Ki-67-dependent cell proliferation.

    Get PDF
    Nucleolar protein interacting with the FHA domain of pKi-67 (NIFK) is a Ki-67-interacting protein. However, its precise function in cancer remains largely uninvestigated. Here we show the clinical significance and metastatic mechanism of NIFK in lung cancer. NIFK expression is clinically associated with poor prognosis and metastasis. Furthermore, NIFK enhances Ki-67-dependent proliferation, and promotes migration, invasion in vitro and metastasis in vivo via downregulation of casein kinase 1α (CK1α), a suppressor of pro-metastatic TCF4/β-catenin signaling. Inversely, CK1α is upregulated upon NIFK knockdown. The silencing of CK1α expression in NIFK-silenced cells restores TCF4/β-catenin transcriptional activity, cell migration, and metastasis. Furthermore, RUNX1 is identified as a transcription factor of CSNK1A1 (CK1α) that is negatively regulated by NIFK. Our results demonstrate the prognostic value of NIFK, and suggest that NIFK is required for lung cancer progression via the RUNX1-dependent CK1α repression, which activates TCF4/β-catenin signaling in metastasis and the Ki-67-dependent regulation in cell proliferation

    Sustainable Solution for Shoring Method of Cross-Creek Bridge in Ankeng MRT System in New Taipei City: A Case Study

    Get PDF
    In the Ankeng Light Rail MRT system (ALRMS) project, the U7 box girder passes crossing the Erbads creek and needs a temporary supporting system for the construction work.  In this study, three temporary shoring system options were proposed to be the construction method.  The D-B Contractor, New Asia construction and Development Corporation, evaluated and selected the optimal choice, The Steel truss frame with supporting beams, to serve as the temporary supporting system.  Compare the deflection of Δmax and Δactual, which are 1.609 cm and 1.59 cm, respectively.  This result presented that the shoring system composed of the H912*302*18*37 supporting beams and steel truss frame had achieved outstanding performance and work to construct the U7 box girder.  This paper presents how the three options are evaluated and the detailed construction processes along with the survey verification for the method

    A retrospective study on the course and outcome of fetal ventriculomegaly

    Get PDF
    AbstractObjectiveTo evaluate the outcomes associated with fetal ventriculomegaly.Materials and methodsReports of women who underwent ultrasound scanning between 18 and 36 weeks of gestation during the period from January 1, 2000, to December 31, 2010, were reviewed. According to the defined severity of ventriculomegaly of affected fetuses, the women were divided into the following groups: (1) mild ventriculomegaly (Group A); (2) moderate ventriculomegaly (Group B); and (3) severe ventriculomegaly (Group C). The women were classified into the “gray zone” group if the fetal lateral ventricle measured between 7 mm and <10 mm. All cases were followed up with additional ultrasound scans. Postnatal information was obtained from the computer database or the medical charts.ResultsA total of 41 cases were recruited for this analysis. Four (9.8%) cases had an abnormal karyotype. Twelve women (29.3%) opted for termination of pregnancy. Of the 29 women who delivered, 56.1% (N = 23) were from Group A, 14.6% (N = 6) were from Group B, and none was from Group C. All children in Group A had normal neurological development. Three children in Group B had normal neurological development, whereas the other three had neurologic deficits. A total of 432 cases were classified into the “gray zone” group. Of these cases, 2.8% (N = 12) progressed to ventriculomegaly.ConclusionCases of isolated and mild ventriculomegaly without additional structural anomalies or chromosomal aberrations had good prognoses. However, the parents of fetuses with moderate or severe ventriculomegaly should be counseled regarding related risks. If the ventricular size of the fetus falls within the “gray zone”, at least one additional exam in the third trimester should be performed, for early detection of ventriculomegaly and other related abnormalities. It is important to make the parents of these fetuses aware of these risks, from a medico-legal point of view

    The study on the structure of exotic states χc1(3872)\chi_{c 1}(3872) via beauty-hadron decays in pppp collisions at s=8TeV\sqrt{s}=8\,\mathrm{TeV}

    Full text link
    A dynamically constrained phase-space coalescence (DCPC) model was introduced to study the exotic state χc1(3872)\chi_{c 1}(3872) yield for three possible structures: tetraquark state, nuclear-like state, and molecular state respectively, where the hadronic final states generated by the parton and hadron cascade model (PACIAE). The χc1(3872)\chi_{c 1}(3872)/ψ(2S)\psi (2S) cross-section ratio from beauty-hadron decays (non-prompt) based on the χc1(3872)\chi_{c 1}(3872) or ψ(2S)J/ψπ+π\psi (2S)\to J/\psi{\pi^+}{\pi^-} bound state in the decay chains as a function of charged-particle multiplicity and transverse momentum in pppp collisions at s=8TeV\sqrt{s}=8\,\mathrm{TeV} are calculated. A tetraquark state scenario from PACIAE+DCPC model shows better agreement with the LHCb and ATLAS measurements for the non-prompt χc1(3872)\chi_{c 1}(3872)/ψ(2S)\psi(2S) cross-section ratio distributions, indicating that the χc1(3872)\chi_{c 1}(3872) is more likely to be a compact tetraquark state
    corecore