87 research outputs found

    Dynamic response of elastic beam to a moving pulse: finite element analysis of critical velocity

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    Dynamic behaviour of a semi-infinite elastic beam subjected to a moving single sinusoidal pulse was investigated by using finite element method associated with dimensionless analysis. The typical features of the equivalent stress and beam deflection were presented. It is found that the average value of maximal equivalent stress in the beam reaches its maximum value when the velocity of moving pulse is closed to a critical velocity. The critical velocity decreases as the pulse duration increases. The material, structural and load parameters influencing the critical velocity were analysed. An empirical formula of the critical velocity with respect to the speed of elastic wave, the gyration radius of the cross-section and the pulse duration was obtained

    Zerumbone, a Southeast Asian Ginger Sesquiterpene, Induced Apoptosis of Pancreatic Carcinoma Cells through p53 Signaling Pathway

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    Pancreatic carcinoma is one common cancer with gradually increasing incidence during the past several decades. However, currently the candidate drugs to suppress pancreatic cancer remain lacking. This research was carried out to investigate if zerumbone, a natural cyclic sesquiterpene isolated from Zingiber zerumbet Smith, will produce the anticancer effects on pancreatic carcinoma cell lines. The results showed that zerumbone concentration, and time, dependently produced inhibitory actions on cell viability of PANC-1 cells. In addition, Hoechst 33342, AO/EB, TUNEL staining, and caspase-3 activity assay further showed that zerumbone induced apoptosis of PANC-1 cells. The expression of p53 protein was markedly upregulated, and the p21 level was also obviously elevated in zerumbone-treated PANC-1 cells. Moreover, ROS production was increased by about 149% in PANC-1 cells treated by zerumbone 30 μM. Zerumbone also produced the same antitumor activity in pancreatic carcinoma cell lines SW1990 and AsPC-1. In summary, we found that zerumbone was able to induce apoptosis of pancreatic carcinoma cell lines, indicating to be a promising treatment for pancreatic cancer

    Preparation for SiGe/Si heterogeneous nanostructures via a two-step approach strategy

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    SiGe/Si heterogeneous nanostructures were prepared by electrochemical anodization of SiGe/Si MQWs. Structural and optical properties of the materials were characterized. The origin of the photoluminescence from the heterogeneous nanostructures at room temperature is discussed

    The first compound heterozygous mutations in SLC12A3 and PDX1 genes: a unique presentation of Gitelman syndrome with distinct insulin resistance and familial diabetes insights

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    BackgroundGitelman Syndrome (GS) patients frequently exhibit disrupted glucose metabolism, attributed to hypokalemia, hypomagnesemia and heightened aldosterone. This study delved into the genetic underpinnings linked to insulin resistance and diabetes in a GS patient, contextualized within his family history.MethodsThe hydrochlorothiazide and furosemide loading test were performed to ascertain the presence of GS. Oral glucose tolerance test (OGTT) evaluated glucose metabolism and insulin sensitivity. Whole-exome sequencing, validated by Sanger sequencing, was employed to confirm gene mutations, which were then tracked among the patient’s relatives.ResultsSymptoms and laboratory examination confirmed the clinical diagnosis of GS. Comprehensive whole-exome sequencing, augmented by Sanger sequencing validation, revealed a compound heterozygous mutation within the SLC12A3 gene (c.1108G>C in exon 9, c.676G>A in exon 5 and c.2398G>A in exon 20) in the patient. The OGTT affirmed diabetes and heightened insulin resistance, distinct from previous patients with GS we evaluated. Further genetic analysis identified a missense heterozygous mutation (c.97C>G in exon 1) within the PDX1 gene, inherited from the patient’s diabetic mother without GS. Furthermore, the patient’s brother, with impaired glucose tolerance but regular potassium levels, also bore this mutation, hinting at additional impacts of the PDX1 gene mutation on glucose metabolism regulation beyond the known impacts of GS.ConclusionThis study unveils unprecedented compound heterozygous mutations in the SLC12A3 and PDX1 genes in a GS patient. These findings illuminate the potential complex genetic factors influencing glucose metabolism disruptions in GS.Take-home messageThis research uncovers a novel combination of SLC12A3 and PDX1 gene mutations in a Gitelman Syndrome patient, revealing intricate genetic factors that potentially disrupt glucose metabolism and shedding light on familial diabetes links

    Correction to: Growth mechanism identification of sputtered single crystalline bismuth nanowire

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    The article listed above was initially published with incorrect copyright information

    Growth mechanism identification of sputtered single crystalline bismuth nanowire

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    Abstract(#br)Single crystalline bismuth nanowire is recently considered as one of the most attractive low dimensional materials for the exploration of exotic higher-order topological properties. However, its growth mechanism by sputtering, which is regarded as one of the most cost-effective and simplest method, is still unrevealed. In this work, a bismuth nanowire growth model based on surface diffusion driven by chemical potential difference among crystal facets is proposed for sputtering method. The morphology evolution of bismuth nanowires is captured for the first time, and three corresponding growth stages are clearly discriminated. The possible self-catalyzed, stress-driven, and screw dislocation-driven nanowire growth mechanisms are precluded separately based on the theoretical and..
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