11 research outputs found

    Focal shift and focal switch of broadband hollow Gaussian beams passing through an aperture-lens system

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    In this paper, we deduce the approximate analytical formula for the distribution of axial intensity for broadband hollow Gaussian beams (HGBs) passing through an optical system with an aperture and a lens separated based on the Collins formula. Moreover, the focal shift and focal switch effect of broadband HGBs passing through the system is investigated in detail. As demonstrated by the numerical results, whether the focal switch of broadband HGBs occurs is primarily dependent on the size of the aperture, the effective Fresnel number, as well as the relative separation between the aperture and the lens. Furthermore, the bandwidth may have effects on the behavior of the focal switch and reduce the relative focal shift. In this paper, the focal shift of HGBs through a thin lens is recognized as a special case

    Human Epididymis Protein 4 Inhibits Proliferation of Human Ovarian Cancer Cells Via the Mitogen-Activated Protein Kinase and Phosphoinositide 3-Kinase/AKT Pathways

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    Objectives Human epididymis protein 4 (HE4) is a promising novel biomarker for the detection of epithelial ovarian cancer (EOC). The role of HE4 in EOC tumorigenesis is unclear. This study investigated the cellular and molecular mechanisms of HE4 in ovarian cancer cell proliferation. Methods We generated HE4-overexpressing SKOV3 cells and silenced HE4 gene expression in SKOV3.ip1 cells. We used the cell counting kit 8 assay to evaluate cell proliferation and Western blotting to analyze the expression of proliferation- and apoptosis-associated proteins such as Bax, Bcl-2, and caspase 3. Results Overexpression of HE4 in SKOV3, an ovarian carcinoma cell line, inhibited cell proliferation, In contrast, HE4 silencing in SKOV3.ip1 cells promoted cell proliferation; however, conditioned medium containing HE4 and human recombinant HE4 protein had no effect on proliferation in both SKOV3 and SKOV3.ip1 cells. Human epididymis protein 4 inhibited MEK, extracellular signal-regulating kinase 1/2, and AKT phosphorylation but promoted c-Jun N-terminal protein kinase 1/2/3 and c-JUN phosphorylation; however, p38 phosphorylation was impaired in HE4-overexpressing and silenced cells. Human epididymis protein 4 had no effect on epidermal growth factor receptor phosphorylation or on the apoptosis-associated proteins Bax, Bcl-2, and caspase 3. Conclusions Human epididymis protein 4 might play a protective role in the progression of EOC by inhibiting cell proliferation. Antiproliferative activity was mediated by intracellular HE4 and not the secreted protein. Human epididymis protein 4 might inhibit cell proliferation by regulating the mitogen-activated protein kinase and phosphoinositide 3-kinase/AKT signal transduction pathways in vitro.OncologyObstetrics & GynecologySCI(E)[email protected]

    Ovarian endometrioid carcinoma and clear cell carcinoma: A 21-year retrospective study

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    Abstract Objective This study aimed to identify the clinical characteristics of Chinese patients with ovarian endometrioid carcinoma (EC) and clear cell carcinoma (CCC) and to assess the impact of concurrent endometriosis on this group. Methods The present study reviewed the medical records of patients who received initial treatment and a postoperative pathological diagnosis of EC or CCC at our center in China between 1998 and 2018. Results Of 211 patients, 73 had pure EC, and 91 had pure CCC, and the remaining 47 had mixed cancer. The proportion of EC and CCC remained stable over past 21 years. The proportion of EC declined with aging and the age of EC onset to incline to the young. And the age of CCC onset had two peaks, namely, 36 and 77 years. After review by the pathologist, the number of endometriosis cases found in the pathological section of the analysis increased to 114, accounting for 54% of patients. As the stage progressed, the appearance of endometriosis became increasingly scarce in pathological sections(p = 0.001). Compared with CCC, EC had a higher frequency of concurrent endometrial cancer (independent endometrial lesions) and estrogen and progesterone receptor expression(p = 0.000). And more patients were in premenopausal state in EC group(p = 0.040). In the pure group, multivariate analysis showed that correlation existed between relevance to endometriosis and worse outcomes(p = 0.041). In patients with mixed cancer, mixed endometrioid histology was associated with better survival than other subtypes, even with stage III or poorly differentiated tumors(p = 0.001). Conclusions CCC and EC which are common in ovarian cancer patients who have associated with endometriosis have distinct clinicopathological characteristics. Attention should be paid to ovarian cancer patients with a history of endometriosis and those with concurrent endometriosis in pathological sections

    DNA-PK autophosphorylation facilitates Artemis endonuclease activity

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    The Artemis nuclease is defective in radiosensitive severe combined immunodeficiency patients and is required for the repair of a subset of ionising radiation induced DNA double-strand breaks (DSBs) in an ATM and DNA-PK dependent process. Here, we show that Artemis phosphorylation by ATM and DNA-PK in vitro is primarily attributable to S503, S516 and S645 and demonstrate ATM dependent phosphorylation at serine 645 in vivo. However, analysis of multisite phosphorylation mutants of Artemis demonstrates that Artemis phosphorylation is dispensable for endonuclease activity in vitro and for DSB repair and V(D)J recombination in vivo. Importantly, DNA-dependent protein kinase catalytic subunit (DNA-PKcs) autophosphorylation at the T2609-T2647 cluster, in the presence of Ku and target DNA, is required for Artemis-mediated endonuclease activity. Moreover, autophosphorylated DNA-PKcs stably associates with Ku-bound DNA with large single-stranded overhangs until overhang cleavage by Artemis. We propose that autophosphorylation triggers conformational changes in DNA-PK that enhance Artemis cleavage at single-strand to double-strand DNA junctions. These findings demonstrate that DNA-PK autophosphorylation regulates Artemis access to DNA ends, providing insight into the mechanism of Artemis mediated DNA end processing
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