109 research outputs found

    Presenteeism in Chinese health and educational institutions

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    ProjectThis research aims to study the possible relation between presenteeism and other factors which are considered to be connected with presenteeism in former studies in Chinese health and educational institutions. Presenteeism, asa new concept in organizational behavior literature, refers to working performance and productivity loss that occurs when employees come to work but are not well-functional due to physical and psychological causes. Next, we clarify factors connected to presenteeism: work-family conflict, family-work conflict, role ambiguity, performance and supervisor support. The results from a sample of 258 health and educational institutions revealed that work/family conflict and role ambiguity are predictive of presenteeism. We also found that employees in health institutions exhibited higher level of supervisor support and lower level of presenteeism compare to employees in educational institutions. Finally the implications and limitations of these results and directions for further research are discussed.Este estudo tem como objetivo estudar a possível relação entre o presentismo e outras variáveis consideradas importantes na relação com o presentismo em instituições de saúde e educação Chinesas. Presentismo – aparece como um novo conceito na literatura de comportamento organizacional - refere-se ao desempenho de trabalho e perda de produtividade que ocorre quando os funcionários vão trabalhar, mas não conseguem o maior rendimento devido a causas físicas e psicológicas. No presente trabalho pretendemos esclarecer a sua relação com variáveis associadas ao conflito trabalho-família , a ambiguidade, de papel, o desempenho individual e o suporte do supervisor. Os resultados obtidos incidiram numa amostra de 258 sujeitos pertencentes a instituições de saúde e educação, tendo revelado que o trabalho / conflito familiar e a ambiguidade de papel são preditores de presentismo. Os dados revelam ainda que os trabalhadores das instituições de saúde apresentaram maior nível de apoio do supervisor e menor nível de presentismo. Finalmente, são discutidas as implicações destes resultados e as direções para futuras pesquisas

    Epithelial Neoplasia Coincides with Exacerbated Injury and Fibrotic Response in the Lungs of \u3cem\u3eGprc5a\u3c/em\u3e-Knockout Mice Following Silica Exposure

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    Exposure to crystalline silica is suggested to increase the risk for a variety of lung diseases, including fibrosis and lung cancer. However, epidemiological evidences for the exposure-risk relationship are ambiguous and conflicting, and experimental study from a reliable animal model to explore the relationship is lacking. We reasoned that a mouse model that is sensitive to both lung injury and tumorigenesis would be appropriate to evaluate the exposure-risk relationship. Previously, we showed that, Gprc5a-/- mice are susceptible to both lung tumorigenesis and endotoxin-induced acute lung injury. In this study, we investigated the biological consequences in Gprc5a-/- mouse model following silica exposure. Intra-tracheal administration of fine silica particles in Gprc5a-/- mice resulted in more severe lung injury and pulmonary inflammation than in wild-type mice. Moreover, an enhanced fibrogenic response, including EMT-like characteristics, was induced in the lungs of Gprc5a-/- mice compared to those from wild-type ones. Importantly, increased hyperplasia or neoplasia coincided with silica-induced tissue injury and fibrogenic response in lungs from Gprc5a-/- mice. Consistently, expression of MMP9, TGFβ1 and EGFR was significantly increased in lungs from silica-treated Gprc5a-/- mice compared to those untreated or wild-type ones. These results suggest that, the process of tissue repair coincides with tissue damages; whereas persistent tissue damages leads to abnormal repair or neoplasia. Thus, silica-induced pulmonary inflammation and injury contribute to increased neoplasia development in lungs from Gprc5a-/- mouse model

    Formation of sclerotia in Sclerotinia ginseng and composition of the sclerotial exudate

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    Background Sclerotinia ginseng is a major devastating soil-borne pathogen of ginseng that can cause irreparable damage and large economic losses. This pathogen produces sclerotia, which are among the most persistent resting structures produced by filamentous fungi. The production of an exudate is a common feature of sclerotial development. Methods S. ginseng was cultured on 10 different media and the following parameters were measured: mycelial growth rate (mm/day), initial formation time of exudate droplets, total quantity of exudate, number of sclerotia per dish, and sclerotial fresh/dry weight. The composition of the sclerotial exudate was analyzed using four methods (high performance liquid chromatography, gas chromatography-mass spectrometry, flame atomic absorption spectrometry, and Nessler’s reagent spectrophotometry). Results We found that PDA was the optimal medium for exudate production, while SDA medium resulted in the highest mycelial growth rate. The earliest emergence of exudate droplets from sclerotia was on OA-YE and V8 media. The largest amount of sclerotia and the smallest sclerotia were produced on V8 medium. The maximum and minimum dry/fresh weight were obtained on MEA medium and V8 medium, respectively. The exudate contained organic acids (oxalic acid, gallic acid, ferulic acid, vanillic acid, caffeic acid, and tannic acid), carbohydrates (inositol, glucose, and trehalose), various ions (potassium, sodium, and magnesium), and ammonia. Discussion The functions of the identified compounds are discussed within the context of pathogenicity, sclerotial development, and antimicrobial activity. Our findings provide information about the production of sclerotia and the composition of sclerotial exudate that may be useful to develop strategies to control this disease

    Production of the neutral toppion at the e gamma colliders

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    In the framework of topcolor-assisted technicolor(TC2) model, we study a neutral toppion production process eγeΠt0e^{-}\gamma\to e^{-}\Pi^{0}_{t} in this paper. Our results show that the production cross section of eγeΠt0e^{-}\gamma\to e^{-}\Pi^{0}_{t} can reach the level of several tens fb, and over 10310^{3} neutral toppion events can be produced in the planned e+ee^+e^- linear colliders each year. Therefore, such a toppion production process provides us a unique chance to detect toppion events and test the TC2 model. On the other hand, the cross section of eγeΠt0e^{-}\gamma\to e^{-}\Pi^{0}_{t} is about one order of magnitude larger than those of some similar processes in SM and MSSM(i.e., eγeHe^{-}\gamma\to e^{-}H in SM and eγeH0(A0,h0)e^{-}\gamma\to e^{-}H^{0}(A^0,h^0) in MSSM). So, we can easily distinguish the neutral toppion from other neutral Higgs bosons in SM and MSSM.Comment: 12 pages, 4 figures, The paper has been accepted by Phys.Rev.

    G9a Is Essential for EMT-Mediated Metastasis and Maintenance of Cancer Stem Cell-Like Characters in Head and Neck Squamous Cell Carcinoma

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    Head and neck squamous cell carcinoma (HNSCC) is a particularly aggressive cancer with poor prognosis, largely due to lymph node metastasis and local recurrence. Emerging evidence suggests that epithelial-to-mesenchymal transition (EMT) is important for cancer metastasis, and correlated with increased cancer stem cells (CSCs) characteristics. However, the mechanisms underlying metastasis to lymph nodes in HNSCC is poorly defined. In this study, we show that E-cadherin repression correlates with cancer metastasis and poor prognosis in HNSCC. We found that G9a, a histone methyltransferase, interacts with Snail and mediates Snail-induced transcriptional repression of E-cadherin and EMT, through methylation of histone H3 lysine-9 (H3K9). Moreover, G9a is required for both lymph node-related metastasis and TGF-β-induced EMT in HNSCC cells since knockdown of G9a reversed EMT, inhibited cell migration and tumorsphere formation, and suppressed the expression of CSC markers. Our study demonstrates that the G9a protein is essential for the induction of EMT and CSC-like properties in HNSCC. Thus, targeting the G9a-Snail axis may represent a novel strategy for treatment of metastatic HNSCC

    Autocrine Epiregulin Activates EGFR Pathway for Lung Metastasis Via EMT in Salivary Adenoid Cystic Carcinoma

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    Salivary adenoid cystic carcinoma (SACC) is characterized by invasive local growth and a high incidence of lung metastasis. Patients with lung metastasis have a poor prognosis. Treatment of metastatic SACC has been unsuccessful, largely due to a lack of specific targets for the metastatic cells. In this study, we showed that epidermal growth factor receptors (EGFR) were constitutively activated in metastatic lung subtypes of SACC cells, and that this activation was induced by autocrine expression of epiregulin (EREG), a ligand of EGFR. Autocrine EREG expression was increased in metastatic SACC-LM cells compared to that in non-metastatic parental SACC cells. Importantly, EREG-neutralizing antibody, but not normal IgG, blocked the autocrine EREG-induced EGFR phosphorylation and the migration of SACC cells, suggesting that EREG-induced EGFR activation is essential for induction of cell migration and invasion by SACC cells. Moreover, EREG-activated EGFR stabilized Snail and Slug, which promoted EMT and metastatic features in SACC cells. Of note, targeting EGFR with inhibitors significantly suppressed both the motility of SACC cells in vitro and lung metastasis in vivo. Finally, elevated EREG expression showed a strong correlation with poor prognosis in head and neck cancer. Thus, targeting the EREG-EGFR-Snail/Slug axis represents a novel strategy for the treatment of metastatic SACC even no genetic EGFR mutation

    EGFR phosphorylates and inhibits lung tumor suppressor GPRC5A in lung cancer

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    BACKGROUND: GPRC5A is a retinoic acid inducible gene that is preferentially expressed in lung tissue. Gprc5a- knockout mice develop spontaneous lung cancer, indicating Gprc5a is a lung tumor suppressor gene. GPRC5A expression is frequently suppressed in majority of non-small cell lung cancers (NSCLCs), however, elevated GPRC5A is still observed in a small portion of NSCLC cell lines and tumors, suggesting that the tumor suppressive function of GPRC5A is inhibited in these tumors by an unknown mechanism. METHODS: In this study, we examined EGF receptor (EGFR)-mediated interaction and tyrosine phosphorylation of GPRC5A by immunoprecipitation (IP)-Westernblot. Tyrosine phosphorylation of GPRC5A by EGFR was systematically identified by site-directed mutagenesis. Cell proliferation, migration, and anchorage-independent growth of NSCLC cell lines stably transfected with wild-type GPRC5A and mutants defective in tyrosine phosphorylation were assayed. Immunohistochemical (IHC) staining analysis with specific antibodies was performed to measure the total and phosphorylated GPRC5A in both normal lung and lung tumor tissues. RESULT: We found that EGFR interacted with GPRC5A and phosphorylated it in two conserved double-tyrosine motifs, Y317/Y320 and Y347/ Y350, at the C-terminal tail of GPRC5A. EGF induced phosphorylation of GPRC5A, which disrupted GPRC5A-mediated suppression on anchorage-independent growth of NSCLC cells. On contrary, GPRC5A-4 F, in which the four tyrosine residues have been replaced with phenylalanine, was resistant to EGF-induced phosphorylation and maintained tumor suppressive activities. Importantly, IHC analysis with anti-Y317/Y320-P sites showed that GPRC5A was non-phosphorylated in normal lung tissue whereas it was highly tyrosine-phosphorylated in NSCLC tissues. CONCLUSION: GPRC5A can be inactivated by receptor tyrosine kinase via tyrosine phosphorylation. Thus, targeting EGFR can restore the tumor suppressive functions of GPRC5A in lung cancer
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