7,551 research outputs found
Period and toroidal knot mosaics
Knot mosaic theory was introduced by Lomonaco and Kauffman in the paper on
`Quantum knots and mosaics' to give a precise and workable definition of
quantum knots, intended to represent an actual physical quantum system. A knot
(m,n)-mosaic is an matrix whose entries are eleven mosaic
tiles, representing a knot or a link by adjoining properly. In this paper we
introduce two variants of knot mosaics: period knot mosaics and toroidal knot
mosaics, which are common features in physics and mathematics. We present an
algorithm producing the exact enumeration of period knot (m,n)-mosaics for any
positive integers m and n, toroidal knot (m,n)-mosaics for co-prime integers m
and n, and furthermore toroidal knot (p,p)-mosaics for a prime number p. We
also analyze the asymptotics of the growth rates of their cardinality
Variables Assemblage
Variables Assemblage focuses on everyday urban objects that are ubiquitous and non-descript. These objects are embedded parts and foundations of cities that have specific functions. These objects possess no significant characteristics, but they are structural elements in their everyday urban environment, and the relationship between the objects and the environment is reciprocal. Through examining and transforming these objects, their presence and new contexts in Variables Assemblage interact in new and different ways according to the viewers understanding and perception of these objects. This transformation considers the inherent quality of insignificant everyday objects, ones perception of them, and their relation to their environment
Matrix metalloproteinases as therapeutic targets in breast cancer
Matrix metalloproteinases (MMPs) are the most prominent proteinases involved in tumorigenesis. They were initially recognized to promote tumor progression by remodeling the extracellular matrix through their proteolytic activity. However, accumulating evidence has revealed that some MMPs have protective roles in cancer progression, and the same MMP can exert opposing roles depending on the cell type in which it is expressed or the stage of cancer. Moreover, studies have shown that MMPs are involved in cancer progression through their roles in other biological processes such as cell signaling and immune regulation, independent of their catalytic activity. Despite the prognostic significance of tumoral or stromal expression of MMPs in breast cancer, their roles and molecular mechanisms in breast cancer progression remain unclear. As the failures of early clinical trials with broad-spectrum MMP inhibitors were mainly due to a lack of drug specificity, substantial efforts have been made to develop highly selective MMP inhibitors. Some recently developed MMP inhibitory monoclonal antibodies demonstrated promising anti-tumor effects in preclinical models of breast cancer. Importantly, anti-tumor effects of these antibodies were associated with the modulation of tumor immune microenvironment, suggesting that the use of MMP inhibitors in combination with immunotherapy can improve the efficacy of immunotherapy in HER2-positive or triple-negative breast cancer. In this review, the current understanding of the roles of tumoral or stromal MMPs in breast cancer is summarized, and recent advances in the development of highly selective MMP inhibitors are discussed
Overexpression of Cancer-Associated Genes via Epigenetic Derepression Mechanisms in Gynecologic Cancer
Like other cancers, most gynecologic cancers are caused by aberrant expression of cancer-related genes. Epigenetics is one of the most important gene expression mechanisms, which contribute to cancer development and progression by regulating cancer-related genes. Since the discovery of differential gene expression patterns in cancer cells when compared with normal cells, extensive efforts have been made to explore the origins of abnormal gene expression in cancer. Epigenetics, the study of inheritable changes in gene expression that do not alter DNA sequence is a key area of this research. DNA methylation and histone modification are well-known epigenetic mechanisms, while microRNAs and alternative splicing have recently been identified as important regulators of epigenetic mechanisms. These mechanisms not only affect specific target gene expression but also regulate the functioning of other epigenetic mechanisms. Moreover, these diverse epigenetic regulations occur simultaneously. Epigenetic regulation of gene expression is extraordinarily complicated and all epigenetic mechanisms to be studied at once to determine the exact gene regulation mechanisms. Traditionally, the contribution of epigenetics to cancer is thought to be mediated through the inactivation of tumor suppressor genes expression. But recently, it is arising that some oncogenes or cancer-promoting genes (CPGs) are overexpressed in diverse type of cancers through epigenetic derepression mechanism, such as DNA and histone demethylation. Epigenetic derepression arises from diverse epigenetic changes, and all of these mechanisms actively interact with each other to increase oncogenes or CPGs expression in cancer cell. Oncogenes or CPGs overexpressed through epigenetic derepression can initiate cancer development, and accumulation of these abnormal epigenetic changes makes cancer more aggressive and treatment resistance. This review discusses epigenetic mechanisms involved in the overexpression of oncogenes or CPGs via epigenetic derepression in gynecologic cancers. Therefore, improved understanding of these epigenetic mechanisms will provide new targets for gynecologic cancer treatment
Gender differences in participatory leadership: An examination of principals’ time spent working with others
The purpose of this study was to examine whether female principals have a more participatory style compared to their male counterparts by examining principals’ daily time allocation patterns. The study analyzed data from End of Day (EOD) survey logs from principals in an urban school district. Results from hierarchical linear modeling (HLM) results showed that female principals, when compare to male principals, spent a higher proportion of their time working with others in planning/setting goals. At the same time, there were no differences in how principals allocated their time total working alone or working with others and their time distribution in other leadership domains. The findings suggest that gender differences in leadership style depend on specific activity domains and that there are significant differences in the key domain of strategic planning
Synergistic Effect between Cryptotanshinone and Antibiotics against Clinic Methicillin and Vancomycin-Resistant Staphylococcus aureus
Cryptotanshinone (CT), a major tanshinone of medicinal plant Salvia miltiorrhiza Bunge, demonstrated strong antibacterial activity against clinic isolated methicillin and vancomycin-resistant Staphylococcus aureus (MRSA and VRSA) in this experiment. The CT was determined against clinic isolated MRSA 1–16 with MIC and MBC values ranging from 4 to 32 and 8 to 128 μg/mL; for MSSA 1-2 from 16 to 32 μg/mL and 64 to 128 μg/mL; for VRSA 1-2 from 2 to 4 μg/mL and 4 to 16 μg/mL, respectively. The range of MIC50 and MIC90 of CT was 0.5–8 μg/mL and 4–64 μg/mL, respectively. The combination effects of CT with antibiotics were synergistic (FIC index <0.5) against most of tested clinic isolated MRSA, MSSA, and VRSA except additive, MRSA 4 and 16 in oxacillin, MRSA 6, 12, and 15 in ampicillin, and MRSA 6, 11, and 15 in vancomycin (FIC index < 0.75–1.0). Furthermore, a time-kill study showed that the growth of the tested bacteria was completely attenuated after 2–6 h of treatment with the 1/2 MIC of CT, regardless of whether it was administered alone or with ampicillin, oxacillin, or vancomycin. The results suggest that CT could be employed as a natural antibacterial agent against multidrug-resistant pathogens infection
Contrast and analysis between Chinese character lexicon and Korean Chinese character lexicon——Example based on the Chinese character lexicon of two syllables from the Korean National Open University’s language textbook《Intermediate LevelⅠ•Ⅱ》
韩半岛与中国山水相依,虽因政治格局、社会形态等问题分为南北两半,但中韩两国在语言、文化以及经贸方面却始终密不可分。特别是中韩两国建交以后,随着两国文化交流和经济合作的不断发展,在韩国学习汉语和在中国学习韩语的人数不断攀升,这给针对两国词汇进行深入对比的研究带来了机遇。 诚然,韩国使用的汉字词大部分是由中国传入的,但因政治和社会历史等因素,汉字词在韩半岛长期使用的过程中不断发展变化,有些词形和词义也随之发生了变化。尽管韩语系统中汉字词的比例占60%以上,但词形和词义的不同使两国学习者在习得这些语言的过程中容易产生偏误,给准确理解词义和有效掌握语用带来了障碍。 为了解决上述问题,本研究拟采用对...The Korean Peninsula and China lie adjacent to one another. Although issues such as government structure and social systems are at polar opposites, the two nations have maintained a long-standing close connection in areas such as language, culture, and economic trade. In particular, after diplomatic relations were established between China and Korea, the cultural exchange and economical co-operat...学位:文学硕士院系专业:海外教育学院_语言学及应用语言学学号:2642011115427
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Work-Related Perceptions, Injuries, and Musculoskeletal Symptoms: Comparison Between U.S.-Educated and Foreign-Educated Nurses.
Immigrants account for a significant proportion of the nursing workforce in the United States (U.S.). Although different cultural backgrounds may affect immigrant nurses' perceptions of work and occupational health risks, little research has been conducted. Defining immigrant nurses as those who received initial nursing education in foreign countries, this study examined the differences in work-related perceptions and experiences of musculoskeletal (MS) symptoms and injuries between U.S.-educated and foreign-educated nurses. We analyzed data from a cross-sectional study using a statewide random sample of 419 California registered nurses. Foreign-educated nurses reported a more positive safety climate (p = .017) and perceived their jobs as less demanding (p = .008) than did U.S.-educated nurses. The prevalence of work-related MS symptoms was significantly lower in foreign-educated nurses than in U.S.-educated nurses (p = .044), but the difference was not significant in the multivariable analyses. Positive safety climate was significantly associated with a decreased risk of work-related MS symptoms and injuries, and this relationship was greater among U.S.-educated nurses than among foreign-educated nurses. Our findings suggest that immigrant nurses may have different perceptions about safety climate and job demand, which may modify their occupational health risks
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