376 research outputs found

    The Chinese Hospitality Industry: A perspective article

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    This paper illustrates the logics shifting in the Chinese hotel industry since1949 and offers a better understanding of how and why the Chinese hotel industry has evolved into its present situation. The logic evolution and future trends in this market were also discussed

    Synthesis of Selenium-Quinone Hybrid Compounds with Potential Antitumor Activity via Rh-Catalyzed C-H Bond Activation and Click Reactions

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    In continuation of our quest for new redox-modulating catalytic antitumor molecules, selenium-containing quinone-based 1,2,3-triazoles were synthesized using rhodium-catalyzed C-H bond activation and click reactions. All compounds were evaluated against five types of cancer cell lines: HL-60 (human promyelocytic leukemia cells), HCT-116 (human colon carcinoma cells), SF295 (human glioblastoma cells), NCIH-460 (human lung cells) and PC3 (human prostate cancer cells). Some compounds showed good activity with IC50 values below 1 µM. The cytotoxic potential of the naphthoquinoidal derivatives was also evaluated in non-tumor cells, exemplified by L929 cells. Overall, these compounds represent promising new lead derivatives and stand for a new class of chalcogenium-containing derivatives with potential antitumor activity

    Bond-charge Interaction in the extended Hubbard chain

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    We study the effects of bond-charge interaction (or correlated hopping) on the properties of the extended ({\it i.e.,} with both on-site (UU) and nearest-neighbor (VV) repulsions) Hubbard model in one dimension at half-filling. Energy gaps and correlation functions are calculated by Lanczos diagonalization on finite systems. We find that, irrespective of the sign of the bond-charge interaction, XX, the charge--density-wave (CDW) state is more robust than the spin--density-wave (SDW) state. A small bond-charge interaction term is enough to make the differences between the CDW and SDW correlation functions much less dramatic than when X=0X=0. For X=tX=t and fixed V<2tV<2t (tt is the uncorrelated hopping integral), there is an intermediate phase between a charge ordered phase and a phase corresponding to singly-occupied sites, the nature of which we clarify: it is characterized by a succession of critical points, each of which corresponding to a different density of doubly-occupied sites. We also find an unusual slowly decaying staggered spin-density correlation function, which is suggestive of some degree of ordering. No enhancement of pairing correlations was found for any XX in the range examined.Comment: 10 pages, 7 PostScript figures, RevTeX 3; to appear in Phys Rev

    Early numerical competencies in 5- and 6-year-old children with autism spectrum disorder

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    Research Findings: To date, studies comparing the mathematical abilities of children with autism spectrum disorder (ASD) and typically developing children are scarce, and results remain inconclusive. In general, studies on this topic focus on mathematical abilities learned from elementary school onward, with little attention for possible precursors at younger ages. The current exploratory study focused on the important developmental period of preschool age, investigating 5 early numerical competencies in 30 high-functioning children with ASD and 30 age-matched control children: verbal subitizing, counting, magnitude comparison, estimation, and arithmetic operations. Children were examined at 5 or 6 years of age, attending the 3rd and final year of preschool. Overall, rather similar early number processing was found in children with and without ASD, although marginally significant results indicated a weaker performance of children with ASD on verbal subitizing and conceptual counting. Practice or Policy: Given the pervasiveness and impact of ASD on other domains of functioning, it is important to know that no general deficits in early numerical competencies were found in this study. However, some downward trends in mathematics performance were identified in children with ASD, which can serve as the basis for additional research in this field

    Profiling the Essential Nature of Lipid Metabolism in Asexual Blood and Gametocyte Stages of Plasmodium falciparum

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    SummaryDuring its life cycle, Plasmodium falciparum undergoes rapid proliferation fueled by de novo synthesis and acquisition of host cell lipids. Consistent with this essential role, Plasmodium lipid synthesis enzymes are emerging as potential drug targets. To explore their broader potential for therapeutic interventions, we assayed the global lipid landscape during P. falciparum sexual and asexual blood stage (ABS) development. Using liquid chromatography-mass spectrometry, we analyzed 304 lipids constituting 24 classes in ABS parasites, infected red blood cell (RBC)-derived microvesicles, gametocytes, and uninfected RBCs. Ten lipid classes were previously uncharacterized in P. falciparum, and 70%–75% of the lipid classes exhibited changes in abundance during ABS and gametocyte development. Utilizing compounds that target lipid metabolism, we affirmed the essentiality of major classes, including triacylglycerols. These studies highlight the interplay between host and parasite lipid metabolism and provide a comprehensive analysis of P. falciparum lipids with candidate pathways for drug discovery efforts

    Analyzing the Economic Sustainability of Tourism Development: Evidence from Hong Kong

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    Despite increased concerns about the negative economic impacts of tourism on host communities, insufficient attention has been paid to assess tourism economic sustainability. This paper aims to develop and validate a framework for assessing economic sustainability from the perspective of local stakeholders. In-depth interviews with 12 major stakeholders and a telephone survey with 1839 Hong Kong citizens were conducted. The tourism economic sustainability construct consisted of three dimensions: economic positivity, development control and individual welfare. The reliability and validity of the dimensions were confirmed by the data of sub-samples. The links between socio-demographic characteristics and attitudes toward tourism economic sustainability were evaluated. This paper enhanced our understanding of tourism economic sustainability by expanding the measurement from the macro level to micro level. Using the study setting in Hong Kong, it transcends previous analysis by providing a context to learn from ongoing controversies about the effects of tourism on host community

    Fatigue in patients with chronic disease:results from the population-based Lifelines Cohort Study

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    (1) To evaluate the prevalence of severe and chronic fatigue in subjects with and without chronic disease; (2) to assess to which extent multi-morbidity contributes to severe and chronic fatigue; and (3) to identify predisposing and associated factors for severe and chronic fatigue and whether these are disease-specific, trans-diagnostic, or generic. The Dutch Lifelines cohort was used, including 78,363 subjects with (n = 31,039, 53 ± 12 years, 33% male) and without (n = 47,324, 48 ± 12 years, 46% male) ≥ 1 of 23 chronic diseases. Fatigue was assessed with the Checklist Individual Strength-Fatigue. Compared to participants without a chronic disease, a higher proportion of participants with ≥ 1 chronic disease were severely (23% versus 15%, p < 0.001) and chronically (17% versus 10%, p < 0.001) fatigued. The odds of having severe fatigue (OR [95% CI]) increased from 1.6 [1.5–1.7] with one chronic disease to 5.5 [4.5–6.7] with four chronic diseases; for chronic fatigue from 1.5 [1.5–1.6] to 4.9 [3.9–6.1]. Multiple trans-diagnostic predisposing and associated factors of fatigue were found, explaining 26% of variance in fatigue in chronic disease. Severe and chronic fatigue are highly prevalent in chronic diseases. Multi-morbidity increases the odds of having severe and chronic fatigue. Several trans-diagnostic factors were associated with fatigue, providing a rationale for a trans-diagnostic approach

    Antimicrobial activity of sesquiterpene lactones isolated from traditional medicinal plant, Costus speciosus (Koen ex.Retz.) Sm

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    <p>Abstract</p> <p>Background</p> <p><it>Costus speciosus </it>(Koen ex.Retz.) Sm (Costaceae) is an Indian ornamental plant which has long been used medicinally in traditional systems of medicine. The plant has been found to possess diverse pharmacological activities. Rhizomes are used to treat pneumonia, rheumatism, dropsy, urinary diseases, jaundice, skin diseases and leaves are used<b/>to treat mental disorders.</p> <p>Method</p> <p>Antibacterial and antifungal activities were tested using Disc diffusion method and Minimum Inhibitory <b>Concentration </b>(MIC). Column chromatography was used to isolate compounds from hexane extract. X-ray crystallography technique and GC-MS analysis were used to identify the compounds</p> <p>Results</p> <p>Antibacterial and antifungal activities were observed in hexane, chloroform, ethyl acetate and methanol extracts. Hexane extract of <it>C.speciosus </it>showed good activity against tested fungi also. Two sesquiterpenoid compounds were isolated (costunolide and eremanthin) from the hexane extract. Both the compounds did not inhibit the growth of tested bacteria. But, both the compounds inhibited the tested fungi. The compound costunolide showed significant antifungal activity. The MIC values of costunolide were; 62.5 ÎĽg/ml against <it>Trichophyton mentagrophytes</it>, 62. ÎĽg/ml against <it>T. simii</it>, 31.25 ÎĽg/ml against <it>T. rubrum </it>296, 62.5 ÎĽg/ml against <it>T. rubrum </it>57, 125 ÎĽg/ml against <it>Epidermophyton floccosum</it>, 250 ÎĽg/ml against <it>Scopulariopsis </it>sp, 250 ÎĽg/ml against <it>Aspergillus niger</it>, 125 ÎĽg/ml against <it>Curvulari lunata</it>, 250 ÎĽg/ml against <it>Magnaporthe grisea</it>.</p> <p>Conclusion</p> <p>Hexane extract showed promising antibacterial and antifungal activity. The isolated compound costunolide showed good antifungal activity.</p
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