1,496 research outputs found

    ENERGY EFFICIENCY OF DIFFERENT TENNIS RACKET STIFFNESS AND STRING TENSION DUE TO CENTER AND OFF-CENTER IMPACT

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    The purpose of this study was to investigate the power of vibration responses and moments of different racket flexibilities and string tensions following center and off-center impacts. Three rackets, classed as stiff, medium, and flexible by their manufacturers, were strung at three string tensions and subjected to 15 trials. The rackets were gripped on a KISTLER force plate and impacted at designated areas by a rigid ball. The stiff racket had smaller powers of vibration and twisting moment for each string tension in offcenter impact. The largest power of vibration and twisting moment occurred respectively in the flexible racket strung with 50pound and medium racket strung with 70 pound in offcenter impact

    Develop a Multiple Interface Based Fire Fighting Robot

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    High expression FUT1 and B3GALT5 is an independent predictor of postoperative recurrence and survival in hepatocellular carcinoma.

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    Cancer may arise from dedifferentiation of mature cells or maturation-arrested stem cells. Previously we reported that definitive endoderm from which liver was derived, expressed Globo H, SSEA-3 and SSEA-4. In this study, we examined the expression of their biosynthetic enzymes, FUT1, FUT2, B3GALT5 and ST3GAL2, in 135 hepatocellular carcinoma (HCC) tissues by qRT-PCR. High expression of either FUT1 or B3GALT5 was significantly associated with advanced stages and poor outcome. Kaplan Meier survival analysis showed significantly shorter relapse-free survival (RFS) for those with high expression of either FUT1 or B3GALT5 (P = 0.024 and 0.001, respectively) and shorter overall survival (OS) for those with high expression of B3GALT5 (P = 0.017). Combination of FUT1 and B3GALT5 revealed that high expression of both genes had poorer RFS and OS than the others (P < 0.001). Moreover, multivariable Cox regression analysis identified the combination of B3GALT5 and FUT1 as an independent predictor for RFS (HR: 2.370, 95% CI: 1.505-3.731, P < 0.001) and OS (HR: 2.153, 95% CI: 1.188-3.902, P = 0.012) in HCC. In addition, the presence of Globo H, SSEA-3 and SSEA-4 in some HCC tissues and their absence in normal liver was established by immunohistochemistry staining and mass spectrometric analysis

    A randomized controlled trial of a homeâ based training programme to decrease depression in family caregivers of persons with dementia

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    AimsThe aim of this study was to explore distinct trajectories of caregiversâ depressive symptoms and the effects of a training programme on these trajectories over 18 months after the programme.BackgroundOverall effects of caregiverâ training programmes on family caregiversâ depressive symptoms have been reported, but few studies explored distinct courses of changes in caregiversâ depressive symptoms and followed up intervention effects on these distinct courses.DesignRandomized clinical trial.MethodsFamily caregivers (n = 116) were randomly assigned into experimental (n = 57) and control (n = 59) groups. The experimental group received the training programme with telephone consultation and the control group received written educational materials and social telephone followâ ups. Caregiversâ depressive symptoms were assessed from June 2009 â March 2012 by selfâ completed questionnaires before, at 2 weeks and 3, 6, 12 and 18 months after the intervention. Groups of individual trajectories were distinguished using groupâ based trajectory modelling.ResultsCaregiversâ depressive symptoms fell into three stable trajectories: nonâ depressed, mildly blue and depressed. After controlling for covariates, caregivers who received the caregiverâ training programme were less likely than those who did not experience persistent depressive symptoms (b = â 1·92, odds ratio = 0·15, P < 0·05).ConclusionDepressive symptoms of family caregivers of persons with dementia were relatively stable and followed three distinct courses: nonâ depressed, mildly blue and depressed. Therefore, caregiversâ depressive symptoms should be assessed as early as possible. Caregivers in the experimental group had a lower probability of persistent depressive symptoms than caregivers in the control group. Therefore, this training programme can be used by healthcare providers for persons with dementia and their caregivers. Trial registration number: NCT02667951.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136266/1/jan13157.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136266/2/jan13157_am.pd

    Porphyrin-based metal–organic frameworks for neuromorphic electronics

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    Porphyrin-based metal–organic frameworks (PP-MOFs) have some special features beyond ordinary MOFs, including superior optoelectronic characteristics, the ability to form 2D layered structure, and customizability, which prompt the increasing attention of PP-MOFs in the field of neuromorphic electronics. The related application research is in the initial stage, and a timely summary and guidance are necessary. The PP-MOFs fabrication should be shifted from powder synthesis in a chemistry laboratory to high-quality film preparation under a clean environment to ensure device performance. This article highlights the PP-MOFs film preparation methods and the application advances in neuromorphic electronics, performs comparative analysis in detail, and puts forward the challenges and future research directions, with the aim to attract the attention of experts in various areas (e.g., chemists, materials scientists, and engineers) and promote the application of PP-MOFs in neuromorphic electronics

    Anti-AIDS agents 85. Design, synthesis, and evaluation of 1R,2R-dicamphanoyl-3,3-dimethyldihydropyrano-[2,3-c]xanthen-7(1H)-one (DCX) derivatives as novel anti-HIV agents

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    In this study, 1R,2R-dicamphanoyl-3,3-dimethydihydropyrano[2,3-c]xanthen-7(1H)-one (DCX) derivatives were designed and synthesized as novel anti-HIV agents against both wild-type and nonnucleoside reverse transcriptase (RT) inhibitor-resistant HIV-1 (RTMDR-1) strains. Twenty-four DCX analogs (6-29) were synthesized and evaluated against the non-drug-resistant HIV-1 NL4-3 strain, and selected analogs were also screened for their ability to inhibit the RTMDR-1 strain. Compared with the control 2-ethyl-3′,4′-di-O-(-)-camphanoyl-2′,2′-dimethyldihydropyrano[2,3-f]chromone (2-EDCP, 2), one of the best anti-HIV coumarin derivatives in our prior study, three DCX compounds (7, 12, and 22) showed better activity against both HIV strains with an EC50 range of 0.062 – 0.081 μM, and five additional compounds (8, 11, 16, 18, and 21) exhibited comparable anti-HIV potency. Six DCX analogs (7, 11-12, 18, and 21-22) also showed enhanced selectivity index (SI) values in comparison to the control. Structure-activity relationship (SAR) information suggested that the extended conjugated system of the pyranoxanthone skeleton facilitates the interaction of the small DCX molecule within the viral binding pocket, consequently leading to enhanced anti-HIV activity and selectivity. Compared to DCP compounds, DCX analogs are a more promising new class of anti-HIV agents

    A cytoplasmic RNA virus generates functional viral small RNAs and regulates viral IRES activity in mammalian cells

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    The roles of virus-derived small RNAs (vsRNAs) have been studied in plants and insects. However, the generation and function of small RNAs from cytoplasmic RNA viruses in mammalian cells remain unexplored. This study describes four vsRNAs that were detected in enterovirus 71-infected cells using next-generation sequencing and northern blots. Viral infection produced substantial levels (\u3e105 copy numbers per cell) of vsRNA1, one of the four vsRNAs. We also demonstrated that Dicer is involved in vsRNA1 generation in infected cells. vsRNA1 overexpression inhibited viral translation and internal ribosomal entry site (IRES) activity in infected cells. Conversely, blocking vsRNA1 enhanced viral yield and viral protein synthesis. We also present evidence that vsRNA1 targets stem-loop II of the viral 5′ untranslated region and inhibits the activity of the IRES through this sequence-specific targeting. Our study demonstrates the ability of a cytoplasmic RNA virus to generate functional vsRNA in mammalian cells. In addition, we also demonstrate a potential novel mechanism for a positive-stranded RNA virus to regulate viral translation: generating a vsRNA that targets the IRES

    Design, synthesis, cytotoxic activity and molecular docking studies of new 20(S)-sulfonylamidine camptothecin derivatives

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    20(S)-Sulfonylamidine CPT-derivatives were prepared and tested for cytotoxicity.Several analogs showed superior cytotoxic activity compared to irinotecan.Key structural features related to cytotoxicity were identified by SAR analysis.Compounds 9 and 15c interacted with Topo I-DNA by a different binding mode from CPT.These compounds are new generation CPT-derived antitumor agents.In an ongoing investigation of 20-sulfonylamidine derivatives (9, YQL-9a) of camptothecin (1) as potential anticancer agents directly and selectively inhibiting topoisomerase (Topo) I, the sulfonylamidine pharmacophore was held constant, and a camptothecin derivatives with various substitution patterns were synthesized. The new compounds were evaluated for antiproliferative activity against three human tumor cell lines, A-549, KB, and multidrug resistant (MDR) KB subline (KBvin). Several analogs showed comparable or superior antiproliferative activity compared to the clinically prescribed 1 and irinotecan (3). Significantly, the 20-sulfonylamidine derivatives exhibited comparable cytotoxicity against KBvin, while 1 and 3 were less active against this cell line. Among them, compound 15c displayed much better cytotoxic activity than the controls 1, 3, and 9. Novel key structural features related to the antiproliferative activities were identified by structure–activity relationship (SAR) analysis. In a molecular docking model, compounds 9 and 15c interacted with Topo I-DNA through a different binding mode from 1 and 3. The sulfonylamidine side chains of 9 and 15c could likely form direct hydrogen bonds with Topo I, while hydrophobic interaction with Topo I and π–π stacking with double strand DNA were also confirmed as binding driving forces. The results from docking models were consistent with the SAR conclusions. The introduction of bulky substituents at the 20-position contributed to the altered binding mode of the compound by allowing them to form new interactions with Topo I residues. The information obtained in this study will be helpful for the design of new derivatives of 1 with most promising anticancer activity.CPT (green), 9 (magenta), and 15c (blue) in the binding site of DNA-Topo-I

    Design and synthesis of gambogic acid analogs as potent cytotoxic and anti-inflammatory agents

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    Prenyl- and pyrano-xanthones derived from 1,3,6-trihydroxy-9H-xanthen-9-one, a basic backbone of gambogic acid (GA), were synthesized and evaluated for in vitro cytotoxic effects against four human cancer cell lines (KB, KBvin, A549, and DU-145) and anti-inflammatory activity toward superoxide anion generation and elastase release by human neutrophils in response to fMLP/CB. Among them, prenylxanthones 7-13 were generally less active than pyranoxanthones 14-21 in both anticancer and anti-inflammatory assays. Furthermore, two angular 3,3-dimethypyranoxanthones (16 and 20) showed the greatest and selective activity against the KBvin multidrug resistant (MDR) cell line with IC50 values of 0.9 and 0.8 Îź g/mL, respectively. An angular 3-methyl-3-prenylpyranoxanthone (17) selectively inhibited elastase release with 200 times more potency than phenylmethylsulfonyl fluoride (PMSF), the positive control
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