Interlocked molecules are a type of supramolecules whose sub-components are held together not by covalent bonds but non-covalent interactions. Examples include rotaxanes, catenanes, Solomon links, ring-in-ring complex...
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Interlocked molecules are a type of supramolecules whose sub-components are held together not by covalent bonds but non-covalent interactions. Examples include rotaxanes, catenanes, Solomon links, ring-in-ring complexes, molecular Borromean rings, molecular knots and interlocked cages. The design and manufacture of these architectures is mainly based on self-assembly and template-directed methodologies. Inspired by the successful utilization of coordination-driven assembly in metallasupramolecular systems, the metallacyclic assembly of interlocked superstructures is developing rapidly and as such makes a fascinating topic for reviewing. In this review we will focus on the metal-directed synthesis of the different types of interlocked superstructures, as well as their functional applications.
We have demonstrated the high yield and highly single wall selective synthesis of carbon nanotube forest grown using a MgO single crystal as a catalyst underlayer without any surface treatment. Such efficiency has not...
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We have demonstrated the high yield and highly single wall selective synthesis of carbon nanotube forest grown using a MgO single crystal as a catalyst underlayer without any surface treatment. Such efficiency has not been previously reported using this underlayer system. Our investigation revealed that the growth ambient which contained no hydrogen but small amounts of water is essential for such efficiency. Evaluation of the growth kinetics by in-situ height monitoring revealed that the 350 m tall forest with 65% single wall selectivity possessed a catalyst lifetime of about 5 minutes. Investigation by AFM, and XPS depth profiling revealed that this longer lifetime compared with as-deposited MgO can be attributed to the stability of the catalyst particle array with small size and high number density on MgO single crystal substrate. Shorter growth lifetime, when compared to the alumina underlayer system, resulted from an instability in the catalyst nanoparticle size and composition.
AIM To investigate the relationships among diverse metalloproteases(MMPs) and their tissue inhibitors(TIMPs) and non-alcoholic liver fibrosis in human immunodeficiency virus(HIV)-infected *** Single nucleotide polymor...
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AIM To investigate the relationships among diverse metalloproteases(MMPs) and their tissue inhibitors(TIMPs) and non-alcoholic liver fibrosis in human immunodeficiency virus(HIV)-infected *** Single nucleotide polymorphisms(SNPs) in MMPs, TNF-α and ccR5 genes, and serum levels of MMPs and TIMPs were determined in HIV-infected individuals with/out hepatitis c virus(HcV) coinfection. A total of 158 patients were included, 57 of whom were HcVcoinfected. All patients drank < 50 g ethanol/day. Diverse SNPs(MMP-1-1607 1G/2G, MMP-8-799c/T, MMP-9-1562 c/T, MMP-13-77A/G, TNF-α-308 G/A,ccR5-?32), and serum levels of MMPs(2, 3, 8, 9 and 10) and TIMPs(1, 2 and 4) were assessed. Liver fibrosis was determined by transient elastometry, although other non-invasive markers of fibrosis were also considered. Significant liver fibrosis(F ≥ 2) was defined by a transient elastometry value ≥ 7.1 kP *** A total of 34 patients(21.5%) had liver fibrosis ≥ F2. MMP-2 and TIMP-2 serum levels were higher in patients with liver fibrosis ≥ F2(P = 0.02 and P = 0.03, respectively) and correlated positively with transient elastometry values(P = 0.02 and P = 0.0009, respectively), whereas MMP-9 values were negatively correlated with transient elastometry measurements(P = 0.01). Multivariate analyses showed that high levels of MMP-2(OR = 2.397; 95%cI: 1.191-4.827, P = 0.014) were independently associated with liver fibrosis ≥ F2 in the patients as a whole. MMP-2(OR = 7.179; 95%cI: 1.210-42.581, P = 0.03) and male gender(OR = 10.040; 95%cI: 1.621-62.11, P = 0.013) were also independent predictors of fibrosis ≥ F2 in the HcV-infected subgroup. Likewise, MMP-2, TIMP-2 and MMP-9 were independently associated with transient elastometry values and other non-invasive markers of liver fibrosis. None of the six SNPs evaluated had any significant association with liver fibrosis ≥ *** certain MMPs and TIMPs, particularly MMP-2, seems to be associated with non-alcoholic liver fibrosis
We demonstrate anisotropic, vertical deep etching of graphite and densely packed carbon nanotube (cNT) thick layer beyond the micrometer scale, which representing the first step toward nanocarbon bulk micromachining. ...
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We demonstrate anisotropic, vertical deep etching of graphite and densely packed carbon nanotube (cNT) thick layer beyond the micrometer scale, which representing the first step toward nanocarbon bulk micromachining. This micromachining process is compatible with standard lithography and therefore allows the fabrication of graphite and cNT architectures with 1 mu m lateral resolution and up to 10 mu m scale depth.
A textile mill provides one of the hardest and rigorous environments to a ring and a traveler of a spinning machine. Generation of high contact pressure between the ring and the traveler during winding led to degradat...
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A textile mill provides one of the hardest and rigorous environments to a ring and a traveler of a spinning machine. Generation of high contact pressure between the ring and the traveler during winding led to degradation of the internal surface of the ring, thus its working life. This study elucidated towards enhancing the working life of the ring as well as decreasing the time required to reinstate the rings on the spindle periodically during spinning. The objective was carried out by comparing four different detonation gun (D-Gun) thermal sprayed coatings on bearing alloy steel (E52100) ring in a laboratory test using pin-on-disc apparatus. The microstructure and mechanical properties of the Wc-co-cr, cr 3 c 2 Nicr, Al 2 O 3 +TiO 2 (Alumina-Titania) and Stellite-6 coatings were comparatively studied with those of uncoated E52100. The coated E52100 showed significantly less wear loss as compared to bare E52100. The investigations revealed that the cumulative volume loss for detonation sprayed coatings increased with increase in load. The Wc-co-cr coating underwent minimum wear and the Wc-co-cr–E52100 coating-substrate combination exhibited highest abrasive wear resistance. The results obtained during pin-on-disc laboratory test may be used for comparison of wear resistance of different coatings deposited on E52100 alloy steel rings in the textile mill.
Thermal spring water (17–28°c) occurring in crystalline rocks at the Grimsel area, Switzerland, represents a mixture of an old geothermal component with a surface-derived, young cold water component. comparison ...
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Thermal spring water (17–28°c) occurring in crystalline rocks at the Grimsel area, Switzerland, represents a mixture of an old geothermal component with a surface-derived, young cold water component. comparison of chemical and isotope data of cold and thermal spring water collected in 1991/92 and 2014/15 allows deciphering the residence time and evolution of the geothermal component. Accounting for changes in atmospheric input for d 18 O, d 2 H, 3 H and 14 c, a meteoric origin from similar moisture source(s) for the cold and geothermal component is proposed, a 3 H-PF model age of about 7 years for the cold component and infiltration of the geothermal component before 30 ka during an interglacial cycle. Deep circulation of the geothermal component is inferred from water temperatures of 110–120°c and the uptake of geogeniccO 2 and/or cH 4 .
Stable isotope analysis has been extensively used as an effective tool in determination of trophic relationship in ecosystems. In freshwater ecosystem, aquatic invertebrates represent main component of a river food we...
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Stable isotope analysis has been extensively used as an effective tool in determination of trophic relationship in ecosystems. In freshwater ecosystem, aquatic invertebrates represent main component of a river food web. This study was carried out to determine potential food sources of freshwater organism together with pattern of trophic position along the river food web. In this study, rivers of Belum-Temengor Forest complex (BTFc) has been selected as sampling site as it is a pristine area that contains high diversity and abundance of organisms and can be a benchmark for other rivers in Malaysia. Stable isotope ratios of carbon ( δ 13 c) and nitrogen ( δ 15 N) were applied to estimate trophic position and food web paradigm. Analysis of stable isotopes based on organic material collected from the study area revealed that the highest δ 13 c value was reported from filamentous algae (− 22.68 ± 0.126 0 / 00 ) and the lowest δ 13 c was in allocthonous leaf packs (− 31.58 ± 0.187 0 / 00 ). Meanwhile the highest δ 15 N value was in fish (8.45 ± 0.177 0 / 00 ) and the lowest value of δ 15 N was in autochthonous aquatic macrophyte (2.00 ± 1.234 0 / 00 ). Based on the δ 15 N results, there are three trophic levels in the study river and it is suggested that the trophicchain begins with organic matter followed by group of insects and ends with fish (organic matter < insects < fish).
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