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Fluorescence turn-on aptamers, in vitro evolved RNA molecules that bind conditional fluorophores and activate their fluorescence, have emerged as RNA counterparts of the fluorescent proteins. Turn-on aptamers have been selected to bind diverse fluorophores, and they achieve varying degrees of specificity and affinity. These RNA–fluorophore complexes, many of which exceed the brightness of green fluorescent protein and their variants, can be used as tags for visualizing RNA localization and transport in live cells. Structure determination of several fluorescent RNAs revealed that they have diverse, unrelated overall architectures. As most of these RNAs activate the fluorescence of their ligands by restraining their photoexcited states into a planar conformation, their fluorophore binding sites have in common a planar arrangement of several nucleobases, most commonly a G-quartet. Nonetheless, each turn-on aptamer has developed idiosyncratic structural solutions to achieve specificity and efficient fluorescence turn-on. The combined structural diversity of fluorophores and turn-on RNA aptamers has already produced combinations that cover the visual spectrum. Further molecular evolution and structure-guided engineering is likely to produce fluorescent tags custom-tailored to specific applications.
A straightforward intuitive user-friendly compact graphical interface, PreDICT (Premier DICVOL Tool) has been developed to take full advantage of the new capabilities of the most recent version of the DICVOL14 Indexing Software. The latter, an updated version of DICVOL04, includes optimizations, e.g. for monoclinic and triclinic cases, a detailed review of the input data from the indexing solutions, cell centering tests, as well as the handling of a moderate number of impurity peaks. Among the most salient features of PreDICT, one can mention the ability (1) to use 2θ non-equistepped input 1D X-ray powder diffraction patterns as can be obtained from 2D detectors, (2) to strip laboratory data from its Kα2 contribution when present, (3) to generate 2θ equistepped output 1D X-ray powder diffraction patterns in both the “.XY” and “.GSA” formats. In addition, PreDICT allows for the following features: (1) full access to the native DICVOL14 input/output ASCII file system is retained, (2) for any selection of a DICVOL14 suggested unit cell, all predicted Bragg peaks up to a certain 2θMAX value are clearly displayed and indicated, thereby emphasizing the contribution of the unaccounted peaks (if any) to the 1D X-ray powder diffraction pattern under current investigation.
Chemical bonding in native oxides of GaAs, before and after etching, is detected by X-Ray Photoelectron Spectroscopy (XPS). It is correlated with surface energy engineering (SEE), measured via Three Liquid Contact Angle Analysis (3LCAA), and oxygen coverage, measured by High Resolution Ion Beam Analysis (HR-IBA).
Before etching, GaAs native oxides are found to be hydrophobic with an average surface energy, γT, of 33 ± 1 mJ/m2, as measured by 3LCAA. After dilute NH4OH etching, GaAs becomes highly hydrophilic and its surface energy, γT, increases by a factor 2 to a reproducible value of 66 ± 1 mJ/m2. Using HR-IBA, oxygen coverage on GaAs is found to decrease from 7.2 ± 0.5 monolayers (ML) to 3.6 ± 0.5 ML. The 1.17 ratio of Ga to As, measured by HR-IBA, remains constant after etching.
XPS is used to measure oxidation of Ga and As, as well as surface stoichiometry on two locations of several GaAs(100) wafers before and after etching. The relative proportions of Ga and As are unaffected by adventitious carbon contamination. The 1.16 Ga:As ratio, measured by XPS, matches HR-IBA analysis. The proportions of oxidized Ga and As do not change significantly after etching. However, the initial ratio of As2O5 to As2O3, within the oxidized As, significantly decreases after etching from approximately 3:1 to 3:2.
Absolute oxygen coverage, as a function of surface processing, is determined within 0.5 ML by HR-IBA. XPS offers insight into these modifications by detecting electronic states and phase composition changes of GaAs oxides. The changes in surface chemistry are correlated to changes in hydro-affinity and surface energies measured by 3LCAA.
To determine the attributable cost and length of stay of hospital-acquired Clostridioides difficile infection (HA-CDI) from the healthcare payer perspective using linked clinical, administrative, and microcosting data.
A retrospective, population-based, propensity-score–matched cohort study.
Acute-care facilities in Alberta, Canada.
Admitted adult (≥18 years) patients with incident HA-CDI and without CDI between April 1, 2012, and March 31, 2016.
Incident cases of HA-CDI were identified using a clinical surveillance definition. Cases were matched to noncases of CDI (those without a positive C. difficile test or without clinical CDI) on propensity score and exposure time. The outcomes were attributable costs and length of stay of the hospitalization where the CDI was identified. Costs were expressed in 2018 Canadian dollars.
Of the 2,916 HA-CDI cases at facilities with microcosting data available, 98.4% were matched to 13,024 noncases of CDI. The total adjusted cost among HA-CDI cases was 27% greater than noncases of CDI (ratio, 1.27; 95% confidence interval [CI], 1.21–1.33). The mean attributable cost was $18,386 (CAD 2018; USD $14,190; 95% CI, $14,312–$22,460; USD $11,046-$17,334). The adjusted length of stay among HA-CDI cases was 13% greater than for noncases of CDI (ratio, 1.13; 95% CI, 1.07–1.19), which corresponds to an extra 5.6 days (95% CI, 3.10–8.06) in length of hospital stay per HA-CDI case.
In this population-based, propensity score matched analysis using microcosting data, HA-CDI was associated with substantial attributable cost.
Replicate radiocarbon (14C) measurements of organic and inorganic control samples, with known Fraction Modern values in the range Fm = 0–1.5 and mass range 6 μg–2 mg carbon, are used to determine both the mass and radiocarbon content of the blank carbon introduced during sample processing and measurement in our laboratory. These data are used to model, separately for organic and inorganic samples, the blank contribution and subsequently “blank correct” measured unknowns in the mass range 25–100 μg. Data, formulas, and an assessment of the precision and accuracy of the blank correction are presented.
Clinical Enterobacteriacae isolates with a colistin minimum inhibitory concentration (MIC) ≥4 mg/L from a United States hospital were screened for the mcr-1 gene using real-time polymerase chain reaction (RT-PCR) and confirmed by whole-genome sequencing. Four colistin-resistant Escherichia coli isolates contained mcr-1. Two isolates belonged to the same sequence type (ST-632). All subjects had prior international travel and antimicrobial exposure.
In this essay on Hegel’s philosophy of absolute spirit, I am going to pursue some of his most important concepts – the concept of recognition, the master/slave relationship, and the true infinite – in one of Hegel’s least-read texts, even by Hegel scholars, his Lectures on the Philosophy of Religion: vol. 2, Determinate Religion. Here he employs these concepts heuristically, freely, and creatively in his studies of Asian, Jewish, Greek, and Roman religions. I confine my attention in Section I of this essay to Hegel’s discussion of Greek Kunstreligion (the religion of Art and Beauty), and in Section II to the Jewish Religion of the Sublime. Hegel identifies these as religions of freedom, of the elevation of spirit over nature. Each asserts a different version of the important theme that runs throughout the history and philosophy of religion, namely, that spirit has a human presence, or, the humanity of God.
Angiostrongylus cantonensis is a pathogenic nematode and the cause of neuroangiostrongyliasis, an eosinophilic meningitis more commonly known as rat lungworm disease. Transmission is thought to be primarily due to ingestion of infective third stage larvae (L3) in gastropods, on produce, or in contaminated water. The gold standard to determine the effects of physical and chemical treatments on the infectivity of A. cantonensis L3 larvae is to infect rodents with treated L3 larvae and monitor for infection, but animal studies are laborious and expensive and also raise ethical concerns. This study demonstrates propidium iodide (PI) to be a reliable marker of parasite death and loss of infective potential without adversely affecting the development and future reproduction of live A. cantonensis larvae. PI staining allows evaluation of the efficacy of test substances in vitro, an improvement upon the use of lack of motility as an indicator of death. Some potential applications of this assay include determining the effectiveness of various anthelmintics, vegetable washes, electromagnetic radiation and other treatments intended to kill larvae in the prevention and treatment of neuroangiostrongyliasis.
Reflection is an important component in design skill development that helps designers better understand their design problem, develop better solutions, and improve their design approaches. This study explored the information that a student design team reflected on as part of a needs finding experience and the outcomes from these reflections. During the needs finding experience, the team exhibited reflection-in- action behavior as they used available data to form and iterate on explanatory hypotheses about potential community needs. After the needs finding experience, the team exhibited reflection-on-action behavior as they drew connections between their interview approaches and stakeholder responses and discussed changes they might make in the future. The team also identified situations where contextual factors of the stakeholder impacted their interviews, but during these reflections did not indicate how they might adapt their approaches to account for such factors in the future. These findings show that student designers can use reflection as a tool to improve their needs finding process but would benefit from pedagogical structures that might help them reflect more effectively.
Primary care physicians can play a key role in supporting patients after behavioural weight loss, though little is known about communication between patients and physicians during this time. Adults (n=139) in a behavioural weight loss trial (delivered outside of primary care) who attended a primary care appointment after an initial weight loss period were surveyed to assess weight-related communication at their most recent appointment. Most participants (78%) reported discussing weight with their physician. Participants who discussed weight, compared to those who did not, lost more weight, had higher blood pressure, and were more likely to be male. Most (89%) reported that their physician was supportive of their weight loss, but only a few participants (6.9%) reported that their physician gave feedback on medical parameters. Areas for improvement identified include physicians providing universal support for modest weight changes and providing interpretation of medical measurements that changed due to weight loss.