340 research outputs found
Solid-state metathesis reactions under pressure: A rapid route to crystalline gallium nitride
High pressure chemistry has traditionally involved applying pressure and increasing temperature until conditions become thermodynamically favorable for phase transitions or reactions to occur. Here, high pressure alone is used as a starting point for carrying out rapid, self-propagating metathesis reactions. By initiating chemical reactions under pressure, crystalline phases, such as gallium nitride, can be synthesized which are inaccessible when initiated from ambient conditions. The single-phase gallium nitride made by metathesis reactions under pressure displays significant photoluminescence intensity in the blue/ultraviolet region. The absence of size or surface-state effects in the photoluminescence spectra show that the crystallites are of micron dimensions. The narrow lines of the x-ray diffraction patterns and scanning electron microscopy confirm this conclusion. Brightly luminescent thin films can be readily grown using pulsed laser deposition
Considering the impact of situation-specific motivations and constraints in the design of naturally ventilated and hybrid buildings
A simple logical model of the interaction between a building and its occupants is presented based on the principle that if free to do so, people will adjust their posture, clothing or available building controls (windows, blinds, doors, fans, and thermostats) with the aim of achieving or restoring comfort and reducing discomfort. These adjustments are related to building design in two ways: first the freedom to adjust depends on the availability and ease-of-use of control options; second the use of controls affects building comfort and energy performance. Hence it is essential that these interactions are considered in the design process. The model captures occupant use of controls in response to thermal stimuli (too warm, too cold etc.) and non-thermal stimuli (e.g. desire for fresh air). The situation-specific motivations and constraints on control use are represented through trigger temperatures at which control actions occur, motivations are included as negative constraints and incorporated into a single constraint value describing the specifics of each situation. The values of constraints are quantified for a range of existing buildings in Europe and Pakistan. The integration of the model within a design flow is proposed and the impact of different levels of constraints demonstrated. It is proposed that to minimise energy use and maximise comfort in naturally ventilated and hybrid buildings the designer should take the following steps: 1. Provide unconstrained low energy adaptive control options where possible, 2. Avoid problems with indoor air quality which provide motivations for excessive ventilation rates, 3. Incorporate situation-specific adaptive behaviour of occupants in design simulations, 4. Analyse the robustness of designs against variations in patterns of use and climate, and 5. Incorporate appropriate comfort standards into the operational building controls (e.g. BEMS)
Preclincial evaluation of Gold-DTDTPA Nanoparticles As Theranostic Agents In Prostate Cancer Radiotherapy
International audienceAim: Gold nanoparticles have attracted significant interest in cancer diagnosis and treatment. Herein, we evaluated the theranostic potential of dithiolated diethylenetriamine pentaacetic acid (DTDTPA) conjugated AuNPs (Au@DTDTPA) for CT-contrast enhancement and radiosensitization in prostate cancer. Materials & methods: In vitro assays determined Au@DTDTPA uptake, cytotoxicity, radiosensitizing potential and DNA damage profiles. Human PC3 xenograft tumor models were used to determine CT enhancement and radiation modulating effects in vivo. Results: Cells exposed to nanoparticles and radiation observed significant additional reduction in survival compared with radiation only. Au@DTDTPA produced a CT enhancement of 10% and a significant extension in tumor growth delay from 16.9 days to 38.3 compared with radiation only. Conclusion: This study demonstrates the potential of Au@DTDTPA to enhance CT-image contrast and simultaneously increases the radiosensitivity of prostate tumors
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A high-resolution map of human evolutionary constraint using 29 mammals.
The comparison of related genomes has emerged as a powerful lens for genome interpretation. Here we report the sequencing and comparative analysis of 29 eutherian genomes. We confirm that at least 5.5% of the human genome has undergone purifying selection, and locate constrained elements covering âŒ4.2% of the genome. We use evolutionary signatures and comparisons with experimental data sets to suggest candidate functions for âŒ60% of constrained bases. These elements reveal a small number of new coding exons, candidate stop codon readthrough events and over 10,000 regions of overlapping synonymous constraint within protein-coding exons. We find 220 candidate RNA structural families, and nearly a million elements overlapping potential promoter, enhancer and insulator regions. We report specific amino acid residues that have undergone positive selection, 280,000 non-coding elements exapted from mobile elements and more than 1,000 primate- and human-accelerated elements. Overlap with disease-associated variants indicates that our findings will be relevant for studies of human biology, health and disease
Phylogenetic congruence and ecological coherence in terrestrial Thaumarchaeota
This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the articleâs Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. Acknowledgements We would like to thank Dr Robert Griffith/CEH for providing DNA from soil samples and Dr Anthony Travis for his help with BioLinux. Sequencing was performed in NERC platform in Liverpool. CG-R was funded by a NERC fellowship NE/J019151/1. CQ was funded by a MRC fellowship (MR/M50161X/1) as part of the cloud infrastructure for microbial genomics consortium (MR/L015080/1).Peer reviewedPublisher PD
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A study protocol for a randomised feasibility study Comparing Urolift and Standard Transurethral resection of prostate Ahead of Radiotherapy in men with urinary symptoms secondary to prostate enlargement in Southwest London and North Cumbria (COSTAR)
Introduction
Patients undergoing prostate radiotherapy with an enlarged prostate can have short and long term urinary complications. Currently, Transurethral resection of the prostate (TURP) is the mainstay surgical intervention for men with urinary symptoms due to an enlarged prostate prior to radiotherapy. UroLift (NeoTract Inc., Pleasanton, CA USA) is a recent minimally invasive alternative, widely used in benign disease but is untested in men with prostate cancer.
Methods and Analysis
A multi-centre, two-arm study designed in collaboration with a Patient Reference Group to assess the feasibility of randomising men with prostate cancer and co-existing urinary symptoms due to prostate enlargement to TURP or UroLift ahead of radiotherapy. 45 patients will be enrolled and randomised (1:1) using a computer-generated programme to TURP or UroLift.
Recruitment and retention will be assessed over a 12-month period. Information on clinical outcomes, Adverse Events, and costs will be collected. Clinical outcomes and Patient Reported Outcome Measures (PROMs) will be measured at baseline, six-weeks post-intervention and three months following radiotherapy. A further 12 in-depth interviews will be conducted with a subset of patients to assess acceptability using the Theoretical Framework of Acceptability. Descriptive analysis on all outcomes will be performed using Stata (StataCorp 2021).
Ethics and Dissemination
The trial has been approved by the Research Ethics Committee (REC) NHS Health Research Authority (HRA) and Health and Care Research Wales (HCRW). The results will be published in peer-reviewed journals, presented at national meetings and disseminated to patients via social media, charity and hospital websites
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