58 research outputs found
Freeze protection in gasholders
In cold weather, the water seals of gasholders need protection from freezing to avoid compromising the seal. These holders have a large reservoir of "tank water" at the base which is below ground. At present freeze-protection is achieved by external heating of the seal water which is in a slotted channel called a cup. Electrical heating or circulation of heated tank water to the cup are examples of systems presently used.
The tank water has a large thermal capacity and National Grid wishes to investigate whether circulation of the tank water without external heating could provide sufficient energy input to avoid freezing. Only tanks in which the tank water is below ground are investigated in the report. The soil temperature under the reservoir at depth of 10m and lower is almost constant
Endovascular control of haemorrhagic urological emergencies: an observational study
BACKGROUND: Transarterial embolisation (TAE) is an effective method in control of haemorrhage irrespective of the nature of urological emergency. As the technique and technology have evolved, it is now possible to perform highly selective embolisation. The aim of this study was to critically appraise feasibility and efficacy of therapeutic TAE in control of haemorrhagic urological emergencies using selective and non-selective embolisation. Specifically, we aimed to assess the impact of timing of embolisation on the requirement of blood transfusion and long-term morphological and functional follow-up of embolised organs. METHODS: This is a single institutional observational study carried out between March 1992 and March 2006. Records of all patients who underwent selective and non-selective angioembolisation to control bleeding in urological emergencies were reviewed. Data on success rate, periprocedural complications, timing of embolisation, requirement of blood transfusion and the long-term morphological and functional outcomes of embolised organs was recorded. RESULTS: Fourteen patients underwent endovascular control of bleeding as a result of trauma, iatrogenic injury and spontaneous perinephric haemorrhage during a period of 14 years. All these patients would have required emergency open surgery without the option of embolisation procedure. The mean time between the first presentation and embolisation was 22 hours (range 30 minutes to 60 hours). Mean pre-embolisation transfusion requirement was 6.8 units (range 0–22 units). None of the patients with successful embolisation required post-procedural blood transfusion. Permanent haemostasis was achieved in all but one patient, who required emergency nephrectomy. There were no serious procedure related post-embolisation complications. CONCLUSION: Endovascular control using transarterial angioembolisation is an effective method for managing haematuria or haemorrhage in urological emergencies. Wherever and whenever indicated, this option should be considered early in the management of these cases
Laser Ablation Efficiency, Laser Ablation Speed, and Laser Energy Consumption During Lithotripsy: What Are They and How Are They Defined? A Systematic Review and Proposal for a Standardized Terminology
Context
Laser performance for lithotripsy is currently reported using units of measurement such as J/mm3, mm3/J, mm3/s, s/mm3, and mm3/min. However, there are no current standardized definitions or terminology for these metrics. This may lead to confusion when assessing and comparing different laser systems.
Objective
The primary objective was to summarize outcome values and corresponding terminology from studies on laser lithotripsy performance using stone volume in relation to time or energy. The secondary objective was to propose a standardized terminology for reporting laser performance metrics.
Evidence acquisition
A systematic review of the literature was conducted using the search string (“j*/mm3” OR “mm3/j*” OR “mm3/s*” OR “s*/mm3” OR “mm3/min*” OR “min*/mm3” AND “lithotripsy”) on Scopus, Web of Science, Embase, and PubMed databases. Study selection, data extraction, and quality assessment were performed independently by two authors.
Evidence synthesis
A total of 28 studies were included, covering holmium:yttrium-aluminum-garnet (Ho:YAG), MOSES, and thulium fiber laser (TFL) technologies. Laser energy consumption values reported for the studies ranged from 2.0 – 43.5 J/mm3 in vitro and from 2.7 – 47.8 J/mm3 in vivo, translating to laser ablation efficiency of 0.023 – 0.500 mm3/J and 0.021 – 0.370 mm3/J, respectively. Laser ablation speeds ranged from 0.3 – 8.5 mm3/s in vivo, translating to lasing time consumption of 0.12 – 3.33 s/mm3. Laser efficacy ranged from 4.35 – 51.7 mm3/min in vivo. There was high heterogeneity for the terminology used to describe laser performance for the same metrics.
Conclusions
The range of laser performance metric values relating stone volume to energy or time is wide, with corresponding differing terminology. We propose a standardized terminology for future studies on laser lithotripsy, including laser ablation efficiency (mm3/J), laser ablation speed (mm3/s), and laser energy consumption (J/mm3). Laser efficacy (mm3/min) is proposed as a broader term that is based on the total operative time, encompassing the whole technique using the laser.
Patient summary
We reviewed studies to identify the units and terms used for laser performance when treating urinary stones. The review revealed a wide range of differing units, outcomes, and terms. Therefore, we propose a standardized terminology for future studies on laser stone treatment.
Keywords
UreteroscopyPercutaneous nephrolithotomyLaserStone diseaseLithotripsyPerformanceUrolithiasi
Impact of safety-related dose reductions or discontinuations on sustained virologic response in HCV-infected patients: Results from the GUARD-C Cohort
BACKGROUND:
Despite the introduction of direct-acting antiviral agents for chronic hepatitis C virus (HCV) infection, peginterferon alfa/ribavirin remains relevant in many resource-constrained settings. The non-randomized GUARD-C cohort investigated baseline predictors of safety-related dose reductions or discontinuations (sr-RD) and their impact on sustained virologic response (SVR) in patients receiving peginterferon alfa/ribavirin in routine practice.
METHODS:
A total of 3181 HCV-mono-infected treatment-naive patients were assigned to 24 or 48 weeks of peginterferon alfa/ribavirin by their physician. Patients were categorized by time-to-first sr-RD (Week 4/12). Detailed analyses of the impact of sr-RD on SVR24 (HCV RNA <50 IU/mL) were conducted in 951 Caucasian, noncirrhotic genotype (G)1 patients assigned to peginterferon alfa-2a/ribavirin for 48 weeks. The probability of SVR24 was identified by a baseline scoring system (range: 0-9 points) on which scores of 5 to 9 and <5 represent high and low probability of SVR24, respectively.
RESULTS:
SVR24 rates were 46.1% (754/1634), 77.1% (279/362), 68.0% (514/756), and 51.3% (203/396), respectively, in G1, 2, 3, and 4 patients. Overall, 16.9% and 21.8% patients experienced 651 sr-RD for peginterferon alfa and ribavirin, respectively. Among Caucasian noncirrhotic G1 patients: female sex, lower body mass index, pre-existing cardiovascular/pulmonary disease, and low hematological indices were prognostic factors of sr-RD; SVR24 was lower in patients with 651 vs. no sr-RD by Week 4 (37.9% vs. 54.4%; P = 0.0046) and Week 12 (41.7% vs. 55.3%; P = 0.0016); sr-RD by Week 4/12 significantly reduced SVR24 in patients with scores <5 but not 655.
CONCLUSIONS:
In conclusion, sr-RD to peginterferon alfa-2a/ribavirin significantly impacts on SVR24 rates in treatment-naive G1 noncirrhotic Caucasian patients. Baseline characteristics can help select patients with a high probability of SVR24 and a low probability of sr-RD with peginterferon alfa-2a/ribavirin
A systems-level analysis highlights microglial activation as a modifying factor in common forms of human epilepsy
The common human epilepsies are associated with distinct patterns of reduced cortical thickness, detectable on neuroimaging, with important clinical consequences. To explore underlying mechanisms, we layered MRI-based cortical structural maps from a large-scale epilepsy neuroimaging study onto highly spatially-resolved human brain gene expression data, identifying >2,500 genes overexpressed in regions of reduced cortical thickness, compared to relatively-protected regions. The resulting set of differentially-expressed genes shows enrichment for microglial markers, and in particular, activated microglial states. Parallel analyses of cell-specific eQTLs show enrichment in human genetic signatures of epilepsy severity, but not epilepsy causation. Post mortem brain tissue from humans with epilepsy shows excess activated microglia. In an experimental model, depletion of activated microglia prevents cortical thinning, but not the development of chronic seizures. These convergent data strongly implicate activated microglia in cortical thinning, representing a new dimension for concern and disease modification in the epilepsies, potentially distinct from seizure control
Advances in lasers for the treatment of stones: a systematic review
PURPOSE OF REVIEW: Laser lithotripsy is increasingly used worldwide and is a continuously evolving field with new and extensive research being published every year.RECENT FINDINGS: Variable pulse length Ho:YAG lithotripters allow new lithotripsy parameters to be manipulated, and there is an effort to integrate new technologies into lithotripters. Pulsed thulium lasers seem to be a viable alternative to holmium lasers. The performance of similar laser fibers varies from manufacturer to manufacturer. Special laser fibers and "cleaving only" fiber tip preparation can be beneficial for the lithotripsy procedure. Different laser settings and the surgical technique employed can have significant impact on the success of laser lithotripsy. When safely done, complications of laser lithotripsy are rare and concern the endoscopic nature of procedure, not the technology itself, making laser lithotripsy one of the safest tools in urology. SUMMARY. Laser lithotripsy has had several new developments and more insight has been gained in recent years with many more advances expected in the future.</p
Processing of Ni-Mn-Sn Magnetic Shape Memory Alloys
Superelastic strain of 4.9% obtained for Ni-Mn-Sn Magnetic Shape Memory Alloy (MSMA) raises interest in this alloy for application as magneto-mechanical energy harvesting device. We explore different compositions and heat treatments to obtain polycrystalline Ni-Mn-Sn MSMAs with magnetic field-induced superelasticity at room temperature. We annealed as-cast Ni-Mn-Sn alloys to reduce micro-segregation and secondary, interdendritic phases and to grow large grains. We analyzed the samples with optical microscopy, x-ray diffractometry, and energy-dispersive x-ray spectroscopy, vibrating sample magnetometer to determine grain size, phases present, chemical composition, chemical homogeneity and magnetization curves. Samples were cut through heat treated polycrystalline Ni-Mn-Sn alloys to obtain oligocrystalline wires with bamboo grain structure for magneto-mechanical experiments under rotating magnetic field. We found segregation of Mn and Sn with Ni homogeneously distributed in induction melted alloy, showing dendritic structure. The annealing treatment reduced the segregation of Mn and Sn, removed dendritic structure to a large extent and caused grain growth from about 500 micrometer to 4-5 millimeter
Designing an Internet-based intervention for improving wellbeing in people with acquired vision loss: A Delphi consensus study
Purpose:
Vision impairment (VI) may impact a person’s functional ability resulting in a loss of independence, anxiety, depression, social isolation and reduced quality of life. Caregivers also experience similar problems due to the increased burden placed on them. Support to address these difficulties encountered by those with VI and their caregivers may not always be accessible. An internet-based intervention may provide more accessible support. The aim of this study was to obtain consensus regarding the content and accessibility features required to design an internet-based intervention to promote wellbeing for people with VI and their caregivers.
Method:
A three-round Delphi review was conducted with a panel of 30 stakeholders. Three stakeholder groups were included, namely individuals with vision loss, experts in the field of vision loss and mental health and carers of individuals with vision loss. Conceptual wellbeing ideas were examined in round 1, the intervention modules and module content were proposed in round 2 and refined in round 3.
Results:
Consensus of 75% or more was reached to include 18 modules into the intervention. These were divided into seven sections: understanding vision loss, emotional wellbeing, functional wellbeing, social wellbeing, physical wellbeing, wellbeing for carers and maintaining wellbeing. The accessibility features deemed most important were font size, colour and contrast options, compatibility with low vision aids and layout of the intervention.
Conclusions:
The Delphi process positively informed the design of an internet-based intervention for individuals with acquired VI and their caregivers. Suggestions provided by stakeholders should now be incorporated into the intervention. Future evaluation of efficacy and cost-effectiveness of such an intervention are necessary
Image-Guided Biopsy-Diagnosed Renal Cell Carcinoma:Critical Appraisal of Technique and Long-Term Follow-Up
Music-based interventions to address wellbeing in people with a vision impairment: protocol for a scoping review
Introduction- Music-based interventions are used to improve well-being in individuals who are psychologically vulnerable and have long-term illnesses. To date, no study has systematically assessed the literature on music-based interventions aimed at improving well-being in people who have a vision impairment (VI). The purpose of the current protocol is to provide the methodology for a scoping review, to explore the therapeutic outcomes and strategies used in music-based interventions aimed specifically at people with a VI.
Methods and analysis- This scoping review protocol was developed according to the Joanna Briggs Institute methodology and reporting will follow the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews checklist and guidelines. The anticipated start date for this study was July 2021. The proposed review will include studies that use music therapeutically as part of a treatment intervention for all VI populations. Studies that meet the inclusion criteria with regards to population, concept and context will be included. Electronic database searches will be conducted independently by two researchers and include MEDLINE, EMBASE, CINAHL Plus, PsycINFO and Web of Science. Further searches will include the reference lists of included studies and grey literature. A narrative synthesis will be conducted to map out the types of therapeutic music interventions undertaken and to compare therapeutic outcomes.
Ethics and dissemination- As the methodology of this study consists of collecting data from publicly available articles, it does not require ethics approval. The findings of the planned scoping review are important to guide the development of future interventions, or strategies, that will attempt to use music to improve well-being in people with a VI. The results will be disseminated through a peer-reviewed publication and conference presentations
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