366 research outputs found
Experimental Investigation of Hybrid Air-Conditioning System with Desiccant-Coated Heat Exchanger Using CO2 Refrigerant
Is propofol injection pain really important to patients?
BACKGROUND: Propofol injection pain (PIP) has been adequately studied during the past decades. However, patients’ opinion on this problem and the incidence of patients’ recall of this brief discomfort are still unknown. Thus, we conducted this study to know the patients’ perspectives on PIP and provide useful information about the incidence of recall of PIP under our routine general anesthesia. METHODS: Five hundred preoperative questionnaires were distributed to patients who were scheduled for elective open thyroidectomy under general anesthesia from May 2016 to July 2016. They were asked to rank ten possible adverse effects associated with general anesthesia from their most undesirable to their least undesirable effect. Patients who completed the preoperative questionnaires were asked whether they could recall PIP and to grade the severity of PIP on the first postoperative day. RESULTS: A total of 448 preoperative questionnaires were returned and analyzed with an efficient rate of 89.6%. Incisional pain was ranked as most undesirable, followed (in order) by vomiting, gagging on the tracheal tube, nausea, sore throat, propofol injection pain, shivering, intravenous puncture pain, and anxiety. The majority (91.5%) of surveyed patients could not recall any discomfort or pain during anesthetics injection. Of those who could recall PIP, 89.5% grade it as mild pain, 7.9% moderate pain, and 2.6% severe pain. CONCLUSIONS: Most of patients undergoing elective open thyroidectomy in our hospital viewed PIP as a relatively minor problem. The incidence of recall of PIP was low and the majority of those who recalled regarded it as mild, temporary and acceptable pain. However, further investigations into propofol injection pain may be warranted as patients’ perspectives on propofol injection pain and its severity may differ between patient populations
Utility-scale Subsurface Hydrogen Storage: UK Perspectives and Technology
To reduce effects from anthropogenically induced climate change renewable energy systems are being implemented at an accelerated rate, the UKs wind capacity alone is set to more than double by 2030. However, the intermittency associated with these systems presents a challenge to their effective implementation. This is estimated to lead to the curtailment of up to 7.72TWh by 2030. Through electrolysis, this surplus can be stored chemically in the form of hydrogen to contribute to the 15TWh required by 2050. The low density of hydrogen constrains above ground utility-scale storage systems and thus leads to exploration of the subsurface. This literature review describes the challenges and barriers, geological criteria and geographical availability of all utility-scale hydrogen storage technologies with a unique UK perspective. This is furthered by discussion of current research (primarily numerical models), with particular attention to porous storage as geographical constraints will necessitate its deployment within the UK. Finally, avenues of research which could further current understanding are discussed
Joint task scheduling and multi-UAV deployment for aerial computing in emergency communication networks
This article studies mobile edge computing technologies enabled by unmanned aerial vehicles (UAVs) in disasters. First, considering that the ground servers may be damaged in emergency scenarios, we proposed an air-ground cooperation architecture based on ad-hoc UAV networks. We defined the system cost as the weighted sum of task delay and energy consumption because of different delay sensitivity and energy sensitivity tasks in emergency communication networks. Then, we formulated the system cost-minimization problem of task scheduling and multi-UAV deployments. To solve the proposed mixed integer nonlinear programming problem, we decomposed it to two sub-problems that were solved by proposing a swap matching-based task scheduling sub-algorithm and a successive convex approximation-based multi-UAV deployment sub-algorithm. Accordingly, we propose a joint optimization algorithm by iterating the two sub-algorithms to obtain a low complexity sub-optimal solution. Finally, the simulation results show that (i) the proposed algorithm converges in several iterations, and (ii) compared with the benchmark algorithms, the proposed algorithm has better performance of reducing task delay and energy consumption and achieves a good trade-off between them for diverse tasks
The application of the yield approach to study slurry migration in drill cuttings waste underground disposal
The underground disposal of drill cuttings waste is a common practice for the gas/oil industry to achieve zero-discharge sustainable development. In this study, a numerical modeling approach was developed to simulate the slurry flow for underground disposal of drill cuttings waste. The modeling approach was coupled with and implemented in the well-known general purpose subsurface multiphase flow simulator, TOUGH2. The new modeling approach treats the slurry flow behavior in subsurface systems as Bingham plastic liquid, with a linear relationship representing the yield stress and the concentration of the gelatinizer in the slurry. In addition, the precipitation-dissolution process was taken into account for solid-aqueous phase changes of the water-slurry mixture under and over the threshold pressure. The model has been verified by the analytical solution of a transient flow of single-phase Bingham fluid, and has further been tested by modeling field-scale injection of drill cutting wastes into a multi-layered geological formation in Texas. A hypothetical model has also been used to conduct sensitivity analysis of the impact of slurry density, injection depth and injection pattern on the storage formation performance. The results revealed that the effect of injection volume is greater than the mass on pressure buildup. In addition, a short period of intermittent reinjection can lead to an earlier formation breakdown due to particle sedimentation and reduce the storage capacity. The developed model can be used to evaluate the prediction of slurry transport, storage capacity, pressure distribution, and the formation breakdown time in a drill cuttings waste disposal project
High-efficiency CRISPR/Cas9 multiplex gene editing using the glycine tRNA-processing system-based strategy in maize
BACKGROUND: CRISPR/Cas9 genome editing strategy has been applied to a variety of species and the tRNA-processing system has been used to compact multiple gRNAs into one synthetic gene for manipulating multiple genes in rice. RESULTS: We optimized and introduced the multiplex gene editing strategy based on the tRNA-processing system into maize. Maize glycine-tRNA was selected to design multiple tRNA-gRNA units for the simultaneous production of numerous gRNAs under the control of one maize U6 promoter. We designed three gRNAs for simplex editing and three multiple tRNA-gRNA units for multiplex editing. The results indicate that this system not only increased the number of targeted sites but also enhanced mutagenesis efficiency in maize. Additionally, we propose an advanced sequence selection of gRNA spacers for relatively more efficient and accurate chromosomal fragment deletion, which is important for complete abolishment of gene function especially long non-coding RNAs (lncRNAs). Our results also indicated that up to four tRNA-gRNA units in one expression cassette design can still work in maize. CONCLUSIONS: The examples reported here demonstrate the utility of the tRNA-processing system-based strategy as an efficient multiplex genome editing tool to enhance maize genetic research and breeding. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12896-016-0289-2) contains supplementary material, which is available to authorized users
Trait divergence and opposite above- and below-ground strategies facilitate moso bamboo invasion into subtropical evergreen broadleaf forest
Understanding the invasion of moso bamboo (Phyllostachys edulis) into adjacent evergreen broadleaf forest based on functional traits is crucial due to its significant influence on ecosystem processes. However, existing research has primarily focused on above- or below-ground traits in isolation, lacking a comprehensive integration of both. In this study, we conducted a trait-based analysis including 23 leaf traits and 11 root traits in three forest types - bamboo forest, mixed bamboo and broadleaf forest, and evergreen broadleaf forest - to investigate trait differences, phenotypic integration, and above- and below-ground resource strategies in bamboo and broadleaf species. Our findings demonstrated significant differences in leaf and root key traits between bamboo and broadleaf species, strongly supporting the "phenotypic divergence hypothesis". Bamboo exhibited stronger trait correlations compared to broadleaf species, indicating higher phenotypic integration. Above- and below-ground strategies were characterized by trade-offs rather than coordination, resulting in a multi-dimensional trait syndrome. Specifically, a unidimensional leaf economics spectrum revealed that bamboo with higher leaf N concentrations (LNC), P concentrations (LPC), and specific leaf area (SLA) adopted a "fast acquisitive" above-ground strategy, while broadleaf species with thicker leaves employed a "slow conservative" above-ground strategy. A two-dimensional root trait syndrome indicated a "conservation" gradient with bamboo adopting a "slow conservative" below-ground strategy associated with higher root tissue density (RTD), and broadleaf species exhibiting a "fast acquisitive" below-ground strategy linked to higher root N concentrations (RNC) and P concentrations (RPC), and a "collaboration" gradient probably ranging from broadleaf species with a "do-it-yourself" strategy characterized by high specific root length (SRL), to bamboo adopting an "outsourcing" strategy with thicker roots. In conclusion, key trait divergence from coexisting broadleaf species, higher phenotypic integration, and multi-dimensional opposite above- and below-ground resource strategies confer competitive advantages to moso bamboo, shedding light on the mechanistic understanding of its invasion into subtropical evergreen broadleaf forest and providing theoretical guidance for maintaining the stability of subtropical forest ecosystem
An increased abundance of tumor-infiltrating regulatory t cells is correlated with the progression and prognosis of pancreatic ductal adenocarcinoma
CD4+CD25+Foxp3+ regulatory T cells (Tregs) can inhibit cytotoxic responses. Though several studies have analyzed Treg frequency in the peripheral blood mononuclear cells (PBMCs) of pancreatic ductal adenocarcinoma (PDA) patients using flow cytometry (FCM), few studies have examined how intratumoral Tregs might contribute to immunosuppression in the tumor microenvironment. Thus, the potential role of intratumoral Tregs in PDA patients remains to be elucidated. In this study, we found that the percentages of Tregs, CD4+ T cells and CD8+ T cells were all increased significantly in tumor tissue compared to control pancreatic tissue, as assessed via FCM, whereas the percentages of these cell types in PBMCs did not differ between PDA patients and healthy volunteers. The percentages of CD8 + T cells in tumors were significantly lower than in PDA patient PBMCs. In addition, the relative numbers of CD4+CD25+Foxp3+ Tregs and CD8+ T cells were negatively correlated in the tissue of PDA patients, and the abundance of Tregs was significantly correlated with tumor differentiation. Additionally, Foxp3+ T cells were observed more frequently in juxtatumoral stroma (immediately adjacent to the tumor epithelial cells). Patients showing an increased prevalence of Foxp3+ T cells had a poorer prognosis, which was an independent factor for patient survival. These results suggest that Tregs may promote PDA progression by inhibiting the antitumor immunity of CD8+ T cells at local intratumoral sites. Moreover, a high proportion of Tregs in tumor tissues may reflect suppressed antitumor immunity. Copyright: © 2014 Tang et al
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