Autologous serum eye drops for treatment of dry eye syndrome

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Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Utilization of excess heat from data centers.

Digitalization has influenced the rapid growth of data centers around the world. The advancement of IT and telecommunication also played a vital role in is this expansion of data centers. Data centers facilitate the storage and access of data when required. Electric power is the main energy input and heat is the main energy output from the data center. This work is about the utilization of the excess heat which is the by-product of data center operation. To connect the heat from data centers to a district heating network, a heat pump might be necessary to increase the temperature of the heat. The economic potential for different conditions and different heat recovery solutions are evaluated. Simulations and economical optimization at different conditions in Aspen HYSYS were carried out. Especially three alternatives were evaluated. The first is an alternative without a heat pump in which the cooling water leaves the data center at 80 ºC and enters the district heat network at 70 ºC. The second is an alternative with a slight temperature increase in the heat pump. The cooling water temperature from the data center is 65 ºC and the temperature to the district heat system is 70 ºC. The third is an alternative with a higher temperature increase in the heat pump. The cooling water temperature from the data center is 65 ºC and the temperature to the district heat system is 80 ºC. The COP (Coefficient of Performance) in a heat pump for these alternatives were calculated using the refrigerant R-22 in the simulation program Aspen HYSYS. The estimated economic potential for each alternative was calculated by estimated values on electricity cost and district heat price. In one alternative, the electricity cost was specified to 0.1 EUR/kWh, and the district heat price was specified to 0.05 EUR/kWh. For the alternatives using heat pumps, the capital cost was estimated assuming that the heat pump investment was dominating. The COPs for the two heat pump alternatives were calculated to be 8.66 and 5.4, respectively. The economy for a large data center facility with recovered waste heat of 200 GWh/year was calculated for 10 years. For the specified conditions, the net present value was calculated to be large and positive for all the alternatives. As expected, the most economical alternative was without a heat pump, and the most economical heat pump was the one with the highest COP. Sensitivity calculations were performed to show dependencies of temperatures, district heating price, electricity cost, heat pump cost, COP, and pipeline cost. Pipeline cost is very much dependent on the length and the local conditions for which it was not possible to make a reasonable estimation. The calculations show that there is a large potential in using waste heat from data centers for district heating

鋼構造骨組の柱梁耐力比に関する確率論的評価

甲第776号　主査：井戸田　秀

Effects of systematic increase in pozzolanic materials on the mechanical, durability, and microstructural characteristics of concrete

The use of high performance concrete in construction has been enhanced by the use ofpozzolanic materials. However, the use of these materials has not been optimized.Such optimization may be achieved by a systematic increase in the amount andcombination of pozzolanic material additions, with accompanying studies of theireffects on the mechanical, durability and microstructural characteristics of blendedconcrete.This work evaluated various concrete durability issues by studying systematic increasesof pozzolanic materials such as fly ash and blast furnace slag (BFS) in the range of 25,50 and 70%, and silica fume at 10% of total cementitious materials, forming variousbinary and ternary concrete blends. The concrete specimens were cured for a period ofseven days after demoulding in line with widely practiced commercial curingprocedures.The research explored the role and effectiveness of various binary and ternary blends ofpozzolanic materials on the mechanical, durability and microstructural characteristics ofconcrete. Durability was evaluated by two independent rapid chloride permeability testsmeasured as charge passed and chloride conductivity from the RCPT and UCT testsrespectively. These two rapid tests were coupled with long-term ponding tests toevaluate chloride ingress and the extent of corrosion for a period of two years. Furtherdurability tests such as carbonation, drying shrinkage and porosity of these blends werealso undertaken. This study also utilized micro-analytical techniques such as X-raydiffraction and Scanning Electron Microscopy to follow the hydration mechanism invarious binary and ternary blends. Statistical significance testing was used to analyseand confirm all experimental results and conclusions.It is well known that a level of caution is exercised in the construction industry in theuse of ternary blends. This study aims to evaluate the durability aspects of ternaryconcrete blends, in addition to binary blends, for resistance to chloride, corrosion,carbonation attacks and provide recommendations relating to the limits of blendinglevel, as well as exposure conditions for blended concretes, based on the results of thisstudy. It is expected that this will fill a major knowledge gap observed in the concreteindustry.A comparison of two rapid chloride permeability tests such as UCT and RCPT indicatesthat the UCT test is easy and practicable, and does not contradict results obtained in thestandard RCPT. However, the statistical significance of results obtained for someblends was only able to be established by using the RCPT. This effect can be attributedto the larger size specimens compared to UCT.The recommended blend to acquire both early-age and long-term strength developmentin fly ash is the ternary blends comprising 10% silica fume and 25% fly ash cast usinglower w/b ratio. In addition, the same blend exhibited lower carbonation depth, lowercharge passed from RCPT, lower chloride ingress and higher corrosion resistancecharacteristics from long-term ponding test compared to other blends of fly ash. In BFSblends, an increase in compressive strength was observed only in the specimens of 25%BFS compared to other higher percentage blends, while the higher addition of 50 and70% replacement showed no significant difference in compressive strength betweenthem and their corresponding ternary blends with addition of silica fume.The results of this study indicate that control (OPC) specimens cast with increased w/bratio of 0.48 showed higher chloride ingress compared to both binary blends of 70% flyash and 70% BFS specimens. This indicates that (OPC) cast using higher w/b ratio is tobe avoided in chloride environments. On the other hand, though, the ternary blends of10% silica fume and up to 50% fly ash exhibited lower chloride ingress compared totheir respective binary blends of fly ash. However, these ternary blends exhibited lowercompressive strength, more negative corrosion potential and higher corrosion rate,compared to the respective binary blends of 25% fly ash and its ternary blends.Therefore, the recommended blend observed in the long-term ponding test is the ternaryblend of 25% fly ash and 10% silica fume. The recommended level of corrosionresistance in slag specimens is achieved by the use of ternary blends comprising silicafume at 10% added to the blend that contains up to 70% slag. However, therecommended level of slag for a lower carbonation effect is the use of a ternary blendcomprising 50% slag and 10% silica fume (3B5S1) which showed a carbonation depthof 10.8 mm and a compressive strength of 53.2 MPa after 365 days of exposure.The drying shrinkage of concrete increased with the increase in fly ash and the sametrend was observed in BFS specimens. However, the results were not significantlydifferent between their respective blends. The extent of carbonation in fly ashspecimens was higher compared to BFS blends specimens. This can be attributed to theformation of dusty and weak surfaces on the outer surface in addition to the excessiveleaching of sodium chloride solution from the long-term ponding test in the formerspecimens compared to later.The high volume pozzolanic materials, irrespective of fly ash or BFS and addition ofsilica fume (70% fly ash and 10% silica fume, and 70% BFS and 10% silica fume),showed higher cumulative pore volume indicating that these blends with seven days ofcuring were not beneficial. These high volume ternary blends required prolongedcuring to release portlandite from the hydration of cement to continue the pozzolanicreaction. This study has shown that 7-days curing of the pozzolanic concrete isinadequate if pozzolanic activity is to be invoked. This is particularly the case when itis expected that the concrete is likely to be subjected to a harsher than usualenvironment characterised by a dry atmosphere

Experimental and computational studies of circulating fluidized bed

Biomass gasification represents an efficient process for the production of power, heat and biofuels. Different technologies are used for gasification and this article focuses on a circulating fluidized bed (CFB) system. Understanding the behaviour of particles is of primary importance and a cold flow CFB experimental unit was constructed and tested. The particle circulation rate is greatly affected by the loop seal performance, and therefore the loop seal should be properly optimized to maintain an uninterrupted operation. Smooth flow regimes were obtained for the CFB by varying the loop seal aeration rates. Particles with size 850–1000 µm and 1000–1180 µm were chosen for the experiments. The minimum flow rates of air into the riser for the two particle sizes were found to be 1.3 and 1.5 Sm3/ min, respectively. To obtain a smooth flow regime, a velocity range for aeration in the loop seal was found for the two particle sizes. Based on the experimental results, combinations of flow rates were suggested for the simulations. A Computational Particle Fluid Dynamic (CPFD) model was developed using Barracuda VR, and the model was validated against experimental results. The simulated results for the system regarding the pressure and the height of the bed material in the standpipe agreed well with the experimental results. The deviation between the experimental and computational pressure was less than 0.5% at all the locations for both the particle sizes. The deviation in particle level was about 6% for the 850–1000 µm particles and 17% for the 1000–1150 µm particles. Both the experiments and the simulations predicted that a small fraction of the circulating sands are emitted from the top of the rig. The validated CPFD model was further used to predict the flow behaviour and the particle circulation rate in the CFB

Comparison of trauma management between two major trauma services in Riyadh, Kingdom of Saudi Arabia and Melbourne, Australia

Introduction The burden of injury in the Kingdom of Saudi Arabia (KSA) has increased in recent years, but the country has lacked a consistent methodology for collecting injury data. A trauma registry has been established at a large public hospital in Riyadh from which these data are now available.Objectives We aimed to provide an overview of trauma epidemiology by reviewing the first calendar year of data collection for the registry. Risk-adjusted analyses were performed to benchmark outcomes with a large Australian major trauma service in Melbourne. The findings are the first to report the trauma profile from a centre in the KSA and compare outcomes with an international level I trauma centre.Methods This was an observational study using records with injury dates in 2018 from the registries at both hospitals. Demographics, processes and outcomes were extracted, as were baseline characteristics. Risk-adjusted endpoints were inpatient mortality and length of stay. Binary logistic regression was used to measure the association between site and inpatient mortality.Results A total of 2436 and 4069 records were registered on the Riyadh and Melbourne databases, respectively. There were proportionally more men in the Saudi cohort than the Australian cohort (86% to 69%). The Saudi cohort was younger, the median age being 36 years compared with 50 years, with 51% of injuries caused by road traffic incidents. The risk-adjusted length of stay was 4.4 days less at the Melbourne hospital (95% CI 3.95 days to 4.86 days, p<0.001). The odds of in-hospital death were also less (OR 0.25; 95% CI 0.15 to 0.43, p<0.001).Conclusions This is the first hospital-based study of trauma in the kingdom that benchmarks with an individual international centre. There are limitations to interpreting the comparisons, however the findings have established a baseline for measuring continuous improvement in outcomes for KSA trauma services