Relative High Cost Research Articles

Top-Down Synthesis of N-Type PbS Quantum Dots with High Photoluminescence Quantum Yield from Microsized Pb(OH)Cl.

Synthesis of PbS quantum dots (QDs) with uniform and controllable size is of great importance in realizing functionality manipulation, as well as building advanced devices, and these QDs have been normally synthesized via "bottom-up" colloidal chemistry. However, the problems of complicated techniques and the relative high cost of the "bottom-up" methods still need to be overcome. Herein, we present a facile and cost-effective "top-down" strategy for the production of PbS QDs with controllable sizes and narrow dispersions (4.8% < σ < 7%) based on the sulfuration reaction of highly active lead oxide and oxychloride intermediates. We investigated the two-step reaction mechanism of the QD synthesis. Initially, Pb(OH)Cl undergoes a reaction with oleic acid in the presence of oleylamine as an activator, leading to the formation of active lead oxide/oxychloride intermediates. Notably, this distinctive reaction induces the creation of numerous cracks within the intermediates, thereby augmenting the active sites available for the subsequent sulfuration reactions. In that, the sulfur precursor reacts with the intermediates, resulting in the rapid generation of a substantial number of PbS fragments. Over time, these small fragments undergo "ripening" until reaching the "critical" size threshold. Different from the ones obtained by the traditional "bottom-up" method, our synthesized colloidal QDs exhibit a S-rich surface and are confirmed to be N-type. In addition, size-tunable near-infrared photoluminescence renders these QDs a promising material for various applications.

The first magnetic resonance imaging compatible 3D printer

Background: The current study presents the development of a magnetic resonance imaging (MRI)-compatible silicone-based 3D printer capable of producing patient-specific implants within MRI scanners. Methods: The printing device incorporates 3 piezoelectrically-actuated linear motion stages assigned for navigating a custom-made silicone extruder to develop the desired 3D model based on preoperative MRI scans of the damaged anatomy. The structural components were manufactured on a rapid prototyping machine with thermoplastic and compactly assembled utilizing non-magnetic materials to ensure fit and safe functioning of the system within the MRI bore. Results: The printing system was successfully integrated with a high-field MRI scanner and operated safely while maintaining sufficient imaging quality. The robotic motion mechanism exhibited excellent repeatability and achieved submillimeter accuracy, demonstrating its capability for precise positioning of the extruder. Conclusion: The proposed 3D printer may hold promise as valuable tool for personalized tissue reconstruction by real-time printing with biocompatible silicone on the MRI table. However, challenges such as prolonged processing times and related high costs will possibly hinder its adoption in clinical practice.

Systematic Review of Economic Evaluations of Systemic Treatments for Advanced and Metastatic Gastric Cancer.

Recent advances in the development of biomarker-directed therapy and immunotherapy, for advanced and metastatic gastric cancers, have the potential to improve survival and quality of life.Much attention has been directed towards second- and later-line treatments, and the landscape here is evolving rapidly. However, uncertainty in relative effectiveness, high costs and uncertainty in cost effectiveness represent challenges for decision makers. To identify economic evaluations for the second-line or later-line treatment of advanced and metastatic gastric cancer. Also, to assess key criteria (including model assumptions, inputs and outcomes), reporting completeness andmethodological quality to inform future cost-effectiveness evaluations. A systematic literature search (from database inception to 5 March 2023) of EconLit via EBSCOhost, Cochrane Library (restricted to National Health Service [NHS] Economic Evaluation Database and Health Technology Assessment [HTA] Database), Embase, MEDLINE and of grey literature was conducted. This aimed to identify systemic treatments that align with National Comprehensive Cancer Network (NCCN) and European Society for Medical Oncology (ESMO) Clinical Practice Guidelines. Data were collected on key criteria and on reporting completeness and methodological quality. A narrative synthesis focussed on cost-effectiveness and cost-of-illness studies. Outcomes of interest included total and incremental costs and outcomes (life-years and quality-adjusted life-years), ratios of incremental costs per unit outcome and other summary cost and outcome measures. Also, for cost-effectiveness studies, reporting completeness and the methodological quality were assessed using the Consolidated Health Economic Evaluation Reporting Standards (CHEERS) and the Philips Checklist, respectively. A total of 19 eligible economic evaluations were identified (cost-effectiveness studies [n = 15] and cost-of-illness studies [n = 4]). There was a general lack of consistency in the methodological approaches taken across studies. In the main, the cost-effectiveness studies indicated that the intervention under consideration was more effective and more costly than the comparator(s). However, most interventions were not cost effective. No studies were fully compliant with reporting-completeness and methodological-quality requirements. Given the lack of consistency in the approaches taken across cost-of-illness studies, outcomes could not be directly compared. To our knowledge, this is the first published systematic literature review that has qualitatively synthesised economic evaluations for advanced and metastatic gastric cancer. There were differences in the approaches taken across the cost-effectiveness studies and the cost-of-illness studies. The conclusions of most of the cost-effectiveness studies were consistent despite identified differences in approaches. In the main, the interventions under consideration were not cost effective, presenting challenges to sustainability and affordability. We highlight a requirement for cost-effectiveness evaluations and for second-line or later-line treatments of advanced and metastatic gastric cancer that consider all relevant comparators and that are compliant with reporting-completeness and methodological-quality requirements. By addressing the methodological gaps identified here, future healthcare decision-making, within the context of this rapidly changing treatment landscape, would be better informed. CRD42023405951.

Multi-stage incentive contract design of aviation complex product multi-task delivery strategy

The increasing demand for aviation complex products makes complex product manufacturers pay more attention to delivery efficiency, and the efficiency and effect of delivery problems are the key factors that restrict delivery efficiency. A series of delivery strategy combinations of delivery subjects will affect delivery output and delivery efficiency. This study aims to design a long-term effective incentive contract, which stimulates the subjective initiative of the subject and then investigates the effect of the incentive contract on delivery efficiency under different combinations of delivery strategies. We consider the behavioral characteristics of each technical business department to expand the benchmark incentive model, such as the degree of perceived revenue fairness, the variation of the three relationships (neutrality, competition, and cooperation), and the level of technological transformation capability. The multi-stage incentive mechanism which combines explicit incentives and implicit incentives is developed to explore the optimal delivery strategies based on a benchmark model. The results show that incentive contracts can improve delivery efficiency and benefit delivery centers and technical business departments. The delivery decisions of the department are influenced by the closeness of department relationships and the fairness of assignment, and the departments tend to pay more effort in tasks with high relative importance and low effort cost. When the relative importance of tasks is equal to the ratio of marginal cost, a weak incentive zone in the delivery incentive contract exists. The incentive effect of reputation effect is obvious except for the last stage. Based on the designed incentive contracts, the subjective initiative of the participants can be effectively stimulated to empower complex product delivery.

Evaluation on novel Kalina power generation system through exergoenvironmental analysis

First law analysis assesses the performance of the system considered for investigation in the energy aspect. Low-temperature power generation system suitable to recover waste heat from a renewable source is investigated in the present work. The system is adopted to work at hot sink conditions and investigation on performance assessment is carried out in exergy aspect. Exergy analysis in both conventional and advanced methods proposes the system components which need improvements in themselves and associated with other components more properly. Exergoenvironmental analysis using the Life cycle assessment (LCA) method is examined in the system under the same sink conditions. Exergy analysis reveals that the component with a high source will yield more losses resulting in higher irreversibility. Hence turbine and evaporator need investigation in improving the system’s performance. Exergoenvironmental investigation suggests that the highest impact results in the low-temperature regenerator (LTRGN). The improvement in these components' designs and limitations in the characteristics of the material chosen and the manufacturing methods involved will favor a higher performance of the system. LTRGN has resulted in with high relative cost difference value of 23.85 % and seeks improvement. The exergy destruction is in a larger amount in the components evaporator and turbine with 70.66 kW and 30.99 kW respectively. Avoidable exergy destruction value of evaporator, condenser results 51.11 $/hr and 16.64 $/hr respectively. The LTRGN has an environmental effect rate of 54.83 mPts/hr and device-related environmental effects of 45.16 mPts/hr. The (ĖD/ĖP), (Ẏ/ĖP) and (Ż/ĖP), values at 85% pump efficiency results 2.16, 0.00946 and 0.30871.

Predictors of hospital length of stay and long-term care facility placement in aneurysmal subarachnoid hemorrhage

BackgroundAneurysmal subarachnoid hemorrhage (aSAH) is frequently associated with complications, extended hospital length of stay (LOS) and high health care related costs. We sought to determine predictors for hospital LOS and discharge disposition to a long-term care facility (LTCF) in aSAH patients. MethodsWe performed a retrospective study of a prospectively collected cohort of consecutive patients with aSAH admitted to an academic referral center from 2016 to 2021. Multiple linear regression was performed to identify predictors for hospital LOS. We then created a 10-point scoring system to predict discharge disposition to a LTCF. ResultsIn a cohort of 318 patients with confirmed aSAH, mean age was 57 years (SD 13.7), 61% were female and 70% were white. Hospital LOS was longer for survivors (median 19 days, IQR 14–25) than for non-survivors (median 5 days, IQR 2–8; p < 0.001). Main predictors for longer LOS for this cohort were ventriculoperitoneal shunt (VPS) requirement (p < 0.001), delayed cerebral ischemia (p = 0.026), and pneumonia (p = 0.014). The strongest predictor for LTCF disposition was age older than 60 years (OR 1.14, 95% CI 1.07–1.21; p < 0.001). LTCF score had high accuracy in predicting discharge disposition to a LTCF (area under the curve [AUC] 0.83; 95% CI 0.75–0.91). Forty-one percent of patients who were discharged to a LTCF had significant functional recovery at 3 months post-discharge. ConclusionsVPS requirement and aSAH related complications were associated with longer hospital LOS compared to other factors. LTCF score has high accuracy in predicting discharge disposition to a LTCF.

On the feasibility of Vis–NIR spectroscopy and machine learning for real time SARS-CoV-2 detection

The pandemic caused by Covid-19 is still present around the world. Despite advances in combating the disease, such as vaccine development, identifying infected individuals is still essential to optimize the control of human-to-human transmission of the virus. The main technique for detecting the virus is the RT-PCR method, which, despite its high relative cost, has a high accuracy in detecting the coronavirus. Given this, a method capable of performing the identification quickly, accurately, and inexpensively is necessary. Thus, this work aimed to analyze the feasibility of a new technique for identifying SARS-CoV-2 through the use of optical spectroscopy in the visible and near-infrared range (Vis–NIR) combined with machine learning algorithms. Spectral signals were obtained from nasopharyngeal swab samples previously analyzed using the RT-PCR method. The specimens were provided by the Molecular Diagnosis Laboratory of Covid-19 at Univasf. A total of 314 samples were analyzed, comprising 42 testing positive and 272 testing negative for Covid-19. Digital signal processing techniques, such as Savitzky–Golay filters and statistical methods were used to eliminate spurious elements from the original data and extract relevant features. Supervised machine learning algorithms such as SVM, Random Forest, and Naive Bayes classifiers were used to perform automatic sample identification. To evaluate the performance of the models, a 5-fold cross-validation technique was applied. With the proposed methodology, it was possible to achieve an accuracy of 75%, a sensitivity of 80%, and a specificity of 70%, in addition to an area under the ROC curve of 0.81, in the identification of nasopharyngeal swab samples from previously diagnosed individuals. From these results, it was possible to conclude that Vis–NIR spectroscopy is a promising, fast and relatively low cost technique to identify the SARS-CoV-2.

Weak grip strength predicts higher unplanned healthcare utilization among patients with heart failure.

Frailty increases healthcare utilization and costs for patients with heart failure but is challenging to assess in clinical settings. Hand grip strength (GS) is a single-item measure of frailty yet lacks evidence as a potential screening tool to identify patients at risk of higher unplanned events and related healthcare costs. We examined the association of baseline and longitudinal GS measurements with healthcare utilization and costs among patients with advanced heart failure. Between July 2017 and April 2019, we enrolled 251 patients with symptoms of advanced heart failure (New York Heart Association class III or IV) in a prospective cohort study in Singapore. We measured GS at baseline and every 4months for 2years and linked patients' survey data with their medical and billing records. We categorized patients as having weak GS if their GS measurement was below the 5th percentile of the age- and gender-specific normative GS values in Singapore. We assessed the association between baseline GS and healthcare utilization (unplanned and planned events and healthcare costs, total costs, and length of inpatient stay) over the next 2years using regression models. We investigated the association between longitudinal 4-monthly GS assessments and the ensuing 4months of healthcare utilization and costs using mixed-effects logistic and two-part regression models. At baseline, 22.5% of patients had weak GS. Baseline and longitudinal GS measurements were significantly associated with longer length of inpatient stay, greater likelihood of unplanned events, and higher related costs. Patients with weak GS had higher odds of an unplanned event occurring by 8 percentage points [95% confidence interval (CI) (0.01, 0.14), P=0.026], incurred longer inpatient stays by 4days [95% CI (1.97, 6.79), P=0.003], and additional SG$ 4792 [US$~3594, 95% CI (1894, 7689), P=0.014] in unplanned healthcare costs over the next 4months. GS is a simple tool to identify and monitor heart failure patients at risk of unplanned events, longer inpatient stays, and higher related healthcare costs. Findings support its routine use in clinical settings.

As time goes by – Overlooking 40 years of inpatient burn treatment at a national pediatric burn center in Switzerland

BackgroundDespite extensive prevention programs, burns remain a frequent cause of injury in Switzerland with a known age peak in children. Pediatric burns may cause substantial morbidity, a psyochological burden and therapy related high economic costs. To improve preventive measures, precise knowledge of etiology and treatment of pediatric burns in Switzerland as well as their temporal evolution is indispensable. MethodsThe present retrospective analysis included pediatric burn patients admitted for acute treatment to the Pediatric Burn Center of the University Children`s Hospital Zurich over the last four decades. Sociodemographic, injury related, and treatment related data were extracted from medical records. Linear regression analysis was applied to determine temporal changes during the past four decades and chi-square and t-tests were applied wherever applicable. ResultsA total of 3425 acute burn patients were included in the study between 1977 and 2020, corresponding to a mean of 89 patients/year. Mean age was 3.60 ± 4.12 years, three quarters of all patients were preschool children (0–5 years) and mean total body surface area (TBSA) burned was 8.01% ± 9.57%, however only around one fifth had severe burns (>10% TBSA). Scald burns (65.31%) and flame burns (32.99%) were most commonly seen. Linear regression analysis showed the total number of thermal injuries treated at our center to have increased significantly as of 2004 (p < 0.001). Separate analysis showed the same for small and medium (<10% TBSA) burns (p < 0.001), whereas the number of severe burns did not increase significantly. Length of stay (LOS) was highly associated with %TBSA burned. The percentage of female patients amongst all patients increased over time (p = 0.012). LOS per TBSA burned decreased significantly (p < 0.001). ConclusionThe present data show pediatric burns to remain a major health burden in Switzerland, especially small and medium burns in preschool children. Prevention programs should focus on this age population as well as on scald and flame burns as most common etiologies. The observed decrease in length of stay suggests a major improvement in overall quality of care in pediatric burns and supports centralization of care.

A novel hybrid assembly method to reduce operational costs of selective assembly

Selective assembly is a technique whereby components are smartly matched depending on their measured feature values. Although it can reduce scrap by allowing more relaxed tolerances on components when compared to traditional random assembly, it is often not adopted due to the high related operational costs. Therefore, this study proposes a novel hybrid strategy whereby a number of traditional assembly rounds are performed before switching to selective assembly. At each round, the components which did not lead to a feasible assembly are put into their respective unmatched piles and are used for the next traditional assembly round. When N such rounds have been performed, the remaining unmatched components will finally be assembled via selective assembly.To determine the optimal number of traditional assembly rounds before moving on to selective assembly, a cost function depending on the matching probabilities at each round and the relative costs of selective and traditional assembly is developed together with an optimality condition. Since the analytic calculation of the matching probabilities is in most of the practical cases infeasible, these are estimated using simulation. Particular attention is paid to reducing the variance of the estimators for the matching probabilities, and to their impact on the total variability of the cost function. The application of this innovative method to two case studies demonstrates that the proposed hybrid technique can significantly reduce operational costs of selective assembly, while still taking advantage of its typical benefits.

Remaining Oil Distribution Law and Development Potential Analysis after Polymer Flooding Based on Reservoir Architecture in Daqing Oilfield, China.

Polymer flooding has drawn more and more attention in the world for its high incremental oil recovery factor and relative low costs compared with water flooding and other chemically enhanced oil recovery techniques. However, for many oilfields, such as Daqing Oilfield, China, that have already been flooded with polymers, how to further improve recovery remains a big problem. Traditional intralayer, interlayer and plane heterogeneity studies cannot accurately characterize the remaining oil distribution after polymer flooding. To solve this problem, we established a method to quantitatively describe the reservoir's architecture. Then, the architecture elements were dissected hierarchically and the interface of each architecture level in Daqing Oilfield was identified. The distribution pattern and development potential of the remaining oil after polymer flooding under the influence of reservoir architecture was analyzed. The results show that, regarding the sedimentary process from north to south in Daqing Oilfield, the channel becomes narrower, the thickness decreases, the point bar's width increases and the thickness of the meandering river decreases. The braided bar scale becomes larger and the thickness becomes smaller in the braided river. According to the reservoir's architecture, the remaining oil was divided into four categories of plane remaining oil (abandoned channel occlusion type, interfluvial sand body occlusion type, inter-well retention type and well pattern uncontrollable type) and three types of vertical remaining oil (in-layer interlayer occlusion type, rhythm type and gravity type). About 40% of the original oil in place (OOIP) of Daqing Oilfield has not yet been produced, which indicates that there is great potential for development. This study is important for improving oil recovery in polymer-flooded reservoirs.

Application of the Hybrid MCDM Method for Energy Modernisation of an Existing Public Building—A Case Study

The existing public utility building belonging to the Forest Experimental Station of the Poznań University of Life Sciences, due to high energy consumption and related costs, has qualified for deep energy modernisation or consideration for the construction of a new building. One of the goals is to achieve carbon neutrality and have a positive energy balance. The article uses the hybrid DEMATEL-AHP/ANP-VIKOR method. The methodology used is distinguished by the creation of a set of decision-making criteria and the identification of the relationship between them, which is determined by conducting a survey of a group of experts using the Delphi method, as well as determining the preferences of the decision-maker using a survey of the target group using social research. Two different models of the decision-maker’s preferences have been developed, taking into account the selected decision criteria, and four acceptable technical solutions have been identified. As a result of the calculations performed, a ranking of the solutions has been developed, from the most preferred to the least accepted. Variant 3B has been identified as the best solution with respect to eight evaluation criteria for both of the adopted models of the decision-maker’s preferences. The ranking index Ri coefficient for this variant ranged between 0.733 and 0.901, while for the other variants, it was lower and amounted to between 0.106 and 0.274 for variant 1, 0.166 and 0.290 for variant 2 and 0.403 and 0.437 for variant 3A. The methodology used for the case study has proved to be applicable. The presented methodology can be used to design new buildings (not only residential) with almost zero energy consumption, as well as those with a positive energy balance, and can also be used for deep energy modernisation. In this article, it was applied for the first time to the energy modernisation of an existing public building.

Learning vs. minding: How subjective costs can mask motor learning.

When learning new movements some people make larger kinematic errors than others, interpreted as a reduction in motor-learning ability. Consider a learning task where error-cancelling strategies incur higher effort costs, specifically where subjects reach to targets in a force field. Concluding that those with greater error have learned less has a critical assumption: everyone uses the same error-canceling strategy. Alternatively, it could be that those with greater error may be choosing to sacrifice error reduction in favor of a lower effort movement. Here, we test this hypothesis in a dataset that includes both younger and older adults, where older adults exhibited greater kinematic errors. Utilizing the framework of optimal control theory, we infer subjective costs (i.e., strategies) and internal model accuracy (i.e., proportion of the novel dynamics learned) by fitting a model to each population's trajectory data. Our results demonstrate trajectories are defined by a combination of the amount learned and strategic differences represented by relative cost weights. Based on the model fits, younger adults could have learned between 65-90% of the novel dynamics. Critically, older adults could have learned between 60-85%. Each model fit produces trajectories that match the experimentally observed data, where a lower proportion learned in the model is compensated for by increasing costs on kinematic errors relative to effort. This suggests older and younger adults could be learning to the same extent, but older adults have a higher relative cost on effort compared to younger adults. These results call into question the proposition that older adults learn less than younger adults and provide a potential explanation for the equivocal findings in the literature. Importantly, our findings suggest that the metrics commonly used to probe motor learning paint an incomplete picture, and that to accurately quantify the learning process the subjective costs of movements should be considered.

Suppressing Unfavorable Interfacial Reactions Using Polyanionic Oxides as Efficient Buffer Layers: Low-Cost Li3PO4 Coatings for Sulfide-Electrolyte-Based All-Solid-State Batteries

The poor electrochemical performance of all solid-state batteries (ASSBs) that use sulfide electrolytes can be attributed to undesirable side reactions at the cathode/sulfide-electrolyte interface; this issue can be addressed via surface coating. Ternary oxides such as LiNbO3 and Li2ZrO3 are generally used as coating materials because of their high chemical stabilities and ionic conductivities. However, their relative high cost discourages their use in mass production. In this study, Li3PO4 was introduced as a coating material for ASSBs, because phosphates possess good chemical stabilities and ionic conductivities. Phosphates also prevent the exchange of S2- and O2- in the electrolyte and cathode and, thus, inhibit interfacial side reactions caused by ionic exchange, because they contain the same anion (O2-) and cation (P5+) species as those present in the cathode and sulfide electrolyte, respectively. Furthermore, the Li3PO4 coatings can be prepared using low-cost source materials such as polyphosphoric acid and lithium acetate. We investigated the electrochemical performance of the Li3PO4-coated cathodes and found that the Li3PO4 coating significantly improved the discharge capacities, rate capabilities, and cyclic performances of the all-solid-state cell. While the discharge capacity of the pristine cathode was ∼181 mAh·g-1, that of 0.15 wt % Li3PO4-coated cathode was ∼194-195 mAh·g-1. And the capacity retention of the Li3PO4-coated cathode over 50 cycles was much superior (∼84-85%) to that of the pristine sample (∼72%). Simultaneously, the Li3PO4 coating reduced the side reactions and interdiffusion at the cathode/sulfide-electrolyte interfaces. The results of this study demonstrate the potential of low-cost polyanionic oxides, such as Li3PO4, as commercial coating materials for ASSBs.

Racial/ethnic disparities in costs, length of stay, and severity of severe maternal morbidity

In contrast to other high-resource countries, the United States has experienced increases in the rates of severe maternal morbidity. In addition, the United States has pronounced racial and ethnic disparities in severe maternal morbidity, especially for non-Hispanic Black people, who have twice the rate as non-Hispanic White people. This study aimed to examine whether the racial and ethnic disparities in severe maternal morbidity extended beyond the rates of these complications to include disparities in maternal costs and lengths of stay, which could indicate differences in the case severity. This study used California's linkage of birth certificates to inpatient maternal and infant discharge data for 2009 to 2011. Of the 1.5 million linked records, 250,000 were excluded because of incomplete data, for a final sample of 1,262,862. Cost-to-charge ratios were used to estimate costs from charges (including readmissions) after adjusting for inflation to December 2017. Mean diagnosis-related group-specific reimbursement was used to estimate physician payments. We used the Centers for Disease Control and Prevention definition of severe maternal morbidity, including readmissions up to 42 days after delivery. Adjusted Poisson regression models estimated the differential risk of severe maternal morbidity for each racial or ethnic group, compared with the non-Hispanic White group. Generalized linear models estimated the associations of race and ethnicity with costs and length of stay. Asian or Pacific Islander, Non-Hispanic Black, Hispanic, and other race or ethnicity patients all had higher rates of severe maternal morbidity than non-Hispanic White patients. The largest disparity was between non-Hispanic White and non-Hispanic Black patients, with unadjusted overall rates of severe maternal morbidity of 1.34% and 2.62%, respectively (adjusted risk ratio, 1.61; P<.001). Among patients with severe maternal morbidity, the adjusted regression estimates showed that non-Hispanic Black patients had 23% (P<.001) higher costs (marginal effect of $5023) and 24% (P<.001) longer hospital stays (marginal effect of 1.4 days) than non-Hispanic White patients. These effects changed when cases, such as cases where a blood transfusion was the only indication of severe maternal morbidity, were excluded, with 29% higher costs (P<.001) and 15% longer length of stay (P<.001). For other racial and ethnic groups, the increases in costs and length of stay were smaller than those observed for non-Hispanic Black patients, and many were not significantly different from non-Hispanic White patients. Hispanic patients had higher rates of severe maternal morbidity than non-Hispanic White patients; however, Hispanic patients had significantly lower costs and length of stay than non-Hispanic White patients. There were racial and ethnic differences in the costs and length of stay among patients with severe maternal morbidity across the groupings that we examined. The differences were especially large for non-Hispanic Black patients compared with non-Hispanic White patients. Non-Hispanic Black patients experienced twice the rate of severe maternal morbidity; in addition, the higher relative costs and longer lengths of stay for non-Hispanic Black patients with severe maternal morbidity support greater case severity in that population. These findings suggest that efforts to address racial and ethnic inequities in maternal health need to consider differences in case severity in addition to the differences in the rates of severe maternal morbidity and that these differences in case severity merit additional investigation.

Study of early-age performance of cementitious backfills with alkali activated slag under internal sulfate attack

The vulnerability to internal sulfate attack of calcium-rich ordinary Portland cement (OPC) and its relative high cost force mines to explore technically effective and low cost alternative binders to solidify sulfate-containing tailings. Alkali activated slag (AAS) has been established to be a promising substitute for OPC due to its superior strength, good resistance to chemical attack and low cost. This study shows results of a laboratory research dealing the characteristics of cemented paste backfill (CPB) with AAS under internal sulfate attack. A blend of two alkali activators (SS: sodium silicate, SH: sodium hydroxide) was considered. To assess the behavior of CPB materials subjected to diverse conditions, a total of 4 different SS/SH ratio (e.g., 0.5, 0.75, 1, and 1.25) were used within CPB. Results shows that initial/final setting times tend to drop with growing sulfate content up to 5000 ppm, followed by gradual increases. Increasing sulfate content leads to higher yield stresses and viscosities and the degree of this negative impact is much severer in samples having the high SS/SH ratio. The presence of sulfate can enhance or deteriorate the strength of AAS-CPB depending on activator type, cure age and initial sulfate content. CPB with high SS/SH ratio reveals weaker resistance to internal sulfate attack due to their lower pH values. The key outcome of this work will be beneficial to optimally design of sulfate bearing CPB-AAS structures.

P455 Comparison of two strategies for the management of post-operative recurrence in Crohn’s disease patients with one clinical risk factor: a multicentre IG-IBD study

Abstract Background Prevention of postoperative recurrence (POR) in Crohn’s disease (CD) after ileo-colonic (IC) resection is still a highly debated topic. Prophylactic immunosuppression after surgery is currently recommended in presence of at least one clinical risk factor (RF). Due to drug-related adverse events and the relative high cost of biologics, we aimed to determine whether prevention of POR can be postponed and guided by endoscopy in CD patients with only one RF. Methods A multicentre retrospective study was conducted in 12 IG-IBD Italian centres. CD patients with only one RF for POR, including previous intestinal resection, extensive small intestine resection (&amp;gt;50 cm), fistulising phenotype, history of perianal disease, or active smoking were considered. Patients who performed a colonoscopy between 6 to 12 months after curative IC resection were included. Two groups were formed based on whether immunosuppressive therapy was started immediately after surgery (prophylaxis group) or guided by endoscopy (observation group). Primary endpoints were the rates of any endoscopic recurrence (Rutgeerts ≥i2a) and severe endoscopic recurrence (i4) within 12 months after surgery. Secondary outcomes were clinical recurrence (HBI≥5) rates at 6, 12 and 24 months after surgery. Results A total of 195 patients were enrolled. Out of all, 61 (31.3%) received immunoprophylaxis at a median time of 32 days [IQR 26-55] after surgery (n=14 infliximab, n=37 adalimumab, n=7 azathioprine, n=3 ustekinumab). Baseline patient characteristics are detailed in Table 1. Particularly, risk factors for POR were homogeneously distributed between the 2 groups. Colonoscopy was performed after a median time of 8 months [IQR 6-11]. No differences between immunoprophylaxis and endoscopy-driven approach was found regarding any endoscopic recurrence (36.1% in prophylaxis group vs 45.5% in observation group, p=0.10) and severe endoscopic recurrence (9.8% in prophylaxis group vs 15.7% in observation group, p=0.15). In 32 patients with a second colonoscopy at a median time of 30.5 months [IQR 22-43.75] after surgery, any recurrence and severe recurrence rates were also similar (p=0.55 and p=0.43, respectively). Early clinical recurrence at 6 months was reported in 23.4% of patients on immunoprophylaxis vs 31.5% who were not (p=0.43). Clinical recurrence rates between prophylaxis and observation group were also similar at 12 months (17.9% vs 34.8%, respectively, p=0.09) and at 24 months (17.9% vs 24.1%, respectively, p=0.63). Conclusion In CD patients with only one RF for POR, immediate immunoprophylaxis after curative IC resection does not decrease the rate of early clinical and endoscopic recurrence. Prospective and larger studies are needed to confirm our results.

Techno-economic evaluation of supercritical fluid extraction of flaxseed oil

Green and promising technologies are current interests of the developing societies. Advantages of supercritical fluid extraction (SFE) overcome traditional extraction processes due to the quality aspects and environmental benefits. However, the relative high cost of the system makes these technologies commercial applicability in question for some products species. In our study, we intended to investigate the SFE of flaxseed oil in pilot scale system. Techno-economic analyses of SFE of flaxseed oil was evaluated using computational simulation software. The results demonstrated that high scales of SFE systems are feasible due to the high productivity. Although high investment is necessary for high-capacity extraction systems, low Cost of Manufacturing (COM) and short payback time can be accomplished.

Are we making progress on decarbonization? A panel heterogeneous study of the long-run relationship in selected economies

This study investigates the long-run relationship between carbon emissions (CO2) and technological progress, capital intensity, GDP per capita, population, and labor productivity for 23 selected economies from 1890 to 2019. The study's originality emerges from using the most comprehensive panel time-series data available (1890–2019), adopting the most recent panel empirical modeling techniques. We use different estimation techniques fully modified ordinary least square (FMOLS), dynamic ordinary least square (DOLS), canonical cointegration regression (CCR) to evaluate whether the decarbonization process is significant and its progress comparing findings with mean-group error correction model with variable cross-sectional averages (CCEMG) for robustness. The results reported here underline that carbon emissions are slowing down, but the decarbonization process remains sluggish. Limiting factors for decarbonization are GDP per capita growth, population, capital intensity, total factor productivity, labor productivity, emissions inequality, high relative costs of renewables, economy structure (share of labor/capital intensive industries). The study results provide evidence countries with higher GDP per capita, total factor productivity growth, population growth, and increasing capital intensity drive global carbon emissions up. The findings of this study have several significant implications for global CO2 policymakers and carbon emissions reduction initiatives. It also has important implications for practitioners facing policy and technological choices toward corporate social responsibility management. This article provides new insights into empirical modeling for carbons emissions-effects under heterogeneity (endogeneity), non-stationarity, cross-sectional dependence, and unobservable technological progress effect.

Intranasal delivery of replicating mRNA encoding hACE2-targeting antibody against SARS-CoV-2 Omicron infection in the hamster

The Omicron variant is sweeping the world, which displays striking immune escape potential through mutations at key antigenic sites on the spike protein, making broad-spectrum SARS-CoV-2 prevention or therapeutical strategies urgently needed. Previously, we have reported a hACE2-targeting neutralizing antibody 3E8, which could efficiently block both prototype SARS-CoV-2 and Delta variant infections in prophylactic mouse models, having the potential of broad-spectrum to prevent SARS-CoV-2. However, preparation of monoclonal neutralizing antibodies is severely limited by the time-consuming process and the relative high cost. Here, we utilized a modified VEEV replicon with two subgenomic (sg) promoters engineered to express the light and heavy chains of the 3E8 mAb. The feasibility and protective efficacy of replicating mRNA encoding 3E8 against Omicron infection in the hamster were demonstrated through the lung targeting delivery with the help of VEEV-VRP. Overall, we developed a safe and cost-effective platform of broad-spectrum to prevent SARS-CoV-2 infection.