Lower Recovery Rate Research Articles

Predictors of trastuzumab-induced cardiotoxicity among racially and ethnically diverse patients with HER2-positive breast cancer

BackgroundWhile trastuzumab has been shown to improve disease-free and overall survival in patients with HER2-positive breast cancer, it may also cause trastuzumab-induced cardiotoxicity (TIC). Although racial and ethnic minorities are at higher risk for cardiovascular disease (CVD) compared to non-Hispanic Whites (NHW), limited data exists on TIC incidence in diverse multi-ethnic populations. Our objective was to assess racial and ethnic differences in TIC and left ventricular ejection fraction (LVEF) recovery among patients with HER2-positive breast cancer.MethodsWe conducted a retrospective cohort study including patients diagnosed with stage I-III HER2-positive breast cancer between 2007 and 2022 who had received adjuvant trastuzumab. We analyzed associations between sociodemographic factors, tumor characteristics, treatment regimens, and CVD risk factors with the primary outcomes of TIC and LVEF recovery, using multivariable logistic regression models. TIC was defined as > 10% decrease in LVEF to an overall LVEF < 50%; LVEF recovery as a return to a LVEF > 50%.ResultsAmong 496 evaluable patients, median age was 53 years (IQR: 45.0–62.0) with 36.6% NHW, 15.8% non-Hispanic Black (NHB), 27.8% Hispanic, and 19.8% Other. Fifty-three (10.6%) patients developed TIC, half of whom experienced LVEF recovery. Compared to NHW, NHB had a higher rate of TIC (9.3% vs. 17.7%, respectively) and lower rate of LVEF recovery (70.6% vs. 21.4%, respectively), however, race/ethnicity was not a significant predictor of TIC after adjusting for confounders. Increasing age, lower baseline LVEF, anthracycline use, and presence of hypertension or coronary artery disease were significantly associated with TIC in multivariable analysis.ConclusionsTIC was more common among NHB compared to NHW, however, Black race was not consistently associated with TIC after adjustment for CVD risk factors. This suggests that CVD comorbidities (e.g., hypertension) that more frequently affect racial and ethnic minorities and are modifiable may explain differences in TIC incidence and recovery.

Sustainable fungi-based protein extraction from agro-waste mushroom stem using deep eutectic solvents

This study evaluated the nutritional and functional qualities of the mushroom stem (MS) powder and its protein concentrates, which were extracted using alkaline and deep eutectic solvent (DES)-based methods. MS powder is rich in protein (23.02 %) and carbohydrates (63.01 %). Alkaline extraction yielded the highest protein content (45.90 %) but lower recovery rates (15.39 %) compared to DES extractions using a 1:2 M ratio of choline chloride: glycerol (DES-CG) and choline chloride: lactic acid (DES-CL), which had recovery rates of 22.04 % and 21.47 %, respectively. DES solvents provided strong hydrogen bonding, as indicated by FTIR analysis, and produced uniform, smooth particles according to SEM imaging. Both DES and alkaline methods achieved similar protein solubility values (72–75 %). However, DES methods better preserved emulsion capabilities and balanced foaming properties, enhancing foam capacity and maintaining stability. The findings suggest that DES methods are more sustainable and efficient for extracting proteins from MS powder, optimizing both functional properties and environmental sustainability in food applications.

Clinical evaluation of greater palatine artery hemodynamics in Le Fort I osteotomy

ObjectiveLe Fort I osteotomy (LIO) is a widely known standard orthognathic surgical treatment. However, complications such as osteonecrosis of the jaw due to poor postoperative blood flow to tissues of the maxilla have been reported. This study measured the hemodynamics of the greater palatine artery (GPA) in patients who underwent LIO to explore the factors that affect postoperative blood flow. MethodsWe included 15 patients who underwent LIO and sagittal split ramus osteotomy (SSRO), and 8 patients, who only underwent SSRO, were included as controls. Preoperative, intraoperative, and postoperative blood flow in the oral mucosa anterior to the foramen magnum was measured with a laser Doppler blood flow meter. ResultsOn average blood flow at immediately after downfracture in LIO patients reduced to 24.8% of baseline blood flow and patients who underwent anterior maxillary movement had a lower recovery rate at any time. Multiple regression analysis showed that the greater the maxillary anterior shift and the longer the time from maxillary disarticulation to fixation (mandibular fracture time: DFT), the more delayed was the blood flow recovery. ConclusionsSince blood flow decreased after downfracture and recovered only to around 85.4% of baseline after 6 months in LⅠO, preserving blood vessels is important. Furthermore, the recovery rate was lower in patients who underwent anterior movement, and blood flow reduced more in patients with longer DFT, suggesting the importance of determining the direction and distance of movement preoperatively, and repositioning and fixing the maxilla as quickly as possible during surgery.

The Accelerating Loss of Resilience in Suburban Woodlands Can Largely Be Attributed to the Changes in Urban Precipitation Patterns.

Vegetation resilience holds significant importance for stabilizing ecosystem service functions in a changing climate. While global land surface vegetation resilience changes have been extensively studied, the impact of urbanization on the resilience of suburban woodlands remains inadequately understood. In this study, we utilized two critical slowing down (CSD) indicators, namely lag-one autocorrelation (LOA) and variance (VA), to assess the vegetation resilience, its long-term trends, and influencing factors in suburban woodlands across 1356 cities worldwide. The recovery rates estimated by LOA ( ) and VA ( ) showed close alignment in suburban woodlands with low suburban forest coverage (SFC) areas (correlation coefficient (r) = 0.95). However, a notable divergence was observed in areas with high SFC (r = 0.73). Suburban woodlands with high SFC typically exhibited lower recovery rate estimates, thus indicating greater vegetation resilience compared to areas with lower SFC. From 1986 to 2022, the recovery rates of suburban woodland areas in over 83% of the cities demonstrated a significant upward trend, with an average of 3.23 × 10-3 year-1 for both and , signifying a widespread decline in vegetation resilience. The accelerating pace of urbanization led to higher rising rates of and during 2010-2022 (5.11 × 10-3 year-1) compared to 1986-1999 (0.49 × 10-3 year-1). The notable decrease in resilience of forestland was primarily attributed to reduced precipitation in urban suburbs, which can be explained by urbanization-induced heat island and building barrier effects, causing a shift of precipitation center from urban suburbs to central cities. In summary, this study revealed that urbanization diminishes the vegetation resilience of urban suburban woodlands by altering urban precipitation patterns. These findings underscore the necessity of augmenting water availability in urban suburbs to restore resilience in these woodlands, thereby enhancing their ecosystem service value.

Childhood and adult socioeconomic status influence on late-life healthy longevity: evidence from the Chinese longitudinal healthy longevity survey.

Older people in low- and middle-income countries are more susceptible to the impact of childhood experiences. This study comprehensively examines how childhood socioeconomic status (SES) and adult SES collectively influence late-life healthy longevity from a life course perspective, providing insights for shaping health-related policies. This study analyzed data from the Chinese Longitudinal Healthy Longevity Survey (1998-2018) with 37,264 individuals aged 65 and above. Using R software, we applied continuous-time multi-state models incorporating the Rockwood frailty index with 38 indicators to assess participants' health. Childhood SES or life course SES trajectories were core explanatory variables, while age and gender were controlled. Multinomial regression estimated annual transition probabilities between different states, and the multi-state life table method calculated total and frailty-specific life expectancy (LE). (1) Social mobility among older people in China showed an upward trend from childhood to adulthood. (2) Transition probabilities for robust-frailty, robust-dead, and frailty-dead increased with age, while frailty-robust decreased. Transition probabilities and LE varied across different childhood SES (low, medium, high) or life-course SES trajectory categories (low-low, low-medium, low-high, medium-low, medium-medium, medium-high, high-low, high-medium, high-high), with probabilities of robust-frailty, robust-dead, and frailty-dead decreasing sequentially across different categories, and frailty-robust increasing sequentially across different categories. Total LE, robust LE, and robust LE proportion increased sequentially across different categories, while frailty LE decreased sequentially across different categories. (3) Women had higher total LE and frailty incidence, but lower recovery rate, mortality risk, robust LE, and robust LE proportion compared to men. Favorable childhood SES and lifelong accumulation of SES advantages protect against frailty morbidity, improve recovery rate, reduce mortality risk, and increase total LE, robust LE, and robust LE proportion. High childhood SES has a stronger protective effect than high adult SES, indicating the lasting impact of childhood conditions on healthy longevity. Systematic interventions in education, food supply, and medical accessibility for children from impoverished families are crucial.

Kinetics of Viral Shedding for Outbreak Surveillance of Emerging Infectious Diseases: Modeling Approach to SARS-CoV-2 Alpha and Omicron Infection.

Previous studies have highlighted the importance of viral shedding using cycle threshold (Ct) values obtained via reverse transcription polymerase chain reaction to understand the epidemic trajectories of SARS-CoV-2 infections. However, it is rare to elucidate the transition kinetics of Ct values from the asymptomatic or presymptomatic phase to the symptomatic phase before recovery using individual repeated Ct values. This study proposes a novel Ct-enshrined compartment model to provide a series of quantitative measures for delineating the full trajectories of the dynamics of viral load from infection until recovery. This Ct-enshrined compartment model was constructed by leveraging Ct-classified states within and between presymptomatic and symptomatic compartments before recovery or death among people with infections. A series of recovery indices were developed to assess the net kinetic movement of Ct-up toward and Ct-down off recovery. The model was applied to (1) a small-scale community-acquired Alpha variant outbreak under the "zero-COVID-19" policy without vaccines in May 2021 and (2) a large-scale community-acquired Omicron variant outbreak with high booster vaccination rates following the lifting of the "zero-COVID-19" policy in April 2022 in Taiwan. The model used Bayesian Markov chain Monte Carlo methods with the Metropolis-Hastings algorithm for parameter estimation. Sensitivity analyses were conducted by varying Ct cutoff values to assess the robustness of the model. The kinetic indicators revealed a marked difference in viral shedding dynamics between the Alpha and Omicron variants. The Alpha variant exhibited slower viral shedding and lower recovery rates, but the Omicron variant demonstrated swifter viral shedding and higher recovery rates. Specifically, the Alpha variant showed gradual Ct-up transitions and moderate recovery rates, yielding a presymptomatic recovery index slightly higher than 1 (1.10), whereas the Omicron variant had remarkable Ct-up transitions and significantly higher asymptomatic recovery rates, resulting in a presymptomatic recovery index much higher than 1 (152.5). Sensitivity analysis confirmed the robustness of the chosen Ct values of 18 and 25 across different recovery phases. Regarding the impact of vaccination, individuals without booster vaccination had a 19% higher presymptomatic incidence rate compared to those with booster vaccination. Breakthrough infections in boosted individuals initially showed similar Ct-up transition rates but higher rates in later stages compared to nonboosted individuals. Overall, booster vaccination improved recovery rates, particularly during the symptomatic phase, although recovery rates for persistent asymptomatic infection were similar regardless of vaccination status once the Ct level exceeded 25. The study provides new insights into dynamic Ct transitions, with the notable finding that Ct-up transitions toward recovery outpaced Ct-down and symptom-surfacing transitions during the presymptomatic phase. The Ct-up against Ct-down transition varies with variants and vaccination status. The proposed Ct-enshrined compartment model is useful for the surveillance of emerging infectious diseases in the future to prevent community-acquired outbreaks.

Utilization of Assisted Reproductive Technologies in Breeding Auliekol Cattle: A Comparative Study.

This study evaluates the utilization of in vitro embryo production (IVEP) technology for the conservation and breeding of the Auliekol cattle breed, a primary beef breed in Kazakhstan facing population decline due to the cessation of breeding programs and the incursion of transboundary diseases. We assessed the effect of consecutive ovum pick-up (OPU) procedures on oocyte yield and embryo production in Auliekol and Aberdeen Angus cows. A total of 2232 and 3659 oocytes were aspirated from Auliekol and Aberdeen Angus donors, respectively, with significantly higher yields and embryo production observed in Aberdeen Angus cows. The application of a meiotic block using Butyrolactone I (BLI) and subsequent in vitro fertilization (IVF) protocols was employed, with embryo development monitored up to the morula/blastocyst stage. Results indicated that Auliekol cows exhibited lower oocyte recovery, cleavage, and blastocyst rates compared to Aberdeen Angus cows, likely due to genetic characteristics. Despite the challenges, IVEP presents a valuable tool for the preservation and future propagation of the Auliekol breed, highlighting the need for further research to enhance reproductive outcomes and conservation strategies.

Impact of Non-Dialysis-Requiring Acute Kidney Injury on Survival Outcomes in Non-critically Ill Hospitalized Medical Patients in a Resource-Limited Setting: A Retrospective Cohort Study.

Introduction The severe consequences of acute kidney injury (AKI) have been well-documented in high-risk patient populations. However, the effects of milder forms in non-critically ill patients remain understudied, particularly in resource-limited settings. While the risk of mortality associated with these cases is considered low, it can still lead to various complications including prolonged hospitalization, which may influence long-term renal and patient survival.Hence, the objective of this study was to studythe impact of non-dialysis-requiring AKI (NDR-AKI) on survival outcomes of non-critically ill medical patients admitted to St. Paul's Hospital Millennium Medical College in Ethiopia during the period from July 2019 to January 2022. Methods A retrospective cohort study was conducted among 300 non-critically ill medical patients, 93 with NDR-AKI and 207 without AKI.Descriptive statistics, including frequency distributions and median survival times, were employed to summarize the data. Kaplan-Meier curves and the log-rank test were utilized to compare survival experiences of groups. A Cox proportional hazards survival model was fitted to estimate the impact of NDR-AKI on time to recovery. Adjusted hazard ratio (AHR) with 95% confidence interval (CI) was used to report findings. Results Two hundred four (68.0%) were discharged after improvement and the median recovery time was 16 days (95%CI: 13.5-18.5 days). Having NDR-AKI was associated with a 43% lower rate of achieving recovery (AHR=0.57, 95%CI=0.38, 0.84, p-value=0.004). Females were found to have a 1.41 times higher rate of recovery (AHR=1.41, 95%CI=1.03,1.94, p-value=0.033). Additionally, having tuberculosis (AHR=0.41, 95%CI=0.23,0.72, p-value=0.002) and being on anticoagulant (AHR=0.67, 95%CI=0.47,0.95, p-value=0.027) were associated with a 59% and 33% lower rate of recovery, respectively. Conclusion NDR-AKI significantly delays recovery compared to patients without AKI suggesting that even milder forms of AKI in non-critically ill patients can negatively impact patient outcomes. Early identification, prompt management, and addressing underlying causes are key to improving recovery and reducing long-term morbidity and mortality. Strict screening and monitoring of high-risk groups such as men, patients with tuberculosis, and those on anticoagulants is also crucial.

Lessons learned from a one-year study of Legionella spp. cultivation from activated sludge samples

Risk assessment and management of Legionella spp. contamination in activated sludge in wastewater treatment plants is carried out using the culture method. Underestimation of Legionella spp. is frequently reported in the literature, but a comprehensive long-term study of the performance of the method under comparable conditions is still lacking. The aim of this study is to evaluate the recovery rate and limit of detection of the culture method for Legionella spp. from activated sludge samples collected during the different seasons of the year. Activated sludge samples spiked with Legionella pneumophila subsp. pneumophila strain Philadelphia-1 (mean concentration 5.2 ± 0.35 logCFU/mL) were analysed monthly for one year using the culture method. Three different sample pre-treatments were compared, namely filtration, acid treatment and thermal treatment, and the recovery rate and limit of detection were assessed for each. The recovery rate of the culture method for Legionella spp. depended on the type of sample pre-treatment and the season of activated sludge sampling, while the limit of detection depended only on the sample pre-treatment. The best performance of the culture method, defined as the combination of the highest recovery rate and lowest limit of detection, was obtained for the filtered acid pre-treated samples (recovery rate: 89 ± 4 %; limit of detection: 1.3 logCFU/mL in 83 % of the samples). The lowest limit of detection was observed for the filtered thermally pre-treated samples (1.0 logCFU/mL in 93 % of the samples). Simultaneously, both thermally pre-treated samples showed up to a third lower recovery rates than the other pre-treatments in winter, while untreated and acid pre-treated samples showed consistently high recovery rates (>80%, logCFU/mL). The recovery rates of the unfiltered and filtered thermally pre-treated samples showed significant weak to strong positive correlations with the organic and phosphorus load in the influent as well as with the water and atmospheric temperatures, indicating that the recovery rate depends on the seasonal variation of the wastewater composition. This study presents new insights into the detection and quantification of Legionella spp. in activated sludge samples and considers seasonal dependencies in analytical results.

Comparison of Recovery Rates of Sudden Sensorineural Hearing Loss by Age Group.

Background: While numerous studies have been conducted on sudden sensorineural hearing loss (SSNHL), research on how treatment outcomes and prognosis vary by age remains insufficient. This study aims to investigate the differences in recovery rates among SSNHL patients divided by age groups. Methods: A retrospective study was conducted on 177 patients diagnosed with SSNHL from 2020 to 2023. The patients were categorized into four age groups: under 20, 30-40, 50-60, and over 70. Recovery rates and associated symptoms were compared across these groups. Results: Significant recovery rates were observed in all age groups except for those over 70 (p = 0.006, p = 0.003, p = 0.009). No significant differences were found in recovery rates based on gender (p > 0.75) or symptoms such as tinnitus, ear fullness, and dizziness (p > 0.05). Conclusions: The study revealed that younger and middle-aged adults showed statistically significant improvements in recovery rates, while the elderly exhibited relatively lower recovery rates.

Separation methods for food protein purification and analysis

The extraction, separation, and purification of dietary proteins from a variety of food sources are crucial for their targeted use in food applications. To achieve this, proteins should be effectively separated from non-protein components such as cell wall structures, polysaccharides, and lipids. Traditional protein purification methods can be time-consuming, highlighting the need for automated, cost-effective, and sustainable alternatives. This comprehensive review critically assesses various protein purification instruments from an analytical perspective, weighing their advantages and disadvantages. The methods under evaluation include ultrafiltration, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), fast protein liquid chromatography (FPLC), high-performance liquid chromatography (HPLC), ultra performance liquid chromatography (UPLC), and microfluidic chips. Among these, FPLC stands out as an affordable and efficient technique that allows for high protein recovery. However, HPLC and UPLC provide faster results but may denature proteins, leading to lower recovery rates. Ultrafiltration is a cost-effective and straightforward method that doesn’t require complex equipment. Microchip-based approaches are emerging as innovative techniques for rapidly analyzing small samples. While SDS-PAGE is user-friendly, it denatures proteins, particularly those linked to other biomolecules. The choice of the most appropriate instrument depends on factors such as cost, energy efficiency, processing time, the characteristics of the target protein, desired outcomes, protein recovery, and resource availability. By critically examining these analytical instruments for protein purification, this review aims to assist researchers and practitioners in selecting the most suitable method for their specific needs, ultimately promoting efficient and successful protein purification endeavors in the field of food science and technology.

Changes in Intramedullary Increased Signal Intensity on Axial T2-weighted MRI After Laminoplasty for Cervical Spondylotic Myelopathy: A 10-year Follow-up Study.

A retrospective study. To investigate whether the preoperative classification and changes in the intramedullary increased signal intensity (ISI) on axial T2-weighted magnetic resonance imaging (MRI) reflect the postoperative functional outcome in patients after laminoplasty for cervical spondylotic myelopathy (CSM). Although patients with CSM exhibit ISI on axial MRI, the association between ISI (preoperative classification and changes) and surgical outcomes has not been investigated. We retrospectively included patients with CSM who underwent MRI preoperatively and at least 10 years postoperatively after laminoplasty between January 2009 and December 2010. According to axial images for the cervical compressive myelopathy (Ax-CCM) system, the ISI on axial images was classified as follows: type 0, normal; type 1, diffuse; type 2, fuzzy focal; and type 3, discrete focal. Functional outcomes, as measured by the Japanese Orthopaedic Association (JOA) score and JOA recovery rate, were evaluated based on the Ax-CCM classification. Forty-three patients were enrolled. The mean follow-up time was 11.0±1.0 years. At the final follow-up, postoperative changes in the type of ISI were observed in 62.8% of patients. The type of ISI improved in 5 patients (11.6%), remained unchanged in 16 patients (37.2%), and worsened in 22 patients (51.2%). Patients with preoperative type 2 ISI had worse postoperative JOA scores and JOA recovery rates than those with other types. A worse ISI type was related to a lower postoperative JOA score and a lower recovery rate at the final follow-up. Type 2 ISI was associated with poor postoperative symptoms and low postoperative function improvement. ISI changed after laminoplasty in 27 patients (62.8%), and worsened ISI was related to poor surgical outcomes.

A novel closed-loop biotechnology for recovery of cobalt from a lithium-ion battery active cathode material.

In recent years, the demand for lithium-ion batteries (LIBs) has been increasing rapidly. Conventional recycling strategies (based on pyro- and hydrometallurgy) are damaging for the environment and more sustainable methods need to be developed. Bioleaching is a promising environmentally friendly approach that uses microorganisms to solubilize metals. However, a bioleaching-based technology has not yet been applied to recover valuable metals from waste LIBs on an industrial scale. A series of experiments was performed to improve metal recovery rates from an active cathode material (LiCoO2; LCO). (i) Direct bioleaching of ≤0.5 % LCO with two prokaryotic acidophilic consortia achieved >80 % Co and 90 % Li extraction. Significantly lower metal recovery rates were obtained at 30 °C than at 45 °C. (ii) In contrast, during direct bioleaching of 3 % LCO with consortia adapted to elevated LCO levels, the 30 °C consortium performed significantly better than the 45 °C consortium, solubilizing 73 and 93 % of the Co and Li, respectively, during one-step bioleaching, and 83 and 99 % of the Co and Li, respectively, during a two-step process. (iii) The adapted 30°C consortium was used for indirect leaching in a low-waste closed-loop system (with 10 % LCO). The process involved generation of sulfuric acid in an acid-generating bioreactor (AGB), 2-3 week leaching of LCO with the biogenic acid (pH 0.9), selective precipitation of Co as hydroxide, and recirculation of the metal-free liquor back into the AGB. In total, 58.2 % Co and 100 % Li were solubilized in seven phases, and >99.9 % of the dissolved Co was recovered after each phase as a high-purity Co hydroxide. Additionally, Co nanoparticles were generated from the obtained Co-rich leachates, using Desulfovibrio alaskensis, and Co electrowinning was optimized as an alternative recovery technique, yielding high recovery rates (91.1 and 73.6% on carbon felt and roughened steel, respectively) from bioleachates that contained significantly lower Co concentrations than industrial hydrometallurgical liquors. The closed-loop system was highly dominated by the mixotrophic archaeon Ferroplasma and sulfur-oxidizing bacteria Acidithiobacillus caldus and Acidithiobacillus thiooxidans. The developed system achieved high metal recovery rates and provided high-purity solid products suitable for a battery supply chain, while minimizing waste production and the inhibitory effects of elevated concentrations of dissolved metals on the leaching prokaryotes. The system is suitable for scale-up applications and has the potential to be adapted to different battery chemistries.

What Is the Trajectory of Recovery in the Early Postoperative Period after the Big 3 Shoulder Surgeries? Comparative Analysis Using 3 Previous Prospective Studies.

(1) Background: The aims of this study were to compare serial changes in outcome measures in the early postoperative period after rotator cuff repair (RCR), anatomical total shoulder replacement (ATSR), and reverse total shoulder replacement (RTSR). (2) Methods: In total, 143 patients who underwent RCR (n = 47), ATSR (n = 46), and RTSR (n = 50) were included. The visual analogue scale (VAS) for pain, the activity of daily living (ADL) score, and the American Shoulder and Elbow Surgeons (ASES) score were completed. (3) Results: At 3 months, the recovery rate for the VAS pain score was 43.7% in the RCR, 89.1% in the ATSR, and 78.4% in RTSR. The recovery rate for the ADL score was 36.3%, 69.5%, and 76.4%. The recovery rate for ASES score was 40.9%, 79.5%, and 77.4%. For all outcome measures, a lower recovery rate was observed in the RCR group than in the ATSR and RTSR groups. At 6 months after surgery, the recovery rate for the VAS pain score was 69.9%, 100%, and 90.3%. The recovery rate for the ADL score was 66.8%, 92.8%, and 91.5%. The recovery rate for the ASES score was 68.7%, 96.5%, and 90.9%. (4) Conclusion: Compared with ATSR and RTSR, a slower recovery rate was observed for RCR, measured to be approximately 40% at 3 months and 70% at 6 months after surgery. Rapid improvement in pain and shoulder function was achieved after ATSR and RTSR, with a recovery rate of over 70% at 3 months and over 90% at 6 months after surgery.

Study on the Occurrence Characteristics of the Remaining Oil in Sandstone Reservoirs with Different Permeability after Polymer Flooding.

After polymer flooding, the heterogeneity between different layers intensifies, forming intricate seepage channels and fluid diversions, which results in decreased circulation efficiency and lower recovery rates, leaving a significant amount of residual oil trapped within the reservoir. Understanding the characteristics of residual oil occurrence is crucial for enhancing oil recovery post-polymer flooding. This study focused on sandstone reservoirs with varying permeability in the Saertu block of the Daqing oilfield. Using cryosectioning and laser scanning confocal microscopy, the occurrence characteristics of the residual oil in these sandstone reservoirs post-polymer flooding were investigated. Additionally, micro-CT and scanning electron microscopy were employed to analyze the impact of the pore structure on the distribution characteristics of the residual oil. The results indicate that laser scanning confocal images reveal that post-polymer flooding, the residual oil in high- and low-permeability sandstone reservoirs predominantly exists in a bound state (average > 47%), mostly as particle-adsorbed oil. In contrast, the residual oil in medium-permeability reservoirs is primarily in a free state (average > 49%), mostly as intergranular-adsorbed oil. In high-permeability sandstone reservoirs, heavy oil components are mainly in a particle-adsorbed form; in medium-permeability sandstone reservoirs, residual oil predominantly consists of heavy components, with most light components occurring in a clustered form; in low-permeability sandstone reservoirs, clustered residual oil exists in a balanced coexistence of light and heavy components, while the heavy components primarily exist in a particle-adsorbed form. Post-polymer flooding, the large pore-throat structure in high-permeability sandstone reservoirs results in effective displacement and less free residual oil; medium-permeability sandstone reservoirs, with medium-large pores and throats, have preferential channels and fine particles blocking the throats, leading to some unswept pores and more free residual oil; low-permeability sandstone reservoirs, with small pores and throats, exhibit weak displacement forces and poor mobility, resulting in more bound residual oil. The distribution and content of clay particles and clay minerals, along with the complex microscopic pore structure, are the main factors causing the differences in the residual oil occurrence states in sandstones with varying permeability.

Analysis of Total Microcystins using LC-MS/MS: Assessment of Pretreatment Technique for MMPB(2-methyl-3-methoxy-4-phenylbutyric acid)

Algal toxin analysis, particularly for microcystin (MC) variants, is commonly performed using LC-MS/MS as the standard method. In 2016, the environmental protection agency (EPA) published method 546 for the determination of total MCs by ELISA. However, the limited availability of commercial algal toxin standards limits the efficacy of the LC-MS/MS method. This study proposes a novel approach using the 2-methyl-3-methoxy-4-phenylbutyric acid (MMPB) structure generated by oxidizing MCs with potassium permanganate and sodium periodate. MMPB is formed through the oxidation of the common (all-S,all-E)-3-amino-9-methoxy-2,6,8-trimethyl-10-phenyldeca-4,6-dienoic acid (ADDA) structure, eliminating the need for specific standard materials for each MC variant. This provides a method for measuring the total MCs. This study focused on optimizing sample pretreatment before oxidation, salt removal as a post-oxidation step, and the quantitative method to establish a comprehensive total MC detection approach applicable to surface water samples. The whole process included pretreatment using a freeze-drying method, purification using liquid-liquid extraction (LLE) for salt removal, and a comparison of quantitative methods using internal standards. Additionally, an evaluation of internal standards was conducted to assess availability during the oxidation process. In this study, an MMPB recovery rate of up to 50% was achieved, with an analysis precision of 14%. According to the results of QAQC, the satisfactory linearity of the calibration curve was a precision and the performance of the method for spiked samples was verified. The MMPB analysis method developed in this study showed relatively lower quantification limits and recovery rates than individual MC analysis methods. We believe these results stem from the inherent sensitivity differences between MCs and MMPB, as well as the complexity of the pre-treatment process centered around the oxidation process.

A novel method of microscale gas migration and production characteristics simulation considering adsorption characteristics

One challenge to the effective development of coalbed methane and shale gas is the complexity of their migration mechanism and production characteristics. Recognizing this, our study has devised an indoor experimental simulation system for production characteristics of coalbed methane or shale gas with a consideration of the effect of adsorbed gas. Firstly, we carried out a theoretically-informed quantitative identification of adsorbed gas, pore-confined gas, and free gas in the production process. Then, the theory was combined with experiments to quantitatively evaluate the production rates of these gases in different occurrence states and their contribution to the yield. This paper presents an application of this new method to coal-seam samples from the Da Ningji County Block. Our research suggests that during the extraction process, a higher gas production rate would lead to a higher pressure in the eventually abandoned formation, and ultimately a lower recovery rate. Specific findings include, firstly, that before extraction, the proportion of adsorbed gas in the samples is 80%, which then gradually increases during the extraction process, eventually reaching 90% at the end of production, with an average contribution of 70% to yield. Secondly, a greater contribution of adsorbed gas to production leads to a higher ultimate recovery rate. Thirdly, the desorption rate shows an upward trend in the stable production phase, gradually decreasing during the depletion production period, but the rate of decrease slows down as the development progresses. Fourthly, a higher desorption rate in the later stage of extraction is positively correlated with a higher ultimate recovery rate. Lastly, the contribution of pore-confined gas and free gas to production exceeds 70% in the early stage before gradually declining as extraction progresses, and no relationship of significance has been found between the production rate and recovery rate in the later stage. It is hoped that our study can provide theoretical underpinning for the optimization of coalbed methane and shale gas development.

Incidence of acute kidney injury and attributive mortality in acute respiratory distress syndrome randomized trials.

The development of acute kidney injury (AKI) after the acute respiratory distress syndrome (ARDS) reduces the chance of organ recovery and survival. The purpose of this study was to examine the AKI rate and attributable mortality in ARDS patients. We performed an individual patient-data analysis including 10 multicenter randomized controlled trials conducted over 20years. We employed a Super Learner ensemble technique, including a time-dependent analysis, to estimate the adjusted risk of AKI. We calculated the mortality attributable to AKI using an inverse probability of treatment weighting estimator integrated with the Super Learner. There were 5148 patients included in this study. The overall incidence of AKI was 43.7% (n = 2251). The adjusted risk of AKI ranged from 38.8% (95% confidence interval [CI], 35.7 to 41.9%) in ARMA, to 55.8% in ROSE (95% CI, 51.9 to 59.6%). 37.1% recovered rapidly from AKI, with a significantly lower recovery rate in recent trials (P < 0.001). The 90-day excess in mortality attributable to AKI was 15.4% (95% CI, 12.8 to 17.9%). It decreased from 25.4% in ARMA (95% CI, 18.7 to 32%), to 11.8% in FACTT (95% CI, 5.5 to 18%) and then remained rather stable over time. The 90-dayoverall excess in mortality attributable to acute kidney disease was 28.4% (95% CI, 25.3 to 31.5%). The incidence of AKI appears to be stable over time in patients with ARDS enrolled in randomized trials. The development of AKI remains a significant contributing factor to mortality. These estimates are essential for designing future clinical trials for AKI prevention or treatment.

Large-eddy simulation study on wave-wake interactions past an offshore wind turbine

Large-eddy simulations (LES) of the flow past an offshore wind turbine under different underlying wave fields have been performed. A one-way coupling between the air and water flows has been realized through a hybrid immersed-boundary/level-set method. The velocity in the water domain is forced with the potential flow solution, while the response of the atmospheric boundary layer to the changes in the sea-surface height (tracked by the level-set equation) is simulated with a LES approach coupled to a rotating actuator disk model to mimic the effect of the wind turbine. A parametric study has been performed varying the wave period and wavelength while keeping the amplitude constant, resulting in different wave age parameters ranging from young developing waves to old swell waves. The wave field has a significant effect on the lower region of the atmospheric boundary layer, slowing down the wind field in proximity of the air-water interface and considerably increasing the local turbulence kinetic energy (TKE). The interaction between the wave evolution and the TKE results in a non-monotonic trend of the wake recovery rate with the wave age, when compared to the baseline value in the wake of a turbine over a flat wall. Both developed waves results in a lower recovery rate, whereas intermediate-age waves present a larger value than the baseline. The increased TKE in the lower layers of the rotor revolution induces an increased fluctuating component in the power production and blade loads. Nevertheless, for the parameters considered in this study, the spectra of the blade loads do not show a clear signature at the wave frequency, but the increased fluctuating component occurs over a broad range of frequencies.

Insights for the strength and ductility of precipitation hardening Al–Li–Sc alloys

Al–Li alloys with high elastic modulus, low density and high specific strength have been widely used in aerospace industry. However, although Al3Li precipitates enhance the strength significantly, the appearance of shearable Al3Li precipitates usually decreases the ductility, leading to the strength-ductility trade-off. In this study, the strategy of microalloying is applied to fabricate an Al–2.46 Li–0.2 Sc (wt.%) alloy with tunable precipitate sizes by heat treatment. This alloy exhibits a good combination of strength and ductility when the precipitate radius is smaller than 6.7 nm or larger than 16.4 nm. The strengthening mechanisms in Al–Li–Sc alloy with different precipitate sizes are quantitatively discussed. With the increase of precipitate size, the dominant precipitation strengthening mechanism changes. The influence of precipitate on ductility is mainly achieved by influencing the dynamic recovery rate of dislocation which can be illustrated by a dislocation-based model. When the precipitate size is relatively small or large, the Al–Li–Sc alloy exhibits a higher ductility owing to a lower dynamic recovery rate. This study provides insight for understanding the strength and ductility in Al–Li–Sc alloy as well as potential theoretical guideline for designing novel high-performance Al–Li based alloys.