High Conversion Rate Research Articles

Small Molecules Effective for Conversion of Lignocellulosic Biomass to Furfural and Its Derivatives

This review summarizes recent applications of small organic and inorganic molecules as catalysts or solvents (chemical hands and scissors) in the production of furfural (FA), 5-(hydroxymethyl)furfural (HMF), and 5-(chloromethyl)furfural (CMF). The possible transformation of lignocellulosic biomass into a one-pot configuration and two-step technique based on the preliminary separation of hemicellulose, lignin and cellulose with the subsequent hydrolysis of separated polysaccharides is compared and discussed. Interestingly, these rather simple and cheap molecules are catalytically active and enable a high rate of conversion of polysaccharides into furfural and its derivatives. Usually, elevated pressure and reaction temperatures above 150 °C are necessary for effective hydrolysis and dehydration of in situ formed monosaccharides; nevertheless, ionic liquids or deep eutectic solvents enable a significant decrease in the reaction temperature and performance of the discussed process at ambient pressure.

Fixed-term contracts and firm productivity: Do workers’ skills and firm conversion rates from fixed-term to permanent contracts matter?

PurposeWe aim to elucidate the relationship between fixed-term employment and firm productivity by examining workers’ skills and considering how firm-level conversion rates influence this relationship.Design/methodology/approachWe use longitudinal employer-employee data between 2011 and 2017 in the Netherlands to estimate a nonlinear regression derived from a production function proposed by Addessi (2014) and Castellani et al. (2020).FindingsThe contribution of fixed-term contracts to firm-level productivity is less than that of permanent contracts. However, this contribution is greater when firms exhibit a high conversion rate from fixed-term to permanent positions. The effect of the conversion rate is more substantial for high-skilled fixed-term workers than for low-skilled ones.Originality/valueOur results suggest the extent to which firms benefit from fixed-term contracts when these are used for screening high-skilled workers for permanent employment.

Facile access to highly functionalized polyacrylamide with ultra-high molecular weight: Multicomponent initiators-based free radical polymerization

We report a novel multicomponent initiators-based copolymerization strategy for synthesizing of acrylamide (AM) and 2-acrylamide-2-methylpropane sulfonic acid (AMPS) copolymers, denoted by P(AM-co-AMPS), with an ultra-high content of AMPS (≥ 50 mol%) and an ultra-high molecular weight (> 107 g/mol), while achieving a high conversion rate of monomer (∼100.0%). The multicomponent initiators contain a redox couple, an azo compound, and a catalyst. Our investigation into the mechanism suggested that the synergistic effect in different rate constant for initiator decomposition between redox and azo initiators was responsible for actualizing ultra-high molecular weight copolymers with high conversion rates of monomer. Moreover, copolymers with 75 mol% and 100 mol% of AMPS were synthesized to verify the advantage of the multicomponent initiators-based strategy, both of which exhibited ultra-high molecular weight and ultra-high monomer conversion rates. This study fills a long-standing gap in research on the polyacrylamide family by providing highly functionalized P(AM-co-AMPS) with an ultra-high molecular weight. Moreover, it reveals how multicomponent initiators reconcile the contradiction between the ultra-high molecular weight and the high conversion rate in copolymerization.

Clinical outcomes of conversion surgery after induction immunochemotherapy for borderline resectable T4 esophageal squamous cell carcinoma

BackgroundThe current treatment strategies for borderline resectable esophageal squamous cell carcinoma remain controversial. This study aimed to evaluate the efficacy and safety of programmed cell death 1 inhibitors combined with chemotherapy, followed by conversion surgery, for borderline resectable esophageal squamous cell carcinoma.MethodsPatients with borderline resectable esophageal squamous cell carcinoma treated with induction immunochemotherapy from January 1, 2020 to July 1, 2023 at our hospital were retrospectively analyzed. The primary study outcome was the R0 resection rate. Secondary study outcomes included progression-free survival (PFS), overall survival (OS), pathological complete remission (pCR) rate, and safety.ResultsForty patients with borderline resectable esophageal squamous cell carcinoma were included in the analysis. The R0 resection rate was 23/40 (57.5%); the conversion success rate was 27/40 (67.5%), and the pCR rate was 11/40 (27.5%). The median follow-up was 23.6 months (95% CI, 19.1–28.2). One-year OS and PFS rates were 77.7% and 71.8%, respectively. The incidence rate of Grade 3–4 adverse events was 10%. There was a significant difference in PFS between patients who underwent surgery and those who did not (P = 0.008, HR: 0.144 95%CI: 0.034–0.606). However, the difference in OS was not significant (P = 0.128, HR: 0.299 95%CI: 0.063–1.416). Patients who achieved clinical downstaging after induction therapy had significantly better OS (P = 0.004 h: 0.110 95%CI: 0.025–0.495) and PFS (P = 0.0016, HR: 0.106 95%CI: 0.026–0.426) compared to those who did not.ConclusionsConversion surgery after induction immunochemotherapy is a promising new strategy with a high conversion rate, inspiring R0 resection rate, significant pathological remission rate, and mild toxicity for borderline resectable esophageal squamous cell carcinoma.

Model-based optimization strategies for direct hydrogenation of carbon dioxide to dimethyl ether

This study discusses model-based optimization strategies for CO2 hydrogenation to dimethyl ether (DME) over a CuZnZr (CZZ) and ferrite (FER) mixed catalyst system in a packed-bed reactor configuration. A two-dimensional axisymmetric, nonisothermal packed-bed reactor model was developed using COMSOL Multiphysics 6.2 software. The model solves two-dimensional (radial and axial) heat and mass transport equations in the packed-bed and integrates intraparticle diffusion and heat transfer in a 1D approach. This powerful feature differs from a traditional porous media approach and takes into account any heat and mass transfer limitations that may exist. Analysis shows that the heat transfer limitations are negligible, but strong internal mass transfer limitations were observed at 10 ≤ WHSV ≤ 90 h−1 on the FER catalyst and at 240 °C. The optimum catalyst composition (i.e., mixing ratio) varies depending on the operating regime. The FER catalyst weight in the mixture can be as low as 5 wt.%, but the ideal composition depends on the internal mass transfer limitation and its relationship with the operating regime (i.e., weight hourly space velocity, temperature). A catalyst composition of 80 wt.% CZZ and 20 wt.% FER was suggested; this composition can provide high CO2 conversion and DME production rates at a wide range of temperatures and flow rates.

A systematic study on Au-PDA@Fe3O4 core-shell catalysts for enhanced catalytic reduction of 4-nitrophenol

The development of nanogold catalysts with high activity and high stability is of great significance for their industrial applications. In this paper, Au-PDA@Fe3O4 catalysts were prepared through the gold sol adsorption method. First, micron-sized magnetic Fe3O4 spheres were synthesized via a solvothermal method, serving as the core to endow the catalyst with excellent recyclability. Subsequently, a layer of polydopamine (PDA) shell was polymerized on the magnetic core surface. By controlling the timing of introducing the gold sol containing Au nanoparticles (NPs), the spatial position of Au NPs within the PDA layer was regulated, leading to a series of magnetic core-shell nano gold catalysts with varying spatial positions of Au. Using the 4-nitrophenol (4-NP) hydrogenation as the probe, the influence of Au spatial position, Au size, and other conditions on the catalytic performance was investigated. Results showed that, in the prepared Au-PDA@Fe3O4-16 catalyst, the Au NPs are encapsulated within the PDA shell and positioned close to the outer layer. This not only provides remarkable stability to the Au NPs but also maintains their proximity to the surface of the PDA shell, allowing easier access of the substrate 4-NP to the Au NPs and conferring good reactivity upon the catalyst. The strong electron metal-support interaction between PDA and Au enables PDA to effectively stabilize Au NPs. The prepared Au-PDA@Fe3O4-16 catalyst exhibits excellent stability, maintaining a high conversion rate of 91% even after 14 cycles of use. Our findings not only deepen the understanding of the catalytic mechanisms involved but also pave the path towards the creation of highly efficient and robust gold-based catalysts, facilitating their widespread utilization in industrial applications.

Constructing Organic-Inorganic Woven Hybrid Membrane for Highly-Selective Catalytic Conversion of Lignin-based Phenolic Molecule to Value-added Products

Addressing the global need for sustainable chemical processes, this study introduces an innovative Woven Hybrid Membrane (WHM) specifically designed for the efficient oxidation of vanillyl alcohol (VAA) to vanillin (VLN). This transformation is crucial for converting lignocellulosic biomass into valuable chemical products, aligning with sustainable development goals. Utilizing a novel catalytic system that combines 2,2,6,6-tetramethylpiperidine 1-oxyl (TMP) and copper on a unique mesh-like structure, the WHM enhances both the economic and environmental viability of the process. This design not only overcomes the limitations of powdered catalysts, which are challenging to recover and reuse, but also promotes high catalytic efficiency and selectivity. By employing oxygen as the oxidant, our system maintains near 100% selectivity for VLN, demonstrating high conversion rates across multiple cycles without significant degradation in performance. Advanced analytical techniques, including electrochemical analysis and Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS), were used to explore the catalyst’s functionality and the reaction mechanism. The results confirm the stability and effectiveness of the WHM, showcasing its potential as a reusable, highly efficient, and environmentally friendly catalyst. This research represents a significant step forward in the field of sustainable industrial chemistry, offering a robust solution for the bio-refinery industry's push towards greener processes.

A Fully Saturated Covalent Organic Framework.

We report the design and synthesis of the first aliphatic covalent organic framework (COF), NUS-119, and its subsequent conversion to NUS-120, marking the first fully saturated COF. NUS-119 is built by imine-linkages exhibiting high crystallinity and porosity, achieved by using a Lewis acid as a reaction modulator to circumvent compatibility issues between the Brønsted acid and the strong basic monomer. The structure was successfully solved using 3D microelectron diffraction (microED) techniques. NUS-119 and NUS-120 demonstrated remarkable catalytic performance in base-catalyzed Knoevenagel condensation reactions, exhibiting high conversion rates, excellent size selectivity, and good recyclability. This work advances the understanding of COF materials and paves the way for future research and applications.

Exploring Alternative Revenue Models for Construction Consulting Firms in the Digital Era

The AEC industry, including construction consulting, is experiencing digitalization through technologies like Building Information Modeling (BIM), impacting firms’ business models. The traditional hourly-based model does not align with shortened project timelines driven by digitalization, design automation, and product-based approaches. This study uses a case study approach and explores and evaluates four selected alternative revenue models (freemium, subscription, out-come-based, and performance-based) for value creation using a digital tool developed by the consulting firm. The freemium model enhances market reach but requires a high conversion rate. The subscription model offers steady recurring revenue and supports client relationships. Out-come-based and performance-based models link payments to client outcomes and performance metrics, fostering efficiency and competitive advantages. The study identified multiple target markets for this tool and emphasized the importance of a portfolio revenue model to meet specific client needs in the digital era. Implementing alternative revenue models aids return on investments and avoids the digitalization paradox. Construction consulting firms must adeptly manage these models’ complexities to address diverse client needs and leverage digital transformation opportunities.

Flecainide acetate inhalation solution for cardioversion of recent-onset, symptomatic atrial fibrillation: results of the phase 3 RESTORE-1 trial

Abstract Introduction Safe, rapid, and efficacious drugs for acute cardioversion of paroxysmal AF (PAF) are needed. In an open-label, Phase 2 study (INSTANT), orally inhaled flecainide was safe and efficacious for acute conversion of PAF to sinus rhythm (SR).[1, 2] Purpose Evaluate the efficacy and safety of flecainide acetate inhalation solution (FlecIH-103) compared to placebo in patients with short-duration, symptomatic, newly diagnosed, or recurrent PAF. Methods RESTORE-1 was a multicentre, randomized, double-blind, placebo-controlled trial in patients with symptomatic PAF (≤48 hours). Patients received FlecIH-103 at an estimated total lung dose of 120 mg or placebo (3:1) over 8 minutes using a breath-actuated nebulizer and were continuously monitored for 90 minutes (observation period), using a single-lead patch ECG electrode. Results The study was stopped prematurely after 55 of the expected 400 patients had been enrolled due to lower-than-expected flecainide peak plasma levels (197.8 ng/mL; 1.85-fold lower than those observed with the same target dose in INSTANT) and modest efficacy. The Data Monitoring Committee confirmed that there were no safety risks. Fifty-four of the enrolled patients (42 active; 12 placebo) were in AF at the start of inhalation. Baseline characteristics were well-balanced between treatment groups; overall mean age was 59.6 years (SD: 13.5) and 31.5% of patients were female. Cardioversion rates during the observation period in the efficacy population (n=51; 39 active, 12 placebo) were 30.8% (95% CI: 18.5-46.5%) in the active group and 0% (95% CI: 0.0-28.2%) in the placebo group (p=0.04; figure 1). In the active group, the median time to conversion from start of inhalation was 12.8 minutes (IQR: 7.8-25.0 minutes), which includes an 8-minute inhalation period. Among the 12 patients whose AF converted to SR, only 1 (8.3%) still had AF-related symptoms compared to 71.8% of patients whose AF did not convert to SR (p<0.001). Time to discharge-eligible status was 1.6h for patients whose AF cardioverted and 3.3h for those whose AF did not (p=0.002; figure 2). The most common adverse events (AEs; ≥8%) occurring more frequently in the active than the placebo group were the following: dyspnoea (14.3%), dysgeusia (14.3%) and cough (11.9%). No serious AEs or cardiovascular events of special interest (hypotension, ventricular tachycardia, bradycardia, sinus pause, atrial flutter 1:1, other arrhythmias) were reported. Conclusions Orally inhaled flecainide, at approximately half of the targeted dose, was modestly effective and safe. The 1.5-fold lower conversion rate observed in this study, compared to the same dose in the INSTANT trial, is consistent with the lower plasma levels of flecainide achieved. Future studies will be designed to improve drug delivery to yield peak plasma levels of flecainide associated with higher conversion rates.

Efficiently controllable synthesis of high performance Na3V2(PO4)2O2F/C hybrid cathode with robust micro-nano architecture

The Na3V2(PO4)2O2F (NVPOF) is synthesized with high conversion rates and uniform morphology, by rapid precipitation of adjusting the pH and temperature. And the effect of reaction temperature on the performance is mainly investigated, and the results show that the rise of reaction temperature is beneficial to the increase of F content and conversion rate. Furthermore, micro morphology can be designed by adjusting temperature and other conditions. Then the NVPOF/C with modification of robust carbon coating is conducted, and the surface structure has been characterized. The optimized NVPOF/C based hybrid exhibits a specific capacity of 116.7 mAh·g−1 at 0.1C and it has long cycle performance (92.0 % retention rate after 200 cycles at 1C) and high capacity at high current density (78 mAh·g−1 at 10C). Consequently, a simple and controllable precipitation method is provided to prepare micro-nano NVPOF/C with high rate performance and indicate the importance of morphology and surface stability control.

Mapping Tropical Dry Forest Gradients in an Andean Region with High Environmental Variability

Tropical Dry Forest (TDF) is one of the most threatened terrestrial environments in the neotropics because of high rates of conversion to agriculture. Despite this high degree of threat, many regions lack detailed maps on the actual extent and boundaries of their TDFs, which is fundamental information for their conservation. We developed a methodological framework to map TDF at 10 m in regions where they grade into other forest types. The approach uses climate variables, altitude, soil properties, and remote sensing data (multispectral and SAR − Synthetic Aperture Radar-SAR imagery) to predict TDF in the Department of Caldas, Colombia. Accuracy of the resulting map was confirmed with field observations (Overall Accuracy = 0.88, Kappa = 0.73, Area Under the Receiver Operating Characteristics Curve = 0.87, and True Skill Statistic = 0.73). We estimated ∼ 54 km2 of TDF, which represents 9.2 % of its potential area of occurrence in the study area. TDF gradually transitions to Tropical Moist Forest (TMF) from two main low altitude river valleys to higher altitudes in the Andes Mountains. With modification, our methods could be applied for mapping TDF in other tropical regions.

Exploring the efficacy of Re-Ni embedded KIT-6/H-Mor catalysts for renewable energy – A comprehensive experimental and theoretical (DFT) exploration

The global market for n-propyl benzene value is projected to reach $30.47 billion by 2030, with a CAGR of 4.3% from 2023 to 2030. This market analysis identifies diverse applications for propyl benzene, spanning the petroleum industry, industrial chemicals, automotive sector, and more. The research introduces eugenol, a compound derived from lignin, as a model compound for bio-oil to n-propyl benzene (bio-fuel analogs) production. A novel Re-Ni/KIT-6-H-Mordenite catalyst is developed for efficient hydrodeoxygenation of eugenol, showcasing high conversion rates and selectivity under moderate temperatures. Comprehensive characterization techniques and theoretical calculations highlight the synergistic interaction between Re and Ni metals. The catalyst’s reusability and successful application for bio-fuel production under atmospheric conditions further validate its potential. This study pioneers the exploration of Re-Ni bimetallic catalysts for HDO of lignin-derived compounds, offering valuable insights into sustainable bio-fuel development.

Preparation of nano Cu-Mo2C interface supported on ordered mesoporous biochar of ultrahigh surface area for reverse water gas shift reaction

High conversion rate and selectivity are challenges for CO2 utilization through catalytic reverse water gas shift (RWGS) reaction. Herein, a novel mesoporous biochar (MB) supported Cu-Mo2C nano-interface was prepared by consecutive physical activation of coconut shells followed by carbothermal hydrogen reduction of bimetal. As compared with traditional carbon materials, this MB exhibited ultra-high specific surface area (2693 m2 g–1) and mesopore volume of mesopore (0.81 cm3 g–1) with a narrow distribution (2–5 nm), responsible for the high dispersion of binary Cu-Mo2C sites, CO2 adsorption and mass transfer in the reaction system. Moderate carbothermal reduction led to the sufficient reduction of Mo ion with carbon matrix of MB and dispersive growth of nano Cu-Mo2C binary sites (~ 6.1 nm) on the surface of MB. Cu+ species were formed from Cu0 via electron transfer and showed high dispersion with simultaneous boosted bimetal loading due to the strong interaction between nano Mo2C and Cu. These were advantageous to the intrinsic activity and stability of the Cu-Mo2C binary sites and their accessibility to the reactant molecules. Under the RWGS reaction conditions of 500 °C, atmospheric pressure, and 300,000 ml/g/h gas hour space velocity, the CO2 conversion rate over Cu-Mo2C/MB reached 27.74 × 10–5 molCO2/gcat/s at very low H2 partial pressure, which was more than twice that over traditional carbon supported Cu-Mo2C catalysts. In addition, this catalyst exhibited 99.08% CO selectivity and high stability for more than 50 h without a decrease in activity and selectivity. This study offers a new development strategy and a promising candidate for industrial RWGS.Graphical

Development and performance evaluation of a novel solar mid-and-low temperature receiver/reactor with packed metal foam

Solar-driven hydrogen production from methanol decomposition (MD) is an important method of storing solar energy as clean fuels and improving the solar energy utilization efficiency. Catalyst preparation is one of the key steps, but conventional Cu-ZnO-Al2O3 particle catalysts lead to uneven reactor temperature, reducing the efficient conversion of solar energy into fuels. To alleviate this challenge, a monolithic catalyst utilizing packed foamy copper as a carrier is developed with exceptional thermal and mass transfer properties. The experimental results validate its excellent performance in hydrogen production using MD. The absolute conversion increases by an average of 12.11 % at 250 °C and further by 14.43 % at 270 °C compared to the particle catalyst. Based on these findings, a novel solar reactor is proposed, and a multi-field coupling model is built. The comparative results verify the performance advantage of the developed solar thermochemical receiver/reactor with packed metal foam-based catalyst. It maintains high conversion rates and solar-to-fuel energy efficiency, while alleviating overheating problems caused by traditional particle catalysts. Under the design conditions, the new reactor significantly improves the absolute conversion of methanol and the energy efficiency of solar-to-fuel conversion by 4.57 % and 3.00 %, respectively, resulting in 92.64 % and 67.56 %. This study provides a theoretical basis and technical solution for more stable and efficient use of mid-and-low temperature solar energy.

Preparation and properties of polyamide elastomers by a new synthesis route of Michael addition reaction

At present, the mainstream industrial synthesis method of polyamide is still bulk fusion polymerization, which is not in line with the concept of green synthesis because of the high threshold of reaction conditions and large energy consumption. Based on this, a new synthesis route of polyamide elastomer was studied in this paper. By synthesizing the end-functionalized long carbon chain diacrylamide (DDA) containing amide bonds, the synthesis mechanism was made by the thiol double bond Michael addition reaction. A series of polyamide elastomers with different ratios of hard and soft segments were synthesized by using dimercaptan chain extenders with different molecular weights. The results showed that the new synthesis route successfully prepared DDA and polyamide elastomers. The mechanical properties of the products were excellent, and the strain rate could reach 383 %. Tensile strength up to 23.08 MPa. The synthesis route has the characteristics of simple reaction process, mild reaction conditions and high reaction conversion rate. It provides theoretical guidance for the new synthesis route of polyamide elastomer.

Optimization control strategy for diesel urea-selective catalytic reduction (SCR) urea injection based on the interior point method (IP) + higher order SCR model

In order to ensure that the NOx and NH3 emissions of diesel engines comply with the Euro VII emission standards, this paper optimizes the urea injection using a SCR model combined with the interior point method. First, the equations of the higher-order SCR model were simplified by the variable substitution method and the line method and solved by the backward difference formula to improve computational accuracy. The Levenberg-Marquardt algorithm was used to calibrate the chemical reaction rate parameters to optimize model performance. Second, an optimization cost function was designed to optimize the upstream NH3 concentration in combination with the interior point method and the higher-order SCR model to meet the requirements of Euro VII emission standards. Third, the model effect was verified by performing WHTC hot-start testing on an engine complying with the National VI emission standard. The results show that the average error between the measured NOx concentration and the calculated is 1.49 ppm, which verifies the high accuracy of the model. Finally, the effects of the interior point method, NSGA-II, and MOPSO algorithms in optimizing the upstream NH3 concentration were compared. The results showed that the interior point method outperformed the other algorithms in terms of optimization time and effect, with an optimization time of 149 s, a NOx conversion rate of 97.36 %, and an average downstream NH3 concentration of 4.65 ppm. This achieved a high NOx conversion rate and low NH3 slip in accordance with the requirements of the Euro VII regulation.

Use of embedding immobilized biofillers to improve hydrolysis acidification efficiency in domestic wastewater treatment

This study evaluated the effectiveness of embedding immobilization technology in wastewater treatment and its capacity to enhance the hydrolysis acidification process. Based on this technology, a stable anaerobic environment has been maintained. Results showed that the rates of dissolved organic nitrogen (DON) and dissolved organic phosphorus (DOP) conversion both exceeded 98 % under short hydraulic retention time (HRT = 2h) and ambient temperature. Notably, acetic acid and propionic acid comprised up to 90.9 % of the total volatile fatty acids in the effluent, providing suitable carbon sources for downstream denitrification. 16S rRNA gene sequencing indicated that biofillers effectively enriched and retained functional bacteria, causing norank_Anaerolineaceae (11.6 %-29.7 %) and norank_Bacteroidetes_vadinHA17 (10.8 %-14.9 %) as the dominant genera in the reactor, which were crucial for refractory organic matter degradation. Immobilized biofillers effectively improved wastewater biodegradability, supporting a stable microbial community with high DON and DOP conversion rates as well as increased VFA accumulation.

Room-Temperature Single-Phase Synthesis of Semiconducting Metal-Covalent Organic Frameworks With Microenvironment-Tuned Photocatalytic Efficiency.

In order to improve the solubility of metallated monomers and product crystallinity, metal-covalent organic frameworks (MCOFs) are commonly prepared via high-temperature sol-vothermal synthesis. However, it hampers the direct extraction of crystallization evolution information. Exploring facile room-temperature strategies for both synthesizing MCOFs and exploiting the crystallinity mechanism is extremely desired. Herein, by a novel single-phase synthetic strategy, three MCOFs with different microstructure is rapidly prepared based on the Schiff base reaction between planarity-tunable C3v monomers and metallated monomers at room temperature. Based on detailed time-dependent experiments and theoretical calculations, it is found that there is a planarity-tuned and competitive growth relationship between disordered structures and crystal nucleus for the first time. The high planarity of monomers boosts the formation of crystal nucleus and rapid growth, suppressing the forming of amorphous structures. In addition, the microenvironment effect on selective photocatalytic coupling of benzylamine (BA) is investigated. The strong donor-acceptor (D-A) MCOF exhibits efficient photocatalytic activity with a high conversion rate of 99% and high selectivity of 99% in 5h under the 520nm light irradiation. This work opens a new pathway to scalable and efficient synthesis of highly crystalline MCOFs.

Measurable residual disease as predictor of post–day +100 relapses after allografting in adult AML

AbstractMeasurable residual disease (MRD) by multiparametric flow cytometry (MFC) before allogeneic hematopoietic cell transplantation (HCT) identifies patients at high risk of acute myeloid leukemia (AML) relapse, often occurring early after allografting. To examine the role of MFC MRD testing to predict later relapses, we examined 935 adults with AML or myelodysplastic neoplasm/AML transplanted in first or second morphologic remission who underwent bone marrow restaging studies between day 70 and 100 after HCT and were alive and without relapse by day +100. Of 935 adults, 136 (15%) had MRD before HCT, whereas only 11 (1%) had MRD at day +70 to +100. In day +100 landmark analyses, pre-HCT and day +70 to +100 MFC MRD were both associated with relapse (both P < .001), relapse-free survival (RFS; both P < .001) overall survival (OS; both P < .001), and, for post-HCT MRD, nonrelapse mortality (P = .001) after multivariable adjustment. Importantly, although 126/136 patients (92%) with MRD before HCT tested negative for MRD at day +70 to +100, their outcomes were inferior to those without MRD before HCT and at day +70 to +100, with 3-year relapse risk of 40% vs 15% (P < .001), 3-year RFS of 50% vs 72% (P < .001), and 3-year OS of 56% vs 76% (P < .001), whereas 3-year nonrelapse mortality estimates were similar (P = .53). Thus, despite high MRD conversion rates, outcomes MRD positive/MRD negative (MRDneg) patients are inferior to those of MRDneg/MRDneg patients, suggesting all patients with pre-HCT MRD should be considered for preemptive therapies after allografting.