Successful Transfer Research Articles

(Invited) Enhancing the Performance of Microbial Fuel Cells Via Metabolic Engineering of Escherichia coli for Phenazine Production

Establishing an efficient and successful extracellular electron transfer (EET) between microorganisms and electrode surfaces plays a critical role in the design, development, and application of mediated microbial electrochemical technologies, such as microbial fuel cells (MFCs). Most microbial-based systems require the use of artificial, redox-active mediator systems in order to facilitate and/or increase electron transfer. Our previous work established an exogenous phenazine-based library as a mediator system to enable electron transfer from the model microorganism Escherichia coli. However, the addition of exogenous mediators to a microbial electrochemical system has certain limiting downsides, specifically with regard to mediator toxicity to cells and increased operational expenses. Herein, we demonstrate the metabolic and genetic engineering of E. coli to self-generate phenazine metabolites endogenously by introducing the phenazine biosynthetic pathway from Pseudomonas aeruginosa into E. coli. This pathway consists of a seven-gene phenazine biosynthetic cluster phzA-G responsible for the synthesis of phenazine-1-carboxylic acid (PCA) and two phenazine accessory genes phzM and phzS to produce pyocyanin (PYO). We present the characterization of the engineered E. coli cells via electrochemical measurements, RNA sequencing, and microscopy imaging. Finally, the engineered E. coli cells were used for the design of a microbial fuel cell with enhanced performances, demonstrating a maximum power density increase from 305 mW/m2 with non-engineered E. coli cells to 1555 mW/m2 with the genetically engineered, phenazine-producing E. coli. Our results indicate that introducing a heterologous electron shuttle into E. coli can be an efficient approach to establishing efficacious mediation in living bioelectrochemical systems and improving the performance of MFCs.

(Invited) Stereoselective Synthesis of Molecular Nanographenes

The precise control of stereogenic elements in chemical structures has always been a higly demanding synthetic task.1 In this regard, most of the currently available asymmetric methods require the presence of a heteroatom in the starting substrates that serves as an anchoring point for the successful transfer of chiral information. This eventually emerges, typically, in the form of a new stereogenic centre while the heteroatom remains in the product. This general procedure could account for the lack of stereoselective protocols in all-carbon atom compounds.2,3 Actually, optically active nanographenes have so far been obtained only by either top-down or bottom-up racemic syntheses, followed by time consuming chiral chromatographic separations.4-6 In this presentation, we will introduce a general overview on the efforts carried out in our group in the search for stereoselectivity to introduce and extend stereogenic elements into polyaromatic sp2 carbon-based molecular nanographenes. Acknowledgements The author acknowledge support from the MICIN of Spain (project: PID2020-114653RB-I00) and the European Research Council (ERC) Synergy Grant “TOMATTO” (Project 951224). References H. Kuang, C. Xu, Z. Tang, “Emerging Chiral Materials”, Adv. Mater. 2020, 32, e2005110.M. Rickhaus, M. Mayor, M. Juricek, “Strain-induced helical chirality in polyaromatic systems”, Chem. Soc. Rev. 2016, 45, 1542-1556.J. M. Fernández-García, P. Izquierdo-Garcia, M. Buendia, S. Filippone, N. Martín, “Synthetic chiral molecular nanographenes: the key figure of the racemization barrier”, Chem. Commun. 2022, 58, 2634-2645.P. J. Evans, J. Ouyang, L. Favereau, J. Crassous, I. Fernández, J. Perles-Hernáez, N. Martín "Synthesis of a Helical Bilayer Nanographene" Angew. Chem. Int. Ed. 2018, 57, 6774 –6779.P. Izquierdo-García, J. M. Fernández-García, I. Fernández, J. Perles, N. Martín, “Helically Arranged Chiral Molecular Nanographenes", J. Am. Chem. Soc., 2021, 143, 11864−11870.M. Vázquez-Nakagawa, L. Rodríguez-Pérez, N. Martín, M. A. Herránz, “Supramolecular Assembly of Edge Functionalized Top-Down Chiral Graphene Quantum Dots”, Angew. Chem. Int. Ed. 2022, 61, e202211365.

Chemicals-CO2 mechanisms of inhibiting steam heat transfer and enhancing oil film strip: Steam flow through the wall-adhering oil film surface in porous medium

The CO2 and Sodium Dodecyl Sulfate (SDS) assisted steam flooding technology was an effective approach addressed the persistent issues that have hindered the stable development of high-viscosity cold oil through steam injection. However, in the process of steam flow through porous media, the synergistic influence of the oil film adsorbed in near wellbore porous media, and the CO2-SDS on steam heat transfer has not been investigated. Steam heat transfer is the key factors affecting heavy oil recovery. The primary objective of this study was to research the effect of CO2-SDS on steam heat transfer and oil film stripping by designing experiments. The study results demonstrated that in the initial stage of displacement, the heat transfer resistance between the steam and the porous medium was increased by the oil film adsorbed in near wellbore area. In additional, the condensation mode of the steam was altered from bead condensing to film condensing by the composite thermal fluid flooding, preventing the steam heat dissipation near wellbore area and transferring more thermal to the long-distance area. At the later stage of displacement, the interfacial tension between oil-water and oil-gas was reduced by CO2-SDS, improving the fluidity of oil and providing the seepage channel for steam, and increasing the steam thermal sweep range. Compared to the sandpack experiment of steam flooding, the temperature at the output end of the sandpack model increased from 69.8 °C to 88.7 °C, indicating an expansion of the steam heat sweep range and successful long-distance heat transfer during composite thermal fluid flooding. In the process of composite thermal fluid flooding, the maximum displacement pressure difference increased from 2.28 MPa to 3.07 MPa, and the maximum oil recovery rate increased from 2.48 g/mL to 2.81 g/mL. The peak of the high production period was raised, resulting in a 40.97% to 51.86% increase in recovery rates.

Photoinduced Nitroarenes as Versatile Anaerobic Oxidants for Accessing Carbonyl and Imine Derivatives.

Herein, we report a protocol for the anaerobic oxidation of alcohols, amines, aldehydes, and imines promoted by photoexcited nitroarenes. Mechanistic studies support the idea that photoexcited nitroarenes undergo double hydrogen atom transfer (HAT) steps with alcohols and amines to provide the respective ketone and imine products. In the presence of aldehydes and imines, successive HAT and oxygen atom transfer (OAT) events occur to yield carboxylic acids and amides, respectively. This transformation is amenable to a continuous-photoflow setup, which led to reduced reaction times.

Optimization and reactor-scale production of plant growth regulators by Pleurotus eryngii.

The aims of the this study are to select the best cultivation type for plant growth regulator (PGR) production, to optimize PGR production with statistical experimental design, and to calculate bioprocess parameters and yield factors during PGR production by P. eryngii in flask and reactor scales. Submerged fermentation was the best cultivation type with 4438.67 ± 37.14, 436.95 ± 27.31, and 54.32 ± 3.21mg/L of GA3, ABA, and IAA production values, respectively. The Plackett-Burman and Box-Behnken designs were used to determine effective culture parameters and interactive effects of the selected culture parameters on PGR production by Pleurotus eryngii under submerged fermentation. The statistical model is valid for predicting PGR production by P. eryngii. After these studies, maximum PGR production (7926.17 ± 334.09, 634.92 ± 12.15, and 55.41 ± 4.38mg/L for GA3, ABA, and IAA, respectively) was reached on the 18th day of fermentation under optimized conditions. The optimum formula was 50g/L fructose, 3g/L NaNO3, and 1.5g/L KH2PO4, 1mg/L thiamine, incubation temperature 25°C, initial medium pH 7.0, and an agitation speed of 150rpm. The kinetics of PGR production was investigated in batch cultivation under 3-L stirred tank reactor conditions. Concentrations of GA3, ABA, and IAA of 10,545.00 ± 527.25, 872.32 ± 21.81, and 60.48 ± 3.48mg/L were obtained at the reactor scale which were 4.1, 3.4, and 2.3 times higher than the initial screening values. The specific growth rate (µ), the volumetric (rp) and specific (Qp) PGR production rates, 486.11mg/L/day and 107.43mg/g biomass/day for GA3, confirmed the successful transfer of optimized conditions to the reactor scale. In the presented study, PGR production of P. eryngii is reported for the first time.

Is the corpus uteri a suitable site for embryo transfer in the pig?

Numerous attempts to establish a practicable means of non-surgical embryo transfer in pigs were unsuccessful until instruments were developed to permit deposition of embryos deep inside a uterine horn. Recently, however, successful non-surgical transfer of embryos to the uterine body in non-sedated recipients has been reported. These reports have prompted us to present data from a study that addresses the question of whether the commonly experienced low pregnancy rates following transfers to the corpus uteri results from the inability of endometrial receptors to recognize the presence of embryos or to the prevailing unfavorable local conditions. Blastocysts were transferred to the corpus uteri of recipients in which maintenance of pregnancy was assured by the transfer of additional embryos to the tip of a uterine horn. Embryos from pigmented and unpigmented donors were used to be able to differentiate between fetuses from embryos transferred to different sites. Fewer fetuses developed from embryos transferred to the corpus uteri than from embryos transferred to the uterine horn. This leads to the conclusion that prolonged retention of blastcysts in the uterine body under conditions inappropriate for their stage of development is responsible for an unsatisfactory pregnancy rate.

Addressing illegal practices: intergenerational transfer and creative engagement as a way to compensate boomerang effects

IntroductionThis study investigates the effectiveness of using an educational comic book to facilitate the intergenerational transfer of knowledge and intentions concerning dynamite fishing in Borneo, Malaysia. The aim is to explore how children can influence their parents' understanding of the issue and their willingness to address it within the community. Additionally, the research examines unintended reactions within the participant groups.MethodsThe study employed a controlled experimental design with two groups: a treatment group exposed to the educational comic book and a control group without this intervention. Participants were families residing in communities where dynamite fishing is still practiced. Data collection included pre- and post-intervention surveys and follow-up measurements to assess short-term and long-term effects on knowledge and intentions.ResultsThe findings revealed a successful intergenerational transfer of knowledge from children to parents, evident both in the short and long term. Furthermore, the intergenerational transfer of intentions demonstrated a two-fold pattern. The intention to discuss the dynamite fishing problem within the community was transferred from children to their parents at the second measurement point, highlighting the time required for the development of new intentions. A boomerang effect was observed for the intention to cease dynamite fishing among individuals reliant on fishing for their livelihood. This rebound effect was solely observed in the control group but was effectively mitigated in the treatment group, where engagement with the comic book influenced positive outcomes.DiscussionThe study's results underscore the power of intergenerational transfer of knowledge and intentions from younger to older generations, facilitated by educational comic books as a communication tool for addressing environmental issues. Moreover, a boomerang effect seen in the control group highlights the complexity of behavior change in economically motivated practices like dynamite fishing. Engaging interventions, such as educational materials, can play a crucial role in curbing these behaviors. Furthermore, the study emphasizes the necessity of carefully monitoring unintended reactions within participant groups, particularly in research related to sensitive topics.

Transition Readiness Assessment Questionnaire: Skill gaps and psychosocial predictors of transition readiness among adolescents and young adults with chronic medical conditions.

Transferring from paediatric to adult care can be challenging. Adolescents and young adults (AYAs) with chronic health conditions need to develop a specific set of skills to ensure lifelong medical follow-up due to the chronicity of their condition. The Transition Readiness Assessment Questionnaire-French version (TRAQ-FR) is a 19-item questionnaire measuring such skills. The aims of the study were to (1) describe participant characteristics and (2) identify constructs related to, and predictors of, having learned domain-specific transition readiness skills. Participants included 216 AYAs aged 14-20 years (M = 15.93; SD = 1.35; 54.1% male) recruited from five outpatient clinics in a Canadian tertiary hospital. AYAs completed the TRAQ-FR, the Pediatric Quality of Life Inventory 4.0 (PedsQL) and a sociodemographic questionnaire. Descriptive, bivariate and binary logistic regression analyses were conducted. Overall, participants reported significantly higher scores on the Talking with Providers, Managing Daily Activities and Managing Medications subscales than on the Appointment Keeping and Tracking Health Issues subscales (F[41075] = 168.970, p < .001). At the item level, median scores (on a 5-point Likert scale) suggest that AYAs had begun practising five of the 19 skills (median scores ≥4; 'Yes, I have started doing this'), while a median score of 1 ('No, I don't know how') was found for one item ('Do you get financial help with school or work?'). At the subscale level, TRAQ-FR skills and skill gaps were related to AYAs' age, sex and PedsQL scores (ps < .05). Older and female AYAs were more likely to have begun practising specific TRAQ-FR subscale skills. Better psychosocial functioning was also related to having learned specific transition readiness skills. AYAs show several gaps in transition readiness. Targeted intervention in transition readiness skill development could take into account AYAs' age, sex and psychosocial functioning for a successful transfer to adult care.

Factors That Enhance and Hinder the Retention and Transfer of Online Pre-Clinical Skills Training to Facilitate Blended Learning.

During the SARS-CoV-2 pandemic, various online instructional strategies in clinical skills training were piloted. The sudden transition to the remote platform circumvented the rigorous planning associated with curriculum reform. This study aimed to explore students' and tutors' perceptions of factors that promoted or hindered successful learning transfer and to propose a blended conceptual model to guide affective, cognitive, and psychomotor clinical skills training in the pre-clinical phase of medical education. A mixed-method quasi-experimental study assessed third-year students' transfer of clinical skills and knowledge following online learning in 2021. Students and their tutors completed online surveys that included open and closed-ended questions regarding factors influencing their experience of the adapted teaching methods. Descriptive statistical analysis was used for the quantitative data. Qualitative responses were thematically analyzed. One hundred fourteen students (48%) and seven tutors (100%) responded to the surveys. The questionnaires' internal consistency and construct validity were determined using Cronbach's α-Coefficient. There was an overall positive response (86%) to the acceptability of the online platform in clinical skills training. Using online simulations with targeted onsite practice was reported as effective in clinical skills training. Tutors perceived students as well-prepared for the skills laboratory. Five emergent themes, qualified by a linear model of asynchronous and synchronous online and onsite teaching with the evaluation of the instructional design and institutional support, informed the proposed blended learning guide for clinical skills training in the pre-clinical phase. Blended clinical skills learning that included the flipped classroom concept was well-accepted. Virtual patients proved a convenient cognitive preparation tool for skills training and potentially optimized teaching delivery. The study found that the adapted teaching frameworks incorporating an online clinical skills component into a modified onsite curriculum augmented learners' ability to transfer knowledge to the clinical skills laboratory. An integrated five-step blended model is proposed for future interventions.

Perceived Barriers to Transfer that Rural Community College Students Experience when Transitioning to a Regional University

ABSTRACT This exploratory, phenomenological study explored how rural community college students perceived barriers from the transfer process and the support services they had needed for their successful transfers to 4-year universities in rural Texas. Transfer shock and transfer student capital were the two frameworks employed to model sampled students’ transfer experiences and the barriers to transfer. Data sourced from questionnaires and one-on-one interviews with 15 representative transfer students illuminated major barriers in academic advising and financial aid, which mirror the experiences of urban transfer students. Results also indicate that sampled students wanted more remote options and infrastructure (e.g., internet) for learning in rural areas. Most striking among the study’s findings was the nature of personal barriers experienced among the nonwhite students sampled, their unique challenges suggested there may be demographic differences among minoritized sub-groups in rural areas as they held different types of transfer capital and experienced transfer shock differently.

Virtual reality: a promising instrument to promote sail education.

Sailing has gained an increasing attention among children and adolescents in China, which raised a strong need for sail courses through physical education (PE). However, challenges in teaching practice arise with rapid development of the sport. In the current study, we proposed a perspective that virtual reality (VR) technology makes high-quality sail education accessible for students. Critical analysis summarized the prominent features that enhance sail education, including immersive experience, interactive learning, the first-person view, and practice under well-controlled conditions. Further, research on VR sport training indicated successful transfer from virtual environment to real situation. Specifically, significant improvement in skill performance and tactical behaviors were identified, which was attributed to the enhanced perception-action coupling after VR training. Additionally, VR-based coding programs provide students with affordances of designing the virtual environment. The content design education promotes comprehension and application of knowledge and theories when students develop the simulated environment with a high level of presence. Therefore, VR technology is a promising instrument to meet the increasing demand on sail education. While VR enriches educational resources for a large class size, the interdisciplinary feature of VR-based sail course can attract students with different study interests and backgrounds to the class.

Dynamics of Microbiome Changes in the Endometrium and Uterine Cervix during Embryo Implantation: A Comparative Analysis.

BACKGROUND The microbiome is the collection of all micro-organisms and their genes, which naturally live in and on the body. The cervical and endometrial bacterial microbiome has previously been reported to affect fertility and influence the outcomes of assisted reproductive therapy (ART), including embryo transfer. This study aimed to evaluate the cervical and endometrial bacterial microbiome in 177 women treated for infertility before, during, and after embryo implantation, and the outcomes. MATERIAL AND METHODS Cervical and endometrial swabs were collected from 177 women diagnosed with infertility at 3 time points: (1) during the initial examination, (2) during implantation, (3) 10-14 days after implantation. Next-generation sequencing (NGS) was used to analyze the bacterial microbiome. Taxonomic identification was performed with the Usearch algorithm. RESULTS There was a significant change in the number of patients with Escherichia coli depending on the collection time. For the first swab collection, there were significant negative relationships between the percentage of Gardnerella vaginalis and Lactobacillus spp. For the second collection, there was a negative relationship between Lactobacillus helveticus and Lactobacillus jensenii. For the third collection, negative relationships were found between Escherichia coli and Lactobacillus spp. A similar distribution of the bacterial microbiome was observed in all 3 swab collections. CONCLUSIONS Lactobacillus spp. were the main bacteria identified in the cervix and endometrium, present before, during, and after successful embryo transfer. E. coli and G. vaginalis reduced the protective effect of Lactobacilli before, during, and after embryo transfer.

Formation flying orbits and GNC design in binary asteroid systems

Formation flying represents a promising opportunity for next space missions, due to its benefits in cost saving, redundancy and fault tolerance given by multiple small and cheap space segments exploitation, with comparable performance of a single, large monolithic spacecraft. That is even more relevant in asteroid exploration, as the harsh environment poses great risks to the probes survival. The low, irregular gravity field, the poor knowledge of shape and composition, and the possible presence of floating particles in the surroundings suggest adopting a low-risk strategy for the exploration of these bodies, delegating proximity operations to multiple nanosatellites, while keeping the main spacecraft at safe distance. As a downside, multiple cooperating spacecraft imply advanced capabilities in accurately reconstructing the relative positions and displacements and in fixing reconfiguration manoeuvres. Moreover, whenever relative distance is very close, agents’ guidance and control shall be autonomously computed by the spacecraft, as promptness of commands is not ensured relying on ground segment only. The partially unknown environment exacerbates this issue, demanding navigation and control schemes capable of withstanding potentially large uncertainties in the dynamics. If a binary system is considered, the multiple gravitational sources complicate even more the setup of the formation, requiring an accurate search and selection of operative orbits. This study will be thus defined by three different steps. First the search and development of suitable trajectories to host a reconfigurable satellite formation is carried out. Then the design of a Model Predictive on-board guidance and control law is performed to assess the capability of the spacecraft to execute successful reconfiguration transfers relying on a simplified dynamical model (namely the Circular Restricted Three-Body Problem). At the end the navigation error requirements are derived, in order to ensure the feasibility of the guidance and control scheme. Inspired by the Hera mission, this study explores the aforementioned aspects of the design of a formation for the exploration of the Didymos binary asteroid system, which comprises many complications but also challenges for many other future missions to fly in unexplored environments.

Mid-infrared spectroscopy for large-scale phenotyping of bovine colostrum gross composition and immunoglobulin concentration

Immunoglobulin G is the fundamental antibody for acquisition of passive transfer of immunity in ruminant newborns. Colostrum, in fact, must be administered as soon as possible after birth to ensure a successful transfer of IgG from the dam to the calf. Assessment of colostrum Ig concentration and gross composition via gold standards is expensive, time consuming, and hardly implementable for large-scale investigations. Therefore, in the present study we evaluated the predictive ability of mid-infrared spectroscopy (MIRS) as an indirect determination method. A total of 714 colostrum samples collected within 6 h from parturition from Italian Holstein cows, 30% primiparous and 70% pluriparous, were scanned using a benchtop spectrometer after dilution in pure water. The prediction models were developed by correlating spectral information with the reference measurements: IgG concentration (93.54 ± 33.87 g/L), total Ig concentrations (102.82 ± 35.04 g/L), and content of protein (14.71 ± 3.51%), fat (4.61 ± 3.04%), and lactose (2.36 ± 0.51 mg/100 mg). We found a good to excellent performance in prediction of colostrum IgG concentration and traditional composition traits in cross-validation (R2CV ≥ 0.92) and a promising and good predictive ability in external validation with R2V equal to 0.84, 0.89, and 0.74 for IgG, protein, and fat, respectively. In the case of IgG and protein content, for example, the coefficient of determination in external validation was greater than 0.84. The other Ig fractions, A and M, presented insufficient prediction accuracy likely due to their extremely low concentration compared with IgG (4.56 and 5.06 g/L vs. 93.54 g/L). The discriminant ability of MIRS-predicted IgG and protein content was outstanding when trying to classify samples according to the quality level (i.e., low vs. high concentration of IgG). In particular, the cut-off that better discriminate low- from high-quality colostrum was 75.40 g/L in the case of the MIRS-predicted IgG and 13.32% for the MIRS-predicted protein content. Therefore, MIRS is proposed as a rapid and cheap tool for large-scale punctual IgG, protein, and lactose quantification and for the screening of low-quality samples. From a practical perspective, there is the possibility to install colostrum models in the MIRS benchtop machineries already present in laboratories in charge of official milk testing. Colostrum phenotypes collected on an individual basis will be useful to breeders for the definition of specific selection strategies and to farmers for management scopes. Finally, our findings may be relevant for other stakeholders, given the fact that colostrum is an emerging ingredient for the animal and human food and pharmaceutical industry.

Cross‐Border Knowledge Transfer in the Digital Age: The Final Curtain Call for Long‐Term International Assignments?

AbstractDigital technology has altered how multinational companies (MNCs) transfer knowledge across borders. With digital communication media (DCM), knowledge exchange can become more cost‐effective, thereby reducing the need for face‐to‐face exchange. DCM's influence on long‐term international assignment management for cross‐border knowledge transfer remains unclear. Based on 71 interviews with German human resource (HR) managers and subsidiary HR counterparts, we investigated the use of DCM to exchange knowledge across country borders. Exploring these conditions alongside HR managers’ unique perspective on global mobility management prior to and during the global COVID‐19 pandemic, we present two major findings. First, 12 facilitating conditions are necessary for digital knowledge transfer across borders to be accepted as a valuable alternative to long‐term international assignments. Second, we identified individual connections between facilitating conditions and found that five conditions decreased in relevance, while the remaining seven became core aspects of successful digital knowledge transfer during COVID‐19 and possibly beyond.

Nanostructures, Linear Rheological Responses, and Tunable Mechanical Properties of Microphase-Separated Cellulose-graft-Diblock Bottlebrush Copolymer Elastomers.

A series of cellulose-graft-diblock bottlebrush copolymer elastomers (cellulose-graft-poly(n-butyl acrylate)-block-poly(methyl methacrylate) (Cell-g-PBA-b-PMMA)) with short side chains were synthesized via successive atom transfer radical polymerization (ATRP) to study the influence of varying compositions and lengths of the graft diblock side chains on microphase morphologies and properties. The microphase-separated morphologies from misaligned spheres to cylinders were observed by atomic force microscopy (AFM) and small-angle X-ray scattering (SAXS) measurements. These bottlebrush copolymer elastomers possessed thermal stability and enhanced mechanical properties because the PMMA outer block could self-assemble into hard microdomains, which served as physical cross-links. The viscoelastic responses of these bottlebrush copolymers within the linear viscoelastic (LVE) regime were carried out by the oscillatory shear rheology. The time-temperature superposition (tTs) principle was applied to construct the master curves of the dynamic moduli, and the sequential relaxation of dense bottlebrush copolymers with different PMMA hard outer block lengths was analyzed. The rheological behaviors in this work could be utilized to build up the connection of microstructures and properties for the application of these bottlebrush copolymers as high-performance thermoplastic elastomers.

A Bimetallic Benzene-1,2,4,5-Tetrathiolate (btt) Molybdenocene Complex Cp2 Mo(btt)MoCp2 : Radical and Diradical States.

Benzene-1,2,4,5-tetrathiolate (btt) has been used as a bridging ligand to prepare a redox active (molybdenocene dithiolene)-based bimetallic complex Cp2 Mo(btt)MoCp2 , which exhibits four successive electron transfers up to the tetracation. Spectro-electrochemical investigations together with DFT and TD-DFT calculations evidence that the two electroactive MoS2 C2 metallacycles are electronically coupled in the monocationic as in the dicationic state. Two salts of the dication [Cp2 Mo(btt)MoCp2 ]2+ have been structurally characterized with PF6 - and HSO4 - counterions, showing different chair or boat conformations associated with variable folding angles of the two MoS2 C2 metallacycles along the S-S hinge. The bis-oxidized dicationic complex exhibits a diradical character, with both radicals essentially localized on the metallacycles and with antiferromagnetic coupling evidenced from magnetic susceptibility measurements.

Photocatalytic Cross-Pinacol Coupling Promoted by Carbon Dioxide.

Cross-pinacol coupling of two different carbonyl compounds was achieved through successive one-electron transfer processes under photocatalytic conditions. In the reaction, an umpoled anionic carbinol synthon was generated in situ to react nucleophilically with a second electrophilic carbonyl compound. We revealed that a CO2 additive promoted the photocatalytic generation of the carbinol synthon to suppress undesired radical dimerization. A wide variety of aromatic and aliphatic carbonyl substrates underwent the cross-pinacol coupling to afford the corresponding unsymmetric vicinal 1,2-diols, where even a combination of carbonyl reactants with similar structures such as two aldehydes and two ketones were also well tolerated with high cross-coupling selectivity.

Poster 136: Augmented Meniscus Radial Tear Healing via Local Transforming Growth Factor-beta 1 (TGF- β1) Gene Therapy in a Rat Model

Objectives: Meniscus tears cause significant musculoskeletal impairment and are among the most common knee injuries. Tears in the inner third of the meniscus have intrinsically poor healing capacity due to insufficient blood supply. In an effort to improve healing, use of biologic augments is a promising area of investigation. Tissue engineering strategies, such as growth factor gene therapy, have emerged as encouraging approaches to improving meniscal healing. Transforming Growth Factor-Beta 1 (TGF-β1) gene therapy has shown promise in vitro and ex vivo as a therapeutic strategy, but its effects on meniscus healing in vivo remain unknown. This study aimed to determine whether local delivery of viral vectors carrying the TGF-β1 gene could improve the healing of a meniscus tear involving the avascular zone in vivo in a rat model. Methods: Recombinant adenoviruses were generated using the AdEasy system. Briefly, the coding regions of mouse TGFβ1 were PCR amplified and cloned into an adenoviral shuttle vector and subsequently used to generate recombinant adenoviruses in HEK293 cells. The resulting adenoviruses were designated as Adv-TGF-β1. An analogous adenovirus expressing only GFP (Adv-GFP) was used as mock virus controls. To achieve local delivery of viral vectors to the injury site, we utilized a thermoresponsive biodegradable polydiolcitrate-gelatin delivery scaffold (PPCNg). A full-thickness radial tear was made in the medial meniscus of the left hind leg of twelve Wistar rats. Rats were divided into two groups: one receiving a mixture of PPCNg+TGF-β1 (n = 3) and the other receiving PPCNg+GFP (n = 3). A 4ºC pre-chilled solution of PPCNg seeded with Adv-TGF-β1 or Adv-GFP at 1011 infectious viral particles/injection was administered at the site of the induced meniscus tear. After 3 weeks, rats were euthanized, and the menisci were histologically evaluated by hematoxylin and eosin (H&amp;E) staining. The histologic assessment and scoring of meniscus tissue wound healing were done by one blinded and one unblinded observer, each using selected wound healing parameters as described in Table 1, and the results were averaged. The intra-class correlation coefficient (ICC) was computed based on a mean rating (k=2), absolute agreement, and two-way random effects model to assess the agreement between the wound healing score rating of the two observers. Statistical significance between groups was determined using the Mann-Whitney Wilcoxon rank sum test. A value of p &lt; 0.05 was considered statistically significant. All animal procedures were performed according to an Institutional Animal Care and Use Committee protocol at the home institution. Results: Immediately after and 3 weeks post-surgery, there was no evidence of infection, dehiscence, or functional deficit. Histologic evaluation of the sections (n = 8/group) of harvested rat menisci (n = 2/group) revealed improved healing of tears in the PPCNg+TGF-β1 group compared to the control group (5.7 ± 0.48 vs. 5.0 ± 0.89, p = 0.011) (Figure 1B). The lesion area demonstrated significantly greater neovascularization (2.75 ± 0.45 vs. 2.06 ± 0.68, p = 0.004), better collagen organization (1.94 ± 0.25 vs. 1.62 ± 0.50, p = 0.038), and increased hypercellularity (1.0 ± 0.00 vs. 1.3 ± 0.48, p = 0.018) in the PPCNg+TGF-β1 group compared to the controls (Figure 1C). Moderate absolute agreement between the two raters was observed in their wound healing score ratings (ICC = 0.615). Conclusions: Our results indicate that PPCNg-mediated delivery of Adv-TGF-β1 enhanced the early (3 weeks) healing of the meniscus lesion in rats compared with control (Adv-GFP) gene therapy. Further, localized administration of Adv-TGF-β1 induced greater neovascularization, better organization of collagen fibers, and increased hypercellularity at the injury site in the Adv-TGFβ-1 rat group compared with controls at 3 weeks post-injury. These results together suggest that TGF-β1 gene therapy may enhance meniscus healing by inducing more cellular proliferation and infiltration and greater neovascularization at the injury site to serve as nourishment for the establishment of new wound matrix, leading to more significant deposition and remodeling of mature collagen matrix. Further study that includes larger sample sizes, confirmation of successful gene transfer to meniscal cells around the tear site, and investigations of both later time points of wound healing and the mechanisms by which local TGF-β1 gene therapy may modulate augmented meniscus healing in this rat model of meniscal defect is necessary to better determine the potential future clinical utility of local TGF-β1 gene therapy to treat of meniscus tears with poor healing capacity. [Table: see text]

P-658 Clinical outcomes from ART in predicted hyperresponders: in-vitro maturation of oocytes versus conventional ovarian stimulation

Abstract Study question Do ongoing pregnancy rates (OPR) differ in predicted hyperresponders undergoing ART after in-vitro maturation of oocytes (IVM) compared with conventional ovarian stimulation (COS)? Summary answer One cycle of IVM is non-inferior to one cycle of COS in women with serum AMH levels &amp;gt;10ng/mL. What is known already Women with high antral follicle count (AFC) and elevated serum AMH levels, indicating an increased functional ovarian reserve, are prone to hyperresponse during ART treatment. To avoid iatrogenic complications of COS, IVM has been proposed as a mild-approach alternative treatment in predicted hyperresponders, including women with polycystic ovary syndrome (PCOS) who are eligible for ART. To date, inferior pregnancy rates from IVM compared to COS have hampered the uptake of IVM by ART clinics. However, it is unclear whether the efficiency gap between IVM and COS may differ depending on the extent of AMH elevation. Study design, size, duration This study is a retrospective cohort analysis of clinical and laboratory data from the first completed highly purified human menopausal gonadotropin (HP-hMG) primed, non-hCG triggered IVM or COS (FSH or HP-hMG stimulation in a GnRH antagonist protocol) cycle with ICSI in predicted hyperresponders ≤36 years of age at a tertiary referral university hospital. A total of 1707 cycles were included between January 2016 and June 2022. Participants/materials, setting, methods Predicted hyperresponse was defined as a serum AMH level &amp;gt;3.25ng/mL (Elecsys® AMH, Roche Diagnostics). The primary outcome was cumulative ongoing pregnancy rate (OPR) assessed 10-11 weeks after embryo transfer. The predefined non-inferiority limit was -10.0%. The analysis was adjusted for AMH strata. Time-to-pregnancy (TTP), defined by the time interval between egg retrieval and date of successful embryo transfer, was a secondary outcome. Statistical analysis was performed using a multivariable regression model controlling for potential confounders. Main results and the role of chance Data from 463 IVM cycles were compared with those from 1244 COS cycles. Women in the IVM group more often had a diagnosis of Rotterdam PCOS (434/463, 93.7%) compared to those undergoing COS (522/1193, 43.8%), were significantly younger (29.5 years vs 30.5 years, p ≤ 0.001), had a higher BMI (25.7kg/m² vs 25.1kg/m², p ≤ 0.01) and higher AMH (11.6ng/mL vs 5.3ng/mL, p ≤ 0.001). Although IVM cycles yielded more cumulus oocyte complexes (COCs) (25.8 COC vs 15.0 COC, p ≤ 0.001), both groups had similar numbers of mature oocytes (MII) (11.9 MII vs 10.6 MII, p = 0.9). In the entire cohort, non-adjusted cumulative OPR from IVM was significantly lower (198/463, 42.8%) compared to COS (794/1244, 63.8%), p ≤ 0.001. When analysing OPR across different serum AMH strata, cumulative OPR in both groups converged with increasing serum AMH, and OPR from IVM was non-inferior compared to COS from serum AMH levels &amp;gt;10ng/mL onwards (113/221, 51.1% [IVM]; 29/48, 60.4% [COS]). Time-To-Pregnancy was shorter in the IVM group compared to COS (11.3 weeks vs 21.0 weeks, p ≤ 0.001). Multivariable regression analysis adjusting for ART type, age, BMI, oocyte number and PCOS phenotype showed that the number of COCs was the only parameter associated with OPR in predicted hyperresponders with a serum AMH &amp;gt;10ng/mL. Limitations, reasons for caution These data should be interpreted with caution as the retrospective nature of the study holds the possibility of unmeasured confounding factors. Patients enrolled in a clinical IVM program received one-to-one care, in contrast with COS patients who received standard care, which may have influenced TTP. Wider implications of the findings Among subfertile women who are eligible for ART, IVM and COS resulted in comparable reproductive outcomes in a subset of women with a serum AMH &amp;gt;10ng/mL. These findings should be corroborated by an RCT comparing both treatments in selected patients with elevated AMH. Trial registration number Not applicable