CO2 Electrolyzers.

CO2 electrolyzers have progressed rapidly in energy efficiency and catalyst selectivity toward valuable chemical feedstocks and fuels, such as syngas, ethylene, ethanol, and methane. However, each component within these complex systems influences the overall performance, and the further advances needed to realize commercialization will require an approach that considers the whole process, with the electrochemical cell at the center. Beyond the cell boundaries, the electrolyzer must integrate with upstream CO2 feeds and downstream separation processes in a way that minimizes overall product energy intensity and presents viable use cases. Here we begin by describing upstream CO2 sources, their energy intensities, and impurities. We then focus on the cell, the most common CO2 electrolyzer system architectures, and each component within these systems. We evaluate the energy savings and the feasibility of alternative approaches including integration with CO2 capture, direct conversion of flue gas and two-step conversion via carbon monoxide. We evaluate pathways that minimize downstream separations and produce concentrated streams compatible with existing sectors. Applying this comprehensive upstream-to-downstream approach, we highlight the most promising routes, and outlook, for electrochemical CO2 reduction.

Molecular tuning of CO2-to-ethylene conversion.

The electrocatalytic reduction of carbon dioxide, powered by renewable electricity, to produce valuable fuels and feedstocks provides a sustainable and carbon-neutral approach to the storage of energy produced by intermittent renewable sources1. However, the highly selective generation of economically desirable products such as ethylene from the carbon dioxide reduction reaction (CO2RR) remains a challenge2. Tuning the stabilities of intermediates to favour a desired reaction pathway can improve selectivity3-5, and this has recently been explored for the reaction on copper by controlling morphology6, grain boundaries7, facets8, oxidation state9 and dopants10. Unfortunately, the Faradaic efficiency for ethylene is still low in neutral media (60 per cent at a partial current density of 7 milliamperes per square centimetre in the best catalyst reported so far9), resulting in a low energy efficiency. Here we present a molecular tuning strategy-the functionalization of the surface of electrocatalysts with organic molecules-that stabilizes intermediates for more selective CO2RR to ethylene. Using electrochemical, operando/in situ spectroscopic and computational studies, we investigate the influence of a library of molecules, derived by electro-dimerization of arylpyridiniums11, adsorbed on copper. We find that the adhered molecules improve the stabilization of an 'atop-bound' CO intermediate (that is, an intermediate bound to a single copper atom), thereby favouring further reduction to ethylene. As a result of this strategy, we report the CO2RR to ethylene with a Faradaic efficiency of 72 per cent at a partial current density of 230 milliamperes per square centimetre in a liquid-electrolyte flow cell in a neutral medium. We report stable ethylene electrosynthesis for 190 hours in a system based on a membrane-electrode assembly that provides a full-cell energy efficiency of 20 per cent. We anticipate that this may be generalized to enable molecular strategies to complement heterogeneous catalysts by stabilizing intermediates through local molecular tuning.

Selective Electrified Propylene-to-Propylene Glycol Oxidation on Activated Rh-Doped Pd.

Renewable-energy-powered electrosynthesis has the potential to contribute to decarbonizing the production of propylene glycol, a chemical that is used currently in the manufacture of polyesters and antifreeze and has a high carbon intensity. Unfortunately, to date, the electrooxidation of propylene under ambient conditions has suffered from a wide product distribution, leading to a low faradic efficiency toward the desired propylene glycol. We undertook mechanistic investigations and found that the reconstruction of Pd to PdO occurs, followed by hydroxide formation under anodic bias. The formation of this metastable hydroxide layer arrests the progressive dissolution of Pd in a locally acidic environment, increases the activity, and steers the reaction pathway toward propylene glycol. Rh-doped Pd further improves propylene glycol selectivity. Density functional theory (DFT) suggests that the Rh dopant lowers the energy associated with the production of the final intermediate in propylene glycol formation and renders the desorption step spontaneous, a concept consistent with experimental studies. We report a 75% faradic efficiency toward propylene glycol maintained over 100 h of operation.

Distinguishing between resilience and posttraumatic growth: perceptions of and attitudes toward depression.

The current study investigated differences between resilience and posttraumatic growth (PTG) by examining their distinctive roles in perceptions of and attitudes toward depression. A series of mixed ANOVAs analyzed the differences in individuals' perceptions of and attitudes towards depression. College students (N = 300) completed a survey including the Brief Resilience Scale and the short form of the PTG Inventory and then read and evaluated vignettes describing an individual with either modern-type or traditional-type depression. Those high in resilience found individuals with depression, especially modern-type, less familiar and were less likely to think therapy would effectively help them. Those high in PTG found depressed individuals more familiar and were more willing to provide support regardless of depression type. These results suggest differing attitudes toward mental disorders based on levels of PTG and resilience, displaying critical differences in their nature.

'Pain-free TRUS B': a phase 3 double-blind placebo-controlled randomized trial of methoxyflurane with periprostatic local anaesthesia to reduce the discomfort of transrectal ultrasonography-guided prostate biopsy (ANZUP 1501).

OBJECTIVE: To determine whether the addition of inhaled methoxyflurane to periprostatic infiltration of local anaesthetic (PILA) during transrectal ultrasonography-guided prostate biopsies (TRUSBs) improved pain and other aspects of the experience. PATIENTS AND METHODS: We conducted a multicentre, placebo-controlled, double-blind, randomized phase 3 trial, involving 420 men undergoing their first TRUSB. The intervention was PILA plus a patient-controlled device containing either 3 mL methoxyflurane, or 3 mL 0.9% saline plus one drop of methoxyflurane to preserve blinding. The primary outcome was the pain score (0-10) reported by the participant after 15 min. Secondary outcomes included ratings of other aspects of the biopsy experience, willingness to undergo future biopsies, urologists' ratings, biopsy completion, and adverse events. RESULTS: The mean (SE) pain scores 15 min after TRUSB were 2.51 (0.22) in those assigned methoxyflurane vs 2.82 (0.22) for placebo (difference 0.31, 95% confidence interval [CI] -0.75 to 0.14; P = 0.18). Methoxyflurane was associated with better scores for discomfort (difference -0.48, 95% CI -0.92 to -0.03; P = 0.035, adjusted [adj.] P = 0.076), whole experience (difference -0.50, 95% CI -0.92 to -0.08; P = 0.021, adj. P = 0.053), and willingness to undergo repeat biopsies (odds ratio 1.67, 95% CI 1.12-2.49; P = 0.01) than placebo. Methoxyflurane resulted in higher scores for drowsiness (difference +1.64, 95% CI 1.21-2.07; P < 0.001, adj. P < 0.001) and dizziness (difference +1.78, 95% CI 1.31-2.24; P < 0.001, adj. P < 0.001) than placebo. There was no significant difference in the number of ≥ grade 3 adverse events. CONCLUSIONS: We found no evidence that methoxyflurane improved pain scores at 15 min, however, improvements were seen in patient-reported discomfort, overall experience, and willingness to undergo repeat biopsies.

Screening for eating disorders across genders in college students: Initial validation of the brief assessment of stress and eating.

Given that eating disorders (EDs) are relatively common in college populations, it is important to have reliable and valid tools to identify students so that they can be referred to evidence-based care. Although research supports the psychometric properties of existing ED screens for identifying cases of EDs, most studies have been conducted in samples of young white-majority women or have not reported the psychometric properties of the screening tool in men. OBJECTIVE: The purpose of the current study was to validate a brief, 10-item screening tool for the identification of EDs-the brief assessment of stress and eating (BASE). METHOD: Participants were college students (N = 596; 68.2% cisgender women) from a large Midwestern university who completed the BASE and SCOFF. The Eating Disorders Diagnostic Survey was used to generate DSM-5 ED diagnoses. We evaluated area under the curve (AUC) for both receiver operating curves (ROC) and precision-recall curves (PRC). RESULTS: Both the BASE and SCOFF performed significantly better than chance at identifying probable EDs in cisgender women (BASE AUC: ROC = .787, PRC = .633, sensitivity = .733, specificity = .697; SCOFF AUC: ROC = .810, PRC = .684, sensitivity = .793, specificity = .701). However, the BASE (AUC: ROC = .821, PRC = .605, sensitivity = .966, specificity = .495) significantly outperformed the SCOFF (AUC: ROC = .710, PRC = .354, sensitivity = .828, specificity = .514) for identifying probable EDs in cisgender college men. DISCUSSION: The BASE is appropriate for student healthcare and college research settings. Because the BASE outperforms the SCOFF in college men, results from the current study are expected to contribute to improved identification of EDs on college campuses. PUBLIC SIGNIFICANCE: The BASE is a new screening tool to identify eating disorders. The BASE performed as well as, if not better than, the SCOFF (particularly in men). Given the need for brief, psychometrically strong, and unbiased ED screening tools in college students, the current study helps address an unmet student healthcare need that we expect will contribute to improved identification of EDs on college campuses.

Codesigning a patient support portal with health professionals and men with prostate cancer: An action research study.

INTRODUCTION: The supportive care needs of men with prostate cancer (PCa) have been well documented, but little is known about how an online portal may address these. This study sought to determine priority issues facing men with PCa, barriers and enablers to accessing care and whether health professionals (HPs) and men would support the inclusion of a patient-reported outcome (PRO) comparator tool. METHODS: We conducted four online focus groups with HPs recruited from healthcare services in Victoria, followed by seven online codesign workshops with men with PCa, recruited through the Victorian Prostate Cancer Outcomes Registry, Prostate Cancer Foundation Australia and the Cancer Council Victoria. Men were eligible to participate if they had lived experience of PCa and access to the internet. We analysed focus groups thematically. Workshops were analysed using descriptive-content analysis. RESULTS: HPs (n = 39) highlighted that men had shifting priorities over time, but noted the importance of providing information to men in lay terms to assist in treatment decision-making and side-effect management. HPs identified key enablers to men accessing support services such as practice nurses, partners and having men share their stories with each other. HPs raised financial, cultural, geographic and emotional barriers to accessing supportive care. Inclusion of a PRO comparator tool received mixed support from HPs, with 41% (n = 16) supportive, 49% (n = 19) unsure and 10% (n = 4) not supportive. Men involved in workshops (n = 28) identified informational needs to assist in treatment decision-making and side-effect management as the top priority throughout care. Men described support groups and practice nurses as key enablers. Short consultation times and complex information were described as barriers. Unlike HPs, all men supported the inclusion of a PRO comparator tool in a portal. CONCLUSIONS: Our findings suggest that a patient support portal should provide information in lay terms that address the shifting priorities of men with PCa. Men with PCa would welcome the development of a portal to centralize support information and a PRO comparator tool to prompt health-seeking behaviour. Future research will implement these findings in the development of a portal, and pilot and evaluate the portal within a population-based sample. PATIENT OR PUBLIC CONTRIBUTION: This project adopted a codesign approach including both men with PCa and HPs involved in PCa care. Men with PCa also formed part of the study's steering committee and consumer advisory groups. HPs were consulted in a serious of online focus groups. Subsequently, men with PCa and their support persons participated in workshops. Men with PCa were also involved in the preparation of this manuscript.

Engaging High-Need Patients in Intensive Outpatient Programs: A Qualitative Synthesis of Engagement Strategies.

BACKGROUND: Intensive outpatient programs address the complex medical, social, and behavioral needs of individuals who account for disproportionate healthcare costs. Despite their promise, the impact of these programs is often diminished due to patient engagement challenges (i.e., low rates of patient participation and partnership in care). OBJECTIVE: The objective of this study was to identify intensive outpatient program features and strategies that increase high-need patient engagement in these programs. DESIGN: Qualitative study. PARTICIPANTS: Twenty program leaders and clinicians from 12 intensive outpatient programs in academic, county, Veterans Affairs, community, and private healthcare settings. APPROACH: A questionnaire and semi-structured interviews were used to identify common barriers to patient engagement in intensive outpatient programs and strategies employed by programs to address these challenges. We used content analysis methods to code patient engagement barriers and strategies and to identify program features that facilitate patient engagement. KEY RESULTS: The most common barriers to patient engagement in intensive outpatient programs included physical symptoms/limitations, mental illness, care fragmentation across providers and services, isolation/lack of social support, financial insecurity, and poor social and neighborhood conditions. Patient engagement strategies included concrete services to support communication and use of recommended services, activities to foster patient trust and relationships with program staff, and counseling to build insight and problem-solving capabilities. Program features that were identified as enhancing engagement efforts included: 1) multidisciplinary teams with diverse skills, knowledge, and personalities to facilitate relationship building; 2) adequate staffing and resources to handle the demands of high-need patients; and 3) a philosophy that permitted flexibility and patient-centeredness. CONCLUSIONS: Promising clinical, interpersonal, and population-based approaches to engaging high-need patients frequently deviate from standard practice and require creative and proactive staff with adequate time, resources, and flexibility to address patients' needs on patients' terms.

Scaling CO2 Electrolyzer Cell Area from Bench to Pilot.

To contribute meaningfully to carbon dioxide (CO2) emissions reduction, CO2 electrolyzer technology will need to scale immensely. Bench-scale electrolyzers are the norm, with active areas <5 cm2. However, cell areas on the order of 100s or 1000s of cm2 will be required for industrial deployment. Here, we study the effects of increasing cell area, scaling over 2 orders of magnitude from a 5 cm2 lab-scale cell to an 800 cm2 pilot plant-scale cell. A direct scaling of the bench-scale cell architecture to the larger area results in a ∼20% drop in ethylene (C2H4) selectivity and an increase in the parasitic hydrogen (H2) evolution reaction (HER). We instrument an 800 cm2 electrolyzer cell to serve as a diagnostic tool and determine that nonuniformities in electrode compression and flow-influenced local CO2 availability are the key drivers of performance loss upon scaling. Machining of an initial 800 cm2 cell results in a standard deviation in MEA compression that is 7-fold that of a similarly produced 5 cm2 cell (0.009 mm). Using these findings, we redesign an 800 cm2 cell for compression tolerance and increased CO2 transport and achieve an H2 FE in the revised 800 cm2 cell similar to that of the 5 cm2 case (16% at 200 mA cm-2). These results demonstrate that by ensuring uniform compression and fluid flow, the CO2 electrolyzer area can be scaled over 100-fold and retain C2H4 selectivity (within 10% of small-scale selectivity).

Reactive capture of CO2 via amino acid.

Reactive capture of carbon dioxide (CO2) offers an electrified pathway to produce renewable carbon monoxide (CO), which can then be upgraded into long-chain hydrocarbons and fuels. Previous reactive capture systems relied on hydroxide- or amine-based capture solutions. However, selectivity for CO remains low (<50%) for hydroxide-based systems and conventional amines are prone to oxygen (O2) degradation. Here, we develop a reactive capture strategy using potassium glycinate (K-GLY), an amino acid salt (AAS) capture solution applicable to O2-rich CO2-lean conditions. By employing a single-atom catalyst, engineering the capture solution, and elevating the operating temperature and pressure, we increase the availability of dissolved in-situ CO2 and achieve CO production with 64% Faradaic efficiency (FE) at 50 mA cm-2. We report a measured CO energy efficiency (EE) of 31% and an energy intensity of 40 GJ tCO-1, exceeding the best hydroxide- and amine-based reactive capture reports. The feasibility of the full reactive capture process is demonstrated with both simulated flue gas and direct air input.

Early Warning for the Electrolyzer: Monitoring CO2 Reduction via In-Line Electrochemical Impedance Spectroscopy.

The electrochemical CO2 reduction reaction (CO2 RR) to fuels and feedstocks presents an opportunity to decarbonize the chemical industry, and current electrolyzer performance levels approach commercial viability. However, stability remains below that required, in part because of the challenge of probing these electrolyzer systems in real time and the challenge of determining the root cause of failure. Failure can result from initial conditions (e. g., the over- or under-compression of the electrolyzer), gradual degradation of components (e. g., cathode or anode catalysts), the accumulation of products or by-products, or immediate changes such as the development of a hole in the membrane or a short circuit. Identifying and mitigating these assembly-related, gradual, and immediate failure modes would increase both electrolyzer lifetime and economic viability of CO2 RR. We demonstrate the continuous monitoring of CO2 RR electrolyzers during operation via non-disruptive, real-time electrochemical impedance spectroscopy (EIS) analysis. Using this technique, we characterise common failure modes - compression, salt formation, and membrane short circuits - and identify electrochemical parameter signatures for each. We further propose a framework to identify, predict, and prevent failures in CO2 RR electrolyzers. This framework allowed for the prediction of anode degradation ~11 hours before other indicators such as selectivity or voltage.

Design and methods of the Longitudinal Eating Disorders Assessment Project research consortium for veterans.

INTRODUCTION: Military service members must maintain a certain body mass index and body fat percentage. Due to weight-loss pressures, some service members may resort to unhealthy behaviors that place them at risk for the development of an eating disorder (ED). OBJECTIVES: To understand the scope and impact of EDs in military service members and veterans, we formed the Longitudinal Eating Disorders Assessment Project (LEAP) Consortium. LEAP aims to develop novel screening, assessment, classification, and treatment tools for veterans and military members with a focus on EDs and internalizing psychopathology. METHODS: We recruited two independent nationally representative samples of post-9/11 veterans who were separated from service within the past year. Study 1 was a four-wave longitudinal survey and Study 2 was a mixed-methods study that included surveys, structured-clinical interviews, and qualitative interviews. RESULTS: Recruitment samples were representative of the full population of recently separated veterans. Sample weights were created to adjust for sources of non-response bias to the baseline survey. Attrition was low relative to past studies of this population, with only (younger) age predicting attrition at 1-week follow-up. CONCLUSIONS: We expect that the LEAP Consortium data will contribute to improved information about EDs in veterans, a serious and understudied problem.

Single-site decorated copper enables energy- and carbon-efficient CO2 methanation in acidic conditions.

Renewable CH4 produced from electrocatalytic CO2 reduction is viewed as a sustainable and versatile energy carrier, compatible with existing infrastructure. However, conventional alkaline and neutral CO2-to-CH4 systems suffer CO2 loss to carbonates, and recovering the lost CO2 requires input energy exceeding the heating value of the produced CH4. Here we pursue CH4-selective electrocatalysis in acidic conditions via a coordination method, stabilizing free Cu ions by bonding Cu with multidentate donor sites. We find that hexadentate donor sites in ethylenediaminetetraacetic acid enable the chelation of Cu ions, regulating Cu cluster size and forming Cu-N/O single sites that achieve high CH4 selectivity in acidic conditions. We report a CH4 Faradaic efficiency of 71% (at 100 mA cm-2) with <3% loss in total input CO2 that results in an overall energy intensity (254 GJ/tonne CH4), half that of existing electroproduction routes.

Concentrated Ethanol Electrosynthesis from CO2 via a Porous Hydrophobic Adlayer.

Electrochemical CO2 reduction can convert waste emissions into dense liquid fuels compatible with existing energy infrastructure. High-rate electrocatalytic conversion of CO2 to ethanol has been achieved in membrane electrode assembly (MEA) electrolyzers; however, ethanol produced at the cathode is transported, via electroosmotic drag and diffusion, to the anode, where it is diluted and may be oxidized. The ethanol concentrations that result on both the cathodic and anodic sides are too low to justify the energetic and financial cost of downstream separation. Here, we present a porous catalyst adlayer that facilitates the evaporation of ethanol into the cathode gas stream and reduces the water transport, leading to a recoverable stream of concentrated ethanol. The adlayer is comprised of ethylcellulose-bonded carbon nanoparticles and forms a porous, electrically conductive network on the surface of the copper catalyst that slows the transport of water to the gas channel. We achieve the direct production of an ethanol stream of 12.4 wt %, competitive with the concentration of current industrial ethanol production processes.

Bipolar membrane electrolyzers enable high single-pass CO2 electroreduction to multicarbon products.

In alkaline and neutral MEA CO2 electrolyzers, CO2 rapidly converts to (bi)carbonate, imposing a significant energy penalty arising from separating CO2 from the anode gas outlets. Here we report a CO2 electrolyzer uses a bipolar membrane (BPM) to convert (bi)carbonate back to CO2, preventing crossover; and that surpasses the single-pass utilization (SPU) limit (25% for multi-carbon products, C2+) suffered by previous neutral-media electrolyzers. We employ a stationary unbuffered catholyte layer between BPM and cathode to promote C2+ products while ensuring that (bi)carbonate is converted back, in situ, to CO2 near the cathode. We develop a model that enables the design of the catholyte layer, finding that limiting the diffusion path length of reverted CO2 to ~10 µm balances the CO2 diffusion flux with the regeneration rate. We report a single-pass CO2 utilization of 78%, which lowers the energy associated with downstream separation of CO2 by 10× compared with past systems.

Outcomes of Simulation in Resident Imaging-Guided Breast Biopsy Training.

Introduction We evaluate diagnostic radiology residents' perceptions of an ultrasound-guided and stereotactic breast biopsy simulator used at an academic medical center. This simulator is low-cost and easily reproducible. We aim to understand if this simulator improves residents' self-reported confidence in performing breast biopsy procedures on live patients. Methods Twenty-eight diagnostic radiology residents were instructed in how to perform ultrasound-guided breast biopsies and stereotactic breast biopsies using real biopsy and imaging equipment, but with tissue models in lieu of live persons. The hands-on experience was preceded by a didactic lecture. The ultrasound-guided tissue model was created with blueberries that were inserted in tofu, and the stereotactic tissue model was created by placing crushed calcium carbonate tablets into cored eggplant. Residents were asked to fill out a survey before and after participating in the simulation, where they self-reported their confidence level at performing ultrasound-guided and stereotactic breast biopsies. Results Twenty-eight diagnostic radiology residents participated in the simulation. All residents completed the pre-simulation survey and of these residents, twenty-one completed the post-simulation survey. Prior to the simulation residents reported a median confidence level of 3.5 out of 10 in performing ultrasound-guided breast biopsies, and a median confidence level of 1.0 out of 10 in performing stereotactic-guided breast biopsies. After the simulation, residents reported a median confidence level of 7.0 out of 10 in performing ultrasound-guided breast biopsies, and a median confidence level of 3.0 out of 10 in performing stereotactic-guided breast biopsies. Increases in resident confidence level were statistically significant for both biopsy types (p < 0.01).  Conclusion Simulated biopsies can increase the confidence of diagnostic radiology residents that are learning to perform breast biopsies before they perform real biopsies on live patients. Providing simulation training and thereby improving resident confidence may help reduce physician error and patient harm due to poor biopsy techniques.

In Situ Formation of Nano Ni-Co Oxyhydroxide Enables Water Oxidation Electrocatalysts Durable at High Current Densities.

The oxygen evolution reaction (OER) limits the energy efficiency of electrocatalytic systems due to the high overpotential symptomatic of poor reaction kinetics; this problem worsens over time if the performance of the OER electrocatalyst diminishes during operation. Here, a novel synthesis of nanocrystalline Ni-Co-Se using ball milling at cryogenic temperature is reported. It is discovered that, by anodizing the Ni-Co-Se structure during OER, Se ions leach out of the original structure, allowing water molecules to hydrate Ni and Co defective sites, and the nanoparticles to evolve into an active Ni-Co oxyhydroxide. This transformation is observed using operando X-ray absorption spectroscopy, with the findings confirmed using density functional theory calculations. The resulting electrocatalyst exhibits an overpotential of 279 mV at 0.5 A cm-2 and 329 mV at 1 A cm-2 and sustained performance for 500 h. This is achieved using low mass loadings (0.36 mg cm-2 ) of cobalt. Incorporating the electrocatalyst in an anion exchange membrane water electrolyzer yields a current density of 1 A cm-2 at 1.75 V for 95 h without decay in performance. When the electrocatalyst is integrated into a CO2 -to-ethylene electrolyzer, a record-setting full cell voltage of 3 V at current density 1 A cm-2 is achieved.

Low coordination number copper catalysts for electrochemical CO2 methanation in a membrane electrode assembly.

The electrochemical conversion of CO2 to methane provides a means to store intermittent renewable electricity in the form of a carbon-neutral hydrocarbon fuel that benefits from an established global distribution network. The stability and selectivity of reported approaches reside below technoeconomic-related requirements. Membrane electrode assembly-based reactors offer a known path to stability; however, highly alkaline conditions on the cathode favour C-C coupling and multi-carbon products. In computational studies herein, we find that copper in a low coordination number favours methane even under highly alkaline conditions. Experimentally, we develop a carbon nanoparticle moderator strategy that confines a copper-complex catalyst when employed in a membrane electrode assembly. In-situ XAS measurements confirm that increased carbon nanoparticle loadings can reduce the metallic copper coordination number. At a copper coordination number of 4.2 we demonstrate a CO2-to-methane selectivity of 62%, a methane partial current density of 136 mA cm-2, and > 110 hours of stable operation.

Accelerated ovarian aging in the absence of the transcription regulator TAF4B in mice.

The mammalian ovary is unique in that its reproductive life span is limited by oocyte quantity and quality. Oocytes are recruited from a finite pool of primordial follicles that are usually exhausted from the ovary during midadult life. If regulation of this pool is perturbed, the reproductive capacity of the ovary is compromised. TAF4B is a gonad-enriched subunit of the TFIID complex required for female fertility in mice. Previous characterization of TAF4B-deficient ovaries revealed several reproductive deficits that collectively result in infertility. However, the etiology of such fertility defects remains unknown. By assaying estrous cycle, ovarian pathology, and gene expression changes in young Taf4b-null female mice, we show that TAF4B-deficient female mice exhibit premature reproductive senescence. The rapid decline of ovarian function in Taf4b-null mice begins in early postnatal life, and follicle depletion is completed by 16 wk of age. To uncover differences in gene expression that may underlie accelerated ovarian aging, we compared genome-wide expression profiles of 3-wk-old, prepubescent Taf4b-null and wild-type ovaries. At 3 wk of age, decreased gene expression in Taf4b-null ovaries is similar to that seen in aged ovaries, revealing several molecular signatures of premature reproductive senescence, including reduced Smc1b. One significantly reduced transcript in the young TAF4B-null ovary codes for MOV10L1, a putative germline-specific RNA helicase that is related to the Drosophila RNA interference protein, armitage. We show here that Mov10l1 is expressed in mouse oocytes and that its expression is sensitive to TAF4B level, linking TAF4B to the posttranscriptional control of ovarian gene expression.