Nickel-Catalyzed Atroposelective Cross-Electrophile Coupling of Aryl Halides: A General and Practical Route to Diverse MOP-Type Ligands.

We report a highly cross- and atroposelective coupling between ortho-(chloro)arylphosphine oxides and ortho-(bromo)aryl ethers. This previously unknown asymmetric nickel-catalyzed reaction offers a direct route to highly enantioenriched axially chiral biaryl monophosphine oxides that are difficult to access by other means. These products can be readily reduced to generate chiral MOP-type ligands bearing complex skeletal backbones. The utility of these chiral ligands in asymmetric catalysis is also demonstrated.

A predictive ensemble classifier for the gene expression diagnosis of ASD at ages 1 to 4 years.

Autism Spectrum Disorder (ASD) diagnosis remains behavior-based and the median age of diagnosis is ~52 months, nearly 5 years after its first-trimester origin. Accurate and clinically-translatable early-age diagnostics do not exist due to ASD genetic and clinical heterogeneity. Here we collected clinical, diagnostic, and leukocyte RNA data from 240 ASD and typically developing (TD) toddlers (175 toddlers for training and 65 for test). To identify gene expression ASD diagnostic classifiers, we developed 42,840 models composed of 3570 gene expression feature selection sets and 12 classification methods. We found that 742 models had AUC-ROC ≥ 0.8 on both Training and Test sets. Weighted Bayesian model averaging of these 742 models yielded an ensemble classifier model with accurate performance in Training and Test gene expression datasets with ASD diagnostic classification AUC-ROC scores of 85-89% and AUC-PR scores of 84-92%. ASD toddlers with ensemble scores above and below the overall ASD ensemble mean of 0.723 (on a scale of 0 to 1) had similar diagnostic and psychometric scores, but those below this ASD ensemble mean had more prenatal risk events than TD toddlers. Ensemble model feature genes were involved in cell cycle, inflammation/immune response, transcriptional gene regulation, cytokine response, and PI3K-AKT, RAS and Wnt signaling pathways. We additionally collected targeted DNA sequencing smMIPs data on a subset of ASD risk genes from 217 of the 240 ASD and TD toddlers. This DNA sequencing found about the same percentage of SFARI Level 1 and 2 ASD risk gene mutations in TD (12 of 105) as in ASD (13 of 112) toddlers, and classification based only on the presence of mutation in these risk genes performed at a chance level of 49%. By contrast, the leukocyte ensemble gene expression classifier correctly diagnostically classified 88% of TD and ASD toddlers with ASD risk gene mutations. Our ensemble ASD gene expression classifier is diagnostically predictive and replicable across different toddler ages, races, and ethnicities; out-performs a risk gene mutation classifier; and has potential for clinical translation.

Early Penile and Donor Site Sensory Outcomes After Innervated Radial Forearm Free Flap Phalloplasty: A Pilot Prospective Study.

BACKGROUND: Radial forearm free flap phalloplasty (RFFF) is a set of complex reconstructive procedures aimed at creating an aesthetic and functional penis in transgender patients. Sensory recovery in the neophallus and donor site is crucial for optimizing outcomes, but the few prior studies that exist assess neophallus sensation at limited locations and time points. The purpose of this study was to prospectively quantify sensory outcomes in the neophallus and donor site following RFFF phalloplasty. METHODS: Sensation testing occurred prospectively over February 2019-January 2021 on Stage 1 RFFF phalloplasty patients using the Pressure Specified Sensory Device (PSSD). On the neophallus, one-point discrimination (1PS) pressure threshold and lengthwise sensory recovery were measured at six circumferential locations proximally to distally. On the donor site, 1PS was measured at three locations on the donor hand. RESULTS: Nineteen patients were included (average age 34.0 years old, range 18-53 years). Among patients that received neophallus testing (n = 13), eight had at least two follow-up appointments. Six of these patients had sensation as of their most recent measurement (75.0%), with an average of 73 days to regain sensation. There was a significantly greater proportion of patients with sensation at the right ventral (80.0% after 3 months vs. 11.1%-60.0% before 3 months, p = 0.024) and right lateral (100.0% after 3 months vs. 11.1%-60.0% before 3 months, p = 0.004) aspects of the neophallus over time. Pressure required to elicit sensation decreased by 18.0% from 1 week-1 month postoperatively to 3-7.7 months postoperatively in the right ventral neophallus (96.2 g/mm2 ± 11.3 g/mm2 to 56.6 ± 39.9 g/mm2, p = 0.037). Among patients that received donor site testing (n = 11), mixed effects regression analysis with random intercepts demonstrated significant changes in the thumb (3.4 g/mm2 ± 1.4 g/mm2, p < 0.05) and webspace (13.5 g/mm2 ± 4.9 g/mm2, p < 0.01) that returned to baseline at 3 months postoperatively (1.7 g/mm2 ± 1.0 g/mm2, p > 0.05, and 2.3 g/mm2 ± 4.0 g/mm2, p > 0.05, respectively). CONCLUSION: This pilot study demonstrates that quantitative sensory testing can be used to monitor post-phalloplasty sensory changes. Recovery was significantly associated with contralateral (i.e, right side in a left forearm RFF) aspects of the neophallus, suggesting a possible pattern of circumferential sensory innervation via RFFF sensory nerves. Future studies with a larger sample size and longer follow-ups are necessary to fully characterize sensory recovery in phalloplasty patients.

Photoredox-Nickel Dual-Catalyzed C-Alkylation of Secondary Nitroalkanes: Access to Sterically Hindered α-Tertiary Amines.

The preparation of tertiary nitroalkanes via the nickel-catalyzed alkylation of secondary nitroalkanes using aliphatic iodides is reported. Previously, catalytic access to this important class of nitroalkanes via alkylation has not been possible due to the inability of catalysts to overcome the steric demands of the products. However, we have now found that the use of a nickel catalyst in combination with a photoredox catalyst and light leads to much more active alkylation catalysts. These can now access tertiary nitroalkanes. The conditions are scalable as well as air and moisture tolerant. Importantly, reduction of the tertiary nitroalkane products allows rapid access to α-tertiary amines.

Derivation and validation of risk prediction for posttraumatic stress symptoms following trauma exposure.

BACKGROUND: Posttraumatic stress symptoms (PTSS) are common following traumatic stress exposure (TSE). Identification of individuals with PTSS risk in the early aftermath of TSE is important to enable targeted administration of preventive interventions. In this study, we used baseline survey data from two prospective cohort studies to identify the most influential predictors of substantial PTSS. METHODS: Self-identifying black and white American women and men (n = 1546) presenting to one of 16 emergency departments (EDs) within 24 h of motor vehicle collision (MVC) TSE were enrolled. Individuals with substantial PTSS (⩾33, Impact of Events Scale - Revised) 6 months after MVC were identified via follow-up questionnaire. Sociodemographic, pain, general health, event, and psychological/cognitive characteristics were collected in the ED and used in prediction modeling. Ensemble learning methods and Monte Carlo cross-validation were used for feature selection and to determine prediction accuracy. External validation was performed on a hold-out sample (30% of total sample). RESULTS: Twenty-five percent (n = 394) of individuals reported PTSS 6 months following MVC. Regularized linear regression was the top performing learning method. The top 30 factors together showed good reliability in predicting PTSS in the external sample (Area under the curve = 0.79 ± 0.002). Top predictors included acute pain severity, recovery expectations, socioeconomic status, self-reported race, and psychological symptoms. CONCLUSIONS: These analyses add to a growing literature indicating that influential predictors of PTSS can be identified and risk for future PTSS estimated from characteristics easily available/assessable at the time of ED presentation following TSE.

Synthesis of Axially Chiral 2,2'-Bisphosphobiarenes via a Nickel-Catalyzed Asymmetric Ullmann Coupling: General Access to Privileged Chiral Ligands without Optical Resolution.

We report an asymmetric homocoupling of ortho-(iodo)arylphosphine oxides and ortho-(iodo)arylphosphonates resulting in highly enantioenriched axially chiral bisphosphine oxides and bisphosphonates. These products are readily converted to enantioenriched biaryl bisphosphines without need for chiral auxiliaries or optical resolution. This provides a practical route for the development of previously uninvestigated atroposelective biaryl bisphosphine ligands. The conditions have also proven effective for asymmetric dimerization of other, non-phosphorus-containing aryl halides.

Arylphosphonate-Directed Ortho C-H Borylation: Rapid Entry into Highly-Substituted Phosphoarenes.

Phosphonate-directed ortho C-H borylation of aromatic phosphonates is reported. Using simple starting materials and commercially accessible catalysts, this method provides steady access to o-phosphonate arylboronic esters bearing pendant functionality and flexible substitution patterns. These products serve as flexible precursors for a variety of highly substituted phosphoarenes, and in situ downstream functionalization of the products is described.

Cobalt Catalysis for Enantioselective Cyclobutanone Construction.

Over the past 40 years, intramolecular hydroacylation has favored five-membered rings, in preference to four membered rings. Herein, we report a catalyst derived from earth-abundant cobalt that enables preparation of cyclobutanones, with excellent regio-, diastereo-, and enantiocontrol, under mild conditions (2 mol % catalyst loading and as low as 50 °C).

Did we personalize? Assessing personalization by an online reinforcement learning algorithm using resampling.

There is a growing interest in using reinforcement learning (RL) to personalize sequences of treatments in digital health to support users in adopting healthier behaviors. Such sequential decision-making problems involve decisions about when to treat and how to treat based on the user's context (e.g., prior activity level, location, etc.). Online RL is a promising datadriven approach for this problem as it learns based on each user's historical responses and uses that knowledge to personalize these decisions. However, to decide whether the RL algorithm should be included in an "optimized" intervention for real-world deployment, we must assess the data evidence indicating that the RL algorithm is actually personalizing the treatments to its users. Due to the stochasticity in the RL algorithm, one may get a false impression that it is learning in certain states and using this learning to provide specific treatments. We use a working definition of personalization and introduce a resampling-based methodology for investigating whether the personalization exhibited by the RL algorithm is an artifact of the RL algorithm stochasticity. We illustrate our methodology with a case study by analyzing the data from a physical activity clinical trial called HeartSteps, which included the use of an online RL algorithm. We demonstrate how our approach enhances data-driven truth-in-advertising of algorithm personalization both across all users as well as within specific users in the study.

Selected Ion Monitoring Using Low-Cost Mass Spectrum Detectors Provides a Rapid, General, and Accurate Method for Enantiomeric Excess Determination in High-Throughput Experimentation.

High-Throughput Experimentation (HTE) workflows are efficient means of surveying a broad array of chiral catalysts in the development of catalytic asymmetric reactions. However, use of traditional HPLC-UV/vis methodology to determine enantiomeric excess (ee) from the resulting reactions is often hampered by co-elution of other reaction components, resulting in erroneous ee determination when crude samples are used, and ultimately requiring product isolation prior to ee analysis. In this study, using four published reactions selected as model systems, we demonstrate that the use of LC-MS, SFC-MS, and selected ion monitoring (SIM) mass chromatography provides a highly accurate means to determine ee of products in crude reaction samples using commonplace, low-cost MS detectors. By using ion selection, co-eluting signals can be deconvoluted to provide accurate integrations of the target analytes. We also show that this method is effective for samples lacking UV/vis chromophores, making it ideal for HTE workflows in asymmetric catalysis.

Copper-Catalyzed Propargylation of Nitroalkanes.

Using a commercially available, inexpensive, and abundant copper catalyst system, an efficient α-functionalization of nitroalkanes with propargyl bromides is now established. This mild and robust method is highly functional group tolerant and provides straightforward access to complex secondary and tertiary homopropargylic nitroalkanes. Moreover, the utility of these α-propargylated nitroalkanes is demonstrated through downstream functionalization to biologically relevant, five-membered N-heterocycles such as pyrroles and 2-pyrrolines.