Elucidating Local Structure and Positional Effect of Dopants in Colloidal Transition Metal Dichalcogenide Nanosheets for Catalytic Hydrogenolysis.

Tailoring nanoscale catalysts to targeted applications is a vital component in reducing the carbon footprint of industrial processes; however, understanding and controlling the nanostructure influence on catalysts is challenging. Molybdenum disulfide (MoS2), a transition metal dichalcogenide (TMD) material, is a popular example of a nonplatinum-group-metal catalyst with tunable nanoscale properties. Doping with transition metal atoms, such as cobalt, is one method of enhancing its catalytic properties. However, the location and influence of dopant atoms on catalyst behavior are poorly understood. To investigate this knowledge gap, we studied the influence of Co dopants in MoS2 nanosheets on catalytic hydrodesulfurization (HDS) through a well-controlled, ligand-directed, tunable colloidal doping approach. X-ray absorption spectroscopy and density functional theory calculations revealed the nonmonotonous relationship between dopant concentration, location, and activity in HDS. Catalyst activity peaked at 21% Co:Mo as Co saturates the edge sites and begins basal plane doping. While Co prefers to dope the edges over basal sites, basal Co atoms are demonstrably more catalytically active than edge Co. These findings provide insight into the hydrogenolysis behavior of doped TMDs and can be extended to other TMD materials.

Rapid Prediction of a Liquid Structure from a Single Molecular Configuration Using Deep Learning.

Molecular dynamics simulation is an indispensable tool for understanding the collective behavior of atoms and molecules and the phases they form. Statistical mechanics provides accurate routes for predicting macroscopic properties as time-averages over visited molecular configurations - microstates. However, to obtain convergence, we need a sufficiently long record of visited microstates, which translates to the high-computational cost of the molecular simulations. In this work, we show how to use a point cloud-based deep learning strategy to rapidly predict the structural properties of liquids from a single molecular configuration. We tested our approach using three homogeneous liquids with progressively more complex entities and interactions: Ar, NO, and H2O under varying pressure and temperature conditions within the liquid state domain. Our deep neural network architecture allows rapid insight into the liquid structure, here probed by the radial distribution function, and can be used with molecular/atomistic configurations generated by either simulation, first-principle, or experimental methods.

Acute Adductor Muscle Injury: A Systematic Review on Diagnostic Imaging, Treatment, and Prevention.

BACKGROUND: Controversies remain regarding the diagnosis, imaging, and treatment of acute adductor injuries in athletes. PURPOSE: To investigate the diagnostic imaging, treatment, and prevention of acute adductor injuries based on the most recent and relevant scientific evidence. STUDY DESIGN: Systematic review; Level of evidence, 4. METHODS: The PubMed and Web of Science databases were searched according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to identify articles studying acute adductor injury in athletes. Inclusion criteria were original publication on acute adductor injury in amateur or professional athletes, level 1 to 4 evidence, mean patient age >15 years, and results presented as return-to-sport, pain, or functional outcomes. Quality assessment was performed with the CONSORT (Consolidated Standards of Reporting Trials) statement or the methodological index for non-randomized studies criteria. Articles were grouped as imaging, treatment, prevention focused, or mixed. RESULTS: A total of 30 studies published between 2001 and 2021 were selected, involving 594 male patients with a mean age 26.2 years (range, 16-68 years). The most frequent sports were soccer (62%), basketball (14%), futsal (6%), American football (3%), and ice hockey and handball (2%). Risk factors for acute adductor injury were previous acute groin injury, adductor weakness compared with the uninjured side, any injury in the previous season, and reduced rotational hip range of motion. The frequency of complete adductor muscle tears on magnetic resonance imaging was 21% to 25%. For complete adductor tears, the average time to return to play was 8.9 weeks in patients treated nonoperatively and 14.2 weeks for patients treated surgically. Greater stump retraction was observed in individuals treated surgically. Partial acute adductor tears were treated nonoperatively with physical therapy in all studies in the present systematic review. The average time to return to play was 1 to 6.9 weeks depending on the injury grade. The efficacy of adductor strengthening on preventing acute adductor tears has controversial results in the literature. CONCLUSION: Athletes with partial adductor injuries returned to play 1 to 7 weeks after injury with physical therapy treatment. Nonoperative or surgical treatment is an acceptable option for complete adductor longus tendon tear.

Transcriptional changes before and after forgetting of a long-term sensitization memory in Aplysia californica.

Most long-term memories are forgotten, becoming progressively less likely to be recalled. Still, some memory fragments may persist, as savings memory (easier relearning) can be detected long after recall has become impossible. What happens to a memory trace during forgetting that makes it inaccessible for recall and yet still effective to spark easier re-learning? We are addressing this question by tracking the transcriptional changes that accompany learning and then forgetting of a long-term sensitization memory in the tail-elicited siphon withdrawal reflex of Aplysia californica. First, we tracked savings memory. We found that even though recall of sensitization fades completely within 1 week of training, savings memory is still detectable at 2 weeks post training. Next, we tracked the time-course of regulation of 11 transcripts we previously identified as potentially being regulated after recall has become impossible. Remarkably, 3 transcripts still show strong regulation 2 weeks after training and an additional 4 are regulated for at least 1 week. These long-lasting changes in gene expression always begin early in the memory process, within 1 day of training. We present a synthesis of our results tracking gene expression changes accompanying sensitization and provide a testable model of how sensitization memory is forgotten.

Quantitative changes in the cervical neural foramen resulting from axial traction: in vivo imaging study.

BACKGROUND CONTEXT: Cervical traction has a long history as a method of conservative treatment for cervical spine diseases. However, information on quantitative changes in the cervical neural foramen resulting from axial traction in vivo is lacking. PURPOSE: To quantitatively evaluate the changes in the neural foramen of the cervical spine during axial traction in vivo. STUDY DESIGN: A prospective radiographic analysis of the cervical neural foramen of adult volunteers. PATIENT SAMPLE: Fifteen healthy volunteers (10 men, 5 women) without any history of cervical spine disease. OUTCOME MEASURES: The changes in cervical cross-sectional foraminal areas and heights were measured. METHODS: Cervical magnetic resonance (MR) images of the volunteers were taken at the neutral position and were reconstructed in the oblique plane perpendicular to the long axis of each neural foramen from the C2-3 to the C6-7 level. The changes in the neural foraminal dimensions at incremental axial traction forces (0, 5, 10, and 15 kg) were analyzed. RESULTS: After each 5-kg incremental increase in traction weight, there was a significant (p value less than .05) increase in area and height of the intervertebral foramen compared with the position in which no weight was applied. There was an average increase of 5.81%, 16.56%, and 18.9% in the foraminal area and an average increase of 3.75%, 8.67%, and 10.43% in foraminal height compared with the position with no weight at traction of 5, 10, and 15 kg, respectively. There was no statistically significant difference for the increase in foraminal area and height from 10 to 15 kg of traction (p value greater than .05). CONCLUSIONS: There was a significant increase in intervertebral foraminal area and height after each 5-kg increment in traction weight compared with the position in which no weight was applied. From 10 to 15 kg of traction, there was no significant change in the foraminal area and height.