Atomic Structure of Ultrathin Gold Nanowires

Understanding of the atomic structure and stability of nanowires (NWs) is critical for their applications in nanotechnology, especially when the diameter of NWs reduces to ultrathin scale (1–2 nm). Here, using aberration-corrected high-resolution transmission electron microscopy (AC-HRTEM), we report a detailed atomic structure study of the ultrathin Au NWs, which are synthesized using a silane-mediated approach. The NWs contain large amounts of generalized stacking fault defects. These defects evolve upon sustained electron exposure, and simultaneously the NWs undergo necking and breaking. Quantitative strain analysis reveals the key role of strain in the breakdown process. Besides, ligand-like morphology is observed at the surface of the NWs, indicating the possibility of using AC-HRTEM for surface ligand imaging. Moreover, the coalescence dynamic of ultrathin Au NWs is demonstrated by in situ observations. This work provides a comprehensive understanding of the structure of ultrathin metal NWs at atomic-scale and could have important implications for their applications

proof of equation 30 from Physically motivated models of polymer networks with dynamic cross-links: comparative study and future outlook

Polymer networks consisting of a mixture of chemical and physical cross-links are known to exhibit complex time-dependent behaviour due to the kinetics of bond association and dissociation. In this article, we highlight and compare two recent physically based constitutive models which describe the nonlinear viscoelastic behaviour of such transient networks. These two models are developed independently by two groups of researchers using different mathematical formulations. Here, we show that this difference can be attributed to different viewpoints: Lagrangian versus Eulerian. We establish the equivalence of the two models under the special situation where chains obey Gaussian statistics and steady-state bond dynamics. We provide experimental data demonstrating that both models can accurately predict the time-dependent uniaxial behaviour of a poly(vinylalcohol) PVA dual cross-link hydrogel. We review the advantages and disadvantages of both approaches in applications and close by discussing a list of open challenges and questions regarding the mathematical modelling of soft, viscoelastic networks

Flow diagram of the study.

TKA, total knee arthroplasty; CKD, chronic kidney disease; ASA, American Society of Anesthesiologists; PCIA, patient-controlled intravenous analgesia.</p

Intraoperative data.

Intraoperative data.</p

Safety outcomes.

Safety outcomes.</p

Epidural morphine improves postoperative analgesia in patients after total knee arthroplasty: A randomized controlled trial - Fig 2

The NRS pain scores at rest (A) and with movement (B). The pain score with movement at different time-points were significantly lower in the epidural morphine group than in the placebo group (P = 0.020 [mixed-effects maximum likelihood regression model]). The box and whiskers plots show medians, interquartile ranges and outer ranges, and individual points mean mild outliers (o, which are outside 1.5 times of interquartile range) and extreme outliers (*, which are outside 3 times of interquartile range). NRS, numerical rating scale.</p

Epidural morphine improves postoperative analgesia in patients after total knee arthroplasty: A randomized controlled trial - Fig 3

The percentages with moderate to severe pain at rest (A) and with movement (B). The percentage with movement at different time-points were significantly lower in the epidural morphine group than in the placebo group (P = 0.016 [mixed-effects logistic regression model]).</p

Effectiveness outcomes.

Effectiveness outcomes.</p

Epidural morphine improves postoperative analgesia in patients after total knee arthroplasty: A randomized controlled trial - Fig 4

The numbers of required (A) and given (B) boluses of the PCIA pump. The numbers of both required and given boluses during different time-intervals were significantly less in the epidural morphine group than in the placebo group (P = 0.017 and 0.005, respectively [mixed-effects maximum likelihood regression model]). The box and whiskers plots show medians, interquartile ranges and outer ranges, and individual points mean mild outliers (o, which are outside 1.5 times of interquartile range) and extreme outliers (*, which are outside 3 times of interquartile range). PCIA, patient-controlled intravenous analgesia.</p

Baseline data.

Baseline data.</p