Thermal-Assisted Multiscale Patterning of Nonplanar Colloidal Nanostructures for Multi-Modal Anti-Counterfeiting.

Nanotransfer printing of colloidal nanoparticles is a promising technique for the fabrication of functional materials and devices. However, patterning nonplanar nanostructures pose a challenge due to weak adhesion from the extremely small nanostructure-substrate contact area. Here, the study proposes a thermal-assisted nonplanar nanostructure transfer printing (NP-NTP) strategy for multiscale patterning of polystyrene (PS) nanospheres. The printing efficiency is significantly improved from ≈3.1% at low temperatures to ≈97.2% under the glass transition temperature of PS. Additionally, the arrangement of PS nanospheres transitioned from disorder to long-range order. The mechanism of printing efficiency enhancement is the drastic drop of Young's modulus of nanospheres, giving rise to an increased contact area, self-adhesive effect, and inter-particle necking. To demonstrate the versatility of the NP-NTP strategy, it is combined with the intaglio transfer printing technique, and multiple patterns are created at both micro and macro scales at a 4-inch scale with a resolution of ≈2757 pixels per inch (PPI). Furthermore, a multi-modal anti-counterfeiting concept based on structural patterns at hierarchical length scales is proposed, providing a new paradigm of imparting multiscale nanostructure patterning into macroscale functional devices.

[Risk Factors of Bleeding-related Perioperative Cardiac Arrest].

Objective To reveal the incidence,mortality,and risk factors of bleeding-related perioperative cardiac arrest(POCA). Methods We carried out a single-center retrospective case-control study which enrolled all the POCA cases reported from January 2010 to September 2020 in the patient safety incident reporting system of Peking Union Medical College Hospital.For the screening of risk factors,the patients were respectively assigned into the POCA group and the control group at a ratio of 1∶3 according to the same sex,age,American Society of Anesthesiologists(ASA)physical status,and type of surgery in the same month.Potential risk factors for POCA were first selected by univariate analysis.The significant risk factors were then checked based on the clinical experience and further included in the multivariate Logistic regression model. Results Totally 16 bleeding-related POCA cases were collected from the patient safety incident reporting system among the study period,with an overall incidence of 0.36/10 000.The blood loss volume of POCA group and control group was(7 037.50±5 477.70)ml and(375.63±675.14)ml,respectively(P<0.001),and 14(87.5%)patients suffering from bleeding-related POCA died within three days after anesthesia.According to the univariate analysis,patients' body mass index[(21.79±3.57)kg/m2 vs.(24.26±3.91)kg/m2,P=0.043],hemoglobin level[(113.44±31.08)g/L vs.(131.75±19.70)g/L,P=0.039],and alanine aminotransferase level[(17.31±7.73)U/L vs.(26.91±24.73)U/L,P=0.022]were significantly lower in the POCA group than in the control group.Further Logistic regression analysis showed that smaller body mass index and lower preoperative hemoglobin level were independently associated with the occurrence of bleeding-related POCA. Conclusions Bleeding-related POCA rarely occurred but had high mortality.Adequate precautions should be taken for the patients who are to receive surgeries with high risk of intraoperative massive bleeding.Elevating preoperative hemoglobin level might decrease the incidence of bleeding-related POCA.

Heterogeneous nucleation and growth of highly crystalline imine-linked covalent organic frameworks.

A heterogeneous nucleation and growth method is reported to synthesize imine-linked covalent organic frameworks (COFs). Excellent crystallinity and a high surface area are obtained. The introduction of heterogeneous nuclei suppresses the fast precipitation of amorphous structures at the early stage while promoting the crystallization of COFs during the growth process.