555 research outputs found
Tunable solid-state fluorescent materials for supramolecular encryption
Tunable solid-state fluorescent materials are ideal for applications in security printing technologies. A document possesses a high level of security if its encrypted information can be authenticated without being decoded, while also being resistant to counterfeiting. Herein, we describe a heterorotaxane with tunable solid-state fluorescent emissions enabled through reversible manipulation of its aggregation by supramolecular encapsulation. The dynamic nature of this fluorescent material is based on a complex set of equilibria, whose fluorescence output depends non-linearly on the chemical inputs and the composition of the paper. By applying this system in fluorescent security inks, the information encoded in polychromic images can be protected in such a way that it is close to impossible to reverse engineer, as well as being easy to verify. This system constitutes a unique application of responsive complex equilibria in the form of a cryptographic algorithm that protects valuable information printed using tunable solid-state fluorescent materials
Comparing levonorgestrel intrauterine system versus hysteroscopic resection in patients with postmenstrual spotting related to a niche in the caesarean scar (MIHYS NICHE trial) : Protocol of a randomised controlled trial
Funding This work was supported by National Key Research and Development Programme (2018YFC1002102), Research Project of Shanghai Health and Fitness Commission (201940012,20184Y0344)),Shanghai Municipal Key Clinical Specialty (shslczdzk01802), Medical Engineering Cross Funds from Shanghai Jiao Tong University (YG2017QN38, ZH2018QNA36, YG2021ZD31), Medical innovation research project of the 2020 'Science and Technology Innovation Action Plan' of Shanghai Science and Technology Commission (20Y11907700), and Clinical Science and Technology Innovation Project of Shanghai Hospital Development Center(SHDC22020216).Peer reviewedPublisher PD
Relative Unidirectional Translation in an Artificial Molecular Assembly Fueled by Light
Advanced Polymer Designs for Direct‐Ink‐Write 3D Printing
The rapid development of additive manufacturing techniques, also known as three-dimensional (3D) printing, is driving innovations in polymer chemistry, materials science, and engineering. Among current 3D printing techniques, direct ink writing (DIW) employs viscoelastic materials as inks, which are capable of constructing sophisticated 3D architectures at ambient conditions. In this perspective, polymer designs that meet the rheological requirements for direct ink writing are outlined and successful examples are summarized, which include the development of polymer micelles, co-assembled hydrogels, supramolecularly cross-linked systems, polymer liquids with microcrystalline domains, and hydrogels with dynamic covalent cross-links. Furthermore, advanced polymer designs that reinforce the mechanical properties of these 3D printing materials, as well as the integration of functional moieties to these materials are discussed to inspire new polymer designs for direct ink writing and broadly 3D printing
A 4-node quadrilateral flat shell element formulated by the shape-free HDF plate and HSF membrane elements
An ultra-dynamic anion-cluster-based organic framework
Porous organic frameworks that can dynamically expand their voids to guest uptake remain formidable to design. The challenge comes from finding the balance between rigidity and flexibility. Rigidity is required to retain the framework, and the flexibility is needed for reversible expansion/contraction. Herein, we introduced bisulfate anion clusters as soft joints to construct a single-crystalline hydrogen-bonded cross-linked organic framework HCOF-6. Upon the uptake of guest molecules, the anion clusters of HCOF-6 were disrupted, allowing the crystal to expand rapidly (<40 min) to more than twice its original length. Removing these guests restored the anion clusters and the crystallinity of HCOF-6 quickly (<10 min). These guest-induced material size expansions and contractions are highly reversible, and the dynamic anion cluster dissociation-reassociation is confirmed by molecular dynamics simulations and solid-state NMR experiments. The guest-induced size change of HCOF-6 highlights a new approach to synthesize dynamic framework materials by introducing anion clusters.This is a manuscript of an article published as Samanta, Jayanta, Rick W. Dorn, Wenlin Zhang, Xuanfeng Jiang, Mingshi Zhang, Richard J. Staples, Aaron J. Rossini, and Chenfeng Ke. "An ultra-dynamic anion-cluster-based organic framework." Chem 8, no. 1 (2022): 253-267. DOI: 10.1016/j.chempr.2021.11.014. Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0). Copyright 2021 Elsevier Inc. DOE Contract Number(s): AC02-07CH11358; DMR‐1844920; 1919565.
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The effect of a hysteroscopic niche resection compared with Levonorgestrel-releasing intrauterine device on postmenstrual spotting in patients with a symptomatic niche in the uterine cesarean scar: A prospective cohort study
Objective: To compare the effect of a hysteroscopic niche resection with a Levonorgestrel-releasing intrauterine device (LNG-IUD, 52 mg) on postmenstrual spotting duration in patients with a symptomatic niche in the uterine cesarean scar. Study design: This prospective cohort study was conducted at the International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiaotong University, China. Patients with postmenstrual spotting symptomatic niches were allocated to hysteroscopy group or LNG-IUD group based on the shared medical decision-making approach, and were followed up for 1 year after treatment. Main outcome measures: The primary outcome was reduced postmenstrual spotting days at 6th month after treatment. Secondary outcomes were effectiveness rate (proportion of patients with spotting days reduced by at least 50% from baseline), menstrual characteristics, menstruation satisfaction, direct medical costs, complications and side effects. Results: 78 out of the 82 eligible patients were included, 36 patients in both group finished 1-year follow-up. Reduced spotting days at the 6th month was 7 days in LNG-IUD group, significantly higher than 5 days in hysteroscopy group, P = 0.004; The effectiveness rate increased over time within 1 year after the insertion of LNG-IUD (63.89%, 83.33%, 88.89%, 88.89%, P for trend = 0.006), while no trend change was observed in hysteroscopy group (71.05%, 71.05%, 66.67%, 61.11%, P for trend = 0.77). The mean direct medical costs were 817[785,856] in the LNG-IUD group (p<0.001). 2 patients removed IUD and 2 patients reported weight gain of more than 5 kg and breast distended pain in LNG-IUD group; 2 patients got pregnant in hysteroscopy group. No serious complications were observed in both groups. Conclusions: LNG-IUD is more effective in the treatment of postmenstrual spotting from the 6th month onwards than a hysteroscopic niche resection in patients with a symptomatic niche at lower direct costs
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