The effect of junction modes between backbones and side chains of polyimides on the stability of liquid crystal vertical alignment.

Polyimides (PI-N9 and PI-N12) were synthesized from two kinds of functional diamines, whose junction modes between backbones and side chains were different. Side chains of PI-N9 were linked to the backbones with an ether bond spacer; and side chains of PI-N12 were directly linked to the backbones without any spacer. The PI alignment layer surfaces were investigated by atomic force microscopy, surface free energy measurements, X-ray photo-electron spectroscopy and polarized attenuated total reflection Fourier transformed infrared spectroscopy. It was found that PI-N9 lost the vertical alignment capability after high-strength rubbing, while PI-N12 could still induce liquid crystals (LCs) to align vertically under the same condition. The mechanism of the macroscopic molecular orientation of the PI surface is proposed. During the high-strength rubbing process, the side chain could rotate around the flexible ether bond which existed between the side chain and the main chain of PI-N9 and then fell over. Therefore, PI-N9 could not induce the vertical alignment of LCs anymore. But PI-N12 could keep LCs aligning vertically all the time, which proved that the stability of LC alignment induced by PI-N12 was better.

Hybrid Bioactive Hydrogel Promotes Liver Regeneration through the Activation of Kupffer Cells and ECM Remodeling After Partial Hepatectomy.

Partial hepatectomy is an essential surgical technique used to treat advanced liver diseases such as liver tumors, as well as for performing liver transplants from living donors. However, postoperative complications such as bleeding, abdominal adhesions, wound infections, and inadequate liver regeneration pose significant challenges and increase morbidity and mortality rates. A self-repairing mixed hydrogel (O5H2/Cu2+/SCCK), containing stem cell derived cytokine (SCCK) derived from human umbilical cord mesenchymal stem cells (HUMSCs) treated with the traditional Chinese remedy Tanshinone IIA (TSA), is developed. This SCCK, in conjunction with O5H2, demonstrates remarkable effects on Kupffer cell activation and extracellular matrix (ECM) remodeling. This leads to the secretion of critical growth factors promoting enhanced proliferation of hepatocytes and endothelial cells, thereby facilitating liver regeneration and repair after partial hepatectomy. Furthermore, the hydrogel, featuring macrophage-regulating properties, effectively mitigates inflammation and oxidative stress damage in the incision area, creating an optimal environment for postoperative liver regeneration. The injectability and strong adhesion of the hydrogel enables rapid hemostasis at the incision site, while its physical barrier function prevents postoperative abdominal adhesions. Furthermore, the hydrogel's incorporation of Cu2+ provides comprehensive antibacterial effects, protecting against a wide range of bacteria types and reducing the chances of infections after surgery.

Investigation on the hesitancy of COVID-19 vaccination among liver transplant recipients: A cross-sectional study in China.

Objectives: The hospitalization and mortality rate from COVID-19 appears to be higher in liver transplant recipients when compared with general populations. Vaccination is an effective strategy to reduce the risk during the COVID-19 pandemic. We aimed to evaluate COVID-19 vaccine hesitancy in liver transplant recipients. Methods: In April 2022, we conducted an online-based survey through WeChat platform to investigate the vaccination hesitancy among liver transplant recipients followed at Shanghai Renji Hospital and further explore possible influencing factors. Survey items included multiple choice, Likert-type rating scale and open-ended answers. Participants were classified as no hesitancy group and hesitancy group. Using univariate analysis, ROC curve analysis and multiple logistic regression to evaluate associations between baseline characteristics and COVID-19 vaccine hesitancy. Results: 449 liver transplant recipients participated in the survey with 299 (66.6%) of them being categorized as vaccine hesitancy. In no hesitancy group, 73 (48.7%) recipients had completed vaccination, while 77 (51.3%) were not yet but intended to be vaccinated. In contrast, 195 (65.2%) recipients in hesitancy group were hesitant to get vaccinated, while the remaining 104 (34.8%) refused. The most common side effect was injection arm pain (n = 9, 12.3%). The common reasons for vaccine willingness was trusted in the effectiveness of the vaccine and fear of contracting COVID-19. The most common reason for vaccination hesitancy is fear of side effects, and the most effective improvement was the support from the attending physician. Factors associated with vaccine hesitancy include female sex, influenza vaccination status, awareness of the importance and safety of vaccine, attitudes of doctors and others toward vaccine, medical worker source information of vaccine, relative/friend with medical background, total score of VHS (Vaccine Hesitancy Scale), accessibility of vaccine. Conclusion: For liver transplant recipients, COVID-19 vaccine is an important preventive measure. Identifying the factors influencing COVID-19 vaccine hesitancy is therefore critical to developing a promotion plan. Our study shows that more comprehensive vaccine knowledge popularization and relevant medical workers' training can effectively improve the acceptance of COVID-19 vaccine in this population.