Copolyester toughened poly(lactic acid) biodegradable material prepared by in situ formation of polyethylene glycol and citric acid.

Polylactic acid (PLA) is a high-modulus, high-strength bio-based thermoplastic polyester with good biodegradability, which is currently a promising environmentally friendly material. However, its inherent brittleness has hindered its widespread use. In this study, we reported a simple and non-toxic strategy for toughening PLA, using biodegradable materials such as polyethylene glycol (PEG) and citric acid (CA) as precursors. Through reactive melt blending with PLA, PEG and CA form PEGCA copolyesters in situ during blending. At the same time, CA can react with PLA and PEG, forming a copolyester structure at the interface of the two phases, improving the interfacial compatibility between PEG and PEGCA with PLA. Fourier transform infrared spectroscopy confirms this. Experimental results show that when the content of PEG/CA reaches 15% (PLA/PEG/CA-15%) in the blends, the impact strength of the blend was 4.47 kJ m-2, and the maximum elongation at break was as high as 360.1%, which were about 2 and 44 times higher than those of pure PLA, respectively. Moreover, the tensile strength was still maintained at the level of 70%. This work can expand the application of PLA in food packaging and medical supplies.

Trimethyl chitosan-cysteine-based nanoparticles as an effective delivery system for portulacerebroside A in the management of hepatocellular carcinoma cells in vitro and in vivo.

Portulacerebroside A (PCA), a cerebroside compound extracted from Portulaca oleracea L., has been shown to suppress hepatocellular carcinoma (HCC) cells. This study aims to investigate the effectiveness of trimethyl chitosan-cysteine (TMC-Cys) nanocarrier in delivering PCA for HCC management and to elucidate the molecular mechanisms behind PCA's function. TMC-Cys nanocarriers notably augmented PCA's function, diminishing the proliferation, migration, and invasiveness of HCC cells in vitro, reducing hepatocellular tumorigenesis in immunocompetent mice, and impeding metastasis of xenograft tumours in nude mice. Comprehensive bioinformatics analyses, incorporating Super-PRED systems alongside pathway enrichment analysis, pinpointed toll-like receptor 4 (TLR4) and epidermal growth factor receptor (EGFR) as two promising targets of PCA, enriched in immune checkpoint pathway. PCA/nanocarrier (PCA) reduced levels of TLR4 and EGFR and their downstream proteins, including programmed cell death ligand 1, thereby increasing populations and activity of T cells co-cultured with HCC cells in vitro or in primary HCC tumours in mice. However, these effects were counteracted by additional artificial activation of TLR4 and EGFR. In conclusion, this study provides novel evidence of PCA's function in immunomodulation in addition to its direct tumour suppressive effect. TMC-Cys nanocarriers significantly enhance PCA efficacy, indicating promising application as a drug delivery system.

Exposure to low humidex increases the risk of hip fracture admissions in a subtropical coastal Chinese city.

OBJECTIVE: The adverse impacts of meteorological factors on human health have attracted great attention. However, no studies have investigated the nonlinear effects of humidex on hip fractures (HF), particularly in middle-aged and older adults. This study aimed to quantify the impacts of humidex, a comprehensive index of temperature and relative humidity, on HF admissions. METHODS: Daily HF admissions, meteorological variables and air pollutants in the subtropical coastal city of Shantou, China, from 2015 to 2020 were collected. A generalized linear regression model combined with a distributed lag nonlinear model was applied to explore the exposure-lag-response relationship between humidex and HF admissions. Subgroup analyses were also conducted by gender, age and season. Attributable fractions (AF) and attributable numbers (AN) were used to represent the burden of disease. RESULTS: A total of 6200 HF admissions were identified during the study period. Taking the median humidex (31.9) as a reference, the single-day lag effects of low humidex (13, 2.5th percentile) were significant at lag 0 [relative risk (RR) = 1.145, 95 % confidence interval (CI): 1.041-1.259] to lag 2 (RR = 1.049, 95 % CI: 1.010-1.089). The cumulative lag effects of low humidex were significant at lag 0-0 (RR = 1.145, 95 % CI: 1.041-1.259) to lag 0-6 (RR = 1.258, 95 % CI: 1.010-1.567) and reached a maximum at lag 0-3 (RR = 1.330, 95 % CI: 1.113-1.590). High humidex (44, 97.5th percentile) was not associated with the risk of HF. Females and people over the age of 75 appeared to be more susceptible to low humidex. In addition, the adverse effects of low humidex were more pronounced in the cold season. The AF and AN of low humidex on HF admissions were 24.8 % (95 % CI: 10.2-37.1 %) and 1538, respectively. CONCLUSION: Low humidex was associated with an increased risk of HF admissions. The government should take timely measures to prevent people from being exposed to low humidex to effectively reduce HF admissions.

A multicenter retrospective analysis: Factors influencing hepatic adverse events induced by immunotherapy in advanced liver cancer.

OBJECTIVES: To analyze the clinical characteristics and influencing factors of hepatotoxicity in patients with advanced hepatocellular carcinoma (HCC) treated with programmed cell death protein-1 (PD-1) inhibitors, and to provide a theoretical basis for the treatment of immune-related hepatotoxicity in patients with advanced HCC. METHODS: Retrospective analysis of clinical data of patients with advanced HCC from February 2021 to February 2023, in order to summarize and statistically analyze the influencing factors of immune-related liver adverse reactions. RESULTS: A total of 135 patients met the inclusion criteria, among whom 46 patients experienced varying degrees of immune-related liver adverse reactions, with an incidence rate of 34.1% (46/135). The time range of immune-related liver adverse reactions was 3-26 weeks, with a median time of 4 weeks. The age range of immune-related liver adverse reactions was 34-73 years, with a median age of 62 years. Statistical analysis of the influencing factors and liver adverse reactions showed that age, total bilirubin level, and Child-Pugh (C-P) grading were influencing factors for the occurrence of liver adverse reactions (p < .05), and among these three influencing factors, the proportion of males with ≥2 influencing factors was higher than that of females; liver function C-P B was an independent influencing factor for liver adverse reactions (p < .05). CONCLUSION: For male patients over 60 years old, with bilirubin levels ≥51 µmol/L and liver function C-P B, close observation of the occurrence of immune-related adverse reactions during treatment is recommended.

Strong synergistic toughening and compatibilization enhancement of carbon nanotubes and multi-functional epoxy compatibilizer in high toughened polylactic acid (PLA)/poly (butylene adipate-co-terephthalate) (PBAT) blends.

Different carbon nanotubes (CNTs) contents on high-toughness polylactic acid (PLA)/poly (butylene adipate-co-terephthalate) (PBAT) blends were prepared by one-step melt blending using multifunctional epoxy oligomers (ADR) as reactive compatibilizer. During reactive blending, the PLA or PBAT chains were grafted onto the CNTs by allowing the carboxyl or hydroxyl groups to react with epoxy groups and form a branched CNTs-based copolymer. The branched copolymer at the interface between PLA and PBAT was dispersed through emulsion to improve the polymer-polymer or polymer-nanoparticle entanglement between the molecular chains. Interfacial adhesion, interface layer stability, and system viscoelasticity and compatibility were improved as indicated by rheological curves and dynamic mechanical analysis. The strength and toughness of the sample were simultaneously improved by the addition of CNTs and ADR. The impact strength reached 35.3 kJ/m2, which was approximately 7 times that of the PLA/PBAT blend, and the tensile strength was also increased from 33.6 MPa to 42.8 MPa. The properties of PLA/PBAT blend synergistically modified by ADR and CNTs were obviously better than those of PLA/PBAT blend modified by ADR or CNTs. The toughening synergistic effect of ADR and CNTs on PLA/PBAT was observed with efficiency reaching 3.05. With the further understanding of the toughening mechanism, the branched CNTs-based copolymers and CNTs clusters induce a synergistic effect, which increased the interfacial adhesion and ability of energy dissipation and stress transmission.

Risk assessment and disease burden of extreme precipitation on hospitalizations for acute aortic dissection in a subtropical coastal Chinese city.

Background: Extreme precipitation events are becoming more frequent due to climate change. The present study aimed to explore the impacts of extreme precipitation on hospitalizations for acute aortic dissection (AAD) and to identify susceptible populations and quantify the corresponding disease burden. Methods: The present study used a distributed lag nonlinear model (DLNM) with a quasi-Poisson function to investigate the association between extreme precipitation (≥95th percentile) and the risk of hospitalizations for AAD from 2015 to 2020 in Shantou, Guangdong Province, China. Results: The significant adverse effects of extreme precipitation (relative to no precipitation) on daily AAD hospitalizations lasted from lag 5 [relative risk (RR): 1.0318, 95% confidence interval (CI): 1.0067-1.0575] to lag 9 (RR: 1.0297, 95% CI: 1.0045-1.0555) and reached its maximum at lag 7 (RR: 1.0382, 95% CI: 1.0105-1.0665). Males and older adult individuals (≥60 years) were more susceptible to extreme precipitation. A total of 3.68% (118 cases) of AAD hospitalizations were due to extreme precipitation. Conclusion: Extreme precipitation was significantly correlated with AAD hospitalizations. Government departments should actively implement extreme precipitation intervention measures to strengthen the protection of males and the older adult (≥60 years) and effectively reduce AAD hospitalizations.

Impacts of short-term air pollution exposure on appendicitis admissions: Evidence from one of the most polluted cities in mainland China.

Background: Emerging evidence indicates that air pollutants contribute to the development and progression of gastrointestinal diseases. However, there is scarce evidence of an association with appendicitis in mainland China. Methods: In this study, Linfen city, one of the most polluted cities in mainland China, was selected as the study site to explore whether air pollutants could affect appendicitis admissions and to identify susceptible populations. Daily data on appendicitis admissions and three principal air pollutants, including inhalable particulate matter (PM10), nitrogen dioxide (NO2), and sulfur dioxide (SO2) were collected in Linfen, China. The impacts of air pollutants on appendicitis were studied by using a generalized additive model (GAM) combined with the quasi-Poisson function. Stratified analyses were also performed by sex, age, and season. Results: We observed a positive association between air pollution and appendicitis admissions. For a 10 µg/m3 increase in pollutants at lag01, the corresponding relative risks (RRs) and 95% confidence intervals (95% CIs) were 1.0179 (1.0129-1.0230) for PM10, 1.0236 (1.0184-1.0288) for SO2, and 1.0979 (1.0704-1.1262) for NO2. Males and people aged 21-39 years were more susceptible to air pollutants. Regarding seasons, the effects seemed to be stronger during the cold season, but there was no statistically significant difference between the seasonal groups. Conclusions: Our findings indicated that short-term air pollution exposure was significantly correlated with appendicitis admissions, and active air pollution interventions should be implemented to reduce appendicitis hospitalizations, especially for males and people aged 21-39 years.

Crystallization behaviors regulations and mechanical performances enhancement approaches of polylactic acid (PLA) biodegradable materials modified by organic nucleating agents.

Polylactic acid (PLA) has attracted much attention because of its good biocompatibility, biodegradability, and mechanical properties. However, the slow crystallization rate of PLA during molding leads to its poor heat resistance, which limit its diffusion for many industrial applications. In this review, the relationship between PLA crystallization and its molecular structure and processing conditions is summarized. From the perspective of the regulation of PLA crystallization by organic nucleating agents, the research progress of organic micromolecule (e.g., esters, amides, and hydrazides), organic salt, supramolecular, and macromolecule nucleating agents on the crystallization behavior of PLA is mainly introduced. The nucleation mechanism of PLA is expounded by organic nucleating agents, and the effect of the interaction force between organic nucleating agents and PLA molecular chains on the crystallization behavior of PLA is analyzed. The effects of the crystallization behavior of PLA on its mechanical properties and heat resistance are discussed. It will provide a theoretical reference for the development and application of high-efficiency nucleating agents.

Factors associated with behavioral intention of free and self-paid severe acute respiratory coronavirus virus 2 (SARS-CoV-2) vaccination based on the social cognitive theory among nurses and doctors in China.

OBJECTIVE: To examine the associations between factors based on the social cognitive theory (SCT) and behavioral intention among doctors and nurses in China toward free and self-paid (600 RMB or US$91) severe acute respiratory coronavirus virus 2 (SARS-CoV-2) vaccination given 80% effectiveness and rare mild side effects. DESIGN: Cross-sectional study. SETTING: Public hospitals. PARTICIPANTS: The study included 362 doctors and 1,702 nurses in major departments of 5 hospitals of 3 Chinese provinces. METHODS: An anonymous online survey was conducted from October to November 2020, facilitated by hospital administrators through online WeChat/QQ working groups. Data on outcome expectations, self-efficacy, norms, and COVID-19-related work experiences were collected. Multivariate logistic regression models were used for data analyses. RESULTS: The logistic regression analysis showed that physical (eg, protective effect of vaccination) and self-evaluative outcome expectations (eg, anticipated regret), self-efficacy, norms (eg, descriptive norm, subjective norm, professional norm, and moral norm), and job satisfaction were significantly and positively associated with the free and self-paid SARS-CoV-2 vaccination intention outcomes among doctors and nurses, adjusted for background variables. Doctors who had engaged in COVID-19-related work reported higher self-paid vaccination intention. CONCLUSIONS: Health promotion is needed to improve the uptake of SARS-CoV-2 vaccination among healthcare workers. Such interventions may consider modifying the identified factors of vaccination intention, including strengthening perceived efficacy, positive feelings about vaccination, the need to avoid future regret, self-efficacy, and social norms. Future studies should examine the actual behavior patterns of SARS-CoV-2 vaccination, and the efficacy of promotion intervention should be tested in randomized controlled studies.

Parental acceptability of COVID-19 vaccination for children under the age of 18 years among Chinese doctors and nurses: a cross-sectional online survey.

This study investigated parental acceptability of COVID-19 vaccination for children under the age of 18 years among Chinese parents who are healthcare workers. A closed online survey among full-time doctors or nurses employed by the five collaborative hospitals who had access to smartphones was conducted. Facilitated by the hospital administrators, prospective participants received an invitation sent by the research team via the existing WeChat/QQ groups to complete an online questionnaire. A total of 2,281 participants completed the survey. This study was a sub-analysis of 1332 participants who had at least one child under the age of 18 years. Among the participants, 44.5% reported that they would likely or very likely to have their children under the age of 18 years take up COVID-19 vaccination in the next six months. After adjusting for significant background characteristics, perceived higher vaccine efficacy, longer protection duration, perceived high/very high chance for China to prevent another wave of COVID-19 outbreak with vaccines in place and willingness to receive a COVID-19 vaccination for themselves were associated with higher parental acceptability of COVID-19 vaccination. At interpersonal level, higher frequency of information exposure through social media and direct interpersonal communication were associated with higher parental acceptability of COVID-19 vaccination, while knowing some people who experienced serious side effects following COVID-19 vaccination were associated with lower parental acceptability of COVID-19 vaccination. Despite their important roles in vaccination promotion, Chinese doctors and nurses showed low parental acceptability of COVID-19 vaccination. Effective health promotion is needed when COVID-19 vaccination become available.

Risk Factors Associated with Peer Victimization and Bystander Behaviors among Adolescent Students.

Despite the prevalence of the phenomena of peer victimization and bystander behaviors, little data has generated to describe their relationships and risk factors. In this paper, a self-administered survey using a cross-sectional cluster-random sampling method in a sample of 5450 participants (2734 girls and 2716 boys) between 4th and 11th grades was conducted at six schools (two primary schools and four middle schools) located in Shantou, China. Self-reported peer victimization, bystander behaviors and information regarding parents' risky behaviors and individual behavioral factors were collected. Multinomial logistic regression analysis was applied to evaluate risk factors affecting peer victimization and bystander behaviors. The results indicated that urban participants were more likely to become bullying victims but less likely to become passive bystanders. Contrarily, bullying victimization was related to the increasing of passive bystander behaviors. Father drinking and mother smoking as independent factors were risk factors for peer victimization. Participants who were smoking or drinking had a tendency to be involved in both peer victimization and passive bystander behaviors. This study suggested that bystander behaviors, victims' and parents' educations play a more important role in peer victimization than previously thought.