Explore the vast range of titles available.

Julius Caesar is the most important man in Rome. But many Romans fear that his power is too great, and that he plans to make himself king. A plot is hatching against him. Will Brutus and Mark Antony join the conspiracy against their friend for the good of Rome?

Chitosan, which is derived from chitin, is the only known natural alkaline cationic polymer. Chitosan is a biological material that can significantly improve the living standard of the country. It has excellent properties such as good biodegradability, biocompatibility, and cell affinity, and has excellent biological activities such as antibacterial, antioxidant, and hemostasis. In recent years, the demand has increased significantly in many fields and has huge application potential. Due to the poor water solubility of chitosan, its wide application is limited. However, chemical modification of the chitosan matrix structure can improve its solubility and biological activity, thereby expanding its application range. The review covers the period from 1996 to 2022 and was elaborated by searching Google Scholar, PubMed, Elsevier, ACS publications, MDPI, Web of Science, Springer, and other databases. The various chemical modification methods of chitosan and its main activities and application research progress were reviewed. In general, the modification of chitosan and the application of its derivatives have had great progress, such as various reactions, optimization of conditions, new synthetic routes, and synthesis of various novel multifunctional chitosan derivatives. The chemical properties of modified chitosan are usually better than those of unmodified chitosan, so chitosan derivatives have been widely used and have more promising prospects. This paper aims to explore the latest progress in chitosan chemical modification technologies and analyze the application of chitosan and its derivatives in various fields, including pharmaceuticals and textiles, thus providing a basis for further development and utilization of chitosan.

Burns can cause tremendous economic problems associated with irreparable harm to patients and their families. To characterize marine collagen peptides (MCPs) from the skin of Nile tilapia (Oreochromis niloticus), molecular weight distribution and amino acid composition of MCPs were determined, and Fourier transform infrared spectroscopy (FTIR) was used to analyze the chemical structure. Meanwhile, to evaluate the wound healing activity, in vitro and in vivo experiments were carried out. The results showed that MCPs prepared from the skin of Nile tilapia by composite enzymatic hydrolysis were composed of polypeptides with different molecular weights and the contents of polypeptides with molecular weights of less than 5 kDa accounted for 99.14%. From the amino acid composition, the majority of residues, accounting for over 58% of the total residues in MCPs, were hydrophilic. FTIR indicated that the main molecular conformations inside MCPs were random coil. In vitro scratch assay showed that there were significant effects on the scratch closure by the treatment of MCPs with the concentration of 50.0 μg/mL. In the experiments of deep partial-thickness scald wound in rabbits, MCPs could enhance the process of wound healing. Therefore, MCPs from the skin of Nile tilapia (O. niloticus) have promising applications in wound care.

Uncontrolled massive hemorrhage is one of the principal causes of death in trauma emergencies. By using catechol-modified chitosan (CS-C) as the matrix material and β glycerol phosphate (β-GP) as a thermo-sensitive agent, chitosan-based thermo-sensitive hydrogel loading oyster peptides (CS-C/OP/β-GP) were prepared at physiological temperature. The hemostatic performance of CS-C/OP/β-GP hydrogel was tested in vivo and in vitro, and its biological safety was evaluated. The results showed that the in vitro coagulation time and blood coagulation index of CS-C/OP/β-GP hydrogel were better than those of a commercial gelatin sponge. Notably, compared with the gelatin sponge, CS-C/OP/β-GP hydrogel showed that the platelet adhesion and erythrocyte adsorption rates were 38.98% and 95.87% higher, respectively. Additionally, the hemostasis time in mouse liver injury was shortened by 19.5%, and the mass of blood loss in the mouse tail amputation model was reduced by 18.9%. The safety evaluation results demonstrated that CS-C/OP/β-GP had no cytotoxicity to L929 cells, and the hemolysis rates were less than 5% within 1 mg/mL, suggesting good biocompatibility. In conclusion, our results indicate that CS-C/OP/β-GP is expected to be a promising dressing in the field of medical hemostasis.

As a key enabler of the access traffic steering, switching and splitting (ATSSS) feature, multipath transport can leverage the simultaneous use of several network paths and support seamless failover to improve both communication throughput and resilience. Therefore, a traffic scheduling strategy is necessary to determine the best network path combination that may improve the performance of multipath transport. To address this need, we developed a multiservice-type based transmission (MSTT) traffic scheduling optimization strategy, which involves three steps. First, the user equipment (UE) selects the number of data stream transmission paths, considering the service utility function, and either transmits all data streams via the 3GPP network or sends two streams, one via the 3GPP network and the other via the non-3GPP network. Second, the proposed method is used to select the transmission path for each data stream based on load balancing. Finally, an algorithm for optimizing traffic scheduling is formulated by applying the convex optimization problem to maximize the effective network capacity under a Delay Quality of Service (DQoS) constraint. The proposed traffic scheduling strategy is validated through simulation experiments. The results indicate that user satisfaction and effective capacity realized are always better than when using the always-best-connected and fixed-ratio power-allocation algorithms.

Our earlier research indicated that chitosan-gentamicin conjugate (CS-GT) possesses superior antimicrobial activity and good water solubility. To develop CS-GT-based scald dressings, the antibacterial properties of CS-GT were further studied, and the biosafety of CS-GT and the healing mechanism of CS-GT hydrogel was systematically explored in this article. It was found that cell viability shows a declined inclination with the prolonged culture time and the increased concentration of CS-GT. After three day’s culture, the cell viability could still remain at 79.72% when CS-GT concentration was as high as 1000 μg/mL. On the other hand, the hemolysis rate of CS-GT was lower than 5% when its concentration is 800 μg/mL. Therefore CS-GT has good cytocompatibility and hemocompatibility. A wound-healing experiment has shown that the skin healing rate of CS-GT hydrogel was the highest at 99.61%, followed by the positive control (wet burn ointment) 94.98%, GT hydrogel 87.50%, and matrix 77.39%. The blank control group, however, possessed the lowest healing rate of 75.45%. Further analysis indicated that CS-GT hydrogel could promote the synthesis of total protein (TP) in skin granulation tissue, resulting in the enhanced hydroxyproline (HYP) content, which facilitated collagen fibrogenesis, reduced cytokine expression in an inflammatory response, and, ultimately, accelerated wound healing. To sum up, CS-GT hydrogel is a promising scald dressing.

Stress may increase the risk of cardiovascular disease (CVD). Most studies on stress and CVD have been conducted in high-income Western countries, but whether stress is associated with CVD in other settings has been less well studied. To investigate the association of a composite measure of psychosocial stress and the development of CVD events and mortality in a large prospective study involving populations from 21 high-, middle-, and low-income countries across 5 continents. This population-based cohort study used data from the Prospective Urban Rural Epidemiology study, collected between January 2003 and March 2021. Participants included individuals aged 35 to 70 years living in 21 low-, middle-, and high-income countries. Data were analyzed from April 8 to June 15, 2021. All participants were assessed on a composite measure of psychosocial stress assessed at study entry using brief questionnaires concerning stress at work and home, major life events, and financial stress. The outcomes of interest were stroke, major coronary heart disease (CHD), CVD, and all-cause mortality. A total of 118 706 participants (mean [SD] age 50.4 [9.6] years; 69 842 [58.8%] women and 48 864 [41.2%] men) without prior CVD and with complete baseline and follow-up data were included. Of these, 8699 participants (7.3%) reported high stress, 21 797 participants (18.4%) reported moderate stress, 34 958 participants (29.4%) reported low stress, and 53 252 participants (44.8%) reported no stress. High stress, compared with no stress, was more likely with younger age (mean [SD] age, 48.9 [8.9] years vs 51.1 [9.8] years), abdominal obesity (2981 participants [34.3%] vs 10 599 participants [19.9%]), current smoking (2319 participants [26.7%] vs 10 477 participants [19.7%]) and former smoking (1571 participants [18.1%] vs 3978 participants [7.5%]), alcohol use (4222 participants [48.5%] vs 13 222 participants [24.8%]), and family history of CVD (5435 participants [62.5%] vs 20 255 participants [38.0%]). During a median (IQR) follow-up of 10.2 (8.6-11.9) years, a total of 7248 deaths occurred. During the course of follow-up, there were 5934 CVD events, 4107 CHD events, and 2880 stroke events. Compared with no stress and after adjustment for age, sex, education, marital status, location, abdominal obesity, hypertension, smoking, diabetes, and family history of CVD, as the level of stress increased, there were increases in risk of death (low stress: hazard ratio [HR], 1.09 [95% CI, 1.03-1.16]; high stress: 1.17 [95% CI, 1.06-1.29]) and CHD (low stress: HR, 1.09 [95% CI, 1.01-1.18]; high stress: HR, 1.24 [95% CI, 1.08-1.42]). High stress, but not low or moderate stress, was associated with CVD (HR, 1.22 [95% CI, 1.08-1.37]) and stroke (HR, 1.30 [95% CI, 1.09-1.56]) after adjustment. This cohort study found that higher psychosocial stress, measured as a composite score of self-perceived stress, life events, and financial stress, was significantly associated with mortality as well as with CVD, CHD, and stroke events.

Hemorrhea is one of the major problems in war, trauma care, and surgical operation that threaten the life of the injured and patients. As a novel polymeric hemostatic agent, biodegradable chitosan can stop bleeding through a variety of approaches. In this paper, chitosan with various molecular parameters was prepared from chitin as raw material through deacetylation, oxidative degradation, hydrophilic modification, and salt formation reactions. The influence of different polymer parameters on the hemostatic effects of chitosan was investigated by in vitro coagulation time and dynamic coagulation assay. The results showed that when the molecular weights were high (105–106) and approximate, the coagulation effect of chitosan improved with a decrease of the deacetylation degree and achieved a prominent level in a moderate degree of deacetylation (68.36%). With the same degree of deacetylation, the higher the molecular weight of chitosan, the better the procoagulant effect. The substituent derivatives and acid salts of chitosan showed significant procoagulant effects, especially the acid salts of chitosan. In addition, the hemostasis mechanism of chitosan with various parameters was preliminarily explored by analyzing the plasma recalcification time (PRT). The efforts in this paper laid a basis for further study of the structure–activity relationship and the mechanism of chitosan hemostasis.

Chitosan is a linear polysaccharide produced by deacetylation of natural biopolymer chitin. Owing to its good biocompatibility and biodegradability, non-toxicity, and easy processing, it has been widely used in many fields. After billions of years of survival of the fittest, many organisms have already evolved a nearly perfect structure. This paper reviews the research status of biomimetic functional materials that use chitosan as a matrix material to mimic the biological characteristics of bivalves, biological cell matrices, desert beetles, and honeycomb structure of bees. In addition, the application of biomimetic materials in wound healing, hemostasis, drug delivery, and smart materials is briefly overviewed according to their characteristics of adhesion, hemostasis, release, and adsorption. It also discusses prospects for their application and provides a reference for further research and development.

Background Recent publications reported a paradoxical finding that there was an inverse association between the number of standard modifiable risk factors (SMuRFs; smoking, hypertension, diabetes, and hyperlipidemia) and mortality in patients with myocardial infarction. However, the current evidence is only limited to those highly developed countries with advanced medical management systems. Methods The China Acute Myocardial Infarction registry is a prospective observational study including patients with acute myocardial infarction from three-level hospitals across 31 administrative regions throughout mainland China. A total of 16,228 patients with first-presentation ST-elevation myocardial infarction (STEMI) admitted to hospitals from January 2013 to September 2014 were enrolled in the current analysis. Cox proportional hazard models adjusting for baseline characteristics, clinical profiles at presentation, and in-hospital treatments were used to assess the association of the number of SMuRFs with all-cause mortality at 30 days after STEMI presentation. Results A total of 1918 (11.8%), 11,503 (70.9%), and 2807 (17.3%) patients had 0, 1–2, and 3–4 SMuRFs at presentation, respectively. Patients with fewer SMuRFs were older and more likely to be females, experienced longer pre-hospital delays, and were less likely to receive primary percutaneous coronary intervention and evidence-based medications. Compared with those without any SMuRF, patients with 1–2 SMuRFs and 3–4 SMuRFs were associated with an HR of 0.74 (95% CI, 0.63–0.87) and 0.63 (0.51–0.77) for all-cause mortality up to 30 days in the unadjusted model ( P trend < 0.0001). However, after multivariate adjustment, the number of SMuRFs was positively associated with increased mortality risk (HR for 1–2 SMuRFs, 1.15 [0.95–1.39]; HR for 3–4 SMuRFs, 1.31 [1.02–1.68]; P trend = 0.03), and the association was only significant among patients admitted to hospitals beyond 12 h from onset (HR for 1–2 SMuRFs, 1.39 [1.03–1.87]; HR for 3–4 SMuRFs, 2.06 [1.41–3.01]) but not their counterparts ( P interaction = 0.01). Conclusions The increased crude mortality risk among patients without SMuRFs is explained by confounding factors related to their poor risk profiles (old age, longer pre-hospital delays, and poor clinical management). After multivariate adjustment, a higher risk-factor burden was associated with poor prognosis among patients with STEMI.