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Functional polymer material is a type of polymer materials with special functions such as catalysis, conductivity, photosensitivity, and biological activity. They have the function of transmitting, converting, or storing substances, energy, and information. Functional polymer materials have the characteristics of light weight, numerous varieties and strong specialty, which make them widely used in machinery, information technology, biomedicine and other fields. The development of functional polymer materials is very rapid. In order to meet the needs of new technologies in various fields, functional polymer materials are gradually developing towards multi-function such as electromagnetic materials and photothermal materials. With the emergence of smart polymers, functional polymer materials are gradually being developed towards intelligence, such as self-healing functional polymer materials and shape memory materials. The research progress of functional polymer materials in recent years was summarized in this article and their applications were briefly described, with emphasis on reactive functional polymer materials, optical functional polymer materials, electrical functional polymer materials, biomedical functional polymer materials, environmentally degradable polymer materials, shape memory polymer materials and smart polymer hydrogel. At present, most functional polymer materials only have traditional functions such as photoelectricity or special functions such as shape memory. It is believed that functional polymer materials with both traditional and special functions will be the development direction of future materials.

Objective To analyze the factors related to gallbladder cholesterol polyp (GCP) and gallbladder adenoma (GA) and establish predictive model for distinction between GCP and GA before surgery. Methods Patients with gallbladder polyps diameter≥10 mm diagnosed by ultrasonography in Xuanwu Hospital Capital Medical University and the First Hospital of Peking University from January 2015 to December 2019 were studied. There were GCP group and GA group based pathological diagnosis. Univariate and multivariate analyses were used to study the factors related to GCP and GA. Logistic linear regression was used to establish a predictive model and to evaluate the diagnostic effect. Results A total of 384 patients with gallbladder polyp were in this study with male to female ratio of 1:1.49 and age of (50.32±14.15) years. There were 250 patients (65.1%) in GCP group and 134 patients (34.9%) in GA group. Univariate analysis showed that five factors in quantitative data including age, blood glucose, low density lipoprotein, albumin, and total bile acid and three factors in count data including age 50 years or older, low density lipoprotein ≥3.1 mmol/L and total bile acid ≥10.0 μmol/L had significant difference statistically between two groups (P

Poloxamer is a thermo-sensitive synthetic polymer that can achieve sol-gel transition with temperature change, but its relative molecular mass is low, and the hydrogel structure is difficult to maintain for a long time. The thermo-sensitive sodium alginate/poloxamer composite hydrogel (SA/P407) was synthesized by mixing poloxamer with sodium alginate. The chemical structures, temperature sensitivity, microscopic morphology, dynamic viscoelasticity and in vitro drug release behaviors of sodium alginate/poloxamer composite hydrogels were investigated by FT-IR, test tube inversion, SEM, rheometer and UV-Vis spectroscopy. In addition, the swelling properties of sodium alginate/poloxamer composite hydrogels were also studied. These results show that the sodium alginate/poloxamer composite hydrogel is thermo-sensitive, and the gelation concentration (mass fraction is 6%) of poloxamer at body temperature can be reduced by adding sodium alginate. By controlling the mass ratio of sodium alginate and poloxamer, the sol-gel transition temperature can be kept between room temperature and body temperature (25-37 ℃), and the gelation time can be shortened to 84 s. The sodium alginate/poloxamer composite hydrogel has a structural feature of high porosity and interconnected pores, and its pore size ranges from 20 μm to 80 μm. With the increase of sodium alginate, the swelling rate of the sodium alginate/poloxamer composite hydrogel is gradually decreased. The sodium alginate/poloxamer composite hydrogel shows sustained release of the anticancer drug gemcitabine, and the drug release time can reach 72 hours. Sodium alginate/poloxamer composite hydrogel has an important application prospect in the field of injectable carriers for sustained drug release.

Carboxymethyl chitosan is an important chitosan derivative with good biocompatibility and degradability, and has a wide range of biomedical applications. In this study, water-soluble carboxymethyl chitosan derivative that can be photo-crosslinked by UV irradiation was synthesized. Methacrylated carboxymethyl chitosan (M-CMCS) was synthesized by N-methacrylation of carboxymethyl chitosan (CMCS). The chemical structures of M-CMCS were characterized by 1H NMR and FT-IR. The M-CMCS hydrogels with different degrees of crosslinking was prepared by UV-triggered photo-crosslinking. The microscopic morphology, mechanical properties, swelling properties, enzymatic degradation properties and in vitro drug release behaviors of M-CMCS hydrogels were investigated by SEM, rheometer, and UV-Vis spectroscopy, respectively. The results show that the degree of methacrylation is gradually increased as the molar ratio of glycidyl methacrylate to carboxymethyl chitosan increases. M-CMCS hydrogels have the structure of high porosity and interconnected pores with the pore size of 1-20 μm. The swelling ratio of M-CMCS hydrogels is decreased as the degree of crosslinking increases. M-CMCS hydrogel can be slowly degraded by lysozyme, and the degradation rate is decreased by increasing the degree of crosslinking. M-CMCS hydrogels show sustained release behavior for anticancer drug gemcitabine, and the drug release can be extended to 4 days. Photo-crosslinked M-CMCS hydrogels show great promise for drug release and tissue engineering.

Poloxamer is a thermo-sensitive polymer that can form gel at a concentration of 15.0%(mass fraction, the same as below)-30.0%.In order to decrease the gelatinization concentration and improve drug release properties of poloxamer at body temperature, thermo-sensitive N-acetyl glycol chitosan/poloxamer composite hydrogel was prepared by complexing N-acetyl glycol chitosan with poloxamer 407 (GC/P407).The structure, thermo-sensitivity, mechanical properties, morphology and in vitro drug release properties of GC/P407 were characterized by FT-IR, tube inverting method, rheometer, SEM and UV-vis spectroscopy. The GC/P407 solution shows reversible thermo-sensitive sol-gel transition behavior, and the sol-gel transition temperature is well controlled in the range of 25-37℃ by regulating the ratio of GC/P407, which shortens the gelation time and the gelatinization concentration(6%) of poloxamer 407 at body temperature. GC/P407 composite hydrogel, which has a highly porous three-dimensional structure with pore size of 10-60 μm as demonstrated by SEM, exhibits high mechanical properties. In addition, the GC/P407 composite hydrogel shows sustained release behavior of the anticancer drug gemcitabine, and the release time of the drug-loaded gel can reach 72 h. GC/P407 composite hydrogel shows the potential for biomedical application as injectable drug delivery carrier.

Polymer hydrogel is a soft material with a three-dimensional network structure that can absorb and retain a large amount of water. Polymer hydrogels have good biocompatibility, mechanical properties and important application value in biomedical and bioengineering fields. Self-healing hydrogels are smart hydrogels that respond to external stimuli and repair their own damage. Compared with the traditional hydrogel, the self-healing hydrogel has the property of repairing damage, and received extensive attention in the scientific field in recent years. Dynamic chemistry-based self-healing hydrogels are novel self-healing hydrogels that can reshape three-dimensional network structures by dynamic covalent or non-covalent bonding to repair damage. The new self-healing hydrogel can quickly repair its own damage and has good environmental adaptability, laying the foundation for the development of self-healing hydrogels as multifunctional new materials. The research progress of recent self-healing hydrogels based on dynamic chemistry was reviewed in this paper, especially focusing on the updated development on self-healing hydrogels based on hydrogen bonds, metal coordination interactions, host-guest interactions, ionic bonds, hydrophobic interactions, imine bonds/acylhydrazone bonds, borate bonds and disulphide bonds, and meanwhile, the problem of self-healing hydrogels was put forward, and the future direction of development was finally predicted.

The pandemic of Coronavirus Disease 2019(COVID-19) could be sources of anxiety among pregnant women and health care workers, which might affect the decision making on the mode of delivery. The aim of this study was to explore whether the cesarean section rates had significantly increased after the outbreak of COVID-19. We analyzed the labor data with cesarean rates in a tertiary maternity center during COVID-19 epidemic months from January to March in 2020, compared with pre-epidemic parallel months in 2019 by using Z-score test for proportions. Even though none of the staff or patient suffered with COVID-19 in the hospital, we found the cesarean section rates slightly increased in a non-infected population after the outbreak of COVID-19. Obstetricians should beware of the possible effects of COVID-19 on the mode of delivery. [ABSTRACT FROM AUTHOR]