A review of recent advances of piezoelectric poly-L-lactic acid for biomedical applications.

Poly-L-lactic acid (PLLA), recognized as a piezoelectric material, not only demonstrates exceptional piezoelectric properties but also exhibits commendable biocompatibility and biodegradability. These properties render PLLA highly promising for diverse applications, including sensors, wearable devices, biomedical engineering, and related domains. This review offers a comprehensive overview of the distinctive piezoelectric effect of PLLA-based material and delves into the latest advancements in its preparation strategies as a piezoelectric material. It further presents recent research progress in PLLA-based piezoelectric materials, particularly in the realms of health monitoring, skin repair, nerve regeneration, and tissue repair. The discourse extends to providing insights into potential future trajectories for the development of PLLA-based piezoelectric materials.

A case with no administration of protamine to neutralize heparin in aortic valve replacement with cardiopulmonary bypass.

Systemic heparinization is necessary before cardiopulmonary bypass (CPB) in cardiac surgery, and protamine administration to neutralize heparin for hemostasis is required at the end of CPB. Because protamine is an allogeneic protein extracted from the sperm of specific fish, serious adverse reactions can occur during clinical application, with potentially catastrophic outcomes. A male patient received aortic valve replacement with CPB. Severe allergic reactions occurred postoperatively after protamine administration for neutralization. Emergency heparinization and CPB re-establishment were conducted with no further hemostatic treatment with protamine. However, the patient suffered a massive hemorrhage and was treated symptomatically with blood transfusion and rehydration. Following two thoracotomies for hemostasis, the patient healed and was eventually discharged. Protamine is irreplaceable as the only hemostatic that neutralizes heparin for cardiac CPB at present. However, because it is an alloprotein, it can cause serious allergic reactions after entering the human body, and caution should be exercised during the process of its clinical application.

[Three-dimensional Medical Electronic Laparoscope System].

This paper presents a three-dimensional electronic laparoscopy system, including three-dimensional laparoscope pipe and medical video system. The three-dimensional laparoscope pipe adopts a dual-optical structure, which can collect three-dimensional information of the surgical region. By selecting a reasonable initial structure, the MTF curve of the objective lens is close to the diffraction limit, and the distortion is less than 25%. The medical video system also achieved high-definition image with 1 080 P, 30 Hz by GPU. At the mean time, the three-dimensional electronic laparoscope has achieved quantitative production and has been tested in a number of animals, which has broad application prospects and significant clinical application value.

Thermal decomposition and kinetics of coal and fermented cornstalk using thermogravimetric analysis.

The thermal behavior and kinetics of Yiluo coal (YC) and the residues of fermented cornstalk (FC) were investigated in this study. The Kissinger-Akahira-Sunose (KAS) and Flynn-Wall-Ozawa (FWO) methods were used for the kinetic analysis of the pyrolysis process. The results showed that the activation energy (Eα) was increased with the increase of the thermal conversion rate (α), and the average values of Eα of YC, FC and the blend (mYC/mFC = 6/4) were 304.26, 224.94 and 233.46 kJ/mol, respectively. The order reaction model function for the blend was also developed by the master-plots method. By comparing the Ea and the enthalpy, it was found that the blend was favored to format activated complex due to the lower potential energy barrier. Meanwhile, the average value of Gibbs free energy of the blend was 169.83 kJ/mol, and the changes of entropies indicated that the pyrolysis process was evolved from ordered-state to disordered-state.

[Studies on structure characteristic of polysaccharide P1A from Dicliptera chinensis].

The chemical structures of P1 A was identified by complete acid hydrolysis, partial acid hydrolysis, periodate oxidation-Smith degradation, methylation analysis, IR and NMR. The results showed that P1 A had a backbone consisting rhamnose, mannose, glucose and galactose. The side chain possessed arabinose and xylose. 1-->, 1-->6 and non-reducing terminal linkages existed in polysaccharide P1A, but there are doubling amount of 1-->2 and 1-->4 linkages. Oxidable linkage of P1 A accounted for 45%, and inoxidable linkage of P1A accounted for 55%. Mannose, glucose and galactose were mainly linked by 1-->2 linkage. Rhamnose, arabinose and xylose were mainly linked by 1-->2 and 1-->4 linkages. PlA contained beta-Glc(1,6)-,beta-Gal(1,3)-,beta-Man(1,4)-beta-Rha,-Glc(1,4)-, Glc(1)-,-Gal(1,4)- and Man(1)-.