Poly amino acids are a class of polymers composed of α-amino acids as structural units linked by peptide bonds, exhibiting structural similarity to natural proteins. This class can be degraded into polypeptides, amino acids, and small molecules, demonstrating unique advantages in the field of bone repair. Various functionalized amino acid monomers and their polymerization methods have been developed, primarily including ring-opening polymerization, polycondensation, enzymatic catalysis, and solid-phase synthesis. These methods enable the polymerization of poly glutamic acid, poly lysine, poly aspartic acid, and others into polypeptides to meet the requirements for bone injury repair. However, as the number of amino acids increases and the polypeptide chains extend, molecular chains can form secondary structures such as α-helices and β-sheets through non-covalent interactions like hydrogen bonds and van der Waals forces. These structures play a decisive role in the bioactivity and functionality of poly(amino acid). Therefore, the function of poly(amino acid) is highly dependent on its monomer composition, sequence, secondary structure, and charge characteristics, allowing precise design to effectively regulate biological effects. Nevertheless, the major challenges in applying poly (amino acid) to bone defect repair remain unresolved, namely scalable production and long-term safety and efficacy. It is believed that, with interdisciplinary integration, a new generation of poly(amino acid) materials, combining excellent properties, bioactivity, and smart-responsive traits, is expected to advance bone repair strategies toward precision, personalization, and efficiency.

The number of patients with reduced blood volume due to haemorrhage, fractures, severe infections, extensive burns and tumours is increasing, and traditional blood products are no longer able to meet the increasing clinical demand. Therefore, plasma substitutes have become particularly important in fluid resuscitation, especially artificial colloidal solutions, which have a sustained volume expansion time and a good volume expansion effect, and can significantly improve the circulatory status of patients. This article aims to review the classification of artificial colloidal plasma substitutes and their research progress in clinical practice, in order provide a more rigorous, professional and standardized reference for medicine.

Poly amino acids are a class of polymers composed of α-amino acids as structural units linked by peptide bonds, exhibiting structural similarity to natural proteins. This class can be degraded into polypeptides, amino acids, and small molecules, demonstrating unique advantages in the field of bone repair. Various functionalized amino acid monomers and their polymerization methods have been developed, primarily including ring-opening polymerization, polycondensation, enzymatic catalysis, and solid-phase synthesis. These methods enable the polymerization of poly glutamic acid, poly lysine, poly aspartic acid, and others into polypeptides to meet the requirements for bone injury repair. However, as the number of amino acids increases and the polypeptide chains extend, molecular chains can form secondary structures such as α-helices and β-sheets through non-covalent interactions like hydrogen bonds and van der Waals forces. These structures play a decisive role in the bioactivity and functionality of poly(amino acid). Therefore, the function of poly(amino acid) is highly dependent on its monomer composition, sequence, secondary structure, and charge characteristics, allowing precise design to effectively regulate biological effects. Nevertheless, the major challenges in applying poly (amino acid) to bone defect repair remain unresolved, namely scalable production and long-term safety and efficacy. It is believed that, with interdisciplinary integration, a new generation of poly(amino acid) materials, combining excellent properties, bioactivity, and smart-responsive traits, is expected to advance bone repair strategies toward precision, personalization, and efficiency.

Objective To investigate the risk factors contributing to hyperlipidemia and fatty liver in pilots.Methods Two hundred and forty-six pilots received the physical examination and were asked to fill out a questionnaire.Physical examination information included height,weight,abdominal ultrasonography result and blood lipid.The questionnaire included the pilots' age,flying hours time,physical exercise amount,working pressure,sleep condition,optimistic mood status,dietary habits,nutrition knowledge awareness,smoking and drinking habit.According to the results of physical examination,the pilots with hyperlipidemia and(or) fatty liver were selected as case group,and the pilots without hyperlipidemia or fatty liver were in control group.The scores of two groups were compared.According to the caculated BMI,pilots were also divided into normal(BMI 18.5-23.9 kg/m2)overweight(BMI 24 27.9 kg/m2) obesity(BMI＞27.9 kg/m2) groups.The differences on prevalence of hyperlipidemia and fatty liver were compared among different BMI groups.Results ①There were 225 valid questionnaires out of 246 pilots and the valid rate was 91.5％.There were 60 pilots had fatty liver and the prevalence of fatty liver was 26.7％(60/225).There were 42 pilots had hyperlipidemia and the prevalence of hyperlipidemia was 18.7％ (42/225).According to the physical examination,there were 138 pilots in control group and 87 pilots in case group.②In case group,pilots' age,daily cigarette consumption and daily alcohol consumption were higher than those in control group (Z=2.008,2.934,2.153,P＜0.05).The pilots' BMI of case group were higher than that of control group (t=35.793,P＜0.05).The scores of exercise and sleep of case group were lower than those of control group (t=19.518,5.701,P＜0.05).③The detection rates of overweight and obesity in case group were higher than those in control group (x2 =16.327,13.157,P＜0.05).The prevalence differences of hyperlipidemia and fatty liver were statistically significant among different BMI groups (x2 =37.505,P＜0.05).④The smoking and drinking rates of case group were higher than those of control group (x2 =8.636,4.497,P＜0.05).Conclusions The main risk factors of hyperlipidemia and fatty liver in pilots are obesity and lack of exercise.Other factors like age,sleepquality,smoking or drinking habit have certain extent impacts on the diseases.Pilots should strengthen the physical exercise and control BMI to effectively reduce the incidence of hyperlipidemia and fatty liver in order to prolong the pilot's flying career.

Objective To investigate the risk factors contributing to hyperlipidemia and fatty liver in pilots.Methods Two hundred and forty-six pilots received the physical examination and were asked to fill out a questionnaire.Physical examination information included height,weight,abdominal ultrasonography result and blood lipid.The questionnaire included the pilots' age,flying hours time,physical exercise amount,working pressure,sleep condition,optimistic mood status,dietary habits,nutrition knowledge awareness,smoking and drinking habit.According to the results of physical examination,the pilots with hyperlipidemia and(or) fatty liver were selected as case group,and the pilots without hyperlipidemia or fatty liver were in control group.The scores of two groups were compared.According to the caculated BMI,pilots were also divided into normal(BMI 18.5-23.9 kg/m2)overweight(BMI 24 27.9 kg/m2) obesity(BMI＞27.9 kg/m2) groups.The differences on prevalence of hyperlipidemia and fatty liver were compared among different BMI groups.Results ①There were 225 valid questionnaires out of 246 pilots and the valid rate was 91.5％.There were 60 pilots had fatty liver and the prevalence of fatty liver was 26.7％(60/225).There were 42 pilots had hyperlipidemia and the prevalence of hyperlipidemia was 18.7％ (42/225).According to the physical examination,there were 138 pilots in control group and 87 pilots in case group.②In case group,pilots' age,daily cigarette consumption and daily alcohol consumption were higher than those in control group (Z=2.008,2.934,2.153,P＜0.05).The pilots' BMI of case group were higher than that of control group (t=35.793,P＜0.05).The scores of exercise and sleep of case group were lower than those of control group (t=19.518,5.701,P＜0.05).③The detection rates of overweight and obesity in case group were higher than those in control group (x2 =16.327,13.157,P＜0.05).The prevalence differences of hyperlipidemia and fatty liver were statistically significant among different BMI groups (x2 =37.505,P＜0.05).④The smoking and drinking rates of case group were higher than those of control group (x2 =8.636,4.497,P＜0.05).Conclusions The main risk factors of hyperlipidemia and fatty liver in pilots are obesity and lack of exercise.Other factors like age,sleepquality,smoking or drinking habit have certain extent impacts on the diseases.Pilots should strengthen the physical exercise and control BMI to effectively reduce the incidence of hyperlipidemia and fatty liver in order to prolong the pilot's flying career.