The core message: With the convenience of transportation and the prosperity of urban and rural agricultural (collective) trade markets, piglet market transactions are frequent, grassroots animal quarantine supervision and law enforcement personnel should carefully grasp the experience of piglets, provide quality services for the majority of farmers. 1, the main features of healthy piglets (1) Action elves, more stable gait, quick start, lively spirit. (2) Breathing is uniform, there is a sense of rhythm in both eyes, and there is a good sense of rhythm. (3) The coat is neat, the lustre is strong, the skin temperature is balanced, and the body temperature is normal. (4) After the abdomen is fed, the sleeping position is mostly on the side and natural. (5) There was no abnormality in fecal urine. (6) When he was struggling, he was struggling with a strong voice. 2, the main features of diseased piglets (1) Slow action, lameness, and unstable gait. (2) The coat is confusing, pale, or red and other abnormalities. (3) chills, convulsions, and more eyelids. (4) uneven breathing, severe asthma, purulent nasal discharge. (5) Manure is hard, with a lot of mucus, pseudomembrane or blood on the surface. (6) The body temperature is not normal, above 40 degrees. (7) He was unresponsive, struggling, and hoarse when caught. (8) Overeat, vomiting, disturbed or depressed. (9) Lymph node swelling or head edema on the surface, bleeding spots on the skin, and finger pressure does not fade. During the quarantine process, if a suspected outbreak is found, it shall be immediately disposed of according to procedures. Polyhydroxyalkanoates (PHAs) comprise a group of natural biodegradable polyesters that are synthesized by microorganisms. However, several disadvantages limit their competition with traditional synthetic plastics or their application as ideal biomaterials. These disadvantages include their poor mechanical properties, high production cost, limited functionalities, incompatibility with conventional thermal processing techniques and susceptibility to thermal degradation. To circumvent these drawbacks, PHAs need to be modified to ensure improved performance in specific applications. In this review, well-established modification methods of PHAs are summarized and discussed. The improved properties of PHA that blends with natural raw materials or other biodegradable polymers, including starch, cellulose derivatives, lignin, poly(lactic acid), polycaprolactone and different PHA-type blends, are summarized. The functionalization of PHAs by chemical modification is described with respect to two important synthesis approaches: block copolymerization and graft copolymerization. The expanded utilization of the modified PHAs as engineering materials and the biomedical significance in different areas are also addressed. Polyhydroxyalkanoates Phas,Bacterial Fermentation Pha,Elastomeric Materials Pha,Pha Suture Fasteners Xingbang High Molecular Materials Co., Ltd. , https://www.chemicaladditive.com