TCP family as plant specific transcription factor, plays an important role in different aspects of plant development. In order to screen TCP family members in tobacco, the homologous sequences of tobacco and Arabidopsis TCP family were identified by genome-wide homologous alignment. The physicochemical properties, phylogenetic relationships and cis-acting elements were analyzed by bioinformatics. The homologous genes of AtTCP3/AtTCP4 were screened, and RT-qPCR was used to detect the changes of gene expression upon 20% PEG6000 treatment. The results show that tobacco contains 63 TCP family members. Their amino acid sequence length ranged from 89 aa to 596 aa, and their protein hydropathicity grand average of hydropathicity (GRAVY) ranged from -1.147 to 0.125. The isoelectric point (pI) ranges from 4.42 to 9.94, the number of introns is 0 to 3, and the subcellular location is all located in the nucleus. The results of conserved domain and phylogenetic relationship analysis showed that the tobacco TCP family can be divided into PCF, CIN and CYC/TB1 subfamilies, and each subfamily has a stable sequence. The results of cis-acting elements in gene promoter region showed that TCP family genes contain low docile acting elements (LTR) and a variety of stress and metabolic regulation related elements (MYB, MYC). Analysis of gene expression patterns showed that AtTCP3/AtTCP4 homologous genes (NtTCP6, NtTCP28, NtTCP30, NtTCP33, NtTCP42, NtTCP57, NtTCP63) accounted for 20% PEG6000 treatment significantly up-regulated/down-regulated expression, and NtTCP30 and NtTCP57 genes were selected as candidate genes in response to drought. The results of this study analyzed the TCP family in the tobacco genome and provided candidate genes for the study of drought-resistance gene function and variety breeding in tobacco.
Nicotiana/genetics* ; Phylogeny ; Plant Breeding ; Amino Acid Sequence ; Arabidopsis ; Polyethylene Glycols

Polyethylene terephthalate (PET) is one of the most widely used synthetic polyester. It poses serious threat to terrestrial, aquatic ecosystems and human health since it is difficult to be broken down and deposited in the environment. The biodegradation based on enzymatic catalysis offers a sustainable method for recycling PET. A number of PET hydrolases have been discovered in the last 20 years, and protein engineering has increased their degradation capabilities. However, no PET hydrolases that are practical for widespread industrial use have been identified. Screening of PET hydrolase using conventional detection techniques is laborious and inefficient process. Effective detection techniques are required to promote the commercialization of PET hydrolases. Using efficient detection techniques to screen potent industrial enzymes is essential for supporting the widespread industrial implementation of PET hydrolases. To define PET hydrolase, scientists have created a number of analytical techniques recently. The detection techniques that can be used to screen PET hydrolase, including high performance liquid chromatography, ultraviolet absorption spectrometric, and fluorescence activated droplet sorting method, are summarized in this study along with their potential applications.
Humans ; Polyethylene Terephthalates ; Ecosystem ; Biodegradation, Environmental ; Catalysis ; Hydrolases

Plastics are widely used in human daily life, which bring great convenience. Nevertheless, the disposal of a large amount of plastic wastes also brings great pressure to the environment. Polyethylene terephthalate (PET) is a polymer thermoplastic material produced from petroleum. It has become one of the most commonly used plastics in the world due to its durability, high transparency, light weight and other characteristics. PET can exist in nature for a long time due to its complex structure and the difficulty in degradation, which causes serious pollution to the global ecological environment, and threatens human health. The degradation of PET wastes has since become one of the global challenges. Compared with physical and chemical methods, biodegradation is the greenest way for treating PET wastes. This review summarizes the recent advances on PET biodegradation including microbial and enzymatic degradation of PET, biodegradation pathway, biodegradation mechanisms, and molecular modification of PET-degrading enzymes. In addition, the prospect for achieveing efficient degradation of PET, searching and improving microorganisms or enzymes that can degrade PET of high crystallinity are presented, with the aimto facilitate the development, application and molecular modification of PET biodegradation microorganisms or enzymes.
Humans ; Polyethylene Terephthalates/metabolism* ; Polymers ; Biodegradation, Environmental ; Petroleum

With the continuous exploration of microemulsions as solvents for traditional Chinese medicine extraction, polyoxyethy-lene(35) castor oil(CrEL), a commonly used surfactant, is being utilized by researchers. However, the problem of detecting residues of this surfactant in microemulsion extracts has greatly hampered the further development of microemulsion solvents. Based on the chemical structures of the components in CrEL and the content determination method of castor oil in the 2020 edition of the Chinese Pharmacopoeia(Vol. Ⅳ), this study employed gas chromatography(GC) and single-factor experiments to optimize the preparation method of methyl ricinoleate from CrEL. The conversion coefficient between the two was validated, and the optimal sample preparation method was used to process microemulsion extracts of Zexie Decoction from three batches. The content of methyl ricinoleate generated was determined, and the content of CrEL in the microemulsion extracts of Zexie Decoction was calculated using the above conversion coefficient. The results showed that the optimal preparation method for CrEL was determined. Specifically, 10 mL of 1 mol·L~(-1) KOH-methanol solution was heated at 60 ℃ for 15 min in a water bath. Subsequently, 10 mL of boron trifluoride etherate-methanol(1∶3) solution was heated at 60 ℃ for 15 min in a water bath, followed by extraction with n-hexane twice. CrEL could stably produce 20.84% methyl ricinoleate. According to this conversion coefficient, the average mass concentration of CrEL in the three batches of Zexie Decoction microemulsion extracts was 11.94 mg·mL~(-1), which was not significantly different from the CrEL mass concentration of 11.57 mg·mL~(-1) during microemulsion formulation, indicating that the established content determination method of this study was highly accurate, sensitive, and repeatable. It can be used for subsequent research on microemulsion extracts of Zexie Decoction and provide a reference for quality control of other drug formulations containing CrEL.
Polyethylene Glycols/chemistry* ; Castor Oil ; Methanol ; Surface-Active Agents/chemistry* ; Solvents ; Water/chemistry* ; Emulsions/chemistry*

The clinical performance and failure issues are significantly influenced by prosthetic malposition in unicompartmental knee arthroplasty (UKA). Uncertainty exists about the impact of the prosthetic joint line height in UKA on tibial insert wear. In this study, we combined the UKA musculoskeletal multibody dynamics model, finite element model and wear model to investigate the effects of seven joint line height cases of fixed UKA implant on postoperative insert contact mechanics, cumulative sliding distance, linear wear depth and volumetric wear. As the elevation of the joint line height in UKA, the medial contact force and the joint anterior-posterior translation during swing phase were increased, and further the maximum von Mises stress, contact stress, linear wear depth, cumulative sliding distance, and the volumetric wear also were increased. Furthermore, the wear area of the insert gradually shifted from the middle region to the rear. Compared to 0 mm joint line height, the maximum linear wear depth and volumetric wear were decreased by 7.9% and 6.8% at -2 mm joint line height, and by 23.7% and 20.6% at -6 mm joint line height, the maximum linear wear depth and volumetric wear increased by 10.7% and 5.9% at +2 mm joint line height, and by 24.1% and 35.7% at +6 mm joint line height, respectively. UKA prosthetic joint line installation errors can significantly affect the wear life of the polyethylene inserted articular surfaces. Therefore, it is conservatively recommended that clinicians limit intraoperative UKA joint line height errors to -2-+2 mm.
Humans ; Arthroplasty, Replacement, Knee ; Knee Joint ; Knee Prosthesis ; Mechanical Phenomena ; Polyethylene ; Osteoarthritis, Knee/surgery* ; Tibia/surgery* ; Biomechanical Phenomena

Soft tissue is an indispensable tissue in human body. It plays an important role in protecting the body from external physical, chemical or biological factors. Mild soft tissue injuries can self-heal, while severe soft tissue injuries may require related treatment. Natural polymers (such as chitosan, hyaluronic acid, and collagen) and synthetic polymers (such as polyethylene glycol and polylactic acid) exhibit good biocompatibility, biodegradability and low toxicity. It can be used for soft tissue repairs for antibacterial, hemostatic and wound healing purposes. Their related properties can be enhanced through modification or preparation of composite materials. Commonly used soft tissue repairs include wound dressings, biological patches, medical tissue adhesives, and tissue engineering scaffolds. This study introduces the properties, mechanisms of action and applications of various soft tissue repair medical materials, including chitosan, hyaluronic acid, collagen, polyethylene glycol and polylactic acid, and provides an outlook on the application prospects of soft tissue repair medical materials and products.
Humans ; Biocompatible Materials/chemistry* ; Chitosan/chemistry* ; Hyaluronic Acid ; Tissue Scaffolds/chemistry* ; Collagen/chemistry* ; Polymers/chemistry* ; Polyethylene Glycols ; Soft Tissue Injuries

The large scale production and indiscriminate use of plastics led to serious environmental pollution. To reduce the negative effects of plastics waste on the environment, an approach of enzymatic degradation was put forward to catalyze plastics degradation. Protein engineering strategies have been applied to improve the plastics degrading enzyme properties such as activity and thermal stability. In addition, polymer binding modules were found to accelerate the enzymatic degradation of plastics. In this article, we introduced a recent work published in Chem Catalysis, which studied the role of binding modules in enzymatic hydrolysis of poly(ethylene terephthalate) (PET) at high-solids loadings. Graham et al. found that binding modules accelerated PET enzymatic degradation at low PET loading (< 10 wt%) and the enhanced degradation cannot be observed at high PET loading (10 wt%-20 wt%). This work is beneficial for the industrial application of polymer binding modules in plastics degradation.
Polyethylene Terephthalates/metabolism* ; Polymers ; Plastics ; Ethylenes

Polyethylene (PE) is the most abundantly used synthetic resin and one of the most resistant to degradation, and its massive accumulation in the environment has caused serious pollution. Traditional landfill, composting and incineration technologies can hardly meet the requirements of environmental protection. Biodegradation is an eco-friendly, low-cost and promising method to solve the plastic pollution problem. This review summarizes the chemical structure of PE, the species of PE degrading microorganisms, degrading enzymes and metabolic pathways. Future research is suggested to focus on the screening of high-efficiency PE degrading strains, the construction of synthetic microbial consortia, the screening and modification of degrading enzymes, so as to provide selectable pathways and theoretical references for PE biodegradation research.
Polyethylene/metabolism* ; Bacteria/metabolism* ; Plastics/metabolism* ; Biodegradation, Environmental ; Microbial Consortia

Plastics have brought invaluable convenience to human life since it was firstly synthesized in the last century. However, the stable polymer structure of plastics led to the continuous accumulation of plastic wastes, which poses serious threats to the ecological environment and human health. Poly(ethylene terephthalate) (PET) is the most widely produced polyester plastics. Recent researches on PET hydrolases have shown great potential of enzymatic degradation and recycling of plastics. Meanwhile, the biodegradation pathway of PET has become a reference model for the biodegradation of other plastics. This review summarizes the sources of PET hydrolases and their degradation capacity, degradation mechanism of PET by the most representative PET hydrolase-IsPETase, and recently reported highly efficient degrading enzymes through enzyme engineering. The advances of PET hydrolases may facilitate the research on the degradation mechanism of PET and further exploration and engineering of efficient PET degradation enzymes.
Humans ; Hydrolases/metabolism* ; Polyethylene Terephthalates/metabolism* ; Plastics/metabolism* ; Ethylenes

PET (polyethylene terephthalate) is one of the most important petrochemicals that is widely used in mineral water bottles, food and beverage packaging and textile industry. Because of its stability under environmental conditions, the massive amount of PET wastes caused serious environmental pollution. The use of enzymes to depolymerize PET wastes and upcycling is one of the important directions for plastics pollution control, among which the key is the depolymerization efficiency of PET by PET hydrolase. BHET (bis(hydroxyethyl) terephthalate) is the main intermediate of PET hydrolysis, its accumulation can hinder the degradation efficiency of PET hydrolase significantly, and the synergistic use of PET hydrolase and BHET hydrolase can improve the PET hydrolysis efficiency. In this study, a dienolactone hydrolase from Hydrogenobacter thermophilus which can degrade BHET (HtBHETase) was identified. After heterologous expression in Escherichia coli and purification, the enzymatic properties of HtBHETase were studied. HtBHETase shows higher catalytic activity towards esters with short carbon chains such as p-nitrophenol acetate. The optimal pH and temperature of the reaction with BHET were 5.0 and 55 ℃, respectively. HtBHETase exhibited excellent thermostability, and retained over 80% residual activity after treatment at 80 ℃ for 1 hour. These results indicate that HtBHETase has potential in biological PET depolymerization, which may facilitate the enzymatic degradation of PET.
Hydrolases/metabolism* ; Bacteria/metabolism* ; Hydrolysis ; Polyethylene Terephthalates/metabolism*