Preparation and Application of Degradable Lignin/Poly (Vinyl Alcohol) Polymers as Urea Slow-Release Coating Materials.

The massive amount of water-soluble urea used leads to nutrient loss and environmental pollution in both water and soil. The aim of this study was to develop a novel lignin-based slow-release envelope material that has essential nitrogen and sulfur elements for plants. After the amination reaction with a hydrolysate of yak hair keratin, the coating formulation was obtained by adding different loadings (2, 5, 8, 14 wt%) of aminated lignin (AL) to 5% polyvinyl alcohol (PVA) solution. These formulations were cast into films and characterized for their structure, thermal stability, and mechanical and physicochemical properties. The results showed that the PVA-AL (8%) formulation had good physical and chemical properties in terms of water absorption and mechanical properties, and it showed good degradation in soil with 51% weight loss after 45 days. It is suitable for use as a coating material for fertilizers. Through high-pressure spraying technology, enveloped urea particles with a PVA-AL (8%) solution were obtained, which showed good morphology and slow-release performance. Compared with urea, the highest urea release was only 96.4% after 30 days, conforming to Higuchi model, Ritger-Peppas model, and second-order dynamic model. The continuous nitrogen supply of PVA-AL coated urea to Brassica napus was verified by potting experiments. Therefore, the lignin-based composite can be used as a coating material to produce a new slow-release nitrogen fertilizer for sustainable crop production.

Research Progress on hCNT3 Structure/Function and Nucleoside Anticancer Drugs.

Membrane protein human concentrative nucleoside transporter 3 (hCNT3) can not only transport extracellular nucleosides into the cell but also transport various nucleoside-derived anticancer drugs to the focus of infection for therapeutic effects. Typical nucleoside anticancer drugs, including fludarabine, cladabine, decitabine, and clofarabine, are recognized by hCNT3 and then delivered to the lesion site for their therapeutic effects. hCNT3 is highly conserved during the evolution from lower to higher vertebrates, which contains scaffold and transport domains in structure and delivers substrates by coupling with Na+ and H+ ions in function. In the process of substrate delivery, the transport domain rises from the lower side of transmembrane 9 (TM9) in the inward conformation to the upper side of the outward conformation, accompanied by the collaborative motion of TM7b/ TM4b and hairpin 1b (HP1b)/ HP2b. With the report of a series of three-dimensional structures of homologous CNTs, the structural characteristics and biological functions of hCNT3 have attracted increasing attention from pharmacists and biologists. Our research group has also recently designed an anticancer lead compound with high hCNT3 transport potential based on the structure of 5-fluorouracil. In this work, the sequence evolution, conservation, molecular structure, cationic chelation, substrate recognition, elevator motion pattern and nucleoside derivative drugs of hCNT3 were reviewed, and the differences in hCNT3 transport mode and nucleoside anticancer drug modification were summarized, aiming to provide theoretical guidance for the subsequent molecular design of novel anticancer drugs targeting hCNT3.

Prognostic Factors and Outcomes in Elderly Esophagectomy Patients with Esophageal Cancer.

BACKGROUND: Choosing the appropriate treatment for elderly patients with esophageal cancer remains a contentious issue. While surgery is still a valid option, we aimed to identify predictors and outcomes in elderly esophagectomy patients with esophageal cancer. PATIENTS AND METHODS: We analyzed characteristics, surgical outcomes, survival rates, cause-specific mortality, and recurrence in 120 patients with stage I-IV esophageal cancer. Univariate and multivariate analyses were used to identify risk factors for event-free survival (EFS) and overall survival (OS). RESULTS: The median follow-up period was 31 months, with 5-year overall survival (OS) and event-free survival (EFS) rates standing at 45.2% and 41.5%, respectively. Notably, lower body mass index (BMI ≤ 22 kg/m2) and reduced preoperative albumin levels (pre-ALB < 40 g/L) led to a significant decrease in OS rates. Postoperative pulmonary complications resulted in higher in-hospital and 90-day mortality rates. After about 31 months post-surgery, the rate of cancer-specific deaths stabilized. The most common sites for distant metastasis were the lungs, supraclavicular lymph nodes, liver, and bone. The study identified lower BMI, lower pre-ALB levels, and postoperative pulmonary complications as independent risk factors for poorer EFS and OS outcomes. CONCLUSIONS: Esophagectomy remains a safe and feasible treatment for elderly patients, though the prevention of postoperative pulmonary infection is crucial. Factors such as lower BMI, lower pre-ALB levels, advanced tumor stage, postoperative pulmonary complications, and certain treatment modalities significantly influence the outcomes in elderly esophagectomy patients. These findings provide critical insights into the characteristics and outcomes of this patient population.

Uncovering the interactions between PME and PMEI at the gene and protein levels: Implications for the design of specific PMEI.

CONTEXT: Pectin methylesterase inhibitor (PMEI) can specifically bind and inhibit the activity of pectin methylesterase (PME), which has been widely used in fruit and vegetable juice processing. However, the limited three-dimensional structure, unclear action mechanism, low thermal stability and biological activity of PMEI severely limited its application. In this work, molecular recognition and conformational changes of PME and PMEI were analyzed by various molecular simulation methods. Then suggestions were proposed for improving thermal stability and affinity maturation of PMEI through semi-rational design. METHODS: Phylogenetic trees of PME and PMEI were established using the Maximum likelihood (ML) method. The results show that PME and PMEI have good sequence and structure conservation in various plants, and the simulated data can be widely adopted. In this work, MD simulations were performed using AMBER20 package and ff14SB force field. Protein interaction analysis indicates that H-bonds, van der Waals forces, and the salt bridge formed of K224 with ID116 are the main driving forces for mutual molecular recognition of PME and PMEI. According to the analyses of free energy landscape (FEL), conformational cluster, and motion, the association with PMEI greatly disrupts PME's dispersed functional motion mode and biological function. By monitoring the changes of residue contact number and binding free energy, IG35M/ IG35R: IT93F and IT113W/ IT113W: ID116W mutations contribute to thermal stability and affinity maturation of the PME-PMEI complex system, respectively. This work reveals the interaction between PME and PMEI at the gene and protein levels and provides options for modifying specific PMEI.

High-dose chemotherapy sensitizes locally advanced esophageal squamous cell carcinoma to PD-1 blockade for a higher pathological complete response rate and survival.

BACKGROUND: PD-1 inhibitor and chemotherapy demonstrated durable antitumor activity with a manageable safety profile as the first-line treatment in patients with advanced esophageal squamous cell carcinoma (ESCC). The present study aimed to evaluate the efficacy of PD-1 inhibitors plus different dose intensity neoadjuvant chemotherapy in the treatment of locally advanced ESCC. METHODS: Patients with locally advanced but resectable thoracic ESCC, staged as T3 or T4a, N0-3, and M0 or M1 lymph node metastasis (confined to the supraclavicular lymph nodes), were enrolled in this study. The eligible patients received tislelizumab plus different dose intensity chemotherapy for a 21-day cycle with repeated 2-4 cycles before surgery. The primary endpoints are pathological complete response (pCR) and major pathological response (MPR), and the secondary endpoints are objective response rate (ORR), disease control rate (DCR), and disease-free survival (DFS). RESULTS: From November 2019 to February 2022, 122 cases received at least two cycles neoadjuvant chemoimmunotherapy and were evaluated by imaging examination. Subsequently, 99 patients underwent surgery and were evaluated by pathological evaluation. According to chemotherapy dose intensity, the patients were divided into three cohorts: cohort 1 (<80% dose intensity), cohort 2 (80-90% dose intensity), cohort 3 (90-100% dose intensity). All surgery patients underwent minimally invasive esophagectomy (MIE). The average pCR was identified in 22.22%; 16% had pCR in cohort 1, 17.65% had pCR in cohort 2, and 30.00% had pCR in cohort 3. MPR was observed in 9 (36.00%) patients in cohort 1, 18 (52.94%) patients in cohort 2, 22 (55.00%) patients in cohort 3. In univariable and multivariable analysis, dose intensity was significantly associated with MPR (p = 0.048) in patients who underwent esophagectomy. For surviving patients, the median follow-up was 13.76 months after esophagectomy. Compared to cohort 1, cohorts 2 and 3 had better DFS (p = 0.056). In addition, the prognosis of patients with MPR was better than that of patients without MPR (p = 0.014). CONCLUSIONS: The robust antitumor activity of neoadjuvant chemoimmunotherapy for locally advanced but resectable thoracic ESCC was confirmed. More than 80% of chemotherapy dose intensity combined with immunotherapy resulted in a high pCR rate and prolonged DFS.

Molecular recognition of SARS-CoV-2 spike protein with three essential partners: exploring possible immune escape mechanisms of viral mutants.

OBJECTIVE: The COVID-19 epidemic is raging around the world, with the emergence of viral mutant strains such as Delta and Omicron, posing severe challenges to people's health and quality of life. A full understanding life cycle of the virus in host cells helps to reveal inactivation mechanism of antibody and provide inspiration for the development of a new-generation vaccines. METHODS: In this work, molecular recognitions and conformational changes of SARS-CoV-2 spike protein mutants (i.e., Delta, Mu, and Omicron) and three essential partners (i.e., membrane receptor hACE2, protease TMPRSS2, and antibody C121) both were compared and analyzed using molecular simulations. RESULTS: Water basin and binding free energy calculations both show that the three mutants possess higher affinity for hACE2 than WT, exhibiting stronger virus transmission. The descending order of cleavage ability by TMPRSS2 is Mu, Delta, Omicron, and WT, which is related to the new S1/S2 cutting site induced by transposition effect. The inefficient utilization of TMPRSS2 by Omicron is consistent with its primary entry into cells via the endosomal pathway. In addition, RBD-directed antibody C121 showed obvious resistance to Omicron, which may have originated from high fluctuation of approaching angles, high flexibility of I472-F490 loop, and reduced binding ability. CONCLUSIONS: According to the overall characteristics of the three mutants, high infectivity, high immune escape, and low virulence may be the future evolutionary selection of SARS-CoV-2. In a word, this work not only proposes the possible resistance mechanism of SARS-CoV-2 mutants, but also provides theoretical guidance for the subsequent drug design against COVID-19 based on S protein structure.

Nucleotide and codon usage biases involved in the evolution of African swine fever virus: A comparative genomics analysis.

Since African swine fever virus (ASFV) replication is closely related to its host's machinery, codon usage of viral genome can be subject to selection pressures. A better understanding of codon usage can give new insights into viral evolution. We implemented information entropy and revealed that the nucleotide usage pattern of ASFV is significantly associated with viral isolation factors (region and time), especially the usages of thymine and cytosine. Despite the domination of adenine and thymine in the viral genome, we found that mutation pressure alters the overall codon usage pattern of ASFV, followed by selective forces from natural selection. Moreover, the nucleotide skew index at the gene level indicates that nucleotide usages influencing synonymous codon bias of ASFV are significantly correlated with viral protein hydropathy. Finally, evolutionary plasticity is proved to contribute to the weakness in synonymous codons with A- or T-end serving as optimal codons of ASFV, suggesting that fine-tuning translation selection plays a role in synonymous codon usages of ASFV for adapting host. Taken together, ASFV is subject to evolutionary dynamics on nucleotide selections and synonymous codon usage, and our detailed analysis offers deeper insights into the genetic characteristics of this newly emerging virus around the world.

Controlling the Triplet Potential Energy Surface of Bimetallic Platinum(II) Complex by Constructing Structure-Property Relationship: A Theoretical Exploration.

For phosphorescent materials, managing the triplet potential energy surface stands for controlling the phosphorescence quantum yield. However, due to the complexity and variability, the triplet potential energy surface can be managed with difficulty. In this work, a series of bimetallic Pt(II) complexes, namely Pt-1, Pt-1-1, Pt-1-2, Pt-2, Pt-3-5, and Pt-6-7, are employed as models to construct a relationship between the structures and triplet potential energy surfaces, aiming to achieve meaningful information to manage the triplet potential energy surface. On the basis of the results, it is observed that the triplet potential energy surface has an intimate connection with the structures of bimetallic Pt(II) complexes. In the case of the primordial Pt(II) complex, the triplet potential energy surface consists of two minimal points, illustrating various properties, which can largely affect the phosphorescence quantum yield. Once the intramolecular steric hindrance, restriction effect, and metallophilic interaction (Pt-Pd/Pd-Pd) are employed by tailoring the structures of primordial Pt(II) complexes, the triplet potential energy surface can be reconstructed via one minimal point-charactered short metal-metal distance, resulting in different photophysical properties. The relationship between the triplet potential energy surface and structure is essentially unveiled from the structural and electronic viewpoints. The conclusions originated from the structural and electronic investigations can be regarded as indicators to accurately and expediently predict the triplet potential energy surfaces of bimetallic Pt(II) complexes. The results presented here are helpful in addressing the designed strategies as they show that the triplet potential energy surfaces of bimetallic Pt(II) complexes can be properly tuned.

Purse-indigitation mechanical anastomosis vs. traditional mechanical anastomosis undergoing McKeown esophagectomy: a retrospective comparative cohort study.

Background: Postoperative anastomosis-related complication rates remain high in patients undergoing McKeown esophagectomy with cervical anastomosis, and the optimal anastomotic technique remains under debate. We describe a new method of anastomosis, referred to as purse-indigitation mechanical anastomosis (PIMA) by reinforcing esophagogastric anastomosis, which can be performed after minimally invasive surgery. This study was designed to compare its feasibility, efficacy, and safety with those of traditional mechanical anastomosis (TMA). Methods: Between September 2020 and January 2022, 264 patients undergoing McKeown esophagectomy at a single center were included. Demographic data, including patient age, sex, diagnosis, neoadjuvant chemotherapy/radiation therapy in cases of malignancy, comorbidities, and operation time, anastomotic time, estimated blood loss, post­operative complications were collected. Their medical records were retrospectively reviewed, analyzed and compared between the PIMA and TMA cohorts. Results: The baseline comparability of the PIMA and TMA before the comparisons is no statistical difference. Univariable analysis revealed significantly decreased anastomotic leak rate with PIMA compared to TMA (4.10% vs. 11.59%, P=0.04). No significant difference was demonstrated in total operation time, estimated blood loss, postoperative hospital stay, or pulmonary complications between PIMA and TMA (243.94±21.98 vs. 238.70±28.45 min; 201.10±67.83 vs. 197.39±65.13 mL; 8.83±2.77 vs. 9.35±3.78 days; 8.21% vs. 11.59%; all P>0.05). The incidence of postoperative pulmonary complications (3.44% vs. 50%) was significantly associated with an increased rate of anastomotic leak [odds ratio (OR): 15.50; 95% confidence interval (CI): 4.81-43.71; P<0.01]. Conclusions: PIMA is feasible, safe to perform, and demonstrated a leak rate less than half that of TMA in this study. PIMA may represent a superior alternative to standard esophagogastric cervical anastomosis techniques. Larger sample size and long-term survival are required to fully evaluate PIMA.

Genetic features of bovine viral diarrhea virus subgenotype 1c in newborn calves at nucleotide and synonymous codon usages.

Bovine viral diarrhea virus (BVDV), serving as an important pathogen for newborn calves, poses threat to reproductive and economic losses in the cattle industry. To survey the infection rate and genetic diversity of BVDV in newborn calves in northern China, a total of 676 sera samples of newborn calves were collected from four provinces between 2021 and 2022. All sera samples were individually detected for BVDV infection by RT-PCR and ELISA. Our results showed that the overall serological rate was 9.76% (66/676) and the average positive rate of BVDV RNA was 8.14% (55/676) in the newborn calves. Eight BVDV strains were successfully isolated from RT-PCR positive sera samples, and four isolates displayed the cytopathic effect (CPE). Based on phylogenetic tree at the genome level, the eight strains were classified into subgenotype 1c. Moreover, the BVDV isolates had a close genetic relationship with the GSTZ strain at either nucleotide or codon usage level. Interestingly, in comparison of synonymous codon usage patterns between the BVDV isolates with CPE and ones without CPE, there were four synonymous codons (UCG, CCC, GCA, and AAC) which displayed the significant differences (p < 0.05) at codon usage pattern, suggesting that synonymous codon usage bias might play a role in BVDV-1c biotypes. In addition, the usage of synonymous codons containing CpG dinucleotides was suppressed by the BVDV-1c isolates, reflecting one of strategies of immune evasion of BVDV to its host. Taken together, our study provided data for monitoring and vaccination strategies of BVDV for newborn calves in northern China.

Research Progress of Pectin Methylesterase and its Inhibitors.

As an important pectin enzyme, pectin methylesterase (PME) can hydrolyze methyl esters, release methanol and reduce esterification. It is essential in regulating pollen tube development, root extension, and fruit ripening. Pectin methylesterase inhibitors (PMEI) can specifically bind PME and inhibit its activity, which jointly determines the esterification degree of pectin. PMEI has important application prospects in plant pest control, fruits and vegetable processing fields. In this paper, the gene families, crystal structures, molecular recognition, and applications in plants and industry are reviewed for the PME and PMEI systems. Finally, the semi-rational design of PMEI is discussed and discussed prospected.

Evolutionary dynamics of codon usages for peste des petits ruminants virus.

Peste des petits ruminants virus (PPRV) is an important agent of contagious, acute and febrile viral diseases in small ruminants, while its evolutionary dynamics related to codon usage are still lacking. Herein, we adopted information entropy, the relative synonymous codon usage values and similarity indexes and codon adaptation index to analyze the viral genetic features for 45 available whole genomes of PPRV. Some universal, lineage-specific, and gene-specific genetic features presented by synonymous codon usages of the six genes of PPRV that encode N, P, M, F, H and L proteins reflected evolutionary plasticity and independence. The high adaptation of PPRV to hosts at codon usages reflected high viral gene expression, but some synonymous codons that are rare in the hosts were selected in high frequencies in the viral genes. Another obvious genetic feature was that the synonymous codons containing CpG dinucleotides had weak tendencies to be selected in viral genes. The synonymous codon usage patterns of PPRV isolated during 2007-2008 and 2013-2014 in China displayed independent evolutionary pathway, although the overall codon usage patterns of these PPRV strains matched the universal codon usage patterns of lineage IV. According to the interplay between nucleotide and synonymous codon usages of the six genes of PPRV, the evolutionary dynamics including mutation pressure and natural selection determined the viral survival and fitness to its host.

Transcriptome and proteome analysis of pregnancy and postpartum anoestrus ovaries in yak.

BACKGROUND: Domestic yaks are the most important livestock species on the Qinghai-Tibetan Plateau. Adult female yaks normally breed in the warm season (July to September) and enter anestrous in the cold season (November to April). Nevertheless, it is unclear how ovarian activity is regulated at the molecular level. OBJECTIVES: The peculiarities of yak reproduction were assessed to explore the molecular mechanism of postpartum anestrus ovaries in yaks after pregnancy and parturition. METHODS: Sixty female yaks with calves were observed under natural grazing in Haiyan County, Qinghai Province. Three yak ovaries in pregnancy and postpartum anestrus were collected. RNA sequencing and quantitative proteomics were employed to analyze the pregnancy and postpartum ovaries after hypothermia to identify the genes and proteins related to the postpartum ovarian cycle. RESULTS: The results revealed 841 differentially expressed genes during the postpartum hypoestrus cycle; 347 were up-regulated and 494 genes were down-regulated. Fifty-seven differential proteins were screened: 38 were up-regulated and 19 were down-regulated. The differential genes and proteins were related to the yak reproduction process, rhythm process, progesterone-mediated oocyte maturation, PI3K/AKT signaling pathway, and MAPK signaling pathway categories. CONCLUSIONS: Transcriptome and proteomic sequencing approaches were used to investigate postpartum anestrus and pregnancy ovaries in yaks. The results confirmed that BHLHE40, SF1IX1, FBPX1, HSPCA, LHCGR, BMP15, and ET-1R could affect postpartum hypoestrus and control the state of estrus.

A comparative transcriptome and proteomics study of post-partum ovarian cycle arrest in yaks (Bos grunniens).

Post-partum ovarian cycle arrest is the main factor affecting yak reproductive efficiency. There are few reports regarding the molecular regulatory mechanism of post-partum oestrus at transcriptome and proteome levels in yaks. Our previous studies focussed on the ovaries of yaks with post-partum ovarian cycle arrest and post-partum oestrus yaks. In this study, RNA sequencing transcriptomic study was combined with quantitative proteomic analyses to identify post-partum ovarian cycle-related genes and proteins. Consequently, 1,149 genes and 24 proteins were found to be up- or downregulated during post-partum oestrus. The analysis of differentially regulated genes identified three gene or protein pairs that were synchronously upregulated and no gene or protein pairs that were synchronously downregulated, suggesting that these upregulated genes may regulate the post-partum ovarian cycle. The functional classification of these differentially expressed genes and proteins indicated their connection with the oocyte meiosis, the oestrogen signalling pathway, the progesterone-mediated oocyte maturation and the gonadotrophin-releasing hormone (GnRH) signalling pathway. In this study, a total of six genes and two proteins involved in the oocyte meiosis, the oestrogen signalling pathway, the progesterone-mediated oocyte maturation and the GnRH signalling pathway were identified. The CSNK1A1, M91_09723, M91_11326, M91_21439, M91_19073, SHC2, Atf6b, M91_03062, HSPCA and calmodulin could regulate oestrus, respectively, in the post-partum so as to control the anoestrus status.

The relationship between complement changes with vaccination and length of stay in COVID-19 patients / 中国热带医学

@#Abstract: Objective　To investigate whether the complement system of COVID-19 is affected by vaccination, and also to explore the relationship between complement and length of stay in hospital, with a view to providing input for clinical diagnosis and the management of COVID-19 patients. Methods　The patients admitted from November 1st to November 30th, 2021 in the Eighth Affiliated Hospital of Guangzhou Medical University were selected as subjects. According to the time of vaccination, the patients were divided into two groups as vaccinated within half a year and over half a year. Then C3, C4, IgG, IgM, IgA, COVID-19 IgG and IgM, neutral granulocyte and lymphocyte count were detected and all patients' hospitalized days were recorded. With their hospitalization days of 14 d as a threshold, the patients were divided into two groups, and the above indicators were compared. Results　C3 concentration was (0.86±0.157) g/L in patients with vaccination within six months, which is significantly lower than (0.96±0.172) g/L in those over six months (P<0.05), but as for C4, IgG, IgM, IgA, COVID-19 IgG and IgM, neutral granulocyte and lymphocyte counts, there were no significant difference between two groups; as for the patients within 14 days of hospitalization, C3 and C4 concentrations were lower than those for more than 14 days, but the COVID-19 antibody IgG and IgM, lymphocyte counts were higher (all P<0.05). Conclusion　Vaccination within half a year can make the body's immune function and complement system to identify viruses earlier, more beneficial to remove viruses, but this effect is weakened after half a year; when admission, C3, C4, COVID-19 IgG level and lymphocyte counts can be used to predict hospitalization time in COVID-19 patients.

Concepts and Application of DNA Origami and DNA Self-Assembly: A Systematic Review.

With the arrival of the post-Moore Era, the development of traditional silicon-based computers has reached the limit, and it is urgent to develop new computing technology to meet the needs of science and life. DNA computing has become an essential branch and research hotspot of new computer technology because of its powerful parallel computing capability and excellent data storage capability. Due to good biocompatibility and programmability properties, DNA molecules have been widely used to construct novel self-assembled structures. In this review, DNA origami is briefly introduced firstly. Then, the applications of DNA self-assembly in material physics, biogenetics, medicine, and other fields are described in detail, which will aid the development of DNA computational model in the future.

High-Strength and Low-Cost Biobased Polyurethane Foam Composites Enhanced by Poplar Wood Powder Liquefaction.

An environmentally friendly liquefaction of wood powder was prepared by atmospheric pressure liquefaction technology to replace the non-renewable petroleum polyols in the preparation of polyurethane foam composites. The liquefaction time varied from 0 min to 140 min. The composition of liquefied products and the effects of liquefaction time on the morphology, apparent density and mechanical properties of polyurethane foam composites were investigated. The results showed that the optimal process time for the preparation of wood powder liquefaction products, which could replace traditional petroleum polyols, was 110 min. At this time, polyether polyols are the main liquefaction products, with an average molecular weight in Mn reaching 237 and average molecular weight in Mw reaching 246. The functional group of the liquefied product consisted mainly of hydroxyl, with the highest content of 1042 mg KOH/g and the lowest acid number of 1.6 mg KOH/g. In addition, the surface of the polyurethane foam based on poplar wood is dominated by closed cell foam; thus its foam has good heat insulation and heat preservation properties. At 110 min liquefaction time, the apparent density of polyurethane foam is 0.164 g/cm3 and the compression strength is 850 kPa, which is higher than that of traditional polyurethane foam (768 kPa), which is without wood powder modification. Replacing petroleum polyol with renewable wood powder liquefaction products to prepare biomass-based polyurethane foam composite materials, researching complex chemical changes in different liquefaction stages, and finding the best liquefaction conditions are of great significance to optimize the performance of polyurethane, address the shortage of resources and reduce environmental pollution.

Inhibiting pyrimidine biosynthesis impairs Peste des Petits Ruminants Virus replication through depletion of nucleoside pools and activation of cellular immunity.

Replication of peste des petits ruminants virus (PPRV) strongly depends on the cellular environment and resources of host cells including nucleoside pool. Thus, enzymes involved in nucleoside biosynthesis (such as pyrimidine biosynthesis pathway) are regarded as attractive targets for antiviral drug development. Here, we demonstrate that brequinar (BQR) and leflunomide (LFM) which are two specific inhibitors of DHODH enzyme and 6-azauracil (6-AU) which is an ODase enzyme inhibitor robustly inhibit PPRV replication in HEK293T cell line as well as in peripheral blood mononuclear cells isolated from goat. We further demonstrate that these agents exert anti-PPRV activity via the depletion of purimidine nucleotide. Interestingly, these inhibitors can trigger the transcription of antiviral interferon-stimulated genes (ISGs). However, the induction of ISGs is largely independent of the classical JAK-STAT pathway. Combination of BQR with interferons (IFNs) exerts enhanced ISG induction and anti-PPRV activity. Taken together, this study reveals an unconventional novel mechanism of crosstalk between nucleotide biosynthesis pathways and cellular antiviral immunity in inhibiting PPRV replication. In conclusion, targeting pyrimidine biosynthesis represents a potential strategy for developing antiviral strategies against PPRV.

Lignin-Based Phenolic Foam Reinforced by Poplar Fiber and Isocyanate-Terminated Polyurethane Prepolymer.

Phenolic foams (PFs) are lightweight (<200 kg/m3), high-quality, and inexpensive thermal insulation materials whose heat and fire resistance are much better than those of foam plastics such as polyurethane and polystyrene. They are especially suitable for use as insulation in chemical, petroleum, construction, and other fields that are prone to fires. However, PFs have poor mechanical properties, poor abrasion resistance, and easy pulverization. In this paper, a polyurethane prepolymer was treated with an isocyanate, and then the isocyanate-terminated polyurethane prepolymer and poplar powder were used to prepare modified lignin-based phenolic foams (PUPFs), which improved the abrasion resistance and decreased the pulverization of the foam. The foam composites were comprehensively evaluated by characterizing their chemical structures, surface morphologies, mechanical properties, thermal conductivities, and flame-retardant properties. The pulverization ratio was reduced by 43.5%, and the thermal insulation performance and flame-retardancy (LOI) were improved. Compared with other methods to obtain lignin-based phenolic foam composites with anti-pulverization and flame-retardant properties, the hybrid reinforcement of foam composites with an isocyanate-terminated polyurethane prepolymer and poplar powder offers a novel strategy for an environmentally friendly alternative to the use of woody fibers.

The nucleotide usages significantly impact synonymous codon usage in Mycoplasma hyorhinis.

Five annotated genomes of Mycoplasma hyorhinis were analyzed for clarifying evolutionary dynamics driving the overall codon usage pattern. Information entropy used for estimating nucleotide usage pattern at the gene level indicates that multiple evolutionary dynamics participate in forcing nucleotide usage bias at every codon position. Moreover, nucleotide usage bias directly contributes to synonymous codon usage biases with two different extremes. The overrepresented codons tended to have A/T in the third codon position, and the underrepresented codons strongly used G/C in the third position. Furthermore, correspondence analysis and neutrality plot reflect an obvious interplay between mutation pressure and natural selection mediating codon usage in M. hyorhinis genome. Due to significant bias in usages between A/T and G/C at the gene level, different selective forces have been proposed to contribute to codon usage preference in M. hyorhinis genome, including nucleotide composition constraint derived from mutation pressure, translational selection involved in natural selection, and strand-specific mutational bias represented by different nucleotide skew index. The systemic analyses of codon usage for M. hyorhinis can enable us to better understand the mechanisms of evolution in this species.