Formation and Oxidation Reactivity of MnO2+(HCO3-)n in the MnII(HCO3-)-H2O2 System.

The MnII(HCO3-)-H2O2 (MnII-BAP) system shows high reactivity toward oxidation of electron-rich organic substrates; however, the predominant oxidizing species and its formation pathways involved in the MnII-BAP system are still under debate. In this study, we used the MnII-BAP system to oxidize As(III) in that As(III), Mn2+, and HCO3- are common components in As(III)-contaminated groundwater. Kinetic results show that MnII(HCO3-)n [including MnII(HCO3)+ and MnII(HCO3)2] is a key factor in the MnII-BAP system to oxidize As(III). Quenching experiments rule out contributions of OH• and 1O2 to As(III) oxidation and reveal that O2•- and the oxidizing species generated from O2•- play predominant roles in the oxidation of As(III). We further reveal that the MnO2+(HCO3-)n intermediate generated in the reaction between MnII(HCO3-)n and O2•-, instead of O2•-, is the predominant oxidizing species. Although CO3•- also contributes to As(III) oxidation, the high reaction rate constant between CO3•- and O2•- indicates that CO3•- is not the predominant oxidizing species in the As(III)-MnII-BAP system. In addition, the presence of Mn(III) further indicates the important Mn(II)-Mn(III) cycling in the MnII-BAP system. We therefore suggest two important roles of MnII(HCO3-)n in the MnII-BAP system: (i) MnII(HCO3-)n reacts with H2O2 to form the MnIII(HCO3)3 intermediate, followed by a subsequent reaction between MnIII(HCO3)3 and H2O2 to produce O2•-; (ii) MnII(HCO3-)n can also stabilize O2•- with the formation of MnO2+(HCO3-)n. MnO2+(HCO3-)n is an electrophilic reagent and plays the predominant role in the oxidation of As(III) to As(V).

Formation of hydroperoxo (-OOH) species on the surface of self-doped Bi2.15WO6: reactivity towards As(iii) oxidation.

Bi2+xWO6 is a cost-effective and environmentally friendly photocatalyst that shows high reactivity in the oxidation of various contaminants under visible light. However, under alkaline conditions, the reactive oxidative species in the Bi2+xWO6 system are still not clear yet. In this study, it is observed that the oxidation rates of As(iii) increase with increasing pH values in the Bi2.15WO6 system. Photoluminescence and the Mott-Schottky analyses confirm that OH- promotes the separation and transfer of photogenerated electron-hole pairs over Bi2.15WO6, thus facilitating the oxidation of As(iii). Electron spin resonance spectra analysis and quenching experiments rule out contributions of •OH, O2˙-, 1O2 and superoxo species to As(iii) oxidation and indicate that surface -OOH and/or H2O2 are indeed the predominant species under alkaline conditions. The improved production of H2O2 by H-donors such as glucose and phenol, as well as the UV-vis diffuse reflectance and Raman analyses, further confirms the formation of surface -OOH on Bi2.15WO6 under alkaline conditions. In the dark, the significant higher oxidation rate of As(iii) by H2O2-Bi2.15WO6 than that by H2O2 alone reveals that surface -OOH, instead of H2O2, plays an important role in As(iii) oxidation. This study enriches our understanding of the diversity of reactive oxygen species (ROS) in the Bi2.15WO6 system and gives new insight into the mechanism involved in the oxidation of As(iii) under alkaline conditions.

Identification of Transient Receptor Potential Vanilloid 3 Antagonists from Achillea alpina L. and Separation by Liquid-Liquid-Refining Extraction and High-Speed Counter-Current Chromatography.

Bioassay-guided fractionation of the ethanol extract of whole herbs of Achillea alpina led to the isolation of isochlorogenic acids A and B as transient receptor potential vanilloid 3 (TRPV3) channel antagonists by using a calcium fluorescent assay. The structures were identified by spectroscopic analysis and the inhibitory activities of isochlorogenic acids A and B were confirmed by whole-cell patch clamp recordings of human embryonic kidney 293 (HEK293) cells expressing human TRPV3. Molecular docking results revealed that these two compounds reside in the same active pocket of human TRPV3 channel protein with lower binding energy than the agonist 2-aminoethoxydiphenyl borate (2-APB). High-speed counter-current chromatography (HSCCC) coupled with a liquid-liquid extraction approach was successfully established for the separation of isochlorogenic acids A and B from the whole herbs of A. alpina. Ethyl acetate and n-hexane-ethyl acetate-water (3:3:4 and 1:5:4, v/v/v) were selected as liquid-liquid extraction solvent systems to remove high- and low-polarity impurities in the mixture. Sixty g of ethanol extract was refined by solvent partition to yield 1.7 g of the enriched fraction, of which 480 mg in turn obtained 52.5 mg of isochlorogenic acid B (purity 98.3%) and 37.6 mg isochlorogenic acid A (purity 96.2%) after HSCCC with n-hexane-ethyl acetate-water containing 1% acetic acid (1:4:8, v/v/v).

An Improved Method for the Synthesis of Butein Using SOCl2/EtOH as Catalyst and Deciphering Its Inhibition Mechanism on Xanthine Oxidase.

Butein (3,4,2',4'-tetrahydroxychalcone) belongs to the chalcone family of flavonoids and possesses various biological activities. In this study, butein was synthesized through aldol condensation catalyzed by thionyl chloride (SOCl2)/ethyl alcohol (EtOH) for the first time. The optimal reaction conditions including the molar ratio of reactants, the dosage of catalyst, and the reaction time on the yield of product were investigated, and the straightforward strategy assembles the yield of butein up to 88%. Butein has been found to inhibit xanthine oxidase (XO) activity. Herein, the inhibitory mechanism of butein against XO was discussed in aspects of inhibition kinetic, fluorescence titration, synchronous fluorescence spectroscopy, and molecular docking. The inhibition kinetic analysis showed that butein possessed a stronger inhibition on XO in an irreversible competitive manner with IC50 value of 2.93 × 10-6 mol L-1. The results of fluorescence titrations and synchronous fluorescence spectroscopy indicated that butein was able to interact with XO at one binding site, and the fluorophores of XO were placed in a more hydrophobic environment with the addition of butein. Subsequently, the result of molecular docking between butein and XO protein revealed that butein formed hydrogen bonding with the amino acid residues located in the hydrophobic cavity of XO. All the results suggested that the inhibitory mechanism of butein on XO may be the insertion of butein into the active site occupying the catalytic center of XO to avoid the entrance of xanthine and inducing conformational changes in XO.

Isolation of Tricin as a Xanthine Oxidase Inhibitor from Sweet White Clover (Melilotus albus) and Its Distribution in Selected Gramineae Species.

Xanthine oxidase, an enzyme present in significant levels in the intestine and liver, metabolizes hypoxanthine to xanthine and xanthine to uric acid in the purine catabolic pathway. An inhibitory compound acting against xanthine oxidase was isolated from sweet white clover (Melilotus albus) by bioassay and high-performance liquid chromatography guided separation. It was identified as tricin by spectroscopic analysis. Tricin possessed a potent xanthine oxidase inhibitory activity with an IC50 value of 4.13 µM. Further inhibition kinetics data indicated it to be a mixed-type inhibitor and Ki and KI values were determined to be 0.47 µM and 4.41 µM. To find a rich source of tricin, the distribution of tricin in seven different tissues from four Gramineae species was investigated by high-performance liquid chromatography analysis. The highest amount (1925.05 mg/kg dry materials) was found in the straw of wheat, which is considered as a potentially valuable source of natural tricin.

[Cloning and expression analysis of transcription factor gene DoWRKY1 in Dendrobium officinale].

WRKY transcription factors are novel transcriptional regulatory factors, which play an important role in regulating plant development, metabolism and other physiological processes. In this study, a new Dendrobium officinale WRKY transcription factor, designated as DoWRKY1 was cloned by using RT-PCR and RACE (GenBank Accession No. KF953910). Bioinformatic analysis demonstrated that, the full-length cDNA of DoWRKY1 was 1,704 bp. And DoWRKY1 contained a 1,629 bp open reading frame (ORF) that encoding a peptide of 542 amino acid residues. The putative DoWRKY1 protein contained two conserved WRKY domains and it belonged to the group I WRKY family protein. Yeast one-hybrid experiment showed that DoWRKY1 had transcriptional activation ability in yeast, and it could activate the expression of downstream report genes (His3 and Ade2). Semi-quantitative RT-PCR experiment showed that DoWRKY1 expressed in roots, stems, leaves and protocorm-like bodies. Real-time qRT-PCR proved that DoWRKY1 could be induced by methyl jasmonate (MeJA) and chitosan (Chitosan), and the expression level of this gene can reach the expression peak at 2 h and 1 h, respectively. These results are useful for further determination of the regulation function of this gene in secondary metabolism of D. officinale.

Three new polyketides from marine-derived fungus Aspergillus glaucus HB1-19.

Two new benzyl derivatives, aspergentisyl A (1) and aspergentisyl B (2), as well as one new naphthoquinone derivative, aspergiodiquinone (3), together with seven known prenylated benzaldehyde derivatives (4-10) were isolated from the marine-derived fungus Aspergillus glaucus HB1-19. The structures of these compounds were characterized based on 1D and 2D NMR spectra analyses and comparison with those reported in the literature. In addition, each isolate was tested for its 1,1-diphenyl-2-picrylhydrazyl radical-scavenging property and all these compounds except compound 3 exhibited strong radical-scavenging activity.

Differential microbial composition in parasitic vs. questing ticks based on 16S next-generation sequencing.

Introduction: As tick-borne diseases rise to become the second most prevalent arthropod-transmitted disease globally, the increasing investigations focus on ticks correspondingly. Factors contributed to this increase include anthropogenic influences, changes in vertebrate faunal composition, social-recreational shifts, and climatic variation. Employing the 16S gene sequence method in next-generation sequencing (NGS) allows comprehensive pathogen identification in samples, facilitating the development of refined approaches to tick research omnidirectionally. Methods: In our survey, we compared the microbial richness and biological diversity of ticks in Wuwei City, Gansu province, differentiating between questing ticks found in grass and parasitic ticks collected from sheep based on 16S NGS method. Results: The results show Rickettsia, Coxiella, and Francisella were detected in all 50 Dermacentor nuttalli samples, suggesting that the co-infection may be linked to specific symbiotic bacteria in ticks. Our findings reveal significant differences in the composition and diversity of microorganisms, with the Friedmanniella and Bordetella genera existing more prevalent in parasitic ticks than in questing ticks (p < 0.05). Additionally, the network analysis demonstrates that the interactions among bacterial genera can be either promotive or inhibitive in ticks exhibiting different lifestyles with the correlation index |r| > 0.6. For instance, Francisella restrains the development of 10 other bacteria in parasitic ticks, whereas Phyllobacterium and Arthrobacter enhance colonization across all tick species. Discussion: By leveraging NGS techniques, our study reveals a high degree of species and phylogenetic diversity within the tick microbiome. It further highlights the potential to investigate the interplay between bacterial genera in both parasitic and questing ticks residing in identical habitat environments.

[Rapid identification of variable star spectrum based on information entropy].

Variable star is very important for mankind studying cosmic origin and evolution. For studying variable star, the chief difficulty results from the filtration and identification of variable star, that is how to validly identify variable star spectra from large high-dimensional star spectra data. The traditional outlier definition tries to find the difference between the outlier data and the general model by different ways, and then the result is quantitatively analyzed and filtrated. However, the time complexity of this method is over size and its results are inscrutable and unaccountable. Information entropy is a measure of the uncertainty associated with a random variable. In the present paper, information entropy is imported as the standard of dataset common mode. A novel method is proposed to identify the variable star spectrum rapidly based on information entropy. The time complexity of this method is observably reduced and the man-made impact is effectively overcome. The preliminary experimental results based on Sloan star spectrum data show that the method is workable for rapid identification of variable star spectrum.

Effects of 2,2',4'-trihydroxychalcone on the proliferation, metastasis and apoptosis of A549 human lung cancer cells.

The aim of the present study was to evaluate the antitumor effects of 2,2',4'-trihydroxychalcone (7a) on the A549 human lung cancer cell line. A549 cells were treated with different concentrations of 7a for different time periods. Cells without 7a were used as the negative control group. Cell proliferation, invasion, vasculogenic mimicry (VM) formation, heterogeneous adhesion and apoptosis were measured using Cell Counting Kit-8, Transwell invasion, VM, adhesion and flow cytometric assays, respectively. In addition, the expression of related proteins was determined using western blot analysis or ELISA. The present study found that 7a had a significant inhibitory effect on the survival rate of the A549 lung cancer cells but almost no effect on BEAS-2B human lung epithelial cells or human venous endothelial cells. The migration rate, VM length, invasion rate and heterogeneous adhesion number of cells treated with 7a significantly decreased as the concentration increased, while the apoptosis rate increased. Western blot analysis showed that 7a treatment significantly increased the expression levels of E-cadherin, cleaved poly (ADP-ribose) polymerase, Bax and caspase-3 and simultaneously decreased the expression levels of metalloproteinase-2/9, Bcl-2, phosphorylated (p)-PI3K, p-AKT, p-mTOR, vascular endothelial growth factor (VEGF), E-selectin and N-cadherin. At the same time, the ELISA results showed that the level of the pro-angiogenic factor VEGF in the culture media was reduced in the presence of 7a. In addition, 7a could also reduce the nuclear NF-κB protein expression, which could inhibit the gene transcription of tumor apoptosis and metastasis-related proteins. Therefore, 7a may exert inhibitory effects on A549 cells by inhibiting cell proliferation, migration, VM formation and heterogeneous adhesion, as well as by inducing apoptosis through the suppression of the PI3K/AKT/NF-κB signaling pathway; these findings suggested that 7a may be a promising agent for the treatment of lung cancer.

Alterations in the Composition of Intestinal DNA Virome in Patients With COVID-19.

Patients with Coronavirus Disease 2019 (COVID-19), due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection mainly present with respiratory issues and related symptoms, in addition to significantly affected digestive system, especially the intestinal tract. While several studies have shown changes in the intestinal flora of patients with COVID-19, not much information is available on the gut virome of such patients. In this study, we used the viromescan software on the latest gut virome database to analyze the intestinal DNA virome composition of 15 patients with COVID-19 and investigated the characteristic alternations, particularly of the intestinal DNA virome to further explore the influence of COVID-19 on the human gut. The DNA viruses in the gut of patients with COVID-19 were mainly crAss-like phages (35.48%), Myoviridae (20.91%), and Siphoviridae (20.43%) family of viruses. Compared with healthy controls, the gut virome composition of patients with COVID-19 changed significantly, especially the crAss-like phages family, from the first time of hospital admission. A potential correlation is also indicated between the change in virome and bacteriome (like Tectiviridae and Bacteroidaceae). The abundance of the viral and bacterial population was also analyzed through continuous sample collection from the gut of patients hospitalized due to COVID-19. The gut virome is indeed affected by the SARS-CoV-2 infection, and along with gut bacteriome, it may play an important role in the disease progression of COVID-19. These conclusions would be helpful in understanding the gut-related response and contribute to the treatment and prevention strategies of COVID-19.

Separation of New Coumarin Glycosides from Toddalia asiatica Using Offline Two-Dimensional High-Performance Liquid Chromatography.

Coumarins and flavonoids are the major constituents of Toddalia asiatica. The separation and purification of ingredients from T. asiatica is an important procedure to acquire high-purity compounds for subsequent pharmacological investigation to discover leading compounds. In the present work, an offline two-dimensional high-performance liquid chromatography (HPLC) method was successfully established for the separation of high-purity glycosides from T. asiatica. Based on the separation results obtained with two different chromatographic stationary phases, a phenyl-bonded silica-based reversed-phase column was employed as the first HPLC preparation, and three fractions were obtained from the sample. Then, the fractions were isolated and purified on an octadecyl-bonded silica-based reversed-phase column to obtain high-purity compounds in the second HPLC separation. As a result, three coumarin glycosides, including two undescribed and one known, along with one known flavonoid glycoside with more than 98% purity were isolated from the sample. The structures of the isolated compounds were elucidated on the basis of extensive spectroscopic evidence derived from optical rotation, mass spectrometry, and nuclear magnetic resonance experiments. Two-dimensional HPLC with different stationary phases has the potential to be an efficient method for the separation of high-purity compounds from T. asiatica.

Physiological and Biochemical Mechanisms Mediated by Allelochemical Isoliquiritigenin on the Growth of Lettuce Seedlings.

Isoliquiritigenin, a natural chalcone-type flavonoid, has been recognized as an allelochemical with phytotoxicity to lettuce; however, not enough attention has been paid to the mechanisms of this secondary metabolite. In this work, we investigated the physiological and biochemical mechanisms of isoliquiritigenin on lettuce seedlings. The results show that isoliquiritigenin has a concentration-dependent inhibitory effect on radicle elongation of lettuce seedlings, but no significant impact on lettuce germination. Microscopy analyses suggest that the surface morphology of lettuce radicle tips was atrophied and the intracellular tissue structure deformed at high concentrations. Isoliquiritigenin induced the overproduction of reactive oxygen species (ROS), which led to loss of cell viability in the radicle cells. In addition, malondialdehyde (a product of lipid peroxidation) and free proline levels were found to have increased, while chlorophyll content in lettuce seedlings decreased. All these changes suggest that the primary allelopathic mechanism of isoliquiritigenin by which it inhibits radicle elongation in lettuce seedlings might be due to the overproduction of ROS, which causes oxidative damage to membrane lipids and cell death.

Cyclic Dipeptides Mediating Quorum Sensing and Their Biological Effects in Hypsizygus Marmoreus.

A novel quorum sensing (QS) system was discovered in Serratia odorifera, the symbiotic bacterium of Hypsizygus marmoreus. This system uses cyclo(Pro-Phe), cyclo(Pro-Tyr), cyclo(Pro-Val), cyclo(Pro-Leu), cyclo(Tyr-Leu), and cyclo(Tyr-Ile) as autoinducers. This discovery is the first attempt to characterize cyclic dipeptides as QS signaling molecules in S. odorifera and improves the classical QS theory. Significantly, except for cyclo(Tyr-Leu), these QS autoinducers can increase the transcription level of lignin-degrading enzyme genes of H.marmoreus. The cyclo(Pro-Phe) can increase the activity of extracellular laccase (1.32-fold) and manganese peroxidase (20%), which may explain why QS potentially regulates the hyphal growth, primordium formation, and fruit body development of H. marmoreus. Furthermore, it was demonstrated that the cyclo(Tyr-Ile) biosynthesis in S. odorifera was catalyzed by the nonribosomal peptide synthetase (NRPS). This study supports exploring the growth and development of H.marmoreus promoted by its symbiotic bacteria at QS signal transduction level.

Polyvinyl alcohol degradation by Bacillus cereus RA23 from oil sludge sample.

A novel polyvinyl alcohol (PVA)-degrading strain Bacillus cereus RA23 was isolated from an oil sludge sample and environmental factors affecting its PVA degradation efficiency were optimized in detail. Inorganic nitrogen source, ammonium chloride (NH4Cl), was found to be the best nitrogen source and enhanced the PVA degradation rate greatly. The optimal medium for PVA biodegradation consisted of (g/L) PVA 1, NH4Cl 1, K2HPO4 1.6, MgSO4·7H2O 0.05, FeSO4·6H2O 0.02, CaCl2 0.05, NaCl 0.02. The optimal temperature and pH for PVA biodegradation by strain RA23 was 28 °C and 7.0, respectively, and 85% of 0.1% PVA was degraded after 5 days under these conditions. FTIR studies showed that the carboxylic acids (possibly including aldehyde or ketone) could be the intermediate product of PVA biodegradation. The investigation of strain RA23 for PVA degradation will provide important information to facilitate the removal of wastewater pollution in industrial zones.

Significantly improved production of Welan gum by Sphingomonas sp. WG through a novel quorum-sensing-interfering dipeptide cyclo(L-Pro-L-Phe).

A variety of physiological functions such as exopolysaccharide synthesis, antibiotic production, and primary metabolism are tightly controlled by quorum sensing in microorganisms. In this study, a marine-derived bacterium Sphingomonas sp. WG was found to possess a cyclo(L-Pro-L-Phe)-mediated quorum sensing mechanism. The cyclo(L-Pro-L-Phe) produced by Sphingomonas sp. WG functions as a signalling molecule in this quorum sensing system. It is the first attempt to characterize cyclic dipeptides as quorum sensing signalling molecules in Sphingomonas sp. and the results effectively make the classical quorum sensing theory more perfect. Furthermore, the supplementation with isolated cyclo(L-Pro-L-Phe) resulted in a 15% increase in the production of welan gum secreted by Sphingomonas sp. WG in the submerged fermentation. The data presented in this study will provide evidences for exploring the role of cyclic dipeptides in regulating the production of welan gum.

Epidemiology of traumatic spinal cord injury in Tianjin, China: An 18-year retrospective study of 735 cases.

Study Design: Hospital-based retrospective studyObjectives: To evaluate the pathogenetic features of traumatic spinal cord injury (TSCI) during 1999-2016 according to changed injury etiology with time, explore different characteristics of patients suffered a TSCI during 1999-2007 and 2008-2016 in Tianjin, China.Setting: Tianjin Medical University General HospitalMethods: In this study, the medical records of TSCI patients were obtained from Tianjin Medical University General Hospital (TMUGH) from 1st January 1999 to 31th December 2016. Variables were recorded, including age, gender occupation, etiology, the level of injury, America Spinal Injury Association (ASIA) impairment scale, the severity, concomitant injuries, death and its cause. To explore the differences in characteristics by etiology and by two periods, related statistical methods were used to calculate the correlation of some variables. Differences in etiology of TSCI during 1999-2016 were evaluated and differences in epidemiological characteristics were separately compared and analyzed between the 1999-2007 period and the 2008-2016 period.Results: From 1999-2016, 831 TSCI cases were identified and 96 cases were excluded from analyses. The male-to-female ratio was 2.9:1 and the mean age was 49.7±15.2 years, which changed significantly between 1999-2007 (45.1±14.2) and 2008-2016 (51.6±15.2). Traffic accidents (45.8%) were the leading cause of TSCI during the 1999-2007 period, followed by low falls (30.7%). However, the opposite result was observed during the 2008-2016 period. Significant difference was observed compared with thoracic, lumbar and sacral levels, cervical level was the most commonly affected levels and the percentage decreased to a certain degree between 1999-2007 and 2008-2016 (from 84.4% to 68.9%). The proportions of ASIA grades A, B, C, and D were 20.5%, 10.3%, 23.3%, and 45.9%, respectively. The percentage of complete tetraplegia decreased from 22.9% in 1999-2007 to 13.2% in 2008-2016, and the percentage of incomplete paraplegia increased from 9.7% to 27.9%.Conclusion: According to the changes in the epidemiological characteristics of TSCI, relevant health service, laws and regulations, preventative strategies should be readjusted to follow up the changing situation and epidemiological characteristics of TSCI.

Identification and expression analysis of novel LAGE-1 alleles with single nucleotide polymorphisms in cancer patients.

OBJECTIVE: The purpose of this study is to identify single nucleotide polymorphisms (SNPs) in the coding region alleles of the X chromosomal LAGE-1 gene, and investigate the frequency of such SNPs in both cancer patients and healthy controls, and thus determine the potential significance of these SNPs with respect to cancer vaccine therapy. METHODS: In this study, different mRNAs transcribed from the LAGE-1 gene were identified by RT-PCR from healthy donors and cancer patients samples. RESULTS: A new LAGE-1 allele containing three coding region SNPs (69A/G, 317C/G, and 397T/G) were identified. The allele is highly expressed as the LAGE-1a mRNA variant AY679089 in some of the cancer patients. The three SNPs altered the LAGE-1 gene sequence to that of NYESO-1 at both the nucleotide and amino acid level. CONCLUSION: There is a high frequency of the LAGE-1 gene allele with SNPs in coding regions in cancer patients. There was a clear relationship between the variant AY679089 and gastric cancer. The SNPs may lead to accelerated progress of poorly differentiated gastric cancer. The SNPs found in these alleles may also alter the immunological characteristics of LAGE-1a and should be taken into account if this antigen is adopted as a cancer vaccine component.

Degradation of polyvinyl alcohol by a novel bacterial strain Stenotrophomonas sp. SA21.

In this study, polyvinyl alcohol (PVA)-degrading bacteria were screened from oil sludge using PVA as a sole source of carbon in the culture medium. A novel strain, SA21, was obtained and identified as a member of the Stenotrophomonas genus based on the analysis of a partial 16S rDNA nucleotide sequence, morphological and biochemical characteristics, and phylogenetic analysis. This Stenotrophomonas isolate had not previously been reported as a PVA-degrading bacterium. Stenotrophomonas sp. strain SA21 degraded 90% of the PVA present in the culture medium after 4 days. The effect of nitrogen sources on the production of PVA-degrading enzyme involved in the biodegradation process was significant, and the enzymatic activity reached 82 U/ml when ammonium nitrate or urea was used in the optimized medium. The information obtained in this study will provide a foundation for improving industrial wastewater treatment. ABBREVIATIONS: DCW: dry cell weight; FTIR: Fourier Transform Infrared Spectroscopy; NCBI: National Center for Biotechnology Information; PCR: polymerase chain reaction; PVA: polyvinyl alcohol; SEM: scanning electron microscope.

[Ankle arthroscopy for ankle impingement syndrome through anterior and posterior passage].

OBJECTIVE: To analyze clinical efficiency and intraoperative considerations of ankle arthroscopy for ankle impingement syndrome through anterior and posterior passage. METHODS: From April 2011 to April 2015, the clinical data of 17 patients diagnosed as ankle impingement syndrome were performed arthroscopy, including 12 males and 5 females, with an average age of 32.4 years (ranging from 22 to 47). Ankle arthroscopy cleaning were carried out according to clinical symptoms and radiological imaging, crashed part were cleaned too. Non steroidal anti-inflammatory drugs and intra-articular injection of sodium hyaluronate were used as conventional postoperatively treatment. AOFAS score and Ogilvie-Harris score were used to assess preoperative situation and postoperative situation. RESULTS: Intra-operative conditions showed 8 cases with anterior lateral impingement syndromes, 2 cases with anterior medial impingement syndromes, 2 cases with posterior impingement syndromes and 3 cases combined with anterior and posterior impingement syndromes. Distal bundle of anterior tibiofibular ligament, anterior talusfibular ligament and synovial tissue and scar tissue were cleared up during operation. Four patients were combined with concomitant articular cartilage injury, and damage area were about 1 mm×3 mm to 1.5 mm×4 mm. Microfracture treatment were performed by 1.2 mm diameter Kirschner wire. All patients were followed up from 8 to 24 months with an average of 14.3 months. AOFAS score increased from 62.3±5.20 preoperatively to 87.6±5.40 postoperatively, Ogilvie-Harris ankle score increased from 6.70±0.98 preoperatively to 12.80±1.21 postoperatively. No neurovascular damage, wound infection or wound healing problem occurred. Ankle swelling were appeared with different degrees, but disappeared at 4 to 8 weeks postoperatively. CONCLUSIONS: For ankle impingement syndrome patients, ankle arthroscopy through anterior with posterior passage could effectively clear up bone and soft tissue impingement. Postoperatively non-steroidal anti-inflammatory drugs and intra-articular injection of sodium hyaluronate could effectively relieve ankle pain and swollen and achieve good therapeutic effect.