Research on Crack Propagation of Nitrate Ester Plasticized Polyether Propellant: Experiments and Simulation.

To understand the fracture properties of the nitrate ester plasticized polyether (NEPE) propellant, single-edge notched tension (SENT) tests were carried out at room temperature (20 °C) under different tensile rates (10-500 mm/min). The mechanical response, crack morphology, evolution path, and crack propagation velocity during the fracture process were studied using a combination of a drawing machine and a high-speed camera. The mode I critical stress intensity factor KIc was calculated to analyze the tensile fracture toughness of the NEPE propellant, and a criterion related to KIc was proposed as a means of determining whether the solid rocket motors can normally work. The experimental results demonstrated that the NEPE propellant exhibited blunting fracture phenomena during crack propagation, resulting in fluctuating crack propagation velocity. The fracture toughness of the NEPE propellant exhibited clear rate dependence. When the tensile rate increased from 10 mm/min to 500 mm/min, the magnitude of the critical stress intensity factor increased by 62.3%. Moreover, numerical studies based on bond-based peridynamic (BBPD) were performed by modeling the fracture process of the NEPE propellant, including the crack propagation speed and the load-displacement curve of the NEPE propellant. The simulation results were then compared with the experiments.

[Research on the method of loading exosomes onto absorbable stents].

Objective: To explore a method of loading exosomes onto absorbable stents. Methods: By building a stent-(3-aminopropyl) triethoxysilane-1, 2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy (polyethylene glycol) 5000]-exosomes connection, the exosomes were loaded onto absorbable stents to obtained the exosome-eluting absorbable stents. The surface conditions of the stents and absorption of exosomes were observed by scanning electron microscope and identified through the time-of-flight mass spectrometry; the roughness of the stents' surfaces was observed by atomic force microscope; the appearances and sizes of the stents were observed by stereomicroscope; and the radial force was tested by tensile test machine. The absorbable stents were used as control. Results: The scanning electron microscope observation showed that the exosome-eluting absorbable stents had some small irregular cracks on the surface where many exosomes could be seen. The atomic force microscopy observation showed that within the range of 5 µm 2, the surface roughness of the absorbable stents was ±20 nm, while the surface roughness of the exosome-eluting absorbable stents was ±70 nm. In the results of time-of-flight mass spectrometry, both the exosome-eluting absorbable stents and exosomes had a peak at the mass charge ratio of 81 (m/z 81), while the absorbable stents did not have this peak. The peak of exosome-eluting absorbable stents at m/z 73 showed a significant decrease compared to the absorbable stents. The stereomicroscope observation showed that the sizes of exosome-eluting absorbable stents met standards and the surfaces had no cracks, burrs, or depressions. The radial force results of the exosome-eluting absorbable stents met the strength standards of the original absorbable stent. Conclusion: By applying the chemical connection method, the exosomes successfully loaded onto the absorbable stents. And the sizes and radial forces of this exosome-eluting absorbable stents meet the standards of the original absorbable stents.

Myricetin exerts anti-biofilm activity and attenuates osteomyelitis by inhibiting the TLR2/MAPK pathway in experimental mice.

AIMS: To evaluate the potential of Myricetin against S.aureus induced osteomyelitis. BACKGROUND: Osteomyelitis is infected condition of bone by micro-organisms. The mitogen-activated protein kinase (MAPK), inflammatory cytokines and Toll-like receptor-2 (TLR-2) pathway are mainly involved in osteomyelitis. Myricetin is a plant-food derived flavonoid which shows anti-inflammatory activity. OBJECTIVE: In the present study, we evaluated the potential of Myricetin against S.aureus induced osteomyelitis. MC3T3-E1 cells were used for in vitro studies. METHOD: Murine model of osteomyelitis was developed in BALB/c mice by injecting S.aureus in the medullary cavity of the femur. The mice were studied for bone destruction, anti-biofilm activity, osteoblast growth markers alkaline phosphatase (ALP), osteopontin (OCN) and collagen type-I (COLL-1) were studied by RT-PCR, ELISA analysis for levels of proinflammatory factors CRP, IL-6 and IL-1ß. Expression of proteins by Western blot analysis and anti-biofilm effect by Sytox green dye fluorescence assay. Target confirmation was done by performing in silico docking analysis. RESULTS: Myricetin reduced bone destruction in osteomyelitis induced mice. The treatment decreased bone levels of ALP, OCN, COLL-1 and TLR2. Myricetin decreased serum levels of CRP, IL-6 and IL-1ß. The treatment suppressed activation of MAPK pathway and showed anti-biofilm effect. Docking studies suggested high binding affinity of Myricetin with MAPK protein in silico, by showing lower binding energies. CONCLUSION: Myricetin suppresses osteomyelitis by inhibiting ALP, OCN, COLL-1 via the TLR2 and MAPK pathway involving inhibition of biofilm formation. In silico studies suggested MAPK as potential binding protein for myricetin.

Molecular Dynamic Simulations and Experiments Study on the Mechanical Properties of HTPE/PEG Interpenetrating Polymer Network (IPN) Binders.

The mechanical properties of HTPE/PEG interpenetrating polymer network (IPN) binders were systemically studied with molecular dynamics (MDs) simulations and experiments. In this study, an algorithm was used to construct the crosslinking interpenetrating polymer network models and then the mechanical behaviors of Hydroxyl-terminated polyethylene glycol-tetrahydrofuran co-polyether/poly ethylene glycol (HTPE/PEG) IPN models were analyzed at a molecular scale. Firstly, glass transition temperatures (Tg), mean square displacement (MSD) and mechanical properties of IPN crosslinked model simulations showed that better thermomechanical parameters appeared at low temperatures, which were in good agreement with the experimental methods, including dynamic mechanical analysis and uniaxial tensile. Then bond-length distribution was performed to verify the crosslinked structures between prepolymers and curing agents. FTIR-ATR spectra analysis of four IPN binder specimens also gave a convictive result to the special interpenetrating polymer network of polyether polyurethane binders. Cohesive energy density and friction-free volume explained how the micro-structures of IPN crosslinked models and the force of inter-molecule chains affected the mechanical behaviors of the HTPE/PEG polyurethane matrix. Lastly, the morphology of IPN binder specimen tensile fracture indicated the mechanism at different temperatures. These studies were helpful in understanding the mechanical properties of HTPE/PEG interpenetrating polymer network binders and provide molecular insight into mechanisms of mechanical behaviors, which would guide the property improvement of HTPE propellant.

Molecular Dynamic Simulations and Experiments Study on the Mechanical Properties of HTPE Binders.

The mechanical properties of HTPE binders have been systemically studied through combining the microstructure molecular simulations with macroscopic experiments. In this study, the crosslinking structures of HTPE binders were established by a computational procedure. Based on the optimized crosslinking models, the mechanical properties and the glass transition temperatures (Tg) of HTPE/N-100, HTPE/HDI, HTPE/TDI, and HTPE/IPDI binder systems were simulated; specifically, the Tg were 245.758 K, 244.573 K, 254.877 K, and 240.588 K, respectively. Then the bond-length distributions, conformation properties, cohesive energy densities, and fraction free volume were investigated to analyze how the microstructures of the crosslinking models influenced the mechanical properties of HTPE binders. Simultaneously, FTIR-ATR spectra analysis of HTPE binders proved that the special peaks, such as -NH and -NCO, could be seen in the crosslinking polyurethane structures synthesized between prepolymers and curing agents. The dynamic mechanical analysis was carried out, and it found that the Tg of HTPE/N-100, HTPE/HDI, HTPE/TDI, and HTPE/IPDI binder systems were -68.18 °C, -68.63 °C, -65.67 °C, and -68.66 °C, respectively. In addition, the uniaxial tension verified that both the ultimate stress and Young's modulus of HTPE binder systems declined with the rising temperatures, while the strains at break presented a fluctuant variation. When it was closer to glass temperatures, especially -40 °C, the mechanical properties of HTPE binders were more prominent. The morphology of the fractured surface revealed that the failure modes of HTPE binders were mainly intermolecular slipping and molecular chain breakage. In a word, the experimental results were prospectively satisfied using the simulations, which confirmed the accuracy of the crosslinking models between prepolymers and curing agents. This study could provide a scientific option for the HTPE binder systems and guide the design of polyurethanes for composite solid propellant applications.

A study of the mechanical properties of the NEPE binders by molecular dynamic simulations and experiments.

In this study, the crosslinking structures of nitrate ester plasticized polyether (NEPE) binders were constructed by a computational procedure. Based on the final crosslinking models, the glass transition temperatures, mechanical properties, and thermal expansion coefficients of polyethylene glycol400/multi-functional isocyanate (PEG400/N-100), polyethylene glycol400/toluene diisocyanate (PEG400/HDI), polyethylene glycol400/hexamethylene diisocyanate (PEG400/TDI) and polyethylene glycol400/isophorone diisocyanate (PEG400/IPDI) models were simulated by molecular dynamics, and could be confirmed by experiments. Then the bond-length distributions, conformation properties and cohesive energy densities were used to analyze in detail how the different cured structures influenced the mechanical and thermal properties. Furthermore, the radial distribution function, mean square radius of gyration, volume shrinkage and fraction free volume were calculated, which could directly explain the relationships between the intermolecular chains and macroscopical properties of the NEPE binders. Lastly, PEG400/N-100 and PEG400/HDI systems were chosen for the experiments. The dynamic mechanical analysis results explained that PEG400-HDI showed better flexibility and its T g value was 45 °C lower than that of PEG400-N100. The mechanical properties illustrated that the ultimate tensile strength and Young's modulus of PEG400/N-100 were both to an extent higher than that of PEG400/HDI in the temperature range of -40 °C to 50 °C, according to the results provided by a universal tensile test machine. The experimental results were in good agreement with the simulation analysis. This work can help us to have an efficient comprehension on the crosslinking structures and micro-property relationships of the NEPE binders and act as a guidance for designing applicable polyurethanes in propellant applications.

Theoretical Calculations and Experiments on the Thermal Properties of Fluorinated Graphene and Its Effects on the Thermal Decomposition of Nitrate Esters.

Fluorinated graphene contains F atoms with high levels of chemical activity, and the application of fluorinated graphene in energetic materials may greatly contribute to the progress of combustion reactions. However, there is a lack of research on the thermal properties of fluorinated graphene and its application on nitrate esters. In this paper, theoretical calculations and experiments were used to study the thermal properties of fluorinated graphene and its application on nitrate esters. The anaerobicity and poor thermal stability of fluorinated graphene were proved by ab initio molecular dynamics (AIMD) calculations and TG-DSC experiments. The ester weakening effect of fluorinated graphene on nitroglycerin was determined via wavefunction analysis, with the greater the fluorination degree, the stronger the ester weakening effect. The existence of fluorinated graphene can significantly increase the heat dissipation of the composites, which was concluded by TG-DSC experiments and TG-DSC-MS-FTIR. The research in this article provides an important reference for the application of fluorinated graphene in energetic materials.

Successful application of extracorporeal circulation compression perfusion in the treatment of diabetic foot: a retrospective cross-sectional study.

OBJECTIVE: To investigate the clinical effect of extracorporeal circulation compression perfusion (ECCP) in the treatment of diabetic foot. METHODS: We retrospectively evaluated 89 patients with diabetic foot admitted from January 2017 to April 2019. The patients were grouped according to whether they received ECCP treatment; experimental group: 27 patients, controls: 62 patients. After applying the inclusion criteria and exclusion criteria, there were 21 patients in the experimental group and 21 patients in the control group. Foot microcirculation was evaluated by measuring the percutaneous oxygen partial pressure (TcPO2) and infrared thermography (IRT). Wound healing time and ulcer recurrence rate 1 year after discharge were compared between the groups. RESULTS: TcPO2 and IRT values in the experimental group differed significantly compared with the control group. Foot ulcer healing time in the experimental group was shorter than that in the control group (17.10 ± 3.08 days vs 25.38 ± 4.40 days, respectively), and the recurrence rate after 1 year in the experimental group was lower than that in the control group (2/21, 9.5% vs 9/21, 42.8%, respectively). CONCLUSION: ECCP improved foot microcirculatory perfusion in diabetic foot treatment. ECCP has clinical practicality and may accelerate wound healing speed and reduce ulcer recurrence.

Combination of kaempferol and azithromycin attenuates Staphylococcus aureus-induced osteomyelitis via anti-biofilm effects and by inhibiting the phosphorylation of ERK1/2 and SAPK.

Osteomyelitis is bacterial infection of bone, commonly caused by Staphylococcus aureus. This work aims to study the potential of azithromycin and kaempferol against chronic osteomyelitis induced by azithromycin-resistant Staphylococcus aureus (ARSA). It was noticed that rats tolerated the treatments with no diarrhoea or weight loss; also, no deaths were observed in rats. The treatment by azithromycin alone failed to inhibit bacterial growth and also had no effect on the infection condition of bone, although the treatment decreased the levels of interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α), but did not improve the oxidative stress levels. Kaempferol monotherapy slightly inhibited bacterial growth and bone infection; the treatment also inhibited the levels of IL-6 and (TNF-α). The treatment also improved the antioxidant status. However, the combined treatment of azithromycin and kaempferol significantly suppressed bacterial growth and bone infection and modulated oxidative stress. In vitro, the combined treatment inhibited the levels of IL-6 and TNF-α, and also suppressed the phosphorylation of ERK1/2 and stress-activated protein kinase (SAPK). The combined treatment also showed anti-biofilm activity in ARSA. The combination attenuates ARSA-induced osteomyelitis in rats compared with their treatments alone by reducing oxidative stress, inhibiting the phosphorylation of ERK1/2 and SAPK and inhibiting biofilm formation.

Nanoscale Au@SiO2-drug/VEGF as an in vivo probe for osteosarcoma diagnosis and therapy.

Osteosarcoma is a common primary bone malignancy, with a 5-year survival rate of only 20-30% in patients undergoing surgical treatment. Thus, it is important to identify novel methods for diagnosing and treating osteosarcoma, which was the aim of the present study. Vascular endothelial growth factor (VEGF) was used as the tumor-targeting protein to synthesize a multifunctional core-shell nanostructure, Au@SiO2-drug/VEGF, in which the drug can be indocyanine green (ICG; as an optical tracer) or doxorubicin (DOX; as a chemotherapeutic agent). With VEGF as the osteosarcoma-targeting protein, Au exhibited optimal photothermal transformation performance, while SiO2 served as the carrier for the drug. Au@SiO2-ICG/VEGF nanoparticles (NPs) were evaluated for imaging and for the monitoring of drug accumulation in a tumor region in mice. Once the optimal drug accumulation was achieved, combined treatment of osteosarcoma (chemotherapy and photothermal therapy) was assessed. In the perioperative period associated with minimal invasive embolization of osteosarcoma, photothermal therapy and chemotherapy were applied for osteosarcoma diagnosis using Au@SiO2-DOX/VEGF NPs. Taken together, the results of the present study provide a promising strategy for tumor detection prior to surgical treatment to improve the survival outcome of patients with osteosarcoma.

Consensus on the application of negative pressure wound therapy of diabetic foot wounds.

Because China is becoming an aging society, the incidence of diabetes and diabetic foot have been increasing. Diabetic foot has become one of the main health-related killers due to its high disability and mortality rates. Negative pressure wound therapy (NPWT) is one of the most effective techniques for the treatment of diabetic foot wounds and great progress, both in terms of research and its clinical application, has been made in the last 20 years of its development. However, due to the complex pathogenesis and management of diabetic foot, irregular application of NPWT often leads to complications, such as infection, bleeding and necrosis, that seriously affect its treatment outcomes. In 2020, under the leadership of Burns, Trauma and Tissue Repair Committee of the Cross-Straits Medicine Exchange Association, the writing group for 'Consensus on the application of negative pressure wound therapy of diabetic foot wounds' was established with the participation of scholars from the specialized areas of burns, endocrinology, vascular surgery, orthopedics and wound repair. Drawing on evidence-based practice suggested by the latest clinical research, this consensus proposes the best clinical practice guidelines for the application and prognostic evaluation of NPWT for diabetic foot. The consensus aims to support the formation of standardized treatment schemes that clinicians can refer to when treating cases of diabetic foot.

Identifying Habitat Elements from Bird Images Using Deep Convolutional Neural Networks.

With the rapid development of digital technology, bird images have become an important part of ornithology research data. However, due to the rapid growth of bird image data, it has become a major challenge to effectively process such a large amount of data. In recent years, deep convolutional neural networks (DCNNs) have shown great potential and effectiveness in a variety of tasks regarding the automatic processing of bird images. However, no research has been conducted on the recognition of habitat elements in bird images, which is of great help when extracting habitat information from bird images. Here, we demonstrate the recognition of habitat elements using four DCNN models trained end-to-end directly based on images. To carry out this research, an image database called Habitat Elements of Bird Images (HEOBs-10) and composed of 10 categories of habitat elements was built, making future benchmarks and evaluations possible. Experiments showed that good results can be obtained by all the tested models. ResNet-152-based models yielded the best test accuracy rate (95.52%); the AlexNet-based model yielded the lowest test accuracy rate (89.48%). We conclude that DCNNs could be efficient and useful for automatically identifying habitat elements from bird images, and we believe that the practical application of this technology will be helpful for studying the relationships between birds and habitat elements.

An intelligent identification system combining image and DNA sequence methods for fruit flies with economic importance (Diptera: Tephritidae).

BACKGROUND: Images and DNA sequences are two important methods for identifying fruit fly species. In addition, the identification of insect species complexes is highly problematic when attempting to utilize automatic identification methods in an actual environment. We integrated the image and DNA sequence identification methods into a single system for the first time and explored an open interactive multi-image comparison function for solving the problem of species complexes. The Automated Fruit Fly Identification System 1.0 (AFIS1.0) was updated to AFIS2.0 by employing different models and developing the system under a novel framework. RESULTS: AFIS2.0 was developed using 83 species belonging to eight genera in the Tephritidae, which includes most pests of this family. The system applies the Mask Region Convolutional Neural Network (Mask R-CNN) and discriminative deep metric learning (AlexNet based) methods for image identification, integrates Blast+ for DNA sequence comparison and specific weighting for the fusion result. At the species level, the best classification success rate for wing images (as the Top 1 species in the species list of outcomes) reached 90%, and the average classification success rate for wing, thorax, and abdomen images (as the Top 5 species in the species list of outcomes) was 94%. CONCLUSION: AFIS2.0 is more accurate and convenient than AFIS1.0 and can be beneficial for users with or without specific expertise regarding Tephritidae. It also provides a more compact and fluent computer system for fruit fly identification, and can be easily applied in practice. © 2021 Society of Chemical Industry.

Randomized research on the mechanism of local oxygen therapy promoting wound healing of diabetic foot based on RNA-seq technology.

BACKGROUND: High purity oxygen therapy has good clinical efficacy in the treatment of diabetic foot (DF), but its mechanism of promoting wound healing has been unclear. METHODS: Patients with DF were randomly divided into an experimental group and a control group. The experimental group was given local oxygen therapy (LOT) by a micro-oxygen therapy instrument, which administered uninterrupted >95% pure oxygen for 24 h at a flow rate of 3 mL/h. Six skin samples from the experimental group before and after treatment underwent RNA sequencing (RNA-seq), and the differentially expressed genes (DEGs) were screened. RESULTS: The clinical results showed that the mean wound healing time of the experimental group was 26 days (P<0.05); the healing area of the experimental group was 3.1-15.3 cm3 , with a mean of 8.8 cm3 , and that of the control group was 2.4-10.4 cm3 (P<0.05). LOT promoted the healing of DF wounds mainly through the tumor necrosis factor (TNF) signaling pathway and the apoptosis pathway. CONCLUSIONS: According to our results, LOT can promote DF healing mainly by inhibiting the local oxidative stress reaction of wound skin and by inhibiting the inflammatory and apoptotic pathways. The molecular markers and pathways screened warrant further study.

Cosmetic and functional results of a newly reconstructed thumb by combining the phalanx of second toe and the great toenail flap transplantation.

BACKGROUND: Microsurgical toe-to-hand transfer is a gold standard when it comes to repairing a thumb defect. Great toenail flap, thumbnail valva flap, free great toe, and second toe transplantation are the common methods in thumb reconstruction. Second toe transplantation achieves good function, but poor esthetics. Great toe transplantation achieves better esthetics, but hindered walking, due to the foot's loss of the great toe and moreover suboptimal thumb function. It is difficult to maintain both functional and esthetic satisfaction in thumb reconstruction. METHODS: We experimented with three different methods of toe to hand transfer. From October 2009 to July 2019, 30 patients with traumatic thumb defects received one of 3 different kinds of thumb reconstruction in our clinic according to their level of amputation. Divided evenly into three groups of ten, group one received a great toe transplantation, group two received a second toe transplantation, and group three received a combined great toenail flap and second toe phalanx transplantation. Each of the patients' thumbs had different levels of amputation at the metatarsophalangeal joint (MPJ) or distal interphalangeal joint (DIPJ). RESULTS: One patient suffered from a partial flap necrosis and received a groin flap to cover the defect. No other thumbs had any complications. The functional and esthetic results of both the donor and the recipient sites were satisfactory. Results show that, for patients with traumatic thumb defects, the combined transfer of flap and second toe phalanx was the best option. CONCLUSIONS: Compared to the great toe or second toe transfer, combined free transfer of the great toenail flap and second toe phalanx achieved a substantially better functional and esthetic result in the thumb reconstruction.

[Interpretation of 2019 International Working Group on Diabetic Foot guidelines on the prevention and management of diabetic foot disease].

The 8th World International Symposium on the Diabetic Foot (ISDF) Conference which was sponsored by the International Working Group on Diabetic Foot (IWGDF) was held in the Hague between May 22nd and May 25th, 2019. The conference issued the 2019 IWGDF guidelines on the prevention and management of diabetic foot disease. The update to the 2015 edition of the guidelines involves the following 6 chapters: prevention of foot ulcers in patients with diabetes; offloading foot ulcers in patients with diabetes; diagnosis, prognosis, and management of peripheral arterial disease in patients with a foot ulcer and diabetes; diagnosis and treatment of foot infection in patients with diabetes; interventions to enhance healing of foot ulcers in patients with diabetes; classification of diabetic foot ulcers. This guideline has been changed more than the previous edition. In this paper, the guidelines will be interpreted to provide cutting-edge information for domestic diabetic foot researchers.

Atherogenic Index of Plasma: A Potential Biomarker for Clinical Diagnosis of Diabetic Foot Osteomyelitis.

Background: Osteomyelitis of the diabetic foot is a costly health problem worldwide. Early and accurate diagnosis of the disease in patients with diabetic foot infections is needed urgently and will have an important role in diabetic foot management. Methods: This was a case-control study of subjects with diabetic foot ulcers admitted to Beijing Shijitan Hospital from September 2015 to April 2018. We compared differences in the atherogenic index of plasma (AIP) in patients with or without osteomyelitis. Results: The mean AIP of 165 patients with osteomyelitis was 0.23 ± 0.24, which was significantly higher than the mean AIP of patients without osteomyelitis. Higher AIP values were associated with a considerably higher risk of osteomyelitis with an odds ratio of 1.81 (95% confidence interval [CI] 0.71-4.61), 4.70 (1.88-11.75), 5.03 (2.06-12.25) and 1.74 (1.33-2.28). Moreover, at a cut-off of 0.184, the AIP value showed a sensitivity of 84.3% and a specificity of 83.1% in the discriminatory identification of diabetic foot osteomyelitis. Conclusions: Elevated AIP was significantly associated with diabetic foot osteomyelitis, supporting the use of this index as a biomarker for the diagnosis in clinical practice.

[Clinical study of local injection of autologous platelet-rich plasma in treatment of diabetic foot ulcer].

OBJECTIVE: To investigate the effectiveness of local injection of autologous platelet-rich plasma (PRP) in treatment of diabetic foot ulcer. METHODS: Between October 2017 and October 2018, 90 diabetic foot ulcer patients who met the selection criteria were randomly divided into 3 groups: PRP injection group (group A, PRP was injected and hydrogel dressing covered the wounds), PRP covered group (group B, PRP gel and hydrogel dressing covered the wounds), and the control group (group C, hydrogel dressing covered the wounds), 30 cases in each group. There was no significant difference in gender, age, injured side, disease duration, preoperative glycosylated hemoglobin, wound size, and Wagner grading between groups (P>0.05). The frequency of treatments and hospitalization day in all groups and the total amount of PRP application in groups A and B were recorded. The wound healing condition was recorded during the treatment, and the wound healing rate was calculated at 3 months after the first debridement. RESULTS: The frequency of treatments in groups A, B, and C were (10.2±0.8), (11.4±0.6), (12.5±0.5) times, respectively. The total amount of PRP application of groups A and B were (306±24) and (342±18) mL, respectively. There was no significant difference in the frequency of treatments and the total amount of PRP application between groups (P>0.05). The hospitalization days of groups A, B, and C were (40.5±1.8), (62.1±2.3), and (88.6±1.4) days, respectively, showing significant differences between groups (P<0.05). In the course of treatment, the necrosis and exudation of the wounds gradually reduced, the areas of wounds gradually reduced; and the above conditions of group A were significantly better than groups B and C, and group B was better than group C. At 3 months after the first debridement, the wound healing rates of groups A, B, and C were 93.2%±0.8%, 52.1%±1.1%, and 21.3%±1.3%, respectively, with significant differences between groups (P<0.05). CONCLUSION: PRP can effectively promote the repair of diabetic foot ulcer. The effectiveness of local injection of PRP is superior to the local coverage.

Thalassotalea mangrovi sp. nov., a bacterium isolated from marine mangrove sediment.

A novel Gram-stain-negative, strictly aerobic bacterium that has a rod-like shape with a single polar flagellum in the exponential phase of growth and a spherical or ovoid shape without a flagellum in the stationary phase was isolated from a mangrove wetland sediment sample collected at Beilun Estuary National Nature Reserve, Guangxi Province, PR China and designated strain ZS-4T. This strain grew optimally at pH 6.0-8.0, at a temperature of 37 °C and in the presence of 3-4 % (w/v) NaCl. Its polar lipid profile included phosphatidylethanolamine, phosphatidylglycerol, one unidentified aminophospholipid and two uncharacterized lipids. Ubiquinone 8 (Q-8) was the sole respiratory quinone and the cellular fatty acids were dominated by C17 : 1ω8c and C16 : 0. A phylogenetic analysis based on the 16S rRNA gene sequence showed that strain ZS-4T exhibited its highest similarities to the type strains Thalassotalea litorea HMF4135T (97.8 %) and Thalassotalea ponticola GJSW-36T (95.9 %). A whole genome-level comparison of strain ZS-4T with T. litorea MCCC 1K03283T revealed an average nucleotide identity value of 75.6 % and a calculated DNA-DNA hybridization value of 19.6 %. In addition, the genomic DNA G+C content of strain ZS-4T was 45.9 mol%. Thus, based on analyses of its morphology, physiology, fatty acid composition and 16S rRNA gene sequence, strain ZS-4T should be considered a novel species of the genus Thalassotalea, with the proposed name Thalassotaleamangrovi sp. nov. The type strain is ZS-4T (=KCTC 72399T=MCCC 1K03630T).