BACKGROUND:Our previous studies have found that poly(vinylidene fluoride)bionic periosteum prepared by electrospinning has good cytocompatibility,but its biocompatibility is unknown. OBJECTIVE:To evaluate the biocompatibility of poly(vinylidene fluoride)bionic periosteum doped with Zn2+and Mg2+. METHODS:Poly(vinylidene fluoride),poly(vinylidene fluoride)bionic periosteum doped with 1％Zn2+,doped with 1％Mg2+,and doped with 1％(Zn2++Mg2+)were prepared by electrospinning to make bionic periosteum extract.SD rats were selected as the experimental subjects for hemolysis test,short-term systemic toxicity test,and heat source test.Guinea pigs were selected as the experimental subjects for skin sensitization test.The biocompatibility of bionic periosteum of four groups was tested. RESULTS AND CONCLUSION:(1)The hemolysis test results showed that the hemolysis rates of 1％Zn2+poly(vinylidene fluoride),1％Mg2+poly(vinylidene fluoride),1％Zn2++1％Mg2+poly(vinylidene fluoride)bionic periosteum and poly(vinylidene fluoride)extract were(0.130±0.013)％,(0.149±0.020)％,(0.466±0.018)％,and(0.037±0.018)％,respectively,which met the hemocompatibility standard of biomaterials.(2)The results of short-term systemic toxicity test showed that the four groups of bionic periosteal extract had no toxic signs such as body mass reduction,food intake changes,and dyspnea in SD rats,and had no toxic effects on major organs of rats.(3)Heat source test results showed that after intervention with poly(vinylidene fluoride)bionic periosteum doped with 1％Zn2+,doped with 1％Mg2+,and doped with 1％(Zn2++Mg2+),and poly(vinylidene fluoride)bionic periosteum extract,the elevated body temperature values of SD rats were(0.133±0.058),(0.100±0.010),(0.300±0.010),and(0.300±0.017)℃respectively.All were less than 0.6 ℃and the total temperature increase was less than 1.4 ℃.(4)The results of skin sensitization test showed that no erythema or edema was observed under the skin of guinea pigs after the intervention of bionic periosteum extract of four groups.(5)The results showed that poly(vinylidene fluoride)and poly(vinylidene fluoride)bionic periosteum doped with Zn2+and Mg2+had good biocompatibility.

BACKGROUND:Due to the unstable drug release rate of uniaxial bone scaffolds,multi-structure composite printing methods have been sought in and outside China in recent years.Currently,coaxial drug-loaded bone scaffolds,which combine drug-loaded sustained release system with bone transplantation and repair technology,not only replace the defective bone after implantation,but also release drugs slowly,providing a microenvironment conducive to bone formation at the implant site. OBJECTIVE:To explore and assess the in vitro antibacterial properties of uniaxial and coaxial minocycline hydrochloride bone scaffolds. METHODS:Rapid prototyping technology was used to prepare uniaxial hydroxyapatite/silk fibroin-polyvinyl alcohol scaffold,uniaxial hydroxyapatite/silk fibroin-polyvinyl alcohol scaffold,coaxial hydroxyapatite/silk fibroin-polyvinyl alcohol scaffold,and coaxial hydroxyapatite/silk fibroin-polyvinyl alcohol scaffold,respectively,which were named S1,S2,T1 and T2.The morphology,porosity,degradation performance,in vitro sustained-release performance and cytotoxicity of scaffolds were characterized.Four kinds of bone scaffolds were immersed in PBS to prepare the extracts at different time points(1,3,5,7,14,21,and 28 days).The qualitative filter paper was placed into the extract for 24 hours.The filter paper was co-cultured with Porphyromonas gingivalis and Fusobacterium nucleatum for 72 hours.The bacteriostatic effect of four groups of scaffolds was detected by the agar diffusion method. RESULTS AND CONCLUSION:(1)Scaffold characterization:Four groups of scaffolds were well formed.The surface of micro-wires in the S1 and S2 groups was dense and smooth,and the surface of micro-wires in the T1 and T2 groups was rough.Porosity was between 40%-47%and met the requirements of bone scaffolds.Compared with the S2 group,sustained release time was longer in the T2 group.The sustained release concentration of the drug was between 1-10 μg/mL for a long time,which was more conducive to bacteriostasis and osteogenesis.After 10 weeks of immersion in PBS in vitro,the degradation rate of the coaxial printed bone scaffold was faster than that of the corresponding uniaxial printed bone scaffold,and the degradation rate of the coaxial loaded bone scaffold was lower than that of the coaxial non-loaded bone scaffold.The four groups of scaffold extracts were co-cultured with osteoblasts respectively.CCK-8 assay displayed that the cell proliferation rate was greater than 75%,which met the requirements of biocompatibility.(2)In vitro antibacterial effect:S1 and T1 did not have antibacterial activity.S2 and T2 had an obvious antibacterial effect.Under the extraction solution on day 28,the diameter of Porphyromonas gingivalis and Fusobacterium nucleatum inhibition zone in the S2 group was smaller than that in the T2 group(P<0.05).(3)These findings exhibit that hydroxyapatite/silk fibroin-polyvinyl alcohol scaffolds with coaxial minocycline have good physical properties and bacteriostatic properties.

BACKGROUND:Polyvinylidene fluoride(PVDF)with piezoelectric properties,good biocompatibility and nontoxicity make it a suitable candidate for periosteal repair. OBJECTIVE:To evaluate the cytotoxicity of PVDF bionic periosteum by electrospinning with zinc and magnesium ions in vitro. METHODS:Pure PVDF,zinc-doped PVDF,magnesium-doped PVDF and Zinc-magnesium ion PVDF piezoelectric bionic periosteum were prepared by electrospinning technology,respectively.They were named PVDF,PVDF-Zn,PVDF-Mg and PVDF-Zn-Mg,in which the mass fraction of zinc and magnesium ions were all 1%.Osteoblasts and vascular endothelial cells were co-cultured with four groups of bionic periosteum.Cell compatibility of bionic periosteum was determined by alkaline phosphatase staining,CD31 immunofluorescence staining,and scanning electron microscopy. RESULTS AND CONCLUSION:(1)Osteoblasts:Alkaline phosphatase staining after 7 days of culture showed that the PVDF-Zn group secreted more alkaline phosphatase than the other three groups.Under a scanning electron microscopy,after 1 day of culture,the cells had a certain spread on the surface of PVDF-Mg and PVDF-Zn-Mg bionic periosteum,and the pseudopod extended to all sides.On day 3,the cell edge of each group extended pseudopods to the material.By days 5 and 7,the cells were fully spread,well grown and firmly covered the surface of the fibers,and the cellular pseudopods extended around and into the interstitial space of the fibers.CCK-8 assay showed that the cell proliferation on the bionic periosteum of each group showed an increasing trend over time and the relative proliferation rate of cells at 1,3,5,and 7 days was≥75%,and the cytotoxicity was≤grade 1.(2)Vascular endothelial cells:CD31 immunofluorescence staining for 3 days showed that the cells adhered and spread well on the bionic periosteum of each group and connected with each other,and the number of cells in the PVDF-Zn-Mg group was more than that in the other three groups.Under scanning electron microscope,the cells began to adhere to the surface of each group of fibers after 1 and 3 days of culture.On day 5,the cells were well spread on the surface of the fibers and extended obvious pseudopods.On day 7,the cells on the PVDF-Mg and PVDF-Zn-Mg bionic periosteum grew in multiple layers and extended the pseudopod into the fibrous void.CCK-8 assay showed that the cell proliferation on the bionic periosteum of each group showed a downward trend over time,and the relative proliferation rate of cells at 1,3,5 and 7 days was≥125%,and the cytotoxicity was grade 0.(3)The results showed that Zn-Mg electrospun PVDF piezoelectric bionic periosteum had good cytocompatibility.

Purpose To investigate the value of ultrasound radiomics nomogram in predicting lymph node metastasis(LNM)of papillary thyroid carcinoma(PTC).Materials and Methods A retrospective analysis was conducted on 400 cases of PTC in the First Hospital of Shanxi Medical University from March 2021 to January 2022 confirmed by surgery and pathology,all of which underwent preoperative ultrasound examination,and were randomly divided into training cohort(n=280)and testing cohort(n=120)in a ratio of 7∶3.The relationship between ultrasound clinical features and LNM was evaluated via univariate analysis and a clinical model was established via multivariable Logistic regression.A total of 3 348 features were extracted from preoperative ultrasound images.Pearson correlation coefficient was used to screen the features,and Logistic regression was used to establish the radiomics model.Clinical risk factors and rad scores were combined to construct the nomogram,and the receiver operating characteristic curves and decision curve analysis were applied to evaluate the predictive efficacy and clinical benefit of each model for LNM of PTC.Results Age,primary lesion size,C-TIRADS and ultrasound-reported LNM were the independent risk factors for LNM(t/χ2=2.938,55.923,30.081,34.639,all P<0.05).The area under the curve of ultrasound radiomics nomogram to predict LNM of PTC in the training cohort and the testing cohort was 0.860 and 0.847,respectively;the combined model in 43%-85%had the highest clinical benefit.Conclusion Ultrasound radiomics nomogram has a certain value in predicting LNM of PTC.

Objective To analyze the correlation between plasma Pannexin-1(Panx-1)level and no-reflow after percutaneous coronary intervention(PCI)in patients with ST-segment elevation my-ocardial infarction(STEMI).Methods A prospective trial was performed on 218 STEMI patients who underwent PCI in our hospital from January 2019 to December 2021.According to the blood flow classification of myocardial infarction thrombolysis(TIMI)after PCI,they were divided into normal reflow group(110 cases),slow reflow group(69 cases)and no reflow group(39 cases).The plasma Panx-1 level was determined by ELISA,and the levels of P-selectin,activated glyco-protein Ⅱ b/Ⅲ a(aGP Ⅱ b/Ⅲ a)and platelet-leukocyte aggregates(PLA)were determined by flow cytometry.Results Older age,larger ratio of diabetes mellitus,longer time from symptom onset to PCI,higher platelet count and levels of LDL-C,D-dimer,P-selectin,GP Ⅱ b/Ⅲ a,PNA,PM A,PLyA and plasma Panx-1 were observed in the no-reflow group than the normal and slow reflow groups(P＜0.05).The plasma Panx-1 level in STEMI patients was positively correlated with P-selectin,GP Ⅱ b/Ⅲ a,PNA,PM A and PLyA(P＜0.05,P＜0.01).LDL-C ≥3.20 mmol/L and plasma Panx-1＞0.88 μg/mL were independent risk factors for no-reflow after PCI in STEMI pa-tients(OR=2.198,95％CI:1.252-3.858,P=0.006;OR=16.849,95％CI:4.481-63.357,P=0.000).The AUC value of Panx-1 was 0.826(95％CI:0.744-0.907,P＜0.01)in predicting no re-flux in STEMI patients after PCI.Conclusion The increase of plasma Panx-1 level is closely asso-ciated with the occurrence of no reflow in STEMI patients after PCI,and the protein can be used as a predictive biomarker for the phenomenon.

In 2009,the World Health Organization included snakebite on the list of neglected tropical diseases,acknowledging it as a common occupational hazard for farmers,plantation workers,and others,causing tens of thousands of deaths and chronic physical disabilities every year.This guideline aims to provide practical information to help clinical professionals evaluate and treat snakebite victims.These recommendations are based on clinical experience and clinical research evidence.This guideline focuses on the following topics:snake venom,clinical manifestations,auxiliary examination,diagnosis,treatments,and prevention.

Using methylated pyrroloxicam as a starting material and following the principles of drug design such as bioisosterism and active site binding,we designed and synthesized ten structurally novel target compounds,whose structures were characterized by 1H NMR and MS analysis.The in vitro antitumor activity of these title compounds was evaluated by measuring their inhibitory activity against pancreatic cancer cells Capan-1,leukemia cells L1210,and human liver cancer cells SMMC-7721.The results showed that compound 6f(IC50=4.8±0.5 μmol/L)exhibited good inhibitory activity against Capan-1 pancreatic cancer cells,that compound 6b(IC50=2.6±0.3 μmol/L)showed good inhibitory activity against L1210 leukemia cells,and that compound 6c(IC50=2.1±0.2 μmol/L)displayed good inhibitory activity against SMMC-7721 human liver cancer cells.These preliminary results from the antitumor activity experiments suggest that the introduction of benzothiazine derivatives plays a certain role in enhancing the antitumor activity of this class of compounds.

Objective:To study the effects of metformin on marginal bone resorption of implants in patients with type 2 diabetes melli-tus(T2DM)and exercise habit.Methods:63 cases with 73 implants were included.Among them,there were 41 cases(47 implants)without T2DM in group N,10 cases(13 implants)with T2DM and without exercise habit in group M,12 cases(12 implants)with T2DM and exercise habit in the MR group.The patients were followed up at 6 months,1 and 2 years after implantation.The marginal bone loss(MBL).Implantation success rate and peri-implantitis incidence rate were compared among the groups.Results:The bone resorption of the proximal and median margins of the long-term bone level of the implants in the N and MR groups were significantly lower than that in the M group(P=0.001 and P=0.000 5,respectively).The implant success rates of group N,MR and M were 95.74％,100％and 76.92％,respectively.The incidence of peri-implantitis of the three groups was 2.13％,0 and 15.38％,respec-tively.Conclusion:Metformin is more effective in the improvement of the long-term marginal bone resorption of implants,increase the success rate of implants,and reduce the incidence of peri-implantitis in patients with T2DM and exercise habit in the mandibular first molar area.

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

Objective To investigate the predictive value of preoperative fibrinogen/albumin ratio (FAR) and systemic immune inflammation index (SII) on the postoperative prognosis of patients with pancreatic ductal adenocarcinoma. Methods An ROC curve was used in determining the best cutoff values of FAR and SII and then grouped. The Cox proportional hazards model was used in analyzing the prognostic factors of radical pancreatic cancer surgery, and then a Nomogram prognostic model was established. C-index, AUC, and calibration curve were used in evaluating the discrimination and calibration ability of the Nomogram. DCA curves were used in assessing the clinical validity of the Nomograms. Results The optimal cutoff values for preoperative FAR and SII were 0.095 and 532.945, respectively. FAR≥ 0.095, SII≥ 532.945, CA199≥ 450.9 U/ml, maximum tumor diameter≥ 4 cm, and the absence of postoperative chemotherapy were independent risk factors for the poor prognosis of pancreatic cancer (P<0.05). The discrimination ability, calibration ability, and clinical effectiveness of Nomogram prognostic model were better than those of the TNM staging system. Conclusion The constructed Nomogram prognostic model has higher accuracy and level of discrimination and more clinical benefits than the TNM staging prognostic model.