BACKGROUND:Platelet-rich fibrin(PRF)has many advantages,such as simple preparation,low production cost,and high safety,and has been widely used in the study of bone defect repair in oral and maxillofacial surgery,but there are problems such as too fast degradation rate and short release time of growth factors. OBJECTIVE:PRF was loaded into gelatin methacryloyl(GelMA)hydrogel and its osteogenic properties were analyzed by in vivo and in vitro experiments. METHODS:(1)New Zealand white rabbit venous blood was extracted to prepare PRF.GelMA hydrogels containing 0,0.05,0.075,and 0.1 g PRF were prepared,respectively,and were recorded as GelMA,GelMA/PRF-0.05,GelMA/PRF-0.075,and GelMA/PRF-0.1,respectively,to characterize the micromorphology and in vitro slow-release properties of the hydrogels.(2)Four kinds of hydrogels were co-cultured with MC3T3-E1 cells,respectively,and the cell proliferation activity was detected with the single cultured cells as the control.After osteogenic induction,alkaline phosphatase activity,mineralization ability,mRNA and protein expression levels of osteogenic genes(osteocalcin,osteopontin,RUNX2),ERK1/2-p38 MAPK pathway protein mRNA and protein expression levels were detected.(3)Fifteen New Zealand white rabbits were taken.Four full-layer bone defects of 8 mm diameter were prepared in the skull of each rabbit,one of which was implanted without any material(blank control group),and the other three were implanted with GelMA hydrogel,PRF,and GelMA/PRF-0.1 hydrogel,respectively.The bone defect was detected by Micro-CT and bone morphology was observed at 4,8,and 12 weeks after operation. RESULTS AND CONCLUSION:(1)Scanning electron microscopy observed that all the hydrogels of the four groups had honeycomb pore structure,and the pore size of the hydrogels decreased slightly with the increase of PRF content,but there was no significant difference between the groups.The three groups of GelMA/PRF hydrogel could release transforming growth factor β1 and insulin-like growth factor 1 at a certain rate,and the cumulative release of transforming growth factor β1 and insulin-like growth factor 1 increased significantly with the extension of time.(2)CCK-8 assay and live/dead staining showed that GelMA/PRF hydrogel could promote the proliferation of MC3T3-E1 cells.The results of alkaline phosphatase staining,alizarin red staining,and osteogenic gene detection showed that GelMA/PRF hydrogel could promote the osteogenic differentiation of MC3T3-E1 cells,and inhibit the expression of ERK1/2-p38 MAPK pathway protein,and showed a PRF content dependence.(3)Micro-CT scan showed that the bone mineral density and bone volume fraction in the bone defect of GelMA/PRF-0.1 hydrogel group were higher than those in the other three groups(P<0.05).Hematoxylin-eosin staining showed that compared with the other three groups,GelMA/PRF-0.1 hydrogel group had faster and more mature new bone formation at the bone defect.(4)These findings indicate that GelMA/PRF hydrogel has good osteogenic activity both in vivo and in vitro,which may be related to inhibiting the expression of ERK1/2-p38 MAPK pathway protein.

The plasma matrix is a kind of autologous blood conduct.It has been widely used in maxillofacial tissue regeneration,skin cosmetology and some other fields.Recently,to preserve the dental pulp as well as the teeth,pulp re-generation therapy and apical surgery have become increasingly important as well as the applications of bioactive materi-als.As a kind of autologous bioactive material,the plasma matrix has some natural advantages as it is easy to obtain and malleable.The plasma matrix can be used in the following cases:①pulp revascularization of young permanent teeth with open apical foramina that cannot stimulate apical bleeding;② apical barrier surgery with bone defects and large ar-ea perforation repair with bone defects or root sidewall repair surgery;③ apical surgeries of teeth with large area of api-cal lesions,with or without periodontal diseases.The plasma matrix is a product derived from our blood,and there are no obvious contraindications for its use.Several systematic reviews have shown that the plasma matrix can effectively promote the regenerative repair of dental pulp in patients with periapical diseases.However,the applications of plasma matrix are different because its characteristics are affected by different preparation methods.In addition,there is still a lack of long-term clinical researches on the plasma matrix,and the histological evidences are difficult to obtain,so a large number of in vitro and in vivo experimental studies are still needed.This article will describe the applications of different kinds of plasma matrix for dental pulp regeneration and bone tissue regeneration in apical surgeries to provide references for clinicians in indication selection and prognosis evaluation.

OBJECTIVE To study the pharmacodynamics and pharmacokinetics of semaglutide(Sem)capsules in type 2 diabetic model rats.METHODS Male SD rats were divided into the normal control group,type 2 diabetic model group and model+Sem capsules(0.839,1.678 and 2.517 mg·kg-1)groups.A type 2 diabetic rat model was induced by high sugar and high fat diet feeding combined with ip given streptozotocin(STZ)injection.Seven days after modeling,the model+Sem capsules group was ig given Sem capsules at the corresponding dose in a fasting state,once a day,for 14 d.Body mass,fasting blood glucose(FBG),and glycosylated hemoglobin(HbA1c)levels were regularly mea-sured in each group of rats.Plasma from rats in the model+Sem capsules 0.839,1.678 and 2.517 mg·kg-1 groups at different time points was collected at the end of the continuous administration of Sem capsules,and the content of Sem in the plasma of rats was determined by liquid chromatography-tandem mass spectrometry.Concentration-time curves were plotted,and the main pharmacokinetic parameters were fitted by the WinNonlin non-atrial model method.RESULTS Compared with the model group,the body mass of rats in model+Sem capsules dosing groups decreased significantly after 7 and 14 d of Sem capsules intervention(P<0.05,P<0.01),so did FBG(P<0.01)and the HbA1c level(P<0.01).Meanwhile,FBG and HbA1c levels of rats in model+Sem capsules 1.678 and 2.517 mg·kg-1 groups were not significantly different from those of the normal control group after 14 d of Sem capsules intervention,suggesting that FBG and HbA1c levels were basically restored to normal.Phar-macokinetic results showed that the elimination half-life(t1/2)of Sem in plasma after ig administration of Sem capsules 0.839,1.678,and 2.517 mg·kg-1 for 14 d in rats was 7.40±1.34,7.48±0.33 and(8.23±0.90)h,respectively,the peak concentration(Cmax)was 18±9,81±23 and(256±53)μg·L-1,time to peak(Tmax)was 0.06±0.13,1.56±0.88,(1.50±1.00)h,respectively,the area under the curve(AUC0-t)was 158±76 μg·h·L-1,858±310 and(3795±1539)μg·h·L-1,and the accumulation index was 1.12±0.05,1.12±0.01 and 1.15±0.04,respectively.CONCLUSION Sem capsules ig administrated can effectively reduce body mass,FBG and HbA1c levels in type 2 diabetic model rats,and lead to glucose reduction and by mass loss.After 14 d of continuous administration of Sem capsules,there is no accu-mulation of semaglutide in rats in the dose range of 0.839-2.517 mg·kg-1,and the exposure increases with the dose.

Objective:To study the collapse of the contralateral femoral head after the total hip arthroplasty (THA) in patients with bilateral steroid-induced femoral head necrosis leg-length discrepancy (LLD) influences.Methods:A total of 108 patients with bilateral steroid-induced femoral head necrosis who were treated in Honghui Hospital Affiliated to Xi′an Jiaotong University from June 2014 to June 2016 underwent THA surgery on the hip joints that had symptoms and developed to Association Research Circulation Osseous (ARCO) Ⅲ. At the same time, the non-surgical hip-preserving treatment of the non-collapsed femoral head developed to the ARCO Ⅱ stage was performed. The follow-up period was 2 years, and 98 cases were finally included. According to the size of the leg-length discrepancy [LLD<3 mm group ( n=50), LLD≥3 mm group ( n=48)] and the type of leg-length discrepancy[non collapse side longer group ( n=58) and shorter group ( n=58)], the collapse of the femoral head and the THA were observed. Results:Finally, a total of 56 cases of femoral head collapse occurred in the non collapse side of the hip, of which 50 cases underwent THA within 24 months. There were significant statistical differences in THA and femoral head collapse between LLD<3 mm group and LLD≥3 mm group, non collapse side longer group and non collapse side shorter group ( P<0.05). The 2-year survival rate without collapse in the LLD<3 mm group and LLD≥3 mm group were 52.1% and 34.0%, respectively, and the 2-year survival rates in the longer and shorter non-collapsed limb groups were 56.9% and 22.5%, respectively. Compared with patients with moderate lesions, the survival rate of femoral heads in patients with larger lesions was lower ( OR: 4.25, 95% CI: 1.55-11.26; P=0.003). LLD<3 mm group ( OR: 0.24, 95% CI: 0.06-0.50; P<0.01) or non collapse side longer group ( OR: 0.13, 95% CI: 0.04-0.29; P<0.01) had lower risk of contralateral femoral head collapse after THA. Conclusions:For patients with bilateral steroid-induced femoral head necrosis who have collapsed lateral THA, postoperative leg-length discrepancy extremities is a potential risk factor for collapse of non-collapsed femoral head. LLD<3 mm and avoiding shortening of the uncollapsed limb may reduce the risk of collapse of the uncollapsed femoral head.

The administration of nanoparticles (NPs) first faces the challenges of evading renal filtration and clearance of reticuloendothelial system (RES). After that, NPs infiltrate through the expanded endothelial space and penetrated the dense stroma of tumor microenvironment to tumor cells. As long as possible to prolong the time of NPs remaining in tumor tissue, NPs release active agent and induce pharmacological action. This review provides a comprehensive summary of the physical and chemical properties of NPs and the influence of various biological factors in tumor microenvironment, and discusses how to improve the final efficacy through adjusting the characteristics and structure of NPs. Perspectives and future directions are also provided.

This study aims to propose a multifrequency time-difference algorithm using spectral constraints. Based on the knowledge of tissue spectrum in the imaging domain, the fraction model was used in conjunction with the finite element method (FEM) to approximate a conductivity distribution. Then a frequency independent parameter (volume or area fraction change) was reconstructed which made it possible to simultaneously employ multifrequency time-difference boundary voltage data and then reduce the degrees of freedom of the reconstruction problem. Furthermore, this will alleviate the illness of the EIT inverse problem and lead to a better reconstruction result. The numerical validation results suggested that the proposed time-difference fraction reconstruction algorithm behaved better than traditional damped least squares algorithm (DLS) especially in the noise suppression capability. Moreover, under the condition of low signal-to-noise ratio, the proposed algorithm had a more obvious advantage in reconstructions of targets shape and position. This algorithm provides an efficient way to simultaneously utilize multifrequency measurement data for time-difference EIT, and leads to a more accurate reconstruction result. It may show us a new direction for the development of time-difference EIT algorithms in the case that the tissue spectrums are known.

Objective:To investigate the effect of mannose on the radiosensitivity of six human non-small cell lung cancer cell lines and its possible mechanism.Methods:The expression of mannose phosphate isomerase in six lung cancer cell lines were detected by Western blot. The inhibitory effect of mannose on the proliferation of lung cancer cell lines were observed by MTT assay. When irradiated with 0, 2, 4, 6, 8 and 10 Gy, the effect of mannose on the radiosensitivity of six lung cancer cell lines was detected by plate clone formation assay, respectively; and the apoptosis rates of normal control, mannose, irradiation and combined groups were detected by flow cytometry.Results:The expression levels of mannose phosphate isomerase were different among six lung cancer cell lines. Among them, A549 cells had the highest expression level and H460 cells showed the lowest expression level. When aD ministrated with 11.1 mmol/L mannose, the same inhibitory effect was observed on both A549 and H460 cell lines. Moreover, the inhibitory effect on H460 cell line was significantly increased with the increase of mannose concentration. In addition, aD ministration of 11.1 mmol/L mannose could significantly increase the radiosensitivity and apoptosis rate of H460 cell line. However, it exerted limited effect upon the radiosensitivity and apoptosis rate of A549 cell line. Conclusion:In six lung cancer cell lines with high expression of mannose phosphate isomerase, the aD ministration of mannose can enhance the radiosensitivity of partial tumors cells.

Oral squamous cell carcinoma (OSCC) is the most common oral cancer. Previous studies have found significantly high miR-155 expression in OSCC. However, the mechanism by which miR-155 plays a role in OSCC oncogenesis is not yet clear. This article reviews the function of the relationship between miR-155 and tumors and the potential role of miR-155 in the development of OSCC. A literature review showed that mir-155, as a small carcinogenic RNA, can inhibit CDC73, BCL6, P27Kip1 and other target genes that play a role in cancer inhibition; promote the proliferation, migration and invasion of OSCC cells; and inhibit apoptosis. miR-155 can also be combined with biological factors (Epstein-Barr virus, human papillomavirus) to promote the development of OSCC.

Objective To investigate the effects of rapamycin on the biological behaviors of human non-Hodgkin lymphoma Raji cells with different concentrations and time, and to explore its mechanism. Methods Different concentrations (0, 10, 50, 100, 250, 500 nmol/L) of rapamycin were used in Raji cells for 24, 48, 72 h respectively. The apoptosis of Raji cells was detected by using CCK-8 method, and flow cytometry was used to detect the cell apoptosis and cycle of Raji cells. The enzymatic activity of Caspase-3 and Caspase-9 in Raji cells was detected by Caspase-3 and Caspase-9 activity testing kit. The expressions of bcl-2, p53 protein and mRNA were detected by Western blot method and reverse transcription-polymerase chain reaction (RT-PCR). Results The proliferative inhibition rate of Raji cells was increased from (23.7 ± 4.2)％to (51.7±3.7)％, the cell apoptosis rate was increased from (4.9±1.9)％to (20.5±1.5)％, the proportion of G0/G1 was increased from (40.8±1.4) ％to (63.6±1.7) ％, the Caspase-3 enzyme activity of Raji cell in 24 h was increased from 0.16±0.05 to 1.08±0.04, Caspase-9 enzyme activity was increased from 0.19±0.04 to 1.34± 0.06 after 24 h with the increasing concentration of rapamycin from 0 nmol/L to 500 nmol/L (P<0.01). The mRNA of bcl-2 was decreased from 0.90±0.03 to 0.46±0.03, and mRNA of p53 was increased from 2.51±0.41 to 5.85±0.21. The protein expression of bcl-2 was reduced and the protein expression of p53 was increased. The experimental results of Raji cells in 48 h and 72 h were consistent with the experimental results of 24 h. Conclusion Rapamycin may inhibit the proliferation of Raji cells through Caspase-3, Caspase-9, bcl-2, p53 and induce its cell apoptosis.

Objective To explore the safety and efficacy of rivaroxaban after interventional treatment of pulmonary embolism.Methods Patients with acute pulmonary embolism undergoing pulmonary indwelling catheter thrombolysis at Chifeng Municipal Hospital from Jun 2016 to Jun 2017 were divided into a group of 23 patients,who afterwards receiving rivaroxaban as a long-term anticoagulant,and that of 45 patients treated with traditional anticoagulant therapy (low molecular weight heparin bridged warfarin).Results The short and mid-term follow-up for the cure rate in the rivaroxaban group was higher than that in the traditional anticoagulation group (60.9％ vs.35.6％,P ＜0.05,and 73.9％ vs.44.4％,P ＜0.05).The incidence of adverse reactions such as bleeding (4.3％) was significantly lower than that of the heparin warfarin group (28.9％),there was no recurrence of venous thromboembolism (VTE) in the rivaroxaban group,and 3 cases in the traditional anticoagulant group;there was no death in either group.Conclusions In the interventional treatment of acute pulmonary embolism,single-agent oral rivaroxaban is equivalent to low-molecular-weight heparin-bridged warfarin;rivaroxaban can effectively reduce pulmonary embolism and the occurrence of bleeding complications after endovascular intervention.