[An in vitro model study of the accuracy and operation time of oral surgery robot-assisted endodontic microsurgery].

Objective: To explore the operational accuracy and operative time of oral surgery robot-assisted endodontic microsurgery on a head-simulator for clinical reference. Methods: Three pairs of surgical simulation models were set up on head-simulator. Each model included 10 positions anteriorly and posteriorly, 20 teeth for each technique, for a total of 60 teeth. An attending physician with more than 3 years clinical experience in endodontic microsurgery completed fixed-point osteotomy and apicoectomy in three groups of endodontic microsurgery under freehand (FH), static navigation (SN), and surgery robot (SR). The duration of each operation was recorded. Cone-beam CT was taken before the operation and the surgical path was planned in the software; after surgery, a plug gauge (precision gauge for measuring hole dimensions) was inserted into the surgical path for intraoral scanning. Surgical accuracy (starting point, end point, and angular deviation) was assessed in all 3 groups, and surgery time was compared. Results: The deviation at the starting point and the end point, and angular deviation was (0.37±0.11), (0.37±0.10) mm, and 0.71°±0.17°in the SR group. The deviations in the SR group were significantly lower than those in the SN group [(0.59±0.14), (0.65±0.18) mm, and 2.64°±0.75°] (P<0.05), and both groups were significantly lower than the FH group [(1.37±0.31), (1.10±0.21) mm, and 9.84°±3.15°] (P<0.05). The operative time in the SN group [(1.20±0.03) min] was significantly less than that in the SR group [(2.18±0.03) min] (P<0.05), and both groups were significantly less than that in the FH group [(8.70±3.15) min] (P<0.05). Starting point deviation, end point deviation, and angular deviation [(1.09±0.10), (0.90±0.07) mm, 7.22°±1.13°] in anterior teeth using the FH was significantly lower than the starting deviation, endpoint deviation, and angular deviation [(1.65±0.14), (1.30±0.06) mm, 12.46°±2.10°] in the posterior teeth using FH (P<0.05), and the operative time in the anterior teeth using the FH [(5.75±0.57) min] was significantly less than that in the posterior teeth using [(11.65±1.14) min] (P<0.05). The difference in accuracy and operative time between using SN and SR on anterior and posterior teeth was not statistically significant (P>0.05). Conclusions: Oral surgery robot-assisted endodontic microsurgery helps improving the accuracy of clinicians' operations and shorten the operation time.

Correlation of serum IL-6, TNF-α levels and disease activity in patients with ankylosing spondylitis.

OBJECTIVE: The aim of this study was to investigate the serum interleukin (IL)-6 and tumor necrosis factor-alpha (TNF-α) levels in patients with ankylosing spondylitis (AS), and the correlation between serum levels and disease activity. PATIENTS AND METHODS: ELISA was used to detect the serum TNF-α and IL-6 levels of AS patients (n=40) and normal controls (n=40) who were hospitalized or outpatient-diagnosed from June 2021 to May 2023. C-reactive protein (CRP) was detected by immune-enhanced turbidimetry. The erythrocyte sedimentation rate was determined by Wei's manual method. The correlation was analyzed by Pearson's correlation analysis. RESULTS: The levels of TNF-α and IL-6 in the AS group were significantly higher than those in the control group, and the levels of TNF-α and IL-6 in AS patients in the active phase were higher than those in the stable phase (p<0.05). CRP level was positively correlated with TNF-α, and IL-6 (r=0.02886 and 0.0273, p<0.05). Erythrocyte sedimentation rate (ESR) level was also positively correlated with TNF-α, and IL-6 (r=0.07568 and 0.0613, p<0.05). CONCLUSIONS: Serum TNF-α and IL-6 levels are correlated with AS disease activity, suggesting that they may be involved in the inflammatory response of AS.

Structure Evolution and Multiferroic Properties in Cobalt Doped Bi4NdTi3Fe1-xCoxO15-Bi3NdTi2Fe1-xCoxO12-δ Intergrowth Aurivillius Compounds.

Here, we report the structure evolution, magnetic and ferroelectric properties in Co-doped 4- and 3-layered intergrowth Aurivillius compounds Bi4NdTi3Fe1-xCoxO15-Bi3NdTi2Fe1-xCoxO12-δ. The compounds suffer a structure evolution from the parent 4-layered phase (Bi4NdTi3FeO15) to 3-layered phase (Bi3NdTi2CoO12-δ) with increasing cobalt doping level from 0 to 1. Meanwhile the remanent magnetization and polarization show opposite variation tendencies against the doping level, and the sample with x = 0.3 has the largest remanent magnetization and the smallest polarization. It is believed that the Co concentration dependent magnetic properties are related to the population of the Fe3+ -O-Co3+ bonds, while the suppressed ferroelectric polarization is due to the enhanced leakage current caused by the increasing Co concentration. Furthermore, the samples (x = 0.1-0.7) with ferromagnetism show magnetoelectric coupling effects at room temperature. The results indicate that it is an effective method to create new multiferroic materials through modifying natural superlattices.

Surface modification using photocrosslinkable chitosan for improving hemocompatibility.

Immobilization of the anticoagulative or antithrombogenic biomolecule has been considered as one of the important methods to improve the blood compatibility of artificial biomaterials. In this study, a novel immobilization reaction scheme was utilized to incorporate O-butyrylchitosan (OBCS) onto the activated glass surface with an aim to develop an anticoagulative substrate. Activation of the glass surface was carried out by silanization and then OBCS was grafted to the silanized surface via a radiation grafting technique. The OBCS-grafted glass surfaces were characterized by electron spectroscopy for chemical analysis (ESCA) and atomic force microscopy (AFM). The blood compatibility of the OBCS-grafted glass was evaluated by platelet rich plasma (PRP) contacting experiments and protein adsorption experiments in vitro. These results have demonstrated that the surface with immobilized OBCS shows much less platelet adhesive and fibrinogen adsorption compared to the control surface. Therefore, the novel reaction scheme proposed here is very promising for future development of an anticoagulative glass substrate.

[Immunohistochemical study of the sinus mucosa during chronic maxillary sinusitis].

OBJECTIVE: To study the protective role of some immunocompetent cells and some humoral immune factors in the local mucosa during chronic sinusitis. METHOD: Using immunohistochemical streptavidinbiotin peroxide complex (SABC) method to investigate the distribution and the numbers about the T-lymphocytes and subsets, B-cells, macrophages, NK cells, mast cells eosinophils, HLA-DR antigen and IgA, IgG, complement C3, lysozyme in the local mucosa of two type chronic sinusitis. RESULT: The numbers of T-lymphocytes, T helper/inducer cells, B-cells and macrophages in the mucosa of chronic sinusitis type 1 was significantly more than these in the healthy control (P < 0.01). The number of T-lymphocytes, T suppressor cells, B cells, mast cells and eosinophils in the type 2 was significantly more than these in the healthy control (P < 0.01). The ratio of the helper cells to T suppressor cells significant different in the two type chronic sinusitis. CONCLUSION: The study showed that the infiltrating of immunocompetent cells was different between the two type chronic sinusitis.

[A study of the cyclic development of poliomylitic virus in pond foul water during a two-year span].

A study on polio virus in pond foul water of town and counties in Lian Yun Gang city which had a reported case of polio. Foul water was examined by 1% NaCl-AlCl3 precipitated method quarterly during 1993-1995, to observe the cyclic development of the virus. Results showed that the isolation rate of polio virus was 57.95% with 21 strains of 18 PV I, 1 PV II and 2 PV III and 30 strains of NPEV (31.09%). In view of PV I as main epidemic strain in our country, and related strains to sabin was confirmed using RT-PCR. The above data suggested that polio virus in the pond water had been replaced by relative strains of sabin.