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.

BACKGROUND:The mechanisms underlying the occurrence of pressure injuries are complex,and it is not entirely clear which factors play a central role in the development of pressure injuries and how these factors operate. OBJECTIVE:To investigate the relationship between Piezo-type mechanosensitive ion channel component 1(Piezo1)and the occurrence of pressure injuries. METHODS:(1)Cellular experiment:Human immortalized keratinocytes(HaCaT)were treated with Yoda1,a Piezo1 agonist,at different concentrations.Cell viability,calcium ion influx,Piezo1,and apoptosis-related protein expression were detected.(2)Animal experiment:Twelve Sprague-Dawley rats were randomly divided into a control group and three experimental groups,with three rats in each group.The control group was not subjected to pressure,while in the three experimental groups,magnets with a thickness of 1,2,and 3 mm were used to press on both sides of the rats'back for 1 hour,respectively,to establish the animal models of pressure injuries.After modeling,all traumatic tissues were excised and subjected to hematoxylin-eosin,Masson,immunofluorescence staining and western blot assay. RESULTS AND CONCLUSION:Cellular experiments:The results of live/dead cell staining showed that HaCaT cell apoptosis increased with the increase of Yoda1 concentration(0,2.5,5,and 10 μmol/L),and calcium ion influx increased with the increase of Yoda1 concentration(0,5,and 10 μmol/L),as well as with the prolongation of treatment time.Western blot assay results showed an increase in the expression of BAX,TG2,and PIEZO1 and a decrease in the expression of the expression of Bcl-2 protein in HaCaT cells in 5 and 10 μmol/L Yoda1 groups compared with the control group(0 μmol/L Yoda1).Animal experiments:The results of hematoxylin-eosin and Masson staining showed that the skin structure of the three experimental groups was damaged at the compression site,there was subcutaneous fat liquefaction and necrosis,and collagen was sparse and disorganized,and damage to the skin structure at the compression site was aggravated with the increase of magnet thickness.Immunofluorescence staining and western blot results showed that compared with the control group,the expression of BAX,TG2,Yap1 and PIEZO1 proteins was elevated,and the expression of Bcl-2 proteins was lowered in the three experimental groups.Moreover,the expression of related proteins showed more significant changes with the increase of magnet thickness(pressure).To conclude,skin compression activates PIEZO1,leading to a significant influx of calcium ions.As the pressure increases,this ultimately results in cell apoptosis due to calcium overload.

Objectives:To investigate the correlation between resting heart rate(RHR)and atherosclerotic cardiovascular disease(ASCVD)and all-cause death in young and middle-aged people.Methods:A prospective cohort study was conducted enrolling 72 642 young and middle-aged participants(aged<60 years),who participated in the medical examination of the Kailuan Study from June 2006 to October 2007.According to the quartile of the RHR level,the participants were divided into Q1 group(<67 beats/min,n=14 381),Q2 group(67-70 beats/min,n=15 815),Q3 group(71-75 beats/min,n=15 876),Q4 group(76-80 beats/min,n=13 933)and Q5 group(>80 beats/min,n=12 637).Cox proportional hazard regression model was used to analyze the effect of RHR on ASCVD and all-cause death.The dose-response relationship between RHR and the risk of ASCVD and all-cause death was investigated using a restricted cubic spline regression model.Results:During a mean follow-up of(10.0±4.85)years,2 898 patients(3.99%)developed ASCVD.Multivariate Cox regression analysis showed that after adjusting for confounding factors,the risk of RHR and ASCVD in group Q5 increased by 20%compared with group Q1(HR=1.20,95%CI:1.06-1.35,P<0.05).There was no significant risk in groups Q2 to Q4 compared to Q1 group(all P>0.05).In addition,the risk of ASCVD increased by 4%for every 10 beats/min increase in RHR(HR=1.04,95%CI:1.01-1.07,P=0.009).During the follow-up period of(10.2±4.82)years,all-cause death occurred in 2 175 participants(2.99%).The results showed that compared with Q1 group,the risk of all-cause death in Q3 to Q5 groups increased by 33%(HR=1.33,95%CI:1.15-1.54,P<0.001),33%(HR=1.33,95%CI:1.14-1.54,P<0.001),and 78%(HR=1.78,95%CI:1.54-2.05,P<0.001)respectively,and there was no statistical significance between group Q2 and group Q1.The risk of all-cause death increased by 15%for every 10 beats/min increase in RHR(HR=1.15,95%CI:1.11-1.19,P<0.001).Restricted cubic spline analysis showed that RHR was linearly correlated with risk of ASCVD(Poverall=0.022,Pnon-linear=0.617),and the risk of ASCVD increased significantly with RHR>72 beats/min.RHR was linearly associated with the risk of all-cause death(Poverall<0.001,Pnon-linear=0.212),and the risk of all-cause death was significantly increased with RHR>72 betas/min.Conclusions:Higher RHR is associated with an increased risk of ASCVD and all-cause mortality in young and middle-aged individuals.

Objectives:To investigate the association between the triglyceride-glucose(TyG)index and risk of non-alcoholic fatty liver disease(NAFLD)in young and middle-aged(<60 years)adults.Methods:From June 2006 to October 2007,47 675 employees of Kailuan Group with no liver disease were selected as the study objects.Based on the TyG index quartile,participants were divided into Q1 group(TyG index≤8.08,n=11 924),Q2 group(8.0836.46,n=11 919),the association between TyG index,cum-TyG and cumulative exposure time and the risk of NAFLD was analyzed.Results:The average age of the study population was(44.3±8.7)years,36 345 participants were males(76.23%).During a median follow-up period of 11.55(7.28,13.89)years,4 635(9.72%)participants developed new-onset NAFLD.After adjusting for confounders,cox regression analysis showed that compared with the Q1 group,the HR(95%CI)for NAFLD in the Q2 to Q4 groups were 1.328(1.191-1.480),1.591(1.430-1.770),and 2.106(1.861-2.384),respectively,Ptrend<0.001.Compared with the cum-Q1 group,the HR(95%CI)for NAFLD in the cum-Q2 to cum-Q4 groups were 1.571(1.426-1.730),2.123(1.935-2.330)and 2.593(2.367-2.840),respectively,Ptrend<0.001.Compared with the TyG index for 0 year,the HR(95%CI)of NAFLD for 2,4 and 6 years was 1.333(1.196-1.486),1.879(1.690-2.088)and 3.184(2.860-3.545),respectively,Ptrend<0.001.Conclusions:Increased TyG index is an independent risk factor for the new-onset NAFLD in young and middle-aged population.

Objectives:To investigate the correlation between resting heart rate(RHR)and atherosclerotic cardiovascular disease(ASCVD)and all-cause death in young and middle-aged people.Methods:A prospective cohort study was conducted enrolling 72 642 young and middle-aged participants(aged<60 years),who participated in the medical examination of the Kailuan Study from June 2006 to October 2007.According to the quartile of the RHR level,the participants were divided into Q1 group(<67 beats/min,n=14 381),Q2 group(67-70 beats/min,n=15 815),Q3 group(71-75 beats/min,n=15 876),Q4 group(76-80 beats/min,n=13 933)and Q5 group(>80 beats/min,n=12 637).Cox proportional hazard regression model was used to analyze the effect of RHR on ASCVD and all-cause death.The dose-response relationship between RHR and the risk of ASCVD and all-cause death was investigated using a restricted cubic spline regression model.Results:During a mean follow-up of(10.0±4.85)years,2 898 patients(3.99%)developed ASCVD.Multivariate Cox regression analysis showed that after adjusting for confounding factors,the risk of RHR and ASCVD in group Q5 increased by 20%compared with group Q1(HR=1.20,95%CI:1.06-1.35,P<0.05).There was no significant risk in groups Q2 to Q4 compared to Q1 group(all P>0.05).In addition,the risk of ASCVD increased by 4%for every 10 beats/min increase in RHR(HR=1.04,95%CI:1.01-1.07,P=0.009).During the follow-up period of(10.2±4.82)years,all-cause death occurred in 2 175 participants(2.99%).The results showed that compared with Q1 group,the risk of all-cause death in Q3 to Q5 groups increased by 33%(HR=1.33,95%CI:1.15-1.54,P<0.001),33%(HR=1.33,95%CI:1.14-1.54,P<0.001),and 78%(HR=1.78,95%CI:1.54-2.05,P<0.001)respectively,and there was no statistical significance between group Q2 and group Q1.The risk of all-cause death increased by 15%for every 10 beats/min increase in RHR(HR=1.15,95%CI:1.11-1.19,P<0.001).Restricted cubic spline analysis showed that RHR was linearly correlated with risk of ASCVD(Poverall=0.022,Pnon-linear=0.617),and the risk of ASCVD increased significantly with RHR>72 beats/min.RHR was linearly associated with the risk of all-cause death(Poverall<0.001,Pnon-linear=0.212),and the risk of all-cause death was significantly increased with RHR>72 betas/min.Conclusions:Higher RHR is associated with an increased risk of ASCVD and all-cause mortality in young and middle-aged individuals.

Objectives:To investigate the association between the triglyceride-glucose(TyG)index and risk of non-alcoholic fatty liver disease(NAFLD)in young and middle-aged(<60 years)adults.Methods:From June 2006 to October 2007,47 675 employees of Kailuan Group with no liver disease were selected as the study objects.Based on the TyG index quartile,participants were divided into Q1 group(TyG index≤8.08,n=11 924),Q2 group(8.0836.46,n=11 919),the association between TyG index,cum-TyG and cumulative exposure time and the risk of NAFLD was analyzed.Results:The average age of the study population was(44.3±8.7)years,36 345 participants were males(76.23%).During a median follow-up period of 11.55(7.28,13.89)years,4 635(9.72%)participants developed new-onset NAFLD.After adjusting for confounders,cox regression analysis showed that compared with the Q1 group,the HR(95%CI)for NAFLD in the Q2 to Q4 groups were 1.328(1.191-1.480),1.591(1.430-1.770),and 2.106(1.861-2.384),respectively,Ptrend<0.001.Compared with the cum-Q1 group,the HR(95%CI)for NAFLD in the cum-Q2 to cum-Q4 groups were 1.571(1.426-1.730),2.123(1.935-2.330)and 2.593(2.367-2.840),respectively,Ptrend<0.001.Compared with the TyG index for 0 year,the HR(95%CI)of NAFLD for 2,4 and 6 years was 1.333(1.196-1.486),1.879(1.690-2.088)and 3.184(2.860-3.545),respectively,Ptrend<0.001.Conclusions:Increased TyG index is an independent risk factor for the new-onset NAFLD in young and middle-aged population.

Objective:To observe and analyze the effect of double and single bridge exercise on the electromyographic activities of related core muscle groups in stroke patients, and to explore its rules and characteristics.Methods:A prospective cohort study was conducted on 40 stroke patients hospitalized in the Department of rehabilitation medicine, Hefei second people's Hospital, Anhui Province from March 2020 to May 2021.The surface electromyography (sEMG) instrument was used to collect the surface electromyographic signals of erector spinalis, rectus abdominis, gluteus maximus and biceps femoris during double and single bridge exercise, and the root mean square (RMS) and integrated electromyography (iEMG) of the time domain indexes were analyzed. The measurement data conforming to normal distribution was expressed in xˉ± s.The non normal distribution data was expressed in M (Q1, Q3). Wilcoxon rank sum test was used to compare the difference between the two groups. Results:There was significant difference between RMS (30.0 (21.3, 45.5) μV vs. 24.0 (14.0, 35.8) μV) and IEMG (15.5. (10.0, 23.0) μV?s vs. 9.0 (5.0, 13.0) μV?s s) values of gluteus maximus on the healthy side and the affected side during double bridge exercise ( Z values were 2.07, 4.19; P values were 0.039, <0.001, respectively). There was significant difference in RMS (31.0 (15.3, 70.0) μV ratio of the healthy and affected biceps femoris 17.0 (11.0, 28.8) μV) and IEMG (14.5 (8.0, 26.5) μV?s vs. 7.0 (5.0, 10.8) μV?s) values of biceps femoris on the healthy side during double bridge exercise ( Z values were 3.44, 3.64; P values were 0.001 and <0.001, respectively ). There was significant difference between RMS(38.5(32.3, 46.0) μV vs. 35.0(22.3, 43.0) μV) and IEMG (16.5(12.0, 22.8) μV?s vs. 12.0(7.0, 21.0) μV?s) values of the gluteus maximus on the healthy side during single bridge exercise ( Z values were 2.24, 2.45; P values were 0.025, 0.014, respectively). There was significant difference between RMS (38.0 (15.3, 70.0) μV vs. 19.0 (12.0, 35.5) μV) and IEMG (16.0 (10.0, 27.0) μV?s vs. 6.5 (5.0, 12.5) μV?s s) values of biceps femoris on the healthy side during single bridge exercise ( Z values were 2.98,4.34; P values were 0.003 and <0.001, respectively). There was significant difference between RMS (24.0 (14.0, 35.8) μV vs. 35.0 (22.3, 43.0) μV) and IEMG (9.0 (5.0, 13.0) μV?s vs. 12.0 (7.0, 21.0) μV?s) values of double and single gluteus maximus on the affected side ( Z values were 2.24, 1.99; P values were 0.025,0.047, respectively). Conclusion:Double bridge and single bridge exercise could improve the related core muscle groups of stroke patients with hemiplegia, and single bridge was better than double bridge for the activation of gluteus maximus

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.