Improving Bond Strength of Translucent Zirconia Through Surface Treatment With SiO2-ZrO2 Coatings.

BACKGROUND: Translucent monolithic zirconia ceramics have been applied in dental clinics due to their esthetic translucent formulations and mechanical properties. Considering inherent ceramic brittleness, adhesive bonding with resin composite increases the fracture resistance of ceramic restorations. However, zirconia is a chemically stable material that is difficult to adhesively bond with resin. OBJECTIVES: To investigate the influences of SiO2-ZrO2 coatings on adhesive bonding of zirconia and the surface characterization of those coatings. METHODS AND MATERIALS: Translucent zirconia discs were classified into groups based on surface treatments: CT (control), SB (sandblasting), C21(SiO2:ZrO2=2:1), C11(SiO2:ZrO2=1:1), and C12 (SiO2:ZrO2=1:2) (n=10). Surface characterization of coatings on zirconia were analyzed by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), surface roughness assessment (Ra), X-ray diffraction (XRD), water contact angle (WCA), translucency parameter (TP), and shear bond strength (SBS). Two-way ANOVA for shear bond strength results and ANOVA for Ra and WCA were performed. RESULTS: SEM images revealed SiO2 islands on zirconia disks coated with SiO2-ZrO2. Surface roughness of C12, C11, and C21 groups was significantly larger than those of groups SB and CT (p<0.05). XRD results showed that phase transformation of zirconia disks was detected only in the SB group. In addition, SiO2-ZrO2 coatings reduced WCA. The translucency decreased only in group C21. Group C11 showed the highest shear bond strength under both aging conditions. CONCLUSION: SiO2-ZrO2 coating is a promising method to enhance the adhesive resin bonding of translucent zirconia without causing phase transformation of translucent zirconia.

Learning Intention-Aware Policies in Deep Reinforcement Learning.

Deep reinforcement learning (DRL) provides an agent with an optimal policy so as to maximize the cumulative rewards. The policy defined in DRL mainly depends on the state, historical memory, and policy model parameters. However, we humans usually take actions according to our own intentions, such as moving fast or slow, besides the elements included in the traditional policy models. In order to make the action-choosing mechanism more similar to humans and make the agent to select actions that incorporate intentions, we propose an intention-aware policy learning method in this letter To formalize this process, we first define an intention-aware policy by incorporating the intention information into the policy model, which is learned by maximizing the cumulative rewards with the mutual information (MI) between the intention and the action. Then we derive an approximation of the MI objective that can be optimized efficiently. Finally, we demonstrate the effectiveness of the intention-aware policy in the classical MuJoCo control task and the multigoal continuous chain walking task.

Effects of plasma-induced grafting modification on the adhesive strength and mechanical properties of fiber posts.

OBJECTIVE: This study aimed to assess the effects of plasma grafting modification on the micro-push-out adhesive strength and mechanical properties of fiber posts and to assess the stability of these treatment effects. MATERIALS AND METHODS: Glass-fiber posts were divided into four groups based on the treatment methods used, as follows: (1) Group NT: no treatment; (2) Group PT: Helium (He) plasma treatment; (3) Group PIG: He-plasma-induced post-irradiation grafting; and (4) Group SIG: He-plasma-induced syn-irradiation grafting. The treated fiber posts were bonded using self-adhesive resin cement exposure to air for 0, 1, 6 or 12 hours separately after surface treatment. Micro-push-out adhesive strength, flexural modulus, and flexural strength were measured. RESULTS: Plasma treatment, post-irradiation grafting, and syn-irradiation grafting improved adhesive strength at the 0-hours level. However, the improved adhesive strength disappeared in group PT after exposure for one or more hours. In group PIG, the adhesive strength after 1-hour exposure was 20.5% lower than that of 0-hour exposure (adhesive immediately after treatment), and no statistically significant differences in adhesive strength were observed between the 1, 6, and 12-hour exposure. In group SIG, no statistically significant differences in adhesive strength were observed among the 0, 1, and 6-hour exposure. Although the adhesive strength was 23% lower at the 12-hour exposure than that of 0-hour exposure in group SIG, the adhesive strength of fiber posts received syn-irradiation grafting still presented the best adhesive strength compared with the other treatment methods. The three-point flexural modulus and strength remained unaffected by the treatment methods used. CONCLUSIONS: Plasma-induced syn-irradiation grafting provided the ideal improvement and stability in adhesive strength in fiber posts. In addition, plasma-induced grafting modification successfully overcame the surface aging effect caused by plasma treatment alone without affecting the bulk mechanical properties of fiber posts.

A Hierarchical Bayesian Latent Class Model for the Diagnostic Performance of Mini-Mental State Examination and Montreal Cognitive Assessment in Screening Mild Cognitive Impairment Due to Alzheimer's Disease.

BACKGROUND: The Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) are low costing and noninvasive neuropsychological tests in screening Mild Cognitive Impairment (MCI) due to Alzheimer's disease (AD). There is no consensus on which test performs better in detecting MCI due to AD based on the different imperfect reference standards. Therefore, we conducted a meta-analysis to assess the diagnostic performance of MMSE and MoCA for screening MCI due to AD in the absence of a gold standard. METHODS: Six electronic databases were searched for relevant studies until April, 2022. A hierarchical Bayesian latent class model was used to estimate the pooled sensitivity and specificity of MoCA and MMSE in the absence of a gold standard. RESULTS: 90 eligible studies covering 21273 individuals for MMSE, 26631 individuals for MoCA were included in this meta-analysis. The pooled sensitivity was 0.71(95%CI: 0.67-0.74) for MMSE and 0.85(95%CI: 0.83-0.88) for MoCA, while the pooled specificity was 0.71(95%CI: 0.68-0.74) for MMSE and 0.79(95%CI: 0.76-0.81) for MoCA. MoCA was useful to "rule in" and "rule out" the diagnosis of MCI due to AD with higher positive likelihood ratio (4.07; 95%CI: 3.60-4.62) and lower negative likelihood ratio (0.18; 95%CI: 0.16-0.22). Moreover, the diagnostic odds ratio of MoCA was 22.08(95%CI: 17.24-28.29), which showed significantly favorable diagnostic performance. CONCLUSIONS: It suggests that MoCA has greater diagnostic performance than MMSE for differentiating MCI due to AD when the gold standard is absent. However, these results should be taken with caution given the heterogeneity observed.

[Effect of SiO2-ZrO2 slurry coating on shear bond strength of zirconia to resin cement].

Objective: To evaluate the effect of shear bond strength between resin cement and zirconia using SiO2-ZrO2 slurry coating. Methods: One hundred and forty pre-sintered zirconia discs were randomly divided into seven groups (n=20) according to the surface treatments: AS (as-sintered), SB (sand blasting with Al2O3), 2SiO2-1ZrO2 (2∶1 mole ratio SiO2-ZrO2 coating), 1SiO2-1ZrO2 (mole ratio 1∶1 SiO2-ZrO2 coating), 1SiO2-2ZrO2 (mole ratio 1∶2 SiO2-ZrO2 coating), 1SiO2-3ZrO2 (mole ratio 1∶3 SiO2-ZrO2 coating), 1SiO2-4ZrO2 (mole ratio 1∶4 SiO2-ZrO2 coating). Each zirconia disc was bonded to composite resin cylinder using resin cement. All specimens were stored in distilled water (37 ℃, 24 h). Each group was divided into two subgroups in which half specimens were tested using universal testing machine and another half specimens accepted artificial aging of 5 000 times thermocycling then tested. Scaning electron microscopy (SEM) was used to observe the micro-morphology of coating surface etched by hydrofluoric acid,then the coating thickness was measured. Results: Before artificial aging, 1SiO2-1ZrO2 showed a higher shear bond strength [(41.69±6.28) MPa] than all the other group (P<0.05). 1SiO2-2ZrO2 gained a higher strength than AS, SB, 1SiO2-3ZrO2 and 1SiO2-4ZrO2 (P<0.05). However, 1SiO2-2ZrO2 did not get a significant higher shear bond strength than 2SiO2-1ZrO2 (P>0.05). No significant differences were found among SB, 2SiO2-1ZrO2 and 1SiO2-3ZrO2 (P>0.05). After artificial aging, shear bond strength of all groups were decreased significantly besides 2SiO2-1ZrO2. 2SiO2-1ZrO2, 1SiO2-1ZrO2 and 1SiO2-2ZrO2 [(24.13±5.50), (22.28±4.40), (23.11±4.80) MPa] showed higher shear bond strength than SB and 1SiO2-3ZrO2 (P<0.05),no intergroup differences were observed (P>0.05). Shear bond strength of AS and 1SiO2-4ZrO2 fell to 0 MPa approximately. The SEM images of etched coating surface showed contraction fissure due to different thermal expansion coefficient between SiO2 and ZrO2 and intercrystal pores of zirconia. The thickness of coating was measured to be less than 30 µm. Conclusions: Mole ratio 1∶1 SiO2-1ZrO2 slurry coating showed the highest shear bond strength of resin cement to zirconia.

[A survey on clinical practice of tracheostomy decannulation in medical institutions at all levels across the country].

Objective: A questionnaire survey was conducted on the clinical practice of tracheostomy decannulation among medical staff in medical institutions at all levels across the country. Methods: The questionnaire was determined by literature review and expert consultation to investigate the clinical practice of tracheostomy decannulation among medical staff in comprehensive and rehabilitation hospitals of different levels across the country and the factors considered when deciding to decannulate. Statistical methods used χ² test and one-way ANOVA. Results: A total of 570 questionnaires were collected from all over the country, with 463 valid questionnaires. The survey results showed that the most important factors in clinical practice to determine the decannulation of the tracheostomy tube were upper airway patency, cough effectiveness, level of consciousness and oxygenation. Before decannulation, 220 (47.50%) would choose to change to metal cannula, and 384 (82.90%) would routinely occlude the tube. 294 (63.50%) thought that re-intubation within 24 hours after decannulation of the tracheostomy tube was failure of decannulation. The decannulation failure rate was mostly 2%-5%. Conclusions: Upper airway patency, cough effectiveness, level of consciousness and oxygenation were important factors when considering decannulation. Reintubation within 24 hours of decannulation was defined as failure by the majority of respondents.

[Single center experience of transcatheter aortic valve replacement with a simplified operative protocol].

Objective: To summarize the single center experience of transcatheter aortic valve replacement (TAVR) with a simplified operative protocol. Methods: Consecutive patients who underwent transfemoral TAVR (TF-TAVR) from July 2020 to December 2020 in Fuwai Hospital were retrospectively analyzed. We compared the baseline characteristic, procedure information, 30-day follow-up outcomes of the patients who underwent TF-TAVR without the simplified operative protocol (routine group) or with the simplified operative protocol (simplified protocol group). Results: 93 patients were collected, 42 patients belonging to routine group, 51 patients belonging to simplified protocol group. In simplified protocol group, there were 51 patients planned to use ultrasound-guided femoral access puncture, procedure was successful in all 51 patients (100%). There were 49 patients planned to use the radial artery as the secondary access, procedure was successful in 45 patients (92%). There were 48 patients planned to use the strategy of avoidance of urinary catheter, this strategy was achieved in 35 patients (73%). There were 12 patients planned to use the left ventricular guidewire to pace, procedure was successful in 11 patients (92%). There were no differences in baseline characteristics, major clinical endpoints and 30-day follow-up outcomes between the two groups. Meanwhile, the procedure time ((62.5±17.9)min vs. (78.3±16.7)min, P<0.001), operation room time ((133.7±25.1)min vs. (159.2±42.6)min, P<0.001), X-ray exposure time ((17.2±6.5)min vs. (20.2±7.7)min, P=0.027) were significantly shorten in simplified protocol group compared with the routine group. Conclusion: Our study results indicate that the simplified operative protocol of TF-TAVR is as effective and safe as the routine operative protocol, meanwhile using the simplified operative protocol can significantly increase the operative efficiency of TF-TAVR.

[Initial clinical experience of left bundle branch pacing after transcatheter aortic valve implantation].

Objective: To investigate the efficacy and safety of left bundle branch pacing(LBBP) in patients after transcatheter aortic valve implantation (TAVI). Methods: This is a retrospective study. A total of 35 patients underwent TAVI and received pacemaker implantation from January 2018 to December 2020 in Beijing Fuwai Hospital were enrolled. Patients were divided into LBBP group (n=12) and right ventricular apex pacing (RVAP) group (n=23) according to the pacing position. The success rate of operation in LBBP group was calculated, and the occurrence of complications were observed, and the parameters of pacemaker were measured on the 3rd day and 1, 3 and 6 months after operation. The N-terminal pro-B-type natriuretic peptide (NT-proBNP), echocardiographic and ECG indexes were compared between the two groups on the 3rd day and 1, 3, and 6 months after pacemaker implantation. Result: A total of 35 patients were included, The age was (76.4±7.7) years, including 19 males (54.3%). The procedure time ((86.58±17.10)min vs. (68.74±9.18)min, P<0.001) and fluoroscopy duration ((20.08±4.44)min vs. (17.00±2.26)min, P<0.001) were significantly longer in LBBP group compared with RVAP group. The operation success rate of LBBP group was 11/12. There was no serious operation related complications such as pneumothorax, hemothorax, electrode dislocation, infection, and lower limb bleeding. The patients were followed up for 7.43 (5.21, 9.84) months. The programmed parameters of pacemaker were in the ideal range and stable during follow-up. At 3 and 6 months after operation, the left ventricular ejection fraction in LBBP group was higher than that in RVAP Group (at 3 months: (60.75±2.89)% vs. (57.35±3.33)%, P=0.004; at 6 months: (63.17±3.33)% vs. (56.17±3.97)%, P<0.001), NT-proBNP values was lower in LBBP group than that in RVAP Group (at 3 months: 822 (607, 1 150)ng/L vs. 1 052 (902, 1 536)ng/L, P=0.006; at 6 months: 440 (330,679)ng/L vs. 783 (588, 1 023)ng/L, P=0.001). At 1, 3 and 6 months after operation, the QRS duration was shorter in LBBP group than that in RVAP group (1 month: 99 (97, 107)ms vs. 126(124, 130)ms, P<0.001; 3 months: 98(96, 105)ms vs. 129(128, 133)ms, P<0.001; 6 months: 96(94, 104)ms vs. 130(128, 132)ms, P<0.001). Conclusions: For patients with permanent pacemaker indications after TAVI, LBBP is feasible, safe and reliable. It could improve the cardiac function in the short term, the long-term effect of LBBP needs to be further observed.

[Prevention and treatment strategies for intestinal failure-associated liver disease].

Long-term parenteral nutrition-associated liver dysfunction is caused by intestinal failure and associated complications rather than the parenteral nutrition administration. Intestinal failure-associated liver disease has a diverse etiology, so its prevention and treatment usually require multiple measures at the same time. This article provides a summary of the preventative as well as treatment options for intestinal failure-associated liver disease.

[Radiofrequency catheter ablation of ventricular tachycardia in patients post surgical repair of tetralogy of Fallot].

Objective: To investigate the clinical and electrophysiological features of ventricular tachycardia (VT) in tetralogy of Fallot (TOF) patients post surgical repair (rTOF) and to analyze the therapeutic effect and prognosis of radiofrequency ablation of rTOF-VT. Methods: This is a retrospective study. Consecutive patients with rTOF-VT, who were treated in Fuwai Hospital from January 2015 to March 2020, were enrolled. All the patients underwent right ventricular voltage mapping following routine cardiac electrophysiological examination, followed by linear or homogenizing radiofrequency ablation based on the low-voltage substrate. The clinical features, 3-dimentional electrophysiological substrate mapping, radiofrequency ablation and long-term prognosis of the enrolled patients were analyzed. Acute ablation success was defined as completion of linear or homogenizing ablation or intraoperative evoked VT as destination of the procedure. Patients were followed up at 3 and 6 months post operation and every year thereafter. The endpoints were sudden cardiac death (SCD) and recurrence of ventricular tachycardia. Results: A total of 20 patients with rTOF-VT were enrolled including 14 males with an age of (35.8±11.8) years. The electrocardiogram identified 23 types of ventricular tachycardia, 19 of which were originated from right ventricular inflow tract outlet. The most common clinical manifestations were heart murmur (19 cases, 95%) and syncope (4 cases, 25%). Electroanatomical substrate mapping was performed in 20 patients and evidenced localized or diffuse scar or low-voltage area of right ventricle. Intraoperative electrophysiological tests provoked ventricular tachycardia in 6 patients (30%), including 5 patients with hemodynamics disturbance. The acute success rate of radiofrequency ablation was 95% (19/20). The follow-up time was (31.1±17.7) months and the recurrence rate of ventricular tachycardia was 30% during follow-up period and 5 cases received repeat radiofrequency ablation and there was no recurrent ventricular tachycardia during follow-up post repeat radiofrequency ablation. Conclusions: The voltage substrate mapping under sinus rhythm is a feasible mapping method for rTOF-VT. Linear or flaky radiofrequency ablation of the slow conduction zone is safe and effective treatment strategy, the recurrence rate after the first radiofrequency ablation is still high, and the effectiveness of repeat radiofrequency ablation is satisfactory in this patient cohort.

[Left ventricular guidewire pacing during transcatheter aortic valve replacement].

Objective: To investigate the safety and efficacy of left ventricular guidewire pacing during transcatheter aortic valve replacement (TAVR). Methods: This is a retrospective study. Thirteen patients, who underwent TAVR with left ventricular guidewire pacing from October 2019 to December 2019 in Fuwai Hospital, were included. Clinical data and operational procedure data of the patients were collected. Changes in blood pressure and electrocardiogram were observed during operations. Ascending aorta angiography was performed to evaluate the regurgitation of aortic valve after valve implantion. The incidence of major adverse cardiac events during hospitalization and at 3-months after discharge was recorded. Results: There were 7 male and 6 female patients in this cohort,and age was (73.8±8.3) years old. Among the 13 patients, 9 were tricuspid aortic valves, 3 were bicuspid aortic valves, and 1 was degenerated bioprosthetic surgical aortic valve. TAVR were successfully performed in all of the 13 cases using pacing through the left ventricular guidewire. During balloon dilation, the blood pressure decreased to below 60 mmHg (1 mmHg=0.133 kPa) after 180 beats/min pacing, and the valve release process was smooth and the position was stable. The results of aortography showed that there was no regurgitation in 7 cases, mild regurgitation in 5 cases and moderate regurgitation in 1 case. Three patients required temporary pacing during the procedure due to complete heart block, among whom 1 patient was implanted with permanent pacemaker during hospitalization, and the other 2 patients recovered within 24 hours after operation. In another case, there was no significant change of electrocardiogram during the operation, and complete heart block occurred 10 days after the operation, and treated with permanent pacemaker. The other 10 patients began to carry out bedside activities and rehabilitation training 24 hours after operation. There was no death, myocardial infarction, stroke and other major adverse cardiac events during hospitalization and at 3-month follow-up after discharge. Conclusion: Left ventricular guidewire pacing is a safe and effective strategy for TAVR.

Characterizing the air pollution of the cities in the closure of corona virus disease 2019 in China.

With the rapid development of industrialization and urbanization in China, energy and vehicle consumption have continued to increase in recent years and air pollution has become serious. In early 2020, Corona Virus Disease 2019 broke out in Wuhan, China. From January 29, 2020, several sources of the air pollution almost all stopped working, including gasoline burning vehicles, dust producing building sites, coal-fired factories, etc. Five indicators of the atmospheric environmental quality were observed from December 19, 2019 to April 30, 2020 in nine cities and 1-h average concentrations, 24-h average concentrations and Air Quality Index were assessed. The 1-h average concentrations of the nitrogen dioxide, the ozone and the sulfur dioxide showed obvious difference though the closure did not change the sequence of the five pollutants' concentrations in the air at diverse sampling moments. The changing of the 24-h average concentrations of the five pollutants indicated the amount of pollutants in the air were greatly affected by human activities. The nitrogen dioxide, the sulfur dioxide and the particulate matters decreased obviously in the closure. The air in the metropolis and the south-east cities were relatively clean and the pollutants' concentrations decreased slightly during the closure period. The northern and the heavy industrial cities showed significant drop on air pollution indicators and the air quality of the two city groups could be greatly improved if some effective measures could be taken of environmental management and regional development.

[Feasibility of single-stage stent implantation following rotational atherectomy combined with TAVR].

Objective: To explore the feasibility of the single-stage stent implantation following rotational atherectomy combined with transcatheter aortic valve replacement (TAVR) in treating patients with severe aortic stenosis(AS) and severe calcified coronary artery stenosis. Methods: Three patients who received single-stage stent implantation following rotational atherectomy combined with TAVR in Fuwai hospital from April to October 2019 were included in this retrospective analysis. Clinical and anatomical features (including echocardiography and aortic CT) of the patients were collected, efficacy and safety of this operation strategy were observed and 6 months follow up results were summarized. Results: Three patients (2 females, 66-80 years old) were included. The mean Society of Thoracic Surgeons (STS) risk score was 7.8%. The mean maximum velocity of aortic valve was 4.4 m/s, the mean transvalvular pressure gradient was 53.2 mmHg (1 mmHg=0.133 kPa), mean left ventricular ejection fraction (LVEF) was 48.6%. All three patients had severe calcified coronary artery stenosis: left anterior descending artery (LAD, n=2) and left main coronary artery (LM, n=1), requiring rotary grinding. The mean SYNTAX score was 20. All the procedures were performed through transfemoral access. After aortic valve crossing, all coronary lesions were successfully treated with stent implantation following rotational atherectomy, transfemoral TAVR was then immediately performed with a self-expandable Venus-A valve. One patient underwent"valve-in-valve"implantation due to the high-implantation position of the first valve. The procedures were completed without complications in all the three patients. The immediate effect was satisfactory. Echocardiography results showed that the mean maximum velocity of aortic valve was 2.1 m/s, mean gradient was 9.3 mmHg, and mean LVEF was 59% after the procedure. There was no death and revascularization during the 6 months follow-up. Conclusion: In patients with severe calcified coronary artery and severe AS with high risk of cardiac surgery, the single-stage stent implantation following rotational atherectomy combined with TAVR is feasible and results are satisfactory in this patient cohort.

Effects of lncRNA gm4419 on rats with hypertensive cerebral atherosclerosis through NF-κB pathway.

OBJECTIVE: To explore the effects of long non-coding ribonucleic acid (lncRNA) Gm4419 on rats with hypertensive cerebral atherosclerosis through the nuclear factor-kappa B (NF-κB) pathway. MATERIALS AND METHODS: Healthy male rats were selected and randomly divided into control group, model group (hypertensive cerebral atherosclerosis model), and lncRNA group (hypertensive cerebral atherosclerosis model + lncRNA injection). Neurological deficit scoring criteria, flow cytometry, Western blotting, and staining method were adopted to measure the differences in the neurological function score, NF-κB activity, and chemerin level of rats in the three groups. RESULTS: The neurological scores revealed that the neurological function of rats was not damaged in control group, while it was severely damaged in model group. However, the neurological function of rats was more severely damaged in lncRNA group than that in control group and model group, while the neurological function deficits were slighter in model group. In terms of NF-κB expression activity in mononuclear cells, the serum activity of NF-κB in control group appeared the lowest among the three groups and was significantly higher in lncRNA group than in model group. The serum chemerin level was evidently increased in model group compared with control group, while it was significantly decreased in lncRNA group compared with model group and control group. Moreover, the levels of NF-κB and chemerin were most evidently influenced in lncRNA group. CONCLUSIONS: Activating the NF-κB signal, lncRNA Gm4419 promotes the expression of chemerin signal, accelerates the apoptosis of nerve cells, and motivates the deterioration of hypertensive cerebral arteriosclerosis.

Simulation of postoperative occlusion and direction in autotransplantation of teeth: application of computer-aided design and digital surgical templates.

Autotransplantation of teeth requires optimisation of both occlusion and direction to ensure minimal injury to the dental crown and the alveolar bone. We describe a method that could simulate postoperative occlusion and direction of the donor tooth by using CAD and digital surgical templates, and evaluate the postoperative effect in five patients who had teeth autotransplanted. Computed tomographic data were imported into ProPlan CMF 3.0 software, the donor tooth was simulated to replace the recipient site according to the position of the occlusion and alveolar bone, and a digital template was designed to guide preparation of the socket. A computer-aided, rapid prototyped, tooth was used to match the socket and, finally, an occlusal template was designed to ensure that the donor tooth was in the simulated position. We compared the position of the tooth in the simulation with its postoperative position using ProPlan CMF 3.0 software. In this way it was possible to simulate and guide the donor tooth accurately to the recipient site. At six-month follow up all teeth had survived successfully. Given the efficiency and precision of placement and the success, we conclude that CAD can successfully help to simulate occlusion and direction in autotransplantation of teeth while simplifying the procedure.

Microstructure Evolution and Nanotribological Properties of Different Heat-Treated AISI 420 Stainless Steels after Proton Irradiation.

In this paper, low-energy proton irradiation experiments with different cumulative fluences were performed on samples of AISI 420 stainless steel that were either annealed or tempered at 600 or 700 °C. The effects of the cumulative proton irradiation fluence on the evolution of the microstructure of AISI 420 were studied by transmission electron microscopy (TEM). Scratch tests were performed using a Tribo Indenter nanomechanical tester, in order to investigate the effects of the cumulative fluence on the tribological properties of the AISI 420 stainless steel. The results indicate that the dislocation density of the microstructure near the surface of the AISI 420 stainless steel increases with higher cumulative proton irradiation fluences. Under the same load, the nanoscale friction coefficient and wear rate both decreased with increasing cumulative proton irradiation fluence. This indicates that the surface hardening effect induced by proton irradiation can diminish the nanoscale friction coefficient and wear rate.

Local retro-orbicularis oculus fat (ROOF) resection in upper blepharoplasty: A retrospective evaluation study of 65 bilateral upper blepharoplasties.

BACKGROUND: Puffy upper eyelids are normal in Asians, and full-incision blepharoplasty is commonly performed to remove some orbital fat to ameliorate the problem, but not all patients would exhibit obvious improvement. Local retro-orbicularis oculus fat (ROOF) is a layer of fibrofatty soft tissue that lies much deep into the orbicularis oculi in the upper eyelid, which is an important factor in the formation of puffy upper eyelids. This study was carried out to evaluate the clinical application (including the evaluation of photographs for the thickness of upper eyelid) of upper blepharoplasty combined with ROOF resection for correcting puffy upper eyelids. METHOD: A total of 65 patients (5 males, 60 females) with puffy upper eyelids recruited from October 2015 to October 2016 were included in the study. Full-incision blepharoplasty combined with partial ROOF resection was performed on all patients. The thickness of soft tissue in the upper eyelid was measured by ultrasound biomicroscopy preoperatively and at 12 months postoperatively. RESULT: All patients underwent surgery successfully, and 62 patients (124 eyes) were followed up for 12-15 months (mean 13.8 ±â€¯2.7 months). Before the surgery, the thickness of the ROOF was 0.35 ± 0.12 mm on the left and 0.42 ± 0.08 mm on the right. Twelve months postsurgery, the thickness of the ROOF was 0.18 ± 0.03 mm on the left and 0.20 ± 0.02 mm on the right. During the follow-up period, all patients were satisfied with the esthetic effect, and no severe postoperative complications were observed. CONCLUSION: Puffy upper eyelids can be corrected effectively by local ROOF resection in esthetic blepharoplasty.

Influence of lncRNA MALAT1 on septic lung injury in mice through p38 MAPK/p65 NF-κB pathway.

OBJECTIVE: To investigate the influence of long non-coding ribonucleic acid (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) on septic lung injury in mice and its mechanism, so as to provide references for the clinical prevention and treatment of septic lung injury in the future. MATERIALS AND METHODS: A total of 60 male C57 mice were randomly divided into Control group (n=20), lipopolysaccharide (LPS) group (n=20), and LPS+MALAT1 siRNA group (n=20) using a random number table. The mouse model of septic lung injury was established via intraperitoneal injection of LPS (10 mg/kg), and the MALAT1 knockdown model was established via tail intravenous injection of MALAT1 siRNA. After 12 h, the lung was taken to measure the wet weight/dry weight ratio. Also, the activity of myeloperoxidase (MPO) in lung tissues was detected. The number of neutrophils and macrophages in bronchoalveolar lavage fluid (BALF) was detected via bronchoalveolar lavage. Moreover, the messenger RNA (mRNA) expression levels of inflammatory cytokines, including tumor necrosis factor-α (TNF-α), interleukin-1 (IL-1), and IL-6, in lung tissues were detected via Reverse Transcription-Polymerase Chain Reaction (RT-PCR). Finally, the expression level of p38 in lung tissues was detected via immunohistochemical staining, and the expressions of p38 mitogen-activated protein kinase (MAPK)/p65 nuclear factor-κB (NF-κB) signaling pathway-related proteins in lung tissues of mice were detected via Western blotting. RESULTS: The expression of lncRNA MALAT1 in lung tissues of mice with septic lung injury was significantly increased (p<0.05). After knockdown of lncRNA MALAT1, the LPS-induced pathological injury of lungs could be improved, and the wet weight/dry weight ratio of lungs could be reduced (p<0.05). Compared with those in LPS group, the total number of inflammatory cells and the number of neutrophils and macrophages in BALF were significantly decreased in LPS+MALAT1 siRNA group (p<0.05), and the levels of inflammatory cytokines were also significantly inhibited (p<0.05). The immunohistochemical results manifested that the knockdown of lncRNA MALAT1 could inhibit the LPS-induced up-regulation of p38 in lung tissues in mice. According to the results of Western blotting, the p38 MAPK/p65 NF-κB signaling pathway was significantly activated in lung tissues in LPS group (p<0.05), while it was significantly suppressed after inhibition on lncRNA MALAT1 (p<0.05). CONCLUSIONS: The knockdown of lncRNA MALAT1 can significantly improve the septic lung injury in mice, whose mechanism may be related to its inhibition on the p38 MAPK/p65 NF-κB signaling pathway.

Individualized small-incision orbicularis-levator fixation blepharoplasty for unilateral single-eyelid Asians.

Unilateral double-eyelid blepharoplasty is often required by people with unilateral single eyelid. The full incisional method may cause permanent skin scar formation, and the buried suture method may lead to early eyelid fold loosening, which could not reduce the soft tissue thickness of eyelid. A total of 85 patients (8 males and 77 females) with unilateral single eyelids were studied between January 2015 and January 2016, with a mean age of 25.57 ± 6.5 years. Small-incision orbicularis-levator fixation blepharoplasty was performed on all patients on the single eyelid side. During surgery, the orbicularis oculi (OO) muscle and the orbital fat (OF) were selectively removed through the small skin incisions. The thicknesses of upper eyelid were measured preoperatively and at 6 months postoperatively. The position and tension of the eyelid creases, eyelids symmetry, and satisfaction status were also evaluated. Eighty patients (10 left eyes and 70 right eyes) were followed up for 19 ± 3.4 months. Before surgery, the average thickness of OO muscle is 0.895 ± 0.199 mm (left) and 0.970 ± 0.185 mm (right) (P = 0.0127), the thickness of OF is 0.717 ± 0.154 mm (left) and 0.867 ± 0.143 mm (right) (P = 0.0187). Six months postsurgery, the average thickness of OO muscle is 0.894 ± 0.199 mm (left) and 0.907 ± 0.188 mm (right) (P = 0.293), the thickness of OF is 0.703 ± 0.143 mm (left) and 0.747 ± 0.0957 mm (right) (P = 0.534). In conclusion, small-incision orbicularis-levator fixation blepharoplasty can produce a desired aesthetic effect for unilateral single-eyelid patients as its personalized designing, symmetrical eyelid thickness, and slight skin scar formation.