[In vivo osteogenic evaluation of titanium implants with strontium loaded nanotubes]

Objective: To evaluate the in vivo osteogenic activity of titanium implants with strontium loaded TiO₂ nanotubes (NTSr). Methods: The strontium loaded titanium nanotubes were formed on pure titanium implants through anodization and hydrothermal treatment, and the unmodified titanium (Control) and sheer TiO₂ nanotubes (NT) were set to be control groups and treatment group. Inductively coupled plasma mass spectrometry (ICP-MS) was used to evaluate the Sr release at 28 days. Field emission scanning electron microscopes (FE-SEM) was used to view the micro-topography, atomic force microscope was used to exam the surface roughness, and nano-indenter was used to evaluate the hardness of three groups (n=3). Three groups of implant samples were inserted into the distal femoral metaphysis of New Zealand rabbits (n=4 at each time point). After 4 weeks and 12 weeks, samples were harvested. Micro-CT scanning, immunofluorescent and histological examinations were carried out. Results: The strontium ions could be released slowly for at least 28 days [the Sr concentration at 28 Day was (2.6±1.5) ng/ml]. NTSr coating exhibited a nanoscale tube array (the diameter was about 70 nm), and the surface roughness of implant was increased with the nanobube coating [Control (34.8±5.3) nm, NT (66.2±4.3) nm, NTSr (85.7±10.6) nm, F=37.59, P<0.001]. The surface roughness (Ra) of NT and NTSr groups was higher than the control group (P<0.05). Comparing to Control implants, NTSr implants exhibited a better osteogenic ability [the bone volume/total volume (BV/TV) value was Control (24.7±1.1)% vs. NTSr (37.7±1.9)% at 4 weeks (P<0.05), and Control (40.7±0.9)% vs. NTSr (51.9±2.1)% at 12 weeks (P<0.05)]. The fluorescent examination revealed that NTSr coating can also accelerated the generation of new bone tissue (bone tissue area% labelled by alizarin red at day 7 was Control (19.2±2.9)% vs. NT (35.4±3.7)% vs. NTSr (40.9±0.9)% (F=42.74, P<0.01). The results in the NT and NTSr group were statistically higher than that in the control group (P<0.05). Conclusions: The strontium loaded TiO₂ nanotubes can enhance new bone formation around titanium implants.

[Effect of non-surgical periodontal treatment on blood inflammatory parameters, glucose and lipid metabolism in patients with periodontitis and type 2 diabetes mellitus]

Non-surgical periodontal treatment (NSPT) is the most essential part of periodontal treatment. Most patients with periodontitis and type 2 diabetes mellitus (T2DM) can achieve a satisfying outcome by NSPT. For these patients, NSPT can not only improve clinical periodontal parameters significantly and decrease the serum inflammatory status,but also improve glucose and lipid metabolism to some extent. Thus, NSPT is of great significance in preventing or retarding the progress of T2DM or even its complications. However, the special general condition of T2DM makes NSPT effects on periodontitis patients partially differ from those without systemic diseases. Therefore, the special characteristic led by T2DM should be taken into account in the decision and implementation of treatment plans for periodontitis patients. This paper will review the above issues mainly based on the studies of our research group.

[Safety and efficacy evaluation of laparoscopic and open hepatectomy for hepatolithiasis: a propensity score matched analysis]

Objective: To compare the safety and efficacy of laparoscopic and open hepatectomy for hepatolithiasis. Methods: Between January 2014 and May 2020, the clinicopathological data of 254 patients with hepatolithiasis who underwent laparoscopic or open hepatectomy at the First Department of Hepatobiliary Surgery,Affiliated Hospital of North Sichuan Medical College were collected retrospectively. There were 74 males and 180 females with age of (56±8) years (range: 38 to 77 years). Of the 254 patients, 162 underwent laparoscopic surgery (laparoscopic group) and 92 underwent open surgery (open group). Propensity score matching(PSM) was performed to match baseline characteristics of the two groups,and then the perioperative results and follow-up efficacy were compared between the two groups. The t-test, Mann-Whitney U test, χ² test or Fisher's exact probability method was used to compare the perioperative data and follow-up results of the two groups after matching, respectively. Results: Each group had 63 patients after PSM with well-balanced baseline characteristics. There was no statistic difference in the type of hepatectomy,combined common bile duct exploration rate,T tube drainage placement rate,operation time,intraoperative transfusion rate,intraoperative accidental injury rate,initial and final stone clearance rate,and stone recurrence rate between the two groups. However,compared with the open hepatectomy group, the laparoscopic group had significantly lower intraoperative blood loss (M(IQR))(300(175)ml vs. 350(145)ml, Z=3.227,P=0.001),shorter postoperative hospital stay((10.6±4.1)days vs. (14.0±4.0)days,t=4.634,P<0.01),shorter time to postoperative oral intake ((1.8±1.1)days vs. (2.9±1.6)days, t=4.556, P<0.01), and lower postoperative complication rate (25.4%(16/63) vs. 49.2%(31/63), χ²=7.635, P=0.006). Conclusion: Laparoscopic hepatectomy is safe and effective for hepatolithiasis with the advantages of less intraoperative blood loss,lower postoperative complications and faster postoperative recovery.

Apelin controls emotional behavior in age- and metabolic state-dependent manner

Apelin is a small peptide secreted by the adipose tissue notably in conditions of obesity-induced hyper-insulinemia. Apelin exerts a range of physiological functions at the periphery including the improvement of insulin sensitivity and the increase of muscle strength or cardiac contractibility. Interestingly, the brain is endowed with a high density of APJ, the single target of apelin, and growing evidence suggests various central actions of this adipokine. Recent studies reported that the intracerebroventricular infusion of apelin modulates emotional states in middle age stressed animals. However, results are so far been mixed and have not allowed for definitive conclusions about the impact of apelin on anxio-depressive-like phenotype. This study aims 1) to evaluate whether serum apelin levels are associated with mood in older adults and 2) to determine the impact of the genetic apelin inactivation in 12-month old mice fed a standard diet (STD) or in 6-month old mice fed a high fat diet (HFD). A higher plasma apelin level was associated with higher depressive symptoms in older adults. In line with these clinical findings, 12-month old apelin knock-out (Ap^-/-) mice displayed a spontaneous antidepressant-like phenotype. In a marked contrast, 6-month old Ap^-/- mice harbored a higher degree of peripheral insulin resistance than wild-types in response to HFD and were more prone to develop anxiety while the depressive-like state was not modified. We also provided evidence that such anxious behavior was associated with an impairment of central serotonergic and dopaminergic neuronal activities. Finally, although the insulin sensitizing drug metformin failed to reverse HFD-induced insulin resistance in 6-month old Ap^-/- mice, it reversed their anxious phenotype. These results emphasize a complex contribution of apelin in the regulation of emotional state that might depend on the age and the metabolic status of the animals. Further investigations are warranted to highlight the therapeutic potential of manipulating the apelinergic system in mood-related disorders.

[A randomized double-blinded placebo-controlled clinical trial of minodronate tablet in postmenopausal Chinese women with osteoporosis]

Objective: To verify the efficacy and safety of daily oral minodronate in postmenopausal women with established osteoporosis. Methods: In this randomized, double-blinded, placebo-controlled trial, 262 postmenopausal women were enrolled. Patients were randomized to receive daily oral minodronate 1 mg with supplements of 500 mg calcium and 200 U vitamin D₃ (n=130) or placebo (n=132) with daily supplements of 500 mg calcium and 200 U vitamin D₃, for 48 weeks. The primary endpoint was the average bone mineral density (BMD) change in the lumbar vertebrae 48 weeks post-treatment. Secondary outcome measures was the incidence of vertebral fractures. Safety assessments included the rate of adverse events. Results: At the end of 48 weeks treatment, the average BMD change rate from baseline were: full analysis set results: (3.52±4.82)% in the minodronate group and (2.00±5.74)% in the placebo group; per-protocol set results: (3.99±5.05)% in the minodronate group and (2.07±6.20)% in the placebo group; the differences were all significant (all P<0.05). Vertebral fracture occured in 3 patients (2.3%, 3/132) in the placebo group, and 1 case (0.8%, 1/130) in the minodronate group (P>0.05). The incidence of adverse events was 71.5% (93/130) in the minodronate group and 78.0% (103/132) in the placebo group (P>0.05). Conclusion: Minodronate is effective and safe in the treatment of postmenopausal osteoporosis without severe side effects.

Quantum Simulation of the Two-Dimensional Weyl Equation in a Magnetic Field

Quantum simulation of 1D relativistic quantum mechanics has been achieved in well-controlled systems like trapped ions, but properties like spin dynamics and response to external magnetic fields that appear only in higher dimensions remain unexplored. Here we simulate the dynamics of a 2D Weyl particle. We show the linear dispersion relation of the free particle and the discrete Landau levels in a magnetic field, and we explicitly measure the spatial and spin dynamics from which the conservation of helicity and properties of antiparticles can be verified. Our work extends the application of an ion trap quantum simulator in particle physics with the additional spatial and spin degrees of freedom.

[Recommendations of diagnosis and treatment of Takayasu's arteritis in China]

Takayasu's arteritis (TAK) mainly involves the aorta and its major branches, which is characterized as a chronic, progressive and inflammatory disease. China belongs to one of the regions with a high prevalence of TAK referring to its global distribution. However, it is insufficient for the spread and update of standardized diagnosis and treatment of TAK. Based on the evidence and guidelines from China and other countries, Chinese Rheumatology Association developed the standardized diagnosis and treatment of TAK in China. The purpose is to standardize the methods for diagnosis of TAK, assessment of disease activity and disease severity, strategies of internal treatment and timing of surgical intervention, and further leading to protect the function of important organs and improve the disease prognosis.

[The relationship between fasting blood glucose level and thromboembolism events in patients with non-valvular atrial fibrillation]

Objective: To explore the relationship between fasting blood glucose level and thromboembolism events in patients with non-valvular atrial fibrillation (NVAF). Methods: This was an observational study based on data from a multicenter, prospective Chinese atrial fibrillation registry cohort, which included 18 703 consecutive patients with atrial fibrillation (AF) in 31 hospitals in Beijing from August 2011 to December 2018. Patients were divided into 5 groups according to status of comorbid diabetes and fasting glucose levels at admission: normal blood glucose (normal glucose group), pre-diabetes group, strict glycemic control group, average glycemic control group and poor glycemic control group. Patients were followed up by telephone or outpatient service every 6 months. The primary follow-up endpoint was thromboembolic events, including ischemic stroke and systemic embolism. The secondary endpoint was the composite endpoint of cardiovascular death and thromboembolic events. Kaplan-Meier survival analysis and multifactorial Cox regression were used to analyze the correlation between fasting glucose levels and endpoint events. Results: The age of 18 703 patients with NVAF was (63.8±12.0) years, and there were 11 503 (61.5%) male patients. There were 11 877 patients (63.5%) in normal blood glucose group, 2 023 patients (10.8%)in pre-diabetes group, 1 131 patients (6.0%) in strict glycemic control group, 811 patients in average glycemic control group and 2 861 patients(4.3%) in poor glycemic control group. Of the 4 803 diabetic patients, 1 131 patients (23.5%) achieved strict glycemic control, of whom 328 (29.0%) were hypoglycemic (fasting blood glucose level<4.4 mmol/L at admission). During a mean follow-up of (51±23) months (up to 82 months), thromboembolic events were reported in 984 patients (5.3%). The survival curve analysis of Kaplan Meier showed that the incidence rates of thromboembolic events in normal glucose group, pre-diabetes group, strict glycemic control group, average glycemic control group and poor glycemic control group were 1.10/100, 1.41/100, 2.09/100, 1.46/100 and 1.71/100 person-years, respectively (χ²=53.0, log-rank P<0.001). The incidence rates of composite endpoint events were 1.86/100, 2.17/100, 4.08/100, 2.58/100, 3.16/100 person-years (χ²=72.3, log-rank P<0.001). The incidence of thromboembolic events and composite endpoint events in the other four groups were higher than that in the normal blood glucose group (P<0.001). Multivariate Cox regression analysis showed that compared with normal glucose group, the risk of thromboembolism increased in pre-diabetes group(HR=1.23, 95%CI 1.00-1.51, P=0.049), strict glycemic control group(HR=1.32, 95%CI 1.06-1.65, P=0.013) and poor glycemic control group(HR=1.26, 95%CI 1.01-1.58, P=0.044). Conclusion: Both high or low fasting glucose may be an independent risk factor for thromboembolic events in patients with NVAF.

[Efficacy and safety of non-vitamin K antagonist oral anticoagulants in patients with atrial fibrillation and hypertrophic cardiomyopathy]

Objective: To evaluate the efficacy and safety of non-vitamin K antagonist oral anticoagulants (NOAC) in patients with atrial fibrillation (AF) and hypertrophic cardiomyopathy (HCM). Methods: This study was a prospective cohort study. The data of this study were based on the Chinese Atrial Fibrillation Registry (CAFR) Study, which was a prospective, multicenter registry study. The CAFR Study enrolled inpatients and outpatients with AF from 31 hospitals. Patients with AF and HCM were selected from August 2011 to December 2018. The patients were divided into NOAC-treated group and warfarin-treated group. General clinical data, echocardiographic results and treatment options were collected and compared between the two groups. Patients were followed up every 6 months; outcome events included effective endpoint events(thromboembolism)and safety endpoint events(major bleeding). The incidence of endpoint events in both groups was calculated and compared. Cox proportional hazards regression models and Kaplan-Meier survival analysis were performed to determine the association between NOAC use and endpoint events. Results: A total of 393 patients were included (average age: (60.5±11.8) years, 252 men (64.1%)). There were 133 (34.0%) patients in the NOAC-treated group and 260 (66.0%) patients in the warfarin-treated group. Compared with the warfarin-treated group, the patients in the NOAC-treated group had a higher proportion of paroxysmal AF, catheter ablation of AF, a lower proportion of hypertension, ischemic stroke/transient ischemic attack (TIA), lower heart rate, lower usage rate of angiotensin-converting enzyme inhibitors(ACEI)/angiotensin receptor blockers(ARB), β-blockers, non-dihydropyridine calcium channel blockers(NDH-CCB)(P<0.05). There were no significant differences on the echocardiographic results, including interventricular septal thickness, left ventricular posterior wall thickness, left ventricular end-diastolic diameter, left atrial diameter, left ventricular ejection fraction(P>0.05). After a follow-up of 42 (24, 60)months, the incidence rates of thromboembolism were 1.63 and 2.10 events per 100 person-years for NOAC-and warfarin-treated group, and those of major bleeding were 0.66 and 1.03 events per 100 person-years. Kaplan-Meier survival analysis showed survival rates free from endpoint events were similar between NOAC-treated group and warfarin-treated group(thromboembolism-free survival comparison, P=0.476; major bleeding-free survival comparison, P=0.855). Cox multivariate regression analysis revealed that there was no significant difference on risk of thromboembolism(HR=1.21, 95%CI: 0.42-3.50, P=0.720) and major bleeding(HR=1.50, 95%CI: 0.27-8.41, P=0.642) between NOAC-treated and warfarin-treated group. Conclusion: Patients with AF and HCM can be safely and effectively treated with NOAC.

[The value of ischemia modified albumin level for predicting in-hospital mortality in patients with acute aortic dissection]

Objective: To investigate the value of ischemia modified albumin (IMA) level for predicting in-hospital mortality in patients with acute aortic dissection (AAD). Methods: A total of 195 patients with AAD from the Department of Cardio-Vascular Surgery of Affiliated Hospital of North Sichuan Medical College from January 2017 to November 2019 were consecutively collected, with 126 males and 69 females. Based on whether they died during hospitalization or not, these patients were divided into 2 groups: survival group and mortality group. The baseline data and IMA levels at admission of the two groups were recorded. Univariate logistic regression analysis was used to identify the independent risk factors, and multivariate logistic regression analysis was further performed on variables with statistical significance in univariate analysis. The area under the receiver operating characteristic (ROC) curve was calculated to determine the value of IMA for predicting in-hospital mortality in patients with AAD. Results: Forty-two AAD patients died and 153 survived, and the mortality rate was 21.5%. Logistic regression analysis showed that age (OR=2.143,95%CI:1.247-4.826,P=0.011), Stanford type A (OR=6.751,95%CI:3.189-14.291,P<0.001), drug therapy (OR=5.133,95%CI:2.463-10.700,P<0.001), IMA level (OR=4.452,95%CI:2.231-8.953,P=0.004) were independent risk factors for in-hospital mortality in patients with AAD, however surgery was a protective factor (OR=0.195,95%CI:0.093-0.406,P<0.001). The area under the ROC curve for IMA level in predicting in-hospital mortality with AAD was 0.838 (95%CI: 0.774-0.901, P<0.001), with a cut-off value of 86.55 U/ml, and the sensitivity and specificity were 83.3% and 75.2%, respectively. Conclusions: IMA may serve as a simple risk assessment indicator for patients with AAD. IMA level at admission is an independent predictor of in-hospital mortality. For patients with higher IMA level, early surgical intervention should be performed.

[Retrospective analysis of infliximab in the treatment of Kawasaki disease]

Objective: To investigate the efficacy and safety of infliximab (IFX) therapy for children with Kawasaki disease. Methods: Sixty-eight children with Kawasaki disease who received IFX therapy in Children's Hospital of Fudan University from January 2014 to April 2021 were enrolled. The indications for IFX administration, changes in laboratory parameters before and after IFX administration, response rate, drug adverse events and complications and outcomes of coronary artery aneurysms (CAA) were retrospectively analyzed. Comparisons between groups were performed with unpaired Student t test or Mann-Whitney U test or chi-square test. Results: Among 68 children with Kawasaki disease, 52 (76%) were males and 16 (24%) were females. The age of onset was 2.1 (0.5, 3.8) years. IFX was administered to: (1) 35 children (51%) with persistent fever who did not respond to intravenous immunoglobulin (IVIG) or steroids, 28 of the 35 children (80%) developed CAA before IFX therapy; (2) 32 children (47%) with continuous progression of CAA; (3) 1 child with persistent arthritis. In all cases, IFX was administered as an additional treatment (the time from the onset of illness to IFX therapy was 21 (15, 30) days) which consisted of second line therapy in 20 (29%), third line therapy in 20 (29%), and fourth (or more) line therapy in 28 (41%). C-reactive protein (8 (4, 15) vs. 16 (8, 43) mg/L, Z=-3.38, P=0.001), serum amyloid protein A (17 (10, 42) vs. 88 (11, 327) mg/L, Z=-2.36, P=0.018) and the percentage of neutrophils (0.39±0.20 vs. 0.49±0.21, t=2.63, P=0.010) decreased significantly after IFX administration. Fourteen children (21%) did not respond to IFX and received additional therapies mainly including steroids and cyclophosphamide. There was no significant difference in gender, age at IFX administration, time from the onset of illness to IFX administration, the maximum coronary Z value before IFX administration, and the incidence of systemic aneurysms between IFX-sensitive group and IFX-resistant group (all P>0.05). Infections occurred in 11 cases (16%) after IFX administration, including respiratory tract, digestive tract, urinary tract, skin and oral infections. One case had Calmette-Guérin bacillus-related adverse reactions 2 months after IFX administration. All of these adverse events were cured successfully. One child died of CAA rupture, 6 children were lost to follow up, the remaining 61 children were followed up for 6 (4, 15) months. No CAA occurred in 7 children before and after IFX treatment, while CAA occurred in 54 children before IFX treatment. CAA regressed in 23 (43%) children at the last follow-up, and the diameter of coronary artery recovered to normal in 10 children. Conclusion: IFX is an effective and safe therapeutic choice for children with Kawasaki disease who are refractory to IVIG or steroids therapy or with continuous progression of CAA.

Association between Dietary Theobromine and Cognitive Function in a Representative American Population: A Cross-Sectional Study

BACKGROUND

Despite reports on neuroprotective effects of dietary theobromine intake, whether dietary theobromine has beneficial effects on cognitive function is unclear.

OBJECTIVES

To investigate the association between dietary theobromine and cognitive function.

DESIGN

A cross-sectional study.

SETTING

Data were collected from the 2011-2014 cycles of the National Health and Nutrition Examination Survey conducted by the Centers for Disease Control and Prevention of the USA.

PARTICIPANTS

A representative American population aged ≥60 years.

MEASUREMENTS

L-theobromine was treated as a log transform and dichotomous form (the highest quantile vs. others). Cognitive function was measured using four tests: Consortium to Establish a Registry for Alzheimer's Disease Word Learning tests, Consortium to Establish a Registry for Alzheimer's Disease delayed recall test, animal fluency test, and digit symbol substitution test. We conducted multiple regression analyses and subgroup analyses to study the association between theobromine and cognitive performance. Basic characteristics, lifestyle factors, disease history, and nutritional intake were adjusted for in these models.

RESULTS

A total of 2,845 participants were included in the study. The highest quantile of L-theobromine intake was positively associated with sores of delayed recall, animal fluency, and digit symbol substitution tests (β, 95% confidence interval, P: 0.11, -0.00-0.30, 0.049; 0.50, 0.02-0.99, 0.043; 1.55, 0.33-2.77, 0.015; respectively) in the fully adjusted model, but not with immediate recall score (β=0.13, 95% confidence interval -0.16-0.43, P=0.361). Subgroup analyses showed that L-theobromine intake was associated with cognitive performance in the highest quantile of caffeine intake.

CONCLUSIONS

Daily theobromine intake was associated with cognitive performance in a large nationally representative population. However, further research is needed to corroborate our findings.

Circulating Levels of Apelin, GDF-15 and Sarcopenia: Lack of Association in the MAPT Study

OBJECTIVES

Apelin and GDF-15 have been proposed as biomarkers of age-related sarcopenia but evidence in human models is scarce. This study aimed to explore the associations between blood apelin and GDF-15 with sarcopenia incidence and the evolution of sarcopenia components over two years in older adults >70 years.

DESIGN

Secondary longitudinal analysis of the Multidomain Alzheimer Preventive Trial.

PARTICIPANTS

Older adults (>70 years) attending primary care centers in France and Monaco.

SETTING

Community.

MEASUREMENTS

Serum Apelin (pg/mL) and plasma GDF-15 (pg/mL) were measured. Outcomes included sarcopenia defined by the European Working Group on Sarcopenia in Older People (EWGSOP) and its determinants (appendicular lean mass [ALM] evaluated through a Dual-energy X-ray Absorptiometry (DXA) scan, handgrip strength (HGS) and the 4-meter gait speed) measured over 2 years. Linear mixed models and logistic regression were used to explore the longitudinal associations.

RESULTS

We included 168 subjects from MAPT (median age=76y, IQR=73-79; 78% women). Serum apelin was not significantly associated with sarcopenia incidence (OR=1.001;95%CI=1.000,1.001;p-value>0.05 in full-adjusted models) nor with ALM (β=-5.8E-05;95%CI=-1.0E-04,2.12E-04;p>0.05), HGS (β=-1.1E-04;95%CI=-5.0E-04,2.8E-04;p>0.05), and GS (β=-5.1E-06;95%CI=-1.0E-05,2.0E-05;p>0.05) in fully adjusted models. Similarly, plasma GDF-15 was not associated with both the incidence of sarcopenia (OR=1.001,95%CI=1.000,1.002,p>0.05) and the evolution of its determinants ([ALM, β=2.1E-05;95%CI=-2.6E-04,3.03E-04;p>0.05], HGS [β=-5.9E-04;95%CI=-1.26E-03,8.1E-05; p>0.05] nor GS [β=-2.6E-06;95%CI=-3.0E-05, 2.3E-05;p>0.05]) in fully adjusted models.

CONCLUSIONS

Blood apelin and GDF-15 were not associated with sarcopenia incidence or with the evolution of sarcopenia components over a 2-year follow-up in community-dwelling older adults. Well-powered longitudinal studies are needed to confirm or refute our findings.

Improving early running-in wear characteristics for dental lithium disilicate glass-ceramics by ion-exchange

OBJECTIVES

This study examined the effects of Li⁺→Na⁺ ion-exchange on the early wear performance of dental lithium disilicate (LD) glass-ceramics.

METHODS

Specimens with different shapes were prepared using IPS e.max Press as the LD glass-ceramics. Ion-exchange was conducted by placing polished specimens in molten salt containing 25% NaNO₃ and 75% KNO₃ at 385 °C for 16 or 64 h. The ion-exchanged specimens were analyzed using X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDS) to investigate the structure and the elemental distribution. Thereafter, the specimens were tested for flexural strength, Vickers hardness, and fracture resistance. A portion of the specimens were tested with a pin-on-disk tribometer with 10 N for 40 × 10⁴ wear cycles in artificial saliva. Wear analysis of the specimens was performed using a 3D profilometer and analyzed with one-way analyses of variance and Tukey's post hoc pairwise comparisons. Worn surfaces were examined with scanning electron microscopy.

RESULTS

The LD glass-ceramics exhibited strong time-dependent wear behavior, with typical running-in and steady wear stages. Ion-exchange treatments at 385 °C for 16 h and 64 h both enhanced the mechanical properties and decreased the wear rates of early running-in wear stage. The early wear performance of specimens treated with ion-exchange for long time (64 h) was improved significantly.

CONCLUSION

A thicker ion-exchange layer may be obtained by processing ion-exchange for a long time. This protocol improves the early wear performance of the glass-ceramics effectively.

CLINICAL SIGNIFICANCE

Dental restorations may fail prematurely due to excessive wear. It is important to improve the early wear performance of the glass-ceramics. Ion-exchange has the potential to strengthen dental LD glass-ceramics. Understanding the effect of ion-exchange on the early wear performance of glass-ceramics provides insight improving the early wear performance of these restorations.

[A cross-sectional study of periodontal pathogens in saliva of edentulous patients]

Objective: To investigate the prevalence of five specific periodontal pathogens in the saliva of edentulous patients and to compare the differences in the saliva of dentulous individuals with various periodontal conditions. Methods: All the subjects were patients who received regular care at the Beijing Hypertension Prevention and Management Institute. Twenty-seven edentulous patients (edentulous group) were included. According to age (age gap≤5 years), gender, smoking status, diabetes status and hypertension status, each edentulous patient was paired with dentulous individuals suffering from various severity of periodontitis in the same cohort. Then, we selected 3 groups of patients (n=27 in each group) with no or mild periodontitis (mild group), moderate periodontitis (moderate group) and severe periodontitis (severe group). The whole unstimulated saliva was collected before the periodontal examination. Questionnaire survey and periodontal parameters, including plaque index (PLI), probing depth (PD), bleeding index (BI) and clinical attachment loss (CAL), were examined at mesial-buccal and distal-lingual sites of each tooth respectively. DNA was extracted from each sample of the salivary deposition. Porphyromonas gingivalis (Pg), Tannerella forsythia (Tf), Treponema denticola (Td), Campylobacter rectus (Cr) and Prevotella nigrescens (Pn) were detected by using PCR method based on 16SrRNA. The prevalence and quantity of the pathogens under various severity of periodontitis were compared. Results: One or more periodontal pathogens could be detected from the 78% (21/27) of the salivary samples in edentulous group. Thereinto, the prevalences of the five periodontal pathogens were ranked as (from high to low): Cr [56% (15/27)], Tf [44% (12/27)], Pn [26% (7/27)], Pg [22% (6/27)] and Td [11% (3/27)]. All five pathogens' prevalences and Pg, Tf, Td and Pn's quantities showed statistical differences among the four groups. The numbers of detected bacterial species in the mild, moderate and severe groups were significantly higher than that in the edentulous group (P<0.01). Furthermore, the prevalences of the red complex in three dentulous groups [96% (26/27) in each group] were significantly higher than the edentulous group [48% (13/27)] (P<0.05). The proportions of the red complex among all five pathogens (83%) in moderate and severe groups were significantly higher than that in the edentulous group (37%) (P<0.01). Conclusions: All five periodontal pathogens could be detected in most of the saliva samples from edentulous individuals. Nevertheless, the prevalence and quantity were lower than dentulous individuals.

Effect of Li+/Na+ exchange on mechanical behavior and biological activity of lithium disilicate glass-ceramic

Lithium disilicate (LD) glass-ceramics with a stoichiometric composition were ion-exchanged in pure NaNO₃ or mixed NaNO₃ + KNO₃ molten salt baths below the glass transition temperature (T_g). The microstructures, surface morphologies, mechanical properties and bioactivities of the ion-exchanged glass-ceramics were studied in detail. It was found that the strength and toughness of LD glass-ceramic could be enhanced from 175 MPa to 0.96 MPa m^1/2 before ion-exchange to 546 MPa and 4.31 MPa m^1/2 respectively under a lowered ion-exchange temperature because the less stress relaxation. In addition, a gradient of Na⁺ rich layer in the surface of glass-ceramic was induced by Li⁺/Na⁺ exchange, which could be beneficial to the formation of HA (Hydroxyapatite) with nano-size porous after soaking in SBF (Simulated Body Fluid) solution and exhibited better bioactivity compared with the original LD glass-ceramic. The results might provide a reference for the strengthening and biological activation of LD glass-ceramics in bone restoration applications.

Significance of cutting plane in liquid metal embrittlement severity quantification

The automotive industry is turning to advanced high strength steels (AHSS) to reduce vehicle weight and increase fuel efficiency. However, the zinc coating on AHSS can cause liquid metal embrittlement (LME) cracking during resistance spot welding. To understand the problem, the severity of the cracking must be measured. Typically, this is done from the weld cross-section. Currently, there is no standard procedure to determine which plane through the weld must be examined to gauge cracking severity, leading to a variety of practices for choosing a cutting plane. This work compares the magnitude and variability of LME severity measured from the plane of exhibiting the most severe surface cracking to arbitrarily chosen planes. The plane exhibiting the most severe cracks had more and longer cracks on the cross-section than the arbitrarily chosen plane, resulting in a higher crack severity measurement. This higher absolute measurement increased the relative accuracy of the examination, allowing for fewer welds to be examined to precisely determine the effect of LME mitigation methods on cracking severity, how welding parameters affect LME cracking severity and the predicted LME affected strength of a particular weld.

Time-resolved relaxation and fragmentation of polycyclic aromatic hydrocarbons investigated in the ultrafast XUV-IR regime

Polycyclic aromatic hydrocarbons (PAHs) play an important role in interstellar chemistry and are subject to high energy photons that can induce excitation, ionization, and fragmentation. Previous studies have demonstrated electronic relaxation of parent PAH monocations over 10-100 femtoseconds as a result of beyond-Born-Oppenheimer coupling between the electronic and nuclear dynamics. Here, we investigate three PAH molecules: fluorene, phenanthrene, and pyrene, using ultrafast XUV and IR laser pulses. Simultaneous measurements of the ion yields, ion momenta, and electron momenta as a function of laser pulse delay allow a detailed insight into the various molecular processes. We report relaxation times for the electronically excited PAH^*, PAH^+* and PAH^2+* states, and show the time-dependent conversion between fragmentation pathways. Additionally, using recoil-frame covariance analysis between ion images, we demonstrate that the dissociation of the PAH²⁺ ions favors reaction pathways involving two-body breakup and/or loss of neutral fragments totaling an even number of carbon atoms.

Carbapenem-resistant Enterobacterales colonization and subsequent infection in a neonatal intensive care unit in Shanghai, China

Background

Colonization has been reported to play an important role in carbapenem-resistant Enterobacterales (CRE) infection; however, the extent to which carriers develop clinical CRE infection and related risk factors in neonatal intensive care unit (NICU) patients is unclear.

Aim

To investigate the frequency of CRE colonization and its contribution to infections in NICU patients.

Methods

CRE colonization screening and CRE infection surveillance were performed in the NICU in 2017 and 2018.

Findings

Among 1230 unique NICU patients who were screened for CRE colonization, 144 patients tested positive (11.7%, 144/1230), with 9.2% (110/1197) in the intestinal tract, which was higher than that in the upper respiratory tract (6.6%, 62/945) (P=0.026). Gestational age, low birth weight and prolonged hospitalization were risk factors for CRE colonization (all P<0.001). Diversilab homology monitoring found an overall 17.4% (25/144) risk of infection among patients colonized with CRE. For carbapenem-resistant Klebsiella pneumoniae (CR-KP) and carbapenem-resistant Escherichia coli (CR-ECO), the risks were 19.1% (21/110) and 13.8% (4/29), respectively. The independent risk factors for CR-KP clinical infection among CR-KP carriers were receiving mechanical ventilation (odds ratio (OR), 10.177; 95% confidence interval (CI), 2.667–38.830; P=0.013), a high level of neonatal nutritional risk assessment (OR, 0.251; 95% CI, 0.072–0.881; P=0.031) and a high neonatal acute physiology II (SNAP-II) score (OR, 0.256; 95% CI, 0.882–1.034; P=0.025).

Conclusions

The colonization of CRE may increase the incidence of corresponding CRE infection in NICU patients. Receiving mechanical ventilation, malnutrition and critical conditions with high SNAP-II scores were independent risk factors for subsequent CR-KP clinical infection.

Impact of nodular calcification on the outcomes of patients with acute coronary syndrome (ACS) treated with primary percutaneous coronary intervention (PCI)

Background

Calcified plaque is thought to adversely impact clinical outcomes but the impact of nodular calcification after percutaneous coronary intervention (PCI) in patients with acute coronary syndrome (ACS) remains unclear.

Purpose

This study sought to explore the impact of nodular calcification on the outcomes of patients undergoing percutaneous coronary intervention for acute coronary syndromes.

Methods

Five-hundred culprit plaque with calcification were analysed from 495 ACS patients in whom PCI was performed. Plaques were divided into nodular calcification group (n=238) and non-nodular calcification group (n=262). Calcification is defined as an area with low back-scattering signal and a sharp border. Nodular calcification was defined as a protruding mass with an irregular surface, high backscattering, and signal attenuation on optical coherence tomography (OCT).

Results

Patients with nodular calcification were older (p&lt;0.001) and had lower left ventricular ejection fraction (p=0.006) compared to patients with non-nodular calcification. Lesion length (31 (25.2, 38.5) vs. 29 (22.8, 34.1), p&lt;0.001) was longer in plaques with nodular calcification. A higher prevalence of superficial calcium (p&lt;0.001) was observed in plaques with nodular calcification compared with non-nodular calcification group. Minimum stent area (MSA) (5.0 (3.9, 6.3) vs. 5.4 (4.2, 6.7), p=0.011) and stent expansion (70 (62.7, 81.8) vs. 75 (65.2, 86.6), p=0.004) were significantly smaller in the nodular calcification group than in the non-nodular calcification group. Independent predictors of nodular calcification were age (p&lt;0.001) lesion length (p=0.002) and calcium depth (p&lt;0.001).

Conclusion

This study demonstrated that the presence of nodular calcification is associated with unfavourable outcomes with smaller minimum stent area and higher incidence of stent under expansion in patients with ACS treated with primary PCI.

Funding Acknowledgement

Type of funding sources: None.

Frequency and predictors of thin-cap fibroatheroma progression: a comprehensive and dynamic in-vivo OCT study

Purpose

To assess the evolution of thin-cap fibroatheroma (TCFA) and to explore predictors for its progression by using optical coherence tomography (OCT) in patients with acute coronary syndrome (ACS).

Methods

We enrolled ACS patients with non-culprit TCFA at baseline and corresponding OCT images at follow-up of 9 to 15 months. Clinical, angiographic and OCT data were collected and analyzed according to established methods. TCFA was defined as a lipid plaque with maximum lipid arc &gt;90° and fibrous cap thickness &lt;65μm. Considering the resolution of OCT, the regression of TCFA was defined as an increase of fibrous cap thickness &gt;10μm. Inversely, TCFA progression was defined as a decrease, constant or ≤10μm increase of fibrous cap thickness.

Results

41 patients with 55 non-culprit TCFAs were taken into final analysis. 17 patients (41.5%) had patient-level progression and 22 TCFAs (40.0%) progressed at plaque-level with a median follow-up duration of 371 days. 11 (20.0%) of the 55 TCFAs happened subclinical rupture at follow-up, including 10 with the formation a new layer and 1 without the detection of the new layer. Besides, another patient suffered re-myocardial infarction because of the rupture of TCFA induced acute thrombosis and lumen occlusion during follow-up. The baseline clinical and angiographic characteristics were similar between the two cohorts. The progression group had a significantly higher prevalence of macrophage infiltration and vasa vasorum at baseline than the non-progression group (Figure 1). Multivariate analysis identified macrophage infiltration (odds ratio [OR]: 5.30; 95% confidence interval [CI]: 1.01 to 27.91; p=0.049]) as the independent predictor of TCFA progression. When it came to the evolution of lesion morphology and lipid components, the progression cohort had a higher percent change of lumen stenosis and lipid length (Figure 2).

Conclusions

About 40% of non-culprit TCFAs in ACS patients progressed in fibrous cap thickness at a median interval of 1 year. Macrophage infiltration was the independent predictor of non-culprit TCFA progression. The progression of fibrous cap thickness was usually accompanied with an aggressive evolution of other lesion characteristics.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): the National Key R&D Program of China Baseline OCT characteristicsPercent change of lesion morphology

Prevalence, predictors, and clinical prognosis of macrophage infiltrates in patients with ST-segment elevation myocardial infarction caused by plaque erosion as assessed by OCT

Background

Autopsy series showed that one of most common plaque phenotypes underlying coronary thrombi was plaque erosion. Identification of erosion may permit a less invasive management. Chronic inflammation is a common process in atherosclerosis. The severity of plaque inflammation can be assessed by optical coherence tomography (OCT) defined macrophages density. The impact of macrophage infiltrates (MØI) in ST-segment elevation myocardial infarction (STEMI) patients caused by plaque erosion was still unknown.

Purpose

The aim of this study was to evaluate plaque morphology and clinical prognosis associated with MØI as assessed by optical coherence tomography in STEMI patients caused by plaque erosion.

Methods

From October 2014 to December 2017, 1561 STEMI with OCT imaging before percutaneous coronary intervention were enrolled in this study. Finally, 312 STEMI patients caused by plaque erosion were split into two group according to the presence of MØI in culprit eroded plaques.

Results

163 (52.2%) STEMI patients presented plaque erosion with MØI, whereas 149 (47.8%) patients had no evidence of MØI. MØI were more frequency appeared in older patients (p=0.015). The severity and vulnerability of culprit lesions were higher in patients with MØI characterized by more aggressive and vulnerable features. Patients with MØI had worse long-term prognosis, compared with patient without MØI, mainly driven by a higher rate of target lesion revascularization (p=0.046), especially in STEMI patients presented plaque erosion with intensive antiplatelet therapy (p=0.035).

Conclusions

In the present study, we demonstrated that macrophage infiltrates at the site of erode plaques were associated with severity and vulnerability of culprit lesions. The long-term prognosis in patients with MØI were poorer especially in patients without stent implantation.

Funding Acknowledgement

Type of funding sources: None. Study flow chartPredictors of plaque erosion with MØI