Test of a multi-gigawatt, 800 ns high power microwave driver based on Marx generator and metal-oxide varistors

High power microwave (HPM) sources usually require a well-defined rectangular pulse waveform, which is especially true for the case of long pulse (>100 ns), stable, and high efficiency operation. Most long pulse HPM drivers are realized with pulse forming networks. This paper presents a long pulse driver composed of a conventional Marx generator and metal-oxide varistors (MOVs), utilizing the MOV's nonlinear V-I characteristic. This method is easy to implement, and it has an additional benefit that the voltage can be stabilized even if the load's impedance changes slightly. A low inductance zig-zag folding structure of the MOV is designed to decrease its size and self-inductance. An LC filter is used to reduce the energy loss in the MOV. In the experiment, a 400 kV, 800 ns long pulse is achieved at a foil-less electron diode, and longer than 300 ns HPM generation is obtained.

Data-driven nonlinear model reduction to spectral submanifolds in mechanical systems

While data-driven model reduction techniques are well-established for linearizable mechanical systems, general approaches to reducing nonlinearizable systems with multiple coexisting steady states have been unavailable. In this paper, we review such a data-driven nonlinear model reduction methodology based on spectral submanifolds. As input, this approach takes observations of unforced nonlinear oscillations to construct normal forms of the dynamics reduced to very low-dimensional invariant manifolds. These normal forms capture amplitude-dependent properties and are accurate enough to provide predictions for nonlinearizable system response under the additions of external forcing. We illustrate these results on examples from structural vibrations, featuring both synthetic and experimental data. This article is part of the theme issue 'Data-driven prediction in dynamical systems'.

Physical activity patterns, genetic susceptibility, and risk of hip/knee osteoarthritis: a prospective cohort study based on the UK Biobank

OBJECTIVES

The effect of physical activity on hip/knee osteoarthritis (OA) and how it varies by genetic susceptibility to OA remains inconclusive.

METHODS

In a cohort study of UK Biobank, 436,166 OA-free participants were recruited in 2006-2010 and followed for knee/hip OA until the end of 2020. 28 physical activity-related items were collected at baseline. Cox regression was used to estimate associations between physical activity behaviors, as well as major activity patterns (i.e., significant principal components[PCs] identified by principal component analysis), and risk of OA, adjusting for multiple confounders. We further stratified the analyses by polygenic risk score (PRS) for OA to examine the impact of genetic susceptibility to OA on the studied association.

RESULTS

During a mean follow-up of 11.15 years, 13,227 hip and 21,119 knee OA cases were identified. 19, out of 28, studied items showed associations with increased OA risk. Compared with low adherence group(<1^st tertile of PC score for each pattern), individuals with high adherence to five identified patterns were associated with increased risk of OA. The moderate adherence to "strenuous sports"(HR = 0.93, 95%CI: 0.89-0.97) and "walking for pleasure"(HR = 0.93, 95%CI: 0.89-0.98) patterns was associated with reduced OA. Similar risk patterns were obtained in the stratified analysis by PRS levels for OA.

CONCLUSION

High intensity of most activity patterns were associated with increased OA. However, a protective effect was suggested for moderate adherence to patterns of "strenuous sports" and "walking for pleasure" that consistent across different genetic susceptibilities, underscoring the potential benefits of moderate-intensity physical activity on OA.

Transcriptome dissection of candidate genes associated with lentil seed quality traits

Lentils provide a rich plant-based protein source and staple food in many parts of the world. Despite numerous nutritional benefits, lentil seeds also possess undesirable elements, such as anti-nutritional factors. Understanding the genetic networks of seed metabolism is of great importance for improving the seed nutritional profile. We applied RNA sequencing analysis to survey the transcriptome of developing lentil seeds and compared this with that of the pod shells and leaves. In total, we identified 2622 genes differentially expressed among the tissues examined. Genes preferentially expressed in seeds were enriched in the Gene Ontology (GO) terms associated with development, nitrogen and carbon (N/C) metabolism and lipid synthesis. We further categorized seed preferentially expressed genes based on their involvement in storage protein production, starch accumulation, lipid and suberin metabolism, phytate, saponin and phenylpropanoid biosynthesis. The availability of transcript profile datasets on lentil seed metabolism and a roadmap of candidate genes presented here will be of great value for breeding strategies towards further improvement of lentil seed quality traits.

<em>Gardenia jasminoides</em> J. Ellis extract GJ-4 attenuates hyperlipidemic vascular dementia in rats via regulating PPAR-γ-mediated microglial polarization

Background

GJ-4 is extracted from Gardenia jasminoides J. Ellis (Fructus Gardenia) with crocin composition and has been demonstrated to improve memory deficits in several dementia models in our previous studies.

Objective

This study aimed to evaluate the effects of GJ-4 on hyperlipidemic vascular dementia (VD) and explore the underlying mechanisms.

Design

In the current study, we employed a chronic hyperlipidemic VD rat model by permanent bilateral common carotid arteries occlusion (2-VO) based on high-fat diet (HFD), which is an ideal model to mimic the clinical pathogenesis of human VD.

Results

Our results showed that GJ-4 could significantly reduce serum lipids level and improve cerebral blood flow in hyperlipidemic VD rats. Additionally, treatment with GJ-4 remarkedly ameliorated memory impairment and alleviated neuronal injury. Mechanistic investigation revealed that the neuroprotective effects of GJ-4 might be attributed to the inhibition of microglia-mediated neuro-inflammation via regulating the M1/M2 polarization. Our data further illustrated that GJ-4 could regulate the phenotype of microglia through activating the peroxisome proliferator-activated receptor-γ (PPAR-γ) and subsequently inhibited nuclear factor-κB (NF-κB) nuclear translocation and increased CCAAT/enhancer-binding protein β (C/EBPβ) expression.

Conclusion

Our results implied that GJ-4 might be a promising drug to improve VD through the regulation of microglial M1/M2 polarization and the subsequent inhibition of neuro-inflammation.

Luminescence-enhanced conjugated polymer dots through thermal treatment for cell imaging

Conjugated polymer dots (Pdots) are often used as excellent fluorescent probes in the biomedical field. In the process of preparing Pdots, the rapid change of the solvent polarity will result in a messy and defective stacking of the polymer chains in the particle, and these stacking defects of the polymer chains may weaken its luminescence properties. Here, we try to optimize the stacking of the conjugated polymer chains by the thermal annealing treatment. After the low temperature thermal treatment, the fluorescence intensity of Pdots can be enhanced by about 11%-29%, and Pdots maintain their original stability and biosafety. We used transmission electron microscopy (TEM) and single particle fluorescence imaging to reveal the possible mechanism of the chain stacking optimization process, that is, the thermal annealing process of Pdots is the competition between internal chain rearrangement in the particle and particle aggregation. The luminescence-enhanced Pdots exhibit good cellular imaging performance. These results prove that it is feasible to extend the thermal annealing treatment from planar polymer devices to polymer nanoparticles. It provides the possibility to realize stable and complex biological imaging applications using Pdots with a simple molecular structure, and a mature improvement scheme for the mass preparation of Pdots.

[Preconception reproductive health and birth outcome cohort in Chongqing: the cohort profile]

Birth cohort is an important platform to study the effect of early-life exposure on health outcome, but large cohorts to investigate the effect of preconception exposure, especially paternal exposure, on reproductive health and birth outcome are limited. The Preconception Reproductive Health and Birth Outcome Cohort (PREBIC) is a prospective birth cohort study which pays equal attention to the contribution of environmental, psychological, behavioral as well as other factors to reproductive health and adverse birth outcomes in both men and women in Chongqing, China. PREBIC started in 2019 and plans to recruit 20 800 reproductive-age couples with child-bearing willingness. Followed up was conducted to understand the conception status of the women within two years. Women in pregnancy would be visited at first, second, third trimesters and after delivery. The offspring would be monitored until 2 years old to understand the incidences of preterm birth, low birth weight, birth defects, neurodevelopmental disorders and other outcomes. Related information and biospecimen collections (including semen, peripheral blood, urine, placenta, umbilical cord, cord blood and oral swab) were scheduled in each period. By January 2022, PREBIC had recruited 8 698 participants from all 38 districts in Chongqing. The goal of PREBIC is to establish one of the largest prospective preconception birth cohorts covering both men and women, which might provide a unique insight to understand the effects of the full reproductive cycle on reproductive health and adverse outcomes, with especial emphasis on preconception exposures.

Bone microarchitecture impairment in prolactinoma patients assessed by HR-pQCT

PURPOSE

Prolactinoma may reduce bone mineral density (BMD) and increase fracture risk, but its influence on bone microarchitecture remains to be elucidated. The purpose of this study is to evaluate bone microarchitecture parameters by high-resolution peripheral quantitative computed tomography (HR-pQCT) in prolactinoma patients.

METHODS

31 prolactinoma patients and 62 age- and sex-matched healthy controls in our center were included, and HR-pQCT was used to evaluate their bone microarchitecture at the radius and tibia. Z-scores for bone microarchitecture parameters were calculated based on previously published reference.

RESULTS

After adjusting for height and weight, prolactinoma patients had lower trabecular (- 0.011 mm, p = 0.005) and cortical thickness (- 0.116 mm, p = 0.008) and cortical area (- 6.0 mm2, p = 0.013) at radius, as well as lower trabecular (- 0.014 mm, p = 0.008) and cortical (- 0.122 mm, p = 0.022) thickness at tibia compared with the controls. Patients with higher prolactin level had more severe bone microarchitecture impairments. After adjusting for prolactin level and age, male patients had lower trabecular volumetric BMD (vBMD), trabecular number, trabecular thickness, and cortical porosity at radius, as well as lower trabecular vBMD, trabecular bone volume fraction, trabecular number, and cortical area, and higher trabecular separation at tibia compared with female patients. Z-score for radius vBMD was correlated with Z-score for areal BMD (aBMD) at lumbar and femoral neck, while Z-score for tibia vBMD was correlated with Z-score for lumbar aBMD, and some patients with vBMD Z-score below - 2.0 had aBMD Z-score within normal range.

CONCLUSION

Peripheral bone microarchitecture was impaired in prolactinoma patients, especially in patients with higher prolactin level. We compared the bone microarchitecture of prolactinoma patients and healthy controls by high-resolution peripheral quantitative computed tomography (HR-pQCT), and found that many bone microarchitecture parameters were impaired among prolactinoma patients. Such impairment was more prominent among patients with higher prolactin level.

A portrait of the Higgs boson by the CMS experiment ten years after the discovery

In July 2012, the ATLAS and CMS collaborations at the CERN Large Hadron Collider announced the observation of a Higgs boson at a mass of around 125 gigaelectronvolts. Ten years later, and with the data corresponding to the production of a 30-times larger number of Higgs bosons, we have learnt much more about the properties of the Higgs boson. The CMS experiment has observed the Higgs boson in numerous fermionic and bosonic decay channels, established its spin-parity quantum numbers, determined its mass and measured its production cross-sections in various modes. Here the CMS Collaboration reports the most up-to-date combination of results on the properties of the Higgs boson, including the most stringent limit on the cross-section for the production of a pair of Higgs bosons, on the basis of data from proton-proton collisions at a centre-of-mass energy of 13 teraelectronvolts. Within the uncertainties, all these observations are compatible with the predictions of the standard model of elementary particle physics. Much evidence points to the fact that the standard model is a low-energy approximation of a more comprehensive theory. Several of the standard model issues originate in the sector of Higgs boson physics. An order of magnitude larger number of Higgs bosons, expected to be examined over the next 15 years, will help deepen our understanding of this crucial sector.

P-355 Association between high serum uric acid level and adverse reproductive outcomes in infertile women with polycystic ovary syndrome

Study question

Does high serum uric acid (SUA) level affect the reproductive outcomes in women with polycystic ovary syndrome (PCOS) undergoing in-vitro fertilization (IVF)?

Summary answer

Elevated SUA is associated with decreased live birth rate, biochemical pregnancy rate and clinical pregnancy rate, and increased miscarriage rate in women with PCOS.

What is known already

SUA levelsand the prevalence of hyperuricemia (25.48%) are both significantly higher in women with PCOS than in women without PCOS (8.74%). SUA levels also can be used as a predictor of pregnancy complications (gestational diabetes mellitus and hypertensive disorders of pregnancy) and adverse foetal outcomes (preterm birth and low birth weight).

Study design, size, duration

This retrospective cohort study was conducted ininfertile women with PCOS between September 2012 and December 2019.

Participants/materials, setting, methods

A total of 1,032 infertile PCOS women undergoing their first IVF/ICSI cycle were observed. Data of reproductive outcomes including live birth rate, biochemical pregnancy rate, clinical pregnancy rate, and miscarriage rate were analyzed according to the quartile groups of SUA levels.

Main results and the role of chance

In quartiles of SUA levels, there was a significant decreasing trend in live birth rate from the lowest quartile (Q1: 34.5%) to the highest (Q4: 19.2%) (Pfor trend &lt;0.001). Notably, the miscarriage rate in Q4 was significantly higher than that in the other 3 quartiles (all P values &lt; 0.05). From Q1 to Q4, the incidence of miscarriage dramatically increased from 15.5% to 31.0% (Pfor trend &lt;0.05). In addition, the biochemical pregnancy rate and clinical pregnancy rate decreased significantly from the lowest quartile to the highest (Pfor trend &lt;0.05). With the first quartile of uric acid as the reference group, the logistic regression analysis showed that in both unadjusted and adjusted models, elevated SUA level was associated with significantly lower probabilities of live birth, biochemical pregnancy, and clinical pregnancy, and a higher risk of miscarriage in a linear fashion (all Pfor trend&lt; 0.05).

Limitations, reasons for caution

This study is limited by its retrospective design. It was difficult to ensure consistency in clinical practice among the physicians.

Wider implications of the findings

Our study suggeststhat clinical physicians need to pay close attention to PCOS women with high SUA levelsbefore IVF treatment. Prospective studies to determine an appropriate range of lower-SUA levels prior to treatment is necessary to support our findings.

Trial registration number

not applicable

[Protective effect of excretory-secretory proteins from Trichinella spiralis muscle larvae against myocardial injury in septic mice]

OBJECTIVE

To evaluate the protective effect of excretory-secretory proteins from Trichinella spiralis muscle larvae (Ts-MES) on sepsis-induced myocardial injury in mice.

METHODS

Eighty male BALB/C mice were randomized equally into sham-operated group, myocardial injury group, Ts-MES treatment group and dexamethasone treatment group. In the latter 3 groups, sepsis-induced myocardial injury models were established by cecal ligation and perforation; the sham operation was performed by exposure of the cecum without ligation or perforation. Forty minutes after the operation, the mice were given intraperitoneal injections 150 μL PBS, 20 μg TS-MES or 0.3 mg/kg dexamethasone as indicated. At 12 h after the operation, 6 mice were randomly selected from each group for echocardiography, and 8 mice were used for observing the survival rate within 72 h. The remaining 6 mice were examined for myocardial pathologies with HE staining and serum levels of NTPro-BNP and cTnI with ELISA; the expressions of TNF-α, IL-6, IL-10 and TGF-β in the serum and myocardial tissue were detected using ELISA and qRT-PCR.

RESULTS

Compared with the sham-operated mice, the septic mice showed significantly decreased cardiac function indexes (LVEF, LVFS, and E/A) with lowered survival rate within 72 h (P < 0.001) and significantly higher myocardial injury scores and serum levels of NTPro-BNP and cTnI (P < 0.01). Treatment with TS-MES significantly improved the cardiac function and 72-h survival rate (P < 0.05) and lowered the myocardial injury scores and serum levels of NTPro-BNP and cTnI (P < 0.05) in the septic mice. Compared with the sham-operated mice, the septic mice had obviously increased TNF-α and IL-6 levels in the serum and myocardial tissue (P < 0.001), which were significantly lowered by treatment with TS-MES (P < 0.05). TS-MES and dexamethasone both increased the levels of IL-10 and TGF-β in the septic mice, but the changes were significant only in TS-MES-treated mice (P < 0.05).

CONCLUSION

Ts-MES are capable of protecting against myocardial injury in septic mice by reducing the production of pro-inflammatory cytokines and enhancing the levels of regulatory cytokines.

[Correlation of nonalcoholic fatty liver disease at different ages of onset with new-onset diabetes mellitus]

Objective: To investigate the effect of nonalcoholic fatty liver (NAFLD) at different ages of onset with new-onset diabetes mellitus. Methods: The cohort study was conducted in Kailuan Group Company. Active and retired employees were used as study subjects. After excluding NAFLD diagnosed at baseline, previous history of diabetes mellitus, and long-term history of heavy drinking, 43 317 cases were finally included in the cohort. The study subjects were divided into five groups according to age (<30 years old as group 1, 30-39 years old as group 2, 40-49 years as group 3, 50-59 years as group 4, and ≥60 years as group 5). The prevalence and incidence density of new-onset diabetes mellitus were compared between each NAFLD and non-fatty liver population group. The effect of NAFLD at different ages of onset with new-onset diabetes mellitus was analyzed by multivariate Cox's regression model. Statistical analysis was performed using one-way ANOVA, χ² test or multivariate Cox's regression model. Results: The prevalence and incidence density of diabetes mellitus was significantly higher in NAFLD than non-fatty liver population. The prevalence of diabetes mellitus in different age groups were 6.45%, 6.88%, 9.94%, 10.83%, and 11.43%, respectively. The incidence density of each age group was 9.21/1 000 person-years, 11.10/1 000 person-years, 16.17/1 000 person-years, 18.72/1 000 person-years, and 22.13/1 000 person-years, and the differences were statistically significant (P<0.001). Multivariate Cox's regression model result showed that after adjusting for confounding factors such as gender, systolic blood pressure, and fasting blood glucose, the HRs (95%CI) for diabetes mellitus in each age group were 3.992 (1.897, 8.400), 2.321 (1.589, 3.392), 2.041 (1.667, 2.500), 2.007 (1.708, 2.360), and 1.908 (1.570, 2.319), and the differences were statistically significant (P＜0.001). Conclusion: Newly developed NAFLD is an independent risk factor for new-onset diabetes mellitus. Early exposure to NAFLD increases the risk of developing diabetes mellitus compared with the same age group. Younger age of onset of NAFLD should be given attention and active treatment.

[Effectiveness of statin treatment strategies for primary prevention of cardiovascular diseases in a community-based Chinese population: A decision-analytic Markov model]

OBJECTIVE

To evaluate the effectiveness of statin treatment strategies based on risk assessment for the primary prevention of cardiovascular diseases by the Western guidelines in a community-based Chinese population from economically developed areas using data from the Chinese electronic health records research in Yinzhou (CHERRY) study.

METHODS

A Markov model was used to evaluate the effectiveness of the following statin treatment strategies, including: (1) usual care without cardiovascular risk assessment(Strategy 0); (2) using the World Health Organization (WHO) non-laboratory-based risk charts with statin treatment for high-risk group (risk ≥ 20%) (Strategy 1); (3) using the WHO laboratory-based risk charts with statin treatment for high-risk group (risk ≥ 20%) (Strategy 2); and (4) using the Prediction for Atherosclerotic cardiovascular disease Risk in China (China-PAR) model with statin treatment for high-risk group (risk ≥ 10%, Strategy 3). According to the guidelines, adults in the medium-risk group received lifestyle intervention, and adults in the high-risk group received life-style intervention and statin treatment under these strategies. The Markov model simulated different strategies for ten years (cycles) using parameters from the CHERRY study, published data, meta-analyses and systematic reviews for Chinese. The number of cardiovascular events or deaths, as well as the number need to treat (NNT) with statin per cardiovascular event or death prevented, were calculated to compare the effectiveness of different strategies. One-way sensitivity analysis on the uncertainty of incidence rate of cardiovascular diseases, and probabilistic sensitivity analysis on the uncertainty of hazard ratios of interventions were conducted.

RESULTS

Totally 225 811 Chinese adults aged 40-79 years without cardiovascular diseases at baseline were enrolled. In contrast to the usual care without risk assessment-based statin treatment strategy, Strategy 1 using the WHO non-laboratory-based risk charts could prevent 3 482 [95% uncertainty interval (UI): 2 110-4 661] cardiovascular events, Strategy 2 using the WHO laboratory-based risk charts could prevent 3 685 (95%UI: 2 255-4 912) events, and Strategy 3 using the China-PAR model could prevent 3 895 (95%UI: 2 396-5 181) events. NNTs with statin per cardiovascular event prevented were 22 (95%UI: 14-54), 21 (95%UI: 14-52), and 27 (95%UI: 17-67), respectively. Strategy 3 could prevent more cardiovascular events, while Strategies 1 and 2 required fewer numbers need to treat with statin per cardiovascular event prevented. The results were consistent in the sensitivity analyses.

CONCLUSION

The statin treatment strategies based on risk assessment for the primary prevention of cardiovascular diseases recommended by the Western guidelines could achieve substantive health benefits in adults from developed areas of China. Using the China-PAR model for cardiovascular risk assessment could prevent more cardiovascular diseases while using the WHO risk charts seems more efficient.

[Study of cytogenetics and molecular biology in typical and atypical immunophenotypic chronic lymphocytic leukemia]

Objective: To analyze the differences in immunophenotype, cytogenetics, and molecular biology between typical and atypical immunophenotype chronic lymphocytic leukemia (CLL) , and explore the correlation of cytogenetic anomalies with gene mutations. Methods: This study included 488 patients diagnosed in the First Affiliated Hospital of Nanjing Medical University between November 2014 and May 2021. Of these, 382 patients scored 4-5 points, which was typical CLL (tCLL) , and 106 scored 3 points, which was atypical CLL (aCLL) as per the Royal Marsden Hospital Immunomarker Integral System. Peripheral blood cells were collected for immunophenotype by multiparameter flow cytometry in 488 patients, fluorescence in situ hybridization (FISH) was employed to detect cytogenetic anomalies in 359 patients, and gene mutations were detected by next-generation sequencing (NGS) in 330 patients. Results: The positive rates of CD10, CD22, CD49d, CD81, and FMC7 were significantly higher in the aCLL compared with the tCLL group (P=0.020, P<0.001, P<0.001, P=0.027, and P<0.001, respectively) , while the positive rates of CD5, CD23, CD148, and CD200 were lower in the former compared to the latter (P<0.001, P=0.017, P=0.041, and P<0.001, respectively) . aCLL exhibited a higher frequency of trisomy 12 and lower frequency of del (13q14) compared to the tCLL group (P<0.001 and P<0.001, respectively) . Moreover, aCLL patients also showed a higher incidence of NOTCH1 mutations than the tCLL patients (P=0.038) , while no statistically significant differences in other gene mutations occurred between the two groups. No significant differences in overall survival (OS) and treatment-free survival (TFS) occurred between aCLL and tCLL using Kaplan-Meier analysis (P>0.05) . Conclusion: aCLL has characteristic immunophenotype, cytogenetic, and somatic mutation that differ from tCLL, and this can provide reliable information for the diagnosis and differential diagnosis between the two groups.

[Annual review of bronchiectasis in 2021]

Bronchiectasis, a common chronic respiratory disease, is characterized by irreversible and abnormal bronchial dilatation due to multiple causes. In 2021, a series of significant research progress have been made in bronchiectasis, focusing on the mechanism, diagnosis, clinical phenotypes, treatment, comorbidities, etc. Several studies have shown that many mediators are involved in the pathogenesis of bronchiectasis, such as lipids, platelets, and respiratory microorganisms, providing new insights into the development of prevention and therapy targets of bronchiectasis. At the same time, an international expert consensus proposed radiological and clinical diagnosis criteria for inclusion of bronchiectasis patients in clinical trials. Moreover, the proposal of new phenotype, measurement tools and predictors on bronchiectasis, promote the process of individualized therapy for patients. Regarding the clinical trials on bronchiectasis, several important studies have been published, including tobramycin inhalation powder, airway clearance techniques, tiotropium bromide and so forth. In addition, researches on bronchiectasis comorbidities also have new findings. This review summarized the recent published literatures in order to help clinicians better understand bronchiectasis.

Observation of B 0 → ψ (2S)K S 0 π + π - and B s 0 → ψ (2S)K S 0 decays

Using a data sample of s = 13 TeV proton-proton collisions collected by the CMS experiment at the LHC in 2017 and 2018 with an integrated luminosity of 103 fb - 1 , the B s 0 → ψ ( 2S ) K S 0 and B 0 → ψ ( 2S ) K S 0 π + π - decays are observed with significances exceeding 5 standard deviations. The resulting branching fraction ratios, measured for the first time, correspond to B ( B s 0 → ψ ( 2S ) K S 0 ) / B ( B 0 → ψ ( 2S ) K S 0 ) = ( 3.33 ± 0.69 ( stat ) ± 0.11 ( syst ) ± 0.34 ( f s / f d ) ) × 10 - 2 and B ( B 0 → ψ ( 2S ) K S 0 π + π - ) / B ( B 0 → ψ ( 2S ) K S 0 ) = 0.480 ± 0.013 ( stat ) ± 0.032 ( syst ) , where the last uncertainty in the first ratio is related to the uncertainty in the ratio of production cross sections of B s 0 and B 0 mesons, f s / f d .

[Effects of powder size and pre-sintering heating rate on dental recycled zirconia]

Objective: To evaluate the effects of pre-sintering heating rate and powder size on dental recycled zirconia. Methods: Recycled zirconia powders were sieved to obtain the large (50 μm<particle diameter≤125 μm) and small (particle diameter≤50 μm) particles, these powders were then formed into green bodies. According to the pre-sintering heating rates, the recycled-zirconia green bodies were divided into 3 groups: group A, pre-sintering heating rate of 2 ℃/min; group B, pre-sintering heating rate of 5 ℃/min; group C, pre-sintering heating rate of 8 ℃/min. The relative density open porosity and machinability of the recycled zirconia pre-sintered bodies were evaluated and compared with the commercial zirconia pre-sintered bodies. Zirconia pre-sintered bodies were then fully sintered according to the manufacturer's instructions. The relative density, open porosity, linear shrinkage and flexural strength of fully sintered zirconia were further compared. The microstructure of fracture surfaces and the crystalline structure were analyzed by scanning electron microscope and X-ray diffractometer, respectively. Results: With the same particle size, the recycled zirconia pre-sintered at different heating rates showed no significant differences in the relative densities, and the open porosities (P>0.05). When the pre-sintering heating rates were 2 ℃/min, 5 ℃/min, and 8 ℃/min, the flexural strengths of the large-particle recycled zirconia were (421.2±54.7), (444.2±70.1) and (427.5±68.4) MPa, the flexural strengths of the small-particle recycled zirconia were (750.1±74.1), (777.2±95.5) and (746.7±73.0) MPa, respectively. The flexural strength of commercial zirconia was (988.4±129.8) MPa. The flexural strengths of the recycled zirconia were significantly lower than that of the commercial zirconia (P<0.05). At the same pre-sintering heating rate, the flexural strengths of the small-particle recycled zirconia were significantly higher than that of the large-particle recycled zirconia (P<0.05). Conclusions: Compared with the large particles, small-particle recycled zirconia powders can effectively improve the properties of recycled zirconia, while the pre-sintering heating rate has no effect on the properties of the recycled zirconia.

[Analysis of clinical phenotype and genotype of Chinese children with disorders of sex development]

Objective: To explore the heterogeneity and correlation of clinical phenotypes and genotypes in children with disorders of sex development (DSD). Methods: A retrospective study of 1 235 patients with clinically proposed DSD in 36 pediatric medical institutions across the country from January 2017 to May 2021. After capturing 277 DSD-related candidate genes, second-generation sequencing was performed to analyzed the heterogeneity and correlation combined with clinical phenotypes. Results: Among 1 235 children with clinically proposed DSD, 980 were males and 255 were females of social gender at the time of initial diagnosis with the age ranged from 1 day of age to 17.92 years. A total of 443 children with pathogenic variants were detected through molecular genetic studies, with a positive detection rate of 35.9%. The most common clinical phenotypes were micropenis (455 cases), hypospadias (321 cases), and cryptorchidism (172 cases) and common mutations detected were in SRD5A2 gene (80 cases), AR gene (53 cases) and CYP21A2 gene (44 cases). Among them, the SRD5A2 mutation is the most common in children with simple micropenis and simple hypospadias, while the AMH mutation is the most common in children with simple cryptorchidism. Conclusions: The SRD5A2 mutation is the most common genetic variant in Chinese children with DSD, and micropenis, cryptorchidism, and hypospadias are the most common clinical phenotypes. Molecular diagnosis can provide clues about the biological basis of DSD, and can also guide clinicians to perform specific clinical examinations. Target sequence capture probes and next-generation sequencing technology can provide effective and economical genetic diagnosis for children with DSD.

The strategy of non-intubated spontaneous ventilation anesthesia for upper tracheal surgery: a retrospective case series study

Background

Upper tracheal surgery is used to treat patients who with tracheal tumors or tracheal stenosis. The non-intubated spontaneous ventilation anesthesia (NSVA) may have advantages over endotracheal intubation and surgical cross-field intubation in upper tracheal surgery. This study aimed to illustrate and assess the feasibility of NSVA strategy for upper tracheal surgery.

Methods

This is a retrospective case series study in which 51 patients (from May 2015 to August 2020) who met the criteria in NSVA strategy were analyzed. Anesthesia was performed using total intravenous anesthesia (TIVA) combined with bilateral superficial cervical plexus block (CPB) or thoracic epidural anesthesia (TEA). Patients received spontaneous ventilation through laryngeal mask airway (LMA) during the surgery. Anesthesia conversion technique was applied to patients who met the anesthesia conversion criteria.

Results

In total, 51 patients met the NSVA criteria and were included in this study. Forty-six out of 51 patients (90%) had TIVA + bilateral superficial CPB and five patients (10%) had TIVA + TEA + CPB. During the airway-opened period, 46 patients had stable spontaneous ventilation. Five patients need anesthesia conversion, two patients had high-frequency ventilation (HFV), and three patients required cross-field intubation. Postoperative complications occurred in seven (14%) patients, no reintubation was needed after surgery. The median postoperative hospital stay was 6.31±4.30 days.

Conclusions

This NSVA strategy includes criteria for patient selection, preoperative assessment, surgical technique, airway management, criteria and technique for anesthesia conversion. The NSVA strategy is a feasible procedure in upper tracheal surgery.

PXR activation impairs hepatic glucose metabolism partly via inhibiting the HNF4α-GLUT2 pathway

Drug-induced hyperglycemia/diabetes is a global issue. Some drugs induce hyperglycemia by activating the pregnane X receptor (PXR), but the mechanism is unclear. Here, we report that PXR activation induces hyperglycemia by impairing hepatic glucose metabolism due to inhibition of the hepatocyte nuclear factor 4-alpha (HNF4α)‒glucose transporter 2 (GLUT2) pathway. The PXR agonists atorvastatin and rifampicin significantly downregulated GLUT2 and HNF4α expression, and impaired glucose uptake and utilization in HepG2 cells. Overexpression of PXR downregulated GLUT2 and HNF4α expression, while silencing PXR upregulated HNF4α and GLUT2 expression. Silencing HNF4α decreased GLUT2 expression, while overexpressing HNF4α increased GLUT2 expression and glucose uptake. Silencing PXR or overexpressing HNF4α reversed the atorvastatin-induced decrease in GLUT2 expression and glucose uptake. In human primary hepatocytes, atorvastatin downregulated GLUT2 and HNF4α mRNA expression, which could be attenuated by silencing PXR. Silencing HNF4α downregulated GLUT2 mRNA expression. These findings were reproduced with mouse primary hepatocytes. Hnf4α plasmid increased Slc2a2 promoter activity. Hnf4α silencing or pregnenolone-16α-carbonitrile (PCN) suppressed the Slc2a2 promoter activity by decreasing HNF4α recruitment to the Slc2a2 promoter. Liver-specific Hnf4α deletion and PCN impaired glucose tolerance and hepatic glucose uptake, and decreased the expression of hepatic HNF4α and GLUT2. In conclusion, PXR activation impaired hepatic glucose metabolism partly by inhibiting the HNF4α‒GLUT2 pathway. These results highlight the molecular mechanisms by which PXR activators induce hyperglycemia/diabetes.

[Clinical analysis of chronic eosinophilic pneumonia in 9 cases]

Objective: To investigate the clinical features, treatment and prognosis of chronic eosinophilic pneumonia. Methods: Nine patients with chronic eosinophilic pneumonia diagnosed in Shandong Provincial Qianfoshan Hospital from January 2014 to December 2020 were enrolled and followed up. The data of clinically proven chronic eosinophilic pneumonia were reviewed. Results: The 9 cases included one male and eight females, aged from 16 to 71 years (median 47 years). Among them, 5 cases were complicated with asthma, 1 case was complicated with allergic rhinitis, and 1 case had an allergic history of pollen. All the patients had cough, expectoration, chest tightness and wheezing, and a few had fatigue (3/9), fever (1/9) and chest pain (1/9). Single or multiple patchy high-density shadows (9/9), mediastinal lymphadenopathy (7/9), air bronchogram (2/9), and reticular shadow (1/9) were observed in chest CT. Peripheral eosinophils (EOS) and serum total IgE increased to varying degrees in the 9 patients. Meanwhile, the bronchoscopy of 5 cases showed elevated percentage of eosinophils in alveolar lavage fluid, and the lung biopsy of remaining 4 cases showed EOS infiltration in lung alveolar and interstitium. After receiving glucocorticoid therapy for 0.5 to 1 month, the clinical symptoms of all 9 patients had been improved and lung lesions on CT scans had been obviously absorbed. Four cases relapsed during follow-up. Conclusions: For patients especially women who have a history of allergy, elevated blood eosinophils and serum total IgE with pulmonary high-density shadow or consolidation, chronic eosinophilic pneumonia should be considered, and bronchoscopy or percutaneous lung biopsy is indicated for a definite diagnosis. Glucocorticoid therapy is effective, but the rate of recurrence is high.

[The incidence of myopia and myopic progression from 2019 to 2020 in school-age children in Zhuozhou]

Objective: To analyze the changes in refractive status and prevalence of myopia in 6-to 14-year-old children at 2 time points in Zhuozhou, Hebei Province. Methods: In the current cohort study, the visual acuity and refractive status of primary and secondary school students aged 6 to 14 years were examined from June to August 2019 and reexamined from June to August 2020. A total of 30 412 subjects with examination data were enrolled, including 15 861 males (52.2%) and 14 551 females (47.8%), with an average age of (10.0±2.7) years. The participants underwent autorefraction without cycloplegia and a naked eye visual acuity test with a standard logarithmic visual acuity chart. Myopia was screened by the standard of equivalent spherical refraction less than -0.75 diopter (D). The categorical data were analyzed by the Chi-square or Fisher's exact test. Clopper-Pearson was used to estimate the 95% confidence intervals for the incidence of myopia. Results: After the 1-year interval, the change of equivalent spherical refraction was(-0.67±1.11) D and(-0.76±1.11) D, respectively, in male and female participants, and their visual acuity decreased by 0.11±0.19 and 0.12±0.21, respectively. There were significant inter-group differences in the annual change of spherical power in different age groups (χ²=276.23, P<0.001). The naked eye visual acuity reduction was greatest in the 10-year-old students. The incidence of myopia was 42.2% (95% confidence intervals of 41.47% to 42.93%) during the 1-year follow-up period. The incidence of myopia was highest at the age of 14 (52.0% in males and 54.2% in females) and lowest at the age of 6 (31.0% in males and 33.1% in females). Conclusions: The 1-year follow-up revealed an obvious myopic shift in the refractive status of school students in Zhuozhou, with their naked eye visual acuity decreased. The incidence of myopia was higher in females than that in males.

[Numerical simulation modeling of middle ear-eustachian tube ventilation based on Chinese digital visual human body]

Objective: To establish a three-dimensional model of middle ear-eustachian tube based on Chinese digital visual human dataset, and the deformation and pressure changes of the middle ear-eustachian tube system after eustachian tube opening are simulated by computer numerical simulation. Methods: The first female Chinese Digital Visual Human data was adopted. The images were imported by Amira image processing software, and the images were segmented by Geomagic software to form a three-dimensional model of middle ear-eustachian tube system, including eustachian tube, tympanum, tympanic membrane, auditory ossicles, and mastoid air cells system. The 3D model was imported into Hypermesh software for meshing and analysis. The structural mechanics calculation was carried out by Abaqus, and gas flow was simulated by Xflow. The tissue deformation and middle ear pressure changes during eustachian tube opening were numerically simulated by fluid-solid coupling algorithm. Several pressure monitoring points including tympanum, mastoid, tympanic isthmus, and external auditory canal were set up in the model, and the pressure changes of each monitoring point were recorded and compared. Results: In this study, a three-dimensional model of middle ear-eustachian tube and a numerical simulation model of middle ear ventilation were established, including eustachian tube, tympanum, mastoid air cells, tympanic membrane, and auditory ossicles. The dynamic changes of the model after ventilation could be divided into five stages according to the pressure. In addition, the pressure changes of tympanum and tympanic isthmus were basically synchronous, and the pressure changes of mastoid air cells system were later than that of tympanum and tympanic isthmus, which verified the pressure buffering effect of mastoid. The extracted pressure curve of the external auditory canal was basically consistent with that of tympanometry in terms of value and trend, which verified the effectiveness of the model. Conclusions: The numerical simulation model of middle ear-eustachian tube ventilation established in this paper can simulate the tissue deformation and middle ear pressure changes after eustachian tube opening, and its accuracy and effectiveness are also verified. This not only lays a foundation for further research, but also provides a new research method for the study of middle ear ventilation.

Impedance matching system using triple liquid stub tuners for high-power ion cyclotron resonance heating in EAST tokamak

Ion cyclotron resonance heating (ICRH), one of the main auxiliary methods, for high-power and long-pulse plasma heating had been developed in Experimental Advanced Superconducting Tokamak (EAST). An impedance matching system, one important part of ICRH, had been developed for high-power injection and transmitter protection by reducing the reflected power from the antenna. The input impedance in the outlet of the stub tuner can be measured by voltage-current probes installed on the coaxial transmission line between the antenna and triple liquid stub tuners, and the optimum liquid levels in the stub tuners can be calculated based on the input impedance. The calculation and adjustment process of the optimum liquid levels are described comprehensively in this article. Finally, impedance matching had been achieved between two shots during EAST experiments. In the near future, a real-time impedance matching system will be developed to prevent large variations of the ICRH antenna impedance and achieve steady-state and long-pulse operation with the ICRH system.

Plasma Steroids and Endocannabinoids Used as Biomarkers to Assess the Pruritus Severity of Patients With Prurigo Nodularis

BACKGROUND

Prurigo nodularis (PN) as an extremely pruritic and hyperplastic chronic dermatosis induces psychologically and physiologically stressful responses. PN-induced responses in the hypothalamic-pituitary-adrenal, hypothalamic-pituitary-gonadal axes and endocannabinoid system are abnormal. Extant studies on the PN's pathogenesis mostly focused on the PN's psychological responses. To date, the PN's physiological responses remain not been fully uncovered yet.

OBJECTIVES

To investigate the PN-induced physiological responses via the levels of 5steroids and 2endocannabinoids combined with their ratios in plasma and examine the association between the psychological and physiological responses.

MATERIALS AND METHODS

Thirty-six patients with PN, 36 age- and gender-matched healthy controls were recruited. The PN's psychological symptoms including pruritus severity, pain and life quality were measured with the visual analogue scale, the prurigo score index, numerical rating scale, verbal rating scale and dermatology life quality index. Their concentrations of steroids and endocannabinoids were determined with liquid chromatography-tandem mass spectrometry.

RESULTS

Compared to controls, the PN patients showed lower plasma levels in cortisol, cortisone, N-arachidonoyl-ethanolamine, and the ratio of DHEA to 1-arachydonoyl glycerol (1-AG), which negatively moderately and over correlated with PN's symptoms, especially with the pruritus severity. Additionally, the PN patients exhibited higher levels in the ratios of testosterone and 1-AG to cortisol, which positively moderately and over correlated with pruritus severity. Thus, the 7biomarkers would be sensitive and reliable biomarkers for assessing the pruritus severity of PN because they met the screening criteria that the biomarkers show intergroup differences and showed moderate or over correlation with the pruritus severity of PN.

CONCLUSIONS

To the best of our knowledge, this is the first study exploring PN-induced physiological responses. The findigs suggest that alterations in these 3endocrine systems may lead to new insights to psychological mechanisms and responses to PN.

[Efficacy analysis of selective genicular artery embolization in the treatment of knee pain secondary to osteoarthritis]

Objective: To evaluate the efficacy and safety of selective genicular artery embolization for the treatment of the knee pain secondary to osteoarthritis. Methods: From October 2020 to July 2021, 17 patients (23 knees) aged (68±7) years with moderate to severe knee pain secondary to knee osteoarthritis were prospectively included in the General Hospital of Ningxia Medical University. There were 6 males and 11 females included in this research. Patients were assessed with knee pain, stiffness, and function with the Visual Analogue Scale (VAS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) at baseline, using the Kellgren-Lawrence (K-L) grading to evaluate the severity of KOA, and using the Magnetic Resonance Knee Osteoarthritis Score (MOAKS) to evaluate the MR imaging characteristics of the affected knee. Selective genicular artery embolization (GAE) was performed in all patients. The patients were followed up for 6 months after the procedure. Patients were assessed with the VAS score and WOMAC scale at 1 d, 1 week and 1, 3 and 6 months after the procedure to evaluate the clinical outcomes, including the improvement of knee joint pain, stiffness and function, as well as the occurrence of adverse reactions. Results: Three to seven genicular artery branches were superselected and embolized in 23 knees, and 4 to 7 genicular artery branches were embolized in 7 patients with K-L grade 4. The clinical improvement was 95.6% (22/23) at 1 month, 86.9% (20/23) at 3 months, and 91.3% (21/23) at 6 months. Twenty-three knees completed the 6-month follow-up, and the VAS score, WOMAC pain score, and total WOMAC score at 1, 3, and 6 months after surgery were (2.5±1.3), (3.4±2.4), and (19.7±9.8) points, (3.0±1.8), (4.5±3.4), and (22.3±11.3) points, (2.8±1.5), (4.1±3.0), and (20.5±11.0) points, which were lower than the (6.6±0.9), (11.4±2.6) and (47.0±12.0) points at baseline (all P<0.001). During the follow-up period, 7 patients had adverse reactions: 3 cases had skin ecchymosis in the femoral artery puncture area, 4 cases had knee joint stiffness and pain within 1 day after operation, which were relieved spontaneously in 1 week, 6 patients had joint clicking during extension and flexion activities after operation, of which 3 cases subsided spontaneously within 3 months after operation. None of the patients had major procedure-related adverse events. Conclusion: GAE has a high clinical improvement rate and a low incidence of adverse reactions in the treatment of the pain secondary to knee osteoarthritis, which provides a new treatment option for patients who fail to respond to conservative treatment.

Characterization of Restenosis following Carotid Endarterectomy Using Contrast-Enhanced Vessel Wall MR Imaging

BACKGROUND AND PURPOSE

Restenosis is an important determinant of the long-term efficacy of carotid endarterectomy. Our aim was to assess the role of high-resolution vessel wall MR imaging for characterizing restenosis after carotid endarterectomy.

MATERIALS AND METHODS

Patients who underwent vessel wall MR imaging after carotid endarterectomy were included in this study. Restenotic lesions were classified as myointimal hyperplasia or recurrent atherosclerotic plaques based on MR imaging features of lesion compositions. Imaging characteristics of myointimal hyperplasia were compared with those of normal post-carotid endarterectomy and recurrent plaque groups. Recurrent plaques were matched with primary plaques by categories of stenosis, and differences in plaque features were compared between the 2 groups.

RESULTS

Twenty-two recurrent lesions from 18 patients (14 unilateral and 4 bilateral) were classified as myointimal hyperplasia or recurrent plaque. Myointimal hyperplasia showed no difference in enhancement compared with normal post-carotid endarterectomy vessels (5 unilateral) but showed stronger enhancement than recurrent plaques (80.10% [SD, 42.42%] versus 56.74% [SD, 46.54%], P = .042). A multivariate logistic regression model of plaque-feature detection in recurrent plaques compared with primary plaques adjusted for maximum wall thickness revealed that recurrent plaques were longer (OR, 4.27; 95% CI, 1.32-13.85; P = .015) and more likely to involve a flow divider and side walls (OR, 6.96; 95% CI, 1.37-35.28; P = .019). Recurrent plaques had a higher prevalence of intraplaque hemorrhage (61.5% versus 30.8%, P = .048) by a χ² test, but compositional differences were not significant in the multivariate model.

CONCLUSIONS

Vessel wall MR imaging can distinguish recurrent plaques from myointimal hyperplasia and reveal features that may differ between primary and recurrent plaques, highlighting its value for evaluating patients with carotid restenosis.

Injectable adipose-derived stem cells-embedded alginate-gelatin microspheres prepared by electrospray for cartilage tissue regeneration

Objective

To prepare adipose-derived stem cells (ADSCs)-embedded alginate-gelatinemicrospheres (Alg-Gel-ADSCs MSs) by electrospray and evaluate their feasibility for cartilage tissue engineering. To observe the efficacy of Alg-Gel-ADSCs MSs in repairing articular cartilage defects in SD rats.

Methods

ADSCs were isolated and characterized by performing induced differentiation and flow cytometry assays. Alginate-gelatine microspheres with different gelatine concentrations were manufactured by electrospraying, and the appropriate alginate-gelatine concentration and ratio were determined by evaluating microsphere formation. Alg-Gel-ADSCs MSs were compared with Alg-ADSCs MSs through the induction of chondrogenic differentiation and culture. Their feasibility for cartilage tissue engineering was analysed by performing Live/Dead staining, cell proliferation analysis, toluidine blue staining and a glycosaminoglycan (GAG) content analysis. Alg-Gel-ADSCs MSs were implanted in the cartilage defects of SD rats, and the cartilage repair effect was evaluated at different time points. The evaluation included gross observations and histological evaluations, fluorescence imaging tracking, immunohistochemical staining, microcomputed tomography (micro-CT) and a CatWalk evaluation.

Results

The isolated ADSCs showed multidirectional differentiation and were used for cartilage tissue engineering. Using 1.5 w:v% alginate and 0.5 w:v% gelatine (Type B), we successfully prepared nearly spherical microspheres. Compared with alginate microspheres, alginate gel increased the viability of ADSCs and promoted the proliferation and chondrogenesis of ADSCs. In our experiments on knee cartilage defects in SD rats in vivo, the Alg-Gel-ADSCs MSs showed superior cartilage repair in cell resides, histology evaluation, micro-CT imaging and gait analysis.

Conclusions

Microspheres composed of 1.5 w:v% alginate-0.5 w:v% gelatine increase the viability of ADSCs and supported their proliferation and deposition of cartilage matrix components. ADSCs embedded in 1.5 w:v% alginate-0.5 w:v% gelatine microspheres show superior repair efficacy and prospective applications in cartilage tissue repair.

The translational potential of this article

In this study, injectable adipose-derived stem cells-embedded alginate-gelatin microspheres (Alg-Gel-ADSCs MSs) were prepared by the electrospray . Compared with the traditional alginate microspheres, its support ability for ADSCs is better and shows a better repair effect. This study provides a promising strategy for cartilage tissue regeneration.

Plasma Steroids and Endocannabinoids Used as Biomarkers to Assess the Pruritus Severity of Patients With Prurigo Nodularis

BACKGROUND

Prurigo nodularis (PN) as an extremely pruritic and hyperplastic chronic dermatosis induces psychologically and physiologically stressful responses. PN-induced responses in the hypothalamic-pituitary-adrenal (HPA), hypothalamic-pituitary-gonadal (HPG) axes and endocannabinoid system (ECS) are abnormal. Extant studies on the PN's pathogenesis mostly focused on the PN's psychological responses. To date, the PN's physiological responses remain not been fully uncovered yet.

OBJECTIVES

To investigate the PN-induced physiological responses via the levels of five steroids and two endocannabinoids combined with their ratios in plasma and examine the association between the psychological and physiological responses.

MATERIALS AND METHODS

Thirty-six patients with PN, 36 age- and gender-matched healthy controls were recruited. The PN's psychological symptoms including pruritus severity, pain and life quality were measured with the visual analog scale, the prurigo score index, numerical rating scale, verbal rating scale and dermatology life quality index. Their concentrations of steroids and endocannabinoids were determined with liquid chromatography-tandem mass spectrometry.

RESULTS

Compared to controls, the PN patients showed lower plasma levels in cortisol, cortisone, N-arachidonoyl-ethanolamine (AEA), and the ratio of DHEA to 1-arachydonoyl glycerol (1-AG), which negatively moderately and over correlated with PN's symptoms, especially with the pruritus severity. Additionally, the PN patients exhibited higher levels in the ratios of testosterone and 1-AG to cortisol, which positively moderately and over correlated with pruritus severity. Thus, the seven biomarkers would be sensitive and reliable biomarkers for assessing the pruritus severity of PN because they met the screening criteria that the biomarkers show intergroup differences and showed moderate or over correlation with the pruritus severity of PN.

CONCLUSIONS

To the best of our knowledge, this is the first study exploring PN-induced physiological responses. The findings suggest that alterations in these three endocrine systems may lead to new insights to psychological mechanisms and responses to prurigo nodularis.

[Predictive value of impedance of leadless pacemaker during implantation on trend changes of pacing threshold]

Objective: To explore the predictive value of the impedance measured during leadless pacemaker Micra implantation on the trend of changes of pacing threshold post implantation. Methods: This is a retrospective cross-sectional study. Patients who received implantation of leadless pacemaker Micra at the Second Xiangya Hospital of Central South University from December 2019 to August 2020 were enrolled. The clinical data and the intraoperative electrical parameters during leadless pacemaker implantation were collected. The impedance and pacing threshold data were analyzed at three time points: immediate release, 5-10 min after release, and after traction test. Receiver operating characteristic (ROC) curves and the area under the curve (AUC) were used to analyze the value of the impedance at immediate release on predicting the trend of changes of pacing threshold post implantation. Results: A total of 21 patients (mean age: (72.2±12.5) years, 12 males) were included. The impedance of 21 patients was (798.1±35.3) Ω immediately after implantation, (800.9±35.6) Ω after 5-10 minutes of release, and (883.6±31.7) Ω after traction test. Impedance was similar between the three time points (P>0.05). The threshold was (0.97±0.11) V/0.24 ms immediately after implantation, (0.95±0.12) V/0.24 ms at 5-10 min after the release, and (0.59±0.06) V/0.24 ms after the traction test. The threshold was significantly lower after the traction test than that immediately after release (P=0.003) and than that at 5-10 minutes after release (P=0.008), suggesting a decreased tendency of the threshold over time. According to the analysis of the ROC curve, the immediate impedance after the release ≥680 Ω could predict the ideal pacing threshold after the traction test (AUC=0.989, 95%CI 0.702-0.964, P<0.001), the prediction sensitivity was 87%, and the specificity was 100%. The pacing threshold would be not ideal with the immediate impedance ≤ 520 Ω (95%CI 0.893-1.000, P<0.001), the sensitivity was 100%, and the specificity was 80%. Conclusions: The impedance immediately after the release has predictive value for the changing trend of threshold post leadless pacemaker Micra implantation. Impedance ≥680 Ω immediately after release is often related with ideal pacing threshold after the traction test. In contrast, the impedance ≤ 520 Ω pacing is often related with unsatisfactory threshold after the traction test, therefore, it is recommended to find a new pacing site to achieve the impedance ≥680 Ω immediately after release during leadless pacemaker Micra implantation.

A40 IDENTIFYING NOVEL ROLES FOR TLR2 SIGNALING IN THE INTESTINAL EPITHELIUM USING ORGANOIDS

Background

Inflammatory bowel disease (IBD) is thought to result from an imbalance between protective and damaging immune responses to the resident microbiota and other luminal antigens. Increasing evidence suggests that toll-like-receptor (TLR)-mediated innate immune dysfunction contributes to the pathogenesis of IBD. Among the receptors in the TLR family, TLR2 and its signalling pathway appears to play an important protective role in the gastrointestinal (GI) tract. Notably, our group previously discovered that Tlr2 expression by nonhematopoietic cells played an important protective role in the Citrobacter rodentium model of infectious colitis.

Aims

To determine if intestinal epithelial cells (IECs) control Tlr2 dependent tissue protective responses, we sought to characterize the role of Tlr2 signalling in intestinal organoids. In addition, to better define the role of Tlr2 during C. rodentium infection, we developed a novel in vitro model of C. rodentium infection using organoid-derived monolayers.

Methods

Organoids were derived from the colonic tissue of wild type (C57BL/6J) and Tlr2 deficient (-/-) mice and then stimulated with Tlr2 agonists, and their responses were evaluated by qPCR, ELISA, Western blot and immunostaining. In addition, 2D monolayers were grown from organoids, and infected with C. rodentium to explore whether Tlr2 signaling regulates other protective IEC functions such as barrier proteins and cell death in response to noxious stimuli.

Results

Stimulation of WT, but not Tlr2-/- mouse orgnaoids led to increased transcription of chemokine and cytokine genes Ccl20, Mcp-1, Cxcl1 and Tnf-α. This was accompanied by increased protein secretion through a NF-κB and p38 MAP kinase dependent mechanism. Interestingly, organoids derived from the distal colon displayed stronger Tlr2 responses than organoids from the proximal colon. During C. rodentium infection of monolayers, Tlr2 signaling had no effect on the distribution of tight junction proteins such as ZO-1 or Claudin3, however, Tlr2 did regulate levels of IEC apoptosis upon C. rodentium infection.

Conclusions

Our study demonstrates that colonic organoids express functional Tlr2, which upon stimulation, leads to pro-inflammatory responses as well as control over cell death. Our novel C. rodentium infection model enables us to further study the role of IEC in promoting host defense during bacterial infection. Futher work will examine how interactions with Tlr2 dependent cytokines (ie. IL-6, IL-22) impact IEC responses to C. rodentium.

Funding Agencies

CCC, CIHRCH.I.L.D

A136 A RARE CAUSE OF AUTOIMMUNE ATROPHIC PANGASTRITIS COMPLICATED WITH GASTRIC OUTLET OBSTRUCTION

Background

Chronic gastritis comes in two well recognized forms: environmental, which is most commonly antral or multifocal in distribution and is typically caused by Helicobacter Pylori (HP) infection, and autoimmune gastritis(AIG), which affects the corpus and fundus. Presented here is a case of autoimmune atrophic pangastritis(AIAP).

Aims

To increase awareness of a rare condition with limited data on available treatment modalities.

Methods

Case Report

Results

A 68-year old female with autoimmune hypothyroidism, presented with weight loss and elevated anti-TTG serology. Index esophagogastroduodenoscopy (EGD) biopsies demonstrated chronic non-specific gastritis limited to the antrum. Strict gluten free diet adherence was initiated. Testing for HLA revealed HLADq2 and HLADq8 negativity but HLADq2.5 positivity. Subsequent EGD showed a markedly atrophic appearing gastric body. The corresponding biopsies demonstrated persistent moderately chronic active gastritis with severe atrophy now involving the body, fundus and antrum. The biopsies were negative for HP. Notably, there was a lack of ECL-cell hyperplasia and the number of antral G cells appeared decreased. Anti-parietal cell antibody serology was positive with a titre of 1:80. Despite combination therapy with budesonide and mesalamine and treatment for HP given persistent symptoms, the patient’s course was further complicated by gastric-outlet obstruction (GOO). Urgent EGD biopsies showed pyloric stenosis requiring dilation. Endoscopic Ultrasound (EUS) guided biopsies were negative for malignancy. The patient was started on corticosteroids and azathioprine(AZA). Most recently, an EGD on AZA, continued to demonstrate severe chronic active pangastritis now with intestinal metaplasia involving the body. Corticosteroid therapy was reinitiated with a plan to start mycophenolate mofetil (MMF).

Conclusions

AIAP is a rarely described entity, not well documented in the literature. An eight patient case series reported a distinctive form of atrophic gastritis that was independent of HP infection with the absence of neuroendocrine hyperplasia that involved the body and antrum. Thyroid disease, specifically Hashimoto thyroiditis is present in about 40% of patients with AIG. Additionally, AIG progression to atrophic gastritis with intestinal metaplasia confers an increased risk for gastric adenocarcinoma in more than 10% of patients.

Limited literature exists regarding the management of AIAP. Pediatric data suggests the use of prednisone and/or azathioprine for AIAP. Furthermore, a recent case report of AIAP demonstrated clinical and endoscopic remission with MMF. Currently, no guidelines exist for the treatment, screening and monitoring of patients with AIAP. This case report presents a rare case of AIAP refractory to AZA complicated with GOO and adds to the little literature that exists.

Funding Agencies

None

Anatomical characteristics and significance of the metopism and Wormian bones in dry adult-Chinese skulls

BACKGROUND

This study aimed to investigate the incidence, topographical distribution, morphology, and interrelationship of the metopism and Wormian bones (WBs) in dry adult-Chinese skulls.

MATERIALS AND METHODS

In this study, 285 dried adult-Chinese skull specimens from the Department of Anatomy at the Southern Medical University were examined. The incidence of different types of metopism and WBs were recorded. The length of the metopic suture was measured using a flexible ruler. Additionally, the lengths and widths of the WBs were measured using a vernier calliper.

RESULTS

The incidence of metopism and WBs in Chinese adults were estimated at 10.18% (29/285) and 63.86% (182/285), respectively. The metopism always accompanied WBs (26/29, 89.66%), but the WBs did not necessarily accompany metopism (26/182, 14.29%). The locations of the WBs in the order of decreasing incidence were the lambdoid suture (78.57%, 143/182), pterion (34.62%, 63/182), asterion (12.09%, 22/182), lambda (8.24%, 15/182), sagittal suture (4.95%, 9/182), and Inca bone (3.85%, 7/182). These locations differed in topographical distribution and morphological patterns.

CONCLUSIONS

Chinese adults differ in incidence of metopism and WBs from adults of other races, indicating racial differences. The characteristics of WBs vary depending on the cranial site of occurrence. The metopism always accompanies WBs, but the WBs do not necessarily accompany metopism.

[Identification of traditional Chinese drugs containing active ingredients for treating myocardial infarction and analysis of their therapeutic mechanisms by network pharmacology and molecular docking]

OBJECTIVE

To identify traditional Chinese drugs that contain active ingredients for treatment of myocardial infarction (MI) and explore their therapeutic mechanisms using network pharmacology and molecular docking technology.

METHODS

The TCMSP database was used for screening the traditional Chinese drugs containing active ingredients for treating MI, and the related targets of MI and the candidate drugs were obtained from Genecards, OMIM, PharmGkb and PharmMapper databases. The common target network of the drug targets and disease targets was established using Venny2.1.0 software. GO and KEGG signal pathway enrichment analysis of the common targets was performed, and the protein-protein interaction (PPI) network was constructed for the targets. The targets in the PPI network were analyzed to identify the key targets, for which GO and KEGG pathway enrichment analyses were performed. Molecular docking was performed for the candidate ingredients and the key targets, and a total score ≥6 was used as the criteria for screening the therapeutic ingredients and their docking binding with key targets was verified. A human umbilical vein endothelial cell (HUVEC) model of oxygen-glucose deprivation (OGD) was used to validate the candidate ingredients and the key therapeutic targets for MI by Western blotting.

RESULTS

Our analysis identified Salvia miltiorrhiza and Dalbergiae odoriferae as the candidate drugs rich in active ingredients for treatment of MI. These ingredients involved 16 key therapeutic targets for MI, which participated in such biological processes as inflammatory response, angiogenesis, energy metabolism and oxidative stress and the pathways including HIF-1, VEGF, and TNF pathways. Sclareol and PTGS2 in Salvia miltiorrhiza and formononetin and KDR in Dalbergiae odoriferae all had high docking total scores. Western blotting showed that at medium and high doses, sclareol significantly inhibited PTGS2 expression and formononetin promoted KDR expressions in the cell models in a dose-dependent manner (P < 0.05).

CONCLUSION

Both Salvia miltiorrhiza and Dalbergiae odoriferae have good therapeutic effects on MI. Sclareol in Salvia miltiorrhiza and formononetin in Dalbergiae odoriferae regulate the expressions of KDR and PTGS2, respectively, to modulate the inflammatory response, angiogenesis, oxidative stress and energy metabolism and thus produce myocardial protective effects.

A 2-year locomotive exploration and scientific investigation of the lunar farside by the Yutu-2 rover

The lunar nearside has been investigated by many uncrewed and crewed missions, but the farside of the Moon remains poorly known. Lunar farside exploration is challenging because maneuvering rovers with efficient locomotion in harsh extraterrestrial environment is necessary to explore geological characteristics of scientific interest. Chang'E-4 mission successfully targeted the Moon's farside and deployed a teleoperated rover (Yutu-2) to explore inside the Von Kármán crater, conveying rich information regarding regolith, craters, and rocks. Here, we report mobile exploration on the lunar farside with Yutu-2 over the initial 2 years. During its journey, Yutu-2 has experienced varying degrees of mild slip and skid, indicating that the terrain is relatively flat at large scales but scattered with local gentle slopes. Cloddy soil sticking on its wheels implies a greater cohesion of the lunar soil than encountered at other lunar landing sites. Further identification results indicate that the regolith resembles dry sand and sandy loam on Earth in bearing properties, demonstrating greater bearing strength than that identified during the Apollo missions. In sharp contrast to the sparsity of rocks along the traverse route, small fresh craters with unilateral moldable ejecta are abundant, and some of them contain high-reflectance materials at the bottom, suggestive of secondary impact events. These findings hint at notable differences in the surface geology between the lunar farside and nearside. Experience gained with Yutu-2 improves the understanding of the farside of the Moon, which, in return, may lead to locomotion with improved efficiency and larger range.

Effects of Hydrothermal Treatment on the Phase Transformation, Surface Roughness, and Mechanical Properties of Monolithic Translucent Zirconia

OBJECTIVES

This study aimed to investigate the effects of hydrothermal treatment on four types of monolithic, translucent, yttria-stabilized, tetragonal zirconia polycrystals (Y-TZPs).

METHODS AND MATERIALS

Two commercially available Y-TZP brands-SuperfectZir High Translucency (Aidite Technology Co, China) and Katana HT (Kuraray Noritake Dental, Japan) were assessed. For each brand of Y-TZP, materials of four coloring types, including noncolored (NC), colored by staining (CS), precolored (PC), and multilayered (ML) specimens were investigated after hydrothermal aging in an autoclave at 134°C/0.2 MPa for 0 (control group), 5, 10, and 20 hours. The tetragonal-to-monoclinic phase transformation, surface roughness, flexural strength, and structural reliability (Weibull analysis) were measured and statistically analyzed (α=0.05). The subsurface microstructure was analyzed with scanning electron microscopy.

RESULTS

The group ML exhibited the lowest flexural strength and Weibull characteristic strength among the four coloring types (p<0.05). Slight increases in the monoclinic phase volume, flexural strength, and Weibull characteristic strength were observed after hydrothermal aging (pall<0.05). Regardless of coloring type, no significant effects of aging on the Weibull modulus or surface roughness were found for the tested materials. Compared with the Katana HT cross-sections, the SuperfectZir High Translucency cross-sections exhibited a similar but thicker transformation zone.

CONCLUSIONS

The coloring procedure and material type were found to affect the mechanical properties and aging resistance of translucent monolithic Y-TZP ceramics. Regardless of the aging time, the surface roughness of the tested Y-TZP ceramics remained unchanged.