[Microcontact printing and its application prospect in bone tissue engineering]

The application of bone tissue engineering regeneration technology is expected to repair maxillofacial bone tissue defects caused by tumors, trauma, etc. Surface patterning occupies an important position in bone tissue engineering. Microcontact printing is an emerging technology through which the elastic stamp contacts with the substance and materials used as ink can be transferred from stamp to substance to form patterns. The biggest characteristic of the technology is to fabricate high-throughput and high-accuracy patterned surface, making it widely applied. This review summarized the application and optimization of microcontact printing, and prospected its application in bone tissue engineering.

POS0320 POOR PROGNOSIS PREDICTION IN ANTI-MDA5 POSITIVE DERMATOMYOSITIS ASSOCIATED WITH INTERSTITIAL LUNG DISEASE: THE CROSS-CAR DECISION TREE MODEL

Background:

The prognosis of anti-melanoma differentiation-associated gene 5 positive dermatomyositis (anti-MDA5+ DM) – associated interstitial lung disease (ILD) is poor and heterogeneity.

Objectives:

The aim of this study was to evaluate prognostic factors and to develop a simple and generally applicable bedside decision tree model for predicting outcomes in patients with anti-MDA5+ DM and to guide treatment.

Methods:

We analyzed data for 246 anti-MDA5+ DM patients from Myositis Study Group-Jiangsu, a multicenter cohort across eighteen tertiary hospitals in Jiangsu province, from March 2019 to October 2020. The primary end point was all-cause death, and the secondary end point was occurring of rapidly progressive-ILD (rp-ILD). We used a multivariable Cox proportional hazards model to identify the independent prognostic risk factors of death and rp-ILD respectively. A decision-tree prediction model was developed by using data from 10 hospital of southern region (n=163), with validation by using contemporaneous data from northern region (n=83).

Results:

To assess the risk of rp-ILD, we developed a combined risk score, the CROSS score, that included the following values and scores: C-reactive protein (≤8mg/L, 0; >8mg/L, 3), anti-Ro52 antibody (negative, 0; positive, 4), Sex (Female, 0; Male, 2) and Short course of disease (More than 3 months, 0; Less than 3 months, 2). The mortality risk was identified by the CAR score, including C-reactive protein (≤8mg/L, 0; >8mg/L, 1), Alanine Transaminase (≤50units/L, 0; >50units/L, 1) and rp-ILD (non-rpILD, 0; rp-ILD, 3). We divided patients into three risk groups according to the CROSS score: low, 0 to 3; medium, 4 to 7; and high 8-11. And then Use of a simple decision tree prediction model permitted stratification into three different outcome prediction groups. High-risk patients had significantly higher mortality rates than low- and medium-risk patients in both discovery and validation cohorts (p < 0.0001).

Conclusion:

The CROSS-CAR decision tree model is easy to evaluate the poor prognostic risk in MDA5+ DM patients during any follow-up period. Unnecessary lung examination, such as chest CT scan and arterial blood gas analysis was avoided in low- and medium- rpILD risk patients. The special ambulance, with red cross sign tagged on car in China, may help to screen the high risk patients and to guide further treatment.

Disclosure of Interests:

None declared

Remote Mesoscopic Signatures of Induced Magnetic Texture in Graphene

Mesoscopic conductance fluctuations are a ubiquitous signature of phase-coherent transport in small conductors, exhibiting universal character independent of system details. In this Letter, however, we demonstrate a pronounced breakdown of this universality, due to the interplay of local and remote phenomena in transport. Our experiments are performed in a graphene-based interaction-detection geometry, in which an artificial magnetic texture is induced in the graphene layer by covering a portion of it with a micromagnet. When probing conduction at some distance from this region, the strong influence of remote factors is manifested through the appearance of giant conductance fluctuations, with amplitude much larger than e^{2}/h. This violation of one of the fundamental tenets of mesoscopic physics dramatically demonstrates how local considerations can be overwhelmed by remote signatures in phase-coherent conductors.

Diverse crystal size effects in covalent organic frameworks

Crystal size effect is of vital importance in materials science by exerting significant influence on various properties of materials and furthermore their functions. Crystal size effect of covalent organic frameworks (COFs) has never been reported because their controllable synthesis is difficult, despite their promising properties have been exhibited in many aspects. Here, we report the diverse crystal size effects of two representative COFs based on the successful realization of crystal-size-controlled synthesis. For LZU-111 with rigid spiral channels, size effect reflects in pore surface area by influencing the pore integrity, while for flexible COF-300 with straight channels, crystal size controls structural flexibility by altering the number of repeating units, which eventually changes sorption selectivity. With the understanding and insight of the structure-property correlation not only at microscale but also at mesoscale for COFs, this research will push the COF field step forward to a significant advancement in practical applications.

Crystal size effects are of vital importance to understand various properties and functions of a material but have not been reported for Covalent Organic Frameworks (COFs). Here, the authors report a crystal-size-controlled synthesis of two COFs and look into different crystal size effects.

Antimalarial agent artesunate induces G0/G1 cell cycle arrest and apoptosis via increasing intracellular ROS levels in normal liver cells

Artesunate (ARS) has been shown to be highly effective against chloroquine-resistant malaria. In vitro studies reported that ARS has anticancer effects; however, its detrimental action on cancer cells may also play a role in its toxicity toward normal cells and its potential toxicity has not been sufficiently researched. In this study, we investigated the possible cytotoxic effects using normal BRL-3A and AML12 liver cells. The results showed that ARS dose-dependently inhibited cell proliferation and arrested the G0/G1 phase cell cycle in both BRL-3A and AML12 liver cells. Western blotting demonstrated that ARS induced a significant downregulation of cyclin-dependent kinase-2 (CDK2), CDK4, cyclin D1, and cyclin E1 in various levels and then caused apoptosis when the Bcl-2/Bax ratio decreased. Conversely, the levels of intracellular reactive oxygen species (ROS) were increased. The ROS scavenger N-acetylcysteine can significantly inhibit cell cycle arrest and apoptosis induced by ARS. Thus, the data confirmed that ARS exposure impairs normal liver cell proliferation by inducing G0/G1 cell cycle arrest and apoptosis, and this detrimental action may be associated with intracellular ROS accumulation. Collectively, the possible side effects of ARS on healthy normal cells cannot be neglected when developing therapies.

0559 Association of Rapid Eye Movement Sleep with Insulin Resistance in Han Chinese Patients With Obstructive Sleep Apnea

Introduction

Obstructive sleep apnea (OSA) is increasingly associated with insulin resistance. The underlying pathophysiology remains unclear but rapid eye movement (REM) sleep has been hypothesized to play a key role. To investigate the associations of insulin resistance with respiratory events and sleep duration during REM sleep, 4,062 Han Chinese individuals with suspected OSA were screened and 2,899 were analyzed.

Methods

We screened 4,062 participants with suspected OSA who underwent polysomnography in our sleep center from 2009 to 2016. Polysomnographic variables, biochemical indicators, and physical measurements were collected. Logistic regression analyses were conducted to determine the odds ratios (ORs) and 95% confidence intervals (95% CIs) for insulin resistance as assessed by hyperinsulinemia, the homeostasis model assessment of insulin resistance (HOMA-IR), fasting insulin resistance index (FIRI), and Bennet’s insulin sensitivity index (ISI).

Results

The final analyses included 2,899 participants. After adjusting for age, gender, body mass index, waist circumference, mean arterial pressure, smoking status, alcohol consumption, and the apnea and hypopnea index during non-REM sleep (AHINREM), the results revealed that AHI during REM sleep (AHIREM) was independently associated with insulin resistance; across higher AHIREM quartiles, the ORs (95% CIs) for hyperinsulinemia were 1.340 (1.022, 1.757), 1.210 (0.882, 1.660), and 1.632 (1.103, 2.416); those for abnormal HOMA-IR were 1.287 (0.998, 1.661), 1.263 (0.933, 1.711), and 1.556 (1.056, 2.293); those for abnormal FIRI were 1.386 (1.048, 1.835), 1.317 (0.954, 1.818), and 1.888 (1.269, 2.807); and those for abnormal Bennet’s ISI were 1.297 (1.003, 1.678), 1.287 (0.949, 1.747), and 1.663 (1.127, 2.452) (P &lt; 0.01 for all linear trends). Additionally, the results showed that for every 1-h increase in REM duration, the risk of hyperinsulinemia decreased by 22.3% (P &lt; 0.05).

Conclusion

The present study demonstrated that AHIREM was independently associated with hyperinsulinemia and abnormal HOMA-IR, FIRI, and Bennet’s ISI. Additionally, REM sleep duration was independently associated with hyperinsulinemia.

Support

This study was supported by Grants-in-aid from Shanghai Municipal Commission of Science and Technology (No.18DZ2260200).

0713 Association Between Obesity Indices And Obstructive Sleep Apnea Is Modified By Age In A Sex-specific Manner

Introduction

The beneficial effects of weight loss on obstructive sleep apnea (OSA) are highly variable. Whether the variability is associated with the effects of age and sex remains unclear. This study examined this issue with large cross-sectional data.

Methods

A total of 4600 adult males and 1156 females with suspected OSA were included in the study. Anthropometric measurements, polysomnographic variables, biochemical indicators, and medical history were collected for each subject. Multivariable linear regression with interaction terms was used to estimate the modification effect of age on the associations between OSA severity (assessed by apnea-hypopnea index, AHI) with obesity indices (body mass index, BMI; neck circumference, NC; waist circumference, WC) in a sex-specific manner, and vice versa.

Results

BMI, NC, and WC were all positively correlated with AHI after adjusting for potential confounders in all populations. In males, these associations were much stronger and more significant in younger than older individuals (P for interaction &lt; 0.001). For example, a 10% increase in BMI was independently associated with a 31.6% increase in AHI for males &lt; 40 years old, whereas the corresponding increases were 20.8% and 16.7% for males 40-60 and &gt;60 years old, respectively. By contrast, no modification effect of age was observed in females (P for interaction &gt; 0.05). A 10% increase in BMI was associated with 25.6%, 26.8%, and 23.8% increases in AHI for females &lt; 40, 40-60, and &gt;60 years old, respectively.

Conclusion

Age modifies the associations between obesity indices and OSA severity in a sex-specific manner, and vice versa. These findings may broaden the understanding of age- and sex-related heterogeneities in the pathogenic role of obesity in OSA, and may be beneficial for individualized risk evaluation and treatment management for patients with OSA.

Support

This study was funded by Shanghai Municipal Commission of Science and Technology (grant number.18DZ2260200); the National Key R&D Program of China (grant number: 2017YFC0112500); Multi-Center Clinical Research Project from the School of Medicine, Shanghai Jiao Tong University (grant number: DLY201502); and the Shanghai Shen-Kang Hospital Management Center Project (grant number: SHDC12015101 and 16CR3103B).

0601 Use of The Epworth Sleepiness Scale, the NoSAS, and the STOP-BANG Questionnaire to Identify Patients with Moderate-to-Severe Obstructive Sleep Apnea

Introduction

A variety of scales and questionnaires regarding sleep and sleep-related disorders have been widely used in scientific research and clinical practice, as important tools for differential diagnosis and rapid screening of complex sleep disorders, especially obstructive sleep apnea (OSA). However, the diagnostic efficacy of different scales and questionnaires for patients with different severity of OSA and of different demographic characteristics has not been clearly described. In this study, we evaluated the ability of the most popular scales, including the Epworth Sleepiness Scale (ESS), the NoSAS, and the STOP-BANG questionnaire in predicting moderate-to-severe obstructive sleep apnea (OSA) by gender.

Methods

This cross-sectional study screened 2,031 consecutive subjects referred with suspected OSA from 2012 to 2016. Anthropometric measurements, polysomnographic data, ESS, NoSAS scores and STOP-BANG scores were recorded. Receiver operating characteristic curve analyses were performed, and the final predictive models were verified in a validation cohort.

Results

A total of 1,840 adults were finally included. The STOP-BANG questionnaire afforded a better diagnostic accuracy than did the ESS, with different cutoffs for the two genders: 3 in males and 1 in females. A predictive model based on STOP-BANG yielded an area under the curve (AUC) of 0.918 (0.897-0.935), a sensitivity of 79.89%, and a specificity of 89.19%, in males; and an AUC of 0.951 (0.914-0.975), a sensitivity of 80.52%, and a specificity of 95.92%, in females. In the validation cohort, the sensitivity and specificity were respectively 85.44 and 93.00% in males and respectively 83.02 and 87.60% in females.

Conclusion

The STOP-BANG questionnaire was moderately effective when used to screen for moderate-to-severe OSA. A STOP-BANG-based predictive model afforded excellent diagnostic efficacy, which could be applied in clinical practice. However, gender differences must be considered.

Support

This study was supported by Grants-in-aid from Shanghai Municipal Commission of Science and Technology (Grant No.18DZ2260200).

0565 Obstructive Sleep Apnea, But Not Short Sleep Duration, is Independently Associated with Insulin Resistance: A Large-Scale Cohort Study

Introduction

Both short sleep duration and obstructive sleep apnea (OSA) seem to be associated with insulin resistance. However, the majority of previous studies addressing the relationship between OSA and insulin resistance did not evaluate short sleep duration, and vice versa. In this study, we used a large-scale hospital-based cross-sectional dataset, including 5,447 participants, to examine 1) whether objectively measured short sleep duration and OSA are independently associated with insulin resistance, and 2) whether the presence of OSA modulates the association between sleep duration and insulin resistance.

Methods

Participants were consecutively enrolled from our sleep center during the period from 2007 to 2017. The index of homeostasis model assessment insulin resistance (HOMA-IR) was calculated from insulin and glucose. Sleep duration was determined by standard polysomnography. The associations between sleep duration and insulin resistance were estimated by logistic regression analyses.

Results

A total of 5,447 participants (4507 OSA and 940 primary snorers) were included in the study. In comparison to primary snorers, OSA combined with extremely short sleep duration (&lt; 5 hours) increased the risk of insulin resistance by 34% (OR, 1.34; 95% CI, 1.01-1.77) after adjusting for confounding factors that are frequently associated with insulin resistance and OSA. In subgroup analysis stratified by sleep duration, the risk of insulin resistance in patients with a short sleep duration (5-6 hours or &lt; 5 hours) was increased in those with OSA compared to primary snorers, but not in the other three sleep duration groups (6 - 7, 7 - 8, and &gt; 8 hours).

Conclusion

OSA, but not short sleep duration, was independently associated with insulin resistance. It is worth noting that OSA combined with extremely short sleep duration showed a greater detrimental effect than OSA itself with regard to insulin resistance.

Support

This study was supported by grants-in-aid from Shanghai Municipal Commission of Science and Technology (Grant No.18DZ2260200).

Universal scaling of weak localization in graphene due to bias-induced dispersion decoherence

The differential conductance of graphene is shown to exhibit a zero-bias anomaly at low temperatures, arising from a suppression of the quantum corrections due to weak localization and electron interactions. A simple rescaling of these data, free of any adjustable parameters, shows that this anomaly exhibits a universal, temperature- (T) independent form. According to this, the differential conductance is approximately constant at small voltages (V < kBT/e), while at larger voltages it increases logarithmically with the applied bias. For theoretical insight into the origins of this behaviour, which is inconsistent with electron heating, we formulate a model for weak-localization in the presence of nonequilibrium transport. According to this model, the applied voltage causes unavoidable dispersion decoherence, which arises as diffusing electron partial waves, with a spread of energies defined by the value of the applied voltage, gradually decohere with one another as they diffuse through the system. The decoherence yields a universal scaling of the conductance as a function of eV/kBT, with a logarithmic variation for eV/kBT > 1, variations in accordance with the results of experiment. Our theoretical description of nonequilibrium transport in the presence of this source of decoherence exhibits strong similarities with the results of experiment, including the aforementioned rescaling of the conductance and its logarithmic variation as a function of the applied voltage.

Clinical characteristics of exposures to liquid laundry detergent packets

INTRODUCTION

Our objective was to describe the characteristics of liquid laundry detergent packet (LDP) exposures and to develop referral and treatment recommendations.

METHODS

This retrospective cohort study investigated LDP exposures reported to the National Poison Data System from January 1, 2013 through June 30, 2014. Three medical toxicologists reviewed the most significant exposures (n = 450).

RESULTS

Of 17,857 reported LDP exposures, 13,307 involved only an LDP (no other substance) and were followed to a known medical outcome. The median age was 2 years (range 12 days to 100 years). Approximately 10% of exposures reported a major or moderate effect. The most common symptom was vomiting (51.7%; n = 6875), but stridor or aspiration pneumonia and respiratory depression secondary to central nervous system effects also occurred. Two pediatric and two adult deaths occurred, but no causal mechanism leading to death could be identified in any of the deaths.

CONCLUSIONS

LDPs occasionally produce a toxidrome of vomiting, stridor, hypoxia, and sedation with metabolic acidosis and respiratory failure. These symptoms and the availability of LDPs highlight the need for referral and treatment recommendations and efforts to minimize unintentional exposures. Review of data from US poison centers may provide referral and treatment recommendations that improve patient outcomes.

Melioidosis in patients with suspected tuberculosis in Cambodia: a single-center cross-sectional study

SETTING

Melioidosis-Burkholderia pseudomallei infection-is increasingly recognized in Cambodia, a country with a high incidence of tuberculosis (TB). Melioidosis and TB can be clinically indistinguishable.

OBJECTIVE

To quantify the proportion of patients with clinically suspected TB who had melioidosis by testing sputum for B. pseudomallei.

DESIGN

This was a prospective, 6-month cross-sectional single-center study at a Cambodian provincial referral hospital among patients with suspicion of TB who provided sputum specimens for testing. TB was diagnosed using sputum Xpert^® MTB/RIF molecular assay or culture; melioidosis was diagnosed using sputum culture for B. pseudomallei.

RESULTS

Of 404 patients evaluated for possible TB, 52 (12.9%, 95%CI 9.8-16.5) had TB. Four patients (1.0%, 95%CI 0.3-2.5) had melioidosis; none had concurrent TB or an existing medical risk factor for melioidosis, although two were farmers, an occupational risk factor.

CONCLUSION

One per cent of patients being evaluated for TB at a Cambodian provincial referral hospital had culture-proven respiratory melioidosis, a highly lethal infection. None had previously recognized medical conditions that would increase their risk of melioidosis. Testing for melioidosis should be considered in patients presenting with suspected TB in Cambodia.

Identification of differential abundances of mRNA transcript in cumulus cells and CCND1 associated with yak oocyte developmental competence

The development of an accurate and noninvasive preselection process for competent oocytes is essential to achieve a highly efficient in vitro production (IVP) of embryos. Cumulus cells (CCs) have important functions in oocyte growth, development, maturation, and fertilization. It, therefore, is important to know if the quality of oocytes can be ascertained by assessment of gene expression of the surrounding CCs or not. The aim of this study was to identify differentially expressed genes in yak CCs from oocytes with varying developmental competences as possible biomarkers for distinguishing oocyte competence. The isolated CCs were pooled into immature and mature groups in accordance with the maturation outcome of oocytes. A total of 9516 genes were differentially expressed in the two CC categories (P <  0.05). With a minimum change of 2.5-fold, 45 up-regulated and 79 down-regulated genes were observed in CCs belonging to the mature group compared with those in the immature group (P <  0.01). These genes were primarily enriched for the cell cycle, meiosis, cell signaling, metabolism, and apoptosis. The selected candidate genes (CCND1, BMP15, GDF9, H19, KLF4, GPC1, SYCP3, and CTSB) were validated using quantitative real-time polymerase chain reaction (RT-qPCR) and there were expression patterns similar to those detected with transcriptome analysis. The CCs from fertilized oocytes arrested at the 2-cell (2-cell group), or 8-cell (8-cell group) stages or that developed into blastocysts (the blastocyst group) had a 1.5-, 1.8-, and 2.3-fold increase, respectively, in mRNA relative abundance of CCND1 compared with CCs from unfertilized oocytes (P <  0.05). The results with the RT-qPCR analysis confirmed that the relative abundance of CCND1 mRNA in CCs was associated with oocyte developmental competence. In conclusion, RNA-Seq is useful in extracting transcriptomes and selecting markers associated with oocyte developmental competence. Furthermore, the expression of the CCND1 gene in yak CCs can be used to preselect oocytes for IVP efficiency.