N-Net: A novel dense fully convolutional neural network for thyroid nodule segmentation

Medical image segmentation is an essential component of computer-aided diagnosis (CAD) systems. Thyroid nodule segmentation using ultrasound images is a necessary step for the early diagnosis of thyroid diseases. An encoder-decoder based deep convolutional neural network (DCNN), like U-Net architecture and its variants, has been extensively used to deal with medical image segmentation tasks. In this article, we propose a novel N-shape dense fully convolutional neural network for medical image segmentation, referred to as N-Net. The proposed framework is composed of three major components: a multi-scale input layer, an attention guidance module, and an innovative stackable dilated convolution (SDC) block. First, we apply the multi-scale input layer to construct an image pyramid, which achieves multi-level receiver field sizes and obtains rich feature representation. After that, the U-shape convolutional network is employed as the backbone structure. Moreover, we use the attention guidance module to filter the features before several skip connections, which can transfer structural information from previous feature maps to the following layers. This module can also remove noise and reduce the negative impact of the background. Finally, we propose a stackable dilated convolution (SDC) block, which is able to capture deep semantic features that may be lost in bilinear upsampling. We have evaluated the proposed N-Net framework on a thyroid nodule ultrasound image dataset (called the TNUI-2021 dataset) and the DDTI publicly available dataset. The experimental results show that our N-Net model outperforms several state-of-the-art methods in the thyroid nodule segmentation tasks.

Roseburia hominis Alleviates Neuroinflammation via Short-Chain Fatty Acids through Histone Deacetylase Inhibition

SCOPE

The gut microbiota plays a prominent role in gut-brain interactions and gut dysbiosis is involved in neuroinflammation. However, specific probiotics targeting neuroinflammation need to be explored. In this study, the antineuroinflammatory effect of the potential probiotic Roseburia hominis (R. hominis) and its underlying mechanisms is investigated.

METHODS AND RESULTS

First, germ-free (GF) rats are orally treated with R. hominis. Microglial activation, proinflammatory cytokines, levels of short-chain fatty acids, depressive behaviors, and visceral sensitivity are assessed. Second, GF rats are treated with propionate or butyrate, and microglial activation, proinflammatory cytokines, histone deacetylase 1 (HDAC1), and histone H3 acetyl K9 (Ac-H3K9) are analyzed. The results show that R. hominis administration inhibits microglial activation, reduces the levels of IL-1α, INF-γ, and MCP-1 in the brain, and alleviates depressive behaviors and visceral hypersensitivity in GF rats. Moreover, the serum levels of propionate and butyrate are increased significantly in the R. hominis-treated group. Propionate or butyrate treatment reduces microglial activation, the levels of proinflammatory cytokines and HDAC1, and promotes the expression of Ac-H3K9 in the brain.

CONCLUSION

These findings suggest that R. hominis alleviates neuroinflammation by producing propionate and butyrate, which serve as HDAC inhibitors. This study provides a potential psychoprobiotic to reduce neuroinflammation.

Active and passive defects in tetragonal tungsten bronze relaxor ferroelectrics

Tetragonal tungsten bronze (TTB) based oxides constitute a large family of dielectric materials which are known to exhibit complex distortions producing incommensurately modulated superstructures as well as significant local deviations from their average symmetry. The local deviations produce diffuse scattering in diffraction experiments. The structure as well as the charge dynamics of these materials are anticipated to be sensitive to defects, such as cation or oxygen vacancies. In this work, in an effort to understand how the structural and charge dynamical properties respond to these two types of vacancy defects, we have performed measurements of dielectric susceptibilities and single crystal diffraction experiments of two types of TTB materials with both 'filled' (Ba₂NdFeNb₄O₁₅and Ba₂PrFeNb₄O₁₅) and 'unfilled' (Sr_0.5Ba_0.5Nb₂O₆) cation sublattices. We also perform these measurements before and after oxygen annealing, which alters the oxygen vacancy concentrations. Surprisingly, we find that many of the diffuse scattering features that are present in the unfilled structure are also present in the filled structure, suggesting that the random fields and disorder that are characteristic of the unfilled structure are not responsible for many of the local structural features that are reflected in the diffuse scattering. Oxygen annealing clearly affected both color and dielectric properties, consistent with a diminishment of the oxygen vacancy concentration, but had little effect on observed diffuse patterns.

Hot Carrier Transport and Carrier Multiplication Induced High Performance Vertical Graphene/Silicon Dynamic Diode Generator

Dynamic semiconductor diode generators (DDGs) offer a potential portable and miniaturized energy source, with the advantages of high current density, low internal impedance, and independence of the rectification circuit. However, the output voltage of DDGs is generally as low as 0.1-1 V, owing to energy loss during carrier transport and inefficient carrier collection, which requires further optimization and a deeper understanding of semiconductor physical properties. Therefore, this study proposes a vertical graphene/silicon DDG to regulate the performance by realizing hot carrier transport and collection. With instant contact and separation of the graphene and silicon, hot carriers are generated by the rebounding process of built-in electric fields in dynamic graphene/silicon diodes, which can be collected within the ultralong hot electron lifetime of graphene. In particular, monolayer graphene/silicon DDG outputs a high voltage of 6.1 V as result of ultrafast carrier transport between the monolayer graphene and silicon. Furthermore, a high current of 235.6 nA is generated due to the carrier multiplication in graphene. A voltage of 17.5 V is achieved under series connection, indicating the potential to supply electronic systems through integration design. The graphene/silicon DDG has applications as an in situ energy source for harvesting mechanical energy from the environment.

POS0343 TREATMENT PERSISTENCE AND ADHERENCE AMONG PATIENTS WITH JUVENILE IDIOPATHIC ARTHRITIS RECEIVING ABATACEPT OR TNF INHIBITORS USING US CLAIMS DATA

Background

Juvenile idiopathic arthritis (JIA) is the most common rheumatic condition among children and teens1 and contributes to a diminished quality of life.2 Previous data underscore the potential for abatacept to improve health-related outcomes in patients with JIA after demonstrating poor responses to other DMARDs.3 Patients with RA show greater persistence on abatacept vs TNF inhibitors (TNFi), and this should also be confirmed in patients with JIA.4

Objectives

To evaluate treatment persistence and adherence at 12- and 18-month follow-up in patients with JIA newly initiating either abatacept or a TNFi.

Methods

This analysis used data from the IQVIA PharMetrics Plus claims database from Jan 2008–Apr 2021. We identified patients with ≥ 1 claim of JIA diagnosis after Jan 2008, who were < 18 years old at initial diagnosis, had ≥ 1 claim of abatacept or TNFi treatment (adalimumab, etanercept, golimumab) following diagnosis, had continuous enrollment in medical and pharmacy benefits for ≥ 12 months before index date (first prescription of abatacept or TNFi), and had 12 or 18 months’ continuous medical and pharmacy enrollment after index date. Patients receiving abatacept or TNFi treatment ≤ 12 months prior to index date and patients initiating combined abatacept + TNFi treatment on the index date were excluded. Specific outcomes included: discontinuation (absence of a new prescription for index treatment within the gap of 5× treatment half-life), persistence rate (proportion of patients continuing index medication without any gaps exceeding 5× treatment half-life), and treatment adherence (defined as medication possession ratio [MPR, proportion of follow-up period where medication supply is available] and proportion of days covered [PDC, proportion of follow-up period where a patient is covered by a given drug]). All outcomes were reported at 12 and 18 months. All statistical analyses are descriptive with the intent for hypothesis generation.

Results

There were 2847 patients (abatacept, n = 111; TNFi, n = 2736) at 12-month follow-up; fewer completed the 18-month follow-up (2403 patients: abatacept, n = 94; TNFi, n = 2309). At index date, treatment groups were similar for sex, geographic location, and comorbidities (Table 1). Numerically higher persistence was observed in patients prescribed abatacept compared with TNFi overall at both time points. Abatacept persistence was higher than etanercept but similar to adalimumab (Figure 1). At 12 months, the percent of patients with PDC ≥ 0.8 was 57% for abatacept, 51% for adalimumab, and 38% for etanercept, while MPR ≥ 0.8 was 63% for abatacept, 55% for adalimumab, and 42% for etanercept. Patients prescribed abatacept had numerically greater proportions of PDC ≥ 0.8 (abatacept, 48%; adalimumab, 40%; etanercept, 29%) and MPR ≥ 0.8 (abatacept, 53%; adalimumab, 44%; etanercept, 33%) at 18 months.

Table 1.

Baseline characteristics of patients with 12-month follow-up data

CharacteristicAbatacept (n = 111)TNFi (n = 2736)Age, years, mean (SD)14.4 (3.8)12.6 (4.6)Female sex89 (80.2)1930 (70.5)Geographic region South43 (38.7)865 (31.6) Midwest40 (36.0)818 (29.9) West9 (8.1)408 (14.9) East19 (17.1)540 (19.7) Unknown0 (0)105 (3.8)Comorbidities Asthma9 (8.1)275 (10.1) COPD11 (9.9)323 (11.8) Cardiovascular disease14 (12.6)222 (8.1) Uveitis14 (12.6)321 (11.7) Iridocyclitisa12 (10.8)216 (7.9)CCI score, mean (SD)0.58 (0.73)0.46 (0.68)

Data are shown as n (%) unless otherwise specified.

aSubgroup disease under uveitis.

CCI, Charlson Comorbidity Index; COPD, chronic obstructive pulmonary disease.

Conclusion

The present findings suggest that patients with JIA initiating abatacept treatment display numerically higher persistence and adherence compared with patients treated with TNFis at both 12- and 18-months’ follow-up.

References

[1]Prakken B, et al. Lancet 2011;377:2138–49.

[2]Lovell DJ, et al. Arthritis Rheumatol 2015;67:2759–70.

[3]Ruperto N, et al. Lancet 2008;372:383–91.

[4]Han X, et al. J Health Econ Outcomes Res 2021;8:71–8.

Acknowledgements

This study was sponsored by Bristol Myers Squibb. Medical writing and editorial assistance were provided by Ryan Miller, of Caudex, and were funded by Bristol Myers Squibb. Project analysis was provided by Akshay Vinod (Mu Sigma).

Disclosure of Interests

Ching-An Wang Consultant of: Novartis (used to work there as an external contractor from Jan 2016 to Apr 2021), Employee of: Bristol Myers Squibb, Robert Wong Shareholder of: Bristol Myers Squibb, Employee of: Bristol Myers Squibb, Tzuyung Douglas Kou Shareholder of: Bristol Myers Squibb, Employee of: Bristol Myers Squibb, Hanke Zheng Employee of: Bristol Myers Squibb, Keith Wittstock Shareholder of: Bristol Myers Squibb, Employee of: Bristol Myers Squibb, Vadim Khaychuk Shareholder of: Bristol Myers Squibb, Employee of: Bristol Myers Squibb, Vardhaman PATEL Shareholder of: Bristol Myers Squibb, Employee of: Bristol Myers Squibb

[Self-awareness rate and its influencing factors of their infection status among hepatitis B surface antigen-positive persons aged 15-69 years in China]

Objectives: To understand the awareness rate and its influencing factors of their HBV infection status among HBsAg-positive persons aged 15-69 years in China. Methods: A cross-sectional design was used to conduct a questionnaire survey on the awareness of their infection status among HBsAg-positive persons aged 15-69 years who were identified in the 2020 national hepatitis B seroepidemiology survey. The awareness rate of the whole respondent and respondents with different characteristics were described, and the differences were compared with the χ² test. The logistic regression model was used to analyze the factors influencing the awareness rate. Results: The overall awareness rate among the respondents was 43.10% (1 828/4 241). The awareness rate was lower in males than in females (41.30% vs. 44.65%). The awareness rate was lower in the 60-69-years-old age group than in other age groups (30.38% vs. 36.77%-57.58%). The awareness rate was lower in rural areas than in urban areas (39.43% vs. 47.32%). The awareness rate was lower in regions with a per capita gross domestic product (GDP) below RMB 54 000 than in regions with a per capita GDP of RMB 54 000 and above (36.81% vs. 41.61%-50.30%). The awareness rate was lower in respondents without other liver diseases than with other liver diseases (41.52% vs. 60.68%). The awareness rate was lower in respondents without a family history of hepatitis B-related disease or unknown family history than with a family history (43.58% vs. 68.26%; 24.71% vs. 68.26%). Multivariate logistic regression analysis showed that male [odds ratio (OR)=0.841, 95% confidence interval (CI): 0.734-0.964], high school and below [primary school and below, junior middle school, high school/technical secondary school, OR (95%CI): 0.247 (0.190-0.321), 0.451 (0.352-0.577), 0.634 (0.486-0.827)], rural areas (OR=0.822, 95%CI: 0.715-0.945) and regions with a per capita GDP below RMB 80 000 [54 000-80 000, OR (95%CI): 0.810 (0.688-0.954), below RMB 54 000, OR (95%CI): 0.793 (0.669-0.941)] were the negative factors influencing the awareness rate. While 30-39-years-old (OR=2.089, 95%CI: 1.626-2.683) and 40-49-years-old (OR=1.590, 95%CI: 1.250-2.023) age groups, with other liver diseases (OR=2.244, 95%CI: 1.754-2.871) and family history related to hepatitis B (OR=2.688, 95%CI: 2.242-3.223) were the positive factors influencing the awareness rate. Conclusion: The overall awareness rate of their infection status among HBsAg-positive persons aged 15-69 years is 43.10% in China. Health promotion and coverage expansion on HBV screening should be further strengthened to achieve the proposed World Health Organization's target of 90% HBV infection diagnosis rate by 2030.

A Multi-Scale Densely Connected Convolutional Neural Network for Automated Thyroid Nodule Classification

Automated thyroid nodule classification in ultrasound images is an important way to detect thyroid nodules and to make a more accurate diagnosis. In this paper, we propose a novel deep convolutional neural network (CNN) model, called n-ClsNet, for thyroid nodule classification. Our model consists of a multi-scale classification layer, multiple skip blocks, and a hybrid atrous convolution (HAC) block. The multi-scale classification layer first obtains multi-scale feature maps in order to make full use of image features. After that, each skip-block propagates information at different scales to learn multi-scale features for image classification. Finally, the HAC block is used to replace the downpooling layer so that the spatial information can be fully learned. We have evaluated our n-ClsNet model on the TNUI-2021 dataset. The proposed n-ClsNet achieves an average accuracy (ACC) score of 93.8% in the thyroid nodule classification task, which outperforms several representative state-of-the-art classification methods.

Dual Functions of MDP Monomer with De- and Remineralizing Ability

Methacryloyloxydecyl dihydrogen phosphate (MDP) has been speculated to induce mineralization, but there has been no convincing evidence of its ability to induce intrafibrillar mineralization. Polymers play a critical role in biomimetic mineralization as stabilizers/inducers of amorphous precursors. Hence, MDP-induced biomimetic mineralization without polymer additives has not been fully verified or elucidated. By combining 3-dimensional stochastic optical reconstruction microscopy, surface zeta potentials, contact angle measurements, inductively coupled plasma-optical emission spectroscopy, transmission electron microscopy, atomic force microscopy, and Fourier transform infrared spectroscopy with circular dichroism, we show that amphiphilic MDP can not only demineralize dentin by releasing protons as an acidic functional monomer but also infiltrate collagen fibrils (including dentin collagen), unwind the triple helical structure by breaking hydrogen bonds, and finally immobilize within collagen. MDP-bound collagen functions as a huge collagenous phosphoprotein (HCPP), in contrast to chemical phosphorylation modifications. HCPP can induce biomimetic mineralization itself without polymer additives by alternatively attracting calcium and phosphate through electrostatic attraction. Therefore, we herein propose the dual functions of amphiphilic MDP monomer with de- and remineralizing ability. MDP in the free state can demineralize dentin substrates by releasing protons, whereas MDP in the collagen-bound state as HCPP can induce intrafibrillar mineralization. The dual functions of MDP monomer with de- and remineralization properties might create a new epoch in adhesive dentistry and preventive dentistry.

[Yi Wan She--Huzhou medical association in the late Ming Dynasty]

Yi Wan She, as a medical association in the Huzhou area, was organised by Lu Mingquan, Lu Shilong, Jin Desheng and other doctors in the late Ming Dynasty, developing daily medical theoretical discussions. It built up a hospital named Tian, paid deference to ancient medical doctors, and participated in activities to fight epidemics, organised by Hui Min Pharmacy, such as drug delivery, as an association of local affairs. This was recorded in Yi Wan She Cao and Lu Shi San Shi Yi Yan.

Effects of ciprofol for the induction of general anesthesia in patients scheduled for elective surgery compared to propofol: a phase 3, multicenter, randomized, double-blind, comparative study

OBJECTIVE

Ciprofol is a newly developed intravenous sedative-hypnotic drug. The objective of the study was to prove whether ciprofol was non-inferior to propofol for the successful induction of general anesthesia. The ideal post-induction sedation level was assessed by comparing patients' clinical symptoms and their hemodynamic effects in responding to noxious stimuli, mostly tracheal intubation and bispectral index (BIS) alterations following ciprofol/propofol administration.

PATIENTS AND METHODS

In this multi-center, randomized, double-blind phase 3 trial, selective surgery patients were randomly assigned in a 1:1 ratio to either ciprofol 0.4 mg/kg (n = 88) or propofol 2.0 mg/kg (n = 88) groups. The primary endpoint was the percentage of patients with successful anesthesia inductions. Secondary endpoints included the times to successful induction of general anesthesia and loss of the eyelash reflex, changes in BIS, as well as safety indicators.

RESULTS

The anesthesia induction success rates for both ciprofol 0.4 mg/kg and propofol 2 mg/kg groups were 100.0%, with a 95% CI lower success limit of -4.18% difference between the two groups, indicating that ciprofol was non-inferior to propofol. For secondary outcomes, the average time to successful anesthesia and loss of the eyelash reflex were 0.91 min and 0.80 min for ciprofol and 0.80 min and 0.71 min for propofol, respectively. The pattern of BIS changes with ciprofol was similar to propofol and stable during the anesthesia maintenance period. Safety was comparable with 88.6% TEAEs in the ciprofol group compared to 95.5% in the propofol group. The incidence of injection pain was significantly lower in the ciprofol group compared to the propofol group (6.8% vs. 20.5%, p < 0.05). In addition, the patients treated with ciprofol had a lesser increase in blood pressure and heart rate, and fewer cases with BIS > 60 within 15 min of intravenous administration, which indicated that ciprofol may provide a better ideal sedation level during the post-induction period under an equivalent dosing regimen to propofol.

CONCLUSIONS

Ciprofol for patients undergoing selective surgery is a new option for the induction of general anesthesia.

Dlx3 Ubiquitination by Nuclear Mdm2 Is Essential for Dentinogenesis in Mice

Dentin is a major mineralized component of teeth. Odontoblasts are responsible for synthesis and secretion of dentin matrix. Previously, it has been demonstrated in a cell culture system that the E3 ubiquitin ligase, murine double minute 2 (Mdm2), promotes odontoblast-like differentiation of mouse dental papilla cells (mDPCs) by ubiquitinating p53 and the odontoblast-specific substrate Dlx3. However, whether Mdm2 plays an essential role in vivo in odontoblast differentiation and dentin formation remains unknown. In this study, we investigated the in vivo functions of Mdm2 using Dmp1-Cre;Mdm2 flox/flox mice combined with multiple histological and molecular biological methods. The results showed that Mdm2 deletion in the odontoblast layer led to defects in odontoblast differentiation and dentin formation. Unexpectedly, specific inhibition of the Mdm2-p53 axis in wild-type mice by injection of a small-molecule inhibitor Nutlin-3a indicated that the role of Mdm2 in dentinogenesis was p53 independent, which was inconsistent with the previous in vitro study. In situ proximity ligation assay (PLA) showed that Mdm2 interacted with and ubiquitinated Dlx3 in the odontoblast nucleus of mouse molars. Dlx3 promoted the translocation of Mdm2 to the nucleus, and in turn, the nuclear Mdm2 mediated ubiquitination of Dlx3 and promoted the odontoblast-like differentiation of mDPCs. Dlx3 interacted with Mdm2 through its C-terminal domain. Deletion of the C-terminal domain of Dlx3 reversed the enhanced odontoblast-like differentiation and the activation of Dspp promoter mediated by overexpression of wild-type or nuclear Mdm2. Our findings suggest that nuclear Mdm2 mediates ubiquitination of the transcription factor Dlx3, which is essential for Dlx3 transcriptional activity on Dspp as well as subsequent odontoblast differentiation and dentin formation.

[Differential expression profile of miRNAs in amniotic fluid exosomes from fetuses with Down syndrome]

OBJECTIVE

To investigate the role of miRNAs in amniotic fluid exosomes in growth and development of fetuses with Down syndrome (DS).

METHODS

Amniotic fluid were collected from 20 fetuses with DS and 20 normal fetuses (control) to extract amniotic exosome miRNA. MicroRNA sequencing technique was used to identify the differentially expressed miRNAs between the two groups, for which gene ontology (GO) and pathway analysis was performed. Three differentially expressed miRNAs with the strongest correlation with DS phenotype were selected for qPCR verification. Dual luciferase reporter assay was used to verify the activity of let-7d-5p for targeted regulation of BACH1.

RESULTS

We identified 15 differentially expressed miRNAs in DS as compared with the control group, among which 7 miRNAs were up-regulated and 8 were down-regulated. Target gene prediction results showed that the differentially expressed miRNAs targeted 17 DS-related genes. GO analysis revealed that the main functions of the target genes involved protein binding, protein transport, ATP binding, transferase activity and synapses. Pathway analysis revealed that the functional pathways were closely related with the development of the nervous system. qPCR results showed that the expression levels of miR-140-3p and let-7d-5p were significantly lower in DS group than in the control group (P < 0.05), as was consistent with miRNA sequencing results; the expression level of miR-4512 was significantly higher in DS group than in control group (P < 0.05), which was contrary to miRNA sequencing results. The results of double luciferase reporter gene assay confirmed that let-7d-5p was capable of targeted regulation of BACH1 expression.

CONCLUSION

Let-7d-5p in amniotic fluid exosomes may promote oxidative stress events in the brain of fetuses with DS by regulating BACH1 expression.

Efficacy and safety of HSK3486 for the induction and maintenance of general anesthesia in elective surgical patients: a multicenter, randomized, open-label, propofol-controlled phase 2 clinical trial

OBJECTIVE

To evaluate the efficacy and safety of HSK3486 for the induction and maintenance of general anesthesia in elective surgical patients, but excluding emergency, cardiothoracic, cerebral and endoscopic sinus cases.

PATIENTS AND METHODS

A total of 40 eligible patients were randomly assigned to HSK3486 (n = 30) or propofol (n = 10) dosage groups in a ratio of 3:1. Drugs were administered as a bolus injection of 0.4 mg/kg (HSK3486) or 2.0 mg/kg (propofol) for induction, followed by maintenance infusion with the same anesthetic. An additional 6 non-randomized patients received propofol (2.0 mg/kg) for induction and were given HSK3486 for maintenance.

RESULTS

The primary efficacy endpoint - the success rate of anesthesia maintenance - was 100% in the 3 arms. The secondary efficacy endpoints included times from discontinuation of HSK3486 or propofol maintenance to full alertness, respiratory recovery, extubation and reaching the goal of the Aldrete score. Also, the proportion of patients who constantly maintained BIS40-60 or those with a period of BIS40-60 during maintenance anesthesia showed no significant difference in the HSK3486 and propofol groups (all p > 0.05). Patients who received HSK3486 exhibited a higher satisfaction score from anesthesiologists during the induction period (p = 0.024). The occurrence and types of treatment-emergent adverse events were similar among the 3 arms, both with a severity of grade 1 or 2. Drug-related hypotension occurred in 14 (46.7%) and 7 (70.0%) patients treated with HSK3486 and propofol, respectively.

CONCLUSIONS

HSK3486 exhibited good efficacy for the induction and maintenance of general anesthesia and was well tolerated by patients who underwent elective surgery.

[Effects on extravascular lung water of lung protective ventilation strategy applied on piglets with acute respiratory distress syndrome induced by paraquat]

Objective: To study the effects on extravascular lung water of lung protective ventilation strategy applying on piglets with acute respiratory distress syndrome (ARDS) induced by paraquat (PQ) under pulse indicating continuous cardiac output (PiCCO) monitoring. Methods: The piglets models with ARDS induced by PQ were established in June 2020 and all of them were received mechanical ventilation and divided into three groups according to tidal volume (V(T)) : small V(T) group (6 ml/kg) , middle V(T) group (10 ml/kg) and large V(T) group (15 ml/kg) , there were 5 piglets in each group. The positive end expiratory pressure (PEEP) were all setup on 10 cmH(2)O. The indexes such as arterial blood gas analysis, oxygenation index (OI) , extravascular lung water index (ELWI) and pulmonary vascular permeability index (PVPI) were monitored at time of before the model was established (baseline) , time of the model was established (t(0)) and 2 h (t(2)) , 4 h (t(4)) , 6 h (t(6)) after mechanical ventilation. Lung tissue were punctured at time of baseline, t(0) and t(6) to be stained by Hematoxylin-eosin (HE) staining and pulmonary pathology were observed under light microscopy. Results: The heart rate (HR) , mean arterial pressure (MAP) and partial pressure of carbon dioxide (PaCO(2)) of all groups were higher than the base value while the pH values, partial pressure of oxygen (PaO(2)) and OI were lower than the base value when the models were established (P<0.05) . After mechanical ventilation, the HR and MAP values of all groups at t(2), t(4) and t(6) were lower than t(0) while the PaCO(2) of t(4) and t(6) were all higher than t(0), the differences were statistically significant (P<0.05) . The PaO(2) and OI of all groups showed a trend of rising at first and then decreasing after mechanical ventilation. The MAP, PaO(2), PaCO(2) and OI of the middle V(T) group and large V(T) group were apparently lower than that of the small V(T) group at t(2), t(4) and t(6) (P<0.05) . The ELWI and PVPI at t(0) of all groups were higher than that of baseline (P<0.05) . The ELWI of the small V(T) group at t(6) were lower than t(0) of the same group and t(6) of the middle V(T) group and large V(T) group (P<0.05) . HE staining showed congestion and edema of alveolar tissue, swelling of capillaries, exudation of red blood cells and widening of alveolar septum in piglets after successful modeling. And further widening of alveolar septum and rupture of alveolar septum could be seen in the lung tissues of each group at t(6), and the injury was the slightest in the small V(T) group. Conclusion: The lung protective ventilation strategy can alleviate the extravascular lung water and ARDS induced by PQ and improve oxygenation.

Restoring Carboxylates on Highly Modified Alginates Improves Gelation, Tissue Retention and Systemic Capture

Alginate hydrogels are gaining traction for use in drug delivery, regenerative medicine, and as tissue engineered scaffolds due to their physiological gelation conditions, high tissue biocompatibility, and wide chemical versatility. Traditionally, alginate is decorated at the carboxyl group to carry drug payloads, peptides, or proteins. While low degrees of substitution do not cause noticeable mechanical changes, high degrees of substitution can cause significant losses to alginate properties including complete loss of calcium cross-linking. While most modifications used to decorate alginate deplete the carboxyl groups, we propose that alginate modifications that replenish the carboxyl groups could overcome the loss in gel integrity and mechanics. In this report, we demonstrate that restoring carboxyl groups during functionalization maintains calcium cross-links as well as hydrogel shear-thinning and self-healing properties. In addition, we demonstrate that alginate hydrogels modified to a high degree with azide modifications that restore the carboxyl groups have improved tissue retention at intramuscular injection sites and capture blood-circulating cyclooctynes better than alginate hydrogels modified with azide modifications that deplete the carboxyl groups. Taken together, alginate modifications that restore carboxyl groups could significantly improve alginate hydrogel mechanics for clinical applications. STATEMENT OF SIGNIFICANCE: Chemical modification of hydrogels provides a powerful tool to regulate cellular adhesion, immune response, and biocompatibility with local tissues. Alginate, due to its biocompatibility and easy chemical modification, is being explored for tissue engineering and drug delivery. Unfortunately, modifying alginate to a high degree of substitution consumes carboxyl group, which are necessary for ionic gelation, leading to poor hydrogel crosslinking. We introduce alginate modifications that restore the alginate's carboxyl groups. We demonstrate that modifications that reintroduce carboxyl groups restore gelation and improve gel mechanics and tissue retention. In addition to contributing to a basic science understanding of hydrogel properties, we anticipate our approach will be useful to create tissue engineered scaffolds and drug delivery platforms.

Overoxidized poly(3,4-ethylenedioxythiophene)-gold nanoparticles-graphene-modified electrode for the simultaneous detection of dopamine and uric acid in the presence of ascorbic acid

An innovative, ternary nanocomposite composed of overoxidized poly(3,4-ethylenedioxythiophene) (OPEDOT), gold nanoparticles (AuNPs), and electrochemically reduced graphene oxide (ERGO) was prepared on a glassy carbon electrode (GCE) (OPEDOT–AuNPs–ERGO/GCE) through homogeneous chemical reactions and heterogeneous electrochemical methods. The morphology, composition, and structure of this nanocomposite were characterized by transmission electron microscopy, scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The electrochemical properties of the OPEDOT–AuNPs–ERGO/GCE were investigated by cyclic voltammetry using potassium ferricyanide and hexaammineruthenium(III) chloride redox probe systems. This modified electrode shows excellent electro-catalytic activity for dopamine (DA) and uric acid (UA) under physiological pH conditions, but inhibits the oxidation of ascorbic acid (AA). Linear voltammetric responses were obtained when DA concentrations of approximately 4.0–100 μM and UA concentrations of approximately 20–100 μM were used. The detection limits (S/N=3) for DA and UA were 1.0 and 5.0 μM, respectively, under physiological conditions and in the presence of 1.0 mM of AA. This developed method was applied to the simultaneous detection of DA and UA in human urine, where satisfactory recoveries from 96.7% to 105.0% were observed. This work demonstrates that the developed OPEDOT–AuNPs–ERGO ternary nanocomposite, with its excellent ion-selectivity and electro-catalytic activity, is a promising candidate for the simultaneous detection of DA and UA in the presence of AA in physiological and pathological studies.

•

Facile preparation of graphene-based hybrid composite OPEDOT–AuNPs–ERGO onto GCE.

•

The OPEDOT–AuNPs–ERGO/GCE was endued with excellent electrocatalytic activity and ion-selectivity.

•

The OPEDOT–AuNPs–ERGO/GCE was found highly selective and sensitive determination of DA and UA in the presence of AA.

•

The method is expected to be applied to the detection of DA and UA under physiological and pathological conditions.