Filler Mixed Into Adhesives Does Not Necessarily Improve Their Mechanical Properties

OBJECTIVES

To investigate the influence of filler type/loading on the micro-tensile fracture strength (μTFS) of adhesive resins, as measured 'immediately' upon preparation and after 1-week water storage ('water-stored').

METHODS

The morphology and particle-size distribution of three filler particles, referred to as 'Glass-S' (Esschem Europe), 'BioUnion' (GC), and 'CPC_Mont', were correlatively characterized by SEM, TEM, and particle-size analysis. These filler particles were incorporated into an unfilled adhesive resin ('BZF-29unfilled', GC) in different concentrations to measure the 'immediate' μTFS. After 1-week water storage, the 'water-stored' μTFS of the experimental particle-filled adhesive resins with the most optimum filler loading, specific for each filler type, was measured. In addition, the immediate and water-stored μTFS of the adhesive resins of three experimental two-step universal adhesives based on the same resin matrix but varying for filler type/loading, coded as 'BZF-21' (containing silica and bioglass), 'BZF-29' (containing solely silica), and 'BZF-29_hv' (highly viscous with a higher silica loading than BZF-29), and of the adhesive resins of the gold-standard adhesives OptiBond FL ('Opti-FL', Kerr) and Clearfil SE Bond 2 ('C-SE2', Kuraray Noritake) was measured along with that of BZF-29unfilled (GC) serving as control/reference. Statistics involved one-way and two-way ANOVA followed by post-hoc multiple comparisons (α<0.05).

RESULTS

Glass-S, BioUnion, and CPC_Mont represent irregular fillers with an average particle size of 8.5-9.9 μm. Adding filler to BZF-29unfilled decreased μTFS regardless of filler type/loading. One-week water storage reduced μTFS of all adhesive resins except BZF-21, with the largest reduction in μTFS recorded for BZF-29unfilled. Among the three filler types, the μTFS of the 30 wt% Glass-S and 20 wt% BioUnion filled adhesive resin was not significantly different from the μTFS of BZF-29unfilled upon water storage.

CONCLUSIONS

Adding filler particles into adhesive resin did not enhance its micro-tensile fracture strength but appeared to render it less sensitive to water storage as compared to the unfilled adhesive resin investigated.

One-Step Multiview Clustering via Adaptive Graph Learning and Spectral Rotation

In graph based multiview clustering methods, the ultimate partition result is usually achieved by spectral embedding of the consistent graph using some traditional clustering methods, such as k -means. However, optimal performance will be reduced by this multistep procedure since it cannot unify graph learning with partition generation closely. In this article, we propose a one-step multiview clustering method through adaptive graph learning and spectral rotation (AGLSR). For every view, AGLSR adaptively learns affinity graphs to capture similar relationships of samples. Then, a spectral embedding is designed to take advantage of the potential feature space shared by different views. In addition, AGLSR utilizes a spectral rotation strategy to obtain the discrete clustering labels from the learned spectral embeddings directly. An effective updating algorithm with proven convergence is derived to optimize the optimization problem. Sufficient experiments on benchmark datasets have clearly demonstrated the effectiveness of the proposed method in six metrics. The code of AGLSR is uploaded at https://github.com/tangchuan2000/AGLSR.

Graphene Failure under MPa: Nanowear of Step Edges Initiated by Interfacial Mechanochemical Reactions

The low wear resistance of macroscale graphene coatings does not match the ultrahigh mechanical strength and chemical inertness of the graphene layer itself; however, the wear mechanism responsible for this issue at low mechanical stress is still unclear. Here, we demonstrate that the susceptibility of the graphene monolayer to wear at its atomic step edges is governed by the mechanochemistry of frictional interfaces. The mechanochemical reactions activated by chemically active SiO2 microspheres result in atomic attrition rather than mechanical damage such as surface fracture and folding by chemically inert diamond tools. Correspondingly, the threshold contact stress for graphene edge wear decreases more than 30 times to the MPa level, and mechanochemical wear can be described well with the mechanically assisted Arrhenius-type kinetic model, i.e., exponential dependence of the removal rate on the contact stress. These findings provide a strategy for improving the antiwear of graphene-based materials by reducing the mechanochemical interactions at tribological interfaces.

Effect of COVID-19 infection on pregnant women in plateau regions

OBJECTIVE

The present study aims to explore the effect of COVID-19 infection on pregnant women in plateau regions.

STUDY DESIGN

Data from 381 pregnant women infected with COVID-19 who underwent prenatal examination or treatment at Women and Children's Hospital of Tibet Autonomous Region between January 2020 and December 2022 and 314 pregnant women not infected with COVID-19 were retrospectively collected.

METHODS

The study participants were divided into an infected and non-infected group according to whether they were infected with COVID-19. Basic information (ethnicity, age, body mass index and gestational age [GA]), vaccination status, intensive care unit (ICU) admission and delivery outcomes were compared. Binary logistic regression was used to analyse the influencing factors of ICU admission.

RESULTS

The results revealed significant differences in the GA, vaccination rate, blood pressure, partial pressure of oxygen, white blood cell (WBC) count, ICU admission rate, preeclampsia rate, forearm presentation rate, thrombocytopenia rate, syphilis infection rate and placental abruption rate between the two groups (P < 0.05). A univariate analysis showed that COVID-19 infection, hepatitis B virus infection, the WBC count and hypoproteinaemia were risk factors for ICU admission. The results of the multivariate analysis of the ICU admission of pregnant women showed that COVID-19 infection (odds ratio [OR] = 4.271, 95 % confidence interval [CI]: 3.572-5.820, P < 0.05) was a risk factor for ICU admission and the WBC count (OR = 0.935, 95 % CI: 0.874-0.947, P < 0.05) was a protective factor for ICU admission.

CONCLUSION

Pregnant women are vulnerable to the adverse consequences of COVID-19 infection, and public health measures such as vaccination are needed to protect this population subgroup.

Molecular docking technology and network pharmacology based on Rhapontici Radix-Cremastrae Pseudobulbus drug pair in treating breast cancer

OBJECTIVE

Network pharmacology is a bioinformatics-based research strategy for identifying the mechanisms of drugs and promoting drug development. This study used network pharmacology to investigate the mechanism of the Loulu-Cremastrae Pseudobulbus drug pair treating breast cancer (BC).

MATERIALS AND METHODS

The ingredients and potential targets of the drug pair were searched with Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCSMP). National Center for Biotechnology Information (NCBI) and gene cards were used to search the targets of BC. Networks of "drugs-components-targets" and protein-protein interaction were constructed through Cytoscape. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were carried out through common targets. Using AutoDock tool, molecular docking was performed to verify the binding between key targets and compounds.

RESULTS

Finally, we selected 6 active compounds from the drug pair. A total of 61 targets were associated with the drug pair, and 15,295 targets were related to BC. 55 common targets were obtained after the intersection. The key targets included Transcription factor Jun (JUN), Heat shock protein HSP 90-alpha (HSP90AA1), and Caspase-3(CASP3). 327 terms were obtained by GO analysis. 78 pathways (p < 0.05) were identified through KEGG analysis. Molecular docking indicated that important compounds combined well with key targets.

CONCLUSIONS

Various active compounds, including beta-sitosterol, 2-methoxy-9,10-dihydrophenanthrene-4,5-diol, and stigmasterol, can regulate multiple signaling pathways related to BC, such as the estrogen and prolactin signaling pathways, playing therapeutic roles in BC.

Nanoscale Wear Triggered by Stress-Driven Electron Transfer

Wear of sliding contacts causes device failure and energy costs; however, the microscopic principle in activating wear of the interfaces under stress is still open. Here, the typical nanoscale wear, in the case of silicon against silicon dioxide, is investigated by single-asperity wear experiments and density functional theory calculations. The tests demonstrate that the wear rate of silicon in ambient air increases exponentially with stress and does not obey classical Archard's law. Series calculations of atomistic wear reactions generally reveal that the mechanical stress linearly drives the electron transfer to activate the sequential formation and rupture of interfacial bonds in the atomistic wear process. The atomistic wear model is thus resolved by combining the present stress-driven electron transfer model with Maxwell-Boltzmann statistics. This work may advance electronic insights into the law of nanoscale wear for understanding and controlling wear and manufacturing of material surfaces.

Peripheral T-Cell Priming and Micrometastatic Disease Control with Metastasis-Directed Therapy: Multidimensional Immunogenomic Profiling of Oligometastatic Prostate Cancer in the EXTEND Trial

PURPOSE/OBJECTIVE(S)

Comprehensive metastasis-directed therapy (MDT) for oligometastatic prostate cancer extended progression-free survival (PFS) and time to new lesion formation in the intermittent hormone therapy (HT) basket of EXTEND. To better understand the mechanism of MDT benefit, we pooled the intermittent and continuous HT baskets of EXTEND and tested the hypothesis that adding MDT to HT would program systemic T-cells to control micrometastatic disease.

MATERIALS/METHODS

A total of 174 men were randomized to HT with or without MDT to up to 5 sites of metastases. HT was given for 6 months (intermittent basket, n = 87) or indefinitely (continuous basket, n = 87). Peripheral blood samples were drawn at enrollment, at the end of MDT, at 3 months follow-up (3 mo F/U), and at progression and then analyzed by flow cytometry, T-cell receptor (TCR)-β CDR3 variable region sequencing, multiplex cytokine profiling, and next-generation circulating tumor DNA (ctDNA) sequencing. TCR clonal expansion was determined using a published betabinomial model. Repertoire changes were assessed by Morisita's index, and dominant TCR repertoire motifs were characterized with ImmunoMap. Associations between blood markers and PFS were evaluated with Cox regression adjusted hazard ratios (aHR) accounting for randomization arm and stratifying for intermittent vs continuous HT.

RESULTS

Randomization to MDT+HT was associated with T-cell activation, proliferation, and clonal expansion. This response was first observed at end-MDT as upregulated expression of T-cell activation and inhibition markers (i.e., ICOS, Tim-3, and LAG-3) and increases in highly proliferative CD4+ and CD8+ Ki67hi T-cells (all P<0.05). TCR sequencing of 7,678,911 T-cells revealed that MDT+HT was associated with TCR clonal expansion, remodeling of the TCR repertoire, and changes in dominant TCR motifs at end-MDT and 3 mo F/U (all P<0.05). Observed T-cell priming could be driven by signaling networks of canonical T-cell stimulatory cytokines (IL-2, IL-12, and IL-15), which were upregulated at end-MDT and persisted at 3 mo F/U (all P<0.05). This modulation of T-cell phenotype, clonotype, and cytokine concentrations was not observed in the HT-monotherapy arm. At end-MDT, systemic T-cell responses were associated with improved PFS, most notably CD8+ T-cell expression of LAG-3 (aHR 0.22, 95% CI 0.03-0.91) and high TCR clonal expansion (aHR 0.13, 95% CI 0.02-0.52). High ctDNA burden at end-MDT correlated with worse PFS (aHR 1.41, 95% CI 1.04-2.54), as did CD8+ T-cell expression of inhibitory receptor TIGIT at 3 mo F/U (aHR 1.03, 95% CI 1.01-1.06).

CONCLUSION

The addition of MDT to HT induced systemic T-cell activation and expansion, which was not observed in the HT-only arm. This systemic immune response was independently associated with improved PFS. In addition to cytoreduction of macroscopic disease, MDT-induced immune education may be an important complementary mechanism of micrometastatic control in oligometastatic prostate cancer.

Addition of Metastasis-Directed Therapy to Standard of Care Systemic Therapy for Oligometastatic Breast Cancer (EXTEND): A Multicenter, Randomized Phase II Trial

PURPOSE/OBJECTIVE(S)

Prior retrospective and prospective evidence have suggested a potential survival benefit of adding metastasis-directed therapy (MDT) to standard of care systemic therapy for oligometastatic breast cancer. This has led to the increased utilization of MDT in this setting despite the lack of randomized evidence to support this approach. Furthermore, the recent presentation of NRG-BR002 has questioned the value of MDT. Thus, we evaluated whether the addition of MDT to systemic therapy improves PFS in oligometastatic breast cancer.

MATERIALS/METHODS

EXTEND (NCT03599765) is a phase II randomized basket trial for multiple solid tumors testing whether the addition of MDT improves PFS. The primary endpoint was pre-specified to be independently assessed and reported for the breast basket when a minimum of 6 months of follow-up had been reached. Patients with ≤5 metastases were randomized to standard of care systemic therapy with or without MDT. The choice of systemic therapy was at the discretion of the treating medical oncologist. Number of metastatic lesions and prior lines of systemic therapy for metastatic disease were used as stratification variables pre-randomization. The primary endpoint was progression-free survival (PFS) defined as time to randomization to date of clinical or radiographic progression or death. The study was designed to have 80% power to detect an improvement in median PFS from 18 to 36 months, with a type I error of 0.1.

RESULTS

Between September 2018 to July 2022, 43 patients were randomized. 22 patients were assigned to the MDT arm, and 21 patients to the no MDT arm. Three patients were not evaluable. The MDT arm patients were older vs the no-MDT arm patients (median 61.5 years vs 48 years, p = 0.01). Otherwise, the arms were well-balanced. Overall, 8 patients had triple negative disease (18.6%), and 12 patients (30%) had de novo metastatic disease. Of those patients with de novo presentation randomized to MDT, all except one had the primary tumor treated with surgery and radiation. At a median follow-up of 19.4 months, 20 events were observed. Among the 40 evaluable patients, there were 5 deaths (3 in the MDT arm and 2 in the no MDT arm). There was no difference in PFS between the MDT and no MDT arms (median 15.6 v 24.9 months, p = 0.66). Similarly, there was no difference in the secondary endpoint of time to new metastatic lesion appearance between the MDT and no MDT arms (median 15.6 months vs not reached, p = 0.09). Two grade 3 toxicities were observed in the MDT arm, and 1 in the no MDT arm. Further analysis of correlative translational biomarkers, including immune markers and ctDNA, are ongoing.

CONCLUSION

The addition of MDT to standard of care systemic therapy did not improve PFS or time to new metastatic lesion in patients with oligometastatic breast cancer. This data coupled with the recently presented NRG-BR002 results, suggests there is no benefit to MDT in an otherwise unselected oligometastatic breast cancer population.

Validation of the Prognostic Index for Spine Metastasis (PRISM) Score for Stratifying Survival in Patients Treated with Spinal Stereotactic Radiosurgery

PURPOSE/OBJECTIVE(S)

Stereotactic spinal radiosurgery (SSRS) has been increasingly utilized as a first-line treatment for the management of spine metastases due to its ability to prolong survival and improve symptom control. Studies have shown that SSRS is helpful for select patients; however, there is no universal scoring system utilized to predict patient response to treatment. The Prognostic Index for Spinal Metastases (PRISM) score was shown to predict the likelihood of patients benefiting from SSRS. We sought to further demonstrate its generalizability by performing validation with a large dataset from a second high-volume institution.

MATERIALS/METHODS

We performed a retrospective review from 2017-2019 of 424 patients treated with SSRS at a single institution. Patients were stratified on the previously described PRISM criteria: Female sex (+2), solitary bone disease (+3), performance status (0 through +3.5), prior surgery at the SSRS site (+1), number of other metastatic sites (-N), prior radiation at the SSRS site (-1), and latency to treatment ≥ 5 months (+3). Patients were grouped based on PRISM scores: >7, Group 1; 4-7, Group 2; 1-3, Group 3; <1 Group 4. There were 89, 188, 88, and 59 patients in Groups 1, 2, 3, and 4, respectively. Most patients were male (70%) with a performance status of 0 (53%). The most common tumor histologies were prostate (34%), renal (18%), and lung (11%). The median biological effective dose (BED10) was 60 Gy (interquartile range [IQR], 60-82). We performed Cox proportional hazards analysis on overall survival (OS) based on PRISM score and patient and tumor characteristics. Concordance indices created from PRISM criteria and the multivariate Cox proportional analysis were compared.

RESULTS

The median follow-up time was 50.5 months (95% confidence interval [CI], 45.8-54.7) with a median overall survival of 30.3 months (95% CI, 27.3-38.4). The median overall survivals for PRISM Groups 1, 2, 3, and 4 were 57.1, 37, 23.7, and 8.8 months, respectively. There were significant differences in overall survival among PRISM groups with hazard ratios of 0.49 (95% CI, 0.35-0.69; P<0.001) for Group 1, 0.71 (95% CI, 0.55-0.91); P<0.007) for Group 2, 1,45 (95% CI, 1.08-1.94); P = 0.010) for Group 3, and 3.47 (95% CI, 2.56-4.70; P<0.001) for Group 4. Multivariable Cox analysis for patient and tumor characteristics revealed only the number of organs involved and performance status as significant clinicopathologic prognostic attributes. However, the C-index using the PRISM criteria was 0.76, which was superior to the C-index when using the significant clinicopathologic attributes by themselves (0.71).

CONCLUSION

These data demonstrate robust validation of the PRISM score to stratify OS in patients treated with SSRS and may help guide optimal treatment selection in prospective trials and clinical settings.

Real-world implementation of non-endoscopic triage testing for Barrett's oesophagus during COVID-19

BACKGROUND

The Coronavirus pandemic (COVID-19) curtailed endoscopy services, adding to diagnostic backlogs. Building on trial evidence for a non-endoscopic oesophageal cell collection device coupled with biomarkers (Cytosponge), an implementation pilot was launched for patients on waiting lists for reflux and Barrett's oesophagus surveillance.

AIMS

(i) To review reflux referral patterns and Barrett's surveillance practices. (ii) To evaluate the range of Cytosponge findings and impact on endoscopy services.

DESIGN AND METHODS

Cytosponge data from centralized laboratory processing (trefoil factor 3 (TFF3) for intestinal metaplasia (IM), haematoxylin & eosin for cellular atypia and p53 for dysplasia) over a 2-year period were included.

RESULTS

A total of 10 577 procedures were performed in 61 hospitals in England and Scotland, of which 92.5% (N = 9784/10 577) were sufficient for analysis. In the reflux cohort (N = 4074 with gastro-oesophageal junction sampling), 14.7% had one or more positive biomarkers (TFF3: 13.6% (N = 550/4056), p53: 0.5% (21/3974), atypia: 1.5% (N = 63/4071)), requiring endoscopy. Among samples from individuals undergoing Barrett's surveillance (N = 5710 with sufficient gland groups), TFF3-positivity increased with segment length (odds ratio = 1.37 per cm (95% confidence interval: 1.33-1.41, P < 0.001)). Some surveillance referrals (21.5%, N = 1175/5471) had ≤1 cm segment length, of which 65.9% (707/1073) were TFF3 negative. Of all surveillance procedures, 8.3% had dysplastic biomarkers (4.0% (N = 225/5630) for p53 and 7.6% (N = 430/5694) for atypia), increasing to 11.8% (N = 420/3552) in TFF3+ cases with confirmed IM and 19.7% (N = 58/294) in ultra-long segments.

CONCLUSIONS

Cytosponge-biomarker tests enabled targeting of endoscopy services to higher-risk individuals, whereas those with TFF3 negative ultra-short segments could be reconsidered regarding their Barrett's oesophagus status and surveillance requirements. Long-term follow-up will be important in these cohorts.

Understanding and Preventing Lubrication Failure at the Carbon Atomic Steps

Two-dimensional (2D) lamellar materials are normally capable of rendering super-low friction, wear protection, and adhesion reduction in nanoscale due to their ultralow shear strength between two basal plane surfaces. However, high friction at step edges prevents the 2D materials from achieving super-low friction in macroscale applications and eventually leads to failure of lubrication performance. Here, taking graphene as an example, the authors report that not all step edges are detrimental. The armchair (AC) step edges are found to have only a minor topographic effect on friction, while the zigzag (ZZ) edges cause friction two orders of magnitude larger than the basal plane. The AC step edge is less reactive and thus more durable. However, the ZZ structure prevails when step edges are produced mechanically, for example, through mechanical exfoliation or grinding of graphite. The authors found a way to make the high-friction ZZ edge superlubricious by reconstructing the (6,6) hexagon structure to the (5,7) azulene-like structure through thermal annealing in an inert gas environment. This will facilitate the realization of graphene-based superlubricity over a wide range of industrial applications in which avoiding the involvement of step edges is difficult.

Multi-view subspace clustering via adaptive graph learning and late fusion alignment

Multi-view subspace clustering has attracted great attention due to its ability to explore data structure by utilizing complementary information from different views. Most of existing methods learn a sample representation coefficient matrix or an affinity graph for each single view, then the final clustering result is obtained from the spectral embedding of a consensus graph using certain traditional clustering techniques, such as k-means. However, clustering performance will be degenerated if the early fusion of partitions cannot fully exploit relationships between all samples. Different from existing methods, we propose a multi-view subspace clustering method via adaptive graph learning and late fusion alignment (AGLLFA). For each view, AGLLFA learns an affinity graph adaptively to capture the similarity relationship among samples. Moreover, a spectral embedding learning term is designed to exploit the latent feature space of different views. Furthermore, we design a late fusion alignment mechanism to generate an optimal clustering partition by fusing view-specific partitions obtained from multiple views. An alternate updating algorithm with validated convergence is developed to solve the resultant optimization problem. Extensive experiments on several benchmark datasets are conducted to illustrate the effectiveness of the proposed method when compared with other state-of-the-art methods. The demo code of this work is publicly available at https://github.com/tangchuan2000/AGLLFA.

Resonant plasmonic detection of terahertz radiation in field-effect transistors with the graphene channel and the black-As[Formula: see text]P[Formula: see text] gate layer

We propose the terahertz (THz) detectors based on field-effect transistors (FETs) with the graphene channel (GC) and the black-Arsenic (b-As) black-Phosphorus (b-P), or black-Arsenic-Phosphorus (b-As[Formula: see text]P[Formula: see text]) gate barrier layer. The operation of the GC-FET detectors is associated with the carrier heating in the GC by the THz electric field resonantly excited by incoming radiation leading to an increase in the rectified current between the channel and the gate over the b-As[Formula: see text]P[Formula: see text] energy barrier layer (BLs). The specific feature of the GC-FETs under consideration is relatively low energy BLs and the possibility to optimize the device characteristics by choosing the barriers containing a necessary number of the b-As[Formula: see text]P[Formula: see text] atomic layers and a proper gate voltage. The excitation of the plasma oscillations in the GC-FETs leads to the resonant reinforcement of the carrier heating and the enhancement of the detector responsivity. The room temperature responsivity can exceed the values of [Formula: see text] A/W. The speed of the GC-FET detector's response to the modulated THz radiation is determined by the processes of carrier heating. As shown, the modulation frequency can be in the range of several GHz at room temperatures.

Bonding performance of experimental HEMA-free two-step universal adhesives to low C-factor flat dentin

OBJECTIVES

Experimental two-step universal adhesives (2-UAs) providing a particle-filled hydrophobic adhesive resin with a significant film thickness to hydrophobically seal the adhesive interface were designed and synthesized. This study aimed to characterize their interfacial interaction with dentin, to determine whether the 2-UA formulations achieve durable bonding to low C-factor flat dentin and to measure their water sorption.

METHODS

Bonding effectiveness of 2-UAs that combine a 10-MDP-based primer with hydrophobic adhesive resins differing only for filler (BZF-21, BZF-29, and BZF-29_hv) were comparatively investigated with the commercial adhesive Clearfil SE Bond 2 (C-SE2, Kuraray Noritake). Adhesive-dentin interfaces were characterized with TEM. Adhesive-resin disks were immersed in distilled water at 37 °C for 1 week, 6 months and 1 year to measure water sorption and solubility. 'Immediate' and 'aged' micro-tensile bond strength (μTBS) of the adhesives applied in etch-and-rinse (E&R) and self-etch (SE) bonding mode to low C-factor flat dentin were measured. Statistical analyses involved linear mixed-effects (LME) modelling and Kruskal-Wallis testing (p < 0.05).

RESULTS

TEM revealed that E&R hybrid layers were more sensitive to aging than SE hybrid layers. Lower water sorption was recorded for all UAs compared with C-SE2. The immediate μTBS of BZF-21 and BZF-29 was not significantly different from that of C-SE2. The 1-year aged μTBS of all 2-UAs was significantly lower than that of C-SE2, except for BZF-29 applied in E&R mode. A significant reduction in μTBS upon 1-year aging was recorded for BZF-21 and BZF-29 applied in E&R mode. A significant difference in μTBS between E&R and SE bonding modes was recorded for all adhesives except BZF-21.

SIGNIFICANCE

Experimental 2-UAs with a hydrophobic adhesive-resin design produced± 20-μm thick adhesive-resin layers, absorbed less water and resulted in bonding performance that was more aging-resistant when applied in SE than in E&R bonding mode. The silica-filled BZF-29 2-UA revealed the most comparable bonding performance with C-SE2 in a low C-factor condition (flat dentin).

Layer-Dependent Nanowear of Graphene Oxide

The mechanical performance and surface friction of graphene oxide (GO) were found to inversely depend on the number of layers. Here, we demonstrate the non-monotonic layer-dependence of the nanowear resistance of GO nanosheets deposited on a native silicon oxide substrate. As the thickness of GO increases from ∼0.9 nm to ∼14.5 nm, the nanowear resistance initially demonstrated a decreasing and then an increasing tendency with a critical number of layers of 4 (∼3.6 nm in thickness). This experimental tendency corresponds to a change of the underlying wear mode from the overall removal to progressive layer-by-layer removal. The phenomenon of overall removal disappeared as GO was deposited on an H-DLC substrate with a low surface energy, while the nanowear resistance of thicker GO layers was always higher. Combined with density functional theory calculations, the wear resistance of few-layer GO was found to correlate with the substrate's surface energy. This can be traced back to substrate-dependent adhesive strengths of GO, which correlated with the GO thickness originating from differences in the interfacial charge transfer. Our study proposes a strategy to improve the antiwear properties of 2D layered materials by tuning their own thickness and/or the interfacial interaction with the underlying substrate.

Adaptive Discriminative Regions Learning Network for Remote Sensing Scene Classification

As an auxiliary means of remote sensing (RS) intelligent interpretation, remote sensing scene classification (RSSC) attracts considerable attention and its performance has been improved significantly by the popular deep convolutional neural networks (DCNNs). However, there are still several challenges that hinder the practical applications of RSSC, such as complex composition of land cover, scale-variation of objects, and redundant and noisy areas for scene classification. In order to mitigate the impact of these issues, we propose an adaptive discriminative regions learning network for RSSC, referred as ADRL-Net briefly, which locates discriminative regions effectively for boosting the performance of RSSC by utilizing a novel self-supervision mechanism. Our proposed ADRL-Net consists of three main modules, including a discriminative region generator, a region discriminator, and a region scorer. Specifically, the discriminative region generator first generates some candidate regions which could be informative for RSSC. Then, the region discriminator evaluates the regions generated by region generator and provides feedback for the generator to update the informative regions. Finally, the region scorer makes prediction scores for the whole image by using the discriminative regions. In such a manner, the three modules of ADRL-Net can cooperate with each other and focus on the most informative regions of an image and reduce the interference of redundant regions for final classification, which is robust to the complex scene composition, object scales, and irrelevant information. In order to validate the efficacy of the proposed network, we conduct experiments on four widely used benchmark datasets, and the experimental results demonstrate that ADRL-Net consistently outperforms other state-of-the-art RSSC methods.

Polyketides with anti-inflammatory activity isolated from Rhodiola tibetica endophytic fungus Penicillium sp. HJT-A-10

Seven undescribed polyketide compounds (1-4, 9-11) and six known polyketide compounds (5-8,12, 13) were isolated from Rhodiola tibetica endophytic Penicillium sp. HJT-A-10. The structural of seven undescribed polyketides metabolites were established on the basis of spectroscopic methods. The results of anti-inflammatory activity showed that compounds 1-8，10-13 had significant inhibitory effects on LPS-induced NO production in RAW 264.7 cells.

The biological alterations of synapse/synapse formation in sepsis-associated encephalopathy

Sepsis-associated encephalopathy (SAE) is a common complication caused by sepsis, and is responsible for increased mortality and poor outcomes in septic patients. Neurological dysfunction is one of the main manifestations of SAE patients. Patients may still have long-term cognitive impairment after hospital discharge, and the underlying mechanism is still unclear. Here, we first outline the pathophysiological changes of SAE, including neuroinflammation, glial activation, and blood-brain barrier (BBB) breakdown. Synapse dysfunction is one of the main contributors leading to neurological impairment. Therefore, we summarized SAE-induced synaptic dysfunction, such as synaptic plasticity inhibition, neurotransmitter imbalance, and synapses loss. Finally, we discuss the alterations in the synapse, synapse formation, and mediators associated with synapse formation during SAE. In this review, we focus on the changes in synapse/synapse formation caused by SAE, which can further understand the synaptic dysfunction associated with neurological impairment in SAE and provide important insights for exploring appropriate therapeutic targets of SAE.

Development of a bending-stress-controllable micro-clamp and applications in nanowear study of polyimide terephthalate

Inner stress that exists in most natural and artificial materials, such as rocks, coatings, glasses, and plastic products, has a significant impact on their tribological properties at any length scale. Here, we designed a bending-stress controllable micro-clamp that can be applied in a high-vacuum atomic force microscope with limited chamber space for the investigation of stress-dependent nanowear behavior. By accurately quantifying the bending degree of the sample in different directions, the mutual transformation and adjustment of tensile or compressive stress could be realized. The stability of the micro-clamp structure was further verified by simulating the bending deformation state of the sample through Ansys calculations. The maximum applied scratch area on the bended sample surface where the variation of bending-induced stress below 5% was defined by the Ansys simulations. The consistency of polyimide terephthalate (PET) wear inside this defined region under both bending-free and bending states verified the stability and reliability of micro-clamp. Finally, the designed micro-clamp was applied to study the effect of bending deformation on friction and wear of PET in the atomic force microscope tests, where the tensile stress generated with bending deformation was found to facilitate the nanowear of PET material sliding against a diamond probe.

Polyketides with anti-inflammatory activity from Rhodiola tibetica endophytic fungus Alternaria sp. HJT-Y7

Seven undescribed polyketides with particular ortho-trisubstituted benzo[c]furan and benzo[c]oxepin spiro structures were isolated from Rhodiola tibetica endophytic fungus Alternaria sp. HJT-Y7. Structural elucidations of these compounds were determined mainly by NMR and HR-ESI-MS analysis. An assumed polyketide biosynthetic pathway of these isolates was proposed. Two undescribed compounds and four known compounds showed significant inhibitory effects on LPS-induced NO production in RAW 264.7 cells without cytotoxicity at their effective concentrations.

Processed electroencephalography: impact of patient age and surgical position on intraoperative processed electroencephalogram monitoring of burst-suppression

We previously reported that processed EEG underestimated the amount of burst suppression compared to off-line visual analysis. We performed a follow-up study to evaluate the reasons for the discordance. Forty-five patients were monitored intraoperatively with processed EEG. A computer algorithm was used to convert the SedLine® (machine)-generated burst suppression ratio into a raw duration of burst suppression. The reference standard was a precise off-line measurement by two neurologists. We measured other potential variables that may affect machine accuracy such as age, surgery position, and EEG artifacts. Overall, the median duration of bust suppression for all study subjects was 15.4 min (Inter-quartile Range [IQR] = 1.0-20.1) for the machine vs. 16.1 min (IQR = 0.3-19.7) for the neurologists' assessment; the 95% limits of agreement fall within - 4.86 to 5.04 s for individual 30-s epochs. EEG artifacts did not affect the concordance between the two methods. For patients in prone surgical position, the machine estimates had significantly lower overall sensitivity (0.86 vs. 0.97; p = 0.038) and significantly wider limits of agreement ([- 4.24, 3.82] seconds vs. [- 1.36, 1.13] seconds, p = 0.001) than patients in supine position. Machine readings for younger patients (age < 65 years) had higher sensitivity (0.96 vs 0.92; p = 0.021) and specificity (0.99 vs 0.88; p = 0.007) for older patients. The duration of burst suppression estimated by the machine generally had good agreement compared with neurologists' estimation using a more precise off-line measurement. Factors that affected the concordance included patient age and position during surgery, but not EEG artifacts.

Synthesis, Structure Determination, and Characterizations of a Polar Salt-Inclusion Scandium Germanate, Rb10Li3Sc4Ge12O36F

A noncentrosymmetric salt-inclusion germanate, Rb₁₀Li₃Sc₄Ge₁₂O₃₆F, was grown through spontaneous crystallization from a LiF-RbF flux. It crystallizes in the polar space group P31c with cell parameters of a = 10.7587(3) Å, c = 21.6691(10) Å, and Z = 2. Its structure features a complex 3D framework composed of helical [Ge₄O₁₂] chains from condensed [GeO₄] tetrahedra running along the c axis, which are interconnected by the [ScO₆] octahedra. Voids of the 3D net are filled with Rb⁺ ions, Li⁺ ions, and isolated trigonal-bipyramidal [Rb₃Li₂F] superalkali clusters. The title compound has a large band gap of 5.6 eV, a moderate powder second-harmonic-generation response of 0.9KDP, and an extremely small birefringence of 0.001, as was further unraveled by theoretical calculations.

Preparation and characterization of sodium cellulose sulfate/chitosan composite films loaded with curcumin for monitoring pork freshness

Colorimetric films were prepared by incorporating curcumin into a sodium cellulose sulfate/chitosan composite. The morphology mechanical, and water vapor properties of the films were investigated, and their practical use in pork preservation was evaluated. The formula with the same charge ratio of sodium cellulose sulfate and chitosan had the highest tensile strength (TS). After the addition of curcumin, the tensile strength increased, whereas the water vapor permeability (WVP) decreased. The colorimetric film showed distinguishable color changes between the pH ranges of 3–10. The colorimetric film packaging extended the shelf life of the pork samples by 4 days. Moreover, the composite films were able to effectively monitor pork freshness. In conclusion, curcumin incorporated into sodium cellulose sulfate/chitosan composite films may have great potential in food packaging.

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Sodium cellulose sulfate/chitosan/curcumin films were produced for food packaging.

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The properties of composite films were enhanced due to electrostatic interaction.

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The composite films changed their colors in response to the change of pH.

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The composite films could monitor the freshness and extend shelf life of pork.

Morphological classification and clinical significance of medial malleolus based on computed tomography three-dimensional reconstruction

BACKGROUND

Internal malleolus fractures and postoperative functional limitations are serious complications of deltoid ligament repair, reconstruction, while studies on conducting beak. Anatomical structure classification of medial malleolus at home and abroad is reported rarely. Hence, this morphological study is mainly designed to investigate the anatomical morphological classification and clinical significance of medial malleolus based on computed tomography (CT) three-dimensional reconstruction.

MATERIALS AND METHODS

From October 2018 to January 2021, 373 patients who underwent CT examination of malleolus medialis joint in the Jiang'an Hospital of Traditional Chinese Medicine were observed. The medial malleolus was observed and classified; then, geometric parameters were measured according to different medial malleolus types.

RESULTS

According to the results of 373 cases, medial malleolus can be divided into four types: omega type (66%), radical sign type (16%), inverted triangle type (14%), and wave type (4%).

CONCLUSIONS

There are four main shapes: omega, inverted triangle, radical sign, and wave in the medial malleolus of all normal ankles. The measurement of medial malleolus parameters according to medial malleolus in different shapes was of importance to guide smooth operation of medial malleolus fixation and deltoid ligament reconstruction and epidemiological.

57 A Closed Loop Audit of Post-Operative Driving Advice Documentation

Aim

The Driving and Vehicle Licensing Agency state post-operatively it is between the patient and doctor to establish when would be safe to resume driving, providing recovery does not exceed three months. This audit aimed to assess and improve the documentation rate of driving advice in the discharge summaries given to patients post abdominal surgery.

Method

Retrospective data collection from electronic records over the months of August and September 2020. 132 discharge summaries were screened to assess the baseline rate of verbal/documented driving advice given on discharge. Following the 1st cycle, posters encouraging the inclusion of driving advice and demonstrating how to access driving advice to discharge summaries were developed and distributed across the surgical wards. A 2nd cycle re-audit was conducted in October 2020 to measure the effect of change, and a further 3rd cycle audit was conducted in November 2020.

Results

1st cycle included 132 patients. 62% had documented advice on their discharge summaries, while 38% had no proof of driving advice. After intervention, 2nd cycle included 30 patients. Results showed a significant increase in advice documentation (80%). A 3rd cycle was carried out with 47 patients. This showed a reduction in advice documentation (66%).

Conclusions

Driving advice on discharge in post-operative patients is crucial part of patient safety. Implementation of intervention has increased the documentation of driving advice showing enhancing patient safety. However, 3rd cycle after registrar’s changeover showed a decrease in the rate of documentation. A teaching session is planned for new doctors followed by 4th cycle.

[Evaluation of classification of petroclival meningiomas and proposed selection of microsurgical approach: a single center experience of 179 cases]

Objective: To evaluate the classification of petroclival meningiomas(PCM), proposed selection of microsurgical approach and therapeutic outcomes. Methods: Retrospectively analyzed clinical data of 179 cases of PCM from Department of Neurosurgery, Xiangya Hospital, Central South University between January 2011 and November 2020. There were 28 males and 151 females with an age of(49.9±10.2) years(range: 22 to 75 years) and the tumor size of(44.8±10.3)mm(range: 15 to 80 mm). The mean duration of symptom(M(QR)) was 18.0(40.6)months(range:1 week to 320 months) and the mean preoperative Karnofsky performance scale(KPS) was 78.6±13.3(range: 40 to 100). The PCM were classified into 5 types according to the difference in the origin of dural attachment, involvement of adjacent structures and growth patterns through preoperative MRI. The surgical approaches were selected based on the proposed classification, and the clinical characteristics, surgical record, and follow-up data of each type were reviewed. Results: The PCM were divided into clivus type(CV, 4 cases), petroclival type(PC, 60 cases), petroclivosphenoidal type(PC-S, 62 cases), sphenopetroclival type with 2 subtypes(S-PC, 50 cases) and central skull base type(CSB, 3 cases). All of 176 cases were obtained microsurgical treatment except CSB type. The gross total resection reached in 124 cases(70.5%) with 112 cases of retrosigmoid approach(RSA), 27 cases of subtemporal transtentorial transpetrosal approach, 13 cases of pretemporal trancavernous anterior transpetrosal approach(PTCA), 12 cases of extended pterional transtentorial approach(EPTA) and presigmoid combined supra-infratentorial approach, respectively. The RSA could be adopted in both of CV type and PC type and most of PC-S type(71.0%). S-PC subtype Ⅰ and subtype Ⅱ were mainly underwent EPTA(40.8%) and PTCA(52.2%), respectively. Seventy-two cases(40.9%) gained new neurological dysfunctions mainly with the cranial nerve paralysis. The postoperative morbidity and complications were recovered or improved with conservative and positive symptomatic and supportive treatment. There was no intraoperative and postoperative death case. One hundred and sixty four cases(93.2%) of operative patients were followed with the duration of 24(48)months(range:3 to 108 months). Tumor recurrence and progress were identified in 14 cases(10.4%) and 14 cases(28.6%), respectively. Compared with postoperative neurological status, 89 patients(54.3%) had improved and 38 patients(23.2%) were still suffering various degrees of neurological dysfunctions during the follow-up. The recent KPS was 84.2±11.4(range: 50 to 100) without statistical difference from preoperative KPS(t=-1.356,P=0.125). As for each type, there were statistically significant differences in brain stem edema(χ2=3.482,P=0.038), gross total resection(χ2=9.127,P=0.001), surgical duration(F=8.954, P=0.013), postoperative length of stay(F=3.652, P=0.025), postoperative complications(χ2=1.550,P=0.024), postoperative KPS(F=2.856, P=0.042) and tumor recurrence/progress(χ2=4.824,P=0.013). Conclusion: The precise and comprehensive classification of PCM and specific individual treatment strategy are benefit to evaluate the diverse clinical prognosis, choose optimal surgical approaches, elevate gross total resection, diminish neurological dysfunctions and restraint tumor recurrence, so as to improve the quality of life for patients.

[Relapse of ankylosing spondylitis and its predictors after withdrawal of tumor necrosis factor-α inhibitors: a 52-week follow-up study]

OBJECTIVE

To investigate the recurrence of ankylosing spondylitis (AS) that has been relieved by standard-dose adalimumab (ADA) after dose reduction or withdrawal of tumor necrosis factor-α inhibitor (TNFi) and explore the factors that predict AS occurrence.

OBJECTIVE

This study was conducted among 63 patients with AS who reduced the dose of or discontinued TNFi after completing at least 12 treatment cycles with ADA (40 mg/2 weeks) to achieve ASAS20 improvement with a BATH disease activity index (BASDAI) < 4 for more than 8 weeks. The patients were followed up every 12 weeks for a total of 52 weeks, and the recurrence of AS, changes of BASDAI, C-reactive protein (CRP)-based disease activity score (ASDASCRP), low back pain (LBP) score, Bath Ankylosing Spondylitis Metrology Index (BASMI), CRP and ESR were recorded and analyzed. Cox regression model and ROC curve analyses were performed to analyze the risk factors of AS relapse after dose reduction or discontinuation of TNFi.

OBJECTIVE

Of the 63 patients enrolled, 57 completed the follow-up study, among whom 22 (38.6%) patients experienced AS relapse within 52 weeks, with a median clinical recurrence time of 31 weeks. The recurrence rate of AS was significantly higher in patients with complete withdrawal of medications (89.0%) than in those with TNFi dose reduction and TNFi discontinuation (P < 0.001), and did not differ significantly between the latter two groups of patients (χ²= 0.071, P=0.791). The Cox regression model showed that a high baseline LBP score (HR=1.438, P=0.027) and a high BASMI score (HR=1.29, P=0.049) were the risk factors for AS recurrence after TNFi dose reduction or discontinuation, while maintenance of medication during follow-up was a protective factor (HR=0.209, P=0.001). ROC curve analysis showed that the combination of baseline LBP score, BASMI and medication during follow-up had a good predictive value for AS relapse (AUC=0.819) with a sensitivity of 0.772 and a specificity of 0.718.

OBJECTIVE

Dose reduction or discontinuation of TNFi is associated with a high recurrence rate of AS that has been relieved by TNFi treatment. A high LBP score, a high BASMI score and discontinuation of maintenance medication are the risk factors for AS recurrence in patients after dose reduction or withdrawal of TNFi.

Effect modification of the association between diurnal temperature range and hospitalisations for ischaemic stroke by temperature in Hefei, China

OBJECTIVES

Diurnal temperature range (DTR) is an important indicator of global climate change. Many epidemiological studies have reported the associations between high DTR and human health. This study investigated the association between DTR and hospitalisations for ischaemic stroke in Hefei, China.

STUDY DESIGN

This is an ecological study.

METHODS

Data of daily hospital admissions for ischaemic stroke and meteorological variables from 1 January 2009 to 31 December 2017 were collected in Hefei, China. A generalised additive model combined with distributed lag non-linear model was used to quantify the effects of DTR on ischaemic stroke. The interactive effect between DTR and temperature was explored with a non-parametric bivariate response surface model.

RESULTS

High DTR was associated with hospitalisations for ischaemic stroke. The adverse effect of extremely high DTR (99th percentile [17.1 °C]) occurred after 8 days (relative risk [RR] = 1.021, 95% confidence interval [CI] = 1.002, 1.041) and the maximum effect appeared after 12 days (RR = 1.029, 95% CI = 1.011, 1.046). The overall trend of the effect of DTR on ischaemic stroke was decreasing. In addition, there was a significant interactive effect of high DTR and low temperature on ischaemic stroke.

CONCLUSIONS

This study suggests that the impact of high DTR should be considered when formulating targeted measures to prevent ischaemic stroke, especially for those days with high DTR and low mean temperature.

CNN-based qualitative detection of bone mineral density via diagnostic CT slices for osteoporosis screening

The features extracted from diagnostic computed tomography (CT) slices were used to qualitatively detect bone mineral density (BMD) through neural network models, and the evaluation results indicated that it may be a promising approach to perform osteoporosis screening in clinical practice.

INTRODUCTION

The purpose of this study is to design a novelty diagnostic method for osteoporosis screening by using the convolutional neural network (CNN), which can be incorporated into the procedure of routine CT diagnostic in medical examination thereby improving the osteoporosis diagnosis and reducing the patient burden.

METHODS

The proposed CNN-based method mainly comprises two functional modules to perform qualitative detection of BMD by analyzing the diagnostic 2D CT slice. The first functional module aims to locate and segment the ROI of diagnostic 2D CT slice, called Mark-Segmentation-Network (MS-Net). The second functional module is used to determine the category of BMD by the features of ROI, called BMD-Classification-Network (BMDC-Net). The diagnostic 2D CT slice of pedicle level in lumbar vertebrae (L1) was selected from 3D CT image in our experiments firstly. Then, the trained MS-Net can get the mark image of input original 2D CT slice, thereby obtain the segmentation image. Finally, the trained BMDC-Net can obtain the probability value of normal bone mass, low bone mass, and osteoporosis by inputting the segmentation image. On the basis of network results, the radiologists can provide preliminary qualitative diagnosis results of BMD.

RESULTS

Training of the network was performed on diagnostic 2D CT slices of 150 patients. The network was tested on 63 patients. Each patient corresponds to a 2D CT slice. The proposed MS-Net has an excellent segmentation precision on the shape preservation of different lumbar vertebra. The dice index (DI), pixel accuracy (PA), and intersection over union (IOU) of segmentation results are greater than 0.8. The proposed BMDC-Net achieved an accuracy of 76.65% and an area under the receiver operating characteristic curve of 0.9167.

CONCLUSIONS

This study proposed a novel method for qualitative detection of BMD via diagnostic CT slices and it has great potential in clinical applications for osteoporosis screening. The method can potentially reduce the manual burden to radiologists and diagnostic cost to patients.