Macroscopic Level Research Articles

Microstructure evolution from silicon core to surface in electronic-grade polycrystalline silicon

Large-size electronic-grade polycrystalline silicon is an important material in the semiconductor industry with broad application prospects. However, electronic-grade polycrystalline silicon has extremely high requirements for production technology and currently faces challenges such as carbon impurity breakdown, microstructure and composition nonuniformity and a lack of methods for preparing large-size mirror-like polycrystalline silicon samples. This paper innovatively uses physical methods such as wire cutting, mechanical grinding and ion thinning polishing to prepare large-size polycrystalline silicon samples that are clean, smooth, free from wear and have clear crystal defects. The material was characterized at both macroscopic and microscopic levels using metallographic microscopy, scanning electron microscopy (SEM) with backscattered electron diffraction (EBSD) techniques and scanning transmission electron microscopy (STEM). The crystal structure changes from single crystal silicon core to the surface of the bulk in the large-size polycrystalline silicon samples were revealed, providing a technical basis for optimizing and improving production processes.

Deformation mechanisms in the α phase of the Ti-6Al-2Sn-4Zr-2Mo titanium alloy: In situ experiments and simulations

Titanium alloys are widely employed in aerospace applications due to an outstanding combination of properties. The variety of loading conditions and microstructures encountered in industrial components is urging the development of microstructure sensitive modeling capabilities. In particular, reliable predictions require a good knowledge of operating deformation mechanisms. The present study aims at providing a thorough characterization of deformation mechanisms in the near-α Ti-6Al-2Sn-4Zr-2Mo alloy using experiments and simulations. The sequential activation of deformation mechanisms in the α phase was monitored in situ during a tensile test carried out in a scanning electron microscope using a combination of slip traces analysis and electron back-scattered diffraction. Basal slip is activated first, and prismatic slip activity, which proceeds at a higher macroscopic stress level, is needed for a significant creep/relaxation to occur. While little evidence of 〈a〉-type pyramidal slip was found, 〈c + a〉 pyramidal slip involved first-order pyramidal planes and operates at stress levels near or above the 0.2% proof stress. Atomic force microscopy characterization of the features of the different slip modes revealed that 〈a〉 slip is coarser and wavier than 〈c + a〉 slip. Twinning, which is usually neglected in such alloys within this strain regime, was observed to be slip stimulated at a plastic strain as low as 0.5%. Crystal plasticity parameters leading to an accurate simulation of the activation sequence of deformation mechanisms were then determined. For this purpose, critical resolved shear stress values were derived for the different slip and twinning modes using specific approaches and subsequently validated using crystal plasticity simulations based on fast-Fourier transforms.

Study on the strength deterioration characteristic and damage model of coal pillar dams with repeated water immersion in underground reservoirs

The continuous operation of coal mine underground reservoirs exposes the coal pillar dams to mining disturbances and prolonged water immersion, resulting in the deterioration of coal pillars' mechanical properties and posing a serious threat to the dam stability. To this end, coal samples from the proposed pillar dam in the 5–2 coal seam of Daliuta Mine in Shendong Mining Area were selected for conducting water absorption tests and triaxial compression tests under conditions of repeated water immersion, in order to study the deterioration of the mechanical properties and acoustic emission damage characteristic of coal samples as well as the mechanism behind the deterioration of coal samples under the water–rock interaction. The results indicated that: (1) the saturated water content of coal samples exhibited a progressive increase as the water immersion times increased, but with a diminishing rate of growth. (2) As the water immersion times increased, the compressive strength, cohesive force, and internal friction angle of coal samples gradually decreased. Notably, the deterioration effect was more pronounced in compressive strength and cohesive force, while the decline in internal friction angle was relatively minor, and the total deterioration degree and the stage deterioration degree of the above three had evident cumulativity and non-uniformity. The progressive rise in water immersion times led to a gradual attenuation of the deterioration effect. Meanwhile, the confining pressure exhibited a certain inhibitory impact on the strength deterioration of coal samples. (3) Compared to the dry coal samples, the average AE count rate of coal samples subjected to a single water immersion exhibited a significant decrease, and subsequent water immersion for two, three, and four times resulted in a very minor decrease in the average AE count rate. (4) The AE cumulative ringing counts in coal samples exhibited varying degrees of reduction as water immersion times increased. Specifically, the most significant decrease in AE cumulative ringing counts occurred after the initial water immersion, followed by a gradual decrease thereafter. The energy-releasing capacity of coal samples decreased, while their plasticity exhibited a gradual increase. (5) A damage model was developed for coal samples based on the water immersion times. The model indicated that the damage to coal samples increased as the water immersion times increased, and the damage rate gradually decreased and eventually stabilized. (6) The deterioration mechanism of coals under the water–rock interaction was explained. Through repeated water immersion, the physical, chemical, and mechanical interactions between water and coal induced alterations in the internal microstructure of coal samples, resulting in the deterioration of mechanical properties such as compressive strength, cohesive force, and internal friction angle, which was a cumulative damage process from the microscopic to the macroscopic level.

Study on the Mechanism of Water and Sand Leakage in a Foundation Pit Retaining Structure Based on the Computational Fluid Dynamics–Discrete Element Method

The existence of defects in the enclosure structure is the primary cause of water and sand leakage in foundation pits, as well as being a significant source of danger in pit construction, but current research lacks an in-depth investigation of the generation mechanism and gestation process. In this paper, which comprehensively considers the microscopic particles and macroscopic level, the development mechanism of a water and sand leakage disaster in a foundation pit with a water-rich sand layer was studied using the principle of computational fluid dynamics and discrete element method coupled analysis (CFD–DEM); moreover, based on the anisotropy of the particle force and fluid energy analysis, the deformation of the stratum and ground stress field were analyzed. The results show that the stress field will produce a plugging effect at a certain distance from the defect, and the strata exhibit a dominant displacement tendency in the vertical direction, resulting in the emergence of a gradually concave stress relaxation zone and an elliptical contour in the strata displacement map near the defect. The fluid energy describes the displacement of the sand layer very well, and it is separated into the sand layer’s centralized loss region and the major loss area based on the high and low levels of the fluid energy class. The impact of fluid at the defect reaches the maximum kinetic energy, which penetrates the structural weakness and causes the loss of sand particles, and the cross-section of the water influx near the defect gradually expands with the loss of particles, indicating that there is a danger of further expansion of the defect under the impact of water flow. These results have technical implications for the management of water and sand leakage disasters in foundation pit engineering.

Macro-micro analysis of ground response to circular tunnel excavation in granular media

Ground reaction in terms of stress and displacement analysis is one of the major challenges in tunnel design and is helpful for understanding the stability around the excavation zone. In this paper, the analysis of stress, strain responses and radial displacement around circular tunnel excavated in cohesive-frictional granular materials is discussed via an innovative multi-scale approach (FEM × DEM) that combined finite element (FEM) and discrete element (DEM) methods and compared to other solutions obtained with conventional constitutive laws. Thanks to simulations, (i) the Ground response curve is then established and provides a better understanding of the complex behaviour in the vicinity of the tunnel; (ii) the prediction by FEM × DEM approach differs considerably from conventional constitutive laws; and (iii) in a unique manner, macroscopic and microscopic analyses are simultaneously performed showing that at the macroscopic level (FE mesh), diffuse failure mode are observed, while at the microscopic level (DEM level), microscopic evolutions are observed to be strictly related to the macroscopic behaviour.

Analysis of the effect of the scorpion toxin AaH-II on action potential generation in the axon initial segment

The toxin AaH-II, from the scorpion Androctonus australis Hector venom, is a 64 amino acid peptide that targets voltage-gated Na+ channels (VGNCs) and slows their inactivation. While at macroscopic cellular level AaH-II prolongs the action potential (AP), a functional analysis of the effect of the toxin in the axon initial segment (AIS), where VGNCs are highly expressed, was never performed so far. Here, we report an original analysis of the effect of AaH-II on the AP generation in the AIS of neocortical layer-5 pyramidal neurons from mouse brain slices. After determining that AaH-II does not discriminate between Nav1.2 and Nav1.6, i.e. between the two VGNC isoforms expressed in this neuron, we established that 7 nM was the smallest toxin concentration producing a minimal detectable deformation of the somatic AP after local delivery of the toxin. Using membrane potential imaging, we found that, at this minimal concentration, AaH-II substantially widened the AP in the AIS. Using ultrafast Na+ imaging, we found that local application of 7 nM AaH-II caused a large increase in the slower component of the Na+ influx in the AIS. Finally, using ultrafast Ca2+ imaging, we observed that 7 nM AaH-II produces a spurious slow Ca2+ influx via Ca2+-permeable VGNCs. Molecules targeting VGNCs, including peptides, are proposed as potential therapeutic tools. Thus, the present analysis in the AIS can be considered a general proof-of-principle on how high-resolution imaging techniques can disclose drug effects that cannot be observed when tested at the macroscopic level.

Dissolved organic nitrogen is a key to improving the biological treatment potential of landfill leachate

Biological treatment is one of the most promising efficient, low-carbon and affordable approaches for the treatment of recalcitrantly degradable wastewater, such as landfill leachate. However, even the macroscopic molecular level analysis of dissolved organic matter (DOM) is limiting to the enhancement of biological treatment efficacy, and there is an urgent need for deeper exploration of DOM to gain insights into the key constraining substances. In the present study targeting at piercing leachate organic at molecular level, nitrogen-containing dissolved organic matter (DOMN) was identified to be the bottleneck that govern the biotreatment potential. The conclusion was made based on two series of experiments that compared the same anoxic-aerobic membrane bioreactor process (A process) operated stably at different regions, and compared with C process that coupling A process with a circulation aeration membrane bioreactor to improve aeration efficiency. The results confirmed that the relative abundance of DOMN was absolutely dominant among the three categories of DOM in all biologically treated samples, contributing to 60.36 %–65.81 % in removed-DOM, 60.33 %–70.95 % in refractory-DOM and 63.14 %–71.36 % in derived-DOM. Specifically, the high latitude A process had much lower DOMN removal rate than the low latitude A process (p < 0.05) and much higher refractory and derivatization rates than the low latitude A process (p < 0.05). DOM had similar results. No statistically significant differences were observed in the proportion of the three categories of DOM (DOMN), the elements composition, and the subcategory composition of the C process compared to the A process, in which the DOM (DOMN) derivation rate of NEC1-C (31.92 % and 33.41 %) was much higher than that of NEC1-A (20.88 % and 22.19 %). However, the AIwa and AImodwa of the derived-DOM (DOMN) were significantly higher in the C process than in the A process, which implied that excessive aeration did not enhance the biological treatment potential of the A process, but instead led to the proliferation of microorganisms and the secretion of extracellular polymer substances, which resulted in the derivation of more complex compounds. The results of the correlation analysis indicated that there were some regional differences in the molecular information of DOMN driven by climate temperature. In addition, it was worth mentioning that the nominal oxidation state of carbon (NOSCwa) of derived-DOMN in different regions of A process was noticeably higher than the corresponding DOM (p < 0.0001), implying that the derived-DOMN were still highly biodegradable, in other words, there was still great room for improving the biological treatment potential of landfill leachate. The present study provided a deeper insight and analysis of landfill leachate at the molecular level (DOMN) through multiple practical engineering cases, with a view to providing a theoretical basis for efficient optimization of biological treatment.

Confinement Effects in Droplet Formation on a Solid Particle.

Formation of a droplet around a spherical solid particle in supersaturated vapor is considered. The number and stability of equilibrium solutions in a closed small system are studied in the canonical ensemble in comparison to an open system in the grand canonical ensemble. Depending on the system's parameters, two modes exist in the canonical ensemble: the first one with only one solution and the second one with three solutions; the presence of the third solution is due to confinement. The analysis is conducted first on a macroscopic thermodynamic level of description, and then the results are supported by studies within two versions of classical density functional theory: the square-gradient approximation with the Carnahan-Starling equation of state for hard spheres on a completely wettable particle and the random-phase approximation with the fundamental measure theory on a poorly wettable particle. In the latter case, a solution breaking the spherical symmetry is observed at a small total number of molecules.

First report of Pyricularia oryzae the cause of blast disease in upland rice, in Lombok, West Nusa Tenggara

Rice (Oryza sativa L.) is a maincrop cultivated by farmers in Indonesia. The demand for rice has increased, but rice production has decreased due to attacks by plant pests, including pathogen blast disease. This research aims to (i) determine the symptoms of blast disease in upland rice in Lombok, (ii) determine the incidence of blast disease in upland rice in Lombok, (iii) and identify the pathogen that causes blast disease in upland rice in Lombok. The research was conducted in Lombok, West Nusa Tenggara. A sampling of rice crop tissue infected by blast disease was taken from 50 dryland locations in Lombok West Nusa Tenggara. From each point, three samples of rice crops with blast symptoms were taken to obtain 150 samples. Samples are then isolated and identified at the macroscopic, microscopic, and molecular levels. The study results showed that the macroscopic characteristics of rice leaves were rhombus-shaped and brown, and the pathogen produced white mycelium with a fine structure. In contrast, microscopic characteristics showed that the shape of the hyphae was septate, the structure of conidiophore with autophagic cell death, long pyriform microconidia, and long pyriform macroconidia. Based on 18S rRNA gene analysis, the Blast Lombok isolate had a DNA fragment of ±550bp. Based on these results, it can be concluded that the cause of blast disease in upland rice in Lombok, West Nusa Tenggara, is P. oryzae.

Unveiling salinity-driven shifts in microbial community composition across compartments of naturally saline inland streams

Riverine environments host diverse microbial communities, exhibiting distinctive assemblies at both microscopic and macroscopic levels. Despite the complexity of microbial life in rivers, the underlying factors that shape the community structure across different compartments remain elusive. Herein, we characterized microbial community composition of biofilm and planktonic (water column) compartments in five naturally saline inland streams and a freshwater stream to examine changes in microbial communities following salinization via sequencing of the microbial 16S rRNA gene. Significant differences in specific conductivity, oxidation–reduction potential, dissolved oxygen, and pH among the sampled streams were measured, as were significant differences in the microbial community composition between the planktonic and biofilm. The bacterial families Bacillaceae, Vicinamibacterceae, and Micrococcaceae were significantly more abundant in the biofilm compartment, while Methylophilaceae, Alcaligenaceae, Spirosomaceae, Burkholderiaceae, and Comamonadaceae were more abundant in the planktonic compartment. In addition, salinity (based on specific conductivity) influenced the microbial community composition in both compartments, with higher sensitivity of the planktonic compartment. Increases in the bacterial families Shewanellaceae, Marinomonadaceae, and Saccharospirillaceae or loss of Anaeromyxobacteraceae could be indicative of increased salinity within inland streams. Our results suggest that monitoring of microbial assemblages of freshwater ecosystems could be used as early warning signs of increased salinization levels.

Atomistic understanding of the variable nano-hardness of C-plane sapphire considering the crystal anisotropy

Nanoindentation test method is widely used to measure the material hardness, which is a standard test and the effect of measurement error is limited. However, the measured results of the nano-hardness for the same plane of single crystal materials, such as sapphire, were very different. The possible reason for the difference of nano-hardness is induced by the anisotropy of single crystal materials. In this study, nanoindentation tests were carried out to obtain the nano-hardness of C-plane sapphire. The tests with two different indenter orientations were designed as follow. On C-plane, one edge of the Berkovich indenter was indented parallel to the direction [101‾0], as well as one edge indented perpendicular to the direction [101‾0] for comparison. The average hardness was 25.58 GPa and 29.64 GPa respectively. Molecular dynamics simulation was employed to reveal the generation mechanism of anisotropy in nanoindentation process. The results showed that the distribution of subsurface dislocations and the activation of slip systems were affected by indenter orientations, which resulted in the difference in nano-hardness. When one edge of the Berkovich indenter was indented perpendicular to the direction [101‾0], C-plane sapphire had a stronger ability to resist deformation, showing a higher hardness on the macroscopic level.

Polypropylene Fiber’s Effect on the Features of Combined Cement-Based Tailing Backfill: Micro- and Macroscopic Aspects

In undercut-and-fill mining, backfills show weak tensile strength and poor ductility properties since they act as artificial pillars to support stope roofs. Hence, the enhancement of the stability of mining structures and backfills is a crucial requisite for underground mining backfill operations. This study addresses the reinforcing effect of polypropylene (PP) on the strength features of combined cement-based tailing backfill (CCTB) with varied cement/tail ratios (c/t: 1:8 to 1:4) at both macroscopic and microscopic levels. Fill specimens containing a fixed solid content of 70 wt% were reinforced with fiber (0.6 wt%) and with no fiber (classified as a reference sample). They were then cast in mold sizes of 160 × 40 × 40 mm3, and cured for 7 days. Following curing, some experiments covering three-point bending assisted by DIC and SEM were performed to inspect the microstructure and strength features of CCTB. The results illustrate that the flexural strength of fiber-oriented CCTB increases along with the c/t fraction, but it is not greater than that of specimens with a high c/t fraction without fiber. Adding PP fiber, the peak deflection of CCTB specimens was improved, and the increment of peak deflection increased linearly with rising c/t fraction, enhancing CCTB’s bending characteristics. CCTB damage starts from the bottom to the middle, and the main cause of the damage is the stress distribution at the lowest section. The addition of fiber to CCTBs increases the ability to dissipate energy, which helps to hinder crack extension and prevent brittle damage from occurring. The microstructure shows that AFt and CSH were key hydrate materials in CCTB. As a result, this study develops the security of mining with backfill and helps to determine its design properties for safe production inputs and sustainable filling operations.

Discrepancy of Growth Toxicity of Polystyrene Nanoplastics on Soybean (Glycine max) and Mung Bean (Vigna radiata).

Nanoplastics, as a hot topic of novel contaminants, lack extensive concern in higher plants; especially the potential impact and mechanism of nanoplastics on legume crops remains elusive. In this study, the toxicity of polystyrene nanoplastics (PS-NPs, 200 nm) with diverse doses (control, 10, 50, 100, 200, 500 mg/L) to soybean and mung bean plants grown hydroponically for 7 d was investigated at both the macroscopic and molecular levels. The results demonstrated that the root length of both plants was markedly suppressed to varying degrees. Similarly, mineral elements (Fe, Zn) were notably decreased in soybean roots, consistent with Cu alteration in mung bean. Moreover, PS-NPs considerably elevated malondialdehyde (MDA) levels only in soybean roots. Enzyme activity data indicated mung bean exhibited significant damage only at higher doses of PS-NPs stress than soybean, implying mung bean is more resilient. Transcriptome analysis showed that PS-NPs stimulated the expression of genes associated with the antioxidant system in plant roots. Furthermore, starch and sucrose metabolism might play a key role in coping with PS-NPs to enhance soybean resistance, but the MAPK pathway was enriched in mung bean. Our findings provide valuable perspectives for an in-depth understanding of the performance of plants growing in waters contaminated by nanoplastics.

An assessment system for clinical and biological interpretability in ulcerative colitis.

Ulcerative colitis (UC) is a serious inflammatory bowel disease (IBD) with high morbidity and mortality worldwide. As the traditional diagnostic techniques have various limitations in the practice and diagnosis of early ulcerative colitis, it is necessary to develop new diagnostic models from molecular biology to supplement the existing methods. In this study, we developed a machine learning-based synthesis to construct an artificial intelligence diagnostic model for ulcerative colitis, and the correctness of the model is verified using an external independent dataset. According to the significantly expressed genes related to the occurrence of UC in the model, an unsupervised quantitative ulcerative colitis related score (UCRScore) based on principal coordinate analysis was established. The UCRScore is not only highly generalizable across UC bulk cohorts at different stages, but also highly generalizable across single-cell datasets, with the same effect in terms of cell numbers, activation pathways and mechanisms. As an important role of screening genes in disease occurrence, based on connectivity map analysis, 5 potential targeting molecular compounds were identified, which can be used as an additional supplement to the therapeutic of UC. Overall, this study provides a potential tool for differential diagnosis and assessment of bio-pathological changes in UC at the macroscopic level, providing an opportunity to optimize the diagnosis and treatment of UC.

Low-frequency rTMS induces modifications in cortical structural connectivity - functional connectivity coupling in schizophrenia patients with auditory verbal hallucinations.

Auditory verbal hallucinations (AVH) are distinctive clinical manifestations of schizophrenia. While low-frequency repetitive transcranial magnetic stimulation (rTMS) has demonstrated potential in mitigating AVH, the precise mechanisms by which it operates remain obscure. This study aimed to investigate alternations in structural connectivity and functional connectivity (SC-FC) coupling among schizophrenia patients with AVH prior to and following treatment with 1 Hz rTMS that specifically targets the left temporoparietal junction. Initially, patients exhibited significantly reduced macroscopic whole brain level SC-FC coupling compared to healthy controls. Notably, SC-FC coupling increased significantly across multiple networks, including the somatomotor, dorsal attention, ventral attention, frontoparietal control, and default mode networks, following rTMS treatment. Significant alternations in SC-FC coupling were noted in critical nodes comprising the somatomotor network and the default mode network, such as the precentral gyrus and the ventromedial prefrontal cortex, respectively. The alternations in SC-FC coupling exhibited a correlation with the amelioration of clinical symptom. The results of our study illuminate the intricate relationship between white matter structures and neuronal activity in patients who are receiving low-frequency rTMS. This advances our understanding of the foundational mechanisms underlying rTMS treatment for AVH.

Study on fracture characteristics and mechanisms of red sandstone under high-voltage pulse discharge

To investigate the influences of geometrical size and discharge voltage of the pulse discharge equipment on the fracture characteristics and mechanisms of sandstone under high-voltage pulses, a series of experiments was conducted using a high-voltage pulse discharge device on sandstone circular disc specimens of sandstone with a thickness of 10 mm. These experiments covered a range of disc diameters ranging from 50 mm to 142 mm and discharge voltages from 15 kV to 40 kV. Through these experiments, the fracture characteristics of sandstone at both macroscopic and microscopic levels were investigated. In the experiments, a quantitative analysis of surface fracture was undertaken based on fracture density and fractal damage. Additionally, using the principle of energy equivalence, numerical simulation methods were used to study the damage evolution process in sandstone. The research results indicate that the formation and distribution of fractures in the sandstone specimens are significantly affected by geometrical size and discharge voltage. By analyzing the interaction between stress waves and fracture propagation, combined with indoor experimental results, the fracture mechanism was revealed. The high temperature and shock wave generated by the plasma channel leads to the crushing zone near the electrode, while the circumferential tensile component of the stress wave can result in radial fractures, and the reflected tensile wave leads to circumferential and radial fractures near the boundary.

Dislocation structure evolution during room temperature dwell loading of a Ti-6Al-4 V alloy

The current work examines the evolution of the dislocation structure, within both the α and β phases, of a Ti-6Al-4 V alloy subjected to room temperature dwell loading performed at about 96% of the macroscopic yield stress level for several durations, as part of a synchrotron in-situ deformation experiment. The obtained findings represent a vital contribution to creating a scientific basis for improving lifing predictions for aero-propulsion components. The dislocation configuration, type and density were examined post-mortem using transmission electron microscopy (TEM). Despite the relatively low applied stress level, well-developed dislocation structures were already formed within the α phase at a dwell duration of 10 min and changed only modestly up to 60 min. The plastic deformation of the above phase took place solely via dislocation slip. To facilitate a comparison between different dwell durations, the TEM investigation focused on the regions oriented for the prismatic glide that represented the main deformation mode due to the starting crystallographic texture. After deformation, the regions oriented for the prismatic slip contained planar slip bands largely consisting of dislocations of a screw type. There was rather limited interaction between different bands, as the dislocation arrays passed through the slip band intersections with only minor difficulty. The screw-type dislocations seemed to preferentially form during straining. Dislocation Burgers vectors experimentally determined within the β phase occasionally departed from the Schmid rule and such dislocations typically showed a prevalent screw component. Some deformation banding and {112} 〈111〉 − type mechanical twin formation were locally detected within the β phase.

Physical Chemistry Models for Chemical Research in the XXth and XXIst Centuries.

Thermodynamic hypotheses and models are the touchstone for chemical results, but the actual models based on time-invariance, which have performed efficiently in the development of chemistry, are nowadays invalid for the interpretation of the behavior of complex systems exhibiting nonlinear kinetics and with matter and energy exchange flows with the surroundings. Such fields of research will necessarily foment and drive the use of thermodynamic models based on the description of irreversibility at the macroscopic level, instead of the current models which are strongly anchored in microreversibility.

“Steric Armor” Strategy of Blue Fluorescent Emitters against Photooxidation‐Induced Degradation

Comprehensive SummaryStability against oxygen is an important factor affecting the performance of organic semiconductor devices. Improving photooxidation stability can prolong the service life of the device and maintain the mechanical and photoelectric properties of the device. Generally, various encapsulation methods from molecular structure to macroscopic device level are used to improve photooxidation stability. Here, we adopted a crystallization strategy to allow 14H‐spiro[dibenzo[c,h]acridine‐7,9′‐uorene] (SFDBA) to pack tightly to resist fluorescence decay caused by oxidation. In this case, the inert group of SFDBA acts as a “steric armor”, protecting the photosensitive group from being attacked by oxygen. Therefore, compared with the fluorescence quenching of SFDBA powder under 2 h of sunlight, SFDBA crystal can maintain its fluorescence emission for more than 8 h under the same conditions. Furthermore, the photoluminescence quantum yields (PLQYs) of the crystalline film is 327% higher than that of the amorphous film. It shows that the crystallization strategy is an effective method to resist oxidation.

Emerging Role of Interleukin-38 (IL-38) in the Development of Rheumatoid Arthritis.

Rheumatoid arthritis (RA) is an incurable autoimmune disease. The role of interleukin-38 (IL-38), an anti-inflammatory cytokine, in RA is not fully understood, and its clinical relevance in RA remains unclear. This study aims to investigate the correlation of IL-38 with disease activity and the clinical manifestation of RA. In this cross-sectional study, patients with treatment-naïve RA (n = 63) and healthy controls (HC) (n = 60) were consecutively enrolled over a 15-month period. Patients with RA were categorized into three subgroups-low disease activity (LDA), moderate disease activity (MDA) and high disease activity (HDA)-using the Disease Activity Score in 28 joints based on C-reactive protein (DAS28-CRP). Circulating levels of IL-38, tumour necrosis factor (TNF), IL-6, IL-17, IL-1β, and 25(OH)D were assessed using enzyme-linked immunosorbent assay (ELISA). Clinical data, including duration, tender joints count (TJC), swollen joints count (SJC), patient global assessment (PGA), evaluator global assessment (EGA), bone mineral density (BMD), clinical disease activity index (CDAI), simplified disease activity index (SDAI), DAS28-CRP, joint musculoskeletal ultrasound (MSUS), and serological indicators were recorded. We determined the correlation between IL-38 and disease activity, as well as clinical manifestation in RA. At the macroscopic level, musculoskeletal ultrasonography of joints in different stages of disease activity in RA suggests that, as the disease progresses, arthritis in the hand becomes more severe, accompanied by synovial thickening and pronounced blood flow signals in the joint area. The expression of IL-38, TNF, IL-6, IL-17 and IL-1β significantly increased in patients with RA compared to HC. Noteworthy differences were observed in the blood flow signal score, synovial signal score, IL-38, TNF, IL-6, IL-17 and IL-1β among the three subgroups (LDA, MDA and HDA). As disease activity increased in patients with RA, the blood flow signal score, synovial signal score and expression of TNF, IL-6, IL-17 and IL-1β exhibited a gradual increase, while the expression of IL-38 showed the opposite pattern. Inverse correlations were identified between IL-38 and pro-inflammatory cytokines (IL-6, IL-17), as well as key clinical parameters, including disease duration, SJC, TJC and DAS28-CRP score. IL-38, intricately linked to the pathogenesis of RA, emerges as a promising therapeutic target for the management of this debilitating disease.