Hasil untuk "Chemical technology"

R. Adcock, T. Chen, N. Click et al.

Metal separation and recovery are a key aspect of silicon solar module recycling. This paper provides a fundamental understanding of the leaching and electrowinning in hydrochloric acid of two critical metals in silicon solar cells: copper and tin. A leaching model for solder-coated copper wires was developed to reveal rate orders with respect to concentrations of leaching agents and stirring. Kinetic parameters for electrowinning of copper and tin were determined through Tafel and electrochemical impedance spectroscopy analysis. Cyclic voltammetry was used to determine redox potentials of copper and tin allowing their electrochemical separation. Finally high recovery rates and high metal purity, both over 99 %, were achieved for copper and tin through sequential electrowinning. Hydrochloric acid leaching and sequential electrowinning provide a simple and effective option for the recovery of copper and tin from silicon solar modules.

Jinming Fan, Chao Qian, Wilhelm T. S. Huck et al.

Accurate prediction of the physicochemical properties of molecular mixtures using graph neural networks remains a significant challenge, as it requires simultaneous embedding of intramolecular interactions while accounting for mixture composition (i.e., concentrations and ratios). Existing approaches are ill-equipped to emulate realistic mixture environments, where densely coupled interactions propagate across hierarchical levels - from atoms and functional groups to entire molecules - and where cross-level information exchange is continuously modulated by composition. To bridge the gap between isolated molecules and realistic chemical environments, we present ChemFlow, a novel hierarchical framework that integrates atomic, functional group, and molecular-level features, facilitating information flow across these levels to predict the behavior of complex chemical mixtures. ChemFlow employs an atomic-level feature fusion module, Chem-embed, to generate context-aware atomic representations influenced by the mixture state and atomic characteristics. Next, bidirectional group-to-molecule and molecule-to-group attention mechanisms enable ChemFlow to capture functional group interactions both within and across molecules in the mixture. By dynamically adjusting representations based on concentration and composition, ChemFlow excels at predicting concentration-dependent properties and significantly outperforms state-of-the-art models in both concentration-sensitive and concentration-independent systems. Extensive experiments demonstrate ChemFlow's superior accuracy and efficiency in modeling complex chemical mixtures.

Devin H. Bemis, Carly E. Camphausen, Esther Liu et al.

Kimchi is a fermented Korean food typically made with napa cabbage, garlic, radish, ginger, and chili pepper. It is becoming increasingly popular due to its flavor, high fiber content, and purported probiotic benefits. The microbial ecology of the fermentation community has been extensively studied, though what’s less understood is how its microbial community changes when nutrients or pathogens are introduced. To study this, we used gnotobiotic cabbage media inoculated with a kimchi starter culture as a model system. These inoculated samples were exposed to <i>E. coli</i> or <i>Bacillus cereus</i>, with or without added nutrients in the form of tryptic soy broth (TSB). We tracked pH, colony-forming units (CFUs), and community composition over time. We also used Oxford Nanopore sequencing to analyze the 16S rRNA gene (V4–V9), followed by use of the Emu algorithm for taxonomic assignments. As expected, LABs suppressed pathogens, but this effect was weaker early on in the nutrient-rich condition. Pathogen exposure changed the overall community—<i>Lactobacillus</i> species became more common, and <i>Leuconostoc mesenteroides</i> less so. Interestingly, adding nutrients alone caused similar microbial shifts to those seen with pathogen exposure. This could suggest that nutrient levels have a larger impact on the final microbiome structure than direct microbial competition. Together, these findings suggest that monitoring total microbial composition, and not just the presence of pathogens, may be important for ensuring kimchi fermentation reproducibility.

Ning Li, Zhiyu Xiang, Liang Feng et al.

As advancements in autonomous underwater vehicle (AUV) technology unfold, the role of underwater wireless sensor networks (UWSNs) is becoming increasingly pivotal. However, the high energy consumption in these networks can significantly reduce their operational lifespan, while latency issues can impair overall network performance. To address these challenges, a novel mixed packet forwarding strategy is developed, which incorporates a wakeup threshold and a dynamically adjusted access probability for the cluster head (CH). This approach aims to conserve energy while maintaining acceptable network latency levels. The wakeup threshold restricts the frequency of state switching for the CH, thereby reducing energy consumption. Meanwhile, the dynamic access probability regulates the influx of packets to mitigate system congestion based on current network conditions. Furthermore, to accommodate the network’s varied transmission demands, packets generated by sensor nodes (SNs) are categorized into two types according to their sensitivity to latency. A discrete−time queueing model with preemptive priority is then established to evaluate the performance of different packets and the CH. Numerical results show how different parameters affect network performance and demonstrate that the proposed mixed packet forwarding mechanism can effectively manage the trade−off between latency and energy consumption, outperforming the traditional mechanism within a specific range of parameters.

Yi Shuai, Bo Chen, Tao Jiang et al.

Abstract Background Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a severe, therapy-refractory condition driven by ferroptotic disruption of jawbone-derived mesenchymal stem cells (MSCs) biology. We dissect this mechanism to validate ferroptosis as a therapeutic target. Methods We first demonstrated that miR-145-3p is mechanistically coupled to ferroptosis and osteogenesis in BRONJ model by gain- and loss-of-function studies. To evaluate therapeutic efficacy under pathologically relevant conditions, we designed three models: (i) Local BRONJ repair model: miR-145-3p-enriched exosomes were encapsulated in an injectable hydrogel scaffold and grafted into necrotic alveolar bone to assess direct BRONJ resolution. After local BRONJ treatment, endogenous MSCs were re-isolated, and both cellular and exosomal miR-145-3p levels were quantified. (ii) Osteoporosis treatment model: The reprogrammed MSCs derived from treated BRONJ rats were then administered intravenously to osteoporotic littermates to evaluate whether these MSCs retain systemic osteogenic competence. (iii) Critical-sized calvarial defect repair model: To further dissect the intrinsic osteogenic capacity, reprogrammed MSCs derived from treated BRONJ rats were fabricated into cell-sheet/HA-TCP “sandwich” constructs and transplanted into calvarial defects. Results BRONJ markedly compromised MSCs viability while elevating hallmarks of ferroptosis that were reversed by the ferroptosis inhibitor. Concomitantly, osteogenic capacity declined, as shown by reduced ALP activity, mineralized nodules, new bone formation and expression of RUNX2 and OCN. Mechanistically, we identified a miR-145-3p/IREB2 regulatory circuit that governs ferroptosis in BRONJ-derived MSCs; exosome-mediated delivery of miR-145-3p reinstated this axis, thereby reactivating the MSCs osteogenesis and driving in situ bone regeneration. Critically, after local BRONJ therapy, the reprogrammed MSCs were (i) infused via tail vein into osteoporotic rats, significantly elevating bone mass, and (ii) engineered into cell-sheet/HA-TCP “sandwich” constructs that achieved robust repair of critical-sized calvarial defects. These data establish exosomal miR-145-3p as a therapeutic that mitigates ferroptosis and restores the osteogenic competence of jawbone-derived MSCs for bone regeneration. Conclusion Collectively, our findings establish the miR-145-3p/IREB2/ferroptosis axis as an important regulator of BRONJ pathology and demonstrate that exosomal delivery of miR-145-3p not only ameliorates localized BRONJ but also substantially reinstates the systemic osteogenic potential of jawbone-derived MSCs, offering a pre-clinical promising strategy to combat both BRONJ and associated bone loss disorders. Graphical Abstract

Yuwei WU, Yu TIE, Zhixing TANG et al.

Bacillus bacteria are critical functional strains during fermentation of Sichuan bran vinegar that contribute to maintain the quality of vinegar. In this study, some functional Bacillus bacteria were isolated from the Cupei (grains undergoing acetic acid fermentation) of Sichuan bran vinegar, and the strains were identified by biochemical tests and 16S rRNA sequencing. The fermentation properties of these strains were studied, and the 5 Bacillus strains with great fermentation performance were discovered. They were identified as Paenibacillus cookii BA-6, Bacillus velezensis BA-9, Bacillus tropicus BB-5, Bacillus subtilis BB-13, and Calidifontibacillus erzurumensis BC-11. The five strains grew well at 30~40 ℃ and pH5~7 (OD600=0.23~0.52), with a certain degree of tolerance for environmental factor. Some of the Bacillus strains had a strong ability to hydrolyze protein (proteolytic ring of B. velezensis BA-9: 3.7±0.3) and starch (starch hydrolysis ring of P. cookie BA-6: 3.8±0.5). The simulated solid-state fermentation of inoculation with Bacillus and Acetobacter was carried out to investigate their potential use in industrial bran vinegar fermentation. Results showed that inoculation of P. cookie BA-6, B. velezensis BA-9, and C. erzurumensis BC-11 could increase total acid, lactic acid, acetic acid, and volatile flavor compounds content (e.g., phenyl ethanol, benzyl alcohol, isopentanol, and guaicol), further raise the overall fermentation quality of the Cupei. Overall, the 5 strains of Bacillus identified in the study were beneficial for the formation of flavor compounds during the Cupei fermentation of bran vinegar. The study provides a theoretical foundation for enhancing the quality of Sichuan bran vinegar.

C. V. Morr, E. Ha

CHEN Meng-han, Amel Mohamed, XU Ying-shu, YANG Zi-fan, JIA Hong-bing*

"Rubber blending was an effective way to develop new rubber materials that could achieve better properties than those of single components. The properties of blend could be precisely controlled by using different types of rubbers. However, most blends tended to phase separation, which led to deterioration in mechanical properties. Graphene oxide (GO) could be used as a novel compatibilizer to improve compatibility between rubbers［1-2］. 　In this work, GO was added to the blends of carboxylated nitrile butadiene rubber (XNBR) and styrene-butadiene rub-ber (SBR). The XNBR/SBR blend with different blend ratios were designed, and the effect of GO on the mechanical properties of GO/XNBR/SBR blended systems was analyzed in detail by a combination of molecular dynamics (MD) simulations and experiments. The formulation of rubber compounds was XNBR/SBR 100 phr (in mass, the same below), GO 0 or 3.0 phr, antideteriorant 4010 NA 2.0 phr, zinc oxide 2.0 phr, stearic acid 2.4 phr, accelerator CZ 2.2 phr and sulfur 1.5 phr. The mass ratios of XNBR/SBR were 25/75, 50/50 and 75/25, respectively. 　Through MD simulation, the number of hydrogen bonds of GO/XNBR/SBR blends was shown in Fig 1. The results showed that plenty of hydrogen bonds existed in GO/XNBR/SBR blends, and both the total number of hydrogen bonds and the number of interfacial hydrogen bonds increased with increasing XNBR content, indicating that the interfacial interaction of GO/XNBR/SBR blends was enhanced. After adding 75 phr of XNBR, the number of hydrogen bonds was the highest［3］. ■ Fig 1 Number of hydrogen bonds of GO/XNBR/SBR blends 　Tensile strength of XNBR/SBR and GO/XNBR/SBR blends were shown in Fig 2. It could be seen that the tensile strength of XNBR/SBR blend increased gradually with the growing of XNBR content, mainly due to the higher strength of XNBR compared to SBR. The higher the proportion of XNBR rubber was, the better the mechanical properties of the blends were. Compared to that of XNBR/SBR blend, the tensile strength of GO/XNBR/SBR blend increased by 86% when adding XNBR of 75 phr. The strong interfacial interactions, such as hydrogen bonds, may lead to a remarkable increase in the mechanical properties of the blend. ■ Fig 2 Tensile strength of XNBR/SBR and GO/XNBR/SBR blends"

Subrata Chakraborty, Biswajeet Pradhan

Machine learning (ML) models have experienced remarkable growth in their application for multimodal data analysis over the past decade [...]

Efrida Basri, Istie Sekartining Rahayu, Saefudin Saefudin et al.

Lactic acid (LA), citric acid (CA), and glycerol (G) are renewable and environmentally friendly chemicals that could improve the qualities of short-rotation teak (SRT) woods. This study investigated the effect of thermal and chemical modification using 20% aqueous solutions (w/w) of LA, CA, and G and their mixtures in the same composition on physical and mechanical properties of SRT teak wood. The impregnation process was initiated by vacuum process for 1 h and pressure (12.2 bar) for 2 h, followed by thermal (150 °C) treatment for 6 h on the SRT wood samples after being removed from the vacuum-pressure tube. Retention (R), weight percent gain (WPG), density (D), anti-swelling efficiency (ASE), leachability (WL), modulus of elasticity (MOE), and modulus of rupture (MOR) were measured. FTIR spectrometry and SEM analyses were performed. The wood impregnated with a mixture of 10% LA + 10% CA provided the highest ASE values of 50.1%, and the lowest leaching resistance of 1.54%. Based on wood strengths (MOE and MOR) and physical properties, as well as supported by FTIR and SEM analysis, the use of 10% LA + 10% CA is the most prospective as an impregnant formula for SRT wood modification of this research.

Han Na Suh, Sung-Hoon Yoon, Yoo Min Park et al.

Yi-Fan Hou, Lina Zhang, Quanhao Zhang et al.

Quantum chemical simulations can be greatly accelerated by constructing machine learning potentials, which is often done using active learning (AL). The usefulness of the constructed potentials is often limited by the high effort required and their insufficient robustness in the simulations. Here we introduce the end-to-end AL for constructing robust data-efficient potentials with affordable investment of time and resources and minimum human interference. Our AL protocol is based on the physics-informed sampling of training points, automatic selection of initial data, uncertainty quantification, and convergence monitoring. The versatility of this protocol is shown in our implementation of quasi-classical molecular dynamics for simulating vibrational spectra, conformer search of a key biochemical molecule, and time-resolved mechanism of the Diels-Alder reactions. These investigations took us days instead of weeks of pure quantum chemical calculations on a high-performance computing cluster. The code in MLatom and tutorials are available at https://github.com/dralgroup/mlatom.

Alaukik Saxena, Nikita Polin, Navyanth Kusampudi et al.

Atom probe tomography (APT) is ideally suited to characterize and understand the interplay of chemical segregation and microstructure in modern multicomponent materials. Yet, the quantitative analysis typically relies on human expertise to define regions of interest. We introduce a computationally efficient, multistage machine learning strategy to identify chemically distinct domains in a semi automated way, and subsequently quantify their geometric and compositional characteristics. In our algorithmic pipeline, we first coarse grain the APT data into voxels, collect the composition statistics, and decompose it via clustering in composition space. The composition classification then enables the real space segmentation via a density based clustering algorithm, thus revealing the microstructure at voxel resolution. Our approach is demonstrated for a Sm(Co,Fe)ZrCu alloy. The alloy exhibits two precipitate phases with a plate-like, but intertwined morphology. The primary segmentation is further refined to disentangle these geometrically complex precipitates into individual plate like parts by an unsupervised approach based on principle component analysis, or a U-Net based semantic segmentation trained on the former. Following the chemical and geometric analysis, detailed chemical distribution and segregation effects relative to the predominant plate-like geometry can be readily mapped without resorting to the initial voxelization.

Luana Hildever, Thiago Ferro, José Holanda

Fundamental interactions are the basis of the most diverse phenomena in science that allow the dazzling of possible applications. In this work, we report a new interaction, which we call chemical-quantum-magnetic interaction. This interaction arises due to the difference in valence that the Fe3O4/PANI nanostructure acquires under certain conditions. In this study, PANI activates the chemical part of the oscillations, leaving the quantum and magnetic part for the double valence effect and consequently for changing the number of spins of the nanostructure sites. We also observed using interaction measurements that chemical-quantum-magnetic interactions oscillate in a subcritical regime satisfying the behavior of a damped harmonic oscillator.

Liangrong Peng, Liu Hong

Partial equilibrium approximation (PEA) and quasi-steady-state approximation (QSSA) are two classical methods for reducing complex macroscopic chemical reactions into simple computable ones. Previous studies mainly focus on the accuracy of solutions before and after applying model reduction. While, in this paper we start from a thermodynamic view, and try to establish a quantitative connection on the essential thermodynamic quantities, like entropy production rate, free energy dissipation rate and entropy flow rate, between the original reversible chemical mass-action equations and the reduced models by either PEA or QSSA. Our results reveal that the PEA and QSSA do not necessarily preserve the nice thermodynamic structure of the original full model during the reduction procedure (e.g. the loss of non-negativity of free energy dissipation rate), especially when adopting the algebraic relations in replace of differential equations. These results are further validated though the application to Michaelis-Menten reactions analytically and numerically as a prototype. We expect our study would motivate a re-examination on the effectiveness of various model reduction or approximation methods from a new perspective of non-equilibrium thermodynamics.

James I Macdonald, Henrik K. Munch, T. Moore et al.

Junhua Liu, Mei Dai, Jiangtao Li et al.

Dehydrins (DHNs) belong to group II of late embryogenesis-abundant (LEA) proteins, which are up-regulated in most plants during cold, drought, heat, or salinity stress. Despite the importance of dehydrins for the plants to resist abiotic stresses, it is necessary to obtain plant-derived dehydrins from different biomass. Generally, dehydrin PicW1 from Picea wilsonii is involved in Kn-type dehydrin with five K-segments, which has a variety of biological activities. In this work, Picea wilsonii dehydrin PicW1 was expressed in Escherichia coli and purified by chitin-affinity chromatography and size-exclusion chromatography, which showed as a single band by SDS-PAGE. A cold-sensitive enzyme of lactate dehydrogenase (LDH) is used to explore the protective activities of other proteins. Temperature stress assays showed that PicW1 had an effective protective effect on LDH activity, which was better than that of bovine serum albumin (BSA). This study provides insights into the purification and protective activity of K5 DHNs for the advancement of dehydrin structure and function from biomass.

Sulaiman Oladipo Lawal, Hiroki Nagasawa, Toshinori Tsuru et al.

This work investigated the long-term hydrothermal performance of composite carbon-SiO₂-ZrO₂ membranes. A carbon-SiO₂-ZrO₂ composite was formed from the inert pyrolysis of SiO₂-ZrO₂-polybenzoxazine resin. The carbon-SiO₂-ZrO₂ composites prepared at 550 and 750 °C had different surface and microstructural properties. A carbon-SiO₂-ZrO₂ membrane fabricated at 750 °C exhibited H₂ selectivity over CO₂, N₂, and CH₄ of 27, 139, and 1026, respectively, that were higher than those of a membrane fabricated at 550 °C (5, 12, and 11, respectively). In addition to maintaining high H₂ permeance and selectivity, the carbon-SiO₂-ZrO₂ membrane fabricated at 750 °C also showed better stability under hydrothermal conditions at steam partial pressures of 90 (30 mol%) and 150 kPa (50 mol%) compared with the membrane fabricated at 500 °C. This was attributed to the complete pyrolytic and ceramic transformation of the microstructure after pyrolysis at 750 °C. This work thus demonstrates the promise of carbon-SiO₂-ZrO₂ membranes for H₂ separation under severe hydrothermal conditions.

Masaru Murata, Md Arafat Kabir, Yukito Hirose et al.

The aim of this clinical case study was to observe biopsy tissues at 5 months after an autograft of a partially demineralized dentin/cementum matrix (pDDM) into a tooth-extracted socket exhibiting healing failure. A 66-year-old female presented with healing failure in the cavity for 2 months after the extraction (#36). Initial X-ray photos showed a clear remainder of lamina dura (#36), a residual root (#37), and a horizontal impaction (#38). The vital tooth (#38) was selected for pDDM. The third molar crushed by electric mill was decalcified in 1.0 L of 2.0% HNO₃ for 20 min and rinsed in cold distilled water. The pDDM granules (size: 0.5–2.0 mm) were grafted immediately into the treated socket. X-ray views just after pDDM graft showed radio-opaque granules. At 5 months after pDDM graft, the surface of regenerated bone was harmonized with the mandibular line, and bone-like radio-opacity was found in the graft region. The biopsy tissue (diameter: 3.0 mm) at 5 months after pDDM graft showed that mature bone was interconnected with the remaining pDDM. The novel histological evidence highlighted that newly formed bone was connected directly with both dentin-area and cementum-area matrix of pDDM. We concluded that pDDM contributed to the regeneration of bone in the unhealed socket, and this regeneration prepared the socket for implant placement. Autogenous pDDM could be immediately recycled as an innovative biomaterial for local bone regeneration.

Yi Li, Yue Zang, Tianda Fan et al.

Up to 20% of patients treated with anti-PD-1/PD-L1 inhibitors suffered from thyroid dysfunctions, yet the mediators associated with their occurrence remain unclear. The increasing coincidence of papillary thyroid carcinoma (PTC) with Hashimoto thyroiditis (HT) and the high vulnerability of thyroid to immunotherapy motivated us to discover the similarities and their underlying transcriptomic basis. Clinical characteristics analysis of 468 PTC patients from two independent cohorts and meta-analysis of 22,155 PTC patients unveiled a strong negative association between HT and recurrence in PTC patients. Transcriptome analysis of both cohorts showed PTC patients with HT were enriched in macrophages, CD8+ and CD4+ cytotoxic T cells, which was further validated by single-cell transcriptome analysis of 17,438 cells from PTC patients, and CD8+ T cells were correlated with disease-free survival of PTC patients. In both cohorts and single-cell dataset, elevated expression of PD-1-related genes was observed in the HT group, and CD3D appeared to be a target for enhancing the activation of CD8+ T cells. Correlation analysis of 3,318 thyroid adverse events from 39,123 patients across 24 tumor types and molecular signatures demonstrated similar signatures associated with autoimmune thyroiditis in PTC and thyroid immune-related adverse events (irAEs), and several multi-omics signatures, including signatures of CD8A and CD8+ T cells, showed positive associations with the odds ratio of thyroid irAEs. Our results unveil shared molecular signatures underlying thyroid dysfunction between patients receiving immunotherapies and PTC patients suffering from HT, which may shed light on managing the adverse events during cancer immunotherapy.