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Objective: To investigate the association between single nucleotide polymorphisms (SNPs) of tryptophan hydroxylase 2 (TPH2) (rs11178997, rs11178998, and rs120074175) and negative life events in adolescent depression with Non-suicidal self-injury (NSSI). Methods: Genomic DNA was extracted from 197 adolescents with depression (participants group, including NSSI group and non-NSSI group), as well as from 100 healthy controls (control group), in northern China. PCR technology was utilized to amplify DNA fragments and detect genotypes in both groups. The Adolescent Life Event Scale (ASLEC) was employed to conduct a questionnaire survey among the participants and control groups. Differences in allele and genotype frequency distribution between the two groups were analyzed using the X^2 test, while generalized multifactor dimensionality reduction (GMDR) was used to analyze gene-environment interactions. Results: Significant differences were observed in ASLEC scores between the control group and both the NSSI group and non-NSSI group (P<0.05). Additionally, significant differences were found in the interpersonal relationship factor and punishment factor between the NSSI group and non-NSSI group (P < 0.05). Moreover, a significant difference was identified in SNP genotype of rs11178997 between the depression group (NSSI group + non-NSSI group) and control group (P<0.05). GMDR analysis revealed an interaction among rs11178997, rs11178998, and ASLEC. Conclusion: Adolescents with depression, particularly females, may exhibit a tendency to employ NSSI as an emotional coping mechanism when confronted with greater family and interpersonal challenges. The AT genotype of TPH2 gene locus rs11178997 is more prevalent among adolescents with depression. Furthermore, the occurrence of NSSI may be associated with an interaction involving polymorphic sites rs11178997 and rs11178998 along with life events.
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Although hydrophobic interactions provide the main driving force for initial peptide aggregation, their role in regulating suprastructure handedness of higher-order architectures remains largely unknown. We here interrogate the effects of hydrophobic amino acids on handedness at various assembly stages of peptide amphiphiles. Our studies reveal that relative to aliphatic side chains, aromatic side chains set the twisting directions of single ß-strands due to their strong steric repulsion to the backbone, and upon packing into multi-stranded ß-sheets, the side-chain aromatic interactions between strands form the aromatic ladders with a directional preference. This ordering not only leads to parallel ß-sheet arrangements but also induces the chiral flipping over of single ß-strands within a ß-sheet. In contrast, the lack of orientational hydrophobic interactions in the assembly of aliphatic peptides implies no chiral inversion upon packing into ß-sheets. This study opens an avenue to harness peptide aggregates with targeted handedness via aromatic side-chain interactions.
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Interações Hidrofóbicas e Hidrofílicas , Peptídeos , Peptídeos/química , Peptídeos/metabolismo , Conformação Proteica em Folha beta , Estereoisomerismo , Estrutura Secundária de Proteína , Aminoácidos Aromáticos/química , Dicroísmo Circular , Modelos Moleculares , Aminoácidos/químicaRESUMO
OBJECTIVE: Segmentectomy has been widely performed in clinical practice, which required a comprehensive understanding of anatomical structure. In right lower lobe, studies of superior segment (S6) were relatively small-sized. And only one study focusing on subsuperior segment (S∗) was published, which showed different results with previous ones. As the close relationship between S6 and S∗, variation types and their prevalence rate were reported, aiming to providing larger-size study of S6 and showing new evidence on anatomical structure of S∗. METHODS: 800 CT imaging data were collected from patients in our hospital. Three-dimensional reconstruction was performed after quality check. All images were screened according to the definition of corresponding segment and anatomical variations were analyzed. RESULTS: The proportion of S6 variation types in the largest scale (718 patients) was reported with no significant difference compared to previous studies and newly classified subtypes of two-stem V6. The prevalence rate for S∗ in right lower lobe reached 28.3 % (203/718) with similar proportion of three types. Variation types and origins of pulmonary artery were analyzed in detail, finding two-stem A∗ only be observed in type III B∗. CONCLUSIONS: Through this study, the variation types and incidence rate of S6 were confirmed, and a different result of S∗ has been provided as well. The feasibility of the current classification standards and proposed new subclassifications were verified. The results would be a supplement to lung segmental anatomy and could advance researches in the future.
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Chiral Plasmonic nanomaterials have gradually illustrated intriguing circularly polarized light (CPL)-dependent properties in photocatalysis due to their unique chiral optical activity. However, the connection between chiral characteristics and catalytic performance of these materials in cooperative systems is rarely reported and remains a challenge task. In this work, branched AgAuPt nanoparticles induced by L/d-cysteine (Cys) with strong and perfectly symmetric circular dichroism (CD) signals are synthesized. Chiral branched AgAuPt nanoparticles firstly exhibit superior typical electrocatalytic performance. In the photoelectrocatalytic system, chiral branched AgAuPt nanoparticles demonstrate selective catalytic water splitting performance. Specifically, chiral branched AgAuPt with related CPL irradiation exhibits enhanced acidic hydrogen evolution reaction (HER) performance. Under the continuous irradiation of related CPL, the chiral catalyst generates more heat, which further increases the catalytic activity. This contribution of heat is supported by density functional theory (DFT) calculation results. The changes in chiroptical activity during this process are recorded by variable temperature CD spectra. This work provides a novel paradigm for designing chiral catalysis systems and emphasizes the profound promise of chiral plasmonic nanomaterials as chiral catalysts.
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Interface engineering and vacancy engineering play an important role in the surface and electronic structure of nanomaterials. The combination of the two provides a feasible way for the development of efficient photocatalytic materials. Here, we use glutathione (GSH) as a coordination molecule to design a series of CuxS nanomaterials (CuxS-GSH) rich in sulfur vacancies using a simple ultrasonic-assisted method. Interface engineering can induce amorphous structure in the crystal while controlling the formation of porous surfaces of nanomaterials, and the formation of a large number of random orientation bonds further increases the concentration of sulfur vacancies in the crystal structure. This study shows that interface engineering and vacancy engineering can enhance the light absorption ability of CuxS-GSH nanomaterials from the visible to the near-infrared region, improve the efficiency of charge transfer between CuxS groups, and promote the separation and transfer of optoelectronic electron-hole pairs. In addition, a higher specific surface area can produce a large number of active sites, and the synergistic and efficient photothermal conversion efficiency (58.01%) can jointly promote the better photocatalytic performance of CuxS-GSH nanomaterials. Based on the excellent hot carrier generation and photothermal conversion performance of CuxS-GSH under illumination, it exhibits an excellent ability to mediate the production of reactive oxygen species (ROS) through peroxide cleavage and has excellent peroxidase activity. Therefore, CuxS-GSH has been successfully developed as a nanoenzyme platform for detecting tannic acid (TA) content in tea, and convenient and rapid detection of tannic acid is achieved through the construction of a multi-model strategy. This work not only provides a new way to enhance the enzyme-like activity of nanomaterials but also provides a new prospect for the application of interface engineering and vacancy engineering in the field of photochemistry.
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Bone tunnel enlargement has been troubling the clinical adoption of braided artificial ligaments for decades, to which mechanical and tribological performance promotion shall be an effective and promising approach. Herein, a "carrot and stick" strategy has been introduced with two types of polyethylene terephthalate (PET) fibers to fabricate hybrid textures, which is expected to advance fatigue and tribological performance without yielding essential mechanical strength and biocompatibility. Owing to advancements in such a "carrot and stick" strategy, the obtained grafts present three promising properties: i) enhancement of mechanical strength; ii) coefficient of friction (COF) reduction of 25% at the greatest extent, thus lowering the risk of bone tunnel enlargement; iii) final displacement shrinkage of graft length after cyclic loadings, favored in the clinic for isometric reconstruction. The results obtained in this study show that the "carrot and stick" strategy can be a creative and convenient method to optimize the service life, saving the complication rate of artificial ligaments for clinical applications.
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Reconstrução do Ligamento Cruzado Anterior , Polietilenotereftalatos , Reconstrução do Ligamento Cruzado Anterior/métodos , Polietilenotereftalatos/química , Humanos , Teste de Materiais , Fricção , Materiais Biocompatíveis/química , Ligamentos , Ligamento Cruzado Anterior/cirurgia , Animais , Estresse MecânicoRESUMO
BACKGROUND: Pectus excavatum, the most common chest wall deformity, is frequently treated with Nuss procedure. Here we will describe non-invasive procedure and analyze the variables associated vacuum bell therapy for patients with pectus excavatum. METHODS: Retrospective case-control study in a single center between July 2018 and February 2022, including patients with pectus excavatum treated with vacuum bell. Follow-up was continued to September 2022. The Haller index and Correction index was calculated before and after treatment to analysis the effectiveness of vacuum bell therapy. RESULTS: There were 98 patients enrolled in the treatment group, with 72 available for analysis, and the follow-up period ranged from 1.1 to 4.4 years (mean 3.3 years). When analyzing with the Haller Index, 18 patients (25.0%) showed excellent correction, 13 patients (18.1%) achieved good correction, and 4 patients (5.6%) had fair correction. The remaining patients had a poor outcome. Characteristics predicting a non-poor prognosis included initial age ≤ 11 years (OR = 3.94, p = 0.013) and patients with use over 24 consecutive months (OR = 3.95, p = 0.013). A total of 9 patients (12.5%) achieved a CI reduction below 10. Patients who started vacuum bell therapy at age > 11 had significantly less change compared to those who started at age ≤ 11 (P < 0.05). Complications included chest pain (5.6%), swollen skin (6.9%), chest tightness (1.4%) and erythema (15.3%). CONCLUSIONS: A certain percentage of patients with pectus excavatum can achieve excellent correction when treated with pectus excavatum therapy. Variables predicting better outcome including initial age ≤ 11 years both in HI and CI and vacuum bell use over 24 consecutive months in HI. In summary, pectus excavatum is an emerging non-invasive therapy for pectus excavatum and will be widely performed in a certain group of patients.
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Tórax em Funil , Parede Torácica , Humanos , Criança , Tórax em Funil/terapia , Estudos Retrospectivos , Estudos de Casos e Controles , VácuoRESUMO
The packaging problem with petroleum-based synthetic polymers prompts the development of edible packaging films. The high value-added reuse of navel orange peel pomace, which is rich in bioactive compounds, merited more considerations. Herein, nanocellulose (ONCC) and soluble dietary fiber (OSDF) from navel orange peel pomace are firstly used to prepare dietary fiber-based edible packaging films using a simple physical blend method, and the impact of ONCC on the film's properties is analyzed. Adopting three methods in a step-by-step approach to find the best formula for edible packaging films. The results show that dietary-fiber-based edible packaging films with 4 wt.% ONCC form a network structure, and their crystallinity, maximum pyrolysis temperature, and melting temperature are improved. What's more, dietary-fiber-based edible packaging films have a wide range of potential uses in edible packaging.
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BACKGROUND: Aortoesophageal fistula (AEF) is an extremely rare and highly fatal complication leading to a high risk of morbidity and mortality. Successful management of AEF after esophagectomy for esophageal carcinoma has rarely been reported in the literature. CASE PRESENTATION: Here we present a rare case of a 44-year-old female with complications of AEF after esophagectomy for esophageal carcinoma, mainly presented as vomiting of blood. Both computed tomographic and computed tomography angiography of the chest showed bilateral pleural effusion and atelectasis, while gastroscopy showed large gastrointestinal bleeding. Emergency surgery was performed that included the removal of the mediastinal abscess, left lower pulmonary wedge resection, and thoracic endovascular aortic repair (TEVAR), followed by supportive treatment. The surgery went successful, and the patient was followed up for 1 year after discharge and showed good recovery. We also reviewed previous literature on the history, causes, pathophysiology, clinical presentation, diagnosis, and treatment of AEF after esophagectomy for esophageal adenocarcinoma. CONCLUSIONS: In our case, thoracotomy combined with TEVAR was effective in treating AEF after esophagectomy for esophageal adenocarcinoma. This case provides successful experiences for clinical diagnosis and treatment of AEF after esophagectomy for esophageal carcinoma.
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Adenocarcinoma , Doenças da Aorta , Carcinoma , Fístula Esofágica , Fístula Vascular , Adulto , Feminino , Humanos , Adenocarcinoma/cirurgia , Adenocarcinoma/complicações , Doenças da Aorta/cirurgia , Doenças da Aorta/complicações , Carcinoma/cirurgia , Correção Endovascular de Aneurisma , Fístula Esofágica/etiologia , Fístula Esofágica/cirurgia , Esofagectomia/efeitos adversos , Hemorragia Gastrointestinal , Fístula Vascular/etiologia , Fístula Vascular/cirurgiaRESUMO
Pickled radish is a traditional fermented food with a unique flavor after long-term preservation. This study analyzed the organoleptic and chemical characteristics of pickled radish from different years to investigate quality changes during pickling. The results showed that the sourness, saltiness, and aftertaste-bitterness increased after pickling, and bitterness and astringency decreased. The levels of free amino acids, soluble sugars, total phenols, and total flavonoids initially decreased during pickling but increased with prolonged pickling. The diversity of organic acids also increased over time. Through non-targeted metabolomics analysis, 349 differential metabolites causing metabolic changes were identified to affect the quality formation of pickled radish mainly through amino acid metabolism, phenylpropane biosynthesis and lipid metabolism. Correlation analysis showed that L*, soluble sugars, lactic acid, and acetic acid were strongly associated with taste quality. These findings provide a theoretical basis for standardizing and scaling up traditional pickled radish production.
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Brassicaceae , Raphanus , Nariz Eletrônico , Metabolômica/métodos , AçúcaresRESUMO
The co-assembly of different peptide chains usually leads to the formation of intricate architectures and sophisticated functions in biological systems. Although the co-assembly of stereoisomeric peptides represents a facile and flexible strategy for the synthesis of peptide-based nanomaterials with novel structures and potentially interesting properties, there is a lack of a general knowledge on how different isomers pack during assembly. Through the combined use of simulations and experimental observations, we report that heterochiral pairing is preferred to homochiral pairing at the molecular scale but self-sorting dictates beyond the molecular level for the mixtures of the short stereoisomeric ß-sheet peptides I3K (Ile-Ile-Ile-Lys). Furthermore, we demonstrate that flat ß-sheets and fibril morphology are always preferred to twisted ones during heterochiral pairing and subsequent assembly. However, the heterochiral pairing into flat morphology is not always at an equimolar ratio. Instead, a non-equimolar ratio (1:2) is observed for the mixing of homochiral LI3LK and heterochiral LI3DK, whose strand twisting degrees differ greatly. Such a study provides a paradigm for understanding the co-assembly of stereoisomeric peptides at the molecular scale and harnessing their blending for targeted nanostructures.
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Nanoestruturas , Peptídeos , Estereoisomerismo , Peptídeos/química , Nanoestruturas/química , Conformação Proteica em Folha betaRESUMO
From the view of geometry, chirality is that an object cannot overlap with its mirror image, which has been a fundamental scientific problem in biology and chemistry since the 19th century. Chiral inorganic nanomaterials serve as ideal templates for investigating chiral transfer and amplification mechanisms between molecule and bulk materials, garnering widespread attentions. The chiroptical property of chiral plasmonic nanomaterials is enhanced through localized surface plasmon resonance effects, which exhibits distinctive circular dichroism (CD) response across a wide wavelength range. Recently, 3D chiral plasmonic nanomaterials are becoming a focal research point due to their unique characteristics and planar-independence. This review provides an overview of recent progresses in 3D chiral plasmonic nanomaterials studies. It begins by discussing the mechanisms of plasmonic enhancement of molecular CD response, following by a detailed presentation of novel classifications of 3D chiral plasmonic nanomaterials. Finally, the applications of 3D chiral nanomaterials such as biology, sensing, chiral catalysis, photology, and other fields have been discussed and prospected. It is hoped that this review will contribute to the flourishing development of 3D chiral nanomaterials.
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Pathogenic bacteria in daily life, such as Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli), often seriously affect human life and health. The extensive use of antibiotics has led to the emergence of drug-resistant bacteria, so it is urgent to develop efficient and non-drug-resistant sterilization methods. Here, we use small-molecule cysteine (Cys) as an auxiliary agent to synthesize spherical porous amorphous CuS-Cysteine (CuS-C) nanoparticles, which have good dispersion in aqueous solutions, and explore the reaction mechanism of Cys-induced CuS synthesis. The synthesized composite nanomaterials have strong near-infrared light absorption ability and efficient photothermal conversion ability and can effectively ablate pathogenic bacteria under the irradiation of an 808 nm laser. In addition, antibacterial experiments showed that CuS-C composites had no bactericidal effect without near-infrared light, but they had a good photothermal bactericidal effect on S. aureus and E. coli under radiation conditions. Considering the simple synthesis process, strong photothermal conversion ability, low cost, and suitability for large-scale production, CuS-C nanocomposites, as a promising antibacterial material, will provide a feasible scheme for the treatment of drug-resistant pathogens.
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Nanocompostos , Nanopartículas , Humanos , Cobre/farmacologia , Aminoácidos , Cisteína , Escherichia coli , Staphylococcus aureus , Antibacterianos/farmacologia , SulfetosRESUMO
Bi2O2Se, a newly emerging two-dimensional (2D) material, has attracted significant attention as a promising candidate for optoelectronics applications due to its exceptional air stability and high mobility. Generally, mica and SrTiO3substrates with lattice matching are commonly used for the growth of high-quality 2D Bi2O2Se. Although 2D Bi2O2Se grown on these insulating substrates can be transferred onto Si substrate to ensure compatibility with silicon-based semiconductor processes, this inevitably introduces defects and surface states that significantly compromise the performance of optoelectronic devices. Herein we employ Bi2Se3as the evaporation source and oxygen reaction to directly grow Bi2O2Se nanosheets on Si substrate through a conventional chemical vapor deposition method. The photodetector based on the Bi2O2Se nanosheets on Si substrate demonstrates outstanding optoelectronics performance with a responsivity of 379 A W-1, detectivity of 2.9 × 1010Jones, and rapid response time of 0.28 ms, respectively, with 532 nm illumination. Moreover, it also exhibits a broadband photodetection capability across the visible to near-infrared range (532-1300 nm). These results suggest that the promising potential of Bi2O2Se nanosheets for high-performance and broadband photodetector applications.
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Realization of nonreciprocal transport is of great importance in the development of devices and systems that require the directional manipulation of signals or particles in information processing and modern physics. For ultracold atomic systems, the approaches based on synthetic dimensions have led to rapid advances in engineering quantum transport. Here, we use laser-coupled discrete momentum states of noninteracting ultracold atoms to synthesize a momentum lattice, and construct a closed ring with controllable tunneling phase in the momentum lattice. We measure the density evolution of atoms in the synthetic lattice with the single-site resolution, and observe the nonreciprocal dynamics by controlling the tunneling phase. We show the effect of both the applied phase and the coupling strength between two distinct population regions on the population distribution of atoms in the momentum lattice, and provide the optimal parameters for achieving the nonreciprocal transport.
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The development of edible packaging films was motivated due to resource waste and environmental damage caused by chemically produced plastic packaging. The development of edible packaging film based on grapefruit peel pomace dietary fiber has significant technological and functional potential because grapefruit processing waste is a potential source of high-quality dietary fiber. In this study, the first successful development of an edible packaging film based on dietary fiber using grapefruit soluble dietary fiber (GSDF) from grapefruit peel pomace as a substrate and nanocellulose (GNCC) as a filler was developed. Principal component analysis, membership function synthesis, and response surface methods were used to determine the optimal process to prepare the edible packaging films, and the impact of GNCC on this material was analyzed. The results showed that the overall performance score of the edible packaging film with 1 wt% GNCC was 0.764. The maximum pyrolysis temperature increased from 226.36 °C to 227.10 °C, the melting temperature (Tm) increased by 5.54 °C, the crystallinity increased by 2.95 %. The film solution exhibited non-Newtonian characteristics and a solid-like property. Our results showed that the edible packaging film developed from grapefruit peel pomace and dietary fiber could have several potential applications in the food packaging field.
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Citrus paradisi , Filmes Comestíveis , Fibras na Dieta , Embalagem de Alimentos/métodosRESUMO
BACKGROUND: Neoadjuvant chemoimmunotherapy is an important therapeutic modality for resectable nonsmall cell lung cancer (NSCLC). The roles of the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio, and lymphocyte-to-monocyte ratio in predicting the efficacy and prognosis of patients with resectable NSCLC receiving neoadjuvant chemoimmunotherapy remain uncertain. This study aimed to explore the association of baseline and preoperative NLR, platelet-to-lymphocyte ratio, and lymphocyte-to-monocyte ratio with the treatment response and survival of patients with resectable NSCLC treated with neoadjuvant chemoimmunotherapy. MATERIALS AND METHODS: Data of patients with resectable NSCLC treated with neoadjuvant chemoimmunotherapy between May 2019 and July 2022 at our institute, were retrospectively analyzed. Peripheral blood cell counts were obtained at baseline and before surgery. Data that may affect treatment efficacy were also collected and analyzed, including age, sex, BMI, cumulative smoking exposure, pathological type, clinical stage, PD-L1 tumor proportion score, immune checkpoint inhibitors, dosage of neoadjuvant therapy, duration from final therapy to surgery, and baseline and preoperative oncological markers. The present work has been reported in compliance with REporting recommendations for tumor MARKer prognostic studies (REMARK) criteria and guidelines (Supplemental Digital Content 1, http://links.lww.com/JS9/A860 ). RESULTS: A total of 116 patients were included in the study. Univariate logistic regression analysis showed that a higher baseline NLR ( P =0.001) and preoperative NLR ( P =0.001) were associated with a lower incidence of pathological complete response (pCR) following neoadjuvant therapy. Multivariate analysis indicated that a lower incidence of pCR was achieved in the high baseline NLR group ( P =0.014). Higher baseline NLR ( P =0.021), preoperative NLR ( P =0.004) and higher preoperative CEA levels ( P =0.059) were associated with shorter disease-free survival (DFS). Multivariate Cox proportional hazard regression analyses showed that shorter DFS was achieved in the high preoperative NLR group ( P =0.033). CONCLUSION: In patients with resectable NSCLC treated with neoadjuvant chemoimmunotherapy, a higher baseline NLR was associated with a lower incidence of pCR, and a higher preoperative NLR was associated with a shorter DFS. However, a future prospective study with a large sample size and long-term follow-up is needed to verify the predictive value of NLR in these patients.
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Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/cirurgia , Terapia Neoadjuvante , Estudos Retrospectivos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/cirurgia , Estudos Prospectivos , Linfócitos/patologia , Prognóstico , Neutrófilos/patologiaRESUMO
Citrus fruits were widely used in processing and production, generating a large amount of peel pomace and a low utilization rate, resulting in substantial economic losses and environmental risks. It was important to extract compounds from citrus peel pomaces and find suitable preparation methods to improve their yield and physicochemical properties. Grapefruit peel pomace (GP) and navel orange peel pomace (OP) were used as raw materials in this study to prepare green and edible soluble dietary fiber (SDF) and insoluble dietary fiber (IDF). Analysis was done on the effects of solid-liquid ratio, cellulase hydrolysis time, cellulase dosage, and ultrasonic time on dietary fiber (DF) yield. To obtain the best DF preparation conditions, we used range analysis, variance analysis, and orthogonal experimental design. We also analyzed the structural, physicochemical, and rheological characteristics of SDF and IDF. According to the study's findings, SDF and IDF showed a loose and expansive structure with reduced particle size, higher specific surface area, and noticeably better physical and chemical properties after treating GP and OP with ultrasound-assisted composite enzyme method. Both SDF solution and IDF suspension were discovered through rheological analysis to be non-Newtonian pseudoplastic fluids, which was advantageous for expanding their applications in the field of food packaging. In conclusion, DF prepared using the ultrasound-assisted composite enzyme method was an excellent source of edible packaging materials, offering a benchmark for the recycling of other citrus peel wastes and ultimately paving the way for new methods of recycling citrus waste.
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Celulases , Citrus sinensis , Citrus , Citrus sinensis/química , Tamanho da Partícula , Fibras na Dieta/análiseRESUMO
Surfactant-like short peptides are a kind of ideal model for the study of chiral self-assembly. At present, there are few studies on the chiral self-assembly of multicharged surfactant-like peptides. In this study, we adopted a series of short peptides of Ac-I4KGK-NH2 with different combinations of L-lysine and D-lysine residues as the model molecules. TEM, AFM and SANS results showed that Ac-I4LKGLK-NH2, Ac-I4LKGDK-NH2, and Ac-I4DKGLK-NH2 formed the morphologies of nanofibers, and Ac-I4DKGDK-NH2 formed nanoribbons. All the self-assembled nanofibers, including the intermediate nanofibers of Ac-I4DKGDK-NH2 nanoribbons, showed the chirality of left handedness. Based on the molecular simulation results, it has been demonstrated that the supramolecular chirality was directly dictated by the orientation of single ß strand. The insertion of glycine residue demolished the effect of lysine residues on the single strand conformation due to its high conformational flexibility. The replacement of L-isoleucine with Da-isoleucine also confirmed that the isoleucine residues involved in the ß-sheet determined the supramolecular handedness. This study provides a profound mechanism of the chiral self-assembly of short peptides. We hope that it will improve the regulation of chiral molecular self-assembly with achiral glycine, as well.
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Nanofibras , Nanotubos de Carbono , Surfactantes Pulmonares , Nanofibras/química , Glicina , Tensoativos/química , Lisina/química , Isoleucina , Lateralidade Funcional , Peptídeos/química , LipoproteínasRESUMO
Exposure of concrete to acidic environments can cause the degradation of concrete elements and seriously affect the durability of concrete. As solid wastes are produced during industrial activity, ITP (iron tailing powder), FA (fly ash), and LS (lithium slag) can be used as admixtures to produce concrete and improve its workability. This paper focuses on the preparation of concrete using a ternary mineral admixture system consisting of ITP, FA, and LS to investigate the acid erosion resistance of concrete in acetic acid solution at different cement replacement rates and different water-binder ratios. The tests were performed by compressive strength analysis, mass analysis, apparent deterioration analysis, and microstructure analysis by mercury intrusion porosimetry and scanning electron microscopy. The results show that when the water-binder ratio is certain and the cement replacement rate is greater than 16%; especially at 20%, the concrete shows strong resistance to acid erosion; when the cement replacement rate is certain and the water-binder ratio is less than 0.47; especially at 0.42, the concrete shows strong resistance to acid erosion. Microstructural analysis shows that the ternary mineral admixture system composed of ITP, FA, and LS promotes the formation of hydration products such as C-S-H and AFt, improves the compactness and compressive strength of concrete, and reduces the connected porosity of concrete, which can obtain good overall performance. In general, concrete prepared with a ternary mineral admixture system consisting of ITP, FA, and LS has better acid erosion resistance than ordinary concrete. The use of different kinds of solid waste powder to replace cement can effectively reduce carbon emissions and protect the environment.