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1.
Proc Natl Acad Sci U S A ; 121(17): e2318853121, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38630722

RESUMO

Recently, there has been a notable surge in interest regarding reclaiming valuable chemicals from waste plastics. However, the energy-intensive conventional thermal catalysis does not align with the concept of sustainable development. Herein, we report a sustainable electrocatalytic approach allowing the selective synthesis of glycolic acid (GA) from waste polyethylene terephthalate (PET) over a Pd67Ag33 alloy catalyst under ambient conditions. Notably, Pd67Ag33 delivers a high mass activity of 9.7 A mgPd-1 for ethylene glycol oxidation reaction (EGOR) and GA Faradaic efficiency of 92.7 %, representing the most active catalyst for selective GA synthesis. In situ experiments and computational simulations uncover that ligand effect induced by Ag incorporation enhances the GA selectivity by facilitating carbonyl intermediates desorption, while the lattice mismatch-triggered tensile strain optimizes the adsorption of *OH species to boost reaction kinetics. This work unveils the synergistic of strain and ligand effect in alloy catalyst and provides guidance for the design of future catalysts for PET upcycling. We further investigate the versatility of Pd67Ag33 catalyst on CO2 reduction reaction (CO2RR) and assemble EGOR//CO2RR integrated electrolyzer, presenting a pioneering demonstration for reforming waste carbon resource (i.e., PET and CO2) into high-value chemicals.

2.
Nat Chem Biol ; 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38649452

RESUMO

The stabilization of stalled forks has emerged as a crucial mechanism driving resistance to poly(ADP-ribose) polymerase (PARP) inhibitors in BRCA1/2-deficient tumors. Here, we identify UFL1, a UFM1-specific E3 ligase, as a pivotal regulator of fork stability and the response to PARP inhibitors in BRCA1/2-deficient cells. On replication stress, UFL1 localizes to stalled forks and catalyzes the UFMylation of PTIP, a component of the MLL3/4 methyltransferase complex, specifically at lysine 148. This modification facilitates the assembly of the PTIP-MLL3/4 complex, resulting in the enrichment of H3K4me1 and H3K4me3 at stalled forks and subsequent recruitment of the MRE11 nuclease. Consequently, loss of UFL1, disruption of PTIP UFMylation or overexpression of the UFM1 protease UFSP2 protects nascent DNA strands from extensive degradation and confers resistance to PARP inhibitors in BRCA1/2-deficient cells. These findings provide mechanistic insights into the processes underlying fork instability in BRCA1/2-deficient cells and offer potential therapeutic avenues for the treatment of BRCA1/2-deficient tumors.

3.
Artigo em Inglês | MEDLINE | ID: mdl-38648861

RESUMO

BACKGROUND: The extraction of horizontally impacted mandibular third molars (HM3) can be a complicated surgery. Appropriate tooth sectioning methods can reduce the operation time and postoperative complications. PURPOSE: The current study compares operative time and postoperative pain between HM3 removed using the three-piece or T-shaped tooth sectioning techniques. STUDY DESIGN, SETTING, SAMPLE: A randomized single-blind prospective clinical trial on HM3 extraction was carried out between June and December 2022 in the Department of Oral and Maxillofacial Surgery, the Affiliated Stomatological Hospital, Southwest Medical University. Patients with local or systemic infection, poor oral hygiene, and systemic disease were excluded. PREDICTOR VARIABLE: The predictor variable was the tooth sectioning method. The subjects were randomized to a three-piece or T-shaped group. MAIN OUTCOME VARIABLE(S): The primary outcome variables were the operative time and postoperative pain measured using a visual analog scale (VAS). The secondary outcome variables were the rates of primary bleeding, mouth opening reduction, swelling, patient satisfaction measured using a VAS, and quality of life measured using a postoperative symptom severity scale. COVARIATES: The covariates included age, sex, side and classification of HM3, and the relationship of HM3 to the inferior alveolar nerve canal. ANALYSES: The data were analyzed using the independent samples t-test, paired t-test, χ2, and rank sum test. A significance level set at P < .05. RESULTS: The sample included 60 patients in the three-piece group and 66 patients in the T-shaped group. The operative time of the three-piece group (14.73 ± 3.21 minutes) was shorter than that of the T-shaped group (19.25 ± 4.29 minutes) (P < .05). On days 3 and 7, VAS of pain were 2.24 ± 1.89 and 0.15 ± 0.40 in the three-piece group and 3.95 ± 2.44 and 0.48 ± 0.68 in the T-shaped group (P < .05). The VAS of patient satisfaction in the three-piece group (6.05 ± 1.29) was better than the T-shaped group (4.90 ± 1.05) on day 7 (P < .05). CONCLUSION AND RELEVANCE: The three-piece tooth sectioning for HM3 removal was associated with shorter duration, slighter postoperative symptoms, and higher patient satisfaction and may be considered as a recommended practice for dentists.

4.
Proc Natl Acad Sci U S A ; 118(8)2021 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-33602814

RESUMO

The ubiquitin E3 ligase Bre1-mediated H2B monoubiquitination (H2Bub) is essential for proper DNA replication and repair in eukaryotes. Deficiency in H2Bub causes genome instability and cancer. How the Bre1-H2Bub pathway is evoked in response to DNA replication or repair remains unknown. Here, we identify that the single-stranded DNA (ssDNA) binding factor RPA acts as a key mediator that couples Bre1-mediated H2Bub to DNA replication and repair in yeast. We found that RPA interacts with Bre1 in vitro and in vivo, and this interaction is stimulated by ssDNA. This association ensures the recruitment of Bre1 to replication forks or DNA breaks but does not affect its E3 ligase activity. Disruption of the interaction abolishes the local enrichment of H2Bub, resulting in impaired DNA replication, response to replication stress, and repair by homologous recombination, accompanied by increased genome instability and DNA damage sensitivity. Notably, we found that RNF20, the human homolog of Bre1, interacts with RPA70 in a conserved mode. Thus, RPA functions as a master regulator for the spatial-temporal control of H2Bub chromatin landscape during DNA replication and recombination, extending the versatile roles of RPA in guarding genome stability.


Assuntos
Reparo do DNA , Replicação do DNA , Histonas/metabolismo , Proteína de Replicação A/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , DNA de Cadeia Simples , Histonas/genética , Recombinação Homóloga , Metanossulfonato de Metila/toxicidade , Domínios e Motivos de Interação entre Proteínas/genética , Proteína de Replicação A/genética , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação
5.
Odontology ; 112(1): 242-249, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37273122

RESUMO

The present study aims to determine the optimum sectioning depth for the extraction of low-level horizontally impacted mandibular third molar (LHIM3M) using mechanical and finite element analysis. One hundred and fifty extracted mandibular third molars were randomly divided into three groups: 1, 2 or 3 mm of tooth tissue was retained at the bottom of the crown. The breaking force of teeth was tested in a universal strength testing machine. The fracture surface was observed and the type of tooth breakage was recorded. According to the three groups, corresponding 3D finite element models were created. The breaking force obtained in the mechanical study was, respectively, applied and the stress and strain of the teeth and surrounding tissues were analysed. Breaking force decreased as sectioning depth increased. The 2 mm group produced the lowest rate of incomplete breakage (10%). In the 2 mm model, the stresses were evenly distributed in the tooth tissue at the bottom of the fissure, and the maximal stress was located in the tissue close to the root segment. The maximum values of stresses in the bone and of strains in the periodontal ligament of the second molar and bone were lower in the 1 mm model than in other models. Their distribution was similar in the three models. A sectioning depth of 1 mm group saves labour during the extraction of LHIM3M, compared to 2 and 3 mm; 2 mm might be the appropriate sectioning depth in terms of breakage shapes.


Assuntos
Dente Serotino , Dente Impactado , Humanos , Análise de Elementos Finitos , Dente Molar , Dente Impactado/cirurgia , Coroas , Extração Dentária , Mandíbula
6.
Odontology ; 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38717525

RESUMO

The purpose of this study was to analyze the biomechanical properties of implants made of different materials to replace missing teeth by using three-dimensional finite element analysis and provide a theoretic basis for clinical application. CBCT data was imported into the Mimics and 3-Matic to construct the three-dimensional finite element model of a missing tooth restored by an implant. Then, the model was imported into the Marc Mentat. Based on the variations of the implant materials (titanium, titanium-zirconia, zirconia and poly (ether-ether-ketone) (PEEK)) and bone densities (high and low), a total of eight models were created. An axial load of 150 N was applied to the crown of the implant to simulate the actual occlusal situation. Both the maximum values of stresses in the cortical bone and implant were observed in the Zr-low model. The maximum displacements of the implants were also within the normal range except for the PEEK models. The cancellous bone strains were mainly distributed in the apical area of the implant, and the maximum value (3225 µstrain) was found in PEEK-low model. Under the premise of the same implant material, the relevant data from various indices in low-density bone models were larger than that in high-density bone models. From the biomechanical point of view, zirconia, titanium and titanium-zirconia were all acceptable implant materials for replacing missing teeth and possessed excellent mechanical properties, while the application of PEEK material needs to be further optimized and modified.

7.
Fish Physiol Biochem ; 50(1): 225-237, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37594622

RESUMO

The aim of this study was to investigate the effect of dietary vitamin A on juvenile Chinese perch (Siniperca chuatsi). Chinese perch were fed with five experimental diets containing 0, 20, 40, 60, and 80 mg VA·kg-1 for 8 weeks. Results showed that dietary vitamin A significantly influenced the fish's growth, feed utilization, glucose and lipid metabolism, appetite, and antioxidant capacity. Vitamin A-supplemented groups had higher weight gain rate (WGR) and specific growth rate (SGR) compared to the control group. Feed conversion ratio (FCR) was also lower in the vitamin A-supplemented groups. Dietary vitamin A had no significant effect on the survival rate (SR). Compared to the control group, fish fed with vitamin A had increased feed intake (FI), and the expression of appetite-promoting genes (npy and agrp) was significantly higher in the 40 mg VA·kg-1 group. Vitamin A also enhanced the utilization of dietary protein by Chinese perch. The serum glucose content of the fish fed with 40 mg VA·kg-1 diet was significantly higher than that of the control group and 20 mg VA·kg-1 diet, indicating that the promoting effect of VA on gluconeogenesis was greater than that on glycolysis. Additionally, dietary vitamin A increased the expression of lipid metabolism-related genes (hl and fas) and antioxidant genes (nrf2 and gpx) in the fish. These results suggest that the optimal vitamin A requirement of juvenile Chinese perch bream was estimated to be 37.32 mg VA·kg-1 based on broken-line regression analysis of WGR. In conclusion, this study provides valuable insights into the potential benefits of dietary vitamin A on the growth, metabolism, and antioxidant capacity of Chinese perch.


Assuntos
Antioxidantes , Percas , Animais , Antioxidantes/metabolismo , Metabolismo dos Lipídeos , Vitamina A/farmacologia , Vitamina A/metabolismo , Apetite , Glucose/metabolismo , Suplementos Nutricionais/análise , Dieta/veterinária , Ração Animal/análise
8.
Environ Geochem Health ; 46(6): 197, 2024 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-38696118

RESUMO

Micro/nanoplastics (MNPs) are emerging as environmental pollutants with potential threats to human health. The accumulation of MNPs in the body can cause oxidative stress and increase the risk of cardiovascular disease (CVD). With the aim to systematically evaluate the extent of MNPs-induced oxidative damage and serum biochemical parameters in rats and mice, a total of 36 eligible articles were included in this meta-analysis study. The results reported that MNPs can significantly increase the levels of oxidants such as reactive oxygen species (ROS) and malondialdehyde (MDA) (P < 0.05), and resulted in notable increase in serum biochemical parameters including aspartate aminotransferase (AST) and alanine aminotransferase (ALT) (P < 0.05). Conversely, MNPs significantly reduced levels of antioxidants such as superoxide dismutase (SOD), glutathione (GSH), glutathione peroxidase (GPx) and catalase (CAT) (P < 0.05). Subgroup analysis revealed that smaller MNPs with oral administration and prolonged treatment, were associated with more pronounced oxidative stress and enhanced serum biochemical parameters alteration. In addition, after affected by MNPs, the levels of ALT and AST in liver group (SMD = 2.26, 95% CI = [1.59, 2.94] and SMD = 3.10, 95% CI = [1.25, 4.94]) were higher than those in other organs. These comprehensive results provide a scientific foundation for devising strategies to prevent MNPs-induced damage, contributing to solution of this environmental and health challenge.


Assuntos
Estresse Oxidativo , Animais , Camundongos , Ratos , Alanina Transaminase/sangue , Antioxidantes/metabolismo , Aspartato Aminotransferases/sangue , Poluentes Ambientais/toxicidade , Fígado/efeitos dos fármacos , Fígado/metabolismo , Malondialdeído/sangue , Microplásticos/toxicidade , Nanopartículas , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/metabolismo
9.
J Biol Chem ; 298(9): 102288, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35926713

RESUMO

Mechanistic target of rapamycin complex 2 (mTORC2) is a multi-subunit kinase complex, central to multiple essential signaling pathways. Two core subunits, Rictor and mSin1, distinguish it from the related mTORC1 and support context-dependent phosphorylation of its substrates. mTORC2 structures have been determined previously; however, important questions remain, particularly regarding the structural determinants mediating substrate specificity and context-dependent activity. Here, we used cryo-EM to obtain high-resolution structures of the human mTORC2 apo-complex in the presence of substrates Akt and SGK1. Using functional assays, we then tested predictions suggested by substrate-induced structural changes in mTORC2. For the first time, we visualized in the apo-state the side chain interactions between Rictor and mTOR that sterically occlude recruitment of mTORC1 substrates and confer resistance to the mTORC1 inhibitor rapamycin. Also in the apo-state, we observed that mSin1 formed extensive contacts with Rictor via a pair of short α-helices nestled between two Rictor helical repeat clusters, as well as by an extended strand that makes multiple weak contacts with Rictor helical cluster 1. In co-complex structures, we found that SGK1, but not Akt, markedly altered the conformation of the mSin1 N-terminal extended strand, disrupting multiple weak interactions while inducing a large rotation of mSin1 residue Arg-83, which then interacts with a patch of negatively charged residues within Rictor. Finally, we demonstrate mutation of Arg-83 to Ala selectively disrupts mTORC2-dependent phosphorylation of SGK1, but not of Akt, supporting context-dependent substrate selection. These findings provide new structural and functional insights into mTORC2 specificity and context-dependent activity.


Assuntos
Proteínas Imediatamente Precoces , Proteínas Monoméricas de Ligação ao GTP , Proteínas Serina-Treonina Quinases , Proteínas Proto-Oncogênicas c-akt , Proteína Companheira de mTOR Insensível à Rapamicina , Humanos , Proteínas Imediatamente Precoces/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Proteínas Monoméricas de Ligação ao GTP/metabolismo , Fosforilação , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteína Companheira de mTOR Insensível à Rapamicina/genética , Proteína Companheira de mTOR Insensível à Rapamicina/metabolismo , Sirolimo/farmacologia , Fatores de Transcrição/metabolismo
10.
J Mol Recognit ; 36(8): e3046, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37455320

RESUMO

As a natural carrier protein, zein was intensively studied for the construction of a flavonoid delivery system. Chrysin has presented superior tumor-resistant, anti-inflammatory, and anti-oxidation potentials among the flavonoid candidates in clinical practice. However, due to inadequate research, the binding mechanism and structural affinity of zein to chrysin are still indeterminate. Therefore, multispectral methods were employed to explore the molecular interaction of zein and chrysin in this work. These techniques showed that chrysin reduced the intrinsic fluorescence of zein via a static process and that the interaction between zein and chrysin was mainly driven spontaneously by hydrophobic forces. Additionally, the experimental results revealed the changed microenvironment in the vicinity of tyrosine and affected secondary structure in the presence of chrysin, indicating zein's conformation were altered by chrysin. This work provided comprehensive insight into the combination of plant-derived protein (zein) and flavonoids (chrysin) and helped rationalize the protection, transportation, and release of chrysin through a zein-based delivery system.


Assuntos
Zeína , Zeína/química , Flavonoides/química
11.
Artigo em Inglês | MEDLINE | ID: mdl-38050066

RESUMO

BACKGROUND: An oral sodium phenylbutyrate and taurursodiol combination (PB and TURSO) significantly reduced functional decline in people living with amyotrophic lateral sclerosis (ALS) in the CENTAUR trial. Biomarkers linking clinical therapeutic effect with biological changes are of high interest in ALS. We performed analyses of neuroinflammatory biomarkers associated with ALS in the literature, including YKL-40 (also known as chitinase-3-like protein 1), chitinase 1 (CHIT1) and C reactive protein (CRP), in plasma samples collected in CENTAUR. METHODS: Log10-transformed plasma biomarker measurements were analysed using a linear mixed-effects model. Correlation between paired biomarker concentrations and ALS Functional Rating Scale-Revised (ALSFRS-R) total scores was assessed via Pearson correlation coefficients. RESULTS: By week 24, geometric least squares mean YKL-40 plasma concentration decreased by approximately 20% (p=0.008) and CRP by 30% (p=0.048) in the PB and TURSO versus placebo group. YKL-40 (r of -0.21; p<0.0001) and CRP (r of -0.19; p=0.0002) concentration correlated with ALSFRS-R total score. CHIT1 levels were not significantly different between groups. CONCLUSIONS: YKL-40 and CRP plasma levels were significantly reduced in participants with ALS receiving PB and TURSO in CENTAUR and correlated with disease progression. These findings suggest YKL-40 and CRP could be treatment-sensitive biomarkers in ALS, pending further confirmatory studies. TRIAL REGISTRATION NUMBER: https://clinicaltrials.gov/study/NCT03127514.

12.
Fish Shellfish Immunol ; 142: 109135, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37797869

RESUMO

The purpose of this experiment was to study the mitigation effect of sulforaphane (SFN) on fish toxicological damage caused by triphenyltin (TPT) pollution. A total of 320 healthy fish (56.9 ± 0.4g) were randomly placed into four groups, each with four duplicates. The control group was fed the basal diet, the TPT group was exposed to 10 ng/L TPT on the basis of the control group, the SFN group was fed a diet supplemented with 10 mg/kg SFN, the SFN + TPT group was exposed to 10 ng/L TPT on the basis of the SFN group. Each tank had 20 fish and the breeding lasted for 8 weeks. The present study found that the antioxidant enzyme activity in the TPT group was significantly lower than that of the control group (P < 0.05). In addition, compared with the control group, the mRNA expression of pro-inflammatory factors (IL-6, TNF-α) were significantly induced, and the anti-inflammatory factor genes (IL-10, TGF) were significantly inhibited (P < 0.05) in TPT group. SFN relieved the changes of inflammatory factors caused by TPT, ameliorated oxidative stress, improved antioxidant enzyme (include SOD, CAT, GSH, GPx) activities (P < 0.05). 16s RNA analysis indicated that exposure to TPT caused changes in intestinal microflora. The results of the study showed that after exposure to TPT, some beneficial genera of bacteria in the gut of Rhizobiaceae, Bdellovibrio and Candidatus Alysiosphaera were decreased. The bacteria associated with intestinal inflammation including Propionibacterium, Rubrobacter, Anaerorhabdus_furcosa_group, Rikenellaceae and Eubacterium_brachy were upregulated. However, the SFN treatment group significantly down-regulated the above five inflammation-related bacteria. The above results indicated that TPT caused oxidative stress and inflammation in fish intestines, changed the intestinal microflora, and dietary SFN could improve antioxidant status, regulate inflammation and intestinal health. Therefore, SFN is a promising diet additive for improving fish damage caused by TPT contamination.


Assuntos
Antioxidantes , Carpas , Animais , Antioxidantes/metabolismo , Carpas/metabolismo , Disbiose , Inflamação/induzido quimicamente , Inflamação/veterinária , Estresse Oxidativo
13.
J Nanobiotechnology ; 21(1): 266, 2023 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-37563585

RESUMO

Bacterial infections can significantly impede wound healing and pose a serious threat to the patient's life. The excessive use of antibiotics to combat bacterial infections has led to the emergence of multi-drug-resistant bacteria. Therefore, there is a pressing need for alternative approaches, such as photothermal therapy (PTT), to address this issue. In this study, for the first time, CuS NPs with photothermal properties were synthesized using sericin as a biological template, named CuS@Ser NPs. This method is simple, green, and does not produce toxic and harmful by-products. These nanoparticles were incorporated into a mixture (XK) of xanthan gum and konjac glucomannan (KGM) to obtain XK/CuS NPs composite hydrogel, which could overcome the limitations of current wound dressings. The composite hydrogel exhibited excellent mechanical flexibility, photothermal response, and biocompatibility. It also demonstrated potent antibacterial properties against both Gram-positive and negative bacteria via antibacterial experiments and accelerated wound healing in animal models. Additionally, it is proved that the hydrogel promoted tissue regeneration by stimulating collagen deposition, angiogenesis, and reducing inflammation. In summary, the XK/CuS NPs composite hydrogel presents a promising alternative for the clinical management of infected wounds, offering a new approach to promote infected wound healing.


Assuntos
Infecções Bacterianas , Hidrogéis , Animais , Hidrogéis/farmacologia , Cicatrização , Antibacterianos/farmacologia , Colágeno
14.
Nucleic Acids Res ; 49(19): 11224-11240, 2021 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-34606619

RESUMO

The human RecQ helicase BLM is involved in the DNA damage response, DNA metabolism, and genetic stability. Loss of function mutations in BLM cause the genetic instability/cancer predisposition syndrome Bloom syndrome. However, the molecular mechanism underlying the regulation of BLM in cancers remains largely elusive. Here, we demonstrate that the deubiquitinating enzyme USP37 interacts with BLM and that USP37 deubiquitinates and stabilizes BLM, thereby sustaining the DNA damage response (DDR). Mechanistically, DNA double-strand breaks (DSB) promotes ATM phosphorylation of USP37 and enhances the binding between USP37 and BLM. Moreover, knockdown of USP37 increases BLM polyubiquitination, accelerates its proteolysis, and impairs its function in DNA damage response. This leads to enhanced DNA damage and sensitizes breast cancer cells to DNA-damaging agents in both cell culture and in vivo mouse models. Collectively, our results establish a novel molecular mechanism for the USP37-BLM axis in regulating DSB repair with an important role in chemotherapy and radiotherapy response in human cancers.


Assuntos
Neoplasias da Mama/genética , Reparo do DNA , Endopeptidases/genética , Regulação Neoplásica da Expressão Gênica , RecQ Helicases/genética , Animais , Proteínas Mutadas de Ataxia Telangiectasia/genética , Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Neoplasias da Mama/metabolismo , Neoplasias da Mama/mortalidade , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , DNA/genética , DNA/metabolismo , Quebras de DNA de Cadeia Dupla , Replicação do DNA , Endopeptidases/metabolismo , Feminino , Células HEK293 , Células HeLa , Humanos , Células MCF-7 , Camundongos , Fosforilação , Ligação Proteica , Estabilidade Proteica , Proteólise , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , RecQ Helicases/metabolismo , Análise de Sobrevida , Ubiquitinação , Ensaios Antitumorais Modelo de Xenoenxerto
15.
Molecules ; 28(24)2023 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-38138559

RESUMO

Lactobacillus plantarum is a kind of probiotic that benefits the host by regulating the gut microbiota, but it is easily damaged when passing through the gastrointestinal tract, hindering its ability to reach the destination and reducing its utilization value. Encapsulation is a promising strategy for solving this problem. In this study, transglutaminase (TGase)-crosslinked gelatin (GE)/sodium hexametaphosphate (SHMP) hydrogels were used to encapsulate L. plantarum. The effects of TGase concentration and drying method on the physiochemical properties of the hydrogels were determined. The results showed that at a TGase concentration of 9 U/gGE, the hardness, chewiness, energy storage modulus, and apparent viscosity of the hydrogel encapsulation system were maximized. This concentration produced more high-energy isopeptide bonds, strengthening the interactions between molecules, forming a more stable three-dimensional network structure. The survival rate under the simulated gastrointestinal conditions and storage stability of L. plantarum were improved at this concentration. The thermal stability of the encapsulation system dried via microwave vacuum freeze drying (MFD) was slightly higher than that when dried via freeze drying (FD). The gel structure was more stable, and the activity of L. plantarum decreased more slowly during the storage period when dried using MFD. This research provides a theoretical basis for the development of encapsulation technology of probiotics.


Assuntos
Lactobacillus plantarum , Probióticos , Gelatina/farmacologia , Viabilidade Microbiana , Transglutaminases/farmacologia , Hidrogéis/farmacologia , Liofilização , Probióticos/química
16.
J Sci Food Agric ; 103(6): 2815-2823, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36576000

RESUMO

BACKGROUND: Infrared-assisted spouted bed drying (IRSBD) is an innovative hybrid drying technology based on infrared drying and spouted bed drying, which has the advantages of higher drying efficiency and better uniformity. Temperature is an important process parameter that affects drying characteristics and product quality. Considering the overall quality of the product, drying at a constant temperature may not be the best solution. However, there is a lack of research on dynamically varying drying schemes. In this study, the effects of constant and variable temperature drying processes on the drying characteristics, uniformity, energy consumption, and quality of Chinese yams were evaluated. RESULTS: The shortest drying time and lowest energy consumption were obtained by IRSBD at 70 °C, followed by staged rising temperature drying (SRTD). However, SRTD achieved the best drying uniformity. The Peleg model could describe the dehydration kinetics of dried yams well (R2 > 0.99). A high drying temperature (70 °C) favored the preservation of bioactive compounds (polyphenols and flavonoids) and gave the best antioxidant activity and equilibrium rehydration ratio of dried yams but resulted in poor color. Samples dried with SRTD showed comparable good antioxidant activity and better color than those dried at 70 °C. CONCLUSION: A reasonable variable temperature drying scheme using IRSBD is considered to be better when considering the drying performance and overall quality of the products. © 2022 Society of Chemical Industry.


Assuntos
Dioscorea , Temperatura , Antioxidantes , Manipulação de Alimentos/métodos , Dessecação/métodos
17.
Fish Physiol Biochem ; 49(6): 1063-1078, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37542702

RESUMO

This study aimed to assess the effect of pyridoxine supplementation in the mandarin fish diet on growth performance, protein and lipid metabolism, and liver and intestinal histology. Mandarin fish were fed six diets with different levels of pyridoxine (2.67 mg/kg (control), 4.41 mg/kg, 6.57 mg/kg, 10.25 mg/kg, 17.93 mg/kg, 33.12 mg/kg diet) for 8 weeks, and samples were collected for analysis. The findings demonstrated that feeding mandarin fish a diet with 6.57 mg/kg pyridoxine led to a significant increase in weight gain rate (WGR), protein efficiency ratio (PER), whole-body crude protein, whole-body crude lipid, serum protein, cholesterol (CHO), triacylglycerol (TG), high-density lipoprotein-cholesterol (HDL-C), low-density lipoprotein-cholesterol (LDL-C), and alkaline phosphatase (ALP), as well as significantly lower serum glucose (GLU) and feed conversion ratio (FCR), compared to the control group (P < 0.05). Furthermore, we found a significant upregulation of the relative expression of genes associated with hepatic lipid oxidation and synthesis (hl, lpl, pparα, cpt1, cs, srebp1, and fas) and proteolysis (ast, alt, and gdh) in fish fed a diet containing 6.57 mg/kg pyridoxine (P < 0.05). Regarding the histological analysis, we observed a notable decrease in the quantity of intestinal mucus-secreting cells when the fish fed a diet containing 10.25 mg/kg pyridoxine (P < 0.05). These findings suggest that dietary pyridoxine supplementation promotes mandarin fish growth by improving the efficiency of protein and lipid utilization. Additionally, we used a broken-line regression analysis to estimate the optimal dietary pyridoxine requirement for mandarin fish in the range of 6.17-6.41 mg/kg based on WGR, FCR, and PER.


Assuntos
Dieta , Piridoxina , Animais , Piridoxina/farmacologia , Dieta/veterinária , Triglicerídeos/metabolismo , Peixes/metabolismo , Colesterol , Suplementos Nutricionais , Ração Animal/análise , Metabolismo dos Lipídeos
18.
Fish Physiol Biochem ; 49(6): 1097-1114, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37855970

RESUMO

To explore the potential benefits of dietary phospholipids (PLs) in fish glucose metabolism and to promote feed culture of Chinese perch (Siniperca chuatsi), we set up six diets to feed Chinese perch (initial mean body weight 37.01 ± 0.20 g) for 86 days, including: Control diet (CT), 1% (SL1), 2% (SL2), 3% (SL3), 4% (SL4) soybean lecithin (SL) and 2% (KO2) krill oil (KO) supplemental diets (in triplicate, 20 fish each). Our study found that the SL2 significantly improved the weight gain rate and special growth rate, but the KO2 did not. In addition, the SL2 diet significantly improved feed intake, which is consistent with the mRNA levels of appetite-related genes (npy, agrp, leptin A). Additionally, in the CT and SL-added groups, leptin A expression levels were nearly synchronized with serum glucose levels. Besides, the SL2 significantly upregulated expression levels of glut2, gk, cs, fas and downregulated g6pase in the liver, suggesting that it may enhance glucose uptake, aerobic oxidation, and conversion to fatty acids. The SL2 also maintained the hepatic crude lipid content unchanged compared to the CT, possibly by significantly down-regulating the mRNA level of hepatic lipase gene (hl), and by elevating serum low-density lipoprotein (LDL) level and intraperitoneal fat ratio in significance. Moreover, the serum high-density lipoprotein levels were significantly increased by PL supplementation, and the SL2 further significantly increased serum total cholesterol and LDL levels, suggesting that dietary PLs promote lipid absorption and transport. Furthermore, dietary SL at 1% level could enhance non-specific immune capacity, with serum total protein level being markedly higher than that in the CT group. In conclusion, it is speculated that the promotion of glucose utilization and appetite by 2% dietary SL could be linked. We suggest a 1.91% supplementation of SL in the diet for the best growth performance in juvenile Chinese perch.


Assuntos
Lecitinas , Percas , Animais , Lecitinas/farmacologia , Lecitinas/metabolismo , Glycine max , Leptina/metabolismo , Dieta/veterinária , Ácidos Graxos/metabolismo , Metabolismo dos Lipídeos , Glucose/farmacologia , Glucose/metabolismo , RNA Mensageiro/metabolismo
19.
Angew Chem Int Ed Engl ; 62(5): e202217071, 2023 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-36468671

RESUMO

The electrochemical nitrate reduction reaction (NO3 RR) is an appealing technology for regulating the nitrogen cycle. Metallic iron is one of the well-known electrocatalysts for NO3 RR, but it suffers from poor durability due to leaching and oxidation of iron during the electrocatalytic process. In this work, a graphene-nanochainmail-protected iron nanoparticle (Fe@Gnc) electrocatalyst is reported. It displays superior nitrate removal efficiency and high nitrogen selectivity. Notably, the catalyst delivers exceptional stability and durability, with the nitrate removal rate and nitrogen selectivity remained ≈96 % of that of the first time after up to 40 cycles (24 h for one cycle). As expected, the conductive graphene nanochainmail provides robust protection for the internal iron active sites, allowing Fe@Gnc to maintain its long-lasting electrochemical nitrate catalytic activity. This research proposes a workable solution for the scientific challenge of poor lasting ability of iron-based electrocatalysts in large-scale industrialization.

20.
Angew Chem Int Ed Engl ; 62(38): e202310383, 2023 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-37550249

RESUMO

One-dimensional fiber architecture serves as an excellent catalyst support. The orderly arrangement of active materials on such a fiber substrate can enhance catalytic performance by exposing more active sites and facilitating mass diffusion; however, this remains a challenge. We developed an interfacial assembly strategy for the orderly distribution of metal nanocrystals on different fiber substrates to optimize their electrocatalytic performance. Using electrochemical nitrate reduction reaction (NO3 - RR) as a representative reaction, the iron-based nanofibers (Fe/NFs) assembly structure achieved an excellent nitrate removal capacity of 2317 mg N/g Fe and N2 selectivity up to 97.2 %. This strategy could promote the rational design and synthesis of fiber-based electrocatalysts.

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