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1.
Prep Biochem Biotechnol ; : 1-9, 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38984870

RESUMO

L-proline is widely used in the fields of food, medicine and agriculture, and is also an important raw material for the synthesis of trans-4-hydroxy-L-proline. In this study, enhancing the production of L-proline by metabolic engineering was investigated. Three genes, proB, proA and proC, were introduced into Escherichia coli BL21 by molecular biology technology to increase the metabolic flow of L-proline from glucose. The genes putP and proP related to the proline transfer were knocked out by CRISPR/Cas9 gene editing technology to weaken the feedback inhibition of proB to increase the production of L-proline. The fermentation curves of the engineered strain at different glucose concentrations were determined, and a glucose concentration of 10 g/L was chosen to expand the batch culture to 1 L shake flask. Ultimately, through these efforts, the titer of L-proline reached 832.19 mg/L in intermittent glucose addition fermentation in a 1 L shake flask.

2.
Foods ; 13(13)2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38998512

RESUMO

Heat stress has received growing concerns regarding the impact on seafood quality. However, the effects of heat stress on the sensory properties of seafood remain unknown. In this study, the sensory properties of fresh oyster (Crassostrea ariakensis) treated with chronic heat stress (30 °C) for 8 weeks were characterized using electronic nose, electronic tongue, sensory evaluation, HS-SPME-GC-MS, LC-MS and transcriptomics. Overall, chronic heat stress reduced the overall sensory properties of oysters. The metabolic network constructed. based on enrichment results of 423 differential metabolites and 166 differentially expressed genes, showed that the negative effects of chronic heat stress on the sensory properties of oysters were related to oxidative stress, protein degradation, lipid oxidation, and nucleotide metabolism. The results of the study provide valuable insights into the effects of heat stress on the sensory properties of oysters, which are important for ensuring a sustainable supply of high-quality seafood and maintaining food safety.

3.
Artigo em Inglês | MEDLINE | ID: mdl-38937951

RESUMO

A 50-day feeding trial was conducted to evaluate the effects of mulberry leaf powder water extract (MLE) on the growth performance, immunity, antioxidant, meat quality and intestinal microbiota of yellow feather broilers. A total of 720 birds (initial body weight 40.07 ± 0.05 g) were randomly distributed into four groups with six replicates per group and 30 birds per replicate. Four diets were formulated with 0% (CON), 200 mg/kg MLE (MLE200), 400 mg/kg MLE (MLE400) and 600 mg/kg MLE (MLE600) supplementation. Results showed that the addition of 200-600 mg/kg MLE to the diet significantly increased the body weight (BW) and average daily weight gain (ADG), but feed to gain ratio (F/G) were linearly decreased (p = 0.045) as dietary MLE increased. Birds fed MLE400 had higher (p < 0.05) total antioxidant capacity (T-AOC), interleukin-10 (Il-10), secretory immunoglobulin A (SIgA) and complement 3 (C3) contents than those fed CON, whereas MLE400 had lower malondialdehyde (MDA) content than CON (p < 0.05). Analysis of 16 S rDNA indicated that supplementation with 200 mg/kg MLE increased the Shannon indices in the caecum (p < 0.05). Supplementation with MLE decreased the abundance of the phylum Proteobacteria and genus Helicobacter, and increased the abundance of the phylum Bacteroidetes in the caecum in broiler chickens (p < 0.05). The drip loss rate in the MLE600 was significantly diminished (p < 0.05), whereas the shear force was significantly elevated (p < 0.05). In summary, dietary supplementation with MLE can effectively improve growth performance, intestinal immunity, serum antioxidant capacity, meat quality and intestinal microbiota of yellow feather broilers. The most appropriate MLE supplementation level was 400 mg/kg. This study provides a practical strategy for the dietary application of MLE in yellow feather broilers.

4.
Behav Sci (Basel) ; 14(6)2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38920805

RESUMO

Personalized recommendations that use digital technologies to predict user interests and preferences and give guiding conclusions have become a widely used digital marketing tool on e-commerce platforms. Given that existing consumer behavior research has not reached a consensus on the relationship between age and the adoption of innovative products, whether recommendation novelty can stimulate older consumers' acceptance of innovative products remains uncertain. Grounded in the aging and social influence literature, this experimental study investigated the moderating role of individual cognitive age on the impact of recommendation novelty on consumer perceptions regarding stereotype threat and receptiveness to innovativeness. An experiment involving 239 online shoppers was conducted to investigate the experiences of cognitively younger and older adults while using low or high levels of recommendation novelty designed for this study. Results reveal the tension for older adults when using highly recommended novelty, as they perceive these to be more of a stereotype threat, but they also have a higher level of receptiveness to innovativeness. This finding is contrary to the common belief that "the older the consumer, the less receptive to innovativeness", providing novel insight into the information systems literature. Theoretically, this research shows how increasing the level of recommended novelty affects stereotype threat and receptiveness to innovativeness (of consumers of different cognitive ages). For practitioners, the results provide important guidelines on the kind of personalized recommendations that are appropriate for consumers with different cognitive ages.

5.
Sci Rep ; 14(1): 14023, 2024 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-38890348

RESUMO

The mechanism of spinal cord injury (SCI) is highly complex, and an increasing number of studies have indicated the involvement of pyroptosis in the physiological and pathological processes of secondary SCI. However, there is limited bioinformatics research on pyroptosis-related genes (PRGs) in SCI. This study aims to identify and validate differentially expressed PRGs in the GEO database, perform bioinformatics analysis, and construct regulatory networks to explore potential regulatory mechanisms and therapeutic targets for SCI. We obtained high-throughput sequencing datasets of SCI in rats and mice from the GEO database. Differential analysis was conducted using the "limma" package in R to identify differentially expressed genes (DEGs). These genes were then intersected with previously reported PRGs, resulting in a set of PRGs in SCI. GO and KEGG enrichment analyses, as well as correlation analysis, were performed on the PRGs in both rat and mouse models of SCI. Additionally, a protein-protein interaction (PPI) network was constructed using the STRING website to examine the relationships between proteins. Hub genes were identified using Cytoscape software, and the intersection of the top 5 hub genes in rats and mice were selected for subsequent experimentally validated. Furthermore, a competing endogenous RNA (ceRNA) network was constructed to explore potential regulatory mechanisms. The gene expression profiles of GSE93249, GSE133093, GSE138637, GSE174549, GSE45376, GSE171441_3d and GSE171441_35d were selected in this study. We identified 10 and 12 PRGs in rats and mice datasets respectively. Six common DEGs were identified in the intersection of rats and mice PRGs. Enrichment analysis of these DEGs indicated that GO analysis was mainly focused on inflammation-related factors, while KEGG analysis showed that the most genes were enriched on the NOD-like receptor signaling pathway. We constructed a ceRNA regulatory network that consisted of five important PRGs, as well as 24 miRNAs and 34 lncRNAs. This network revealed potential regulatory mechanisms. Additionally, the three hub genes obtained from the intersection were validated in the rat model, showing high expression of PRGs in SCI. Pyroptosis is involved in secondary SCI and may play a significant role in its pathogenesis. The regulatory mechanisms associated with pyroptosis deserve further in-depth research.


Assuntos
Biologia Computacional , Redes Reguladoras de Genes , Mapas de Interação de Proteínas , Piroptose , Traumatismos da Medula Espinal , Animais , Traumatismos da Medula Espinal/genética , Traumatismos da Medula Espinal/metabolismo , Traumatismos da Medula Espinal/patologia , Camundongos , Piroptose/genética , Ratos , Biologia Computacional/métodos , Mapas de Interação de Proteínas/genética , Perfilação da Expressão Gênica
6.
Nat Commun ; 15(1): 3884, 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38719909

RESUMO

Only a minority of cancer patients benefit from immune checkpoint blockade therapy. Sophisticated cross-talk among different immune checkpoint pathways as well as interaction pattern of immune checkpoint molecules carried on circulating small extracellular vesicles (sEV) might contribute to the low response rate. Here we demonstrate that PD-1 and CD80 carried on immunocyte-derived sEVs (I-sEV) induce an adaptive redistribution of PD-L1 in tumour cells. The resulting decreased cell membrane PD-L1 expression and increased sEV PD-L1 secretion into the circulation contribute to systemic immunosuppression. PD-1/CD80+ I-sEVs also induce downregulation of adhesion- and antigen presentation-related molecules on tumour cells and impaired immune cell infiltration, thereby converting tumours to an immunologically cold phenotype. Moreover, synchronous analysis of multiple checkpoint molecules, including PD-1, CD80 and PD-L1, on circulating sEVs distinguishes clinical responders from those patients who poorly respond to anti-PD-1 treatment. Altogether, our study shows that sEVs carry multiple inhibitory immune checkpoints proteins, which form a potentially targetable adaptive loop to suppress antitumour immunity.


Assuntos
Antígeno B7-1 , Antígeno B7-H1 , Vesículas Extracelulares , Receptor de Morte Celular Programada 1 , Vesículas Extracelulares/metabolismo , Vesículas Extracelulares/imunologia , Receptor de Morte Celular Programada 1/metabolismo , Humanos , Antígeno B7-1/metabolismo , Antígeno B7-H1/metabolismo , Antígeno B7-H1/imunologia , Animais , Camundongos , Linhagem Celular Tumoral , Feminino , Neoplasias/imunologia , Neoplasias/patologia , Inibidores de Checkpoint Imunológico/uso terapêutico , Inibidores de Checkpoint Imunológico/farmacologia , Tolerância Imunológica , Camundongos Endogâmicos C57BL , Masculino , Microambiente Tumoral/imunologia
7.
Synth Syst Biotechnol ; 9(3): 503-512, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38680946

RESUMO

Vitamin B2 is an essential water-soluble vitamin. For most prokaryotes, a bifunctional enzyme called FAD synthase catalyzes the successive conversion of riboflavin to FMN and FAD. In this study, the plasmid pNEW-AZ containing six key genes for the riboflavin synthesis was transformed into strain R2 with the deleted FMN riboswitch, yielding strain R5. The R5 strain could produce 540.23 ± 5.40 mg/L riboflavin, which was 10.61 % higher than the R4 strain containing plasmids pET-AE and pAC-Z harboring six key genes. To further enhance the production of riboflavin, homology matching and molecular docking were performed to identify key amino acid residues of FAD synthase. Nine point mutation sites were identified. By comparing riboflavin kinase activity, mutations of T203D and N210D, which respectively decreased by 29.90 % and 89.32 % compared to wild-type FAD synthase, were selected for CRISPR/Cas9 gene editing of the genome, generating engineered strains R203 and R210. pNEW-AZ was transformed into R203, generating R6. R6 produced 657.38 ± 47.48 mg/L riboflavin, a 21.69 % increase compared to R5. This study contributes to the high production of riboflavin in recombinant E. coli BL21.

8.
Carbohydr Polym ; 335: 122084, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38616102

RESUMO

Mapping the N-glycome of porcine sperm before and after sperm capacitation is important for understanding the rearrangement of glycoconjugates during capacitation. In this work, we characterized the N-glycome on the membranes of 18 pairs of fresh porcine sperm before capacitation and porcine sperm after capacitation by MALDI-MS (Matrix-assisted laser desorption/ionization-mass spectrometry). A total of 377 N-glycans were detected and a comprehensive N-glycome map of porcine sperm membranes before and after capacitation was generated, which presents the largest N-glycome dataset of porcine sperm cell membranes. Statistical analysis revealed a significantly higher level of high mannose glycosylation and a significantly lower level of fucosylation, galactosylation, and α-2,6-NeuAc after capacitation, which is further verified by flow cytometry and lectin blotting. This research reveals new insights into the relationship between N-glycosylation variations and sperm capacitation, including the underlying mechanisms of the capacitation process.


Assuntos
Peróxido de Benzoíla , Sêmen , Masculino , Suínos , Animais , Membranas , Membrana Celular , Espermatozoides
9.
Int J Bipolar Disord ; 12(1): 11, 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38592605

RESUMO

BACKGROUND: Rapid cycling bipolar disorder (RCBD), characterized by four or more episodes per year, is a complex subtype of bipolar disorder (BD) with poorly understood characteristics. METHOD: This multicenter, observational, longitudinal cohort study enrolled 520 BD patients across seven psychiatric institutions in China from January 2013 to January 2014. Participants were divided into RCBD and non-RCBD (NRCBD) groups based on the frequency of mood episodes in the preceding year. Data collection utilized a standardized form, supplemented by a medical record review, focusing on sociodemographic, clinical, and treatment characteristics. Statistical analysis involved independent samples t-tests, Kruskal-Wallis H tests, Chi-square or Fisher's exact tests, with Bonferroni correction applied to account for multiple comparisons, and multivariable logistic regression to identify characteristics associated with RCBD. RESULTS: Among the BD cohort, 9.4% were identified as current RCBD. Compared to NRCBD, RCBD patients had a shorter duration from the first psychiatric consultation to the diagnosis of BD, a reduced duration of their longest period of euthymia, a lower proportion of lifetime hospitalization history due to BD, and less use of electroconvulsive therapy (ECT) within the last 12 months. Additionally, they presented higher baseline scores on the Mood Disorder Questionnaire (MDQ) and the Brief 16-item Quick Inventory of Depressive Symptomatology Self-Report (QIDS-SR16). However, after applying the Bonferroni correction, these differences were not statistically significant. Multivariable logistic regression analysis identified three factors that were independently associated with RCBD: time from first psychiatric consultation to BD diagnosis (Odds Ratio [OR] = 0.512, P = 0.0416), lifetime hospitalization history due to BD (OR = 0.516, P = 0.0476), and ECT treatment within the past 12 months (OR = 0.293, P = 0.0472). CONCLUSION: This study revealed that the duration from first psychiatric consultation to BD diagnosis, lifetime hospitalization history due to BD, and ECT treatment in the past year were associated with RCBD. Recognizing these factors could contribute to enhance the early identification and clinical outcomes of RCBD. Trial Registration Number Registry ClinicalTrials.gov NCT01770704. Date of Registration: First posted on January 18, 2013.

10.
Midwifery ; 132: 103973, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38442529

RESUMO

BACKGROUND: Although the stigma associated with seeking professional psychological help has received significant attention, few studies have focused on the status and factors influencing this stigma among pregnant women, especially those with a Chinese cultural background. This study aimed to assess the status of stigma associated with seeking professional psychological help and its influencing factors. METHODS: A total of 1325 pregnant women were recruited from Hunan Province, China. The Stigma for Seeking Professional Psychological Help questionnaire, Patient Health Questionnaire-9, Perceived Social Support Scale, Simplified Coping Style Questionnaire, and questionnaires on sociodemographic characteristics and pregnancy-related information were used. Descriptive, univariate, correlation, and multivariate linear regression analyses were used to investigate the status of stigma and identify its influencing factors. FINDINGS: Pregnant Chinese women experienced a mild to moderate level of stigma associated with seeking professional psychological help, and self-stigma was more common than social stigma associated with seeking psychological help. The results of the multivariate analysis suggested that perceived social support, positive coping styles, negative coping styles, and depressive symptoms were the factors influencing self-stigma and social stigma associated with seeking professional psychological help. Advanced age and a low educational level were the only predictors associated with self-stigma, while a history of multiple pregnancies had an effect only on social stigma associated with seeking professional psychological help. CONCLUSION: Chinese pregnant women experienced a mild to moderate level of stigma associated with seeking professional psychological help. Destigmatizing interventions focusing on self-stigma and social stigma should be designed according to maternal characteristics, social support, coping style, and depressive symptoms.


Assuntos
Gestantes , Estigma Social , Humanos , Feminino , Gravidez , Adulto , Estudos Transversais , China , Gestantes/psicologia , Inquéritos e Questionários , Apoio Social , Adaptação Psicológica , Aceitação pelo Paciente de Cuidados de Saúde/psicologia , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Comportamento de Busca de Ajuda
11.
Toxins (Basel) ; 16(3)2024 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-38535815

RESUMO

Microcystin-LR (MC-LR) is a cyanobacterial metabolite produced during cyanobacterial blooms and is toxic to aquatic animals, and the liver is the main targeted organ of MC-LR. To comprehensively understand the toxicity mechanism of chronic exposure to environmental levels of MC-LR on the liver of fish, juvenile Nile tilapia were exposed to 0 µg/L (control), 1 µg/L (M1), 3 µg/L (M3), 10 µg/L (M10), and 30 µg/L (M30) MC-LR for 60 days. Then, the liver hepatotoxicity induced by MC-LR exposure was systematically evaluated via histological and biochemical determinations, and the underlying mechanisms were explored through combining analysis of biochemical parameters, multi-omics (transcriptome and metabolome), and gene expression. The results exhibited that chronic MC-LR exposure caused slight liver minor structural damage and lipid accumulation in the M10 group, while resulting in serious histological damage and lipid accumulation in the M30 group, indicating obvious hepatotoxicity, which was confirmed by increased toxicity indexes (i.e., AST, ALT, and AKP). Transcriptomic and metabolomic analysis revealed that chronic MC-LR exposure induced extensive changes in gene expression and metabolites in six typical pathways, including oxidative stress, apoptosis, autophagy, amino acid metabolism, primary bile acid biosynthesis, and lipid metabolism. Taken together, chronic MC-LR exposure induced oxidative stress, apoptosis, and autophagy, inhibited primary bile acid biosynthesis, and caused fatty deposition in the liver of Nile tilapia.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas , Ciclídeos , Toxinas Marinhas , Microcistinas , Animais , Multiômica , Ácidos e Sais Biliares , Lipídeos
12.
Front Oncol ; 14: 1334082, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38410115

RESUMO

Objective: The aim of this study was to develop and validate a series of breast cancer-related lymphoedema risk prediction models using machine learning algorithms for early identification of high-risk individuals to reduce the incidence of postoperative breast cancer lymphoedema. Methods: This was a retrospective study conducted from January 2012 to July 2022 in a tertiary oncology hospital. Subsequent to the collection of clinical data, variables with predictive capacity for breast cancer-related lymphoedema (BCRL) were subjected to scrutiny utilizing the Least Absolute Shrinkage and Selection Operator (LASSO) technique. The entire dataset underwent a randomized partition into training and test subsets, adhering to a 7:3 distribution. Nine classification models were developed, and the model performance was evaluated based on accuracy, sensitivity, specificity, recall, precision, F-score, and area under curve (AUC) of the ROC curve. Ultimately, the selection of the optimal model hinged upon the AUC value. Grid search and 10-fold cross-validation was used to determine the best parameter setting for each algorithm. Results: A total of 670 patients were investigated, of which 469 were in the modeling group and 201 in the validation group. A total of 174 had BCRL (25.97%). The LASSO regression model screened for the 13 features most valuable in predicting BCRL. The range of each metric in the test set for the nine models was, in order: accuracy (0.75-0.84), sensitivity (0.50-0.79), specificity (0.79-0.93), recall (0.50-0.79), precision (0.51-0.70), F score (0.56-0.69), and AUC value (0.71-0.87). Overall, LR achieved the best performance in terms of accuracy (0.81), precision (0.60), sensitivity (0.79), specificity (0.82), recall (0.79), F-score (0.68), and AUC value (0.87) for predicting BCRL. Conclusion: The study established that the constructed logistic regression (LR) model exhibits a more favorable amalgamation of accuracy, sensitivity, specificity, recall, and AUC value. This configuration adeptly discerns patients who are at an elevated risk of BCRL. Consequently, this precise identification equips nurses with the means to undertake timely and tailored interventions, thus averting the onset of BCRL.

14.
Ecotoxicol Environ Saf ; 269: 115775, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-38070413

RESUMO

Geosmin is an environmental pollutant that causes off-flavor in water and aquatic products. The high occurrence of geosmin contamination in aquatic systems and aquaculture raises public awareness, however, few studies have investigated the response pathways of geosmin stress on freshwater fish. In this research, grass carp were exposed to 50 µg/L geosmin for 96 h, liver tissue was sequenced and validated using real-time qPCR. In total of 528 up-regulated genes and 488 down-regulated genes were observed, includes cytochrome P450 and uridine diphosphate (UDP)-glucuronosyltransferase related genes. KEGG analysis showed that chemical carcinogenesis-DNA adducts, metabolism of xenobiotics by cytochrome P450, drug metabolism-cytochrome P450 pathway was enriched. Common genes from the target genes of microRNAs and differential expression genes are enriched in metabolism of xenobiotics cytochrome P450 pathway. Two miRNAs (dre-miR-146a and miR-212-3p) down regulated their target genes (LOC127510138 and adh5, respectively) which are enriched cytochrome P450 related pathway. The results present that geosmin is genetoxic to grass carp and indicate that cytochrome P450 system and UDP-glucuronosyltransferase play essential roles in biotransformation of geosmin. MicroRNAs regulate the biotransformation of geosmin by targeting specific genes, which contributes to the development of strategies to manage its negative impacts in both natural and artificial environments.


Assuntos
Carpas , Doenças dos Peixes , MicroRNAs , Naftóis , Animais , MicroRNAs/genética , MicroRNAs/metabolismo , Carpas/genética , Carpas/metabolismo , RNA Mensageiro , Sistema Enzimático do Citocromo P-450/genética , Água Doce , Glucuronosiltransferase/genética , Difosfato de Uridina , Proteínas de Peixes/genética , Proteínas de Peixes/metabolismo
15.
J Diabetes ; 16(1): e13472, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37749943

RESUMO

AIMS: We aim to explore the cumulative predictive value of elevated serum thyroid stimulating hormone (TSH) and visceral fat area (VFA) for metabolic syndrome (MS) development in postmenopausal women. METHODS: A total of 1006 postmenopausal females were enrolled in a 10-year prospective longitudinal study from 2011 to 2021 in the community of Banknote Printing Company of Chengdu. The sociodemographic information collection and anthropometric measurements were made by a professional nurse. Fasting blood samples were drawn for chemical analysis of fasting plasma glucose, triglycerides, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and TSH. Magnetic resonance imaging was performed to measure VFA. All the participants were categorized into four groups according to median VFA and serum level of TSH. RESULTS: A total of 793 postmenopausal females without MS underwent a 10-year follow-up study grouping by TSH and VFA: Group 1 (TSH level <4.2 µIU/mL, and VFA < 70 cm2 ), Group 2 (TSH level ≥4.2 µIU/mL, and VFA < 70 cm2 ), Group 3 (TSH level <4.2 µIU/mL, and VFA ≥70 cm2 ) and Group 4 (TSH level ≥4.2 µIU/mL, and VFA ≥70 cm2 ). During the 10-year follow-up, MS was newly developed in 326 (41.1%) subjects. The incidence of MS was 29.8% (n = 53), 35.2% (n = 63), 41% (n = 87), and 55% (n = 123) from Group 1 to Group 4 (Group 4 vs other groups, p < .001). Cox regression analysis for MS prediction demonstrated that both TSH (Model 3, hazard ratio [HR] = 1.07 [95% confidence interval, 1.05-1.09]) and VFA (Model 4, HR = 1.02 [95% confidence interval, 1.01-1.08]) were not only independent predictors of MS but also involved some interaction between each other (p for interaction = .021). CONCLUSION: Our findings suggested that mutual interaction between higher TSH and VFA contributed to the development of MS. Further studies are needed to clarify these contributions.


Assuntos
Síndrome Metabólica , Humanos , Feminino , Síndrome Metabólica/diagnóstico , Síndrome Metabólica/epidemiologia , Seguimentos , Tireotropina , Gordura Intra-Abdominal/diagnóstico por imagem , Gordura Intra-Abdominal/patologia , Pós-Menopausa , Estudos Prospectivos , Estudos Longitudinais , LDL-Colesterol , China/epidemiologia
16.
Int J Biol Macromol ; 258(Pt 1): 128951, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38143054

RESUMO

In this study, the biosynthesis of phycocyanin ß-subunit (CpcB) in Escherichia coli BL21 was investigated, and its antioxidant activity and application in anti-browning of fresh-cut apples was explored. Four genes (cpcB, cpeS, hox1 and pcyA) involved in the biosynthesis of CpcB were cloned and transformed into E. coli BL21 by constructing recombinant plasmid pETDuet-5. The positive transformant was screened by ampicillin resistance. The analysis of SDS-PAGE and zinc fluorescence spectrum showed that CpcB was successfully expressed in E. coli BL21 with a molecular weight of 21 kDa. The purified CpcB had a maximum absorption peak at 615 nm, and its maximum florescence emission wavelength was 640 nm. It exhibited a stronger ability to scavenge four free radicals than Vc. The color change in fresh-cut apples was obviously delayed by the CpcB treatment. These results suggest that CpcB may be used as a potential anti-browning agent for food preservation.


Assuntos
Antioxidantes , Malus , Ficocianina , Escherichia coli/genética , Plasmídeos
17.
Ying Yong Sheng Tai Xue Bao ; 34(11): 2947-2957, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37997405

RESUMO

To clarify the alleviation effect of exogenous melatonin (MT) on Agropyron mongolicum under drought stress, we examined the response of A. mongolicum 'Yanchi' seedlings to simulated drought stress with polyethylene glycol 6000 (PEG-6000), by investigating the effects of exogenous addition of different concentrations (0, 1, 10, 50, 100, 150 and 200 mg·L-1) of MT on seedlings growth and physiological characteristics under drought stress. The results showed that drought stress significantly inhibited the growth of A. mongolicum seedlings, and that exogenous addition of different concentrations of MT could alleviate the growth inhibition caused by drought stress, with the strongest mitigation effect observed at MT concentration of 100 mg·L-1. Compared with the drought stress treatment alone, exogenous addition of 100 mg·L-1 MT under drought stress increased plant height, aboveground dry weight, and leaf relative water content by 58.2%, 121.2% and 48.1%. The contents of chlorophyll a, chlorophyll b, carotenoids increased by 48.7%, 80.8% and 38.3%, superoxide dismutase, peroxidase and root activity increased by 12.6%, 33.9% and 39.1%, and the contents of ascorbic acid and glutathione increased by 19.5% and 18.3%, respectively. The contents of proline, soluble sugar and soluble protein were increased by 16.2%, 32.6% and 14.3%, while that of malondialdehyde, hydrogen peroxide and superoxide anion radical were decreased by 45.8%, 65.8% and 30.8%, respectively. In summary, exogenous addition of 100 mg·L-1 MT could improve drought tolerance of A. mongolicum seedlings by promoting growth, enhancing antioxidant capacity, increasing the content of osmoregulation substances, inhibiting the excessive production of reactive oxygen, and reducing membrane peroxide level.


Assuntos
Agropyron , Melatonina , Melatonina/farmacologia , Plântula , Agropyron/metabolismo , Secas , Clorofila A/metabolismo , Estresse Fisiológico , Antioxidantes/metabolismo , Superóxidos/metabolismo , Superóxidos/farmacologia
18.
Psychiatry Res ; 328: 115467, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37690191

RESUMO

Few studies focused on the trajectory of perinatal suicidal ideation from early pregnancy and covered whole routine perinatal periods. This study aimed to investigate the prevalence of suicidal ideation from early pregnancy to six weeks postpartum, and further explore the trajectories of perinatal suicidal ideation and their risk factors. A prospective longitudinal study was conducted in a comprehensive tertiary hospital in Hunan province, China among 1089 participants. Perinatal suicidal ideation and depression were assessed by item 9 of Patient Health Questionnaire 9 and the remaining eight items. Sociodemographic and psychological factors were collected by self-reported comprehensive questionnaires. Latent Growth Curve and Growth Mixture Modeling were used to identify the trajectories of suicidal ideation and logistic regression was used to explore risk factors of trajectories. A total of 629 participants were included. The prevalence of suicidal ideation was 16.4% from early pregnancy to six weeks postpartum, with 12.1% in pregnancy and 7.8% in postpartum. Two trajectories were identified: "persistent low levels of suicidal ideation" (92.9%) and "persistent high levels of suicidal ideation" (7.1%). 40.63% of women who screened positive for suicidal ideation during early pregnancy were in the "persistent high level of suicidal ideation" trajectory. A low level of neuroticism and anxiety symptoms during early pregnancy was associated with "persistent high levels of suicidal ideation". In conclusion, suicidal ideation of women during the perinatal period was dynamic, Suicidal ideation screening and identification in early pregnancy should be addressed for perinatal women to facilitate timely early interventions.


Assuntos
Período Pós-Parto , Ideação Suicida , Gravidez , Feminino , Humanos , Estudos Prospectivos , Estudos Longitudinais , Período Pós-Parto/psicologia , Fatores de Risco , Depressão/epidemiologia , Depressão/diagnóstico
19.
Nat Chem ; 15(10): 1400-1407, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37500951

RESUMO

Microbe-semiconductor biohybrids, which integrate microbial enzymatic synthesis with the light-harvesting capabilities of inorganic semiconductors, have emerged as promising solar-to-chemical conversion systems. Improving the electron transport at the nano-bio interface and inside cells is important for boosting conversion efficiencies, yet the underlying mechanism is challenging to study by bulk measurements owing to the heterogeneities of both constituents. Here we develop a generalizable, quantitative multimodal microscopy platform that combines multi-channel optical imaging and photocurrent mapping to probe such biohybrids down to single- to sub-cell/particle levels. We uncover and differentiate the critical roles of different hydrogenases in the lithoautotrophic bacterium Ralstonia eutropha for bioplastic formation, discover this bacterium's surprisingly large nanoampere-level electron-uptake capability, and dissect the cross-membrane electron-transport pathways. This imaging platform, and the associated analytical framework, can uncover electron-transport mechanisms in various types of biohybrid, and potentially offers a means to use and engineer R. eutropha for efficient chemical production coupled with photocatalytic materials.


Assuntos
Imagem Multimodal , Transporte de Elétrons
20.
J Hazard Mater ; 458: 131813, 2023 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-37339576

RESUMO

Microplastics (MPs) are 1-5 mm plastic particles that are serious global contaminants distributed throughout marine ecosystems. However, their impact on intertidal sediment microbial communities is poorly understood. In this study, we conducted a 30-day laboratory tidal microcosm experiment to investigate the effects of MPs on microbial communities. Specifically, we used the biodegradable polymers polylactic acid (PLA) and polybutylene succinate (PBS), as well as the conventional polymers polyethylene terephthalate (PET), polycarbonate (PC), and polyethylene (PE). Treatments with different concentrations (1-5%, w/w) of PLA- and PE-MPs were also included. We analyzed taxonomic variations in archaeal and bacterial communities using 16S rRNA high-throughput sequencing. PLA-MPs at concentrations of 1% (w/w) rapidly altered microbiome composition. Total organic carbon and nitrite nitrogen were the key physicochemical factors and urease was the major enzyme shaping MP-exposed sediment microbial communities. Stochastic processes predominated in microbial assembly and the addition of biodegradable MPs enhanced the contribution of ecological selections. The major keystone taxa of archaea and bacteria were Nitrososphaeria and Alphaproteobacteria, respectively. MPs exposure had less effect on archaeal functions while nitrogen cycling decreased in PLA-MPs treatments. These findings expanded the current understanding of the mechanism and pattern that MPs affect sediment microbial communities.


Assuntos
Microbiota , Microplásticos , Microplásticos/farmacologia , Plásticos , Archaea/genética , RNA Ribossômico 16S/genética , Bactérias/genética , Poliésteres , Nitrogênio/farmacologia , Solo
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