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1.
Front Immunol ; 15: 1379175, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39086481

RESUMO

Introduction: Intra-tumoral B cells mediate a plethora of immune effector mechanisms with key roles in anti-tumor immunity and serve as positive prognostic indicators in a variety of solid tumor types, including epithelial ovarian cancer (EOC). Several aspects of intra-tumoral B cells remain unclear, such as their state of activation, antigenic repertoires, and capacity to mature into plasma cells. Methods: B lymphocytes were isolated from primary EOC tissue and malignant ascites and were maintained in cell culture medium. The stably maintained cell lines were profiled with flow cytometry and B cell receptor sequencing. Secreted antibodies were tested with a human proteome array comprising more than 21,000 proteins, followed by ELISA for validation. Originating tumor samples were used for spatial profiling with chip cytometry. Results: Antibody-secreting B lymphocytes were isolated from the ovarian tumor microenvironment (TME) of four different EOC patients. The highly clonal cell populations underwent spontaneous immortalization in vitro, were stably maintained in an antibody-secreting state, and showed presence of Epstein-Barr viral (EBV) proteins. All originating tumors had high frequency of tumor-infiltrating B cells, present as lymphoid aggregates, or tertiary lymphoid structures. The antigens recognized by three of the four cell lines are coil-coil domain containing protein 155 (CCDC155), growth factor receptor-bound protein 2 (GRB2), and pyruvate dehydrogenase phosphatase2 (PDP2), respectively. Anti-CCDC155 circulating IgG antibodies were detected in 9 of 20 (45%) of EOC patients' sera. Tissue analyses with multiparameter chip cytometry shows that the antibodies secreted by these novel human B cell lines engage their cognate antigens on tumor cells. Discussion: These studies demonstrate that within the tumor-infiltrating lymphocyte population in EOC resides a low frequency population of antibody-secreting B cells that have been naturally exposed to EBV. Once stably maintained, these novel cell lines offer unique opportunities for future studies on intratumor B cell biology and new target antigen recognition, and for studies on EBV latency and/or viral reactivation in the TME of non-EBV related solid tumors such as the EOC.


Assuntos
Ascite , Linfócitos B , Herpesvirus Humano 4 , Neoplasias Ovarianas , Humanos , Feminino , Neoplasias Ovarianas/imunologia , Herpesvirus Humano 4/imunologia , Linfócitos B/imunologia , Ascite/imunologia , Infecções por Vírus Epstein-Barr/imunologia , Latência Viral/imunologia , Microambiente Tumoral/imunologia , Linfócitos do Interstício Tumoral/imunologia , Linfócitos do Interstício Tumoral/metabolismo , Carcinoma Epitelial do Ovário/imunologia , Anticorpos Antivirais/imunologia , Linhagem Celular Tumoral
2.
J Agric Food Chem ; 2024 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-39096296

RESUMO

The increasing resistance of agricultural pests to existing acaricides presents a significant challenge to sustainable agriculture. Therefore, this study introduced FM-1088, a novel isoindolinone-based phenyl trifluoroethyl thioether derivative generated through an innovative design strategy combining bioisosterism and novel cyclization methods. We synthesized several compounds and evaluated their acaricidal efficacy against Tetranychus cinnabarinus in greenhouses and Panonychus citri in field settings. FM-1088 emerged as a standout candidate, demonstrating a lower median lethal concentration (LC50) of 0.722 mg/L compared to the commercial acaricide, cyetpyrafen. Notably, 30 days after application, FM-1088 showed a field control efficacy of 96.4% against P. citri, highlighting its potential for broader applications. The results underscore the utility of the isoindolinone scaffold in pesticide development, offering a promising solution to combat pest resistance with implications for enhanced crop protection and agricultural productivity. Future studies should explore the detailed mode of action of FM-1088 and its potential applicability across diverse agricultural settings, further confirming its role as a sustainable solution for pest management.

3.
PLoS One ; 19(7): e0307091, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39028695

RESUMO

The world-wide prevalence of myopia (nearsightedness) is increasing, but its pathogenesis is incompletely understood. Among many putative mechanisms, laboratory and clinical findings have implicated circadian biology in the etiology of myopia. Consistent with a circadian hypothesis, we recently reported a marked variability in diurnal patterns of gene expression in two crucial tissues controlling post-natal refractive development - the retina and choroid-at the onset of form-deprivation myopia in chick, a widely studied and validated model. To extend these observations, we assayed gene expression by RNA-Seq in retina and choroid during the progression of established unilateral form-deprivation myopia of chick. We assayed gene expression every 4 hours during a single day from myopic and contralateral control eyes. Retinal and choroidal gene expression in myopic vs. control eyes during myopia progression differed strikingly at discrete times during the day. Very few differentially expressed genes occurred at more than one time in either tissue during progressing myopia. Similarly, Gene Set Enrichment Analysis pathways varied markedly by time during the day. Some of the differentially expressed genes in progressing myopia coincided with candidate genes for human myopia, but only partially corresponded with genes previously identified at myopia onset. Considering other laboratory findings and human genetics and epidemiology, these results further link circadian biology to the pathogenesis of myopia; but they also point to important mechanistic differences between the onset of myopia and the progression of established myopia. Future laboratory and clinical investigations should systematically incorporate circadian mechanisms in studying the etiology of myopia and in seeking more effective treatments to normalize eye growth in children.


Assuntos
Galinhas , Corioide , Ritmo Circadiano , Progressão da Doença , Miopia , Retina , Corioide/metabolismo , Corioide/patologia , Retina/metabolismo , Retina/patologia , Animais , Miopia/genética , Miopia/metabolismo , Ritmo Circadiano/genética , Galinhas/genética , Humanos , Modelos Animais de Doenças , Regulação da Expressão Gênica , Perfilação da Expressão Gênica
4.
Eur J Pharmacol ; : 176855, 2024 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-39059570

RESUMO

Phenotypic transformation of pulmonary artery smooth muscle cells (PASMCs) contributes to vascular remodeling in hypoxic pulmonary hypertension (PH). Recent studies have suggested that circular RNAs (circRNAs) may play important roles in the vascular remodeling of hypoxia-induced PH. However, whether circRNAs cause pulmonary vascular remodeling by regulating the phenotypic transformation in PH has not been investigated. Microarray and RT-qPCR analysis identified that circLMBR1, a novel circRNA, decreased in mouse lung tissues of the hypoxia-SU5416 PH model, as well as in human PASMCs and mouse PASMCs exposed to hypoxia. Overexpression of circLMBR1 in the Semaxinib (SU5416) mouse model ameliorated hypoxia-induced PH and vascular remodeling in the lungs. Notably, circLMBR1 was mainly distributed in the nucleus and bound to the splicing factor PUF60. CircLMBR1 suppressed the phenotypic transformation of human PASMCs and vascular remodeling by inhibiting PUF60 expression. Furthermore, we identified U2AF65 as the downstream regulatory factor of PUF60. U2AF65 directly interacted with the pre-mRNA of the contractile phenotype marker smooth muscle protein 22-α (SM22α) and inhibited its splicing. Meanwhile, hypoxia exposure increased the formation of the PUF60-U2AF65 complex, thereby inhibiting SM22α production and inducing the transition of human PASMCs from a contractile phenotype to a synthetic phenotype. Overall, our results verified the important role of circLMBR1 in the pathological process of PH. We also proposed a new circLMBR1/PUF60-U2AF65/pre-SM22α pathway that could regulate the phenotypic transformation and proliferation of human PASMCs. This study may provide new perspectives for the diagnosis and treatment of PH.

7.
Anal Methods ; 16(28): 4794-4806, 2024 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-38961818

RESUMO

In quantitative analysis of spectral data, traditional linear models have fewer parameters and faster computation speed. However, when encountering nonlinear problems, their predictive accuracy tends to be lower. Nonlinear models provide higher computational accuracy in such situations but may suffer from drawbacks such as slow convergence speed and susceptibility to get stuck in local optima. Taking into account the advantages of these two algorithms, this paper introduces the single-hidden layer feedforward neural network named stochastic configuration networks (SCNs) into chemometrics analysis. Firstly, the model termination parameters, that is, the error tolerance and the allowed maximum number of hidden nodes are analyzed. Secondly, times of random configuration are discussed and analyzed, and then the appropriate number is determined by considering the efficiency and stability comprehensively. Finally, predictions made by the SCN are tested on two public datasets. The performance of the SCN is then compared with that of other techniques, including principal component regression (PCR), partial least squares (PLS), back propagation neural network (BPNN), and extreme learning machine (ELM). Experimental results show that the SCN has good stability, high prediction accuracy and efficiency, making it suitable for quantitative analysis of spectral data.

8.
Biometals ; 2024 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-39073690

RESUMO

Phytoextraction of lead (Pb) is a challenging task due to its extremely low mobility within soil and plant systems. In this study, we tested the influence of some novel chelating agents for Pb-phytoextraction using sunflower. The Pb was applied at control (0.0278 mM) and 4.826 mM Pb as Pb(NO3)2 through soil-spiking. After 10 days of Pb addition, four different organic ligands (aspartic, ascorbic, tartaric, and pantothenic acids) were added to the soil at 1 mM concentration each. respectively. In the absence of any chelate, sunflower plants grown at 4.826 mM Pb level accumulated Pb concentrations up to 104 µg g-1 DW in roots, whereas 64 µg g-1 DW in shoot. By contrast, tartaric acid promoted significantly Pb accumulation in roots (191 µg g-1 DW; + 45.5%) and shoot (131.6 µg g-1 DW; + 51.3%). Pantothenic acid also resulted in a significant Pb-uptake in the sunflower shoots (123 µg g-1 DW; + 47.9%) and in roots (177.3 µg g-1 DW; + 41.3%). The least effective amongst the chelates tested was aspartic acid, but it still contributed to + 40.1% more Pb accumulation in the sunflower root and shoots. In addition, plant growth, biochemical, and ionomic parameters were positively regulated by the organic chelates used. Especially, an increase in leaf Ca, P, and S was evident in Pb-stressed plants in response to chelates. These results highlight that the use of biocompatible organic chelates positively alters plant physio-biochemical traits contributing to higher Pb-sequestration in sunflower plant parts.

9.
Nat Prod Rep ; 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38888887

RESUMO

Covering: up to the end of 2023Type I CRISPR-Cas systems are widely distributed, found in over 40% of bacteria and 80% of archaea. Among genome-sequenced actinomycetes (particularly Streptomyces spp.), 45.54% possess type I CRISPR-Cas systems. In comparison to widely used CRISPR systems like Cas9 or Cas12a, these endogenous CRISPR-Cas systems have significant advantages, including better compatibility, wide distribution, and ease of operation (since no exogenous Cas gene delivery is needed). Furthermore, type I CRISPR-Cas systems can simultaneously edit and regulate genes by adjusting the crRNA spacer length. Meanwhile, most actinomycetes are recalcitrant to genetic manipulation, hindering the discovery and engineering of natural products (NPs). The endogenous type I CRISPR-Cas systems in actinomycetes may offer a promising alternative to overcome these barriers. This review summarizes the challenges and recent advances in CRISPR-based genome engineering technologies for actinomycetes. It also presents and discusses how to establish and develop genome editing tools based on type I CRISPR-Cas systems in actinomycetes, with the aim of their future application in gene editing and the discovery of NPs in actinomycetes.

10.
Sci Rep ; 14(1): 13261, 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38858469

RESUMO

Predicting and optimizing the mechanical performance of the helically wound nylon-reinforced rubber fertilizer hose (HWNR hose) is crucial for enhancing the performance of hose pumps. This study aims to enhance the service life of HWNR hoses and the efficiency of liquid fertilizer transport. First, a finite element simulation model and a mathematical model were established to analyze the influence of fiber layer arrangement on the maximum shear strain on the coaxial surface (MSS) and the reaction force on the extrusion roller (RF). For the first time, the Crested Porcupine Optimizer algorithm was used to improve the Generalized Regression Neural Network (CPO-GRNN) method to establish a surrogate model for predicting the mechanical properties of HWNR hoses, and it was compared with Response Surface Methodology (RSM). Results showed CPO-GRNN's superiority in handling complex nonlinear problems. Finally, the Non-dominated Sorting Genetic Algorithm II (NSGA-II) was employed for optimization design. Compared to the original HWNR hose with an MSS of 0.906 and an RF of 30,376N, the optimized design reduced the MSS by 7.99% and increased the RF by 2.46%, significantly enhancing their service life and liquid fertilizer transport capacity. However, further research on fatigue damage is needed.

11.
Synth Syst Biotechnol ; 9(4): 684-693, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38846337

RESUMO

Four new N-acylated aminoalkanoic acids, namely clonoroseins E-H (1-4), together with three previously identified analogs, clonoroseins A, B, and D (5-7), were identified from the endophytic fungus Clonostachys rosea strain 15020 (CR15020), using Feature-based Molecular Networking (FBMN). The elucidation of their chemical structures, including their absolute configurations, was achieved through spectroscopic analysis combined with quantum chemical calculations. Bioinformatics analyses suggested that an iterative type I HR-PKS (CrsE) generates the polyketide side chain of these clonoroseins. Furthermore, a downstream adenylate-forming enzyme of the PKS (CrsD) was suspected to function as an amide synthetase. CrsD potentially facilitates the transformation of the polyketide moiety into an acyl-AMP intermediate, followed by nucleophilic substitution with either ß-alanine or γ-aminobutyric acid to produce amide derivatives. These findings significantly expand our understanding of PKS-related products originating from C. rosea and also underscore the powerful application of FBMN analytical methods in characterization of new compounds.

12.
Mar Drugs ; 22(6)2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38921570

RESUMO

A new dimeric C-glycoside polyketide chrysomycin F (1), along with four new monomeric compounds, chrysomycins G (2), H (3), I (4), J (5), as well as three known analogues, chrysomycins A (6), B (7), and C (8), were isolated and characterised from a strain of Streptomyces sp. obtained from a sediment sample collected from the South China Sea. Their structures were determined by detailed spectroscopic analysis. Chrysomycin F contains two diastereomers, whose structures were further elucidated by a biomimetic [2 + 2] photodimerisation of chrysomycin A. Chrysomycins B and C showed potent anti-tuberculosis activity against both wild-type Mycobacterium tuberculosis and a number of clinically isolated MDR M. tuberculosis strains.


Assuntos
Antituberculosos , Testes de Sensibilidade Microbiana , Mycobacterium tuberculosis , Policetídeos , Streptomyces , Streptomyces/química , Streptomyces/metabolismo , Mycobacterium tuberculosis/efeitos dos fármacos , Antituberculosos/farmacologia , Antituberculosos/química , Antituberculosos/isolamento & purificação , Policetídeos/farmacologia , Policetídeos/química , Policetídeos/isolamento & purificação , Glicosídeos/química , Glicosídeos/farmacologia , Glicosídeos/isolamento & purificação , China , Estrutura Molecular , Antraquinonas/farmacologia , Antraquinonas/química , Antraquinonas/isolamento & purificação
13.
Angew Chem Int Ed Engl ; : e202406246, 2024 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-38934471

RESUMO

Terpene synthases (TPSs) play pivotal roles in generating diverse terpenoids through complex cyclization pathways. Protein engineering of TPSs offers a crucial approach to expanding terpene diversity. However, significant potential remains untapped due to limited understanding of the structure-function relationships of TPSs. In this investigation, using a joint approach of molecular dynamics simulations-assisted engineering and site-directed mutagenesis, we manipulated the aromatic residue cluster (ARC) of a bifunctional terpene synthase (BFTPS), Pestalotiopsisfici nigtetraene synthase (PfNS). This led to the discovery of previously unreported catalytic functions yielding different cyclization patterns of sesterterpenes. Specifically, a quadruple variant (F89A/Y113F/W193L/T194W) completely altered PfNS's function, converting it from producing the bicyclic sesterterpene nigtetraene to the tricyclic ophiobolin F. Additionally, analysis of catalytic profiles by double, triple, and quadruple variants demonstrated that the ARC functions as a switch, unprecedently redirecting the production of 5/11 bicyclic (Type B) sesterterpenes to 5/15 bicyclic (Type A) ones. Molecular dynamics simulations and theozyme calculations further elucidated that, in addition to cation-π interactions, C-H∙∙∙π interactions also play a key role in the cyclization patterns. This study offers a feasible strategy in protein engineering of TPSs for various industrial applications.

14.
J Agric Food Chem ; 72(27): 15276-15283, 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38943575

RESUMO

Using nicofluprole as the lead compound, we designed and synthesized a series of new phenylpyrazole analogues through substituting the methyl group on the nitrogen atom of the amide with an acyl group. Bioassay results showed that compounds A12-A17 with a 1-cyanocyclopropimide group exhibited outstanding insecticidal activity. The LC50 values for compounds A12-A17 against Tetranychus cinnabarinus ranged from 0.58 to 0.91 mg/L. Compound A15 showed an LC50 value of 0.29 and 3.10 mg/L against Plutella xylostella and Myzus persicae, respectively. Molecular docking indicated the potential binding interactions of compound A15 with a gamma-aminobutyric acid receptor. Additionally, density functional theory calculations implied that the 1-cyanocyclopropimide structure might be essential for its biological activity. Phenylpyrazole derivatives, containing a 1-cyanocyclopropimide fragment, have the potential for further development as potential insecticides.


Assuntos
Acaricidas , Desenho de Fármacos , Inseticidas , Simulação de Acoplamento Molecular , Pirazóis , Animais , Pirazóis/química , Pirazóis/farmacologia , Pirazóis/síntese química , Acaricidas/química , Acaricidas/farmacologia , Acaricidas/síntese química , Inseticidas/química , Inseticidas/farmacologia , Inseticidas/síntese química , Relação Estrutura-Atividade , Imidas/química , Imidas/farmacologia , Imidas/síntese química , Afídeos/efeitos dos fármacos , Mariposas/efeitos dos fármacos , Tetranychidae/efeitos dos fármacos , Estrutura Molecular
15.
J Viral Hepat ; 31(8): 504-507, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38855857

RESUMO

The understanding of viral transcription and replication activity in HBeAg-positive chronic hepatitis B (CHB) patients with low-level viraemia (LLV) or previous low-level viraemia (pre-LLV) remains unclear. Our aim was to evaluate and compare circulating hepatitis B virus (HBV) RNA levels in these patient groups with those achieving maintained virological response (MVR). This cross-sectional study included 147 patients: 43 in the LLV group, 25 in the pre-LLV group and 79 in the MVR group. Serum HBV RNA levels were assessed using specific RNA target capture combined with simultaneous amplification and testing method. Propensity score matching (PSM) was used to balance baseline characteristics between groups. Median HBV RNA levels were 6.9 copies/mL in the LLV group, 6.1 copies/mL in the pre-LLV group and 3.8 copies/mL in the MVR group. After PSM, significantly higher HBV RNA levels were observed in the LLV group compared to the MVR group (p < .001), and the pre-LLV group also showed higher HBV RNA levels than the MVR group (p < .001). Both LLV and pre-LLV HBeAg-positive CHB patients exhibited elevated circulating HBV RNA levels compared to those achieving MVR.


Assuntos
Antígenos E da Hepatite B , Vírus da Hepatite B , Hepatite B Crônica , RNA Viral , Carga Viral , Viremia , Humanos , Masculino , Feminino , Estudos Transversais , Adulto , RNA Viral/sangue , Antígenos E da Hepatite B/sangue , Vírus da Hepatite B/genética , Hepatite B Crônica/virologia , Hepatite B Crônica/sangue , Viremia/virologia , Pessoa de Meia-Idade , Resposta Viral Sustentada , DNA Viral/sangue
16.
Nat Biotechnol ; 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38839873

RESUMO

Porphyrins and their derivatives find extensive applications in medicine, food, energy and materials. In this study, we produced porphyrin compounds by combining Rhodobacter sphaeroides as an efficient cell factory with enzymatic catalysis. Genome-wide CRISPRi-based screening in R. sphaeroides identifies hemN as a target for improved coproporphyrin III (CPIII) production, and exploiting phosphorylation of PrrA further improves the production of bioactive CPIII to 16.5 g L-1 by fed-batch fermentation. Subsequent screening and engineering high-activity metal chelatases and coproheme decarboxylase results in the synthesis of various metalloporphyrins, including heme and the anti-tumor agent zincphyrin. After pilot-scale fermentation (200 L) and setting up the purification process for CPIII (purity >95%), we scaled up the production of heme and zincphyrin through enzymatic catalysis in a 5-L bioreactor, with CPIII achieving respective enzyme conversion rates of 63% and 98% and yielding 10.8 g L-1 and 21.3 g L-1, respectively. Our strategy offers a solution for high-yield bioproduction of heme and other valuable porphyrins with substantial industrial and medical applications.

17.
J Colloid Interface Sci ; 674: 289-296, 2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38936085

RESUMO

Iron sulfides (FeS2) are promising anode materials for sodium ion batteries (SIBs); however, their inferior electronic conductivity, large volume swelling, and sluggish sodium ion diffusion kinetics lead to unsatisfactory rate performance and cycling durability. Heteroatom doping plays a crucial role in modifying the physicochemical properties of FeS2 anodes to enhance its sodium storage. Herein, ultra-fine Ni-doped FeS2 nanocrystals derived from a metal-organic framework (MOF) and in-situ anchored on a nitrogen doped carbon skeleton (Ni-FeS2@NC) are proposed to enhance both structural stability and reaction kinetics. Material characterization, electrochemical performance, and kinetics analysis demonstrate the critical role of Ni doping in sodium storage, particularly in accelerating Na+ diffusion efficiency. The N-doped carbon derived from the MOF can buffer the volume expansion and enhance the structural stability of electrode materials during sodiation/desodiation processes. As expected, Ni-FeS2@NC exhibits a high reversible capacity of 656.6 ± 65.1 mAh g-1 at 1.0 A g-1 after 200 cycles, superior rate performance (308.8 ± 6.0 mAh g-1 at 10.0 A g-1), and long-term cycling durability over 2000 cycles at 1.0 A g-1. Overall, this study presents an effective approach for enhancing the sodium storage performance and kinetics of anode materials for high efficiency SIBs.

18.
Front Mol Biosci ; 11: 1364637, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38836107

RESUMO

The gut microbiota in cattle is essential for protein, energy, and vitamin production and hence, microbiota perturbations can affect cattle performance. This study evaluated the effect of intramammary (IMM) ceftiofur treatment and lactation stage on the functional gut microbiome and metabolome. Forty dairy cows were enrolled at dry-off. Half received IMM ceftiofur and a non-antibiotic teat sealant containing bismuth subnitrate (cases), while the other half received the teat sealant (controls). Fecal samples were collected before treatment at dry off, during the dry period (weeks 1 and 5) and the first week after calving (week 9). Shotgun metagenomic sequencing was applied to predict microbial metabolic pathways whereas untargeted metabolomics was used identify polar and nonpolar metabolites. Compared to controls, long-term changes were observed in the cows given ceftiofur, including a lower abundance of microbial pathways linked to energy production, amino acid biosynthesis, and other vital molecules. The metabolome of treated cows had elevated levels of stachyose, phosphatidylethanolamine diacylglycerol (PE-DAG), and inosine a week after the IMM ceftiofur application, indicating alterations in microbial fermentation, lipid metabolism, energy, and cellular signaling. Differences were also observed by sampling, with cows in late lactation having more diverse metabolic pathways and a unique metabolome containing higher levels of histamine and histamine-producing bacteria. These data illustrate how IMM ceftiofur treatment can alter the functionality of the hindgut metabolome and microbiome. Understanding how antibiotics and lactation stages, which are each characterized by unique diets and physiology, impact the function of resident microbes is critical to define normal gut function in dairy cattle.

19.
Synth Syst Biotechnol ; 9(4): 658-666, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38817825

RESUMO

Parageobacillus thermoglucosidasius is emerging as a highly promising thermophilic organism for metabolic engineering. The utilization of CRISPR-Cas technologies has facilitated programmable genetic manipulation in P. thermoglucosidasius. However, the absence of thermostable NHEJ enzymes limited the capability of the endogenous type I CRISPR-Cas system to generate a variety of extensive genomic deletions. Here, two thermophilic NHEJ enzymes were identified and combined with the endogenous type I CRISPR-Cas system to develop a genetic manipulation tool that can achieve long-range genomic deletion across various lengths. By optimizing this tool-through adjusting the expression level of NHEJ enzymes and leveraging our discovery of a negative correlation between GC content of the guide RNA (gRNA) and deletion efficacy-we streamlined a comprehensive gRNA selection manual for whole-genome editing, achieving a 100 % success rate in randomly selecting gRNAs. Notably, using just one gRNA, we achieved genomic deletions spanning diverse length, exceeding 200 kilobases. This tool will facilitate the genomic manipulation of P. thermoglucosidasius for both fundamental research and applied engineering studies, further unlocking its potential as a thermophilic cell factory.

20.
Materials (Basel) ; 17(10)2024 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-38793460

RESUMO

A crimping and pultruding forming process for truss rods using Carbon Fiber (CF)/Polyether-Ether-Ketone (PEEK) prepreg tape as the raw material is proposed to address the problem of continuous manufacturing of space trusses on orbit. The proposed process provides material rods for continuous truss manufacturing. Through numerical simulation and experimental verification, the effects of relevant parameters on the forming process are determined, an efficient method of rod curl pultrusion, in-rail, equal material forming is proposed, and the structural configuration of the rod curl pultrusion forming mold is determined. The equivalent macroscopic mechanical properties of unidirectional CF/PEEK prepreg strips are considered, and the rod-forming process is investigated. Rod samples with different process parameters are prepared, and several tests are conducted on them. The results show that the forming load pull is negatively correlated with the temperature at the same forming speed, and forming speed is positively correlated with the forming load pull at a certain temperature. Temperature and speed affect the surface quality of the rod, the density of the material filling, and the mechanical properties of the rod. The optimal forming process parameters are determined through numerical simulation and experimental verification. The developed molding technology has the advantages of high efficiency, low energy consumption, and high integration. It reduces manufacturing costs and improves manufacturing efficiency, so it can serve as a new and effective solution for the manufacturing of high-performance truss rods in the aerospace field.

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