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1.
Small ; 20(9): e2307598, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37852941

RESUMO

Lithium, is the most ideal anode material for lithium-based batteries. However, the overgrowth of lithium dendrites and the low lithium-ion diffusion rate at low temperatures limit the further application of lithium metal anodes. Here, the applied magnetic field is introduced inside the lithium metal anode by using a novel magnetic metal-organic framework as a current collector. The magnetic field can improve the conductivity of this novel current collector, thus accelerating the diffusion of lithium ions in the battery, an advantage that is particularly prominent at low temperatures. In addition, the current collector can stabilize the solid electrolyte interface and inhibit the growth of lithium dendrites, resulting in excellent electrochemical performance. The symmetrical cell at room temperature can exceed 4600 h with a hysteresis voltage of only 9 mV. After 300 cycles at room temperature, the capacity of full cell is still 142 mA h g-1 , and it remains stable for 380 cycles at 5 °C (capacity above 120 mA h g-1 ). The strategy of constructing novel current collector with magnetic field can promote the further application of lithium batteries in extreme conditions such as low temperatures.

2.
Metab Eng ; 82: 69-78, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38316239

RESUMO

Microbial synthesis has emerged as a promising and sustainable alternative to traditional chemical synthesis and plant extraction. However, the competition between synthetic pathways and central metabolic pathways for cellular resources may impair final production efficiency. Moreover, when the synthesis of target product requires multiple precursors from the same node, the conflicts of carbon flux have further negative impacts on yields. In this study, a self-regulated network was developed to relieve the competition of precursors in complex synthetic pathways. Using 4-hydroxycoumarin (4-HC) synthetic pathway as a proof of concept, we employed an intermediate as a trigger to dynamically rewire the metabolic flux of pyruvate and control the expression levels of genes in 4-HC synthetic pathway, achieving self-regulation of multiple precursors and enhanced titer. Transcriptomic analysis results additionally demonstrated that the gene transcriptional levels of both pyruvate kinase PykF and synthetic pathway enzyme SdgA dynamically changed according to the intermediate concentrations. Overall, our work established a self-regulated network to dynamically balance the metabolic flux of two precursors in 4-HC biosynthesis, providing insight into balancing biosynthetic pathways where multiple precursors compete and interfere with each other.


Assuntos
Vias Biossintéticas , Engenharia Metabólica , Vias Biossintéticas/genética , Engenharia Metabólica/métodos , Redes e Vias Metabólicas
3.
Environ Res ; 242: 117715, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-37996000

RESUMO

The thermocatalytic conversion of carbon dioxide (CO2) into high value-added chemicals provides a strategy to address the environmental problems caused by excessive carbon emissions and the sustainable production of chemicals. Significant progress has been made in the CO2 hydrogenation to long chain α-olefins, but controlling C-O activation and C-C coupling remains a great challenge. This review focuses on the recent advances in catalyst design concepts for the synthesis of long chain α-olefins from CO2 hydrogenation. We have systematically summarized and analyzed the ingenious design of catalysts, reaction mechanisms, the interaction between active sites and supports, structure-activity relationship, influence of reaction process parameters on catalyst performance, and catalyst stability, as well as the regeneration methods. Meanwhile, the challenges in the development of the long chain α-olefins synthesis from CO2 hydrogenation are proposed, and the future development opportunities are prospected. The aim of this review is to provide a comprehensive perspective on long chain α-olefins synthesis from CO2 hydrogenation to inspire the invention of novel catalysts and accelerate the development of this process.


Assuntos
Alcenos , Dióxido de Carbono , Hidrogenação
4.
Anal Chem ; 95(22): 8613-8620, 2023 06 06.
Artigo em Inglês | MEDLINE | ID: mdl-37229528

RESUMO

We report methods that improve the quantification of digital bead assays (DBA)─such as the digital enzyme-linked immunosorbent assay (ELISA)─that have found widespread use for high sensitivity measurement of proteins in clinical research and diagnostics. In digital ELISA, proteins are captured on beads, labeled with enzymes, individual beads are interrogated for activity from one or more enzymes, and the average number of enzymes per bead (AEB) is determined based on Poisson statistics. The widespread use of digital ELISA has revealed limitations to the original approaches to quantification that can lead to inaccurate AEB. Here, we have addressed the inaccuracy in AEB due to deviations from Poisson distribution in a digital ELISA for Aß-40 by changing the AEB calculation from a fixed threshold between digital counting and average normalized intensity to a smooth, continuous combination of digital counting and intensity. We addressed issues with determining the average product fluorescence intensity from single enzymes on beads by allowing outlier, high intensity arrays to be removed from average intensities, and by permitting the use of a wider range of arrays. These approaches improved the accuracy of a digital ELISA for tau protein that was affected by aggregated detection antibodies. We increased the dynamic range of a digital ELISA for IL-17A from AEB ∼25 to ∼130 by combining long and short exposure images at the product emission wavelength to create virtual images. The methods reported will significantly improve the accuracy and robustness of DBA based on imaging─such as single molecule arrays (Simoa)─and flow detection.


Assuntos
Anticorpos , Proteínas , Ensaio de Imunoadsorção Enzimática/métodos
5.
Metab Eng ; 75: 68-77, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36404524

RESUMO

The RNA-guided Cas9s serve as powerful tools for programmable gene editing and regulation; their targeting scopes and efficacies, however, are always constrained by the PAM sequence stringency. Most Streptococci Cas9s, including the prototype SpCas9 from S. pyogenes, specifically recognize a canonical NGG PAM via a conserved RxR PAM-binding motif within the PAM-interaction (PI) domain. Here, SpCas9-based mining unveils three distinct and rarely presented PAM-binding motifs (QxxxR, QxQ and RxQ) among Streptococci Cas9 orthologs. With the catalytically-dead QxxxR-containing SedCas9 from S. equinus, we dissect its NAG PAM specificity and elucidate its underlying recognition mechanism via computational prediction and mutagenesis analysis. Replacing the SedCas9 PI domain with alternate PAM-binding motifs rewires its PAM specificity to NGG or NAA. Moreover, a semi-rational design with minimal mutation creates a SedCas9-NQ variant showing robust activity towards expanded NNG and NAA PAMs, based upon which we engineered a compact ω-SedCas9-NQ transcriptional regulator for PAM-directed bifunctional and titratable gene control. The ω-SedCas9-NQ mediated metabolic reprogramming of endogenous genes in Escherichia coli affords a 2.6-fold increase of 4-hydroxycoumarin production. This work reveals new Cas9 scaffolds with distinct PAM-binding motifs for PAM relaxation and creates a new PAM-diverse Cas9 variant for versatile gene control in bacteria.


Assuntos
Proteína 9 Associada à CRISPR , Sistemas CRISPR-Cas , Proteína 9 Associada à CRISPR/química , Proteína 9 Associada à CRISPR/genética , Proteína 9 Associada à CRISPR/metabolismo , Edição de Genes , Mutagênese , Streptococcus pyogenes/genética , Streptococcus pyogenes/metabolismo
6.
Opt Express ; 31(20): 33064-33076, 2023 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-37859094

RESUMO

In this paper, we studied a series of high-speed photodetectors (PD) with different super-lattice interlayer periods and the scale of the effective area to examine their communication performance. The mini-PDs are designed with a single 1 mm × 1 mm effective area. The mini-PDs have three different super-lattice (SL) periods in the interlayer: 8, 15, and 32. The micro-PD sample has multiple 50um by 50um photosensitive areas that form a 4 × 4 receiver array, which shares a common N electrode. Its SL period is 26. The experiment shows that mini-PDs have the advantages such as better tolerance to beam spot deviation, larger field of view (FoV), higher responsibility, and wider peak width in spectral response. But micro-LED samples outperform the others in communication capacity and wavelength selectivity. The 8, 15, and 32 SL mini-PD samples achieve 6.6, 7.3, and 8.8 Gb/s data rates, respectively. The micro-PD gains the maximum data rate of 14.38Gb/s without applying waveform level post-equalization, and 15.26Gb/s after using an NN-based post-equalizer. This experiment shows that with proper DSP, GaN-based PD would be suitable for high-speed VLC systems, especially for the short wavelength spectrum in visible light.

7.
BMC Cancer ; 23(1): 1055, 2023 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-37919691

RESUMO

BACKGROUND & AIMS: This study aims to assess the nutritional status of patients during the different phases of the Chimeric Antigen Receptor (CAR)-T cell therapy and to identify prominent risk factors of hypoalbuminemia in patients after CAR-T treatment. The clinical consequences of malnutrition in cancer patients have been highlighted by growing evidence from previous clinical studies. Given CAR-T cell therapy's treatment intensity and possible side effects, it is important to provide patients with sufficient medical attention and support for their nutritional well-being. METHODS: This study was conducted from May 2021 to December 2021 among patients undergoing CAR-T cell therapy at the Bone Marrow Transplantation Center in The First Affiliated Hospital of Zhejiang University School of Medicine. Logistic regression analysis was performed to investigate the risk factors associated with hypoalbuminemia. Participants were divided into the cytokine release syndrome (CRS) group (n = 60) and the non-CRS group (n = 11) to further analyze the relationship between hypoalbuminemia and CRS. RESULTS: CRS (OR = 13.618; 95% CI = 1.499-123.709; P = 0.013) and baseline albumin (ALB) (OR = 0.854; 95% CI = 0.754-0.967; P = 0.020) were identified as the independent clinical factors associated with post-CAR-T hypoalbuminemia. According to the nadir of serum albumin, hypoalbuminemia occurred most frequently in patients with severe CRS (78.57%). The nadir of serum albumin (r = - 0.587, P < 0.001) and serum albumin at discharge (r = - 0.315, P = 0.01) were negatively correlated for the duration of CRS. Furthermore, patients with hypoalbuminemia deserved longer hospitalization (P = 0.04). CONCLUSIONS: CRS was identified as a significant risk factor associated with post-CAR-T hypoalbuminemia. An obvious decline in serum albumin was observed as the grade and duration of CRS increase. However, further research is still needed to elucidate the mechanisms of CRS-associated hypoalbuminemia.


Assuntos
Neoplasias Hematológicas , Hipoalbuminemia , Receptores de Antígenos Quiméricos , Humanos , Síndrome da Liberação de Citocina/tratamento farmacológico , Síndrome da Liberação de Citocina/etiologia , Hipoalbuminemia/complicações , Imunoterapia Adotiva/efeitos adversos , Neoplasias Hematológicas/terapia , Neoplasias Hematológicas/tratamento farmacológico , Fatores de Risco , Albumina Sérica , Terapia Baseada em Transplante de Células e Tecidos
8.
Artigo em Inglês | MEDLINE | ID: mdl-37068122

RESUMO

Strain R10T was isolated from a gravel soil sample obtained from Deception Island, Antarctica. The isolate was a Gram-stain-negative, strictly aerobic, motile, short-rod-shaped bacterium, and its colonies were orange yellow in colour. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain R10T belonged to the family Aurantimonadaceae and shared highest sequence similarity with Jiella aquimaris LZB041T (96.3 % sequence similarity), Aurantimonas aggregata R14M6T (96.0 %) and Aureimonas frigidaquae JCM 14755T (96.0 %). Phylogenetic analysis showed that strain R10T affiliated with members of the family Aurantimonadaceae and represented an independent lineage. Growth occurred at 10-37 °C (optimum, 28-32 °C), up to 1.0 % (w/v) NaCl (optimum, 0 %) and pH 5.5-9.0 (optimum, pH 7.0). The major respiratory quinone of strain R10T was Q-10. Its major fatty acids were C18 : 1 ω7c and C16 : 0. The polar lipid profile of strain R10T comprised diphosphatidylglycerol, phosphatidylmonomethylethanolamine, phosphatidylethanolamine, phosphatidylglycerol, two unknown phospholipids and two unknown aminophospholipids. The genome of strain R10T was 5.92 Mbp with a G+C content of 69.1 % based on total genome calculations. Average nucleotide identity (ANI) values between R10T and other related species of the family Aurantimonadaceae were found to be low (ANIm <87.0 %, ANIb <75.0 % and OrthoANIu <77.0 %). Furthermore, digital DNA-DNA hybridization (dDDH) and average amino acid identity (AAI) values between strain R10T and the closely related species ranged from 19.5-20.6% and from 60.6-64.0 %, respectively. Based on the results of our phylogenetic, phenotypic, genotypic and chemotaxonomic analyses, it is concluded that strain R10T represents a novel genus and species of the family Aurantimonadaceae, for which the name Antarcticirhabdus aurantiaca gen. nov., sp. nov. is proposed. The type strain is R10T (=KCTC 72466T=CGMCC 1.17155T).


Assuntos
Ácidos Graxos , Ubiquinona , Ácidos Graxos/química , Regiões Antárticas , Filogenia , RNA Ribossômico 16S/genética , Ubiquinona/química , Composição de Bases , Técnicas de Tipagem Bacteriana , DNA Bacteriano/genética , Análise de Sequência de DNA , Fosfolipídeos/química
9.
BMC Musculoskelet Disord ; 24(1): 522, 2023 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-37355606

RESUMO

PURPOSE: Insufficient coverage causes hip joint instability and results in hip pain. Anterior hip coverage can be determined on both pelvic anteroposterior (AP) radiographs and false profile (FP) radiographs. Four parameters are commonly used to determine the anterior coverage on pelvic AP radiographs: the crossover index, crossover sign, anterior wall index (AWI), and rule of thirds. This study aims to clarify the relationship between these 4 parameters on AP radiographs and the anterior center edge angle (ACEA) on FP radiographs. METHODS: In this study, 53 patients who underwent periacetabular osteotomy for hip dysplasia at our center between July 2020 and October 2020 were retrospectively reviewed. Four parameters on AP radiographs and the ACEA on FP radiographs before surgery and 6 months after surgery were measured and compared for each hip. RESULTS: Upon examining the 53 hips in this study, there was no correlation between either the crossover index and the ACEA (P = 0.66) or the crossover sign before surgery. The postoperative correlation between the crossover index and the ACEA was weak (r = 0.36, P = 0.007), and that between the crossover sign and the ACEA was moderate (r = 0.41, P = 0.003). There was a weak correlation between the AWI and ACEA both before (r = 0.288, P = 0.036) and after (r = 0.349, P = 0.011) the operation. Evaluation of the anterior coverage by the rule of thirds was also not consistent when determining the anterior coverage with the ACEA. CONCLUSION: Anterior coverage on AP radiographs is largely inconsistent with ACEA on FP radiographs, especially before the surgery. It is recommended to take FP radiographs routinely for determining anterior hip coverage.


Assuntos
Luxação Congênita de Quadril , Luxação do Quadril , Humanos , Luxação do Quadril/diagnóstico por imagem , Luxação do Quadril/cirurgia , Acetábulo/diagnóstico por imagem , Acetábulo/cirurgia , Estudos Retrospectivos , Articulação do Quadril/diagnóstico por imagem , Articulação do Quadril/cirurgia , Luxação Congênita de Quadril/diagnóstico por imagem , Luxação Congênita de Quadril/cirurgia
10.
Tohoku J Exp Med ; 259(3): 221-227, 2023 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-36596502

RESUMO

Inter-α-trypsin inhibitor heavy chain H4 (ITIH4) modulates atherosclerosis, lipid, and inflammation, which is involved in the development of acute ischemic stroke. Hence, this study aimed to investigate the longitudinal change and prognostic role of ITIH4 in acute ischemic stroke. In 267 patients with acute ischemic stroke, serum ITIH4 after admission (baseline), the 1st day after admission (D1), D3, D7, and D30, and inflammatory cytokines at baseline were detected by enzyme-linked immunosorbent assay (ELISA). Additionally, serum ITIH4 of 30 controls after enrollment was detected by ELISA. ITIH4 was reduced in acute ischemic stroke patients than controls [median (interquartile range, IQR): 131.0 (95.5-194.3) vs. 418.6 (241.5-506.8) ng/mL] (P < 0.001). Among acute ischemic stroke patients, ITIH4 was negatively associated with tumor necrosis factor-alpha (r = -0.211, P = 0.001), interleukin (IL)-1ß (r = -0.164, P = 0.007), IL-6 (r = -0.121, P = 0.049), and IL-17A (r = -0.188, P = 0.002). ITIH4 presented a decreased trend from admission to D3, then increased from D3 to D30 (P < 0.001). The 1-year, 2-year, and 3-year cumulative recurrence rate was 7.5%, 18.0%, and 19.1%, respectively; meanwhile, 1-year, 2-year, and 3-year cumulative death rate was 2.2%, 7.1%, and 7.1%, accordingly. The further analysis presented that ITIH4 at baseline (P = 0.002), D1 (P = 0.049), D3 (P = 0.003), D7 (P < 0.001), and D30 (P < 0.001) was decreased in recurrent patients than non-recurrent patients; besides, ITIH4 at D3 (P = 0.017), D7 (P = 0.004), and D30 (P = 0.002), but not at baseline (P = 0.151) or D1 (P = 0.013), was decreased in deaths than survivors. Serum ITIH4 declines at first and then elevates with time, and its reduction is correlated with higher inflammation, increased risk of recurrence and mortality in acute ischemic stroke patients.


Assuntos
AVC Isquêmico , Acidente Vascular Cerebral , Humanos , alfa-Globulinas/análise , Inflamação , Citocinas
11.
Ecotoxicol Environ Saf ; 263: 115256, 2023 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-37454484

RESUMO

The pathophysiology of osteoporosis (OP) is influenced by exposure to nonessential harmful metals and insufficient or excessive intake of necessary metals. Investigating multiple plasma metals, metabolites, and OP risk among older adults may reveal novel clues of underlying mechanisms for metal toxicity on bone mass. A total of 294 adults ≥ 55 years from Wuhan communities were included. Plasma concentrations of 23 metals and metabolites were measured via inductively coupled plasma-mass spectrometry and global metabolite detection. To investigate the relationships between plasma metals, OP risk, and OP-related metabolites, three different statistical techniques were used: generalized linear regression model, two-way orthogonal partial least-squares analysis (O2PLS), and weighted quantile sum (WQS). The mean ages were 66.82 and 66.21 years in OP (n = 115) and non-OP (n = 179) groups, respectively. Of all 2999 metabolites detected, 111 differential between-group members were observed. The OP risk decreased by 58.5% (OR=0.415, 95% CI: 0.237, 0.727) per quartile increment in the WQS index indicative of metal mixture exposure. Consistency remained for bone mineral density (BMD) measurements. The O2PLS model identified the top five OP-related metabolites, namely, DG(18:2_22:6), 3-phenoxybenzoic acid, TG(16:1_16:1_22:6), TG(16:0_16:0_20:4), and TG(14:1_18:2_18:3), contributing most to the joint covariation between the metal mixture and metabolites. Significant correlations between each of them and the metal mixture were found using WQS regression. Furthermore, the five metabolites mediated the associations of the metal mixtures, BMD, and OP risk. Our findings shed additional light on the mediation functions of plasma metabolites in the connection between multiple metal co-exposure and OP pathogenesis and offer new insights into the probable mechanisms underpinning the bone effects of the metal mixture.


Assuntos
Osteoporose , Humanos , Idoso , Osteoporose/induzido quimicamente , Densidade Óssea , Metais/toxicidade , Osso e Ossos , Modelos Lineares
12.
Molecules ; 28(14)2023 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-37513393

RESUMO

The process of Fischer-Tropsch synthesis is commonly described as a series of reactions in which CO and H2 are dissociated and adsorbed on the metals and then rearranged to produce hydrocarbons and H2O. However, CO dissociation adsorption is regarded as the initial stage of Fischer-Tropsch synthesis and an essential factor in the control of catalytic activity. Several pathways have been proposed to activate CO, namely direct CO dissociation, activation hydrogenation, and activation by insertion into growing chains. In addition, H2O is considered an important by-product of Fischer-Tropsch synthesis reactions and has been shown to play a key role in regulating the distribution of Fischer-Tropsch synthesis products. The presence of H2O may influence the reaction rate, the product distribution, and the deactivation rate. Focus on H2O molecules and H2O-derivatives (H*, OH* and O*) can assist CO activation hydrogenation on Fe- and Co-based catalysts. In this work, the intermediates (C*, O*, HCO*, COH*, COH*, CH*, etc.) and reaction pathways were analyzed, and the H2O and H2O derivatives (H*, OH* and O*) on Fe- and Co-based catalysts and their role in the Fischer-Tropsch synthesis reaction process were reviewed.

13.
Molecules ; 28(13)2023 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-37446790

RESUMO

Neurofibromatosis type 1 is a rare autosomal dominant genetic disorder, with up to 50% of patients clinically displaying skeletal defects. Currently, the pathogenesis of bone disorders in NF1 patients is unclear, and there are no effective preventive and treatment measures. In this study, we found that knockout of the NF1 gene reduced cAMP levels and osteogenic differentiation in an osteoblast model, and icariin activated the cAMP/PKA/CREB pathway to promote osteoblast differentiation of the NF1 gene knockout cell model by increasing intracellular cAMP levels. The PKA selective inhibitor H89 significantly impaired the stimulatory effect of icariin on osteogenesis in the NF1 cell model. In this study, an osteoblast model of NF1 was successfully constructed, and icariin was applied to the cell model for the first time. The results will help to elucidate the molecular mechanism of NF1 bone disease and provide new ideas for the clinical prevention and treatment of NF1 bone disease and drug development in the future.


Assuntos
Doenças Ósseas , Neurofibromatose 1 , Humanos , Osteogênese/genética , Neurofibromatose 1/tratamento farmacológico , Neurofibromatose 1/genética , Neurofibromatose 1/metabolismo , Genes da Neurofibromatose 1 , Técnicas de Inativação de Genes , Diferenciação Celular/genética , Doenças Ósseas/metabolismo , Osteoblastos
14.
Molecules ; 28(19)2023 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-37836763

RESUMO

Here, we report a Na-promoted FeCu-based catalyst with excellent liquid hydrocarbon selectivity and catalytic activity. The physiochemical properties of the catalysts were comprehensively characterized by various characterization techniques. The characterization results indicate that the catalytic performance of the catalysts was closely related to the nature of the metal promoters. The Na-AlFeCu possessed the highest CO2 conversion due to enhanced CO2 adsorption of the catalysts by the introduction of Al species. The introduction of excess Mg promoter led to a strong methanation activity of the catalyst. Mn and Ga promoters exhibited high selectivity for light hydrocarbons due to their inhibition of iron carbides generation, resulting in a lack of chain growth capacity. The Na-ZnFeCu catalyst exhibited the optimal C5+ yield, owing to the fact that the Zn promoter improved the catalytic activity and liquid hydrocarbon selectivity by modulating the surface CO2 adsorption and carbide content. Carbon dioxide (CO2) hydrogenation to liquid fuel is considered a method for the utilization and conversion of CO2, whereas satisfactory activity and selectivity remains a challenge. This method provides a new idea for the catalytic hydrogenation of CO2 and from there the preparation of high-value-added products.

15.
Metab Eng ; 70: 67-78, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35033655

RESUMO

Dynamic regulation has been proved efficient in controlling gene expression at transcriptional, translational, and post-translational level. However, the dynamic regulation at gene replication level has been rarely explored so far. In this study, we established dynamic regulation at gene copy level through engineering controllable plasmid replication to dynamically control the gene expression. Prototypic genetic circuits with different control logic were applied to enable diversified dynamic behaviors of gene copy. To explore the applicability of this strategy, the dynamic gene copy control was employed in regulating the biosynthesis of p-coumaric acid, which resulted in an up to 78% increase in p-coumaric acid titer to 1.69 g/L in shake flasks. These results indicated the great potential of applying dynamic gene copy control for engineering biosynthesis of valuable compounds in metabolic engineering.


Assuntos
Bactérias , Engenharia Metabólica , Bactérias/genética , Plasmídeos/genética
16.
Metab Eng ; 74: 1-10, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36041638

RESUMO

Endogenous metabolic pathways in microbial cells are usually precisely controlled by sophisticated regulation networks. However, the lack of such regulations when introducing heterologous pathways in microbial hosts often causes unbalanced enzyme expression and carbon flux distribution, hindering the construction of highly efficient microbial biosynthesis systems. Here, using naringenin as the target compound, we developed an Autonomous Cascaded Artificial Dynamic (AutoCAD) regulation system to automatically coordinate the pathway expression and redirect carbon fluxes for enhanced naringenin production. The AutoCAD regulation system, consisting of both intermediate-based feedforward and product-based feedback control genetic circuits, resulted in a 16.5-fold increase in naringenin titer compared with the static control. Fed-batch fermentation using the strain with AutoCAD regulation further enhanced the naringenin titer to 277.2 mg/L. The AutoCAD regulation system, with intermediate-based feedforward control and product-triggered feedback control, provides a new paradigm of developing complicated cascade dynamic control to engineer heterologous pathways.


Assuntos
Engenharia Metabólica , Redes e Vias Metabólicas , Engenharia Metabólica/métodos , Fermentação
17.
Opt Express ; 30(18): 33337-33352, 2022 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-36242375

RESUMO

Recently, visible light communication (VLC) has emerged as a promising communication method in 6G. To achieve 6G high-speed transmission, wavelength division multiplexing (WDM) based VLC systems are a highly promising candidate. However, the "yellow and green gap" greatly limits the yellow light efficiency of InGaN-based LEDs and also restricts the transmission rate of yellow LEDs. In addition, pre-equalization and post-equalization also have an important impact on high-speed communication. In this paper, we propose to employ a vertical InGaN-based Si-substrate yellow LED with bit-power loading discrete multitone (DMT) modulation and a novel cascaded pre-equalizer network to achieve a high-speed yellow-light VLC system. The proposed cascaded pre-equalizer network is based on a digital Zobel network and a partial nonlinear pre-equalizer (DZNPN). The microscopic time-domain transient response of the high-speed and large-amplitude signal is also investigated to show a severe impairment. Utilizing the DZNPN cascaded pre-equalizer network based on the third-order Volterra series, a record-breaking data rate of 3.764Gbps over 1.2 m free space and 3.808Gbps over 0.7 m are experimentally demonstrated under the hard decision-forward error correction (HD-FEC) threshold of 3.8 × 10-3. The rate can be improved from 2.818Gbps to 3.764Gbps with 650Mbaud compared to the un-preprocessed signal. This is the highest data rate ever reported for yellow-light VLC systems based on a single LED to the best of our knowledge.

18.
Artigo em Inglês | MEDLINE | ID: mdl-35195511

RESUMO

A Gram-stain-positive, facultative anaerobic, motile and rod-shaped bacterial strain, DG-18T, was isolated from desert soil sampled at the Kubuqi Desert in Inner Mongolia, China. Strain DG-18T grew at 4-40 °C (optimum, 25-30 °C), at pH 8.0-10.0 (optimum, pH 9.0) and with 0-8.0 % (w/v) NaCl (optimum 2.0%). 16S rRNA gene sequence analysis placed strain DG-18T within the genus Sutcliffiella of the family Bacillaceae with Sutcliffiella halmapala DSM 8723T (98.2%), Sutcliffiella zhanjiangensis JSM 099021T (97.6%), Sutcliffiella horikoshii DSM 8719T (97.4%), Sutcliffiella catenulata 18CT (96.6 %) and Sutcliffiella cohnii NBRC 15565T (96.5%) as its closest relatives. The major respiratory quinone of strain DG-18T was MK-7 and the major polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol. Its major fatty acids were iso-C15 : 0 and iso-C17 : 1 ω10c. The genomic DNA G+C content of strain DG-18T was 38.7 mol% based on total genome calculations. The average nucleotide identity score between the genomic sequence of strain DG-18T and that of S. halmapala DSM 8723T was 76.7 %. The Genome-to-Genome Distance Calculator showed that the DNA-DNA hybridization value for strain DG-18T and S. halmapala DSM 8723T was 21.8%. Based on the polyphasic taxonomic data, strain DG-18T represents a novel species of the genus Sutcliffiella, for which the name Sutcliffiella deserti sp. nov. is proposed. The type strain is DG-18T (=GDMCC 1.17773T=KCTC 43170T).


Assuntos
Bacillaceae , Clima Desértico , Filogenia , Microbiologia do Solo , Bacillaceae/classificação , Bacillaceae/isolamento & purificação , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Mongólia , Hibridização de Ácido Nucleico , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/química
19.
Artigo em Inglês | MEDLINE | ID: mdl-35085061

RESUMO

Strain 3F2T was isolated from a soil sample obtained from the surface of Deception Island, Antarctica. The isolate was a Gram-stain-negative, aerobic, non-motile, rod-shaped bacterium, and its colonies were red to pink in colour. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain 3F2T belonged to the genus Hymenobacter, family Hymenobacteraceae and was most closely related to Hymenobacter sedentarius DG5BT (97.0% sequence similarity), Hymenobacter soli PB17T (96.9%), Hymenobacter terrae DG7AT (96.8%) and Hymenobacter rufus S1-2-2-6T (96.5%). Growth occurred at 4-20 °C (optimum, 10 °C), up to 1.0 % (w/v) NaCl (optimum, 0%) and pH 6.0-8.0 (optimum, pH 7.0). The chemotaxonomic characteristics of strain 3F2T, which had MK-7 as its predominant menaquinone and summed feature 3 (C16:1 ω7c and/or C16:1 ω6c), iso-C15:0, anteiso-C15:0 and C16:1 ω5c as its major fatty acids, were consistent with classification in the genus Hymenobacter. The polar lipid profile of strain 3F2T comprised phosphatidylethanolamine, two unidentified aminolipids, two unidentified aminophospholipids and three unidentified polar lipids. The genome of strain 3F2T was 6.56 Mbp with a G+C content of 61.5 mol%. Average nucleotide identity (ANI) values between 3F2T and the other species of the genus Hymenobacter were found to be low (ANIm <87.0%, ANIb <82.0% and OrthoANIu <83.0%). Furthermore, digital DNA-DNA hybridization and average amino acid identity values between strain 3F2T and the closely related species ranged from 20.0 to 26.3% and from 64.0 to 81.1 %, respectively. Based on the results of our phylogenetic, phenotypic, genotypic and chemotaxonomic analyses, it is concluded that strain 3F2T represents a novel species within the genus Hymenobacter, for which the name Hymenobacter terricola sp. nov. is proposed. The type strain is 3F2T (=KCTC 72468T=CGMCC 1.13716T).


Assuntos
Cytophagaceae , Filogenia , Microbiologia do Solo , Regiões Antárticas , Técnicas de Tipagem Bacteriana , Composição de Bases , Cytophagaceae/classificação , Cytophagaceae/isolamento & purificação , DNA Bacteriano/genética , Ácidos Graxos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
20.
Int J Syst Evol Microbiol ; 72(12)2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36748610

RESUMO

A Gram-stain positive, facultatively anaerobic, motile rod-shaped strain, BY-33T, was isolated from a soil sample obtained from the Kubuqi Desert, PR China. Phylogenetic analysis based on 16S rRNA gene sequence similarity revealed that strain BY-33T was most closely related to the genus Actinotalea, including Actinotalea ferrariae CF5-4T (98.2 % similarity), 'Actinotalea subterranea' HO-Ch2T (98.0 %), Actinotalea solisilvae THG-T121T (97.6 %), 'Actinotalea bogoriensis' 69B4T (97.5 %), Actinotalea fermentans MT (97.3 %) and 'Actinotalea carbonis' T26T (97.0 %). The strain grew at 0‒37 °C (optimum, 28-30 °C) and pH 6.0-11.0 (optimum, pH 9.0-10.0) and with 0‒8.0 % (w/v) NaCl (optimum, 3.0%) on tryptic soy agar. It had catalase activity, but no oxidase activity. The polar lipids of strain BY-33T contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, and phosphatidylinositol mannosides. The major respiratory quinone of strain BY-33T was MK-10 (H4). Its major fatty acids were anteiso-C15 : 0, anteiso-C15 : 1 A and C16 : 0. The genomic DNA G+C content of strain BY-33T was 73.0 mol% based on total genome calculations. The average nucleotide identity scores between the genomic sequences of strain BY-33T and the other species of the genus Actinotalea were found to be low (ANIm <85.0 %, ANIb <77.0 % and OrthoANIu <78.0 %). Furthermore, the digital DNA-DNA hybridization and average amino acid identity values between strain BY-33T and the closely related species ranged from 20.5 to 21.0% and from 62.2 to 72.2 %, respectively. Based on the results of phylogenetic, phenotypic, genotypic and chemotaxonomic analyses, it is concluded that strain BY-33T represents a novel species within the genus Actinotalea, for which the name Actinotalea soli sp. nov. is proposed. The type strain is BY-33T (=CGMCC 1.17460T=KCTC 49362T).


Assuntos
Actinomycetales , Filogenia , Actinomycetales/classificação , Actinomycetales/isolamento & purificação , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Fosfatidilinositóis/análise , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Solo , China , Clima Desértico , Microbiologia do Solo
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