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1.
Biotechnol Adv ; 70: 108298, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38048920

RESUMEN

Polyunsaturated fatty acids (PUFAs), especially docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA) and arachidonic acid (ARA), are beneficial for reducing blood cholesterol and enhancing memory. Traditional PUFA production relies on extraction from plants and animals, which is unsustainable. Thus, using microorganisms as lipid-producing factories holds promise as an alternative way for PUFA production. Several oleaginous microorganisms have been successfully industrialized to date. These can be divided into universal and specialized hosts according to the products range of biosynthesis. The Yarrowia lipolytica is universal oleaginous host that has been engineered to produce a variety of fatty acids, such as γ-linolenic acid (GLA), EPA, ARA and so on. By contrast, the specialized host are used to produce only certain fatty acids, such as ARA in Mortierella alpina, EPA in Nannochloropsis, and DHA in Thraustochytrids. The metabolic engineering and fermentation strategies for improving PUFA production in universal and specialized hosts are different, which is the subject of this review. In addition, the widely applicable strategies for microbial lipid production that are not specific to individual hosts were also reviewed.


Asunto(s)
Ácidos Grasos Insaturados , Ácidos Grasos , Animales , Ácido Eicosapentaenoico/metabolismo , Ingeniería Metabólica , Ácidos Docosahexaenoicos/metabolismo
2.
BMC Ophthalmol ; 23(1): 486, 2023 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-38012561

RESUMEN

BACKGROUND: Myopia has recently emerged as a significant threat to global public health. The high and pathological myopia in children and adolescents could result in irreversible damage to eye tissues and severe impairment of visual function without timely control. Posterior scleral reinforcement (PSR) can effectively control the progression of high myopia by limiting posterior scleral expansion, improving retrobulbar vascular perfusion, thereby stabilizing the axial length and refraction of the eye. Moreover, orthokeratology and low concentrations of atropine are also effective in slowing myopia progression. CASE PRESENTATION: A female child was diagnosed with binocular congenital myopia and amblyopia at the age of 3 and the patient's vision had never been rectified with spectacles at the first consultation. The patient's ophthalmological findings suggested, high refractive error with low best corrected visual acuity, longer axial length beyond the standard level of her age, and fundus examination suggesting posterior scleral staphyloma with weakened hemodynamics of the posterior ciliary artery. Thereby, PSR was performed to improve fundus health and the combination of orthokeratology and 0.01% atropine were performed to control the development of myopia. Following up to 8 years of clinical treatment and observations, the progression of myopia could be well controlled and fundus health was stable. CONCLUSION: In this report, 8-year of clinical observation indicated that PSR could improve choroidal thickness and hemodynamic parameters of the retrobulbar vessels, postoperative orthokeratology combined with 0.01% atropine treatment strategy may be a good choice for myopia control effectively.


Asunto(s)
Anomalías del Ojo , Miopía Degenerativa , Humanos , Niño , Adolescente , Femenino , Atropina/uso terapéutico , Miopía Degenerativa/diagnóstico , Refracción Ocular , Procedimientos Quirúrgicos Oftalmológicos , Anomalías del Ojo/patología , Longitud Axial del Ojo/patología
3.
Hum Vaccin Immunother ; 19(2): 2254239, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37799074

RESUMEN

The infiltration of immune cells can significantly affect the prognosis and immune therapy of patients with cervical squamous cell carcinoma (CSCC). This study aimed to explore key immune cell-related genes in the tumorigenesis and prognosis of CSCC. The module significantly related to immunity was screened by weighted gene co-expression network analysis (WGCNA) and ESTIMATE analysis, followed by correlation analysis with clinical traits. Key candidate genes were intersected with the protein-protein interaction (PPI) network genes for immune-related genes. The relationship between immune cell infiltration and key genes was analyzed. Tumor immune dysfunction and exclusion (TIDE) and immunophenoscore (IPS) predicted the response to immunotherapy in CSCC patients. Clinically, quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry were manipulated for analyzing the changes in mRNA and protein expression of key genes in cancer. Western blot was conducted to assess the correlation between key genes and immune infiltration. The brown module was notably associated with the immune microenvironment of CSCC, from which three immune-related key genes (TYROBP, CCL5, and HLA-DRA) were obtained. High expression of these genes was significantly positively associated with the infiltration abundance of T cells, B cells, and other immune cells. High expression levels of three key genes were confirmed in para-cancer tissue and correlated with the abundance of immune cells. The high-expression group of key genes was more sensitive to immunotherapy. We provide a theoretical basis for searching for potential targets for effective treatment and diagnosis of CSCC and provide new ideas for developing novel immunotherapy strategies.


Asunto(s)
Carcinoma de Células Escamosas , Neoplasias del Cuello Uterino , Humanos , Femenino , Carcinoma de Células Escamosas/genética , Neoplasias del Cuello Uterino/genética , Carcinogénesis/genética , Pronóstico , Linfocitos B , Microambiente Tumoral/genética
4.
Heliyon ; 9(8): e19151, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37664753

RESUMEN

Traditional Chinese medicine (TCM) is characterized by multi-components, multiple targets, and complex mechanisms of action and therefore has significant advantages in treating diseases. However, the clinical application of TCM prescriptions is limited due to the difficulty in elucidating the effective substances and the lack of current scientific evidence on the mechanisms of action. In recent years, the development of network pharmacology based on drug systems research has provided a new approach for understanding the complex systems represented by TCM. The determination of drug targets is the core of TCM network pharmacology research. Over the past years, many web tools for drug targets with various features have been developed to facilitate target prediction, significantly promoting drug discovery. Therefore, this review introduces the widely used web tools for compound-target interaction prediction databases and web resources in TCM pharmacology research, and it compares and analyzes each web tool based on their basic properties, including the underlying theory, algorithms, datasets, and search results. Finally, we present the remaining challenges for the promising future of compound-target interaction prediction in TCM pharmacology research. This work may guide researchers in choosing web tools for target prediction and may also help develop more TCM tools based on these existing resources.

5.
Medicine (Baltimore) ; 102(29): e34210, 2023 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-37478270

RESUMEN

To investigate the potential effect of repeated intravitreal injection of anti-vascular endothelial growth factor (anti-VEGF) drugs on corneal nerves. A total of 64 patients were treated with intravitreal injection of anti-VEGF drugs. There were 19 cases of neovascular age-related macular degeneration (AMD), 20 cases of diabetic macular edema (DME) and 25 cases of retinal vein occlusion (RVO). Twenty-nine cases were treated with aflibercept (2 mg/0.05 mL) whereas 35 cases were managed with ranibizumab (0.5 mg/0.05 mL). A corneal confocal microscope was used to collect images of corneal subbasal nerve plexus, and Image J was used for image analysis. The changes in corneal nerve were compared between 1 month after each injection and before injection. There were no significant differences in the density and length of corneal nerve at specific time after the surgery in comparison with baseline in patients who were given 3 intravitreal injections. There was no significant correlation between the numbers of injections and the changes of the corneal nerves. After 3rd injection, the nerve length of the DME group was markedly lower than that of AMD and RVO groups, the difference was statistically significant (P < .05). The nerve density of the DME group was not significantly different from that of AMD and RVO groups, whereas the nerve length and nerve density of the AMD and RVO groups were not statistically significant between each other also. The corneal nerve length after the 2nd and 3rd injections of Aflibercept were lower than that before surgery, the difference was statistically significant. There were no significant differences in nerve density and nerve length at each time point after Ranibizumab injection. The length and density of the corneal nerve after multiple injections in contralateral eye displayed no significant changes compared with the baseline. Repeated intravitreal anti-VEGF drug can reduce the length of corneal nerves. For patients who need repeated intravitreal injections of anti-VEGF drugs, especially in DM, attention should be paid on the changes affecting the corneal nerves. It is also needed to strengthen the local anti-inflammatory therapy to avoid infection and to use artificial tears to protect the microenvironment of the ocular surface after the surgery.


Asunto(s)
Retinopatía Diabética , Edema Macular , Oclusión de la Vena Retiniana , Humanos , Ranibizumab/uso terapéutico , Inhibidores de la Angiogénesis/uso terapéutico , Retinopatía Diabética/tratamiento farmacológico , Edema Macular/tratamiento farmacológico , Factor A de Crecimiento Endotelial Vascular/uso terapéutico , Oclusión de la Vena Retiniana/tratamiento farmacológico , Oclusión de la Vena Retiniana/inducido químicamente , Receptores de Factores de Crecimiento Endotelial Vascular/uso terapéutico , Factores de Crecimiento Endotelial Vascular/uso terapéutico , Inyecciones Intravítreas , Proteínas Recombinantes de Fusión/uso terapéutico
6.
J Agric Food Chem ; 71(25): 9847-9855, 2023 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-37326390

RESUMEN

Odd chain fatty acids (OCFAs) are high-value-added compounds with great application in the field of food and medicine. As an oleaginous microorganism, Schizochytrium sp. has the potential to produce OCFAs efficiently. Propionyl-CoA is used as a precursor to synthesize OCFAs through the fatty acid synthetase (FAS) pathway, so its flow direction determines the yield of OCFAs. Here, different substrates were assessed to promote propionyl-CoA supply for OCFA accumulation. Moreover, the methylmalonyl-CoA mutase (MCM) was identified as the key gene responsible for propionyl-CoA consumption, which promotes the propionyl-CoA to enter into the tricarboxylic acid cycle rather than the FAS pathway. As one of the classic B12-dependent enzymes, the activity of MCM can be inhibited in the absence of B12. As expected, the OCFA accumulation was greatly increased. However, the removal of B12 caused growth limitation. Furthermore, the MCM was knocked out to block the consumption of propionyl-CoA and to maintain cell growth; results showed that the engineered strain achieved the OCFAs titer of 2.82 g/L, which is 5.76-fold that of wild type. Last, a fed-batch co-feeding strategy was developed, resulting in the highest reported OCFAs titer of 6.82 g/L. This study provides guidance for the microbial production of OCFAs.


Asunto(s)
Acilcoenzima A , Ácidos Grasos , Ácidos Grasos/metabolismo , Acilcoenzima A/metabolismo , Ciclo del Ácido Cítrico
7.
ACS Synth Biol ; 12(6): 1586-1598, 2023 06 16.
Artículo en Inglés | MEDLINE | ID: mdl-37224027

RESUMEN

Base editors (BE) based on CRISPR systems are practical gene-editing tools which continue to drive frontier advances of life sciences. BEs are able to efficiently induce point mutations at target sites without double-stranded DNA cleavage. Hence, they are widely employed in the fields of microbial genome engineering. As applications of BEs continue to expand, the demands for base-editing efficiency, fidelity, and versatility are also on the rise. In recent years, a series of optimization strategies for BEs have been developed. By engineering the core components of BEs or adopting different assembly methods, the performance of BEs has been well optimized. Moreover, series of newly established BEs have significantly expanded the base-editing toolsets. In this Review, we will summarize the current efforts for BE optimization, introduce several novel BEs with versatility, and look forward to the broadened applications for industrial microorganisms.


Asunto(s)
Sistemas CRISPR-Cas , Edición Génica , Sistemas CRISPR-Cas/genética , Edición Génica/métodos , Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas/genética
8.
ACS Synth Biol ; 12(5): 1396-1407, 2023 05 19.
Artículo en Inglés | MEDLINE | ID: mdl-37084707

RESUMEN

Due to the complexity of metabolic and regulatory networks in microorganisms, it is difficult to obtain robust phenotypes through artificial rational design and genetic perturbation. Adaptive laboratory evolution (ALE) engineering plays an important role in the construction of stable microbial cell factories by simulating the natural evolution process and rapidly obtaining strains with stable traits through screening. This review summarizes the application of ALE technology in microbial breeding, describes the commonly used methods for ALE, and highlights the important applications of ALE technology in the production of lipids and terpenoids in yeast and microalgae. Overall, ALE technology provides a powerful tool for the construction of microbial cell factories, and it has been widely used in improving the level of target product synthesis, expanding the range of substrate utilization, and enhancing the tolerance of chassis cells. In addition, in order to improve the production of target compounds, ALE also employs environmental or nutritional stress strategies corresponding to the characteristics of different terpenoids, lipids, and strains.


Asunto(s)
Microalgas , Terpenos , Terpenos/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Microalgas/genética , Lípidos/genética , Ingeniería Metabólica/métodos
9.
J Ethnopharmacol ; 308: 116273, 2023 May 23.
Artículo en Inglés | MEDLINE | ID: mdl-36822343

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: Vitex rotundifolia L. f. and Vitex trifolia L. belong to the genus Vitex, and Vitex rotundifolia L. f. evolved from Vitex trifolia L. Both are essential ethnic medicinal plants with a long history, commonly used to treat headaches, fever, diarrhea, hair loss, wound recovery, and other diseases. AIM OF THE REVIEW: The research status of Vitex trifolia L. and its relative species Vitex rotundifolia L. f. were reviewed from the aspects of traditional medicinal use, phytochemistry, and pharmacological activities, to provide a reference for the further development and utilization of Vitex rotundifolia L. f. and Vitex trifolia L. MATERIALS AND METHODS: In this paper, a comprehensive search of published literature was conducted through various books and online databases to obtain relevant information on Vitex rotundifolia L. f. and Vitex trifolia L. The search terms "(Vitex rotundifolia) OR (Vitex trifolia) OR (Fructus viticis)" were entered in PubMed, Web of Science, China national knowledge infrastructure (CNKI), Wanfang Data, Baidu Scholar, respectively. In addition to setting the year threshold of "2018-2022" on Baidu Scholar, other databases searched all fields and found 889, 283, 1263, 1023, and 147 articles, respectively. Among them, review, repetition, overlapping data, and other reasons were excluded, and finally, a total of 164 articles were included in the review study. RESULTS: A total of 369 compounds have been identified, including 159 terpenoids, 51 flavonoids, 83 phenylpropanoids, and 76 other compounds. Pharmacological studies have shown that Vitex rotundifolia L. f. and Vitex trifolia L. have a variety of pharmacological activities, such as anti-tumor, analgesic, antipyretic, anti-inflammatory, antioxidant, antibacterial, and estrogen-like activity. Modern clinical use for treating cold headaches, diarrhea dysentery, irregular menstruation, and other diseases. CONCLUSIONS: As traditional medicinal plants, Vitex rotundifolia L. f. and Vitex trifolia L. have wealthy chemical constituents and extensive pharmacological activities and are widely used in clinical practice from traditional to modern times. However, the research on the pharmacological activities of Vitex rotundifolia L. f. and Vitex trifolia L. is not in-depth, and the potential active components still need to be explored.


Asunto(s)
Plantas Medicinales , Vitex , Vitex/química , Medicina Tradicional , Antiinflamatorios/farmacología , China , Fitoquímicos , Etnofarmacología , Extractos Vegetales/farmacología
10.
Biotechnol J ; 18(4): e2200510, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36689702

RESUMEN

Auxotrophic marker genes have been widely used for genetic engineering in yeast. However, the effects of amino acids or nucleotides deficiency in auxotrophic strains on cell growth and product synthesis were rarely reported. In this study, a total of eight auxotrophic strains of Saccharomyces cerevisiae with single knockout of selection markers were obtained. Cell growth and free fatty acid (FFA) production of these auxotrophic strains were evaluated with supplementation of different concentrations of amino acids or nucleotides. Generally, except ade2Δ mutants, most auxotrophic strains showed decreased cell growth and FFA production, which could be recovered by adding higher concentrations of supplements. LEU2 deletion (leu2Δ) damaged both cell growth and FFA production even with supplementation of 1000 mg L-1 leucine. This study shows that growth and product biosynthesis of auxotrophs could be limited by insufficient supplementation of amino acids or nucleotides, and provides guidance on supplementation of these nutrients during fermentation to maximize cell growth and product biosynthesis.


Asunto(s)
Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Saccharomyces cerevisiae/metabolismo , Ácidos Grasos/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Fermentación , Aminoácidos/metabolismo
11.
Trends Biotechnol ; 41(7): 857-859, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-36709095

RESUMEN

Polyunsaturated fatty acids (PUFAs) are important nutrients for humans and animals. Microorganisms, such as yeast, filamentous fungi, and microalgae, have successfully been modified to produce PUFAs. Apart from strain improvement and fermentation optimization, efficient and cost-effective downstream processing will determine whether production can advance from the laboratory to the factory.


Asunto(s)
Ácidos Grasos Insaturados , Microalgas , Animales , Humanos , Hongos/genética , Fermentación , Saccharomyces cerevisiae , Ácidos Grasos
12.
Microb Cell Fact ; 21(1): 191, 2022 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-36109777

RESUMEN

Escherichia coli, one of the most efficient expression hosts for recombinant proteins (RPs), is widely used in chemical, medical, food and other industries. However, conventional expression strains are unable to effectively express proteins with complex structures or toxicity. The key to solving this problem is to alleviate the host burden associated with protein overproduction and to enhance the ability to accurately fold and modify RPs at high expression levels. Here, we summarize the recently developed optimization strategies for the high-level production of RPs from the two aspects of host burden and protein activity. The aim is to maximize the ability of researchers to quickly select an appropriate optimization strategy for improving the production of RPs.


Asunto(s)
Escherichia coli , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas Recombinantes
13.
Comput Intell Neurosci ; 2022: 1265837, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35720892

RESUMEN

As a new type of electronic currency, bitcoin is more and more recognized and sought after by people, but its price fluctuation is more intense, the market has certain risks, and the price is difficult to be accurately predicted. The main purpose of this study is to use a deep learning integration method (SDAE-B) to predict the price of bitcoin. This method combines two technologies: one is an advanced deep neural network model, which is called stacking denoising autoencoders (SDAE). The SDAE method is used to simulate the nonlinear complex relationship between the bitcoin price and its influencing factors. The other is a powerful integration method called bootstrap aggregation (Bagging), which generates multiple datasets for training a set of basic models (SDAES). In the empirical study, this study compares the price sequence of bitcoin and selects the block size, hash rate, mining difficulty, number of transactions, market capitalization, Baidu and Google search volume, gold price, dollar index, and relevant major events as exogenous variables uses SDAE-B method to compare the price of bitcoin for prediction and uses the traditional machine learning method LSSVM and BP to compare the price of bitcoin for prediction. The prediction results are as follows: the MAPE of the SDAE-B prediction price is 0.016, the RMSE is 131.643, and the DA is 0.817. Compared with the other two methods, it has higher accuracy and lower error, and can well track the randomness and nonlinear characteristics of bitcoin price.


Asunto(s)
Aprendizaje Profundo , Humanos , Aprendizaje Automático , Redes Neurales de la Computación
14.
Appl Microbiol Biotechnol ; 106(9-10): 3449-3464, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35538374

RESUMEN

Methylotrophic yeasts have been widely recognized as a promising host for production of recombinant proteins and value-added chemicals. Promoters for controlled gene expression are critical for construction of efficient methylotrophic yeasts cell factories. Here, we summarized recent advances in characterizing and engineering promoters in methylotrophic yeasts, such as Komagataella phaffii and Ogataea polymorpha. Constitutive and inducible promoters controlled by methanol or other inducers/repressors were introduced to demonstrate their applications in production of proteins and chemicals. Furthermore, efforts of promoter engineering, including site-directed mutagenesis, hybrid promoter, and transcription factor regulation to expand the promoter toolbox were also summarized. This mini-review also provides useful information on promoters for the application of metabolic engineering in methylotrophic yeasts. KEY POINTS: • The characteristics of six methylotrophic yeasts and their promoters are described. • The applications of Komagataella phaffii and Ogataea polymorpha in metabolic engineeringare expounded. • Three promoter engineering strategies are introduced in order to expand the promoter toolbox.


Asunto(s)
Ingeniería Metabólica , Saccharomycetales , Pichia/genética , Pichia/metabolismo , Saccharomycetales/genética , Levaduras/genética
15.
Synth Syst Biotechnol ; 7(1): 498-505, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-34977394

RESUMEN

Bio-manufacturing via microbial cell factory requires large promoter library for fine-tuned metabolic engineering. Ogataea polymorpha, one of the methylotrophic yeasts, possesses advantages in broad substrate spectrum, thermal-tolerance, and capacity to achieve high-density fermentation. However, a limited number of available promoters hinders the engineering of O. polymorpha for bio-productions. Here, we systematically characterized native promoters in O. polymorpha by both GFP fluorescence and fatty alcohol biosynthesis. Ten constitutive promoters (P PDH , P PYK , P FBA , P PGM , P GLK , P TRI , P GPI , P ADH1 , P TEF1 and P GCW14 ) were obtained with the activity range of 13%-130% of the common promoter P GAP (the promoter of glyceraldehyde-3-phosphate dehydrogenase), among which P PDH and P GCW14 were further verified by biosynthesis of fatty alcohol. Furthermore, the inducible promoters, including ethanol-induced P ICL1 , rhamnose-induced P LRA3 and P LRA4 , and a bidirectional promoter (P Mal -P Per ) that is strongly induced by sucrose, further expanded the promoter toolbox in O. polymorpha. Finally, a series of hybrid promoters were constructed via engineering upstream activation sequence (UAS), which increased the activity of native promoter P LRA3 by 4.7-10.4 times without obvious leakage expression. Therefore, this study provided a group of constitutive, inducible, and hybrid promoters for metabolic engineering of O. polymorpha, and also a feasible strategy for rationally regulating the promoter strength.

16.
Front Microbiol ; 12: 763498, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34880839

RESUMEN

Traditional Chinese medicines (TCMs), as a unique natural medicine resource, were used to prevent and treat bacterial diseases in China with a long history. To provide a prediction model of screening antibacterial TCMs for the design and discovery of novel antibacterial agents, the literature about antibacterial TCMs in the China National Knowledge Infrastructure (CNKI) and Web of Science database was retrieved. The data were extracted and standardized. A total of 28,786 pieces of data from 904 antibacterial TCMs were collected. The data of plant medicine were the most numerous. The result of association rules mining showed a high correlation between antibacterial activity with cold nature, bitter and sour tastes, hemostatic, and purging fire efficacies. Moreover, TCMs with antibacterial activity showed a specific aggregation in the phylogenetic tree; 92% of them came from Tracheophyta, of which 74% were mainly concentrated in rosids, asterids, Liliopsida, and Ranunculales. The prediction models of anti-Escherichia coli and anti-Staphylococcus aureus activity, with AUC values (the area under the ROC curve) of 77.5 and 80.0%, respectively, were constructed by the Neural Networks (NN) algorithm after Bagged Classification and Regression Tree (Bagged CART) and Linear Discriminant Analysis (LDA) selection. The in vitro experimental results showed the prediction accuracy of these two models was 75 and 60%, respectively. Four TCMs (Cirsii Japonici Herba Carbonisata, Changii Radix, Swertiae Herba, Callicarpae Formosanae Folium) were proposed for the first time to show antibacterial activity against E. coli and/or S. aureus. The results implied that the prediction model of antibacterial activity of TCMs based on properties and families showed certain prediction ability, which was of great significance to the screening of antibacterial TCMs and can be used to discover novel antibacterial agents.

17.
Sci Total Environ ; 788: 147825, 2021 Sep 20.
Artículo en Inglés | MEDLINE | ID: mdl-34034172

RESUMEN

This study investigated a new way to improve the performance of simultaneous nitrification denitrification and phosphorus removal (SNDPR) system by regularly changing the anaerobic/micro-aerobic/anoxic mode to the anaerobic/anoxic mode with 30 mg/L of nitrite dosing. The results indicated that the removal efficiency of total inorganic nitrogen and PO43--P was improved from 75.44% and 85.14% to 98.89% and 98.17%, respectively. And the good performance of the SNDPR showed a long-time sustainability when the C/N ratio was 5. The results of microbial community illustrated that the abundance of the main nitrite-oxidizing bacteria (NOB), Nitrospira sp., dropped from 5.71% to 0.85% and the abundance of denitrifying polyphosphate-accumulating organisms (DPAOs), Pseudomonas sp. and Acinetobacter sp., increased by 5 times after nitrite stress. The high level of nitric oxide (NO) and free nitrite acid produced by addition of nitrite strongly suppressed the undesired organisms NOB and ordinary heterotrophic denitrifying organisms, and promoted the enrichment of DPAOs. The NO accumulated in the nitrite denitrification process could inhibit NOB and promote AOB. This study revealed that NO plays an important role in regulating the microbial community in the SNDPR system.


Asunto(s)
Nitrificación , Fósforo , Reactores Biológicos , Desnitrificación , Nitritos , Nitrógeno , Aguas del Alcantarillado , Eliminación de Residuos Líquidos
18.
RSC Adv ; 11(56): 35245-35257, 2021 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-35493143

RESUMEN

Traditional air filter papers can only filter toxic aerosols without the function of decontamination. If the poison stagnating in the paper is desorbed, it may pose a secondary threat to personnel and make it more difficult to dispose of the scrapped paper. Using an alkali-free glass fiber as the base material and zirconium hydroxide as the decontaminant, a self-decontaminating air filter paper that can degrade HD and VX simultaneously was successfully prepared by an intra-pulp addition method, with high filtration efficiency, low pressure drop and moderate tensile strength. The physicochemical properties were characterized by FE-SEM, EDX, XRD and TGA, and the results indicated that Zr(OH)4 was dispersed uniformly in the paper and filled in the interstices of the glass fiber. The preparation of the composite material had no impact on the structure of fibers and Zr(OH)4. The preparation technology of the self-decontaminating air filter paper was optimized. It was found that the paper with a fiber grammage of 50 g m-2, the adhesive of 2% and a Zr(OH)4 retention rate of 175.0 wt% could completely degrade HD and VX, whose conversion rate exceeded 99.0%, and had a tensile strength of 0.1193 kN m-1, a filtration efficiency of 99.995%, and a pressure drop of 313.6 Pa. Using GC-MS to detect the decontamination products, it was speculated that HD mainly underwent hydrolysis and elimination reactions, VX mainly underwent hydrolysis and polymerization reactions, and their products were non-toxic or low-toxic. The reaction kinetics of HD and VX on the paper was investigated and the half-lives were 2.6 h and 16.2 min, respectively, which demonstrated an outstanding degradation performance. This work manifested for the first time that the air filter paper can be optimized as an efficient self-decontaminating material, which will open up new possibilities for the design and manufacture of multifunctional protective materials.

19.
Ann Transl Med ; 8(20): 1294, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-33209874

RESUMEN

BACKGROUND: Aberrant expression of up-regulated long non-coding RNA [LncRNA highly upregulated in liver cancer (HULC)] has been observed to play an important regulatory role in the development of multiple human diseases. However, the molecular mechanism underlying the role of HULC and miR-377-5p in HCC needs to be urgently explored. METHODS: The mRNA and protein expression levels of HULC were detected by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot in hepatocellular carcinoma (HCC) cell line HB611, HepG2 and H22, respectively. HULC-shRNA was transfected into HepG-2 cells, which were randomly divided into the control, shRNA-NC, and sh-HULC groups. The correlation between HULC and miR-377-5p was analyzed by performing a luciferase reporter assay. The targeting relationship between miR-377-5p and hypoxia-inhibitory factor-1α (HIF-1α) was also investigated using a luciferase reporter assay. Sh-HULC and miR-377-5p inhibitors were transfected either alone or together into HepG2 cells, and which were divided into the control group, the sh-HULC group, the miR-377-5p inhibitor, and the sh-HULC + inhibitor group for subsequent experiments. HepG2 cell proliferation and invasion were measured by 5-Ethynyl-2-Deoxyuridine (EdU) staining and Transwell invasion assay, respectively. Western plot was carried out to detect the protein expression levels of Ki67, PCNA, E-cadherin, and N-cadherin. Tumor xenograft mouse models were established to confirm the effect of HULC down-regulation on the development of HCC in vivo. RESULTS: The mRNA and protein expression levels of HULC were markedly increased, whereas the mRNA expression levels of miR-377-5p were decreased in HCC cell lines. HepG2 cell proliferation and invasion were suppressed in the Sh-HULC group, while miR-377-5p showed the opposite. Further experiments exhibited that miR-377-5p was targeted by HULC, and an negative correlation between HULC and miR-377-5p was observed. Importantly, the in vivo experiments indicated that down-regulation of HULC could inhibit tumor growth. Taken together, our research demonstrated that down-regulation of HULC plays an anti-cancer role through restrainingHepG2 cell proliferation and invasion. CONCLUSIONS: In summary, our in vitro and in vivo findings confirmed HULC to play a role in the progression of HCC, with the underlying mechanism possibly involving the miR-377-5p/HIF-1α pathway.

20.
Anal Bioanal Chem ; 411(12): 2577-2585, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-30847569

RESUMEN

G-series nerve agents, such as sarin, tabun, and soman, would cause tremendous harm in military and terrorist attacks, so it is necessary to develop a simple method for the rapid and efficient detection of these hazardous substances. We have developed a tunable acetylcholinesterase (AChE)-functionalized two-dimensional photonic crystal (2D PhC) for the detection of a real nerve agent, sarin. In accordance with the 2D PhC previously prepared by our group, the AChE-functionalized 2D PhC was optimized by adjustment of the amount of monomer in the hydrogel, which not only increased the sensitivity of the 2D PhC, with the detection limit decreasing by two orders of magnitude, but also ensured the structural color spanned the whole visible region in the detection range. A linear relationship between the logarithm of the sarin concentration and the particle spacing of the AChE-functionalized 2D PhC was observed from 7.1 × 10-17 to 7.1 × 10-4 mol/L. The AChE-functionalized 2D PhC also responded to mimics of G-series nerve agents, including dimethyl methylphosphonate, diisopropyl methylphosphonate, and isodipropyl methylphosphonate, to various degrees. The proposed 2D-PhC hydrogel has potential for low-cost, trace-level, and on-site monitoring of other G-series nerve agents. Graphical abstract.


Asunto(s)
Acetilcolinesterasa/química , Agentes Nerviosos/análisis , Cristalización , Hidrogeles , Cinética , Límite de Detección , Microscopía Electrónica de Rastreo , Fotones
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