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1.
Environ Sci Technol ; 58(15): 6552-6563, 2024 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-38571383

RESUMEN

Extracellular polymeric substances (EPS) ubiquitously encapsulate microbes and play crucial roles in various environmental processes. However, understanding their complex interactions with dynamic bacterial behaviors, especially during the disinfection process, remains very limited. In this work, we investigated the impact of EPS on bacterial disinfection kinetics by developing a permanent EPS removal strategy. We genetically disrupted the synthesis of exopolysaccharides, the structural components of EPS, in Pseudomonas aeruginosa, a well-known EPS-producing opportunistic pathogen found in diverse environments, creating an EPS-deficient strain. This method ensured a lasting absence of EPS while maintaining bacterial integrity and viability, allowing for real-time in situ investigations of the roles of EPS in disinfection. Our findings indicate that removing EPS from bacteria substantially lowered their susceptibility threshold to disinfectants such as ozone, chloramine B, and free chlorine. This removal also substantially accelerated disinfection kinetics, shortened the resistance time, and increased disinfection efficiency, thereby enhancing the overall bactericidal effect. The absence of EPS was found to enhance bacterial motility and increase bacterial cell vulnerability to disinfectants, resulting in greater membrane damage and intensified reactive oxygen species (ROS) production upon exposure to disinfectants. These insights highlight the central role of EPS in bacterial defenses and offer promising implications for developing more effective disinfection strategies.


Asunto(s)
Desinfectantes , Desinfección , Desinfección/métodos , Matriz Extracelular de Sustancias Poliméricas , Desinfectantes/farmacología , Cloro/farmacología , Cinética
2.
J Am Chem Soc ; 2023 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-36661845

RESUMEN

The synthesis of structurally diverse amines is of fundamental significance in the pharmaceutical industry due to the ubiquitous presence of amine motifs in biologically active molecules. Biocatalytic reductive amination for amine production has attracted great interest owing to its synthetic advantages. Herein, we report the direct synthesis of a wide range of sterically demanding secondary amines, including several important active pharmaceutical ingredients and pharmaceutical intermediates, via reductive amination of carbonyl substrates and bulky amine nucleophiles employing imine reductases. Key to success for this route is the identification of an imine reductase from Penicillium camemberti with unusual substrate specificity and its further engineering, which empowered the accommodation of a broad range of sterically demanding amine nucleophiles encompassing linear alkyl and (hetero)aromatic (oxy)alkyl substituents and the formation of final amine products with up to >99% conversion. The practical utility of the biocatalytic route has been demonstrated by its application in the preparative synthesis of the anti-hyperparathyroidism drug cinacalcet.

3.
Clin Immunol ; 247: 109221, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36610524

RESUMEN

The current study was initiated to comprehensively evaluate renal NLRP3 inflammasome pathway activation in lupus nephritis (LN) patients and their clinicopathological significances based on a Chinese LN cohort. We found that the expressions of NLRP3, ASC, caspase-1, IL-1ß and IL-18 were all significantly higher in the kidneys of LN patients and were predominantly expressed in glomerular mesangial cells, podocytes, renal tubular epithelial cells and macrophages. The expressions of NLRP3, ASC, caspase-1 and IL-1ß were positively correlated to SLEDAI scores and several renal pathological activity indices, while the expression of NLRP3 was negatively associated with chronicity scores. Moreover, the foot process width was positively correlated with glomerular caspase-1 levels, and several podocyte injury markers were decreased significantly in LN patients with higher caspase-1 expression compared with those with lower expression. Our findings indicated that renal NLRP3 inflammasome was activated in LN patients and correlated with disease activity, which needs further explorations.


Asunto(s)
Nefritis Lúpica , Humanos , Nefritis Lúpica/patología , Inflamasomas/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Riñón/patología , Caspasa 1/metabolismo
4.
Eur J Neurol ; 30(3): 762-773, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36380711

RESUMEN

BACKGROUND AND PURPOSE: Non-ergot dopamine agonists (NEDAs) have been used as an adjunct therapy to levodopa in advanced Parkinson's disease (PD) for many years. However, there is no strong evidence that a given NEDA is more potent than another. To compare and rank the efficacy, tolerability, and safety of six commonly used NEDAs as an adjunct to levodopa in advanced PD, which includes long-acting and standard formulations, a network meta-analysis was performed. METHODS: The MEDLINE, Embase, Cochrane Central Register of Controlled Trials, China National Knowledge Infrastructure, and Wanfang databases were searched from January 1996 to June 2022 for eligible randomized controlled trials (RCTs). Six NEDAs, including rotigotine transdermal patch, ropinirole immediate-release (IR)/prolonged-release (PR), pramipexole IR/extended-release (ER), and piribedil, were investigated. RESULTS: A total of 34 RCTs (7868 patients) were included in the current study. The surface under the cumulative ranking curve indicated that ropinirole PR was associated with the best improvement in Unified Parkinson's Disease Rating Scale (UPDRS)-II, UPDRS-III, and UPDRS-II + III (0.811, 0.742, and 0.827). For OFF time reduction, pramipexole IR ranked first (0.979), and ropinirole PR ranked first in OFF time responder rate (0.927). Pramipexole ER ranked first in overall withdrawals, and rotigotine transdermal patch ranked first in the incidence of adverse events (≥1 AEs). CONCLUSIONS: This network meta-analysis suggests six commonly used NEDAs are effective as an adjunct to levodopa in advanced PD. In comprehensive consideration of better symptomatic management, ropinirole PR may be a better choice than other NEDAs in advanced PD. Six NEDAs showed different profiles of AEs.


Asunto(s)
Agonistas de Dopamina , Enfermedad de Parkinson , Humanos , Agonistas de Dopamina/efectos adversos , Levodopa/efectos adversos , Pramipexol , Enfermedad de Parkinson/tratamiento farmacológico , Dopamina , Metaanálisis en Red , Antiparkinsonianos/efectos adversos
5.
BMC Neurol ; 23(1): 422, 2023 Nov 27.
Artículo en Inglés | MEDLINE | ID: mdl-38012577

RESUMEN

BACKGROUND: Repeated intravenous thrombolysis (RIVT) within 3 months is an off-guideline therapy, however, may be an effective and safe way to treat early recurrent ischemic stroke. This study was conducted to assess the potential influencing factors on the efficacy and safety of RIVT in recurrent ischemic stroke within 3 months and to explore the strategy of RIVT within 3 months. METHODS: PubMed, Cochrane Library, Embase, China National Knowledge Infrastructure, and Wanfang Database were searched for cases of RIVT in recurrent ischemic stroke within 3 months up to February 1, 2023. Clinical characteristics were compared and analyzed between the good-outcome and poor-outcome groups and between the symptomatic intracranial hemorrhage (sICH) and non-sICH groups respectively. RESULTS: A total of 16 studies including 24 cases of RIVT within 3 months were retrospectively analyzed in the present study. The patients' ages ranged from 42 to 87 years (median 73.5 years) and the intervals between thrombolysis were from 0.25 to 90 days (median 9.5 days). Comparing the clinical characteristics between the good-outcome group and the poor-outcome group, no statistically significant differences were found (P > 0.05), but the differences in baseline National Institutes of Health stroke scale (NIHSS) score of the recurrent stroke (P = 0.056) and good outcome after the previous IVT (P = 0.054) nearly reached statistical significance. Comparing the data between the non-sICH group and the sICH group, statistically significant differences were found in terms of the proportion of cardiogenic embolism (P = 0.036), baseline NIHSS score in the recurrent stroke (P = 0.007) and the interval between thrombolysis (P = 0.041), but no significant difference was found by regression analysis. CONCLUSION: In patients with recurrent ischemic stroke within 3 months, those with a good outcome after the previous IVT and a low baseline NIHSS score in the recurrent stroke may be considered for RIVT, whereas those with a high baseline NIHSS score, a short interval between thrombolysis, and cardiogenic embolism may suffer a higher risk of sICH. Due to sample size and publication bias, more studies with larger sample sizes and more rigorous designs are needed to confirm this conclusion.


Asunto(s)
Isquemia Encefálica , Embolia , Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , Humanos , Lactante , Fibrinolíticos/uso terapéutico , Activador de Tejido Plasminógeno/uso terapéutico , Accidente Cerebrovascular/tratamiento farmacológico , Terapia Trombolítica , Isquemia Encefálica/tratamiento farmacológico , Estudios Retrospectivos , Accidente Cerebrovascular Isquémico/tratamiento farmacológico , Hemorragias Intracraneales , Infarto Cerebral , Resultado del Tratamiento
6.
Ren Fail ; 45(1): 2161396, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36648027

RESUMEN

OBJECTIVES: This study was initiated to establish a renal thrombotic microangiopathy (TMA) scoring system based on clinical needs and investigate its predictive value for patients' long-term outcomes. METHODS: Kidney biopsy-proven Complement-mediated TMA (C-TMA) patients from January 2000 to December 2017 in Peking University First Hospital were retrospectively studied. Both acute and chronic TMA-related lesions, including 15 pathologic indices, were semiquantitatively scored. The interobserver and intraobserver reproducibility and correlation between the pathologic indices and clinical parameters were analyzed. Furthermore, the patients were divided into 2 groups by dialysis use at baseline, and the association of these pathologic indices with their prognostic outcomes was assessed between the two groups. RESULTS: Ninety-two patients with renal biopsy-proven C-TMA were enrolled. All fifteen included pathology indices showed good or moderate interobserver and intraobserver reproducibility and correlated well with several clinical parameters. Several clinicopathological indices were worse in the dialysis group than in the nondialysis group, such as serum creatinine, hemoglobin, platelet count, and estimated glomerular filtration rate. Moreover, morphologic features in the dialysis group presented with more severe vascular lesions. Interstitial fibrosis and chronic tubulointerstitial lesions were related to a trend of high risk of continuous dialysis in the dialysis group. Based on univariate and multivariable Cox regression analysis, more severe glomerular lesions, including glomerular mesangiolysis, glomerular basement membrane double contours and glomerular mesangial proliferation, were identified as risk factors predicting worse prognosis. CONCLUSIONS: Our renal C-TMA semiquantitative scoring system is reliable with good reproducibility and prognostic value in clinical practice, which needs further validation.


Asunto(s)
Enfermedades Renales , Microangiopatías Trombóticas , Humanos , Estudios Retrospectivos , Reproducibilidad de los Resultados , Microangiopatías Trombóticas/complicaciones , Microangiopatías Trombóticas/patología , Pronóstico , Diálisis Renal/efectos adversos , Enfermedades Renales/complicaciones
7.
Zhongguo Zhong Yao Za Zhi ; 47(16): 4358-4364, 2022 Aug.
Artículo en Zh | MEDLINE | ID: mdl-36046862

RESUMEN

Epimedii Folium possesses many pharmacological activities including immunomodulation, anti-oxidation, and anti-tumor. Polysaccharides are the main components of Epimedii Folium, and their activities are closely related to the structure. The present study isolated a neutral polysaccharide(EPS-1-1) and an acidic polysaccharide(EPS-2-1) from the aqueous extract of Epimedii Folium through DEAE-52 cellulose anion-exchange chromatography and Sephadex G-100. The structures were characterized by chemical composition analysis, high-performance gel permeation chromatography(HPGPC), Fourier-transform infrared spectrometry(FT-IR), 1-phenyl-3-methyl-5-pyrazolone(PMP) derivatization, scanning electron microscopy(SEM), Congo red test, etc. The immunomodulatory activity of polysaccharides in vitro was determined by investigating the effects on the maturation of bone marrow-derived dendritic cells(BMDCs) and the release of inflammatory cytokines. According to the structural characterization analysis, EPS-1-1 was composed of fructose(Fuc), mannose(Man), ribose(Rib), rhamnose(Rha), glucose(Glc), galactose(Gal), xylose(Xyl), and arabinose(Ara) at 1.90∶0.67∶0.05∶0.08∶3.29∶1.51∶0.05∶0.37(molar ratio), while EPS-2-1 was mainly composed of Fuc, Man, Rha, glucuronic acid(GlcA), galacturonic acid(GalA), Glc, Gal, Xyl, and Ara at 5.25∶0.18∶0.32∶0.13∶1.14∶0.16∶0.55∶0.08∶0.2. EPS-1-1 and EPS-2-1 could promote the maturation and function of BMDCs through up-regulating the expression of MHC-Ⅱ, CD86, CD80, and CD40, and increasing the levels of inflammatory cytokines(IL-6, IL-12, and TNF-α) in vitro experiments, which suggested that EPS-1-1 and EPS-2-1 possessed good immunomodulatory activity.


Asunto(s)
Citocinas , Polisacáridos , Citocinas/metabolismo , Medicamentos Herbarios Chinos , Cromatografía de Gases y Espectrometría de Masas , Humanos , Inmunomodulación , Polisacáridos/química , Espectroscopía Infrarroja por Transformada de Fourier
8.
Chemistry ; 27(11): 3786-3792, 2021 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-33200430

RESUMEN

Photocatalytic syngas (CO and H2 ) production with CO2 as gas source not only ameliorates greenhouse effect, but also produces valuable chemical feedstocks. However, traditional photocatalytic systems require noble metal or suffers from low yield. Here, we demonstrate that S vacancies ZnIn2 S4 (VS -ZnIn2 S4 ) nanosheets are an ideal photocatalyst to drive CO2 reduction into syngas. It is found that building S vacancies can endow ZnIn2 S4 with stronger photoabsorption, efficient electron-hole separation, and larger CO2 adsorption, finally promoting both hydrogen evolution reaction (HER) and CO2 reduction reaction (CO2 RR). The syngas yield of CO and H2 is therefore significantly increased. In contrast to pristine ZnIn2 S4 , the syngas yield over VS -ZnIn2 S4 can be improved by roughly ≈4.73 times and the CO/H2 ratio is modified from 1:4.18 to 1:1. Total amount of syngas after 12 h photocatalysis is as high as 63.20 mmol g-1 without use of any noble metals, which is even higher than those of traditional noble metal-based catalysts in the reported literatures. This work demonstrates the critical role of S vacancies in mediating catalytic activity and selectivity, and highlights the attractive ability of defective ZnIn2 S4 for light-driven syngas production.

9.
J Nutr ; 151(7): 1791-1801, 2021 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-33982120

RESUMEN

BACKGROUND: Selenium (Se) status is closely related to skeletal muscle physiological status. However, its influence on skeletal muscle growth has not been well studied. OBJECTIVES: This study aimed to analyze the impacts of overall Se status (deficient, adequate, and high) on skeletal muscle growth using a growing zebrafish model. METHODS: Zebrafish (1.5-mo-old) were fed graded levels of Se (deficient: 0.10 mg Se/kg; marginally deficient: 0.22 mg Se/kg; adequate: 0.34 mg Se/kg; high: 0.44, 0.57, and 0.69 mg Se/kg) as Se-enriched yeast for 30 d. Zebrafish growth, and Se accumulation, selenoenzyme activity, selenotranscriptome profiles, and oxidative status in the whole body, and selenotranscriptome profiles, histological characteristics, biochemicals, and gene and protein expression profiles related to muscle growth in the skeletal muscle were analyzed by model fitting and/or 1-factor ANOVA. RESULTS: Se status biomarkers within the whole body and skeletal muscle indicated that 0.34 mg Se/kg was adequate for growing zebrafish. For biomarkers related to skeletal muscle growth, compared with 0.34 mg Se/kg, 0.10 mg Se/kg decreased the white muscle cross-sectional area (WMCSA) and the mean diameter of white muscle fibers (MDWMF) by 14.4%-15.1%, inhibited protein kinase B-target of rapamycin complex 1 signaling by 63.7%-68.5%, and stimulated the autophagy-lysosome pathway by 1.07 times and the ubiquitin-proteasome pathway (UPP) by 96.0% (P < 0.05), whereas 0.22 mg Se/kg only decreased the WMCSA by 7.8% (P < 0.05); furthermore, 0.44 mg Se/kg had no clear effects on skeletal muscle biomarkers, whereas 0.57-0.69 mg Se/kg decreased the WMCSA and MDWMF by 6.3%-25.9% and 5.1%-21.3%, respectively, and stimulated the UPP by 2.23 times (P < 0.05). CONCLUSIONS: A level of 0.34 mg Se/kg is adequate for the growth of zebrafish skeletal muscle, whereas ≤0.10 and ≥0.57 mg Se/kg are too low or too high, respectively, for maintaining efficient protein accretion and normal hypertrophic growth.


Asunto(s)
Selenio , Animales , Antioxidantes/metabolismo , Músculo Esquelético/metabolismo , Proteolisis , Selenio/metabolismo , Pez Cebra/metabolismo
10.
Inorg Chem ; 60(14): 10738-10748, 2021 Jul 19.
Artículo en Inglés | MEDLINE | ID: mdl-34212711

RESUMEN

The metal/carbon composites prepared by direct pyrolysis of metal-organic frameworks (MOFs) are regarded as ideal catalysts. However, conventional MOFs show a three-dimensional bulk structure. For bulk MOF-derived catalysts, most active metal sites are confined in the interior and not fully utilized. In this work, metal-organic monolayers (MOLs) are used as the starting precursors to prepare carbon-wrapped metal nanoparticles, which are further employed as catalysts for photocatalytic CO2 reduction. The as-prepared Ni-MOLs and Co-MOLs have an ultrathin thickness of ∼1 nm. It is interestingly found that their derived Ni@C and Co@C nanoparticles are highly dispersive and connected with each other like a piece of paper. As compared with bulk MOF-derived counterparts, MOL-derived catalysts increase the accessibility of active metal sites, which can accelerate electron transfer from photosensitizers to Ni@C and Co@C nanoparticles. In this way, the catalytic activity can be greatly improved. Besides, the magnetic nature of Ni@C and Co@C nanoparticles enables the easy separation and recycling of catalysts. It is expected that this work will provide instructive guidelines for the rational design of MOL-derived catalysts.

11.
Zhongguo Zhong Yao Za Zhi ; 46(22): 5825-5831, 2021 Nov.
Artículo en Zh | MEDLINE | ID: mdl-34951171

RESUMEN

This study evaluated the effects of epimedium polysaccharide(EPS) on the solubility of icariin and baohuoside Ⅰ so as to preliminary explore its solubilization function and the underlying mechanism. The solubility of these two insoluble flavonoids in water and polysaccharide solutions was compared by high performance liquid chromatography, and the mechanism was investigated by diffe-rential scanning calorimetry(DSC) and critical micelle concentration determination. The results indicated that their solubilization in crude EPS solutions was concentration-dependent. The solubility of icariin and baohuoside Ⅰ in 20 mg·mL~(-1) EPS-1-1 was 9.05 times and 5.76 times that in water, respectively; while their solubility in 20 mg·mL~(-1) EPS-2-1 was 10.55 and 8.39 times that in water, respectively. The change of the DSC thermograms suggested the formation of new complexes from icariin and baohuoside Ⅰ with polysaccharides. The critical micelle concentrations proved the micellar properties of both EPS-1-1 and EPS-2-1. In short, EPS can significantly increase the solubility of icariin and baohuoside Ⅰ, the mechanism of which may be related to the formation of micellar complexes between EPS and insoluble flavonoids.


Asunto(s)
Epimedium , Flavonoides , Polisacáridos , Solubilidad
12.
Chemistry ; 25(46): 10918-10925, 2019 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-31211454

RESUMEN

Security inks based on photoluminescent materials are mostly investigated for security applications, such as information encryption and decryption, anti-counterfeiting, and data storage. Although they are invisible to the naked eye under ambient light, they can be detected under ultraviolet or near-infrared light. Herein, a new kind of secret paper made from network-structured ultralong hydroxyapatite nanowires and cellulose fibers has been developed. White vinegar, a common cooking ingredient, is used as an invisible security ink. Covert information on the secret paper written with white vinegar is totally invisible under natural light, but it can be decrypted and clearly read after exposure to fire; the response time to fire is short (<10 s). The ways of writing on the secret paper are diverse by using various pens loaded with white vinegar.

13.
J Org Chem ; 84(22): 14987-14993, 2019 11 15.
Artículo en Inglés | MEDLINE | ID: mdl-31644289

RESUMEN

(R)-Amination mediated by (R)-specific ω-transaminases generally requires costly d-alanine in excess to obtain the desired chiral amines in high yield. Herein, a one-pot, trienzymatic cascade comprising an (R)-specific ω-transaminase, an amine dehydrogenase, and a formate dehydrogenase was developed for the economical and eco-friendly synthesis of (R)-chiral amines. Using inexpensive ammonium formate as the sole sacrificial agent, the established cascade system enabled efficient ω-transaminase-mediated (R)-amination of various ketones, with high conversions and excellent ee (>99%); water and CO2 were the only waste products.

14.
Ren Fail ; 41(1): 1045-1053, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31809666

RESUMEN

A 43-year-old Chinese man with a silicosis history was admitted to our hospital due to bilateral lower extremity edema for 1 year, exacerbating with hematuria for 2 months. He started working as a coal miner 30 years ago, and was diagnosed as silicosis 3 months ago. Lab tests revealed hematuria 3+, proteinuria 3+, and a serum creatinine value 2.47 mg/dl on routine check. He was diagnosed with focal proliferative IgA nephropathy (IgAN) and acute tubulo-interstitial nephritis by renal biopsy. He was treated with corticosteroids and got a remission 4 months later. Immunohistochemical staining showed the deposition of macrophage receptor with collagenous structure (MARCO), nod-like receptor pyrin domain-containing-3 (NLRP3), Caspase-1, apoptosis-associated speck (ASC), interleukin (IL)-1ß, and IL-18 in both glomerular and tubulo-interstitial areas. We proposed that the silicon exposure could be related to his kidney disease in the patient and NLRP3 mediated inflammation might be involved in its pathogenesis which needs further explorations.


Asunto(s)
Enfermedades Renales/etiología , Riñón/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Silicosis/complicaciones , Adulto , Humanos , Riñón/ultraestructura , Enfermedades Renales/metabolismo , Enfermedades Renales/patología , Masculino , Silicosis/metabolismo
15.
Small ; 14(50): e1803387, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-30370652

RESUMEN

Efficient utilization of abundant solar energy for clean water generation is considered a sustainable and environment friendly approach to mitigate the global water crisis. For this purpose, this study reports a flexible fire-resistant photothermal paper by combining carbon nanotubes (CNTs) and fire-resistant inorganic paper based on ultralong hydroxyapatite nanowires (HNs) for efficient solar energy-driven water steam generation and water purification. Benefiting from the structural characteristics of the HN/CNT photothermal paper, the black CNT surface layer exhibits a high light absorbability and photothermal conversion capability, the HN-based inorganic paper acts as a thermal insulator with a high temperature stability, low thermal conductivity, and interconnected porous structure. By combining these advantages, high water evaporation efficiencies of 83.2% at 1 kW m-2 and 92.8% at 10 kW m-2 are achieved. In addition, the HN/CNT photothermal paper has a stable water evaporation capability during recycling and long-time usage. The promising potential of the HN/CNT photothermal paper for efficient production of drinkable water from both actual seawater and simulative wastewater samples containing heavy metal ions, dyes, and bacteria is also demonstrated. The highly flexible HN/CNT photothermal paper is promising for application in highly efficient solar energy-driven seawater desalination and wastewater purification.

16.
Small ; 14(51): e1804321, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-30417599

RESUMEN

In vivo mineralization is a multistep process involving mineral-protein complexes and various metastable compounds in vertebrates. In this complex process, the minerals produced in the mitochondrial matrix play a critical role in initiating extracellular mineralization. However, the functional mechanisms of the mitochondrial minerals are still a mystery. Herein, an in vitro enzymatic reaction strategy is reported for the generation of biomimic amorphous calcium phosphate (EACP) nanominerals by an alkaline phosphatase (ALP)-catalyzed hydrolysis of adenosine triphosphate (ATP) in a weakly alkalescent aqueous condition (pH 8.0-8.5), which is partially similar to the mitochondrial environment. Significantly, the EACP nanomineral obviously promotes autophagy and osteogenic differentiation of human bone marrow-derived mesenchymal stem cells by activating an AMPK related pathway, and displays a high performance in promoting bone regeneration. These results provide in vitro evidence for the effect of ATP on the formation and stabilization of the mineral in the mineralization process, demonstrating a potential strategy for the preparation of the biomimic mineral for treating bone related diseases.


Asunto(s)
Biomimética/métodos , Fosfatasa Alcalina/metabolismo , Autofagia/fisiología , Fosfatos de Calcio/química , Diferenciación Celular/fisiología , Humanos , Concentración de Iones de Hidrógeno , Células Madre Mesenquimatosas/citología , Células Madre Mesenquimatosas/metabolismo , Osteogénesis/fisiología
17.
Chembiochem ; 19(4): 347-353, 2018 02 16.
Artículo en Inglés | MEDLINE | ID: mdl-28926166

RESUMEN

Ursodeoxycholic acid (UDCA) is an effective drug for the treatment of hepatitis. In this study, 7α-hydroxysteroid dehydrogenase (7α-HSDH) and lactate dehydrogenase (LDH), as well as 7ß-hydroxysteroid dehydrogenase (7ß-HSDH) and glucose dehydrogenase (GDH), were co-immobilized onto an epoxy-functionalized resin (ES-103) to catalyze the synthesis of UDCA from chenodeoxycholic acid (CDCA). Through optimizing the immobilization pH, time, and loading ratio of enzymes to resin, the specific activities of immobilized LDH-7αHSDH@ES-103 and 7ßHSDH-GDH@ES-103 were 43.2 and 25.8 U g-1 , respectively, which were 12- and 516-fold higher than that under the initial immobilization conditions. Continuous production of UDCA from CDCA was subsequently achieved by using immobilized LDH-7αHSDH@ES-103 and 7ßHSDH-GDH@ES-103 in two serial packed-bed reactors. The yield of UDCA reached nearly 100 % and lasted for at least 12 h in the packed-bed reactors, which was superior to that of the batchwise reaction. This efficient continuous approach developed herein might provide a feasible route for large-scale biotransformation of CDCA into UDCA.


Asunto(s)
Reactores Biológicos , Enzimas Inmovilizadas/metabolismo , Glucosa 1-Deshidrogenasa/metabolismo , Hidroxiesteroide Deshidrogenasas/metabolismo , L-Lactato Deshidrogenasa/metabolismo , Ácido Ursodesoxicólico/biosíntesis , Biotransformación , Concentración de Iones de Hidrógeno , Factores de Tiempo , Ácido Ursodesoxicólico/química
18.
Metab Eng ; 47: 184-189, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-29477859

RESUMEN

Biocatalytic C-H amination is one of the most challenging tasks. C-H amination reaction can hardly be driven efficiently by solely one enzyme so far. Thus, enzymatic synergy represents an alternative strategy. Herein, we report an "Artificially Bioamination Pathway" for C-H amination of cyclohexane as a model substrate. Three enzymes, a monooxygenase P450BM3 mutant, an alcohol dehydrogenase ScCR from Streptomyces coelicolor and an amine dehydrogenase EsLeuDH from Exiguobacterium sibiricum, constituted a clean cascade reaction system with easy product isolation. Two independent cofactor regeneration systems were optimized to avoid interference from the endogenous NADH oxidases in the host E. coli cells. Based on a stepwise pH adjustment and ammonium supplement strategy, and using an in vitro mixture of cell-free extracts of the three enzymes, cyclohexylamine was produced in a titer of 14.9 mM, with a product content of up to 92.5%. Furthermore, designer cells coexpressing the three required enzymes were constructed and their capability of alkane bio-amination was examined. This artificially designed bioamination paves an attractive approach for enzymatic synthesis of amines from accessible and cheap alkanes.


Asunto(s)
Alcanos/metabolismo , Aminas Biogénicas/biosíntesis , Escherichia coli , Aminación , Bacillales/enzimología , Bacillales/genética , Proteínas Bacterianas/biosíntesis , Proteínas Bacterianas/genética , Sistema Enzimático del Citocromo P-450/biosíntesis , Sistema Enzimático del Citocromo P-450/genética , Escherichia coli/genética , Escherichia coli/metabolismo , Streptomyces coelicolor/enzimología , Streptomyces coelicolor/genética
19.
Chemistry ; 24(2): 416-424, 2018 Jan 09.
Artículo en Inglés | MEDLINE | ID: mdl-29072343

RESUMEN

To date, the scaled-up production and large-area applications of superhydrophobic coatings are limited because of complicated procedures, environmentally harmful fluorinated compounds, restrictive substrates, expensive equipment, and raw materials usually involved in the fabrication process. Herein, the facile, low-cost, and green production of superhydrophobic coatings based on hydroxyapatite nanowire bundles (HNBs) is reported. Hydrophobic HNBs are synthesised by using a one-step solvothermal method with oleic acid as the structure-directing and hydrophobic agent. During the reaction process, highly hydrophobic C-H groups of oleic acid molecules can be attached in situ to the surface of HNBs through the chelate interaction between Ca2+ ions and carboxylic groups. This facile synthetic method allows the scaled-up production of HNBs up to about 8 L, which is the largest production scale of superhydrophobic paint based on HNBs ever reported. In addition, the design of the 100 L reaction system is also shown. The HNBs can be coated on any substrate with an arbitrary shape by the spray-coating technique. The self-cleaning ability in air and oil, high-temperature stability, and excellent mechanical durability of the as-prepared superhydrophobic coatings are demonstrated. More importantly, the HNBs are coated on large-sized practical objects to form large-area superhydrophobic coatings.

20.
Chemistry ; 23(14): 3328-3337, 2017 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-27862430

RESUMEN

The templated synthesis of hydroxyapatite (HAP) nanowires@metal-organic framework (MOF) core/shell nanofibers (named HAP@MIL-100(Fe) nanofibers) is demonstrated. The ultralong hydroxyapatite nanowires are adopted as a hard template for the nucleation and growth of MIL-100(Fe) (a typical MOF) through the layer-by-layer method. The Coulombic and chelation interactions between Ca2+ ions on the surface of the HAP nanowires and the COO- organic linkers of MIL-100(Fe) play key roles in the formation process. The as-prepared, water-stable HAP@MIL-100(Fe) nanofibers exhibit peroxidase-like activity toward the oxidation of different peroxidase substrates in the presence of H2 O2 , accompanied by a clear color change of the solution. Furthermore, a flexible, recyclable HAP@MIL-100(Fe) test paper is prepared successfully by using HAP@MIL-100(Fe) nanofibers as building blocks. A simple, low-cost, and sensitive colorimetric method for the detection of H2 O2 and glucose is established based on the as-prepared, flexible, recyclable HAP@MIL-100(Fe) test paper. More importantly, the HAP@MIL-100(Fe) test paper can be recovered easily for reuse by simply dipping in absolute ethanol for just 30 min, thus showing excellent recyclability. With its combination of advantages such as easy transportation, easy storage and use, rapid recyclability, light weight, and high flexibility, this HAP@MIL-100(Fe) test paper is promising for wide applications in various fields.


Asunto(s)
Durapatita/química , Estructuras Metalorgánicas/química , Nanofibras/química , Nanocables/química , Peroxidasa/química , Ácido Ascórbico/análisis , Bioensayo/métodos , Calcio/química , Glucosa/análisis , Peróxido de Hidrógeno/análisis , Oxidación-Reducción , Tamaño de la Partícula , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Propiedades de Superficie , Termogravimetría/métodos , Agua/química
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