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1.
Food Chem ; 304: 125383, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31479997

RESUMO

An aqueous two-phase system was used in conjunction with ultrasonic cell disruption to extract and separate solanine (mainly solasonine and solamargine) and Solanum nigrum polysaccharide from Solanum nigrum unripe fruit. The optimized conditions of the present study were determined by a single-factor experiment and a multifactor experiment. The concentration of ethanol was set at 60% and the duration of the ultrasonic cell disruption extraction was 50 min. In the ethanol-K2CO3 aqueous two-phase separation system, the concentration of ethanol was 36%, the concentration of K2CO3 was 0.21 mg·mL-1, and the temperature was 15 °C. The solasonine and solamargine were determined by high-performance liquid chromatography, and the Solanum nigrum polysaccharide was determined by an ultraviolet-visible spectrophotometer in accordance with the phenol-sulfuric acid method. xUnder optimized conditions, the average extraction efficiencies of solasonine, solamargine and Solanum nigrum polysaccharide were 95.86%, 95.95% and 96.95%, respectively, and the average separation efficiencies of solasonine, solamargine and Solanum nigrum polysaccharide were 2.07 mg·g-1, 2.05 mg·g-1 and 8.15 mg·g-1, respectively.

2.
Food Chem ; : 125749, 2019 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-31718840

RESUMO

This work was to develop a cost-effective and sustainable method which included metal chelate ionic liquid-based aqueous two-phase flotation (IL-based ATPF) and a two-step precipitation process for purifying bromelain from pineapple. Firstly, the metal chelate IL-based ATPF with a copper chelate-functionalized thermosensitive block copolymer (L64-IDA-Cu(II)) as trapping agent was used as the primary purification to obtain the L64-IDA-Cu(II)-bromelain complex. Secondly, the two-step precipitation process based on the thermosensitive properties of the L64-IDA-Cu(II) was mainly carried out to achieve the further purification of bromelain. According to a series of optimal experiments, the enzymatic activity recovery of final bromelain was 95.22 ±â€¯0.04%, and the purification factor reached 6.56 ±â€¯0.03. The results of recycling of ILs and the trapping agent were satisfactory. Furthermore, the conclusions of comparison with other methods proved the superiority of this method. This novel recycling purification method has a goodindustrial prospect in future.

3.
Adv Ther ; 36(12): 3356-3367, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31598901

RESUMO

INTRODUCTION: The effect of N-acetylcysteine (NAC) treatment for patients with chronic bronchitis (CB) is controversial. To better understand the role of NAC in CB treatment, we performed a meta-analysis to provide a more accurate estimation of the importance of NAC treatment. METHODS: PubMed, Embase, and CNKI were systematically searched. The pooled relative risk (RR) and 95% confidence intervals (CI) were calculated using either fixed-effect model or random-effect model based on heterogeneity examination. Statistical analyses were performed using the STATA 12.0 and RevMan 5.2. RESULTS: A total of 11 publications with 775 patients who were taking NAC and 789 controls who were taking placebo were judged eligible regarding inclusion criteria. The pooled analysis demonstrated significant evidence that NAC reduced the frequency of CB exacerbations (RR = 0.81, 95% CI 0.69-0.93, P = 0.004). Patients treated with NAC had significant symptom improvement compared with controls (RR = 1.68, 95% CI 1.13-2.52, P = 0.01). NAC did not significantly increase the risk of adverse effects compared with placebo (RR 0.86, 95% CI 0.67-1.09, P = 0.22). Subgroup analysis was carried out to assess the stability of results. No publication bias was detected during analyses. CONCLUSION: There is a role for NAC treatment in the management of CB by reducing symptoms and exacerbations compared with placebo, without increasing the risk of adverse effects. A regular treatment of low dosage (< 1200 mg per day) and a duration of at least 3 months seems to be effective.

4.
Wei Sheng Yan Jiu ; 48(5): 717-727, 2019 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-31601310

RESUMO

OBJECTIVE: To investigate the prevalence of early trauma and resilience among adolescents in Wuhan, and explore the relationship between early trauma and resilience. METHODS: Totally 4871 students aged 10-16 years were chosen by cluster sampling in Wuhan city from September to October 2015. All subjects completed self-report questionnaires, including general information, the Childhood Trauma Questionnaire( CTQ), and the Connor Davidson Resilience Scale( CD-RISC). RESULTS: The mean score of CD-RISC of the total sample was( 64. 70 ± 18. 34). Statistical significance in different gender( t = 5. 373, P<0. 001), age( F = 49. 401, P<0. 001), single child( t = 3. 529, P<0. 001), levels of mother's education( F = 36. 129, P< 0. 001), relationship between parents( F = 89. 831, P < 0. 001), family economic status( F = 36. 547, P<0. 001). The rate of early trauma was 30. 1%. Male( χ~2= 42. 272, P < 0. 001), lower levels of mother 's education( χ~2= 44. 345, P < 0. 001), poorer relationship between parents( χ~2= 133. 045, P < 0. 001), and worse family economic status( χ~2= 31. 231, P<0. 001) were associated with increased risk of early trauma. The scores of emotional abuse, physical abuse, sexual abuse, emotional neglect and physical neglect were negatively correlated with the scores of CD-RISC( r followed by-0. 256, -0. 107, -0. 053, -0. 355 and-0. 308, P<0. 01). Regression analysis implied female, older age, emotional abuse, emotional neglect, and physical neglect( B followed by-0. 156, -0. 117, -0. 109, -0. 214 and-0. 149, P < 0. 01) of primary and middle school students assumed predictive resilience. CONCLUSION: Emotional abuse, emotional neglect, and physical neglect are negatively associated with resilience among children and adolescent. The result suggest that reducing emotional abuse, emotional neglect and physical neglect experience may contribute to child resilience.


Assuntos
Maus-Tratos Infantis , Adolescente , Idoso , Criança , Feminino , Humanos , Masculino , Pais , Prevalência , Estudantes , Inquéritos e Questionários
5.
J Food Biochem ; 43(9): e12976, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31489668

RESUMO

Bromelain has wide applications in different industries, such as food, textile, and medicine. Traditional approaches for bromelain separation and purification from solution still have many problems, including unsatisfactory binding efficiency, time-consuming operation, and costly equipment. In the present study, a new type of dendritic polymer-based magnetic carrier (GO@Fe3 O4 @PEI-Cu2+ ) was first prepared for bromelain separation and purification in solution. The histidine existing in bromelain could bind to Cu2+ cations adsorbed on the surface of the magnetic carrier, and the magnetic carrier showed excellent performance for bromelain separation and purification in solution, with the adsorption capacity up to 357 mg/g. The magnetic carrier also exhibited excellent property in the aspect of recyclability. It was found that the magnetic carrier also presented desirable performance for the separation and purification of bromelain from the crude extract of pineapple peel, and the bromelain structure remained intact before and after elution process. PRACTICAL APPLICATIONS: Considering many advantages of bromelain in the applications of pharmaceutical and food industries, this study is aimed at presenting a novel magnetic carrier with high stability and fabulous performance for bromelain separation and purification in solution and achieving the practical application that the magnetic carrier can efficiently separate bromelain from the crude extract of pineapple peel.

7.
J Hazard Mater ; 383: 121130, 2019 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-31518815

RESUMO

Enhancing the catalytic activity and stability of enzymes is of great importance in the development of green chemical and cost-effective application, with removal of bisphenol A (BPA) as a prominent example. Engineering immobilization carriers and immobilization methods of enzymes endows great potential to achieve above goal. Until now, these reports have focused on employing the metal-organic frameworks (MOFs) to increase the stability and reusability of enzymes, an enhancement in its catalytic activity has yet to be addressed. This work introduced a biomimetic mineralization process for facile synthesis of laccase@HKUST-1 biocomposite under mild condition. By exploiting the activity of laccase@HKUST-1, we demonstrated, for the first time, that the integration of laccase and HKUST-1 containing cofactor Cu2+ ions leaded to 1.5-fold enhancement in the catalytic activity compared with free laccase, which was due to the synergistic enhancement of substrate oxidation. Indeed, the laccase@HKUST-1 biocomposite could function as active biocatalysts under biologically challenging conditions, such as acidic condition, high temperature, organic solvent, and continuous operation. The oxidation of phenols, such as BPA, with laccase@HKUST-1 reached higher catalytic performance than free laccase, and gave 100% degradation efficiency within 4 h. This study provides a feasible method to improve the activity and stability of laccase, which enable completely remove of BPA from the environment.

8.
ACS Appl Mater Interfaces ; 11(35): 31878-31888, 2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31433163

RESUMO

Inspired by natural biomineralization process, inorganic phosphates system has been selected as a candidate for the encapsulation of enzyme; however, during the long-term fabrication process, the loss of enzyme activity is unavoidable, and the biomimetic mineralization mechanism is still poorly understood. Meanwhile, the purification process plays a key role in the preparation of immobilized enzyme with high enzyme loading and activity, while the rapid, low-cost, and eco-friendly purification of biocatalyst from crude fermentation broth remains a critical challenge in biochemical engineering. Here, a binary tag composed of elastin-like polypeptide (ELP) and His-tag was presented for the first time to be fused with ß-glucosidase (Glu) to construct a recombinant Glu-linker-ELP-His (GLEH) with the aim of developing a fast synthesis strategy combining purification and immobilization processes for a biocatalyst with better stability and recyclability. The purification fold and activity recovery of GLEH reached 18.1 and 95.2%, respectively, once a single inverse transition cycling was conducted at 25 °C for 10 min. Then, efficient biomineralization of hybrid enzyme-Cu3(PO4)2 nanoflowers was realized in 15 min by the action of His-tag and ultrasonic-assisted reaction method. The activity recovery and relative activity reached the maximum at 90.3 and 111.0%, respectively. We demonstrate that the crystal growth process of a hybrid nanoflower involves obvious nucleation, self-assembly, and the Ostwald ripening process, and the enzyme GLEH acts as a "binder" to assemble Cu3(PO4)2 nanoflakes. The immobilized GLEH nanoflowers show outstanding operation stability and recyclability, and their catalytic efficiency is close to that of free Glu.

9.
Complement Ther Clin Pract ; 36: 100-112, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31383426

RESUMO

BACKGROUND: Acupuncture has been used to treat type 2 diabetes (T2DM) for 2000 years and there are emerging clinical evidence and animal studies for its efficacy. However, we are unable to conclude the effectiveness and safety on this issue yet. OBJECTIVES: To assess the effects and safety of acupuncture for T2DM. METHODS: We systematically searched 5 databases and 2 clinical registry platforms from inception to 2018-6-4. RCTs for acupuncture or its variants compared with sham acupuncture or no acupuncture controls for T2DM were included. The primary outcomes were glycemic control and adverse events. RESULTS: A total of 21 studies, which comprised a total of 1943 participants, were included in the final meta-analysis. Compared with sham acupuncture or no acupuncture plus baseline treatments, acupuncture plus baseline treatments yield reduction in FBG(MD 1.21 mmol/l, 95%CI 1.56 to 0.87), 2 h BG(MD 2.13 mmol/l, 95%CI 2.79 to 1.46), HA1c (MD 1.12%, 95%CI 1.62 to 0.62). Our results also show acupuncture can improve blood lipids and blood pressure control, and reduce weight. CONCLUSIONS: As one type of multifactorial intervention, acupuncture could be recommended as a supplementary treatment in the management of T2DM, especially in those with obesity or metabolic disorders. However, due to the small sample size, poor methodological quality of trials reviewed, the amount of evidence is not fully convincing. There is a need for well-planned, long-term studies. REGISTRATION: International Prospective Register of Systematic Reviews (Number CRD42018094573).

10.
Mol Nutr Food Res ; 63(18): e1801356, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31313461

RESUMO

SCOPE: Multiple sclerosis (MS) is an inflammatory demyelinating autoimmune disorder, with increasing incidence worldwide but unknown etiology. 6-Gingerol (6-GIN), a major dietary compound found in ginger rhizome, has immunomodulatory activity. However, its role in autoimmune diseases, as well as the underlying mechanisms, are unclear. In this study, it is evaluated if 6-GIN can effectively ameliorate the clinical disease severity of experimental autoimmune encephalomyelitis, an animal model of MS. METHODS AND RESULTS: Clinical scores of experimental autoimmune encephalomyelitis (EAE) mice are recorded daily. Inflammation of periphery and neuroinflammation of EAE mice are determined by flow cytometry analysis, ELISA, and histopathological analysis, and results show that 6-GIN significantly inhibits inflammatory cell infiltration from the periphery into the central nervous system and reduces neuroinflammation and demyelination. Flow cytometry analysis, ELISA, and quantitative PCR show that 6-GIN could suppress lipolysaccharide-induced dendritic cell (DC) activation and induce the tolerogenic DCs. Immunoblot analysis reveals that the phosphorylation of nuclear factor-κB and mitogen-activated protein kinase, two critical regulators of inflammatory signaling, are significantly inhibited in 6-GIN-treated DCs. CONCLUSION: The results of this study demonstrate that 6-GIN has significant potential as a novel anti-inflammatory agent for the treatment of autoimmune diseases such as MS via direct modulatory effects on DCs.

11.
J Hazard Mater ; 380: 120901, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31330392

RESUMO

This study first reported a magnetic nanoflower biocatalyst of the core-shell magnetic composite microspheres with a hierarchical flower-like surface structure, which was consist of the organic component (horseradish peroxidase, HRP) and the inorganic component (Fe3O4@PMG-IDA-Cu2+) through self-assembly in the phosphate buffered saline (PBS) solution. The structure, pattern and crystallization of the magnetic nanoflowers were confirmed through a series of characterization. The optimized results of the magnetic nanoflowers formation conditions demonstrated that their hierarchical structure could effectively enhance the enzyme activity. The magnetic nanoflowers exhibited enhanced durability, stability and reusability through the study of enzymatic properties. The magnetic nanoflowers were applied to remove the bisphenol A (BPA) from water and the removal efficiency reached about 92.1%, meanwhile the enzymatic activity of the magnetic nanoflowers was achieved 183% enhancement in comparison with free HRP. In addition, the magnetic nanoflowers showed outstanding reusability and reproducibility, which would have potential application in biocatalysis.

12.
Biomed Pharmacother ; 117: 109071, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31202171

RESUMO

Philadelphia chromosome-positive (Ph+) is considered as a high risk of acute lymphoblastic leukemia (ALL). Tyrosine kinase inhibitors (TKIs) are tailored drug for Ph+ ALL, but Ik6 is associated with TKI resistance and poor outcome of Ph+ ALL. In the present study, we investigated the potential benefit of combination therapy with imatinib and Huaier extract, a traditional Chinese medicine, in Ik6+ Ph+ ALL. The Ik6+ Ph+ -ALL cell lines Sup-B15 or BV173 were treated with Huaier extract, imatinib or the combination of the two. Analysis of cell proliferation showed that the combined treatment of imatinib and Huaier extract exhibited a greater effect on cell inhibition. Using flow cytometry and Western blot, enhanced effects on the induction of cell apoptosis were observed. The combination of the two drugs also exhibited a significant effect in decreasing the protein and enzymatic activity levels of BCR-ABL. The molecular mechanisms may be involved in BCR-ABL related pathways, including the inactivation of p-AKT, p-STAT5, p-mTOR and p-Lyn. Consistent with the in vitro results, the combination of Huaier extract and imatinib inhibit the growth and infiltration of xenografted tumors. Taken together, our findings show that Huaier extract enhances the anticancer efficacy of imatinib in Ik6+ Ph+ ALL Further, it also provides a potential clinical application in the treatment of refractory Ph+ ALL.

13.
Food Chem ; 283: 1-10, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-30722847

RESUMO

Bromelain is an important industrial proteolytic enzyme which has great commercial value and is of wide application in food, beverage, tenderization, cosmetic, textile and pharmaceutical industries. In this work, the core-shell-shell magnetic polymeric microspheres (Fe3O4@SiO2@P(NIPAM-co-AIM)/Ni2+) composed of an SiO2-coated Fe3O4 magnetite core and a Ni2+-immobilized cross-linked poly (N-isopropyl acrylamide-co-propylimidazole) (NIPAM-co-AIM) shell were synthesized via distillation-precipitation polymerization. The Ni2+ cations in the magnetic polymeric microspheres shell provided docking sites for histidine and the microspheres exhibited excellent performance in the separation of bromelain with a binding capacity as high as 198 mg/g, and the recovery of enzyme activity could achieve 80%. It was found that the microspheres showed excellent performance for separation and purification of bromelain from the crude extract of pineapple peel, moreover the enzyme structure remained unchanged before and after elution process.


Assuntos
Acrilamidas/química , Ananas/química , Bromelaínas/isolamento & purificação , Imidazóis/química , Microesferas , Polímeros/química , Bromelaínas/metabolismo , Óxido Ferroso-Férrico/química , Histidina/química , Histidina/metabolismo , Microscopia Eletrônica de Transmissão , Níquel/química , Extratos Vegetais/química , Polimerização , Dióxido de Silício/química , Espectroscopia de Infravermelho com Transformada de Fourier , Termogravimetria , Difração de Raios X
14.
Food Chem ; 282: 48-57, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-30711105

RESUMO

High cost and enzyme deactivation in purification process are the two main obstacles for the use of enzyme as green catalyst. The objective of this work was to overcome these limitations by developing a cost-effective aqueous two-phase system (ATPS) for efficient purification of enzymes with remarkable separation efficiency and high retention of enzyme activity. The ATPS was formed by thermo-responsive block copolymer PEG113-b-PNIPAM149 and salt as phase-forming components combining economy, recovery and sustainability. This strategy fabricated block copolymer with specified molecular weight and low LCST, which not only achieved better phase splitting but also ensured easy recycling for block copolymer. The developed ATPS demonstrated excellent extraction and biocompatibility for bromelain in real sample with 94.87% separation efficiency and 77.06% activity, which were remarkably higher than those obtained in EOPOEO-based ATPS. The recycling of copolymer was introduced to minimize cost, with recovery efficiency of 90% in the five cycles.


Assuntos
Bromelaínas/metabolismo , Sucos de Frutas e Vegetais/análise , Polímeros/química , Sais/química , Resinas Acrílicas/química , Ananas/enzimologia , Bromelaínas/genética , Bromelaínas/isolamento & purificação , Fracionamento Químico , Polietilenoglicóis/química , Polímeros/síntese química , Reciclagem , Água/química
15.
Clin Nutr ; 2019 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-30773371

RESUMO

BACKGROUND & AIMS: Oxidative stress has been implicated in the pathogenesis of gestational diabetes mellitus (GDM). Vitamin C as natural antioxidant may help to increase the body's antioxidant capacity. The study is aimed to determine whether vitamin C intake during pregnancy is associated with lower risk of GDM. METHODS: Women with singleton pregnancy and without any history of diabetes were drawn from the ongoing Tongji Maternal and Child Health Cohort (TMCHC). Oral glucose tolerance tests (OGTT) were conducted during weeks 24-28 of gestation to screen for GDM. A validated food frequency questionnaire (FFQ) was used to assess dietary intake during mid pregnancy. Use of multivitamins and specific supplements of vitamin C was assessed by questionnaires. Odds ratios (ORs) of GDM risk were calculated by logistic regression models, adjusted for potential confounders. RESULTS: 344 (11.4%) of the 3009 women were diagnosed with GDM. Dietary vitamin C intake was inversely associated with the risk of GDM. Women with above adequate dietary vitamin C intake (more than 200 mg/day) experienced lower odds of GDM (OR 0.68, 95% CI: 0.49-0.95) than those with adequate intake (115-200 mg/day). There was no association between the total consumption of vitamin C and the risk of GDM (OR 1.04, 95% CI: 0.71-1.53). CONCLUSION: This data suggests that higher dietary consumption of vitamin C during pregnancy is independently associated with lower odds of GDM. Above 200 mg/day of dietary vitamin C intake may help reduce the odds of GDM. However, no such association between total vitamin C intake and the risk of GDM was found. Hence, sufficient vegetables and fruits rich in vitamin C should be recommended to protect pregnant women from developing gestational diabetes.

16.
Enzyme Microb Technol ; 122: 26-35, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30638506

RESUMO

In the present study, a novel and efficient immobilization for horseradish peroxidase (HRP) had been developed by using 6-arm magnetic composite microsphere (Fe3O4@PAA-6-arm-PEG-NH2) containing 6-arm polyethylene glycol (6-arm-PEG-NH2) and Fe3O4. The morphology and chemical properties of Fe3O4@PAA-6-arm-PEG-NH2 were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectra (FTIR), X-ray powder diffraction (XRD), vibrating sample magnetometer (VSM) and thermogravimetric analysis (TGA). The immobilization conditions and loading capacity of the carrier toward HRP were also investigated. According to the results, the optimum immobilization conditions were as follows: glutaraldehyde concentration of 0.10 mol L-1, the carrier concentration of 7 mg L-1, the temperature of 35 °C and immobilization time of 180 min. The loading capacity of the immobilized HRP arrived to 139.82 mg g-1 (RSD = 0.87%). Compared with free HRP, the stability of the immobilized HRP had been enhanced in a wide range of temperature and pH. The activity of the immobilized HRP retained 71.05% of its initial activity after 60 days storage. It was also found that the activity of the immobilized HRP retained 61.06% of its initial activity after eight times of successive reuse. The immobilized HRP could hydrolyze phenol to 94.4% within 10 min. It proved that the immobilized HRP could improve the performance of HRP, which had a good prospect in biological application.


Assuntos
Enzimas Imobilizadas/química , Peroxidase do Rábano Silvestre/química , Magnetismo , Microesferas , Biocatálise , Estabilidade Enzimática , Enzimas Imobilizadas/metabolismo , Peroxidase do Rábano Silvestre/metabolismo , Concentração de Íons de Hidrogênio , Cinética , Fenol/metabolismo , Polietilenoglicóis/química , Temperatura Ambiente
17.
Eur Phys J E Soft Matter ; 42(1): 5, 2019 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-30656485

RESUMO

By using the traditional perturbation technique, a focusing nonlinear Schrödinger equation (NLSE) for the one-dimensional bead chain with the initial prestress is first obtained. The Peregrine soliton, called the rogue wave in the present paper, and the super rogue wave are investigated both numerically and analytically. It is noted that both the rogue wave and the super rogue wave do exist in the one-dimensional bead chain. The solutions from the NLSE can correctly describe the real rogue wave as well as the real super rogue wave in the limiting case of small amplitude. Both the rogue wave and the super rogue wave propagate in the granular bead chain as if they are solitary waves.

18.
Environ Monit Assess ; 191(2): 90, 2019 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-30666420

RESUMO

Reducing agricultural greenhouse gas (GHG) emissions is attracting increasing attention. Balanced fertilization (BF) of cropland has been widely promoted and applied and has great potential to reduce GHG emissions. This study assesses GHG mitigation of BF cropland systems including winter wheat and summer maize double-cropping system (wheat-maize) and winter oilseed rape (Brassica napus) and rice double-cropping system (rape-rice) in Shaanxi province, China. We determined the boundaries, scenarios, leakage, and sources of GHG mitigation and developed a measurement system for GHG mitigation under these cropping systems for BF farmland. In the measurement system, except for the changes in nitrogen fertilizer rates, soil carbon storage, mechanical fuel consumption, and fertilizer management mode (paddy), change in crop yield was recommended as a primary source of GHG mitigation. The BF cropland areas of wheat-maize and rape-rice were 2818.89 ha and 1671.73 ha, respectively. The use of BF reduced the GHG emissions of wheat-maize by 1.15 tCO2 equivalent (CO2e) ha-1 per year and the emissions of rape-rice by 1.05 tCO2e ha-1 per year. The BF cropland produced 5007.6 tCO2e per year. Our results do not only provide a reference for the assessment of GHG mitigation on BF cropland under double-cropping systems, but also will be helpful for improving the methodology of GHG mitigation on BF cropland.


Assuntos
Produção Agrícola/métodos , Produtos Agrícolas/crescimento & desenvolvimento , Monitoramento Ambiental/métodos , Fertilizantes/análise , Efeito Estufa/prevenção & controle , Gases de Efeito Estufa/análise , China , Fazendas , Estações do Ano , Solo/química
19.
Spectrochim Acta A Mol Biomol Spectrosc ; 208: 299-308, 2019 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-30340210

RESUMO

A dual-functional fluorescent probe based on coumarin fluorophore for monitoring ClO- and Cu2+ was synthesized and characterized. The identification mechanisms for ClO- and Cu2+ induced different colorimetric and ratiometric changes. ClO- caused a colorimetric change from yellow to colorless and 120 nm blue-shifted emission spectra from red to blue. Besides, Cu2+ induced a remarkable fluorescence quenching behavior and 36 nm blue-shifted absorption spectra accompanied by the color change from yellow to luminous yellow. As expected, Probe 1 displayed excellent selectivity and sensitivity for detecting ClO- and Cu2+ over other competing ions in their respective systems. The limits of detection for ClO- and Cu2+ were 24.62 nM and 0.39 nM, respectively. The recognition mechanisms were proved by 1H NMR, mass spectrum and theoretical calculations. More importantly, the reversibility of Cu2+ could be applicable to rapid quantification for ClO-/Cu2+. Thus, the strategy for sensing ClO-/Cu2+ was carried out, which revealed broad applications of Probe 1 in multiple actual water and biology.


Assuntos
Cobre/análise , Cumarínicos/química , Corantes Fluorescentes/química , Ácido Hipocloroso/análise , Cumarínicos/síntese química , Teoria da Densidade Funcional , Corantes Fluorescentes/síntese química , Células HeLa , Humanos , Concentração de Íons de Hidrogênio , Íons , Espectroscopia de Prótons por Ressonância Magnética , Espectrometria de Fluorescência , Espectrofotometria Ultravioleta , Fatores de Tempo , Água/química
20.
Enzyme Microb Technol ; 120: 136-143, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30396394

RESUMO

In this work, a novel Ni2+&AABOB bifunctional core-shell magnetic composite nanoparticles (MNPs), Fe3O4@p(AABOB-co-AIM-Ni2+), were synthesized for the immobilization of horseradish peroxidase (HRP). Two kinds of interaction are simultaneously incorporated to improve the stability and reusability of immobilized HRP: one is the coordination between Ni2+ and amide group in HRP, and the other is the interaction of the wulff-type boronic acid group with cis-diol-containing HRP which belongs to a type of glycoproteins. Accordingly, the proposed approach achieved high enrichment capacity (174.75 mg/g, protein/beads), and the activity of immobilized HRP still achieved 80% after reuse for 5 cycles. The degradation efficiency of phenol in the presence of immobilized HRP reached 93% within 10 min, which was significantly higher than that of free HRP only about 50% within 20 min. In addition, the immobilized HRP can be easily separated from the reaction solution by an external magnetic field.


Assuntos
Benzeno/química , Compostos de Boro/química , Enzimas Imobilizadas/metabolismo , Peroxidase do Rábano Silvestre/metabolismo , Nanopartículas de Magnetita/química , Níquel/química , Sinergismo Farmacológico , Enzimas Imobilizadas/química , Peroxidase do Rábano Silvestre/química , Concentração de Íons de Hidrogênio , Cinética , Temperatura Ambiente
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