Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 309
Filtrar
1.
Aging Cell ; : e13358, 2021 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-33942972

RESUMO

Memory loss is the most common clinical sign in Alzheimer's disease (AD); thus, searching for peripheral biomarkers to predict cognitive decline is promising for early diagnosis of AD. As platelets share similarities to neuron biology, it may serve as a peripheral matrix for biomarkers of neurological disorders. Here, we conducted a comprehensive and in-depth platelet proteomic analysis using TMT-LC-MS/MS in the populations with mild cognitive impairment (MCI, MMSE = 18-23), severe cognitive impairments (AD, MMSE = 2-17), and the age-/sex-matched normal cognition controls (MMSE = 29-30). A total of 360 differential proteins were detected in MCI and AD patients compared with the controls. These differential proteins were involved in multiple KEGG pathways, including AD, AMP-activated protein kinase (AMPK) pathway, telomerase RNA localization, platelet activation, and complement activation. By correlation analysis with MMSE score, three positively correlated pathways and two negatively correlated pathways were identified to be closely related to cognitive decline in MCI and AD patients. Partial least squares discriminant analysis (PLS-DA) showed that changes of nine proteins, including PHB, UQCRH, CD63, GP1BA, FINC, RAP1A, ITPR1/2, and ADAM10 could effectively distinguish the cognitively impaired patients from the controls. Further machine learning analysis revealed that a combination of four decreased platelet proteins, that is, PHB, UQCRH, GP1BA, and FINC, was most promising for predicting cognitive decline in MCI and AD patients. Taken together, our data provide a set of platelet biomarkers for predicting cognitive decline which may be applied for the early screening of AD.

2.
J Cell Mol Med ; 2021 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-33960655

RESUMO

The gene coding interleukin 6 (IL-6) is a promising candidate in predisposition to type 2 diabetes mellitus (T2DM). This study aimed to meta-analytically examine the association of IL-6 gene -174G/C polymorphism with T2DM and circulating IL-6 changes across -174G/C genotypes. Odds ratio (OR) and standard mean difference (SMD) with 95% confidence interval (CI) were calculated. Twenty-five articles were meta-analysed, with 20 articles for T2DM risk and 9 articles for circulating IL-6 changes. Overall, there was no detectable significance for the association between -174G/C polymorphism and T2DM, and this association was relatively obvious under dominant model (OR: 0.82, 95% CI: 0.56-1.21). Improved heterogeneity was seen in some subgroups, with statistical significance found in studies involving subjects of mixed races (OR: 0.63, 95% CI: 0.46-0.86). Begg's and filled funnel plots, along with Egger's tests revealed week evidence of publication bias. In genotype-phenotype analyses, carriers of -174CC and -174CG genotypes separately had 0.10 and 0.03 lower concentrations (pg/mL) of circulating IL-6 than -174GG carriers. Albeit no detectable significance for the association of -174G/C with T2DM, our findings provided suggestive evidence on a dose-dependent relation between -174G/C mutant alleles and circulating IL-6 concentrations, indicating possible implication of this polymorphism in the pathogenesis of T2DM.

3.
Artigo em Inglês | MEDLINE | ID: mdl-33885188

RESUMO

Organic electrical gas sensors have been developed for many decades because of their high sensitivity and selectivity. However, their industrialization is severely hindered by their intrinsic humidity susceptibility and poor recovery. Conventional organic sensory materials can only operate at room temperature owing to their weak intermolecular interactions. In this work, we demonstrate that the concept of ion-in-conjugation enables organic gas sensors to operate at 100 °C and 70% relative humidity (RH) with almost complete recovery using a coronate polymer (poly-4,4'-biphenylcroconate) as a prototype material for detecting nitric dioxide (NO 2 ). The fabricated sensor has a lower detection limit at the parts-per-billion (ppb) level, while affording the highest sensitivity (2526 ppm -1 at 40 ppb) compared with those of all other reported NO 2 chemresistive sensors. In addition, the in-situ sum-frequency generation spectra (SFG) at room temperature and 100 °C reveal that charge transfer increases with temperature. Theoretic calculations and in-situ Fourier transform infrared spectra (FTIR) confirm the ion-in-conjugation-inspired hydrogen bond as key for excellent sensitivity. A NO 2 alarm system operating under the atmosphere is assembled to demonstrate the feasibility of this sensor. This study demonstrates ion-in-conjugation as a promising concept for designing a robust gas sensor and provides a foundation for the practical application of organic gas sensors.

4.
Artigo em Inglês | MEDLINE | ID: mdl-33834585

RESUMO

Supramolecular complexation is a powerful strategy for engineering materials in bulk and at interfaces. Metal-phenolic networks (MPNs), which are assembled through supramolecular complexes, have emerged as suitable candidates for surface and particle engineering owing to their diverse properties. Herein, we examine the supramolecular dynamics of MPNs during thermal transformation processes. Changes in the local supramolecular network including enlarged pores, ordered aromatic packing, and metal relocation arise from thermal treatment in air or an inert atmosphere, enabling the engineering of metal-oxide networks (MONs) and metal-carbon networks, respectively. Furthermore, by integrating stimuli-responsive motifs, the MONs are endowed with reversible superhydrophobic (>150°) and superhydrophilic (~0°) properties. By highlighting the thermodynamics of MPNs and their transformation into diverse materials, this work offers a versatile pathway for advanced materials engineering.

5.
Biomed Pharmacother ; 139: 111127, 2021 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-33819810

RESUMO

Inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), is rising constantly all over the world. However, current medical treatments are not universally practical. Microcin J25 (MccJ25), a member of the lasso peptides class, has excellent antimicrobial activity both in vitro and in vivo. Here, we assessed the anti-inflammatory effects of MccJ25 through DSS-induced UC mouse model. MccJ25 significantly ameliorated the UC-associated parameters such as decreased body weight, increased disease activity index (DAI) and shortened colon length. MccJ25 also provides barrier protection by preserving structural integrity and reducing inflammatory infiltrates of colon epithelium. The underlying mechanism may be associated with gut microbiota. To test this uncertainty, co-housing experiment was performed, and results indicate homogenized microbiota could relief the inflammatory. Meanwhile, we also proved the prominent role of the possible targets of MccJ25, namely genus Lactobacillus, Bacteroides and Akkermansia (as well as the possible strains related to the important OTUs) in inflammation status through comprehensive analysis. In conclusion, MccJ25 effectively attenuates inflammation and improves disrupted barrier function, and the MccJ25-modified gut microbiota plays a central role in this process.

6.
Adv Nutr ; 2021 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-33873200

RESUMO

With the increasing maternal age and the use of assisted reproductive technology in various countries worldwide, the influence of epigenetic modification on embryonic development is increasingly notable and prominent. Epigenetic modification disorders caused by various nutritional imbalance would cause embryonic development abnormalities and even have an indelible impact on health in adulthood. In this scoping review, we summarize the main epigenetic modifications in mammals and the synergies among different epigenetic modifications, especially DNA methylation, histone acetylation, and histone methylation. We performed an in-depth analysis of the regulation of various epigenetic modifications on mammals from zygote formation to cleavage stage and blastocyst stage, and reviewed the modifications of key sites and their potential molecular mechanisms. In addition, we discuss the effects of nutrition (protein, lipids, and one-carbon metabolism) on epigenetic modification in embryos and emphasize the importance of various nutrients in embryonic development and epigenetics during pregnancy. Failures in epigenetic regulation have been implicated in mammalian and human early embryo loss and disease. With the use of reproductive technologies, it is becoming even more important to establish developmentally competent embryos. Therefore, it is essential to evaluate the extent to which embryos are sensitive to these epigenetic modifications and nutrition status. Understanding the epigenetic regulation of early embryo development will help us make better use of reproductive technologies and nutrition regulation to improve reproductive health in mammals.

7.
Endocr J ; 2021 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-33840670

RESUMO

We did a systematic review and meta-analysis, aiming to examine the association of available polymorphisms in the receptor for advanced glycation end products (AGER) gene with the risk of type 2 diabetes. Literature search, eligibility assessment, and data extraction were independently performed by two authors. Risk was expressed as by odds ratio (OR) and 95% confidence interval (CI) under the random-effects model. A total of 26 publications, involving 29 independent studies (8,318 patients with type 2 diabetes and 5,589 healthy or orthoglycemic controls) were included in this meta-analysis. Six polymorphisms in AGER gene, rs2070600, rs1800624, rs1800625, rs184003, rs3134940, and rs55640627, were eligible for inclusion. Overall analyses indicated that the mutations of rs1800624 (-374A) and rs55640627 (2245A) were associated with a significantly increased risk of type 2 diabetes (OR = 1.17 and 1.55, 95% CI: 1.00 to 1.38 and 1.21 to 1.98, respectively). Subsidiary analyses revealed that the mutation of rs2070600 was associated with 2.13-folded increased risk of type 2 diabetes in Caucasians (95% CI: 1.28 to 3.55), and the mutation of rs1800624 was associated with 1.57-folded increased risk in South Asians (95% CI: 1.09 to 2.25), with no evidence of heterogeneity (I2: 42.5% and 44.5%). There were low probabilities of publication bias for all studied polymorphisms. Taken together, our findings indicate an ethnicity-dependent contribution of AGER gene in the pathogenesis of type 2 diabetes, that is, rs2070600 was a susceptibility locus in Caucasians, yet rs1800624 in South Asians.

8.
Oncol Rep ; 45(6)2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33907844

RESUMO

Chemoresistance is the main cause of poor prognosis in colorectal cancer (CRC). Nicotinamide N­methyltransferase (NNMT) is a metabolic enzyme that is upregulated in various tumor types. It has been reported that NNMT inhibits apoptosis and enhances resistance to 5­fluorouracil (5­Fu) via inhibition of the apoptosis signal regulating kinase 1 (ASK1)­p38 MAPK pathway in CRC cells. A natural product library was screened, and it was found that vanillin, also known as 4­hydroxy­3­methoxybenzaldehyde, a plant secondary metabolite found in several essential plant oils, mainly Vanilla planifolia, Vanilla tahitensis, and Vanilla pompon, may be a promising anticancer compound targeted to NNMT. The aim of the present study was to explore the effect of vanillin on promoting apoptosis and attenuating NNMT­induced resistance to 5­Fu in CRC. Lentiviral vectors of short hairpin RNA and small interfering RNA were transfected into HT­29 cells to construct NNMT­knockdown HT­29 cell lines. Vectors containing an open reading frame of NNMT were stably transfected into SW480 cells to induce NNMT overexpression in SW480 cell lines. Vanillin was found to inhibit the mRNA and protein expression levels of NNMT following the inhibition of NNMT activity in HT­29 cell lines. Vanillin was able to reverse NNMT­induced increased cell proliferation, decreased cell apoptosis and resistance to 5­Fu by inhibiting NNMT expression. Furthermore, it increased cell apoptosis by activating the ASK1­p38 MAPK pathway, which could be inhibited by NNMT. In addition, vanillin increased cell apoptosis by promoting mitochondrial damage and reactive oxygen species. In vivo, the combination of vanillin with 5­Fu yielded a notable synergy in inhibiting tumor growth and inducing apoptosis. Considering that vanillin is an important flavor and aromatic component used in foods worldwide, vanillin is deemed to be a promising anticancer candidate by inhibiting NNMT and may attenuate NNMT­induced resistance to 5­Fu in human CRC therapy with few side effects.

9.
J Sci Food Agric ; 2021 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-33709411

RESUMO

BACKGROUND: Egg proteins are effective emulsifiers and gelators in food systems. However, the physicochemical stability and control release properties of egg-protein stabilized emulsions and gels need to be further improved. The potential of sodium tripolyphosphate (St) to improve the functionality of egg proteins was evaluated. RESULTS: The emulsions with St had smaller particle sizes and higher zeta potential, leading to better physical stability. Furthermore, the oxidation stability increased with increasing St contents, possibly due to its metal chelating capacity and the improved emulsifying activity of whole-egg dispersions. Phosphate had a positive impact on the chemical stability of ß-carotene in whole-egg liquids and gels, decreasing the degradation during thermal treatment. The gel made with St was firm and broke down slowly, leading to a low rate of digestion and ß-carotene release in simulated gastric fluid. CONCLUSION: This study shows that St is useful to improve the egg proteins stabilized emulsions and gels, which is applicable in the development of emulsion-based food grade gel products. © 2021 Society of Chemical Industry.

10.
Nano Lett ; 2021 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-33533628

RESUMO

A quantitative structure-activity relationship (QSAR) is revealed based on the real-time sulfurization processes of ZnO nanowires observed via gas-cell in situ transmission electron microscopy (in situ TEM). According to the in situ TEM observations, the ZnO nanowires with a diameter of 100 nm (ZnO-100 nm) gradually transform into a core-shell nanostructure under SO2 atmosphere, and the shell formation kinetics are quantitatively determined. However, only sparse nanoparticles can be observed on the surface of the ZnO-500 nm sample, which implies a weak solid-gas interaction between SO2 and ZnO-500 nm. The QSAR model is verified with heat of adsorption (-ΔH°) and aberration-corrected TEM characterization. With the guidance of the QSAR model, the following adsorbing/sensing applications of ZnO nanomaterials are explored: (i) breakthrough experiment demonstrates the application potential of the ZnO-100 nm sample for SO2 capture/storage; (ii) the ZnO-500 nm sample features good reversibility (RSD = 1.5%, n = 3) for SO2 sensing, and the detection limit reaches 70 ppb.

11.
Drug Des Devel Ther ; 15: 185-193, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33469270

RESUMO

Objectives: This study was conducted to evaluate the bioequivalence (BE) of a generic form of obeticholic acid (OCA) and OcalivaTM under fasting and fed conditions and to determine the effects of food on the pharmacokinetic (PK) profiles of OCA in healthy Chinese subjects. Methods: A randomized, single-dose, three-sequence, three-period, partial replicated crossover study was conducted with a 21-day washout interval between periods under fasting (n=48) and fed (n=48) conditions. Blood samples for OCA and its metabolites Glyco-OCA and Tauro-OCA were collected up to 168 hours after administration in each period. PK parameters were calculated using the non-compartmental method. Geometric mean ratios for PK parameters of the test to reference drug under fasting and fed conditions and their 90% confidence intervals were estimated. Safety evaluations were carried out all through the study. Results: A total of 91 subjects completed the study with 45 in a fasted state and 46 receiving a high-fat diet. There were no serious or unexpected drug-related adverse events occurring during the study. There was no significant difference in the main PK parameters of the two preparations, irrespective of the fasting or fed conditions. Under fasting and fed conditions, the SWR of lnCmax, lnAUC0-t and lnAUC0-∞ were 0.445, 0.370, 0.448, 0.340, 0.168, and 0.180, respectively. Thus, the average BE or the reference-scaled average BE was used to verify that the two preparations were bioequivalent under fasting and fed conditions. Compared with the fasting state, the AUC0-t of the test drug, the AUC0-t, and AUC0-∞ of the reference drug were higher in the fed state. Conclusion: The test drug and the reference drug were BE and well tolerated in Chinese healthy subjects under both fasting and fed conditions. Food-intake may cause a significant difference in the main PK parameters of the two preparations.

12.
J Biochem ; 2021 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-33479730

RESUMO

We investigated the expression and functions of circular RNA (circRNA) circNINL and miR-921 in breast cancer (BC) in this study. We found that the expression of circNINL increased while the expression of miR-921 decreased in BC tissues and cell lines, and their anomalous expressions were associated with malignant features and poor prognostic of BC. Then, we demonstrated that circNINL could interact with miR-921 and facilitate BC cells malignant process including proliferation acceleration, migration enhancement and apoptosis evasion via sponging miR-921 in vitro. Further investigations revealed that circNINL/miR-921 axis could mediate the expression of ADAM9 which was a direct target of miR-921. In addition, we exhibited that ADAM9 may activate ß-catenin signaling by interacting with E-cadherin. We presented the vital roles of circNINL/miR-921/ADAM9/ß-catenin signaling in the progression of BC.

13.
Sleep Breath ; 2021 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-33439416

RESUMO

PURPOSE: Analyzing sleep quality and sleep structure in patients with patent foramen ovale (PFO) complicated with obstructive sleep apnea (OSA) and the interaction between OSA and PFO in sleep. METHODS: We compared patients with PFO complicated with OSA, patients with simple PFO, and controls. Pittsburgh Sleep Quality Index was used to compare sleep quality and polysomnography was used to compare sleep structure of the three groups. RESULTS: Compared with the control group (n = 62), PFO with OSA (n = 48) and simple PFO (n = 61) groups had more frequent occurrence of poor sleep quality (χ2 = 89.901; p < 0.001). These two groups also showed decreased sleep efficiency (p < 0.010), lower percentages of REM sleep, and reduced N3 sleep (p < 0.050). The N2 sleep was prolonged (p < 0.010). The nocturnal lowest SpO2 was lower and the oxygen desaturation index was higher (p < 0.50). Compared with the simple PFO group, the poor sleep quality was more frequent in the PFO with OSA group; sleep latency (p < 0.001) was prolonged; wake after sleep onset (p < 0.001) and arousal times (p = 0.031) were increased; and sleep micro-arousal index (p = 0.037), periodic leg movement index (p = 0.024), and apnea hypopnea index (p < 0.001) were higher in the PFO with OSA group. CONCLUSION: Patients with PFO and OSA have poor sleep quality with changes in sleep stage and high occurrence rate of sleep disorders. OSA further deteriorates sleep quality and alters sleep structure in patients with PFO.

14.
Carbohydr Polym ; 253: 117309, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-33278958

RESUMO

Bacterial resistance to antibiotics is a critical public health concern. Alternatives of antibiotics are needed urgently. Herein, we designed and engineered a new nano-antimicrobial, chitosan nanoparticles (CNs)-antimicrobial peptide microcin J25 (MccJ25) conjugates (CNMs). The engineered CNMs proved to be highly active against Gram-negative and Gram-positive bacteria, and the activity of CNMs and CNs was stable in various thermal and pH environments. Escherichia coli K88 strain treated with CNMs did not acquire resistance in serial passage assays over a period of 18 days. Risk assessment with cell lines showed that CNMs did not cause toxicity. Additionally, CNMs did not reduce the lifespan of C. elegans. In summary, this study demonstrated that CNMs can serve as an excellent novel antimicrobial agent against multi-drug resistance pathogens.


Assuntos
Antibacterianos/química , Bacteriocinas/química , Quitosana/química , Nanopartículas/química , Proteínas Citotóxicas Formadoras de Poros/química , Animais , Células CACO-2 , Caenorhabditis elegans/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Células HEK293 , Humanos , Concentração de Íons de Hidrogênio , Longevidade/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Tamanho da Partícula , Medição de Risco , Temperatura
15.
Opt Express ; 29(1): 377-384, 2021 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-33362123

RESUMO

A vector ray-tracing model (VRT) has been developed to compute the optical caustics associated with the primary rainbow for an oblate spheroidal water drop illuminated by a Gaussian beam. By comparing the optical caustic structures (in terms of limiting rainbow and hyperbolic umbilic fringes) for a water drop with a Gaussian beam (GB) illumination with that for the same drop, but with parallel beam (PB) illumination, the influence of the Gaussian beam on the optical caustics is investigated. For a water drop with GB illumination and different drop/beam ratios (i.e., the ratio between the drop equatorial radius and the Gaussian beam waist), the location of cusp points and the curvature of the limiting rainbow fringe are also studied. We anticipate that these results not only confirm the approach to compute optical caustics for oblate spheroidal drops illuminated by a shaped beam, but may also lead to a new method for measuring the aspect ratio of spheroidal drops.

16.
J Phys Chem Lett ; : 126-131, 2020 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-33307700

RESUMO

The technique of self-assembled monolayers (SAMs) is frequently applied for grafting functional groups or area-selective deposition of thin films on a material surface. The formation and quality of SAMs are fundamentally determined by thermodynamic data, which are difficult to measure with available experimental methods. This work quantitatively extracted thermodynamic parameters including ΔH°, ΔG°, and ΔS° during the SAMs construction process with an ultrasensitive resonant microcantilever as molecule-surface interactions real-time recording tool. By correlating the thermodynamic parameters with self-assembling temperatures, a new thermodynamic phase-like transition effect of molecular self-assembly has been first revealed. The sharp transition of the thermodynamic parameters defines the critical condition for SAMs formation. The thermodynamic data further provide optimized reaction conditions for constructing high-quality SAMs. The explored quantitative thermodynamic analysis method not only plays as criterion for SAM growth but also helps to fundamentally elucidate physicochemical mechanism of spontaneous self-assembly.

17.
Br J Nutr ; : 1-9, 2020 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-33331250

RESUMO

In the present study, we analysed the effects of SNP rs174547 (T/C) in the fatty acid desaturase 1 (FADS1) gene on long-chain PUFA levels. Four databases were searched to retrieve related literature with keywords such as fatty acid (FA), SNP, FADS1 and rs174547. A meta-analysis of the data was performed using Stata12.0 software, including summary statistics, test for heterogeneity, evaluation of publication bias, subgroup analysis and sensitivity analysis. The associations between rs174547 in FADS1 and seven types of FA, and Δ-5 (D5D) and Δ-6 fatty acid desaturase (D6D) activity were assessed based on the pooled results from eleven papers. A total of 3713 individuals (1529 TT and 2184 TC + CC) were included. The results demonstrated that minor C allele carriers of rs174547 had higher linoleic acid (LA; P < 0·001) and α-linolenic acid (P = 0·020) levels, lower γ-linolenic acid (GLA; P = 0·001) and arachidonic acid (P = 0·024) levels, and lower D5D (P = 0·005) and D6D (P = 0·004) activities than the TT genotype group. Stratification analysis showed that minor C allele carriers of rs174547 had higher LA and lower GLA levels and lower D6D activities in plasma (LA, P < 0·001; GLA, P < 0·001; D6D activity, P < 0·001) samples and in Asian populations (LA, P < 0·001; GLA, P = 0·001; D6D activity, P = 0·001) than the TT genotype group. In conclusion, minor C allele carriers of the SNP rs174547 were associated with decreased activity of D5D and D6D.

18.
Discov Med ; 30(159): 49-56, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33357362

RESUMO

Dyslipidemia refers to the abnormality of lipid metabolism. The aberrant lipid profiles are usually characterized by elevated plasma levels of low-density lipoprotein cholesterol (LDL-c), total cholesterol (TC), triglycerides (TGs), apoprotein B (ApoB), and decreased level of high-density lipoprotein cholesterol (HDL-c). Dyslipidemia occurs frequently in autoimmune diseases (ADs), such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), type-1 diabetes mellitus (T1DM), psoriasis, and inflammatory bowel disease (IBD), and many other diseases. An imbalance in lipid metabolism contributes to accelerated inflammatory responses in addition to promoting the formation of atherosclerosis. Although there have been many studies and reports on the relationship between abnormal lipid metabolism and ADs, it remains uncertain as to whether dyslipidemia has a unique role in promoting the occurrence and development of ADs. Here, we discuss the mechanisms of how dyslipidemia accelerates inflammatory response, autoimmunity, and atherosclerosis at epidemiological, molecular, and cellular levels, and the discussion is mainly conducted with SLE as an example.

19.
Mol Nutr Food Res ; : e2000734, 2020 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-33226182

RESUMO

One-carbon metabolism is involved in varieties of physiological processes in mammals, including nucleic acid synthesis, amino acid homeostasis, epigenetic regulation, redox balance and neurodevelopment. The current evidence linking levels of one-carbon nutrients during pregnancy to the development of oocytes, embryos, and placentas, as well as maternal and offspring health, is reviewed. The sources of mammalian one-carbon units, the pathways active in mammalian one-carbon metabolism, the maternal and fetal needs for one-carbon units and their functions during pregnancy are described. The demand for one-carbon metabolism is highest during pregnancy compared to the entire lifetime of a mammal. The primary types of one-carbon metabolism in mammals are the folate cycle, methionine cycle and transsulfuration pathway, which varies at different pregnancy stages (e.g., methylation programming of embryo, neural development of fetus, fetal growth and placenta development). Therefore, an overall consideration of one-carbon metabolism requirements for different pregnancy stages, is called for, specifically, the balance of all nutrients involved, not just one single nutrient in one-carbon metabolism. Moreover, the establishment of an ideal one-carbon metabolism requirement model is suggested according to the requirements for different pregnancy stages to support optimal pregnancy outcomes and maternal and offspring health.

20.
Bioresour Technol ; 320(Pt A): 124306, 2020 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-33157440

RESUMO

Lignocellulose fractionation is a primary treatment to enhance cellulose accessibility and multi-component use. Herein, the development of a one-step fractionation is reported for cellulose enrichment from corn stover using a low concentration of peracetic acid combined with maleic acid (PAM). The effects of pretreatment parameters on the contents of cellulose, hemicellulose, and lignin were investigated. After cooking for 1 h at 130 °C with 1.5 wt% peracetic acid and 3 wt% maleic acid, 86.83% of corn stover cellulose remained in the solid residue while 88.21% of hemicellulose and 87.77% of lignin dissolved into the aqueous liquid. Hemicellulose was primarily hydrolyzed into xylose with 84.58% recovered during the PAM process. The cellulose-rich residue was enzymatically hydrolyzed with a glucose yield of 89.65%, which was two to three times that of untreated substrate. Generally, the proposed process offers a promising approach for efficient fractionation of lignocellulose under mild and environmental-friendly conditions.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...