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1.
Macromol Rapid Commun ; 45(20): e2400414, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39038120

RESUMO

Carbon fiber (CF)-reinforced epoxy resin (EP) composites are lightweight materials with excellent comprehensive performance. However, the flammability of EP and the poor interfacial bonding between CF and EP are two key disadvantages that limit their further applications. Here, a kind of water-soluble lignin-based CF sizing agent (ELBEDK) is prepared through hydrophilic modification of enzymatic lignin, which can significantly enhance the interfacial interaction between CF and EP. Additionally, a highly efficient intumescent flame retardant (LMA) is prepared. The EP, enzymatic lignin, LMA and CF sized ELBEDK are compounded to obtain the fire-safety CF reinforced composites (SCF/FEP/L). The flame retardancy of SCF/FEP/L with 7% LMA (SCF/FEP7) reached V-0 rating. Moreover, SCF/FEP/L with 7% LMA and 15% lignin (SCF/FEP7/L15) present an limiting oxygen index (LOI)of 30.2% and V-0 of UL-94. Specifically, the total smoke production and the heat release rate are 47.8% and 46.81% lower than that of SCF/EP, respectively, indicating the improved smoke suppression and flame retardancy. The IFSS and flexural strength of SCF/FEP7/L15 are improved to be 59.4 MPa and 511.1 MPa, respectively. This study presents a simple approach to fabricate low-cost high performance lignin-based flame retardant CF/EP biocomposites with wide application potential.


Assuntos
Fibra de Carbono , Resinas Epóxi , Retardadores de Chama , Lignina , Lignina/química , Resinas Epóxi/química , Fibra de Carbono/química , Retardadores de Chama/análise , Incêndios
2.
Appl Microbiol Biotechnol ; 108(1): 182, 2024 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-38285115

RESUMO

Mammalian cell lines are frequently used as the preferred host cells for producing recombinant therapeutic proteins (RTPs) having post-translational modified modification similar to those observed in proteins produced by human cells. Nowadays, most RTPs approved for marketing are produced in Chinese hamster ovary (CHO) cells. Recombinant therapeutic antibodies are among the most important and promising RTPs for biomedical applications. One of the issues that occurs during development of RTPs is their degradation, which caused by a variety of factors and reducing quality of RTPs. RTP degradation is especially concerning as they could result in reduced biological functions (antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity) and generate potentially immunogenic species. Therefore, the mechanisms underlying RTP degradation and strategies for avoiding degradation have regained an interest from academia and industry. In this review, we outline recent progress in this field, with a focus on factors that cause degradation during RTP production and the development of strategies for overcoming RTP degradation. KEY POINTS: • The recombinant therapeutic protein degradation in CHO cell systems is reviewed. • Enzymatic factors and non-enzymatic methods influence recombinant therapeutic protein degradation. • Reducing the degradation can improve the quality of recombinant therapeutic proteins.


Assuntos
Apoptose , Indústrias , Animais , Cricetinae , Humanos , Células CHO , Cricetulus , Proteólise
3.
Int J Med Sci ; 21(12): 2414-2429, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39310261

RESUMO

Background: CDK6 is linked to tumor progression and metastasis, although its molecular mechanism and prognostic value are unclear in bladder cancer. Materials and methods: In our study, raw data were obtained from public databases and Single-center retrospective case series. We conducted a bioinformatics analysis and immunohistochemistry to explore the biological landscape of CDK6 in tumors, with a particular focus on bladder cancer. We examined its expression characteristics and prognostic value and performed functional annotation analysis using gene function enrichment. We also assessed the association between bladder cancer molecular subtypes and mutation spectra and analyzed the landscape of the tumor immune microenvironment to predict treatment response sensitivity. Results: Our study found that CDK6 was a potential prognostic marker for bladder cancer. We discovered that bladder cancer patients with high CDK6 expression do not respond well to immunotherapy and have a poor prognosis. CDK6 regulates tumor immune status, metabolism, and cell cycle-related signaling pathways, thereby influencing tumor biological behavior. Furthermore, CDK6 mediated the suppression of the immune microenvironment to weaken anti-tumor immune responses. Finally, a comprehensive characterization of CDK6 was applied in the prognostic prediction of bladder cancer, suggesting that targeting CDK6 represents a potential therapeutic option. Conclusions: These results indicated that CDK6 is an independent biomarker for predicting prognosis and immunotherapy efficacy of bladder cancer. A deeper understanding of its specific molecular mechanisms may provide new treatment strategies.


Assuntos
Biomarcadores Tumorais , Biologia Computacional , Quinase 6 Dependente de Ciclina , Imuno-Histoquímica , Imunoterapia , Microambiente Tumoral , Neoplasias da Bexiga Urinária , Humanos , Quinase 6 Dependente de Ciclina/antagonistas & inibidores , Quinase 6 Dependente de Ciclina/genética , Quinase 6 Dependente de Ciclina/metabolismo , Neoplasias da Bexiga Urinária/tratamento farmacológico , Neoplasias da Bexiga Urinária/genética , Neoplasias da Bexiga Urinária/patologia , Neoplasias da Bexiga Urinária/imunologia , Neoplasias da Bexiga Urinária/mortalidade , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Prognóstico , Microambiente Tumoral/imunologia , Microambiente Tumoral/genética , Imunoterapia/métodos , Estudos Retrospectivos , Masculino , Feminino , Regulação Neoplásica da Expressão Gênica , Mutação
4.
Cell Mol Biol (Noisy-le-grand) ; 69(7): 80-84, 2023 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-37715422

RESUMO

Cervical cancer is the second leading cause of cancer death among women worldwide. Identification of effective genes along with biological markers as targeting agents is very necessary for the diagnosis and treatment of this disease. Bioinformatics techniques along with genetic and molecular investigations have provided the possibility of studying different levels of information such as the genome, transcriptome, proteome, and metabolize with high depth and accuracy. The collection of these data provides comprehensive and valuable information about the investigated phenotypes, including complex diseases such as cancer. In this study, we examined three genes LRP11, FUBP1, and TET1 related to cervical cancer. The results of this study showed that the level of expression of these genes is high in lymph nodes and the thyroid and is less in the pancreas and liver. Also, the expression level of the FUBP1 gene is higher than that of LRP11, and the expression level of the LRP11 gene is higher than that of TET1. Regarding the structure and proteomics of the studied genes, it can be seen that due to the presence of more domains in the LRP11 and FUBP1 genes, these genes probably independently participate in various functions and have a wider range of activity than the TET1 gene. Also, the analysis of the stability of the examined genes showed that the stability of the FUBP1 gene is relatively higher than that of the TET1 gene, and this gene is also more stable than the LRP11 gene. Considering that these genes are effective key genes for the early detection of cervical cancer, it is hoped that they will be used as markers in the diagnosis and treatment of cervical cancer.


Assuntos
Neoplasias do Colo do Útero , Feminino , Humanos , Neoplasias do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/genética , Fígado , Biologia Computacional , Linfonodos , Fenótipo , Oxigenases de Função Mista , Proteínas Proto-Oncogênicas , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a RNA
5.
Phys Chem Chem Phys ; 25(20): 14232-14244, 2023 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-37170792

RESUMO

Pt/CeO2 catalysts exhibit excellent catalytic performance for the methanol dehydrogenation (MD) reaction. In this work, MD reactions on three systems of Pt1/CeO2(110)), Pt7/CeO2(110), and Pt1/Ce1-xO2(110) are investigated via density functional theory (DFT) calculations. The CH3OH adsorption, electronic structure of the catalyst, and mechanism of methanol decomposition (MD) are systematically calculated. The results reveal that the d-band center of the Pt atom moves away from the Fermi level in the order of Pt1/CeO2(110) < Pt7/CeO2(110) < Pt1/Ce1-xO2(110), and the order of the activity of the MD reaction is Pt1/CeO2(110) < Pt7/CeO2(110) < Pt1/Ce1-xO2(110). The results of the microkinetic dynamics simulation verify that only Pt1/Ce1-xO2(110) is conducive to the decomposition of methanol at low temperatures (373 K), and the products CO and H2 are easily dissociated from the catalyst surface. This work uncovers that both the small size and the Ce vacancy substituted sites of Pt favor the performance of the Pt/CeO2 catalyst, and provides theoretical guidance for the construction and design of efficient metal-support catalysts for the MD reaction.

6.
Int J Mol Sci ; 24(22)2023 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-38003651

RESUMO

The anthocyanin biosynthetic pathway is the main pathway regulating floral coloration in Iris germanica, a well-known ornamental plant. We investigated the transcriptome profiles and targeted metabolites to elucidate the relationship between genes and metabolites in anthocyanin biosynthesis in the bitone flower cultivar 'Clarence', which has a deep blue outer perianth and nearly white inner perianth. In this study, delphinidin-, pelargonidin-, and cyanidin-based anthocyanins were detected in the flowers. The content of delphinidin-based anthocyanins increased with the development of the flower. At full bloom (stage 3), delphinidin-based anthocyanins accounted for most of the total anthocyanin metabolites, whereas the content of pelargonidin- and cyanidin-based anthocyanins was relatively low. Based on functional annotations, a number of novel genes in the anthocyanin pathway were identified, which included early biosynthetic genes IgCHS, IgCHI, and IgF3H and late biosynthetic genes Ig F3'5'H, IgANS, and IgDFR. The expression of key structural genes encoding enzymes, such as IgF3H, Ig F3'5'H, IgANS, and IgDFR, was significantly upregulated in the outer perianth compared to the inner perianth. In addition, most structural genes exhibited their highest expression at the half-color stage rather than at the full-bloom stage, which indicates that these genes function ahead of anthocyanins synthesis. Moreover, transcription factors (TFs) of plant R2R3-myeloblastosis (R2R3-MYB) related to the regulation of anthocyanin biosynthesis were identified. Among 56 R2R3-MYB genes, 2 members belonged to subgroup 4, with them regulating the expression of late biosynthetic genes in the anthocyanin biosynthetic pathway, and 4 members belonged to subgroup 7, with them regulating the expression of early biosynthetic genes in the anthocyanin biosynthetic pathway. Quantitative real-time PCR (qRT-PCR) analysis was used to validate the data of RNA sequencing (RNA-Seq). The relative expression profiles of most candidate genes were consistent with the FPKM of RNA-seq. This study identified the key structural genes encoding enzymes and TFs that affect anthocyanin biosynthesis, which provides a basis and reference for the regulation of plant anthocyanin biosynthesis in I. germanica.


Assuntos
Gênero Iris , Transcriptoma , Antocianinas , Gênero Iris/genética , Gênero Iris/metabolismo , Proteínas de Plantas/metabolismo , Fatores de Transcrição/metabolismo , Flores/metabolismo , Regulação da Expressão Gênica de Plantas
7.
J Cell Mol Med ; 26(15): 4254-4267, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35775122

RESUMO

Acute kidney injury (AKI) is mainly caused by renal ischaemia reperfusion injury (IRI). Lots of evidence suggests that ferroptosis and oxidative stress play the vital role in renal IRI. However, the specific mechanism of renal IRI has not been fully elucidated. lysine-specific demethylase 1 (LSD1) has been shown to regulate the pathogenesis of kidney disease. In this study, we firstly found that LSD1 was positively related to renal IRI. TCP, a classical LSD1 inhibitor, could alleviate tissue damage induced by renal IRI. Inhibition of LSD1 with either TCP or LSD1 knockdown could alleviate ferroptosis and oxidative stress caused by IRI both in vivo and in vitro. Furthermore, the results showed that suppression of LSD1 decreased the expression of TLR4/NOX4 pathway in HK-2 cells subjected to H/R. With the si-RNA against TLR4 or NOX4, it showed that the silence of TLR4/NOX4 reduced oxidative stress and ferroptosis in vitro. Moreover, to demonstrate the crucial role of TLR4/NOX4, TLR4 reduction, mediated by inhibition of LSD1, was compensated through delivering the adenovirus carrying TLR4 in vitro. The results showed that the compensation of TLR4 blunted the alleviation of oxidative stress and ferroptosis, induced by LSD1 inhibition. Further study showed that LSD1 activates TLR4/NOX4 pathway by reducing the enrichment of H3K9me2 in the TLR4 promoter region. In conclusion, our results demonstrated that LSD1 inhibition blocked ferroptosis and oxidative stress caused by renal IRI through the TLR4/NOX4 pathway, indicating that LSD1 could be a potential therapeutic target for renal IRI.


Assuntos
Injúria Renal Aguda , Ferroptose , Traumatismo por Reperfusão , Injúria Renal Aguda/metabolismo , Animais , Histona Desmetilases/genética , Histona Desmetilases/metabolismo , Isquemia/patologia , Rim/patologia , Lisina/metabolismo , Camundongos , NADPH Oxidase 4/genética , NADPH Oxidase 4/metabolismo , Estresse Oxidativo , Traumatismo por Reperfusão/patologia , Transdução de Sinais/fisiologia , Receptor 4 Toll-Like/metabolismo
8.
Opt Express ; 30(11): 18219-18237, 2022 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-36221628

RESUMO

Spectral computed tomography (CT) can provide narrow-energy-width reconstructed images, thereby suppressing beam hardening artifacts and providing rich attenuation information for component characterization. We propose a statistical iterative spectral CT imaging method based on blind separation of polychromatic projections to improve the accuracy of narrow-energy-width image decomposition. For direct inversion in blind scenarios, we introduce the system matrix into the X-ray multispectral forward model to reduce indirect errors. A constrained optimization problem with edge-preserving regularization is established and decomposed into two sub-problems to be alternately solved. Experiments indicate that the novel algorithm obtains more accurate narrow-energy-width images than the state-of-the-art method.

9.
Brain ; 144(11): 3355-3370, 2021 12 16.
Artigo em Inglês | MEDLINE | ID: mdl-34196664

RESUMO

HIV-associated neurocognitive disorders (HAND) in the era of combination antiretroviral therapy are primarily manifested as impaired behaviours, glial activation/neuroinflammation and compromised neuronal integrity, for which there are no effective treatments currently available. In the current study, we used doxycycline-inducible astrocyte-specific HIV Tat transgenic mice (iTat), a surrogate HAND model, and determined effects of PNU-125096, a positive allosteric modulator of α7 nicotinic acetylcholine receptor (α7 nAChR) on Tat-induced behavioural impairments and neuropathologies. We showed that PNU-125096 treatment significantly improved locomotor, learning and memory deficits of iTat mice while inhibited glial activation and increased PSD-95 expression in the cortex and hippocampus of iTat mice. Using α7 nAChR knockout mice, we showed that α7 nAChR knockout eliminated the protective effects of PNU-125096 on iTat mice. In addition, we showed that inhibition of p38 phosphorylation by SB239063, a p38 MAPK-specific inhibitor exacerbated Tat neurotoxicity in iTat mice. Last, we used primary mouse cortical individual cultures and neuron-astrocytes co-cultures and in vivo staining of iTat mouse brain tissues and showed that glial activation was directly involved in the interplay among Tat neurotoxicity, α7 nAChR activation and the p38 MAPK signalling pathway. Taken together, these findings demonstrated for the first time that α7 nAChR activation led to protection against HAND and suggested that α7 nAChR modulator PNU-125096 holds significant promise for development of therapeutics for HAND.


Assuntos
Complexo AIDS Demência/metabolismo , Receptor Nicotínico de Acetilcolina alfa7/metabolismo , Animais , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Produtos do Gene tat do Vírus da Imunodeficiência Humana/toxicidade
10.
J Sep Sci ; 45(24): 4460-4468, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36239158

RESUMO

Exploiting adsorbents with highly efficient extraction performance is of great promise for extracting small organic molecules from biological samples. In this work, a novel Zn2+ -immobilized chitosan@silica hybrid monolith was prepared through a simple self-assembly Zn2+ -immobilization process. Exploited as an adsorbent in solid-phase micro-extraction for extracting trace ß-agonists, the monolith exhibited high extraction efficiencies for salbutamol, clenbuterol, and ractopamine with the enrichment factors approaching 120, 85, and 52, respectively. These could be attributed to the effective interaction between Zn2+ ions and the target molecule via coordination or other intermolecular interactions. Under optimized extraction operations, a sensitive determination was successfully developed coupling with high-performance liquid chromatography-ultraviolet detection. The linear range was 0.17-58.8, 0.12-68.5, and 0.18-65.5 ng/ml for salbutamol, clenbuterol, and ractopamine. The limits of detection of the ß-agonists were from 0.04 to 0.07 ng/ml, and the limits of quantification were from 0.12 to 0.18 ng/ml. The recoveries of spiking in mutton samples were observed in the range of 85.9%-95.7%, with relative standard deviations <8.0% (n = 3). Application tests demonstrated this newly developed determination was practical, accurate, and convenient for detecting trace content ß-agonists in meat.


Assuntos
Clembuterol , Dióxido de Silício , Extração em Fase Sólida , Cromatografia Líquida de Alta Pressão , Albuterol , Zinco
11.
Arch Biochem Biophys ; 703: 108846, 2021 05 30.
Artigo em Inglês | MEDLINE | ID: mdl-33744198

RESUMO

CCAAT/enhancer-binding protein ß (C/EBPß) is a transcription factor that is involved in adipocytic and monocytic differentiation. However, the physiological role of C/EBPß in megakaryocytes (MKs) is not clear. In this study, we investigated the effects of C/EBPß on the early-stage differentiation of MKs, and explored the potential mechanisms of action. We established a cytosine arabinoside-induced thrombocytopenia mouse model using C57BL/6 mice. In the thrombocytopenia mice, the platelet count was found to be decreased, and the mRNA and protein expression levels of C/EBPß in MKs were also reduced. Furthermore, the maturation of Dami (MKs cell line) cells was induced by phorbol 12-myristate 13-acetate. When C/EBPß was silenced in Dami cells by transfection using C/EBPß-small interfering RNA, the expression of MKs-specific markers CD41 and CD62P, was dramatically decreased, resulting in morphological changes and differentiation retardation in low ploidy, which were evaluated using flow cytometry, real-time polymerase chain reaction, western blot, and confocal microscopy. The mitogen activated protein kinase-extracellular signal-regulated kinase signaling pathway was found to be required for the differentiation of MKs; knockdown of C/EBPß in MEK/ERK1/2 pathway attenuated MKs differentiation. Overexpression of C/EBPß in MEK/ERK1/2 pathway inhibited by U0126 did not promote MKs differentiation. To the best of our knowledge, C/EBPß plays an important role in MKs differentiation and polyploidy cell cycle control. Taken together, C/EBPß may have thrombopoietic effects in the differentiation of MKs, and may assist in the development of treatments for various disorders.


Assuntos
Proteína beta Intensificadora de Ligação a CCAAT/metabolismo , Diferenciação Celular , Megacariócitos/citologia , Trombopoese , Animais , Proteína beta Intensificadora de Ligação a CCAAT/deficiência , Proteína beta Intensificadora de Ligação a CCAAT/genética , Linhagem Celular , Regulação da Expressão Gênica , Técnicas de Silenciamento de Genes , Sistema de Sinalização das MAP Quinases , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Fatores de Tempo
12.
FASEB J ; 34(3): 3805-3819, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31975555

RESUMO

High-density lipoprotein (HDL), a well-known atheroprotective factor, can be converted to proatherogenic particles in chronic inflammation. HDL-targeted therapeutic strategy for atherosclerotic cardiovascular disease (CVD) is currently under development. This study aims to assess the role of methionine sulfoxide reductase A (MsrA) in abnormal HDL and its related disorders in scavenger receptor class B type I deficient (SR-BI-/- ) mice. First, we demonstrated that MsrA overexpression attenuated ROS level and inflammation in HepG2 cells. For the in vivo study, SR-BI-/- mice were intravenously injected with lentivirus to achieve hepatic MsrA overexpression. High-level hepatic MsrA significantly reduced the plasma free cholesterol contents, improved HDL functional proteins apolipoprotein A-I (apoAI), apoE, paraoxonase1 (PON1), and lecithin:cholesterol acyltransferase (LCAT), while decreased the pro-inflammatory property of dysfunctional HDL, contributing to reduced atherosclerosis and hepatic steatosis in Western diet-fed mice. Furthermore, the study revealed that hepatic MsrA altered the expression of several genes controlling HDL biogenesis, cholesterol esterification, cholesterol uptake mediated by low-density lipoprotein receptor (LDLR) and biliary excretion, as well as suppressed nuclear factor κB (NF-κB) signaling pathway, which largely relied on liver X receptor alpha (LXRα)-upregulation. These results provide original evidence that MsrA may be a promising target for the therapy of dysfunctional HDL-related CVD.


Assuntos
Aterosclerose/metabolismo , Aterosclerose/terapia , Lipoproteínas HDL/sangue , Metionina Sulfóxido Redutases/metabolismo , Receptores Depuradores Classe B/metabolismo , Animais , Aterosclerose/sangue , Aterosclerose/genética , Western Blotting , Colesterol/sangue , Colesterol/metabolismo , Feminino , Células Hep G2 , Humanos , Imuno-Histoquímica , Lentivirus/genética , Macrófagos/metabolismo , Masculino , Metionina Sulfóxido Redutases/genética , Camundongos , Camundongos Endogâmicos C57BL , Plasmídeos/genética , Reação em Cadeia da Polimerase em Tempo Real , Receptores Depuradores Classe B/deficiência , Receptores Depuradores Classe B/genética
13.
Phys Chem Chem Phys ; 23(48): 27340-27347, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34854437

RESUMO

Density functional theory (DFT) calculations are carried out to investigate the effect of point defects on acetylene hydrogenation reaction over Ni(111) surface with three different defect concentrations (DC = 0.0500, 0.0625, and 0.0833), compared with the perfect Ni(111) surface. The adsorptions of C2 species and H atoms and the mechanism of acetylene hydrogenation via the ethylene pathway are systematically analyzed. The results indicate that the existence of defects will make C2 species and H atoms more inclined to adsorb near the defects. Introducing an appropriate amount of point defect concentration can enhance the catalytic activity and ethylene selectivity of Ni. In this work, DC = 0.0625 Ni(111) surface has the highest catalytic activity and selectivity of ethylene. This work provides useful theoretical information on the effect of defects on acetylene hydrogenation and is helpful for the design of Ni and related metal catalysts with defects.

14.
Opt Express ; 28(9): 12780-12794, 2020 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-32403768

RESUMO

The linear reconstruction of narrow-energy-width projections can suppress hardening artifacts in conventional computed tomography (CT). We develop a spectral CT blind separation algorithm for obtaining narrow-energy-width projections under a blind scenario where the incident spectra are unknown. The algorithm relies on an X-ray multispectral forward model. Based on the Poisson statistical properties of measurements, a constrained optimization problem is established and solved by a block coordinate descent algorithm that alternates between nonnegative matrix factorization and Gauss-Newton algorithm. Experiments indicate that the decomposed projections conform to the characteristics of narrow-energy-width projections. The new algorithm improves the accuracy of obtaining narrow-energy-width projections.

15.
Phys Chem Chem Phys ; 22(4): 2521-2529, 2020 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-31939952

RESUMO

The guest anions play a key role in the construction of layered double hydroxide (LDH)-based host-guest functional materials. In this work, the orientation of the interlayer species, interlayer distances, binding energies, electronic density differences and density of states of the MgnAl-LDHs (n = 1.6, 2.0, 2.6, 3.5, 5.0, and 8.0) with nine different anions (F-, Cl-, Br-, I-, OH-, NO3-, CO32-, SO42-, and PO43-) are calculated by density functional theory (DFT). The results reveal that the LDHs containing the anions with more inclined arrangement, larger size, lower charge and with a larger number of interlayer water molecules show larger interlayer distances. The higher anion charge leads to a larger binding energy for LDHs, and the order of binding energy implies that the sequence of anion exchange is PO43- > CO32- > SO42- > OH- > F- > Cl- > Br- > NO3- > I-. The interactions between interlayer species and the host layer or the interlayer water molecules are mainly derived from the electrostatic interactions. The main components of the valence band maximum (VBM) and conduction band minimum (CBM) of MgAl-LDHs are derived from p orbitals of halogen anions or the O-2p orbitals of other anions, and the Mg-2p orbital, respectively. This illustrates that the most basic sites of MgAl-LDHs are the interlayer anions rather than the hydroxyl group in the layer, while the most acidic sites are Mg in the layers. And LDHs containing anions with higher charge show stronger basicity. The calculation results agree well with the experimental findings. This work provides effective theoretical information for the design and preparation of the anion-controlled functional LDHs or related materials with prospective applications.

16.
Phys Chem Chem Phys ; 22(35): 19758-19768, 2020 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-32844826

RESUMO

The ion exchange reaction has been extensively used in the field of synthesis of functionalized supramolecular materials such as layered double hydroxides (LDHs), ion-embedded batteries, sewage disposal and so on. In this work, the factors influencing the anion exchange behavior in the LDH gallery, such as the exchange domain, the exchange order, the driving force, and the diffusion of the anions, are investigated systematically using molecular dynamics (MD) simulations and density functional theory (DFT) methods in view of both thermodynamics and dynamics. 159 models of MIIRAl-A-LDHs (MII = Mg, Ni, Zn; R = 1.4-8, A = OH-, Cl-, Br-, NO3-, HCOO-, C6H5SO3-, CO32-, SO42-, and PO43-, respectively) are calculated. The results reveal that the anion exchange domain (interlayer distance) in LDHs is determined not only by the size and their arrangement modes of the guest anions, but also by the charges the anions carry. The relative binding energies of different anions and the Gibbs free energy changes of the anion exchange reactions in LDHs decrease in the order of PO43- > CO32- > SO42- > OH- > Cl- > Br- > HCOO- > NO3- > C6H5SO3-, which is in accordance with the experimental anion exchange order. The stronger the hydrogen bonding between the anion and the host, the larger the charge transfer, and the smaller the electronegativity of the anion, the more difficult it is for the anion to be exchanged out from LDH interlayer. In addition, for the anions with the same charges, the relative binding energy is linearly well correlated with the interlayer spacing. By analyzing the contribution of each energetic item comprising the total potential energy, it is found that the major driving force of anion exchange is the electrostatic force. The diffusion coefficient (D) along the c direction is nearly equal to zero, suggesting that the diffusion of anions occurs mainly in the ab plane of the LDH cell. It also can be inferred that when the cell parameter c < 24.0 Å, the anion exchange order is mainly determined by the thermodynamic factors, whereas when c > 24.0 Å, both the thermodynamic and the dynamic factors cast the same effect on the anion exchange behavior. This work provides an in-depth understanding of the anion exchange behavior, and is helpful guidance for the design and synthesis of functionalized guest anion intercalated LDHs and related materials using the anion-exchange method.

17.
Plant Biotechnol J ; 17(5): 945-955, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30407717

RESUMO

Although efforts have been taken to exploit diversity for yield and quality improvements, limited progress on using beneficial alleles in domesticated and undomesticated cotton varieties is limited. Given the complexity and limited amount of genomic information since the completion of four cotton genomes, characterizing significant variations and haplotype block inheritance under artificial selection has been challenging. Here we sequenced Gossypium hirsutum L. cv CRI-12 (the cotton variety with the largest acreage in China), its parental cultivars, and progeny cultivars, which were bred by the different institutes in China. In total, 3.3 million SNPs were identified and 118, 126 and 176 genes were remarkably correlated with Verticillium wilt, salinity and drought tolerance in CRI-12, respectively. Transcriptome-wide analyses of gene expression, and functional annotations, have provided support for the identification of genes tied to these tolerances. We totally discovered 58 116 haplotype blocks, among which 23 752 may be inherited and 1029 may be recombined under artificial selection. This survey of genetic diversity identified loci that may have been subject to artificial selection and documented the haplotype block inheritance and recombination, shedding light on the genetic mechanism of artificial selection and guiding breeding efforts for the genetic improvement of cotton.


Assuntos
Genes de Plantas/genética , Gossypium/genética , Haplótipos/genética , Melhoramento Vegetal/métodos , Recombinação Genética/genética , Resistência à Doença/genética , Genes de Plantas/fisiologia , Genoma de Planta/genética , Gossypium/crescimento & desenvolvimento , Polimorfismo de Nucleotídeo Único/genética , Característica Quantitativa Herdável , Análise de Sequência de DNA
18.
BMC Med Imaging ; 19(1): 6, 2019 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-30654748

RESUMO

BACKGROUND: Although independent component analysis (ICA) has been widely applied to functional magnetic resonance imaging (fMRI) data to reveal spatially independent brain networks, the order indetermination of ICA leads to the problem of target component selection. The temporally constrained independent component analysis (TCICA) is capable of automatically extracting the desired spatially independent components by adding the temporal prior information of the task to the mixing matrix for fMRI data analysis. However, the TCICA method can only extract a single component that tends to be a mix of multiple task-related components when there exist several independent components related to one task. METHODS: In this study, we proposed a TCICA with threshold (TCICA-Thres) method that performed TCICA outside the threshold and performed FastICA inside the threshold to automatically extract all the target components related to one task. The proposed approach was tested using simulated fMRI data and was applied to a real fMRI experiment using 13 subjects. Additionally, the performance of TCICA-Thres was compared with that of FastICA and TCICA. RESULTS: The results from the simulation and the fMRI data demonstrated that TCICA-Thres better extracted the task-related components than TCICA. Moreover, TCICA-Thres outperformed FastICA in robustness to noise, spatial detection power and computational time. CONCLUSIONS: The proposed TCICA-Thres solves the limitations of TCICA and extends the application of TCICA in fMRI data analysis.


Assuntos
Encéfalo/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Adulto , Algoritmos , Simulação por Computador , Humanos , Análise de Componente Principal , Processamento de Sinais Assistido por Computador
19.
Hum Brain Mapp ; 36(5): 1705-15, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25545862

RESUMO

Working memory (WM) is essential for individuals' cognitive functions. Neuroimaging studies indicated that WM fundamentally relied on a frontoparietal working memory network (WMN) and a cinguloparietal default mode network (DMN). Behavioral training studies demonstrated that the two networks can be modulated by WM training. Different from the behavioral training, our recent study used a real-time functional MRI (rtfMRI)-based neurofeedback method to conduct WM training, demonstrating that WM performance can be significantly improved after successfully upregulating the activity of the target region of interest (ROI) in the left dorsolateral prefrontal cortex (Zhang et al., [2013]: PloS One 8:e73735); however, the neural substrate of rtfMRI-based WM training remains unclear. In this work, we assessed the intranetwork and internetwork connectivity changes of WMN and DMN during the training, and their correlations with the change of brain activity in the target ROI as well as with the improvement of post-training behavior. Our analysis revealed an "ROI-network-behavior" correlation relationship underlying the rtfMRI training. Further mediation analysis indicated that the reorganization of functional brain networks mediated the effect of self-regulation of the target brain activity on the improvement of cognitive performance following the neurofeedback training. The results of this study enhance our understanding of the neural basis of real-time neurofeedback and suggest a new direction to improve WM performance by regulating the functional connectivity in the WM related networks.


Assuntos
Encéfalo/fisiologia , Imageamento por Ressonância Magnética/métodos , Memória de Curto Prazo/fisiologia , Neurorretroalimentação/métodos , Mapeamento Encefálico , Circulação Cerebrovascular/fisiologia , Feminino , Humanos , Masculino , Vias Neurais/fisiologia , Testes Neuropsicológicos , Oxigênio/sangue , Adulto Jovem
20.
Gynecol Obstet Invest ; 79(1): 1-12, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-24854767

RESUMO

BACKGROUND/AIMS: In recent years, acupuncture has become more and more popular in the management of subfertility. The aim of this study was to evaluate the impact of acupuncture during in vitro fertilization (IVF) treatment on the outcomes of clinical pregnancy in published randomized studies. METHODS: This is a systematic review and meta-analysis. Data sources used were MEDLINE, Embase, Web of Knowledge and the Chinese Biomedical Database. RESULTS: There was no statistically significant difference between the acupuncture group and no acupuncture (intervention) controls around the time of embryo transfer (ET; risk ratio, RR, 1.24, 95% confidence interval, CI, 1.02-1.50) or in unblinded trials, trials blinded to physicians and double-blind trials (95% CI 1.26-1.88, 0.82-1.33 and 0.89-1.25, respectively). This was also the case when comparing acupuncture with sham acupuncture controls around the time of ET (RR, 1.03, 95% CI 0.87-1.22) or when restricting to unblinded trials, trials blinded to physicians and double-blind trials (95% CI 0.80-2.02, 0.82-1.18 and 0.77-1.17, respectively). There was a statistically significant difference when performed at 30 min after ET and implantation phase (RR 1.76, 95% CI 1.22-2.55). There was also a statistically significant difference when performed at follicle phase and 25 min before and after ET (RR 1.56, 95% CI 1.04-2.33). CONCLUSION: Our study showed that acupuncture did not significantly improve the IVF clinical pregnancy rate when performed only at the time of ET, while we found pooled benefit of acupuncture for IVF when performed at follicle phase and 25 min before and after ET, as well as 30 min after ET and implantation phase.


Assuntos
Acupuntura , Fertilização in vitro/métodos , Método Duplo-Cego , Transferência Embrionária/métodos , Feminino , Fase Folicular , Humanos , MEDLINE , Gravidez , Resultado da Gravidez , Ensaios Clínicos Controlados Aleatórios como Assunto , Fatores de Tempo , Resultado do Tratamento
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