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1.
Food Chem ; 337: 127978, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32920268

RESUMO

Aflatoxin B1 (AFB1) contamination causes huge economic losses. To explore the correlation between catalase (CAT) and AFB1 production during fungal development, we fabricated an electrochemical CAT-activity sensor by measuring residual H2O2 after enzymatic degradation. The sensor made by palladium nanoparticles/carbonized bacterial cellulose nanocomposites exhibits a linear range over 0.5-3.5 U/mL and a detection limit of 0.434 U/mL. Both dry weight and CAT activity of mycelia continuously increase. But, the latter shows a greater increase than the former after three days. Specific CAT activity in crude enzyme extract of A. flavus was quantified. It maintains at ~25.00 U/mg for 3 days and enhances to 28.91 and 45.30 U/mg, respectively, on days 4 and 5. AFB1 production follows the same trend. On days 4 and 5, AFB1 concentration reaches 201.35 and 767.9 ng/mL, respectively. The positive correlation between specific CAT activity and AFB1 production suggests that CAT is involved in AFB1 biosynthesis.

2.
Nanoscale Res Lett ; 15(1): 191, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-33001341

RESUMO

Three InGaN/GaN MQWs samples with varying GaN cap layer thickness were grown by metalorganic chemical vapor deposition (MOCVD) to investigate the optical properties. We found that a thicker cap layer is more effective in preventing the evaporation of the In composition in the InGaN quantum well layer. Furthermore, the quantum-confined Stark effect (QCSE) is enhanced with increasing the thickness of GaN cap layer. In addition, compared with the electroluminescence measurement results, we focus on the difference of localization states and defects in three samples induced by various cap thickness to explain the anomalies in room temperature photoluminescence measurements. We found that too thin GaN cap layer will exacerbates the inhomogeneity of localization states in InGaN QW layer, and too thick GaN cap layer will generate more defects in GaN cap layer.

3.
Artigo em Inglês | MEDLINE | ID: mdl-33010017

RESUMO

Perovskite is an efficient and emerging catalyst for NO oxidation. In this study, BaMnO3 and BaCoO3 perovskite catalysts were synthesized by the sol-gel method, and their catalytic oxidation performances of NO were studied. The catalytic performances indicated that BaMnO3 and BaCoO3 perovskites had the highest NO oxidation activities with the NO conversions of 78.2% at 350 °C and 84.3% at 310 °C, respectively. The high activities of BaMnO3 and BaCoO3 perovskite catalysts were related to the abundant surface adsorption oxygen (OA = 76.21% and 78.57%, respectively) and the high concentration of Mn4+ (Mn4+/Mn = 66.95%) and Co3+ (Co3+/Co = 63.8%). Moreover, the results of FT-IR and kinetics revealed that NO and O2 adsorbed on the surface of samples and combined with the B-O band to form bidentate nitrate and bridging nitrate, which eventually was converted into NO2. The kinetics analysis revealed that the NO oxidation reaction followed the Eley-Rideal (E-R) and Langmuir-Hinshelwood (L-H) mechanisms. In addition, the activation energies were 36.453 kJ/mol for BaMnO3 and 30.081 kJ/mol for BaCoO3, implying that BaMnO3 and BaCoO3 provide low-cost and efficient catalysts, which can be comparable to Pt noble metal catalysts.

4.
Plant Biotechnol J ; 2020 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-33010087

RESUMO

Alternative splicing (AS) enhances transcriptome plasticity and proteome diversity in response to diverse growth and stress cues, which places AS at the crossroads of adaptation and environmental stress response (Chen et al., 2019a; Kuang et al., 2017). In recent years, the high-throughput sequencing-based analysis of plant transcriptomes has shown that this alternatively spliced mRNA processing is pervasive across plant species, with more than 80% and 70% of intron-containing genes producing different isoforms in Arabidopsis and rice, respectively (Chen et al., 2019b; Zhu et al., 2017).

5.
Diabetes Metab Res Rev ; : e3414, 2020 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-33010796

RESUMO

Diabetic retinopathy (DR) is one of the leading causes of blindness worldwide, and the limited availability of qualified ophthalmologists restricts its early diagnosis. For the past few years, artificial intelligence technology has developed rapidly and has been applied in DR screening. The upcoming technology provides support on DR screening and improves the identification of DR lesions with a high sensitivity and specificity. This review aims to summarize the progress on automatic detection and classification models for the diagnosis of DR. This article is protected by copyright. All rights reserved.

6.
Mol Aspects Med ; : 100909, 2020 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-33023753

RESUMO

Oxidized phospholipids (OxPLs), complex mixtures of phospholipid oxidation products generated during normal or pathological processes, are increasingly recognized to show bioactive effects on many cellular signalling pathways. There is a growing body of evidence showing that OxPLs play an important role in many diseases, so it is essential to define the specific role of OxPLs in different diseases for the design of disease therapies. In vastly diverse pathological processes, OxPLs act as pro-inflammatory agents and contribute to the progression of many diseases; in addition, they play a role in anti-inflammatory processes, promoting the dissipation of inflammation and inhibiting the progression of some diseases. In addition to participating in the regulation of inflammatory responses, OxPLs affect the occurrence and development of diseases through other pathways, such as apoptosis promotion. In this review, the different and even opposite effects of different OxPL molecular species are discussed. Furthermore, the specific effects of OxPLs in various diseases, as well as the receptor and cellular mechanisms involved, are summarized.

8.
Aging Clin Exp Res ; 2020 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-33026595

RESUMO

BACKGROUND: It was reported that inhaled corticosteroids (ICS) treatment may affect local immunity and microbial community of the airway. However, whether ICS treatment increases the risk of influenza in patients with asthma remains unclear. This meta-analysis aimed to compare the risk of influenza between ICS and non-ICS treatment in patients with asthma. METHODS: PubMed, Embase, Cochrane Library and Clinical Trials.gov were searched from inception until November 2019. Randomized controlled trials (RCTs) were included that compared ICS treatment with non-ICS treatment on the risk of influenza in patients with asthma. Meta-analyses were conducted by the Peto approach and Mantel-Haenszel approach with corresponding 95% CIs. RESULTS: Nine trials involving 6486 patients were included in this meta-analysis. The risk of influenza was not different between ICS treatment and the control groups (Peto OR: 1.01, 95% CI 0.74-1.37, P = 0.95). The results of subgroup analyses based on durations (long-term and short-term treatment), doses (high-, medium- and low-dose treatment) and types (fluticasone and budesonide treatment) of ICS were consistent with the above pooled results. Moreover, subgroup analysis based on patients' age also revealed that use of ICS did not increase the risk of influenza. Results of the two meta-analysis approaches were similar. CONCLUSIONS: Use of ICS does not increase the risk of influenza in patients with asthma. This study adds to safety evidence of ICS as a regular controller treatment for patients with asthma.

9.
J Ultrasound Med ; 2020 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-33026685

RESUMO

OBJECTIVES: To evaluate the feasibility of a new simple ultrasound-guided transforaminal injection in patients with cervical radiculopathy. METHODS: Ultrasound scans of the neck in a plastic model and in 5 unaffected participants were first performed to identify the intervertebral foramen. Then ultrasound-guided transforaminal injections were performed in 20 patients with radiculopathy in the lower cervical spine, and computed tomography was used to verify the accuracy. Complications, the visual analog score, and the neck disability index were assessed at 1 and 3 months after the injection. RESULTS: Computed tomography confirmed that the needle tip was correctly placed in the intervertebral foramen in 88.5% (23 of 26) of injections. No immediate or short-term complications were observed in all patients. The visual analog score and neck disability index at 1 and 3 months were significantly lower than those before the injection (both P < .0001). CONCLUSIONS: Ultrasound may be a feasible and accurate method to guide cervical transforaminal injection.

11.
Blood ; 2020 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-33036023

RESUMO

The final stages of mammalian erythropoiesis involve enucleation, membrane and proteome remodeling, and organelle clearance. Concomitantly, the erythroid membrane skeleton establishes a unique pseudohexagonal spectrin meshwork that is connected to the membrane through junctional complexes. The mechanism and signaling pathways involved in the coordination of these processes are unclear. Here we reveal an unexpected role of membrane skeleton in the modulation of proteome remodeling and organelle clearance during the final stages of erythropoiesis. We found that diaphanous-related formin mDia2 is a master regulator of the integrity of the membrane skeleton through polymerization of actin protofilament in the junctional complex. The mDia2-deficient terminal erythroid cell contained a disorganized and rigid membrane skeleton that was ineffective in detaching the extruded nucleus. In addition, the disrupted skeleton failed to activate the ESCRT-III complex, which led to a global defect in proteome remodeling, endolysosomal trafficking, and autophagic organelle clearance. We revealed that Chmp5, a component of the ESCRT-III complex, is regulated by mDia2-dependent activation of serum response factor and required for membrane remodeling and autophagosome-lysosome fusion. Mice with loss of Chmp5 in hematopoietic cells in vivo resembled the phenotypes in mDia2 knockout mice. Furthermore, over-expression of Chmp5 in mDia2 deficient hematopoietic stem and progenitor cells significantly restored terminal erythropoiesis in vivo. These findings reveal a formin-regulated signaling pathway that connects membrane skeleton to proteome remodeling, enucleation, and organelle clearance during terminal erythropoiesis.

12.
Pharmacol Ther ; : 107697, 2020 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-33035577

RESUMO

Malaria has been a global epidemic health threat since ancient times. It still claims roughly half a million lives every year in this century. Artemisinin and its derivatives, are frontline antimalarial drugs known for their efficacy and low toxicity. After decades of wide use, artemisinins remain our bulwark against malaria. Here, we review decades of efforts that aim to understand the mechanism of action (MOA) of artemisinins, which help explain the specificity and potency of this anti-malarial drug. We summarize the methods and approaches employed to unravel the MOA of artemisinin over the last three decades, showing how the development of advanced techniques can help provide mechanistic insights and resolve some long-standing questions in the field of artemisinin research. We also provide examples to illustrate how to better repurpose artemisinins for anti-cancer therapies by leveraging on MOA. These examples point out a practical direction to engineer artemisinin for broader applications beyond malaria.

13.
Environ Model Softw ; : 104885, 2020 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-33041631

RESUMO

System-of-systems approaches for integrated assessments have become prevalent in recent years. Such approaches integrate a variety of models from different disciplines and modeling paradigms to represent a socio-environmental (or social-ecological) system aiming to holistically inform policy and decision-making processes. Central to the system-of-systems approaches is the representation of systems in a multi-tier framework with nested scales. Current modeling paradigms, however, have disciplinary-specific lineage, leading to inconsistencies in the conceptualization and integration of socio-environmental systems. In this paper, a multidisciplinary team of researchers, from engineering, natural and social sciences, have come together to detail socio-technical practices and challenges that arise in the consideration of scale throughout the socio-environmental modeling process. We identify key paths forward, focused on explicit consideration of scale and uncertainty, strengthening interdisciplinary communication, and improvement of the documentation process. We call for a grand vision (and commensurate funding) for holistic system-of-systems research that engages researchers, stakeholders, and policy makers in a multi-tiered process for co-creation of knowledge and solutions to major socio-environmental problems.

14.
Theranostics ; 10(24): 11197-11214, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33042278

RESUMO

Rationale: The development of a highly effective and tumor-specific therapeutic strategy, which can act against the primary tumor and also condition the host immune system to eliminate distant tumors, remains a clinical challenge. Methods: Herein, we demonstrate a facile yet versatile ZnO-capping and Doxorubicin (DOX)-loaded multifunctional nanocomposite (AuNP@mSiO2@DOX-ZnO) that integrates photothermal properties of gold nanoparticles (NPs), pH-responsive properties and preferential selectivity to tumor cells of ZnO QDs and chemotherapeutic agent into a single NP. The photothermal performance, pH-triggered release and preferential phagocytic ability were assessed. The induced anti-tumor immunity was determined by analyzing immune cell profile in tumor in vivo and molecular mechanism were identified by detecting expression of immunogenic cell death (ICD) markers in vitro. Moreover, mice models of unilateral and bilateral subcutaneous melanoma and lung metastasis were established to evaluate the antitumor effects. Results: As an efficient drug carrier, ZnO-capped NPs guarantee a high DOX payload and an in vitro, efficient release of at pH 5.0. In murine melanoma models, the nanocomposite can significantly inhibit tumor growth for a short period upon low-power laser irradiation. Importantly, ZnO NPs not only demonstrate preferential selectivity for melanoma cells but can also induce ICD. Meanwhile, AuNP@mSiO2-based photothermal therapy (PTT) and DOX are directly cytotoxic towards cancer cells and demonstrate an elevated ICD effect. The induced ICD promotes maturation of dendritic cells, further stimulating the infiltration of effector T cells into tumor sites, preventing tumor growth and distant lung metastases. Conclusions: This study highlights the novel mechanism of ZnO-triggered anti-tumor immunity via inducing ICD. Additionally, we shed light on the multifunctionality of nanocomposites in delivering localized skin tumor therapy as well as inhibiting metastatic growth, which holds great promise in clinical applications.

15.
Artigo em Inglês | MEDLINE | ID: mdl-33046243

RESUMO

Acidithiobacillus ferrooxidans ATCC23270 is a gram-negative and autotrophic bacillus acquiring energy via the oxidation of iron and sulfur. The pet II operon is involved in the sulfur metabolism of A. ferrooxidans. However, the mechanisms that control the expression of the pet II operon are poorly understood. We previously described that the AFE2726 protein is associated with the expression of the pet II operon. Here, we attempted to analyze the involvement of AFE2726 in the regulation of pet II operon expression. First, pEGF recombinant vectors driven by the promotor of the pet II operon, denoted pEGF-pet II, were constructed. Then, DH5α E. coli cultures containing the vector mentioned above were cultivated in Na2S2O3, as this medium substantially enhances the expression of green fluorescent proteins. To examine the regulatory effect of AFE2726 on the pet II operon, the C62/V and C72/V mutants for AFE2726 were constructed in pEGF-pet II vectors using the site-directed deletion method. Compared to pEFG-pet II and pEFG-pet II-Δ-C62/V, pEFG-pet II-Δ-C72/V reduced the expression of green fluorescent proteins dramatically when transformed into DH5α E.coli in Na2S2O3 medium. This suggested that the 72nd cysteine was a crucial residue of the AFE2726 protein, affecting the response of the pet II operon to sodium thiosulfate. Furthermore, the binding site of AFE2726 on the promotor of the pet II operon was identified using the electrophoretic mobility shift assay (EMSA), and it was found to be a 34bp inverted repeat sequence (named IR4), which ranged from -65 to -32. In summary, our results indicated that the AFE2726 protein regulates the pet II operon by binding to the IR4 sequence in its promotor region, whose function is likely affected by Na2S2O3 binding to its Cys72 residue counterpart.

16.
Org Lett ; 22(20): 7930-7935, 2020 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-33001654

RESUMO

Three unprecedented cytochalasan homodimers, bisaspochalasins A-C (1-3), and two known monomers, aspochalasins B and D (4 and 5), were isolated from an endophytic Aspergillus flavipes. Bisaspochalasin A (1) contains a 13-hydroxy-3,24-dioxatricyclo[11.10.11,13.02,15]tetracos-4-one cross-linkage, representing an unprecedented carbon skeleton. Bisaspochalasins B (2) and C (3) share a thioether bridge, while 3 has a peroxy modification at C-7, which may be generated by Schenck-ene photooxygenation. Their structures, including their absolute configurations, were elucidated by HRESIMS, NMR, chemical transformation, and X-ray crystallography. Bisaspochalasin A showed inhibitory activity against human T cell proliferation with an IC50 value of 15.8 µM while maintaining low cytotoxicity to T cells.

17.
Arthritis Res Ther ; 22(1): 239, 2020 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-33054864

RESUMO

BACKGROUND: Necroptosis is a form of regulated necrosis that is involved in various autoimmune diseases. Mixed lineage kinase domain-like pseudokinase (MLKL) has been identified as a key executor of necroptosis; however, the significance of MLKL in peripheral blood mononuclear cells (PBMCs) of systemic lupus erythematosus (SLE) has not been investigated. In this study, we aimed to determine the mRNA level of MLKL in PBMCs and examine its relationship with clinical features and serological parameters in SLE. METHODS: Real-time transcription-polymerase chain reaction (RT-PCR) analysis was used to determine the expression of MLKL mRNA in PBMCs from 59 patients with SLE, 25 patients with rheumatoid arthritis (RA), and 30 age- and sex-matched healthy controls (HC). Spearman's correlation test was performed to assess the correlation of MLKL mRNA with clinical variables. The receiver operating characteristic (ROC) curve was created to evaluate the diagnostic value. RESULTS: Our results showed MLKL mRNA in PBMCs was upregulated in SLE patients compared to that in RA and HC individuals. SLE patients positive for antinuclear antibodies had significantly higher MLKL mRNA than antibody-negative patients. In SLE patients, MLKL mRNA was found to be upregulated in patients with lupus nephritis (LN) as compared with patients without LN, and also higher in active patients than in stable patients. MLKL mRNA level was significantly and positively correlated with c-reaction protein (CRP) (r = 0.3577, p = 0.0237), erythrocyte sedimentation rate (ESR) (r = 0.4091, p = 0.0043), serum immunoglobulin G (IgG) concentration (r = 0.3546, p = 0.0289), and the numbers of positive antinuclear antibodies (ANAs) (r = 0.3945, p = 0.0432). ROC analysis showed that MLKL mRNA in PBMCs had an area under the curve of 0.9277 (95% CI 0.8779-0.9775, p < 0.001) to discriminate SLE from controls. CONCLUSIONS: These results suggest that increased MLKL mRNA level in the PBMCs of SLE patients is correlated with renal involvement and disease activity, identifying a subgroup of patients with SLE or LN who may benefit from early diagnosis and therapies targeting MLKL.

18.
J Struct Biol ; : 107601, 2020 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-33068699

RESUMO

Electron cryo-microscopy (cryoEM) involves the estimation of spatial rotations, or saying orientations, of projection images or three-dimensional (3D) volumes. Euler angle system is widely used to describe spatial rotations in most cryoEM algorithms and software. In this review, we introduce unit quaternion as an alternate to Euler angles for describing spatial rotations, customize and develop corresponding tools for increasing demands of statistical analysis of spatial rotations in cryoEM. Some basic properties and definitions of quaternion are first recalled. Thereafter, distance and geodesic between rotations are introduced to aid comparisons and interpolations between rotations, which are prerequisites of statistics of rotations in 3D cryoEM. Furthermore, statistics of rotations are reviewed. Techniques potentially useful in cryoEM, such as calculations of the average rotation, generation of quasi-regular grids, sampling, inference with uniform distribution and angular central Gaussian (ACG) distribution, and estimation of rotation precision, are reviewed and developed. Finally, molecular symmetry presented in unit quaternion form is discussed. Unit quaternion system is shown as a convenient and comprehensive mathematical tool for cryoEM.

19.
Sci Rep ; 10(1): 17399, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-33060650

RESUMO

In this study, the effects of different feeding frequencies on the growth and the expression of genes in the GH/IGF axis were assessed in juvenile Chinese sturgeon. The newly hatched Chinese sturgeons were bred for 38 days at three different feeding frequencies groups (feeding frequency of two times a day, TWD; three times a day, THD; and four times a day, FOD), and the expression levels of the GH/IGF axis responses to feeding frequency were determined by quantitative real-time PCR. In addition, the full-length of the Coding Sequences of IGF I and IGF II genes (489-bp and 660-bp, respectively), were cloned and analyzed from Chinese sturgeon the first time. Multiple sequence alignments of IGFs revealed that Chinese sturgeon are high sequence identity to IGFs from other species. The phylogenetic relationships based on the IGF I and IGF II amino acid sequences were consistent with the traditional classification. After 38 days of growth, the three different feeding frequencies groups of Chinese sturgeon had no significant difference of body length, body weight, specific growth rate, the survival rate, the rate of weight gain and the condition factor. However, the relative expression of Chinese sturgeon GH in the pituitary decreased with increasing feeding frequency. The relative expression of Chinese sturgeon GHR in liver and skeletal muscle was deceased with increasing feeding frequency, while the relative expression of GHR in stomach and intestines at THD group was significantly higher than that of at TWD group and FOD group (p < 0.05). The relative expression of Chinese sturgeon IGF I in liver increased significantly with increasing feeding frequency (p < 0.05). The relative expression of IGF I in stomach and skeletal muscle was similar at the three groups. The relative expression of IGF I in intestines was significantly higher at FOD group than at TWD group and THD group (p < 0.05). The relative expression of Chinese sturgeon IGF II in liver at TWD group was significantly higher than that at THD group and FOD group (p < 0.05). However, the relative expression of IGF II in stomach, intestines and skeletal muscle at THD group was higher than that at TWD group and FOD group. Based on these previous studies that liver IGF I is regarded as a biomarker of growth performance, this result suggested that the juvenile Chinese sturgeon is better for growth when feeding four times daily compared to twice and thrice daily.

20.
Artigo em Inglês | MEDLINE | ID: mdl-33025280

RESUMO

PURPOSE: Nasal type extranodal natural killer/T-cell lymphoma (ENKTL) can be associated with hemophagocytic lymphohistiocytosis (NK/T-LAHLH), which is a rare and fatal disease with no effective therapy. We evaluated whether etoposide + dexamethasone-based chemotherapy regimens might be useful for treating NK/T-LAHLH. METHODS: This retrospective single-center study evaluated clinical data from 37 patients with NK/T-LAHLH who were treated between May 2008 and January 2020. RESULTS: Among 363 patients with ENKTL, the cumulative incidence of HLH was 11.9%. Among 43 patients with NK/T-LAHLH, 37 patients received etoposide + dexamethasone-based chemotherapy regimens, with an overall response rate of 45.9% for the HLH. The overall response rate was substantially higher for newly diagnosed NK/T-LAHLH than it was for relapsed or refractory NK/T-LAHLH (66.7% vs. 18.8%). The median overall follow-up time was 4 months, with overall survival rates of 81.1% at 1 month, 62.2% at 2 months, 56.8% at 3 months, and 34.4% at 6 months. Significantly better overall survival (all P < 0.05) was observed for patients with newly diagnosed NK/T-LAHLH (vs. relapsed/refractory disease), stage I/II disease (vs. stage III/IV disease), and nasal disease (vs. non-nasal disease). Patients who responded to the ENKTL treatment also experienced response in their HLH; 8 patients experienced continued complete response for both HLH and ENKTL. Multivariate analysis revealed that a poor prognosis among patients with NK/T-LAHLH was independently related to relapsed/refractory ENKTL and non-nasal disease. CONCLUSION: Although patients with NK/T-LAHLH generally experienced poor outcomes, etoposide + dexamethasone-based chemotherapy regimens were associated with good outcomes among select patients with newly diagnosed or stage I/II NK/T-LAHLH.

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