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1.
Am J Bot ; 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31944266

RESUMO

PREMISE: Apocynaceae is common in the fossil record, especially as seed remains from the Neogene of Europe and North America, but rare in Asia. Intrafamilial assignment is difficult due to the lack of diagnostic characters, and new fossil and modern data are needed to understand the paleobiogeography of this group. METHODS: We studied three Apocynaceae seed impressions from the Lower Eocene Niubao Formation, Jianglang village, Bangor County, central Qinghai-Tibetan Plateau. Morphological data from living and fossil species were phylogenetically mapped to enable systematic assignment. RESULTS: We describe a new genus, Asclepiadospermum gen. nov., and two new species, A. marginatum sp. nov. and A. ellipticum sp. nov. These species are characterized by an elliptical seed, a margin surrounding the central part of the seed, and polygonal, irregular, and small epidermal cells, and differ mainly in terms of the size of the margin and the shape of the apex. All these characters indicate that this new genus belongs to the subfamily Asclepiadoideae (Apocynaceae). CONCLUSIONS: These fossils represent the earliest fossil seed records of Asclepiadoideae. Asclepiadospermum indicates a humid tropical to subtropical flora during the early Eocene in central Tibet. Moreover, our discoveries indicate a close floristic connection between Eurasia and Africa during the early Eocene, which expands our knowledge of the floristic linkage between Tibet and other regions at that time.

2.
Nat Immunol ; 2020 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-31932812

RESUMO

Cancer cells subvert immune surveillance through inhibition of T cell effector function. Elucidation of the mechanism of T cell dysfunction is therefore central to cancer immunotherapy. Here, we report that dual specificity phosphatase 2 (DUSP2; also known as phosphatase of activated cells 1, PAC1) acts as an immune checkpoint in T cell antitumor immunity. PAC1 is selectively upregulated in exhausted tumor-infiltrating lymphocytes and is associated with poor prognosis of patients with cancer. PAC1hi effector T cells lose their proliferative and effector capacities and convert into exhausted T cells. Deletion of PAC1 enhances immune responses and reduces cancer susceptibility in mice. Through activation of EGR1, excessive reactive oxygen species in the tumor microenvironment induce expression of PAC1, which recruits the Mi-2ß nucleosome-remodeling and histone-deacetylase complex, eventually leading to chromatin remodeling of effector T cells. Our study demonstrates that PAC1 is an epigenetic immune regulator and highlights the importance of targeting PAC1 in cancer immunotherapy.

3.
Artigo em Inglês | MEDLINE | ID: mdl-31808338

RESUMO

We report the design, preparation of hierarchical hollow-pore nanostructure bilayer conjugated polymer films for high performance resistive memory devices. By taking the merits of chemical and structural stability of two-dimensional conjugated microporous polymer (2D CMP), a poly[2-methoxy-5-(2-ethylhexyloxy)-1,4- phenylenevinylene] (MEH-PPV) film with hollow surface was spin coated onto 2D CMP nanofilm directly, constructing the bilayer heterojunction. A two-terminal diode with a configuration of ITO/2D CMP/hollow MEH-PPV/Al was fabricated by employing the prepared bilayer heterojunction. The device poses flash feature with a high On/Off ratio (>105) and long retention time (>3.0×104 s), which is higher than most of the reported conjugated polymers memories. Our work offers a general guideline to construct high On/Off ratio polymer memories via hierarchical nanostructure engineering in memristive layer.

4.
Medicine (Baltimore) ; 98(52): e18500, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31876738

RESUMO

Developmental dysplasia of the hip (DDH) is common, and features a widened Sharp's angle as observed on pelvic x-ray images. Determination of Sharp's angle, essential for clinical decisions, can overwhelm the workload of orthopedic surgeons. To aid diagnosis of DDH and reduce false negative diagnoses, a simple and cost-effective tool is proposed. The model was designed using artificial intelligence (AI), and evaluated for its ability to screen anteroposterior pelvic radiographs automatically, accurately, and efficiently.Orthotopic anterior pelvic x-ray images were retrospectively collected (n = 11574) from the PACS (Picture Archiving and Communication System) database at Second Hospital of Jilin University. The Mask regional convolutional neural network (R-CNN) model was utilized and finely modified to detect 4 key points that delineate Sharp's angle. Of these images, 11,473 were randomly selected, labeled, and used to train and validate the modified Mask R-CNN model. A test dataset comprised the remaining 101 images. Python-based utility software was applied to draw and calculate Sharp's angle automatically. The diagnoses of DDH obtained via the model or the traditional manual drawings of 3 orthopedic surgeons were compared, each based on the degree of Sharp's angle, and these were then evaluated relative to the final clinical diagnoses (based on medical history, symptoms, signs, x-ray films, and computed tomography images).Sharp's angles on the left and right measured via the AI model (40.07°â€Š±â€Š4.09° and 40.65°â€Š±â€Š4.21°), were statistically similar to that of the surgeons' (39.35°â€Š±â€Š6.74° and 39.82°â€Š±â€Š6.99°). The measurement time required by the AI model (1.11 ±â€Š0.00 s) was significantly less than that of the doctors (86.72 ±â€Š1.10, 93.26 ±â€Š1.12, and 87.34 ±â€Š0.80 s). The diagnostic sensitivity, specificity, and accuracy of the AI method for diagnosis of DDH were similar to that of the orthopedic surgeons; the diagnoses of both were moderately consistent with the final clinical diagnosis.The proposed AI model can automatically measure Sharp's angle with a performance similar to that of orthopedic surgeons, but requires far less time. The AI model may be a viable auxiliary to clinical diagnosis of DDH.


Assuntos
Luxação Congênita de Quadril/diagnóstico por imagem , Pelve/diagnóstico por imagem , Interpretação de Imagem Radiográfica Assistida por Computador , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Inteligência Artificial , Criança , Luxação Congênita de Quadril/diagnóstico , Humanos , Pessoa de Meia-Idade , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Radiografia/métodos , Estudos Retrospectivos , Adulto Jovem
5.
Clin Biochem ; 2019 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-31765635

RESUMO

BACKGROUND: Identification and treatment in the early stage can significantly improve the prognosis of gastric cancer (GC). However, to date, there is still no ideal biomarker that can be used for the screening of early stage GC (EGC). The proteomics supported by mass spectrometry offers more possibilities for discovering tumor biomarkers. The aim of this study was to explore candidate protein biomarkers for EGC screening with mass spectrometry and bioinformatics technology. METHODS: Plasma samples were collected from 15 EGC patients and 15 healthy controls. After a selective immune-depletion to remove high abundance proteins, plasma samples were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) combined with the tandem mass tags (TMT) labeling. RESULTS: A total of 2040 proteins were identified, and 11 proteins were found to be differentially expressed. The results of the logistic regression model and orthogonal signal correction-partial least squares discriminant analysis (OPLS-DA) model showed that the changed proteins identified by plasma proteomics could help distinguish EGC patients from healthy controls. CONCLUSION: The proteins identified by plasma proteomics using LC-MS/MS combined with TMT labeling could help distinguish EGC from healthy controls.

6.
J Endourol ; 33(11): 914-919, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31596612

RESUMO

Objective: To demonstrate the safety and efficacy of flexible ureteroscopy lithotripsy (FURL) and miniaturized percutaneous nephrolithotomy (MPCNL) through the comparative studies in treating medium-sized lower-pole renal calculi. Methods: Two hundred and twenty eligible patients with lower-pole renal calculi (1-2 cm) were enrolled and further randomly assigned into FURL group and MPCNL group. Patients' demographics, preoperative characteristics, intraoperative and postoperative complications, stone-free rate, and comfort and pain indicated by Bruggrmann Comfort Scale (BCS) and visual analog scale (VAS) were evaluated and recorded. Trauma index such as white blood cells, C-reactive protein (CRP), and interleukin (IL)-6 were also detected. Results: The stone-free rate and the operating time were comparable in FURL and MPCNL groups. Intraoperative and postoperative complication analysis showed that blood loss and hospital stay were significantly lower in the FURL group compared with MPCNL group. No significant difference in minor pelvic perforation, false passage, hemoglobin drop, persistent hematuria, ureteral perforation, moderate fever, urosepsis, and postoperative serum creatinine level was observed. However, as to comfort and pain indicated by BCS and VAS and stress indicated by CRP and IL-6, FURL was superior to MPCNL. Conclusion: FURL could be a better alternative surgical method to MPCNL with similar curative effect and less blood loss and hospital stay.

7.
DNA Cell Biol ; 38(11): 1223-1232, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31566423

RESUMO

To date, the clinical course of idiopathic membranous nephropathy (iMN) remains unclear and lacks direct and effective diagnostic methods. To better understand the host gene expression changes involved in the iMN process and identify the potential signatures for clinical diagnosis, we performed a whole genome-wide transcriptome profile of peripheral blood cells (PBC) from patients with iMN and healthy controls (HCs). A total of 188 differentially expressed genes (DEGs) were detected in patients with iMN versus HCs. Gene ontology (GO) functional enrichment and Kyoto Encyclopedia of Genes and Genomes pathway analysis showed that these DEGs were mainly correlated with protein targeting, ion homeostasis GO terms, and ribosome and phagosome pathways. The top 10 differentially expressed protein-coding genes with >2-fold changes and high expression levels were validated using quantitative real-time PCR, and showed high consistency with the high-throughput sequencing results. HLA-C, S100A8, and FTH1 genes were selected for further validation and showed the most significant difference between the iMN and HC group, indicating that they could be used as potential clinical diagnostic biomarkers. Our results provide novel potential diagnostic signatures for iMN and have important implications for better understanding the pathogenesis of iMN.


Assuntos
Biomarcadores/sangue , Células Sanguíneas/metabolismo , Glomerulonefrite Membranosa , Transcriptoma , Biomarcadores/análise , Estudos de Casos e Controles , Perfilação da Expressão Gênica , Glomerulonefrite Membranosa/sangue , Glomerulonefrite Membranosa/diagnóstico , Glomerulonefrite Membranosa/genética , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , RNA/análise , Reação em Cadeia da Polimerase em Tempo Real , Análise de Sequência de RNA
8.
Photodiagnosis Photodyn Ther ; 28: 343-345, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31614224

RESUMO

Hidradenitis suppurativa (HS) is a type of chronic suppurative inflammatory reaction of the hair follicles characterized by recurrent dermal abscesses, sinus tracts and scars. In this report, one case of severe hypertrophic scar induced by facial HS achieved resolution of skin lesions after combined treatment with high concentration single-dose 5-aminolevulinic acid photodynamic therapy (5-ALA PDT). No recurrence was observed up to eleven months of follow-up. The 5-ALA PDT based treatment could improve the severe hypertrophic scar induced by HS in an effective and safe manner.

9.
Res Vet Sci ; 126: 233-239, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31635840

RESUMO

In this study, canine adipose-derived mesenchymal stem cells (cADSCs) therapeutic potential was investigated in artificially induced acute liver injury model by CCl4 in canines. The primary cADSCs cells were cultured and then intravenously administered into the canine animal model. Six cross-breed dogs were divided into three groups including blank control group, CCl4 model group, CCl4 induced cADSCs transplantation group. The results showed that after intraperitoneal injection of CCl4 solution, the levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and Albumin (ALB) in peripheral blood of experimental canines confirmed the correct induction of acute liver injury. Moreover, the liver structure showed clear macroscopic damage. The cADSCs were homed in the liver of the administered animals. The AST, ALT and ALB in the peripheral blood rapidly decreased. H&E and PAS histological evaluation showed that both the structure of canine liver tissue and the ability to synthesize hepatic glycogen could be restored to the control level after cADSCs transplantation. Therefore, cADSCs can play a therapeutic role in the recovery of liver injury. Overall, this study demonstrates that the primary cADSCs transplantation into the acute liver injury model induced by intravenous injection can play a certain therapeutic role in the recovery of liver in canines. These results may provide a new treatment idea for acute liver disease in pets clinically.

10.
Arch Pharm Res ; 42(11): 1021-1029, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31549342

RESUMO

Some flavonoids have been shown to exhibit good antioxidant activity and protect mice from damage induced by radiation. Amentoflavone (AMF), a biflavonoid derived from the traditional herb-Selaginella tamariscina, has been reported to have antioxidant properties. The protective effects and mechanism of action of AMF against radiation injury remain unknown. In this study, male C57BL/6 mice were subjected to total-body 60Co γ-irradiation at 7.5 or 3.0 Gy. The survival rate and mean survival time were evaluated to determine the radioprotective effect of AMF. Number of peripheral blood cells, frequency of colony forming unit-granulocytes, monocytes and micronuclei were measured to assess the protective effects of AMF on the hematopoietic system. Levels of superoxide dismutase and glutathione, and pathological changes in the bone marrow were determined. Additionally, next-generation sequencing technology was used to explore potential targets of AMF. We observed that AMF markedly extends average survival time, reduces injury to the hematopoietic system and promotes its recovery. Furthermore, treatment with AMF significantly attenuated radiation-induced oxidative stress. In addition, AMF had a significant effect on gene tumor necrosis factor alpha-induced protein 2. Together, the results of this study suggest that AMF is a potential protective agent against radiation injury.

11.
J Colloid Interface Sci ; 556: 753-760, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31526914

RESUMO

In this study, we examined the potential for perylene dye doped nanoparticles to enhance Light Emitting Diodes (LED) efficacy by minimizing π-π intermolecular aggregation, and enhancing photoluminescence and photostability of the dye molecules in the solid state. Towards this end, we encapsulated perylene dyes, suitably modified with a reactive silica precursor, into silica nanoparticles within a silica-dye-silica concentric layered shell. We found that the fluorescent yield was higher when the dye was embedded in a buried concentric shell within the silica nanoparticles (NPs) compared to an undoped shell/dye doped core nanoparticle morphology or unencapsulated dye with the same net dye concentration in solution. A strong dependence of relative quantum yield on dye doping concentration in the silica-dye-silica nanoparticles was observed. The uniform ∼ 100 nm large silica-dye-silica layered nanoparticles were used to prepare transparent dye doped silica nanoparticle/silicone nanocomposites. Dye doped silica nanoparticle/silicone nanocomposites exhibited higher photostability than the unencapsulated dye samples during long time aging tests under a blue LED with a wavelength of 455 nm at 300 ±â€¯3% mA for 24 h. Novel dye doped layered silica NPs and their nanocomposites offer scope for developing organic luminescent materials into efficient and color-tunable light emitters for low-cost display, lighting, and optical communication applications.

12.
ACS Appl Mater Interfaces ; 11(41): 38061-38067, 2019 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-31535551

RESUMO

MXenes, an emerging class of two-dimensional (2D) transition-metal carbide materials, have received increasing attention for their interesting physiochemical properties. For not only MXenes but also other 2D materials, delamination is a requisite step for the exploitation of their unique properties. In this work, a facile method for exfoliating Ti3C2Tx MXene to nanosheets of small size with the aid of poly(vinylpyrrolidone) (PVP) is designed, which has never been reported to our knowledge. Since both hydrophobic methylene groups and hydrophilic amide groups are provided with PVP, this method is applicable in a wide range of solvents, such as ethanol, water, and chloroform. Considering the charge detrapping and trapping behavior of 2D transition-metal materials in PVP dielectric, a memory device with the configuration of reduced graphene oxide (rGO)/Ti3C2Tx-PVP/Au is directly fabricated with these well-dispersed Ti3C2Tx-PVP composites by the solution process technique. Interestingly, the resultant device exhibits a typical bistable electrical switching, ultralow switching voltage (∼0.9 V), and a nonvolatile rewritable memory effect with the function of flash. This work might pave the way of using MXenes for future data storage, which is an indispensable field nowadays.

13.
Aging (Albany NY) ; 11(16): 6398-6421, 2019 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-31449493

RESUMO

Type 2 diabetes (T2D) can result in a number of comorbidities involving various organs including heart, eye, kidney and even the brain. However, little is known about the molecular basis of T2D associated brain disorders. In this study, we performed a comprehensive transcriptomic analysis in a total of 304 T2D samples and 608 matched control samples from thirteen distinct brain regions. We observed prominent difference among transcriptomic profiles of diverse brain regions in T2D. The most striking change was found in caudate with thousands of T2D-associated genes identified, followed by hippocampus, while nearly no transcriptomic change was observed in other brain regions. Functional analysis of T2D-associated genes revealed impaired synaptic functions and an association with neurodegenerative diseases. Co-expression analysis of caudate transcriptomic profiles unveiled a core regional specific module that was disorganized in T2D. Sub-modules consisting of regional markers were enriched in T2D risk single nucleotide polymorphisms (SNPs) and implied a causal link with T2D. Hub genes of this module include NSF and ADD2, the former of which has been associated with T2D and neurogenerative diseases. Thus, our work provides useful information for further studies in T2D associated brain disorders.

14.
Sci Rep ; 9(1): 10337, 2019 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-31316141

RESUMO

Building stretchable memory is an effective strategy for developing next-generation memory technologies toward stretchable and wearable electronics. Here we demonstrate a universal strategy for the fabrication of high performance stretchable polymer memory via tailoring surface morphology, in which common conjugated polymers and sharp reduced graphene oxide (r-rGO) films are used as active memristive layers and conductive electrodes, respectively. The fabricated devices feature write-once-read-many-times (WORM) memory, with a low switching voltage of 1.1 V, high ON/OFF current ratio of 104, and an ideal long retention time over 12000 s. Sharp surface-induced resistive switching behavior has been proposed to explore the electrical transition. Moreover, the polymer memory show reliable electrical bistable properties with a stretchability up to 30%, demonstrating their great potential candidates as high performance stretchable memory in soft electronics.

15.
Environ Sci Technol ; 53(15): 8883-8891, 2019 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-31284712

RESUMO

Surface defects have been shown to facilitate electron transfer between Fe(II) and goethite (α-FeOOH) in abiotic systems. It is unclear, however, whether defects also facilitate microbial goethite reduction in anoxic environments where electron transfer between cells and Fe(III) minerals is the limiting factor. Here, we used stable Fe isotopes to differentiate microbial reduction of goethite synthesized by hydrolysis from reduction of goethite that was further hydrothermally treated to remove surface defects. The goethites were reduced by Geobacter sulfurreducens in the presence of an external electron shuttle, and we used ICP-MS to distinguish Fe(II) produced from the reduction of the two types of goethite. When reduced separately, goethite with more defects has an initial rate of Fe(III) reduction about 2-fold higher than goethite containing fewer defects. However, when reduced together, the initial rate of reduction is 6-fold higher for goethite with more defects. Our results suggest that there is a suppression of the reduction of goethite with fewer defects in favor of the reduction of minerals with more defects. In the environment, minerals are likely to contain defects and our data demonstrates that even small changes at the surface of iron minerals may change their bioavailability and determine which minerals will be reduced.


Assuntos
Compostos Férricos , Compostos de Ferro , Disponibilidade Biológica , Minerais , Oxirredução
16.
Ann Bot ; 123(7): 1147-1158, 2019 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-30861064

RESUMO

BACKGROUND AND AIMS: The inverse correlation between atmospheric CO2 partial pressure (pCO2) and stomatal frequency in many plants has been widely used to estimate palaeo-CO2 levels. However, apparent discrepancies exist among the obtained estimates. This study attempts to find a potential proxy for palaeo-CO2 concentrations by analysing the stomatal frequency of Quercus glauca (section Cyclobalanopsis, Fagaceae), a dominant species in East Asian sub-tropical forests with abundant fossil relatives. METHODS: Stomatal frequencies of Q. glauca from three material sources were analysed: seedlings grown in four climatic chambers with elevated CO2 ranging from 400 to 1300 ppm; extant samples collected from 14 field sites at altitudes ranging from 142 to 1555 m; and 18 herbarium specimens collected between 1930 and 2011. Stomatal frequency-pCO2 correlations were determined using samples from these three sources. KEY RESULTS: An inverse correlation between stomatal frequency and pCO2 was found for Q. glauca through cross-validation of the three material sources. The combined calibration curves integrating data of extant altitudinal samples and historical herbarium specimens improved the reliability and accuracy of the curves. However, materials in the climatic chambers exhibited a weak response and relatively high stomatal frequency possibly due to insufficient treatment time. CONCLUSIONS: A new inverse stomatal frequency-pCO2 correlation for Q. glauca was determined using samples from three sources. These three material types show the same response, indicating that Q. glauca is sensitive to atmospheric pCO2 and is an ideal proxy for palaeo-CO2 levels. Quercus glauca is a nearest living relative (NLR) of section Cyclobalanopsis fossils, which are widely distributed in the strata of East Asia ranging from the Eocene to Pliocene, thereby providing excellent materials to reconstruct the atmospheric CO2 concentration history of the Cenozoic. Quercus glauca will add to the variety of proxies that can be widely used in addition to Ginkgo and Metasequoia.

17.
Cell Prolif ; 52(3): e12591, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30896067

RESUMO

OBJECTIVES: To date, many efforts have been made to establish porcine embryonic stem (pES) cells without success. Extraembryonic endoderm (XEN) cells can self-renew and differentiate into the visceral endoderm and parietal endoderm. XEN cells are derived from the primitive endoderm of the inner cell mass of blastocysts and may be an intermediate state in cell reprogramming. MATERIALS AND METHODS: Porcine XEN cells (pXENCs) were generated from porcine pluripotent stem cells (pPSCs) and were characterized by RNA sequencing and immunofluorescence analyses. The developmental potential of pXENCs was investigated in chimeric mouse embryos. RESULTS: Porcine XEN cells derived from porcine pPSCs were successfully expanded in N2B27 medium supplemented with bFGF for least 30 passages. RNA sequencing and immunofluorescence analyses showed that pXENCs expressed the murine and canine XEN markers Gata6, Gata4, Sox17 and Pdgfra but not the pluripotent markers Oct4, Sox2 and TE marker Cdx2. Moreover, these cells contributed to the XEN when injected into four-cell stage mouse embryos. Supplementation with Chir99021 and SB431542 promoted the pluripotency of the pXENCs. CONCLUSIONS: We successfully derived pXENCs and showed that supplementation with Chir99021 and SB431542 confer them with pluripotency. Our results provide a new resource for investigating the reprogramming mechanism of porcine-induced pluripotent stem cells.


Assuntos
Endoderma/citologia , Endoderma/embriologia , Suínos/embriologia , Animais , Técnicas de Cultura de Células , Diferenciação Celular , Linhagem Celular , Técnicas de Cocultura , Cães , Células-Tronco Embrionárias/citologia , Células-Tronco Embrionárias/metabolismo , Endoderma/metabolismo , Expressão Gênica , Camundongos , Células-Tronco Pluripotentes/citologia , Células-Tronco Pluripotentes/metabolismo , Análise de Sequência de RNA , Transdução de Sinais , Suínos/genética , Suínos/metabolismo , Quimeras de Transplante
18.
Biochem Biophys Res Commun ; 512(4): 793-798, 2019 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-30926164

RESUMO

Influenza A virus (IAV) is highly contagious and causes considerable mortality worldwide. TLR3, 7, 8 and 9 recognize viral nucleic acids and rapidly trigger different signaling cascades that contribute to the production of interferons (IFNs) to antiviral defense. Therefore, a host immune response induced by the activation of these receptors can be used as a new antiviral strategy. In this study, the protective effect of sodium ferulate (SF) is investigated on mice infected with influenza virus A/FM/1/47(H1N1). SF improved survival and mitigated weight loss in infected mice. SF inhibited influenza virus replication by activating TLR7 and TLR9, which resulted in the promotion of IRF7 translocation into the nucleus and the production of typeⅠIFNs. Moreover, SF inhibited the NF-κB pathway by preventing p65 translocation from the cytoplasm to the nucleus. These findings demonstrate that SF plays a critical role in protection against IAV infection by activation of the TLR7/9-MyD88-IRF7 signaling pathway and inhibition of the NF-κB signaling pathway.

19.
Environ Sci Process Impacts ; 21(3): 456-468, 2019 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-30714588

RESUMO

The mobilization of arsenic (As) from riverbank sediments affected by the gold mining legacy in north-central South Dakota was examined using aqueous speciation chemistry, spectroscopy, and diffraction analyses. Gold mining resulted in the discharge of approximately 109 metric tons of mine waste into Whitewood Creek (WW) near the Homestake Mine and Cheyenne River at Deal Ranch (DR), 241 km downstream. The highest concentrations of acid-extractable As measured from solid samples was 2020 mg kg-1 at WW and 385 mg kg-1 at DR. Similar sediment mineralogy between WW and DR was identified using XRD, with the predominance of alumino-silicate and iron-bearing minerals. Alkalinity measured in surface water at both sites ranged from 1000 to 2450 mg L-1 as CaCO3 (10-20 mM HCO3- at pH 7). Batch laboratory experiments were conducted under oxidizing conditions to evaluate the effects of NaHCO3 (0.2 mM and 20 mM) and NaH2PO3 (0.1 and 10 mM) on the mobilization of As. These ions are relevant for the site due to the alkaline nature of the river and nutrient mobilization from the ranch. The range of As(v) release with the NaHCO3 treatment was 17-240 µg L-1. However, the highest release (6234 µg L-1) occurred with 10 mM NaH2PO3, suggesting that As release is favored by competitive ion displacement with PO43- compared to HCO3-. Although higher total As was detected in WW solids, the As(v) present in DR solids was labile when reacted with NaHCO3 and NaH2PO3, which is a relevant finding for communities living close to the river bank. The results from this study aid in a better understanding of As mobility in surface water sites affected by the mining legacy.


Assuntos
Monitoramento Ambiental/métodos , Arsênico , Bicarbonatos , Sedimentos Geológicos , Ferro , Mineração , North Dakota , Fosfatos , Rios , South Dakota , Água , Poluentes Químicos da Água
20.
Langmuir ; 35(11): 3871-3879, 2019 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-30807181

RESUMO

We study the effect of the microenvironment on writing chemical patterns into spirothiopyran monolayers over large areas in a single step with light. Surfaces functionalized with photoresponsive spirothiopyran are fabricated by chemically modifying amine-terminated monolayers. The merocyanine isomer selectively participates in a thiol-Michael addition reaction with maleimide-functionalized molecules, rendering these surfaces ideal for fast, mask-less direct writing. The local microenvironment of spirothiopyran is found to strongly influence the kinetics of photoswitching. The quantum yield of ring opening is found to be 17 times faster for spirothiopyran surrounded by a locally charged environment rich in guanidinium diluent molecules as compared to a closed-packed monolayer without diluents. Hydrophilic environments are also found to improve the kinetics of ring closing. Optimization of the diluent concentration leads to dramatic improvements in both contrast and yield of direct writing. This enables the monolayer to be used for maskless two-color photopatterning in which spatial control over patterning is obtained by varying the relative intensity of incident UV and green light. These experiments demonstrate the capacity of spirothiopyran monolayers to serve as a versatile toolbox for rapid, large-area surface functionalization.

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