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1.
Sci Total Environ ; 806(Pt 1): 150517, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34794910

RESUMO

Beta-cypermethrin (ß-CYP), a widely-used pyrethroid pesticide, is considered to have anti-androgenic effects and could impair male reproduction. To ascertain whether MAPK pathways, DNA methyltransferases (DNMTs), and miRNAs played pleiotropic roles in ß-CYP-mediated testicular dysfunction, Sprague-Dawley rats and Leydig cells were employed in this study. Results showed that plasma testosterone levels were declined, testicular histomorphology and ultrastructures were abnormally altered, and Leydig cell functions were damaged after ß-CYP exposure. JNK and p38/MAPK pathways were inactivated, accompanied by the decrease in c-Jun and Sp1 expressions. Specific activators/inhibitors of MAPK pathways and Co-IP demonstrated that DNMT3α was synergistically regulated by JNK/p38 pathways. The activity, mRNA and protein expressions of DNMT3α were all reduced by ß-CYP. ß-CYP induced expressions of intronic miR-140-5p and its host gene Wwp2, and then overexpressed miR-140-5p suppressed steroidogenic StAR, P450scc, and 3ß-HSD by directly targeting SF-1. SF-1 silencing/overexpression, ChIP, and qPCR indicated that SF-1 modulated positively StAR, P450scc, and 3ß-HSD expressions by directly binding to their promoter regions. Intriguingly, 5α-reductase expressions were downregulated after ß-CYP exposure. Collectively, ß-CYP has the anti-androgenic feature and the DNMT3α/miR-140-5p/SF-1 cascade co-regulated by JNK/p38 functions critically in ß-CYP-caused testosterone declines. The downregulation of 5α-reductases may be a potential compensatory mechanism of the organism.

3.
Food Sci Nutr ; 9(10): 5616-5625, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34646531

RESUMO

The kiwi berry (Actinidia arguta) is a new product on the market that expanding worldwide acceptance and consumption. This widespread interest has created an increasing demand to identify the nutritional and health benefits of kiwi berry. Many studies are being actively conducted to investigate the composition and health-promoting effects of kiwi berry. In this study, the phytochemical content of free and bound fractions of eight kiwi berry varieties were systematically investigated in order to better understand the potential of this superfood crop. Nine phenolic monomers were identified and quantified by ultrahigh-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry and ultrahigh-performance liquid chromatography-PAD. Antioxidant activity was further determined via peroxyl radical scavenging capacity and cellular antioxidant activity assays. The free extracts had higher phytochemical contents and antioxidant activities than the corresponding bound extracts among the eight kiwi berry varieties. Bivariate Pearson's and multivariate correlation analyses showed that antioxidant activities were most related to the total phenolic, flavonoid, vitamin C, and phenolic acids contents. The results provide a theoretical basis for the selection of kiwi berry varieties and the utilization of functional foods.

4.
Ecotoxicol Environ Saf ; 225: 112792, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34544022

RESUMO

Cypermethrin (CYP), an extensively-used broad-spectrum pyrethroid pesticide, is regarded as a potential environmental endocrine disruptor with the anti-androgenic characteristic. To explore underlying roles of non-coding RNAs and the Jak/Stat pathway in CYP-mediated testosterone biosynthesis suppression, SD rats and Leydig cells were employed in this work. Results displayed that ß-CYP decreased plasma testosterone levels and led to abnormal alterations of testicular histomorphology and ultrastructures. LncRNA XIST and miR-142-5p were co-localized in the cytoplasm of Leydig cells, but the expression of XIST was inhibited by ß-CYP while that of miR-142-5p was induced. Then overexpressed miR-142-5p dampened the Jak1/Stat1 pathway by directly targeting Jak1. Transcription factors NFκB and YY1 impeded by ß-CYP were positively regulated by the Jak1/Stat1 pathway. Bidirectional Co-IP and ChIP assays demonstrated that NFκB interacted with and modulated YY1 by directly binding to the promoter region of YY1. ChIP, qPCR, and YY1 knockdown/overexpression assays indicated that YY1 acted as a transcriptional activator to directly modulate steroidogenic StAR and 3ß-HSD in Leydig cells. Taken together, miR-142-5p sponged by lncRNA XIST directly targets the Jak1/Stat1 pathway, which regulates steroidogenic StAR and 3ß-HSD via NFκB and YY1, and ultimately dampens testosterone production in Leydig cells.


Assuntos
Células Intersticiais do Testículo , Piretrinas , Animais , Masculino , Piretrinas/toxicidade , Ratos , Ratos Sprague-Dawley , Testosterona , Fator de Transcrição YY1/genética
6.
Am J Transl Res ; 13(7): 8172-8178, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34377302

RESUMO

BACKGROUND: Superior mesenteric arteriovenous fistula (SMAVF) is a very rare disease and mainly manifests as abdominal pain, diarrhea, anorexia, and other portal hypertension symptoms. The diagnosis of the disease mainly relies on abdominal enhanced CT+3D reconstruction or digital subtraction angiography, and the treatment is mainly vascular interventional fistula occlusion. CASE SUMMARY: a 17-year-old female with a history of abdominal trauma and surgery was admitted to our hospital for diarrhea and abdominal distension. The patient was diagnosed with a superior mesenteric arteriovenous fistula after abdominal enhanced CT + 3D reconstruction. The patient was satisfied with the results after the superior mesenteric artery angiography + covered stent implantation. No discomfort symptoms occurred during the two-year follow-up. CONCLUSION: A history of abdominal trauma or surgery and clinical manifestations in combination with a radiological analysis are important indicators in the diagnosis of SMAVF. Interventional therapy is the preferred treatment.

7.
Front Plant Sci ; 12: 689038, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34276738

RESUMO

The kiwi berry (Actinidia arguta) has been widely studied because of its rich phenolic, flavonoid, and vitamin C contents. Numerous reports have demonstrated that fruit peels contain higher phenolic content and antioxidant activity than that of flesh. In this study, the phytochemical content and antioxidant activities of peel and flesh extracts of six kiwi berries were analyzed from four regions (namely, Dandong, Benxi, Taian, and Tonghua) in China. The antioxidant activity was determined using the peroxyl radical scavenging capacity (PSC) and cellular antioxidant activity (CAA) assays. The phenolic, flavonoid, and vitamin C contents of kiwi berry peel were 10.77, 13.09, and 10.38 times richer than that of kiwi berry flesh, respectively. In addition, the PSC and CAA values of kiwi berry peel were higher than those of kiwi berry flesh. The analysis of the separation and contents of phenolics were performed by the high-performance liquid chromatography (HPLC)-diode-array detectormass spectrometry/mass (DAD-MS/MS) system, and the results illustrated that protocatechuic acid, caffeic acid, chlorogenic acid, and quinic acid were the major phenolic compounds. In conclusion, this study indicated that kiwi berry peel contains a rich source of antioxidants. These data are of great significance for the full development and utilization of kiwi berries in these four regions of China to produce nutraceutical and functional foods.

8.
J Sci Food Agric ; 2021 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-34302364

RESUMO

BACKGROUND: Free fractions of different blackberry varieties' extracts are high in phenolic compounds with antioxidant activities. However, the phenolic profiles and antioxidant activities against peroxyl radicals of bound fractions of different blackberry varieties' extracts have not been previously reported. In addition, what the key antioxidant phenolic compounds are in free and bound fractions of blackberry extracts remain unknown. This study aimed to investigate the phenolic profiles and antioxidant activities of free and bound fractions of eight blackberry varieties' extracts and reveal the key antioxidant phenolic compounds by boosted regression trees. RESULTS: Fifteen phenolics (three anthocyanins, four flavonols, three phenolic acids, two proanthocyanidins, and three ellagitannins) were identified in blackberry by ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry. Ferulic acid, ellagic acid, procyanidin C1, kaempferol-O-hexoside, ellagitannins hex, and gallic acid were major bound phenolics. Bound fractions of eight blackberry varieties' extracts were high in phenolics and showed great antioxidant activity. Boosted regression trees analysis showed that cyanidin-3-O-glucoside and chlorogenic acid were the most significant compounds, contributing 48.4% and 15.9% respectively to the antioxidant activity of free fraction. Ferulic acid was the most significant antioxidant compound in bound fraction, with a contribution of 61.5%. Principal component analysis showed that Kiowa was the best among the eight varieties due to its phenolic profile and antioxidant activity. CONCLUSION: It was concluded that blackberry varieties contained high amounts of bound phenolics, which confer health benefits through reducing oxidative stress. Ferulic acid was the key compound to explain the antioxidant activities of bound fractions. © 2021 Society of Chemical Industry.

9.
PLoS One ; 16(6): e0251914, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34097693

RESUMO

Active contour models driven by local binary fitting energy can segment images with inhomogeneous intensity, while being prone to falling into a local minima. However, the segmentation result largely depends on the location of the initial contour. We propose an active contour model with global and local image information. The local information of the model is obtained by bilateral filters, which can also enhance the edge information while smoothing the image. The local fitting centers are calculated before the contour evolution, which can alleviate the iterative process and achieve fast image segmentation. The global information of the model is obtained by simplifying the C-V model, which can assist contour evolution, thereby increasing accuracy. Experimental results show that our algorithm is insensitive to the initial contour position, and has higher precision and speed.


Assuntos
Interpretação de Imagem Assistida por Computador/métodos , Processamento de Imagem Assistida por Computador/métodos , Algoritmos , Simulação por Computador , Modelos Estatísticos , Reconhecimento Automatizado de Padrão/métodos
10.
Diagn Pathol ; 16(1): 21, 2021 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-33706781

RESUMO

BACKGROUND: In lung cancer management, differential diagnosis between multiple primary lung cancer (MPLC) and intrapulmonary metastasis (IMP) is a critical point that is of direct therapeutic and clinical importance. However, this process often suffers from absence of a gold standard, resulting in equivocal cases. Herein, we present a series of three cases, in which genomic alteration patterns revealed by next-generation sequencing (NGS) facilitated the differential diagnosis between MPLC and IMP. CASE PRESENTATION: Case 1 was a 57-year-old female with two separate lesions in the upper lobe and the lower lobe of left lung, which were both histopathologically determined as T2aN0M0 adenocarcinomas. NGS identified an EGFR L858R in one lesion and an EGFR 20 exon insertion in the other one, suggestive of double primary malignancies. The patient underwent wedge resections and received an adjuvant treatment of icotinib and chemotherapy. She had a disease-free survival (DFS) of 19 months and counting. Case 2 was a 55-year-old female with multiple small lesions in both lungs. Histopathological examinations of resected lesions from right upper lobe revealed three subtypes: atypical adenomatous hyperplasia of alveolar epithelium, adenocarcinomas in situ and minimally invasive adenocarcinoma. NGS identified two different BRAF driver mutations G466E and V600_K601delinsE in two lesions of adenocarcinoma in situ, and a BRAF K601E in a lesion of minimally invasive adenocarcinoma. Case 3, a 68-year-old male, had the right upper lobe lesion histophathologically classified as a stage T3NxM0 mixed adenoneuroendocrine carcinoma and the left upper lobe lesion as a stage T1aN0M0 adenocarcinoma. NGS performed with different loci of surgical tissues revealed a rare sensitizing EGFR mutation G719A shared by the right upper lobe lesion and lymph node, and two EGFR mutations L861Q and G719S in left upper lobe lesion. The patient received icotinib treatment postoperatively and achieved a stable disease with a progression-free survival of 5 months. CONCLUSION: Our cases provide evidence for utility of NGS in facilitating diagnosis and treatment decisions.


Assuntos
Adenocarcinoma/patologia , Neoplasias Pulmonares/patologia , Pulmão/patologia , Metástase Neoplásica/patologia , Adenocarcinoma/diagnóstico , Adenocarcinoma/genética , Diagnóstico Diferencial , Feminino , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Humanos , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/genética , Linfonodos/patologia , Pessoa de Meia-Idade , Mutação/genética , Neoplasias Primárias Múltiplas/diagnóstico , Neoplasias Primárias Múltiplas/genética , Neoplasias Primárias Múltiplas/patologia
11.
Medicine (Baltimore) ; 100(8): e24937, 2021 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-33663132

RESUMO

BACKGROUND: No studies were located which used a web-based educational intervention to improve the knowledge about newly diagnosed type 2 diabetes mellitus (T2DM). Therefore, the primary objective of the present study was to evaluate the efficacy of web-based educational intervention on psychological outcomes and glycemic control in newly diagnosed T2DM in rural China. METHODS: This work is a part of a comprehensive research project to assess and provide educational intervention that potentially improve psychological status and blood glucose among patients with T2DM. Eligibility criteria for the study includes newly diagnosed with T2DM, adult patients (age ≥30 years) regardless of gender; speak and understand Chinese languages; having no significant comorbidity; being not involved in any trial/study related to diabetes during last 3 months and able to attend regular visits. Eligible participants were divided into 2 groups according to completely randomized design: education group and control group. The outcomes included fasting blood glucose level, EQ-5D-3L questionnaire, Self-rating Anxiety Scale, and Self-rating Depression Scale. RESULTS: This protocol will provide a reliable theoretical basis for the following research. CONCLUSION: The sample came from a single health centre. Therefore, the results can not be generalized for the entire population. TRIAL REGISTRATION: This study protocol was registered in Research Registry (researchregistry6511).


Assuntos
Glicemia/metabolismo , Diabetes Mellitus Tipo 2/psicologia , Controle Glicêmico/métodos , Intervenção Baseada em Internet , Adulto , China , Diabetes Mellitus Tipo 2/sangue , Feminino , Humanos , Masculino , Ensaios Clínicos Controlados Aleatórios como Assunto , População Rural , Autogestão/educação , Inquéritos e Questionários
12.
Hum Cell ; 34(2): 539-549, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33387362

RESUMO

Hepatocellular Carcinoma (HCC) is the second leading cause of cancer-related deaths. Neuroblastoma associated transcript 1 (NBAT1) is a newly identified long noncoding RNA (lncRNA), which has been reported to play an important role in human cancers. However, the functional role and underlying mechanism of NBAT1 in HCC remains unclear. Here, we found that the expression of NBAT1 was decreased in HCC tissues and cells; as well, the decreased expression of NBAT1 was also associated with tumor size and clinical TNM stages. NBAT1 overexpression, both in vitro and in vivo studies, inhibited tumorigenesis through apoptosis augmentation and cell cycle blockade. Mechanistically, NBAT1 bound to IGF2BP1 and inhibited the interaction between IGF2BP1 and c-Myc mRNA, thus suppressing the stability of c-Myc mRNA. Collectively, NBAT1 is associated with HCC tumorigenesis and could be a therapeutic target for HCC treatment.


Assuntos
Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Regulação Neoplásica da Expressão Gênica/genética , Expressão Gênica/genética , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Proto-Oncogênicas c-myc/metabolismo , RNA Longo não Codificante/fisiologia , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Linhagem Celular , Linhagem Celular Tumoral , Progressão da Doença , Humanos , Terapia de Alvo Molecular , Ligação Proteica/genética , RNA Longo não Codificante/metabolismo
13.
J Phys Chem Lett ; 12(5): 1384-1389, 2021 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-33508197

RESUMO

One of the key parameters required to identify effective drugs is membrane permeability, as a compound intended for an intracellular target with poor permeability will have low efficacy. In this paper, we leverage a computational approach recently developed by our group to study the interactions between nanoparticles and mammalian membranes to study the time of entry of a variety of drugs into the viral envelope of coronavirus as well as cellular organelles. Using a combination of all-atoms molecular dynamics simulations and statistical analysis, we consider both drug characteristics and membrane properties to determine the behavior of 79 drugs and their interactions with the viral envelope, composed of the membrane and spike protein, as well as five other membranes that correspond to various mammalian compartments (lysosome, plasma, Golgi, mitochondrial, and endoplasmic reticulum membranes). The results highlight important trends that can be exploited for drug design, from the relatively high permeability of the viral envelope and the effect of transmembrane proteins, to the differences in permeability between organelles. When compared with bioavailability data present in the literature, the model results suggest a negative correlation between time of permeation and bioavailability of promising drugs. The method is general and flexible and can be employed for a variety of molecules, from small drugs to small nanoparticles, as well to a variety of biological membranes. Overall, the results indicate that this model can contribute to the identification of successful drugs as it predicts the ability of compounds to reach both intended and unintended intracellular targets.


Assuntos
Antivirais/metabolismo , COVID-19/tratamento farmacológico , SARS-CoV-2/efeitos dos fármacos , Sítios de Ligação , Humanos , Interações Hidrofóbicas e Hidrofílicas , Cinética , Bicamadas Lipídicas/química , Glicoproteínas de Membrana/química , Modelos Biológicos , Simulação de Dinâmica Molecular , Nanopartículas/química , Tamanho da Partícula , Permeabilidade , Ligação Proteica , Solubilidade , Glicoproteína da Espícula de Coronavírus/metabolismo , Envelope Viral/efeitos dos fármacos
14.
Science ; 371(6530): 716-721, 2021 02 12.
Artigo em Inglês | MEDLINE | ID: mdl-33479119

RESUMO

The distinctive electronic structure found at interfaces between materials can allow unconventional quantum states to emerge. Here we report on the discovery of superconductivity in electron gases formed at interfaces between (111)-oriented KTaO3 and insulating overlayers of either EuO or LaAlO3 The superconducting transition temperature, as high as 2.2 kelvin, is about one order of magnitude higher than that of the LaAlO3/SrTiO3 system. Notably, similar electron gases at KTaO3 (001) interfaces remain normal down to 25 millikelvin. The critical field and current-voltage measurements indicate that the superconductivity is two-dimensional. In EuO/KTaO3 (111) samples, a spontaneous in-plane transport anisotropy is observed before the onset of superconductivity, suggesting the emergence of a distinct "stripe"-like phase, which is also revealed near the critical field.

15.
Sci Total Environ ; 757: 143727, 2021 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-33250241

RESUMO

Cypermethrin (CYP), a broad-spectrum pyrethroid insecticide is extensively used. CYP is also considered as a potential endocrine disruptor with the thyroid-disturbing property. Protein kinase C alpha (PKCα) is a pleiotropic signal transduction molecule that functions crucially in thyroid hormone (TH) homeostasis and thyroid functions. To explore underlying roles of PKCα in CYP-mediated disturbance of TH homeostasis, Sprague-Dawley rats and rat thyroid cells were used in this study. Results showed that ß-CYP stimulated TH biosynthesis, as shown by the increase in plasma levels of TT4, FT4, TT3, FT3, and TSH. After ß-CYP treatment, expressions of PKCα, three miRNAs (miR-17-5p, miR-330-3p, and miR-331-3p), thyroid transcription factor TTF-1, and thyroid-specific proteins (TSHr, TPO, and Tg) were significantly increased, while expressions of PI3K p110α, p-Akt, FOXA1, and thyroid transcription factors (TTF-2 and Pax8) were decreased. Further studies found that ß-CYP induced PKCα translation by the miR-330-3p-targeted PI3K/Akt-FOXA1 cascade and then PKCα positively regulated TTF-1 to promote TPO and Tg expressions, which in turn facilitated TH biosynthesis. Likewise, PKCα positively modulated TSHr expressions to strengthen the TSH/TSHr signal in the HPT axis, thereby synergistically contributing to TH biosynthesis. Moreover, ß-CYP also disturbed TH biotransformation and biotransport by inducing DIO1 and inhibiting DIO3 in thyroids and TTR expressions in livers. Taken together, ß-CYP has the thyroid-disturbing effect and could promote TH biosynthesis, and PKCα plays vital roles in ß-CYP-caused hyperthyroidism.


Assuntos
Hipertireoidismo , Piretrinas , Animais , Fator 3-alfa Nuclear de Hepatócito , Fosfatidilinositol 3-Quinases/metabolismo , Proteína Quinase C-alfa , Proteínas Proto-Oncogênicas c-akt/metabolismo , Piretrinas/toxicidade , Ratos , Ratos Sprague-Dawley , Transdução de Sinais
16.
J Psychoactive Drugs ; 52(5): 463-471, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32530370

RESUMO

Individuals with substance use disorders (SUD) undergo treatment to recover from addiction. However, exerting self-control, which is essential for successful abstinence from drug addiction, can cause ego depletion. This study experimentally investigated the effect of ego depletion on interpersonal trust and examined possible changes in the ego depletion effect across different abstinence periods. This study employed a 2 (ego depletion: high vs. low) × 2 (partners: non-SUD vs. SUD) mixed factorial design. The participants were 273 male individuals with SUD and with periods of drug abstinence ranging from several days to 2 years, who resided in a compulsory drug rehabilitation center. The participants were first asked to complete an ego depletion task, followed by a decision-making task in a trust game, first with a non-SUD stranger, and then with a SUD stranger. Ego depletion was not related to trust in non-SUD strangers. However, ego depleted participants were more likely to trust SUD strangers than non-ego depleted participants. Moreover, this ego depletion effect fluctuated near the end of SUD treatment. This study highlights the importance to ensure follow-up outpatient care and offer social support services for individuals with SUD after compulsory SUD treatment.


Assuntos
Ego , Transtornos Relacionados ao Uso de Substâncias/psicologia , Confiança/psicologia , Adulto , China , Humanos , Masculino , Pessoa de Meia-Idade , Autocontrole , Adulto Jovem
17.
BMC Med Genet ; 21(1): 86, 2020 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-32354326

RESUMO

BACKGROUND: Vascular endothelial growth factor (VEGF) gene is highly polymorphic, and single nucleotide polymorphisms (SNP) of VEGF gene are associate with cancer prognosis. This study aimed to analyze the correlation of VEGF gene polymorphisms with grade and prognosis of lung cancer. METHODS: A total of 458 Chinese patients with primary lung cancer were enrolled from September 2008 to October 2013. The genotypes of -2578C > A, -1154G > A, - 460 T > C, and + 405G > C were analyzed in white blood cells from patients using polymerase chain reaction based restriction fragment length polymorphism. RESULTS: Our data showed that -1154G > A polymorphism was significantly associated with tumor stages, but all four tested VEGF gene polymorphisms had no significant effect on survival. CONCLUSIONS: VEGF polymorphisms may relate to stage of lung cancer in Chinese population.


Assuntos
Estudos de Associação Genética , Predisposição Genética para Doença , Neoplasias Pulmonares/genética , Fator A de Crescimento do Endotélio Vascular/genética , Adulto , Idoso , China/epidemiologia , Intervalo Livre de Doença , Feminino , Genótipo , Humanos , Neoplasias Pulmonares/epidemiologia , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Polimorfismo de Nucleotídeo Único/genética , Prognóstico
18.
Materials (Basel) ; 13(8)2020 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-32325893

RESUMO

Nanomaterials have been increasingly employed for improving the mechanical properties and durability of ultra-high-performance concrete (UHPC) with high volume supplementary cementitious materials (SCMs). Recently, graphene oxide (GO) nanosheets have appeared as one of the most promising nanomaterials for enhancing the properties of cementitious composites. To date, a majority of studies have concentrated on cement pastes and mortars with fewer investigations on normal concrete, ultra-high strength concrete, and ultra-high-performance cement-based composites with a high volume of cement content. The studies of UHPC with high volume SCMs have not yet been widely investigated. This paper presents an experimental investigation into the mini slump flow and physical properties of such a UHPC containing GO nanosheets at additions from 0.00 to 0.05% by weight of cement and a water-cement ratio of 0.16. The study demonstrates that the mini slump flow gradually decreases with increasing GO nanosheet content. The results also confirm that the optimal content of GO nanosheets under standard curing and under steam curing is 0.02% and 0.04%, respectively, and the corresponding compressive and flexural strengths are significantly improved, establishing a fundamental step toward developing a cost-effective and environmentally friendly UHPC for more sustainable infrastructure.

19.
Environ Sci Pollut Res Int ; 27(17): 22033-22045, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32285396

RESUMO

Using the 2000-2018 MODIS Land Surface Temperature (LST) data and taking 11 cities (counties) in the northern slope of the central Tianshan Mountains in northwestern China as the study area, the spatial-temporal characteristics, landscape indices, centroid, and geo-information Tupu (carto-methodology in geo-information, CMGI) of surface thermal landscape (STL) were analyzed, and the paper draws the following results: (1) There are great differences in the diurnal and seasonal STL. The higher thermal levels are distributed more northerly in spring, summer, and autumn, and more southerly in winter. (2) In terms of class type level and landscape level, different landscape indices show different characteristics in diurnal and seasonal thermal landscapes. (3) Centroids at different thermal levels during the daytime are more dispersed than at nighttime in spring and summer, while the opposite is found in autumn. In winter, centroids of different thermal levels are concentrated in the southern and central-southern regions. During the period of 2000-2018, centroids of different thermal levels tend to move with the varying of STL. (4) The whole STL in same seasons changed little, transition usually happens between adjacent thermal levels. Overall, compared with the eastern monsoon area, there are similarities and differences in the characteristics of the STL.


Assuntos
Monitoramento Ambiental , China , Cidades , Estações do Ano , Temperatura
20.
Nat Commun ; 11(1): 1402, 2020 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-32179750

RESUMO

Amongst the rare-earth perovskite nickelates, LaNiO3 (LNO) is an exception. While the former have insulating and antiferromagnetic ground states, LNO remains metallic and non-magnetic down to the lowest temperatures. It is believed that LNO is a strange metal, on the verge of an antiferromagnetic instability. Our work suggests that LNO is a quantum critical metal, close to an antiferromagnetic quantum critical point (QCP). The QCP behavior in LNO is manifested in epitaxial thin films with unprecedented high purities. We find that the temperature and magnetic field dependences of the resistivity of LNO at low temperatures are consistent with scatterings of charge carriers from weak disorder and quantum fluctuations of an antiferromagnetic nature. Furthermore, we find that the introduction of a small concentration of magnetic impurities qualitatively changes the magnetotransport properties of LNO, resembling that found in some heavy-fermion Kondo lattice systems in the vicinity of an antiferromagnetic QCP.

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