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1.
J Ethnopharmacol ; 246: 112243, 2020 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-31541722

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Ginkgo biloba leaves and Panax ginseng are Chinese medicine commonly used in combination for cerebral disease. AIM OF THE STUDY: To investigate the effect of standard extract of Ginkgo biloba leaves (EGb) on facilitating brain uptake of ginsenoside and its underlying mechanisms. MATERIALS AND METHODS: The increasing uptake of ginsenosides in the brain of rats by EGb were detected by LC-MS/MS analysis. Evans blue and FITC-dextran leakage were determined to evaluate blood-brain barrier (BBB) permeability in vivo. Transendothelial electrical resistance (TEER) and Na-F penetration rate were measured with a co-culture of the human cerebral microvascular endothelial cell line (hCMEC/D3) and human normal glial cell line (HEB) in vitro BBB model. WB were used to analyzed the expression of BBB tight junctions (TJs) related protein (ZO-1, Occludin, Claudin-3, p-ERM, and p-MLC), ultrastructure of TJs was determined by transmission electron microscope. RESULTS: LC-MS/MS analysis demonstrated that EGb could improve brain uptake of ginsenoside Rg1, Re, Rd and Rb1. In vivo study showed that, BBB permeability was significantly increased after EGb administration, evidenced by the markedly increased penetration of FITC-dextran and Evans Blue into the mice brain parenchyma. In the in vitro BBB model, reduced TEER and increased Na-F penetration rate was observed in EGb group, which was associated with alteration of TJs ultrastructure. Furthermore, the expression of p-ERM and p-MLC in hCMEC/D3 as well as mice brain microvessels were significantly upregulated, but no significant change on the expression of TJs proteins (ZO-1, Occludin and Claudin-3). Moreover, the effect of EGb on in vitro BBB permeability and ERM, MLC phosphorylation was counteracted by DPCPX, an A1 adenosine receptor (A1R) antagonist. CONCLUSIONS: EGb might induce ERM/MLC phosphorylation and increase the cell-cell junction gaps to cause a reversible increase of the BBB permeability via A1R signaling pathway. Our results may contribute to better use of EGb in the treatment of brain diseases.

2.
Chemosphere ; 238: 124617, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31450108

RESUMO

Perfluorooctanoic acid (PFOA) in environmental media contains numerous isomers/enantiomers because of the PFOA manufacturing process and biological degradation of PFOA precursors. Few methods for analyzing PFOA enantiomers have been described. A simple derivatization method using (S)-1-phenethyl chloride that was developed to allow PFOA isomers/enantiomers to be separated by gas chromatography and analyzed by electron-capture negative ionization mass spectrometry is described here. PFOA standards were analyzed, and enantiomers of the chiral isomers perfluoro-3-methyl-heptanoic acid, perfluoro-4-methyl-heptanoic acid, and perfluoro-3,5-dimethyl-hexanoic acid were separated using an HP-5MS column. Linear PFOA and perfluoro-6-methyl-heptanoic acid were chromatographically separated from these enantiomers. The linear ranges (giving correlation coefficients r > 0.997) of the calibration curves for the isomers were 0.010-3.00 ng/mL. PFOA isomer/enantiomer concentrations in river water were determined using the method. The method separated the enantiomers of perfluoro-3-methyl-heptanoic acid and perfluoro-4-methyl-heptanoic acid, the isomers of perfluoro-6-methyl-heptanoic acid, and linear PFOA in river water. No significant differences were found between the PFOA enantiomer/isomer compositions of the sample and technical PFOA. Enantiomer ratios can provide information about the sources and transport of pollutant isomers/enantiomers in the environment. Enantiomeric separation requires effective separation techniques. Our method achieved chiral separation using a non-chiral GC column that is often used in general analytical laboratories. The method could be used to investigate the sources and fates of PFOA and the isomers/enantiomers of other potentially toxic persistent pollutants in the environment and the risks posed to humans.

3.
PLoS One ; 14(11): e0225072, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31697754

RESUMO

OBJECTIVES: To assess the prevalence of human immunodeficiency virus (HIV) infection and the correlated risk factors among male clients of female sex workers (FSWs) in a Chinese-Vietnamese border region in Yunnan Province, China. METHODS: A cross-sectional survey was conducted between 2014 and 2015 in Hekou County, Yunnan Province, China. Convenience sampling and snowball sampling methods were used to recruit male clients for a questionnaire survey to collect information on demographics, sexual behavior, and drug use. Blood and urine samples were collected for testing of HIV/sexually transmitted infections (STIs) and drug use. Multivariate logistic regression was used to examine factors correlated with HIV infection. RESULTS: Of 776 respondents who participated in the study, 721 (92.91%) were Chinese and 55 (7.09%) were Vietnamese. Overall HIV prevalence in male clients of FSWs was 2.06%, 128 (16.49%) were infected with HSV-2, and five (0.64%) tested syphilis-positive. Two-thirds (68.81%) of respondents reported always using condoms with FSWs, and 89.05% reported condom use in the last episode of commercial sex. Male clients from Vietnam were significantly more likely to take morphine (9.09%) compared with Chinese male clients of FSWs. Age ≥50 years (OR: 8.11, 95%CI: 1.26-52.16) and morphine positivity (OR: 7.35, 95%CI: 1.42-38.06) were associated with HIV infection in the multivariate logistic regression model. CONCLUSION: The relatively high proportion of male clients of FSWs who have numerous sexual partners and use condoms less frequently make them serve as important bridges for HIV transmission from FSWs to the low-risk general population. The positive association between morphine positivity and HIV infection confirmed illegal drug use as another important route for acquiring HIV infection in addition to sexual transmission, indicating that innovative interventions addressing both drug use and risky sexual behaviors are greatly required for male clients. Respondents aged ≥50 years have a higher risk of HIV infection, which emphasizes that older male clients of FSWs should be focused in future HIV prevention interventions in the border regions of China.

4.
Regul Toxicol Pharmacol ; : 104522, 2019 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-31726191

RESUMO

20(s)-ginsenoside Rg3 is a red ginseng-derived compound with the formula C42H72O13 that has been increasingly used by humans, leading to safety concerns regarding this use. In the current study, we conducted a 26-week study during which 20(S)-ginsenoside Rg3 (0, 7, 20, or 60 mg/kg) was continuously administered orally to Beagle dogs in order to explore its toxicity in these animals, with control dogs receiving a vehicle capsule. In total, 10 dogs received each dose of this compound (n = 5 male, n = 5 female per dose). Animals were continuously monitored for a 26-week administration period and a subsequent 4-week follow-up recovery period. At the end of study, we observed no evidence of 20(S)-ginsenoside Rg3 toxicity in clinical indications, body weight, food intake, ophthalmoscopy, electrocardiogram, urinalysis, hematology, serum biochemistry, gross and histopathology findings. However, the kidney relative weight of animals receiving 60 mg/kg of compound was significantly elevated relative to control animals (5.15 ±â€¯0.88‰ vs. 4.11 ±â€¯0.59‰. P < 0.05), and this effect was reversed after 4-week recovery period. Based on these results, the NOAEL value for orally administered 20(S)-ginsenoside Rg3 in dogs is 20 mg/kg.

5.
Artigo em Inglês | MEDLINE | ID: mdl-31683472

RESUMO

BACKGROUND AND AIM: Both chronic intermittent hypoxia (CIH) and chronic continuous hypoxia (CCH) are risk factors for cardiovascular disease, which are associated with cardiac systolic function and associated with dysfunction of endothelia and coagulation-fibrinolysis system in the vasculature. However, the different effects of these two hypoxic models are not fully understood. In our study, we systemically compared the effects of CIH and CCH on cardiac function and related factor levels in serum using rat model. METHODS: Forty-five male Sprague-Dawley rats were randomly divided into the normoxia control (NC), CIH and CCH groups. The rat CIH and CCH models were established, then the blood and tissue samples were collected to analyze the function of endothelium and the coagulation-fibrinolysis system. Also, the ultrasound cardiogram was performed to directly assess myocardial contractility. RESULTS: Both CIH and CCH significantly decreased the NO, eNOS, P-eNOS and AT-III levels in the rat serum but significantly increased the levels of ET-1, vWF, COX-2, NF-κB, FIB, FVIII and PAI-1 in the rat serum (P < 0.05). The expression of ET-1, VWF and ICAM-1 in CIH group were higher than CCH group (P < 0.05), however, the expression of CD62p was increased in CCH group but not in CIH group. The expression of t-PA in CIH group were lower than CCH group (P < 0.05), but there were no significant differences in CCH group and NC group (P > 0.05). Using transmission electron microscope, we found that the mitochondrial ultrastructure of thoracic aorta endothelial cells in CIH and CCH group were damaged. Moreover, the myocardial contractility in CIH and CCH group were significantly decreased compared with NC group. CONCLUSION: Our results suggested that CIH and CCH could cause endothelial dysfunction, dysfunction of the coagulation-fibrinolysis system and decreasing of myocardial contractility. Compared with CCH, CIH has greater effect on vasoconstriction and adhesion of vascular endothelial cells, and stronger procoagulant effect.

6.
Theor Appl Genet ; 2019 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-31628527

RESUMO

KEY MESSAGE: Major and environmentally stable QTL for flag leaf-related traits in wheat were identified and validated across ten environments using six populations with different genetic backgrounds. Flag leaf size and posture are two important factors of "ideotype" in wheat. Despite numerous studies on genetic analysis of flag leaf size including flag leaf length (FLL), width (FLW), area (FLA) and the ratio of length/width (FLR), few have focused on flag leaf posture including flag leaf angle (FLANG), opening angle (FLOA) and bend angle (FLBA). Further, the numbers of major, environmentally stable and verified genetic loci for flag leaf-related traits are limited. In this study, QTL for FLL, FLW, FLA, FLR, FLANG, FLOA and FLBA were identified based on a recombinant inbred line population together with values from up to ten different environments. Totally, eight major and stably expressed QTL were identified. Three co-located chromosomal intervals for seven major QTL were identified. The five major QTL QFll.sicau-5B.3 and QFll.sicau-2D.3 for FLL, QFlr.sicau-5B for FLR, QFlw.sicau-2D for FLW and QFla.sicau-2D for FLA were successfully validated by the tightly linked Kompetitive Allele Specific PCR (KASP) markers in the other five populations with different genetic backgrounds. A few genes related to leaf growth and development in intervals for these major QTL were predicated. Significant relationships between flag leaf- and yield-related traits were evidenced by analyses of Pearson correlations, conditional QTL and genetic mapping. Taken together, these results provide valuable information for understanding flag leaf size and posture of "ideotype" as well as fine mapping and breeding utilization of promising loci in bread wheat.

8.
Artif Intell Med ; 99: 101696, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31606115

RESUMO

The diagnosis of depression almost exclusively depends on doctor-patient communication and scale analysis, which have the obvious disadvantages such as patient denial, poor sensitivity, subjective biases and inaccuracy. An objective, automated method that predicts clinical outcomes in depression is essential for increasing the accuracy of depression recognition and treatments. This paper aims at better recognizing depression using the transformation of EEG features and machine learning methods. An experiment based on emotional face stimuli task was conducted, and twenty-eight subjects' EEG data were recorded from 128-channel HydroCel Geodesic Sensor Net (HCGSN) by Net Station software. The Mini International Neuropsychiatric Interview (MINI) was used by psychiatrists as the criterion for diagnosis of depression patients. The power spectral density and activity were respectively extracted as original features using Auto-regress model and Hjorth algorithm with different time windows. Two separate approaches processed the features: ensemble learning and deep learning. For the ensemble learning, a deep forest transformed the original features to new features that potentially improve feature engineering and a support vector machine (SVM) that was applied as classifier. For deep learning method, we added spatial information of EEG caps to both features by image conversion and adopted convolutional neural network (CNN) to recognize them. The performance of both methods was evaluated for separated and total frequency bands. As a result, the best accuracy obtained was 89.02% when we used the ensemble model and power spectral density. The best accuracy of deep learning method was 84.75% using the activity. These experimental results prove the efficiency of the proposed methods and show that EEG could be used as a reliable indicator for depression recognition, which makes it possible for EEG-based portable system design and application in auxiliary depression recognition in the future.

9.
Electrophoresis ; 2019 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-31596501

RESUMO

The Microreader™ 20A ID system is designed for forensic applications such as personal identification, parentage testing, and research. It includes 13 combined DNA index system (CODIS) short tandem repeat (STR) loci (CSF1PO, FGA, TH01, TPOX, vWA, D3S1358, D5S818, D7S820, D8S1179, D13S317, D16S539, D18S51, and D21S11), three expanded CODIS STR loci (D12S391, D19S433, and D2S1338), three non-CODIS STR loci (D6S1043, Penta D, and Penta E), and the amelogenin locus in one reaction with a six-dye fluorescent (FAM, HEX, TAMAR, ROX, PUR, and QD550) analysis system. In this study, the Microreader™ 20A ID system was validated according to the Scientific Working Group on DNA Analysis Methods validation guidelines for forensic DNA Analysis methods and Chinese national standard, including PCR-based studies, sensitivity study, precision, and accuracy evaluation, stutter calculation, inhibitor tests, species specificity, and DNA mixture studies. Our results suggest that the Microreader™ 20A ID system is a useful tool for personal identification and parentage testing.

10.
Microbiol Res ; 230: 126348, 2019 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-31639624

RESUMO

The transcription factor PacC/Rim101 participates in environmental pH adaptation, development and secondary metabolism in many fungi, but whether PacC/Rim101 contributes to fungal adaptation to environmental stress remains unclear. In our previous study, a homologous gene of PacC/Rim101 was identified, and PacC-silenced strains of the agaricomycete Ganoderma lucidum were constructed. In this study, we further investigated the functions of PacC in G. lucidum and found that PacC-silenced strains were hypersensitive to environmental stresses, such as osmotic stress, oxidative stress and cell wall stress, compared with wild-type (WT) and empty-vector control (CK) strains. In addition, transmission electron microscopy images of the cell wall structure showed that the cell walls of the PacC-silenced strains were thinner (by approximately 25-30%) than those of the WT and CK strains. Further analysis of cell wall composition showed that the ß-1,3-glucan content in the PacC-silenced strains was only approximately 78-80% of that in the WT strain, and the changes in ß-1,3-glucan content were consistent with downregulation of glucan synthase gene expression. The ability of PacC to bind to the promoters of glucan synthase-encoding genes confirms that PacC transcriptionally regulates these genes.

11.
Stem Cells ; 2019 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-31644832

RESUMO

PURPOSE: To investigate the effects of secreted protein acidic and rich in cysteine (SPARC) on the maintenance of limbal epithelial stem cell (LESC) stemness and restoration of ocular surface. METHODS: To determine the suitable concentration of SPARC for LESC culture, the marker expression, mitogenic effect, and holoclone-forming capacity of LESCs treated with different concentrations of SPARC were analyzed. To investigate the mechanism of SPARC's action on the preservation of LESCs stemness, the phosphorylation of related signaling pathways was evaluated by western blotting. A corneal wound model was established to verify the function of SPARC in ocular surface repair. RESULTS: Consecutive subculturing, colony-forming efficiency, immunofluorescence and 5-ethynyl-2-deoxyuridine incorporation assays indicated that 1 µg/ml SPARC was a suitable concentration to stimulate LESC proliferation and preserve their proliferative potential. Compared to a control group, 1 µg/ml SPARC effectively increased the expression of ABCG-2, Bmi-1 and Ki67, while decreasing that of CK3/12. The mitogenic effect of SPARC on LESCs was found to be mediated by the phosphorylation of JNK and p38-MAPK signaling pathways, whereas the inhibitors of JNK and p38 MAPK reduced the marker expression and mitogenic capacity of LESCs. In a corneal injury model, SPARC facilitated corneal epithelial wound healing and promoted the proliferation of p63α-positive cells both in the limbus and in the epithelial healing front. CONCLUSION: SPARC promotes proliferation while suppressing spontaneous differentiation of LESCs through JNK and p38-MAPK signaling pathways, suggesting that SPARC is a promising factor for the improvement of LESCs culture in vitro and in vivo. © AlphaMed Press 2019 SIGNIFICANCE STATEMENT: In this study, we confirmed that secreted protein acidic and rich in cysteine (SPARC) in proper concentration promoted proliferation while suppressed spontaneous differentiation of limbal epithelial stem cells (LESCs) through JNK/p38 MAPK signal pathway in vitro. In corneal wound model, exogenous SPARC accelerated corneal epithelial wound healing and promoted the proliferation of p63a-positive cells both in limbus and in epithelial healing front. The positive function on LESCs proliferation and stemness preservation and corneal wound healing suggest SPARC as a potential agent to cure LESCs deficiency-related diseases and a potential supplement to expand LESCs in corneal regenerative medicine.

12.
Chem Rev ; 2019 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-31657904

RESUMO

Hydrogen fuel is considered as the cleanest renewable resource and the primary alternative to fossil fuels for future energy supply. Sustainable hydrogen generation is the major prerequisite to realize future hydrogen economy. The electrocatalytic hydrogen evolution reaction (HER), as the vital step of water electrolysis to H2 production, has been the subject of extensive study over the past decades. In this comprehensive review, we first summarize the fundamentals of HER and review the recent state-of-the-art advances in the low-cost and high-performance catalysts based on noble and non-noble metals, as well as metal-free HER electrocatalysts. We systemically discuss the insights into the relationship among the catalytic activity, morphology, structure, composition, and synthetic method. Strategies for developing an effective catalyst, including increasing the intrinsic activity of active sites and/or increasing the number of active sites, are summarized and highlighted. Finally, the challenges, perspectives, and research directions of HER electrocatalysis are featured.

13.
Mol Diagn Ther ; 2019 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-31654347

RESUMO

BACKGROUND: Single-stranded DNA (ssDNA) libraries have been shown to enrich shorter and more degraded DNA fragments than double-stranded DNA (dsDNA) libraries. OBJECTIVE: In this study, we evaluated whether ssDNA libraries captured more circulating tumor DNA (ctDNA) in plasma cell-free DNA (cfDNA). METHODS: We prepared dsDNA, ssDNA and pure-ssDNA (capture the preexisting ssDNA) libraries using ten plasma cfDNA samples. After low-pass whole genome sequencing, we calculated a duplicate rate to estimate library complexity and compared the library insert sizes between the different library methods. Finally, we estimated the ctDNA content and plasma genomic abnormality (PGA) score, an indicator of ctDNA burden. RESULTS: 27 libraries were prepared and sequenced from the ten cfDNA samples. The duplicate rate in the ssDNA and pure-ssDNA libraries was significantly lower than in the dsDNA libraries (p < 0.001 and p < 0.01, respectively). ctDNA content and PGA scores were consistently higher in the ssDNA and pure-ssDNA libraries than in the matched dsDNA libraries (p < 0.005). The higher ctDNA content in ssDNA libraries was associated with smaller library insert size. CONCLUSIONS: ssDNA libraries preserve more diversity and capture more ctDNA than dsDNA libraries. The ssDNA library method is preferred when performing genomic analysis of ctDNA.

14.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 50(3): 373-378, 2019 May.
Artigo em Chinês | MEDLINE | ID: mdl-31631606

RESUMO

Objective: To establish a radiomic model for predicting lymph node (LN) metastasis in patients with non-small cell lung cancer (NSCLC). Methods: The prediction model was developed using a training cohort comprising 100 patients with clinicopathologically confirmed NSCLC. Data were gathered from January 2014 to December 2015. Radiomic features of NSCLC were obtained from non-contrast and enhancement computed tomography (CT). Lasso-logistic regression models were established for data dimension reduction, feature selection, and radiomics signature building. Consistency coefficient ( ICCs) was used to evaluate the consistency between observer interior and interobserver.The consistency index (C-index)is used to evalutate the prediction of lymph node metastasis by using the radiomics signature, shown with the area under the receiver operating characteristic curve ( AUC).Multivariate logistic regression analyses were performed to develop the prediction model, considering radiomics signature and clinicopathologic risk factors. The radiomics model was validated in a validation cohort comprising 100 consecutive NSCLC patients from January 2016 to December 2017 in terms of its calibration and discrimination. AUC was used to evaluate the predictive effectiveness of the model, and Delong test was used to compare models. Hosmer-Lemeshow good of fit test was used to evaluate the calibration of prediction models.The results were represented by correction curves to compare the consistency between the predicted results of the model and the actual probability of LN metastasis. Results: The consistency between observer interior and interobserver was good, with ICCs higher than 0.75.The radiomics signature, including 22 selected features, was associated with LN metastasis. AUC was 0.781 in training cohort and 0.776 in validation cohort. The individualized prediction model identified radiomics signature, neuron specific enolase (CEA), cytokeratin 19 fragment antigen 21-1 (CYFRA21-1), and carbohydrate antigen 125 (CA125) as independent predictors. The model showed good discrimination, with 0.836 AUC in the training cohort, and 0.821 AUC in the validation cohort. The model in both the training and validation cohorts had good calibration,which demonstrated high consistency with the actual LN metastasis. Conclusion: The radiomics model incorporating radiomics signature and clinical risk factors can be conveniently used to facilitate preoperative individualized prediction of LN metastasis in patients with NSCLC.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/patologia , Neoplasias Pulmonares/patologia , Metástase Linfática/diagnóstico , Antígenos de Neoplasias/genética , Antígeno Ca-125/genética , Humanos , Queratina-19/genética , Modelos Logísticos , Linfonodos , Proteínas de Membrana/genética , Fosfopiruvato Hidratase/genética , Valor Preditivo dos Testes , Estudos Retrospectivos
15.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 50(4): 471-477, 2019 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-31642221

RESUMO

OBJECTIVE: To determinethe diagnostic valuesand reliabilityof cardiac magnetic resonance tissue tracking (CMR-TT) derived two-dimensional(2D) and three-dimensional(3D) strains in assessing experimental autoimmunity myocarditis (EAM) in rats. METHODS: 20 Lewis rats were randomly divided into model and control groups. The animal model of autoimmune myocarditis was induced by injecting porcine cardiac myosin into the footpads of the rats.On day 35, all of the rats were examined using the 7.0T CMR cine scan. The cardiac function and global strain of the left ventricular of the rats were analyzed with specific cardiac post-processing. The rats were then sacrificed and myocardial samples were taken and stained with HE and Masson. The diagnostic values of the strain parameters were assessed by receiver operating characteristic (ROC) curves with the pathological results as diagnostic criteria.The reliability of the strain parameters were tested using interclass correlation coefficient (ICC), coefficients of variation (CV) and Bland-Altman. RESULTS: No abnormal pathological changes in myocardial cells were found in the control group. Myocarditis was successfully induced in all of the rats in the model group, showing myocardial fiber arrangement disorder, degeneration, necrosis, inflammatory cell infiltration and interstitial fibrosis. The ROC showed that 2D global strain parameters possessed higher diagnostic values than 3D strain parameters. The 2D had an area under the curve (AUC) of 0.96 in global circumferential strain (GCS), 0.95 in global radial strain (GRS), and 0.90 in global longitudinal strain (GLS), compared with 0.87 GCS, 0.85 GRS, and 0.77 GLS in the 3D, respectively.The reliability of the 2D strain parameters was high, except for inter-observer 2D GRS(ICC=0.893). The 3D strain parameters had lower reliability (ICCs:0.421-0.79) than the 2D strain parameters (ICCs:0.893-0.986). CONCLUSION: The diagnostic values of 2D strain parameters are higher than 3D strain parameters in diagnosing myocarditis.


Assuntos
Doenças Autoimunes/diagnóstico por imagem , Imagem Cinética por Ressonância Magnética , Miocardite/diagnóstico por imagem , Animais , Modelos Animais de Doenças , Distribuição Aleatória , Ratos , Ratos Endogâmicos Lew , Reprodutibilidade dos Testes , Suínos , Função Ventricular Esquerda
16.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 50(4): 478-482, 2019 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-31642222

RESUMO

OBJECTIVE: To determine the potential value of the two-dimensional (2D) cardiac magnetic resonance imaging (CMR) tissue tracking (CMR-TT) method in assessing the cardiac function of tree shrew at 7T. METHODS: Healthy adult tree shrews (male, n=8) and spraguedawley rats(male, n=8) were selected for this study. CMR was performed to acquire the short-axis images of left ventricle at 7T using the same appropriative coil and cine sequence for all experimental animals. The CMR images were processed using the professional cardiac analysis software, calculating ejection fraction (EF), radial peak sysolic strain (Err), circumferential peak sysolic strain (Ecc), radial peak sysolic displacement (DR), and LVM/BM 〔the ratio of left ventricular mass (LVM) to body mass (BM)〕. RESULTS: Cine imaging for the tree shrews was 100% successful following the CMR protocol for the rats, with clearly visible main segments of cardiac. Significant differences in EF, Err, Ecc and DR were found between the two groups of animals (P < 0.01). The tree shrews has lower EF, Err and Ecc than the rats. Err and Ecc appeared in the fifteenth phase in left ventriclar systole in the tree shrews, compared with the tenth phase in the rats.The tree shrews also had higher LVM/BM than the rats. CONCLUSION: The cardiac function of tree shrew can be assessed using the 2D CMR-TT method despite significant differences across species.


Assuntos
Coração/diagnóstico por imagem , Imagem Cinética por Ressonância Magnética , Tupaiidae , Função Ventricular Esquerda , Animais , Imagem por Ressonância Magnética , Masculino , Ratos , Ratos Sprague-Dawley , Reprodutibilidade dos Testes , Volume Sistólico , Sístole
17.
Environ Microbiol ; 2019 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-31608522

RESUMO

Cellulose is a by-product of agricultural production and an abundant waste. As a carbon source, cellulose can be degraded and utilized by fungi. Carbon sources, which act as nutrients, not only provide energy but also serve as regulators of gene expression, metabolism and growth, through various signalling networks that enable cells to sense and adapt to varying environmental conditions. Nutrient-sensing pathways prioritize the use of preferred carbon sources and regulate the production of cellulose-degrading enzymes when necessary. Understanding the regulation of the fungal cellulolytic response will become increasingly important because we strive to increase the efficiency of the utilization of these renewable energy sources. Here, we show that Glsnf1, a sucrose-nonfermenting serine-threonine-protein kinase 1 (Snf1)/AMP-activated protein kinase homologue in medicinal macro basidiomycete Ganoderma lucidum, actively responds to carbon alterations and positively regulates cellulase activity and cellulase-related gene transcription. The carbon catabolite repressor CreA, a zinc binuclear cluster transcription factor that mediates the sensing of nutrients and suppression of the transcription of a number of genes necessary for the consumption of a less preferred carbon source, participates in the Glsnf1-mediated regulation of cellulases. Glsnf1 not only negatively regulates the transcription level of the CreA gene but also hinders its localization in the nucleus. Overall, our findings reveal a key nutrient-sensing mechanism that is critical for the modulation of carbon source adaptation in G. lucidum.

18.
Se Pu ; 37(10): 1129-1133, 2019 Oct 08.
Artigo em Chinês | MEDLINE | ID: mdl-31642294

RESUMO

An effective method was established for the determination and classification of flammable liquids by headspace gas chromatography-mass spectrometry (HS-GC-MS). The volatile components, equilibrium temperature and equilibrium time of gravure ink were investigated. The volatile components of flammable liquids were identified by comparison with the standard mass spectrum databases, and quantified by the external standard method. The recoveries were in the range of 92.8%-103.1% with the relative standard deviations between 0.88% and 2.88%. The flash points of the samples were calculated by a prediction model and compared with the experimentally measured values. The results showed that the maximum deviation between the predicted and measured flash points was 3.2℃. This method provides a novel, efficient and convenient way for the classification of flammable liquids.

19.
Nanoscale ; 11(42): 20301-20306, 2019 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-31633704

RESUMO

Rational designing of catalysts to promote the sluggish kinetics of the cathode oxygen reduction reaction in proton exchange membrane fuel cells is still challenging, yet of crucial importance to its commercial application. In this work, on the basis of theoretical DFT calculations which suggest that order structured fct-phased PtFe (O-PtFe) with an atomic Pt shell exhibits superior electrocatalytic performance towards the ORR, the desired structure was prepared by using a scalable impregnation-reduction method. The as-prepared O-PtFe delivered enhanced activity (0.68 A mg-1Pt) and stability (73% activity retention after 10 000 potential cycles) compared with the corresponding disordered PtFe alloy (D-PtFe) and Pt. To confirm the excellent durability, in situ X-ray absorption fine structure spectroscopy was conducted to probe the local and electronic structure changes of O-PtFe during 10 000 cycle accelerated durability testing. We hope that this facile synthesis method and the in situ XAFS experiment could be readily adapted to other catalyst systems, facilitating the screening of highly efficient ORR catalysts for fuel cell application.

20.
J Appl Behav Anal ; 2019 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-31608982

RESUMO

In teaching conditional discriminations to children with autism spectrum disorder (ASD), practitioners may progress from simple to conditional discriminations or may teach conditional discriminations from the onset of instruction. Some research indicates that teaching simple discriminations first may be unnecessary and that teaching may more efficiently focus on conditional discriminations exclusively. This study replicated comparisons of simple-to-conditional and conditional-only discrimination training methods in teaching audio-visual conditional discriminations to Chinese preschoolers with ASD. Results indicated the conditional-only training method appeared to be more efficient in teaching these skills.

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