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1.
Oncol Rep ; 43(3): 999-1009, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32020232

RESUMEN

Acute myeloid leukemia (AML) is a hematological malignancy derived from immature myeloid cells, which have the characteristics of abnormal proliferation and differentiation. Glycolysis has been a popular topic of research in recent years, with increasing uptake and consumption of glucose. The present study aimed to investigate the glycolysis of tumor cells in patients with AML; in particular, how programmed cell death 1 ligand 1 (PD­L1) regulates tumor cells glycolysis using real time PCR (RT­PCR), western blotting and flow cytometry. PD­L1 high expression predicted poor outcome in patients with AML in the public database Gene Expression Profiling Interactive Analysis. PD­L1 expression was decreased in the samples from patients with AML with complete remission compared to that in patients with relapsed or refractory AML. In AML cell lines, glycolysis­associated genes ALDOA, PGK1, LDHA and HK2 were highly expressed in a PD­L1 high­expressed cell line. Overexpressed PD­L1 enhanced glucose consumption and the extracellular acidification rate, accompanied by decreased apoptosis and accumulation of cells in the S phase. In contrast, the apoptosis rate of tumor cells and the percentage of cells in the S phase were significantly increased following PD­L1 knockdown in the THP1 cell line. HK2 and LDHA expression decreased after AML tumor cells were treated with Akt inhibitor or rapamycin. In addition, the PD­L1­overexpressed cell line (PD­L1­OV) MOLM­13 exhibited rapid tumor progression. Glycolysis­associated genes were highly expressed in tumor tissues of PD­L1­OV MOLM­13, with increased Ki67. Based on these findings, PD­L1 may be considered as a suitable marker for prognosis and treatment in the clinical setting.

2.
Artículo en Inglés | MEDLINE | ID: mdl-32000495

RESUMEN

Surface passivation is a widely used approach to promote the efficiency and stability of perovskite solar cells (PSCs). In the present project, a series of new organic surface passivation molecules, which contain the same triphenylamino group with the hole transfer material of PSCs, have been synthesized. These new passivation molecules are supposed to have both "carrier transfer" capability and "defect passivation" potential. We find that, by using N-((4-(N,N,N-triphenyl)phenyl)ethyl)ammonium bromide (TPA-PEABr) as a surface passivation molecule, the efficiency of the PSCs can be improved from 16.69 to 18.15%, mainly due to an increased Voc (1.09 V compared with 1.02 V in control devices). The increased Voc is due to the reduced surface defect density and a better alignment for the related energy levels after introducing the TPA-PEABr molecules. Moreover, the stability of the PSCs can be significantly improved in TPA-PEABr passivated devices due to the hydrophobic nature of TPA-PEABr. Our results successfully demonstrate that passivation of the perovskite surface with a carefully designed multifunctional small organic molecule should be a useful approach for more stable PSCs with high efficiency.

3.
Medicine (Baltimore) ; 99(2): e18671, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31914057

RESUMEN

Liver cirrhosis is a common chronic progressive liver disease in clinical practice, and intravoxel incoherent motion (IVIM) is a promising magnetic resonance method to assess liver cirrhosis, so our purpose was to investigate association of liver-lobe-based IVIM-derived parameters with hepatitis-B-related cirrhosis and its severity, and esophageal and gastric fundic varices. Seventy-four patients with hepatitis-B-related cirrhotic and 25 healthy volunteers were enrolled and underwent upper abdominal IVIM diffusion-weighted imaging with b-values of 0, 20, 50, 80, 100, 200, 400, 600, and 800 s/mm. IVIM-derived parameters (D, pure molecular diffusion; D, pseudo diffusion; and f, perfusion fraction) of left lateral lobe (LLL), left medial lobe (LML), right lobe (RL), and caudate lobe (CL) were assessed statistically to show their associations with cirrhosis and its severity, and esophageal and gastric fundic varices. In this research, we found that D, D, and f values of LLL, LML, RL, and CL were lower in cirrhotic liver than in normal liver (all P-values <.05). D, D, and f values of LLL, LML, RL, and CL were inversely correlated with Child-Pugh class of cirrhosis (r = -0.236 to -0.606, all P-values <.05). D of each liver lobe, D of LLL and CL, and f of LLL, LML, and CL in patients with esophageal and gastric fundic varices were lower than without the varices (all P-values <.05). D values of RL and CL could best identify cirrhosis, and identify esophageal and gastric fundic varices with areas under receiver-operating characteristic curve of 0.857 and 0.746, respectively. We concluded that liver-lobe-based IVIM-derived parameters can be associated with cirrhosis, and esophageal and gastric fundic varices.


Asunto(s)
Imagen de Difusión por Resonancia Magnética/métodos , Várices Esofágicas y Gástricas/diagnóstico por imagen , Cirrosis Hepática/diagnóstico por imagen , Adulto , Anciano , Várices Esofágicas y Gástricas/etiología , Femenino , Hepatitis B/complicaciones , Humanos , Cirrosis Hepática/etiología , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Estudios Prospectivos , Índice de Severidad de la Enfermedad , Adulto Joven
4.
J Biomater Sci Polym Ed ; 31(1): 53-71, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31566488

RESUMEN

In this study, a novel magnetic solid phase extraction adsorbent was prepared, namely Fe3O4@SiO2 as the carrier, quercetin as the template molecule, acrylamide (AM) as the functional monomer, ethylene glycol dimethacrylamide (EGDMA) as the crosslinker, 2,2'-azobisisobutyronitrile (AIBN) as the initiator to prepare magnetic molecularly imprinted polymer (MMIPs) with specific adsorption of quercetin by surface molecular imprinting technique. MMIPs were characterized by Fourier transform infrared spectrometer (FT-IR), X-ray diffraction (XRD) and transmission electron microscope (TEM). The binding properties of MMIPs were evaluated by isothermal adsorption, kinetic adsorption and selective adsorption experiments. The results showed that the saturated adsorption capacity and adsorption time were 17.9 µmol/g and 20 min, respectively, and showed high selectivity for quercetin. Under optimized conditions, the limit of detection (LOD) and limit of quantitation (LOQ) were 55.327 ng/mL and 184.413 ng/mL, respectively. The recovery and RSD were 85.34-95.67% and 3.36-6.59, respectively. We successfully combined magnetic solid phase extraction with high performance liquid chromatography (MSPE-HPLC-UV) for the enrichment, separation and detection of quercetin in rat plasma. The results showed that the peak and half-life of quercetin in plasma were 1.5 h (32.310 µg/mL) and 3 h, respectively. The method was simple, rapid and efficient, and could be applied to the separation and detection of quercetin in complex matrices, and also provides a basis for the separation and identification of other natural chemical components.

5.
Chem Commun (Camb) ; 56(5): 703-706, 2020 Jan 16.
Artículo en Inglés | MEDLINE | ID: mdl-31845686

RESUMEN

We report the development of a new type of organic semiconductor gas sensor based on a porphyrin-based hydrogen-bonded organic framework (HOF). Owing to the orderly porous structures, the decoration with rich amino sites and the n-type semiconductor nature, this HOF-based sensor exhibits selective NO2 sensing performance with ultra-fast response/recovery rates (17.6 s/15.4 s over 100 ppb) and a limit of detection lower than 40 ppb, together with high sensitivity, good reproducibility, and long-term stability at room temperature. This study demonstrates that HOF-based materials have potential application prospects in gas sensing, thereby offering a new way of thinking for the design and development of sensors.

6.
Org Biomol Chem ; 17(44): 9605-9614, 2019 11 28.
Artículo en Inglés | MEDLINE | ID: mdl-31681917

RESUMEN

Diverse derivatives of amino acids with different steric configurations are important biosynthetic building blocks. In biology, epimerization is an important way to generate steric diversity. MarH catalyzes the epimerization of the ß-position of (3R)-ß-methyl-indolepyruvate (MeInPy), forming (3S)-ß-MeInPy. Both compounds are derivatives of l-tryptophan (l-Trp) and are important precursors of bioactive natural products. Here, we report the crystal structures of MarH and the NMR structure of its complex with l-Trp, an analogue of its native substrate, (3R)-ß-MeInPy. Structural analysis and mutagenesis studies indicated that His25 acts as a base to remove Hß and generate a planar carbanion intermediate, which is then putatively reprotonated on the opposite face by a water molecule to form (3S)-ß-MeInPy in a stereospecific manner. The details of ß-site isomerization at the atomic level provide deeper insights into the epimerization mechanism of MarH and will facilitate further enzyme design to extend the substrate scope.


Asunto(s)
Racemasas y Epimerasas/química , Indoles/química , Indoles/metabolismo , Modelos Moleculares , Resonancia Magnética Nuclear Biomolecular , Conformación Proteica , Piruvatos/química , Piruvatos/metabolismo , Racemasas y Epimerasas/metabolismo
7.
Proc Natl Acad Sci U S A ; 116(48): 24214-24220, 2019 Nov 26.
Artículo en Inglés | MEDLINE | ID: mdl-31723045

RESUMEN

Although CRIg was originally identified as a macrophage receptor for binding complement C3b/iC3b in vitro, recent studies reveal that CRIg functions as a pattern recognition receptor in vivo for Kupffer cells (KCs) to directly bind bacterial pathogens in a complement-independent manner. This raises the critical question of whether CRIg captures circulating pathogens through interactions with complement in vivo under flow conditions. Furthermore, the role of CRIg during parasitic infection is unknown. Taking advantage of intravital microscopy and using African trypanosomes as a model, we studied the role of CRIg in intravascular clearance of bloodborne parasites. Complement C3 is required for intravascular clearance of African trypanosomes by KCs, preventing the early mortality of infected mice. Moreover, antibodies are essential for complement-mediated capture of circulating parasites by KCs. Interestingly, reduced antibody production was observed in the absence of complement C3 during infection. We further demonstrate that CRIg but not CR3 is critically involved in KC-mediated capture of circulating parasites, accounting for parasitemia control and host survival. Of note, CRIg cannot directly catch circulating parasites and antibody-induced complement activation is indispensable for CRIg-mediated parasite capture. Thus, we provide evidence that CRIg, by interacting with complement in vivo, plays an essential role in intravascular clearance of bloodborne parasites. Targeting CRIg may be considered as a therapeutic strategy.

9.
Artículo en Inglés | MEDLINE | ID: mdl-31628812

RESUMEN

OBJECTIVES: This study aimed to compare the outcomes of patients with ocular myasthenia gravis (OMG) who underwent thymectomy before generalization with the outcomes of those who underwent thymectomy after generalization. METHODS: We retrospectively reviewed patients who underwent robotic thymectomy for myasthenia gravis between January 2003 and February 2018. Patients who presented with purely ocular symptoms at myasthenia gravis onset were eligible for inclusion. Exclusion criteria were patients who were lost to follow-up and patients who underwent re-thymectomy. Patients with OMG who developed generalization before thymectomy were categorized into gOMG group and those who did not were categorized into OMG group. The primary outcome was complete stable remission according to the Myasthenia Gravis Foundation of America Post-Intervention Status (MGFA-PIS). RESULTS: One hundred and sixty-five (66 males and 99 females) out of 596 patients with myasthenia gravis were eligible for inclusion. Of these, there were 73 and 92 patients undergoing thymectomy before and after the generalization of OMG, respectively. After propensity score matching, a data set of 130 patients (65 per group) was formed and evaluating results showed no statistical differences between the 2 groups. The estimated cumulative probabilities of complete stable remission at 5 years were 49.5% [95% confidence interval (CI) 0.345-0.611] in the OMG group and 33.4% (95% CI 0.176-0.462) in the gOMG group (P = 0.0053). Similar results were also found in patients with non-thymomatous subgroup [55 patients per group, OMG vs gOMG, 53.5% (95% CI 0.370-0.656) vs 28.9% (95% CI 0.131-0.419), P = 0.0041]. CONCLUSIONS: Thymectomy in OMG before generalization might result in a higher rate of complete stable remission than thymectomy after generalization.

10.
Nat Commun ; 10(1): 4566, 2019 10 08.
Artículo en Inglés | MEDLINE | ID: mdl-31594939

RESUMEN

Fungal dissemination into the bloodstream is a critical step leading to invasive fungal infections. Here, using intravital imaging, we show that Kupffer cells (KCs) in the liver have a prominent function in the capture of circulating Cryptococcus neoformans and Candida albicans, thereby reducing fungal dissemination to target organs. Complement C3 but not C5, and complement receptor CRIg but not CR3, are involved in capture of C. neoformans. Internalization of C. neoformans by KCs is subsequently mediated by multiple receptors, including CR3, CRIg, and scavenger receptors, which work synergistically along with C5aR signaling. Following phagocytosis, the growth of C. neoformans is inhibited by KCs in an IFN-γ independent manner. Thus, the liver filters disseminating fungi from circulation via KCs, providing a mechanistic explanation for the enhanced risk of cryptococcosis among individuals with liver diseases, and suggesting a therapeutic strategy to prevent fungal dissemination through enhancing KC functions.

11.
Chemistry ; 25(71): 16207-16213, 2019 Dec 18.
Artículo en Inglés | MEDLINE | ID: mdl-31602719

RESUMEN

The functionalization of natural 1D architectures is dependent on hierarchically inner nanostructures. However, the artificial supramolecular nanofibers or nanotubes were rarely developed with complex inner structures. Inspired by a biomimetic strategy, single-molecule-diameter nanofibers of double-decker phthalocyanine (EuPc2) with compartmentalized internal space and fantastic electrochemical features were developed upon air/water interfacial assembly with poly-l-lysine. EuPc2/poly-l-lysine nanofibers can be electrochemical sensors both in water and the gas phase and have the best analytical performances for nitrite among all the porphyrins or phthalocyanines monomers and assemblies. Imbedding nitrite in compartments not only promotes the sensing but also changes the supramolecular chirality of nanofibers, and the morphological-dependent sensing properties of EuPc2 assemblies in water are different from that in the gas phase. These results suggest the unprecedented properties for diverse applications of artificial 1D architectures containing complex inner nanostructures.

12.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 27(5): 1387-1394, 2019 Oct.
Artículo en Chino | MEDLINE | ID: mdl-31607288

RESUMEN

OBJECTIVE: To investigate the effect of metformin on the proliferation, apoptosis and energy metabolism of acute myeloid leukemia (AML) K562 cells and the possible mechanism. METHODS: Different doses (0, 5, 10, 20 and 30 mmol/L) of metformin was added into the K562 cells, which were cultivated for 24 h, 48 h and 72 h. The inverted optical microscope was used to observe the cell growth, CCK 8 was used to detect the cell vitality. The appropriate metformin doses (0, 10, 20 and 30 mmol/L) and the best time (48 h) were selected for subsequent experiments. The flow cytometer with Annexin V-FITC /PI doulde staining was used to detect apoptosis; the glucose detection kit and lactate detection kit were used to detect glucose consumption and lactate production; fluorescence quantitative PCR was used to detect glycolysis-related gene expression, and Western blot was used to detect protein expression. RESULTS: Metformin inhibited the proliferation of K562 cells in a dose-dependent manner (r=0.92), and the relative survival in the 30 mmol/L group was as low as 19.84% at 72 h. When treated with metformin for 48 h, the apoptosis rates of 0, 10, 20 and 30 mmol/L groups were 5.14%, 12.19%, 26.29% and 35.5%, respectively. Compared with the control group, the glucose consumption and lactate secretion of K562 cells treated with metformin were significantly reduced (P<0.05), and showed a dose-dependent effect(r=0.94,r=0.93,respectively). Metformin inhibited the expression of GLUT1, LDHA, ALDOA, PDK1, and PGK1 genes of K562 cells (P<0.05) showing a dose-dependent manner(r=0.83,r=0.80,r=0.72,r=0.76,r=0.73,respectively). Metformin inhibited the expression of P-Akt, P-S6, GLUT1, LDHA proteins of K562 cells(P<0.05), showing a dose-dependent relationship(r=0.80,r=0.92,r=0.83,r=0.92,respectively). CONCLUSION: Metformin can inhibit the growth and proliferation of K562 cells and promote the apoptosis of K562 cells by inhibiting glycolysis energy metabolism. PI3K/Akt/mTOR signaling pathway may be one of the molecular mechanisms of metformin on k562 cells.


Asunto(s)
Metformina/farmacología , Apoptosis , Proliferación Celular , Glucólisis , Humanos , Células K562 , Fosfatidilinositol 3-Quinasas
13.
Animals (Basel) ; 9(9)2019 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-31461906

RESUMEN

Fatty acid synthase (FASN) is an enzyme involved in the synthesis of fatty acids (FA) and plays a central role in de novo lipogenesis in mammals. This study was conducted to ascertain the relative level of expression of the FASN gene (FASN) in tissues from the yak (Bos grunniens), and to search for variation in two regions of yak FASN using polymerase chain reaction single-stranded conformational polymorphism (PCR-SSCP) analyses; it also ascertains whether that variation is associated with yak milk traits. The gene was found to be expressed in twelve tissues, with the highest expression detected in the mammary gland, followed by subcutaneous fat tissue. Two regions of the gene were analyzed in 290 Gannan yaks: A region spanning exon 24-intron 24 and a region spanning exon 34. These regions both produced two PCR-SSCP patterns, which, upon sequencing, represented different DNA sequences. This sequence variation resulted from the presence of three nucleotide substitutions: c.4296+38C/T (intron 24), c.5884A/G, and c.5903G/A, both located in exon 34. The exon 34 substitutions would result in the amino acid substitutions p.Thr1962Ala and p.Gly1968Glu if expressed. Four haplotypes spanning from the exon 24-intron 24 region to exon 34 were identified. Of these, two were common (A1-A2 and B1-A2), and two were rare (A1-B2 and B1-B2) in the yaks investigated. The presence of A1-A2 was associated with an increase in milk fat content (p = 0.050) and total milk solid content (p = 0.037), while diplotype A1-A2/B1-A2 had a higher milk fat content (p = 0.038) than the other diplotypes. This study suggests that further characterization of the FASN gene might provide for an improved understanding of milk traits in yaks.

14.
J Thorac Dis ; 11(7): 3084-3092, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31463137

RESUMEN

Background: To explore the risk factors and prevention methods of cervical mechanical anastomotic fistula and stenosis after the radical resection of esophageal cancer. Methods: From March 2018 to November 2018, 128 patients undergoing mechanical anastomosis of esophageal cancer were selected from the Department of Thoracic Surgery of The First Affiliated Hospital of Zhengzhou University. All the enrolled patients were operated on using the Mckeown method, and a retrospective study was conducted. Data for preoperative and postoperative test indices, intraoperative embedding materials, postoperative complications, and preoperative and postoperative treatment were collected, and the relationship between various factors and the incidence of cervical anastomotic fistula and stenosis was analysed. Univariate analysis was conducted using t tests or Fisher's exact probability method, and multivariate analysis was conducted using logistic regression models. Results: All 128 patients successfully underwent surgery without dying. The enrolled patients were evaluated using the Stooler classification, with 28 patients having grade 0, 41 patients having grade 1, 34 patients having grade 2, 21 patients having grade 3, and 4 patients having grade 4 stenosis. Patients with stenosis of grade 3 or above had obvious choking sensation, which could only be relieved by balloon dilation. Symptoms in all patients with stenosis were relieved by balloon dilation. There were no significant differences between the two groups regarding embedding materials, preoperative choking history, history of alcohol consumption, history of hypertension, history of coronary heart disease, history of diabetes, postoperative calcium concentration, average albumin concentration, average platelet concentration, body mass index, anastomotic fistula, preoperative chemotherapy, postoperative chemotherapy, or postoperative cough (P>0.05). There were significant differences in postoperative reflux (χ2=11.338, P<0.05) and scar constitution (χ2=12.497, P<0.05). The effects of embedding materials in patients with anastomotic fistula were significantly different (χ2=4.372, P<0.05). Conclusions: Postoperative reflux and scar constitution may be risk factors for postoperative anastomotic stenosis after resection of esophageal cancer. There was almost no difference in the effects on esophageal anastomotic stenosis between embedding materials and the omentum majus, but Neoveil® may have certain advantages in preventing cervical anastomotic fistula, and thus may have certain clinical application value.

15.
Anal Bioanal Chem ; 411(24): 6427-6434, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31321470

RESUMEN

1H and 2H NMR spectra of 4 natural and synthetic nicotine samples were collected in a non-quantitative way and site-specific 2H/1H peak intensity ratio (SPIR) was calculated for 12 distinct sites of nicotine. Experimental results illustrated that the SPIRs at sites of 6, 2', and 5'ß of natural nicotine were significantly different from those of the synthetic nicotine, and could be used for nicotine authentication as the measured SPIRs were indicative of the site-specific natural isotope fractionation. We demonstrated that this method could be applied to detect adulteration of natural nicotine with as low as 20% synthetic nicotine, without the need to measure the site-specific δD values, which usually required time-consuming quantitative 2H NMR and additional IRMS for the overall 2H/1H isotopic ratio determination. The distinguishable 2H/1H SPIRs of nicotine, which can be quickly measured by NMR in non-quantitative way, can serve as an attractive alternative tool for tobacco authentication. Graphical abstract.


Asunto(s)
Contaminación de Medicamentos , Nicotina/análisis , Espectroscopía de Protones por Resonancia Magnética/métodos , Espectrometría de Masas/métodos
16.
Plant Physiol ; 181(1): 97-111, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31235561

RESUMEN

The appropriate timing of flowering is critical for plant reproductive success. Although the FLOWERING LOCUS T (FT)-FD module plays crucial roles in the photoperiodic flowering pathway, the underlying mechanisms and signaling pathways involved still remain elusive. Here, we demonstrate that class II TCP transcription factors (TFs) integrate into the FT-FD complex to control floral initiation in Arabidopsis (Arabidopsis thaliana). Class II CINCINNATA (CIN) TCP TFs function as transcriptional activators by directly binding to the promoters of downstream floral meristem identity genes, such as APETALA1 (AP1). In addition, these TCPs directly interact with FD, a basic Leu zipper TF that plays a critical role in photoperiodic flowering, which further activates AP1 expression. Genetic analyses indicated that class II CIN TCP TFs function synergistically with FT and FD, to positively regulate flowering in an AP1-dependent manner. Thus, our results provide compelling evidence that class II CIN TCP TFs act directly at the AP1 promoter to enhance its transcription, thus further elucidating the molecular mechanisms underlying the regulation of photoperiodic flowering in Arabidopsis.

17.
Molecules ; 24(9)2019 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-31083563

RESUMEN

Carbon capture from flue gas and natural gas offers a green path to construct a net-zero emissions economic system. Selective adsorption-based gas separation by employing metal-organic frameworks (MOFs) is regarded as a promising technology due to the advantages of simple processing, easy regeneration and high efficiency. We synthesized two Zirconium MOFs (UiO-66 and UiO-66-NH2) nanocrystals for selective capture and further removal of CO2 from flue gas and natural gas. In particular, UiO-66-NH2 nanocrystals have a smaller grain size, a large amount of defects, and pending -NH2 groups inside their pores which display effective CO2 selective adsorption abilities over CH4 and N2 with the theoretical separation factors of 20 and 7. This breakthrough experiment further verified the selective adsorption-based separation process of natural gas and flue gas. In one further step, we used the Monte Carlo simulation to investigate the optimized adsorption sites and energy of CO2, N2 and CH4 molecules in the gas mixture. The significantly large adsorption energy of CO2 (0.32 eV) over N2 (0.19 eV) and N2 (0.2 eV) may help us to reveal the selective adsorption mechanism.


Asunto(s)
Estructuras Metalorgánicas/química , Nanopartículas/química , Gas Natural , Circonio/química , Adsorción , Dióxido de Carbono/química
18.
J Phys Chem Lett ; 10(11): 3006-3012, 2019 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-31117694

RESUMEN

Under compression, "'simple'" alkali metals and their alloys exhibit complex structural and electronic properties, leading to fundamental interest in their high-pressure behaviors. Here, the swarm-intelligence structure-searching method was employed to identify the high-pressure phases of binary interalkali Na2K, which has long been known to possess a MgZn2-Laves phase at ambient pressure, but the high-pressure behavior remains elusive. We uncovered four new structures over a pressure range of 10-500 GPa, although the compound was found to become unstable upon decomposition into Na and K from 37 to 273 GPa. In phases before decomposition, the electrons were gradually delocalized with an increase in pressure and there was charge transfer from K to Na, whereas in phases after recombination, the electrons were gradually localized into the interstitials of the crystals, showing the unexpected opposite trend of charge transfer from Na to K, remarkably, where K was found to exhibit an oxidation state beyond the -1 valence state. The results can improve our understanding of the interaction and evolution of s electrons under compression.

19.
Eur J Radiol ; 112: 112-120, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30777199

RESUMEN

OBJECTIVE: To identify whether whole-tumour histogram analysis of pharmacokinetic parameters from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) could predict T-stage and regional lymph node metastasis (LNM) of resectable oesophageal squamous cell carcinoma (SCC). MATERIALS AND METHODS: Forty-two consecutive patients with confirmed oesophageal SCC underwent thoracic DCE-MRI. Histogram metrics (median, mean, standard deviation [SD], skewness, kurtosis and entropy) of whole-tumour pharmacokinetic parameters including endothelial transfer constant (Ktrans), reflux rate (Kep) and fractional extravascular extracellular space volume (Ve) were generated by the Omni-Kinetics software. Histogram datasets were interpreted using the Mann-Whitney U test and receiver operating characteristic (ROC) statistical analyses. RESULTS: The Mann-Whitney U tests revealed that the median, mean and SD of Ktrans, the SD and entropy of Kep, and the median, mean and entropy of Ve of T1-2 stage oesophageal SCC were lower when compared with T3 stage (all Ps < 0.05); and the ROC analysis showed that the entropy of Ve could reliably distinguish T1-2 stage from T3 stage with an area under ROC (AUC) of 0.773. The Mann-Whitney U tests illustrated that the entropy of Ktrans, and the median, mean, SD and entropy of Kep were higher while the skewness of Kep was lower in tumours with LNM than without LNM (all Ps < 0.05); and the ROC analysis demonstrated that the SD of Kep could best identify tumours with LNM with an AUC of 0.702. CONCLUSION: Whole-tumour histogram analysis of pharmacokinetic parameters of oesophageal SCC on DCE-MRI could be used to predict T-stage and regional LNM.


Asunto(s)
Neoplasias Esofágicas/patología , Carcinoma de Células Escamosas de Esófago/patología , Anciano , Medios de Contraste/farmacocinética , Métodos Epidemiológicos , Femenino , Humanos , Ganglios Linfáticos/patología , Metástasis Linfática , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias
20.
Sci Rep ; 9(1): 124, 2019 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-30644415

RESUMEN

This study aimed to determine whether dynamic contrast-enhanced MRI (DCE-MRI) derived parameters can identify oesophageal squamous cell carcinoma (SCC) and lymphatic metastasis. Thirty-nine oesophageal SCC patients underwent DCE-MRI. Quantitative parameters including endothelial transfer constant (Ktrans), reflux rate (Kep), fractional extravascular extracellular space volume and fractional plasma volume, and semi-quantitative parameters including time to peak (TTP), max concentration, Max Slope and area under concentration-time curve of both oesophageal SCC and normal oesophagus were measured. Mann-Whitney U test revealed that Ktrans and Kep of oesophageal SCC were higher while TTP was shorter when compared to normal oesophagus (all P-values < 0.05); and areas under receiver operating characteristic [ROC] curves displayed that Kep was superior to TTP or Ktrans for identifying oesophageal SCC (0.903 vs. 0.832 or 0.713). Mann-Whitney U test also demonstrated that Kep was higher and TTP was shorter in patients with lymphatic metastasis when compared to non-metastatic cancer patients (both P-values < 0.05), and area under ROC curve also showed that TTP was superior to Kep for predicting lymphatic metastasis (0.696 vs. 0.659). In conclusion, the combination of quantitative and semi-quantitative parameters derived from DCE-MRI can aid in the identification of oesophageal SCC and lymphatic metastasis.

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