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1.
J Pineal Res ; 2020 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-32052470

RESUMO

Melatonin (MT), endogenously secreted by the pineal gland, is closely related to multiple biological processes; however, its effect on thrombopoiesis is still not well illustrated. Here, we demonstrate that MT administration can elevate peripheral platelet levels. Analysis of different stages in thrombopoiesis reveals that MT has the capacity to promote the expansion of CD34+ and CD41+ cells, and accelerate proplatelet formation (PPF) and platelet production. Furthermore, in vivo experiments show that MT has a potential therapeutic effect on radiation-induced thrombocytopenia. The underlying mechanism suggests that both extracellular signal-regulated kinase 1/2 (ERK1/2) and Akt signaling are involved in the processes of thrombopoiesis facilitated by MT. Interestingly, in addition to the direct regulation of Akt signaling by its upstream phosphoinositide 3-kinase (PI3K), ERK1/2 signaling is also regulated by PI3K via its effector, dual adaptor for phosphotyrosine and 3-phosphoinositides (DAPP1), in megakaryocytes after MT treatment. Moreover, the expression level of DAPP1 during megakaryocyte differentiation is closely related to the activation of ERK1/2 and Akt at different stages of thrombopoiesis. In conclusion, our data suggest that MT treatment can promote thrombopoiesis, which is modulated by the DAPP1-orchestrated activation of ERK1/2 and Akt signaling.

2.
BMC Genomics ; 21(1): 62, 2020 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-31959122

RESUMO

BACKGROUND: The APETALA2/ethylene responsive factor (AP2/ERF) superfamily members are transcription factors that regulate diverse developmental processes and stress responses in plants. They have been identified in many plants. However, little is known about the AP2/ERF superfamily in longan (Dimocarpus longan Lour.), which is an important tropical/subtropical evergreen fruit tree that produces a variety of bioactive compounds with rich nutritional and medicinal value. We conducted a genome-wide analysis of the AP2/ERF superfamily and its roles in somatic embryogenesis (SE) and developmental processes in longan. RESULTS: A genome-wide survey of the AP2/ERF superfamily was carried out to discover its evolution and function in longan. We identified 125 longan AP2/ERF genes and classified them into the ERF (101 members), AP2 (19 members), RAV (four members) families, and one Soloist. The AP2 and Soloist genes contained one to ten introns, whereas 87 genes in the ERF and RAV families had no introns. Hormone signaling molecules such as methyl jasmonate (MeJA), abscisic acid (ABA), gibberellin, auxin, and salicylic acid (SA), and stress response cis-acting element low-temperature (55) and defense (49) boxes also were identified. We detected diverse single nucleotide polymorphisms (SNPs) between the 'Hong He Zi' (HHZ) and 'SI JI MI' (SJM) cultivars. The number of insertions and deletions (InDels) was far fewer than SNPs. The AP2 family members exhibited more alternative splicing (AS) events in different developmental processes of longan than members of the other families. Expression pattern analysis revealed that some AP2/ERF members regulated early SE and developmental processes in longan seed, root, and flower, and responded to exogenous hormones such as MeJA, SA, and ABA, and 2,4-D, a synthetic auxin. Protein interaction predictions indicated that the Baby Boom (BBM) transcription factor, which was up-regulated at the transcriptional level in early SE, may interact with the LALF/AGL15 network. CONCLUSIONS: The comprehensive analysis of molecular evolution and expression patterns suggested that the AP2/ERF superfamily may plays an important role in longan, especially in early SE, and in seed, root, flower, and young fruit. This systematic analysis provides a foundation for further functional characterization of the AP2/ERF superfamily with the aim of longan improvement.

3.
BMC Genomics ; 21(1): 4, 2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31898486

RESUMO

BACKGROUND: Somatic embryogenesis (SE) is a process of somatic cells that dedifferentiate to totipotent embryonic stem cells and generate embryos in vitro. Longan SE has been established and wildly used as model system for studying embryogenesis in woody plants, SE-related genes had been characterized. In spite of that, a comprehensive overview of SE at a molecular level is still absent. To understand the molecular mechanisms during longan SE, we examined the transcriptome changes by using Illumina HiSeq from the four distinct developmental stages, including non-embryogenic callus (NEC), embryogenic callus (EC), incomplete compact pro-embryogenic cultures (ICpEC), globular embryos (GE). RESULTS: RNA-seq of the four samples generated a total of 243.78 million high quality reads, approximately 81.5% of the data were mapped to longan genome. The cDNA libraries of NEC, EC, ICpEC and GE, generated 22,743, 19,745, 21,144, 21,102 expressed transcripts, 1935, 1710, 1816, 1732 novel transcripts, 2645, 366, 505, 588 unique genes, respectively. Comparative transcriptome analysis showed that a total of 10,642, 4180, 5846 and 1785 genes were differentially expressed in the pairwise comparisons of NEC_vs_EC, EC_vs_ICpEC, EC_vs_GE, ICpEC_vs_GE, respectively. Among them, plant hormones signalling related genes were significantly enriched, especially the auxin and cytokinin signalling components. The transcripts of flavonoid biosynthesis related genes were mainly expressed in NEC, while fatty acid biosynthesis related genes mainly accumulated in early SE. In addition, the extracelluar protein encoding genes LTP, CHI, GLP, AGP, EP1 were related to longan SE. Combined with the FPKM value of longan nine tissues transcription, 27 SE specific or preferential genes (LEC1, LEC1-like, PDF1.3, GH3.6, AGL80, PIN1, BBM, WOX9, WOX2, ABI3, et al.) and 28 NEC preferential genes (LEA5, CNOT3, DC2.15, PR1-1, NsLTP2, DIR1, PIP1, PIP2.1, TIP2-1, POD-P7 and POD5 et al.) were characterized as molecular markers for longan early SE. qRT-PCR validation of SE-related genes showed a high correlation between RNA-seq and qRT-PCR data. CONCLUSION: This study provides new insights into the role of the transcriptome during early SE in longan. Differentially expressed genes reveal that plant hormones signalling, flavonoid and fatty acid biosynthesis, and extracelluar protein related genes were involved in longan early SE. It could serve as a valuable platform resource for further functional studies addressing embryogenesis in woody plants.

4.
Haematologica ; 2020 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-31974197

RESUMO

Long-term hematopoietic output is dependent on hematopoietic stem cell (HSC) homeostasis which is maintained by a complex molecular network. Among these, microRNAs play crucial roles, while the underlying molecular basis has not been fully elucidated. Here, we show that miR-21 is enriched in murine HSCs, and mice with conditional knockout of miR-21 exhibit an obvious perturbation in normal hematopoiesis. Moreover, significant loss of HSC quiescence and long-term reconstituting ability are observed in the absence of miR-21. Further studies reveal that miR-21 deficiency markedly decreases the NF-κB pathway, accompanied by increased expression of PDCD4, a direct target of miR-21, in HSCs. Interestingly, overexpression of PDCD4 in wild-type HSCs generates similar phenotypes as those of miR-21-deficient HSCs. More importantly, knockdown of PDCD4 can significantly rescue the attenuation of NF-κB activity, thereby improving the defects in miR-21-null HSCs. On the other hand, we find that miR-21 is capable of preventing HSCs from ionizing radiation-induced DNA damage via activation of the NF-κB pathway. Collectively, our data demonstrate that miR-21 is involved in maintaining HSC homeostasis and function, at least in part, by regulating the PDCD4-mediated NF-κB pathway and provide a new insight into the radioprotection of HSCs.

5.
ChemSusChem ; 13(1): 111-115, 2020 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-31721472

RESUMO

In the present study, a sonochemical-based method for one-pot synthesis of entropy-stabilized perovskite oxide nanoparticle catalysts with high surface area was developed. The high-entropy perovskite oxides were synthesized as monodispersed, spherical nanoparticles with an average crystallite size of approximately 5.9 nm. Taking advantage of the acoustic cavitation phenomenon in the ultrasonication process, BaSr(ZrHfTi)O3 , BaSrBi(ZrHfTiFe)O3 and Ru/BaSrBi(ZrHfTiFe)O3 nanoparticles were crystallized as single-phase perovskite structures through ultrasonication exposure without calcination. Notably, the entropically-driven stability of Ru/BaSrBi(ZrHfTiFe)O3 with excellent dispersion of Ru in the perovskite phase bestowed the nanoparticles of Ru/BaSrBi(ZrHfTiFe)O3 with good catalytic activity for CO oxidation.

6.
Eur Radiol ; 30(1): 301-307, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31218429

RESUMO

PURPOSE: To evaluate and compare wall enhancement patterns in saccular and fusiform intracranial aneurysms using high-resolution black-blood MRI at 7 T. METHODS: Thirty-one patients with 32 unruptured intracranial aneurysms (21 saccular and 11 fusiform) underwent 7-T black-blood MRI. Aneurysm wall enhancement (AWE) was categorized as follows: no wall enhancement (NWE), focal wall enhancement (FWE), and uniform wall enhancement (UWE). The degree of enhancement was scored as follows: 0 (no enhancement), 1 (signal intensity (SI) of the aneurysm wall less than that of the pituitary infundibulum), and 2 (equal to that of the pituitary infundibulum). The chi-squared test was used to compare the AWE pattern and degree between saccular and fusiform aneurysms. RESULTS: In saccular aneurysms, 12/21 (57%) enhanced. Of these, 9 showed FWE (5 grade 1 and 4 grade 2), and 3 showed UWE (2 grade 1 and 1 grade 2). In fusiform aneurysms, 11/11 (100%) enhanced. Of these, 1 showed FWE and 10 showed UWE. All fusiform aneurysms had grade-2 enhancement. Fusiform aneurysms had more extensive and higher SI AWE than saccular aneurysms (p < 0.01) despite having a similar size (6.9 ± 3.0 mm vs. 8.0 ± 2.9, p = 0.23). For saccular aneurysm, larger aneurysm size was correlated with higher degree of enhancement with Pearson's r = 0.64 (p = 0.002). CONCLUSION: Intracranial fusiform aneurysms had enhancement of higher SI and that covered a more extensive area than saccular aneurysms, which might indicate differences in vessel wall pathology. KEY POINTS: • Intracranial aneurysm wall enhancement can be reliably characterized by 7-T black-blood MRI. • AWE in intracranial fusiform aneurysms presents over a larger surface area and with greater signal intensity as compared with that in saccular aneurysms, which might indicate differences in pathology. • Stronger signal intensity of AWE correlates with the aneurysm size in saccular aneurysms.

7.
Sci Total Environ ; 705: 135995, 2020 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-31841909

RESUMO

We investigated the occurrence, distribution, and potential sources of 10 organophosphorus flame retardants (OPFRs) in road dust from the urban area of Dalian, China, as well as their associated human exposures and health risks. The total concentration of Σ10OPFRs ranged from 300 to 7480 ng/g with a median of 1600 ng/g. Relatively high concentrations were observed mainly near prosperous business districts or dense residential areas. Tris(2-chloroethyl) phosphate (TCEP), tris(1-chloro-2-propyl) phosphate (TCIPP), and triphenylphosphine oxide (TPPO) were detected in all dust samples. TCIPP was the dominant congener, followed by TPPO. It was found that traffic flow can obviously influence the concentration of OPFRs in road dust, suggesting vehicles may be the major sources of OPFRs in road dust, presumably from materials used in their interiors. Correlations between certain OPFRs and population density indicate a significant influence by anthropogenic activities on OPFR levels. The average daily doses (ADD) of Σ10OPFRs via ingestion, inhalation and dermal absorption from road dust were evaluated as 0.26 and 0.087 ng/(kg-bw·d) for children and adults respectively, with dust ingestion as the main exposure pathway of OPFRs. Although the exposure risk of OPFRs via road dust was relatively low in Dalian, further studies on the exposure of OPFRs are still necessary due to combined effects with other exposure pathways.

8.
ACS Appl Mater Interfaces ; 11(47): 43996-44006, 2019 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-31682099

RESUMO

Liver cancer is a leading cause of cancer morbidity and mortality worldwide, especially in China. Sorafenib (SRF) is currently the most commonly used systemic agent against advanced hepatocellular carcinoma (HCC), which is the most common type of liver cancer. However, HCC patients have only limited benefit and suffer a serious side effect from SRF. Therefore, new approaches are urgently needed to improve the therapeutic effectiveness of SRF and reduce its side effect. In our current study, we developed a self-imaging and self-delivered nanodrug with SRF and indocyanine (ICG) to improve the therapeutic effect of sorafenib against HCC. With the π-π stacking effect between SRF and ICG, a one-step nanoprecipitation method was designed to obtain the SRF/ICG nanoparticles (SINP) via self-assembly. Pluronic F127 was used to shield the SINP to further improve the stability in an aqueous environment. The stability, photothermal effect, cell uptake, ROS production, cytotoxicity, tumor imaging, and tumor-targeting and tumor-killing efficacy of the SINP were evaluated in vitro and in vivo by using an HCC cell line Huh7 and its xenograft tumor model. We found that our designed SINP showed monodisperse stability and efficient photothermal effect both in vitro and in vivo. SINP could rapidly enter Huh7 cells and achieve potent cytotoxicity under near-infrared (NIR) laser irradiation partly by producing a great amount of reactive oxygen species (ROS). SINP had significantly improved stability and blood half-life, and could specifically target tumor via the enhanced permeability and retention (EPR) effect in vivo. In addition, SINP showed improved cytotoxicity in both subcutaneous and orthotopic HCC implantation models in vivo. Overall, this rationally designed sorafenib delivery system with a very high loading capacity (33%) has considerably improved antitumor efficiency in vitro and could completely eliminate subcutaneous tumors without any regrowth in vivo. In conclusion, our self-imaging and self-delivered nanodrug could improve the efficacy of SRF and might be a potential therapy for HCC patients.

9.
Ultrason Imaging ; 41(6): 353-367, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31615352

RESUMO

Breast cancer has become the biggest threat to female health. Ultrasonic diagnosis of breast cancer based on artificial intelligence is basically a classification of benign and malignant tumors, which does not meet clinical demand. Besides, the current target detection method performs poorly in detecting small lesions, while it is clinically required to detect nodules below 2 mm. The objective of this study is to (a) propose a diagnostic method based on Breast Imaging Reporting and Data System (BI-RADS) and (b) increase its detectability of small lesions. We modified the framework of Faster R-CNN (Faster Region-based Convolutional Neural Network) by introducing multi-scale feature extraction and multi-resolution candidate bound extraction into the network. Then, it was trained using 852 images of BI-RADS C2, 739 images of C3, and 1662 images of malignancy (BI-RADS 4a/4b/4c/5/6). We compared our model with unmodified Faster R-CNN and YOLO v3 (You Only Look Once v3). The mean average precision (mAP) is significantly increased to 0.913, while its average detection speed is slightly declined to 4.11 FPS (frames per second). Meanwhile, its detectivity of small lesions is effectively improved. Moreover, we also tentatively applied our model on video sequences and got satisfactory results. We modified Faster R-CNN and trained it partly based on BI-RADS. Its detectability of lesions, as well as small nodules, was significantly improved. In view of wide coverage of dataset and satisfactory test results, our method can basically meet clinical needs.

10.
Stroke ; 50(11): 3128-3134, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31514698

RESUMO

Background and Purpose- Accumulating evidence has demonstrated hemodynamic abnormalities and cerebral hypoperfusion in patients with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). Increased venous susceptibility assessed by susceptibility weighted imaging and mapping has been shown to indicate a decrease in venous oxygen saturation. This study aimed to investigate whether altered venous oxygen saturation is related to clinical phenotypes of CADASIL patients. Methods- Using 7.0-T susceptibility weighted imaging and mapping, we compared venous susceptibility of cortical veins between 41 CADASIL patients and 43 age- and sex-matched healthy controls. The magnetic resonance imaging lesion load, mini-mental state examination score, Barthel Index, and modified Rankin Scale were examined in the patient group, and the correlations between venous susceptibility and clinical characteristics were analyzed. Results- Venous susceptibility increased with age (r=0.508, P=0.001) and was higher in CADASIL patients than in healthy controls (t=-4.673; P<0.001). We found a positive association between venous susceptibility and the age-related white matter change scores (r=0.364; P=0.019), number of lacunar infarctions (r=0.520; P<0.001), number of cerebral microbleeds (ρ=0.445; P=0.004), and small-vessel disease scores (ρ=0.465; P=0.002) in CADASIL patients. Moreover, increased venous susceptibility was associated with higher modified Rankin Scale scores in CADASIL patients after adjustment for age- and small-vessel disease scores (odds ratio=3.178; 95% CI, 1.101-9.179; P=0.033). Conclusions- Our findings indicate that extensive cerebral hypoperfusion may induce central nervous system impairment in CADASIL, and susceptibility weighted imaging and mapping could be used clinically to assess the condition of CADASIL patients.

11.
ChemSusChem ; 12(19): 4400-4404, 2019 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-31419072

RESUMO

The simultaneous conversion of C5 and C6 mixed sugars into methyl levulinate (MLE) has emerged as a versatile strategy to eliminate costly separation steps. However, the traditional upgrading of C5 sugars into MLE is very complex as it requires both acid-catalyzed and hydrogenation processes. This study concerns the development of a one-pot, hydrogenation-free conversion of C5 sugars into MLE over different acid catalysts at near-critical methanol conditions with the help of 1,3,5-trioxane. For the conversion of C5 sugars over zeolites without the addition of 1,3,5-trioxane, the MLE yield is quite low, owing to low hydrogenation activity. The addition of 1,3,5-trioxane significantly boosts the MLE yield by providing an alternative conversion pathway that does not include the hydrogenation step. A direct comparison of the catalytic performance of five different zeolites reveals that Hß zeolite, which has high densities of both Lewis and Brønsted acid sites, affords the highest MLE yield. With the addition of 1,3,5-trioxane, the hydroxymethylation of furfural derivative and formaldehyde is a key step. Notably, the simultaneous conversion of C5 and C6 sugars catalyzed by Hß zeolite can attain an MLE yield as high as 50.4 % when the reaction conditions are fully optimized. Moreover, the Hß zeolite catalyst can be reused at least five times without significant change in performance.

12.
Front Neurol ; 10: 870, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31447773

RESUMO

Background and Purpose: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) mainly affects the cerebral small arteries. We aimed to analyze changes in the lenticulostriate arteries (LSAs) and the basal ganglia in patients with CADASIL using high-field magnetic resonance imaging (7.0-T MRI). Methods: We examined 46 patients with CADASIL and 46 sex- and age-matched healthy individuals using 7.0-T MRI. The number and length of the LSAs, and the proportion of discontinuous LSAs were compared between the two groups. The Mini-Mental State Examination score, the modified Rankin Scale, the Barthel Index, and the MRI lesion load of the basal ganglia were also examined in patients with CADASIL. We analyzed the association between LSA measurements and the basal ganglia lesion load, as well as the association between LSA measurements and clinical phenotypes in this patient group. Results: We observed a decrease in the number of LSA branches (t = -2.591, P = 0.011), and an increase in the proportion of discontinuous LSAs (z = -1.991, P = 0.047) in patients with CADASIL when compared with healthy controls. However, there was no significant difference in the total length of LSAs between CADASIL patients and healthy individuals (t = -0.412, P = 0.682). There was a positive association between the number of LSA branches and the Mini-Mental State Examination scores of CADASIL patients after adjusting for age and educational level (ß = 0.438; 95% CI: 0.093, 0.782; P = 0.014). However, there was no association between LSA measurements and the basal ganglia lesion load among CADASIL patients. Conclusions: 7.0-T MRI provides a promising and non-invasive method for the study of small artery damage in CADASIL. The abnormalities of small arteries may be related to some clinical symptoms of CADASIL patients such as cognitive impairment. The lack of association between LSA measurements and the basal ganglia lesion load among the patients suggests that changes in the basal ganglia due to CADASIL are caused by mechanisms other than anatomic narrowing of the vessel lumen.

13.
J Cancer Res Ther ; 15(4): 927-932, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31436254

RESUMO

Objective: Glioma is one of the leading causes of death worldwide with high incidence, recurrence, and mortality. Interleukin-10 (IL-10) is a cytokine with dual function in many types of tumors. Although IL-10 is overexpressed and promotes tumor progression in human primary brain tumor, the mechanisms are largely unknown. Materials and Methods: Glioma cells were treated with different dosages of IL-10. The cell growth was detected by CCK-8, and the invasion was measured by Transwell. The relative expression of messenger RNAs was detected by quantitative real-time polymerase chain reaction. Results: We found that IL-10 treatment significantly enhanced glioma cell growth and invasion. Moreover, KPNA2 was significantly upregulated after treatment with IL-10. By performing knockdown experiments, we found that the glioma cell growth and invasion were significantly declined. Conclusions: The results indicated that knockdown of KPNA2 significantly inhibited the growth and invasion of glioma cells. Moreover, IL-10 promotes glioma progression via upregulation of KPNA2. This study will be of important significance and provides a potential target for treatment of patients with glioma.

14.
J Cell Mol Med ; 23(10): 7088-7098, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31423730

RESUMO

Vascular calcification (VC) is a pathological process underpinning major cardiovascular conditions and has attracted public attention due to its high morbidity and mortality. Chronic kidney disease (CKD) is a common disease related to VC. Ginsenoside Rb1 (Rb1) has been reported to protect the cardiovascular system against vascular diseases, yet its role in VC and the underlying mechanisms remain unclear. In this study, we established a CKD-associated VC rat model and a ß-glycerophosphate (ß-GP)-induced vascular smooth muscle cell (VSMC) calcification model to investigate the effects of Rb1 on VC. Our results demonstrated that Rb1 ameliorated calcium deposition and VSMC osteogenic transdifferentiation both in vivo and in vitro. Rb1 treatment inhibited the Wnt/ß-catenin pathway by activating peroxisome proliferator-activated receptor-γ (PPAR-γ), and confocal microscopy was used to show that Rb1 inhibited ß-catenin nuclear translocation in VSMCs. Furthermore, SKL2001, an agonist of the Wnt/ß-catenin pathway, compromised the vascular protective effect of Rb1. GW9662, a PPAR-γ antagonist, reversed Rb1's inhibitory effect on ß-catenin. These results indicate that Rb1 exerted anticalcific properties through PPAR-γ/Wnt/ß-catenin axis, which provides new insights into the potential theraputics of VC.

15.
Eur J Radiol ; 118: 271-276, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31439254

RESUMO

PURPOSE: To characterize the orifices of lenticulostriate arteries (LSAs) in vivo by using three-dimensional (3D) time-of-flight magnetic resonance angiography (TOF-MRA) and to investigate the spatial relationship between LSA orifices and atherosclerotic plaques in patients with lacunar infarcts (LI). METHOD: Seventeen healthy volunteers and fifteen patients with LI underwent 3D TOF-MRA and 3D vessel wall imaging (VWI) at 7 T. The orifices of LSAs and the locations of atherosclerotic plaques on MCA walls were categorized based on the involvement of the superior, inferior, ventral or dorsal sides of MCA wall. The distribution quadrants of LSA orifices on MCA walls were compared among different groups. RESULTS: Most orifices were located on the superior side of MCA firstly (46 of 95, 48.4%), followed by the dorsal side (22 of 95, 23.2%). In patients with LI, the visible numbers of ventral and inferior orifices on the ipsilateral side were significantly lower than healthy controls (p = 0.039 for ventral side, p = 0.002 for inferior side). Similarly, plaques occurred more frequently at the ventral (7 of 20, 35.0%) and the inferior (7 of 20, 35.0%) sides of MCA walls. CONCLUSIONS: TOF-MRA at 7 T is capable of imaging orifices of LSA on MCA. In patients with LI, the decreased number of LSA orifices on the ventral and inferior sides corresponded with the distribution of MCA plaques. The results may indicate the vulnerability of LSA orifices in intracranial atherosclerosis, which was supposed to be the cause of LI in basal ganglia.


Assuntos
Arteriosclerose Intracraniana/patologia , Angiografia por Ressonância Magnética/métodos , Placa Aterosclerótica/patologia , Acidente Vascular Cerebral Lacunar/patologia , Adolescente , Adulto , Idoso , Gânglios da Base/patologia , Feminino , Voluntários Saudáveis , Humanos , Imagem Tridimensional , Masculino , Pessoa de Meia-Idade , Artéria Cerebral Média/patologia , Adulto Jovem
16.
J Vis ; 19(7): 12, 2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-31323098

RESUMO

The question of what the basic unit is of visual working memory remains one of the most fundamental and controversial issues. In the current study, we proposed a unique perspective based on early topological perception to describe the nature of representation in visual working memory. In a series of updating change-detection tasks, the repetition-benefit effect on color memory was not affected when items in the second memory array underwent massive changes of nontopological features from the first memory array. However, when the topological properties of an item changed, the repetition-benefit effect was destroyed, suggesting that the item was perceived as a new object impairing the original memory. Hence, our results suggest that a perceptual object defined by its topological invariance might be a unique perspective from which to describe representations of visual working memory.

17.
Angew Chem Int Ed Engl ; 58(31): 10626-10630, 2019 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-31157948

RESUMO

Hexagonal boron nitride (h-BN) is regarded as a graphene analogue and exhibits important characteristics and vast application potentials. However, discovering a facile method for the preparation of nanoporous crystalline h-BN nanosheets (h-BNNS) is still a challenge. Herein, a novel and simple route for the conversion of amorphous h-BN precursors into highly crystalline h-BNNS was achieved through a successive dissolution-precipitation/crystallization process in the presence of magnesium. The h-BNNS has high crystallinity, high porosity with a surface area of 347 m2 g-1 , high purity, and enhanced thermal stability. Improved catalytic performance of crystalline h-BNNS was evidenced by its much higher catalytic efficiency in the dehydrogenation of dodecahydro-N-ethylcarbazole, compared with its amorphous h-BN precursor, as well as other precious-metal-loaded heterogeneous catalysts.

18.
Eur J Med Chem ; 178: 116-130, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31177073

RESUMO

In this study, a series of novel HDAC inhibitors, using 1,2,4-oxadiazole-containing as the cap group, were synthesized and evaluated in vitro. Compound 14b, N-hydroxy-2-(methyl((3-(1-(4-methylbenzyl)piperidin-4-yl)-1,2,4-oxadiazol-5-yl)methyl)amino)pyrimidine-5-carboxamide, displayed the most potent histone deacetylase (HDAC) inhibition, especially against HDAC1, 2, and 3 with IC50 values of 1.8, 3.6 and 3.0 nM, respectively. In vitro antiproliferative studies confirmed that 14b was more potent than SAHA, with IC50 values against 12 types of cancer cell lines ranging from 9.8 to 44.9 nM. The results of Western blot assays showed that compound 14b can significantly up-regulate the acetylation of the biomarker his-H3 and molecular docking analyses revealed the mode of action of compound 14b against HDAC1. The results of flow-cytometry analysis suggested that compound 14b induces cell cycle arrest at the G1 phase and has apoptotic effects. Further investigation of the activity of 14b on the primary cells of three patients, showed IC50 values of 21.3, 61.1, and 77.4 nM. More importantly, an oral bioavailability of up to 53.52% was observed for 14b. An in vivo pharmacodynamic evaluation demonstrated that compound 14b can significantly inhibit tumor growth in a Daudi Burkitt's lymphoma xenograft model, with tumor inhibition rates of 53.8 and 46.1% observed at 20 and 10 mg/kg when administered p.o. and i.v., respectively. These results indicate that compound 14b may be a suitable lead for further evaluation and development as an HDAC inhibitor and a potent anticancer agent.


Assuntos
Antineoplásicos/uso terapêutico , Linfoma de Burkitt/tratamento farmacológico , Inibidores de Histona Desacetilases/uso terapêutico , Ácidos Hidroxâmicos/uso terapêutico , Oxidiazóis/uso terapêutico , Acetilação/efeitos dos fármacos , Animais , Antineoplásicos/síntese química , Antineoplásicos/farmacocinética , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Descoberta de Drogas , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Pontos de Checagem da Fase G1 do Ciclo Celular/efeitos dos fármacos , Histona Desacetilase 1/química , Histona Desacetilase 1/metabolismo , Inibidores de Histona Desacetilases/síntese química , Inibidores de Histona Desacetilases/farmacocinética , Histonas/metabolismo , Humanos , Ácidos Hidroxâmicos/síntese química , Ácidos Hidroxâmicos/farmacocinética , Camundongos Endogâmicos NOD , Camundongos SCID , Simulação de Acoplamento Molecular , Estrutura Molecular , Oxidiazóis/síntese química , Oxidiazóis/farmacocinética , Ligação Proteica , Ratos Sprague-Dawley , Relação Estrutura-Atividade , Tubulina (Proteína)/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
19.
Appl Opt ; 58(16): 4467-4473, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-31251257

RESUMO

A broadband, polarization-insensitive, wide-angle absorber based on a spherical multilayered dielectric-metal structure is numerically designed and experimentally demonstrated in this paper. This absorber has average absorbance of 0.98 between 380 and 1910 nm, indicating a spectral width of 1530 nm with absorbance exceeding 0.9, and covering the entire visible and near-infrared spectrum. The physical mechanism leading to this broadband absorption is discussed along with the effect of structural parameters on the absorber performance. Importantly, the absorbance is hardly affected by incident angle below 45° and it still stays at a high level with incident angle up to 60°, for both transverse magnetic and transverse electric plane waves.

20.
PLoS One ; 14(4): e0216001, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31022263

RESUMO

Amaranth plants contain large amounts of betalains, including betaxanthins and betacyanins. Amaranthin is a betacyanin, and its molecular structure and associated metabolic pathway differ from those of betanin in beet plants. The chlorophyll, carotenoid, betalain, and flavonoid contents in amaranth leaves were analyzed. The abundance of betalain, betacyanin, and betaxanthin was 2-5-fold higher in the red leaf sectors than in the green leaf sectors. Moreover, a transcriptome database was constructed for the red and green sectors of amaranth leaves harvested from 30-day-old seedlings. 22 unigenes were selected to analyze the expression profiles in the two leaf sectors. The RNA-sequencing data indicated that many unigenes are involved in betalain metabolic pathways. The potential relationships between diverse metabolic pathways and betalain metabolism were analyzed. The validation of the expression of 22 selected unigenes in a qRT-PCR assay revealed the genes that were differentially expressed in the two leaf sectors. Betalains were biosynthesized in specific tissues of the red sectors of amaranth leaves. Almost all of the genes related to betalain metabolism were identified in the transcriptome database, and the expression profiles were different between the red sectors and green sectors in the leaf. Amaranth plants consist of diverse metabolic pathways, and the betalain metabolic pathway is linked to a group of other metabolic pathways.


Assuntos
Amaranthus/genética , Betalaínas/metabolismo , Folhas de Planta/genética , Análise de Sequência de RNA/métodos , Carotenoides/metabolismo , Clorofila/metabolismo , Flavonoides/metabolismo , Regulação da Expressão Gênica de Plantas , Ontologia Genética , Genes de Plantas , Anotação de Sequência Molecular , Transcriptoma/genética
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