Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 13 de 13
Filter
Add more filters










Publication year range
1.
J Asian Nat Prod Res ; 24(6): 550-555, 2022 Jun.
Article in English | MEDLINE | ID: mdl-34308728

ABSTRACT

Two new sesquiterpenes, litseachrandaevanes C and D (1 and 2), together with five known sesquiterpenes (3 - 7), were isolated from the stems of Fissistigma glaucescens (Hance) Merr. Their structures were elucidated using comprehensive spectroscopic methods. The inhibitory effect of all compounds on the proliferation of primary synovial cells was evaluated. Compound 3 showed inhibitory effect on the proliferation of synoviocytes, with an IC50 value of 12.5 µM.


Subject(s)
Annonaceae , Sesquiterpenes , Synoviocytes , Annonaceae/chemistry , Cell Proliferation , Molecular Structure , Sesquiterpenes/chemistry , Sesquiterpenes/pharmacology
2.
Oncol Lett ; 22(5): 752, 2021 Nov.
Article in English | MEDLINE | ID: mdl-34539856

ABSTRACT

Human osteosarcoma is the most frequent malignant primary bone tumor that mainly occurs in young adults and children. MicroRNAs (miRNAs/miRs) are abnormally expressed in human osteosarcoma and contribute to osteosarcoma initiation and development. The present study aimed to investigate the role of miR-382-5p in the nosogenesis of osteosarcoma and to identify a novel target for osteosarcoma treatment. miR-382-5p expression was detected in human osteosarcoma clinical tissues and cell lines, including 143B, U2OS and MG63, via reverse transcription-quantitative PCR analysis. Multiple bioinformatic prediction toowe used to identify the potential target genes of miR-382-5p and vascular endothelial zinc finger 1 (VEZF1), which were validated via the dual-luciferase reporter assay. MG63 and U2OS cells were transfected with miR-382-5p mimics. The Cell Counting Kit-8 assay was performed to assess cell proliferation, while the Transwell assay was performed to assess migration and invasion. Cell colony formation was measured via crystal violet staining, and apoptosis was assessed via Annexin V/propidium iodide staining. The wound healing assay was performed to assess the migratory ability of U2OS and MG63 cells. Antitumor effects of miR-382-5p were evaluated in nude mice xenografts using U2OS cells. The results demonstrated that miR-382-5p expression was markedly downregulated in human osteosarcoma tissues and cell lines compared with adjacent normal tissues. Transfection of miR-382-5p mimics into MG63 and U2OS cells significantly inhibited the malignant behaviors of cells, including decreased proliferation, migration, diminished colony formation and invasion, and promoted osteosarcoma cell apoptosis. Bioinformatics prediction indicated that VEZF1 is a direct target gene of miR-382-5p. Overexpression of VEZF1 restored osteosarcoma tumor development inhibited by miR-382-5p in vivo. In addition, overexpression of miR-382-5p restrained the growth of xenograft osteosarcoma in nude mice following co-transfection, and overexpression of VEZF1 attenuated the inhibitory effect of miR-382-5p in nude mice. miR-382-5p acted as a tumor suppressor gene and inhibited the malignant biological behaviors of human osteosarcoma cells and functions associated with directly targeting VEZF1. Taken together, these results suggest that the miR-382-5p/VEZF1 interaction has an important role in osteosarcoma development and progression, and thus may be used as a diagnostic and therapeutic target for osteosarcoma.

3.
Clin EEG Neurosci ; 52(4): 296-306, 2021 Jul.
Article in English | MEDLINE | ID: mdl-34003701

ABSTRACT

INTRODUCTION: Sleep apnea/hypopnea syndrome (SAHS) can change brain structure and function. These alterations are related to respiratory event-induced abnormal sleep, however, how brain activity changes during these events is less well understood. METHODS: To study information content and interaction among various cortical regions, we analyzed the variations of permutation entropy (PeEn) and symbolic transfer entropy (STE) of electroencephalography (EEG) activity during respiratory events. In this study, 57 patients with moderate SAHS were enrolled, including 2804 respiratory events. The events terminated with cortical arousal were independently researched. RESULTS: PeEn and STE were lower during apnea/hypopnea, and most of the brain interaction was higher after apnea/hypopnea termination than that before apnea in N2 stage. As indicated by STE, the respiratory events also affected the stability of information transmission mode. In N1, N2, and rapid eye movement (REM) stages, the information flow direction was posterior-to-anterior, but the anterior-to-posterior increased relatively during apnea/hypopnea. The above EEG activity trends maintained in events with cortical arousal. CONCLUSIONS: These results may be related to the intermittent hypoxia during apnea and the cortical response. Furthermore, increased frontal information outflow, which was related to the compensatory activation of frontal neurons, may associate with cognitive function.


Subject(s)
Sleep Apnea Syndromes , Sleep Stages , Electroencephalography , Humans , Polysomnography , Sleep
4.
Chemistry ; 26(45): 10226-10229, 2020 Aug 12.
Article in English | MEDLINE | ID: mdl-32227370

ABSTRACT

Electrochemical nitrogen fixation techniques have emerged as a promisingly sustainable approach to face the challenge associated with nitrogen activation of ammonia synthesis by the Haber-Bosch process under ambient conditions. Herein, the performance of electrocatalytic nitrogen reduction for the production of α-Fe2 O3 nanospindles coated with mesoporous TiO2 with different crystallinity [denoted as α-Fe2 O3 @mTiO2 -X (X=300, 400, and 500 °C)] were investigated. The as-prepared α-Fe2 O3 @mTiO2 -400 composite exhibits a large NH3 yield (27.2 µg h-1 mgcat. -1 ) at -0. 5 V vs. the reversible hydrogen electrode and a high Faradaic efficiency (13.3 %) in 0.1 m Na2 SO4 , with excellent electrochemical durability. This work presents a novel avenue for the rational design of efficient unique hetero-phase nanocatalysts toward sustainable electrocatalytic N2 fixation.

5.
ACS Appl Mater Interfaces ; 12(15): 17452-17458, 2020 Apr 15.
Article in English | MEDLINE | ID: mdl-32195566

ABSTRACT

Electrochemical conversion of N2 to NH3 under ambient conditions is a promising and environmentally friendly route compared with the CO2-emitting and energy-intensive Haber-Bosch process. Nevertheless, due to ultrahigh stability of N2, it is urgent to explore efficient catalysts to weaken and activate the N≡N bond. Here, we report the Mo-doped iron phosphide (Mo-FeP) nanosphere as a valid transition-metal-based catalyst for electrochemical N2-to-NH3 fixation under ambient conditions. This catalyst exhibits excellent catalytic performance with a NH4+ yield rate (13.1 µg h-1 mg-1) and Faradaic efficiency (7.49%) at -0.3 and -0.2 V vs reversible hydrogen electrode (RHE), respectively. However, the FeP catalyst without doped Mo species displays weak catalytic performance. We found that the better catalytic performance of Mo-FeP might be due to the doping of Mo species, which is favorable for the polarization of adsorbed N2 molecules, making the N≡N bond more viable to dissociate.

6.
EMBO J ; 39(7): e102008, 2020 04 01.
Article in English | MEDLINE | ID: mdl-32115743

ABSTRACT

Deposition of H2A.Z in chromatin is known to be mediated by a conserved SWR1 chromatin-remodeling complex in eukaryotes. However, little is known about whether and how the SWR1 complex cooperates with other chromatin regulators. Using immunoprecipitation followed by mass spectrometry, we found all known components of the Arabidopsis thaliana SWR1 complex and additionally identified the following three classes of previously uncharacterized plant-specific SWR1 components: MBD9, a methyl-CpG-binding domain-containing protein; CHR11 and CHR17 (CHR11/17), ISWI chromatin remodelers responsible for nucleosome sliding; and TRA1a and TRA1b, accessory subunits of the conserved NuA4 histone acetyltransferase complex. MBD9 directly interacts with CHR11/17 and the SWR1 catalytic subunit PIE1, and is responsible for the association of CHR11/17 with the SWR1 complex. MBD9, TRA1a, and TRA1b function as canonical components of the SWR1 complex to mediate H2A.Z deposition. CHR11/17 are not only responsible for nucleosome sliding but also involved in H2A.Z deposition. These results indicate that the association of the SWR1 complex with CHR11/17 may facilitate the coupling of H2A.Z deposition with nucleosome sliding, thereby co-regulating gene expression, development, and flowering time.


Subject(s)
Arabidopsis Proteins/metabolism , Arabidopsis/metabolism , DNA-Binding Proteins/metabolism , Histones/metabolism , Adenosine Triphosphatases/metabolism , Chromatin/metabolism , Chromatin Assembly and Disassembly , Histone Acetyltransferases/metabolism , Nucleosomes/metabolism , Protein Interaction Maps , Transcription Factors/metabolism
7.
Mikrochim Acta ; 186(11): 732, 2019 10 30.
Article in English | MEDLINE | ID: mdl-31667627

ABSTRACT

The authors describe an electrochemical and an optical method for the determination of As(V) by using iron oxyhydroxide (FeOOH) nanorods that display peroxidase-mimicking activity. The nanorods catalyze the oxidation of substrate ABTS by H2O2 to form a green product with an absorption maximum at 418 nm. If, however, As(V) is electrostatically adsorbed on the nanorods, the oxidation is gradually inhibited. A colorimetric assay was worked out based on these findings. Response is linear in the 0 to 8 ppb and 8 to 200 ppb As(V) concentration range, and the detection limit is 0.1 ppb. Even higher sensitivity is achieved in an electrochemical method which is based on the excellent electrical conductivity of FeOOH nanorods. Electrochemical analysis of As(V) was achieved by first adsorbing As(V) on the nanorods. This inhibits the ABTS reduction current signal, best measured at a potential of 150 mV (vs. Ag/AgCl). The linear range extends from 0.04 to 200 ppb, and the detection limit is as low as 12 ppt. Graphical abstract Schematic representation of FeOOH nanorod-based colorimetric and electrochemical assays for arsenate (As(V)). As(V) adsorbed on FeOOH nanorods inhibits the peroxidase-mimicking activity of nanorods, and a colorimetric and electrochemical dual-signal assay was constructed to achieve sensitive determination of As(V).


Subject(s)
Arsenates/analysis , Colorimetry/methods , Electrochemical Techniques/methods , Ferric Compounds/chemistry , Nanotubes/chemistry , Water Pollutants, Chemical/analysis , Benzothiazoles/chemistry , Biomimetic Materials/chemistry , Catalysis , Drinking Water/analysis , Hydrogen Peroxide/chemistry , Lakes/analysis , Limit of Detection , Peroxidase/chemistry , Rivers/chemistry , Sulfonic Acids/chemistry
8.
Chem Commun (Camb) ; 55(51): 7406-7409, 2019 Jun 20.
Article in English | MEDLINE | ID: mdl-31180408

ABSTRACT

In situ-derived boron-doped graphene quantum dots can significantly improve the activity of boron carbide nanosheets for artificial N2 fixation and reduction with superior electrocatalytic activity (NH3 yield: 28.6 µg h-1 mgcat.-1 at -0.45 V vs. RHE; faradaic efficiency: 16.7%), high electrochemical stability, and high selectivity in 0.1 M HCl under ambient conditions.

9.
Annu Int Conf IEEE Eng Med Biol Soc ; 2019: 648-651, 2019 Jul.
Article in English | MEDLINE | ID: mdl-31945981

ABSTRACT

Men and women were reported to be different in brain structure and sleep patterns. Here we analyzed the region, sleep stage and frequency band-specific EEG synchronization intensity of whole night sleep recording of 14 male and 14 age-matched female subjects by calculating weighted phase lag indexes. Moreover, resting wakeful stage EEG was also analyzed and compared. The synchronization intensities showed significant gender differences in all stages and bands: higher in women in non-rapid eye movement (NREM) sleep, and higher in men in α and ß bands in wakeful stage and rapid eye movement (REM) sleep. However, Except for α band, the similar changing trends in characteristics of EEG synchronization during different stages were found in both male and female subjects. These results suggest that there may be some differences in the mechanisms of sleep regulation between men and women. Moreover, the synchronous intensity of different sleep stages in different frequency bands of male and female groups was not consistent with the influence of age, which may be related to the gender differences in aging patterns.


Subject(s)
Electroencephalography , Sleep Stages , Female , Humans , Male , Wakefulness
10.
Sci China Life Sci ; 61(2): 235-243, 2018 02.
Article in English | MEDLINE | ID: mdl-28895115

ABSTRACT

The SU(VAR)-3-9-related protein family member SUVR2 has been previously identified to be involved in transcriptional gene silencing both in RNA-dependent and -independent pathways. It interacts with the chromatin-remodeling proteins CHR19, CHR27, and CHR28 (CHR19/27/28), which are also involved in transcriptional gene silencing. Here our study demonstrated that SUVR2 is almost fully mono-sumoylated in vivo. We successfully identified the exact SUVR2 sumoylation site by combining in vitro mass spectrometric analysis and in vivo immunoblotting confirmation. The luminescence imaging assay and quantitative RT-PCR results demonstrated that SUVR2 sumoylation is involved in transcriptional gene silencing. Furthermore, we found that SUVR2 sumoylation is required for the interaction of SUVR2 with CHR19/27/28, which is consistent with the fact that SUMO proteins are necessary for transcriptional gene silencing. These results suggest that SUVR2 sumoylation contributes to transcriptional gene silencing by facilitating the interaction of SUVR2 with the chromatin-remodeling proteins CHR19/27/28.


Subject(s)
Arabidopsis Proteins/metabolism , Arabidopsis/genetics , Gene Expression Regulation, Plant , Gene Silencing , Sumoylation , Arabidopsis Proteins/genetics , Chromatin Assembly and Disassembly/genetics , Immunoblotting , Mass Spectrometry , Mutation , Nuclear Proteins/metabolism , Plants, Genetically Modified , Small Ubiquitin-Related Modifier Proteins/genetics , Small Ubiquitin-Related Modifier Proteins/metabolism
11.
Plant Cell ; 28(5): 1215-29, 2016 05.
Article in English | MEDLINE | ID: mdl-27113777

ABSTRACT

The mechanism by which MORPHEUS' MOLECULE1 (MOM1) contributes to transcriptional gene silencing has remained elusive since the gene was first identified and characterized. Here, we report that two Arabidopsis thaliana PIAS (PROTEIN INHIBITOR OF ACTIVATED STAT)-type SUMO E3 ligase-like proteins, PIAL1 and PIAL2, function redundantly to mediate transcriptional silencing at MOM1 target loci. PIAL1 and PIAL2 physically interact with each other and with MOM1 to form a high molecular mass complex. In the absence of either PIAL2 or MOM1, the formation of the high molecular mass complex is disrupted. We identified a previously uncharacterized IND (interacting domain) in PIAL1 and PIAL2 and demonstrated that IND directly interacts with MOM1. The CMM2 (conserved MOM1 motif 2) domain of MOM1 was previously shown to be required for the dimerization of MOM1. We demonstrated that the CMM2 domain is also required for the interaction of MOM1 with PIAL1 and PIAL2. We found that although PIAL2 has SUMO E3 ligase activity, the activity is dispensable for PIAL2's function in transcriptional silencing. This study suggests that PIAL1 and PIAl2 act as components of the MOM1-containing complex to mediate transcriptional silencing at heterochromatin regions.


Subject(s)
Arabidopsis Proteins/metabolism , Arabidopsis/metabolism , Nuclear Proteins/metabolism , Transcription Factors/metabolism , ATPases Associated with Diverse Cellular Activities , Arabidopsis/genetics , Arabidopsis Proteins/genetics , Gene Expression Regulation, Plant , Gene Silencing , Nuclear Proteins/genetics , Protein Binding , Transcription Factors/genetics
12.
Biomed Eng Online ; 14: 10, 2015 Feb 13.
Article in English | MEDLINE | ID: mdl-25888748

ABSTRACT

BACKGROUND: This paper presents a Tracer Liquid Image Velocimetry (TLIV) for multi-layer radial flow in bioreactors used for cells cultivation of tissue engineering. The goal of this approach is to use simple devices to get good measuring precision, specialized for the case in which the uniform level of fluid shear stress was required while fluid velocity varied smoothly. METHODS: Compared to the widely used Particles Image Velocimetry (PIV), this method adopted a bit of liquid as tracer, without the need of laser source. Sub-pixel positioning algorithm was used to overcome the adverse effects of the tracer liquid deformation. In addition, a neighborhood smoothing algorithm was used to restrict the measurement perturbation caused by diffusion. Experiments were carried out in a parallel plates flow chamber. And mathematical models of the flow chamber and Computational Fluid Dynamics (CFD) simulation were separately employed to validate the measurement precision of TLIV. RESULTS: The mean relative error between the simulated and measured data can be less than 2%, while in similar validations using PIV, the error was around 8.8%. CONCLUSIONS: TLIV avoided the contradiction between the particles' visibility and following performance with tested fluid, which is difficult to overcome in PIV. And TLIV is easier to popularize for its simple experimental condition and low cost.


Subject(s)
Algorithms , Bioreactors , Computer Simulation , Hydrodynamics , Rheology/methods , Cell Culture Techniques/instrumentation , Coloring Agents/analysis , Culture Media , Diffusion , Equipment Design , Ink , Particle Size , Solubility , Solutions , Tissue Engineering/instrumentation , Water
13.
Zhonghua Yu Fang Yi Xue Za Zhi ; 43(2): 141-5, 2009 Feb.
Article in Chinese | MEDLINE | ID: mdl-19534908

ABSTRACT

OBJECTIVE: To study the factors affecting the management and treatment of immigrant workers with tuberculosis, to determine the most effective measures and to provide an academic basis for tuberculosis control and prevention strategies targeting the immigrant population. METHODS: A self-designed questionnaire was administered to 1364 immigrant workers with tuberculosis (study group) and 436 local residents (control group) with tuberculosis. RESULTS: Whether a patient's tuberculosis status was discovered or not was related to the medical facilities initially visited, job mobility, and the individual worker's economic condition. The percentage of cases discovered was relatively low among those who made their first visit to a private clinic (39.0%), and 58.4% (796) of immigrant workers delayed their first consultation mainly due to neglecting symptoms (55.9%, 445), subjective perception of symptoms being not severe enough (19.3%, 154) to visit a physician and the inconvenience of visiting a hospital because of its being far away from home (15.8%, 47). As comparing immigrant workers with local residents, the differences of the delay reason between the two groups were statistically significant (chi(2) = 21.49, P < 0.01). And 39.9% (544) of immigrant workers and 49.1% (214) of local residents had had late confirmation. The differences of the delay reasons between the two groups were insignificant (chi(2) = 7.31, P = 0.293). And 17.6% (240) patients of immigrant workers and 13.1% (57) patients of local residents did not keep to their drug regimens in a timely fashion. The differences of the reasons between the two groups were insignificant (chi(2) = 6.66, P > 0.05). And 77.5% (1057) of immigrant workers and 31.8% (138) of local residents were considered that taking medicine in supervision spot might have impact on their lives and work. The differences of the reasons between the two groups were significant (chi(2) = 9.71, P < 0.05). All 79.2% (1080) of immigrant workers and 63.3% (276) of local residents did not obtain medicine according to prescriptions. The differences of reasons between the two groups were statistically significant (chi(2) = 24.84, P < 0.01). And 51.2% (699) of immigrant workers and 46.1% (201) of the registered population did not follow up with doctors' directions for lab tests. The differences of the reasons between the two groups were insignificant (chi(2) = 3.26, P > 0.05). CONCLUSION: The influential factors in tuberculosis management and treatment were complex. Prevention strategies should focus on health education and promotion activities to improve awareness in seeking medical services. Also, developing and standardizing reference mechanisms for patients, and alleviating the economic burden of the workers will be critical to reduce the tuberculosis incidence.


Subject(s)
Tuberculosis, Pulmonary/therapy , China/epidemiology , Factor Analysis, Statistical , Humans , Transients and Migrants , Treatment Outcome , Tuberculosis, Pulmonary/epidemiology , Tuberculosis, Pulmonary/prevention & control , Urban Population
SELECTION OF CITATIONS
SEARCH DETAIL
...