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1.
Bioresour Technol ; 306: 123107, 2020 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-32172089

RESUMO

The roles of jasmonic acid (JA) in the regulation of cell growth and lipid biosynthesis under the combination of strigolactone (SL) treatment and nitrogen deficiency (ND) were investigated. In this work, the optimised ND condition (46.18%) and ND combined with SL treatment (53.71%) showed 1.11- and 1.29-fold increases in lipid content in Monoraphidium sp. QLY-1 compared with the control condition (41.57%). The levels of JA, glutathione (GSH), and γ-aminobutyric acid (GABA) and lipogenic genes expression were upregulated by the combination of SL and ND, but the ROS level was decreased. Furthermore, exogenous JA supplementation induced the highest lipid content (57.12%) and productivity (312.35 mg L-1 d-1) under ND combined with SL treatment. This study provided a combined strategy for enhancing lipid production and supplied novel insights into the role of JA signalling in regulating lipid synthesis and oxidative stress in microalgae by combining SL treatment with ND.

2.
Artigo em Inglês | MEDLINE | ID: mdl-32167275

RESUMO

A phenomenon that a few-layer graphene's (FLG) top transformed to single-layer graphene (SLG) with some bilayer/triple-layer patches on its surface during field electron emission was observed using in situ transmission electron microscopy (TEM). During field electron emission with high emission current, the FLG's top five layers split and finally transformed to SLG with some bilayer/triple-layer patches on its surface with a better crystallinity. It was due to thermal exfoliation and atom recombination at high temperatures induced by joule heat. The heat-induced structural self-transformation optimizes the field electron emission from the graphene's top edge. After transformation, the emission current increased with an order of magnitude at high field region (>307 V/µm). A modified field emission theory of graphene with curves of ln (I/E3/2)∼1/E and ln (I/E3)∼1/E2 in high and low field regimes, respectively, has been used to analyze the phenomenon. The graphene's line current density of two-dimensional (2D) structure and its special energy-dispersion relation at K state of Dirac point makes the curves of ln (I/E3/2)∼1/E and ln (I/E3)∼1/E2 to show up-bending features, which leads to the improvement of the field electron emission tunneling efficiency as the applied electric field increases. These results revealed that the intrinsic field emission characteristics of graphene can be achieved after a structural self-optimizing transformation of FLG during high current field electron emission. It offers an efficient post-treatment method to achieve high performance of graphene field emitter.

3.
J Magn Reson Imaging ; 2020 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-32167637

RESUMO

BACKGROUND: The shutter-speed model dynamic contrast-enhanced (SSM-DCE) MRI pharmacokinetic analysis adds a metabolic dimension to DCE-MRI. This is of particular interest in cancers, since abnormal metabolic activity might happen. PURPOSE: To develop a DCE-MRI SSM analysis framework for glioblastoma multiforme (GBM) cases considering the heterogeneous tissue found in GBM. STUDY TYPE: Prospective. SUBJECTS: Ten GBM patients. FIELD STRENGTH/SEQUENCE: 3T MRI with DCE-MRI. ASSESSMENTS: The corrected Akaike information criterion (AICc ) was used to automatically separate DCE-MRI data into proper SSM versions based on the contrast agent (CA) extravasation in each pixel. The supra-intensive parameters, including the vascular water efflux rate constant (kbo ), the cellular efflux rate constant (kio ), and the CA vascular efflux rate constant (kpe ), together with intravascular and extravascular-extracellular water mole fractions (pb and po , respectively) were determined. Further error analyses were also performed to eliminate unreliable estimations on kio and kbo . STATISTICAL TESTS: Student's t-test. RESULTS: For tumor pixels of all subjects, 88% show lower AICc with SSM than with the Tofts model. Compared to normal-appearing white matter (NAWM), tumor tissue showed significantly larger pb (0.045 vs. 0.011, P < 0.001) and higher kpe (3.0 × 10-2 s-1 vs. 6.1 × 10-4 s-1 , P < 0.001). In the contrast, significant kbo reduction was observed from NAWM to GBM tumor tissue (2.8 s-1 vs. 1.0 s-1 , P < 0.001). In addition, kbo is four orders and two orders of magnitude greater than kpe in the NAWM and GBM tumor, respectively. These results indicate that CA and water molecule have different transmembrane pathways. The mean tumor kio of all subjects was 0.57 s-1 . DATA CONCLUSION: We demonstrate the feasibility of applying SSM models in GBM cases. Within the proposed SSM analysis framework, kio and kbo could be estimated, which might be useful biomarkers for GBM diagnosis and survival prediction in future. LEVEL OF EVIDENCE: 4 TECHNICAL EFFICACY: Stage 1.

4.
Mikrochim Acta ; 187(4): 221, 2020 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-32166378

RESUMO

A luminescent metal organic framework was prepared by encapsulating Zn-Ag-In-S quantum dots into "French fries"-like MIL-68(In) metal organic frameworks (ZAISQDs@MIL-68(In)). The ZAISQDs@MIL-68(In) had a maximum excitation wavelength at 370 nm and maximum emission wavelength at 620 nm. It was found that the ZAISQDs@MIL-68(In) was efficiently quenched by cytochrome c (Cyt c), which is an important biomarker of early cell apoptosis. The quenching mechanism was ascribed to be an inner filter effect and dynamic quenching of Cyt c towards the ZAISQDs@MIL-68(In), and the enrichment effect of MIL-68(In). Benefiting from the multiple advantages, ZAISQDs@MIL-68(In) was developed as an assay strategy of Cyt c with logarithmic relation between signal quenching and concentration in the range 0.02 to 3.5 µM. The linear equation was (F0-F)/F0 = 0.5043 + 0.2678 × logcCyt c with a detection limit of 8 nM. Cyt c released by drug induced apoptotic cells was determined by ZAISQDs@MIL-68(In), and this strategy has been utilized for the screening of anticancer drug activity. Graphical abstract Schematic representation of the synthesis of ZAISQDs@MIL-68(In) and its application for Cyt c and screening anticancer drug activity.

5.
Int Heart J ; 2020 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-32173700

RESUMO

Heart failure (HF) is a disease with high morbidity and mortality. In patients with HF, decreased cardiac output and blood redistribution results in decreased intestinal perfusion and destruction of intestinal barrier. Microorganisms and endotoxins can migrate into the blood circulation, aggravating systemic inflammation and HF. Trimethylamine N-oxide (TMAO) is highly closed to the occurrence of HF. However, the exact mechanism between TMAO and HF remains unclear.To investigate the role of TMAO in transverse-tubule (T-tubule) in the cultured cardiomyocytes.T-tubule imaging and analysis detected T-tubule network in cardiomyocytes. Ca2+ handling dysfunction was identified by confocal Ca2+ imaging. Tubulin densification and polymerization were assessed by western blot and immunofluorescent staining of cardiomyocytes.TMAO induced T-tubule network damage in cardiomyocytes and Ca2+ handling dysfunction in cardiomyocytes under the TMAO stress via promoting tubulin densification and polymerization and therefore Junctophilin-2 (JPH2) redistribution. Mice treated with TMAO represented cardiac dysfunction and T-tubule network disorganization.TMAO impairs cardiac function via the promotion of tubulin polymerization, subsequent translocation of JPH2, and T-tubule remodeling, which provides a novel mechanism for the relationship between HF and elevated TMAO.

6.
Curr Med Chem ; 2020 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-32175831

RESUMO

BACKGROUND: Microtubule targeting agents (MTAs) represent the most successful anticancer drugs for cancer chemotherapy. Through interfering with the tubulin polymerization and depolymerization dynamics, MTAs influence intracellular transport and cell signal pathways, inhibit cell mitosis and cell proliferation, and induce cell apoptosis and death. The tubulin maytansine site binding agents are natural or nature-derived products that represent one type of the MTAs that inhibit tubulin polymerization and exhibit potent antitumor activity both in vitro and in vivo. They are used as antibody-drug conjugates (ADCs) in cancer chemotherapy. METHOD: Using SciFinder® as a tool, the publications about maytansine, its derivatives, maytansine binding site, maytansine site binding agents and their applications as MTAs for cancer therapy were surveyed with an exclusion on those published as patents. The latest progresses in clinical trials were obtained from the clinical trial web. RESULTS: This article presents an introduction about MTAs, maytansine, maytansine binding site and its ligands, the applications of these ligands as MTAs and ADCs in cancer therapy. CONCLUSION: The maytansine site binding agents are powerful MTAs for cancer chemotherapy. The maytansine site ligands-based ADCs are used in clinic or under clinical trials as cancer targeted therapy to improve their selectivity and to reduce their side effects. Further improvements in the delivery efficiency of the ADCs will benefit the patients in cancer targeted therapy.

7.
Inorg Chem ; 2020 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-32155053

RESUMO

Noble gases, especially krypton (Kr) and xenon (Xe), are widely applied in diverse fields. Developing new techniques and adsorbents to separate and purify Kr and Xe is in high demand. Herein, we reported a bimetallic metal-organic framework (MOF) (NKMOF-1-Ni) which possesses a narrow pore size (5.36 Å) and ultrahigh stability (e.g., stable in water for 1.5 years). Gas sorption measurements revealed that this MOF possessed much higher uptake for Xe than for Kr, Ar, or N2 at room temperature in all pressure ranges. The calculation of adsorption isosteric heat and Grand Canonical Monte Carlo simulation verified that NKMOF-1-Ni had a stronger interaction with Xe than other tested gases. The results of ideal adsorbed solution theory selectivity and simulated breakthrough further showed that NKMOF-1-Ni had an outstanding separation performance of Xe/Kr, Xe/Ar, and Xe/N2. This study provides important guidance for future research to synthesize ideal sorbents to separate noble gases.

8.
Vet Microbiol ; 242: 108577, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32122587

RESUMO

Since 2016, severe outbreaks of hepatic rupture hemorrhage syndrome (HRHS) associated with infections of tentative novel avian hepatitis E virus (HEV) have emerged in chickens in China, causing increased mortality and decreased laying rate in adult hens and disturbing the hatching and breeding of chicks. To further identify the genotype and gain a better understanding of the genetic properties of the avian HEV responsible for that, a strain from Hebei province was isolated, purified and sequenced in this study. Results identified a novel avian HEV genotype, sharing 79.5-86.9% identities with other published avian HEV strains, and having higher identities with Orthohepevirus A HEV strains. More importantly, the new isolate contains various amino-acid substitutions in its functional proteins, including methyltransferase, helicase, RNA-dependent RNA polymerase. The data presented in this report will enhance the current understanding of the genetic diversity of the avian HEV and provide additional insight into the critical factors that determine the pathogenicity.

9.
Org Lett ; 2020 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-32124613

RESUMO

Mesoionic carbene-iridium complex 1a has been investigated in the hydrogen isotope exchange (HIE) reaction of anilines. By employing 1 mol % of 1a as catalyst, anilines were selectively deuterated at the ortho-position with high deuteration levels. High ortho-selectivity was observed for anilines with various competing directing groups, which is in contrast with catalytic results of Kerr's catalysts.

10.
Cells ; 9(3)2020 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-32155989

RESUMO

Due to the complicated pathogenesis of Alzheimer's disease (AD), the development of multitargeted agents to simultaneously interfere with multiple pathological processes of AD is a potential choice. Glycogen synthase kinase-3ß (GSK-3ß) plays a vital role in the AD pathological process. In this study, we discovered a novel 1H-pyrrolo[2,3-b]pyridine derivative B10 as a GSK-3ß inhibitor that features with a quinolin-8-ol moiety to target the metal dyshomeostasis of AD. B10 potently inhibited GSK-3ß with an IC50 of 66 ± 2.5 nM. At the concentration of 20 µM, B10 increased ß-catenin abundance (ß-catenin/GAPDH: 0.83 ± 0.086 vs. 0.30 ± 0.016), phosphorylated GSK-3ß at Ser9 (p-GSK-3ß/GAPDH: 0.53 ± 0.045 vs. 0.35 ± 0.012), and decreased the phosphorylated tau level (p-tau/GAPDH: 0.33 ± 0.065 vs. 0.83 ± 0.061) in SH-SY5Y cells. Unlike other GSK-3ß inhibitors, B10 had a direct effect on Aß by inhibiting Aß1-42 aggregation and promoting the Aß1-42 aggregate disassociation. It selectively chelated with Cu2+, Zn2+, Fe3+, and Al3+, and targeted AD metal dyshomeostasis. Moreover, B10 effectively increased the mRNA expression of the recognized neurogenesis markers, GAP43, N-myc, and MAP-2, and promoted the differentiated neuronal neurite outgrowth, possibly through the GSK-3ß and ß-catenin signal pathways. Therefore, B10 is a potent and unique GSK-3ß inhibitor that has a direct on Aß and serves as a multifunctional anti-AD agent for further investigations.

11.
Nat Commun ; 11(1): 1366, 2020 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-32170064

RESUMO

In Arabidopsis, a zygote undergoes asymmetrical cell division that establishes the first two distinct cell types of early proembryos, apical and basal cells. However, the genome-wide transcriptional activities that guide divergence of apical and basal cell development remain unknown. Here, we present a comprehensive transcriptome analysis of apical and basal cell lineages, uncovering distinct molecular pathways during cell lineage specification. Selective deletion of inherited transcripts and specific de novo transcription contribute to the establishment of cell lineage-specific pathways for cell fate specification. Embryo-related pathways have been specifically activated in apical cell lineage since 1-cell embryo stage, but quick transcriptome remodeling toward suspensor-specific pathways are found in basal cell lineage. Furthermore, long noncoding RNAs and alternative splicing isoforms may be involved in cell lineage specification. This work also provides a valuable lineage-specific transcriptome resource to elucidate the molecular pathways for divergence of apical and basal cell lineages at genome-wide scale.

12.
BMC Public Health ; 20(1): 160, 2020 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-32013939

RESUMO

BACKGROUND: A series of studies have suggested that teachers are likely to experience professional burnout in various regions around the world. To date, no known research has been conducted to investigate the prevalence and correlates of burnout among preschool teachers in China. This study examined the level of self-reported burnout and correlates of burnout among Chinese preschool teachers. METHODS: A cross-sectional study was conducted among1795 preschool teachers in Tianjin, China, during August 2018-October 2018. The validated Chinese version of the 15-item Maslach Burnout Inventory was used to assess burnout. A self-administered questionnaire collected the sociodemographic factors. The psychological factors were collected by the Chinese version of the 20-item Center for Epidemiologic Studies Depression Scale (CES-D) and the Perceived Stress Scale-14. RESULTS: The prevalence of burnout in Chinese preschool teachers was 53.2% (95% CI:51%─56%). Burnout rate was significantly decreased in overweight (P = 0.001, OR = 0.58, 95% CI: 0.42-0.79) and obesity (P = 0.048, OR = 0.75, 95% CI: 0.56-1.00) teachers compared with teachers with normal weight. The type of school (P = 0.007, OR = 1.45, 95% CI: 1.11-1.91), income satisfaction (P = 0.001, OR = 0.67, 95% CI: 0.53-0.86), depression (P < 0.001, OR = 3.08, 95% CI: 2.34-4.05) and perceived stress (P < 0.001, OR = 1.15, 95%CI: 1.13-1.18) were significantly associated with burnout. CONCLUSIONS: The prevalence of burnout among preschool teachers in Tianjin, China, is high. Burnout was significantly associated with BMI, the type of school, income satisfaction, depression and perceived stress among Chinese preschool teachers.

13.
Sleep Med ; 69: 34-40, 2020 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-32045852

RESUMO

OBJECTIVE: Brain iron deposition in hemodialysis (HD) patients increases over time. Iron deficiency in gray matter nuclei has been reported to lead to idiopathic restless legs syndrome (RLS) symptoms. Regardless of unpleasant RLS sensations, the patterns of iron deposition between hemodialysis patients with RLS (HD-RLS) and hemodialysis patients without RLS (HD-nRLS) are still unclear. To evaluate the differences in iron deposition patterns between HD-RLS and HD-nRLS patients, we utilized quantitative susceptibility mapping (QSM). METHODS: In sum, 24 HD-RLS patients, 25 HD-nRLS patients and 30 age- and sex-matched healthy controls (HCs) were enrolled. The QSM was used to assess susceptibility values of the regions of interest (ROIs), including the caudate nucleus (CN), putamen (PUT), globus pallidus (GP), thalamus (THA), substantia nigra (SN), red nucleus (RN) and dentate nucleus (DN). RESULTS: HD duration was significantly longer in HD-RLS patients than in HD-nRLS patients (P < 0.05). The susceptibility of HD-RLS and HD-nRLS patients in PUT was higher than that in HCs (P < 0.05), illustrating elevated iron content in the nucleus. Compared with HD-nRLS patients, HD-RLS patients demonstrated reduced susceptibility in CN and PUT (both P < 0.05). Compared with HCs, HD-RLS patients displayed decreased susceptibility in DN (P < 0.05). CONCLUSIONS: Different iron deposition patterns between HD-RLS and HD-nRLS patients in PUT and DN, which further support disturbed sensory processing in RLS, may be involved in RLS pathogenesis in HD patients.

14.
Mol Cell Endocrinol ; 506: 110762, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32087276

RESUMO

Rescue chemotherapy is usually the preferred treatment for patients with advanced estrogen receptor-positive (ER+) breast cancer with endocrinotherapy resistance. However, these patients often simultaneously show a poor response to cytotoxic drugs, and thus the detailed mechanism of this resistance needs to be further investigated. Our previous research indicated that the G-protein-coupled estrogen receptor (GPER) is a novel mediator of the development of multidrug resistance, including resistance to both endocrinotherapy and chemotherapy, and ATP binding cassette subfamily G member 2 (ABCG2) has been identified as an engine that confers cancer cells with chemoresistance by expelling xenobiotics and chemotherapeutics. Here, we are the first to show that the expression levels of GPER and ABCG2 are markedly increased in tamoxifen-resistant ER + metastases compared to the corresponding primary tumors. A plasma membrane expression pattern of GPER and ABCG2 was observed in patients with metastases. Furthermore, both ER modulator tamoxifen, GPER-specific agonist G1 and pure ER antagonist ICI 182,780 significantly enhanced ABCG2 expression in tamoxifen-resistant breast cancer cells (MCF-7R) but not in tamoxifen-sensitive cells (MCF-7). The activated downstream GPER/EGFR/ERK and GPER/EGFR/AKT signaling pathways were responsible for regulating the expression and cell membrane localization of ABCG2, respectively, in MCF-7R cells. Interestingly, the above phenomenon could be alleviated by inhibitors of both the indicated signaling pathways and by knockdown of GPER in MCF-7R cells. More importantly, the tamoxifen-induced GPER/ABCG2 signaling axis was shown to play a pivotal role in the development of chemotherapy (doxorubicin) resistance both in vitro and in vivo. The clinical data further revealed that tamoxifen-resistant patients with high GPER/ABCG2 signaling activation had poor progression-free survival (PFS) when given rescue anthracycline chemotherapy. Therefore, our data provide novel insights into GPER-mediated chemoresistance and provide a rationale for the GPER/ABCG2 signaling axis being a promising target for reversing chemoresistance in patients with advanced ER + tamoxifen-resistant breast cancer.

15.
Int J Neurosci ; : 1-7, 2020 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-32098537

RESUMO

Pituitary metastasis(PM) from renal cell carcinoma(RCC) is rare, and is easy to be misdiagnosed. Here, we present a case of pituitary metastasis from clear-cell renal cell carcinoma(ccRCC) which was difficult to distinguish from other sellar region tumors. In addition, we systematically review the literature to find the characteristics of different tumors of the sellar region. It provides a new idea for the diagnosis of sellar region tumors in the clinic.

16.
Fitoterapia ; 142: 104501, 2020 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-32058050

RESUMO

A phytochemical investigation on the leaves of Tripterygium wilfordii Hook. F. was conducted, leading to the isolation of five undescribed dihydro-ß-agarofuran sesquiterpenoids (1-5) and one known analogue (6). Their structures were determined by comprehensive spectroscopic analyses. The absolute configurations of the compounds were determined by comparison of the experimental ECD with the calculated data. In addition, all the compounds were evaluated for their neuroprotective activities against H2O2-induced cell injury in human neuroblastoma SH-SY5Y cells, and 3 showed the better protective effect with 76.63% cell viability comparing with the positive control Trolox (69.84%) at 12.5 µM.

17.
Chem Biol Interact ; 319: 109006, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-32084352

RESUMO

Ketamine is gaining ground as a potential treating depression because it has a distinct mode of action than typical drugs that influence monoamine neurotransmitters including noradrenaline, dopamine, or serotonin. Ketamine is thought to act by blocking N-methyl-d-aspartate (NMDA) receptors in the brain, which interact with the amino acid neurotransmitter glutamate. The resultant chemical changes in the brain caused by ketamine are not yet fully understood but could involve ketamine-induced gene expression and signaling cascades that act long after the drug has been eliminated from the body. Despite these remarkable effects, the widespread use of ketamine is limited by potential side effects including the emergence reactions (hallucinations, dreams, and out-of-body experiences) by recreational users, who need further study before long-term use of ketamine can be approved for depression. Thus, studies are necessary to further elucidate mechanistic actions of ketamine at cellular and network levels. Thus, we are exploring the involvement of molecular targets for the treatment and psychomimetic phenomena of the ketamine.


Assuntos
Anestésicos Dissociativos/farmacologia , Anestésicos Dissociativos/uso terapêutico , Depressão/tratamento farmacológico , Ketamina/farmacologia , Ketamina/uso terapêutico , Animais , Encéfalo/efeitos dos fármacos , Expressão Gênica/efeitos dos fármacos , Humanos , Transdução de Sinais/efeitos dos fármacos
18.
Breast Cancer Res Treat ; 180(2): 423-428, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32034581

RESUMO

OBJECTIVE: The aim of the study is to evaluate the optimal timing of sentinel lymph node biopsy (SLNB) in patients with clinical negative axillary lymph nodes (ALNs) before neoadjuvant therapy (NAT) and the feasibility of SLNB substituting for ALN dissection in patients with positive ALNs who convert to node negative, for HER2-positive disease. METHODS: Patients receiving SLNB with dual tracer mapping in the PEONY trial were analyzed. RESULTS: For 80 patients with clinical negative ALNs, the node negative rate by pathology after NAT was 83.8%. SLNB was performed after NAT in 71 patients. The identification rate of sentinel lymph nodes (SLNs) was 100%. For patients with positive ALNs before NAT, the axillary pathologic complete response rate in the dual HER2 blockade arm was significantly higher than that in the single blockade arm (p = 0.002). SLNB was performed in 71 patients. The identification rate was 100% and the false-negative rate was 17.2%. The false-negative rates were 33.3%, 14.3%, and 0 when 1, 2, and more than 2 SLNs were detected. There was no false-negative case when more than 1 SLN and the clipped nodes were removed simultaneously. CONCLUSIONS: For clinical ALN negative patients, HER2-positive subtype is found to have high node negative rate by pathology and it is recommended to undergo SLNB after NAT. For patients with positive ALNs who convert to negative, the false-negative rate is high. Dual tracer mapping, more than 2 SLNs detected, more than 1 SLN identified plus the clips placed are the guarantees for lower false-negative rate.

19.
Artigo em Inglês | MEDLINE | ID: mdl-32101121

RESUMO

The folate-modified graphene oxide (GO-FA) was successfully prepared, which had good stability and biocompatibility on rat glioma cells. The formation and composition of GO-FA were confirmed by scanning electron microscope (SEM), transmission electron microscope (TEM), fourier transform infrared spectrum (FT-IR), Raman spectra and X-ray photoelectron spectroscopy (XPS spectra). The cell experiment suggested good biocompatibility of GO-FA on rat glioma cells. The experiment of GO-FA loading with temozolomide (TMZ) showed that the maximum drug loading of GO-FA was 8.05 ± 0.20 mg/mg, with the drug loading rate of 89.52 ± 0.19 %. When TMZ was released from the folate-modified graphene oxide loading with temozolomide (GO-FA-TMZ), its release behavior in vitro showed strong pH dependence and sustained release property. The growth of rat glioma cells can be effectively inhibited by GO-FA-TMZ, with the cell inhibition rate as high as 91.72 ± 0.13 % at the concentration of 600 µg/mL and time of 72 h. According to the above experimental results, this composite carrier has potential applications in drug delivery and cancer therapy.

20.
ISA Trans ; 2020 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-32044088

RESUMO

A novel back recursive estimation (BRE) scheme is proposed for superconducting radio frequency (SRF) cavities. Microphonic,the main source of cavities detuning is modeled as unknown frequency sinusoidal disturbance. The disturbance property is excited by an auxiliary filter and the frequency information is estimated in observer framework. Furthermore, the sinusoidal disturbance is rearranged as a series of dynamics form using virtual disturbances. Back recursive signal is calculated according to the correlation between virtual disturbance and equivalent input disturbance. As a result, the asymptotic stability of estimation error can be obtained based on Lyapunov function, and robustness can be obtained if another external bounded disturbance exists. Simulations verify the effectiveness of the proposed method.

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