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2.
Rev Sci Instrum ; 92(6): 063503, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-34243580

RESUMO

This study shows the feasibility of a beam emission spectroscopy (BES) diagnostic in the Helically Symmetric eXperiment (HSX) stellarator for obtaining the spatiotemporal structure of density fluctuation. A beam emission simulation was applied to HSX plasmas to design and optimize viewing chords and to estimate the beam emission spectrum. A Doppler-shifted beam emission spectrum was measured from a 30 kV, 4 A diagnostic neutral beam injected into HSX plasmas. The beam emission was measured with a high-time-resolution avalanche photodiode (APD) assembly to determine the feasibility of BES in HSX. For HSX plasmas heated by 28 GHz electron cyclotron heating, a mode around f = 15 kHz was observed in the BES signal. The coherence between the BES signal and the density fluctuation measured by an interferometer system was significant. A plan for improving the BES system to enable the measurement of higher frequency related to turbulent transport is presented. The array of sightlines proposed in this study can be used to measure beam emission with a Doppler shift larger than 3 nm (blue shift), which enables the use of a wide passband interference filter to obtain higher throughput. The adoption of a large objective optics and a chilled APD assembly will improve the signal-to-noise ratio.

3.
Zhonghua Yan Ke Za Zhi ; 56(5): 376-382, 2020 May 11.
Artigo em Chinês | MEDLINE | ID: mdl-32450671

RESUMO

Objective: To explore the potential neuroprotection effects and associated mechanism of baicalin in a rodent acute hypertensive glaucoma model and oxygen-glucose deprivation/reperfusion (OGD/R) induced retinal ganglion cell (RGC) injury. Methods: Experiment research. A rapid and substantial elevation of intraocular pressure was performed to establish an acute hypertensive glaucoma model, and retinal thickness was assessed at 1, 3, 5, and 7 days. The mice were then randomly divided into three groups: normal control group, hypertension group, and baicalin (50 mg/kg) for hypertension group. The effects of baicalin on the RGCs were evaluated by retrograde transporting of Fluoro-Gold. The mRNA levels of tumor necrosis factor-α, interleukine-1ß (IL-1ß), and inducible nitric oxide synthase were detected by real-time PCR, and the protein levels were measured by Western blot in the retina tissue of acute hypertensive glaucoma model. Purified primary RGC survival under OGD/R stress was measured by flow cytometry, which was also performed to measure the survival rate of RGCs pretreated by different doses of baicalin (2.5 µmol/L, 5.0 µmol/L, and 10.0 µmol/L). The effects of baicalin on primary RGCs co-cultured with mouse microglia cell line BV2 were evaluated by flow cytometry. The cytokine IL-1ß in the culture supernatant was measured by immunochemical analyses. Statistical analysis was performed using analysis of variance. Results: Retinal tissue injuries and RGC loss were observed both in vivo and in vitro. Retinal thickness was decreased to 87.32%±0.94% at 3 days (t=6.73, P<0.01), 74.86%±2.43% at 5 days (t=13.40, P<0.01), and 63.53%±2.15% at 7 days (t=19.46, P<0.01). Treatment of 50 mg/kg baicalin significantly promoted the RGC survival from 61.32%±5.94% to 89.93%±10.08% (t=4.84, P<0.01). Baicalin alleviated the retinal damages by suppressing the expression of inflammatory cytokines as revealed by Western blot and real-time PCR. In vitro the RGC survival under OGD/R stress was increased from 51.53%±1.36% to 69.37%±7.09% and 66.23%±4.25% with 5.0, 10.0 µmol/L baicalin administration (t=5.50, 4.53; both P<0.01). BV2 under OGD/R stress did extra damage to RGCs, and baicalin could reverse the damages and increase the survival from 69.37%±7.09% to 73.00%±5.20% (t=2.82, P=0.048) by reducing the release of IL-1ß [(39.97±8.76) pg/ml vs. (61.33±5.78) pg/ml, t=4.19, P=0.010]. Conclusion: Baicalin could alleviate retina tissue injury directly and promote the survival of RGCs by downregulating the expression of inflammatory cytokines and protecting RGCs from ischemia reperfusion injury. (Chin J Ophthalmol, 2020, 56: 376-382).


Assuntos
Anti-Inflamatórios não Esteroides , Flavonoides , Glaucoma , Hipertensão Ocular , Animais , Anti-Inflamatórios não Esteroides/farmacologia , Anti-Inflamatórios não Esteroides/uso terapêutico , Modelos Animais de Doenças , Flavonoides/farmacologia , Flavonoides/uso terapêutico , Glaucoma/tratamento farmacológico , Camundongos , Hipertensão Ocular/tratamento farmacológico , Células Ganglionares da Retina
4.
Front Pediatr ; 8: 136, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32300579

RESUMO

Background: Despite the rapid advance of neonatal care, bronchopulmonary dysplasia (BPD) remains a significant burden for the preterm population, and there is a lack of effective intervention. Stem cell depletion because of preterm birth is regarded as one of the underlying pathological mechanisms for the arrest of alveolar and vascular development. Preclinical and small-sample clinical studies have proven the efficacy and safety of stem cells in treating and preventing lung injury. However, there are currently no randomized clinical trials (RCTs) investigating the use of autologous cord blood mononuclear cells (ACBMNC) for the prevention of BPD in premature infants. The purpose of this study is to investigate the effects of infusion of ACBMNC for the prevention of BPD in preterm neonates <28 weeks. Methods: In this prospective, randomized controlled double-blind multi-center clinical trial, 200 preterm neonates <28 weeks gestation will be randomly assigned to receive intravenous ACBMNC infusion (5 × 107 cells/kg) or placebo (normal saline) within 24 h after birth in a 1:1 ratio using a central randomization system. The primary outcome will be survival without BPD at 36 weeks of postmenstrual age or at discharge, whichever comes first. The secondary outcomes will include the mortality rate, other common preterm complication rates, respiratory support duration, length, and cost of hospitalization, and long-term outcomes after a 2-year follow-up. Conclusion: This will be the first randomized, controlled, blinded trial to evaluate the efficacy of ACBMNC infusion as a prevention therapy for BPD. The results of this trial will provide valuable clinical evidence for recommendations on the management of BPD in extremely preterm infants. Clinical Trial Registration: ClinicalTrials.gov, NCT03053076, registered 02/14/2017, retrospectively registered, https://register.clinicaltrials.gov/prs/app/action/SelectProtocol?sid=S0006WN4&selectaction=Edit&uid=U0002PLA&ts=2&cx=9y23d4 (Additional File 2).

5.
Braz J Med Biol Res ; 50(10): e6148, 2017 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-28876365

RESUMO

This study aimed to investigate the association between ADAM metallopeptidase domain 33 (ADAM33) gene polymorphisms and the risk of childhood asthma. The relevant studies about the relationship between ADAM33 gene polymorphisms and childhood asthma were searched from electronic databases and the deadline of retrieval was May 2016. The single nucleotide polymorphisms (SNPs) of ADAM33 (rs511898, rs2280092, rs3918396, rs528557, rs2853209, rs44707, rs2280091 and rs2280089) were analyzed based on several models including the allele, codominant, recessive and dominant models. The results showed that the ADAM33 rs2280091 polymorphism in all four genetic models was associated with an increased risk of childhood asthma. Positive associations were also found between the polymorphisms rs2280090, rs2787094, rs44707 and rs528557 and childhood asthma in some genetic models. This meta-analysis suggested that ADAM33 polymorphisms rs2280091, rs2280090, rs2787094, rs44707 and rs528557 were significantly associated with a high risk of childhood asthma.


Assuntos
Proteínas ADAM/genética , Asma/genética , Predisposição Genética para Doença , Polimorfismo de Nucleotídeo Único , Alelos , Criança , Humanos , Fatores de Risco
6.
Rev Sci Instrum ; 83(10): 10E308, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23126968

RESUMO

The interferometer system on the Helically Symmetric eXperiment (HSX) stellarator uses an expanded beam and linear detector array to realize a multichord measurement. Unlike conventional interferometry which determines the plasma phase shift with respect to a reference, directly evaluating the phase between two adjacent chords can be employed to measure the change in plasma phase with impact parameter. This approach provides a measure of the equilibrium density gradient or the density gradient fluctuations and is referred to as differential interferometry. For central chords, measurements are spatially localized due to a geometrical weighting factor and can provide information on core density gradient fluctuations. The measurement requires finite coherence between fluctuations in the two spatially offset chords. This technique is applied on the HSX stellarator to measure both broadband turbulence and coherent modes. Spatial localization is exploited to isolate core turbulence changes associated with change in magnetic configuration or heating location.

7.
Rev Sci Instrum ; 81(10): 10D503, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21033858

RESUMO

The multichannel interferometer system on the helically symmetric experiment (HSX) stellarator is reconfigured to perform far-forward collective scattering measurements of electron density fluctuations. The collective scattering system has nine viewing chords with 1.5 cm spacing. Scattered power is measured using a homodyne detection scheme. Far-forward collective scattering provides a line-integrated measurement of fluctuations within the divergence of the probe beam covering wavenumber range: k(⊥)<2 cm(-1). The perpendicular wavenumber consists of poloidal and radial contributions that vary with chord position. Both coherent modes and broadband fluctuation are measured. When HSX is operated without quasihelical symmetry at B(T)=1 T and n(e)∼4×10(12) cm(-3), a coherent electrostatic fluctuation is observed.

8.
Phys Rev Lett ; 103(2): 025003, 2009 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-19659216

RESUMO

Energetic electrons generated by electron cyclotron resonance heating are observed to drive instabilities in the quasihelically symmetric stellarator device. The coherent, global fluctuations peak in the plasma core and are measured in the frequency range of 20-120 kHz. Mode propagation is in the diamagnetic drift direction of the driving species. When quasihelical symmetry is broken, the mode is no longer observed. Experimental observations indicate that the unstable mode is acoustic rather than Alfvénic.

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