Polarimeter–interferometer diagnostic using terahertz solid-state sources for fluctuation measurements on Keda Torus e Xperiment(KTX)

A multi-channel polarimeter-interferometer has been developed on the Keda Torus eXperiment(KTX)for the study of equilibrium dynamics and internal magnetic fluctuations.A three-wave technique based on terahertz solid-state sources(-650 GHz)is applied for simultaneous measurements of electron density and Faraday rotation angle.The output power of the microwave source is 2 mW.Faraday rotation effect using a rotating wave plate is tested with phase noise less than 0.8°,and the density phase noise is less than 0.9°.Measurement of Faraday rotation angle and density for discharges on KTX have demonstrated high sensitivity to internal MHD activities.

Oxygen-defects evolution to stimulate continuous capacity increase in Co-free Li-rich layered oxides

Though oxygen defects are associated with deteriorated structures and aggravated cycling performance in traditional layered cathodes,the role of oxygen defects is still ambiguous in Li-rich layered oxides due to the involvement of oxygen redox.Herein,a Co-free Li-rich layered oxide Li_(1.286)Ni_(0.071)Mn_(0.643)O_(2)has been prepared by a co-precipitation method to systematically investigate the undefined effects of the oxygen defects.A significant O_(2)release and the propagation of oxygen vacancies were detected by operando differential electrochemical mass spectroscopy(DEMS)and electron energy loss spectroscopy(EELS),respectively.Scanning transmission electron microscopy-high angle annular dark field(STEMHAADF)reveals the oxygen vacancies fusing to nanovoids and monitors a stepwise electrochemical activation process of the large Li_(2)MnO_(3)domain upon cycling.Combined with the quantitative analysis conducted by the energy dispersive spectrometer(EDS),existed nano-scale oxygen defects actually expose more surface to the electrolyte for facilitating the electrochemical activation and subsequently increasing available capacity.Overall,this work persuasively elucidates the function of oxygen defects on oxygen redox in Co-free Li-rich layered oxides.

Detection of cognitive impairment in patients with obstructive sleep apnea hypopnea syndrome using mismatch negativity

In this experiment,97 patients with obstructive sleep apnea hypopnea syndrome were divided into three groups(mild,moderate,severe) according to minimum oxygen saturation,and 35 healthy subjects were examined as controls.Cognitive function was determined using the mismatch negativity paradigm and the Montreal Cognitive Assessment.The results revealed that as the disease worsened,the mismatch negativity latency was gradually extended,and the amplitude gradually declined in patients with obstructive sleep apnea hypopnea syndrome.Importantly,mismatch negativity latency in severe patients with a persistent time of minimum oxygen saturation < 60 seconds was significantly shorter than that with a persistent time of minimum oxygen saturation > 60 seconds.Correlation analysis revealed a negative correlation between minimum oxygen saturation latency and Montreal Cognitive Assessment scores.These findings indicate that intermittent night-time hypoxemia affects mismatch negativity waveforms and Montreal Cognitive Assessment scores.As indicators for detecting the cognitive functional status of obstructive sleep apnea hypopnea syndrome patients,the sensitivity of mismatch negativity is 82.93%,the specificity is 73.33%,the accuracy rate is 81.52%,the positive predictive value is 85.00%,the negative predictive value is 70.21%,the positive likelihood ratio is 3,and the negative likelihood ratio is 0.23.These results indicate that mismatch negativity can be used as an effective tool for diagnosis of cognitive dysfunction in obstructive sleep apnea hypopnea syndrome patients.

Local inhibition of GABA affects precedence effect in the inferior colliculus

The precedence effect is a prerequisite for faithful sound localization in a complex auditory environment,and is a physiological phenomenon in which the auditory system selectively suppresses the directional information from echoes.Here we investigated how neurons in the inferior colliculus respond to the paired sounds that produce precedence-effect illusions,and whether their firing behavior can be modulated through inhibition with gamma-aminobutyric acid(GABA).We recorded extracellularly from 36 neurons in rat inferior colliculus under three conditions: no injection,injection with saline,and injection with gamma-aminobutyric acid.The paired sounds that produced precedence effects were two identical 4-ms noise bursts,which were delivered contralaterally or ipsilaterally to the recording site.The normalized neural responses were measured as a function of different inter-stimulus delays and half-maximal interstimulus delays were acquired.Neuronal responses to the lagging sounds were weak when the inter-stimulus delay was short,but increased gradually as the delay was lengthened.Saline injection produced no changes in neural responses,but after local gamma-aminobutyric acid application,responses to the lagging stimulus were suppressed.Application of gamma-aminobutyric acid affected the normalized response to lagging sounds,independently of whether they or the paired sounds were contralateral or ipsilateral to the recording site.These observations suggest that local inhibition by gamma-aminobutyric acid in the rat inferior colliculus shapes the neural responses to lagging sounds,and modulates the precedence effect.

Development of a compact torus injection system for the Keda Torus eXperiment

A compact torus injection system,KTX-CTI,has been developed for the planned injection experiments on the Keda Torus e Xperiment(KTX)reversed field pinch(RFP)device to investigate the physics and engineering issues associated with interaction between a compact torus(CT)and RFP.The key interests include fueling directly into the reactor center,confinement improvement,and the injection of momentum and helicity into the RFP discharges.The CT velocity and mass have been measured using a multichannel optical fiber interferometer,and for the first time the time evolution of the CT density profile during CT propagation is obtained.The effects of discharge parameters on the number of injected particles,CT velocity and CT density have been characterized:the maximum hydrogen CT plasma mass,m,CTis 50μg,corresponding to 30%of the mass in a typical KTX plasma;the CT velocity exceeds 120 km s-1.It is observed for the first time that multiple CTs can be produced and emitted during a very short period(<100μs)in one discharge,which is significant for the future study of repetitive CT injection,even with an ultra-high frequency.

Construction of an Hα diagnostic system and its application to determine neutral hydrogen densities on the Keda Torus eXperiment

A 10-channel Hα diagnostic system has been designed with the rapid response rate of 300 kHz, spatial resolution of about 40 mm, and overlap between adjacent channels of about 3%, and it has been implemented successfully on Keda Torus eXperiment(KTX), a newly constructed, reversed field pinch(RFP) experimental device at the University of Science and Technology of China(USTC). This diagnostic system is a very important tool for the initial KTX operations. It is compact,with an aperture slit replacing the traditional optical lens system. A flexural interference filter is designed to prevent the center wavelength from shifting too much as the increase of angle from vertical incidence. To eliminate the stray light,the interior of the system is covered with the black aluminum foil having a very high absorptivity. Using the Hαemission data, together with the profiles of electron temperature and density obtained from the Langmuir probe, the neutral density profiles have been calculated for KTX plasmas. The rapid response rate and good spatial resolution of this Hαdiagnostic system will be beneficial for many studies in RFP plasma physics.

Fast radial scanning probe system on KTX

A fast radial scanning probe system was constructed for the Keda Torus eXperiment(KTX)to measure the profiles of boundary plasma parameters such as floating potential,electron density,temperature,transport fluxes,etc.The scanning probe system is driven by slow and fast motion mechanisms,corresponding to the stand-by movement of a stepping motor and the fast scanning movement of a high-torque servo-motor,respectively.In fast scanning,the scanner drives the probe radially up to 20 cm at a maximum velocity of 4.0 m s-1.A noncontact magnetic grating ruler with a high spatial resolution of 5μm is used for the displacement measurement.New scanning probe can reach the center of plasmas rapidly.The comparison of plasma floating potential profiles obtained by a fixed radial rake probe and the single scanning probe suggests that the high-speed scanning probe system is reliable for measuring edge plasma parameter profiles on the KTX device.

马银花MADS-box基因家族系统进化与表达分析

杜鹃花属具有极高的物种多样性和观赏价值,其中马银花(Rhododendron ovatum)花型独特,具有低海拔适应性,在我国南方地区有良好的应用前景。基于杜鹃花目代表性植物的基因组信息,探究MADS-box基因家族在杜鹃花目中的进化特点并挖掘马银花的花器官发育关键基因。系统进化分析表明,杜鹃花科3个代表性物种(马银花、映山红(R.simsii)和马缨杜鹃(R.delavayi))中的MADS-box基因家族成员数目较为一致,包括AP1、AP3、PI、AG和SEP等19个亚家族,其中SVP、ANR1、Mα、Mβ和Mγ亚家族成员数量较多。马银花的AG和SEP基因有多个拷贝,而AP3/PI基因的拷贝数目较少,显示出更加保守的进化模式。基因表达分析表明,马银花MADS-box基因的表达模式存在组织特异性。AP1、AP3/PI、AG、SEP和MIKC*分支基因在花器官中特异性表达。综上,该文探讨了马银花MADS-box基因家族进化历史,以及部分MADS-box基因可能具有的功能,可为深入研究马银花的发育和MADS-box基因功能提供参考。

芳香堆心菊离体再生体系的建立

芳香堆心菊(Helenium aromaticum)全株具芳香气味,且头状花序仅含管状花,是研究菊科植物花香和花型的良好材料,但目前尚缺乏对其转基因技术体系的研究。为建立高效的芳香堆心菊离体再生体系,以叶片、茎段和下胚轴为外植体,进行25组不同激素及不同浓度配比的不定芽诱导研究。结果表明,以芳香堆心菊叶片为外植体,培养基为MS+0.2 mg·L-1 NAA+1 mg·L-16-BA+0.2 mg·L-1 TDZ,培养20天后愈伤组织诱导率高达100%,丛生芽的诱导率为62.10%;将不定芽接种于1/2MS培养基中进行生根培养,16天即可生根,且生根率为63.33%;生根后继续培养14天现蕾,开花率达93.33%。此外,研究表明芳香堆心菊的再生受外植体来源、激素种类和浓度的影响。2,4-D不利于芳香堆心菊不定芽的诱导,适宜浓度的6-BA和TDZ组合能有效促进芳香堆心菊不定芽的形成。研究初步建立了芳香堆心菊组织培养条件下的离体再生体系,为建立其遗传转化体系奠定了坚实的基础。研究结果还可用于后续有关菊科植物花香和花型的研究。

Clinicoradiologic features of Mycoplasma pneumoniae bronchiolitis in children

Importance: Acute Mycoplasma pneumoniae bronchiolitis can progress into bronchiolitis obliterans (BO) in children, which has a major influence on a child's quality of life and is associated with M. pneumoniae bronchiolitis. Early identification and treatment of M. pneumoniae bronchiolitis is important to prevent the development of BO. Objective: To enhance the understanding of the diagnosis and treatment of M. pneumoniae bronchiolitis in children. Methods: Eight patients with M. pneumoniae bronchiolitis were retrospectively analyzed. results: Five of the patients with M. pneumoniae bronchiolitis were male and three of them were female. All patients suffered from fever and cough. Moist rales and wheezing were noted in both lungs in six patients. High-resolution computed tomography of the chest showed bronchiolitis in all patients, with large airway injury in two and focal bronchopneumonia in six. Two patients were confirmed to have asthma. Seven patients had personal and/or family histories of atopic diseases. Allergen testing was performed in six patients, which produced positive results in four;the remaining two patients had negative results, but their total IgE levels were > 200 IU/ml. Azithromycin therapy and glucocorticoid therapy was administered to all eight patients. One patient required noninvasive ventilation. Treatment of all patients was successful, with no development of bronchiolitis obliterans during the 4- to 8-month follow-up. Interpretation: Mycoplasma pneumoniae bronchiolitis can occur in children, especially in atopic individuals. The use, time of initiation, and effects of glucocorticoids administration in these patients for the prevention of BO require further investigation.

Pathogens of first-episode pulmonary infection in 141 children with chronic granulomatous disease

To the Editor:Chronic granulomatous disease(CGD)is an inherited primary immunodeficiency disease characterized by recurrent life-threatening bacterial or fungal infection and tissue granuloma formation.^([1])Pulmonary infection is the most frequent manifestation,affecting nearly 80%of patients,[2]and remains the major cause of morbidity and mortality in patients with CGD.Details of the pathogenic microorganisms responsible for first-episode pulmonary infection provide information on the spectrum of infection in patients with CGD,help guide the empirical choice of antibiotics or antifungal therapy,and contribute to the early identification and management of CGD.Aspergillus is the commonest causative agent of pulmonary infection,but the distribution of other pathogens varies among countries.^([2–5])Few studies have investigated the etiology of pulmonary infection in CGD in a large cohort in China.