[Whole-course management strategies for gastroesophageal reflux disease: an evidence mapping study based on clinical practice guidelines].

Gastroesophageal reflux disease (GERD) is one of the most common digestive diseases with high incidence, complicated clinical symptoms, difficulties in standard treatment, and heavy medical burden. At present, some GERD-relevant clinical practice guidelines (CPGs) have been issued by different countries and academic organizations, but some recommendations were inconsistent, which has caused some problems for the current clinical whole-course management of GERD. To summarize the relevant evidence among the CPGs on GERD and formulate the whole- course management strategies, we included GERD-relevant CPGs published or updated after 2010 by searching websites of guidelines, relevant professional societies, and electronic databases. We extracted the recommendations and summarized the evidence from the aspects of symptoms, epidemiology, diagnosis and treatment, which was presented in the form of evidence mapping. We included 24 CPGs, including three in Chinese and 21 in English. The clinical practice management strategies of GERD were formulated based on the evidence from the aspects of clinical symptoms, diagnostic methods, medical treatment, anti-reflux surgery and endoscopic treatment, psychological treatment, and traditional Chinese medicine treatment.

Visible imaging system with changeable field of view on the HL-2A tokamak.

A new visible imaging system characterizing a flexible optical design and delivering high resolution frames is established on the HL-2A tokamak. It features a modular configuration, consisting of a front-end imaging lens, a set of bilateral telecentric relay lenses, and a camera. To avoid the effects of plasma radiation (x and gamma-rays) and magnetic field variation on the camera, it should be away from the coils. Therefore, the length of the relay lenses determines the total size of the imaging system. The main feature of this imaging system is to realize the variation of field of view (FOV) by interchanging the front-end prime lenses or by using a zoom lens directly rather than designing the optical system afresh, which lowers the cost drastically. The primary purpose of varying FOV is to enrich the versatility of this system, i.e., focusing on a narrow FOV such as gas puff imaging or a wide FOV such as the plasma cross sections. During the HL-2A experiments, this visible imaging system is used to provide high quality pictures of the plasma-wall interaction, divertor detachment, pellet injections, and so on. The frames confirmed that a strong radiation close to the X point is correlated with the completely detached inner target.

[Clinical analysis of pulmonary sequestration with torsion in 4 cases and literature review].

Objective: To summarize and analyze the clinical characteristics of children pulmonary sequestration with torsion. Methods: The main clinical manifestations, auxiliary examinations (chest B ultrasound, chest enhanced CT, pathological results), treatment and prognosis of 4 cases with pulmonary sequestration with torsion in Shenzhen Children's Hospital from November 2010 to November 2020 were retrospectively analyzed. Results: Among the 4 children, 2 were male and female,The age was 3 years and 8 months, 6 years and 9 months, 7 years and 5 months, 10 years old respectively.All the 4 cases were extralobar sequestrations, 2 cases were on the left side and 2 cases were on the right side. Abdominal pain was the first symptom, followed by chest pain in 2 cases, fever in 2 cases, shortness of breath in 1 case; 4 cases of chest color ultrasonography showed the soft tissue masses in the chest, medium volume pleural effusion in 2 cases, small pleural effusion in 2 cases, enhanced chest CT showed soft tissue mass without enhancement or slight enhancement in all 4 cases, and the blood supply artery was not clearly shown. Pathological results showed pulmonary sequestration with hemorrhage and necrosis, and 4 cases were cured after thoracoscopic surgery. Conclusions: Abdominal pain is often the first or main symptom of pulmonary sequestration with torsion in children, accompanied by or without chest pain. Chest ultrasound and CT can reveal the soft tissue density mass which is not enhanced or slightly enhanced during enhancement, and the blood supply artery is unclear. The effect of resection is well.

Visible wide-angle view imaging system for the first plasma on the HL-2M tokamak.

The wide-angle view imaging system, in terms of a tangential view diagnostic with field of view (FOV) of 56.8° and a downward-looking diagnostic from the top of the machine with FOV of 94.7°, has been newly constructed for the first plasma of the HL-2M tokamak achieved in December 2020. Its mission in this stage is to monitor the plasma evolution during its startup, sustainment, and disruption in the visible spectral range as well as the plasma-wall interaction. For the latter ultrawide view diagnostic, nearly three-quarters of the divertor region and half the area of the inner wall are in the view range. Both the diagnostics are characterized by a similar optical structure, i.e., the light emission from the plasma is collected by a front-end lens and transferred through an imaging fiber bundle to the camera. This optical structure is suitable for application in the complex tokamak environment mainly because the fiber bundle is flexible. Photos of glow discharges are acquired prior to the first plasma for testing the FOVs in the vacuum vessel. The spatial resolution is ∼4mm for the tangential view diagnostic and ∼10mm for the downward-looking diagnostic. The temporal resolutions, ranging from 90 to 360 Hz by changing the region of interest or binning acquisition mode of the color camera, are applied to record the plasma evolutions and/or dust creation events during the first plasma campaign.

A preliminary study on colour Doppler ultrasound for the evaluation of intervertebral stenosis of the vertebral artery.

AIM: To determine the optimal thresholds for assessing intervertebral segment stenosis through haemodynamic parameters of colour Doppler ultrasound compared with computed tomography (CT) angiography. MATERIALS AND METHODS: Fifty-four patients diagnosed with intervertebral stenosis on colour Doppler imaging were included. Twenty patients with normal vertebral arteries constituted a control group. Peak systolic velocity at the intervertebral stenosis (PSVIV-S) and the intervertebral segment distal to the stenosis (PSVIV-D), end diastolic velocity at the intervertebral stenosis (EDVIV-S), and the intervertebral segment distal to the stenosis (EDVIV-D) were measured, and the ratios of PSVIV-S/PSVIV-D and EDVIV-S/EDVIV-D were calculated. Cut-off values for the diagnosis of <50%, 50-69%, and 70-99% stenosis were determined using a receiver operating characteristics curve. RESULTS: The optimal cut-off values of haemodynamic parameters for evaluating the intervertebral artery for <50% stenosis were PSVIV-S ≥81.5 cm/s, EDVIV-S ≥24.5 cm/s, PSVIV-S/PSVIV-D ≥1.49, and EDVIV-S/EDVIV-D ≥1.28; for 50-69% stenosis were PSVIV-S ≥137.5 cm/s, EDVIV-S ≥36.5 cm/s, PSVIV-S/PSVIV-D ≥3.14, and EDVIV-S/EDVIV-D ≥2.75; and for 70-99% stenosis were PSVIV-S ≥216 cm/s, EDVIV-S ≥55 cm/s, PSVIV-S/PSVIV-D ≥4.31, and EDVIV-S/EDVIV-D ≥4.16. PSVIV-S/PSVIV-D was the most superior haemodynamic parameter, with areas under the curve of 1.000, 0.906, and 0.968 for the diagnosis of <50%, 50-69%, and 70-99% stenosis, respectively. CONCLUSION: Colour Doppler sonography reliably identifies intervertebral stenosis. The results can be used as a preliminary reference for evaluating intervertebral stenosis.

Fast charge exchange recombination spectroscopy on HuanLiu-2A tokamak.

A Fast Charge eXchange Recombination Spectroscopy (CXRS) diagnostic with eight radial channels has been implemented on a HuanLiu-2A (HL-2A) tokamak with a time resolution of up to 10 kHz monitoring helium II spectra or 1 kHz monitoring carbon VI spectra. The crucial aspects of the fast CXRS are to improve the spectral intensity and the acquisition frequency. The spectral intensity has been greatly enhanced by customized fiber bundles. The main boost in optimizing the acquisition frequency is achieved by binning more pixel rows of the charge coupled device (CCD) representing one radial channel and by reducing the effective image area of the CCD. Consequently, the sawtooth oscillations of ion temperature and rotation velocity are continuously observed for the first time in the HL-2A tokamak.

Note: Real-time wavelength matching system designed for the motional Stark effect polarimeter on HL-2A tokamak.

A 7-channel motional Stark effect diagnostic based on dual photo-elastic modulators is installed and operated routinely for rather low beam energy and magnetic field on the HL-2A tokamak, with a spatial resolution of ∼3 cm and a temporal resolution of 10 ms. The instrument observes the σ component of the full energy Dα from the first or the fourth ion source of a neutral beam injector. However, the change in beam energy during a discharge causes variation of the Doppler shift with the maximum of 1 Å, which leads to the polarization fraction drop from 30%-40% to 10% and then makes the signal-to-noise ratio of the system become very poor. Therefore, a real-time wavelength matching system is designed to promote polarization fraction. The beam emission spectra are filtered by using a monochrometer in real time. And a narrowband filter is tilted by using an absolutely calibrated rotator through beam energy in order to make sure that the deviation of wavelength matching is less than 0.1 Å.

Synchronization of Geodesic Acoustic Modes and Magnetic Fluctuations in Toroidal Plasmas.

The synchronization of geodesic acoustic modes (GAMs) and magnetic fluctuations is identified in the edge plasmas of the HL-2A tokamak. Mesoscale electric fluctuations (MSEFs) having components of a dominant GAM, and m/n=6/2 potential fluctuations are found at the same frequency as that of the magnetic fluctuations of m/n=6/2 (m and n are poloidal and toroidal mode numbers, respectively). The temporal evolutions of the MSEFs and the magnetic fluctuations clearly show the frequency entrainment and the phase lock between the GAM and the m/n=6/2 magnetic fluctuations. The results indicate that GAMs and magnetic fluctuations can transfer energy through nonlinear synchronization. Such nonlinear synchronization may also contribute to low-frequency zonal flow formation, reduction of turbulence level, and thus confinement regime transitions.

The supersonic molecular beam injector as a reliable tool for plasma fueling and physics experiment on HL-2A.

On HL-2A tokamak, supersonic molecular beam injection (SMBI) has been developed as a routine refueling method. The key components of the system are an electromagnetic valve and a conic nozzle. The valve and conic nozzle are assembled to compose the simplified Laval nozzle for generating the pulsed beam. The appurtenance of the system includes the cooling system serving the cooled SMBI generation and the in situ calibration component for quantitative injection. Compared with the conventional gas puffing, the SMBI features prompt response and larger fueling flux. These merits devote the SMBI a good fueling method, an excellent plasma density feedback control tool, and an edge localized mode mitigation resource.

On the interplay between neoclassical tearing modes and nonlocal transport in toroidal plasmas.

This Letter presents the first observation on the interplay between nonlocal transport and neoclassical tearing modes (NTMs) during transient nonlocal heat transport events in the HL-2A tokamak. The nonlocality is triggered by edge cooling and large-scale, inward propagating avalanches. These lead to a locally enhanced pressure gradient at the q = 3/2 (or 2/1) rational surface and hence the onset of the NTM in relatively low ß plasmas (ßN < 1). The NTM, in return, regulates the nonlocal transport by truncation of avalanches by local sheared toroidal flows which develop near the magnetic island. These findings have direct implications for understanding the dynamic interaction between turbulence and large-scale mode structures in fusion plasmas.

Observation of Double Impurity Critical Gradients for Electromagnetic Turbulence Excitation in Tokamak Plasmas.

The impact of impurity ions on a pedestal has been investigated in the HL-2A Tokamak, at the Southwestern Institute of Physics, Chengdu, China. Experimental results have clearly shown that during the H-mode phase, an electromagnetic turbulence was excited in the edge plasma region, where the impurity ions exhibited a peaked profile. It has been found that double impurity critical gradients are responsible for triggering the turbulence. Strong stiffness of the impurity profile has been observed during cyclic transitions between the I-phase and H-mode regime. The results suggest that the underlying physics of the self-regulated edge impurity profile offers the possibility for an active control of the pedestal dynamics via pedestal turbulence.

A novel hemizygous SACS mutation identified by whole exome sequencing and SNP array analysis in a Chinese ARSACS patient.

The array of autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) has expanded worldwide after the first description in the Charlevoix-Saguenay region of Québec. Here, we report a Chinese ARSACS patient presenting progressive peripheral neuropathy (CMTNS2=15) with horizontal gaze nystagmus and mild spastic gait. Genetic studies including whole exome sequencing (WES), Sanger sequencing and single nucleotide polymorphism (SNP) array analysis revealed a novel hemizygous nonsense mutation (c.11803C>T, p.Gln3935X) of SACS and a 1.33Mb deletion involved in SACS on chromosome 13q12.12 in the patient. Our findings highlight the necessity of SACS mutation screening in the gene panel of inherited peripheral neuropathies, and stress the need of testing copy number variation (CNV) in SACS mutation screening.

High spatial and temporal resolution charge exchange recombination spectroscopy on the HL-2A tokamak.

A 32/64-channel charge exchange recombination spectroscopy (CXRS) diagnostic system is developed on the HL-2A tokamak (R = 1.65 m, a = 0.4 m), monitoring plasma ion temperature and toroidal rotation velocity simultaneously. A high throughput spectrometer (F/2.8) and a pitch-controlled fiber bundle enable the temporal resolution of the system up to 400 Hz. The observation geometry and an optimized optic system enable the highest radial resolution up to ∼1 cm at the plasma edge. The CXRS system monitors the carbon line emission (C VI, n = 8-7, 529.06 nm) whose Doppler broadening and Doppler shift provide ion temperature and plasma rotation velocity during the neutral beam injection. The composite CX spectral data are analyzed by the atomic data and analysis structure charge exchange spectroscopy fitting (ADAS CXSFIT) code. First experimental results are shown for the case of HL-2A plasmas with sawtooth oscillations, electron cyclotron resonance heating, and edge transport barrier during the high-confinement mode (H-mode).

Diagnostics for energetic particle studies on the HL-2A tokamak.

About 13 kinds of diagnostics for energetic particle physics studied on the HuanLiuqi-2A (commonly referred to as HL-2A) tokamak are described in this paper. Their measurement ranges, resolutions, and arrangement are presented. Three under-construction diagnostics including imaging fast ion D-alpha, scintillator matrix (for hard X-ray detection), and bundle fission chamber are described in detail.

Progress of neutral-beam-aided diagnostics on the HL-2A tokamak.

A 32/64-channel Charge eXchange Recombination Spectroscopy (CXRS) and a 7-channel motional Stark effect (MSE) polarimeter have been developed on the HL-2A tokamak. To extract the maximum time resolution of the system, the incidence fibers of the spectrometer are pitch-controlled; and the double-slit fiber bundle can increase the spatial channels with one charge-coupled device detector. The ion temperature and plasma rotation with time and spatial resolutions up to 5 ms and 1 cm are obtained. Sawtooth oscillation, transition from intermediate phase (I phase) to high confinement mode (H mode) can be clearly observed by the CXRS. The spectrometer can be utilized as the main component of the MSE polarimeter, which can effectively overcome the weak Stark effect. The pitch angles of magnetic field are obtained for 7 spatial points covering 24 cm along major radius with time resolution of 40 ms.

The motional Stark effect polarimeter in the HL-2A tokamak.

A 7-channel motional Stark effect polarimeter based on four polarizers and a spectrometer has been developed in the HL-2A tokamak, which is the first time successful utilizing this kind of polarimeter on a tokamak. The accuracy of the angle can reach ±0.25° in the calibration experiments. Pilot experiments of measuring the magnetic pitch angle have been successfully carried out in the weak motional Stark effect plasma discharge with toroidal magnetic field of ~1.3 T and beam energy of ~25 keV/amu. The pitch angles of magnetic field are obtained for 7 spatial points covering 24 cm along major radius with time resolution of 40 ms; the profiles of safety factor are obtained by combining with the Equilibrium and Reconstruction Fitting Code. The core value of safety factor (q) is less than 1 during the sawtooth oscillation and the position of q = 1 surface is well consistent with the results measured by soft X-ray array.

Dynamics of low-intermediate-high-confinement transitions in toroidal plasmas.

The dynamic features of the low-intermediate-high-(L-I-H) confinement transitions on HL-2A tokamak are presented. Here we report the discovery of two types of limit cycles (dubbed type-Y and type-J), which show opposite temporal ordering between the radial electric field and turbulence intensity. In type-Y, which appears first after an L-I transition, the turbulence grows first, followed by the localized electric field. In contrast, the electric field leads type-J. The turbulence-induced zonal flow and pressure-gradient-induced drift play essential roles in the two types of limit cycles, respectively. The condition of transition between types-Y and -J is studied in terms of the normalized radial electric field. An I-H transition is demonstrated to occur only from type-J.

Adaptive RBF network for parameter estimation and stable air-fuel ratio control.

In the application of variable structure control to engine air-fuel ratio, the ratio is subjected to chattering due to system uncertainty, such as unknown parameters or time varying dynamics. This paper proposes an adaptive neural network method to estimate two immeasurable physical parameters on-line and to compensate for the model uncertainty and engine time varying dynamics, so that the chattering is substantially reduced and the air-fuel ratio is regulated within the desired range of the stoichiometric value. The adaptive law of the neural network is derived using the Lyapunov method, so that the stability of the whole system and the convergence of the networks are guaranteed. Computer simulations based on a mean value engine model demonstrate the effectiveness of the technique.

Toroidal symmetry of the geodesic acoustic mode zonal flow in a tokamak plasma.

The toroidal symmetry of the geodesic acoustic mode (GAM) zonal flows is identified with toroidally distributed three step Langmuir probes at the edge of the HuanLiuqi-2A (commonly referred to as HL-2A) tokamak plasmas for the first time. High coherence of both the GAM and the ambient turbulence for the toroidally displaced measurements along a magnetic field line is observed, in contrast with the high coherence of the GAM but low coherence of the ambient turbulence when the toroidally displaced measurements are not along the same field line. The radial and poloidal features of the flows are also simultaneously determined. The nonlinear three wave coupling between the high frequency turbulent fluctuations and the flows is demonstrated to be a plausible formation mechanism of the flows.