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1.
Zhonghua Yan Ke Za Zhi ; 59(10): 838-845, 2023 Oct 11.
Artículo en Chino | MEDLINE | ID: mdl-37648680

RESUMEN

Objective: To investigate the clinical presentation pattern of acute primary angle-closure glaucoma (PACG) during the 2019 novel coronavirus (2019-nCoV) pandemic over the past three years, and its relationship with 2019-nCoV infections of Omicron variants in Guangdong province. Methods: Ecological study.Patients who were newly diagnosed with acute PACG from February 2020 to January 2023 at the Zhongshan Ophthalmic Center of Sun Yat-sen University were included in the study, and their basic information was collected. Patients were divided into the 2020 group (diagnosed between February 1st, 2020 and January 31st 2021), the 2021 group (diagnosed between February 1st, 2021 and January 31st 2022), and the 2022 group (diagnosed between February 1st, 2022 and January 31st 2023). The clinical presentation pattern of newly diagnosed acute PACG was observed and compared between groups. The daily number of newly diagnosed 2019-nCoV infections in Guangdong province was obtained from the Chinese Center for Disease Control and Prevention. The correlation between the daily number of newly diagnosed acute PACG and that of newly diagnosed 2019-nCoV infections during the epidemic period of Omicron variants between December 2022 and January 2023 was assessed. Results: The study included 1 048 patients with newly diagnosed acute PACG, with 235 for the 2020 group, 274 for the 2021 group, and 539 for the 2022 group. Our results showed that the average weekly number of newly diagnosed acute PACG patients in 2022 [8 (5, 11)] was significantly larger than that in 2020 (4.52±1.95, P<0.05) and 2021 (5.27±2.76, P<0.05). The average weekly number increased to 22.11±20.84 between December 2022 and January 2023. The total number of newly diagnosed acute PACG patients during this period was 199, which was 36.9% (199/539) of the total number of the same year and was 6.63 and 6.42 times as many as that in the same period (December and January) of 2020 and 2021. The proportion of patients with bilateral eye involvement during this period in 2022 was significantly higher than that in 2020 and 2021 (P<0.05). Further analysis found that 88.6% (109/123) of cases had a history of 2019-nCoV infection 2 (0, 3) days before the onset of acute PACG symptoms in average. The estimated daily number of acute PACG onset increased rapidly, peaked on December 23th, 2022, and then dropped gradually. This trend was similar to that of the daily number of new 2019-nCoV infections in Guangdong province. Changes of the daily number of new 2019-nCoV infections in Guangdong province had a positive correlation with the estimated daily number of acute PACG onset (r=0.84, P<0.001). Conclusion: A dramatic increase in the clinical presentation of acute PACG was observed at Zhongshan Ophthalmic Center between December 2022 and January 2023, which was the epidemic period of Omicron variants. There is a correlation between the trend of the estimated daily number of acute PACG onset and that of new 2019-nCoV infections of Omicron variants in Guangdong province, but the exact reason remains to be further studied. (This article was published ahead of print on the official website of Chinese Journal of Ophthalmology on August 31, 2023).

2.
Phys Rev Lett ; 129(16): 166402, 2022 Oct 14.
Artículo en Inglés | MEDLINE | ID: mdl-36306743

RESUMEN

The interplay between various symmetries and electronic bands topology is one of the core issues for topological quantum materials. Spontaneous magnetism, which leads to the breaking of time-reversal symmetry, has been proven to be a powerful approach to trigger various exotic topological phases. In this Letter, utilizing the combination of angle-resolved photoemission spectroscopy, magneto-optical Kerr effect microscopy, and first-principles calculations, we present the direct evidence on the realization of the long-sought spontaneous ferromagnetism induced topological transition in soft ferromagnetic EuB_{6}. Explicitly, we reveal the topological transition is from Z_{2}=1 topological insulator in paramagnetic state to χ=1 magnetic topological semimetal in low temperature ferromagnetic state. Our results demonstrate that the simple band structure near the Fermi level and rich topological phases make EuB_{6} an ideal platform to study the topological phase physics.

3.
Zhonghua Yi Xue Za Zhi ; 101(30): 2370-2374, 2021 Aug 10.
Artículo en Chino | MEDLINE | ID: mdl-34404129

RESUMEN

Objective: To evaluate the efficacy and safety of giant emphysematous bulla (GEB) volume reduction via medical thoracoscope. Methods: This was a prospective, single-arm study conducted between July 2018 and September 2020 in Ri Zhao Hospital of Traditional Chinese Medicine. Patients who met the inclusion criteria were treated with GEB volume reduction via medical thoracoscope and were followed up to evaluate the efficacy and safety of the technique. According to comparison of preoperative and postoperative chest CT results, the self-designed evaluation criteria of imaging efficacy were as follows: complete or nearly complete disappearance of GEB (GEB volume reduction ≥90%), significant reduction of GEB (75%≤GEB volume reduction<90%), reduction of GEB (50%≤GEB volume reduction<75%) and no change (GEB volume reduction<50%). Results: A total of 47 patients were included, among whom 43 were males, with an age M (Q1, Q3) of 63.0 (55.0, 67.0). The CT results showed complete or nearly complete disappearance of GEB in 43 patients, significant reduction of GEB in 3 patients and reduction of GEB in 1 patient before discharge. The degree of dyspnea improved significantly (P<0.05). Arterial partial pressure of carbon dioxide (PaCO2) decreased from (48.2±8.4)mmHg (1 mmHg=0.133 kPa) to (45.4±7.3)mmHg (P<0.05). The 6-minute walk test (6MWT) increased from (245.6±162.4)m to (283.5±152.2)m (P<0.05). Six-month postoperative follow-up was completed in 24 patients, and CT results showed that the efficacy of volume reduction was continuous compared with that before discharge. GEB was further reduced or even disappeared in 3 of the cases. Besides, the degree of dyspnea, 6MWT (384.4±148.2)m and PaCO2 (42.7±6.6)mmHg were improved significantly (P<0.05). The oxygenation index (356.86±61.21)mmHg was significantly higher than that before surgery (295.20±67.16)mmHg and before discharge (294.50±76.69)mmHg (P<0.05). No perioperative deaths occurred. Conclusions: GEB volume can be completely eliminated or significantly reduced by this innovative technique, while PaCO2, the degree of dyspnea and exercise endurance can be significantly improved after operation. The 6-month follow-up after surgery showed that the above benefits continued, and that the oxygenation index improved significantly.


Asunto(s)
Enfisema Pulmonar , Toracoscopios , Vesícula , Análisis de los Gases de la Sangre , Humanos , Masculino , Estudios Prospectivos , Enfisema Pulmonar/cirugía
4.
Zhonghua Jie He He Hu Xi Za Zhi ; 44(7): 619-623, 2021 Jul 12.
Artículo en Chino | MEDLINE | ID: mdl-34256448

RESUMEN

Objective: To explore the efficacy and safety of position selection in combination with intra-pleural thrombin injection in the treatment of persistent air leakage (PAL) after medical thoracoscopic treatment of bullous pulmonary-pleural diseases (e.g. spontaneous pneumothorax or giant emphysematous bulla). Methods: This was a prospective study conducted in Rizhao Hospital of Traditional Chinese Medicine from August 2018 to November 2020. Twenty patients(19 males,1 female) with a mean age of (62.3±8.1) years met the diagnostic criteria for PAL which was defined as the air leak persisted more than 3 days despite of the closed thoracic drainage after medical thoracoscopic treatment of bullous pulmonary-pleural diseases.They received the following treatment procedures (referred to as "position plus"):①Pleural cavity injection (50% glucose 20 ml+thrombin 5 000 U).②Changing the patient's position under continuous negative pressure suction to find the position causing the complete stop or significant reduction of air leakage, and keeping in the position for 24-48 hours.③If the PAL wasn't stopped 48 hours later, the procedures above would be repeated.The duration of air leakage after "position plus", times of pleural cavity injection, condition of lung re-expansion, recurrence of air leakage and complications during hospitalization were recorded. Descriptive statistics were used to summarize the results:¯x±s or M(P25, P75) for continuous variables; frequency and percentages for categoric variables. Results: A total of 20 patients were included. The average duration of air leakage after"position plus" was (1.32±0.97) days. The times of pleural cavity injection required were 1.0(1.0, 1.0).All the patients showed good lung re-expansion in review of imaging after PAL was stopped. One patient had recurrent air leakage during hospitalization. No serious complications occurred. Conclusion: The comprehensive "position plus" intervention method is effective, safe and easily operating for the treatment of PAL after medical thoracoscopic treatment of bullous pulmonary-pleural diseases.


Asunto(s)
Neumotórax , Trombina , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pleura/diagnóstico por imagen , Pleura/cirugía , Neumonectomía , Neumotórax/diagnóstico por imagen , Neumotórax/tratamiento farmacológico , Neumotórax/cirugía , Complicaciones Posoperatorias/tratamiento farmacológico , Estudios Prospectivos
5.
J Synchrotron Radiat ; 27(Pt 5): 1388-1394, 2020 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-32876617

RESUMEN

The vacuum ultraviolet beamline BL03U with a photon energy range from 7 eV upwards has been constructed at the 3.5 GeV Shanghai Synchrotron Radiation Facility. Equipped with an APPLE-Knot undulator, this beamline is dedicated to angle-resolved photoemission spectroscopy. An energy-resolving power of higher than 4.6 × 104 has been achieved in the photon energy range 21.6-48 eV, which is almost the same as the theoretical estimation.

6.
Eur Rev Med Pharmacol Sci ; 24(14): 7566, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32744671

RESUMEN

Since this article has been suspected of research misconduct and the corresponding authors did not respond to our request to prove originality of data and figures, "Long noncoding RNA PCAT-1 promoted ovarian cancer cell proliferation and invasion by suppressing KLF6, by H.-P. Liu, D. Lv, J.-Y. Wang, Y. Zhang, J.-F. Chang, Z.-T. Liu, N. Tang, published in Eur Rev Med Pharmacol Sci 2019; 23 (11): 4650-4655-DOI: 10.26355/eurrev_201906_18044-PMID: 31210290" has been withdrawn. The Publisher apologizes for any inconvenience this may cause. https://www.europeanreview.org/article/18044.

7.
Eur Rev Med Pharmacol Sci ; 24(15): 7914, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32767307

RESUMEN

Since this article has been suspected of research misconduct and the corresponding authors did not respond to our request to prove originality of data and figures, "MiR-203 regulates proliferation and apoptosis of ovarian cancer cells by targeting SOCS3, by H.-P. Liu, Y. Zhang, Z.-T. Liu, H. Qi, X.-M. Zheng, L.-H. Qi, J.-Y. Wang, published in Eur Rev Med Pharmacol Sci 2019; 23 (21): 9286-9294-DOI: 10.26355/eurrev_201911_19421-PMID: 31773696" has been withdrawn. The Publisher apologizes for any inconvenience this may cause. https://www.europeanreview.org/article/19421.

8.
Phys Rev Lett ; 124(5): 056402, 2020 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-32083898

RESUMEN

Topological nodal-line semimetals with exotic quantum properties are characterized by symmetry-protected line-contact bulk band crossings in the momentum space. However, in most of identified topological nodal-line compounds, these topological nontrivial nodal lines are enclosed by complicated topological trivial states at the Fermi energy (E_{F}), which would perplex their identification and hinder further applications. Utilizing angle-resolved photoemission spectroscopy and first-principles calculations, we provide compelling evidence for the existence of Dirac nodal-line fermions in the monoclinic semimetal SrAs_{3}, which possesses a simple nodal loop in the vicinity of E_{F} without the distraction from complicated trivial Fermi surfaces. Our calculations revealed that two bands with opposite parities were inverted around Y near E_{F}, resulting in the single nodal loop at the Γ-Y-S plane with a negligible spin-orbit coupling effect. The band crossings were tracked experimentally and the complete nodal loop was identified quantitatively, which provide a critical experimental support for the existence of nodal-line fermions in the CaP_{3} family of materials. Hosting simple topological nontrivial bulk electronic states around E_{F} and without complication from the trivial states, SrAs_{3} is expected to be a potential platform for topological quantum state investigation and applications.

9.
Eur Rev Med Pharmacol Sci ; 23(21): 9286-9294, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31773696

RESUMEN

OBJECTIVE: Cytokine signal transduction inhibitor 3 (SOCS3) negatively regulates Janus kinases (JAK) - signal transducer and activator of transcription (STAT) pathway. Bioinformatics analysis revealed a targeted relationship between miR-203 and SOCS3 mRNA. This study investigated the role of miR-203 in ovarian cancer cell proliferation and apoptosis. PATIENTS AND METHODS: Ovarian cancer tissues and adjacent tissues were collected to detect the expression of miR-203 and SOCS3. Ovarian cancer HO8910 cells were divided into miR-NC group, miR-203 inhibitor group, and miR-203 mimic group followed by the analysis of the expression of miR-203 and SOCS3 mRNA by quantitative Reverse Transcription-PCR (qRT-PCR), protein expression of p-JAK2 and p-STAT3 by Western blot, cell apoptosis by flow cytometry, and proliferation by 5-Ethynyl-2'-deoxyuridine (EdU) staining chronologically. RESULTS: Compared with adjacent tissues, miR-203 expression was significantly increased in tumor tissues and SCOS3 mRNA expression was decreased. Compared with those with lower miR-203 expression, the prognosis of patients with higher expression of miR-203 was significantly worse. There was a targeted regulatory relationship between miR-203 and SOCS3 mRNA. Compared with IOSE80 cells, miR-203 expression in HO8910 and SKOV3 cells was increased, and its expressions of SOCS3 mRNA and protein were decreased. Compared with miR-NC group, the transfection of miR-203 inhibitor significantly increased SOCS3 expression, and decreased the expression of p-JAK2 and p-STAT3 protein. We draw the conclusion that miR-203 increased cell apoptosis and decreased cell proliferation. However, opposite results were observed after the transfection of miR-203 mimic. CONCLUSIONS: Abnormal miR-203 and SOCS3 expression are related to the pathogenesis of ovarian cancer. MiR-203 affects the proliferation of JAK-STAT pathway and regulates the proliferation and apoptosis of ovarian cancer cells by targeting the inhibition of SOCS3 expression.


Asunto(s)
Apoptosis/fisiología , Carcinoma Epitelial de Ovario/fisiopatología , Proliferación Celular/fisiología , MicroARNs/fisiología , Neoplasias Ováricas/fisiopatología , Proteína 3 Supresora de la Señalización de Citocinas/fisiología , Carcinoma Epitelial de Ovario/metabolismo , Línea Celular Tumoral , Femenino , Regulación Neoplásica de la Expresión Génica/genética , Humanos , Janus Quinasa 2/biosíntesis , MicroARNs/agonistas , MicroARNs/antagonistas & inhibidores , MicroARNs/biosíntesis , Imitación Molecular/fisiología , Neoplasias Ováricas/metabolismo , Factor de Transcripción STAT3/biosíntesis , Proteína 3 Supresora de la Señalización de Citocinas/biosíntesis , Transfección
10.
Rev Sci Instrum ; 90(6): 063503, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-31255033

RESUMEN

A new correlation electron cyclotron emission (CECE) diagnostic has recently been installed on the HL-2A tokamak in order to study electron temperature fluctuations. Eight radial locations are measured simultaneously through eight pairs of correlated channels. Multiplexers are employed in the intermediate frequency section instead of the conventional separated filter banks to meet strict cross-isolation specifications and lower insertion loss. Relative electron temperature fluctuations are observed by CECE for the first time on the HL-2A by using the spectral decorrelation method. The achieved minimum detectable fluctuation level is up to (T̃e/Te)min∼0.5%. When studying electron temperature fluctuations in the core region with gas puffing, the cross-power spectra show that the amplitude of the electron temperature fluctuation increases in a high temperature and low density plasma. Further analysis demonstrates that the electron temperature gradient ∇Te drives the electron temperature fluctuations together with electron heat transport.

11.
Eur Rev Med Pharmacol Sci ; 23(11): 4650-4655, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-31210290

RESUMEN

OBJECTIVE: Recently, the role of long noncoding RNAs (lncRNAs) in tumor progression has caught attention in numerous researchers. In our investigation, lncRNA PCAT-1 was studied to identify how it functioned in the progression of ovarian cancer. PATIENTS AND METHODS: LncRNA PCAT-1 expression was detected by quantitative Real-time polymerase chain reaction (qRT-PCR) in both ovarian cancer cells and tissue samples. Furthermore, to identify the function of PCAT-1 in ovarian cancer, cell proliferation, transwell assay and Matrigel assay were conducted. In addition, by performing qRT-PCR and Western blot assay, the underlying mechanism was explored. RESULTS: PCAT-1 expression was remarkably higher in ovarian cancer samples when compared with that in corresponding ones. Moreover, cell proliferation, migration and invasion were inhibited after PCAT-1 was knocked down in ovarian cancer cells. Moreover, the mRNA and protein expression of KLF6 (Krüppel-like factor 6) was upregulated after PCAT-1 was knocked down. Furthermore, the KLF6 expression level was negatively related to the PCAT-1 expression level in ovarian cancer samples. CONCLUSIONS: We showed that PCAT-1 promotes the progression of ovarian cancer through enhancing cell metastasis and proliferation via suppressing KLF6, which might be a novel therapeutic strategy in ovarian cancer.

13.
Artículo en Chino | MEDLINE | ID: mdl-30419667

RESUMEN

Objective: To investigate the characteristics, temporal trend of silicosis, and provide basis for risk assessment and precise prevention and control of occupational diseases. Methods: Using descriptive statistics to analyze the reported cases of silicosis by SPSS 20.0 software. Reported silicosis cases, the constituent ratio, the incidence age and the working age at onset were analyzed by a linear trend test. Analyzing the variation trends of regional, industry, economic type and enterprise scale distributions by the chi-square trend test. Moreover, using Moran's I method for spatial autocorrelation analysis and trend-surface analysis. Results: (1) During 2006 to 2015, Guangdong province had reported 1, 428 cases of silicosis, mainly gathered in Foshan, Zhongshan, Guangzhou, Shenzhen, which included 1391 male cases accounting for 97.41%. And the average incidence age was 45 (39, 51) . The average working age of onset was 9 (5.5, 15) . In economic type distribution, the private economy took the main part, accounting for 59.1%. In enterprise scale distribution, it was dominated by small and medium enterprises (SMEs) , accounting for 32.4% and 37.3% respectively. In industry distribution, most cases were gathered in materials and mining industry, accounting for 32.1% and 22.9% respectively. (2) The number of silicosis cases, the incidence age and the working age of onset showed a rising trend (P<0.01) . Meanwhile, the constituent ratios of medium-sized enterprises and building materials industry were increasing (P<0.05) . The annual variation trends of regional, economic type and age distributions were not statistically significant (P> 0.05) . (3) The spatial distribution trend showed an inverted U type, which was firstly raised and then declined from south to north and from east to west. The distribution characteristic demonstrated some high-high cluster areas, including Chancheng, Nanhai, Shunde, Panyu, Dongguan, Pengjiang, and Zhongshan. While Wuhua showed a high-low outlier form (P<0.01) . Conclusion: Silicosis cases, age and working age of onset were on the rise, as well as the industry and enterprise scale distributions of occupational diseases presented a certain trend in Guangdong province from 2006 to 2015. There were high-high cluster and high-low outlier phenomena in spatial distribution with spatial correlation. Therefore, our work of silicosis epidemic trend and distribution may provide some bases for the occupational disease risk assessment and control.


Asunto(s)
Epidemias , Enfermedades Profesionales/epidemiología , Silicosis/epidemiología , Adulto , China/epidemiología , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Ocupaciones/estadística & datos numéricos , Análisis Espacial
14.
Phys Rev Lett ; 121(11): 117002, 2018 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-30265111

RESUMEN

The mechanism of high superconducting transition temperatures (T_{c}) in bismuthates remains under debate despite more than 30 years of extensive research. Our angle-resolved photoemission spectroscopy studies on Ba_{0.51}K_{0.49}BiO_{3} reveal an unexpectedly 34% larger bandwidth than in conventional density functional theory calculations. This can be reproduced by calculations that fully account for long-range Coulomb interactions-the first direct demonstration of bandwidth expansion due to the Fock exchange term, a long-accepted and yet uncorroborated fundamental effect in many body physics.Furthermore, we observe an isotropic superconducting gap with 2Δ_{0}/k_{B}T_{c}=3.51±0.05, and strong electron-phonon interactions with a coupling constant λ∼1.3±0.2. These findings solve a long-standing mystery-Ba_{0.51}K_{0.49}BiO_{3} is an extraordinary Bardeen-Cooper-Schrieffer superconductor, where long-range Coulomb interactions expand the bandwidth, enhance electron-phonon coupling, and generate the high T_{c}. Such effects will also be critical for finding new superconductors.

15.
J Phys Condens Matter ; 29(3): 035401, 2017 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-27845927

RESUMEN

We have studied the phase equilibria of three ceramic quasibinary systems Ti1-x Zr x N, Ti1-x Hf x N and Zr1-x Hf x N (0 ⩽ x ⩽ 1) with density functional theory, cluster expansion and Monte Carlo simulations. We predict consolute temperatures (T C), at which miscibility gaps close, for Ti1-x Zr x N to be 1400 K, for Ti1-x Hf x N to be 700 K, and below 200 K for Zr1-x Hf x N. The asymmetry of the formation energy ΔE f(x) is greater for Ti1-x Hf x N than Ti1-x Zr x N, with less solubility on the smaller cation TiN-side, and similar asymmetries were predicted for the corresponding phase diagrams. We also analyzed different energetic contributions: ΔE f of the random solid solutions were decomposed into a volume change term, [Formula: see text], and a chemical exchange and relaxation term, [Formula: see text]. These two energies partially cancel one another. We conclude that [Formula: see text] influences the magnitude of T C and [Formula: see text] influences the asymmetry of ΔE f(x) and phase boundaries. We also conclude that the absence of experimentally observed phase separation in Ti1-x Zr x N and Ti1-x Hf x N is due to slow kinetics at low temperatures. In addition, elastic constants and mechanical properties of the random solid solutions were studied with the special quasirandom solution approach. Monotonic trends, in the composition dependence, of shear-related mechanical properties, such as Vickers hardness between 18 to 23 GPa, were predicted. Trends for Ti1-x Zr x N and Ti1-x Hf x N exhibit down-bowing (convexity). It shows that mixing nitrides of same group transition metals does not lead to hardness increase from an electronic origin, but through solution hardening mechanism. The mixed thin films show consistency and stability with little phase separation, making them desirable coating choices.

16.
Phys Rev Lett ; 117(4): 045001, 2016 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-27494476

RESUMEN

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.

17.
Sci Rep ; 6: 30309, 2016 07 26.
Artículo en Inglés | MEDLINE | ID: mdl-27457516

RESUMEN

Perovskite SrIrO3 has long been proposed as an exotic semimetal induced by the interplay between the spin-orbit coupling and electron correlations. However, its low-lying electronic structure is still lacking. We synthesize high-quality perovskite SrIrO3 (100) films by means of oxide molecular beam epitaxy, and then systemically investigate their low energy electronic structure using in-situ angle-resolved photoemission spectroscopy. We find that the hole-like bands around R and the electron-like bands around U(T) intersect the Fermi level simultaneously, providing the direct evidence of the semimetallic ground state in this compound. Comparing with the density functional theory, we discover that the bandwidth of states near Fermi level is extremely small, and there exists a pronounced mixing between the Jeff = 1/2 and Jeff = 3/2 states. Moreover, our data reveal that the predicted Dirac degeneracy protected by the mirror-symmetry, which was theoretically suggested to be the key to realize the non-trivial topological properties, is actually lifted in perovskite SrIrO3 thin films. Our findings pose strong constraints on the current theoretical models for the 5d iridates.

18.
Rev Sci Instrum ; 86(7): 076107, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-26233421

RESUMEN

The electron cyclotron emission imaging system on the HL-2A tokamak has been upgraded to 24 (poloidally) × 16 (radially) channels based on the previous 24 × 8 array. The measurement region can be flexibly shifted due to the independence of the two local oscillator sources, and the field of view can be adjusted easily by changing the position of the zoom lenses. The temporal resolution is about 2.5 µs and the achievable spatial resolution is 1 cm. After laboratory calibration, it was installed on HL-2A tokamak in 2014, and the local 2D mode structures of MHD activities were obtained for the first time.

19.
Rev Sci Instrum ; 85(2): 023510, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24593364

RESUMEN

A novel 32-channel electron cyclotron emission radiometer has been designed and tested for the measurement of electron temperature profiles on the HL-2A tokamak. This system is based on the intermediate frequency filter detection technique, and has the features of wide working frequency range and high spatial resolution. Two relative calibration methods have been investigated: sweeping the toroidal magnetic field and hopping the output frequency of the local oscillator. Preliminary results show that both methods can ensure reasonable profiles.

20.
Rev Sci Instrum ; 85(1): 013507, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24517765

RESUMEN

The frequency modulated continuous wave reflectometer was developed for the first time on the HL-2A tokamak. The system utilizes a voltage controlled oscillator and an active multiplier for broadband coverage and detects as heterodyne mode. Three reflectometers have been installed and operated in extraordinary mode polarization on HL-2A to measure density profiles at low field side, covering the Q-band (33-50 GHz), V-band (50-75 GHz), and W-band (75-110 GHz). For density profile reconstruction from the phase shift of the probing wave, a corrected phase unwrapping method is introduced in this article. The effectiveness of the method is demonstrated. The density profile behavior of a fast plasma event is presented and it demonstrates the capability of the reflectometer. These diagnostics will be contributed to the routine density profile measurements and the plasma physics study on HL-2A.

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