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1.
Molecules ; 28(17)2023 Aug 22.
Artículo en Inglés | MEDLINE | ID: mdl-37687005

RESUMEN

Two new compounds named 4,4'-bis(ß-D-glucopyranosyloxy)biphenyl (1) and spirostane-25(27)-en-2α,3ß-diol-3-O-ß-D-xylopyranosyl(1→3)-ß-D-glucopyranosyl(1→4)-ß-D-galactopyranoside (2) were isolated from n-butanol extraction part of 80% ethanol extract of Allii Macrostemonis Bulbus. Alongside these, ten known compounds (3-12) were also identified, including a flavonoid glycoside (3), seven steroids (4-10), a nucleoside (11), and a phenylpropanoid glycoside (12) were found. Notably, compounds 3-6 were isolated from this plant for the first time. The structures of all compounds were confirmed using high-resolution electrospray ionization mass spectrometry (HR-ESI-MS), 1D, and 2D NMR spectroscopy. Some of these compounds showed strong antioxidant activity, and compound 1 demonstrated the most potent reduction of ferric ions (Fe3+) with an IC50 value of 0.59 ± 0.18 mg/mL. Compounds 2 and 3 exhibited the highest scavenging activity against superoxide anion radicals (O2-·) with an IC50 value of 0.02 ± 0.01 mg/mL. Additionally, compound 3 displayed substantial scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) with IC50 values of 0.21 ± 0.17 mg/mL and 0.02 ± 0.01 mg/mL, respectively. The discovery of these two new compounds is a reference for identifying Allii Macrostemonis Bulbus quality markers. Moreover, their exceptional antioxidant activity offers a promising avenue for uncovering novel natural antioxidants.


Asunto(s)
1-Butanol , Antioxidantes , Antioxidantes/farmacología , Nucleósidos
2.
Appl Microbiol Biotechnol ; 99(12): 5295-305, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25605423

RESUMEN

The individual effects of either elevated CO2 or N deposition on soil microbial communities have been widely studied, but limited information is available regarding the responses of the bacteria, fungi, and archaea communities to both elevated CO2 and N in wetland ecosystems with different types of plants. Using a terminal restriction fragment length polymorphism (T-RFLP) analysis and real-time quantitative PCR (RT-Q-PCR), we compared communities of bacteria, fungi, and archaea in a marsh microcosm with one of seven macrophytes, Typha latifolia, Phragmites japonica, Miscanthus sacchariflorus, Scirpus lacustris, Juncus effusus, Phragmites australis, or Zizania latifolia, after exposing them to eCO2 and/or amended N for 110 days. Overall, our results showed that the elevated CO2 and N may affect the bacterial and archaeal communities, while they may not affect the fungal community in terms of both diversity and abundance. The effects of elevated CO2 and N on microbial community vary depending on the plant types, and each microbial community shows different responses to the elevated CO2 and N. In particular, elevated CO2 might force a shift in the archaeal community irrespective of the plant type, and the effect of elevated CO2 was enhanced when combined with the N effect. This study indicates that elevated CO2 and N addition could lead to changes in the community structures of bacteria and archaea. Our results also suggest that the fungal group is less sensitive to external changes, while the bacterial and archaeal groups are more sensitive to them. Finally, the characteristics of the plant type and relevant physicochemical factors induced by the elevated CO2 and N may be important key factors structuring the microbial community's response to environmental change, which implies the need for a more comprehensive approach to understanding the pattern of the wetland response to climate change.


Asunto(s)
Archaea/metabolismo , Bacterias/metabolismo , Dióxido de Carbono/metabolismo , Hongos/metabolismo , Nitrógeno/metabolismo , Plantas/metabolismo , Archaea/clasificación , Archaea/genética , Archaea/aislamiento & purificación , Bacterias/clasificación , Bacterias/genética , Bacterias/aislamiento & purificación , Biodiversidad , Ecosistema , Hongos/clasificación , Hongos/genética , Hongos/aislamiento & purificación , Plantas/clasificación , Microbiología del Suelo , Humedales
3.
Int Immunopharmacol ; 133: 112086, 2024 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-38642441

RESUMEN

Myocardial injury (MI) signifies a pathological aspect of cardiovascular diseases (CVDs) such as coronary artery disease, diabetic cardiomyopathy, and myocarditis. Macrostemonoside T (MST) has been isolated from Allium macrostemon Bunge (AMB), a key traditional Chinese medicine (TCM) used for treating chest stuffiness and pains. Although MST has demonstrated considerable antioxidant activity in vitro, its protective effect against MI remains unexplored. To investigate MST's effects in both in vivo and in vitro models of isoproterenol (ISO)-induced MI and elucidate its underlying molecular mechanisms. This study established an ISO-induced MI model in rats and assessed H9c2 cytotoxicity to examine MST's impact on MI. Various assays, including histopathological staining, TUNEL staining, immunohistochemical staining, DCFH-DA staining, JC-1 staining, ELISA technique, and Western blot (WB), were utilized to explore the potential molecular mechanisms of MI protection. In vivo experiments demonstrated that ISO caused myocardial fiber disorders, elevated cardiac enzyme levels, and apoptosis. However, pretreatment with MST significantly mitigated these detrimental changes. In vitro experiments revealed that MST boosted antioxidant enzyme levels and suppressed malondialdehyde (MDA) production in H9c2 cells. Concurrently, MST inhibited ISO-induced reactive oxygen species (ROS) production and mitigated the decline in mitochondrial membrane potential, thereby reducing the apoptosis rate. Moreover, pretreatment with MST elevated the expression levels of p-PI3K, p-Akt, and p-mTOR, indicating activation of the PI3K/Akt/mTOR signaling pathway and consequent protection against MI. MST attenuated ISO-induced MI in rats by impeding apoptosis through activation of the PI3K/Akt/mTOR signaling pathway. This study presents potential avenues for the development of precursor drugs for CVDs.


Asunto(s)
Allium , Cardiotónicos , Isoproterenol , Infarto del Miocardio , Transducción de Señal , Animales , Masculino , Ratas , Allium/química , Apoptosis/efectos de los fármacos , Cardiotónicos/farmacología , Cardiotónicos/uso terapéutico , Línea Celular , Infarto del Miocardio/inducido químicamente , Infarto del Miocardio/tratamiento farmacológico , Infarto del Miocardio/prevención & control , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/patología , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Ratas Sprague-Dawley , Especies Reactivas de Oxígeno/metabolismo , Saponinas/farmacología , Saponinas/uso terapéutico , Transducción de Señal/efectos de los fármacos , Serina-Treonina Quinasas TOR/metabolismo
4.
Front Neurosci ; 18: 1327293, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38282977

RESUMEN

Propofol is the most widely used intravenous general anesthetic; however, the neuronal circuits that mediate its anesthetic effects are still poorly understood. Glutamatergic neurons in the lateral hypothalamus have been reported to be involved in maintenance of arousal and consciousness. Using Vglut2-Cre transgenic mice, we recorded this group of cells specifically and found that propofol can directly inhibit the glutamatergic neurons, and enhance inhibitory synaptic inputs on these cells, thereby reducing neuronal excitability. Through chemogenetic interventions, we found that inhibition of these neurons increased the duration of propofol-induced anesthesia and reduced movement in the animals after the recovery of right reflex. In contrast, activating this group of cells reduced the duration of propofol anesthesia and increased the animals' locomotor activity after the recovery of right reflex. These results suggest that propofol-induced anesthesia involves the inhibition of glutamatergic neurons in the lateral hypothalamus.

5.
Food Chem X ; 21: 101144, 2024 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-38304049

RESUMEN

Allii Macrostemonis Bulbus (AMB), a traditional Chinese edible and medicinal plant, is considered beneficial to health. In this study, we isolated and purified nine steroidal saponins (compounds 1-9) from AMB. Their structures were characterized using physicochemical properties, HR-ESI-MS, 1D and 2D NMR spectroscopy. Among these compounds, compounds 1-5 were newly discovered named macrostemonoside U-Y, respectively. We assessed the in vitro antioxidant properties of the nine steroidal saponins through free radical scavenging and reducing power assays. This provides options for developing natural antioxidants. Additionally, an HPLC-ELSD quantitative analysis method was developed for the nine saponins in 12 batches of AMB from different origins and processing methods. The results showed that the contents of the nine steroidal saponins in AMB varied greatly among different growing environments and processing methods.

6.
Front Pharmacol ; 15: 1407869, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38983910

RESUMEN

Depression is a prevalent mental disorder that significantly diminishes quality of life and longevity, ranking as one of the primary causes of disability globally. Contemporary research has explored the potential pathogenesis of depression from various angles, encompassing genetics, neurotransmitter systems, neurotrophic factors, the hypothalamic-pituitary-adrenal axis, inflammation, and intestinal flora, among other contributing factors. In addition, conventional chemical medications are plagued by delayed onset of action, persistent adverse effects, and restricted therapeutic efficacy. In light of these limitations, the therapeutic approach of traditional Chinese medicine (TCM) has gained increasing recognition for its superior effectiveness. Numerous pharmacological and clinical studies have substantiated TCM's capacity to mitigate depressive symptoms through diverse mechanisms. This article attempts to summarize the mechanisms involved in the pathogenesis of depression and to describe the characteristics of herbal medicines (including compounded formulas and active ingredients) for the treatment of depression. It further evaluates their effectiveness by correlating with the multifaceted pathogenesis of depression, thereby furnishing a reference for future research endeavors.

7.
World J Surg Oncol ; 11: 144, 2013 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-23782501

RESUMEN

BACKGROUND: The aim of this study was to investigate the differences and influencing factors for postsurgical gastroparesis syndrome incidence after laparoscopic and open radical gastrectomy. METHODS: Clinical data were collected for 563 patients who underwent open radical gastrectomy for gastric cancer and 72 cases receiving laparoscopic radical gastrectomy. We retrospectively analyzed the incidence of postsurgical gastroparesis syndrome, clinical features, course of disease, and risk factors of these two groups. RESULTS: There was no statistical difference for the incident rate of postsurgical gastroparesis syndrome between laparoscopic and open radical gastrectomy (6.9% vs. 3.7%, P > 0.05). Preoperative outflow tract obstruction and Billroth II anastomosis were the two risk factors for postsurgical gastroparesis syndrome in the open radical gastrectomy group and the laparoscopic surgery for gastric cancer group. The same results were obtained from logistic regression statistical analysis. Age greater than 70 years was also one of the risk factors for postsurgical gastroparesis syndrome in the open radical gastrectomy group (P < 0.05). CONCLUSIONS: Laparoscopic radical gastrectomy for gastric cancer does not increase the incident rate of postsurgical gastroparesis syndrome.


Asunto(s)
Gastrectomía/efectos adversos , Gastroenterostomía/efectos adversos , Gastroparesia/etiología , Laparoscopía/efectos adversos , Complicaciones Posoperatorias , Neoplasias Gástricas/complicaciones , Anciano , Femenino , Estudios de Seguimiento , Gastroparesia/epidemiología , Gastroparesia/cirugía , Humanos , Incidencia , Masculino , Estadificación de Neoplasias , Pronóstico , Estudios Retrospectivos , Factores de Riesgo , Neoplasias Gástricas/patología , Neoplasias Gástricas/cirugía
8.
Heliyon ; 9(9): e20285, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37809663

RESUMEN

Background: This study was performed to explore the role of Re in liver IRI progression. Hypoxia and reperfusion (H/R) treated human embryo liver cell line (L-02) was used to establish a liver IRI model. Materials and methods: Cell behaviors were detected using CCK-8, flow cytometry and TUNEL staining assays. The m6A content was detected using m6A dot blot assay. RT-qPCR and western blot assays were used to assessed the relative mRNA and protein levels. MeRIP assay was conducted to determine the m6A levels of P53. The relationship between METTL3 and P53 was demonstrated using RIP and dual-luciferase reporter assays. Results: The results showed that Re treatment significantly decreased the cell apoptosis and promoted the cell viability in the H/R treated L-02 cells. Besides, H/R treatment increased the METTL3 and m6A levels in the L-02 cells, and Re treatment decreased them. Additionally, METTL3 overexpression reversed the role of Re in the H/R treated L-02 cells. Mechanistically, METTL3 overexpression enhanced the m6A levels and mRNA stability and expressions of P53. The combination of METTL3 and P53 was further confirmed. Conclusion: In conclusion, this study demonstrated that Re treatment relieved the H/R induced injury in the L-02 cells through decreasing the METTL3 levels. METTL3 enhanced the mRNA stability and expressions of P53 through m6A modification. Re-METTL3-P53 axis might a new direction for the treatment of liver IRI in the future.

9.
Tohoku J Exp Med ; 227(3): 171-7, 2012 07.
Artículo en Inglés | MEDLINE | ID: mdl-22729250

RESUMEN

Laparoscopic colectomy has been reported as an alternative for treatment of colorectal cancer. However, its long-term efficacy and safety remain obscure. The purpose here was to review our experience with laparoscopic colectomy in 899 patients between June 2001 and December 2008. Of them, 43 patients were converted to open surgery and 846 accepted laparoscopic colorectomy successfully. Among these 846 patients, 790 patients underwent radical resection and 56 patients underwent palliative resection. Only 1 patient died from perioperative pulmonary infection; thus the mortality was 0.12% (1/846). The morbidity of perioperative complications was 18.20% (154/846): intraoperative complication rate was 4.49% (38/846) and the most common intraoperative complication was subcutaneous emphysema and hypercapnia (1.65%, 14/846); postoperative complication rate was 13.71% (116/846) and the most common postoperative complication was ileus (4.37%, 37/846). The overall followed-up rate was 86.41% (731/846, 680 for radical operations and 51 palliative operations). Postoperative deaths happened to 139 patients, including 112 after radical operation and 27 after palliative resection. Of these 112 patients, 97 deaths were cancer-related (14.26%, 97/680) and 15 deaths were non-cancer-related. There were 10 patients encountered local recurrence (1.47%, 10/680) and 105 for metastasis (15.44%, 105/680) after radical operation. Forty-two patients are still alive with tumor. Overall survival rate was 80.98% (592/731), 3-year disease-free survival (DFS) rate after radical operation was 78.0%, and 3-year DFS rate after radical operation for stage I, stage II, and stage III was 89.0%, 85.0%, and 65.0%, respectively. In conclusion, laparoscopic colorectal resection is a feasible and safe technology for colorectal cancer.


Asunto(s)
Neoplasias Colorrectales/epidemiología , Neoplasias Colorrectales/cirugía , Cirugía Colorrectal/estadística & datos numéricos , Laparoscopía/estadística & datos numéricos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Cirugía Colorrectal/efectos adversos , Femenino , Estudios de Seguimiento , Humanos , Complicaciones Intraoperatorias/etiología , Estimación de Kaplan-Meier , Laparoscopía/efectos adversos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Instrumentos Quirúrgicos , Resultado del Tratamiento , Adulto Joven
10.
Evol Appl ; 15(4): 603-617, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35505885

RESUMEN

To meet human needs, domestic pigeons (Columba livia) with various phenotypes have been bred to provide genetic material for our research on artificial selection and local environmental adaptation. Seven pigeon breeds were resequenced and can be divided into commercial varieties (Euro-pigeon, Shiqi, Shen King, Taishen, and Silver King), ornamental varieties (High Fliers), and local varieties (Tarim pigeon). Phylogenetic analysis based on population resequencing showed that one group contained local breeds and ornamental pigeons from China, whereas all commercial varieties were clustered together. It is revealed that the traditional Chinese ornamental pigeon is a branch of Tarim pigeon. Runs of homozygosity (ROH) and linkage disequilibrium (LD) analyses revealed significant differences in the genetic diversity of the three types of pigeons. Genome sweep analysis revealed that the selected genes of commercial breeds were related to body size, reproduction, and plumage color. The genomic imprinting genes left by the ornamental pigeon breeds were mostly related to special human facial features and muscular dystrophy. The Tarim pigeon has evolved genes related to chemical ion transport, photoreceptors, oxidative stress, organ development, and olfaction in order to adapt to local environmental stress. This research provides a molecular basis for pigeon genetic resource evaluation and genetic improvement and suggests that the understanding of adaptive evolution should integrate the effects of various natural environmental characteristics.

11.
World J Surg ; 35(5): 1103-9, 2011 May.
Artículo en Inglés | MEDLINE | ID: mdl-21416173

RESUMEN

BACKGROUND: The goal of the present study was to evaluate the predictive value of serum carbohydrate antigen 19-9 (CA 19-9) in the diagnosis of malignant intraductal papillary mucinous neoplasms of pancreas (IPMNs). METHODS: Eighty-six patients with pathological diagnosis of IPMNs in Zhongshan Hospital between March 1999 and November 2008 were retrospectively reviewed. Data reflecting clinical characteristics, tumor marker level, and prognosis were collected. The potential predictive value of CA 19-9 was analyzed by receiver operating characteristic (ROC) curve. RESULTS: Eighty-six consecutive patients with IPMNs all underwent surgical intervention. A high level of CA 19-9 or carcinoembryonic antigen (CEA) was associated with more advanced stage of malignant IPMNs. Carbohydrate antigen 19-9 was significant for judging malignant IPMNs in the binary logistic regression model (p=0.047). The hazard ratio was 1.014, whose 95.0% confidence interval was 0.91-1.028. Receiver operating characteristic analysis showed that the serum CA 19-9 level had good predictive value for malignant or invasive IPMNs, postoperative survival, and disease-specific recurrence. The area under the curve (AUC) was 0.856, 0.893, 0.815, and 0.857 (p<0.05), respectively. According to the follow-up, mean survival time for groups with CA 19-9>63.60 U/ml was dramatically shorter than that for groups with CA 19-9≤63.60 U/ml (57.38±2.85 versus 29.24±5.82 [months]; p<0.01). CONCLUSIONS: Serum CA 19-9 level has good predictive value for malignant or invasive IPMNs. Patients with CA 19-9 > 63.60 U/ml had poor postoperative prognosis in IPMNs. Preoperative abnormal serum CA 19-9 might be predictive for an aggressive surgical intervention in IPMNs.


Asunto(s)
Adenocarcinoma Mucinoso/sangre , Adenocarcinoma Mucinoso/mortalidad , Antígeno CA-19-9/sangre , Carcinoma Papilar/sangre , Carcinoma Papilar/mortalidad , Neoplasias Pancreáticas/sangre , Neoplasias Pancreáticas/mortalidad , Adulto , Anciano , Área Bajo la Curva , Femenino , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Pronóstico , Curva ROC , Estudios Retrospectivos , Sensibilidad y Especificidad
12.
Rev Sci Instrum ; 92(4): 043502, 2021 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-34243440

RESUMEN

A correlation polarimeter-interferometer system has been developed for the DIII-D tokamak to detect small amplitude magnetic and density fluctuations. Two collinear, frequency-offset (5-15 MHz), orthogonally polarized (right- and left-handed, circularly polarized) electromagnetic waves at 650 GHz probing the plasma are used to detect the Faraday effect. A third, linearly polarized, electromagnetic wave serves as the local-oscillator to provide a measure of the line-averaged density. Correlation polarimetric measurement is accomplished by correlating the Faraday effect measured along the same line of sight using two independent detectors, whereas simultaneous correlation interferometric measurement is realized by correlating the line-averaged density measured at two different intermediate frequencies. The noise floor of the correlation polarimeter-interferometer has been demonstrated to be more than one order of magnitude lower than that of a standard polarimeter-interferometer measurement. Line-averaged correlation polarimetric-interferometric measurements in DIII-D H-mode plasmas show broadband (up to 750 kHz) magnetic and density fluctuations with amplitudes as low as 0.03Gauss/kHz and 4×1013m-3/kHz, respectively.

13.
Rev Sci Instrum ; 92(7): 071101, 2021 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-34340448

RESUMEN

In the past decades, laboratory experiments have contributed significantly to the exploration of the fundamental physics of space plasmas. Since 1908, when Birkeland invented the first terrella device, numerous experimental apparatuses have been designed and constructed for space physics investigations, and beneficial achievements have been gained using these laboratory plasma devices. In the present work, we review the initiation, development, and current status of laboratory plasma devices for space physics investigations. The notable experimental apparatuses are categorized and discussed according to the central scientific research topics they are related to, such as space plasma waves and instabilities, magnetic field generation and reconnection, and modeling of the Earth's and planetary space environments. The characteristics of each device, including the plasma configuration, plasma generation, and control method, are highlighted and described in detail. In addition, their contributions to reveal the underlying physics of space observations are also briefly discussed. For the scope of future research, various challenges are discussed, and suggestions are provided for the construction of new and enhanced devices. The objective of this work is to allow space physicists and planetary scientists to enhance their knowledge of the experimental apparatuses and the corresponding experimental techniques, thereby facilitating the combination of spacecraft observation, numerical simulation, and laboratory experiments and consequently promoting the development of space physics.

14.
Front Genet ; 12: 735795, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34987544

RESUMEN

Pigeon breed resources provide a genetic model for the study of phenomics. The pectoral muscles play a key role for the meat production performance of the meat pigeon and the athletic ability of the High flyers. Euro-pigeons and Silver King pigeons are commercial varieties that exhibit good meat production performance. In contrast to the domestication direction of meat pigeons, the traditional Chinese ornamental pigeon breed, High flyers, has a small and light body. Here, we investigate the molecular mechanism of the pectoral muscle development and function of pigeons using whole-genome and RNA sequencing data. The selective sweep analysis (F ST and log2 (θπ ratio)) revealed 293 and 403 positive selection genes in Euro-pigeons and Silver King, respectively, of which 65 genes were shared. With the Silver King and Euro-pigeon as the control group, the High flyers were selected for 427 and 566 genes respectively. There were 673 differentially expressed genes in the breast muscle transcriptome between the commercial meat pigeons and ornamental pigeons. Pigeon genome selection signal combined with the breast muscle transcriptome revealed that six genes (SLC16A10, S100B, SYNE1, HECW2, CASQ2 and LOC110363470) from commercial varieties of pigeons and five genes (INSC, CALCB, ZBTB21, B2M and LOC110356506) from Chinese traditional ornamental pigeons were positively selected which were involved in pathways related to muscle development and function. This study provides new insights into the selection of different directions and the genetic mechanism related to muscle development in pigeons.

15.
Rev Sci Instrum ; 92(5): 053514, 2021 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-34243270

RESUMEN

A five-chord interferometer based on terahertz solid state sources has been successfully installed on the Keda Torus eXperiment (KTX), a reversed field pinch machine. The optical design has been carefully optimized for the uniform distribution of beam light to fully use the limited power source (∼2 mW). By setting the telescopic mirror unit, the beam waist is located in the center of the vacuum vessel and its diameter is in the range of the Rayleigh length. The beam width across the plasma area is improved to ∼20 mm to minimize crosstalk and beam energy loss. After careful beam alignment, the phase noise for each channel can reach 0.004π. The radial profiles of electron density on the KTX are inverted, and density fluctuation associated with instabilities is shown based on the forward-scattering signals.

16.
Rev Sci Instrum ; 92(9): 093506, 2021 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-34598546

RESUMEN

A two-color homodyne Mach-Zehnder (M-Z) optical fiber interferometer with wavelengths of 1.55 and 1.31 µm was developed for long-time measurement of line-integrated plasma electron density. A novel phase difference demodulation algorithm based on a single 3 × 3 optical coupler was implemented in a two-color optical fiber interferometer scheme for the first time. Our laboratory tests showed that this new optical fiber interferometer could determine the phase shift due to the low-frequency ambient vibration and could maintain high phase resolution measurement. The resolution of the new interferometer was less than 0.04 rad in 1000 s, corresponding to a line-averaged electron density of less than 1.0 × 1019 m-2. Actual plasma discharge experiments performed on KTX-CTI, which is a new compact torus injector (CTI) constructed at the Keda Torus eXperiment (KTX), showed that this interferometer has excellent several-second stability.

17.
Rev Sci Instrum ; 91(6): 063501, 2020 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-32611014

RESUMEN

An optical fiber Mach-Zehnder interferometer at a wavelength of 1.55 µm has been developed for measurements of high electron density on compact torus (CT) plasmas with a high time resolution of 0.1 µs and high phase resolution of 6.4 × 10-4 rad. To improve density measurement accuracy, the phase noise of the interferometer has been investigated in detail and optimized. In the bench test, the interferometer was calibrated using a piezoelectric ceramic actuator with known stroke. Initial results on CT plasma show that the optical fiber interferometer provides reliable density measurements at two spatial locations and the bulk velocity of plasma can be determined by the method of time of flight.

18.
Rev Sci Instrum ; 90(12): 126102, 2019 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-31893807

RESUMEN

An automatic beam alignment system based on relative reference points is developed for the Thomson scattering system on Keda Torus eXperiment. Two critical apertures around the vacuum vessel are designed to shield stray light, and a probe beam is required to go through the centers of these two apertures, which are the reference points for alignment. Since these two apertures are coated with light absorbing materials, three fibers with glowing tips are employed to indicate the centers of two apertures. CMOS cameras are used to monitor beam deviations. The misalignment correction is achieved by driving piezomotor mirror mounts via a program developed with LabVIEW, which includes the image acquisition and processing module and the deviation correction module. As a result, this system can correct beam misalignment in less than 20 s and suppress the long-term drift of laser pointing in ±10 µrad. Also, this system has the capability to correct up to about 2.3 mm of camera shift with our experiment condition.

19.
Rev Sci Instrum ; 90(12): 123513, 2019 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-31893776

RESUMEN

We have developed a parametric method for eliminating the background component of the plasma current, which is measured by a Rogowski coil and polluted by the toroidal magnetic field in the vacuum vessel of the Keda Torus eXperiment (KTX) reversed field pinch (RFP) device. The method considers the toroidal magnetic field windings, the KTX vacuum chamber, and the Rogowski coil as a linear time-invariant system; in this case, a constant frequency response function characterizes the system. Using this response function, the current component caused by pollution from the toroidal magnetic field can be predicted exactly for an arbitrary input current to the toroidal magnetic field windings. Compared with the traditional proportional compensation method, the proposed method has great flexibility and universality and it is potentially applicable to cases in which the toroidal field current signal changes over time with plasma feedback signals. Furthermore, the method can be applied to other similarly affected signals, such as magnetic field signals. As an example, we have corrected the poloidal and toroidal magnetic field signals better to reveal the true physical processes for the RFP state.

20.
Rev Sci Instrum ; 89(10): 10C119, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-30399798

RESUMEN

Laser-induced fluorescence (LIF) using a pulsed laser is successfully applied in an argon plasma. The laser system consists of a pumping pulse laser fixed at 532 nm and a tunable dye laser. Using a homemade Fabry-Perot interferometer, the large linewidth of the original output is reduced by one order from 4 GHz to 340 MHz. The measured ion temperature is 0.15 eV with a velocity resolution about 200 m/s. It provides great possibility for the combination of LIF and planar LIF using the same pulsed laser system.

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