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1.
Nat Prod Res ; : 1-8, 2024 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-38629167

RESUMEN

Tripterygium wilfordii has been historically employed as a conventional botanical insecticide and a plant of medicinal significance. A new dihydroagarofuran sesquiterpene (1) and a new acyclic compound (2), along with seven known compounds (3-9), have been isolated from the aerial parts of Tripterygium wilfordii. The identification of the structures of novel compounds were accomplished through comprehensive spectroscopic analyses, encompassing HRESIMS, NMR, UV, IR, and a comparative analysis with spectroscopic data from compounds previously characterised. In in-vitro bioassay, compound 8 exhibited significant inhibitory activity for NO release in LPS-induced RAW 264.7 cells, with an IC50 value of 15.7 µM.

2.
J Asian Nat Prod Res ; 26(1): 91-101, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38192081

RESUMEN

A new phenolic compound oleiphenol (1), and a new dihydrochalcone oleifechalcone (2) along with seven known compounds (3-9) were isolated from the fruit shell of Camellia oleifera Abel. The planar structures of compounds 1 and 2 were determined on the basis of extensive spectroscopic analyses (IR, UV, NMR, and HR-ESI-MS) and comparison with literature data. The absolute configurations of the new structures were determined by ECD calculations and chemical methods. In addition, compounds 1-9 underwent a series of pharmacological activity tests, including cytotoxic, anti-inflammatory, anti-RSV and antioxidant activities.


Asunto(s)
Camellia , Frutas , Flavonoides/farmacología , Camellia/química , Antioxidantes/farmacología , Antioxidantes/química , Espectroscopía de Resonancia Magnética
3.
mBio ; 14(5): e0211023, 2023 Oct 31.
Artículo en Inglés | MEDLINE | ID: mdl-37796013

RESUMEN

IMPORTANCE: Respiratory syncytial virus (RSV) is the leading etiological agent of lower respiratory tract illness. However, efficacious vaccines or antiviral drugs for treating RSV infections are currently not available. Indeed, RSV depends on host cells to provide energy needed to produce progeny virions. Glycolysis is a series of oxidative reactions used to metabolize glucose and provide energy to host cells. Therefore, glycolysis may be helpful for RSV infection. In this study, we show that RSV increases glycolysis by inducing the stabilization, transcription, translation, and activation of hypoxia-inducible factor (HIF)-1α in infected cells, which is important for the production of progeny RSV virions. This study contributes to understanding the molecular mechanism by which HIF-1α-mediated glycolysis controls RSV infection and reveals an effective target for the development of highly efficient anti-RSV drugs.


Asunto(s)
Enfermedades Transmisibles , Infecciones por Virus Sincitial Respiratorio , Virus Sincitial Respiratorio Humano , Humanos , Subunidad alfa del Factor 1 Inducible por Hipoxia/genética , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Virus Sincitial Respiratorio Humano/genética , Glucólisis
4.
Taiwan J Ophthalmol ; 13(1): 34-42, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37252170

RESUMEN

PURPOSE: To develop a new dry eye syndrome (DES) animal model by injecting mitomycin C (MMC) into the lacrimal glands (LGs) of rabbits evaluated by clinical examinations. MATERIALS AND METHODS: A volume of 0.1 mL of MMC solution was injected in the LG and the infraorbital lobe of the accessory LG of rabbits for DES induction. Twenty male rabbits were separated into three groups, the control group, and different concentration of MMC, (MMC 0.25: 0.25 mg/mL or MMC 0.50: 0.5 mg/mL) were tested. Both MMC-treated groups received MMC twice injection on day 0 and day 7. Assessment of DES included changes in tear production (Schirmer's test), fluorescein staining pattern, conjunctival impression cytology, and corneal histological examination. RESULTS: After MMC injection, no obvious changes in the rabbit's eyes were noted by slit-lamp examination. Both the MMC 0.25 and the MMC 0.5 groups revealed decreased tear secretion after injection, and the MMC 0.25 group showed a continuous decrease in tear secretion up to 14 days. Fluorescent staining showed punctate keratopathy in both MMC-treated groups. In addition, both MMC-treated groups demonstrated decreased numbers of conjunctival goblet cells after injection. CONCLUSION: This model induced decreased tear production, punctate keratopathy, and decreased numbers of goblet cells, which are consistent with the current understanding of DES. Therefore, injecting MMC (0.25 mg/mL) into the LGs is an easy and reliable method to establish a rabbit DES model which can apply in new drug screening.

5.
Int J Nanomedicine ; 18: 1413-1431, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36992821

RESUMEN

Background: Corneal neovascularization (NV) is a process of abnormal vessel growth into the transparent cornea from the limbus and can disturb the light passing through the cornea, resulting in vision loss or even blindness. The use of nanomedicine as an effective therapeutic formulation in ophthalmology has led to higher drug bioavailability and a slow drug release rate. In this research, we designed and explored the feasibility of a new nanomedicine, gp91 ds-tat (gp91) peptide-encapsulated gelatin nanoparticles (GNP-gp91), for inhibiting corneal angiogenesis. Methods: GNP-gp91 were prepared by a two-step desolvation method. The characterization and cytocompatibility of GNP-gp91 were analyzed. The inhibition effect of GNP-gp91 on HUVEC cell migration and tube formation was observed by an inverted microscope. The drug retention test in mouse cornea was observed by in vivo imaging system, fluorescence microscope, and DAPI/TAMRA staining. Finally, the therapeutic efficacy and evaluation of neovascularization-related factors were conducted through the in vivo corneal NV mice model via topical delivery. Results: The prepared GNP-gp91 had a nano-scale diameter (550.6 nm) with positive charge (21.7 mV) slow-release behavior (25%, 240hr). In vitro test revealed that GNP-gp91 enhanced the inhibition of cell migration and tube formation capacity via higher internalization of HUVEC. Topical administration (eyedrops) of the GNP-gp91 significantly prolongs the retention time (46%, 20 min) in the mouse cornea. In chemically burned corneal neovascularization models, corneal vessel area with a significant reduction in GNP-gp91 group (7.89%) was revealed when compared with PBS (33.99%) and gp91 (19.67%) treated groups via every two days dosing. Moreover, GNP-gp91 significantly reduced the concentration of Nox2, VEGF and MMP9 in NV's cornea. Conclusion: The nanomedicine, GNP-gp91, was successfully synthesized for ophthalmological application. These data suggest that GNP-gp91 contained eyedrops that not only have a longer retention time on the cornea but also can treat mice corneal NV effectively delivered in a low dosing frequency, GNP-gp91 eyedrops provides an alternative strategy for clinical ocular disease treatment in the culture.


Asunto(s)
Neovascularización de la Córnea , Nanopartículas , Ratones , Animales , Neovascularización de la Córnea/tratamiento farmacológico , Gelatina/farmacología , Soluciones Oftálmicas/farmacología , Córnea , Péptidos/farmacología , Nanopartículas/química
6.
Food Funct ; 13(1): 437-450, 2022 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-34918725

RESUMEN

Amomum tsao-ko Crevost et Lemarie (A. tsao-ko) is a well-known dietary spice and traditional Chinese medicine. This study aimed to identify the flavonoids in A. tsao-ko and evaluate their antioxidant and antidiabetic activities in in vitro and in vivo studies. A. tsao-ko methanol extracts possessed a high flavonoid content (1.21 mg QE per g DW) and a total of 29 flavonoids were identified by employing UPLC-MS/MS. In vitro, A. tsao-ko demonstrated antioxidant activity (ORAC value of 34276.57 µM TE/100 g DW, IC50 of ABTS of 3.49 mg mL-1 and FRAP value of 207.42 µM Fe2+ per g DW) and α-amylase and α-glucosidase inhibitory ability with IC50 values of 14.23 and 1.76 mg mL-1, respectively. In vivo, type 2 diabetes mellitus (T2DM) models were induced by a combined high-fat diet (HFD) and streptozotocin (STZ) injection in rats. Treatment with the A. tsao-ko extract (100 mg freeze-dried powder per kg bw) for 6 weeks could significantly improve impaired glucose tolerance, decrease the levels of fasting blood glucose (FBG), insulin, and malondialdehyde (MDA), and increase the superoxide dismutase (SOD) level. Histopathology revealed that the A. tsao-ko extract preserved the architecture and function of the pancreas. In conclusion, the flavonoid composition of A. tsao-ko exhibits excellent antioxidant and antidiabetic activity in vitro and in vivo. A. tsao-ko could be a novel natural material and developed as a related functional food and medicine in T2DM management.


Asunto(s)
Amomum/química , Antioxidantes , Diabetes Mellitus Experimental , Flavonoides , Hipoglucemiantes , Animales , Antioxidantes/análisis , Antioxidantes/química , Antioxidantes/farmacología , Glucemia/efectos de los fármacos , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patología , Medicamentos Herbarios Chinos , Flavonoides/análisis , Flavonoides/química , Flavonoides/farmacología , Hipoglucemiantes/análisis , Hipoglucemiantes/química , Hipoglucemiantes/farmacología , Masculino , Páncreas/efectos de los fármacos , Páncreas/patología , Ratas , Ratas Sprague-Dawley , Organismos Libres de Patógenos Específicos
7.
Pharmaceutics ; 13(11)2021 Oct 27.
Artículo en Inglés | MEDLINE | ID: mdl-34834216

RESUMEN

Dry eye syndrome (DES) is a common ophthalmological disease that decreases tear secretion and causes dryness, photophobia, pain, severe corneal rupture, and even blindness. Ocular and lacrimal gland inflammation is one of the pathological mechanisms underlying DES. Therefore, effective suppression of inflammation is a crucial strategy for the treatment of DES. Lutein, commonly found in healthy foods, has anti-inflammatory effects in corneal or retina-related cells and may be a potential therapy for DES. The addition of lutein to artificial tears (AT) as an eye-drop formulation for DES treatment in a mouse model was studied in the present work. Polyvinyl alcohol (PVA) was used as a thickener to increase the viscosity of eye drops to prolong drug retention on the ocular surface. A WST-8 assay in human corneal epithelial cells (HCE-2) showed that a concentration of <5 µM lutein (L5) and <1% PVA (P1) maintained the cell viability at 80%. A real-time PCR showed that the inflamed human corneal epithelial cells (HCECs) cocultured with L5P1 had downregulated expression of inflammatory genes such as IL-1ß, IL-6, and TNF-α. In a benzalkonium chloride- (BAC) induced DES mouse model, AT/L5P1 could repair damaged corneas, elevate tear secretion, increase the number of goblet cells, and inhibit the production of inflammatory cytokines, such as IL-1ß, IL-6, and TNF-α, in the cornea. In conclusion, we demonstrate that lutein/PVA as eye drops could prolong the drug ocular retention time and effectively to decrease inflammation in DES mice. Therefore, lutein, obtained from eye drops, has a potential therapeutic role for DES.

9.
Eur J Nutr ; 60(5): 2855-2875, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-33555375

RESUMEN

PURPOSE: Probiotics have been reported to be beneficial for inflammatory bowel disease (IBD), but the types, number of strains, dosage, and intervention time of probiotics used remain controversial. Furthermore, the changes of gut microbiota in IBD's patients are also intriguing. Thus, this meta-analysis was to explore the clinical effects and gut microbiota changes of using probiotics, prebiotics and synbiotics in IBD. METHODS: The search was performed in PubMed, Web of Science and the Cochrane library from inception to April 2020. Qualified randomized controlled trials were included. IBD's remission rate, disease activity index and recurrence rate were extracted and analyzed. Changes in the gut microbiota of patients with IBD are comprehensively described. RESULTS: Thirty-eight articles were included. Probiotics, prebiotics and synbiotics can induce/maintain IBD's remission and reduce ulcerative colitis (UC) disease activity index (RR = 1.13, 95% CI 1.02, 1.26, P < 0.05; SMD = 1.00, 95% CI 0.27, 1.73, P < 0.05). In subgroup analyses of IBD remission rate and UC disease activity index, we obtained some statistically significant results in some subgroup (P < 0.05). To some extent, probiotic supplements can increase the number of beneficial bacteria (especially Bifidobacteria) in the intestinal tract of patients with IBD. CONCLUSIONS: Our results support the treatment of IBD (especially UC) with pro/pre/synbiotics, and synbiotics are more effective. Probiotic supplements that are based on Lactobacillus and Bifidobacterium or more than one strain are more likely to be beneficial for IBD remission. The dose of 1010-1012 CFU/day may be a reference range for using probiotics to relieve IBD.


Asunto(s)
Microbioma Gastrointestinal , Enfermedades Inflamatorias del Intestino , Probióticos , Simbióticos , Humanos , Enfermedades Inflamatorias del Intestino/terapia , Prebióticos
10.
J Biomater Appl ; 35(7): 823-837, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-32842853

RESUMEN

Minimally invasive implantation of a porous scaffold of large volume into bone defect site remains a challenge. Scaffolds based on shape memory polymer (SMP) show potential to be delivered in the compact form via minimally invasive surgery. The present study chooses poly (ε-caprolactone)-diols (PCL-diols) as the SMP to cross-link carboxyl dextran via ester bonds together with particle leaching method to yield a porous SMP scaffold. The inner surfaces of porous SMP scaffold are then mineralized via in situ precipitation to yield mineralized porous SMP-hydroxyapatite (SMP-HA) scaffold. The porous SMP-HA scaffold possesses pore size of 400-500 µm, with HA particles uniformly distributed and orientationally aligned on the inner surfaces of scaffold. X-ray diffraction (XRD) and differential scanning calorimetry (DSC) are carried out to identify the HA deposition. The phase transition temperature of the scaffold is adjusted to 38°C via changing the dosage of PCL (molecule weight: 2800) to endow the scaffold with shape deformation and fixed properties, as well as well-performed shape recovery property under body temperature. Bone marrow mesenchymal stem cells (BMSCs) adhere on the inner surfaces of SMP-HA scaffold, exhibiting larger spreading area when compared to cells adhered on SMP scaffold without HA, promoting its osteogenesis. In vivo degradation showed that the scaffold degrades completely after 6 months post-implantation. At the same time, significant tissue and capillary invasion indicated that the present porous SMP-HA scaffold hold great promise towards bone tissue engineering applications.


Asunto(s)
Huesos/metabolismo , Dextranos/química , Durapatita/química , Ingeniería de Tejidos/instrumentación , Ingeniería de Tejidos/métodos , Andamios del Tejido , Animales , Diferenciación Celular , Proliferación Celular , Hidrogeles/química , Masculino , Ensayo de Materiales , Osteogénesis , Porosidad , Ratas , Ratas Sprague-Dawley , Difracción de Rayos X
11.
Transl Vis Sci Technol ; 9(13): 1, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-33344045

RESUMEN

Purpose: Analysis of ferning formation after tear drop desiccation on a glass slide has been applied as a simple method to examine tear normality and is referred to as the tear ferning (TF) test. Despite use of the TF test in clinical settings and in some animals, thus far no TF test protocol has been developed for the mouse model. This study aimed to establish a mouse TF test protocol that can be used for dry eye research using the mouse as the study model. Methods: Tear samples were collected from 24 healthy mice after repeated flushes with 2, 5, 10, or 20 µL wash solutions, either 0.9% NaCl saline or sterile water, on the ocular surface. After sample collection, TF tests were performed at variable drop volumes (2-20 µL), at a relative humidity of either 46% ± 2% or 53% ± 2%, and with temperature fixed at 24°C ± 2°C for comparison. Moreover, the influence of osmolarity (between 280 and 360 mOsm/L) and pH values (6.5-8.0) and the effect of centrifugation (4000 rpm, 10 minutes) on ferning formation were examined. Reproducibility and ferning storage stability were also determined. Results: An optimized protocol was established with relative humidity at 46% ± 2% and drop aliquot at 2 µL, using 0.9% NaCl saline as the wash solution. Using sterilized water as the wash solution did not result in any crystalloid formation. Centrifugation did not aid ferning formation in any of the samples. Higher osmolarity increased ferning formation from grades between 0 to 1 to grades between 2 to 3, but pH values that varied between 6.5 and 8.0 did not affect ferning formation. The established mouse TF test protocol also displayed reproducibility and storage stability. Conclusions: A TF test protocol for the mouse model was established that could be used for comparative analyses under various ocular surface disease conditions. Translational Relevance: This mouse TF test protocol will facilitate the application of basic research into the mouse model to clinical care.


Asunto(s)
Síndromes de Ojo Seco , Lágrimas , Animales , Síndromes de Ojo Seco/diagnóstico , Ojo , Ratones , Concentración Osmolar , Reproducibilidad de los Resultados
12.
Nutr J ; 19(1): 52, 2020 06 03.
Artículo en Inglés | MEDLINE | ID: mdl-32493399

RESUMEN

BACKGROUND: Several epidemiological studies have investigated the association between whole grains intake and digestive tract cancer risk; however, the results are still controversial. The purpose of this meta-analysis was to assess the association. METHODS: Studies published before March 2020 were searched in database and other sources. The risk ratio (RR) with the 95% confidence interval (CI) were pooled using fix or random-effects models. RESULTS: This meta-analysis included 34 articles reporting 35 studies, 18 studies of colorectal cancer, 11 studies of gastric cancer and 6 studies of esophagus cancer, involving 2,663,278 participants and 28,921 cases. Comparing the highest-intake participants with the lowest-intake participants for whole grains, we found that the intake of whole grains were inversely related to colorectal cancer (RR = 0.89, 95% CI: 0.84-0.93, P < 0.001), gastric cancer (RR = 0.64, 95% CI: 0.53-0.79, P < 0.001), esophagus cancer (RR = 0.54, 95% CI: 0.44-0.67, P < 0.001), respectively. However, subgroup analysis of colorectal cancer found no significant association in the case-control studies and studies of sample size < 500, and subgroup analysis of gastric cancer found no significant association in the cohort studies and studies of American population. No study significantly affected the findings in the sensitivity analysis. No publication bias was found in the studies for colorectal cancer and esophagus cancer except in the studies for gastric cancer. CONCLUSION: This meta-analysis provides further evidence that whole grains intake was associated with a reduced risk of digestive tract cancer. Our result supports the dietary guidelines that increase whole grains intake to reduce the risk of digestive tract cancer.


Asunto(s)
Neoplasias Gastrointestinales , Granos Enteros , Neoplasias Gastrointestinales/epidemiología , Neoplasias Gastrointestinales/prevención & control , Humanos , Oportunidad Relativa , Factores de Riesgo
13.
Invest Ophthalmol Vis Sci ; 60(6): 2118-2126, 2019 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-31099828

RESUMEN

Purpose: Several pieces of epidemiologic evidence have indicated PM2.5 (particulate matter with a diameter of 2.5 µm or less) as a causing factor of allergic conjunctivitis, but without experimental elucidation of mechanism. In the present study, PM2.5 in solution was directly applied to the mouse ocular surface to elucidate whether PM2.5 might cause allergic conjunctivitis, and its underlying mechanisms were analyzed. Methods: ICR mice were challenged for 18 consecutive days with eye drops containing PM2.5 at 3.2, 6.4, and 12.8 mg/mL in 0.9% NaCl saline, along with the controls prepared in parallel without PM2.5 and another control group treated with both PM2.5 at 12.8 mg/mL and artificial tears. On day 19, the whole eyes and meibomian glands were harvested for histopathological analyses and assessment of clinical scoring, tear volume, tear breakup time, and tear ferning. Furthermore, goblet cells by periodic acid Schiff stain and infiltrated eosinophils by Giemsa stain were quantified and compared among study groups. Results: Clinical scoring showed more eyelid edema, tearing, and scratching behaviors, with longer tear breakup time under the influence of increased PM2.5 concentrations. Tear ferning assay showed less tear crystal formation and decreased crystal branches after exposure to PM2.5. In addition, higher goblet cell density in the upper palpebral conjunctiva and extensive eosinophil infiltration in the entire conjunctiva and in the meibomian glands were induced by PM2.5. Conclusions: These results demonstrate that PM2.5 can induce symptoms similar to clinical allergic conjunctivitis and that the murine acute allergic conjunctivitis model can be induced by direct exposure to PM2.5.


Asunto(s)
Conjuntivitis Alérgica/etiología , Material Particulado/efectos adversos , Animales , Modelos Animales de Enfermedad , Edema/patología , Exposición a Riesgos Ambientales/efectos adversos , Párpados/patología , Masculino , Ratones , Ratones Endogámicos ICR , Tamaño de la Partícula , Lágrimas/metabolismo
14.
Cancer Biomark ; 18(3): 231-239, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28085008

RESUMEN

Chondrosarcomas are malignant cartilage-forming tumors from low-grade to high-grade aggressive tumors characterized by metastasis. Cisplatin is an effective DNA-damaging anti-tumor agent for the treatment against a wide variety of solid tumors. However, chondrosarcomas are notorious for their resistance to conventional chemo- and radio- therapies. In this study, we report miR-23b acts as a tumor suppressor in chondrosarcoma. The expressions of miR-23b are down-regulated in chondrosarcoma patient samples and cell lines compared with adjacent normal tissues and human primary chondrocytes. In addition, overexpression of miR-23b suppresses chondrosarcoma cell proliferation. By comparison of the cisplatin resistant chondrosarcoma cells and parental cells, we observed miR-23b was significantly down regulated in cisplatin resistant cells. Moreover, we demonstrate here Src kinase is a direct target of miR-23b in chondrosarcoma cells. Overexpression of miR-23b suppresses Src-Akt pathway, leading to the sensitization of cisplatin resistant chondrosarcoma cells to cisplatin. This chemo-sensitivity effect by the miR-23b-mediated inhibition of Src-Akt pathway is verified with the restoration of Src kinase in miR-23b-overespressing chondrosarcoma cells, resulting in the acquirement of resistance to cisplatin. In summary, our study reveals a novel role of miR-23b in cisplatin resistance in chondrosarcoma and will contribute to the development of the microRNA-targeted anti-cancer therapeutics.


Asunto(s)
Neoplasias Óseas/genética , Condrosarcoma/genética , Cisplatino/farmacología , Resistencia a Antineoplásicos/genética , Genes src , MicroARNs/genética , Interferencia de ARN , Regiones no Traducidas 3' , Sitios de Unión , Neoplasias Óseas/metabolismo , Línea Celular Tumoral , Condrosarcoma/metabolismo , Regulación Neoplásica de la Expresión Génica , Genes Supresores de Tumor , Humanos , Proteínas Proto-Oncogénicas c-akt/metabolismo , Transducción de Señal/efectos de los fármacos
15.
J Hazard Mater ; 175(1-3): 816-22, 2010 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-19926221

RESUMEN

The removal of Cr (VI) from aqueous solutions using black carbon (BC) isolated from the burning residues of wheat straw was investigated as a function of pH, contact time, reaction temperature, supporting electrolyte concentration and analytical initial Cr (VI) concentration in batch studies. The effect of surface properties on the adsorption behavior of Cr (VI) was investigated with scanning electron microscope (SEM) equipped with the energy dispersive X-ray spectroscope (EDS) and Fourier transform-infrared (FTIR) spectroscopy. The removal mechanism of Cr (VI) onto the BC was investigated and the result showed that the adsorption reaction consumed a large amount of protons along the reduction of Cr (VI) to Cr (III). The oxidation of the BC took place concurrently to the chromium reduction and led to the formation of hydroxyl and carboxyl functions. An initial solution pH of 1.0 was most favorable for Cr (VI) removal. The adsorption process followed the pseudo-second order equation and Freundlich isotherm very well. The Cr (VI) adsorption was temperature-dependent and almost independent on the sodium chloride concentrations. The maximum adsorption capacity for Cr (VI) was found at 21.34 mg/g in an acidic medium, which is comparable to other low-cost adsorbents.


Asunto(s)
Carbono/química , Cromo/química , Triticum/metabolismo , Purificación del Agua/métodos , Adsorción , Electrólitos , Concentración de Iones de Hidrógeno , Cinética , Microscopía Electrónica de Rastreo/métodos , Cloruro de Sodio/química , Espectrometría por Rayos X/métodos , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Temperatura , Factores de Tiempo , Contaminantes Químicos del Agua/aislamiento & purificación
16.
Guang Pu Xue Yu Guang Pu Fen Xi ; 28(11): 2708-12, 2008 Nov.
Artículo en Chino | MEDLINE | ID: mdl-19271524

RESUMEN

Along with the development of micro-electromechanical system technology, the reports on the optical splitting systems and the photoelectric detection systems of spectrometer based on micro-electromechanical system have become increasingly popular, whereas the reports on micro excitation source in the development of micro spectrometer are few. In other words, the development of micro excitation source is the most important part in the development of the micro spectrometer. A novel low-pressure microfabricated inductively coupled plasma source is introduced, which is an emission spectrum excitation source based on surface-micromaching technology. Its radio frequency power consumption is much lower than the general inductively coupled plasma source. The source can work at an argon gas pressure of 100 Pa, and thus consumes less argon. The principle of operation for a microfabricated inductively coupled plasma source is illustrated. The layout of the planar spiral-shaped coil, the matched capacitor and the resonant capacitor is given. The fabrication process and properties of the plasma source are described. Meanwhile a novel inductively coupled plasma based on the technology of printed circuit board is introduced. In the experiment, the planar spiral-shaped coil and interdigatial capacitor were used. When the pressure of argon was 100 Pa and the radio frequency power was 3. 5 W at 13. 56 MHz the novel inductively coupled plasma was ignited. The photo of the argon ignition is given. Finally the potential application of the micro inductively coupled plasma in spectrometers is presented.

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