Tunable emission, energy transfer and charge compensation in SrMoO4:Sm(3+),Tb(3+),Na(+) phosphor.

A series of SrMoO4:Sm(3+),Tb(3+),Na(+) phosphors was synthesized using a high-temperature solid-state reaction method in air. On excitation at 290 nm, SrMoO4:Sm(3+),Tb(3+) phosphor emitted light that varied systematically from green to reddish-orange on changing the Sm(3+) and Tb(3+) ion concentrations. The emission intensities of SrMoO4:Sm(3+) and SrMoO4:Sm(3+),Tb(3+) phosphors were increased two to four times due to charge compensation when Na(+) was added as a charge compensator. The luminescence mechanism and energy transfer could be explained using energy-level diagrams of the MoO4(2-) group, Sm(3+) and Tb(3+) ions. SrMoO4:Sm(3+),Tb(3+),Na(+) could be used as reddish-orange phosphor in white light-emitting diodes (LEDs) based on an ~ 405 nm near-UV LED chip. This research is helpful in adjusting and improving the luminescence properties of other phosphors.

Tunable emission, energy transfer and charge compensation in Sr3(VO4)2:Sm(3+),P(5+),Na(+) phosphor.

A series of Sr3(VO4)2:Sm(3+),P(5+),Na(+) phosphors are synthesized by using solid-state reaction method in air. The strongest emission band peaking at ∼600 nm is assigned to the (4)G5/2→(6)H7/2 transition of Sm(3+) ion, and the strong excitation peak at ∼402 nm due to (6)H5/2→(4)F7/2 transition indicates that these phosphors can be excited by near ultraviolet light emitting diode chip. Energy transfer (ET) between VO4(3-) group and Sm(3+) ion can be observed. Sr3(VO4)2:Sm(3+) phosphor with excitation 320 nm exhibits a systematically varied hues from green to yellow by changing Sm(3+) ion concentration from 0 to 6 mol%. The luminous mechanism of Sr3(VO4)2:Sm(3+) phosphor is explained by using the energy level diagrams of VO4(3-) group and Sm(3+) ion. The luminescence properties of Sr3(VO4)2:Sm(3+) phosphor can be improved and tuned by codoping the P(5+) and Na(+) ions due to ET and charge compensation. Lifetimes of Sr2.925Sm0.05(VO4)2, Sr2.925Sm0.05(V0.9P0.1O4)2, and Sr2.9Na0.05Sm0.05(V0.9P0.1O4)2 phosphors are 1.208, 1.219, and 0.796 ms, respectively. The experiment results are helpful to adjust the luminescence properties of Sm(3+)-doped other phosphors.

Synthesis, optical properties, and energy transfer of Ce(3+)/Tb(3+) co-doped MyGdFx (M=Li, Na, K).

Through a solid-state reaction method, the Ce(3+)/Tb(3+) co-doped MyGdFx (M=Li, Na, K; x=3, 4, 6; y=0, 1, 3) system samples have been synthesized by controlling the annealing temperatures and the ratios of raw materials. The samples were characterized by X-ray diffraction (XRD) patterns, photoluminescence (PL) excitation and emission spectra as well as luminescent dynamic decay curves. The experimental results suggest that the LiF is more difficult to react with the prepared material compared that of NaF or KF under similar reaction conditions. The samples crystallized in different crystalline phases. The energy transfer from Ce(3+) to Tb(3+) or Ce(3+) to Gd(3+) to Tb(3+) has been observed in all the samples. The Ce(3+) and Tb(3+) present different optical properties for they are sensitive to the local environment. In addition, the deduced lifetime of Tb(3+)(5)D4→(7)F5 transition decreases in the same system samples with the annealing temperature increasing. The deduced lifetime of Tb(3+)(5)D4→(7)F5 also decreases with the increase of the KF concentration in the KF system samples.

Interrelationship of circulating matrix metalloproteinase-9, TNF-α, and OPG/RANK/RANKL systems in COPD patients with osteoporosis.

Previous studies have shown that matrix metalloproteinase-9 (MMP-9) and its cognate inhibitor TIMP-1, inflammatory cytokine TNF-α, and the OPG/RANK/RANKL system may each play individual roles in the pathogenesis of osteoporosis in patients with COPD. In the present study, we investigated the interrelationships of these factors in male COPD patients with and without osteoporosis. The serum levels of MMP-9, MMP-9/TIMP-1 ratio, TNF-α, RANKL, OPG, and the RANKL/OPG ratio were higher in COPD patients with osteoporosis than in individuals with normal or low bone mineral density (BMD) (N = 30, all P < 0.05 or < 0.01). The lung function FEV1%Pre and the BMD of the lumbar spine and femoral neck were found to be negatively correlated with MMP-9 serum level (r = -0.36, P < 0.05, r = -0.58, P < 0.001, and r = -0.62, P < 0.01, respectively), RANKL serum level (r = -0.21, P < 0.05, and r = -0.25, P < 0.05, and r = -0.26, P < 0.05, respectively), and RANKL/OPG ratio (r = -0.23, P < 0.05, r = -0.33, P < 0.05, and r = -0.38, P < 0.05, respectively). However, they had no correlation with TIMP-1, TNF-α, OPG, or RANK. The MMP-9 serum level was found to be positively correlated with TNF-α level (r = 0.35, P < 0.05) and RANKL/OPG ratio (r = 0.27, P < 0.05) but not associated with RANKL. These results suggest that MMP-9, TNF-α, and the OPG/RANK/RANKL system may be closely interrelated and may play interactive roles in pathogenesis of osteoporosis in COPD.

A prospective, multicenter survey on causes of chronic cough in China.

BACKGROUND: The causes of chronic cough in China and its relations with geography, seasonality, age, and sex are largely uncertain. METHODS: A prospective, multicenter survey was conducted to evaluate patients with chronic cough across five regions in China by using a modified diagnostic algorithm. The effects of geography, seasonality, age, and sex on spectrum of chronic cough were also investigated. RESULTS: The current study evaluated 704 adult patients, including 315 men (44.7%) and 389 women (55.3%). The causes of chronic cough were determined in 640 subjects (90.9%). Common causes included cough variant asthma (CVA) (32.6%), upper airway cough syndrome (UACS) (18.6%), eosinophilic bronchitis (EB) (17.2%), and atopic cough (AC) (13.2%). Collectively, these four causes accounted for 75.2% to 87.6% across five different regions without significant difference (P > .05), although there was variation on single causes. Gastroesophageal reflux-related cough was identified in 4.6% of causes. Seasonality, sex, and age were not associated with the spectrum of chronic cough (all P > .05). CONCLUSION: CVA, UACS, EB, and AC were common causes of chronic cough in China. Geography, seasonality, age, and sex were not associated with the spectrum of chronic cough.

Effect of carbocisteine on acute exacerbation of chronic obstructive pulmonary disease (PEACE Study): a randomised placebo-controlled study.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is characterised by airflow limitation, and has many components including mucus hypersecretion, oxidative stress, and airway inflammation. We aimed to assess whether carbocisteine, a mucolytic agent with anti-inflammatory and antioxidation activities, could reduce the yearly exacerbation rate in patients with COPD. METHODS: We did a randomised, double-blind, placebo-controlled study of 709 patients from 22 centres in China. Participants were eligible if they were diagnosed as having COPD with a postbronchodilator forced expiratory volume in 1 s (FEV(1)) to forced vital capacity (FVC) ratio (FEV(1)/FVC) of less than 0.7 and an FEV(1) between 25% and 79% of the predicted value, were aged between 40 and 80 years, had a history of at least two COPD exacerbations within the previous 2 years, and had remained clinically stable for over 4 weeks before the study. Patients were randomly assigned to receive 1500 mg carbocisteine or placebo per day for a year. The primary endpoint was exacerbation rate over 1 year, and analysis was by intention to treat. This trial is registered with the Japan Clinical Trials Registry (http://umin.ac.jp/ctr/index/htm) number UMIN-CRT C000000233. FINDINGS: 354 patients were assigned to the carbocisteine group and 355 to the placebo group. Numbers of exacerbations per patient per year declined significantly in the carbocisteine group compared with the placebo group (1.01 [SE 0.06] vs 1.35 [SE 0.06]), risk ratio 0.75 (95% CI 0.62-0.92, p=0.004). Non-significant interactions were found between the preventive effects and COPD severity, smoking, as well as concomitant use of inhaled corticosteroids. Carbocisteine was well tolerated. INTERPRETATION: Mucolytics, such as carbocisteine, should be recognised as a worthwhile treatment for prevention of exacerbations in Chinese patients with COPD.