Ion trap performances are investigated based on digital ion trap technique with different collision gases at different pressures. Collision gases of helium (4 amu), nitrogen (28 amu) and argon (40 amu) with various pressures are adopted in ion excitation and dissociation stages to investigate the ion trap performances, including mass resolution, signal intensity, tandem mass spectrometric analysis ability and low-mass cut off (LMCO) effect. It is found that when heavy gas of argon is used, energy can be efficiently transferred and LMCO effect is decreased with higher ion capture and dissociation efficiencies but with low mass resolution. Higher mass resolution is realized with helium as collision gas. Furthermore, at the same gas pressure, heavy gas is beneficial to abundant fragment ions and structural information of precursor ion.

Objective To investigate the systolic synchrony of the left ventricle in patients with left ventricular hypertrophy (LVH) or with heart failure but preserved ejection fraction (HF-PEF),and to evaluate the impact of systolic dyssynchrony on left ventricular function.Methods During June 2011 to May 2014,a total of 352 patients(160 males,192 females,average age:(67.6±7.8)years) with essential hypertension (EH) were enrolled in this retrospective study.Ultrasonic and G-MP1 were performed for assessment of left ventricular remodeling and systolic synchrony and the results were statistically analyzed by oneway analysis of variance and x2 test.Relationship between BNP and synchronic parameters as well as other clinical factors were analyzed by partial correlation analysis.Results The EH patients were divided into hypertension group (rt =182),LVH group (n =74) and HF-PEF group (n =96).In comparison to hypertension group,significant LVH developed in LVH and HF-PEF groups although the LVEF was still preserved.The LVMI of the 3 groups were (94.4±10.1),(121.1±9.8) and (123.2±10.9) g/m2,respectively(F=8.66,P＜0.05).The LVEF was (58.6±7.3)％,(60.8±10.4)％ and (55.1±4.6)％,respectively(F=2.89,P＞0.05).Diastolic dysfunction was identified in LVH and HF-PEF groups with significantly reduced E/A ratio (1.19±0.23,0.80±0.28,0.67±0.17;F=13.46,P＜0.05).Remarkable left ventricular systolic dyssynchrony with phase histogram bandwidth (PHB) of (88.4±8.6) ° and phase standard deviation (PSD) of (23.6±1.9)° and increased BNP of (228.4±69.7) ng/L were revealed in HF-PEF group.The BNP in HF-PEF group was significantly higher than that in LVH group((92.5±13.6) ng/L;q=8.63,P＜0.05).Positive correlation was found between BNP level and PHB,PSD,LVMI,respectively (r=0.277-0.331,all P＜0.05).Conclusion Left ventricular systolic dyssynchrony is concomitant with HF-PEF patients induced by EH,and this dyssynchrony might be one of the factors leading to diastolic dysfunction.

The development and applucatuon of an on-lune fast gas chromatography-quadrupole mass spectrometer ( FGC-QMS) for loggung technology were ullustrated. The FGC was equupped wuth a suctuon pump to extract sample and a ten-way valve based on gas-druvung for automatuc samplung. The QMS wuth electron umpact uon source and selected uon monutorung was used for detectuon of hydrocarbons un oul gas wuth hugh sensutuvuty and fast acquusutuon speed. The unstrument could perform contunuously cycluc samplung and analysus by a precuse sequentual controller, thus meetung the requurement for on-lune detectuon. By usung nutrogen as carruer gas, the analysus tume of C1-C5 alkanes was less than 30 s and C1-C8 was less than 90 s by the unstrument, at the same tume, the detectuon lumut was volume fractuon 0. 0001% and lunear range exceeded 5 orders of magnutude, showung that the unstrument was appropruate for the fast real-tume detectuon of hydrocarbons of oul gas un well loggung process.