ABSTRACT
Objective@#To evaluate the usefulness of retroauricular hairline incision (RAHI) in partial superficial parotidectomy (PSP) by comparison with modified Blair incision (MBI).@*Methods@#A retrospective analysis of 64 medical records for patients with benign parotid tumors who underwent partial superficial parotidectomy was undertaken (28 were in MBI group, 36 in RAHI group). Size and location of tumors, operative time, occurrence of facial nerve paralysis and Frey′s syndrome, and cosmetic outcomes were compared between RAHI and MBI groups.@*Results@#Compared with MBI group, RAHI group showed better cosmetic results for benign parotid tumors in mean satisfaction score(P<0.001). There were no significant differences in size and location of tumors, operative time, incidence of transient or permanent facial nerve paralysis and Frey′s syndrome between two groups (P>0.05).@*Conclusions@#Partial superficial parotidectomy can be performed safely via RAHI in most cases of benign parotid tumors. Compared with MBI, RAHI for benign parotid tumorscan improve the cosmetic outcome, without increasing the operative time or operative morbidity.
ABSTRACT
A polyimide coated stir bar for sorptive extraction (SBSE) was prepared by immersion precipitation method, and evaluated by using 5 phenols and chlorinated phenols as model samples. The extraction efficiency of the prepared stir bar was the highest compared with commercial extraction phases of SBSE. Experimental parameters including stir speed, ionic strength, extraction temperature, extraction time, desorption temperature and time were optimized. Under the optimal conditions such as 100 mL of sample, 30 g of NaCl, extraction time of 30 min, stirring speed of 800 r/ min and at 25℃, the target compounds were recovered by thermal desorption at 300℃ for 4 min, more than two orders of magnitude of linearity was obtained (R≥0. 9995), LOQs (S/ N=10) were 0. 028-0. 123 μg/ L, and RSDs were in the range of 1. 6% -9. 7% . The polyimide SBSE coupled with gas chromatography-mass spectrometry was applied to the extraction/ enrichment and analysis of phenols in real samples, including tap water, sea water, and waste water. It was found that the polyimide SBSE showed high selectivity towards polar compounds and high thermostability up to 350℃.
ABSTRACT
Selective extraction of low molecular weight ( LMW) proteins and peptides from complex biological samples plays an important role in the discovery of useful biomarkers and signaling molecules. It is demonstrated that the unique pore structure of mesoporous material makes it efficient to enrich LMW proteins and peptides from complex matrixes. In this study, a mesoporous material, alkyl-diol@ phenyl-SiO2 , with modified exterior ( alkyl-diol group) and interior ( phenyl group) surfaces, was synthesized by co-condensation and post-grafting, and its characteristic was evaluated by FTIR and MS. The LMW proteins and peptides enriched by the alkyl-diol@phenyl-SiO2 mesoporous material could be easily eluted by organic solvents, which was compatible with the following detection by mass spectrometry ( MS ) . This new mesoporous material exhibited good selectivity for the extraction of LMW proteins and peptides ( less than 10 kDa) from complex biological samples.
ABSTRACT
A thermal desorption ( TD) device was developed and coupled to gas chromatography ( GC) or gas chromatography-mass spectrometry ( GC-MS ) for the qualitative and quantitative analysis of semi-volatile organic compounds on atmospheric particulate matters ( PM ) . The TD was operated by direct heating and placed on the GC injector, leading to high heating rate and easy transfer of analytes to GC without focusing of analytes by cold trap. For establishing the TD-GC method, the materials used for supporting PM samples, temperature and time of thermal desorption, and types of sample injection were investigated for detection of sixteen polycyclic aromatic hydrocarbons ( PAHs) and nine n-alkanes. The limits of detection of the proposed TD-GC method were in the range of 0. 014-0. 093 ng for PAHs, and 0. 016-0. 026 ng for n-alkanes, respectively, with the correlation coefficients of correlation above 0. 9975. The TD-GC method was applied to the determination of trace PAHs and n-alkanes on PM10 samples from three cities. The recoveries were in the range of 95%-135% ( PAHs) and 95%-115% ( n-alkanes) , respectively. Finally, the TD was coupled to GC-MS for comparison of the contents of PAHs and n-alkanes on PMx with different particulate size ( x=10 , 5, 2, 1, 0. 5, 0. 25, 0. 1).