一种基于统计的地质专业词语识别方法

中文分词是地质大数据智能化知识挖掘难以回避的第一道基本工序。基于统计的分词方法受语料影响,跨领域适应性较差。基于词典的分词方法可以直接利用领域词典进行分词,但不能解决未登录词识别问题。在领域语料不足的情况下,为提高地质文本分词的准确率和未登录词识别率,提出一种基于统计的中文地质词语识别方法。该方法基于质串思想构建了地质基本词典库,用以改善统计分词方法在地质文本分词上的适应性。采用重复串查找方法得到地质词语候选集,并使用上下文邻接以及基于位置成词的概率词典,对地质词语候选集进行过滤,最终实现地质词语识别。实验结果表明,使用该方法对地质专业词语识别准确率达到81.6%,比通用统计分词方法提高了近60%。该方法能够识别地质文本中的未登录词,并保证地质分词的准确率,可以应用到地质文本分词工作中。

阶梯电极离子阱质量分析器的结构与性能

本研究从理论上优化了一种新型结构的线型离子阱质量分析器-阶梯电极离子阱质量分析器,它是由2对阶梯电极与1对端盖电极组成。与传统平板电极矩形离子阱长阶梯电极离子阱相比,具有调节电场分布的优点,同时在几何结构设计上更接近于双曲面电极结构,但比双曲面电极更容易加工。通过改变阶梯电极结构的高度、宽度、场半径比例等几何参数,实现了对离子阱内部电场分布的优化,从而实现离子阱性能的优化。理论模拟研究结果表明,根据几何结构和电场分布优化获得的阶梯电极离子阱质量分析器(X0×Y0=9 mm×5 mm),可以在225 Da/s扫速下获得10150的质量分辨率。阶梯电极离子阱结构简单,分辨能力明显高于矩形离子阱。初步的实验结果表明,阶梯电极离子阱具有较好的串级质谱分析性能。

Identification of Pigments from Jujube Fruit Skin

[Objective]The aim was to identify the composition of pigments from Jujube fruit skin.[Method]Pigments were extracted from＇Lubei Dongzao＇,＇Lajiao Zao＇,＇Chengwu Dongzao＇,＇Dabailing＇and identificated by using high performance liquid chromatography-mass spectrometry（HPLC-MS）.[Result]The results showed that eight flavanols and four to five flavonols were detected,no anthocyanins was detected.The contents of flavonoids were differnt in four varieties.The contents of flavanols（11 mg/g） and flavonols（1.78 mg/g） in＇Dabailing＇ were one-time higher than other varieties.Quercetin 3 rutinoside was the major flavonol.[Conclusion]The research provided theoretical basis for further study on mechanism of Jujube pigment turnning into the red.

Determination of 10 Pyrethroids Pesticide Residues in Rice by GC-MS-MS

[Objective] A method was developed for the determination of 10 pyrethroids pesticide residues in rice by GC-MS-MS. [Method] Pyrethroids were extracted with acetonitrile, followed by a salting-out step with anhydrous magnesium sulfate and sodium chloride, cleaned up by florisil solid phase extraction （SPE） cartridge, and determined by multiple reaction monitoring mode. [Result] The method showed good linearity over the range of 0.010-0.500 mg/L for 10 pyrethroid pesticide with correlation coefficients over 0.99. The detection limits were 0.005 -0.010 mg/kg. The method was validated by analyzing samples spiked with 0.05, 0.10, 0.20 mg/kg of 10 pyrethroid pesticides, respectively. The average recoveries in rice ranged from 75.0-115.5%, and the relative standard deviations （RSD） were between 3.9%-6.9%. [Conclusion] The method is easy, accurate and reliable, which can meet the requirement for the simultaneous determination and confirmation of pyrethroid pesticide residues in rice.

Rapid analysis and identification for the alkaloids from Ranunculus japonicus by UPLC /Q-TOF-MS

To establish a rapid and effective method for analysis and identification of the alkaloids from Ranunculus japoni- cus Thunb by ultra-performance liquid chromatogaraphy with quadruple-time-of-flight mass spectrometry （UPLC/Q-TOF- MS） and discuss their fragmentation regularity, the UPLC/Q-TOF-MS was used to identify the alkaloids from Ranunculus japonicus Thunb by their MS data, tandem characteristic fragment ions and standards. In the end, 12 alkaloids were identi- fied from Ranunculus japonicus for the first time, and their fragmentation regularity was discussed. Thus, a rapid and effec- tive analysis and identification method for the alkaloids from Ranunculus japonicus by UPLC/Q-TOF-MS is established.

Bayesian and Multiple Bayesian Analysis of the Reliability Performances for Series System with Cold Standby Units

By using Bayesian and multiple Bayesian method, the failure probability, reliability and mean time to failure(MTTF) of series system with cold standby units are estimated. At last, we compare the two estimators by means of Monte_Carlo simulation.

Simultaneous identification and quantification of tetrodotoxin in fresh pufferfish and pufferfish-based products using immunoaffinity columns and liquid chromatography/quadrupole-linear ion trap mass spectrometry

In this study, we established a comprehensive method for simultaneous identification and quantification of tetrodotoxin （TTX） in fresh pufferfish tissues and pufferfish-based products using liquid chromatography/quadrupole-linear ion trap mass spectrometry （LC-QqLIT-MS）. TTX was extracted by 1% acetic acid-methanol, and most of the lipids were then removed by freezing lipid precipitation, followed by purification and concentration using immunoaffinity columns （IACs）. Matrix effects were substantially reduced due to the high specificity of the IACs, and thus, background interference was avoided. Quantitation analysis was therefore performed using an external calibration curve with standards prepared in mobile phase. The method was evaluated by fortifying samples at 1, 10, and 100 ng/g, respectively, and the recoveries ranged from 75.8%--107%, with a relative standard deviation of less than 15%. The TTX calibration curves were linear over the range of 1-1 000 ~tg/L, with a detection limit of 0.3 ng/g and a quantification limit of 1 ng/g. Using this method, samples can be further analyzed using an information- dependent acquisition （IDA） experiment, in the positive mode, from a single liquid chromatography-tandem mass spectrometry injection, which can provide an extra level of confirmation by matching the full product ion spectra acquired for a standard sample with those from an enhanced product ion （EPI） library. The scheduled multiple reaction monitoring method enabled TTX to be screened for, and TTX was positively identified using the IDA and EPI spectra. This method was successfully applied to analyze a total of 206 samples of fresh pufferfish tissues and pufferfish-based products. The results from this study show that the proposed method can be used to quantify and identify TTX in a single run with excellent sensitivity and reproducibility, and is suitable for the analysis of complex matrix pufferfish samples.

Detection of 36 antibiotics in coastal waters using high performance liquid chromatography-tandem mass spectrometry

Among pharmaceuticals and personal care products released into the aquatic environment, antibiotics are of particular concern, because of their ubiquity and health effects. Although scientists have recently paid more attention to the threat of antibiotics to coastal ecosystems, researchers have often focused on relatively few antibiotics, because of the absence of suitable analytical methods. We have therefore developed a method for the rapid detection of 36 antibiotic residues in coastal waters, including tetracyclines （TCs）, sulfanilamides （SAs）, and quinolones （QLs）. The method consists of solid-phase extraction （SPE） and liquid chromatography-tandem mass spectrometry （LC-MS/MS） analysis, using electrospray ionization （ESI） in positive mode. The SPE was performed with Oasis HLB and Oasis MCX cartridges. Chromatographic separation on a Cr8 column was achieved using a binary eluent containing methanol and water with 0.1% formic acid. Typical recoveries of the analytes ranged from 67.4% to 109.3% at a fortification level of 100 ng/L. The precision of the method, calculated as relative standard deviation （RSD）, was below 14.6% for all the compounds. The limits of detection （LODs） varied from 0.45 pg to 7.97 pg. The method was applied to detemaine the target analytes in coastal waters of the Yellow Sea in Liaoning, China. Among the tested antibiotics, 31 were found in coastal ＇waters, with their concentrations between the LOD and 212.5 ng/L. These data indicate that this method is valid for analysis of antibiotics in coastal waters. The study first reports such a large number of antibiotics along the Yellow Sea coast of Liaoning, and should facilitate future comprehensive evaluation of antibiotics in coastal ecosystems

Accumulation and depuration of pectenotoxins in brown crab Cancer pagurus

Pectenotoxins (PTXs) are a group of marine algal toxins. In this study, the accumulation and depuration of pectenotoxins in brown crab Cancer pagurus were investigated. Crabs were fed with toxic blue mussels Mytilus edulis for 21 days and then depurated for 42 days. Toxins were extracted with methanol from the digestive glands of contaminated crabs, uncontaminated crabs (control group) and from blue mussels for comparison. Extracts were analyzed by liquid chromatograph coupled with tandem mass spectrometry (LC-MS-MS). The concentrations of PTX-2, PTX-2 SA, 7-epi-PTX-2 SA, and PTX-12 were analyzed in two batches of toxic blue mussels and the crabs. A one-compartment model was applied to describe the depuration of PTXs. The half-life of PTXs was estimated to be 6–7.5 days. After depuration for 42 days, the amount of PTXs measured in the crab digestive glands was less than 1 μg/kg.

Liquid Chromatography-tandem Mass Spectrometry for Analysis of Acylcarnitines in Dried Blood Specimens Collected at Autopsy from Neonatal Intensive Care Unit

Objective To investigate the feasibility of analyzing acylcarnitine in dry filter-paper blood spots by liquid chromatography-tandem mass spectrometry(LC-MS/MS) which could be applied to detect inborn errors of metabolism in neonates.Methods We obtained filter-paper blood from 26 dead infants from a neonatal intensive care unit(NICU) between October 1,2008 and September 30,2009.Acylcarnitine and amino acid profiles were obtained with LC-MS/MS.Four infants underwent routine autopsy.The postmortem blood specimens were compared with newborn blood specimens,and with specimens obtained from older infants with metabolic disorders.Results Of all the 26 patients,5(19.2%) were diagnosed as having different kinds of diseases:3 with methylmalonic acidemia(the concentration of C3,and the ratio of C3/C16,C3/C2 increased),1 with maple syrup urine disease(the concentration of leucine and isoleucine increased),and 1 with isovaleric aci-demia(the concentration of C5 increased).Conclusions Postmortem metabolic test can explain infant deaths and provide estimates of deaths attributable to inborn errors of metabolism in NICU.LC-MS/MS is suitable for analysis of postmortem specimens and can be considered for routine application in NICU autopsy.

Differential diagnosis in patients with suspected bile acid synthesis defects

AIM: To investigate the clinical presentations associated with bile acid synthesis defects and to describe identification of individual disorders and diagnostic pitfalls. METHODS: We describe semiquantitative determination of 16 urinary bile acid metabolites by electrospray ionization-tandem mass spectrometry. Sample preparation was performed by solid-phase extraction. The total analysis time was 2 min per sample. We determined bile acid metabolites in 363 patients with suspected defects in bile acid metabolism. RESULTS: Abnormal bile acid metabolites were found in 36 patients. Two patients had bile acid synthesis defects but presented with atypical presentations. In 2 other patients who were later shown to be affected by biliary atresia and cystic fibrosis the profile of bile acid metabolites was initially suggestive of a bile acid synthesis defect. Three adult patients suffered from cerebrotendinous xanthomatosis. Nineteen patients had peroxisomal disorders, and 10 patients had cholestatic hepatopathy of other cause. CONCLUSION: Screening for urinary cholanoids should be done in every infant with cholestatic hepatopathy as well as in children with progressive neurological disease to provide specific therapy.

Determination of Sulfadimidine in Royal Jelly by C_(18)-functionalized Magnetic Silica Nanoparticles Solid Phase Extraction-High Performance Liquid Chromatography-Tandem Mass Spectrometry

[Objective] This study aimed to develop a method of C_18-functionalized magnetic silica nanoparticles solid phase extraction-high performance liquid chro- matography-tandem mass spectrometry for the determination of sulfadimidine in royal jelly. [Method] The royal jelly samples were pretreated by MCX SPE column and C_18-functionalized magnetic silica nanoparticles, and the purified samples were de- tected by HPLC-MS/MS. [Result] The detection method showed a good linear rela- tionship in the range of 5-80 ugkg （r=0.993 1）. The recovery ranges were between 93%- 104% with the relative standard deviations （RSD） below 11.3%. [Conclusion] Combined with automation equipment, the method is simple, fast, time-saving, and easy to real- ize the automation of sulfadimidine in the royal jelly samples before determination.

Development and Validation of a Liquid Chromatography-Tandem Mass Spectrometry Method for Determination of Artemisinin in Rat Plasma

Artemisinin is a potent anti-malarial drug isolated from traditional Chinese medicinal herb, Artemisia annua. The objective of this study was to develop and validate a sensitive and specific LC-MS/MS method for the determination of artemisinin in rat plasma using amlodipine as Internal Standard. The method consist of a simple liquid-liquid extraction with methyl tertiary butyl ether （MTBE） with subsequent evaporation of the supernatant to dryness followed by the analysis of the reconstituted sample by LC-MS/？vIS with a Z-spray atmospheric pressure ionization （API） interface in the positive ion-multiple reaction monitoring mode to monitor precursor--〉product ions of m/z 282.70--〉m/z 209.0 for artemisinin and m/z 408.9--〉m/z 237.0 for amlodipine respectively. The method was linear （0.999） over the concentration range of 7.8-2000 ng/mL in rat plasma. The intra and inter-day accuracy were measured to be within 94-104.2% and precision （CV） were all less than 5%. The extraction recovery means for internal standard and all the artemisinin concentrations used were between 82-85%.

Elimination of matrix effects during analysis of perfluorinated acids in solid samples by liquid chromatography tandem mass spectrometry

Matrix effects can significantly hamper the accuracy and precision of the analysis results of perfluorinated acids （PFAs） in environmental solid samples. Several methods, such as standard addition, isotopically labeled internal standards, clean-up of SPE （solid phase extraction） eluents by dispersive graphitized carbon sorbent and substitution of eletrospray ionization （ESI） source by atmosphere pressure photoionization （APPI） source, were demonstrated for elimination of matrix effects in quantitative analysis of PFAs in solid samples. The resuRs indicate that matrix effects can be effectively eliminated by standard addition, but instrumental analysis time will be multiplied. Isotopically labeled internal standards can effectively negate matrix effects of PFAs with the same perfluorocarbon chain length, but is not valid for the other analytes. Although APPI can eliminate matrix effects for all analytes, it is only suitable for analysis of high pollution levels samples. Clean-up of SPE eluents by dispersive graphitized carbon sorbent not only effectively negate the impact of matrix effect, but also avoid frequent clean of the ESI in order to maintain instrumental sensitivity. Therefore, the best method for elimination of matrix effects is the usage of dispersive graphitized carbon sorbent for clean-up of SPE elution.

A Study on Triacylglycerol Composition and the Structure of High-Oleic Rapeseed Oil

The composition of fatty acids in triacylglycerides （TAGs） and their position on the glycerol backbone de- termine the nutritional value of vegetable oil. In this study, gas chromatography and high-performance liquid chromatography-tandem mass spectrometry （HPLC-MS/MS） were used to analyze the compo- sition and distribution of fatty acids in TAGs of different rapeseed oils. Our results show the content of oleic acid in higb-oleic-acid rapeseed oil to be about 80%. In terms of the number of acyl carbon atoms （CN）, TAGs with CN52-54 were most abundant, with a maximum concentration at CN54 （80%）. The main type of TAG was oleic-oleic-oleic （OOO）, accounting for 71.75%, while oleic-oleic-linoleic （OOL） accounted for ？.56%, oleic-oleic-linolenic （OOLn） accounted for 4.81%, and stearic-oleic-oleic （SO0） accounted for 4.74%. Oleic acid in high-oleic-acid rapeseed oil was distributed in the following order of preference： sn-2 〉 sn-1/3. In high-erucic-acid rapeseed oil, however, oleic acid was enriched at the sn-1/3. These data show that the content of oleic acid can be as high as about 80% in high-oleic-acid material. This finding suggests that high-oleic-acid rapeseed oil has high nutritional value.

Determination of Forechlorfenuron Residue in Fruits and Vegetables by QuEChERS Extraction and HPLC-MS/MS

[Objective] A quick extraction method of QuEChERS-HPLC-MS/MS was established to determine forechlorfenuron in fruits and vegetables. [Method] Fruits and vegetables were extracted with 0.1% acetic acid of acetonitrile solution and pu- rified by QuEChERS, and then forechlorfenuron residues were determined by HPLC- MS/MS. [Result] The limits of detection （LODs） and low determination limit （LOQ） for the forechlorfenuron was 1.0 vg/kg and 5.0 pg/kg in fruits and vegetables, re- spectively. Regression equations of these hormones had a good linear relationship （FF〉0.999） within 2.0-100.0 vg/L. The average recoveries of forechlorfenuron was in the range of 72.0-115. 0% with the coefficients of variation between 1.5% and 9.8% at the spiked levels of 10.0-500.0 μg/kg. [Conclusion] The method can be applied for the determination of the forechlorfenuron in fruits and vegetables.

Metabolism of pectenotoxins in brown crabs Cancer pagurus fed with blue mussels Mytilus edulis

We investigated the metabolism of pectenotoxins in brown crabs(Cancer pagurus).The crabs were fed with blue mussels(Mytilus edulis) for 21 d then depurated for 42 d.We extracted the toxins from the digestive glands of contaminated crabs,uncontaminated crabs(control group),and the meat of blue mussels using methanol.Extracts of the crab digestive glands were fractionated by liquid-liquid partitioning and solid phase extraction.The fractions were analyzed by liquid chromatography coupled with tandem mass spectrometry(LC-MS/MS) and liquid chromatography coupled with ion-trap mass spectrometry(LC-MSn).We detected a new PTX-like compound,designated as metabolite-1.The MS2 mass spectrum of the metabolite-1 [M+Na]+ ion at m/z 897.5 revealed fragment ions at m/z 853.5 and 555.5,typical of those exhibited by other pectenotoxins.

Comparison in vitro permeation of curcumin from topical gels by liquid chromatography tandem mass spectrometry

Objective： To fred a more effective method of topical transdermal delivery of curcumin. Methods： We prepared curcumin carbopol （CRB） 974P and hydroxypropylcellulose （HPC） gel formulations containing menthol or Azone as permeation enhancers In this study, negative mode electrospray ionization and a triple quadruple LC/MS/MS instrument operated in multiple reaction mode was used for curcumin detection. The assay was linear over a concentration range of 10 ng/mL to 400 ng/mL for curcumin （average R2 = 0.997 2）. Excised nude mouse dorsal side skin was used in an in vitro skirt permeation study performed using the method of Franz. Results： Our results showed that all of the topical gel formulations we developed were free from skin irritation. The percutaneous flux and enhancement ratio of curcumin across nude mouse epidermis were enhanced markedly by the addition of menthol or Azone to both types of gel formulations. We found that the HPC gels containing quantities of Azone showed an enhanced permeation effect as compared to gels containing menthol. In the case of HPC gels containing Azone, the increase in permeability was significant （P〈0.05） as compared to the gels containing menthol. Conclusion： Azone shows a significantly more remarkable permeation effect than menthol. As such, this novel delivery strategy offers significant promise and is worthy of further exploration in attempts to enhance the medicinal application of curcumin

Ribotrap Analysis of Proteins Associated with FHL3 3'Untranslated Region in Glioma Cells

Objective To screen the proteins associated with four-and-a-half LIM domains 3(FHL3) 3' untranslated region(3'UTR) in glioma cells. Methods Western blot was adopted to detect the regulatory effect of poly(C)-binding protein 2(PCBP2) on FHL3. Biotin pull-down and sliver staining were employed to screen and verify the candidate binding proteins of FHL3 3'UTR. Then liquid chromatography-tandem mass spectrometry(LC-MS/MS) and molecule annotation system were used to identify and analyze the candidate binding proteins. Immunoprecipitation was conducted to study the interaction between PCBP2 and polypyrimidine tract-binding protein 1(PTBP1), a binding protein identified by LC-MS/MS. Results PCBP2 could bind to FHL3 mRNA 3'UTR-A and inhibited the expression of FHL3 in T98 G glioms cells. 22 candidate binding proteins were identified. Among them, there were 11 RNA binding proteins, including PCBP2. PTBP1 associated with FHL3 mRNA 3'UTR and interacted with PCBP2 protein. Conclusion PCBP2 and PTBP1 can both associate with FHL3 mRNA 3'UTR through forming a protein complex.

Rapid Analysis of Nicotine in Mushrooms Using QuEChERS Extraction and Liquid Chromatography Tandem Mass Spectrometry

A procedure based on the QuEChERS methodology and Liquid Chromatography Tandem Mass Spectrometry （LC/MS/MS） is described, for the determination of Nicotine in mushrooms. QuEChERS methodology was used to determine Nicotine in dried and fresh mushrooms under basic conditions with primary secondary amino sorbent （PSA） clean up. The chromatography was performed on C 18 reversed phase column using a gradient of acetonitrile and ammonium formiate lmM pH = 3.4 as mobile phase at a flow rate of 0.3 mL min^-1. Nicotine was determined by using Nicotine-d3 as internal standard. Limit of quantification （LOQ） was 0.01 mg kg^-1 for both fresh and dried mushrooms. Calibration curve was linear over the concentration range of 0.01-2.3 mg mL^-1, with r2 〉 0.99. As for recoveries in dried mushrooms, spiking levels of 0.32 mg kg^-1 and 2 mg kg^-1 were considered whereas for the fresh mushrooms the recoveries were determined at 0.036 mg kg^-1 and 0.36 mg kg^-1. Satisfactory results were obtained for both matrices and the recoveries proved to range from 105% to 135%, with a standard deviation in the range 17-20. The method was applied to the analysis of Nicotine to assess the levels of nicotine in fresh and dried mushrooms.