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The Detection of THCA Using 2-dimensional Gas Chromatography-Tandem Mass Spectrometry in Human Fingernail Clippings: Method Validation and Comparison with Head Hair

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American Journal of Analytical Chemistry 2013年第10期4卷 1-8页

作者： Joseph Jones Mary Jones Charles Plate Douglas Lewis United States Drug Testing Laboratories Inc. Des Plaines USA

Marijuana use as well as abuse is a significant public health and public safety concern in the United States and using hair to identify marijuana users and abusers has been gaining acceptance in a number of venues including workplace, court ordered, and substance abuse treatment monitoring. After the presentation of a fully validated 2-dimensional gas chromatography-tandem mass spectrometry method for the detection of 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THCA), the chief metabolite of the main psychoactive compound in marijuana, Δ9-tetrahydrocannabinol (THC), we evaluated the usefulness of fingernail clippings as an alternative specimen type to hair by the analysis of a set of 60 matched pairs of head hair and fingernail clippings. The limit of detection was 10 fg/mg, the limit of quantitation was 20 fg/mg, and the assay was linear from 20 fg/mg to 500 fg/mg. The intra- and inter-assay imprecision and bias studies at 4 different concentrations (50, 100, 500, and 1000 fg/mg) were acceptable where all % Target observations were within 16% of their expected concentrations and all %CV calculations were less than 13.5%. THCA was detectable in more fingernail specimens (53.3%) than hair specimens (46.7%) and the mean concentrations in nails were on average 4.9 times higher than in hair (1813 fg/mg and 364 fg/mg, respectively). The THCA concentrations in hair and nail were strongly associated (r = 0.974, P < 0.01, n = 60) and the association was significant. The study demonstrated that fingernail clippings are a suitable alternative specimen type to hair to monitor for marijuana use and abuse.

关键词： 11-Nor-9-Carboxy-Δ9-Tetrahydrocannabinol THCA Carboxy-THC Hair Fingernail 2D-GC-MS/MS 2-dimensional Gas Chromatography Tandem Mass Spectrometry

Strong Law of Large Numbers for a 2-dimensional Array of Pairwise Negatively Dependent Random Variables

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Open Journal of Statistics 2013年第1期3卷 42-46页

作者： Karn Surakamhaeng Nattakarn Chaidee Kritsana Neammanee Department of Mathematics and Computer Science Chulalongkorn University Bangkok Thailand

In this paper, we obtain the strong law of large numbers for a 2-dimensional array of pairwise negatively dependent random variables which are not required to be identically distributed. We found the sufficient conditions of strong law of large numbers for the difference of random variables which independent and identically distributed conditions are regarded. In this study, we consider the limit as which is stronger than the limit as m× n→?∞ when m, n →?∞?are natural numbers.

关键词： Strong Law of Large Numbers Negatively Dependent 2-dimensional Array of Random Variables

Open-pore 2-dimensional zeolite MFI nanosheets for the fabrication of hydrocarbon isomer-selective membranes on porous supports

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Open-pore 2-dimensional zeolite MFI nanosheets for the fabri...

Two-dimensional electrophoresis analysis of proteomics based on image feature and mathematical morphology

第19届全国分子筛学术大会

作者： Qiang Xiao Xianghai Guo Lukang Zheng Qi Chen Han Zhang Michael Tsapatsis Key Laboratory of the Ministry of Education for Advanced Catalysis Materials Institute of Physical ChemistryZhejiang Normal University Key Laboratory of Systems Bioengineering Ministry of EducationDepartment of Pharmaceutical EngineeringSchool of Chemical Engineering and TechnologyTianjin University Department of Chemical Engineering and Materials Science University of Minnesota

＜正＞Suspensions of 2-dimensional（2D）zeolite nanosheets can provide building blocks for the fabrication of membranes and catalysts[1].Here we initiate a detemplation method to organic structure directing agent（OSDA）-free 2D zeolite *** made on porous supports by simple filtration of the open-pore 2D zeolite nanosheets suspensions make hydrocarbon isomer-selective membrane.

关键词： zeolite nanosheets membranes 2-dimensional separation

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Science China Chemistry 2005年第4期48卷 361-367页

作者： SHEN Peng1,FAN Xiaohui2,ZENG Zhen2 & CHENG Yiyu2 1.The First Affiliated Hospital,College of Medicine,Zhejiang University,Hangzhou 310003,China 2.Pharmaceutical Informatics Institute,Zhejiang University,Hangzhou 310027,China The First Affiliated Hospital College of Medicine Zhejiang University Hangzhou China Pharmaceutical Informatics Institute Zhejiang University Hangzhou China

In this paper,a novel method to automatically detect protein spots on a two-dimensional (2-D) electrophoresis gel image is proposed to implement proteomics analysis of complex *** the basis of the identifying spots results based on color variation and spot size features,morphological feature is introduced as a new criterion to distinguish protein spots from non-protein ***-sharpening,edge-detecting and morphological feature extraction methods were consequently combined to detect protein spots on a 2-D electrophoresis gel image subject to strong *** proposed method was applied to detect the protein spots of proteomic gel images from *** cell,human kidney tissue and human *** results demonstrated that this method is more accurate and reliable than previous methods such as PDQuest 7.2 and ImageMaster 5.0 software for detecting protein spots on gel images with strong interferences.

关键词： proteomics, 2-dimensional electrophoresis, protein spot recognition, analytical chemistry for life, morphological feature, image recognition.

Sonographic evaluation of proximal gastric accommodation in patients with functional dyspepsia

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World Journal of Gastroenterology 2013年第29期19卷 4774-4780页

作者： Xiu-Ping Fan Lin Wang Qiang Zhu Teng Ma Chun-Xia Xia Ya-Jing Zhou Department of Diagnostic Ultrasound Beijing Tongren Hospital Capital Medical University

AIM: To assess the value of ultrasonography (US) in evaluation of proximal gastric accommodation disorder in patients with functional dyspepsia (FD). METHODS: Between April 2011 and March 2012, 45 patients with FD and 27 healthy volunteers were enrolled in this study. Two-dimensional ultrasound (2DUS) and 3-dimensional ultrasound (3DUS) were performed sequentially to measure proximal gastric area (PGA), maximal proximal gastric diameter (MPGD), and proximal gastric volume (PGV). These values were measured separately in the two groups every other 5 min for a duration of 25 min after the beginning of ingestion of a test meal. Air pocket grading was done separately for images of 2DUS and blocks of 3DUS obtained at five scanning time points. RESULTS: Both PGA and PGV of patients were significantly smaller than healthy controls (P = 0.000 and 0.002, respectively). Comparing the two parameters between the groups at each time point, the differences were also statistically significant (P = 0.000-0.013), except at 10 min for the PGV (P = 0.077). However, no overall difference was found between the groups in the MPGD measurements (P = 0.114), though it was statistically significant at a 20-minute examination point (P = 0.026). A total of 360 sets or blocks of images were obtained for both 2DUS and 3DUS. For the images analyzed by 2DUS, none were excluded because of gastric gas, and 50 (13.9%) and 310 (86.1%) sets were determined as air pockets grades 1 and 2, respectively. For the images analyzed by 3DUS, 23 (6.4%) blocks were excluded from the measurement due to presence of a large fundus air pocket (grade 3); fifty (13.9%) and 287 (79.7%) blocks were also graded as 1 and 2, respectively. CONCLUSION: Measurement of both PGA and PGV by 2DUS and 3DUS could be useful for assessment of the proximal gastric accommodation.

关键词： Functional dyspepsia Gastric accommodation Ultrasonography Diagnosis 2-dimensional ultrasound 3-dimensional ultrasound

DISPERSION RELATION AND LANDAU LEVELS OF INVERSION LAYER SUBBAND ON p-HgCdTe

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Science China Mathematics 1990年第10期33卷 1192-1200页

作者：褚君浩 R.SIZMANN F.KOCH National Laboratory for Infrared Physics Shanghai Institute of Technical Physics Chinese Academy of Sciences Shanghai 200083 PRC Physik-Department E-16 T. U. München D-8046 Garching F. R. Germany

Starting from Kane's model and taking into account the surface electron spin-orbit interaction, we have derived the dispersion relation and Landau levels of inversion layer subband on narrow-gap semiconductors. The capacitance-voltage spectroscopy, magnetoconductivity oscillations and cyclotron resonance spectroscopy for the p-Hg_(1-x)Cd_x Te MIS structure sample at temperature 4.2 K have been measured. From the experimental data, the subband parameters and spin-orbit coupling intensity, which are involved in the expressions of subband dispersion relation and Landau levels, have been determined. As a result, the inversion layer electron subband dispersion relation and Landau level fan chart for HgCdTe as well as the zero field spin splitting effect, the shifting and the crossing effect of Landau levels have been described quantitatively.

关键词： narrow-gap semiconductors HgCdTe 2-dimensional electron gas subband Landau level.

THE COHERENCE COEFFICIENT MAP AND RESIDUE GUIDED LEAST SQUARE PHASE UNWRAPPING ALGORITHM

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Geo-Spatial Information Science 1999年第1期2卷 55-62页

作者： Zhang Li Liao Mingsheng Zhang Zuxun Zhang Yong National Laboratory for Information Engineering in Surveying Mapping and Remote Sensing WTUSM Wuhan China

The generation of high-resolution DEM from interferometric SAR has resulted in the need for accurate and efficient methods of 2-dimensional phase unwrapping. In this paper, we give a brief description of the mathematical base of phase unwrapping, and a detailed description of the unweighted and weighted least square phase unwrapping *** our algorithm combining with the weighted least square phase unwrapping guided by the branch-cuts derived from Goldstein’ s algorithm and coherence coefficient map derived from the INSAR data is provided. In our experiment we write subroutines of the Goldstein’s branch-cut algorithm,unweighted and weighted least square phase unwrapping algorithm as well as our algorithm,and construct a small experiment system to resolve the phase unwrapping problem. Finally we test our algorithm on some INSAR data. The result shows that our approach can obtain unwrapped phase correctly and efficiently.

关键词： 2-dimensional phase unwrapping interferometric SAR coherence coefficient map weighted least square phase unwrapping branch-cuts

Global Solar Variations and Effects of Relativistic 2D-Hydrogen

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Journal of Modern Physics 2015年第8期6卷 1095-1103页

作者： G. Dreschhoff H. Jungner K. W. Wong C. A. Perry Department of Physics and Astronomy University of Kansas Lawrence USA Radiocarbon Dating Lab University of Helsinki Helsinki Finland

Characteristics of the temporal evolution of the global solar magnetic field were found to display a 2-step cycling mode consistent with a pattern of a fundamental harmonic progression underlying all solar cycles at all times and having its seat in the fusion region of the core via nuclear magnetic resonance as part of the hydrogen and helium fusion chain. In addition to the three principal zones in the interior of the sun, core, radiative zone, and convection zone, a sub-surface layer is being suggested to take part in the processes of varying solar activity, which would be an extension of relativistic 2D hydrogen being formed throughout the plasma body under the influence of pressure waves originating in the core. The major participants confined to such a 2D layer is for the most part 2D hydrogen particularly in its form of relativistic 2D hydrogen, where the Bohratom binding energies are replaced by binding energies in the range of Eo = 0.5 MeV. For this reason it is conjectured that this condition lends itself to providing contributions to (a) the energy release including 0.5 MeV and lower energy γ-photons as well as (b) superimposing a radial component to the global dipole field.

关键词： Solar Activity Solar Oscillations 2-dimensional Hydrogen

Assessment of Aortic Root Mechanics in Hypertensive Patients by Speckle Tracking Echocardiography

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World Journal of Cardiovascular Diseases 2019年第3期9卷 212-222页

作者： Mahmoud Kamel Ahmed Wassam Eldin El-Shafey Kareem Fathy Adam Department of Cardiology Menoufia University Menoufia Egypt

Objectives: Hypertension is a major risk factor for several cardiovascular diseases, including stroke, atherosclerosis and coronary heart disease. Remodeling of the aortic root may be expected to occur in hypertensive subjects as a result of increased stress on the aortic wall due to the repeated hemodynamic overload. Two-dimensional speckle tracking echocardiography is a promising new imaging modality. The aim of this study is to assess aortic root mechanics in relation to left ventricular mechanics in hypertensive patients by speckle tracking echocardiography. Methods: The study included 50 individuals, 30 patients with hypertension compared with 20 age and sex matched healthy volunteers as control group. For both groups, conventional echo was done and speckle tracking echocardiography of the LV including longitudinal, circumferential, radial strain, LV rotation and the longitudinal strain of the ascending aorta and aortic distensibility were measured. Results: Aortic longitudinal strain of both anterior and posterior walls, andalso LV longitudinal peak systolic strain were lower significantly in patient group, and also in the same group, the apical rotation was higher than control;aortic longitudinal strain was negatively correlated with E/E, and LV global longitudinal strain was correlated positively with septal annular E wave peak velocity and with aortic distensibility. Conclusion: Hypertension significantly lowers ascending aortic longitudinal strain and the changes are correlated significantly with LV longitudinal systolic function and with echo parameters of elevated LV filling pressure.

关键词： Hypertension Aorta 2-dimensional Speckle Tracking Echocardiography