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574 results on '"Qin, Jianwei"'

155. Near infrared hyperspectral imaging of blends of conventional and waxy hard wheats

Author

Delwiche, Stephen R., Qin, Jianwei, Graybosch, Robert A., Rausch, Steven R., Kim, Moon S., Delwiche, Stephen R., Qin, Jianwei, Graybosch, Robert A., Rausch, Steven R., and Kim, Moon S.

Abstract

Recent development of hard winter waxy (amylose-free) wheat adapted to the North American climate has prompted the quest to find a rapid method that will determine mixture levels of conventional wheat in lots of identity preserved waxy wheat. Previous work documented the use of conventional near infrared (NIR) reflectance spectroscopy to determine the mixture level of conventional wheat in waxy wheat, with an examined range, through binary sample mixture preparation, of 0–100% (weight conventional / weight total). The current study examines the ability of NIR hyperspectral imaging of intact kernels to determine mixture levels. Twenty-nine mixtures (0, 1, 2, 3, 4, 5, 10, 15, …, 95, 96, 97, 98, 99, 100%) were formed from known genotypes of waxy and conventional wheat. Two-class partial least squares discriminant analysis (PLSDA) and statistical pattern recognition classifier models were developed for identifying each kernel in the images as conventional or waxy. Along with these approaches, conventional PLS1 regression modelling was performed on means of kernel spectra within each mixture test sample. Results indicated close agreement between all three approaches, with standard errors of prediction for the better preprocess transformations (PLSDA models) or better classifiers (pattern recognition models) of approximately 9 percentage units. Although such error rates were slightly greater than ones previously published using non-imaging NIR analysis of bulk whole kernel wheat and wheat meal, the HSI technique offers an advantage of its potential use in sorting operations.

Published
2018

156. Polymorphisms in thymidylate synthase gene and susceptibility to breast cancer in a Chinese population: a case-control analysis

Author

Liu Jiyong, Jin Guangfu, Wang Xuechen, Wang Shui, Qin Jianwei, Tang Jinhai, Hu Zhibin, Gao Jun, Zhai Xiangjun, Chen Wenshen, Chen Feng, Wang Xinru, Wei Qingyi, and Shen Hongbing

Subjects
Neoplasms. Tumors. Oncology. Including cancer and carcinogens, RC254-282
Abstract

Abstract Background Accumulative evidence suggests that low folate intake is associated with increased risk of breast cancer. Polymorphisms in genes involved in folate metabolism may influence DNA methylation, nucleotide synthesis, and thus individual susceptibility to cancer. Thymidylate synthase (TYMS) is a key enzyme that participates in folate metabolism and catalyzes the conversion of dUMP to dTMP in the process of DNA synthesis. Two potentially functional polymorphisms [a 28-bp tandem repeat in the TYMS 5'-untranslated enhanced region (TSER) and a 6-bp deletion/insertion in the TYMS 3'-untranslated region (TS 3'-UTR)] were suggested to be correlated with alteration of thymidylate synthase expression and associated with cancer risk. Methods To test the hypothesis that polymorphisms of the TYMS gene are associated with risk of breast cancer, we genotyped these two polymorphisms in a case-control study of 432 incident cases with invasive breast cancer and 473 cancer-free controls in a Chinese population. Results We found that the distribution of TS3'-UTR (1494del6) genotype frequencies were significantly different between the cases and controls (P = 0.026). Compared with the TS3'-UTR del6/del6 wild-type genotype, a significantly reduced risk was associated with the ins6/ins6 homozygous variant genotype (adjusted OR = 0.58, 95% CI = 0.35–0.97) but not the del6/ins6 genotype (OR = 1.09, 95% CI = 0.82–1.46). Furthermore, breast cancer risks associated with the TS3'-UTR del6/del6 genotype were more evident in older women, postmenopausal subjects, individuals with a younger age at first-live birth and individuals with an older age at menarche. However, there was no evidence for an association between the TSER polymorphism and breast cancer risks. Conclusion These findings suggest that the TS3'-UTR del6 polymorphism may play a role in the etiology of breast cancer. Further larger population-based studies as well as functional evaluation of the variants are warranted to confirm our findings.

Published
2006
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157. Study on Vanadium Films Deposited on Concave Object by Conventional Direct Current and High Power Pulsed Magnetron Sputtering

Author

Yang Shiqin, Yang Jingjing, Tian Xiubo, Qin Jianwei, Li Chunwei, Gong Chunzhi, and Liu Tianwei

Subjects
Materials science, business.industry, Direct current, General Engineering, Vanadium, chemistry.chemical_element, Crystal structure, Plasma, Sputter deposition, Microstructure, Optics, chemistry, Composite material, High-power impulse magnetron sputtering, Porosity, business
Abstract

High power pulsed magnetron sputtering (HPPMS) is a novel tool to fabricate films with high quality. In this paper, vanadium films on concave object have been deposited by HPPMS and conventional direct current magnetron sputtering (DCMS) under the condition of the same average power. The plasma composition, crystalline structure, surface morphology and film thickness have been investigated. The results show that the plasma produced by HPPMS is composed of Ar(1+), V(0) and a certain amount of V(1+). In contrast, the plasma produced by DCMS is composed of Ar(1+), V(0) and a very small amount of V(1+). Both films fabricated by HPPMS and DCMS demonstrate the similar microstructures. The HPPMS vanadium films are dense and flat on the top surface while the surface of DCMS vanadium films presents very sharp peak with larger height. The DCMS vanadium films exhibit a porous columnar grain structure. In contrast, the HPPMS vanadium films have slightly columnar and denser structure. The thickness of the HPPMS vanadium films is less than that of DCMS vanadium films. Compared with the surface on the top, the thickness of the DCMS vanadium films is decreased to about 32% at the side wall and to about 55% at the bottom. However, the HPPMS vanadium films can reach a thickness of about 35% at the side wall and 69% at the bottom relative to that on the top surface. HPPMS shows a better uniformity in the film thickness on concave object.

Published
2013

175. Surface and Subsurface Inspection of Food Safety and Quality using a Line-Scan Raman System

Author

W. F. Schmidt, Chao Kuanglin, Qin Jianwei, Moon S. Kim, and S. R. Delwiche

Subjects
Chemical imaging, Materials science, Pixel, business.industry, Spatially offset Raman spectroscopy, Laser, Sample (graphics), law.invention, symbols.namesake, Optics, law, symbols, Spectroscopy, business, Raman spectroscopy, Spectrograph
Abstract

This paper presents a line-scan Raman platform for food safety and quality research, which can be configured for Raman chemical imaging (RCI) mode for surface inspection and spatially offset Raman spectroscopy (SORS) mode for subsurface inspection. In the RCI mode, macro-scale imaging was achieved using a 785 nm line laser up to 24 cm long with a push-broom method. In the SORS mode, a 785 nm point laser was used and a complete set of SORS data was collected in an offset range of 0–36 mm with a spatial interval of 0.07 mm using one CCD exposure. The RCI and SORS modes share a common detection module including an imaging spectrograph and a CCD camera, covering a Raman shift range from −674 to 2865 cm−1. A pork shoulder and an orange carrot were used to test large-field-of-view (230 mm wide) and high-spatial-resolution (0.07 mm/pixel) settings of the RCI mode for food surface evaluation. Fluorescence-corrected images at selected Raman peaks were used to view Raman-active analytes on the whole sample surfaces (e.g., fat on the pork shoulder and carotenoids over the carrot cross section).Also, a layered sample, which was created by placing a 5 mm thick carrot slice on top of melamine powder, was used to test the SORS mode for subsurface food evaluation. Raman spectra from carrot and melamine were successfully resolved using self-modeling mixture analysis. The line-scan Raman imaging and spectroscopy platform provides a new tool for surface and subsurface inspection for food safety and quality.

Published
2016

181. Effects of the Adulteration Technique on the Near-Infrared Detection of Melamine in Milk Powder

Author

Scholl, Peter F., primary, Bergana, Marti Mamula, additional, Yakes, Betsy Jean, additional, Xie, Zhuohong, additional, Zbylut, Steven, additional, Downey, Gerard, additional, Mossoba, Magdi, additional, Jablonski, Joseph, additional, Magaletta, Robert, additional, Holroyd, Stephen E., additional, Buehler, Martin, additional, Qin, Jianwei, additional, Hurst, William, additional, LaPointe, Joseph H., additional, Roberts, Dean, additional, Zrybko, Carol, additional, Mackey, Andrew, additional, Holton, Jason D., additional, Israelson, Greg A., additional, Payne, Anitra, additional, Kim, Moon S., additional, Chao, Kuanglin, additional, and Moore, Jeffrey C., additional

Published
2017
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195. A Correction Method of Mixed Pesticide Content Prediction in Apple by Using Raman Spectra.

Author

Li, Yan, Peng, Yankun, Qin, Jianwei, and Chao, Kuanglin

Subjects
RAMAN spectroscopy, PESTICIDES, PESTICIDE residues in food, STANDARD deviations
Abstract

In the study, a new correction method was applied to reduce error during Raman spectral detection on mixed pesticide residue in apples. Combined with self-built pesticide residues detection system by Raman spectroscopy and the application of surface enhancement technology, rapid real-time qualitative and quantitative analysis of deltamethrin and acetamiprid residues in apples could be applied effectively. In quantitative analysis, compared with the intensity value of characteristic peaks of single pesticide with same concentration, the intensity value of characteristic peaks of the two pesticides decreased after mixing the pesticides, which affected the results severely. By comparing the difference in the intensity of characteristic peaks of single and mixed pesticides, a correction method was proposed to eliminate the influence of pesticides mixture. Characteristic peak intensity values of gradient concentration pesticide from 100 mg·kg−1 to 10−3 mg·kg−1 and Lagrangian interpolation were applied in the correction method. And a smooth surface was applied to describe the correction coefficient of characteristic peak intensity. Through detecting the characteristic peak intensity values of the mixed pesticide, correction coefficient would be obtained. Then real values of the peak intensity of pesticides and the content of each component of the mixed pesticide would be acquired by the correction method. Correlation coefficient of model validation exceeded 0.88 generally and Root Mean Square Error also decreased obviously after correction, which proved the reliability of the method. [ABSTRACT FROM AUTHOR]

Published
2019
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