Just-in-Time Learning-Integrated Partial Least-Squares Strategy for Accurately Predicting 71 Chemical Constituents in Chinese Tobacco by Near-Infrared Spectroscopy.

Near-infrared spectroscopy has been widely used to characterize the chemical composition of tobacco because it is fast, economical, and nondestructive. However, few predictive models perform ideally when applied to large spectral libraries of tobacco and its various chemical indicators. In this study, the just-in-time learning-integrated partial least-squares (JIT-PLS) modeling strategy was applied for the first time to quantitatively analyze 71 chemical components in Chinese tobacco. Approximately 18000 tobacco samples from China were analyzed to find appropriately similar measurements and propose suitable and flexible similar subsets from the calibration for each test sample. In total, 879 representative aged tobacco leaf samples and 816 cigarette samples were used as external instances to evaluate the practical predicting ability of the proposed method. The most suitable similar subsets for each test sample could be selected by limiting the Euclidean distance and number of similar subsets to 0-3.0 × 10-9 and 10-300, respectively. The majority of the JIT-PLS models performed significantly better than traditional PLS models. Specifically, using JIT-PLS instead of traditional PLS models increased the R 2 values from 0.347-0.984 to 0.763-0.996, and from 0.179-0.981 to 0.506-0.989 for the prediction of 67 and 71 components in aged tobacco leaf and cigarette samples, respectively. Good prediction ability was demonstrated for routine chemical components, polyphenolic compounds, organic acids, and other compounds, with the mean ratios of prediction to deviation (RPDmean) being 7.74, 4.39, 4.05, and 5.48, respectively). The proposed methodology could simultaneously determine 67 major components in large and complicated tobacco spectral libraries with high precision and accuracy, which will assist tobacco and cigarette quality control in collecting as well as processing stages.

Analysis of tobacco color and location features using visible-near infrared hyperspectral data.

In the present paper, six categories of standard industrial grading tobacco provided by Hongta Group are taken as experimental samples, including three different tobacco locations-upper (B), middle(C) and lower(X) parts, with each part containing two kinds of tobacco colors-orange (O) and lemon yellow (L). Two methods including projection model method based on principal component and Fisher criterion (PPF) and support vector machine (SVM) method are used to analyze color and location features of tobacco based on visible-near infrared hyperspectral data. The results of projection model method indicate that in the projection and similarity analysis of tobacco color, location and six tobacco groups classified by color and location, two kinds of color can be fully differentiated, of which the similarity value is -1.000 8. Tobacco from upper and lower parts can also be fully differentiated with similarity value 0.405 3, but they both have intersections with tobac- co from middle part. Six tobacco groups classified by color and location can be fully differentiated as well and their projection positions meet the actual external features of tobacco. The results of support vector machine method indicate that in the discriminant analysis of tobacco color, location and six tobacco groups classified by color and location, the average recognition rate of tobacco colors reaches 98%. The average recognition rate of tobacco location is 96%. The average recognition rate of six tobacco groups is 94%. Therefore, it's feasible to analyze color and location features of tobacco using visible-near infrared hyperspectral data, which can provide reference for tobacco quality evaluation, computer-aided grading and tobacco intelligent acquisition, and also offers a new approach to the analysis of exterior features of other agricultural products.

[Tobacco quality analysis of producing areas of Yunnan tobacco using near-infrared (NIR) spectrum].

In the present study, tobacco quality analysis of different producing areas was carried out applying spectrum projection and correlation methods. The group of industrial classification data was near-infrared (NIR) spectrum in 2010 year of middle parts of tobacco plant from Hongta Tobacco (Group) Co., Ltd. Twelve hundred seventy six superior tobacco leaf samples were collected from four producing areas, in which three areas from Yuxi, Chuxiong and Zhaotong, in Yunnan province all belong to tobacco varieties of K326 and one area from Dali belongs to tobacco varieties of Hongda. The conclusion showed that when the samples were divided into two parts by the ratio of 2 : 1 randomly as analysis and verification sets, the verification set corresponded with the analysis set applying spectrum projection because their correlation coefficients by the first and second dimensional projection were all above 0.99. At the same time, The study discussed a method to get the quantitative similarity values of different producing areas samples. The similarity values were instructive in tobacco plant planning, quality management, acquisition of raw materials of tobacco and tobacco leaf blending.

Evaluation of P1 adhesin epitopes for the serodiagnosis of Mycoplasma pneumoniae infections.

Most glycolipid antigens used for serological tests of Mycoplasma pneumoniae are not M. pneumonia-specific, and can cross-react with other microorganism antigens and body tissues, resulting in false positives. It is important to identify M. pneumonia-specific antigen(s) for serological testing and correct diagnosis. Two epitopes, rP1-534 and rP1-513, of P1 adhesin predicted by bioinformatics were successfully expressed and purified, and could be recognized by serum samples from M. pneumoniae-infected patients and His tag antibodies by Western blot. There was no cross-reactivity between the anti-recombinant proteins serum and other respiratory antigens. A total of 400 patients were investigated, their respiratory specimens tested by PCR, and sera tested by a commercial test kit; 56 with positive sera and positive respiratory specimens were designated as standard positive serum and 63 patients were designated as standard negative serum. The purified recombinant proteins were used as a combination of antigens or separately to test the serum. Serological test demonstrated that rP1-513 of the C terminal of P1 adhesin is a new candidate antigen with greater sensitivity and specificity for IgG and IgM serodiagnosis of M. pneumoniae-infected patients. The results confirmed that rP1-513 could be a useful new antigen for the immunodiagnosis of M. pneumoniae infection.

[Study of selecting characteristic wavelengths in qualitative analysis of near infrared spectroscopy].

The present article proposed a method of stepwise selecting characteristic wavelengths based on minimum sum of correlation coefficients (SMCC). The maximization of the ratio of inter-class Euclidean distance to the sum of inner-class Euclidean distances was used as evaluation basis in qualitative analysis of near infrared spectroscopy. Seventeen kinds of grading tobacco leaf in 2012, provided by Hongta Group, were used as experimental samples to verify the effectiveness of this new method. CO1 was selected as the reference category and ten points were selected as characteristic wavelengths. The results indicated that the average value of inner-class Euclidean distance, calculated by characteristic wavelengths, was 1.69 times as large as that calculated by all wavelengths. The average value of inter-class Euclidean distance, calculated by characteristic wavelengths, was 3.70 times as large as that calculated by all wavelengths. The average value of the ratio of inter-class Euclidean distance to the sum of inner-class Euclidean distances, calculated by characteristic wavelength, was 2.21 times as large as that calculated by all wavelengths. The ratio of characteristic wavelengths was increased. The characteristic wavelengths can express the classical differences. It was showed that SMCC was an effective way to select characteristic wavelengths in qualitative analyses of near infrared spectroscopy.

[Research on characteristic of tobaccos from different ecological environments base on near infrared spectroscopy].

Four hundred ninety five samples from 3 parts of tobacco were collected from 11 different ecological environments in 2010 to analyze the characteristics of tobaccos in different ecological environments with near infrared spectroscopy. The results indicate that the differences are remarkable both between lower and upper parts and between lower and middle parts of tobacco, while negligible between upper and middle parts of tobacco under the same ecological environment. Good stability and consistency were showed by the similarity of characteristics of tobaccos under different ecological environments, and the projection correlation coefficient of analysis set and validation set is over 98%. This article also proposes a method of measuring the similarity between characteristics of tobaccos from different ecological environments. The results can provide reference data to quantify tobacco's planting programming, production processing and quality management.

[Tobacco quality analysis of industrial classification of different years using near-infrared (NIR) spectrum].

In this study, tobacco quality analysis of main Industrial classification of different years was carried out applying spectrum projection and correlation methods. The group of data was near-infrared (NIR) spectrum from Hongta Tobacco (Group) Co., Ltd. 5730 tobacco leaf Industrial classification samples from Yuxi in Yunnan province from 2007 to 2010 year were collected using near infrared spectroscopy, which from different parts and colors and all belong to tobacco varieties of HONGDA. The conclusion showed that, when the samples were divided to two part by the ratio of 2:1 randomly as analysis and verification sets in the same year, the verification set corresponded with the analysis set applying spectrum projection because their correlation coefficients were above 0.98. The correlation coefficients between two different years applying spectrum projection were above 0.97. The highest correlation coefficient was the one between 2008 and 2009 year and the lowest correlation coefficient was the one between 2007 and 2010 year. At the same time, The study discussed a method to get the quantitative similarity values of different industrial classification samples. The similarity and consistency values were instructive in combination and replacement of tobacco leaf blending.

[Tobacco quality analysis of industrial classification of different producing area using near-infrared (NIR) spectrum].

In this study, tobacco quality analysis of industrial classification of different producing area was carried out applying spectrum projection and correlation methods. The group of industrial classification data was near-infrared (NIR) spectrum in 2010 year from different tobacco plant parts and colors of Hongta Tobacco (Group) Co., Ltd. 6 064 tobacco leaf samples of 17 classes from Yuxi, Chuxiong and Zhaotong, in Yunnan province and 6 industrial classifications were collected using near infrared spectroscopy, which from different parts and colors and all belong to tobacco varieties of K326. The conclusion showed that, the probability of the grading belonging by the first dimension was 84%, the probability of the producing area belonging by the second dimension was 71%. The study can explain the difference of tobacco quality of industrial classification and producing area by a projection method to get the quantitative similarity values. The quantitative similarity values were instructive in combination of tobacco leaf blending.

Serotype distribution and antimicrobial resistance patterns of Streptococcus pneumoniae isolated from children in China younger than 5 years.

This study examined the epidemiology, antibiotic susceptibility, and serotype distribution of Streptococcus pneumoniae associated with invasive and noninvasive pneumococcal disease in children in China. A total of 451 clinical isolates from children (age, <5 years) were collected from 8 cities from January 2005 to December 2006, including 31 isolated from invasive disease. In vitro susceptibility to 14 antimicrobial agents was determined by the agar dilution method. Among all isolates tested, 64.3% were resistant to penicillin, and for invasive isolates, the resistance rate was 55.2%. Isolates from Wuhan and Nanjing showed the highest prevalence of penicillin resistance (89.6% and 85%), followed by those from Shenzhen (72.4%) and Chengdu (56.7%). Multidrug resistance rates to tetracycline, erythromycin, and clindamycin reached 90%. The 6 most common serotypes were 19F, 19A, 14, 6B, 23F, and 15. These accounted for 80.7% of the isolates. Resistance to penicillin varied among the 6 leading serotypes, ranging from 20% in serotype 15 to 87.3% in serotype 19F. Each of the 8 cities had different serotype distribution. The potential coverage by 7-, 10-, and 13-valent pneumococcal conjugate vaccine were 63.6%, 64.8%, and 79.6%, respectively.

Assessment of immunoreactive synthetic peptides from the structural proteins of severe acute respiratory syndrome coronavirus.

BACKGROUND: The widespread threat of severe acute respiratory syndrome (SARS) to human life has spawned challenges to develop fast and accurate analytical methods for its early diagnosis and to create a safe antiviral vaccine for preventive use. Consequently, we thoroughly investigated the immunoreactivities with patient sera of a series of synthesized peptides from SARS-coronavirus structural proteins. METHODS: We synthesized 41 peptides ranging in size from 16 to 25 amino acid residues of relatively high hydrophilicity. The immunoreactivities of the peptides with SARS patient sera were determined by ELISA. RESULTS: Four epitopic sites, S599, M137, N66, and N371-404, located in the SARS-coronavirus S, M, and N proteins, respectively, were detected by screening synthesized peptides. Notably, N371 and N385, located at the COOH terminus of the N protein, inhibited binding of antibodies to SARS-coronavirus lysate and bound to antibodies in >94% of samples from SARS study patients. N385 had the highest affinity for forming peptide-antibody complexes with SARS serum. CONCLUSIONS: Five peptides from SARS structural proteins, especially two from the COOH terminus of the N protein, appear to be highly immunogenic and may be useful for serologic assays. The identification of these antigenic peptides contributes to the understanding of the immunogenicity and persistence of SARS coronavirus.