Semisupervisedmakesfulluseoflargeamountsofunlabeledsamplestomakeuptheinsufficiency of labeled samples. Since it is difficult to obtain a large number of accurate labeled samples and it is a good way for modeling by using a small amount of labeled samples or a large number of inaccurate samples, we proposed a new method named as semi-supervised partial least squares ( SS-PLS) to optimize model based on semi supervised learning. We used 211 samples of tobacco near infrared spectrum and sensory evaluation for modeling and used SS-PLS method to optimize tobacco sensory evaluation model. In the optimized model, the coefficient of determination ( R2 ) can reach up to 90%, the ratio of performance to deviation ( RPD) can reach up to 3 . 0 , and the standard error of cross validation and the standard error of prediction ( SECV and SEP) are below 1. 0. We divided the original sensory evaluation and SS-PLS optimized data into three grades of excellent, medium and poor in accordance with the fixed threshold, the result using projection model of based on principal component and Fisher criterion ( PPF ) shows that the classification of SS-PLS optimized data is better than the original sensory evaluation data. The SS-PLS method can solve the data representation problem of using small sample set for modeling and provides a new chemometrics method for near infrared spectroscopy modeling in case of obtaining a large number of accurately labeled samples is difficult.

OBJECTIVETo investigate the level of zinc (Zn) and copper (Cu) in whole blood among general population from 8 provinces in China, and to analyze the characteristics of distribution among different regions.

METHODSThis cross-sectional study was performed in 8 provinces from eastern, middle and western China between 2009 and 2010, including 13 110 subjects from 24 regions, and the blood and urine samples were collected. The ICP-MS was applied to test the content of ICP-MS in blood samples, and the results were used to analyze the characteristics of contents and distributions of Zn and Cu among population from different ages, genders and regions groups.

RESULTSTotally, the mean (95%CI) contents of Cu and Zn in blood were 795 (791-799)µg/L and 3 996(3 976-4 015) µg/L, respectively. The characteristics of distribution of Cu content were as followed, the content of males were lower than it of females (male:767 µg/L; female: 822 µg/L, t = -13.302, P < 0.01). The contents of blood Cu in groups of people aging 6-12, 13-16, 17-20, 21-30, 31-45 and 46-60 years old were separately 860(853-868), 758(748-769), 734(728-734), 782(774-790), 811(795-827) and 820(815-826) µg/L. The differences showed statistical significance (F = 78.77, P < 0.01). The blood Cu content of people in eastern China (800µg/L) were also significantly higher than it in middle (774 µg/L)and western China (782 µg/L) (F = 10.94, P < 0.01). Distribution of blood Zn content showed characteristics as follows: the Zn content was higher in males than in females (male 4 085 µg/L and female 3 908 µg/L, t = 8.78, P < 0.01). The contents of blood Zn in groups of people aging 6-12, 13-16, 17-20, 21-30, 31-45 and 46-60 years old were separately 3 306 (3 261-3 350), 3 888 (3 839-3 937), 3 948 (3 902-3 994), 4 272(4 228-4 315), 4 231(4 180-4 281) and 4 250 (4 205-4 294)µg/L, which showed significant statistical differences (F = 233.68, P < 0.01). The blood Zn content of people in eastern China (3 938 µg/L) were significantly lower than it in middle (4 237 µg/L)and western China (4 105 µg/L) (F = 53.16, P < 0.01). In addition, the study also compared the relation between content of Cu and Zn and the frequency of eating seafood. The results found that the frequency of eating seafood could influence the content of Cu and Zn (Cu: F = 13.54, P < 0.01; Zn: F = 200.20, P < 0.01).

CONCLUSIONThe contents and distributions of Cu and Zn in blood differs among people from different groups in ages, genders and regions. The baseline data of this study provided reliable scientific evidence for further research.

Adolescent ; Adult ; Child ; China ; epidemiology ; Copper ; blood ; Cross-Sectional Studies ; Female ; Humans ; Male ; Middle Aged ; Young Adult ; Zinc ; blood

OBJECTIVETo evaluated the levels of arsenic (As) in blood and urine among general population in China and analyze its influencing factors.

METHODSA total of 18 120 subjects from general population aged 6-60 years were recruited from 24 districts in 8 provinces in eastern, central and western China mainland from 2009 to 2010, by cluster random sampling method. Blood samples and urine samples were collected, the information of the life-style was collected by questionnaire.Inductive coupled plasma mass spectrometry was applied to test the As level in the samples, and the distribution of As in blood and urine for different ages, genders, areas and life habits were then analyzed.

RESULTSThe geometric mean (GM) of blood As concentration among general population was 2.33 µg/L;the GM of blood As in male (2.35 µg/L) was higher than and female (2.30 µg/L) (Z = -1.42, P < 0.05); from eastern, central to western China, the blood As level were 2.94, 1.30 and 0.98 µg/L (χ(2) = 643.22, P < 0.05) , respectively; the GM in smokers (2.84 µg/L) was higher than non-smokers (2.27) (Z = -6.28, P < 0.05) ;the seafood consumer had a higher blood As level (2.59 µg/L) than people not consuming seafood (1.47 µg/L) (Z = -23.68, P < 0.05). The urine As level of the whole population was 13.72 µg/L;while its GM in male (14.10 µg/L) was higher than female (13.33 µg/L) (Z = -3.94, P < 0.05); the values from eastern, central to western China were 14.14, 16.02 and 9.57 µg/L (χ(2) = 353.89, P < 0.05), respectively;the level in smokers (16.06 µg/L) was higher than nonsmokers (13.70 µg/L) (Z = -2.63, P < 0.05); the level in seafood consumers (14.82 µg/L) was higher than people not consuming seafood (10.99 µg/L) (Z = -3.20, P < 0.05). The blood As level had a positive correlation with urine As level (correlation coefficient:0.285, P < 0.05).

CONCLUSIONThe As level in blood and urine varied by gender and area among general population in China, and related to life-styles. There was a positive correlation between As level in blood and that in urine.

Adolescent ; Adult ; Arsenic ; blood ; urine ; Child ; China ; epidemiology ; Cross-Sectional Studies ; Environmental Exposure ; Female ; Humans ; Male ; Middle Aged ; Sentinel Surveillance ; Young Adult

OBJECTIVETo evaluate the levels of lead (Pb) and cadmium (Cd) in blood and urine among general population in China, and thereby analyze their prevalent features.

METHODSA total of 18 120 subjects from general population aged 6-60 years were recruited from 24 districts in 8 provinces in eastern, central and western China mainland from 2009 to 2010, by cluster random sampling method. The blood samples and urine samples of these people were collected. The questionnaire survey was used to collect the information of the living environment and health conditions.Inductive coupled plasma mass spectrometry was applied to test the Pb and Cd levels in the samples, and the distribution of Pb and Cd in blood and urine for different ages, genders, areas and life habits were then analyzed.

RESULTSAmong the general population in China, the geometric mean (GM) of blood Pb concentration was 34.9 µg/L; the GM of blood Pb in male and female groups were 40.1 and 30.4 µg/L (Z = -28.05, P < 0.05), respectively; the GM from eastern, central and western China were 31.2, 38.8 and 58.9 µg/L (χ(2) = 1 483.33, P < 0.05) , respectively. The GM of urine Pb of the whole population was 1.05 µg/L;while the GM in male and female groups were 1.06 µg/L and 1.05 µg/L (Z = -0.73, P > 0.05) , respectively;the values from eastern, central and western China were 0.76, 2.85 and 3.22 µg/L (χ(2) = 1 982.11, P < 0.05), respectively. The GM of blood Cd concentration among general population was 0.49 µg/L; and the values in male and female group were 0.60 and 0.41 µg/L (Z = -11.79, P < 0.05) , respectively; the GM from eastern, central and western China were 0.45, 0.65 and 0.67 µg/L (χ(2) = 69.87, P < 0.05), respectively; the GM of urine Cd concentration of the whole population was 0.28 µg/L, while the GM in male and female groups were 0.29 and 0.28 µg/L (Z = -3.86, P < 0.05), respectively; the values from eastern, central and western China were 0.29,0.42 and 0.18 µg/L (χ(2) = 402.76, P < 0.05), respectively. the Spearman's rank correlation coefficient for Cd in blood and Cd in urine was 0.22, for Pb in blood and Pb in urine was 0.21. Both the correlations were statistic significant (P < 0.05).

CONCLUSIONThe Pb and Cd levels in blood and urine were relatively higher among general population in China varying by gender and area. There were positive correlations between Pb and Cd levels in blood and those in urine.

Adolescent ; Adult ; Cadmium ; blood ; urine ; Child ; China ; epidemiology ; Cross-Sectional Studies ; Environmental Exposure ; Female ; Humans ; Lead ; blood ; urine ; Male ; Middle Aged ; Sentinel Surveillance ; Young Adult

OBJECTIVETo evaluated the manganese (Mn), cobalt (Co) and molybdenum (Mo) levels in blood and urine among general population in China, and thereby to analyze their prevalent features.

METHODSFrom 2009 to 2010, a total of 18 120 subjects of general population aged 6-60 years were recruited from 24 districts in 8 provinces in eastern, central and western China mainland, by cluster random sampling method. The information about their living environment and health status were collected by questionnaire, and their blood and urine samples were also collected.Inductive coupled plasma mass spectrometry (ICP-MS) was applied to test the Mn, Co and Mo levels of blood and urine samples, and the Mn, Co, Mo distribution in blood and urine among groups of population in different ages and genders were then analyzed.

RESULTSAmong general population in China, the geometric mean (GM) of Mn concentration in blood was 8.98 µg/L. The Mn concentration in blood among males and females were separately 8.14 µg/L and 9.88 µg/L (Z = -18.84, P < 0.01). The GM of Mn concentration in urine was 0.63 µg/L. The Mn concentration in urine among males and females were separately 0.62 µg/L and 0.63 µg/L (Z = -0.67, P > 0.05). The geometric mean (GM) of Co concentration in blood was 0.194 µg/L. The Co concentration in blood among males and females were separately 0.166 µg/L and 0.225 µg/L (Z = -23.04, P < 0.01). The GM of Co concentration in urine was 0.282 µg/L. The Co concentration in urine among males and females were separately 0.260 µg/L and 0.307 µg/L (Z = -7.35, P < 0.01). The GM of Mo concentration in blood was 0.25 µg/L. The Mo concentration in blood among male and female group were separately 0.27 µg/L and 0.23 µg/L (Z = -5.03, P < 0.01). The GM of Mo concentration in urine was 27.7 µg/L. The Mo concentration in urine among males and females were 29.8 µg/L and 25.6 µg/L (Z = -6.31, P < 0.01), respectively.

CONCLUSIONThe Mn, Co and Mo levels in blood and urine varied by gender and area among general population in China, the study provided basic data evidence for the following Mn, Co and Mo biological monitoring studies in near future.

Adolescent ; Adult ; Child ; China ; epidemiology ; Cobalt ; Environmental Exposure ; Environmental Monitoring ; Female ; Humans ; Male ; Manganese ; Middle Aged ; Molybdenum