Twenty kinds of amino acids are simplified into 3 types: hydrophobic amino acids (H), hydrophilic amino acids (P) and neutral amino acids (N). Each residue is reduced to a bead which locates in the position of the C?琢 atom. The off-lattice model is adopted and the relative entropy is used as a minimization function to predict the tertiary structure of a protein. A new contact intensity function is given to consist with protein design research based on the relative entropy. Testing on several real proteins from Protein Data Bank (PDB) shows the good results obtained with the model and method. The root mean square deviations (RMSD) of the predicted structures relative to the native structures range from 0.30 to 0.70 nm. A foundation for studying protein design using the HNP model and the relative entropy was made.

The application of the protein design method based on the HNP model and the relative entropy theory is discussed for four structural classes of real proteins, and the results are compared with that of the HP model. Testing on 190 proteins shows that this method is generally effective for the different structural classes of proteins. Further studies show that the success rate of this method on regular secondary structures is higher than that on the random coil. Additionally, the success rate for different types of amino acids is also analyzed. It is found that the success rate on the hydrophilic residues is higher than those of the other two types. Furthermore, the success rate of this method on the conserved residues is higher than the non-conserved residues. The reasons resulting in the difference of the success rate on different systems were also analyzed. All analyses mentioned above make the foundation for the development and the application of this method in the future.

Adolescent ; Adult ; China ; epidemiology ; Humans ; Middle Aged ; Motor Activity ; Rural Population ; Suburban Population ; Urban Population

Objective: To analyze the status of dietary sodium intake of Chinese adult residents in fifteen provinces in 2015. Methods: Data were collected from 2015 China Nutrition Transition Cohort Study. This cohort study used a three consecutive 24-h retrospective method to record food intake and weighing method to record household condiment consumption. In this study, 14 847 residents aged 18 years and over with complete data from 15 provinces in 2015 were selected for the comparison of dietary sodium intake (median) with different characteristics. Results: Among the 14 847 residents, 47.1% were males, and the rural and northern residents accounted for 60.1% and 37.7%, respectively. Median sodium intake was 3 960.0 mg/d among residents in 2015. The sodium intake of males (4 272.1 mg/d) was higher than that of females (3 716.6 mg/d). Across age subgroups, sodium intake was highest among residents aged 45-59 years (4 257.0 mg/d; 18-44 years old, 3 867.1 mg/d; ≥60 years old, 3 799.0 mg/d). Sodium intake was higher in rural area (4 042.9 mg/d) than in urban area (3 866.8 mg/d), higher in north (4 229.2 mg/d) than in south (3 806.8 mg/d) (all P values <0.05). 11.8% of residents with dietary sodium intake were below 2 000 mg/d. The main sources of dietary sodium were condiments (79.4%), regular cooking foods (11.9%) and processed foods (8.7%). Among the condiments, the salt and soy sauce accounted for 63.6% and 10.4%, respectively. Conclusion In 2015, Chinese adult residents had higher dietary sodium intake with gender and regional differences. Condiments were the main source of dietary sodium.

OBJECTIVETo explore the association between dietary cholesterol intake and hypercholesterolemia among Chinese adults.

METHODSIn 2009, 4 244 adults aged 25-65 years old who participated in both 2004 and 2009 China Health and Nutrition Surveys, and with complete biochemical and dietary data were selected. Hypercholesterolemia were defined as with total cholesterol ≥ 6.22 mmol/L, according to 2007 Chinese Guidelines on Prevention and Treatment of Dyslipidemia in Adults. Non-conditional logistic regression was used to investigate association between dietary cholesterol intake and hypercholesterolemia.

RESULTSThe average total cholesterol was 4.9 mmol/L, with prevalence of hypercholesterolemia as 9.6%, in 2009. During 2004 to 2009, dietary cholesterol showed a dramatical increase, with lower intake groups the most. Males who consumed middle or lower dietary cholesterol in 2004 and high intake in 2009 had significantly higher risk of having hypercholesterolemia. However, similar findings did not appear in females.

CONCLUSIONThe associations between dietary cholesterol intake and hypercholesterolemia were different among Chinese males and females. Dramatic increase of dietary cholesterol intake was related to higher risk of hypercholesterolemia in males.

Adult ; Aged ; China ; epidemiology ; Cholesterol ; Cholesterol, Dietary ; administration & dosage ; Cohort Studies ; Female ; Humans ; Hypercholesterolemia ; epidemiology ; Male ; Middle Aged ; Nutrition Surveys ; Prevalence ; Risk Factors ; Sex Distribution