Objective To investigate the prevalence and correlates of depression in residents aged 15 and older in Hainan province.Methods Stratified multistage random sampling methods were utilized to identify 12 117 individuals (≥15 years old) from 59 villages (neighborhoods) in 24 towns (streets) within 6 counties (cities) in Hainan Province from September 2010 to November 2011.The subjects were screened with an expanded version of the General Health Questionnaire (GHQ-12) and the respondents were divided into three groups by high risk,moderate risk and low risk of mental disorder,followed by formal diagnosis according to the Structured Clinical Interview for DSM-IV-TR (SCID-I/P) by psychiatrists among 100％ subjects in group with high risk,40％ subjects in group with moderate risk and 10％ subjects in group with low risk.The adjusted rate,standardized rate,and 95％ confidence interval (95％CI) of the one-month and lifetime prevalence were also calculated among the 3 groups of individuals who were diagnosed with depressive disorder.The difference in whether they suffered depression was determined by the chi-squared test.Correlations to depressive disorder and the odds ratio (OR) were explored with multiple regression analysis.Results There were 97 cases of depressive disorders (1-month) and 166 cases of lifetime depressive disorders finally confirmed.The adjusted rate of 1-month prevalence was 1.38％ (95％CI:1.12-1.59) and the life-time adjusted prevalence rate was 2.80％ (95％CI:2.51-3.09).Female (OR=1.55,95％CI:1.12-2.14),mid-age(50-64 y,OR=1.84,95％CI:1.13-2.99),being divorced or living separated (OR=4.87,95％CI:1.86-12.73),suffering chronic diseases (OR=2.19,95％CI:1.56-3.07),and low family income were significantly associated with suffering depressive disorder.Conclusions The prevalence of the depressive disorder among residents aged 15 and older in Hainan province is lower than the nationwide prevalence.People who are female,mid-age,being divorced or not living with the partner,earning a low income,and suffering chronic diseases have more predisposition to develop the depressive disorder in Hainan province.

Objective To investigate the prevalence and correlates of depression in residents aged 15 and older in Hainan province.Methods Stratified multistage random sampling methods were utilized to identify 12 117 individuals (≥15 years old) from 59 villages (neighborhoods) in 24 towns (streets) within 6 counties (cities) in Hainan Province from September 2010 to November 2011.The subjects were screened with an expanded version of the General Health Questionnaire (GHQ-12) and the respondents were divided into three groups by high risk,moderate risk and low risk of mental disorder,followed by formal diagnosis according to the Structured Clinical Interview for DSM-IV-TR (SCID-I/P) by psychiatrists among 100％ subjects in group with high risk,40％ subjects in group with moderate risk and 10％ subjects in group with low risk.The adjusted rate,standardized rate,and 95％ confidence interval (95％CI) of the one-month and lifetime prevalence were also calculated among the 3 groups of individuals who were diagnosed with depressive disorder.The difference in whether they suffered depression was determined by the chi-squared test.Correlations to depressive disorder and the odds ratio (OR) were explored with multiple regression analysis.Results There were 97 cases of depressive disorders (1-month) and 166 cases of lifetime depressive disorders finally confirmed.The adjusted rate of 1-month prevalence was 1.38％ (95％CI:1.12-1.59) and the life-time adjusted prevalence rate was 2.80％ (95％CI:2.51-3.09).Female (OR=1.55,95％CI:1.12-2.14),mid-age(50-64 y,OR=1.84,95％CI:1.13-2.99),being divorced or living separated (OR=4.87,95％CI:1.86-12.73),suffering chronic diseases (OR=2.19,95％CI:1.56-3.07),and low family income were significantly associated with suffering depressive disorder.Conclusions The prevalence of the depressive disorder among residents aged 15 and older in Hainan province is lower than the nationwide prevalence.People who are female,mid-age,being divorced or not living with the partner,earning a low income,and suffering chronic diseases have more predisposition to develop the depressive disorder in Hainan province.

Ion trap performances are investigated based on digital ion trap technique with different collision gases at different pressures. Collision gases of helium (4 amu), nitrogen (28 amu) and argon (40 amu) with various pressures are adopted in ion excitation and dissociation stages to investigate the ion trap performances, including mass resolution, signal intensity, tandem mass spectrometric analysis ability and low-mass cut off (LMCO) effect. It is found that when heavy gas of argon is used, energy can be efficiently transferred and LMCO effect is decreased with higher ion capture and dissociation efficiencies but with low mass resolution. Higher mass resolution is realized with helium as collision gas. Furthermore, at the same gas pressure, heavy gas is beneficial to abundant fragment ions and structural information of precursor ion.