Objective: To examine the reliability and validity of the Columbia suicide screen (CSS) in detecting suicide risk for junior middle school students. Methods: Using convenient sampling, 902 students of a junior middle school were tested with CSS and Beck depression inventory (BDI) .Cronbach's alpha coefficient, parity split-half coefficient and test-retest reliability were examined after two weeks.Content validity was evaluated using specialist analysis and sensibility analysis.The BDI was used to explore the correlative validity.The convergent validity of CSS and another suicide risk screening method was examined. Results: The proportion of students with suicide problem (suicide ideation or suicide attempts), suicide ideation within the previous year and suicide attempts in the past were 14.97%(135/902), 14.19%(128/902)and 3.66%(33/902) respectively.The Cronbach's alpha coefficient and Parity split-half coefficient of CSS were 0.844 and 0.908, respectively.The test-retest reliability of CSS were screening of suicide ideation (ICC=0.897), screening of suicide attempts (ICC=0.798), screening of substance use (ICC=0.882), screening of suicide problem (ICC=0.881), and screening of suicide problem combine depression (ICC=0.829) (P<0.01). Sensibility analysis of CSS showed the cronbach α ranged from 0.834 to 0.845.Correlative validity between CSS and BDI were screening of suicide ideation(ρ=0.238, 0.337, 0.334, 0.599), screening of suicide attempts(ρ=0.122, 0.231, 0.310, 0.221), screening of depression(ρ=0.335, 0.309, 0.196, 0.215), screening of suicide problem(ρ=0.240, 0.328, 0.321, 0.590)and screening of suicide problem combine depression(ρ=0.212, 0.324, 0.320, 0.474)(P<0.01). Convergent validity between CSS and another suicide risk screening method were screening of suicide ideation(ρ=0.468), screening of suicide attempts(ρ=0.349), screening of suicide problem(ρ=0.453), and screening of suicide problem combine depression(ρ=0.469)(P<0.01). Conclusion CSS has good internal consistency reliability, split-half reliability and content validity.Screening of suicide ideation, suicide attempts, suicide problem and suicide problem combine depression have good test-retest reliability, but the correlative validity and convergent validity are not satisfying.These four screening methods can only be used for preliminary screening suicide risk in junior middle school students.

Poly (propylene fumarate) is an unsaturated linear polyester, which degrades, in the presence of water, into propylene glycol and fumaric acid, and the degradation products can be cleared from the human body by normal metabolic processes. In this paper, different methods of the synthesis of PPF are listed, the crosslinking characteristics of polymerizing composite as well as the mechanical properties of cross-linked composite are discussed, and the potentialities of PPF composite used as particularly degradable polymeric cement for orthopedic application are reviewed.
Biocompatible Materials ; chemical synthesis ; Biodegradation, Environmental ; Cross-Linking Reagents ; chemical synthesis ; Fumarates ; chemical synthesis ; chemistry ; Humans ; Polypropylenes ; chemical synthesis ; chemistry

Objective:To compare the efficacy of oral sulfate solution (OSS) and polyethylene glycol (PEG) electrolyte powder for colonoscopy bowel preparation.Methods:A total of 283 randomized patients from 9 centers in China taking OSS ( n=143) or PEG ( n=140) using two-day split bowel preparation regimen received colonoscopy and assessment. The primary index was the bowel preparation success rate [global Boston bowel preparation scale (BBPS)≥ 6 by independent assessment center]. Secondary indices included BBPS global and segmental scores, investigator satisfaction (5-point Likert scale) with the quality of bowel preparation, patient satisfaction assessed by questionnaires, and patient tolerance assessed by Sharma scale. Compliance and safety were compared between the two groups. Results:The bowel preparation success rates were 100.0% for OSS and 99.3% for PEG [adjusted difference 0.7% (95% CI: -5.3% - 6.7%), P<0.001 for non-inferiority]. The BBPS global score in OSS group was significantly higher than that in PEG group (8.1 VS 7.7, P<0.001). The segment BBPS scores were also higher in OSS group than those in PEG group for all 3 segments (right colon: 2.4 VS 2.3, P=0.002; transverse colon: 2.8 VS 2.7, P=0.018; left colon: 2.8 VS 2.7, P=0.007). Investigator Likert score in the OSS group was significantly higher than that in the PEG group (2.6 VS 2.3, P<0.001). There was no significant difference in compliance between OSS and PEG, except for the second dose (90.9% VS 82.6%, P=0.039). There was no significant difference in patient satisfaction, Sharma score or proportion of patients with tolerance-related symptoms between the two groups. Safety was comparable between the two groups, and all adverse events were mild to moderate. Conclusion:OSS has comparable efficacy with PEG, with higher BBPS scores in all segments, better investigator satisfaction, better compliance in split dose, and comparable patient tolerance and safety.