ABSTRACT
Objective@#To explore the associations among achievement goal orientation, learning stress and sleep quality among middle school students.@*Methods@#A total of 5 781 students were recruited from 14 middle schools in Guangzhou by a stratified cluster random sampling method. These students were investigated with learning stressors (SSA), achievement goal orientation (ADG), and Pittsburgh Sleep Quality Index (PSQI).@*Results@#The mean score of four aspects of achievement goal orientation was as follows: performance approach (25.98±6.76), performance avoidance (15.52±4.12), mastery approach (25.87±6.77), mastery avoidance (15.19±4.12). The average score of learning stress and sleep quality was (149.53±42.46) and (6.45±2.86), respectively. Performance approach, mastery avoidance and performance avoidance positively associated with learning stress and sleep quality(r=0.12-0.53, P<0.01). Mastery approach was negatively correlated with learning stress and sleep quality (r=-0.14-0.22, P<0.01). Four types of achievement goal orientation both had a direct effect on sleep quality. Performance avoidance and mastery approach indirectly affected sleep quality through learning stress.@*Conclusion@#Achievement goal orientation of middle school students closely relates to learning stress and sleep quality; performance avoidance and mastery approach indirectly affects sleep quality through learning stress. Positive achievement goal orientation helps to reduce learning stress, which would lead to sleep quality improvement among middle school students.
ABSTRACT
To study the chemical constituents from the root of Berchemia lineata (L.) DC., nine compounds were isolated from the EtOAc extract by using silica gel, RP-C18 silica gel column chromatography and preparative HPLC. Based on the spectroscopic analysis, their structures were identified as 5-hydroxy-7-(2'-hydroxypropyl)-2-methyl-chromone (1), (-)-(1'R, 2'S)-erythro-5-hydroxy-7-(1', 2'-dihydroxypropyl)-2-methyl-chromone (2), naringenin (3), eriodictyol (4), (+)-aromadendrin (5), (+)-taxifolin (6), (+)-catechin (7), (+)-epigallocatechin (8) and quercetin (9). Among them, compound 2 is a new chromone derivative. Compound 1 is a known chromone derivative and isolated from this genus for the first time. Compounds 3-9 are known flavonoids and isolated from this plant for the first time.
ABSTRACT
Objective To investigate the corelation between platelet activating factor acetylhydrolase (PAF-AH) genetic polymorphism and ischemic stroke. Methods The plasma PAF-AH genotype was determined in 205 patients with iachemic stroke and 114 normal subjects by the polymerase chain reaction. The levels of plasma platelet activating factor (PAF), platelet α-granule membrane glycoprotein-140(GMP-140), β-thromboglobulin (β-TG) and the levels of platelet factor 4 (PF4) were analyzed. Results The prevalence of the mutation genotype and plasma PAF, GMP-140, β-TG and PF4 in the patients with isehemic stroke [42.44%,(91.08 ± 39.10) ng/L, (36.46 ± 13.10) μg/L, (41.75 ± 11.18) μg/L, (29.05 ± 9.16) g/L, respectively] were significantly higher than those in the controls[21.05%,(64.30 ± 18.81) ng/L, (18.27 ± 7.68) μg/L, (30.94 ± 8.47) μg/L, (18.75 ± 6.06) μg/L](P< 0.01). The levels of plasma PAF, GMP-140 were significantly higher in mutation genotype patients than those in the normal genotype patients (P < 0.01). Conclusions The activation function of platelet in the acute phase of patients with ischemic stroke increases, and it is associated with genetic polymorphism of PAF-AH. The PAF-AH gene mutation may be a novel genetic marker for high risk of ischemic stroke.