Objective To investigate the appropriate age of primary and secondary school students for cardiopulmonary resuscitation (CPR) training.Methods A total of 437 students aged 9-15 years at 3 to 6 grade in the primary schools or 1 to 2 grade in the secondary schools were selected from 2 Yuyao primary and secondary schools by stratified random sampling between March 2017 and January 2018.The numbers of students with the age of 9,10,11,12,13,14 and 15 y were 61,62,66,64,63,63 and 58,respectively.All students received chest compression training provided by Yuyao emergency department People's Hospital according to the 2015 Cardiopulmonary Resuscitation Guidelines.The training included 30 min theoretic teaching and 6 min practice in the simulator.The quality of chest compression performed by students was assessed;the depth,rate,position and retention of chest compression were recorded.Results The mean depth of chest compression in the students aged 9-15 years was 3.8,4.1,4.6,5.1,5.2,5.6 and 5.6 cm,respectively;the accuracy rate was 24.6％(14/61),25.8％ (16/62),50.2％ (33/66),70.5％ (45/64),79.4％(50/63),88.9％(56/63) and 91.4(53/58),respectively.Compared with the students aged 9-11 years,the mean depth of chest compression was significantly increased and accuracy rate was significantly improved in the students aged 12-15 years (Compared with 9-y students,t=-8.936,-9.502,-10.640 and-11.370;x2=35.019,47.599,63.013 and 65.671;compared with 10-y students,t=-6.927,-8.179,-10.70 and-11.047;x2=24.977,35.967,50.916 and 52.727;compared with 1 1-y students,t=-3.095,-4.177,-6.785 and-6.995;x2=5.586,12.114,22.786 and 24.870;all P＜0.05).The mean rate of chest compression was 110-116/min and its accuracy rate was 86.4％-95.2％;the accuracy rate of chest compression position was 90.9％-96.8％ in all students,there were no significant differences among the 7 groups.The mean retention rate of chest compression in the 7 groups was 81.3％(122/150),67.3％(101/150),64.7％ (94/150),48.0％(72/150),48.7％(73/150),33.3％(50/150) and 27.3％(41/150),respectively.Compared with the students aged 9-11 years,the mean retention rate of chest compression was significantly decreased in the students aged 12-15 years (compared with the 9-y students,x2=36.472,35.179,70.64 and 119.92;compared with 10-y students,x2=11.483,10.728,34.682 and 72.150;compared with 11-y students,x2=6.528,5.927,25.855 and 59.11;all P＜0.05).Correlation analysis showed that the depth (r=0.96,0.89,0.91 and 0.86;P＜0.01) and retention rate (r=-0.99,-0.90,-0.93 and-0.86;all P＜0.01) of chest compression were significantly associated with the age,body weight,height and body mass index of students.Conclusion The students with an age of 12 years or more are able to effectively perform chest compression;thus,12 years and above might be the appropriate age for CPR training.

ObjectiveTo observe the intervention effect of Chaihu and Longgu Mulitang （CLMT） on rat depression model prepared by chronic unpredictable mild stress （CUMS） based on cyclic adenosine monophosphate （cAMP）/protein kinase A （PKA）/cAMP-response element-binding protein （CREB）-brain-derived neurotrophic factor （BDNF） signaling pathway. MethodSixty SD rats were divided into normal group， model group， and CLMT low-， medium- and high-dose groups and fluoxetine group （positive control） according to random number table. They， except the normal group， were treated with CUMS for 49 days to prepare the rat depression model. The CLMT low-， medium- and high-dose groups were given 2.89， 5.78 11.56 g·kg^-1 of CHMD granules， respectively， and the fluoxetine group was given 2.06 mg·kg^-1 of fluoxetine hydrochloride on the 29^th day. The normal group and the model group received equal volume of normal saline for 21 days. The behavioral performance of rats were observed by open field test and forced swim test. The levels of 5-hydroxytryptamine （5-HT）， norepinephrine （NE） and cAMP in rat hippocampus were measured by enzyme-linked immunosorbent assay （ELISA）. The mRNA expressions of PKA， CREB， and BDNF in rat hippocampus were detected by real-time fluorescence quantitative polymerase chain reaction （Real-time PCR）， and the protein expressions of PKA and BDNF were detected by Western blot. Immunohistochemistry was used to determine the expression of CREB， and hematoxylin and eosin （HE） staining and Nissl staining were used to observe the morphological changes of hippocampus. ResultCompared with the conditions in the normal group， the immobility time of the model group in the forced swim test was increased （P<0.01） and the total movement distance， residence time in central area， number of entries in central area and movement distance in central area were decreased （P<0.01）. Additionally， the contents of 5-HT， NE and cAMP in hippocampus of the model group as well as the protein expressions of PKA， BDNF and CRE，the mRNA expressions of BDNF and CREB were lower than those in the normal group （P<0.01）. Compared with the model group， the CLMT groups had reduced immobility time （P<0.01）， elevated total movement distance， residence time in central area， number of entries in central area and movement distance in central area （P<0.05， P<0.01）， up-regulated contents of 5-HT， NE and cAMP in hippocampus （P<0.05， P<0.01）， and up-regulated protein expressions of PKA， BDNF and CREB and mRNA expressions of BDNF and CREB （P<0.01）. HE staining and Nissl staining showed that CLMT significantly improved the neuronal structure in rat hippocampus. ConclusionCLMT alleviates the anxiety and depression of rats. These effects may be mediated by regulating monoamine neurotransmitters 5-HT and NE in hippocampus of depressed rats， activating cAMP/PKA/CREB/BDNF signaling pathway， up-regulating the expression of BDNF and protecting hippocampal structure and function .