BACKGROUND: Critical incidents are natural and man-made disasters arising suddenly, which are beyond the ability of the individuals to resist or control. In the situation of stress, individuals feel stuck, and are unable to control the situation.OBJECTIVE: To confirm the assessment model of stress response to critical events and the interventional effect of social support, general self-efficacy and coping efficacy.DESIGN: A randomized sampling, questionnaire-based investigation.PARTICIPANTS: We selected 1016 college students of 17 provinces or cities including Beijing, Guangzhou, Hefei, Jilin, Jiangsu, Jiangxi , Liaoning, Sichuan, Inner Mongolia, Shandong , Shanghai, Hebei, Tianjin,Wuhan, Zhejiang , Chongqing and so on as subjects. Totally 708 college students selected from the above regions received the same survey one year later.METHODS: Depression and anxiety state of the subjects were investigated with Center for Epidemiological Studies Depression Scale (CESD)and Anxiety Inventory (SAS) during SARS. Social support condition was investigated with Social Support Rating Scale, authorized by Xiao Shuiyuan. Related items were amended considering used among college students. The subscale was integrated into 3 subscales including group-support, friend-support and social support utilization. One year later, stress response to SARS was investigated again with self-made coping efficacy scale, self-esteem scale and self-efficacy scale and SARS Stress Response Questionnaire, which included 13 items measuring the students in three aspects: cognitive evaluation to SARS epidemic, such as "I believe human beings can conquer SARS in the end"; panic to SARS, like "worrying about SARS sweats me and makes me feel shiver sometimes"; and defense response to SARS, as "In order to prevent SARS, I have to wear respirator in the public". As far as cognitive, panic emotion and defense behaviors were concerned. The coping efficacy developed by the author covered 18items, such as "I'm afraid that I can not deal with things", "I have enough confidence to conquer any difficulty", and namely as friability, confidence and intelligence.RESULTS: ① The two investigated results were compared through assessment of covariation. There was a significant difference in cognitive condition, panic emotion and defense behavior; that was to say, the stress response to SARS had been obviously relieved . ② Social support and SARS stress response model x2=8.654,df=4,P=0.07;criterion fit index NFI= 1, RFI =0.997 and IFI =1, RMSEA=0.034. ③self-efficacy confirmative factor analysis showed the following: x2=0.536,df=2,P=0.765;x2/df=0.268, NFI=1, RFI=1, IFI=1 and CFI=1, RMSEA=0.000. ④The discriminating and convergent validity of coping efficacy questionnaire was as follows. The coefficient was 0.633 with general efficacy questionnaire, 0.530 with self-respect (SES), 0.481 with CESD, 0.387 with anxiety (SAS), and -0.003 with living events. ⑤ A structural equation model about general self-efficacy, coping efficacy and SARS stress response was established: x2 =2.722 df=3, P=0.437; NFI=1, RFI=0.999,IFI=1, CFI=1, RMSEA=0.068. The model fitted well. According to the data, coping efficacy affected SARS stress response negatively (the coefficient was -0.59)CONCLUSION: ① The three-dimensional assessment model assessed the stress response to critical incidents including cognitive adjustment, emotional response and behavioral tendency. The three-dimensional model stood the test while assessing SARS stress response. Compared with the assessment of emotional disorders, such as depression and anxiety, the model was more sensitive. ②Social support played a vital role in the stress response to critical incidents as a buffer or a regulator. It showed more influence on emotional disorders than on SARS stress response. ③Coping efficacy was a measurable intervening variable, which deserves more attention to in the stress response to critical incidents. Compared with general self-efficacy, coping efficacy had a greater intervening effect on SARS stress response.

To evaluate the clinical effects of rotary nickel-titanium instruments Mtwo in root canal therapy in the aged patients. Using step-back technique,80 teeth with pulpal and periapical involvement were instrumented by Mtwo in the M group, and by K file in the K group. Mtwo could keep the original curvature and flow of the root canals. No transportation, apical blockage, ledge or perforation was found in the M group. There was more complications in the K group than in the M group.The operative time was shorter and posttreatment pain seldom occurred in the M group. With rotary NiTi instruments Mtwo for seniles' root canals treatment, root canals can be prepared effectively and quickly,and is worth of clinical application.

Objective To discuss the application of internal fixation technique in eyebrow lift and infrabrow excision blepharoplasty.Methods With the incision within eyebrow or infrabrow excision incision,fixation of the eyebrow to the brow periosteum using 4-0 silk thread and then suturing the upper and lower border of the incision could lift the eyebrow and correct the ptosis of upper eyelid skin and fishtail lines.Results All the 138 cases got good results,showing that the eyebrow and upper eyelid skin ptosis and lateral fishtail lines were all corrected.Conclusions Internal fixation technique can get better results in eyebrow lift and infrabrow exicion blepheraplasty surgery.

In recent years,the incidence of hepatocellular carcinoma (HCC) has increased with a higher mortality rate.Early detection and early treatment are essential to improving the patients' survival rate. Imaging is widely used HCC and is advantageous because it is non-invasive. The rapid development of imaging calls for higher standards in order to diagnosis hepatocarcinoma at an earlier stage so as to achieve complete treatment.This review describes the scientific progress on imaging differential diagnosis and application on pre-cancerous nodules (dysplastic nodule,DN) and small hepatocellular carcinoma (sHCC) related to hepatocarcinogenesis in cirrhotic livers.

ObjectiveTo explore the theoretical construct of network values and design the network values questionnaire.MethodsThis research was to design the network values questionnaire based on an open-ended inventory survey,overviews of former studies and counseling of experts.Through stratified sampling,832 college students were investigated by the network questionnaire.The data were examined by item analysis,factor analysis,reliability and validity analysis.ResultsThe network values was a multi-dimensional construct which had three factors.The three factors cumulative total explained variance was 50.719％,52.545％ and 50.510％.The questionnaire's internal consistency reliability was 0.931 and 0.809-0.874 for the three subscales.The questionnaire's split-half reliability was 0.902 and 0.772-0.864 for the three subscales.ConclusionThe theoretical construct of network values is rational.The questionnaire has good reliability and validity.

Objective:To establish an in vitro root canal model infected by Enterococcus faecalis and to observe the morphology, distribution and relative position of Enterococcus faecalis in infected root canals.Methods: Ten human healthy premolars extracted for orthodontic reasons were collected. Following sterilization , a total of 5 specimens were aseptically transferred to separate Eppendorf tubes containing 1. 5 mL brain-heart infusion broth (BHI) inoculated with 0.1 mL Enterococcus faecalis suspension that had been adjusted to Mcfarland 5, and were incubated at 37℃ for 21 days. The other 5 specimens were as controls. The roots of all specimens were then split into two halves along the mesiodistal axis. One half was processed with light microscopic ( Brown & Brenn stain) to check the bacteria in dentinal tubules, and the other was observed with SEM to investigate the bacterial status in infected root canals. Results: Enterococcus faecalis could penetrate into the dentinal tubules about 330-1 000μm. A dense bacterial aggregation composed of Enterococcus faecalis and amorphous matrix was observed in the apical third of the root canals, whereas Enterococcus faecalis were seen free-floating or planktonic in the crown and middle third of the root canals . No microorganisms were found in the root canals of the controls. Conclusion:Enterococcus faecalis could form bacterial biofilm on the root canal walls and penetrate into the dentinal tubules. The in vitro model designed was simple, and had good practicability to make a further comparative evaluation of various antimicrobial methods in the reduction of intracanal bacteria.

Objective To construct an infectious full-length cDNA clone of enterovirus 71(EV71)and develop a technological platform for study on vaccine development as well as molecular virology of EV71.Methods According to the nucleotide sequence of EV71 strain 085 isolated in China,four pairs of primers were designed for amplification of four end to end overlapping subgenomic cDNA fragments,the cDNA fragments were directional cloned into pBluescript SK(+)vector,and the virus genome cDNA clone was obtained by ligation orderly.The rescued virus of parental strain 085 from RNA transfected host cells was identified by RT-PCR,IFA,titration as well as transmission electron microscope(TEM)after the transcription of the full-length cDNA clone in vitro.Results The full-length cDNA clone was constructed successfully,and the typical CPE was observed after its transcription into Vero cells.The rescued virus with 20-30 nm in diameter can not only be neutralized by EV71 special anti-serum but also react with anti-EV71 monoclonal antibody that virus infected cells stained with FITC can be detected by IFA.After amplification from the total RNA extraction of virus infected cells by RT-PCR with EV71 special primers,the 226 bp products can be detected.The growth curve showed that the rescued virus can propagate in Vero cells stably with a titer of 4.5 ～6.0 lgCCID50/ml during 8 passages.The plaque formed by rescued virus is identical as parental virus in morphology but smaller in size.Conclusion An infectious full-length clone of EV71 was developed successfully,which will be used for further study on pathogenesis and vaccine development of EV71.

The improvement of oxygenation basis on prone positioning in acute respiratory distress syndrome (ARDS) includes increased end-expiratory lung volume,improved ventilation-perfusion (V/Q) matching,and drainage of secretions.Randomized controlled trials report that prone position ventilation in patients with ARDS tends to reduce mortality rates,especially when used in conjunction with lung protective strategies and greater prone positioning durations.At present,the available data suggest that early prone positioning may provide benefit to ARDS with severe hypoxemia.keeping in mind that a risk of positioning-related complications will have to be taken into account when weighing the risk to benefit for patient with ARDS.There is still limited information available of prone position ventilation application in pediatric ARDS.

Malignant tumor is a serious threat to human health and its pathogenesis is complex , which caused by interaction of a variety of carcinogenic factors in the human body .SALL4 gene is a kind of newly dis-covered gene and it plays an important role in function of embryonic stem cell due to its protein transcription fac -tor with C2H2 zinc finger domain.Studies found that this gene mutation often results in occurrence of malignant tumor.This paper will summarize the molecular mechanism of SALL 4 in the occurrence and development of malig-nant tumor and its diagnosis and treatment on malignant tumor .

Adenovirus,respiratory syncytial virus,influenza virus type A and B,cytomegalovirus and EB virus are the mainly etiology of severe pneumonia in children.New type of virus,such as influenza-H1N1 virus,avian influenza virus(H5N1 or H7N9) can also be epidemic in pediatric population.Ribavirin is effective drugs in the treatment of respiratory syncytial virus and adenovirus pneumonia.Acyclovir or ganciclovir is used for EB virus or immune deficiency and irnmunosuppressive patients with CMV pneumonia.Current opinin strongly recommend treatment with oral oseltamivir as soon as possible in influenza and seasonal influenza.Oseltamivir reduces the severity,duration of the symptoms of influenza,and reduces the frequency of secondary illnesses and exacerbation of underlying conditions.Zanamivir and peramivir may be effective in patients infected with influenza virus,including oseltamivir-resistant virus.Some Chinese medicine such as maxingshigan-yinqiaosan can obtain similar effect of oseltamivir in treatment of influenza virus infection.