Objective To analyze and compare the changes in local functional activity of the brain under different recovery times after a 90-day,-6° head down bed rest(HDBR)experiment,clarify the mechanism of brain function remodeling during gravity adaptation,and provide imaging basis and guidance for the model construction and health assessment.Methods 36 healthy male volunteers underwent resting-state functional magnetic resonance imaging(rs-fMRI)scans before HDBR(PRE),3 days after 90-day HDBR(R+3),and 26-28 days after 90-day HDBR(R+26-28),and calculated regional homogeneity(ReHo)and low-frequency amplitude(ALFF)and perform statistical analysis between different time points.Results Compared with PRE-status,ReHo value in the left inferior parietal gyrus and ALFF value in the right posterior cingulate gyrus decreased significantly in R+3 status,while ReHo value in the left calcarine,right lingual gyrus and ALFF value in the precuneus,left paracentral lobule,and right postcentral gyrus increased significantly.At R+26-28 status,more brain areas showed significant changes.Conclusion 90 days of long-term HDBR and subsequent recovery will lead to changes in the neural functional activities of the brain's default network,sensorimotor network and visual network,and obvious adaptive remodeling will occur after a longer period of gravity re-adaptation and recovery.

OBJECTIVE： To systematically evaluate the efficacy and safety of hydrotalcite combined with omeprazole for gastric ulcer， and to provide evidence-based reference for clinical treatment. METHODS： Retrieved from PubMed， Embase， Medline， the Cochrane library， CNKI， VIP and Wanfang database， randomized controlled trials （RCTs） about hydrotalcite combined with omeprazole （trial group） versus omeprazole alone （control group） for gastric ulcer during the database establishment to Aug. 2018. After data extraction of included literatures met inclusion criteria， and quality evaluation with Cochrane evaluator manual 5.0.1， Meta-analysis was performed for response rate， the incidence of ADR， recurrence rate of gastric ulcer bleeding， needed time of clinical symptom improvement and hospitalization stays by using Rev Man 5.3 statistical software. RESULTS： A total of 16 RCTs， involving 1 802 patients were included. The results of Meta-analysis showed that response rate [RR＝1.24， 95％CI（1.19，1.29）， P＜0.001] of trial group was significantly higher than that of control group； recurrence rate of gastric ulcer [RR＝0.27，95％CI（0.17，0.45），P＜0.001]， clinical symptom improvement time [MD＝－2.04，95％CI（－2.25，       －1.83），P＜0.001] and hospitalization time [MD＝－4.25，95％CI（－4.55，－3.95），P＜0.001] of trial group were significantly lower or shorter than those of control group， with statistical significance. There was no statistical significance in the incidence of ADR [RR＝0.68，95％CI（0.46，1.02），P＝0.06] between 2 groups. CONCLUSIONS： Compared with omeprazole alone， hydrotalcite combined with omeprazole for gastric ulcer can obviously increase the clinical response rate， decrease the recurrence rate of gastric ulcer and shorten the needed time of clinical symptom improvement and hospitalization time， but do not increase the incidence of ADR.

OBJECTIVE： To systematically review therapeutic efficacy and safety of mirtazapine combined with selective calcium channel blocker （SCCB） in the treatment of irritable bowel syndrome （IBS）， and provide evidence-based reference for clinical medication. METHODS： Retrieved from the Cochrane Library， PubMed， Embase， Medline， CNKI， VIP and Wanfang database， randomized controlled trials （RCTs） about mirtazapine combined with SCCB （trial group） versus SCCB （control group） for IBS were collected. After literature screening and data extraction， quality evaluation was performed by using Cochrane system evaluator manual 5.1.0 recommend bias risk evaluation tool. Meta-analysis was performed by using Stata 14.0 software. RESULTS： A total of 14 RCTs involving 1 005 patients were included. The results of Meta-analysis showed that the total response rate [RR＝1.34，95％CI（1.25，1.44），P＜0.001]，neuropeptide-Y level after treatment [SMD＝0.77，95％CI（0.49，1.05），P＜0.001]， response rate of abdominal pain therapy [RR＝1.32，95％CI（1.06，1.66），P＝0.014] and response rate of treatment for abnormal stool characteristics [RR＝1.75，95％CI（1.36，2.27）， P＜0.001] were significantly higher than control group； the scores of depression scale after treatment [SMD＝－1.87， 95％CI （－2.35， －1.39）， P＜0.001]， anxiety scale after treatment [SMD＝－2.25， 95％CI （－3.35， －1.15）， P＜0.001]， abdominal pain symptom score after treatment [SMD＝－7.41， 95％CI  （－8.30，－6.51）， P＜0.001]， diarrhea symptom score after treatment [SMD＝－6.39， 95％CI （－7.96，－4.81）， P＜0.001] were significantly lower than those of the control group. There were no statistical significance in response rate of abdominal distension therapy [RR＝1.07，95％CI（0.90，1.28），P＝0.421] and response rate of abnormal defecation therapy [RR＝1.05，95％CI（0.88，1.26），P＝0.588]， the incidence of abdominal pain [RR＝0.45，95％CI（0.11，1.97）， P＝0.291] and exhaustion [RR＝5.00，95％CI（0.60，41.79），P＝0.137] between 2 groups. CONCLUSIONS： Mirtazapine combined with SCCB can significantly improve therapeutic efficacy of IBS patients， promote clinical symptoms， but do not increase the occurrence of ADR as abdominal pain and exhaustion.

Extraction of teeth is the most basic and widely used operation of oral and maxillofacial surgery. According to characteristics of extraction of teeth, the author views medical ethics principles which in the diagnoses and treatments process from the aspect of medical ethics, they are,①Doctors must intensify their own quality and self - cultivations and establish the idea of " People First ". ②Doctors must carry on the overall and systematic inspection, make the plan of diagnoses and treatments synthetically toimplement the idea of " People First ". ③Doctors should pay attention to interact with patient, meet different patients' demands and create the harmonious medical environment.