AIM: To establish a method for the quality control of Danqi Tablet(Radix et Rhizoma Salviae Miltiorrhizae,Radix et Rhizoma Notoginseng,etc). METHODS: The content of salvianic A and protocatechualdehyde,notoginsenoside R_1 and ginsenoside Rg_1 in Danqi Tablet were determined simultaneously respectively by HPLC. RESULTS: The methodological study showed that a good linear correlation existed in the range of 0.164-3.28 ?g(r=0.999 99) of sodium salvianic A,0.013-0.52 ?g(r=0.999 999) of protocatechualdehyde,0.2-6 ?g(r=0.999 997) of notoginsenoside R_1 and 0.824-24.72 ?g(r=0.999 96) of ginsenoside Rg_1,respectively.The average recovery of sodium salvianic A was 98.34%(n=9),RSD was 2.03%,100.65% for protocatechualdehyde(n=9),RSD was 2.96%,98.97% for notoginsenoside R_1(n=9),RSD was 2.81%;98.93% for ginsenoside Rg_1(n=9),RSD was 0.57%. CONCLUSION: The determination methods are simple,accurate and reproducible.The method can be used for quality control of Danqi Tablet.

An adult patient with skeletal crossbite and mandibular deviation was treated by mandibular molar distalization using micro-im-plant and intermaxillary traction.After treatment,the facial contour of the patient was improved,the Class Ⅰ molar and cuspid relationship was achieved.

An adolescent patient,in the peak of growth and development,with severe skeletal Class Ⅲ malocclusion and maxillary impacted canines was treated by removable and fixed appliances in the upper and lower dental arches.After treatment,the crossbite was relieved,the facial contour was improved,the integrity of the denture was kept and the Class Ⅰ molar relationship was achieved.

Objective:To explore the application effect of magnetic resonance imaging (MRI) sequence experiment based on virtual simulation software in undergraduate teaching of medical imaging technology.Methods:Fifty-six undergraduate students from the Batch 2015 and Batch 2016 medical imaging technology of West China Clinical Medical College of Sichuan University were recruited in this study. They were divided into 2 groups: experimental group (Batch 2016) and control group (Batch 2015). The experimental group adopted the teaching method based on virtual simulation experiment, and the control group used the teaching method based on traditional small-sized magnetic resonance. The after-class test scores and final exam scores of the two groups of students were compared, and the questionnaire survey on teaching effectiveness was conducted for students in the experimental group SPSS 21.0 was used for ttest and Mann-Whitney Utest. Results:The scores of theoretical knowledge and the final grades in the experimental group were significantly higher than those of the control group [(84.55 ± 6.57) points vs. (79.37 ± 6.13) points; (90.03 ± 4.72) points vs. (80.06 ± 7.29) points, all P< 0.05). The effective recovery rate of the questionnaires was 100%, and the questionnaire survey showed that the experimental group was significantly superior to the control group in such four aspects as increasing subject interest, expanding relevant knowledge, solving clinical work, and promoting teamwork ( P< 0.05). Conclusion:In MRI sequence teaching, the teaching method based on virtual simulation software can increase the students' interests in learning, strengthen their understanding of MRI principles, then effectively improve the teaching effect of medical imaging undergraduate education.

Objective To investigate the value of "one-stop" scanning of coronary and head and neck CTA in patients with normal body mass index (18 kg/m2 ≤ BMI ≤ 25 kg/m2) using low tube voltage (80 kVp).Methods In a retrospective analysis 80 patients with normal body mass index who had completed "one-stop" scanning of coronary and head and neck CTA were divided into A and B groups according to different scanning method,and 40 consecutive cases were selected in each group.Scanning parameters of group A and group B were tube voltage 80 kV,coronary CTA tube current 550 mA,head and neck CTA tube current 500 mA,and tube voltage 100 kV,coronary CTA tube current 450 mA,head and neck CTA tube current 400 mA separately.Subjective evaluation and objective evaluation were performed on the image quality of the two groups.CT values of coronary artery and head and neck CTA trunk branch vessel,contrast-to-noise ratio (CNR),image noise (SD) and effective dose between the two groups were compared.Results The image quality of both groups met the diagnostic requirements,and there was no statistically significant difference in subjective scores between two groups (P＞0.05).The CT values of coronary arteries,the main branches of the head and neck (the common carotid artery,the internal carotid artery) and SD of head and neck CTA were significantly different between two groups (t=4.737,6.552,3.359,2.165,2.685,4.617,P＜0.05).There was no statistically significant difference in SD of coronary CTA,CT values and CNR between head and neck vessels (middle cerebral artery) in group A and group B (P＞0.05).The effective dose of coronary CTA in group A (1.16±0.20) mSy was reduced by 51.1％ than that in group B (2.37±0.77) mSv.The effective dose of head and neck CTA in group A (0.37±0.03) mSv was reduced by 47.9％ than that in group B (0.71 ± 0.17) mSv.Conclusions The image quality with subjective evaluation met the diagnostic requirements when using a low-tube voltage for "one-stop"scanning of coronary and head and neck CTA.The CNR values were basically consistent with the conventional scanning method,and the patient effective dose was reduced by about 50％.

Objective: To clone mouse rod opsin promoter (ROP) and establish transgenic mice harboring mouse rod opsin promoter and enhanced green fluorescent protein(mROP-EGFP) fusion gene. Methods: Mouse ROP was cloned from C57BL/6 mouse genomic DNA by polymerase chain reaction (PCR). Expression vector of mROP-EGFP fusion gene were constructed by recombination DNA technique. It was identified by restriction endonucleases digestion and confirmed by DNA sequencing. After Not I restriction endonuclease digestion, the coding elements were microinjected into male pronuclei of mice zygotes to generate transgenic mice. The pups were evaluated by PCR at genomic DNA level and mated with normal mouse. Expression of GFP in retina of transgenic mice was detected by fluorescent microscope. Results: 2. 1 kb mouse rod opsin promoter fragment was amplified from mice genome DNA. Expression vector pmROP-EGFP was constructed successfully. Following microinjection of coding sequence of pmROP-EGFP, 3 pups were verified to integrate the mROP-EGFP fusion gene in their genomic DNA by PCR assay, named C57-TgN (mROP-EGFP )SMMU21, C57-TgN (mROP-EGFP)SM-MU26 and C57-TgN(mROP-EGFP) SMMU27. They could express GFP in retina. Conclusion: 2. 1 kb mouse rod opsin promoter is cloned and expression vector pmROP-EGFP is constructed. mROP-EGFP fusion gene transgenic mice are established, which harboring mROP-EGFP gene and expressing GFP in their retina. This is valuable for studying the development of brain and retina, pathogenesis of retina disorder and retina transplanting.

BackgroundCompared with adult-onset schizophrenia， patients with adolescent-onset schizophrenia experience a high genetic susceptibility， severe negative symptoms， high recurrence rate， poor prognosis and social function recovery. And clarifying the brain functional alterations in adolescent-onset schizophrenia is of great significance for further elucidating the pathogenesis of the disease and exploring personalized and precise treatment. ObjectiveTo investigate the altered functional and effective connectivity of bilateral precuneus in first-episode patients with adolescent-onset schizophrenia based on resting-state functional magnetic resonance imaging （rs-fMRI）， thus providing reliable imaging evidence in guiding the study on mechanism involved in adolescent-onset schizophrenia. MethodsTwenty-one drugnaïve first-episode patients with adolescent-onset schizophrenia who met the Diagnostic and Statistical Manual of Mental Disorders， fifth edition （DSM-5） criteria for schizophrenia were enrolled， and another 21 psychiatrially healthy controls matched on age， educational background and gender were concurrently selected. The schizophrenic subjects were evaluated using the Psychotic Symptom Rating Scales （PSYRATS） and Positive and Negative Symptom Scale （PANSS）. All participants underwent rs-fMRI scans， and the whole-brain seed-based functional and effective connectivity analyses were conducted in bilateral cuneus region. Then the correlation between functional connectivity strength and clinical symptoms of patients was discussed. ResultsIn terms of functional connectivity， the functional connectivity of bilateral precuneus and left middle temporal gyrus was increased in patient group compared with healthy control group ［P<0.01， family-wise error （FWE） correction at cluster level， P<0.05］. In terms of effective connectivity， patient group responded to negative feedback with greater activation of seed region and left middle frontal gyrus than healthy control group. Correlation analysis within patient group denoted that the decreased effective connectivity of bilateral precuneus and left middle frontal gyrus was positively correlated with the total PANSS score （r=0.450， P<0.05）. ConclusionThe resting-state functional and effective connectivity of bilateral precuneus is abnormally alerted in drugnaïve first-episode patients with adolescent-onset schizophrenia， and the decreased effective connectivity of bilateral precuneus and left middle frontal gyrus may be related to the development of clinical symptoms. ［Funded by National Key Research and Development Program of China （number， 2022YFC2009901， 2022YFC2009900）］