A generative adversarial network-based unsupervised domain adaptation method for magnetic resonance image segmentation / 生物医学工程学杂志

Intelligent medical image segmentation methods have been rapidly developed and applied, while a significant challenge is domain shift. That is, the segmentation performance degrades due to distribution differences between the source domain and the target domain. This paper proposed an unsupervised end-to-end domain adaptation medical image segmentation method based on the generative adversarial network (GAN). A network training and adjustment model was designed, including segmentation and discriminant networks. In the segmentation network, the residual module was used as the basic module to increase feature reusability and reduce model optimization difficulty. Further, it learned cross-domain features at the image feature level with the help of the discriminant network and a combination of segmentation loss with adversarial loss. The discriminant network took the convolutional neural network and used the labels from the source domain, to distinguish whether the segmentation result of the generated network is from the source domain or the target domain. The whole training process was unsupervised. The proposed method was tested with experiments on a public dataset of knee magnetic resonance (MR) images and the clinical dataset from our cooperative hospital. With our method, the mean Dice similarity coefficient (DSC) of segmentation results increased by 2.52% and 6.10% to the classical feature level and image level domain adaptive method. The proposed method effectively improves the domain adaptive ability of the segmentation method, significantly improves the segmentation accuracy of the tibia and femur, and can better solve the domain transfer problem in MR image segmentation.

Research progress on screening of pregnancy-related diseases based on fetal cell free DNA / 中华医学遗传学杂志

Fetal cell free DNA (cfDNA) in maternal blood circulation mainly originates from placental trophoblasts which have dual characteristics of apoptotic cells and the embryo, and can be affected by maternal factors. Pregnancy-related diseases including preeclampsia, gestational diabetes mellitus, preeclampsia, macrosomia and fetal growth restriction can seriously affect maternal health and pregnancy outcome. Early prediction and timely intervention are important means to reduce the risk. Fetal cfDNA and prediction of pregnancy-related diseases have become a hot topicfor current research. This paper reviews the latest progress made in the field.

Study of characteristics of three dimensional motion of cervical spine during maximal axial rotation / 天津医药

Objective To determine the three dimensional motion data of each segment of cervical vertebrae and analyze the characteristics of the intervertebral coupled motion during cervical axial rotation under physiological weight bearing. Methods A total of 16 healthy volunteers (ranging from 22 to 29, median age, 23 years) were recruited to our study. Any cervical spine disorder history, pain or other discomfort and malformations were excluded so as to avoid abnormal neck motion. These subjects underwent CT scans of their cervical segments in a supine position, and 3D models of C1-C7 were constructed. Next, each subject was asked to sit up straight and was positioned in the following sequence:maximal left and right twisting, while double oblique images by DFIS were taken simultaneously at each of the positions. Then, the CT models were matched to the osseous outlines of the images from the two oblique views to quantify the position of cervical vertebraes in 3D at each position. Through local coordinate systems at the center of vertebral bodies, changes of position and angle of each cephalad vertebrae relative to the cauddal one were calculated before and after the axial rotation. Results (1) In the axial rotation of the cervical spine, the contribution of C1/2 accounted for the most of the total cervical rotation range. For the lower levels, axial rotation was found to be maximal at C3/4 and C5/6, minimal at C2/3. (2) In cervical axial motion, C1/2 demonstrated a coupled lateral bending opposite to the axial rotation direction, while each segment of C2-7 demonstrated coupled lateral bending towards the same side of the axial rotation. Among these segments the lateral bending angle of C2/3 was smaller than angles of C3/4, C4/5 and C5/6. Conclusion This study investigated the cervical coupling behavior using the noninvasive 2D-3D matching technique and obtained the motion data at each cervical spinal segment. These findings will help to improve the understanding on physiological cervical spine movement and potential biomechanical mechanism and treatment of cervical spondylosis. Also our data may provide useful reference for the prosthesis design.

Reflections on the teaching competition of young teachers in medical colleges / 中华医学教育探索杂志

National Teaching Contests of young teachers from medical colleges in China has been held for several years. Experiences obtained from participating and observing the contest have shown that the teaching ability and quality of young teachers have been dramatically improved over these years. But there are a few problems worthy of attention. First, up-to-date progress in scientific research should be intro-duced to the class in proper way. Applying the scientific material mechanically or overgeneralizing individual findings should be avoided in this process. Secondly, the teachers should strengthen the cultivation of criti-cal thinking and dialectical way of thinking, to enable students to use critical thinking, the integrated point of view to analyze and solve the problem. Thirdly, teaching should also focus on humanistic education, and through the infiltration of human content in the classroom, imperceptibly affect students. Finally, young teachers can give full play to their advantages of rapid learning and to use internet as a platform for the reform of teaching methods to promote the interaction between teachers and students, enriching their class-room.

Study on the Differences of Inorganic Elements in Different Parts of Saururus chinensis / 中国药房

OBJECTIVE:To analyze the differences of inorganic elements in different parts of Saururus chinensis.METHODS:The samples were treated with microwave digestion.The contents of 25 inorganic elements were determined by inductively coupled plasma mass spectrometry (ICP-MS) method:RF power of 1 200 W,cooling gas flow of 14 L/min,auxiliary gas flow of 1.0 L/ min,atomizing air flow of 0.9 L/min,He as collision gas with flow rate of 4.8 mL/min,sampling cone aperture of 1.1 mm,skimmer cone aperture of 0.9 mm,super skimmer cone aperture of 1.0 mm,integral time of 1 s,delay time of 40 s,single hop as scanning mode,repeated for 3 times.The data of principal component analysis and partial least squares discriminant analysis were analyzed with the SIMCA-P 13.0 statistical software.RESULTS:The linear ranges of lithium (Li),beryllium (Be),boron (B),magnesium (Mg),aluminum (Al),titanium (Ti),vanadium (V),chromium (Cr),manganese (Mn),iron (Fe),cobalt (Co),nickel (Ni),copper (Cu),zinc (Zn),gallium (Ga),arsenic (As),cobalt (Sr),cadmium (Cd),tin (Sn),antimony (Sb),barium (Ba),mercury (Hg),thallium (Ti),lead (Pb) and bismuth (Bi) were 0.05-5.0 μg/L(r=0.999 9),0.05-5.0 μg/L(r=0.999 8),0.1-10.0 μg/L(r=0.999 5),1.0-100.0 μg/L(r=0.999 5),1.00-100.0 μg/L(r=0.999 3),0.10-10.0 μg/L(r=0.999 9),0.05-5.0 μg/L (r=0.999 7),0.05-5.0 μg/L(r=0.999 5),0.10-10.0 μg/L(r=0.999 8),1.00-100.0 μg/L(r=0.999 4),0.05-5.0 μg/L(r=0.999 9),0.05-5.0 μg/L(r=0.999 7),0.05-5.0 μg/L(r=0.999 5),0.05-5.0 μg/L(r=0.999 8),0.05-5.0 μg/L(r=0.999 6),0.05-5.0 μg/L(r=0.999 8),0.05-5.0 μg/L(r=0.999 9),0.05-5.0 μg/L(r=0.999 3),0.05-5.0 μg/L(r=0.999 4),0.05-5.0 μg/L(r=0.999 8),0.1-10.0 μg/L(r=0.999 6),0.05-5.0 μg/L(r=0.999 6),0.05-5.0 μg/L(r=0.999 6),0.05-5.0 μg/L(r=0.999 7),0.05-5.0 μg/L(r=0.999 4),respectively.The detection limits were no higher than 13.2 ng/L.RSDs of precision,stability and reproducibility tests were all lower than 5.12％.The recoveries ranged 90.18％-123.01％ (RSD were 2.05％-5.79％,n=6).The contents of Sb,Sn,Mn,Cd,Ti,Ba,Co,As,Be,Ga,Ni were higher in aerial part than in rhizome part,while the content of Cr was higher in rhizome part than in aerial part.CONCLUSIONS:Mg,Fe and A1 are abundant in aerial part and rhizome part of S.chinensis.The contents of inorganic elements are significantly different in different parts of S.chinensis.

Research progress of in-vivo kinematics after cervical arthrodesis / 天津医药

Related literature and studies concerning the kinematics in patients after cervical arthrodesis have extensive?ly reviewed and comprehensively analyzed in 4 terms of changes in adjacent segment range of motion, motion segment per?cent contributions, motion pattern of cervical facet joints, and deviated center of rotation at adjacent segments. These report?ed researches of in-vivo kinematics after cervical arthrodesis are almost on the sagittal plane. Few data have been reported on the 6DOF kinematics under physiological loading conditions. Whether adjacent segment pathology caused by hypermobili?ty remains controversial. Long-term follow-up of large sample randomized controlled studies and obtaining the accurate 6DOF kinematics are the best way to resolve controversy.

Three-dimensional transient motion characteristics of atlanto-axial joint in healthy adults under physiological load / 中国组织工程研究

BACKGROUND:The cervical spine of the human body is an important structure carrying the head and connecting the spine. Its volume is smal, but its flexibility was great. Activity frequency was highest. Simultaneously, cervical spine is the most complicated bony structure of geometric and kinematic characteristics of human body, bears the physiological load of the head, has functions of flexion and extension, lateral bending and rotation. Therefore, the cervical spine has become one of the most vulnerable structures with degenerative diseases of the spine. Analysis of upper cervical spine biomechanics, recognition and understanding of its normal function and mechanical mechanism wil provide a theoretical basis for better treatment of upper cervical spine disorders. OBJECTIVE:To observe thein vivothree-dimensional kinematics of the upper cervical spine in healthy human beings under physiological load with dual fluorescence X-ray imaging system and spiral CT. METHODS:Seventeen healthy volunteers were recruited for this study. The vertebral segment motion of each subject was reconstructed with three-dimensional computed tomography and solid modeling software.In vivo cervical vertebral motion during functional postures was observed with dual fluoroscopic imaging. Coordinate systems were established at the vertebral center to obtain the intervertebral range of motion. RESULTS AND CONCLUSION: (1) During the flexion-extension motion, significant differences in the distance in coronal axis, sagittal axis and angle of rotation were detected in C1-2 and C2-3segments. (2) During the left-right bending motion, the angle of rotation was obviously greater at C1-2 segment than that at C2-3segment. During the left-right twisting motion, significant differences in distance of the vertical axis and the coronal axis, lateral flexion angle and rotation angle were detectable between C1-2and C2-3 segments. (3) These findings confirmed that dual fluorescence X-ray imaging system combined with CT scan can obtain atlanto-axial three-dimensional instantaneous motion of six-DOF data of healthy adults, and found that the main motion of the C1-2 vertebrae is rotating. These data may provide us with some new information about the in vivo kinematics of the upper cervical spine and the non-fixed surgical operation.

Effect of weight-bearing activity on the center of rotation in the lower lumbar vertebrae / 中国组织工程研究

BACKGROUND:Epidemiologic reports have indicated that excessive weight-bearing exercise is one of important risk factors for lumbar degeneration, but the effects of weight-bearing activity on normal lumbar motion pattern are stil not clear. OBJECTIVE:To measure the changing characteristics and rules of position at the center of rotation of the lower lumbar spine during a weight-lifting activity of normal person. METHODS: Fourteen asymptomatic subjects with a mean age of (25±5) years were recruited for this study. The L4-5 and L5-S1 segments of each subject were CT-scanned to construct 3D models using dual X-ray imaging system and spiral CT examination combined technology in the aid of computer software. The physiological load and lumbar spinal 3D motion under the loading condition were reproduced when matching the flexion, neutrality and extension in the dual X-ray imaging system and on dual oblique lumbar X-ray image. Coordinate systems were established at the vertebral body of L4-S1 to obtain the center of rotation during flexion-to-neutral, neutral-to-extension and the ful flexion-extension motion. RESULTS AND CONCLUSION: (1) Under physiological load, the center of rotation of L4-5 of normal person was located about 1.0 mm anterior to the central axis of the vertebral body, and the center of rotation of L5-S1 was located about 0.7 mm anterior to the central axis of the vertebral body. (2) With weight loading, the center of rotation of both two segments shifted backward about 0.5 mm. There was no statistical difference between these two loading conditions. (3) When the center of rotation in flexion and extension was calculated respectively, the moving range of the center of rotation at both L4-5and L5-S1 became larger due to taking loads of 10 kg (P < 0.05). In flexion, the center of rotation at L5-S1 significantly shifted forward during a weight-lifting activity (P < 0.05). (4) These results confirm that compared with non-weight-bearing condition, the trajectory of the center of rotation was found to be increased when taking loads, especialy during the flexion-to-neutral motion.

Open reduction and internal fixation for floating symphysis pubis / 中华骨科杂志

Objective To explore the clinical characteristics of the floating injury of symphysis pubis and clinical outcome of open reduction and internal fixation.Methods A retrospective study was conducted to analyze the 48 patients who had been treated in our department with open reduction and internal fixation for the floating injury of Symphysis pubis from January 2008 to January 2013.There were 31 males and 17 females,with an average age of 36.5 years (range,20 to 61 years).Thirty-five patients were injured in traffic accidents and 8 were injured by falling injuries,and the other 5 were crushed by maehine.Fortyfive cases were complicated with fractures of the posterior pelvis ring; 14 cases were complicated with acetabular fractures; 17 cases were complicated with extremity fractures; 1 1 cases were complicated with thoracic and abdominal injuries and 6 cases were associated with urogenital system injury.The average period from trauma to operation was 7 days (range,3 to 25 days).Operation was performed under general anesthesia.The bilateral pubic ramus fractures were fixed with reconstruction plate in 41 cases,and 7 cases were fixed with cannulated screw through minimally invasive method.Forty-one cases with posterior ring fractures were fixed simulaneously.Results There were 44 patients being followed up with an average period of 16 months (range,12 to 30 months).All the fractures of the pelvis were clinically healed with an average period of 12.6 weeks (range,10 to 16 weeks).According 图o the Majeed score system,the functional results were exc ellent in 30 cases,good in 10 cases,and fair in 4 cases; The average score was 81.5 (range,60 to 100).Two patients who had wound fat liquefaction at 3 days after operation were healed by dressing changing; 8 patients got deep vein thrombosis at 10 days (range,5 to 15 days) after operation were cured by conservative treatment; 3 patients got supra pubic pain at 6 days (range,5 to 7 days) after operation were healed by oral non steroidal anti-inflammatory analgesic drugs and physical therapy in one year.Conclusion Floating injury of symphysis pubis is a kind of severe pelvic fracture which affects the stability of pelvic ring.Open reduction and internal fixation is a good method to stabilize the pelvis ring and to get early rehabilitation.This may contribute to good clinical resuls and good function.

The effect of pathoglycemia on the tumor biomarker expression in pancreatic tumor / 中国综合临床

Objective To investigate the effect of pathoglycemia on the tumor biomarker expression in pancreatic tumor and assess its influence on the diagnostic value of these biomarkers.Methods We recruited 59 patients with malignant pancreatic tumor in total into this study,including 46 cases with pancreatic carcinoma and 13 cases with other pancreatic malignancies.Twenty-seven patients with benign pancreatic diseases were selected as control.All subjects were extracted venous blood and serum samples were separated by centrifugation.Serum levels of CA199,CA125 and CEA were measured by chemiluminescent microparticle immunoassay(CMIA).The positive expression criteria were designated as ＞37 kU/L for CA199;＞35 kU/L for CA125;＞10 μg/L for CEA.Results (1) CA199 showed the highest diagnostic accuracy when the tumor biomarker was used alone.CA199 plus CEA showed the highest diagnostic accuracy when the biomarkers were used pairwisely,even better than three biomarkers used in combination(x2=26.131,P＜0.05).(2)The average rank of all tumor biomarkers were higher in all malignant pancreatic tumor than benign pancreatic diseases,and some of the differences reached statistically significance(CA199,Z=4.682,P=0.000;CA125,Z=1.866,P=0.062;CEA,Z=2.573,P=0.010).(3)When the malignant pancreatic tumor group were further divided into two groups according to their blood sugar level,we found that CA199 were significantly higher in pathoglycemia group than euglycemia group(Z=2.265,P=0.024),while no significant differences were observed in patients with benign pancreatic diseases when compared between patients with different blood sugar levels(Z=4.214,3.224,3.154,Ps＞0.05).Conclusion The combination use of three tumor biomarkers showed no improvements in the diagnosis of pancreatic neoplasm,but with disadvantage of elevated medical expense.CA199 showed the highest diagnostic accuracy when used alone.CA199 plus CEA showed the highest diagnostic accuracy when the biomarkers were used pairwisely.The blood sugar level should be considered when using CA199 in the differential diagnosis of pancreatic neoplasm from benign pancreatic lesions;a new set-point of CA199 should be set by studying the ROC curve and other statistic index to improve the overall accuracy.

Effect of low-level lead exposure on neurobehavioral function in preschool children / 中国组织工程研究

BACKGROUND: Environment pollution due to lead is severe day by day,and the lead-induced developmental toxicity of central nervous system is prominent.OBJECTIVE: To observe the effect of lead at low exposure level on neurobehavioral function of preschool children and provide basis for preventing childhood behavior disorders.DESIGN: Sampling survey.SETTING: Department of Children and Adolescent Health, Public Health College, Sun Yat-sen University.PARTICIPANTS: Totally 211 children of 4-6 years (109 boys and 102girls) were enrolled from a kindergarten of a populated area of Zhuhai City by randomized cluster sampling from September to October 2004.METHODS: 20 mL peripheral blood of finger tip was collected. Blood lead was determined with graphite stove atomic absorption spectrometry.According to the amount of blood lead, the children were divided into high blood lead exposure group (＞100μg/L) and low blood lead exposure group (＜100μg/L). Furthermore, they were also assigned into ＜50 μg/L group, 50μg/L- group, 100μg/L- group, 150 μg/L- group, 250- μg/L group. Achenbach's Child Behavior Checklist (CBCL) and self-designed questionnaire (composed of possibly effective factor on children's neurobehavioral function, such as age, sex, cultivation, family background and so on) were applied, filled by their parents under the instruction of professional staffs. Results and blood lead value were analyzed with first order correlation and multiple factors stepwise regressive analysis.MAIN OUTCOME MEASURES: ①Blood lead level and each factor scores of CBCL, ②correlation analysis between blood lead value and behavioral factor score.RESULTS: A total of 211 questionnaires were sent out, and 211 were retrieved with 211 effective questionnaires. The effective rate was 100%. ①Score on externalizing and behavioral disorder rate in the high blood lead exposure group (13.28±6.26,18.26%) was significantly higher than those in the low blood lead exposure group (9.98±5.46,7.29%)( t=4.067 7,χ2=5.470, P＜0.05). There was insignificant difference in score on internalizing and total score of CBCL between the low and high blood lead exposure groups. ②The behavioral disorder rate of different blood lead level had significance (χ2=13.695,P＜0.01). The behavioral disorder rate in blood lead ≥ 150 μg/L was obviously higher than that of the former 3groups after further pairwise comparison (χ2 were 4.727, 6.261, 5.168;4.503, 5.911, 4.928, P＜0.05), which revealed that the child behavioral disorder rate markedly increased when the blood lead was ≥ 150 μg/L.③Blood lead logarithm value had positive correlation with the scores on hyperactivity, aggression and defiance (r=0.316 4,0.282 8,0.188 6,P ＜0.05), and had no correlation with obesity, desintegration, truculence and sexual questionnaire (r=0.102 4,0.094 2,0.118 3,0.092 6,P ＞ 0.05). ④After the stepwise regression analysis, the scores on hyperactivity, aggression and defiance factors were included in the regression equation. The results suggested that the effect of lead on child externalizing behavior still remained, and kept statistical meaning after confounding factors, such as controlling family and society, etc.CONCLUSION: Low-level lead exposure has adverse effects on externalizing behavior in preschool children.