Small molecule antibodies are naturally existed and well functioned but not structurally related to the conventional antibodies. They are only composed of heavy protein chains or light chains, much smaller than common antibody. The first small molecule antibody, called Nanobody was engineered from heavy-chain antibodies found in camelids. Cartilaginous fishes also have heavy-chain antibodies (IgNAR, "immunoglobulin new antigen receptor"), from which single-domain antibodies called Vnar fragments can be obtained. In addition, free light chain (FLC) antibodies in human bodies are being developed as therapeutic and diagnostic agents. Comparing to intact antibodies, common advantages of small molecule antibodies are with better solubility, tissue penetration, stability towards heat and enzymes, and comparatively low production costs. This article reviews the structural characteristics and mechanism of action of the Nanobody, IgNAR and FLC.

Objective To verify the mediating effect of the moral identity on the relationship between sport moral disengagement and pro-social and anti-social behaviors in competition.Methods Two hundreds and sixty-seven athletes of group events(including 173 males,94 females,with an average age of 22.40,SD=2.75)were selected and investigated using the sport moral disengagement scale,moral identity scale and the scale of pro-social and anti-social behavior in competition.Results (1) The sport moral disengagement had significant influence on the athletes'pro-social and anti-social behaviors in competition.(2)The moral identity has significant positive influence on the athletes' pro-social behavior in competition,but significant negative influence on the athletes' anti-social behavior in competition.(3)The moral identity has significant mediating effect on the relationship between sport moral disengagement and pro-social behavior in competition.Conclusion The moral disengagement in sport has important influence on the athletes' pro-social and anti-social behavior in competition.The moral identity has a significant mediating effect on the relationship between sport moral disengagement and pro-social behaviors in competition.

Objective To analyze the CT features of orbital bone benign tumor and tumor mimics,so that to improve the diagnostic accuracy of these diseases.Methods CT appearances of orbital bone benign tumor and tumor-like lesion in 32cases proved by surgery,pathology and clinical features were reviewed.The lesions included orbital bone benign tumor(n=17)and tumor-like lesions(n=15).Results On CT,orbital osteomas in 9 cases showed homogeneous high density and cavernous bone-like density or ground glass-like density;ossifying fibroma in 5 cases were well-defined expansion of bone with ossification,cystic areas within the lesions;epidermal cyst in 2 displayed cystic density ;calcification and ossification could be seen in 1 case of chondroma ;10 cases of fibrous dysplasia showed ground glass-like density with cystic areas in poor-defined expansion of bone;the osteolytic destruction with well-defined margin were founded in 3 cases of orbital Langerhans' cell histiocytosis;1 case of aneurismal bone cyst appeared as cystic and expansive lesion with thin bone shell;1 case of osteopetrosis showed homogeneous high density in orbital wall.Conclusion Various orbital bone benign tumor and tumor-like lesions have different CT features.CT scan can clearly demonstrate the extent,density,border and the relationship with adjacent tissue of these lesions.

Objective:To compare clinical effects of the open versus closed high tibial osteotomy on knee osteoarthritis.Methods:A total of 100 patients with knee osteoarthritis admitted to our hospital from May 2018 to May 2019 were included.They were randomly divided into groups A and B(n=50, each group)according to the principle of random and double blind.Patients in group A received the medial opening high tibial osteotomy, and group B were treated with lateral closed high tibial osteotomy.The changes in the Lysholm knee score, hospital for special surgery(HSS)knee score and complications were compared between the two groups before and 1 year after surgery.The correction angle, the change of patella height before and after operation, and the change of posterior slope of tibial plateau were compared between the two groups.Results:Before and after treatment, Lysholm scores were(63.51±5.47)and(90.98±5.84)( t=24.275, P=0.000), and HSS scores were(51.85±4.68)and(88.64±5.87)( t=34.652, P=0.000). Lysholm scores were(62.98±6.14)and(91.52±6.54 9)( t=22.497, P=0.000), and HSS scores were(52.05±5.16)and(89.54±5.15)( t=36.362, P=0.000)in group A and B, .After treatment, all index were significantly improved in the two groups, but there was no statistical difference between the two groups( P>0.05). In group A, the posterior slope of tibial plateau were(8.75±1.48)° and(10.25±1.65)°( t=4.785, P=0.000)and the patellar height was(0.890±0.031)and(0.898±0.032)( t=1.270, P=0.207)before and after treatment.Before and after treatment in group B, the posterior slope of tibial plateau were(8.69±1.53)° and(5.26±1.21)°( t=12.434, P=0.000)and the patellar height were(0.889±0.047)and(0.821±0.039)( t=7.873, P=0.000). The correction angle, posterior slope of tibial plateau and patella height were significantly improved after treatment in the two groups.While, the decreases of posterior slope of tibial plateau and patella height were better in the group B than in the group A( P<0.05). There was no significant difference in the incidence of complications between the two groups( P>0.05). Conclusions:For treatment of knee osteoarthritis patients, the medial opening high tibial osteotomy and lateral closed high tibial osteotomy have the same exact effect and high safety, but the two methods have their own advantages and disadvantages in clinical treatment.And the appropriate surgical treatment can be selected according to the characteristics of patients.

Objective To assess the dose reduction potential of adaptive statistical iterative reconstruction(ASiR)and model-based iterative reconstruction(MBIR)in pelvic CT with a standard male phantom.Methods A Fluke Biomedical RANDO standard male phantom was scanned with discovery CT750 HD using different tube currents.CT images were reconstructed with FBP,50％ASiR and MBIR.The CT value,the image noise and the contrast-to-noise ratio(CNR)for the sacral vertebra relative to muscle were measured.The volume CT dose indexes(CTDIvo1)and dose-length product(DLP)were recorded.Results Compared with FBP,using 50％ASiR and MBIR had significant reduced image noise and greater CNR.The effective minimal tube currents for displaying sacral vertebra were 250 mA(FBP),180 mA(50％ASiR),and 100 mA(MBIR).With the similar image quality using FBP,the dose was reduced by 28.0％ and 59.9％ using 50％ASiR and MBIR,respectively.Conclusions Using advanced iterative algorithms can reduce image noise,improve CNR,and reduce the radiation dose in pelvic CT examination.

BACKGROUND: Studies have demonstrated that the freeze-dried and irradiation-sterilized allogeneic bone is an ideal material for bone transplantation, they are present with good biocompatibility and biomechanical property, also maintains some necessary enzymes for bone morphogenetic protein and morphogenesis protein in bone matrix with some osteninductivable potentials. OBJECTIVE: To observe the effect of the compound of placenta tissue injection and allogeneic lyophilized bone on the reconstruction of jaw bone defects of dogs, and to compare with single allogeneic lyophilized bone. DESIGN, TIME AND SETTING: A comparative observational trial was performed in the Animal Experimental Center of Harbin Medical University between December 2007 and September 2008. MATERIALS: Eight healthy hybred adult dogs; allogeneic lyophUized bone was offered by Hubei Osteolink Biomatedals Co.,Ltd; placenta tissue injection was purchased from Livzon Pharmaceutical Factory Zhuhai (2 mL per injection); allogeneic lyophilized bone: placenta tissue injection=(4-5):1.METHODS: A total of 96 experiment areas from hemisphere jaw defect models at 1.0 cm diameter were established in dog jaw bone site corresponding with central incisor, canine teeth and root apex of the first molar. In the experiment group, the allogeneic lyophilized bone and bone particles were soaked in placenta tissue injection and under saturation state, then the compound of placenta tissue injection and allogeneic lyophilized bone were implanted to jaw bone defect. In the positive control group, the allogeneic lyophilized bone and bone particles were soaked in sodium chloride injection and under saturation state, then implanted to jaw bone defect. In the negative control group, nothing was implanted to jaw bone defect. Each experiment area comprised four materials in each group.MAIN OUTCOME MEASURES: The radiological and histological observations were performed at 2, 4, 8 and 12 weeks after operation.RESULTS: In the experiment group, there was obvious cartilaginous osteogenesis in the earlier period and intramombranous osteogenesis in the late period. The new bone was well integrated with the surrounding tissues. In the positive control group, new recovered bone existed but the combination between the new bone and the original bone was not well. In the negative control group, jaw bone defects were not filled with bone trabecula. Histological examination results showed that there were more new bones in the experiment group than the control groups at 2, 4, 8 and 12 weeks after operation. Statistical difference could be observed among them (P < 0.05, P < 0.01 ).CONCLUSION: The compound of placenta tissue injection and allogenalc lyophilized bone can promote recovery of jaw bone defect actively and shorten recovering time effectively.

Objective To describe the MR appearancses of growth-plate of the developmental long bones,and to study the correlativity of MRI with the anatomy and histology findings.Methods 40 pigs with normal knees were examined by 1.0 T scanning system with various orientations and sequences,MR imagings were compared with the results of sectional anatomy and histology.Results According to MRI,we divided the evolution of growth plate into four developmental stages;the earlier forming stage of growth plate(aged the 80～95 days of pregnancy),the forming stage(aged the 95 days of pregnancy-2 months),the maintaining stage (aged 2 months-3.5 years),the closing stage(aged 3.5～4.5 years).The MRI manifestations of growth plate of knees reflected the findings of sectional anatomy perfectly and histology to a certain extent in each developmental stage.Conclusion MRI is very useful and helpful in dividing the developmental stages of growth-plate,guessing the foundation of anatomy and histology,diagnosing and differentiating all kinds of growth plate lesions.

Objective To study radiological characteristics of hand-foot-mouth disease(HFMD) in children. Methods The chest X-ray films of 1295 children patients of HFMD were analyzed,for the general X-ray manifestations and the evolution. Results A total of 1427 films was obtained from all patients, in which 1203 cases were normal and 224 cases were abnormal. The interstitial changes characterized the abnormal group, mainly as increased and vague lung markings, increased hilar shadows (137 cases).The parenchyma changes appeared as patchy exudative shadows(49 cases). Short-term dynamic observation was applied in 62 cases, 38 cases pulmonary disease progression manifested as normal and the interstitial type changing into the parenchyma type and the mixed type, the localized type changing into the diffuse type. Conclusions Most children patients of HFMD showed normal chest films, while the abnormal patients were characterized by interstitial and parenchyma pulmonary edema. Serial chest X-ray examination and short-term dynamic observation were important to identify the severe cases and assess patients' condition.

Objective To explore the imaging characteristics of testicular germ cell tumors and to improve the MRI diagnostic level. Methods MRI and clinical data of 25 cases confirmed testicular germ cell tumor by pathological examination were retrospectively analyzed. All the 25 cases were performed plain scan of MRI,and 16 patients underwent MRI enhanced scan.The size,morphology,signal intensity, adjacent structures,enhancement figure and tumor supplying artery were assessed and the histopathological findings were servered as the standard of reference.Results In the all 25 testicular germ cell tumors,10 cases were seminoma,8 cases showed homogeneous low signal intensity,2 cases of seminoma were low signal intensity on T2 WI,furthermore 5 cases performed poor nodular enhance-ment,2 cases performed homogeneous enhancement,4 cases performed fibrous septa enhancement.4 cases were yolk sac tumor ap-peared equal-low signal on T1 WI,slightly high signal intensity on T2 WI and progressive enhancement.Mature teratoma,pidermoid cyst and mixed germ cell tumor were 3 cases respectively,the MRI demonstrated mixed low signal intensity on T1 WI and mixed high signal on T2 WI.2 cases were embryonal carcinoma demonstrated middle-low signal intensity on T1 WI,and mixed low signal intensity on T2 WI.The two cases revealed bleeding signal intensity and septa enhancement.Conclusion MRI can be used to diagnose germ cell tumors with high accuracy,and provides essential information for pathological type,stage and differential diagnosis.

Objective To explore the imaging characteristics of seminomas and nonseminomatous germ cell tumors (NSGCT) and its pathological foundation. Methods CT and MR imaging manifestations in 25 cases of testicular germ cell tumors proved by pathological examinations were analyzed retrospectively. All tumors were divided into seminomas group (12 cases) and NSGCT group (13 cases). In the seminomas group, 5 cases were examined by CT and 4 of those also had contrast enhanced CT. Seven cases had MRI and 4 of those had dynamic enhanced MRI. In the NSGCT group, 5 were examined by plain CT in which two were by contrast enhanced CT, eight were by MRI in which 4 were by dynamic enhanced MRI. CT or MRI characteristics (morphology, density or intensity, enhancement) in both groups were analyzed by Fisher test. Results Histological examination revealed 25 intratesticular lesions. In 12 seminomas, 10 showed a nodular/lobulated shape, 5 showed a mixed density or intensity. In 13 NSGCT, only one lesion showed a lobular shape, 11 showed a mixed density or intensity. Seven seminomas showed a low signal on T2WI on MRI while only two NSGCT showed this sign. In four lesions underwent dynamic MRI scanning, 3 showed fibrous septum enhancement while no lesions in NSGCT showed this sign. The occurrence rate of the above imaging characteristics in both group was significantly different (P<0.05). Conclusion Seminomas and NSGCT may have their own CT and MRI characteristics, which may be of great value for differential diagnosis .