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BackgroundDuring severe reactor accidents, melten core causes the radioactive source term material to be no longer retained in the fuel but is released into the environment, causing serious radioactive contamination in the surrounding areas.PurposeThis study aims to investigate the release of fission products, both inside and outside the pressure vessel, using different models in order to analyze the effectiveness of the spray system in controlling the source term release and the decay heat generated.MethodsBased on a typical mega kilowatt pressurized water reactor (PWR) nuclear power plant model, the integrated security analysis program MAAP was applied to modeling reactor rupture accident. Then, the accident sequence and consequences of the reactor primary circuit heat pipe breakage superimposed high and low voltage safety injection failure were calculated and analyzed under CORSOR-M, CORSOR-O and ORNL-BOOTH source term release models.ResultsThe findings indicate that the fission product source term is mainly released in the pressure vessel, and the release amount is significantly higher than that released outside the pressure vessel. Under the CORSOR-O model, the pressure vessel fails the last whereas the containment fails the first; although the pressure vessel fails first in the ORNL-BOOTH model, the containment vessel fails much later than that in the other two models. The difference in source term release leads to different decay heat phenomena in different models, and the main heat source is the volatile fission product. Turning on the spray can not only keeps the suspended iodide in the containment vessel but also effectively removes the decay heat generated by the source items and reduces the pressure of containment.ConclusionsThe ORNL-BOOTH model results in lesser release of source term in the pressure vessel, the greatest variety of source term released, and the maximum time to containment failure. In addition, the opening of the spraying system effectively ensures the integrity of the containment.

Objective To investigate the mechanism of formation of traumatic cerebral venous sinus thrombosis (CVST) in children and analyze the clinical manifestations, treatment and prognosis of CVST. Methods We performed a retrospective analysis of 21 children with traumatic CVST treated in our hospital between January 2009 and December 2019. The clinical manifestations, causes of thrombosis, imaging characteristics and the effects of heparin versus non-heparin treatments were analyzed. Results Among the 21 children with CVST, the main clinical symptoms included headache, vomiting, decreased activity, increased intracranial pressure (30.53±5.07 cmH2O), and papilledema (81%). Cranial fractures involving different sinuses or epidural hematoma was common in the children with CVST. The time of first-time hematoma volume reduction was 18.33±6.15 d in these children, and was significantly shorter in children receiving low-molecular-weight heparin (LMWH) treatment than in those without LMWH treatment (15.00±5.13 vs 23.75±2.96 d, P < 0.001). The percentage of residual hematoma was meanly 11% (3.0%, 14.5%) in the cohort, and it was significantly lower in children with LMWH treatment than in those without. The hematoma stabilization time was 31.08±8.81 d and 37.75±5.01 d and the D-dimer stabilization time was 12.92±4.62 d and 14.62±2.82 d in LMWH group and non-LMWH group, respectively, showing no significant differences between the 2 groups (P>0.05). Conclusion CVST in children often occurs following skull fracture across the venous sinuses or epidural hematoma that compresses the venous sinus. Anticoagulation therapy can shorten the time of hematoma volume reduction, reduce the volume of residual hematoma, and accelerate recanalization to improve the short-term outcomes of the patients.

Angiogenesis plays an important role in tumor growth and metastasis, and vascular endothelial growth factor receptor 2 (VEGFR2) is a key regulatory factor in the process of angiogenesis. Apatinib mesylate is a small molecule tyrosine kinase inhibitor developed over ten years in China. At present, apatinib as single agent has been successfully used in the clinical treatment of advanced gastric cancer, non-small cell lung cancer and breast cancer, etc. The combination of apatinib and other anti-tumor therapies often increases the efficacy and reduces side effects at the same time. In this review, the therapeutic effect and mechanism of apatinib combined with other therapies for varies of tumors were briefly summarized, according to recently reported clinical cases and preclinical researches.

The mechanical exoskeleton is a kind of new electromechanical device that imitates the biological exoskeleton. A wearable flexible knee joint exoskeleton is designed,and the kinematics and dynamics analysis of the lower limb is carried out through using the human body 5 bar simplified model. The angle change curve of the knee joint is consistent with the CGA database through the Matlab/Simulink simulation and the correctness of mathematical model is verified. The lower limb exoskeleton can walk normally through the dynamic simulation of ADAMS,the correctness of the driving function of the knee joint is verified and the torque curve of knee joint is prepared for the control. Finally,the physical prototype is developed and the rationality of the exoskeleton is proved through the angle change curve of the knee joint in the contrast experiment of wear or not-wear exoskeleton.

In order to explore the internal relationship between geological parameters of composite strata and underwater large diameter shield tunneling parameters, the correlation prediction model based on Shantou Bay Tunnel project is constructed with BP neural network method to realize the quantitative prediction from geological parameters to shield tunneling parameters. The research results show that: (1) The geological and equipment characteristics can be effectively represented by establishing the databases of geological parameters based on the number of driving rings and tunneling parameters during shield stable driving. (2) Through data preprocessing, optimization of network structure and training function, a correlation prediction model based on BP neural network is constructed. The average error of total thrust, cutter head speed, tunneling speed and cutter head torque is less than 6%, and the maximum error is less than 18%, which basically meet the engineering accuracy requirements. It is concluded that the shield tunneling parameters can be predicted quantitatively by inputting geological parameters based on the BP neural network correlation prediction model featured by simple structure, convenient operation and high precision. [ABSTRACT FROM AUTHOR]

The research status of gearbox test rig system is reviewed at home and abroad. The problem of energy feedback for the gearbox fatigue test rig system is introduced and classified by the energy power flow.The state of the art of research achievements of gearbox test rig system are given as well as the basic working principles and working performances of various dynamometer test bed system are illustrated in detail. The advantages and disadvantages of various structures are compared,and the application scope of various dynamometer test rig system are summarized. The development trends of dynamometer test bed system are reviewed from the energy feedback load and intelligent control.

Aiming at the possible lack of material, air trapping and bleached appearance defects such as gradient in the free spray specular injection-molded grid with a complex curved surface, an optimization was conducted for the design methods based on the Moldflow software. These methods included the optimization of the local wall thickness and the placement sequence valve hot runner system as well as the change of the local melt flow direction. As a result, the production of appearance defects was eliminated, and the optimal surface quality of the product appearance was achieved. This greatly reduced the scrap rate of products and saved the manufacturing costs. [ABSTRACT FROM AUTHOR]

Objective: To study the effects of vitamin C (VC) on reversing cisplatin (DDP) resistance in oral squamous cell carcinoma (OSCC) and the mechanism. Methods: Human OSCC CAL27 cells were cultured in vitro and DDP-resistant CAL27 cell line (CAL27/ DDP) was screened by increasing concentration gradient method. Plate clone formation assay, CCK-8, Wound healing assay, Annexin V-FITC/PI staining flow cytometry were used to determine the effects of DDP alone or in combination with VC on colony formation, proliferation, migration and apoptosis of CAL27/DDP cells. Western blotting was used to detect the expression level of P-gp protein in CAL27 cells, CAL27/DDP cells and VC treated CAL27/DDP cells. Results: The inhibition concentration (IC50) of DDP increased significantly in CAL27/DDP cells as compared with that in CAL27 cells (P<0.05), indicating CAL27/DDP was DDP-resistant. After the combination with VC, the IC50 of DDP on CAL27/DDP cells was significantly reduced compared with that of DDP alone (P<0.05). DDP combined with VC significantly inhibited the migration of CAL27/DDP cells (P<0.01), and promoted the apoptosis rate (P<0.01). The expression level of P-gp protein in CAL27/DDP cells was increased compared with that in CAL27 cells (P<0.05), but decreased after VC intervention (P<0.05). Conclusion: VC can reverse DDP-resistance in OSCC cells by inhibiting P-gp protein expression. [ABSTRACT FROM AUTHOR]

In this study, PAA was grafted onto the surface of CNCs by using ATRP conditions to prepare nano-crystals with pH-sensitivity. The CNCs particles and the modified CNCs were characterized by infrared spectros- copy (FT-IR), X-ray photoelectron spectroscopy (XPS) and particle size analyzer. The pure PES membrane and blended CNCs-g-PAA/PES membranes were prepared by a phase inversion process, and the structure of the membranes were analyzed and characterized by scanning electron microscopy (SEM), water flux test and contact angle test. The results show that the pore size of the porous support layer of the membrane is larger than that of the pure PES film, and the pore size becomes larger and the top layer becomes thinner. When the CNCs-g- AANaloading is 1wt%, the water flux of the CNCs-g-AANa/PES blend film is obviously improved. And the blend film has pH sensitivity. When the pH value is more than 7.2, the water flux of the blend film tends to be constant at 137.47 I//(m² • h), which is 41 % higher than that of pure PES membrane. When the pH value decrease to 3.3, the water flux of the blend film reaches 218.54 L/(m² • h) by an Increase about 124% as compared with pure PES membrane. [ABSTRACT FROM AUTHOR]

Meat pigeon breeding is an emerging farming industry with a high economic benefit. There are some fundamental problems that need to be addressed, such as the fact that artificial feeding work takes a lot of labor power when breeding in a large scale, the low level of feeding precision, and the high waste forage rate, which is also a disadvantage existing in meat pigeon breeding at present. An automated feeding device for meat pigeons which is suitable for three ladder cages was designed in order to solve the problems of automated feeding for large-scale breeding of meat pigeons. The automated feeding device was mainly composed of feeding troughs, a control box, travel switches, three-phase asynchronous motors, wheels, a driveline, and a frame. The frame mainly uses 40 mm× 40 mm× 4 mm square steel welded together. Feeding troughs were mounted on each layer of the frame respectively. The track was made up of 40 mm× 40 mm× 4 mm angle iron, which was bolted to the ground. The automated feeding device for meat pigeons was equipped with cast iron wheels mounted in the bottom of the frame on both sides. The travel switches were located in the outside of underlying level support of the frame and used to control the stroke of the automated feeding device for the meat pigeons. The driveline selected sprocket and chain to transmit output dynamic of the three-phase asynchronous motors to the wheels. The transmission ratio was 1:1. The control system of the device was mainly composed of a frequency converter, the travel switches, time relays, AC contactors, an air switch, buttons, and an indicator light. In the device's control system, a frequency converter was adopted to control the speed of two three-phase asynchronous motors; the travel switches were used as a position detecting component; a time relay was used to set the running time and residence time in the feeding process; and AC contactors were used to control the start and stop of the frequency converter. The control system realized stroke control of the automated feeding device with high precision such as moving, stopping, and reversing. The prototype of the automated feeding device for meat pigeons was designed and tested for the stroke precision and feed wastage rate. And experimental results showed that the stroke precision of the system was controlled at more than 98%. The feed wastage rate was controlled at less than 1%. In conclusion, the automated feeding device for meat pigeons was applicable to factory farming, and had a good stability; feeding. [ABSTRACT FROM AUTHOR]

Objective: To explore the effects of different fluid resuscitation regimens on vascular permeability during burn stage in swines., Methods: A total of 24 Guangxi-BAMA miniature swines were numbered from 1 to 24 and randomly divided by EXCEL 2007 into 4 groups of succinylated gelatin, hydroxyethyl starch (HES 130/0.4), Parkland (lactated Ringer's solution) and allogeneic plasma (n = 6 each). The model of severe burn shock was established. And fluid resuscitation therapy was applied according to the established regimens of burn shock fluid resuscitation. The parameters of heart rate, blood pressure, urine volume, central venous pressure (CVP) and pulmonary capillary wedge pressure (PCWP) were recorded. Blood samples were collected prior to burns and at intervals of 4, 8, 24 and 48 h post-burns. The plasma colloidal osmotic pressure was measured. Evens blue was intravenously injected at 30 min before sacrificing. Then lung tissue samples were obtained and pulmonary vascular permeability index (PMPI) was measured. Statistical analyses were performed., Results: All swines survived shock stage. The inter-group comparison revealed no statistical difference in heart rate, blood pressure, urine volume, CVP or PCWP. The plasma colloidal osmotic pressures (mmHg, 1 mmHg = 0.133 kPa) of four groups at each interval were as follows: (1) pre-burn: 25.4 ± 1.0, 25.9 ± 0.9, 25.5 ± 1.1, 25.0 ± 1.0; (2) 4 h: 24.3 ± 1.0, 25.6 ± 0.9, 13.2 ± 0.5, 25.0 ± 1.1; (3) 8 h: 23.3 ± 0.8, 25.2 ± 1.2, 12.7 ± 0.5, 24.0 ± 0.9; (4) 24 h: 22.0 ± 0.8, 23.1 ± 1.0, 12.4 ± 0.4, 23.3 ± 0.8; (5) 48 h: 22.3 ± 0.8, 24.1 ± 0.8, 18.1 ± 0.4, 23.5 ± 0.9. No statistically significant differences existed at the intervals of pre-burn between four groups (all P > 0.05). The HES 130/0.4 group at 8 h was significantly higher than that of allogeneic plasma group at the same interval (P < 0.05). The Parkland group at 4, 8, 24, 48 h were significantly lower than those of allogeneic plasma group (all P < 0.05). The succinylated gelatin group at 8, 24, 48 h, the HES 130/0.4 group at 8, 24, 48 h, the Parkland group at 4, 8, 24, 48 h and allogeneic plasma at 8, 24, 48 h decreased versus those at pre-burns (all P < 0.05). No statistically significant differences existed in pulmonary vascular permeability between the groups of succinylated gelatin (7.6 ± 0.9) µg/g, HES 130/0.4 (7.9 ± 1.8) µg/g, and allogeneic plasma (7.6 ± 1.2) µg/g, but all lower than the Parkland group (26.1 ± 2.3) µg/g (all P < 0.05)., Conclusions: Natural colloid or artificial colloid (HES 130/0.4 or succinylated gelatin) have similar effects on vascular permeability in swines with severe burns during shock stage. Both are superior to the Parkland group.

Objective: To analyze the value of MR imaging in diagnosis of intraductal papillary neoplasm of the bile duct (IPN-B)., Methods: Fourteen patients with intraductal papillary neoplasms of the bile duct confirmed by surgical pathology were included in this study. The patients underwent MR routine plain scanning and enhancement scanning (including T1WI, T2WI with fat suppression, FALSH T1WI, and three-phase enhancement scanning), diffusion weighted imaging(DWI) and magnetic resonance cholangiopancreatography (MRCP) before operation. The imaging data were reviewed and analyzed retrospectively in comparison with the surgical and pathological results., Results: In these patients, 7 cases had tumors located in the left lobe, 2 cases had tumors in both the left and right lobes, 2 cases in the hepatic hilum, 2 cases in the common bile duct, and 1 case in both the right lobe and the common bile duct. Solitary or multiple intraductal masses could be found in 12 cases, with 11 cases appeared as papillary masses and one case as flat mass. In the other two cases the tumor was not visible (one case had too many stones, and in another case the tumor was too small). The tumors in the 12 cases showed hypointensity on T1WI and hyperintensity on T2WI. On the dynamic contrast-enhanced MRI, 11 cases showed mild and one showed moderate enhancement in arterial phase, and all the cases showed mildly and gradually delayed enhancement. On DWI, the lesion areas showed high signal intensity in all the cases, and the ADC value of the tumor area (1.697×10(-3)mm(2)/s) was significantly lower than that of the normal bile (3.973×10(-3)mm(2)/s) (t = -10.94, P < 0.05). Twelve cases demonstrated filling defects on primary MRCP coronary thin section images. On 3D-reconstruction MRCP images, 7 cases exhibited diffuse bile duct dilatation with the tumor areas more prominent, 3 cases exhibited aneurysmal bile dilatation, while the rest 4 cases exhibited segmental or lobar bile duct dilatation ( including 2 with invisible tumors ). In the 3 cases with aneurysmal bile dilatation, the multiple directions of MRCP images helped to find the communication between the aneurysmal dilatation and the bile duct. All the cases showed significant proximal bile duct dilatation (the extent of dilatation >100%), and 9 cases also showed distal bile duct dilatation. Bile duct stones were noted in 6 cases, 4 at the tumor area, and the other 2 away from the tumor area. No adjacent tissue invasion and no distal tissue or lymph node metastasis were observed., Conclusion: Intraductal papillary neoplasms of the bile ducts have characteristic imaging appearances on MRI, and MRI is an important method helpful to making correct diagnosis.

Objective: To explore the effects on ischemia-reperfusion injury with different regimens of fluid resuscitation during severe burn shock stage in swines., Methods: A total of 24 Guangxi BA-MA mini-swine were numbered from 1 to 24 and randomly divided by EXCEL 2007 into 4 groups of succinylated gelatin, hydroxyethyl starch (HES 130/0.4), Parkland and allogeneic plasma (n = 6 each). Then the burn shock model was established. And fluid resuscitation therapy was applied according to the established regimens of burn shock fluid resuscitation. Blood samples were collected from the animals prior to burn injury and again at intervals of 4, 8, 24 and 48 hours post-injury. The levels of malondialdehyde, superoxide dismutase (SOD), xanthine oxidase (XOD) and total antioxidant capacity (T-AOC) were measured. And the results were analyzed statistically., Results: Six swines within each group survived the shock stage and the outliers in detection index were eliminated. Then there were 5 swines in each group. The MDA of allogeneic plasma group at intervals of 8 hours was significantly lower than that of succinylated gelatin group, but higher than that of Parkland group [(3.46 ± 0.40) vs (4.55 ± 0.82), (2.59 ± 0.35) µmol/L, both P < 0.05]. The level of SOD had statistical difference at 48 hours between the HES 130/0.4 and allogeneic plasma groups ((72.55 ± 5.70) vs (65.42 ± 5.07) U/ml, P < 0.05). The level of XOD of the succinylated gelatin group at 4, 8 hour and they increased when compared to pre-burn ((12.00 ± 0.57), (11.28 ± 0.71) vs (9.12 ± 0.51) U/L, both P < 0.01).Statistical significance was observed at 4, 8 hours between succinylated gelatin and allogeneic plasma groups ((10.39 ± 1.24), (9.59 ± 1.17) U/L, both P < 0.01). The T-AOC of HES 130/0.4 group at 8 hours exceed the pre-burn ((2.06 ± 0.43) vs (1.30 ± 0.35) U/ml, P < 0.05). The allogeneic plasma group at 4, 8 hours showed increase when compared to pre-burn ((1.55 ± 0.37), (2.59 ± 0.60) vs (1.06 ± 0.13) U/ml, both P < 0.05). The succinylated gelatin group at 8, 48 hours decreased during the corresponding phase of allogeneic plasma group ((1.14 ± 0.26), (0.89 ± 0.20) vs (2.59 ± 0.60), (1.16 ± 0.20) U/ml, both P < 0.05). The comparison at 24, 48 hours between HES 130/0.4 and allogeneic plasma groups ((1.84 ± 0.41), (1.53 ± 0.21) vs (1.13 ± 0.35), (1.16 ± 0.20) U/ml) had statistical difference (both P < 0.01). The Parkland group at intervals of 8 hours was lower than that of allogeneic plasma group ((1.31 ± 0.19) vs (2.59 ± 0.60) U/ml, P < 0.01)., Conclusion: HES130/0.4 and allogeneic plasma have comparable the parallel minimum damage effect on ischemia-reperfusion injury during burn shock stage are.

Objective: To analyze the CT and MRI findings and pathological characteristics of retroperitoneal localized Castleman's disease and discuss the diagnostic and differential value of CT and MRI., Methods: CT, MRI and clinical data of retroperitoneal localized Castleman's disease, proved by surgery and pathology, of 13 patients were reviewed. Among them, all the 13 cases received CT, and 4 cases received MRI examination., Results: Among the 13 cases, 12 cases were of hyaline vascular type, and one was of mixed type. All foci were single mass and most foci located in the periphery of the kidney. The maximum diameter was 4.2 cm to 8.6 cm and the mean diameter of all tumors was 5.9 cm. The outline of most tumors was clear and kidney-shaped. On unenhanced CT, 10 cases showed low density and 3 cases showed isodensity. On plain MRI, four cases showed iso-signal on T1WI, three cases showed slightly high signal on T2WI and one showed moderately high signal. The CT and MRI findings were similar on contrast enhanced scan. In arterial phase, 10 cases showed moderate enhancement, 2 cases showed significant enhancement and one case showed moderate enhancement. Five cases showed rather homogeneous enhancement and 8 cases showed heterogeneous enhancement.In venous phase, all the 13 tumors showed continuous enhancement. Eight cases showing heterogeneous enhancement in arterial phase showed expanded range, and among them two cases showed tending to be homogeneous enhancement. Six cases showed areas of low density without enhancement, and 9 cases were accompanied with single or multi-satellite punctuate or striped foci around the tumors., Conclusion: Dynamic contrast-enhanced CT and MRI combined with MR T2WI fat-suppression are of great importance in the diagnosis and identification of retroperitoneal localized Castleman's disease.

Objective: To access the effects of life style interventions on impaired glucose regulation (IGR) in Shanghai urban communities, China., Method: Two communities were randomly cluster-sampled to be carried out epidemiological intervention trial. Totally, 232 subjects with IGR were randomly allocated into 4 groups: control group,sports intervention group, diet intervention group, and sports and diet intervention group with the physical examinations in the baseline and end of this study respectively. Tests for fasting blood glucose, OGTT, HbA1c, total cholesterol,etc. were done. Data statistical analysis was occupied in SPSS 16.0., Results: Compared to subjects of control group,fasting blood glucose, OGTT, HbAlc,total cholesterol,BMI,waist hip ratio and blood pressures were significantly decreased among subjects with three interventions (P < 0.05). Triglyceride were significantly decreased among subjects with sports intervention and sports and diet intervention (P < 0.05). High density lipids was significantly increased among subjects with sports and diet intervention (P < 0.05). There was a significant difference in 6 months cumulative incidence of diabetes mellitus between control group and interventions groups (8.6% vs. 0, Fisher' s exact P = 0.002), and the rate of transferring into normal blood glucose levels (fasting blood glucose < 5.6 mmol/L and 2 hours OGTT < 7.8 mmol/L) in control group was lower than those in three interventions group (3.4% vs. 8.6%, 14.0% and 16.9%, respectively) but only significant difference was observed between control group and sports and diet intervention group (OR = 5.74, 95% CI 1. 19-27. 64, P = 0.029)., Conclusion: The life style interventions could decrease the risk of diabetes mellitus, help their transferring into normal blood glucose, and improve diabetic measures for the IGR population in Shanghai urban communities.