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BACKGROUND: Thymectomy has been identified as an effective strategy for patients with myasthenia gravis (MG) and thymic masses. However, the best surgical approach remains a matter of debate. The aim of the present study was to compare the surgical and neurological outcomes of video-assisted thoracoscopic thymectomy with a modified subxiphoid and bilateral approach in patients with MG and thymic masses. METHODS: From August 2013 to April 2018, 68 patients who were diagnosed with MG and thymic masses and underwent video-assisted thoracoscopic thymectomy with a modified subxiphoid (44 patients) or bilateral (24 patients) approach were included in this retrospective study. The surgical and neurological results were analyzed with propensity score matching. RESULTS: After propensity score matching, the modified subxiphoid approach in video-assisted thoracoscopic thymectomy resulted in an obviously shorter operative time (P=0.00), drainage duration (P=0.00), less intraoperative blood loss (P=0.00), and shorter postoperative hospital stay (P=0.01). In terms of neurological outcomes, no significant difference was observed in the improvement in MG, with 2-year complete stable remission rates of 21.1% and 26.3% (P=0.68) and 2-year pharmacological remission rates of 31.6% and 26.3% (P=0.60) for the bilateral and subxiphoid approaches, respectively. Additionally, the approaches resulted in similar effects on the magnitudes of decrease in the prednisolone and pyridostigmine doses after 2 years, with average pyridostigmine dose reductions of 72.2% and 71.1% (P=0.78) and average prednisolone reductions of 76.8% and 71.7% (P=0.96) for the bilateral and subxiphoid approaches, respectively. CONCLUSIONS: The modified subxiphoid approach was found to be superior to the bilateral approach in video-assisted thoracic surgery thymectomy in terms of the surgical outcomes and yielded similar neurological outcomes. Therefore, the modified subxiphoid approach is recommended as an alternative to the bilateral approach in the treatment of patients with MG and thymic masses.

This review summarizes recent advances, presents the structure engineering strategies, and focuses on the mechanism disclosure and structure–property relationship and provides future challenge and prospect of various iron-based materials towards N2-to-NH3 electrocatalysis.

Friction stir lap welding (FSLW) is expected to join the hybrid structure of aluminum alloy and steel. In this study, the Al-Mg-Si aluminum alloy and 301L stainless steel were diffusion bonded by FSLDW with the addition of 0.1 mm thick pure Zn interlayer, when the tool pin did not penetrate the upper aluminum sheet. The characteristics of lap interface and mechanical properties of the joint were analyzed. Under the addition of Zn interlayer, the diffusion layer structure at lap interface changed from continuous to uneven and segmented. The components of the diffusion layer were more complex, including Fe-Al intermetallic compounds (IMCs), Fe-Zn IMCs and Al-Zn eutectic. The largely changed composition and thickness of uneven and segmented diffusion layer at the lap interface played a significant role in the joint strength. The tensile shear load of Zn-added joint was 6.26 kN, increasing by 41.3% than that of Zn-not-added joint. These two joints exhibited interfacial shear fracture, while the Zn interlayer enhanced the strength of diffusion bonding by extending the propagation path of cracks.

Cold-rolled 2024–T3 sheet alloy was subjected to bobbin-tool friction stir welding (BTFSW). The microstructural characteristics and mechanical properties of the nugget zone in the as-welded state were investigated. The results show that the equiaxed grain size of BTFSW 2024–T3 alloy decreases from 7.6 to 2.8 μm as the welding speed is increased from 80 to 120 mm/min; in addition, fine grains are generated in the nugget zone and the size distribution is non-uniform. All Al2CuMg (S′) precipitates dissolve into the Al matrix, whereas Mn-rich phases confirmed as T phases (Al20Cu2Mn3, Al6Mn, or Al3Mn) remain unchanged. The optimized parameters for BTFSW are verified as the rotation speed of 350 r/min and the travel speed of 100 mm/min. The variations in precipitation and dislocation play more important roles than grain size in the nugget zone with respect to influencing the mechanical properties during the BTFSW process. After the BTFSW process, the fracture mode of base material 2024–T3 alloy transforms from ductile rupture to ductile-brittle mixed fracture.

Al-Li 2198-T8 alloy sheet was processed by friction spot welding (FSpW). The microstructures and tensile properties of FSpW 2198-T8 alloy were studied by means of optical microscopy (OM), transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and tensile testing. The results show that the grain size of Al-Li 2198-T8 alloy processed by FSpW was refined with the strengthening precipitates dissolved into Al matrix and dislocation density decreased. Hence, the plasticityin thermo-mechanical coupling zone (TMCZ) of FSpW 2198-T8 alloy was improved, while the yield strength (YS) of TMCZ zone was lower than the original material (239 MPa

This study was conducted to investigate the effects of soybean antigen proteins on serum cytokine levels and claudin-1 distribution in the intestine of weaned piglets. Seventy piglets (24 d of age) were randomly divided into seven groups. Piglets in group A were fed a basal diet, in groups B, C and D were fed the basal diet supplemented with β-conglycinin; and in groups E, F, G were fed the basal diet supplemented with glycinin. Blood samples were collected and analysed for IFN-γ, IL-2, IL-4 and IL-6 levels on day 24, 26, 28 and 30. At the end of the trial, five piglets per group were sacrificed and the small intestine was collected to evaluate intestinal claudin-1 distribution and OD of the relative staining positivity. β-Conglycinin and glycinin decreased the growth performance in piglets by decreasing ADFI, ADG and increasing F/G. Serum levels of IL-2, IL-4 and IL-6 in β-conglycinin and glycinin groups ranged from 126.067 to 144.067 ng • L−1, 31.798 to 44.360 ng • L−1 and 36.360 to 40.482 ng • L−1 on day 24, 26 and 30. However, serum IFN-γ levels were negatively correlated with soybean antigen proteins supplementation levels ranged from 6.956 to 15.361 ng • L−1. The treatment groups had lower OD values of claudin-1 than those of the control group. The β-conglycinin groups had lower distribution and OD values than the glycinin groups at similar antigen protein supplementation levels. These results suggest that β-conglycinin and glycinin damage the intestinal mucosal immune barrier in weaned piglets.

The U.S.A has launched the Mars Orbiter. It brought a high resolution imaging science equipment, and that is the High Resolution Imaging Science Experiment camera(HIRISE). HIRISE is 0.5 m reflecting telescope, which is the highest one ever carried on a deep space mission, and it has a resolution of 1 microradian (rad), or 0.3 m from an altitude of 300 km. HIRISE can investigate deposits and landforms resulting from geologic and climatic processes and assist in the evaluation of candidate. As a high degree of lightweight ultra-high resolution camera, the design of its FPA is unparalleled .Therefore we should study and learn it carefully. In this article, first of all we discuss and analyze the characters of the HIRISE FPA in terms of the structural layout, material selection, splicing of the CCD, the CCD package, electronics, processing and transmission, and thermal control measures implementation. Next we put forward the design method of highly lightweight space optical remote sensor FPA combined with the characters of the HIRISE FPA, which can provide a reference to the design of the FPA for some space remote sensings. (2013) Trans Tech Publications, Switzerland.

For any On-orbit Space camera, the influence of flutter on the imaging process of TDICCD space camera is inevitable, thus causing the decline of image quality. This paper briefly introduces the principle of TIDCCD camera and how flutter affects the imaging process. Then through the analysis and calculation of practical program, we find the acceleration criterion to avoid the blur of image quality.

Carbon matrix/Carbon fibre reinforced composite(C/C composite) has many special characteristics such as high strength, high elastic modulus, high temperature resistance and ablation resistance. So it is used to manufacture rocket engine nozzle in aerospace filed. But its security will be seriously effected during rocket engine working due to the manufacturing defects. Based on analyzing defect types and structure characteristic of C/C composite, the ultrasonic and infrared testing methods on C/C composite are further studied in this thesis. And effective defect detection has been achieved.

General materials can satisfy the structure strength requirement of space effective payload easily. But it can hardly satisfy the structure stiffness requirement of space payload. Carbon fiber composite has many excellent properties, such as high relative strength, high relative stiffness, small expansion coefficient, good fatigue resistance and excellent vibration resistance. It can be used to make space products. Firstly, this paper discussed the properties of carbon fiber composite material. Compared with common materials, such as aluminum alloy and titanium alloy, carbon fiber composite material is more suitable for applications of space instruments. Secondly, the metal part embedded technique of carbon fiber composite structure was studied. According to the carbon fiber composite structure of a space camera frame, a few structure forms of embedded part ware studied. A space camera frame of carbon fiber composite was designed and manufactured. Finally, finite element analysis and mechanical tests on the space camera frame was carried out. The results reveal that the characteristic frequency of carbon fiber composite frame is up to 104Hz.The space camera frame is of high stiffness and dimensional stability.

The Constant-capacity Adsorption Solution (CAS) model for n-C4∼n-C10 mixture was built. Based on the adsorption experimental data, the Multi-site Langmuir (MSL) model was selected to describing the adsorption isotherms of n-C4∼n-C10 monocomponent. The CAS model was derived based on the IAS theory. The adsorption capacities predicted by the CAS model were compared with the experiment data of mixed gas adsorption. The results show the consistency. From the viewpoint of thermodynamics, the interactions between the normal paraffins of different carbon numbers were discovered. CAS model is applicative for the mixed gas in which the monocomponents have the similar adsorption capacities in the adsorbent.

In order to improve the steam cracking feeds, several model compounds including normal paraffins, iso-paraffins, cyclanes and aromatics were selected as the feeds of steam cracking process and the olefin yields were investigated. In the typical reaction conditions, the normal paraffins in the naphtha contribute most to the ethylene in the products; the iso-paraffins are the main sources of the propylene; the cyclanes mainly produce the butadiene and the aromatics can hardly produce olefins. According to this, the adsorption process and solvent extraction process were adopted to separate the group compositions in naphtha properly to optimize the cracking feeds. The n-paraffins in naphtha were gathered through adsorption process using 5A molecular sieves. The ethylene yield improved by 13% using the desorption oil rich in n-paraffins as the cracking feed. The aromatics and the cyclanes were extracted from the naphtha. Compared with the naphtha, the ethylene and propylene yields of the extraction raffinate oil were 3.0 and 1.5% higher respectively.

To establish a murine uterine cervical cancer cell line and to define its biological characters. Transplanted tumor tissue was used for in vitro primary culture of U14 cervical carcinoma cells. After 20 passages, we examined its morphology, chromosomes, tumorigenicity and produced a growth curve. CK was detected by immunohistochemistry, the cell cycle determined by flow cytometry and the metastatic potential assessed in 615 and C57BL/c mice. We also transfected the cells with the pEGFP-N1 plasmid. A newly established murine cell line was passaged 50 times over a period of 10 months. The cells grow as a partially suspended culture, and are immunohistochemically CK(+). The cell line is characterized by a hypotetraploid karyotype, a chromosomal number of 64–68 and a doubling time of 21.8 h. Exponential growth occurs by the third and forth day of culture. Cell cycle analysis showed G1 34%, G2 26%, and 40% in the S phase. The tumorigenicity was 100% upon implantation. No mycoplasma contamination was detected. A monoclonal continuous U14-GFP cell strain which was 100% GFP (+) was also produced. We successfully established a new murine cervical U14 carcinoma cell line and an U14-GFP monoclonal strain. These cell lines are ideal for combined in vivo and in vitro tumor research.

OBJECTIVE To observe the effects of Jianpi Yishen Recipe (JPYSR), a compound Chinese herbal medicine, on recurrence, metastasis and life span of mice transplanted with proventriculus squamous carcinoma cells after tumorectomy. METHODS JPYSR was orally administered to 615 mice transplanted with proventriculus squamous carcinoma cells in the palma of left hind limb after tumorectomy. The local tumor recurrence, lung metastasis and life span of the mice were evaluated and compared with those of the 5-FU-treated mice and untreated mice. RESULTS The pulmonary metastasis rate was 94.4% and the recurrence rate was 94.44% in untreated group. The pulmonary metastasis rate was 68.4%, the inhibition rate of pulmonary metastasis was 27.5%, the recurrence rate was 78.95%, and the inhibition rate of tumor recurrence was 65.35% in JPYSR-treated group. The average and median life spans were obviously prolonged in JPYSR-treated group, as compared with those in untreated group. The life-prolonging rate was 100%. CONCLUSION JPYSR can effectively inhibit the local recurrence and pulmonary metastasis of the transplanted proventriculus squamous carcinoma in mice after tumorectomy, and prolong the life span.

The objective of this study was to determine whether there was an age-dependent difference in promoting nuclear translocation of NF-kappa B and platelet derived growth factor expression in aortic endothelial cells between two groups of Wistar rats of 2 and 10 months in age, respectively, accompanied by hypercholesterolemia. The serum cholesterol levels became significantly higher in the older rats after taking a cholesterol-enriched diet for 16 weeks (129.3+/-11.9 vs. 194.5+/-22.6 mg/dl, P

The support structure of large aperture mirror of space remote sensor is the key of the space remote sensor development. In this paper, the size of the large aperture mirror is Φ700mm,which is supported in the back of mirror with 3 points ,the composite structure of ball joint and flexible groove is adopted in support structure which can guarantee the mirror surface satisfy the requirement of optical design under the coupled load of gravity and heat. At the same time, the mirror subassembly should have a high enough stiffness through the reasonable lightweight to ensure the camera in transportation and launch process can withstand severe vibration condition. In order to validate the rationality of the design,the finite element analysis is done to the mirror subassembly,which indicates that the shape error variation of mirror RMS is better than λ/50 and PV is better than λ/10 in the coupling load of gravity and heat,and the first natural frequency of the mirror subassembly is higher than the design requirements. Dynamics calculation results of mirror subassembly consistent with mechanics experiment results；the surface precision of the mirror subassembly obtained from the ZYGO interferometer consistent with the results of finite element analysis and meets the design requirements.

The object of study is the electric control box of a certain type of space remote sensor. In view of the existing shortcomings of the original electric control box, the electric control box is designed reasonably. In the result, the design of electronic control box supported by the cylindrical multi-point is proposed, which can solve the series of problem of the original program, such as the large volume, heavy weight, large signal interference. The camera control box is made of magnesium alloy which has light weight and high strength; by the structure design of stacked, the electronics system is classified integration; through the local shielding program, the problem of anti radiation and interference of electronics system is solved; by using the multi supporting structure scheme, the structural rigidity of the electric control box is improved, the modal by 57Hz increased to more than 120Hz, which meet the 100Hz technology of the design specifications; the box body is adopted by nickel for protection, which eliminating the possibility of air and humid environment on the corrosion of magnesium alloy. At present, the electric control box designed has been completed the 2014 SPIE.

Focusing mirror assembly (FMA) is an important component of large space telescope. It can compensate the telescope's defocus caused by environmental factors. Telescope launching vibration and shock, as well as the structure stress of kinematic movement have great impact on focusing mirror assembly. To solve the problems of defocus result from vibration, shock and other environmental factors, a focusing mirror assembly with flexure hinge structure for space telescope is developed. Analysis and tests shows that the natural frequency of mirror assembly up to 130Hz. Before and after the tests, the shape RMS error variation of focusing mirror is less than 0.002 ( = 632.8nm). So the flexure support can well meet the requirements of mirror assembly structure performance. 2014 SPIE.

On the basis of characteristics of optical system of Large aperture three-mirror off-axis, the mirrors’ support structure and the overall frame structure of the optical system was designed and investigated, the first and foremost is the lightweight of the support structure and the overall frame structure, the structure design of the three-mirror off-axis optical system was completed, which characteristic is integrative design of the overall frame structure , also the 3D model of the structure of the optical system was built, by means of the finite element analysis techniques, the modal analysis was done to the overall structure, the analysis results indicate that the first natural frequency of the overall structure is 162Hz，which is higher than 120 Hz requested by the overall structure of the optical system ,the overall structure have a high enough dynamic stiffness and reasonable distribution of modal, which ensure the overall structure in transportation and launch process to withstand severe vibration condition, and the shape error variation RMS and PV of optical mirror which are important indexes of image quality under the comprehensive influence of gravity and thermal load which is in the control range meet the design index.

In course of developing, testing, launching and working in orbit, Space camera has to undergo the shock of external loads and changing environment. The optical performance of a long focal length space camera is largely determined by external mechanical loads and ambient temperature. The performance of the camera is a result of the interaction between environment factors. The performance of the optical system should be making an accurate forecast when a modern optical instrument is designed. In this paper, the research methods are reviewed firstly. Then the related technologies are described. The analysis methods of environment temperature and structural characteristics effecting space camera imaging performance are also discussed.

According to the focal depth and work environment of a space camera, a focusing mechanism is designed, which consists of precision screw ball transmission and linear bearing guidance and accuracy improving. The dynamic- strikeresistance, adaptability to temperature and vacuum are considered into the reliable design method. Furthermore, the linearity error, the structure stability and the mechanism work situation in high and low temperature are tested. The result is that the linearity error of the mechanism is less than 0.003mm, and the sway error of vertical way and level way of the mirror is less than 20". The linearity error of the mechanism and the sway error of the mirror remain unchanged after vibration test. The mechanism can work in the complex space environment.

Tumor dormancy has been defined clinically as a condition in which tumor cells are present but do not grow for a long period of time. Breast cancer is noted for its long periods of tumor dormancy and metastases can occur many years after treatment.Simulating the characteristics of breast cancer patients after treatment, we established the animal model of breast cancer dormancy by inoculating 500 Ca761-03 cells into the limb muscle of 615 mice and then selecting animals with tumor dormancy 2 months post inoculation (corresponding to 5 years for humans).Two months after inoculation of Ca761-03 cells into the muscle of 615 mice, tumor occurred in 30% of the mice. The remaining 70% of mice did not show tumor growth. After repeated traumatic stimulation, 90% of the mice developed tumors after 5 months, therefore representing tumor dormancy.These results demonstrate that breast cancer cells can remain in a dormant state for long periods of time in vivo. Trauma can stimulate the dormant tumor cells to proliferate again, and causes tumor relapse. This murine model system promises a sound animal model for the study of solid tumor dormancy.

To evaluate the effect of combination of eicosapentaenoic acid (EPA) and The effects of EPA and epirubicin (EPI) on the human gastric carcinoma cell MGC-803 in vitro.EPI were measured by MTT assay , and the interaction between these two agents was evaluated by the isobologram technique of Berenbaum. Morphous of cell was observed by phase-contrast and electron microscope. Flow cytometry was used for cell cycle analysis.EPA significantly inhibited the growth of MGC-803 cells in a dose- and time-dependent way (P0.01). Numerous abnormal particles were found around the nucleus of MGC-803 cells under phase-contrast microscope, and also many electron-dense material in cytoplasm were found under electron microscope. EPA significantly stimulated the growth of human embryonal pulmonary fibroblast (HPF) dose-dependently (P0.01). A strong synergism was found between EPA and EPI in MGC-803 cells. EPA induced G0/G1-phase arrest but without statistical significance (P0.05), and EPI significantly induced S-phase arrest (P0.05) in MGC-803 cells.EPA can inhibit cell growth in gastric carcinoma cells but not in normal cells. EPA and EPI have synergetic effect in the inhibition of gastric carcinoma cells. Compared with EPI monotherapy, the combination of EPI and EPA can reduce the dosage of EPI.

To establish a rabbit tumor cell line and to characterize its biological parameters.VX2 tumor tissue was used for the primary culture in vitro. After 40 passages, the cell morphology, CK expression (immunohistochemical staining), cell cycle, karyotype and tumorigenecity in rabbits and nude mice were investigated.The newly established cell line VX2 was maintained in continuous culture for over 70 passages in 10 months. Morphologically, VX2 cells were polygonal to short spindled. Tonal fibril and tight junction were found under the electron microscope. CK was positive. The cell cycle analysis showed 69.3% in G1 phase, 5.6% in G2 phase and 25.1% in S phase. The population doubling time was 34.5 hours. The chromosomal analysis showed a hypotriploidy with a median chromosome number of 58 approximately 62. The tumorigenecity in rabbits and nude mice were both 100%.The established VX2 cell line derived from rabbit squamous carcinoma could serve as a model system for experimental oncology in the rabbit.

To detect whether the activation of nuclear factor-kappa B (NF-kappaB) in endothelial cells induced by mm-LDL can promote platelet-derived growth factor-B (PDGF-B) expression in vitro, and whether it is also present in hypercholesterolemic rats in vivo, influence of age on NF-kappaB and PDGF-B signal transduction pathway.Established hypercholesterolemic rat model by feeding with a high-cholesterol ration. The activation of NF-kappaB in aortic endothelial cells was identified by immunohistochemical staining, the expression of PDGF-B mRNA and PDGF-B protein were examined using in situ hybridization and immunohistochemistry respectively.In comparison with the control rats, a positive immunostaining of NF-kappaB in nuclei of aortic endothelial cells of the experimental rats was detected after a high cholesterol ration for 6 weeks. The number of endothelial cells expressing PDGF-B mRNA increased and the intensity was dependent upon the duration of high-cholesterol intake. NF-kappaB translocation (0.461 +/- 0.075 vs. 0.350 +/- 0.094, P0.05) and PDGF-B expression in 10-month old Wistar rats were more remarkable than that of 2-month old rats after having cholesterol for 16 weeks. Immunohistochemical staining for PDGF-B gave a similar result (0.230 +/- 0.040 vs. 0.185 +/- 0.037, P0.001).Hypercholesterolemia is capable of activating nuclear translocation of NF-kappaB and promoting expression of PDGF-B in rat aortic endothelial cells in vivo, this coincided with the results obtained in ox-LDL or mm-LDL experiments on endothelial cells in vitro. This phenomenon is much more evident in 10-month old rats which indicates that age might have a close relationship with NF-kappaB - PDGF-B signal transduction pathway.