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Hepatocellular carcinoma (HCC) is known as the most common malignancy of the hepatobiliary system with a continued increase in incidence but limited therapeutic options. Nanomedicine has provided a promising strategy through engineered nanocarriers that are capable of targeting therapeutic agents specifically to tumor cells. In this research, two aptamer/peptide-modified lipid-based drug delivery systems (A54-PEG-SLN/OXA and A15-PEG-SLN/SAL) were developed as a sequential therapeutic strategy to conquer specific hepatocellular carcinoma. The nanomedicine A54-PEG-SLN/OXA was able to target specific hepatocellular carcinoma cell BEL-7402 and exhibited a strong targeting ability and antitumor efficiency both in vitro and in vivo. The A15-PEG-SLN/SAL could target and penetrate deeply to the spheroid composed of CD133+ cancer cells. In the study of developing a sequential therapeutic strategy, we demonstrated that A54-PEG-SLN/OXA could kill tumor cells and expose CD133+ cancer cells. After the administration of A15-PEG-SLN/SAL, the growth of the tumors was significantly inhibited. In conclusion, the aptamer/peptide-modified lipid-based drug delivery systems, A54-PEG-SLN/OXA and A15-PEG-SLN/SAL, could specifically target carcinoma cells and had an evident antitumor effect when administrated sequentially.

Drag-free flight has played a more and more important role in many space missions. The thrust control system is the key unit to achieve drag-free flight by providing a precise compensation for the disturbing force except gravity. The cusped field thruster has shown a significant potential to be capable of the function due to its long life, high efficiency, and simplicity. This paper demonstrates a cusped field thruster's feasibility in drag-free flight based on its instinctive characteristics and describes a detailed design of a cusped field thruster made by Harbin Institute of Technology (HIT). Furthermore, the performance test is conducted, which shows that the cusped field thruster can achieve a continuously variable thrust from 1 to 20 mN with a low noise and high resolution below 650 W, and the specific impulse can achieve 1800 s under a thrust of 18 mN and discharge voltage of 1000 V. The thruster's overall performance indicates that the cusped field thruster is quite capable of achieving drag-free flight. With the further optimization, the cusped field thruster will exhibit a more extensive application value.

The cusped field thruster uses several permanent ring magnets of alternating polarity to create a multistage cusp magnetic topology. It has demonstrated a long lifetime because of reduced plasma losses to the discharge channel surface. However, the high beam divergence problem has not been solved in this type of thruster. The purpose of this technical note is to describe a plume control method to reduce its plume angle. The results show that the magnetic field intensity in the plume region and the shape of the last separatrix have great influence on plume divergence.

The cusped field thruster is a new electric propulsion device that is expected to have a non-uniform radial current density at the anode. To further study the anode current density distribution, a multi-annulus anode is designed to directly measure the anode current density for the first time. The anode current density decreases sharply at larger radii; the magnitude of collected current density at the center is far higher compared with the outer annuli. The anode current density non-uniformity does not demonstrate a significant change with varying working conditions.

The cusped field thruster has drawn much attention from many institutions due to its wide thrust range, high impulse, and long lifetime. However, lots of experimental results reveal that the cusped field thruster at low power has a poor performance. A cusped field thruster with a variable cross-section channel by putting a ceramic spacer in the channel is introduced in this paper, aimed at improving the thruster performance at low power. The DSMC results validate that the upstream atom density can be increased by a spacer, especially near the wall. Based on simulated results, spacers are put into different positions of the channel. The experimental results show that a suitable spacer can enhance thruster performance at low power, which can be confirmed by the results that the anode efficiency can achieve 40% at 400 V anode voltage and 20 sccm gas flow rate by contrast to 35% without a spacer under the same condition.

Magnetic mirror used as an efficient tool to confine plasma has been widely adopted in many different areas especially in recent cusped field thrusters. In order to check the influence of magnetic mirror effect on the plasma distribution in a cusped field thruster, three different radii of the discharge channel (6 mm, 4 mm, and 2 mm) in a cusped field thruster are investigated by using Particle-in-Cell Plus Monte Carlo (PIC-MCC) simulated method, under the condition of a fixed axial length of the discharge channel and the same operating parameters. It is found that magnetic cusps inside the small radius discharge channel cannot confine electrons very well. Thus, the electric field is hard to establish. With the reduction of the discharge channel's diameter, more electrons will escape from cusps to the centerline area near the anode due to a lower magnetic mirror ratio. Meanwhile, the leak width of the cusped magnetic field will increase at the cusp. By increasing the magnetic field strength in a small radius model of a cusped field thruster, the negative effect caused by the weak magnetic mirror effect can be partially compensated. Therefore, according to engineering design, the increase of magnetic field strength can contribute to obtaining a good performance, when the radial distance between the magnets and the inner surface of the discharge channel is relatively big.

Background Lateral column tibial plateau fracture fixation with a locking screw plate has higher mechanical stability than other fixation methods. The objectives of the present study were to introduce two newly designed locking anatomic plates for lateral tibial plateau fracture and to demonstrate their characteristics of the fixation complexes under the axial loads. Methods Three different 3D finite element models of the lateral tibial plateau fracture with the bone plates were created. Various axial forces (100, 500, 1000, and 1500 N) were applied to simulate the axial compressive load on an adult knee during daily life. The equivalent maps of displacement and stress were output, and relative displacement was calculated along the fracture lines. Results The displacement and stresses in the fixation complexes increased with the axial force. The equivalent displacement or stress map of each fixation under different axial forces showed similar distributing characteristics. The motion characteristics of the three models differed, and the max-shear stress of trabecula increased with the axial load. Conclusions These two novel plates could fix lateral tibial plateau fractures involving anterolateral and posterolateral fragments. Motions after open reduction and stable internal fixation should be advised to decrease the risk of trabecular microfracture. The relative displacement of the posterolateral fragments is different when using anterolateral plate and posterolateral plate, which should be considered in choosing the implants for different posterolateral plateau fractures.

Background Tibial plateau fractures are of great challenge to treat with open reduction and internal fixation, because fractures vary from simple to complex, with little or extensive articular involvement. Hence, recognition and comprehension of the fracture features will help orthopedic surgeons understand the injury mechanism better and manage these fractures by planning optimal surgical procedures. This study aimed to evaluate the morphological characteristics of tibial plateau fractures based on the Schatzker classification. Methods A total of 186 patients with 188 tibial plateau fractures from 2010 to 2014 in our hospital were reviewed using a computed tomography scan and three-dimensional (3D) reconstruction. The main fracture line angles (FLA) of Schatzker types I, II, and IV were measured. For each fracture, depression depth was measured, and the depression zone was also located. Depression zones were overlapped to obtain a frequency diagram. Results Schatzker type I and II fractures had three subtypes: single anterolateral fracture, single posterolateral fracture, and complex fracture (the anterolateral and posterolateral parts). Schatzker type IV fractures were also divided into three subtypes: single posteromedial fracture, single anteromedial fracture, and the whole medial fracture. For various Schatzker types and subtypes of fracture, fracture depression clustered and occurred at different locations of the tibial plateau. A significant difference was observed in the depression depth among the different Schatzker types (P