Acetylated-PPARγexpression is regulated by different P53 genotypes associated with the adipogenic differentiation of polyploid giant cancer cells with daughter cells

Objective:Polyploid giant cancer cells(PGCCs)with daughter cells express epithelial–mesenchymal transition(EMT)-associated proteins.Highly malignant tumor cells with EMT properties can transdifferentiate into mature tumor cells.In this study,we elucidated the potential for,and underlying mechanism of,adipogenic differentiation of PGCCs with daughter cells(PDCs).Methods:Cobalt chloride was used to induce PGCC formation in HEY(wild-type P53)and MDA-MB-231(mutant P53)cells;these cells were then cultured in adipogenic differentiation medium.Oil red O staining was used to confirm adipogenic differentiation,and the cell cycle was detected with flow cytometry.The expression of adipogenic differentiation-associated proteins and P300 histone acetyltransferase activity were compared before and after adipogenic differentiation.Animal xenograft models were used to confirm the adipogenic differentiation of PDCs.Results:PDCs transdifferentiated into functional adipocytes.Two different cell cycle distributions were observed in PDCs after adipogenic differentiation.The expression levels of PPARγ,Ace-PPARγ,and Ace-P53 were higher in PDCs after adipogenic differentiation than in cells before adipogenic differentiation.Ace-PPARγand FABP4 expression increased in HEY cells and decreased in MDA-MB-231 PDCs after p53 knockdown.A485 treatment increased Ace-P53,Ace-PPARγ,and FABP4 expression in HEY PDCs by inhibiting SUMOylation of P53.In MDA-MB-231 PDCs,A485 treatment decreased Ace-P53,Ace-PPARγ,and FABP4 expression.Animal experiments also confirmed the adipogenic differentiation of PDCs.Conclusions:Acetylation of P53 and PPARγplays an important role in the adipogenic differentiation of PDCs.

The Inhibitory Effect of Endostatin and Doxycycline Administration on B16 Melanoma Angiogenesis and Cellular Proliferation

OBJECTIVE To investigate the effect of endostatin and doxycycline on melanoma cellular proliferation and tumor angiogenesis.METHODS The effects of endostatin and doxycycline were studied in mice transplanted with B16 melanoma cells.The mice were divided into 4 groups that were treated as follows:endostatin treatment(E group),doxycycline treatment(D group),endostatin plus doxycycline trearment(DE group),controls(C group) received no treatment.Following 9 days of treatment the tumor tissue was removed to compare the differences in the tumor necrotic rate and micro-vessel density(MVD) among the different groups.Immunohistochemical staining was conducted to detect the expression of proliferating cell nuclear antigen(PCNA)in the di?erent groups. RESULTS The MVD of the 3 experimental groups was significantly less than the control group,(F=10.888,P<0.05),indicating that doxycycline and endostatin can inhibit tumor angiogenesis by decreasing the tumor blood supply.This effect results in inhibition of tumor cellular proliferation and promotion of tumor cell necrosis.The tumor cell necrotic rate of the 3 experimental groups were all significantly higher than the C group(F=7.229,P<0.05) and the difference between the DE and C groups also was statistically significant.PCNA expression in all 3 experimental groups was statistically less than the C group(F=17.729,P<0.05). CONCLUSION The combined use of endostatin and doxycycline in vivo can influence PCNA expression and angiogenesis in melanoma,and significantly inhibit melanoma cellular proliferation.

In Vivo Selection of Phage Sequences and Characterization of Peptide-specific Binding to Breast Cancer Cells

OBJECTIVE To screen specific polypeptide target binding to breast cancer xenogra s in vivo from a phage-displayed peptide library in order to provide peptide sequences for breast cancer tumor-targeting diagnosis and therapy. METHODS A mouse model for carrying breast cancer xenografts was established using Tientsin Albinao II mice(TA II).A 12-peptide library was biopanned through 4 rounds. Phages were recovered and titrated from tumor xenografts and control tissue(liver).The distribution of phages was detected by immunohistochemical staining. RESULTS Phage homing to breast cancer was enriched through 4 rounds of biopanning,being 14-fold of that recovered from liver tissue.A peptide sequence,ASANPFPTKALL was characterized by randomly picked-up clones which appeared most frequently. Immunohistochemical staining revealed phage localization in cancer xenografts 40 min after injection of the enriched phages. When a specific phage was tested individually,the phage reclaimed from breast cancer xenografts was 14 times as those from control tissues. CONCLUSION Tumor-specific homing peptides may provide an effective tool for breast cancer target therapy.The in vivo phage display selection technique employed in this study was feasible and applicable to screening peptides that home to breast cells.

基于多波段观测的星系循环内流直接观测

在目前基于暗物质的星系演化理论框架下,星系形成在引力自束缚的暗物质系统——暗物质晕中.在引力作用下,暗物质晕相互并合形成今天观测到的“宇宙网”大尺度结构.一般来说,暗物质晕的物理尺度是星系尺度的几十到上百倍.在星系与暗物质晕之间弥散有大量以氢元素和氦元素为主的重子物质,其中氢元素占比约为74%,氦元素占比约为25%,剩下的重元素占比约为1%.

Gait Study and Pattern Generation of a Starfish-Like Soft Robot with Flexible Rays Actuated by SMAs

This paper presents the design and development of a starfish-like soft robot with flexible rays and the implementation of multi-gait locomotion using Shape Memory Alloy （SMA） actuators. The design principle was inspired by the starfish, which possesses a remarkable symmetrical structure and soft internal skeleton. A soft robot body was constructed by using 3D printing technology. A kinematic model of the SMA spring was built and developed for motion control according to displacement and force requirements. The locomotion inspired from starfish was applied to the implementation of the multi-ray robot through the flexible actuation induced multi-gait movements in various environments. By virtue of the proposed ray control patterns in gait transition, the soft robot was able to cross over an obstacle approximately twice of its body height. Results also showed that the speed of the soft robot was 6.5 times faster on sand than on a clammy rough terrain. These experiments demonstrated that the bionic soft robot with flexible rays actuated by SMAs and multi-gait locomotion in proposed patterns can perform successfully and smoothly in various terrains.

A Novel Implementation of a Flexible Robotic Fin Actuated by Shape Memory Alloy

In this paper, study of a novel flexible robotic-fin actuated by Shape Memory Alloy （SMA） is presented. The developed robotic fin is capable of implementing various 3-Dimensional （3D） motions, which plays an important role in robot propulsion and maneuverability. Firstly, the morphological and mechanics parameters of a real pectoral fin from a carp are investigated. Secondly, a detailed design of the flexible pectoral fin driven by SMA is presented according to the previous morphological and mechanics analyses. Thirdly, a simplified theoretical model on the SMA fin plate is derived. The thermodynamics of the SMA plate and the relationship between curvature and phase transformation are analyzed. Finally, several simulations and model experiments are conducted according to the previous analyses. The results of the experiments are useful for the control of the robotic fin. The experimental results reveal that the SMA actuated fin ray has a good actuating performance.

Natural Feature-based Visual Servoing for Grasping Target with an Aerial Manipulator

Aerial transportation and manipulation have attracted increasing attention in the unmanned aerial vehicle field,and visual servoing methodology is widely used to achieve the autonomous aerial grasping of a target object.However,the existing marker-based solutions pose a challenge to the practical application of target grasping owing to the difficulty in attaching markers on targets.To address this problem,this study proposes a novel image-based visual servoing controller based on natural features instead of artificial markers.The natural features are extracted from the target images and further processed to provide servoing feature points.A six degree-of-freedom(6-DoF)aerial manipulator system is proposed with differential kinematics deduced to achieve aerial grasping.Furthermore,a controller is designed when the target object is outside a manipulator's workspace by utilizing both the degrees-of-freedom of nnmanned aerial vehicle and manipulator joints.Thereafter,a weight matrix is used as basis to develop a multi-tasking visual servoing framework to integrate the controllers inside and outside the manipulator's workspace.Lastly,experimental results are provided to verify the effectiveness of the proposed approach.

Locomotion Performance of the Amphibious Robot on Various Terrains and Underwater with Flexible Flipper Legs

Amphibious robots are attracting more and more attentions from researchers worldwide tbr their broad appllcanons m resource exploration, disaster rescue, and reconnaissance. Amphibious robot with transformable flipper-leg composite propul- sion mechanisms can adapt various terrestrial and water environments. In this paper, we explored the locomotion performance of a amphibious robot with flexible flipper legs on various terrains and underwater through dynamical simulation. The influence of the stiffness of the flipper legs on the locomotion performance in various environments was investigated comprehensively. The results indicate that the locomotion with flexible flipper legs is very stable, and the stiffness of the flipper legs has a great impact on the locomotion performance. The verification experiments demonstrate the accuracy of the simulation results. The study facilitates the design of the amphibious robot and indicates that the passively transformable flipper-leg mechanisms also enable amphibious robot to conquer various complex terrestrial environments.

A Three-Dimensional Kinematics Analysis of a Koi Carp Pectoral Fin by Digital Image Processing

Pectoral fins fascinate researchers for their important role in fish maneuvers. By possessing a complicated flexible structure with several fin rays made by a thin film, the fin exhibits a three-dimensional （3D） motion. The complex 3D fin kinematics makes it challenging to study the performance of pectoral fin. Nevertheless, a detailed study on the 3D motion pattern of pectoral fins is necessary to the design and control ofa bio-inspired fin rays. Therefore, a highspeed photography system is introduced in this paper to study the 3D motion ofa Koi Carp by analyzing the two views of its pectoral fin simultaneously. The key motions of the pectoral fins are first captured in both hovering and retreating. Next, the 3D configuration of the pectoral fins is recon- structed by digital image processing, in which the movement of fin rays during fish retreating and hovering is obtained. Fur- thermore, the method of Singular Value Decomposition （SVD） is adopted to extract the basic motion patterns of pectoral fins from extensive image sequences, i.e. expansion, bending, cupping, and undulation. It is believed that the movement of the fin rays and the basic patterns of the pectoral fins obtained in the present work can provide a good foundation for the development and control of bionic flexible pectoral fins for underwater propeller.

Design, fabrication, and testing of a maneuverable underwater vehicle with a hybrid propulsor

Rapidity and agility are equally important to unmanned underwater vehicles(UUVs).In this study we developed a UUV equipped with a hybrid propulsor which consists of a screw propeller and four bio-inspired flippers.The bionic flippers rely on their flapping motion to generate both thrust and lateral forces,and the screw propeller provides additional thrust for fast cruise.The maneuverability is greatly improved while the capability of sailing fast is maintained.For the typical sailing requests,the flapping motions of the flippers were designed meticulously,and a control algorithm based on central pattern generators(CPGs)was built to produce rhythmic locomotor signals considering the motion periodicity.Simultaneously,a feedback control method was merged to correct the deviation of the course.A compact concentric-shafts transmission mechanism was employed to overcome the inadequacy of the inside space,and the vehicle was built.Finally,the sailing and maneuvering performance were tested.It was demonstrated that,the UUV’s overall sailing performance was enhanced significantly due to the combination of the flapping flippers and the screw propeller.The hybrid-propulsor vehicle is capable of sailing in multiplicate environments.

A Water Strider Robot with Five Umbrella-Type Footpads

The design of most water strider robots follows the principle that all supporting legs are in a plane,and each supporting leg bears a certain load and the water strider robot can float on the water.To meet this principle,the number of supporting legs and the spacing between each supporting legs of the water strider robot must be increased,which makes the shape of water strider robots look like octopus.This study proposed a novel water strider robot named 5S-robot,which used five new umbrella-type footpads and a centrifugal pump-based actuating mechanism.Motion analysis model and force analysis model of 5S-robot were built.The general consistency between the results of motion experiments and those of numerical simulation verified the former models.For this 5S-robot,the maximum load of 110.5 g and forward speed of 207.1 mm s^(-1)and rotational speed of 1.22 rad s^(-1)were measured,respectively.

Variable stiffness wires based on magnetorheological liquid metals

Magnetorheological fluid(MRF)has shown its great potential in the development of large mechanical devices,such as dampers,shock absorbers,rotary brakes,clutches,and prosthetic joints.Recently,more research focus has been invested on using MRF to develop soft,stretchable,and miniaturized devices with variable stiffness for realizing functionalities that cannot be achieved using solid smart materials.Here,based on liquid metal magnetoactive slurries(LMMS),a variable stiffness wire with excellent electrical conductivity is demonstrated.Without exposure to a magnetic field,the LMMS wire has an extremely low stiffness,and can be easily stretched while maintaining an excellent electrical conductivity.When applying a magnetic field,the wire becomes much stiffer and can retain its shape even under a load.The combination of properties of flexibility,high electrical conductivity,and variable stiffness of the wire is harnessed to make a flexible gripper that can grasp objects of various shapes.Moreover,by using gallium instead of its liquid metal alloys,the tunable stiffness range of the LMMS wire is signifi-cantly enhanced and can be controlled using both external magnetic fields and temperature-induced phase change.The presented LMMS wire has the potential to be applied in flexible electronics,soft robotics and so on.