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1.
J Exp Biol ; 227(11)2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38752366

RESUMO

The evolution and utilization of limbs facilitated terrestrial vertebrate movement on land, but little is known about how other lateral structures enhance terrestrial locomotion in amphibian fishes without terrestrialized limb structures. Climbing perch (Anabas testudineus) exhibit sustained terrestrial locomotion using uniaxial rotating gill covers instead of appendages. To investigate the role of such simple lateral structures in terrestrial locomotion and the motion-generating mechanism of the corresponding locomotor structure configuration (gill covers and body undulation), we measured the terrestrial kinematics of climbing perch and quantitatively analysed its motion characteristics. The digitized locomotor kinematics showed a unique body postural adjustment ability that enables the regulation of the posture of the caudal peduncle for converting lateral bending force into propulsion. An analysis of the coordination characteristics demonstrated that the motion of the gill cover is kinematically independent of axial undulation, suggesting that the gill cover functions as an anchored simple support pole while axial undulation actively mediates body posture and produces propulsive force. The two identified feature shapes explained more than 87% of the complex lateral undulation in multistage locomotion. The kinematic characteristics enhance our understanding of the underlying coordinating mechanism corresponding to locomotor configurations. Our work provides quantitative insight into the terrestrial locomotor adaptation of climbing perch and sheds light on terrestrial motion potential of locomotor configurations containing a typical aquatic body and restricted lateral structure.


Assuntos
Locomoção , Percas , Animais , Locomoção/fisiologia , Fenômenos Biomecânicos , Percas/fisiologia , Brânquias/fisiologia
2.
Pancreatology ; 19(7): 957-962, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31551162

RESUMO

OBJECTIVES: Percutaneous stenting is a palliative method to relieve obstructive jaundice caused by unresectable pancreatic carcinoma. In this study, we aimed to compare the safety and efficacy of irradiation stents and conventional metal stents. METHODS: A total of 32 patients who received irradiation stents or conventional metal stents to treat obstructive jaundice caused by locally advanced pancreatic cancer were included in this retrospective study. Chemotherapy using gemcitabine was performed after jaundice subsided. Stent patency, technical success, survival, and complications were compared between groups. RESULTS: Seventeen patients were enrolled in the irradiation stent group (ISG), and 15 patients were enrolled in the uncovered stent group (USG). Median and mean stent patency time were 9.8 months (95% CI, 7.682-11.981) and 9.506 months (95% CI, 8.0-11.012) in the ISG, respectively, vs 8.8 months (95% CI, 6.528-11.072) and 7.62 months (95% CI, 5.917-9.323) in the USG, respectively (P = 0.019). Median and mean overall survival were 10.4 months (95% CI, 8.383-12.417) and 9.953 months (95% CI, 8.408-11.498), respectively, in the ISG vs 9.7 months (95% CI, 7.901-11.499) and 8.14 months (95% CI, 6.44-9.84), respectively, in the USG (P = 0.027). CONCLUSIONS: Irradiation stents extend stent patency and overall survival compared with conventional biliary stents for the treatment of pancreatic carcinoma complicated by obstructive jaundice. Irradiation stents combined with chemotherapy may be a better choice for the treatment of obstructive jaundice caused by unresectable pancreatic carcinoma.


Assuntos
Procedimentos Cirúrgicos do Sistema Biliar , Desoxicitidina/análogos & derivados , Cuidados Paliativos/métodos , Neoplasias Pancreáticas/terapia , Stents/classificação , Adulto , Idoso , Antineoplásicos/uso terapêutico , Sistema Biliar , Desoxicitidina/uso terapêutico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Gencitabina , Neoplasias Pancreáticas
3.
Soft Robot ; 6(4): 495-506, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30907704

RESUMO

Soft robots exhibit many exciting properties due to their softness and body compliance. However, to interact with the environment safely and to perform a task effectively, a soft robot faces a series of challenges such as dexterous motion, proprioceptive sensing, and robust control of its deformable bodies. To address these issues, this article presents a method for fabrication and dynamic modeling of a novel bidirectional bending soft pneumatic actuator that embeds a curvature proprioceptive sensor. The bidirectional bending deformation was generated by two similar chambers with a sinusoidal shape for reducing the internal dampness during bending deformation. An optical waveguide made from flexible poly (methyl methacrylate) material that is immune to the inlet pressure was embedded into the actuator body to measure its bending angle. A dynamic modeling framework based on step response and parameter fitting was proposed to establish a simple differential equation that can describe the nonlinear behavior of the soft actuator. Hence, a sliding mode controller is designed based on this differential equation and the Taylor expansion. The proposed dynamical model and the sliding mode controller were validated by trajectory tracking experiments. The performance of the bidirectional bending soft actuator, such as the linear output of the curvature sensor in different inflating patterns, the proprioceptive sensitiveness to the external environment, the output force, and large bending range under relatively small pressure, was evaluated by relevant experimental paradigms. Prototypes from the novel design and fabrication process demonstrated the soft actuator's potential applications in industrial grasping and hand rehabilitation.


Assuntos
Desenho de Equipamento/instrumentação , Robótica/instrumentação , Simulação de Dinâmica Molecular , Movimento (Física) , Propriocepção/fisiologia
4.
Asian Pac J Cancer Prev ; 15(5): 2329-34, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24716979

RESUMO

Curcumin can inhibit proliferation of liver cancer cells by inducing apoptosis, but the specific signaling pathways involved are not completely clear. Here, we report that curcumin inhibited proliferation of MHCC97H liver cancer cells by induction of apoptosis in a concentration dependent manner via stimulating intracellular reactive oxygen species (ROS) generation. Also, we showed that increased intracellular ROS formation activated the TLR-4/MyD-88 signaling pathway, resulting in activation of caspase-8 and caspase-3, which eventually led to apoptosis in MHCC97H cells. These results showed that as an prooxidant, curcumin exerts anti-cancer effects by inducing apoptosis via the TLR-4/MyD-88 signaling pathway.


Assuntos
Caspase 3/metabolismo , Caspase 8/metabolismo , Curcumina/farmacologia , Neoplasias Hepáticas/tratamento farmacológico , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos , Receptor 4 Toll-Like/metabolismo , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Humanos , Neoplasias Hepáticas/metabolismo , Fator 88 de Diferenciação Mieloide/metabolismo
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